Extracellular vesicles (EVs) are an increasingly promising tool for liquid biopsy in liver diseases. Hepatitis C Virus (HCV) infection, alone or together with Human Immunodeficiency Virus (HIV) infection significantly impacts on the microRNA (miRNA) EVs content resembling chronic hepatitis C (CHC) progression. The objective of the study was to delve into the intricate EVs-miRNA profiles in CHC patients with different liver fibrosis stages, aiming to pinpoint non-invasive markers capable of distinguishing significant fibrosis. Plasma EV-miRNAs from 50 CHC patients (HCV+ and HCV+/HIV+) stratified in no significant (F < 2) and significant (F ≥ 2) fibrosis, were massively sequenced. General linear models (GLM) were used to identify significantly differential expressed (SDE) miRNAs according to liver fibrosis stages (F ≥ 2 and F < 2). Dysregulated biological pathways were subsequently analyzed in silico for the following groups: i) all patients; ii) HCV+; and iii) HCV+/HIV+. Multiple-ordered logistic regression analysis was performed to develop a score to identify F ≥ 2 cases. The diagnostic potential of both the SDE miRNAs and the developed score was assessed using ROC curve analysis. With respect to all CHC patients, two SDE miRNAs (hsa-miR-122-5p and hsa-miR-92a-3p) were identified which regulate genes related to cytoskeleton organization. Regarding their diagnostic performance to discriminate F ≥ 2, both miRNAs individually demonstrated acceptable diagnostic values. However, their combined use in a new score enhanced their diagnostic performance (AUROC = 0.833). In the HCV+ subgroup, 8 SDE miRNAs (hsa-miR-122-5p, hsa-miR-320c, hsa-miR-3615, hsa-miR-320a-3p, hsa-miR-374b-5p, hsa-let-7a-3p, hsa-miR-199a-5p, hsa-miR-142-5p), which regulate macrophage activity and cell growth/death regulation, were recognized. Among them, hsa-miR-3615 displayed the highest diagnostic performance to discriminate F ≥ 2 (AUROC = 0.936). With respect to HCV+/HIV+, 18 SDE miRNAs (hsa-miR-4508, hsa-miR-122-5p, hsa-miR-451a, hsa-miR-1290, hsa-miR-1246, hsa-miR-107, hsa-miR-15b-5p, hsa-miR-194-5p, hsa-miR-22-5p, hsa-miR-20b-5p, hsa-miR-142-5p, hsa-miR-328-3p, hsa-miR-335-3p, hsa-miR-125a-5p, hsa-miR-423-3p, hsa-let-7d-3p, hsa-miR-128-3p, hsa-miR-10a-5p) were recognized that regulate RNA silencing processes. In this case, hsa-miR-423-3p and hsa-miR-128-3p showed outstanding diagnostic performances (AUROC > 0.900). Distinct EVs-miRNA profiles were identified in patients with varying liver fibrosis stages, both in the overall CHC cohort and within HCV+ and HCV+/HIV+ subgroups. These specific miRNA signatures would allow the elucidation of potential mechanisms involved in clinical evolution and identification of specific biomarkers of unfavorable progression, plausible to be used in a diagnostic panel. Furthermore, the developed score demonstrates the ability to discriminate within the CHC group those individuals with significant fibrosis regardless of their HIV infection status.

To investigate the hepatoprotective effects of mitochondrial transplantation (MTx) in a murine liver ischemia/reperfusion (I/R) model.

Sequential liver ischemia, followed by reperfusion (I/R), is a pathophysiological process underlying hepatocellular injury in a number of clinical contexts, such as hemorrhagic shock/resuscitation, major elective liver surgery, and organ transplantation. A unifying pathogenic consequence of I/R is mitochondrial dysfunction. Restoration of mitochondria through transplantation (MTx) has emerged as a potential therapeutic in I/R. However, its role in liver I/R and its mechanisms of action remain poorly defined.

We investigated the hepatoprotective effects of MTx in an in vivo mouse model of liver I/R and used in vivo imaging and various knockout and transgenic mouse models to determine the mechanism of protection.

We found that I/R-induced hepatocellular injury was prevented by MTx, as measured by plasma ALT, AST, and liver histology. In addition, I/R-induced pro-inflammatory cytokine release (IL-6, TNFα) was dampened by MTx, and anti-inflammatory IL-10 was enhanced. Moreover, MTx lowered neutrophil infiltration into both the liver sinusoids and lung bronchoalveolar lavage fluid, suggesting a local and distant reduction in inflammation. Using in vivo intravital imaging, we found that I/R-subjected Kupffer cells (KCs), rapidly sequestered transplanted mitochondria, and acidified mitochondria within lysosomal compartments. To specifically interrogate the role of KCs, we depleted KCs using the diphtheria toxin-inducible Clec4f/iDTR transgenic mouse, then induced I/R, and discovered that KCs are necessary for the beneficial effects of MTx. Finally, we induced I/R in the complement receptor of the immunoglobulin (CRIg) superfamily knockout mice and found that CRIg was required for mitochondria capture by KCs and mitochondria-mediated hepatoprotection.

In this study, we demonstrated that CRIg-dependent capture of mitochondria by I/R-subjected KCs is a hepatoprotective mechanism in vivo . These data progress knowledge on the mechanisms of MTx and open new avenues for clinical translation.

Hepatic ischemia-reperfusion injury (HIRI) is a major complication following liver transplantation. Bioinformatic analysis was performed to elucidate the PANoptosis-related molecular mechanisms underlying HIRI. Comprehensive analysis of bulk and single-cell RNA sequencing data from human liver tissue before and after HIRI was performed. Differential expression analysis, weighted gene coexpression analysis, and protein interaction network analysis were used to identify candidate biomarkers. Multiple machine learning methods were utilized to screen for core biomarkers and construct a diagnostic predictive model. Functional and interaction analyses of the genes were also performed. Cellular clustering and annotation, pseudotemporal trajectory, and intercellular communication analyses of HIRI were conducted. Six PANoptosis-associated genes (CEBPB, HSPA1A, HSPA1B, IRF1, SERPINE1, and TNFAIP3) were identified as HIRI-related biomarkers. These biomarkers are regulated by NF-κB and miRNA-155. A nomogram for HIRI prediction based on these biomarkers was constructed and validated. In addition, the heterogeneity and dynamic changes in macrophage subpopulations during HIRI were revealed, highlighting the roles of Kupffer cells and monocyte-derived macrophages in modulating the hepatic microenvironment. The MIF and VISFATIN signaling pathways play important roles in the interaction between macrophages and other cells. These findings enhance our understanding of the mechanisms of PANoptosis in HIRI and provide a new basis and potential targets for prevention and treatment strategies for HIRI.

Curcumin (CUR), a bioactive compound found in turmeric, has garnered attention for its potential anti-inflammatory properties and impact on liver health. Numerous studies suggest that CUR may be crucial in mitigating liver inflammation. The compound's anti-inflammatory effects are believed to be attributed to its ability to modulate various molecular pathways involved in the inflammatory response. Research indicates that CUR may suppress the activation of inflammatory cells and the production of pro-inflammatory cytokines in the liver. Additionally, it has been observed to inhibit the activity of transcription factors that play a key role in inflammation. By targeting these molecular mechanisms, CUR may help alleviate the inflammatory burden on the liver. Moreover, CUR's antioxidant properties are thought to contribute to its protective effects on the liver. Oxidative stress is closely linked to inflammation, and CUR's ability to neutralize free radicals may further support its anti-inflammatory action. While the evidence is promising, it is essential to note that more research is needed to fully understand the precise mechanisms through which CUR influences liver inflammation. Nevertheless, these findings suggest that CUR could be a potential therapeutic agent in managing liver inflammatory conditions. In this review, we explore the potential impact of CUR on inflammation, highlighting the key mechanisms involved, as reported in the literature.

Metabolic dysfunction-associated steatotic liver disease (MASLD), a condition with the potential to progress into liver cirrhosis or hepatocellular carcinoma, has become a significant global health concern due to its increasing prevalence alongside obesity and metabolic syndrome. Despite the promise of existing therapies such as thyroid hormone receptor-β (THR-β) agonists, PPAR agonists, FXR agonists, and GLP-1 receptor agonists, their effectiveness is limited by the complexity of the metabolic, inflammatory, and fibrotic pathways that drive MASLD progression, encompassing steatosis, metabolic dysfunction-associated steatohepatitis (MASH), and reversible liver fibrosis. Recent advances in targeted therapeutics, including RNA interference (RNAi), mRNA-based gene therapies, monoclonal antibodies, proteolysis-targeting chimeras (PROTAC), peptide-based strategies, cell-based therapies such as CAR-modified immune cells and stem cells, and extracellular vesicle-based approaches, have emerged as promising interventions. Alongside these developments, innovative drug delivery systems are being actively researched to enhance the stability, precision, and therapeutic efficacy of these biotherapeutics. These delivery strategies aim to optimize biodistribution, improve target-specific action, and reduce systemic exposure, thus addressing critical limitations of existing treatment modalities. This review provides a comprehensive exploration of the underlying biological mechanisms of MASLD and evaluates the potential of these cutting-edge biotherapeutics in synergy with advanced delivery approaches to address unmet clinical needs. By integrating fundamental disease biology with translational advancements, it aims to highlight future directions for the development of effective, targeted treatments for MASLD and its associated complications.

Non-alcoholic fatty liver disease (NAFLD) has emerged as a significant health concern worldwide, exhibiting an increasing incidence that necessitates immediate intervention. Epigallocatechin-3-gallate (EGCG) has shown significant pharmacological benefits for liver diseases, including NAFLD. However, its efficacy in this context has not been systematically evaluated.

This meta-analysis aimed to consolidate preclinical evidence on the effectiveness and mechanisms of EGCG in treating NAFLD.

We conducted a comprehensive literature search for preclinical studies from the inception of each database to April 2024, including Excerpta Medica Database, PubMed, Web of Science, Cochrane Library, China National Knowledge Infrastructure, Wanfang, and China Science and Technology Journal Database. These studies were manually screened based on predefined criteria. Data extraction was followed by pooled effect size calculations using Stata 16.0. A machine learning approach was also utilized to examine the temporal relationships among variables.

Seventeen studies, involving 293 animals, were analyzed. Our analysis indicates that EGCG significantly reduces ALT, AST, hepatic triglyceride, serum TG, hepatic TC, serum TC. The targets of EGCG may include antioxidants, regulation of lipid metabolism, anti-inflammation, improvement of insulin resistance, and inhibition of hepatic fibrosis. EGCG exerted its effects on NAFLD by modulating key signaling pathways, including PI3K/Akt/AMPK, TGF-β/Smad, Nrf2, NF-κB, and ROS/MAPK, highlighting its multifaceted mechanisms of action. The machine learning methods employed to ascertain the temporal relationship between the intervention and the outcome indicated that the optimal duration of the intervention was 10 to 15 weeks.

The efficacy of EGCG in treating NAFLD has been predicted within a time frame of 10-15 weeks. It may exert its effects primarily through the NF-κB and Nrf2 pathways, which regulate the ROS phenotype. EGCG may represent a promising target for the treatment of NAFLD.

Liver disease that progresses to cirrhosis is an enormous health problem worldwide. The extracellular matrix protein Mindin is known to have immune functions, but its role in liver homeostasis remains largely unexplored. We aimed to characterize the role of Mindin in the regulation of liver fibrosis.

Mindin was upregulated in mice with carbon tetrachloride (CCl4) or thioacetamide (TAA)-induced liver fibrosis, and was primarily expressed in hepatocytes. Global Mindin knockout mice were generated, which were susceptible to liver fibrosis. Notably, Mindin failed to activate hepatic stellate cells directly; however, it played a role in promoting the recruitment and phagocytosis of macrophages, and caused a phenotypic switch toward restorative macrophages during liver fibrosis. Furthermore, Mindin was found to bind to the αM-I domain of CD11b/CD18 heterodimeric receptors. To further explore this mechanism, we created Mindin and CD11b double-knockout (DKO) mice. In DKO mice, phagocytosis was further reduced, and liver fibrosis was markedly exacerbated.

Mindin promotes the resolution of liver fibrosis and the Mindin/CD11b axis might represent a novel target for the macrophage-mediated regression of liver fibrosis.

Mitochondrial oxysterols, cholestenoic acid (CA), 25-hydroxycholesterol (25HC), and 27-hydroxycholesterol (27HC), are potent regulators involved in many important biological events. This study aimed to investigate the metabolic pathways of these oxysterols and their roles between hepatocytes and macrophages. LC-MS/MS analysis showed a novel regulatory molecule, 3β-sulfate-5-cholestenoic acid (3SCA), following the addition of CA in media culturing hepatocytes. Further study showed that 3SCA could also be derived from 27HC. In comparison, 25HC was converted to 25HC3S, which mostly remained in the cells and nuclei. The functional study showed that 3SCA significantly downregulated the expression of genes involved in lipid metabolism in hepatocytes and suppressed gene expression of proinflammatory cytokines induced by lipopolysaccharide in human macrophages. Based on the results, we conclude that 3SCA acts as a secretory regulator for the regulation of lipid metabolism and inflammatory responses in hepatocytes and macrophages. These findings shed light on understanding the unique metabolic pathways of these oxysterols and their possible roles in liver tissues.NEW & NOTEWORTHY This study identifies a novel oxysterol metabolite, 3β-sulfate-5-cholestenoic acid (3SCA), secreted by hepatocytes, which regulates lipid metabolism and inflammatory responses in hepatocytes and macrophages. These findings reveal previously unknown metabolic pathways of mitochondrial oxysterols and their roles in the progression and recovery of metabolic dysfunction-associated steatotic liver disease (MASLD), offering novel insights into potential therapeutic targets.

Since its discovery, the patatin-like phospholipase domain containing 3 (PNPLA3) (rs738409 C>G p.I148M) variant has been studied extensively to unravel its molecular function. Although several studies proved a causal relationship between the PNPLA3 I148M variant and MASLD development and particularly fibrosis, the pathological mechanisms promoting this phenotype have not yet been fully clarified.

We summarise the latest data regarding the PNPLA3 I148M variant in hepatic stellate cells (HSCs) activation and macrophage biology or the path to inflammation-induced fibrosis.

Elegant but contradictory studies have ascribed PNPLA3 a hydrolase or an acyltransferase function. The PNPLA3 I148M results in hepatic lipid accumulation, which predisposes the hepatocyte to lipotoxicity and lipo-apoptosis, producing DAMPs, cytokines and chemokines leading to recruitment and activation of macrophages and HSCs, propagating fibrosis. Recent studies showed that the PNPLA3 I148M variant alters HSCs biology via attenuation of PPARγ, AP-1, LXRα and TGFβ activity and signalling.

The advent of refined techniques in isolating HSCs has made PNPLA3's direct role in HSCs for liver fibrosis development more apparent. However, many other mechanisms still need detailed investigations.

Hepatocellular carcinoma (HCC) is a malignant tumour characterized by high morbidity and mortality. Immunotherapy is an important treatment newly approved for the treatment for advanced hepatocellular carcinoma. However, how NASH progresses to HCC and the association between the immune signature in HCC and patient prognosis remain unclear.

Data from NASH and NASH-HCC patients were obtained from the GEO database. Differentially expressed genes were screened and hub genes were identified. The enrichment analysis, clustering, cibersort, ssGSEA, Xcell and immune checkpoint expression data of the samples were analysed. Survival analysis of dual genes was performed using TCGA liver cancer samples and the lasso regression model, and Cox regression analysis was conducted. Pathology specimens from 21 NASH-associated hepatocellular carcinoma patients were collected, and immunohistochemical staining was used to verify gene expression.

Compared with HCC patients with high CAT and low CXCL8 expression, those with low CAT and high CXCL8 expression had significantly higher levels of infiltration of multiple immune cell types and the common immune checkpoints CD274, PDCD1 and CTLA4. Furthermore, CAT was a protective factor, and CXCL8 was a risk factor for the prognosis of HCC patients.

CAT and CXCL8 might impact NASH-HCC progression. HCC patients with low CAT and high CXCL8 expression might have more extensive immune cell infiltration and stronger tumour immune escape. However, probably due to their different effects on CD8 + T cells and reactive oxygen species, increased expression of CAT contributes to improved prognosis in HCC patients, whereas increased expression of CXCL8 leads to a poor prognosis.

The tumour microenvironment is the "hotbed" of tumour cells, providing abundant extracellular support for growth and metastasis. However, the tumour microenvironment is not static and is constantly remodelled by a variety of cellular components, including tumour cells, through mechanical, biological and chemical means to promote metastasis. Focal adhesion plays an important role in cell-extracellular matrix adhesion. An in-depth exploration of the role of focal adhesion in tumour metastasis, especially their contribution at the biomechanical level, is an important direction of current research. In this review, we first summarize the assembly of focal adhesions and explore their kinetics in tumour cells. Then, we describe in detail the role of focal adhesion in various stages of tumour metastasis, especially its key functions in cell migration, invasion, and matrix remodelling. Finally, we describe the anti-tumour strategies targeting focal adhesion and the current progress in the development of some inhibitors against focal adhesion proteins. In this paper, we summarize for the first time that focal adhesion play a positive feedback role in pro-tumour metastatic matrix remodelling by summarizing the five processes of focal adhesion assembly in a multidimensional way. It is beneficial for researchers to have a deeper understanding of the role of focal adhesion in the biological behaviour of tumour metastasis and the potential of focal adhesion as a therapeutic target, providing new ideas for the prevention and treatment of metastases.

Hepatocellular carcinoma (HCC) is the most common form of hepatic malignancy, with high mortality rates recorded globally. Early detection through clinical biomarkers, medical imaging and histological assessment followed by rapid intervention are integral for positive patient outcomes. Although contrast-enhanced computed tomography scans and magnetic resonance imaging are recognised as the reference standard for the diagnosis and staging of HCC in international guidelines, ultrasound (US) examination is recommended as a screening tool for patients at risk. Contrast-enhanced US (CEUS) elevates the standard of an US examination using US contrast agents (UCAs), capable of diagnosing focal liver lesions with high efficacy. Most UCAs are purely intravascular, offering clinicians a dynamic representation of a lesions' arterial phase vascular kinetics, which is seldom seen in such detail during computed tomography or magnetic resonance imaging assessments. Despite its benefits, there is incongruity between international societies on the role of CEUS in the HCC clinical pathway. The transient nature of pure blood-pool agents is suggested to be insufficient to justify CEUS as a primary modality due to the inability to consistently perform whole liver imaging, alongside disputes regarding its capabilities to differentiate HCC from intrahepatic cholangiocarcinoma. A sinusoidal phase UCA affords clinicians the opportunity to perform whole liver imaging through Kupffer cell uptake in addition to visualising lesion vascular kinetics in the arterial and portal venous phases. Therefore, the purpose of this review was to examine the role of CEUS in the HCC clinical pathway in its current practice and observe how a Kupffer cell sinusoidal phase UCA may supplement contemporary diagnostic techniques through a multi-modality, multi-agent approach.

Preventing the progression of liver damage to fibrosis would be beneficial for patients with steatotic liver disease (SLD). Mesenchymal stem cells (MSC) are a promising therapy for SLD and derived extracellular vesicles (EVs) could even improve the treatment's efficacy and safety. However, the mechanisms of MSC-EVs beneficial effects are not well known. It has been suggested that modifying the EVs cargo could improve their beneficial effects. The aims of this study were to assess if MSC-EVs reduce liver damage in a rat model of mild liver damage; to analyze the underlying mechanisms and to assess if silencing TGFβ enhances the beneficial effects of MSC-EVs. CCl4 was injected three times per week during four weeks to induce mild liver damage. EVs from human adipocyte MSC and from TGFβ-depleted MSC (siTGFβ-MSC-EVs) were injected in the tail vein. Steatosis, fibrosis, liver inflammation, macrophage infiltration and liver content of fibrotic markers, DAMPs, cytokines and bile acids were analyzed. Normal MSC-EVs reduce the CCL2 increase in liver, macrophage infiltration and the increases in the fibrosis markers collagen I and α-SMA. Treatment with siTGFβ-MSC-EVs, in addition, reduces liver steatosis, the increase of bile acids (mainly TCA), and DAMP HMGB1 levels, inducing a larger reduction of collagen I in liver of CCl4 rats. Treatment with MSCs-EVs effectively reduces early liver damage. Silencing of TGFβ in MSCs enhances the beneficial effects by additional mechanisms. Early treatment with MSC-EVs, especially after silencing TGFβ, could improve liver damage in SLD patients.

Hepatic organoids (HOs), primarily composed of hepatobiliary cells, do not represent the pathogenesis of liver diseases due to the lack of non-parenchymal cells. Multi-lineage liver organoids (mLOs) containing various cell types found in the liver offer a promising in vitro disease model. However, their structural complexity remains challenging to achieve due to the difficulty in optimizing culture conditions that meet the growth need of all component cell types. Here, we demonstrate that cystic HOs generated from hPSCs can be expanded long-term and serve as a continuous source for generating complex mLOs. Assembling cystic HOs with hPSC-derived endothelial and hepatic stellate cell-like cells under conventional HO culture conditions failed to support the development of multiple cell types within mLOs, resulting in biased differentiation towards specific cell types. In contrast, modulating the cAMP/Wnt/Hippo signaling pathways with small molecules during assembly and differentiation phases efficiently generate mLOs containing both hepatic parenchymal and non-parenchymal cells. These mLOs exhibited structural complexity and functional maturity, including vascular network formation between parenchymal lobular structures, cell polarity for bile secretion, and the capacity to respond to fibrotic stimuli. Our study underscores the importance of modulating signaling pathways to enhance mLO structural complexity for applications in modeling liver pathologies.

The development of in vitro hepatocyte cell culture systems is crucial for investigating drug-induced liver injury (DILI). One prerequisite for monitoring DILI related immunologic reactions is the extension of primary human hepatocyte (PHH) cultures towards the inclusion of macrophages. Therefore, we developed and characterized an autologous co-culture system of PHH and primary human hepatic macrophages (hepM) (CoC1). We compared CoC1 with a co-culture of the same PHH batch + M0 macrophages derived from THP1 cells (CoC2) in order to represent a donor independent macrophage reaction. Then, we treated the mono- and co-cultures with drugs that cause DILI-menadione (MEN, 1 or 10 µM, 3 h), diclofenac (DIC, 0.5 or 5 mM, 6 h), or acetaminophen (APAP, 0.5 or 5 mM, 6 h)-and assessed culture stability, cell activity, macrophage differentiation, cytokine production and cell viability. Without drug treatment, CoC1 was the most stable over a culture time of up to 60 h. Cytokine array analysis revealed a proinflammatory profile of PHH mono-cultures due to isolation stress but showed different influences of hepM and M0 on the cytokine profile in the co-cultures. MEN, DIC and APAP treatment led to donor-dependent signs of cell stress and toxicity. HepM can either promote or reduce the DILI effects donor dependently in CoC1. CoC2 are slightly less sensitive than CoC1 in representing DILI. In summary, we present a new autologous co-culture system that can mimic DILI in a donor-dependent manner. This cellular system could be useful for new drug testing strategies and reducing animal testing.

Tamoxifen (TAM) is extensively used to manage estrogen receptor-positive breast cancer. Despite its effectiveness, its administration can negatively impact various organs, including the liver. This research focused on the effects of TAM on the pyroptotic pathway in the liver and evaluated the potential of cardamom extract (CRDE) to lessen hepatic damage of TAM in female rats. Rats received 45 mg/kg of TAM injections for 10 days, while the groups treated with CRDE received 12 ml/kg of CRDE for 20 days, commencing 10 days before TAM administration. TAM exposure resulted in apparent degenerations in hepatic tissue with inflammatory cell infiltration and loss of architectures. Serum levels of liver enzymes including alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase were elevated, along with hepatic oxidative stress, as shown by increased lipid peroxidation with lower levels of reduced glutathione. TAM caused inflammation in the liver tissue as indicated by higher levels of tumor necrosis factor-α and interleukin-6 as well as increased expression of CD68; a phagocytic Kupffer's cells marker. Additionally, the protein expression analysis revealed a high expression of pyroptotic markers including NLRP3-inflammasome, caspase-1, and gasdermin D. Conversely, CRDE treatment effectively neutralized the biochemical, histological, and protein expression alterations induced by TAM. In conclusion, CRDE demonstrated the potential to protect the liver from TAM-induced damage by regulating mechanisms involving oxidative damage, inflammation, and pyroptosis.

B cells are an attractive platform for engineering to produce protein-based biologics absent in genetic disorders, and potentially for the treatment of metabolic diseases and cancer. As part of pre-clinical development of B cell medicines, we demonstrate a method to collect, ex vivo expand, differentiate, radioactively label, and track adoptively transferred non-human primate (NHP) B cells. These cells underwent 10- to 15-fold expansion, initiated IgG class switching, and differentiated into antibody-secreting cells. Zirconium-89-oxine-labeled cells were infused into autologous donors without any preconditioning and tracked by PET/CT imaging. Within 24 h of infusion, 20% of the initial dose homed to the bone marrow and spleen and distributed stably and equally between the two. Interestingly, approximately half of the dose homed to the liver. Image analysis of the bone marrow demonstrated inhomogeneous distribution of the cells. The subjects experienced no clinically significant side effects or laboratory abnormalities. A second infusion of B cells into one of the subjects resulted in an almost identical distribution of cells, suggesting possibly a non-limiting engraftment niche and feasibility of repeated infusions. This work supports the NHP as a valuable model to assess the potential of B cell medicines as potential treatment for human diseases.

Liver sinusoidal endothelial cells (LSECs), with their unique morphology and function, have garnered increasing attention in chronic liver disease research. This review summarizes the critical roles of LSECs under physiological conditions and in two representative chronic liver diseases: metabolic dysfunction-associated steatotic liver disease (MASLD) and liver cancer. Under physiological conditions, LSECs act as selective barriers, regulating substance exchange and hepatic blood flow. Interestingly, LSECs exhibit contrasting roles at different stages of disease progression: in the early stages, they actively resist disease advancement and help restore sinusoidal homeostasis; whereas in later stages, they contribute to disease worsening. During this transition, LSECs undergo capillarization, lose their characteristic markers, and become dysfunctional. As the disease progresses, LSECs closely interact with hepatocytes, hepatic stellate cells, various immune cells, and tumor cells, driving processes such as steatosis, inflammation, fibrosis, angiogenesis, and carcinogenesis. Consequently, targeting LSECs represents a promising therapeutic strategy for chronic liver diseases. Relevant therapeutic targets and potential drugs are summarized in this review.

Macrophages are members of the human innate immune system, and the majority reside in the liver. In recent years, they have been recognized as essential players in the maintenance of liver and intestinal homeostasis as well as key guardians of their respective immune systems, and they are increasingly being recognized as such. Paradoxically, they are also likely involved in chronic pathologies of the gastrointestinal tract and potentially in the alteration of the gut-liver axis in alcohol use disorder (AUD) and alcohol-associated liver disease (ALD). To date, the causal relationship between macrophages, the pathogenesis of ALD, and the immune dysregulation of the gut remains unclear. In this review, we will discuss our current understanding of the heterogeneity of intestinal and hepatic macrophages, their ontogeny, the potential factors that regulate their origin, and the evidence of how they are associated with the manifestation of chronic inflammation. We will also illustrate how the micro-environment of the intestine shapes the phenotypes and functionality of the macrophage compartment in both the intestines and liver and how they change during chronic alcohol abuse. Finally, we highlight the obstacles to current research and the prospects for this field.

Drug-induced liver injury (DILI) is an acute liver injury that poses a significant threat to human health. In severe cases, it can progress into chronic DILI or even lead to liver failure. DILI is typically caused by either intrinsic hepatotoxicity or idiosyncratic metabolic or immune responses. In addition to the direct damage drugs inflict on hepatocytes, the immune responses and liver inflammation triggered by hepatocyte death can further exacerbate DILI. Initially, we briefly discussed the differences in immune cell activation based on the type of liver cell death (hepatocytes, cholangiocytes, and LSECs). We then focused on the role of various immune cells (including macrophages, monocytes, neutrophils, dendritic cells, liver sinusoidal endothelial cells, eosinophils, natural killer cells, and natural killer T cells) in both the liver injury and liver regeneration stages of DILI. This article primarily reviews the role of innate immune regulation mediated by these immune cells in resolving inflammation and promoting liver regeneration during DILI, as well as therapeutic approaches targeting these immune cells for the treatment of DILI. Finally, we discussed the activation and function of liver progenitor cells (LPCs) during APAP-induced massive hepatic necrosis and the involvement of chronic inflammation in DILI.

Acute liver failure (ALF) is a fulminant clinical syndrome that usually leads to multiple organ failure and high mortality. Macrophages play a crucial role in the initiation, development, and recovery of ALF. Targeting macrophages through immunotherapy holds significant promise as a therapeutic strategy. These cells exhibit remarkable plasticity, enabling them to differentiate into various subtypes based on changes in their surrounding microenvironment. M1-type macrophages are associated with a pro-inflammatory phenotype and primarily rely predominantly on glycolysis. In contrast, M2-type macrophages, which are characterized by anti-inflammatory phenotype, predominantly obtain their energy from oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO). Shifting macrophage metabolism from glycolysis to OXPHOS inhibits M1 macrophage activation and promotes M2 macrophage activation, thereby exerting anti-inflammatory and reparative effects. This study elucidates the relationship between macrophage activation and glucose metabolism reprograming from an immunometabolism perspective. A comprehensive literature review revealed that several signaling pathways may regulate macrophage polarization through energy metabolism, including phosphatidyl-inositol 3-kinase/protein kinase B (PI3K/AKT), mammalian target of rapamycin (mTOR)/hypoxia-inducible factor 1α (HIF-1α), nuclear factor-κB (NF-κB), and AMP-activated protein kinase (AMPK), which exhibit crosstalk with one another. Additionally, we systematically reviewed several traditional Chinese medicine (TCM) monomers that can modulate glucose metabolism reprograming and influence the polarization states of M1 and M2 macrophages. This review aimed to provide valuable insights that could contribute to the development of new therapies or drugs for ALF.

From their early genesis, tumour cells integrate with the surrounding normal cells to form an abnormal structure that is tightly integrated with the host organism via blood and lymphatic vessels and even neural associations. Using these connections, emerging cancers send a plethora of mediators that efficiently perturb the entire organism and induce changes in distant tissues. These perturbations serendipitously favour early metastatic establishment by promoting a more favourable tissue environment (niche) that supports the persistence of disseminated tumour cells within a foreign tissue. Because the establishment of early metastatic niches represents a key limiting step for metastasis, the creation of a more suitable pre-conditioned tissue strongly enhances metastatic success. In this Review, we provide an updated view of the mechanisms and mediators of primary tumours described so far that induce a pro-metastatic conditioning of distant organs, which favours early metastatic niche formation. We reflect on the nature of cancer-induced systemic conditioning, considering that non-cancer-dependent perturbations of tissue homeostasis are also able to trigger pro-metastatic conditioning. We argue that a more holistic view of the processes catalysing metastatic progression is needed to identify preventive or therapeutic opportunities.

There are limited studies performing paired liver biopsies in chronic hepatitis C (CHC) patients treated with direct-acting antivirals (DAA). We aimed to investigate the predictors of liver fibrosis changes assessed by paired liver biopsies in these patients.

From March 2017 to March 2020, 113 CHC patients were prospectively enrolled to receive DAA therapy at our hospital. Paired liver biopsies were performed at baseline and 12 weeks after the end of treatment.

Among the entire cohort, the rate of sustained virological response (SVR) was 100%. Four baseline variables independently predicted fibrosis regression, including age <65 years [odds ratio (OR) = 2.725, p = 0.036], fibrosis stages (METAVIR scores) < 3 (OR = 4.874, p = 0.040), hemoglobin levels ≥12.5 g/dL (OR = 3.538, p = 0.029), and platelet counts ≥160 103/μL (OR = 2.958, p = 0.023). Besides, five independent predictors of fibrosis progression included baseline age ≥66 years (OR = 16.351, p = 0.024), body mass index (BMI) ≥26.5 kg/m2 (OR = 21.666, p = 0.009), sofosbuvir/ribavirin use (OR = 29.465, p = 0.031), platelet counts <119 103/μL (OR = 33.739, p = 0.026), and the absence of alanine aminotransferase (ALT) levels declining from >35 U/L at baseline to ≤35 U/L at 4 weeks after baseline (OR = 284.534, p = 0.026).

For DAA-treated CHC patients, those with baseline age <65 years, fibrosis stages <3, hemoglobin levels ≥12.5 g/dL, or platelet counts ≥160 103/μL are more likely to attain fibrosis regression. There is a higher risk of fibrosis progression in those with baseline age ≥66 years, BMI ≥26.5 kg/m2, sofosbuvir/ribavirin use, platelet counts <119 103/μL, or the absence of early ALT normalization at 4 weeks after baseline.

HE is a neuropsychiatric complication of liver disease characterized by systemic elevation in ammonia and proinflammatory cytokines. These neurotoxins cross the blood-brain barrier and cause neuroinflammation, which can activate the kynurenine pathway (KP). This results in dysregulated production of neuroactive KP metabolites, such as quinolinic acid, which is known to cause astrocyte and neuronal death. Our aim was to compare KP activity between patients with covert HE (CHE), patients without encephalopathic cirrhosis (NHE), and healthy controls (HCs).

This was a single-center prospective cohort study conducted between 2018 and 2021 at St Vincent's Hospital, Sydney. Overall, 13 patients with CHE, 10 patients with NHE, and 12 with HC were recruited. Patients with cirrhosis were diagnosed with CHE if they scored ≤-4 on the Psychometric Hepatic Encephalopathy Score. KP metabolite levels were quantified on plasma samples via HPLC and gas chromatography/mass spectrometry. One-way Kruskal-Wallis test was used to compare the expression levels of KP enzymes.

KP was highly activated in patients with cirrhosis, demonstrated by higher levels of activity in the rate-limiting enzymes, indoleamine 2,3-dioxygenase, and tryptophan-2,3-dioxygenase in both CHE (65.04±20.72, p=0.003) and patients with NHE (64.85±22.10, p=0.015) compared to HC (40.95±7.301). Higher quinolinic acid concentrations were demonstrated in CHE (3726 nM±3385, p<0.001) and patients with NHE (1788 nM±632.3, p=0.032) compared to HC (624 nM±457). KP activation was positively correlated with inflammatory marker C-reactive protein in patients with CHE (Rs=0.721, p≤0.01).

KP is highly activated in patients with CHE, resulting in heightened production of neurotoxic metabolites. Dysregulation of the pathway is demonstrable in patients who do not yet show clinical signs of neurocognitive impairment. Therapeutic agents that modulate KP activity may be able to alleviate symptoms of patients with CHE.

Lacticaseibacillus rhamnosus SD11 (SD11) has several health benefits for the host, including antidiabetic, anti-inflammatory, and antimicrobial effects. However, the antidiabetic mechanism of SD11 has not been clearly elucidated. The current study assessed the effects of SD11 and the associated underlying mechanisms on streptozotocin (STZ)-induced diabetic mice. Compared with the normal control, SD11 supplementation for 4 weeks significantly improved the metabolic profiles, including body weight (BW), fasting blood glucose (FBG), fasting insulin level (FIN), and liver index (LI), in conjunction with a lower NAS score. A notable reduction in the liver function parameters aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) and total cholesterol (TC), together with histopathology studies, supported diabetic recovery by SD11. A closer examination of two major markers for the insulin pathway, insulin receptor (INSR) and insulin substrate (IRS)-1, revealed that SD11 could exert its glucose control through the upregulation of these molecules, which were almost demolished in nontreated diabetic livers. Additionally, SD11-treated mice exhibited alleviation of oxidative stress enzymes; downregulation of proinflammatory cytokines, including interleukin (IL)-6, IL-1β, tumor necrosis factor (TNF)-α, and interferon (IFN)-γ; and decreased infiltration of macrophages into liver tissue. These findings were concomitant with the preservation of the tight junction proteins occludin and zona occludin (ZO)-1, which in turn lowered the levels of the inflammatory cytokines IL-1β and TNF-α and prevented colon tissue injury to some extent. Notably, the results for the SD11 control mice were identical to those for the normal control mice. Overall, our findings that SD11 delays liver deterioration and reduces colon lesions in diabetic mice provide evidence for the use of SD11 as an effective strategy to improve diabetes-related symptoms.

Non-alcoholic fatty liver disease (NAFLD) is a growing health problem worldwide, ranging from non-alcoholic fatty liver (NAFL) to the more severe metabolic non-alcoholic steatohepatitis (NASH). Although many studies have elucidated the pathogenesis of NAFLD, the epigenetic regulatory mechanism from NAFL to NASH remains incompletely understood. The histone H3 lysine 4 methyltransferase, MLL4 (also called KMT2D), is a critical epigenetic transcriptional coactivator that mediates overnutrition-induced steatosis in mice, but its potential role in the progression of NASH remains largely unknown. Here, we show that mice lacking the one allele of the Mll4 gene are resistant to hepatic steatosis, inflammation, and fibrosis in NASH conditions compared to wild-type controls. Transcriptome analysis of the livers of control and Mll4+/- mice identified pro-inflammatory genes regulated by the nuclear factor kappa B (NF-κB) signaling pathway as major target genes of MLL4. We show that MLL4 binds to p65 and that MLL4 is required for NF-κB transactivation. Myeloid-specific Mll4 knockout mice showed an almost complete block of NASH, while hepatocyte-specific Mll4 knockout mice showed mild inhibition of steatosis. Pro-inflammatory M1 polarization is decreased and anti-inflammatory M2 polarization is increased in liver macrophages from myeloid-specific Mll4 knockout mice. Importantly, we show that histone H3-lysine 4 methylation mediated by the MLL4-complex plays a critical role in promoting the expression of Ccl2 in hepatocytes and M1 marker genes in macrophages. Our results demonstrate that MLL4, through the NF-κB-MLL4 regulatory axis, exacerbates steatohepatitis in the context of an inflammatory response and represents a potential therapeutic target for NASH.

The occurrence of poisoning incidents caused by cyanobacterial blooms has aroused wide public concern. Microcystin-leucine arginine (MC-LR) is a well-established toxin produced by cyanobacterial blooms, which is widely distributed in eutrophic waters. MC-LR is not only hazardous to the water environment but also exerts multiple toxic effects including liver toxicity in both humans and animals. However, the underlying mechanisms of MC-LR-induced liver toxicity are unclear. Herein, we used advanced single-cell RNA sequencing technology to characterize MC-LR-induced liver injury in mice. We established the first single-cell atlas of mouse livers in response to MC-LR. Our results showed that the differentially expressed genes and pathways in diverse cell types of liver tissues of mice treated with MC-LR are highly heterogeneous. Deep analysis showed that MC-LR induced an increase in a subpopulation of hepatocytes that highly express Gstm3, which potentially contributed to hepatocyte apoptosis in response to MC-LR. Moreover, MC-LR increased the proportion and multiple subtypes of Kupffer cells with M1 phenotypes and highly expressed proinflammatory genes. Furthermore, the MC-LR increased several subtypes of CD8+ T cells with highly expressed multiple cytokines and chemokines. Overall, apart from directly inducing hepatocytes apoptosis, MC-LR activated proinflammatory Kupffer cell and CD8+ T cells, and their interaction may constitute a hostile microenvironment that contributes to liver injury. Our findings not only present novel insight into underlying molecular mechanisms but also provide a valuable resource and foundation for additional discovery of MC-LR-induced liver toxicity.

Excessive macrophage activation and production of pro-inflammatory cytokines are hallmarks of the Cytokine Storm Syndrome (CSS), a lethal condition triggered by sepsis, autoimmune disorders, and cancer immunotherapies. While depletion of macrophages at disease onset protects from lethality in an infection-induced CSS murine model, patients are rarely diagnosed early, hence the need to characterize macrophage populations during CSS progression and assess the therapeutic implications of macrophage targeting after disease onset. In this study, we identified MHCII+F4/80+Tim4- macrophages as the primary contributors to the pro-inflammatory environment in CSS, while CD206+F4/80+Tim4+ macrophages, with an anti-inflammatory profile, become outnumbered. Additionally, we observed an expansion of Tim4- macrophages coinciding with increased hematopoietic stem progenitor cells and reduction of committed myeloid progenitors in bone marrow and spleen. Critically, macrophage targeting with clodronate liposomes at disease onset prolonged survival, while their targeting in mice with established CSS exacerbated disease severity, leading to a more dramatic loss of Tim4+ macrophages and an imbalance in pro- versus anti-inflammatory Tim4- macrophage ratio. Our findings highlight the significance of timing in macrophage-targeted interventions for effective management of CSS and suggest potential therapeutic strategies for diseases characterized by uncontrolled inflammation, such as sepsis.

Mesenchymal stem cells (MSCs) are highly effective in the treatment of acute liver failure (ALF). The efficacy of MSCs is closely related to the inflammatory environment. Therefore, we investigated the functional changes of MSCs in response to interleukin-33 (IL-33) stimulation. The results showed that bone marrow mesenchymal stem cells (BMSCs) pretreated with IL-33 had increased CCR2 expression, targeted CCL2 in the injured liver tissue, and improved the migration ability. Under LPS stimulation, the NF-κB pathway of BMDM was activated, and its phenotype polarized to the M1-type, while BMSCs pretreated with IL-33 inhibited the NF-κB pathway and enhanced M2 macrophage polarization. The M2-type macrophages could further inhibit hepatocytes inflammation, reduce hepatocytes apoptosis, and promote hepatocytes repair. These results suggest that IL-33 can enhance the efficacy of BMSCs in ALF and provide a new strategy for cell therapy of liver diseases.

The Kupffer cell was first discovered by Karl Wilhelm von Kupffer in 1876, labeling them as "Sternzellen." Since their discovery as the primary macrophages of the liver, researchers have gradually gained an in-depth understanding of the identity, functions, and influential role of Kupffer cells, particularly in infection. It is becoming clear that Kupffer cells perform important tissue-specific functions in homeostasis and disease. Stationary in the sinusoids of the liver, Kupffer cells have a high phagocytic capacity and are adept in clearing the bloodstream of foreign material, toxins, and pathogens. Thus, they are indispensable to host defense and prevent the dissemination of bacteria during infections. To highlight the importance of this cell, this review will explore the history of the Kupffer cell in the context of infection beginning with its discovery to the present day.

Hepatitis E virus (HEV) infections are a major cause of acute viral hepatitis in humans worldwide. In immunocompetent individuals, the majority of HEV infections remain asymptomatic and lead to spontaneous clearance of the virus, and only a minority of individuals with infection (5-16%) experience symptoms of acute viral hepatitis. However, HEV infections can cause up to 30% mortality in pregnant women, become chronic in immunocompromised patients and cause extrahepatic manifestations. A growing body of evidence suggests that the host immune response to infection with different HEV genotypes is a critical determinant of distinct HEV infection outcomes. In this Review, we summarize key components of the innate and adaptive immune responses to HEV, including the underlying immunological mechanisms of HEV associated with acute and chronic liver failure and interactions between T cell and B cell responses. In addition, we discuss the current status of vaccines against HEV and raise outstanding questions regarding the immune responses induced by HEV and treatment of the disease, highlighting areas for future investigation.

Non-alcoholic steatohepatitis (NASH) is a critical stage in the progression of non-alcoholic fatty liver disease (NAFLD), characterized by obvious inflammation and fibrosis. Because of its high incidence rate and serious consequences, NASH is becoming a global health problem. The influence of endotoxin translocation on NASH is receiving attention. As a traditional Chinese herb that effectively improves hepatic inflammation, Fructus Aurantii (Quzhou origin, FAQ) is widely used in the clinical treatment of NASH. However, the intervention mechanism of FAQ on reg3g and related endotoxin translocation remains unclear.

To study the mechanism of the impact by which ileal regenerating family member 3 gamma (reg3g) deficiency and subsequent endotoxin translocation impact the progression of NASH; To elucidate the efficacy and mechanism of FAQ in the treatment of NASH.

Clinical serum, ileal tissue, and dynamic NASH model-related analyses collectively confirmed that reg3g is a pivotal gene associated with NASH. Reg3g-/- mice were used to assess the impact of reg3g on liver injury, inflammation, and fibrosis, as well as the underlying mechanism involved. In vitro studies elucidated the regulatory effects of FAQ on reg3g, intestinal barrier function, and intestinal permeability. Subsequently, the efficacy of FAQ was investigated in NASH mouse models. Pathological examinations combined with Western blotting (WB), immunohistochemistry (IHC), and multiplex immunohistochemical (mIHC) analyses were used to evaluate the effects of FAQ on mucosal repair and barrier function. Transepithelial electrical resistance (TEER), fluorescein isothiocyanate-dextran 4 (FD-4) experiments, coupled with enzyme linked immunosorbent assay (ELISA) and chromogenic LAL endotoxin assay were used to confirm intestinal permeability and endotoxin translocation. The results of WB and mIHC reflected the levels of endotoxin recruitment and M1 macrophage polarization in the liver. Parameters such as body weight, transaminases, and cholesterol were utilized to assess the metabolic effects of FAQ.

Decreased expression of reg3g was associated with the progression of NASH. Ileal deficiency in reg3g resulted in damage to the intestinal barrier and permeability, leading to the recruitment of endotoxins via the 'gut-liver' axis to the liver, causing the polarization of M1 macrophages, release of inflammatory factors, excessive inflammation, and activation of hepatic stellate cells (HSCs), leading to fibrosis. FAQ significantly upregulated ileal reg3g expression and the expression of intestinal barrier-related proteins tight junction protein 1 (ZO-1) and occludin (OLCN) in mice (p < 0.05), thereby improving intestinal barrier function and permeability. Reduced intestinal permeability led to decreases in endotoxins entering the bloodstream and accumulating in the liver (p < 0.05). The expression of CD68 suggested reduced polarization of M1 macrophages. Expression levels of actin alpha 2, smooth muscle actin (α-SMA) and extracellular matrix (ECM)-related proteins also decreased, indicating improved liver fibrosis.

FAQ ameliorates NASH by upregulating the expression of reg3g. The upregulation of reg3g contributes to the repair of the intestinal barrier and permeability, reducing the recruitment of endotoxins and subsequent polarization of M1 macrophages, excessive inflammation, and fibrosis.

Alcohol-associated hepatitis (AH) is the most life-threatening form of alcohol-associated liver disease (ALD). AH is characterized by severe inflammation attributed to increased levels of ethanol, microbes or microbial components, and damage-associated molecular pattern (DAMP) molecules in the liver. HSPB1 (Heat Shock Protein Family B (Small) Member 1; also known as Hsp25/27) is a DAMP that is rapidly increased in and released from cells experiencing stress, including hepatocytes. The goal of this study was to define the role of HSPB1 in AH pathophysiology.

Serum HSPB1 was measured in a retrospective study of 184 heathy controls (HC), heavy alcohol consumers (HA), patients with alcohol-associated cirrhosis (AC), and patients with AH recruited from major hospital centers. HSPB1 was also retrospectively evaluated in liver tissue from 10 HC and AH patients and an existing liver RNA-seq dataset. Finally, HSPB1 was investigated in a murine Lieber-DeCarli diet model of early ALD as well as cellular models of ethanol stress in hepatocytes and hepatocyte-macrophage communication during ethanol stress.

Circulating HSPB1 was significantly increased in AH patients and levels positively correlated with disease-severity scores. Likewise, HSPB1 was increased in the liver of patients with severe AH and in the liver of ethanol-fed mice. In vitro , ethanol-stressed hepatocytes released HSPB1, which then triggered TNFα-mediated inflammation in macrophages. Anti-HSPB1 antibody prevented TNFα release from macrophages exposed to media conditioned by ethanol-stressed hepatocytes.

Our findings support investigation of HSPB1 as both a biomarker and therapeutic target in ALD. Furthermore, this work demonstrates that anti-HSPB1 antibody is a rational approach to targeting HSPB1 with the potential to block inflammation and protect hepatocytes, without inactivating host defense.

HSPB1 is significantly increased in serum and liver of patients with alcohol-associated hepatitis.Ethanol consumption leads to early increases in HSPB1 in the mouse liver.Hepatocytes subjected to ethanol stress release HSPB1 into the extracellular environment where it activates TNFα-mediated inflammation in macrophages.Anti-HSPB1 antibody blocks hepatocyte-triggered TNFα in a model of hepatocyte-macrophage communication during ethanol stress.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a chronic, progressive liver disease that encompasses a spectrum of steatosis, steatohepatitis (or MASH), and fibrosis. Evidence suggests that dietary restriction (DR) and sleeve gastrectomy (SG) can lead to remission of hepatic steatosis and inflammation through weight loss, but it is unclear whether these procedures induce distinct metabolic or immunological changes in MASLD livers. This study aims to elucidate the intricate hepatic changes following DR, SG or sham surgery in rats fed a high-fat diet as a model of obesity-related MASLD, in comparison to a clinical cohort of patients undergoing SG. Single-cell and single-nuclei transcriptome analysis, spatial metabolomics, and immunohistochemistry revealed the liver landscape, while circulating biomarkers were measured in serum samples. Artificial intelligence (AI)-assisted image analysis characterized the spatial distribution of hepatocytes, myeloid cells and lymphocytes. In patients and experimental MASLD rats, SG improved body mass index, circulating liver injury biomarkers and triglyceride levels. Both DR and SG attenuated liver steatosis and fibrosis in rats. Metabolism-related genes (Ppara, Cyp2e1 and Cyp7a1) were upregulated in hepatocytes upon DR and SG, while SG broadly upregulated lipid metabolism on cholangiocytes, monocytes, macrophages, and neutrophils. Furthermore, SG promoted restorative myeloid cell accumulation in the liver not only ameliorating inflammation but activating liver repair processes. Regions with potent myeloid infiltration were marked with enhanced metabolic capacities upon SG. Additionally, a disruption of periportal hepatocyte functions was observed upon DR. In conclusion, this study indicates a dynamic cellular crosstalk in steatotic livers of patients undergoing SG. Notably, PPARα- and gut-liver axis-related processes, and metabolically active myeloid cell infiltration indicate intervention-related mechanisms supporting the indication of SG for the treatment of MASLD.

Fibrosis, which is primarily marked by excessive extracellular matrix (ECM) deposition, is a pathophysiological process associated with many disorders, which ultimately leads to organ dysfunction and poor patient outcomes. Despite the high prevalence of fibrosis, currently there exist few therapeutic options, and importantly, there is a paucity of in vitro models to accurately study fibrosis. This review discusses the multifaceted nature of fibrosis from the viewpoint of developing organ-on-chip (OoC) disease models, focusing on five key features: the ECM component, inflammation, mechanical cues, hypoxia, and vascularization. The potential of OoC technology is explored for better modeling these features in the context of studying fibrotic diseases and the interplay between various key features is emphasized. This paper reviews how organ-specific fibrotic diseases are modeled in OoC platforms, which elements are included in these existing models, and the avenues for novel research directions are highlighted. Finally, this review concludes with a perspective on how to address the current gap with respect to the inclusion of multiple features to yield more sophisticated and relevant models of fibrotic diseases in an OoC format.

The liver has the great ability to regenerate after partial resection or injury, and the mechanisms underlying liver regeneration have been extensively investigated. Interestingly, acute liver injuries triggered by various etiologies are associated with the formation of necrotic lesions, and such necrotic lesions are also rapidly resolved. However, how necrotic liver lesions are repaired has not been carefully investigated until recently. In this review, we briefly summarize the spatiotemporal process of necrotic liver lesion resolution in several liver injury models including immune-mediated liver injury and drug-induced liver injury. The roles of liver nonparenchymal cells and infiltrating immune cells in controlling necrotic liver lesion resolution are discussed, which may help identify potential therapies for acute liver injury and failure.

Hepatitis B Virus (HBV) is a stealthy and insidious pathogen capable of inducing chronic necro-inflammatory liver disease and hepatocellular carcinoma (HCC), resulting in over one million deaths worldwide per year. The traditional understanding of Chronic Hepatitis B (CHB) progression has focused on the complex interplay among ongoing virus replication, aberrant immune responses, and liver pathogenesis. However, the dynamic progression and crucial factors involved in the transition from HBV infection to immune activation and intrahepatic inflammation remain elusive. Recent insights have illuminated HBV's exploitation of the sodium taurocholate co-transporting polypeptide (NTCP) and manipulation of the cholesterol transport system shared between macrophages and hepatocytes for viral entry. These discoveries deepen our understanding of HBV as a virus that hijacks hepatocyte metabolism. Moreover, hepatic niche macrophages exhibit significant phenotypic and functional diversity, zonal characteristics, and play essential roles, either in maintaining liver homeostasis or contributing to the pathogenesis of chronic liver diseases. Therefore, we underscore recent revelations concerning the importance of hepatic niche macrophages in the context of viral hepatitis. This review particularly emphasizes the significant role of HBV-induced metabolic changes in hepatic macrophages as a key factor in the transition from viral infection to immune activation, ultimately culminating in liver inflammation. These metabolic alterations in hepatic macrophages offer promising targets for therapeutic interventions and serve as valuable early warning indicators, shedding light on the disease progression.

Using a toxin-induced lethal acute liver failure (ALF) monkey model, we have recently shown that early peripheral infusion of human umbilical cord mesenchymal stem cells (hUC-MSCs) can alleviate liver damage and improve animal survival by suppressing the activation of circulating monocytes and the subsequent cytokine storm. Here, we explored whether the administration of hUC-MSCs could still improve ALF when the cytokine storm is fully developed.

We treated ALF monkeys with peripheral delivery of hUC-MSCs at 48 hr after toxin challenge. Liver indices, histology, imaging, and animal survival were recorded and analyzed.

In our cohort study, we conducted and demonstrated that the infusion of hUC-MSCs significantly improved liver histology, effectively controlled inflammatory cytokine storms, and increased survival rates. Additionally, the administration of a higher dose of hUC-MSCs (2 × 107/monkey) yielded superior outcomes compared to a lower dose (1 × 107/monkey).

Treatment of hUC-MSCs can significantly improve the pathological and survival outcomes of ALF even when the cytokine storm has been fully developed, indicating a promising clinical solution for ALF.

Acute liver failure (ALF) is a life-threatening clinical problem with limited treatment options. Administration of human umbilical cord mesenchymal stem cells (hUC-MSCs) may be a promising approach for ALF. This study aimed to explore the role of hUC-MSCs in the treatment of ALF and the underlying mechanisms.

A mouse model of ALF was induced by lipopolysaccharide and d-galactosamine administration. The therapeutic effects of hUC-MSCs were evaluated by assessing serum enzyme activity, histological appearance, and cell apoptosis in liver tissues. The apoptosis rate was analyzed in AML12 cells. The levels of inflammatory cytokines and the phenotype of RAW264.7 cells co-cultured with hUC-MSCs were detected. The C-Jun N-terminal kinase/nuclear factor-kappa B signaling pathway was studied.

The hUC-MSCs treatment decreased the levels of serum alanine aminotransferase and aspartate aminotransferase, reduced pathological damage, alleviated hepatocyte apoptosis, and reduced mortality in vivo. The hUC-MSCs co-culture reduced the apoptosis rate of AML12 cells in vitro. Moreover, lipopolysaccharide-stimulated RAW264.7 cells had higher levels of tumor necrosis factor-α, interleukin-6, and interleukin-1β and showed more CD86-positive cells, whereas the hUC-MSCs co-culture reduced the levels of the three inflammatory cytokines and increased the ratio of CD206-positive cells. The hUC-MSCs treatment inhibited the activation of phosphorylated (p)-C-Jun N-terminal kinase and p-nuclear factor-kappa B not only in liver tissues but also in AML12 and RAW264.7 cells co-cultured with hUC-MSCs.

hUC-MSCs could alleviate ALF by regulating hepatocyte apoptosis and macrophage polarization, thus hUC-MSC-based cell therapy may be an alternative option for patients with ALF.

Spaceflight and terrestrial spaceflight analogs can alter immune phenotypes. Macrophages are important immune cells that bridge the innate and adaptive immune systems and participate in immunoregulatory processes of homeostasis. Furthermore, macrophages are critically involved in initiating immunity, defending against injury and infection, and are also involved in immune resolution and wound healing. Heterogeneous populations of macrophage-type cells reside in many tissues and cause a variety of tissue-specific effects through direct or indirect interactions with other physiological systems, including the nervous and endocrine systems. It is vital to understand how macrophages respond to the unique environment of space to safeguard crew members with appropriate countermeasures for future missions in low Earth orbit and beyond. This review highlights current literature on macrophage responses to spaceflight and spaceflight analogs.