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Husain N, Kumar A, Anbazhagan AN, Gill RK, Dudeja PK. Intestinal luminal anion transporters and their interplay with gut microbiome and inflammation. Am J Physiol Cell Physiol 2025; 328:C1455-C1472. [PMID: 40047092 PMCID: PMC12023768 DOI: 10.1152/ajpcell.00026.2025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2025] [Revised: 01/29/2025] [Accepted: 02/28/2025] [Indexed: 04/16/2025]
Abstract
The intestine, as a critical interface between the external environment and the internal body, plays a central role in nutrient absorption, immune regulation, and maintaining homeostasis. The intestinal epithelium, composed of specialized epithelial cells, harbors apical anion transporters that primarily mediate the transport of chloride and bicarbonate ions, essential for maintaining electrolyte balance, pH homeostasis, and fluid absorption/secretion. In addition, the intestine hosts a diverse population of gut microbiota that plays a pivotal role in various physiological processes including nutrient metabolism, immune regulation, and maintenance of intestinal barrier integrity, all of which are critical for host gut homeostasis and health. The anion transporters and gut microbiome are intricately interconnected, where alterations in one can trigger changes in the other, leading to compromised barrier integrity and increasing susceptibility to pathophysiological states including gut inflammation. This review focuses on the interplay of key apical anion transporters including Down-Regulated in Adenoma (DRA, SLC26A3), Putative Anion Transporter-1 (PAT1, SLC26A6), and Cystic Fibrosis Transmembrane Conductance Regulator [CFTR, ATP-binding cassette subfamily C member 7 (ABCC7)] with the gut microbiome, barrier integrity, and their relationship to gut inflammation.
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Affiliation(s)
- Nazim Husain
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, IL, USA
| | - Anoop Kumar
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, IL, USA
- Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Arivarasu N. Anbazhagan
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, IL, USA
| | - Ravinder K Gill
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, IL, USA
- Jesse Brown VA Medical Center, Chicago, IL, USA
| | - Pradeep. K. Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois Chicago, IL, USA
- Jesse Brown VA Medical Center, Chicago, IL, USA
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Ran P, Jiang F, Pan L, Shu Y, Hu F, Wang Y, Zhao R, Wang W, Mu H, Wang J, Wei J, Fu G. Polysaccharide from Atractylodes macrocephala Koidz. alleviates pyrotinib-induced diarrhea through regulating cAMP/LKB1/AMPK/CFTR pathway and restoring gut microbiota and metabolites. Int J Biol Macromol 2025; 308:142512. [PMID: 40157659 DOI: 10.1016/j.ijbiomac.2025.142512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2024] [Revised: 03/06/2025] [Accepted: 03/24/2025] [Indexed: 04/01/2025]
Abstract
Polysaccharide from Atractylodes macrocephala Koidz. (PAMK), a bioactive component of Atractylodes macrocephala Koidz. (AMK), demonstrates a wide range of pharmacological activities, including the enhancement of gastrointestinal function and regulation of internal homeostasis. This study explores the potential of PAMK in alleviating pyrotinib-induced diarrhea and modulating gut microbiota and its metabolites. Pyrotinib is a tyrosine kinase inhibitor used in cancer treatment, is known for its side effect of diarrhea, which significantly diminishes patients' quality of life. Our prior research suggests that pyrotinib-induced diarrhea may be linked to CFTR-mediated dysregulation of chloride secretion. The present findings indicate that PAMK alleviates pyrotinib-induced diarrhea by reducing cAMP levels, activating the LKB1/AMPK pathway, and inhibiting CFTR activity, as confirmed by enzyme-linked immunosorbent assay (ELISA), qRT-PCR, and western blot analyses. PAMK effectively decreased CFTR-mediated chloride ion secretion in pyrotinib-treated cells, as shown by the MQAE assay. At specific doses, PAMK alleviated pyrotinib-induced diarrhea in rats and significantly restored intestinal barrier integrity. Furthermore, PAMK treatment rebalanced the gut microbiota, reversing the pyrotinib-induced increase in Clostridium and Erysipelotrichi species. Metabolomic profiling further highlighted the involvement of the AMPK signaling pathway. These findings provide a basis for future research aimed at developing cancer treatments with reduced side effects.
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Affiliation(s)
- Pancen Ran
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China; The Second Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, China
| | - Fengxian Jiang
- Department of Radiation Oncology, The 960th Hospital of the PLA Joint Logistics Support Force, Jinan 250031, China
| | - Liying Pan
- The Second Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, China
| | - Yang Shu
- The Second Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, China
| | - Fangyan Hu
- School of Basic Medical Sciences, Shandong University, Jinan, Shandong 250012, China
| | - Yahui Wang
- The Second Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, China
| | - Rui Zhao
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Weihao Wang
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Huaiqian Mu
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China
| | - Juqiong Wang
- School of Basic Medical Sciences, Shandong University, Jinan, Shandong 250012, China
| | - Jian Wei
- School of Basic Medical Sciences, Shandong University, Jinan, Shandong 250012, China.
| | - Guobin Fu
- Department of Oncology, Shandong Provincial Hospital Affiliated to Shandong First Medical University, Jinan, Shandong 250021, China; The Second Clinical Medical College, Shandong University of Traditional Chinese Medicine, Jinan, Shandong 250013, China; Department of Medical Oncology, The Third Affiliated Hospital of Shandong First Medical University, Jinan, Shandong 250031, China.
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Liu L, Rosenbaek LL, Kui M, Svendsen SL, Brethvad AO, Jakobsen A, Sparsoe LV, Hamilton A, Sørensen MV, Skov M, Therkildsen JR, Andresen JK, Laitakari A, Frimurer TM, Jensen BL, Pluznick J, Fenton RA, Holst B, Praetorius H. Renal Ghrelin-Family GPR39 Receptor and Urinary Concentrating Ability. J Am Soc Nephrol 2025:00001751-990000000-00610. [PMID: 40172982 DOI: 10.1681/asn.0000000687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 03/21/2025] [Indexed: 04/04/2025] Open
Abstract
Key Points
This study provides the first functional documentation of the ghrelin receptor family member GPR39 in the kidney.GPR39 activation directly reduced the urine concentrating capacity by reducing the AVP-induced water permeability of the collecting duct.In parallel, GPR39 activation increased the K+ excretion through a specific reduction of phosphorylated Na+-Cl− cotransporter in the distal convoluted tubule.
Background
Low-calorie intake is associated with substantial changes in volume distribution and volume status in the body, resulting in reduced circulatory volume and a reduction in BP. Activation of the orphan receptor GPR39 dampens food intake and causes weight loss in a glucagon like peptide-1–dependent fashion. We speculated that appetite-regulating signaling might also be responsible for the circulatory volume contraction observed in response to anorectic states.
Methods
To assess the effect of GPR39 fluid homeostasis, we combined in vivo, ex vivo, and in vitro studies to assess the effect of a selective GPR39 agonist (Cpd1324).
Results
Oral gavage of Cpd1324 dose-dependently increased the water intake of wild-type (WT) C57BL/6J mice only and was completely absent in global GPR39 knockout mice. GPR39 is expressed in the distal convoluted tubule and collecting duct of the kidney, and WT mice exclusively showed Cpd1324-induced increase in urine production, increased K+ excretion, and reduced urine concentrating capacity both at baseline and after an 8-hour water restriction compared with vehicle controls. Correspondingly, Cpd1324 reduced AVP-induced cAMP production and directly counteracted the AVP-induced water permeability in perfused cortical collecting ducts. Moreover, specific GPR39 activation reduced the baseline and AVP-stimulated abundance of phosphorylated pS256-aquaporin 2 and pT58-Na+-Cl− cotransporter and diminished the AVP-stimulated pS269-aquaporin 2 abundance in renal tubular suspensions. These effects were seen exclusively in GPR39 WT mice and not in knockout mice.
Conclusions
These data suggest that Cpd1324 directly targets renal GPR39 to induce increased diuresis and consequently stimulate drinking behavior. We conclude that the activation of GPR39 causes diuresis by opposing AVP-induced Na+ and Cl− reabsorption in the distal convoluted tubule and water reabsorption in the collecting duct.
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Affiliation(s)
- Lingzhi Liu
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Mackenzie Kui
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | | | - Annemette Overgaard Brethvad
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Alexander Jakobsen
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Laura V Sparsoe
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Aimi Hamilton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mads V Sørensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Mathias Skov
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Jesper Kingo Andresen
- Department of Molecular Medicine, Cardiovascular and Renal Research, The Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Anna Laitakari
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Thomas M Frimurer
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
| | - Boye Lagerbon Jensen
- Department of Molecular Medicine, Cardiovascular and Renal Research, The Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
| | - Jennifer Pluznick
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Robert A Fenton
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Birgitte Holst
- Laboratory for Molecular Pharmacology, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
- Section of Metabolic Receptology, Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, Denmark
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Veshkini A, Kühn C, Dengler F, Bachmann L, Liermann W, Helm C, Ulrich R, Delling C, Hammon HM. Cryptosporidium parvum infection alters the intestinal mucosa transcriptome in neonatal calves: impacts on epithelial barriers and transcellular transport systems. Front Cell Infect Microbiol 2024; 14:1495309. [PMID: 39703373 PMCID: PMC11656319 DOI: 10.3389/fcimb.2024.1495309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2024] [Accepted: 11/18/2024] [Indexed: 12/21/2024] Open
Abstract
Introduction Cryptosporidium parvum (C. parvum) is the most prevalent enteric protozoan parasite causing infectious diarrhea in neonatal calves worldwide with a direct negative impact on their health and welfare. This study utilized next-generation sequencing (NGS) to deepen our understanding of intestinal epithelial barriers and transport mechanisms in the pathophysiology of infectious diarrhea in neonatal calves, which could potentially unveil novel solutions for treatment. Methods At day 1 of life, male Holstein-Friesian calves were either orally infected (n = 5) or not (control group, n = 5) with C. parvum oocysts (in-house strain LE-01-Cp-15). On day 8 after infection, calves were slaughtered and jejunum mucosa samples were taken. The RNA was extracted from collected samples and subjected to sequencing. Differentially expressed genes (DEG) between the infected and CTRL groups were assessed using DESeq2 at a false discovery rate < 0.05 and used for gene ontology (GO) and pathway enrichment analysis in Cytoscape (v3.9.1). Results and discussion To study the pathophysiology of infectious diarrhea on intestinal permeability, 459 genes related to epithelial cell barrier integrity and paracellular and transmembrane transport systems were selected from 12,908 identified genes in mucus. Among, there were 61 increased and 109 decreased gene transcripts belonged to adhesion molecules (e.g. ADGRD1 and VCAM1), ATP-binding cassette (ABC, e.g. ABCC2 and ABCD1) and solute carrier (SLC, e.g. SLC28A2 and SLC38A3) transporters, and ion channels (e.g. KCNJ15). Our results suggest deregulation of cellular junctions and thus a possibly increased intestinal permeability, whereas deregulation of ABC and SLC transporters and ion channels may influence the absorption/secretion of amino acids, carbohydrates, fats, and organic compounds, as well as acid-based balance and osmotic hemostasis. Besides pathogen-induced gene expression alterations, part of the DEG may have been triggered or consequently affected by inflammatory mechanisms. The study provided a deeper understanding of the pathophysiology of infectious diarrhea in neonatal calves and the host-pathogen interactions at the transcript level. For further studies with a particular focus on the transport system, these results could lead to a new approach to elucidating pathophysiological regulatory mechanisms.
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Affiliation(s)
- Arash Veshkini
- Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Christa Kühn
- Friedrich-Loeffler-Institute, Greifswald-Insel Riems, Germany
- Agricultural and Environmental Faculty, University Rostock, Rostock, Germany
| | - Franziska Dengler
- Institute of Animal Sciences, University of Hohenheim, Hohenheim, Germany
| | - Lisa Bachmann
- Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
- Faculty of Agriculture and Food Science, University of Applied Science Neubrandenburg, Neubrandenburg, Germany
| | - Wendy Liermann
- Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
| | - Christiane Helm
- Institute for Veterinary Pathology, Leipzig University, Leipzig, Germany
| | - Reiner Ulrich
- Institute for Veterinary Pathology, Leipzig University, Leipzig, Germany
| | - Cora Delling
- Institute of Veterinary Parasitology, Leipzig University, Leipzig, Germany
| | - Harald M. Hammon
- Research Institute for Farm Animal Biology (FBN), Dummerstorf, Germany
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Shen G, Zhang Y, Cheng X, Li D, Ding Z, Tian J, Chen H, Ding H. Effects of CFTR-ENaC on spinal cord edema after spinal cord injury. Open Med (Wars) 2024; 19:20241082. [PMID: 39588386 PMCID: PMC11587918 DOI: 10.1515/med-2024-1082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2024] [Revised: 09/25/2024] [Accepted: 10/15/2024] [Indexed: 11/27/2024] Open
Abstract
Objective To explore the role of cystic fibrosis transmembrane conduction regulator (CFTR)-Epithelial sodium channel (ENaC) in spinal cord edema after spinal cord injury (SCI) and the related mechanism. Methods Lipopolysaccharide (LPS)-treated M1830 astrocytes were applied as the SCI in vitro model. Immunohistochemistry, real-time PCR, and Western blotting were utilized to detect CFTR and ENaC expression. Enzyme-linked immunosorbent assay was used to measure inflammatory cytokines including TNF-α, IL-1β, IL-6, and IL-18. Transmission electron microscope examined ultrastructure changes, while CFTR-172 or Capsazepine treatment assessed their effects on edema and inflammation. Western blot analysis was employed to evaluate the PI3K, p-PI3K, AKT, and p-AKT signaling pathways in treated cells. Results LPS-treated M1830 cells exhibited increased levels of CFTR and pro-inflammatory cytokines, including TNF-α, IL-1β, IL-6, and IL-18, alongside decreased ENaC expression and suppressed p-PI3K/PI3K and p-AKT/AKT levels. Degeneration of the myelin sheath and axons was observed in LPS-treated M1830, while changes in ultrastructural were recovered after adding CFTR-172 or Capsazepine. The level of CFTR, TNF-α, IL-1β, IL-6, and IL-18 was decreased, while the level of ENaC, p-PI3K/PI3K, and p-AKT/AKT was increased obviously in LPS-treated M1830 with CFTR-172, Capsazepine, or IGF-1. Conclusion Down-regulation of CFTR and up-regulation of ENaC can attenuate inflammation in SCI by activating the PI3K/AKT signaling pathway, highlighting a new therapeutic approach for SCI treatment. These findings address a critical gap in current SCI treatments and suggest a novel intervention strategy targeting ion channel regulation.
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Affiliation(s)
- Guowei Shen
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Yunpeng Zhang
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Xinkun Cheng
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Dongdong Li
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Zhiyong Ding
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Jiwei Tian
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Hui Chen
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, Nanjing, 210019, Jiangsu, China
| | - Huiming Ding
- Department of Orthopaedics, BenQ Medical Center, The Affiliated BenQ Hospital of Nanjing Medical University, No. 71, Hexi Street, Jianye District, Nanjing, 210019, Jiangsu, China
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Haywood LMB, Sheahan BJ. A Review of Epithelial Ion Transporters and Their Roles in Equine Infectious Colitis. Vet Sci 2024; 11:480. [PMID: 39453072 PMCID: PMC11512231 DOI: 10.3390/vetsci11100480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2024] [Revised: 09/04/2024] [Accepted: 09/07/2024] [Indexed: 10/26/2024] Open
Abstract
Equine colitis is a devastating disease with a high mortality rate. Infectious pathogens associated with colitis in the adult horse include Clostridioides difficile, Clostridium perfringens, Salmonella spp., Neorickettsia risticii/findlaynesis, and equine coronavirus. Antimicrobial-associated colitis can be associated with the presence of infectious pathogens. Colitis can also be due to non-infectious causes, including non-steroidal anti-inflammatory drug administration, sand ingestion, and infiltrative bowel disease. Current treatments focus on symptomatic treatment (restoring fluid and electrolyte balance, preventing laminitis and sepsis). Intestinal epithelial ion channels are key regulators of electrolyte (especially sodium and chloride) and water movement into the lumen. Dysfunctional ion channels play a key role in the development of diarrhea. Infectious pathogens, including Salmonella spp. and C. difficile, have been shown to regulate ion channels in a variety of ways. In other species, there has been an increased interest in ion channel manipulation as an anti-diarrheal treatment. While targeting ion channels also represents a promising way to manage diarrhea associated with equine colitis, ion channels have not been well studied in the equine colon. This review provides an overview of what is known about colonic ion channels and their known or putative role in specific types of equine colitis due to various pathogens.
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Affiliation(s)
| | - Breanna J. Sheahan
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA;
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Chen L, Yi H, Li Q, Duan T, Liu X, Li L, Wang HY, Xing C, Wang R. T-bet Regulates Ion Channels and Transporters and Induces Apoptosis in Intestinal Epithelial Cells. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2401654. [PMID: 38650111 PMCID: PMC11267362 DOI: 10.1002/advs.202401654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 03/22/2024] [Indexed: 04/25/2024]
Abstract
T-bet, encoded by TBX21, is extensively expressed across various immune cell types, and orchestrates critical functions in their development, survival, and physiological activities. However, the role of T-bet in non-immune compartments, notably the epithelial cells, remains obscure. Herein, a Tet-O-T-bet transgenic mouse strain is generated for doxycycline-inducible T-bet expression in adult animals. Unexpectedly, ubiquitous T-bet overexpression causes acute diarrhea, intestinal damage, and rapid mortality. Cell-type-specific analyses reveal that T-bet-driven pathology is not attributable to its overexpression in CD4+ T cells or myeloid lineages. Instead, inducible T-bet overexpression in the intestinal epithelial cells is the critical determinant of the observed lethal phenotype. Mechanistically, T-bet overexpression modulates ion channel and transporter profiles in gut epithelial cells, triggering profound fluid secretion and subsequent lethal dehydration. Furthermore, ectopic T-bet expression enhances gut epithelial cell apoptosis and markedly suppresses colon cancer development in xenograft models. Collectively, the findings unveil a previously unrecognized role of T-bet in intestinal epithelial cells for inducing apoptosis, diarrhea, and local inflammation, thus implicating its potential as a therapeutic target for the treatment of cancer and inflammatory diseases.
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Affiliation(s)
- Lang Chen
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of General SurgeryThird Xiangya HospitalXiangya School of MedicineCentral South UniversityChangsha410013China
| | - Hongwei Yi
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of PharmacologySchool of MedicineSoutheast UniversityNanjing210009China
| | - Qingtian Li
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineBaylor College of MedicineHoustonTX77030USA
| | - Tianhao Duan
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Xin Liu
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Linfeng Li
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of Thoracic SurgeryXiangya HospitalCentral South UniversityChangsha410008China
| | - Helen Y. Wang
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Changsheng Xing
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
| | - Rong‐Fu Wang
- Center for Inflammation and EpigeneticsHouston Methodist Research InstituteHoustonTX77030USA
- Department of MedicineKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
- Department of PediatricsChildren's Hospital Los AngelesKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90027USA
- Norris Comprehensive Cancer CenterKeck School of MedicineUniversity of Southern CaliforniaLos AngelesCA90033USA
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Hershfinkel M. Cross-talk between zinc and calcium regulates ion transport: A role for the zinc receptor, ZnR/GPR39. J Physiol 2024; 602:1579-1594. [PMID: 37462604 DOI: 10.1113/jp283834] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 06/26/2023] [Indexed: 04/21/2024] Open
Abstract
Zinc is essential for many physiological functions, with a major role in digestive system, skin health, and learning and memory. On the cellular level, zinc is involved in cell proliferation and cell death. A selective zinc sensing receptor, ZnR/GPR39 is a Gq-coupled receptor that acts via the inositol trisphosphate pathway to release intracellular Ca2+. The ZnR/GPR39 serves as a mediator between extracellular changes in Zn2+ concentration and cellular Ca2+ signalling. This signalling pathway regulates ion transporters activity and thereby controls the formation of transepithelial gradients or neuronal membrane potential, which play a fundamental role in the physiological function of these tissues. This review focuses on the role of Ca2+ signalling, and specifically ZnR/GPR39, with respect to the regulation of the Na+/H+ exchanger, NHE1, and of the K+/Cl- cotransporters, KCC1-3, and also describes the physiological implications of this regulation.
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Affiliation(s)
- Michal Hershfinkel
- Department of Physiology and Cell Biology and the School of Brain Sciences and Cognition, Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer-Sheva, Israel
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Marangi M, Boughattas S, Valzano F, La Bella G, De Nittis R, Margaglione M, Arena F. Prevalence of Blastocystis sp. and other gastrointestinal pathogens among diarrheic COVID-19 patients in Italy. New Microbes New Infect 2024; 58:101228. [PMID: 38406386 PMCID: PMC10884970 DOI: 10.1016/j.nmni.2024.101228] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/05/2024] [Accepted: 02/05/2024] [Indexed: 02/27/2024] Open
Abstract
Background Gastrointestinal pathogens (GPs) contribute significantly to the burden of illness worldwide with diarrhoea being the most common among gastrointestinal symptoms (GSs). In the COVID-19 disease, diarrhoea, could be one of the initial presenting symptoms. However, no data on the potential correlation between diarrhoea-causing pathogens and SARS-CoV-2 infection are available. Therefore, we carried out a 2-years retrospective study aimed to evaluate the prevalence of "classic" GPs among SARS-CoV-2 infected and non-infected patients with diarrhoea in Italy. Methods Results of SARS-CoV-2 research from nasopharyngeal and detection of GPs from stool swab samples by Allplex™ SARS-CoV-2 and GI Virus, Bacteria and Parasite Assay were analysed for all patients with diarrhoea referring to Policlinico Ospedaliero Universitario, Foggia, (Italy) from February 2022 to October 2023. Results Out of the 833 involved patients, 81 (3.9%) were COVID-19 positive, while 752 (90.3%) were COVID-19 negative. Among COVID-19-positive patients, 37% (n = 30/81) were found positive for one or more GPs with a higher prevalence of protozoan parasites (18.5%) (Blastocystis ST1-ST4 subtypes, Dientamoeba fragilis genotype I), followed by bacteria (7.4%) (Campylobacter sp., Salmonella sp.). Viral pathogens were more frequent among COVID-19 negative patients (Adenovirus, Norovirus). Among GPs, Blastocystis ST3 subtype was the most prevalent registered in the 16% of patients (p = 0.0001). Conclusions Based on obtained results, a likely interaction between the classic GPs and SARS-CoV-2 infection can be speculated, driven by protozoan parasites. Moreover, these results also provide baseline data to understand more deeply Blastocystis sp. role in this scenario of dysbiosis, particularly in those cases of SARS-CoV-2 co-infection.
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Affiliation(s)
- Marianna Marangi
- Department of Clinical and Experimental Medicine, University of Foggia, Viale Luigi Pinto, 71122, Foggia, Italy
| | | | - Felice Valzano
- Department of Clinical and Experimental Medicine, University of Foggia, Viale Luigi Pinto, 71122, Foggia, Italy
| | - Gianfranco La Bella
- Department of Clinical and Experimental Medicine, University of Foggia, Viale Luigi Pinto, 71122, Foggia, Italy
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia 20, 71121, Foggia, Italy
| | - Rosella De Nittis
- Microbiology and Virology Unit, Ospedali Riuniti, Viale Luigi Pinto, 71122, Foggia, Italy
| | - Maurizio Margaglione
- Department of Clinical and Experimental Medicine, University of Foggia, Viale Luigi Pinto, 71122, Foggia, Italy
| | - Fabio Arena
- Department of Clinical and Experimental Medicine, University of Foggia, Viale Luigi Pinto, 71122, Foggia, Italy
- Microbiology and Virology Unit, Ospedali Riuniti, Viale Luigi Pinto, 71122, Foggia, Italy
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10
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Wang C, Zhong Y, Liu H, Wang H, Li Y, Wang Q, Li J, Huang P, Yang H. Effects of Dietary Supplementation with Tea Residue on Growth Performance, Digestibility, and Diarrhea in Piglets. Animals (Basel) 2024; 14:584. [PMID: 38396552 PMCID: PMC10886095 DOI: 10.3390/ani14040584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2023] [Revised: 02/05/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Thirty-six healthy 21-day-old weaned ternary piglets (Duroc × Landrace × Yorkshire) were randomly divided into two treatments with 18 replicates per treatment and one pig per replicate. The control group was fed with a basal diet and the test group was fed with diets supplemented with 1 kg/t tea residue. The test period was 28 days. The results are as follows: The addition of tea residue in the diet had no significant effect on the growth performance of weaned piglets (p > 0.05), but it could significantly reduce the diarrhea rate of piglets from 1 to 7 days and 1 to 28 days (p < 0.05). Compared with the control group, the dietary supplementation of tea residue had no significant effect on nutrient apparent digestibility, plasma biochemical indexes and plasma immune indexes (p > 0.05) but increased the content of glutathione in plasma (p < 0.05). Tea residue had no significant effect on the morphology of the jejunum and ileum of piglets (p > 0.05), but it could significantly reduce the content of chloride ions in feces (p < 0.05). Compared with the basal diet group, there was no significant difference in the relative expression of TMEM16A and CFTR mRNA in the colon of weaned piglets (p > 0.05). The whole-cell patch clamp recording showed that the TMEM16A and CFTR ion channels could be activated by ionomycin and forskolin, respectively. However, when HT-29 cells transfected with TMEM16A and CFTR channels were treated with tea residue extract, it could significantly inhibit the chloride current of the TMEM16A and CFTR ion channels (p < 0.05).
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Affiliation(s)
| | | | | | | | | | | | | | - Pengfei Huang
- Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University, Changsha 410081, China
| | - Huansheng Yang
- Hunan Provincial Key Laboratory of Animal Intestinal Function and Regulation, College of Life Sciences, Hunan Normal University, Changsha 410081, China
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11
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de Souza Goncalves L, Chu T, Master R, Chhetri PD, Gao Q, Cil O. Mg2+ supplementation treats secretory diarrhea in mice by activating calcium-sensing receptor in intestinal epithelial cells. J Clin Invest 2024; 134:e171249. [PMID: 37962961 PMCID: PMC10786700 DOI: 10.1172/jci171249] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Accepted: 11/09/2023] [Indexed: 11/16/2023] Open
Abstract
Cholera is a global health problem with no targeted therapies. The Ca2+-sensing receptor (CaSR) is a regulator of intestinal ion transport and a therapeutic target for diarrhea, and Ca2+ is considered its main agonist. We found that increasing extracellular Ca2+ had a minimal effect on forskolin-induced Cl- secretion in human intestinal epithelial T84 cells. However, extracellular Mg2+, an often-neglected CaSR agonist, suppressed forskolin-induced Cl- secretion in T84 cells by 65% at physiological levels seen in stool (10 mM). The effect of Mg2+ occurred via the CaSR/Gq signaling that led to cAMP hydrolysis. Mg2+ (10 mM) also suppressed Cl- secretion induced by cholera toxin, heat-stable E. coli enterotoxin, and vasoactive intestinal peptide by 50%. In mouse intestinal closed loops, luminal Mg2+ treatment (20 mM) inhibited cholera toxin-induced fluid accumulation by 40%. In a mouse intestinal perfusion model of cholera, addition of 10 mM Mg2+ to the perfusate reversed net fluid transport from secretion to absorption. These results suggest that Mg2+ is the key CaSR activator in mouse and human intestinal epithelia at physiological levels in stool. Since stool Mg2+ concentrations in patients with cholera are essentially zero, oral Mg2+ supplementation, alone or in an oral rehydration solution, could be a potential therapy for cholera and other cyclic nucleotide-mediated secretory diarrheas.
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12
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Guo SC, Yu B, Jia Q, Yan HY, Wang LQ, Sun FF, Ma TH, Yang H. Loureirin C extracted from Dracaena cochinchinensis S.C. Chen prevents rotaviral diarrhea in mice by inhibiting the intestinal Ca 2+-activated Cl - channels. JOURNAL OF ETHNOPHARMACOLOGY 2024; 318:117077. [PMID: 37625605 DOI: 10.1016/j.jep.2023.117077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/17/2023] [Accepted: 08/22/2023] [Indexed: 08/27/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Resina Draconis (RD) is the red resin of Dracaena cochinchinensis (Lour.) S.C. Chen and most used as a hemostatic drug in traditional Chinese medicine. Recent studies have reported that RD has a therapeutic effect on gastrointestinal diseases. Loureirin A, B, and C (LA, LB, and LC) are dihydrochalcone compounds isolated from RD. AIM OF THE STUDY Dehydration is the primary cause of death in rotaviral diarrhea. Inhibition of Ca2+-activated Cl- channels (CaCCs)-mediated Cl- secretion significantly reduced fluid secretion in rotaviral diarrhea. RD was used to treat digestive diseases such as diarrhea and abdominal pain; however, the pharmacological mechanism remains unclear. This study investigated the effects of RD and loureirin on intestinal Cl- channels and their therapeutic effects on rotavirus-induced diarrhea, aiming to reveal RD's molecular basis, targets, and mechanisms for treating rotaviral diarrhea. MATERIALS AND METHODS Cell-based fluorescence quenching assays were used to examine the effect of RD and loureirin on Cl- channels activity. Electrophysiological properties were tested using short-circuit current experiments in epithelial cells or freshly isolated mouse intestinal tissue. Fecal water content, intestinal peristalsis rate, and smooth muscle contraction were measured in neonatal mice infected with SA-11 rotavirus before and after LC treatment or adult mice. RESULTS RD, LA, LB, and LC inhibited CaCCs-mediated Cl- current in HT-29 cells and colonic epithelium. The inhibitory effect of LC on CaCCs was primarily on the apical side in epithelial cells, which may be partially produced by affecting cytoplasmic Ca2+ levels. LC significantly inhibited TMEM16A-mediated Cl- current. Characterization studies revealed that LC inhibited basolateral K+ channel activity without affecting Na+/K+-ATPase activity in the colonic epithelium. Although LC activated the cystic fibrosis transmembrane regulator in epithelial cells, its effect was not apparent in colonic epithelium. In vivo, LC significantly reduced the fecal water content, intestinal peristalsis rate, and smooth muscle contraction of mice infected with rotavirus. CONCLUSION RD and its active compound LC inhibit intestinal CaCCs activity, which might mediate the anti-rotaviral diarrheal effect of RD.
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Affiliation(s)
- Si-Cheng Guo
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Bo Yu
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Qian Jia
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Han-Yu Yan
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Li-Qin Wang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Fang-Fang Sun
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China; Nuclear Medicine Department, The First Affiliated Hospital of Dalian Medical University, Dalian, 116021, PR China.
| | - Tong-Hui Ma
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
| | - Hong Yang
- School of Life Sciences, Liaoning Provincial Key Laboratory of Biotechnology and Drug Discovery, Liaoning Normal University, Dalian, 116082, PR China.
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13
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McKnight CA, Diehl LJ, Bergin IL. Digestive Tract and Salivary Glands. HASCHEK AND ROUSSEAUX' S HANDBOOK OF TOXICOLOGIC PATHOLOGY 2024:1-148. [DOI: 10.1016/b978-0-12-821046-8.00001-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2025]
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14
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Elsasser TH, Faulkenberg S. Physiology of Gut Water Balance and Pathomechanics of Diarrhea. PRODUCTION DISEASES IN FARM ANIMALS 2024:179-209. [DOI: 10.1007/978-3-031-51788-4_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2025]
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15
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Detection of Escherichia coli in Food Samples by Magnetosome-based Biosensor. BIOTECHNOL BIOPROC E 2023. [DOI: 10.1007/s12257-022-0235-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
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16
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Cao X, van Putten JPM, Wösten MMSM. Biological functions of bacterial lysophospholipids. Adv Microb Physiol 2023; 82:129-154. [PMID: 36948653 DOI: 10.1016/bs.ampbs.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Lysophospholipids (LPLs) are lipid-derived metabolic intermediates in the cell membrane. The biological functions of LPLs are distinct from their corresponding phospholipids. In eukaryotic cells LPLs are important bioactive signaling molecules that regulate many important biological processes, but in bacteria the function of LPLs is still not fully defined. Bacterial LPLs are usually present in cells in very small amounts, but can strongly increase under certain environmental conditions. In addition to their basic function as precursors in membrane lipid metabolism, the formation of distinct LPLs contributes to the proliferation of bacteria under harsh circumstances or may act as signaling molecules in bacterial pathogenesis. This review provides an overview of the current knowledge of the biological functions of bacterial LPLs including lysoPE, lysoPA, lysoPC, lysoPG, lysoPS and lysoPI in bacterial adaptation, survival, and host-microbe interactions.
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Affiliation(s)
- Xuefeng Cao
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - Jos P M van Putten
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands
| | - Marc M S M Wösten
- Department Biomolecular Health Sciences, Utrecht University, Utrecht, The Netherlands.
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17
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Peritore-Galve FC, Kaji I, Smith A, Walker LM, Shupe JA, Washington MK, Algood HMS, Dudeja PK, Goldenring JR, Lacy DB. Increased intestinal permeability and downregulation of absorptive ion transporters Nhe3, Dra, and Sglt1 contribute to diarrhea during Clostridioides difficile infection. Gut Microbes 2023; 15:2225841. [PMID: 37350393 PMCID: PMC10291935 DOI: 10.1080/19490976.2023.2225841] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Accepted: 06/09/2023] [Indexed: 06/24/2023] Open
Abstract
BACKGROUND & AIM Clostridioides difficile infection (CDI) is the leading cause of hospital-acquired diarrhea and pseudomembranous colitis. Two protein toxins, TcdA and TcdB, produced by C. difficile are the major determinants of disease. However, the pathophysiological causes of diarrhea during CDI are not well understood. Here, we investigated the effects of C. difficile toxins on paracellular permeability and apical ion transporters in the context of an acute physiological infection. METHODS We studied intestinal permeability and apical membrane transporters in female C57BL/6J mice. Üssing chambers were used to measure paracellular permeability and ion transporter function across the intestinal tract. Infected intestinal tissues were analyzed by immunofluorescence microscopy and RNA-sequencing to uncover mechanisms of transporter dysregulation. RESULTS Intestinal permeability was increased through the size-selective leak pathway in vivo during acute CDI in a 2-day-post infection model. Chloride secretory activity was reduced in the cecum and distal colon during infection by decreased CaCC and CFTR function, respectively. SGLT1 activity was significantly reduced in the cecum and colon, accompanied by ablated SGLT1 expression in colonocytes and increased luminal glucose concentrations. SGLT1 and DRA expression was ablated by either TcdA or TcdB during acute infection, but NHE3 was decreased in a TcdB-dependent manner. The localization of key proteins that link filamentous actin to the ion transporters in the apical plasma membrane was unchanged. However, Sglt1, Nhe3, and Dra were drastically reduced at the transcript level, implicating downregulation of ion transporters in the mechanism of diarrhea during CDI. CONCLUSIONS CDI increases intestinal permeability and decreases apical abundance of NHE3, SGLT1, and DRA. This combination likely leads to dysfunctional water and solute absorption in the large bowel, causing osmotic diarrhea. These findings provide insights into the pathophysiological mechanisms underlying diarrhea and may open novel avenues for attenuating CDI-associated diarrhea.
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Affiliation(s)
- F. Christopher Peritore-Galve
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Izumi Kaji
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Anna Smith
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Lauren M. Walker
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Vaccine Center, Vanderbilt University Medical Center, Nashville, TN, USA
| | - John A. Shupe
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
| | - M. Kay Washington
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Holly M. Scott Algood
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
| | - Pradeep K. Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, USA
- Department of Veterans Affairs, Jesse Brown Veterans Affairs Medical Center, Chicago, IL, USA
| | - James R. Goldenring
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Section of Surgical Sciences, Vanderbilt University Medical Center, Nashville, TN, USA
- Epithelial Biology Center, Vanderbilt University School of Medicine, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
- Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - D. Borden Lacy
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN, USA
- Vanderbilt Institute for Infection, Immunology, and Inflammation, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN, USA
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Kaur P, Dudeja PK. Pathophysiology of Enteropathogenic Escherichia coli-induced Diarrhea. NEWBORN (CLARKSVILLE, MD.) 2023; 2:102-113. [PMID: 37388762 PMCID: PMC10308259 DOI: 10.5005/jp-journals-11002-0056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/01/2023]
Abstract
Enteropathogenic Escherichia coli (EPEC) are important diarrheal pathogens of infants and young children. Since the availability of molecular diagnosis methods, we now have new insights into the incidence and prevalence of these infections. Recent epidemiological studies indicate that atypical EPEC (aEPEC) are seen more frequently than typical EPEC (tEPEC) worldwide, including in both endemic diarrhea and diarrhea outbreaks. Therefore, it is important to further characterize the pathogenicity of these emerging strains. The virulence mechanisms and pathophysiology of the attaching and effacing lesion (A/E) and the type-three-secretion-system (T3SS) are complex but well-studied. A/E strains use their pool of locus of enterocyte effacement (LEE)-encoded and non-LEE-encoded effector proteins to subvert and modulate cellular and barrier properties of the host. However, the exact mechanisms of diarrhea in EPEC infection are not completely understood. From the clinical perspective, there is a need for fast, easy, and inexpensive diagnostic methods to define optimal treatment and prevention for children in endemic areas. In this article, we present a review of the classification of EPEC, epidemiology, pathogenesis of the disease caused by these bacteria, determinants of virulence, alterations in signaling, determinants of colonization vs. those of disease, and the limited information we have on the pathophysiology of EPEC-induced diarrhea. This article combines peer-reviewed evidence from our own studies and the results of an extensive literature search in the databases PubMed, EMBASE, and Scopus.
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Affiliation(s)
- Prabhdeep Kaur
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Illinois, United States of America
| | - Pradeep K Dudeja
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois; Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, United States of America
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19
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Natural statin derivatives as potential therapy to reduce intestinal fluid loss in cholera. PLoS Negl Trop Dis 2022; 16:e0010989. [PMID: 36490300 PMCID: PMC9770395 DOI: 10.1371/journal.pntd.0010989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 12/21/2022] [Accepted: 11/28/2022] [Indexed: 12/14/2022] Open
Abstract
As a leading cause of death in children under 5 years old, secretory diarrheas including cholera are characterized by excessive intestinal fluid secretion driven by enterotoxin-induced cAMP-dependent intestinal chloride transport. This study aimed to identify fungal bioactive metabolites possessing anti-secretory effects against cAMP-dependent chloride secretion in intestinal epithelial cells. Using electrophysiological analyses in human intestinal epithelial (T84) cells, five fungus-derived statin derivatives including α,β-dehydrolovastatin (DHLV), α,β-dehydrodihydromonacolin K, lovastatin, mevastatin and simvastatin were found to inhibit the cAMP-dependent chloride secretion with IC50 values of 1.8, 8.9, 11.9, 11.4 and 5 μM, respectively. Being the most potent statin derivatives, DHLV was evaluated for its pharmacological properties including cellular toxicity, mechanism of action, target specificity and in vivo efficacy. DHLV at concentrations up to 20 μM did not affect cell viability and barrier integrity of T84 cells. Electrophysiological analyses indicated that DHLV inhibited cystic fibrosis transmembrane conductance regulator (CFTR), a cAMP-dependent apical chloride channel, via mechanisms not involving alteration of intracellular cAMP levels or its negative regulators including AMP-activated protein kinases and protein phosphatases. DHLV had no effect on Na+-K+ ATPase activities but inhibited Ca2+-dependent chloride secretion without affecting intracellular Ca2+ levels. Importantly, intraperitoneal (2 mg/kg) and intraluminal (20 μM) injections of DHLV reduced cholera toxin-induced intestinal fluid secretion in mice by 59% and 65%, respectively without affecting baseline intestinal fluid transport. This study identifies natural statin derivatives as novel natural product-derived CFTR inhibitors, which may be beneficial in the treatment of enterotoxin-induced secretory diarrheas including cholera.
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20
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Hammers DE, Donahue DL, Tucker Z, Ashfeld BL, Ploplis VA, Castellino FJ, Lee SW. Streptolysin S targets the sodium-bicarbonate cotransporter NBCn1 to induce inflammation and cytotoxicity in human keratinocytes during Group A Streptococcal infection. Front Cell Infect Microbiol 2022; 12:1002230. [PMID: 36389147 PMCID: PMC9663810 DOI: 10.3389/fcimb.2022.1002230] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Accepted: 09/29/2022] [Indexed: 11/30/2022] Open
Abstract
Group A <i>Streptococcus</i> (GAS, <i>Streptococcus pyogenes</i>) is a Gram-positive human pathogen that employs several secreted and surface-bound virulence factors to manipulate its environment, allowing it to cause a variety of disease outcomes. One such virulence factor is Streptolysin S (SLS), a ribosomally-produced peptide toxin that undergoes extensive post-translational modifications. The activity of SLS has been studied for over 100 years owing to its rapid and potent ability to lyse red blood cells, and the toxin has been shown to play a major role in GAS virulence <i>in vivo</i>. We have previously demonstrated that SLS induces hemolysis by targeting the chloride-bicarbonate exchanger Band 3 in erythrocytes, indicating that SLS is capable of targeting host proteins to promote cell lysis. However, the possibility that SLS has additional protein targets in other cell types, such as keratinocytes, has not been explored. Here, we use bioinformatics analysis and chemical inhibition studies to demonstrate that SLS targets the electroneutral sodium-bicarbonate cotransporter NBCn1 in keratinocytes during GAS infection. SLS induces NF-κB activation and host cytotoxicity in human keratinocytes, and these processes can be mitigated by treating keratinocytes with the sodium-bicarbonate cotransport inhibitor S0859. Furthermore, treating keratinocytes with SLS disrupts the ability of host cells to regulate their intracellular pH, and this can be monitored in real time using the pH-sensitive dye pHrodo Red AM in live imaging studies. These results demonstrate that SLS is a multifunctional bacterial toxin that GAS uses in numerous context-dependent ways to promote host cell cytotoxicity and increase disease severity. Studies to elucidate additional host targets of SLS have the potential to impact the development of therapeutics for severe GAS infections.
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Affiliation(s)
- Daniel E. Hammers
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States
| | - Deborah L. Donahue
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Zachary D. Tucker
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Brandon L. Ashfeld
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States
| | - Victoria A. Ploplis
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Francis J. Castellino
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States
| | - Shaun W. Lee
- Department of Biological Sciences, University of Notre Dame, Notre Dame, IN, United States,Eck Institute for Global Health, University of Notre Dame, Notre Dame, IN, United States,William Myron (W. M.) Keck Center for Transgene Research, University of Notre Dame, Notre Dame, IN, United States,*Correspondence: Shaun W. Lee,
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21
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Costas C, Louzao MC, Raposo-García S, Vale C, Vieytes MR, Botana LM. Intestinal secretory mechanisms in Okadaic acid induced diarrhoea. Food Chem Toxicol 2022; 169:113449. [DOI: 10.1016/j.fct.2022.113449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/13/2022] [Accepted: 09/21/2022] [Indexed: 10/31/2022]
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22
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Formulating Diets for Improved Health Status of Pigs: Current Knowledge and Perspectives. Animals (Basel) 2022; 12:ani12202877. [DOI: 10.3390/ani12202877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 10/15/2022] [Accepted: 10/19/2022] [Indexed: 11/17/2022] Open
Abstract
Our understanding of nutrition has been evolving to support both performance and immune status of pigs, particularly in disease-challenged animals which experience repartitioning of nutrients from growth towards the immune response. In this sense, it is critical to understand how stress may impact nutrient metabolism and the effects of nutritional interventions able to modulate organ (e.g., gastrointestinal tract) functionality and health. This will be pivotal in the development of effective diet formulation strategies in the context of improved animal performance and health. Therefore, this review will address qualitative and quantitative effects of immune system stimulation on voluntary feed intake and growth performance measurements in pigs. Due to the known repartitioning of nutrients, the effects of stimulating the immune system on nutrient requirements, stratified according to different challenge models, will be explored. Finally, different nutritional strategies (i.e., low protein, amino acid-supplemented diets; functional amino acid supplementation; dietary fiber level and source; diet complexity; organic acids; plant secondary metabolites) will be presented and discussed in the context of their possible role in enhancing the immune response and animal performance.
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23
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Hassan SU, Chua EG, Kaur P, Paz EA, Tay CY, Greeff JC, Liu S, Martin GB. Contribution of the Immune Response in the Ileum to the Development of Diarrhoea caused by Helminth Infection: Studies with the Sheep Model. Funct Integr Genomics 2022; 22:865-877. [PMID: 35576023 PMCID: PMC9550700 DOI: 10.1007/s10142-022-00864-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/18/2022] [Accepted: 04/20/2022] [Indexed: 11/04/2022]
Abstract
Gastrointestinal helminths are a global health issue, for humans as well as domestic animals. Most studies focus on the tissues that are infected with the parasite, but here we studied the ileum, a tissue that is rarely infected by helminths. We tested whether inflammation in the ileum contributes to the development and severity of diarrhoea, by comparing sheep that are susceptible (n = 4) or resistant (n = 4) to the disease. We analyzed the ileum transcriptome using RNASeq sequencing approach and various bioinformatics tools including FastQC, STAR, featureCounts, DESeq2, DAVID, clusterProfiler, Cytoscape (ClusterONE) and EnrichR. We identified 243 differentially expressed genes (DEGs), of which 118 were up-regulated and 125 were down-regulated DEGs in the diarrhoea-susceptible animals compared to the diarrhoea-resistant animals. The resulting DEGs were functionally enriched for biological processes, pathways and gene set enrichment analysis. The up-regulated DEGs suggested that an inflammatory immune response was coupled with genes involved in 'Th2 immune response' and 'anti-inflammatory response'. The down-regulated DEGs were related to ion transport, muscle contraction and pathways preventing inflammation. We conclude that i) susceptibility to helminth-induced diarrhoea involves an inflammatory response at a non-infectious site; ii) down-regulation of pathways preventing inflammation can contribute to the severity of diarrhoea; and iii) genes involved in anti-inflammatory responses can reduce the inflammation and diarrhoea.
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Affiliation(s)
- Shamshad Ul Hassan
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia
- Helicobacter Research Laboratory, The Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Eng Guan Chua
- Helicobacter Research Laboratory, The Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Parwinder Kaur
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Erwin A Paz
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia
- Helicobacter Research Laboratory, The Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Chin Yen Tay
- Helicobacter Research Laboratory, The Marshall Centre for Infectious Disease Research and Training, School of Biomedical Sciences, University of Western Australia, Perth, WA, Australia
| | - Johan C Greeff
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia
- Department of Primary Industries and Regional Development, Western Australia, 3 Baron Hay Court, South Perth, WA, 6151, Australia
| | - Shimin Liu
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia
| | - Graeme B Martin
- UWA School of Agriculture and Environment, The University of Western Australia, Crawley, WA, 6009, Australia.
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24
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Mphande I, Kataba A, Muzandu K, Gono-Bwalya A. An Evaluation of the Antibacterial Activity of Pterocarpus tinctorius Bark Extract against Enteric Bacteria That Cause Gastroenteritis. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE : ECAM 2022; 2022:7973942. [PMID: 36204123 PMCID: PMC9532075 DOI: 10.1155/2022/7973942] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 11/17/2022]
Abstract
Enteric bacteria are the leading cause of bacterial gastroenteritis worldwide, particularly in low-income countries. The bark decoction of Pterocarpus tinctorius (Fabaceae) has traditionally been used to treat bacterial gastroenteritis. However, studies reporting the antibacterial activity of Pterocarpus tinctorius are rare. Therefore, this study aimed to evaluate the antibacterial activity of stem bark extract of Pterocarpus tinctorius against Escherichia coli, Salmonella typhi, and Shigella dysenteriae. The powdered bark extract was successively extracted with methanol using the cold continuous maceration method, followed by partitioning the crude methanolic extract to obtain methanolic, hexane, and chloroform subextracts. Three fractions were isolated from the methanolic subextract using ordinary normal phase column chromatography. The antibacterial activity of the extracts and fractions was performed using the agar well diffusion method. The minimum inhibitory concentration (MIC) was determined using the agar well diffusion method. While, minimum bactericidal concentration (MBC) was obtained by the subculturing method. The methanolic subextract was the only extract that showed antibacterial activity against the tested bacteria, and its activity was highest on Shigella dysenteriae followed by Salmonella typhi and was least active on Escherichia coli, with mean inhibition zones of 14.3 ± 0.2, 13.7 ± 0.3, and 12.2 ± 0.1 at 200 mg/mL, respectively. Chloroform subextract showed antibacterial activity only on Shigella dysenteriae, while hexane subextract did not show antibacterial activity against all bacteria tested at 100 mg/mL and 200 mg/mL. Among the three subfractions of methanolic subextract, only one subfraction was active and had both mean minimum inhibitory concentration and a minimum bactericidal concentration against Escherichia coli at 1.25 mg/mL, Salmonella typhi at 1.25 mg/mL, and Shigella dysenteriae at 0.6 mg/mL. The findings of this study support the use of Pterocarpus tinctorius in traditional medicine. Therefore, purification and structural elucidation studies are highly recommended.
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Affiliation(s)
- Isaac Mphande
- Department of Pharmacy, School of Health Sciences, University of Zambia, Lusaka, Zambia
| | - Andrew Kataba
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Kaampwe Muzandu
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Zambia, Lusaka, Zambia
| | - Angela Gono-Bwalya
- Department of Pharmacy, School of Health Sciences, University of Zambia, Lusaka, Zambia
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25
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Clerbaux LA, Fillipovska J, Muñoz A, Petrillo M, Coecke S, Amorim MJ, Grenga L. Mechanisms Leading to Gut Dysbiosis in COVID-19: Current Evidence and Uncertainties Based on Adverse Outcome Pathways. J Clin Med 2022; 11:5400. [PMID: 36143044 PMCID: PMC9505288 DOI: 10.3390/jcm11185400] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/24/2022] [Accepted: 09/09/2022] [Indexed: 02/06/2023] Open
Abstract
Alteration in gut microbiota has been associated with COVID-19. However, the underlying mechanisms remain poorly understood. Here, we outlined three potential interconnected mechanistic pathways leading to gut dysbiosis as an adverse outcome following SARS-CoV-2 presence in the gastrointestinal tract. Evidence from the literature and current uncertainties are reported for each step of the different pathways. One pathway investigates evidence that intestinal infection by SARS-CoV-2 inducing intestinal inflammation alters the gut microbiota. Another pathway links the binding of viral S protein to angiotensin-converting enzyme 2 (ACE2) to the dysregulation of this receptor, essential in intestinal homeostasis-notably for amino acid metabolism-leading to gut dysbiosis. Additionally, SARS-CoV-2 could induce gut dysbiosis by infecting intestinal bacteria. Assessing current evidence within the Adverse Outcome Pathway framework justifies confidence in the proposed mechanisms to support disease management and permits the identification of inconsistencies and knowledge gaps to orient further research.
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Affiliation(s)
| | | | - Amalia Muñoz
- European Commission, Joint Research Centre (JRC), 2440 Geel, Belgium
| | | | - Sandra Coecke
- European Commission, Joint Research Centre (JRC), 21027 Ispra, Italy
| | - Maria-Joao Amorim
- Instituto Gulbenkian de Ciência, 2780-156 Oerias, Portugal
- Católica Medical School, Católica Biomedical Research Centre, Universidade Católica Portuguesa, 1649-023 Lisbon, Portugal
| | - Lucia Grenga
- Département Médicaments et Technologies pour la Santé, Commissariat à l’Énergie Atomique et Aux Énergies Alternatives (CEA), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université Paris-Saclay, 30200 Bagnols-sur-Cèze, France
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26
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Qiao J, Yang J, Jalili S. Propolis-Loaded Chitosan Nanoparticles for the Treatment of Bacterial Diarrhea: In Vitro and In Vivo Evaluation. J Biomed Nanotechnol 2022. [DOI: 10.1166/jbn.2022.3382] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diarrhea is a disorder in the gastrointestinal system that is accompanied by cramps, decreased stool’s viscosity, and reduced defecation intervals. In the current study, propolis was loaded into chitosan nanoparticles to develop a potential treatment for gastrointestinal infections.
Various In Vitro experiments were performed to characterize the produced nanoparticles. The healing function of propolis-loaded chitosan nanoparticles (ProCHNPs) was evaluated in a rat model of enteropathogenic Escherichia coli-induced diarrhea. In Vitro studies showed
that ProCHNPs were not toxic against intestinal epithelial cells and improved their viability. Furthermore, these particles had around 261.49±63.22 nm average particle size and showed significantly higher antibacterial and anti-inflammatory activities than propolis-free chitosan nanoparticles.
In Vivo studies showed that ProCHNPs had comparable anti-diarrhea function with norfloxacin as the standard drug. In addition, ProCHNPs increased the number of beneficial bacteria in the intestinal microflora and reduced the level of pro-inflammatory cytokines in the colon tissue. This
study suggests potential use of ProCHNPs as an alternative treatment for bacterial diarrhea.
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Affiliation(s)
- Jie Qiao
- Department of Pediatrics, 3201 Hospital, Hanzhong, 723000, China
| | - Jun Yang
- Department of Pediatrics, Xi’an Gaoxin Hospital, Xi’an, 710061, China
| | - Saman Jalili
- Department of Biomaterials Science and Technology, Isfahan University of Technology, Isfahan, 548987, Iran
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27
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Oak AA, Chu T, Yottasan P, Chhetri PD, Zhu J, Du Bois J, Cil O. Lubiprostone is non-selective activator of cAMP-gated ion channels and Clc-2 has a minor role in its prosecretory effect in intestinal epithelial cells. Mol Pharmacol 2022; 102:MOLPHARM-AR-2022-000542. [PMID: 35680165 PMCID: PMC9341254 DOI: 10.1124/molpharm.122.000542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 05/21/2022] [Accepted: 05/27/2022] [Indexed: 12/14/2022] Open
Abstract
Loss of prosecretory Cl- channel CFTR activity is considered as the key cause of gastrointestinal disorders in cystic fibrosis including constipation and meconium ileus. Clc-2 is proposed as an alternative Cl- channel in intestinal epithelia that can compensate for CFTR loss-of-function. Lubiprostone is an FDA-approved drug with Clc-2 activation as its presumed mechanism of action. However, relative contribution of Clc-2 in intestinal Cl- secretion and the mechanism of action of lubiprostone remain controversial due to lack of selective Clc-2 inhibitors. Using recently identified selective Clc-2 inhibitor AK-42, we characterized the roles of Clc-2 in Cl- secretion in human intestinal epithelial T84 cells. Clc-2 inhibitor AK-42 had minimal (15%) inhibitory effect on secretory short-circuit current (Isc) induced by cAMP agonists, where subsequently applied CFTR inhibitor (CFTRinh-172) caused 2-3 fold greater inhibition. Similarly, AK-42 inhibited lubiprostone-induced secretory Isc by 20%, whereas CFTRinh-172 caused 2-3 fold greater inhibition. In addition to increasing CFTR and Clc-2-mediated apical Cl- conductance, lubiprostone increased basolateral membrane K+ conductance, which was completely reversed by cAMP-activated K+ channel inhibitor BaCl2 All components of lubiprostone-induced secretion (Clc-2, CFTR and K+ channels) were inhibited by ~65% with the extracellular Ca2+-sensing receptor (CaSR) activator cinacalcet that stimulates cAMP hydrolysis. Lastly, EP4 prostaglandin receptor inhibitor GW627368 pretreatment inhibited lubiprostone-induced secretion by 40% without any effect on forskolin response. Our findings suggest that Clc-2 has minor role in cAMP-induced intestinal Cl- secretion; and lubiprostone is not a selective Clc-2 activator, but general activator of cAMP-gated ion channels in human intestinal epithelial cells. Significance Statement Cl- channel Clc-2 activation is the proposed mechanism of action of the FDA-approved constipation drug lubiprostone. Using first-in-class selective Clc-2 inhibitor AK-42, we showed that Clc-2 has minor contribution in intestinal Cl- secretion induced by lubiprostone and cAMP agonists. We also found that lubiprostone is a general activator of cAMP-gated ion channels in human intestinal epithelial cells (via EP4 receptors). Our findings clarify the roles of Clc-2 in intestinal Cl- secretion and elucidate the mechanism of action of approved-drug lubiprostone.
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Affiliation(s)
| | | | | | | | - Jie Zhu
- Stanford University, United States
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28
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Gastrointestinal Involvement in SARS-CoV-2 Infection. Viruses 2022; 14:v14061188. [PMID: 35746659 PMCID: PMC9228950 DOI: 10.3390/v14061188] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 05/26/2022] [Accepted: 05/27/2022] [Indexed: 02/06/2023] Open
Abstract
SARS-CoV-2 has evolved into a virus that primarily results in mild or asymptomatic disease, making its transmission more challenging to control. In addition to the respiratory tract, SARS-CoV-2 also infects the digestive tract. Some gastrointestinal symptoms occur with or before respiratory symptoms in patients with COVID-19. Respiratory infections are known to cause intestinal immune impairment and gastrointestinal symptoms. When the intestine is inflamed, cytokines affect the lung immune response and inflammation through blood circulation. The gastrointestinal microbiome may be a modifiable factor in determining the risk of SARS-CoV-2 infection and disease severity. The development of oral SARS-CoV-2 vaccine candidates and the maintenance of gut microbiota profiles may contribute to the early control of COVID-19 outbreaks. To this end, this review summarizes information on the gastrointestinal complications caused by SARS-CoV-2, SARS-CoV-2 infection, the gastrointestinal–lung axis immune response, potential control strategies for oral vaccine candidates and maintaining intestinal microbiota homeostasis.
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29
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Nikolovska K, Seidler UE, Stock C. The Role of Plasma Membrane Sodium/Hydrogen Exchangers in Gastrointestinal Functions: Proliferation and Differentiation, Fluid/Electrolyte Transport and Barrier Integrity. Front Physiol 2022; 13:899286. [PMID: 35665228 PMCID: PMC9159811 DOI: 10.3389/fphys.2022.899286] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022] Open
Abstract
The five plasma membrane Na+/H+ exchanger (NHE) isoforms in the gastrointestinal tract are characterized by distinct cellular localization, tissue distribution, inhibitor sensitivities, and physiological regulation. NHE1 (Slc9a1) is ubiquitously expressed along the gastrointestinal tract in the basolateral membrane of enterocytes, but so far, an exclusive role for NHE1 in enterocyte physiology has remained elusive. NHE2 (Slc9a2) and NHE8 (Slc9a8) are apically expressed isoforms with ubiquitous distribution along the colonic crypt axis. They are involved in pHi regulation of intestinal epithelial cells. Combined use of a knockout mouse model, intestinal organoid technology, and specific inhibitors revealed previously unrecognized actions of NHE2 and NHE8 in enterocyte proliferation and differentiation. NHE3 (Slc9a3), expressed in the apical membrane of differentiated intestinal epithelial cells, functions as the predominant nutrient-independent Na+ absorptive mechanism in the gut. The new selective NHE3 inhibitor (Tenapanor) allowed discovery of novel pathophysiological and drug-targetable NHE3 functions in cystic-fibrosis associated intestinal obstructions. NHE4, expressed in the basolateral membrane of parietal cells, is essential for parietal cell integrity and acid secretory function, through its role in cell volume regulation. This review focuses on the expression, regulation and activity of the five plasma membrane Na+/H+ exchangers in the gastrointestinal tract, emphasizing their role in maintaining intestinal homeostasis, or their impact on disease pathogenesis. We point to major open questions in identifying NHE interacting partners in central cellular pathways and processes and the necessity of determining their physiological role in a system where their endogenous expression/activity is maintained, such as organoids derived from different parts of the gastrointestinal tract.
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30
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Do C, Evans GJ, DeAguero J, Escobar GP, Lin HC, Wagner B. Dysnatremia in Gastrointestinal Disorders. Front Med (Lausanne) 2022; 9:892265. [PMID: 35646996 PMCID: PMC9136014 DOI: 10.3389/fmed.2022.892265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 04/22/2022] [Indexed: 01/19/2023] Open
Abstract
The primary solute of the milieu intérieur is sodium and accompanying anions. The solvent is water. The kidneys acutely regulate homeostasis in filtration, secretion, and resorption of electrolytes, non-electrolytes, and minerals while balancing water retention and clearance. The gastrointestinal absorptive and secretory functions enable food digestion and water absorption needed to sustain life. Gastrointestinal perturbations including vomiting and diarrhea can lead to significant volume and electrolyte losses, overwhelming the renal homeostatic compensatory mechanisms. Dysnatremia, potassium and acid-base disturbances can result from gastrointestinal pathophysiologic processes. Understanding the renal and gastrointestinal contributions to homeostatis are important for the clinical evaluation of perturbed volume disturbances.
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Affiliation(s)
- Catherine Do
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,New Mexico Veterans Administration Health Care System, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Gretta J. Evans
- University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Joshua DeAguero
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - G. Patricia Escobar
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States
| | - Henry C. Lin
- New Mexico Veterans Administration Health Care System, Albuquerque, NM, United States
| | - Brent Wagner
- Division of Nephrology, Department of Medicine, Kidney Institute of New Mexico, University of New Mexico Health Science Center, Albuquerque, NM, United States,New Mexico Veterans Administration Health Care System, Albuquerque, NM, United States,University of New Mexico Health Sciences Center, Albuquerque, NM, United States,*Correspondence: Brent Wagner
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31
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Djamgoz MBA. Ion Transporting Proteins and Cancer: Progress and Perspectives. Rev Physiol Biochem Pharmacol 2022; 183:251-277. [PMID: 35018530 DOI: 10.1007/112_2021_66] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ion transporting proteins (ITPs) comprise a wide range of ion channels, exchangers, pumps and ionotropic receptors many of which are expressed in tumours and contribute dynamically to the different components and stages of the complex cancer process, from initiation to metastasis. In this promising major field of biomedical research, several candidate ITPs have emerged as clinically viable. Here, we consider a series of general issues concerning the oncological potential of ITPs focusing on voltage-gated sodium channels as a 'case study'. First, we outline some key properties of 'cancer' as a whole. These include epigenetics, stemness, metastasis, heterogeneity, neuronal characteristics and bioelectricity. Cancer specificity of ITP expression is evaluated in relation to tissue restriction, splice variance, functional specificity and macro-molecular complexing. As regards clinical potential, diagnostics is covered with emphasis on enabling early detection. For therapeutics, we deal with molecular approaches, drug repurposing and combinations. Importantly, we emphasise the need for carefully designed clinical trials. We highlight also the area of 'social responsibility' and the need to involve the public (cancer patients and healthy individuals) in the work of cancer research professionals as well as clinicians. In advising patients how best to manage cancer, and live with it, we offer the following four principles: Awareness and prevention, early detection, specialist, integrated care, and psychological support. Finally, we highlight four key prerequisites for commercialisation of ITP-based technologies against cancer. We conclude that ITPs offer significant potential as regards both understanding the intricacies of the complex process of cancer and for developing much needed novel therapies.
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Affiliation(s)
- Mustafa B A Djamgoz
- Department of Life Sciences, Imperial College London, London, UK. .,Biotechnology Research Centre, Cyprus International University, Nicosia, Mersin, Turkey.
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32
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Picci G, Marchesan S, Caltagirone C. Ion Channels and Transporters as Therapeutic Agents: From Biomolecules to Supramolecular Medicinal Chemistry. Biomedicines 2022; 10:biomedicines10040885. [PMID: 35453638 PMCID: PMC9032600 DOI: 10.3390/biomedicines10040885] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 04/07/2022] [Accepted: 04/09/2022] [Indexed: 12/13/2022] Open
Abstract
Ion channels and transporters typically consist of biomolecules that play key roles in a large variety of physiological and pathological processes. Traditional therapies include many ion-channel blockers, and some activators, although the exact biochemical pathways and mechanisms that regulate ion homeostasis are yet to be fully elucidated. An emerging area of research with great innovative potential in biomedicine pertains the design and development of synthetic ion channels and transporters, which may provide unexplored therapeutic opportunities. However, most studies in this challenging and multidisciplinary area are still at a fundamental level. In this review, we discuss the progress that has been made over the last five years on ion channels and transporters, touching upon biomolecules and synthetic supramolecules that are relevant to biological use. We conclude with the identification of therapeutic opportunities for future exploration.
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Affiliation(s)
- Giacomo Picci
- Chemical and Geological Sciences Department, University of Cagliari, 09042 Cagliari, Italy;
| | - Silvia Marchesan
- Chemical and Pharmaceutical Sciences Department, University of Trieste, 34127 Trieste, Italy
- Correspondence: (S.M.); (C.C.)
| | - Claudia Caltagirone
- Chemical and Geological Sciences Department, University of Cagliari, 09042 Cagliari, Italy;
- Correspondence: (S.M.); (C.C.)
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33
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Keely SJ, Barrett KE. Intestinal secretory mechanisms and diarrhea. Am J Physiol Gastrointest Liver Physiol 2022; 322:G405-G420. [PMID: 35170355 PMCID: PMC8917926 DOI: 10.1152/ajpgi.00316.2021] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 01/31/2023]
Abstract
One of the primary functions of the intestinal epithelium is to transport fluid and electrolytes to and from the luminal contents. Under normal circumstances, absorptive and secretory processes are tightly regulated such that absorption predominates, thereby enabling conservation of the large volumes of water that pass through the intestine each day. However, in conditions of secretory diarrhea, this balance becomes dysregulated, so that fluid secretion, driven primarily by Cl- secretion, overwhelms absorptive capacity, leading to increased loss of water in the stool. Secretory diarrheas are common and include those induced by pathogenic bacteria and viruses, allergens, and disruptions to bile acid homeostasis, or as a side effect of many drugs. Here, we review the cellular and molecular mechanisms by which Cl- and fluid secretion in the intestine are regulated, how these mechanisms become dysregulated in conditions of secretory diarrhea, currently available and emerging therapeutic approaches, and how new strategies to exploit intestinal secretory mechanisms are successfully being used in the treatment of constipation.
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Affiliation(s)
- Stephen J Keely
- School of Pharmacy and Biomolecular Sciences, Royal College of Surgeons in Ireland, University of Medicine and Health Sciences, Dublin, Ireland
| | - Kim E Barrett
- Department of Medicine, School of Medicine, University of California San Diego, La Jolla, California
- Department of Physiology and Membrane Biology, School of Medicine, University of California, Davis, Davis, California
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34
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Quach A, Jayaratne RR, Lee BJ, Ibeawuchi SR, Lim E, Das S, Barrett KE. Diarrheal pathogenesis in Salmonella infection may result from an imbalance in intestinal epithelial differentiation through reduced Notch signaling. J Physiol 2022; 600:1851-1865. [PMID: 35100665 DOI: 10.1113/jp282585] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 01/20/2022] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Salmonella is a leading foodborne pathogen known to cause high chloride content diarrhea. Salmonella infection of murine enteroid-derived monolayers decreased DRA expression. Salmonella infection resulted in upregulation of the secretory epithelial marker ATOH1, the goblet cell marker Muc2, and the enteroendocrine cell marker ChgA. Downregulation of DRA may result from infection-induced Notch inhibition, as reflected by decreased expression of Notch intracellular domain and Hes1, as well as from decreased HNF1α signaling. The imbalance in intestinal epithelial differentiation favoring secretory over absorptive cell types is a possible mechanism by which Salmonella elicits diarrhea and may be relevant therapeutically. ABSTRACT Infections with non-typhoidal Salmonella spp. represent the most burdensome foodborne illnesses worldwide, yet despite their prevalence, the mechanism through which Salmonella elicits diarrhea is not entirely known. Intestinal ion transporters play important roles in fluid and electrolyte homeostasis in the intestine. We have previously shown that infection with Salmonella caused decreased colonic expression of the chloride/bicarbonate exchanger SLC26A3 (Down-Regulated in Adenoma; DRA) in a mouse model. In this study, we focused on the mechanism of DRA downregulation during Salmonella infection, by using murine epithelial enteroid-derived monolayers (EDM). The decrease in DRA expression caused by infection was recapitulated in EDM and accompanied by increased expression of ATOH1, the goblet cell marker Muc2, and the enteroendocrine cell marker ChgA. This suggested biased epithelial differentiation towards the secretory, rather than absorptive phenotype. In addition, the downstream Notch effector, Notch Intracellular Domain (NICD) and Hes1 were decreased following Salmonella infection. The relevance of Notch signaling was further investigated using a γ-secretase inhibitor, which recapitulated the downregulation in Hes1 and DRA as well as upregulation in ATOH1 and Muc2 seen following infection. Our findings suggest that Salmonella infection may result in a shift from absorptive to secretory cell types through Notch inhibition, which explains why there is a decreased capacity for absorption and ultimately the accumulation of diarrheal fluid. Our work also shows the value of EDM as a model to investigate mechanisms that might be targeted for therapy of diarrhea caused by Salmonella infection. Abstract figure legend Upon infection of the intestinal epithelium with Salmonella, diarrhea may be explained by an imbalance of intestinal epithelial differentiation. Downregulation of cell-fate commitment to the absorptive lineage, as reflected by decreased Hes1 and DRA, was observed. Conversely, upregulation of epithelial differentiation into secretory cell types was observed, as reflected by increased ATOH1, Muc2, and ChgA. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Andrew Quach
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Rashini R Jayaratne
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Beom Jae Lee
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA.,Department of Gastroenterology, Korea University Guro Hospital, Seoul, 08308, Republic of Korea
| | - Stella-Rita Ibeawuchi
- Department of Pathology, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Eileen Lim
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Soumita Das
- Department of Pathology, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA
| | - Kim E Barrett
- Division of Gastroenterology, Department of Medicine, University of California San Diego, School of Medicine, La Jolla, CA, 92093, USA.,Current affiliation: UC Davis School of Medicine, Education Building, 4610 X Street, Sacramento, CA, 95817, USA
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35
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Melnik LI, Garry RF. Enterotoxigenic Escherichia coli Heat-Stable Toxin and Ebola Virus Delta Peptide: Similarities and Differences. Pathogens 2022; 11:pathogens11020170. [PMID: 35215114 PMCID: PMC8878840 DOI: 10.3390/pathogens11020170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/22/2022] [Accepted: 01/24/2022] [Indexed: 01/27/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) STb toxin exhibits striking structural similarity to Ebola virus (EBOV) delta peptide. Both ETEC and EBOV delta peptide are enterotoxins. Comparison of the structural and functional similarities and differences of these two toxins illuminates features that are important in induction of pathogenesis by a bacterial and viral pathogen.
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Affiliation(s)
- Lilia I. Melnik
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA;
- Viral Hemorrhagic Fever Consortium, New Orleans, LA 70112, USA
- Correspondence: ; Tel.: +1-(504)988-3818
| | - Robert F. Garry
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA;
- Viral Hemorrhagic Fever Consortium, New Orleans, LA 70112, USA
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36
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Melnik LI, Guha S, Ghimire J, Smither AR, Beddingfield BJ, Hoffmann AR, Sun L, Ungerleider NA, Baddoo MC, Flemington EK, Gallaher WR, Wimley WC, Garry RF. Ebola virus delta peptide is an enterotoxin. Cell Rep 2022; 38:110172. [PMID: 34986351 DOI: 10.1016/j.celrep.2021.110172] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 07/27/2021] [Accepted: 12/03/2021] [Indexed: 12/21/2022] Open
Abstract
During the 2013-2016 West African (WA) Ebola virus (EBOV) outbreak, severe gastrointestinal symptoms were common in patients and associated with poor outcome. Delta peptide is a conserved product of post-translational processing of the abundant EBOV soluble glycoprotein (sGP). The murine ligated ileal loop model was used to demonstrate that delta peptide is a potent enterotoxin. Dramatic intestinal fluid accumulation follows injection of biologically relevant amounts of delta peptide into ileal loops, along with gross alteration of villous architecture and loss of goblet cells. Transcriptomic analyses show that delta peptide triggers damage response and cell survival pathways and downregulates expression of transporters and exchangers. Induction of diarrhea by delta peptide occurs via cellular damage and regulation of genes that encode proteins involved in fluid secretion. While distinct differences exist between the ileal loop murine model and EBOV infection in humans, these results suggest that delta peptide may contribute to EBOV-induced gastrointestinal pathology.
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Affiliation(s)
- Lilia I Melnik
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Shantanu Guha
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jenisha Ghimire
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Allison R Smither
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Brandon J Beddingfield
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Andrew R Hoffmann
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Leisheng Sun
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | | | - Melody C Baddoo
- Tulane Cancer Center, Tulane University, New Orleans, LA 70112, USA
| | | | - William R Gallaher
- Department of Microbiology, Immunology and Parasitology, LSU Health Sciences Center, New Orleans, LA 70112, USA; Mockingbird Nature Research Group, Pearl River, LA 70452, USA
| | - William C Wimley
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA 70112, USA.
| | - Robert F Garry
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA; Zalgen Labs, Germantown, MD 20876, USA.
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Jenkin KA, Han Y, Lin S, He P, Yun CC. Nedd4-2-dependent Ubiquitination Potentiates the Inhibition of Human NHE3 by Cholera Toxin and Enteropathogenic Escherichia coli. Cell Mol Gastroenterol Hepatol 2021; 13:695-716. [PMID: 34823064 PMCID: PMC8789535 DOI: 10.1016/j.jcmgh.2021.11.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 11/12/2021] [Accepted: 11/15/2021] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS Diarrhea is one of the most common illnesses and is often caused by bacterial infection. Recently, we have shown that human Na+/H+ exchanger NHE3 (hNHE3), but not non-human NHE3s, interacts with the E3 ubiquitin ligase Nedd4-2. We hypothesize that this property of hNHE3 contributes to the increased severity of diarrhea in humans. METHODS We used humanized mice expressing hNHE3 in the intestine (hNHE3int) to compare the contribution of hNHE3 and mouse NHE3 to diarrhea induced by cholera toxin (CTX) and enteropathogenic Escherichia coli (EPEC). We measured Na+/H+ exchange activity and fluid absorption. The role of Nedd4-2 on hNHE3 activity and ubiquitination was determined by knockdown in Caco-2bbe cells. The effects of protein kinase A (PKA), the primary mediator of CTX-induced diarrhea, on Nedd4-2 and hNHE3 phosphorylation and their interaction were determined. RESULTS The effects of CTX and EPEC were greater in hNHE3int mice than in control wild-type (WT) mice, resulting in greater inhibition of NHE3 activity and increased fluid accumulation in the intestine, the hallmark of diarrhea. Activation of PKA increased ubiquitination of hNHE3 and enhanced interaction of Nedd4-2 with hNHE3 via phosphorylation of Nedd4-2 at S342. S342A mutation mitigated the Nedd4-2-hNHE3 interaction and blocked PKA-induced inhibition of hNHE3. Unlike non-human NHE3s, inhibition of hNHE3 by PKA is independent of NHE3 phosphorylation, suggesting a distinct mechanism of hNHE3 regulation. CONCLUSIONS The effects of CTX and EPEC on hNHE3 are amplified, and the unique properties of hNHE3 may contribute to diarrheal symptoms occurring in humans.
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Affiliation(s)
- Kayte A. Jenkin
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Yiran Han
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Songbai Lin
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia
| | - Peijian He
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia
| | - C. Chris Yun
- Division of Digestive Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, Georgia,Atlanta VA Medical Center, Decatur, Georgia,Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia,Correspondence Address correspondence to: Chris Yun, PhD, Division of Digestive Diseases, Emory University School of Medicine, Atlanta, Georgia 30324. fax: (404) 727-5767.
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Monaghan TM, Seekatz AM, Mullish BH, Moore-Gillon CCER, Dawson LF, Ahmed A, Kao D, Chan WC. Clostridioides difficile: innovations in target discovery and potential for therapeutic success. Expert Opin Ther Targets 2021; 25:949-963. [PMID: 34793686 DOI: 10.1080/14728222.2021.2008907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 11/17/2021] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Clostridioides difficile infection (CDI) remains a worldwide clinical problem. Increased incidence of primary infection, occurrence of hypertoxigenic ribotypes, and more frequent occurrence of drug resistant, recurrent, and non-hospital CDI, emphasizes the urgent unmet need of discovering new therapeutic targets. AREAS COVERED We searched PubMed and Web of Science databases for articles identifying novel therapeutic targets or treatments for C. difficile from 2001 to 2021. We present an updated review on current preclinical efforts on designing inhibitory compounds against these drug targets and indicate how these could become the focus of future therapeutic approaches. We also evaluate the increasing exploitability of gut microbial-derived metabolites and host-derived therapeutics targeting VEGF-A, immune targets and pathways, ion transporters, and microRNAs as anti-C. difficile therapeutics, which have yet to reach clinical trials. Our review also highlights the therapeutic potential of re-purposing currently available agents . We conclude by considering translational hurdles and possible strategies to mitigate these problems. EXPERT OPINION Considerable progress has been made in the development of new anti-CDI drug candidates. Nevertheless, a greater comprehension of CDI pathogenesis and host-microbe interactions is beginning to uncover potential novel therapeutic targets, which can be exploited to plug gaps in the CDI drug discovery pipeline.
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Affiliation(s)
- Tanya M Monaghan
- NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Anna M Seekatz
- Biological Sciences, Clemson University, Clemson, SC, USA
| | - Benjamin H Mullish
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Departments of Gastroenterology and Hepatology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Claudia C E R Moore-Gillon
- Division of Digestive Diseases, Department of Metabolism, Digestion and Reproduction, Faculty of Medicine, Imperial College London, London, UK
- Departments of Gastroenterology and Hepatology, St Mary's Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Lisa F Dawson
- Department of Infection Biology, London School of Hygiene and Tropical Medicine, London, UK
| | - Ammar Ahmed
- NIHR Nottingham Biomedical Research Centre, University of Nottingham, Nottingham, UK
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK
| | - Dina Kao
- Department of Gastroenterology, Zeidler Ledcor Centre, University of Alberta, Edmonton, Alberta, Canada
| | - Weng C Chan
- School of Pharmacy, Biodiscovery Institute, University of Nottingham, University Park, Nottingham, UK
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Neonatal Enteropathogenic Escherichia coli Infection Disrupts Microbiota-Gut-Brain Axis Signaling. Infect Immun 2021; 89:e0005921. [PMID: 33820817 DOI: 10.1128/iai.00059-21] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Diarrheal diseases are a leading cause of death in children under the age of 5 years worldwide. Repeated early-life exposures to diarrheal pathogens can result in comorbidities including stunted growth and cognitive deficits, suggesting an impairment in the microbiota-gut-brain (MGB) axis. Neonatal C57BL/6 mice were infected with enteropathogenic Escherichia coli (EPEC) (strain e2348/69; ΔescV [type III secretion system {T3SS} mutant]) or the vehicle (Luria-Bertani [LB] broth) via orogastric gavage at postnatal day 7 (P7). Behavior (novel-object recognition [NOR] task, light/dark [L/D] box, and open-field test [OFT]), intestinal physiology (Ussing chambers), and the gut microbiota (16S Illumina sequencing) were assessed in adulthood (6 to 8 weeks of age). Neonatal infection of mice with EPEC, but not the T3SS mutant, caused ileal inflammation in neonates and impaired recognition memory (NOR task) in adulthood. Cognitive impairments were coupled with increased neurogenesis (Ki67 and doublecortin immunostaining) and neuroinflammation (increased microglia activation [Iba1]) in adulthood. Intestinal pathophysiology in adult mice was characterized by increased secretory state (short-circuit current [Isc]) and permeability (conductance) (fluorescein isothiocyanate [FITC]-dextran flux) in the ileum and colon of neonatally EPEC-infected mice, along with increased expression of proinflammatory cytokines (Tnfα, Il12, and Il6) and pattern recognition receptors (Nod1/2 and Tlr2/4). Finally, neonatal EPEC infection caused significant dysbiosis of the gut microbiota, including decreased Firmicutes, in adulthood. Together, these findings demonstrate that infection in early life can significantly impair the MGB axis in adulthood.
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Velikova T, Snegarova V, Kukov A, Batselova H, Mihova A, Nakov R. Gastrointestinal mucosal immunity and COVID-19. World J Gastroenterol 2021; 27:5047-5059. [PMID: 34497434 PMCID: PMC8384742 DOI: 10.3748/wjg.v27.i30.5047] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 05/01/2021] [Accepted: 07/12/2021] [Indexed: 02/06/2023] Open
Abstract
As the gastrointestinal tract may also be a crucial entry or interaction site of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the role of the gut mucosal immune system as a first-line physical and immunological defense is critical. Furthermore, gastrointestinal involvement and symptoms in coronavirus disease 2019 (COVID-19) patients have been linked to worse clinical outcomes. This review discusses recent data on the interactions between the virus and the immune cells and molecules in the mucosa during the infection. By carrying out appropriate investigations, the mucosal immune system role in SARS-CoV-2 infection in therapy and prevention can be established. In line with this, COVID-19 vaccines that stimulate mucosal immunity against the virus may have more advantages than the others.
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Affiliation(s)
- Tsvetelina Velikova
- Department of Clinical Immunology, University Hospital Lozenetz, Medical Faculty, Sofia University, St. Kliment Ohridski, Sofia 1407, Bulgaria
| | - Violeta Snegarova
- Clinic of Internal Diseases, Naval Hospital – Varna, Military Medical Academy, Medical Faculty, Medical University, Varna 9000, Bulgaria
| | - Alexander Kukov
- Department of Clinical Immunology, University Hospital Lozenetz, Medical Faculty, Sofia University, St. Kliment Ohridski, Sofia 1407, Bulgaria
| | - Hristiana Batselova
- Department of Epidemiology and Disaster Medicine, Medical University, Plovdiv, University Hospital "St George", Plovdiv 6000, Bulgaria
| | - Antoaneta Mihova
- Department of Clinical Immunology, University Hospital Lozenetz, Medical Faculty, Sofia University, St. Kliment Ohridski, Sofia 1407, Bulgaria
| | - Radislav Nakov
- Clinic of Gastroenterology, Tsaritsa Joanna University Hospital, Medical University of Sofia, Sofia 1527, Bulgaria
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Mahmoud IS, Jarrar YB. Targeting the intestinal TMPRSS2 protease to prevent SARS-CoV-2 entry into enterocytes-prospects and challenges. Mol Biol Rep 2021; 48:4667-4675. [PMID: 34023987 PMCID: PMC8140747 DOI: 10.1007/s11033-021-06390-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 04/29/2021] [Indexed: 02/08/2023]
Abstract
The transmembrane protease serine 2 (TMPRSS2) is a membrane anchored protease that primarily expressed by epithelial cells of respiratory and gastrointestinal systems and has been linked to multiple pathological processes in humans including tumor growth, metastasis and viral infections. Recent studies have shown that TMPRSS2 expressed on cell surface of host cells could play a crucial role in activation of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein which facilitates the rapid early entry of the virus into host cells. In addition, direct suppression of TMPRSS2 using small drug inhibitors has been demonstrated to be effective in decreasing SARS-CoV-2 infection in vitro, which presents TMPRSS2 protease as a potential therapeutic strategy for SARS-CoV-2 infection. Recently, SARS-CoV-2 has been shown to be capable of infecting gastrointestinal enterocytes and to provoke gastrointestinal disorders in patients with COVID-19 disease, which is considered as a new transmission route and target organ of SARS-CoV-2. In this review, we highlight the biochemical properties of TMPRSS2 protease and discuss the potential targeting of TMPRSS2 by inhibitors to prevent the SARS-CoV-2 spreading through gastro-intestinal tract system as well as the hurdles that need to be overcome.
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Affiliation(s)
- Ismail Sami Mahmoud
- Department of Medical Laboratory Sciences, Faculty of Allied Health Sciences, The Hashemite University, Zarqa, 13133, Jordan.
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Laitakari A, Liu L, Frimurer TM, Holst B. The Zinc-Sensing Receptor GPR39 in Physiology and as a Pharmacological Target. Int J Mol Sci 2021; 22:ijms22083872. [PMID: 33918078 PMCID: PMC8070507 DOI: 10.3390/ijms22083872] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Revised: 03/31/2021] [Accepted: 04/06/2021] [Indexed: 12/16/2022] Open
Abstract
The G-protein coupled receptor GPR39 is abundantly expressed in various tissues and can be activated by changes in extracellular Zn2+ in physiological concentrations. Previously, genetically modified rodent models have been able to shed some light on the physiological functions of GPR39, and more recently the utilization of novel synthetic agonists has led to the unraveling of several new functions in the variety of tissues GPR39 is expressed. Indeed, GPR39 seems to be involved in many important metabolic and endocrine functions, but also to play a part in inflammation, cardiovascular diseases, saliva secretion, bone formation, male fertility, addictive and depression disorders and cancer. These new discoveries offer opportunities for the development of novel therapeutic approaches against many diseases where efficient therapeutics are still lacking. This review focuses on Zn2+ as an endogenous ligand as well as on the novel synthetic agonists of GPR39, placing special emphasis on the recently discovered physiological functions and discusses their pharmacological potential.
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Affiliation(s)
- Anna Laitakari
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
| | - Lingzhi Liu
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Thomas M. Frimurer
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
| | - Birgitte Holst
- Novo Nordisk Foundation Center for Basic Metabolic Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark; (A.L.); (L.L.); (T.M.F.)
- Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Correspondence:
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Abundant Monovalent Ions as Environmental Signposts for Pathogens during Host Colonization. Infect Immun 2021; 89:IAI.00641-20. [PMID: 33526568 DOI: 10.1128/iai.00641-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Host colonization by a pathogen requires proper sensing and response to local environmental cues, to ensure adaptation and continued survival within the host. The ionic milieu represents a critical potential source of environmental cues, and indeed, there has been extensive study of the interplay between host and pathogen in the context of metals such as iron, zinc, and manganese, vital ions that are actively sequestered by the host. The inherent non-uniformity of the ionic milieu also extends, however, to "abundant" ions such as chloride and potassium, whose concentrations vary greatly between tissue and cellular locations, and with the immune response. Despite this, the concept of abundant ions as environmental cues and key players in host-pathogen interactions is only just emerging. Focusing on chloride and potassium, this review brings together studies across multiple bacterial and parasitic species that have begun to define both how these abundant ions are exploited as cues during host infection, and how they can be actively manipulated by pathogens during host colonization. The close links between ion homeostasis and sensing/response to different ionic signals, and the importance of studying pathogen response to cues in combination, are also discussed, while considering the fundamental insight still to be uncovered from further studies in this nascent area of inquiry.
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Oak AA, Chhetri PD, Rivera AA, Verkman AS, Cil O. Repurposing calcium-sensing receptor agonist cinacalcet for treatment of CFTR-mediated secretory diarrheas. JCI Insight 2021; 6:146823. [PMID: 33400691 PMCID: PMC7934922 DOI: 10.1172/jci.insight.146823] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 12/29/2020] [Indexed: 12/19/2022] Open
Abstract
Diarrhea is a major cause of global mortality, and outbreaks of secretory diarrhea such as cholera remain an important problem in the developing world. Current treatment of secretory diarrhea primarily involves supportive measures, such as fluid replacement. The calcium-sensing receptor (CaSR) regulates multiple biological activities in response to changes in extracellular Ca2+. The FDA-approved drug cinacalcet is an allosteric activator of CaSR used for treatment of hyperparathyroidism. Here, we found by short-circuit current measurements in human colonic T84 cells that CaSR activation by cinacalcet reduced forskolin-induced Cl– secretion by greater than 80%. Cinacalcet also reduced Cl– secretion induced by cholera toxin, heat-stable E. coli enterotoxin, and vasoactive intestinal peptide (VIP). The cinacalcet effect primarily involved indirect inhibition of cystic fibrosis transmembrane conductance regulator–mediated (CFTR-mediated) Cl– secretion following activation of CaSR and downstream phospholipase C and phosphodiesterases. In mice, cinacalcet reduced fluid accumulation by more than 60% in intestinal closed loop models of cholera and traveler’s diarrhea. The cinacalcet effect involved both inhibition of CFTR-mediated secretion and stimulation of sodium-hydrogen exchanger 3–mediated absorption. These findings support the therapeutic utility of the safe and commonly used drug cinacalcet in CFTR-dependent secretory diarrheas, including cholera, traveler’s diarrhea, and VIPoma.
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Affiliation(s)
| | | | - Amber A Rivera
- Departments of Medicine and Physiology, University of California, San Francisco, California, USA
| | - Alan S Verkman
- Departments of Medicine and Physiology, University of California, San Francisco, California, USA
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Cheuvront SN, Kenefick RW, Luque L, Mitchell KM, Vidyasagar S. Are oral rehydration solutions optimized for treating diarrhea? Nutr Health 2021; 27:461-465. [PMID: 33583247 DOI: 10.1177/0260106021991641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND A historical turning point occurred in the treatment of diarrhea when it was discovered that glucose could enhance intestinal sodium and water absorption. Adding glucose to salt water (oral rehydration solution, ORS) more efficiently replaced intestinal water and salt losses. AIM Provide a novel hypothesis to explain why mainstream use of ORS has been strongly recommended, but weakly adopted. METHODS Traditional (absorptive) and novel (secretory) physiological functions of glucose in an ORS were reviewed. RESULTS Small amounts of glucose can stimulate both intestinal absorption and secretion. Glucose can exacerbate a net secretory state and may aggravate pathogen-induced diarrhea, particularly for pathogens that affect glucose transport. CONCLUSION A hypothesis is made to explain why glucose-based ORS does not appreciably reduce diarrheal stool volume and why modern food science initiatives should focus on ORS formulations that replace water and electrolytes while also reducing stool volume and duration of diarrhea.
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Abstract
Diarrheal disease is still a major public health concern, as it is still considered an important cause of death in children under five years of age. A few decades ago, the detection of enteropathogenic E. coli was made by detecting the O, H, and K antigens, mostly by agglutination. The recent protocols recommend the molecular methods for diagnosing EPEC, as they can distinguish between typical and atypical EPEC by identifying the presence/absence of specific virulence factors. EPEC are defined as diarrheagenic strains of E. coli that can produce attaching and effacing lesions on the intestinal epithelium while being incapable of producing Shiga toxins and heat-labile or heat-stable enterotoxins. The ability of these strains to produce attaching and effacing lesions enable them to cause localized lesions by attaching tightly to the surface of the intestinal epithelial cells, disrupting the surfaces of the cells, thus leading to the effacement of the microvilli. EPEC are classified on typical and atypical isolates, based on the presence or absence of E. coli adherence factor plasmids. All the EPEC strains are eae positive; typical EPEC strains are eae+, bfpA+, while atypical strains are eae+, bfpA−. No vaccines are currently available to prevent EPEC infections.
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Porcine Enterotoxigenic Escherichia coli Strains Differ in Their Capacity To Secrete Enterotoxins through Varying YghG Levels. Appl Environ Microbiol 2020; 86:AEM.00523-20. [PMID: 32561576 DOI: 10.1128/aem.00523-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Accepted: 06/03/2020] [Indexed: 11/20/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are important pathogens for humans and farm animals such as pigs. Porcine ETEC strains induce diarrhea through the production of heat-labile enterotoxin (LT) and/or heat-stable enterotoxins (pSTa/STb). Although LT secretion levels differ between porcine ETEC strains, and this has been linked to virulence, it is unclear whether ST secretion levels also differ between porcine ETEC strains. In addition, the molecular mechanism underlying different LT secretion levels has not been elucidated. In this work, multiple porcine ETEC strains were assessed for their capacity to produce and secrete the enterotoxins LT, pSTa, and STb. The strains differed greatly in their capacity to secrete LT, pSTa, and STb. Remarkably, in some strains, periplasmic production did not correlate with their ability to secrete LT, resulting in high periplasmic production and low LT secretion levels. Furthermore, the results indicated that the type II secretion system (T2SS) protein YghG plays a regulatory role in controlling LT secretion levels. These findings highlight YghG as an important mediator of the secretion of the heat-labile enterotoxin LT by porcine ETEC strains and provide better insights into ETEC enterotoxin secretion.IMPORTANCE Enterotoxigenic E. coli strains are a major health concern. Enterotoxins secreted by enterotoxigenic E. coli are crucial for diarrhea induction. Enterotoxin secretion levels differ between strains; however, it is currently unclear what drives these differences. The discrepancy in the production and secretion capacities of enterotoxins in ETEC is important to clarify their function involved in diarrhea induction. Our results further deepen our understanding of how type II secretion system (T2SS) components of ETEC control enterotoxin secretion levels and may lay the foundation for a better understanding of ETEC molecular pathogenesis.
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Yuan L, van der Mei HC, Busscher HJ, Peterson BW. Two-Stage Interpretation of Changes in TEER of Intestinal Epithelial Layers Protected by Adhering Bifidobacteria During E. coli Challenges. Front Microbiol 2020; 11:599555. [PMID: 33329490 PMCID: PMC7710611 DOI: 10.3389/fmicb.2020.599555] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 10/26/2020] [Indexed: 12/19/2022] Open
Abstract
Mechanisms of gastrointestinal protection by probiotic bacteria against infection involve amongst others, modulation of intestinal epithelial barrier function. Trans-epithelial electrical resistance (TEER) is widely used to evaluate cellular barrier functions. Here, we developed a two-stage interpretative model of the time-dependence of the TEER of epithelial layers grown in a transwell during Escherichia coli challenges in the absence or presence of adhering bifidobacteria. E. coli adhesion in absence or presence of adhering bifidobacteria was enumerated using selective plating. After 4-8 h, E. coli challenges increased TEER to a maximum due to bacterial adhesion and increased expression of a tight-junction protein [zonula occludens-1 (ZO-1)], concurrent with a less dense layer structure, that is indicative of mild epithelial layer damage. Before the occurrence of a TEER-maximum, decreases in electrical conductance (i.e., the reciprocal TEER) did not relate with para-cellular dextran-permeability, but after occurrence of a TEER-maximum, dextran-permeability and conductance increased linearly, indicative of more severe epithelial layer damage. Within 24 h after the occurrence of a TEER maximum, TEER decreased to below the level of unchallenged epithelial layers demonstrating microscopically observable holes and apoptosis. Under probiotic protection by adhering bifidobacteria, TEER-maxima were delayed or decreased in magnitude due to later transition from mild to severe damage, but similar linear relations between conductance and dextran permeability were observed as in absence of adhering bifidobacteria. Based on the time-dependence of the TEER and the relation between conductance and dextran-permeability, it is proposed that bacterial adhesion to epithelial layers first causes mild damage, followed by more severe damage after the occurrence of a TEER-maximum. The mild damage caused by E. coli prior to the occurrence of TEER maxima was reversible upon antibiotic treatment, but the severe damage after occurrence of TEER maxima could not be reverted by antibiotic treatment. Thus, single-time TEER is interpretable in two ways, depending whether increasing to or decreasing from its maximum. Adhering bifidobacteria elongate the time-window available for antibiotic treatment to repair initial pathogen damage to intestinal epithelial layers.
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Affiliation(s)
| | | | | | - Brandon W. Peterson
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
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Ranganathan S, Smith EM, Foulke-Abel JD, Barry EM. Research in a time of enteroids and organoids: how the human gut model has transformed the study of enteric bacterial pathogens. Gut Microbes 2020; 12:1795492. [PMID: 32795243 PMCID: PMC7524385 DOI: 10.1080/19490976.2020.1795389] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/29/2020] [Accepted: 07/01/2020] [Indexed: 02/03/2023] Open
Abstract
Enteric bacterial pathogens cause significant morbidity and mortality globally. Studies in tissue culture and animal models shaped our initial understanding of these host-pathogen interactions. However, intrinsic shortcomings in these models limit their application, especially in translational applications like drug screening and vaccine development. Human intestinal enteroid and organoid models overcome some limitations of existing models and advance the study of enteric pathogens. In this review, we detail the use of human enteroids and organoids to investigate the pathogenesis of invasive bacteria Shigella, Listeria, and Salmonella, and noninvasive bacteria pathogenic Escherichia coli, Clostridium difficile, and Vibrio cholerae. We highlight how these studies confirm previously identified mechanisms and, importantly, reveal novel ones. We also discuss the challenges for model advancement, including platform engineering to integrate environmental conditions, innate immune cells and the resident microbiome, and the potential for pre-clinical testing of recently developed antimicrobial drugs and vaccines.
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Affiliation(s)
- Sridevi Ranganathan
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Emily M. Smith
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Jennifer D. Foulke-Abel
- Department of Medicine, Division of Gastroenterology and Hepatology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Eileen M. Barry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
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Kumar A, Faiq MA, Pareek V, Raza K, Narayan RK, Prasoon P, Kumar P, Kulandhasamy M, Kumari C, Kant K, Singh HN, Qadri R, Pandey SN, Kumar S. Relevance of SARS-CoV-2 related factors ACE2 and TMPRSS2 expressions in gastrointestinal tissue with pathogenesis of digestive symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 patients. Med Hypotheses 2020; 144:110271. [PMID: 33254575 PMCID: PMC7487155 DOI: 10.1016/j.mehy.2020.110271] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 08/21/2020] [Accepted: 09/11/2020] [Indexed: 02/07/2023]
Abstract
COVID-19 is caused by a new strain of coronavirus called SARS-coronavirus-2 (SARS-CoV-2), which is a positive sense single strand RNA virus. In humans, it binds to angiotensin converting enzyme 2 (ACE2) with the help a structural protein on its surface called the S-spike. Further, cleavage of the viral spike protein (S) by the proteases like transmembrane serine protease 2 (TMPRSS2) or Cathepsin L (CTSL) is essential to effectuate host cell membrane fusion and virus infectivity. COVID-19 poses intriguing issues with imperative relevance to clinicians. The pathogenesis of GI symptoms, diabetes-associated mortality, and disease recurrence in COVID-19 are of particular relevance because they cannot be sufficiently explained from the existing knowledge of the viral diseases. Tissue specific variations of SARS-CoV-2 cell entry related receptors expression in healthy individuals can help in understanding the pathophysiological basis the aforementioned collection of symptoms. ACE2 mediated dysregulation of sodium dependent glucose transporter (SGLT1 or SLC5A1) in the intestinal epithelium also links it to the pathogenesis of diabetes mellitus which can be a possible reason for the associated mortality in COVID-19 patients with diabetes. High expression of ACE2 in mucosal cells of the intestine and GB make these organs potential sites for the virus entry and replication. Continued replication of the virus at these ACE2 enriched sites may be a basis for the disease recurrence reported in some, thought to be cured, patients. Based on the human tissue specific distribution of SARS-CoV-2 cell entry factors ACE2 and TMPRSS2 and other supportive evidence from the literature, we hypothesize that SARS-CoV-2 host cell entry receptor-ACE2 based mechanism in GI tissue may be involved in COVID-19 (i) in the pathogenesis of digestive symptoms, (ii) in increased diabetic complications, (iii) in disease recurrence.
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Affiliation(s)
- Ashutosh Kumar
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Anatomy, All India Institute of Medical Sciences (AIIMS), Patna, India.
| | - Muneeb A Faiq
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; New York University (NYU) Langone Health Center, NYU Robert I Grossman School of Medicine, New York, NY, USA
| | - Vikas Pareek
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; National Brain Research Center, Manesar, Haryana, India
| | - Khursheed Raza
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Anatomy, All India Institute of Medical Sciences, Deoghar, India
| | - Ravi K Narayan
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Anatomy, All India Institute of Medical Sciences (AIIMS), Patna, India
| | - Pranav Prasoon
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Pittsburgh Center for Pain Research, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Pavan Kumar
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Pediatrics, Medical University of South Carolina, Charleston, USA
| | - Maheswari Kulandhasamy
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Biochemistry, Maulana Azad Medical College (MAMC), New Delhi, India
| | - Chiman Kumari
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Anatomy, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, India
| | - Kamla Kant
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Microbiology, All India Institute of Medical Sciences (AIIMS), Bathinda, India
| | - Himanshu N Singh
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; TAGC-INSERM, U1090, Aix Marseille University, Marseille, France
| | - Rizwana Qadri
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Neuro-oncology Laboratory, Rockefeller University, New York, NY, USA
| | - Sada N Pandey
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Zoology, Banaras Hindu University (BHU), Varanasi, India
| | - Santosh Kumar
- Etiologically Elusive Disorders Research Network (EEDRN), New Delhi, India; Department of Anesthesiology and Critical Care Medicine, School of Medicine, Johns Hopkins University, Baltimore, USA
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