Stem cell functions and ageing are deeply interconnected, continually influencing each other in multiple ways. Stem cells play a vital role in organ maintenance, regeneration, and homeostasis, all of which decline over time due to gradual reduction in their self-renewal, differentiation, and growth factor secretion potential. The functional decline is attributed to damaging extrinsic environmental factors and progressively worsening intrinsic genetic and biochemical processes. These ageing-associated deteriorative changes have been extensively documented, paving the way for the discovery of novel biomarkers of ageing for detection, diagnosis, and treatment of age-related diseases. Age-dependent changes in adult stem cells include numerical decline, loss of heterogeneity, and reduced self-renewal and differentiation, leading to a drastic reduction in regenerative potential and thereby driving the ageing process. Conversely, ageing also adversely alters the stem cell niche, disrupting the molecular pathways underlying stem cell homing, self-renewal, differentiation, and growth factor secretion, all of which are critical for tissue repair and regeneration. A holistic understanding of these molecular mechanisms, through empirical research and clinical trials, is essential for designing targeted therapies to modulate ageing and improve health parameters in older individuals.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a progressive disease that affects the health of approximately one-third of the world's population. It is the primary cause of end-stage liver disease, liver malignancy, and liver transplantation, resulting in a great medical burden. No medications have yet been approved by the US Food and Drug Administration for treating MASLD without liver inflammation or scarring. Therefore, the development of specific drugs to treat MASLD remains a key task in the ongoing research objective. Extracellular vesicles (EVs) play an important role in the communication between organs, tissues, and cells. Recent studies have found that intestinal microbiota are closely related to the pathogenesis and progression of MASLD. EVs produced by bacteria (BEVs) play an indispensable role in this process. Thus, this study provides a new direction for MASLD treatment. However, the mechanism by which BEVs affect MASLD remains unclear. Therefore, this study investigated the influence and function of intestinal microbiota in MASLD. Additionally, we focus on the research progress of BEVs in recent years and explain the relationship between BEVs and MASLD from the perspectives of glucose and lipid metabolism, immune responses, and intestinal homeostasis. Finally, we summarized the potential therapeutic value of BEVs and EVs from other sources, such as adipocytes, immunocytes, stem cells, and plants.

This study identifies cancer stem cell marker genes in breast cancer through an integrated analysis of single cell RNA sequencing and bulk RNA sequencing data. The breast cancer-related single-cell RNA sequencing dataset GSE180286 was analyzed to identify cancer stem cells populations and their marker genes, which were further validated using data from The Cancer Genome Atlas breast cancer dataset. Weighted gene co-expression network analysis revealed seven co-expression modules, with the Turquoise module showing a strong association with messenger RNA stemness indices. Venn diagram analysis identified 19 cancer stem cell marker genes, among which cyclin B1, cell division cycle associated 8, and kinesin family member 4 A were highlighted as core genes. Both in vitro and in vivo experiments demonstrated that silencing kinesin family member 4 A in breast cancer cell lines significantly reduced tumor sphere formation, proliferation, migration, and invasion. Additionally, the downregulation of kinesin family member 4 A in a nude mouse model markedly suppressed tumor growth. These findings suggest that cyclin B1, cell division cycle associated 8, and particularly kinesin family member 4 A are critical regulators of cancer stem cell properties in breast cancer and represent promising therapeutic targets.

Multiple murine models, including high-fat diet (HFD), methionine-choline-deficient diet (MCD), choline-deficient, L-amino acid-defined high-fat diet (CDA-HFD), Western diet (WD), carbon tetrachloride (CCl₄) injection, and Gubra-Amylin diet (GAN), are widely used for mechanistic studies and therapeutic evaluation in MASH research. However, due to species-specific differences in metabolism, lifespan, and dietary composition, no single model could fully recapitulate the onset and progression of human MASH. Therefore, a detailed transcriptomic reference is urgently needed to better guide model selection and experimental design.

We established three murine MASH models: HFD, MCD and CDA-HFD. Physiological and pathological features were systematically evaluated and compared across models. Bulk and single-cell RNA sequencing were performed, and the resulting data were integrated with transcriptomic profiles from CCl₄-induced models and human MASH datasets, with a focus on metabolism, inflammation, fibrosis, and cellular signaling pathways.

The CDA-HFD and CCl₄ models closely resembled human MASH in inflammation and fibrosis but disrupted key metabolic pathways. Conversely, the HFD model mirrored metabolic abnormalities but lacked severe inflammation and fibrosis. Immunoinfiltration and single-cell analyses revealed that macrophages dominate the inflammatory process, with activation of PPAR signaling, extracellular matrix remodeling, and phagocytosis.

To balance metabolic and pathological fidelity without relying on genetic or toxin means, a combination of the CDA-HFD model with either HFD or WD is recommended as a robust and practical strategy for MASH research.

Metabolic dysfunction-associated steatotic liver disease (MASLD) remains the most common chronic liver disease worldwide, and appropriate in vitro models are of great significance for investigating pathogenesis and drug screening of MASLD. In this study, human expandable cholangiocyte organoids were derived from adult stem cells of normal liver tissue. After differentiation, liver organoids (LOs) exhibited the functional characteristics and genomic features of mature hepatocytes. To induce steatosis, LOs were incubated with a gradient concentration oleic acid, and it was found that the model could recapitulate the development of lipid accumulation and inflammation. In addition, the drug sensitivity of the hepatic steatosis model was further verified through anti-steatosis drug testing. In summary, LOs have great potential for disease modeling, and the results indicate that the hepatic steatosis model may serve as a useful tool for exploring the molecular mechanisms and drug screening of MASLD.

The incidence of nonalcoholic steatohepatitis (NASH) is increasing worldwide, and effective treatment is urgently needed. To understand the molecular mechanisms behind the effectiveness of bariatric surgery in treating NASH, we integrated single-cell and bulk RNA sequencing data to identify the role of liver macrophage polarization in alleviating NASH and screen possible drugs for treatment. Analysis revealed that bariatric surgery alleviates NASH by inhibiting liver M1 macrophage polarization with 12 differentially expressed M1 macrophage-related genes. Additionally, 56 potentially effective drugs were predicted for NASH treatment. These findings shed light on the effectiveness of bariatric surgery in treating NASH and offer potential drug candidates for further exploration.

Metabolic dysfunction-associated steatohepatitis (MASH) is becoming increasingly prevalent. Regulated cell death (RCD) has emerged as a significant disease phenotype and may act as a marker for liver fibrosis. The present study aimed to investigate the regulation of RCD-related genes in MASH to elucidate the role of RCD in the progression of MASH.

The gene expression profiles from the GSE130970 and GSE49541 datasets were retrieved from the Gene Expression Omnibus (GEO) database for analysis. A total of 101 combinations of 10 machine learning algorithms were employed to screen for characteristic RCD-related differentially expressed genes (DEGs) that reflect the progression of MASH. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were conducted to explore the enrichment pathways and functions of the feature genes. we performed cell classification analysis to investigate immune cell infiltration. Consensus cluster analysis was performed to identify MASH subtypes associated with RCD. The GSE89632 dataset was utilized to analyze the correlation of characteristic genes with clinical features of MASH. The DGIdb database was employed to screen for potential therapeutic drugs and compounds targeting the feature genes. In addition, we established mouse liver fibrosis models induced by methionine-choline-deficient (MCD) diet or CCl4 treatment, and further validated the expression of characteristic genes through quantitative real-time PCR (q-PCR). Lastly, we knocked down EPHA3 in LX2 cells to explore its effect on TGFb-induced activation of LX2 cells.

This study discovered a total of 11 RCD-associated DEGs, which predicted the progression of MASH. Advanced MASH has higher levels of immune cell infiltration and is significantly correlated with the RCD-related DEGs expression. MASH can be classified into two subtypes, cluster 1 and cluster 2, based on these feature genes. Compared with cluster 1, cluster 2 has highly expressed RCD-related DEGs, shows an increase in the degree of fibrosis. Furthermore, We discovered that the expression levels of feature genes were positively correlated with AST and ALT levels. Subsequently, We also evaluated the expression of these 11 feature genes in the liver tissues of mice with fibrosis induced by MCD or CCl4, and the results suggested that these genes may be involved in the development of fibrosis. WB results showed that the protein level of EPHA3 significantly increased in both mouse models of liver fibrosis. In vitro, we observed that knocking down EPHA3 in LX2 cells significantly inhibited the activation of the TGF-β/Smad3 signaling pathway.

Our study sheds light on the fact that RCD contribute to the progression of MASH, high lighting potential therapeutic targets for treating this disease.

Metabolic dysfunction-associated steatotic liver disease (MASLD), a chronic inflammatory disorder characterized by alcohol-independent hepatic lipid accumulation, remains poorly understood in terms of PANoptosis involvement.

We integrated high-throughput sequencing data with bioinformatics to profile differentially expressed genes (DEGs) and immune infiltration patterns in MASLD, identifying PANoptosis-associated DEGs (PANoDEGs). Machine learning algorithms prioritized key PANoDEGs, while ROC curves assessed their diagnostic efficacy. Cellular, animal, and clinical validations confirmed target expression.

Three PANoDEGs (SNHG16, Caspase-6, and Dynamin-1-like protein) exhibited strong MASLD associations and diagnostic significance. Immune profiling revealed elevated M1 macrophages, naïve B cells, and activated natural killer cells in MASLD tissues versus controls. Further experiments verified the expression of the key PANoDEGs.

This study provides new insights for further studies on the pathogenesis and treatment strategies of PANoptosis in MASLD.

Recent insights into the immune response in fibrosis have provided valuable perspectives for the treatment of liver fibrosis. Macrophages, as the most abundant immune cells in the liver, are key drivers of liver fibrosis. They are extensively involved in tissue damage, chronic inflammation, and the progression and regression of liver fibrosis. This study aims to conduct a bibliometric analysis and literature review on the mechanisms by which macrophages contribute to liver fibrosis. Specifically, we analyzed a bibliometric dataset comprising 1,312 papers from 59 countries, 1,872 institutions, and 9,784 authors. Keyword co-occurrence analysis identified key research hotspots, including the role of macrophage subtypes in obesity-related metabolic disorders, the crosstalk between macrophages and hepatic stellate cells through mechanoimmunology, emerging strategies for immune modulation targeting macrophages to promote fibrosis regression and liver regeneration, and new discoveries regarding macrophage crosstalk with other immune cells. In conclusion, this study provides a visual analysis of the current research landscape, hotspots, and trends in the field of macrophages and liver fibrosis, and discusses future directions for further exploration in this area.

Non-alcoholic steatohepatitis (NASH) has emerged as a prevalent chronic liver disease with a huge unmet clinical need. A few studies have reported the beneficial effects of Poria cocos Wolf (P. cocos) extract on NASH mice, but the active components were still unknown. In this study we investigated the therapeutic effects of dehydrotrametenolic acid methyl ester (ZQS5029-1), a lanosterol-7,9(11)-diene triterpenes in P. cocos, in a high-fat diet plus CCl4 induced murine NASH model and a GAN diet induced ob/ob murine NASH model. The NASH mice were treated with ZQS5029-1 (75 mg·kg-1·d-1, i.g.) for 6 and 8 weeks, respectively. We showed that ZQS5029-1 treatment markedly relieved liver injury, inflammation and fibrosis in both the murine NASH models. We found that ZQS5029-1 treatment significantly suppressed hepatic NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasome activation in both the NASH murine models, and blocked lipopolysaccharides (LPS)+adenosine 5'-triphosphate (ATP)/Nigericin-induced NLRP3 inflammasome activation in bone marrow-derived macrophages (BMDMs) and Kupffer cells in vitro. We demonstrated that ZQS5029-1 directly bound to the H236 residue of mouse Caspase-1, thereby inhibiting NLRP3 inflammasome activation. The effects of ZQS5029-1 on macrophage-hepatocyte/HSC crosstalk were analyzed using the supernatants from macrophages preconditioned with LPS + ATP introduced into hepatocytes and hepatic stellate cells (HSCs). We found that the conditioned medium from the BMDMs induced injury and death, as well as lipid accumulation in hepatocytes, and activation of HSCs; these effects were blocked by conditioned medium from BMDMs treated with ZQS5029-1. Moreover, the protective effects of ZQS5029-1 on hepatocytes and HSCs were eliminated by H236A-mutation of Caspase-1. We conclude that ZQS5029-1 is a promising lead compound for the treatment of NASH by inhibiting NLRP3 inflammasome activation through targeting Caspase-1 and regulating the macrophage-hepatocyte/HSC crosstalk.

The prevalence of nonalcoholic fatty liver disease (NAFLD), exacerbated by endocrine disruptors like phthalate-plasticizers, underscores the need to understand their impact on hepatic lipid metabolism. Although the suppression of hepatic macrophage M2 polarization is known to contribute to diethylhexyl phthalate (DEHP)-induced hepatic lipid accumulation, the role of intracellular metabolism in macrophages remains unclear. Here, we investigated the role of arachidonic acid metabolism-a key regulator of M2 macrophage polarization-and its metabolite prostaglandin E2 (PGE2) in DEHP-induced hepatic lipid disorders. DEHP exposure disrupted lipid metabolism and reduced hepatic macrophages. Genomic and metabolomic analyses of mice revealed a strong correlation between decreased hepatic M2 macrophages and perturbed arachidonic acid metabolism. Elevating the PGE2 level attenuated the inhibition of M2 macrophages caused by DEHP or its metabolite mono- (2-ethylhexyl) phthalate (MEHP) both in vitro and in vivo. Additionally, PGE2-induced M2 macrophages alleviated DEHP/MEHP-induced lipid metabolism disorders. In summary, arachidonic acid metabolism and PGE2 are critical metabolic regulators in DEHP-induced lipid metabolism disorders. This study identifies a novel metabolic target related to macrophage polarization in phthalates toxicity and provides a foundation for therapeutic strategies against endocrine disruptor-associated NAFLD.

Pathological new bone formation is the main cause of disability in ankylosing spondylitis (AS), and so far, it lacks a targeted therapy. Macrophages are central orchestrators of inflammation progression and tissue remodeling, but their contribution to pathological new bone formation has largely not been explored. Here, it is identified that TREM2+ macrophages predominated within the sites of new bone formation and adjacent to osteogenic precursor cells. In vivo, both depletion of macrophages and knockout of Trem2 significantly reduced pathological new bone formation in a collagen antibody-induced arthritis (CAIA) model. Specifically, TREM2+ macrophages promoted osteogenic differentiation of ligament-derived progenitor cells (LDPCs) by secreting CREG1, a secretory glycoprotein involved in cell differentiation and normal physiology. CREG1-IGF2R-PI3K-AKT signaling pathway is involved in TREM2+ macrophage-mediated pathological new bone formation. In addition, it is found that IL-33 promoted TREM2+ macrophage differentiation through phosphorylation of STAT6. Targeting the above signalings alleviated new bone formation in the CAIA model. The findings highlight the critical role of IL-33-induced TREM2+ macrophages in pathological new bone formation and provide potential therapeutic targets for halting spinal ankylosis in AS.

Macrophage pyroptosis represents a pivotal mechanism underlying acute liver injury during sepsis. Chloride intracellular channel proteins (CLICs) have been linked to inflammatory reflexes, with IAA94 serving as an inhibitor of channel formation characteristic of CLICs. In a mouse model, IAA94 demonstrated efficacy in reducing pro-inflammatory cytokines in liver tissues, decreasing macrophage in the liver, inhibiting the development of the pro-fibrosis phenotype, and alleviating tissue injury. Additionally, IAA94 exhibited inhibitory effects on the activation of NLRP3 inflammasome, leading to the suppression of pyroptosis in J774A.1 cells and the liver. Additionally, IAA94 was observed to impede the interaction between NEK7 and NLRP3. Furthermore, it was observed that the conditioned medium of pyroptotic macrophages treated with IAA94 induced an attenuated inflammatory response in hepatocytes in comparison to that induced by the conditioned medium of pyroptotic macrophages. However, NLRP3 overexpression impeded the beneficial effects of IAA94. In conclusion, IAA94 has the capacity to impede NLRP3 inflammasome formation-mediated pyroptosis by blocking CLICs-mediated chloride efflux and the inhibition of NEK7-NLRP3 interactions, thereby establishing CLICs as a promising therapeutic target against liver inflammation.

Chronic liver injury triggers the activation and recruitment of immune cells, causing antigen-independent tissue damage and liver disease progression. Tissue inflammation can reshape macrophage composition through monocyte replacement. Replacement of tissue macrophages with monocytes differentiating in an inflammatory environment can potentially imprint a phenotype that switches the liver from an immune-tolerant organ to one predisposed to tissue damage. We longitudinally sampled the liver of patients with chronic hepatitis B who had active liver inflammation and were starting antiviral therapy. Antiviral therapy suppressed viral replication and liver inflammation, which coincided with decreased myeloid activation markers. Single-cell RNA-Seq mapped peripheral inflammatory markers to a monocyte-derived macrophage population, distinct from Kupffer cells, with an inflammatory transcriptional profile. The inflammatory macrophages (iMacs) differentiated from blood monocytes and were unique from macrophage found in healthy or cirrhotic liver. iMacs retained their core transcriptional signature after inflammation resolved, indicating inflammation-mediated remodeling of the macrophage population in the human liver that may affect progressive liver disease and immunotherapy.

Obesity, characterized by the excessive accumulation of white adipose tissue, is a significant global health burden and a major risk factor for a range of diseases, including malignancies and metabolic disorders. Individuals with high visceral fat content are particularly susceptible to severe complications such as type 2 diabetes, cardiovascular diseases, and liver disorders. However, the pathogenesis of obesity-related metabolic diseases extends beyond simple adiposity. Chronic obesity triggers a prolonged inflammatory response, which leads to tissue fibrosis and sustained organ damage, contributing to multi-organ dysfunction. This review explores the autoimmune mechanisms and inflammatory pathways underlying obesity-induced type 2 diabetes, atherosclerosis, and non-alcoholic fatty liver disease, with an emphasis on their interrelated pathophysiology and the potential for therapeutic interventions.

MicroRNAs (miRNAs), small and noncoding RNAs that regulate gene expression through hybridization to messenger RNA, play a crucial role in the prevention or progression of non-alcoholic fatty liver disease (NAFLD). There is an urgent demand for the improvement of diagnostic tools and effective pharmacotherapies for the treatment of NAFLD, which can advance to cirrhosis and liver cancer. MiRNAs act as regulatory factors and noninvasive diagnostic agents for NAFLD, enabling the staging of the disorder, prognosis, and identification of pharmaco-therapeutic targets. NAFLD causes alterations in the expression patterns of hepatocyte miRNAs, with some specific miRNAs related to the upgrade from NAFLD to non-alcoholic steatohepatitis (NASH). These miRNAs can activate certain signaling cascade and exacerbate or improve NAFLD, additionally, act as hepatocellular signals or second messengers that transmit information between the liver and other systems. This study provides a comprehensive review of the most important miRNAs and their involvement in the pathophysiology and cellular signaling pathways related to NAFLD.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is characterized by metabolic dysfunction and inflammation burden, involving a significant enhancement of cellular glycolytic activity. Here, we elucidate how a positive feedback loop in liver macrophages drives MASLD pathogenesis and demonstrate that disrupting this cycle mitigates metabolic stress and macrophage M1 activation during MASLD. We detect elevated expression of hexokinase 2 (HK2) and H3K18la in liver macrophages from patients with MASLD and MASLD mice. This lactate-dependent histone lactylation promotes glycolysis and liver macrophage M1 polarization by enriching the promoters of glycolytic genes and activating transcription. Ultimately, the HK2/glycolysis/H3K18la positive feedback loop exacerbates the vicious cycle of enhancing metabolic dysregulation and histone lactylation and the inflammatory phenotype of liver macrophages. Myeloid-specific deletion of Hk2 or pharmacological inhibition of the transcription factor HIF-1α significantly disrupts this deleterious cycle. Therefore, our study illustrates that targeting this amplified pathogenic loop may offer a promising therapeutic strategy for MASLD.

Developing drugs for the treatment of Metabolic Associated Steatohepatitis (MASH) has always been a significant challenge. Researchers have been dedicated to exploring drugs and therapeutic strategies to alleviate disease progression, but treatments remain limited. This is partly due to the complexity of the pathophysiological processes, and inadequate knowledge of the cellular and molecular mechanisms in MASH. Especially, the liver non-parenchymal cells (NPCs) like Kupffer cells, hepatic stellate cells and sinusoidal endothelial cells which play critical roles in live function, immune responses, fibrosis and disease progression. Deciphering how these cells function in MASH, would help understand the pathophysiological processes and find potential drug targets. In recent years, new technologies have been developed for single-cell transcriptomic sequencing, making cell-specific transcriptome profiling a reality in healthy and diseased livers. In this review, we discussed how the use of single-cell transcriptomic sequencing provided us with an in-depth understanding of the heterogeneous, cellular interactions among non-parenchymal cells and tried to highlight recent discoveries in MASH by this technology. It is hoped that the summarized features and markers of various subclusters in this review could provide a technical reference for further experiments and a theoretical basis for clinical applications.

Metabolic dysfunction-associated steatohepatitis (MASH), a severe form of metabolic dysfunction-associated steatotic liver disease (MASLD), involves hepatic lipid accumulation, inflammation, and fibrosis. It can progress to cirrhosis or hepatocellular carcinoma without timely treatment. Current treatment options for MASH are limited. This study explores the therapeutic effects of fluorofenidone (AKF-PD), a novel small-molecule compound with antifibrotic and anti-inflammatory properties, on MASH in mouse model. Mice fed a choline-deficient, l-amino acid-defined, high-fat diet (CDAHFD) were treated with AKF-PD, resulting in reduced serum ALT, AST, hepatic lipid accumulation, liver inflammation, and fibrosis. Network pharmacology and RNA-sequencing analyses suggested that AKF-PD influenced multiple metabolic, inflammatory, and fibrosis-related pathways. Further experiments verified that AKF-PD activated hepatic AMPK signaling, leading to the inhibition of the downstream SREBF1/SCD1 pathway and the activation of autophagy. Additionally, AKF-PD suppressed the expression of various inflammatory factors, reduced macrophage infiltration, and inhibited NLRP3 inflammasome activation. Moreover, AKF-PD attenuated liver fibrosis by inhibiting TGFβ1/SMAD signaling. In conclusion, this study reveals that AKF-PD effectively decreases hepatic lipid accumulation, liver inflammation and fibrosis in a CDAHFD-induced MASH model, positioning AKF-PD as a promising candidate for the treatment of MASH.

This study explores the relationship between gout and metabolic dysfunction-associated steatotic liver disease (MASLD), two metabolic conditions linked to worsening health outcomes. While hyperuricemia's association with MASLD is established, the specific connection between gout and MASLD remains less explored. Using data from the UK Biobank, the study employs COX proportional hazard models, multi-state survival analysis, and Mendelian randomization to assess the independent and mutual risks of gout and MASLD. Findings indicate a mutual risk increase: male gout patients, those younger than 60, and those with high BMI are particularly susceptible to MASLD, while female MASLD patients are at heightened risk for gout. Shared risk factors for both conditions include high BMI, hypertension, diabetes, and hyperuricemia. The study further identifies a bidirectional causal link, with gout leading to MASLD, mediated by gut microbiota Ruminococcaceae and proteins like IL-2 and GDF11, implicating specific metabolic pathways. The findings highlight a clinical and mechanistic correlation, emphasizing the need for targeted interventions to address these overlapping metabolic pathways in future treatments.

Metabolic-associated fatty liver disease (MAFLD) is the leading chronic liver disease globally, impacting a large segment of the population. The Zhuyu Pill (ZYP), a traditional Chinese remedy, has been clinically used for treating MAFLD, with its effectiveness demonstrated in both human patients and animal models. However, the underlying mechanisms of how ZYP addresses MAFLD still require further investigation.

This study investigated the molecular mechanism of ZYP in treating MAFLD through both in vivo and vitro methods.

A murine MAFLD model was induced by a high-fat, high-fructose diet for 12 weeks. ZYP was administered for 4 weeks, with fenofibrate serving as a positive control. Indicators of lipid metabolism in serum and liver tissue were detected by automatic biochemical analyzer and ELISA, respectively. Histopathological evaluation of liver sections was performed using HE and oil red O staining. Transcriptomics was employed to further investigate the therapeutic mechanism of ZYP in MAFLD. Additionally, macrophages and their polarization in the liver were analyzed using ELISA, flow cytometry, immunohistochemistry, and immunofluorescence (IF). Candidate proteins and pathways were validated in vivo and in vitro by western blotting and IF. Validation of the pathway was performed in vitro using inhibitors and co-culture strategies.

ZYP significantly improved obesity and hepatic steatosis in MAFLD mice, reducing body/liver weight and regulating lipid metabolism indicators in serum and liver tissue. Bioinformatics analysis of transcriptomic data highlighted lipid metabolism regulation and inflammation control as key effects of ZYP in treating MAFLD. The in vivo experimental results showed that ZYP inhibited M1 polarization of macrophages (pro-inflammatory) and promoted M2 polarization of macrophages (anti-inflammatory) in MAFLD mice. Further in vivo and vitro experiments indicated that ZYP competes with LPS to bind to Toll-like receptor 4 (TLR4), suppressing M1 polarization in liver macrophages, and improving MAFLD. The in vitro co-culture system also confirmed that ZYP reduces liver lipid deposition by modulating M1 macrophage polarization.

ZYP alleviates MAFLD by inhibiting M1 polarization of liver macrophages, indicating that ZYP may be a promising treatment for MAFLD. Its mechanism of action is to inhibit the TLR4/MyD88/TRAF6 signaling pathway, modulate macrophage polarization, and improve inflammatory response.

The activation of inflammatory macrophages plays a pivotal role in the development of liver fibrosis (LF). Ferroptosis contributes to the clearance of inflammatory macrophages and the release of profibrotic factors. Glycyrrhetic Acid 3-O-Mono-β-d-glucuronide (GAMG) is a natural compound, the potential role of which on LF remains uncertain. In this study, GAMG treatment significantly reduced hepatocyte steatosis, fibroplasia, inflammatory cell infiltration, and collagen fiber deposition in LF mice. In addition, GAMG remarkably decreased the content of collagen protein and improved liver function indicators. Single-cell RNA sequencing revealed that GAMG significantly affected the changes of macrophage subsets in LF, and Funrich analysis identified IRF1 as a key transcription factor regulating the macrophage genome. IRF1 was significantly increased while ferroptosis related SLC7A11 was significantly down-regulated in GAMG treated inflammatory macrophages. Mass spectrometry metabolomics analysis showed that GAMG significantly affected metabolites associated with LF. In vivo and in vitro experiments further verified that GAMG induced ferroptosis of inflammatory macrophages through the IRF1/SLC7A11 axis, and ultimately alleviated LF. Therefore, GAMG induces ferroptosis of inflammatory macrophages by activating the IRF1/SLC7A11 axis, which provides a new strategy for the treatment of LF.

Non-alcoholic fatty liver disease (NAFLD) is a progressive disease. Without effective interventions, NAFLD can gradually develop to non-alcoholic steatohepatitis, fatty liver fibrosis, liver cirrhosis and even hepatocellular carcinoma. It is still to investigate the precise molecular mechanism behind the pathophysiology of NAFLD. Triggering receptor expressed on myeloid cells 2 (TREM2) can sense tissue injury and mediate immune remodeling, thereby inducing phagocytosis, lipid metabolism, and metabolic transfer, promoting cell survival and combating inflammatory activation. NAFLD might develop as a result of TREM2's regulatory role. We here briefly summarize the biological characteristics of TREM2 and its functions in the disease progression of NAFLD. Moreover, we propose to broaden the therapeutic strategy for NAFLD by targeting TREM2.

Dysfunctions within the liver system are intricately linked to the progression of diabetic retinopathy (DR) and non-alcoholic fatty liver disease (NAFLD). This study leverages systematic analysis to elucidate the complex cross-talk and communication pathways among diverse cell populations implicated in the pathogenesis of DR and NAFLD.

Single-cell RNA sequencing data for proliferative diabetic retinopathy (PDR) and NAFLD were retrieved from the Gene Expression Omnibus (GEO) database. Differential gene expression analysis was conducted and followed by pseudo-time analysis to delineate dynamic changes in core cells and differentially expressed genes (DEGs). CellChat was employed to predict intercellular communication and signaling pathways. Additionally, gene set enrichment and variation analyses (GSEA and GSVA) were performed to uncover key functional enrichments.

Our comparative analysis of the two datasets focused on T cells, macrophages and endothelial cells, revealing SYNE2 as a notable DEG. Notably, common genes including PYHIN1, SLC38A1, ETS1 (T cells), PPFIBP1, LIFR, HSPG2 (endothelial cells), and MSR1 (macrophages), emerged among the top 50 DEGs across these cell types. The CD45 signaling pathway was pivotal for T cells and macrophages, exerting profound effects on other cells in both PDR and NAFLD. Moreover, GSEA and GSVA underscored their involvement in cellular communication, immune modulation, energy metabolism, mitotic processes.

The comprehensive investigation of T cells, macrophages, endothelial cells, and the CD45 signaling pathway advances our understanding of the intricate biological processes underpinning DR and NAFLD. This research underscores the imperative of exploring immune-related cell interactions, shedding light on novel therapeutic avenues in these disease contexts.

Metabolic dysfunction-associated steatotic liver disease (MASLD; also known as nonalcoholic fatty liver disease) is a chronic condition associated with metabolic syndrome, a group of conditions that includes obesity, insulin resistance, hyperlipidaemia and cardiovascular disease. Primary growth hormone (GH) deficiency is associated with MASLD, and the decline in circulating levels of GH with weight gain might contribute to the development of MASLD. Raising endogenous GH secretion or administering GH replacement therapy in the context of MASLD enhances insulin-like growth factor 1 (IGF1) production and reduces steatosis and the severity of liver injury. GH and IGF1 indirectly control MASLD progression by regulating systemic metabolic function. Evidence supports the proposal that GH and IGF1 also have a direct role in regulating liver metabolism and health. This Review focuses on how GH acts on the hepatocyte in a sex-dependent manner to limit lipid accumulation, reduce stress, and promote survival and regeneration. In addition, we discuss how GH and IGF1 might regulate non-parenchymal cells of the liver to control inflammation and fibrosis, which have a major effect on hepatocyte survival and regeneration. Development of a better understanding of how GH and IGF1 coordinate the functions of specific, individual liver cell types might provide insight into the aetiology of MASLD initiation and progression and suggest novel approaches for the treatment of MASLD.

Macrophages play crucial roles in immune response and tissue homeostasis, with their functions becoming increasingly complex in obesity-mediated metabolic disorders. This review explores the extensive range of macrophage activities within adipose and liver tissues, emphasizing their contribution to the pathogenesis and progression of obesity and its related metabolic dysfunction-associated steatotic liver disease (MASLD). In the context of obesity, macrophages respond adaptively to lipid overloads and inflammatory cues in adipose tissue, profoundly influencing insulin resistance and metabolic homeostasis. Concurrently, their role in the liver extends to moderating inflammation and orchestrating fibrotic responses, integral to the development of MASLD. Highlighting the spectrum of macrophage phenotypes across these metabolic landscapes, we summarize their diverse roles in linking inflammatory processes with metabolic functions. This review advocates for a deeper understanding of macrophage subsets in metabolic tissues, proposing targeted research to harness their therapeutic potential in mitigating MASLD and other metabolic disorders.

Macrophages play important roles in metabolic dysfunction-associated steatohepatitis (MASH), an advanced and inflammatory stage of metabolic dysfunction-associated steatotic liver disease (MASLD). In humans and mice, the cellular heterogeneity and diverse function of hepatic macrophages in MASH have been investigated by single cell RNA sequencing (scRNA-seq). However, little is known about their roles in rats. Here, we collected liver tissues at the postnatal week 16, when our previously characterized Lep∆I14/∆I14 rats developed MASH phenotypes. By scRNA-seq, we found an increase in the number of macrophages and endothelial cells and a decrease in that of NK and B cells. Hepatic macrophages in rats underwent a unique M1 to M2 transition without expression of the classical markers such as Arg1 and Nos2, except for Cd163. Lipid-associated macrophages (LAMs) were increased, which could be detected by the antibody against Cd63. In the microenvironment, macrophages had an increased number of interactions with hepatocytes, myofibroblasts, T cells, neutrophils, and dendritic cells, while their interaction strengths remained unchanged. Finally, the macrophage migration inhibitory factor (MIF) pathway was identified as the top upregulated cell-communication pathway in MASH. In conclusion, we dissected hepatic macrophage dynamics during MASH at single cell resolution and provided fundamental tools for the investigation of MASH in rat models.

Together with obesity and type 2 diabetes, metabolic dysfunction-associated steatotic liver disease (MASLD) is a growing global epidemic. Activation of the complement system and infiltration of macrophages has been linked to progression of metabolic liver disease. The role of complement receptors in macrophage activation and recruitment in MASLD remains poorly understood. In human and mouse, C3AR1 in the liver is expressed primarily in Kupffer cells, but is downregulated in humans with MASLD compared to obese controls. To test the role of complement 3a receptor (C3aR1) on macrophages and liver resident macrophages in MASLD, we generated mice deficient in C3aR1 on all macrophages (C3aR1-MφKO) or specifically in liver Kupffer cells (C3aR1-KpKO) and subjected them to a model of metabolic steatotic liver disease. We show that macrophages account for the vast majority of C3ar1 expression in the liver. Overall, C3aR1-MφKO and C3aR1-KpKO mice have similar body weight gain without significant alterations in glucose homeostasis, hepatic steatosis and fibrosis, compared to controls on a MASLD-inducing diet. This study demonstrates that C3aR1 deletion in macrophages or Kupffer cells, the predominant liver cell type expressing C3ar1, has no significant effect on liver steatosis, inflammation or fibrosis in a dietary MASLD model.

Non-alcoholic fatty liver disease (NAFLD) constitutes the most prevalent chronic liver disease worldwide. Progression to non-alcoholic steatohepatitis (NASH), the immune cell reservoir within the liver undergoes remodeling, exacerbating liver inflammation and potentially leading to liver fibrosis. Jiangtang Qingre Formula (JQF) is an effective prescription for the clinical treatment of NAFLD. However, its underlying mechanism of action remains unclear.

Using a high-fat diet-induced NAFLD mouse model, we evaluated JQF's effects with biochemical tests and histopathology. Single-cell RNA sequencing and spatial transcriptomics furthered our understanding of NAFLD pathophysiology and JQF's treatment mechanisms.

Our findings initially revealed significant improvements in JQF on hepatic steatosis, inflammation, fibrosis and glucose tolerance in NAFLD mice. Furthermore, significant changes were observed in the immune cells including monocytes, macrophages, and T cells in the livers of NAFLD mice. Notably, regions infiltrated by T cells presented the most severe liver inflammation and fibrosis. Importantly, JQF effectively modulated these immune cells. Advanced subcluster and cell communication analyses identified key macrophage (KCs, MoMFs) and T cell (Tc, Th2) subpopulations in JQF's therapeutic actions. Further SCENIC analysis additionally uncovered the essential transcription factors that regulate these cell subclusters, such as Stat2, Mta3, Eomes, and Etv5.

Overall, our research suggests a promising potential therapeutic agent and identifies critical cell populations and transcription factors that contribute to its therapeutic effects, thereby revealing potential therapeutic targets for NAFLD.

A slew of common metabolic disorders, including type 2 diabetes, metabolic dysfunction-associated steatotic liver disease and steatohepatitis, are exponentially increasing in our sedentary and overfed society. While macronutrients directly impact metabolism and bioenergetics, new evidence implicates immune cells as critical sensors of nutritional cues and important regulators of metabolic homeostasis. A deeper interrogation of the intricate and multipartite interactions between dietary components, immune cells and metabolically active tissues is needed for a better understanding of metabolic regulation and development of new treatments for common metabolic diseases. Responding to macronutrients and micronutrients, immune cells play pivotal roles in interorgan communication between the microbiota, small intestine, metabolically active cells including hepatocytes and adipocytes, and the brain, which controls feeding behavior and energy expenditure. This Review focuses on the response of myeloid cells and innate lymphocytes to dietary cues, their cross-regulatory interactions and roles in normal and aberrant metabolic control.

The mitogen-activated protein kinase kinase 4 (MKK4), a member of the MAP kinase kinase family, directly phosphorylates and activates the c-Jun NH2-terminal kinases (JNK), in response to proinflammatory cytokines and cellular stresses. Regulation of the MKK4 activity is considered to be a novel approach for the prevention and treatment of inflammation. The aim of this study was to identify whether fisetin, a potential anti-inflammatory compound, targets MKK4-JNK cascade to inhibit lipopolysaccharide (LPS)-stimulated inflammatory response. RAW264 macrophage pretreated with fisetin following LPS stimulation was used as a cell model to investigate the transactivation and expression of related-inflammatory genes by transient transfection assay, electrophoretic mobility shift assay (EMSA), or enzyme-linked immunosorbent assay (ELISA), and cellular signaling as well as binding of related-signal proteins by Western blot, pull-down assay and kinase assay, and molecular modeling. The transactivation and expression of cyclooxygenase-2 (COX-2) gene as well as prostaglandin E2 (PGE2) secretion induced by LPS were inhibited by fisetin in a dose-dependent manner. Signaling transduction analysis demonstrated that fisetin selectively inhibited MKK4-JNK1/2 signaling to suppress the phosphorylation of transcription factor AP-1 without affecting the NF-κB and Jak2-Stat3 signaling as well as the phosphorylation of Src, Syk, and TAK1. Furthermore, in vitro and ex vivo pull-down assay using cell lysate or purified protein demonstrated that fisetin could bind directly to MKK4. Molecular modeling using the Molecular Operating Environment™ software indicated that fisetin docked into the ATP-binding pocket of MKK4 with a binding energy of -71.75 kcal/mol and formed a 1.70 Å hydrogen bound with Asp247 residue of MKK4. The IC50 of fisetin against MKK4 was estimated as 2.899 μM in the kinase assay, and the ATP-competitive effect was confirmed by ATP titration. Taken together, our data revealed that fisetin is a potent selective ATP-competitive MKK4 inhibitor to suppress MKK4-JNK1/2-AP-1 cascade for inhibiting LPS-induced inflammation.

The ability to accurately quantify biological age could help monitor and control healthy aging. Epigenetic clocks have emerged as promising tools for estimating biological age, yet they have been developed from heterogeneous bulk tissues, and are thus composites of two aging processes, one reflecting the change of cell-type composition with age and another reflecting the aging of individual cell-types. There is thus a need to dissect and quantify these two components of epigenetic clocks, and to develop epigenetic clocks that can yield biological age estimates at cell-type resolution. Here we demonstrate that in blood and brain, approximately 39% and 12% of an epigenetic clock's accuracy is driven by underlying shifts in lymphocyte and neuronal subsets, respectively. Using brain and liver tissue as prototypes, we build and validate neuron and hepatocyte specific DNA methylation clocks, and demonstrate that these cell-type specific clocks yield improved estimates of chronological age in the corresponding cell and tissue-types. We find that neuron and glia specific clocks display biological age acceleration in Alzheimer's Disease with the effect being strongest for glia in the temporal lobe. Moreover, CpGs from these clocks display a small but significant overlap with the causal DamAge-clock, mapping to key genes implicated in neurodegeneration. The hepatocyte clock is found accelerated in liver under various pathological conditions. In contrast, non-cell-type specific clocks do not display biological age-acceleration, or only do so marginally. In summary, this work highlights the importance of dissecting epigenetic clocks and quantifying biological age at cell-type resolution.

The monocyte-to-Apolipoprotein A1 ratio (MAR) emerges as a potentially valuable inflammatory biomarker indicative of metabolic dysfunction-associated fatty liver disease (MASLD). Accordingly, this investigation primarily aims to assess the correlation between MAR and MASLD risk. A cohort comprising 957 individuals diagnosed with type 2 diabetes mellitus (T2DM) participated in this study. The relationship between MAR and MASLD was analyzed through binomial logistic regression analysis and restricted cubic splines (RCS). Furthermore, a comparative assessment of MAR and monocyte to high-density lipoprotein ratio (MHR) in identifying MASLD efficacy was conducted using receiver operating characteristic curve analysis. Remarkably, even after adjusting for metabolic parameters and hepatic functional markers, MAR stood out as an independent predictor for MASLD (OR 1.58, 95% CI 1.36-1.84; P < 0.001) and displayed a nonlinear positive association with MASLD risk according to RCS analysis (P for nonlinearity and overall < 0.001). Notably, MAR exhibited superior diagnostic accuracy for identifying MASLD compared to MHR (AUC: 0.772 vs 0.722, P < 0.001). In summary, MAR emerges as a promising inflammatory indicator for MASLD, demonstrating potential as a valuable screening tool to bolster the management of MASLD within the T2DM population.

Chronic liver disease has a substantial global prevalence and mortality rate. Macrophages, pivotal cells in innate immunity, exhibit remarkable heterogeneity and plasticity and play a considerable role in maintaining organ homeostasis, modulating inflammatory responses, and influencing disease progression in the liver. Exosomes, which can serve as conduits for intercellular communication, biomarkers, and therapeutic targets for a spectrum of diseases, have recently garnered increasing attention recently. Given that the liver is the organ with the highest macrophage content, a thorough understanding of the influence of macrophage-derived exosomes (MDEs) on noncancer liver disease pathogenesis and their potential therapeutic applications is paramount. Interactions among MDEs, hepatocytes, hepatic stellate cells (HSCs), and other nonparenchymal cells constitute a complex network regulates liver immune homeostasis. In this review, we summarize the latest progress in the current understanding of MDE heterogeneity and cellular crosstalk in noncancer liver diseases, as well as their potential clinical applications. Additionally, challenges and future directions are underscored.

Metabolic syndrome is a group of pathological disorders increasing the risk of serious diseases including cardiovascular disease, stroke, type 2 diabetes. Global widespread of the metabolic syndrome has put a heavy social burden. Interestingly, a crucial link between the metabolic syndrome and a psychiatric disorder may frequently coexist, in which certain shared mechanisms might play a role for the pathogenesis. In fact, some microRNAs (miRNAs) have been detected in the overlap pathology, suggesting a common molecular mechanism for the development of both disorders. Subsequent studies have revealed that these miRNAs and several metabolites of gut microbiota such as short chain fatty acids (SCFAs) might be involved in the development of both disorders, in which the association between gut and brain might play key roles with engram memory for the modulation of immune cells. Additionally, the correlation between brain and immunity might also influence the development of several diseases/disorders including metabolic syndrome. Brain could possess several inflammatory responses as an information of pathological images termed engrams. In other words, preservation of the engram memory might be achieved by a meta-plasticity mechanism that shapes the alteration of neuron linkages for the development of immune-related diseases. Therefore, it might be rational that metabolic syndrome and psychiatric disorders may belong to a group of immune-related diseases. Disrupting in gut microbiota may threaten the body homeostasis, leading to initiate a cascade of health problems. This concept may contribute to the development of superior therapeutic application with the usage of some functional components in food against metabolic and psychiatric disorders. This paper reviews advances in understanding the regulatory mechanisms of miRNAs with the impact to gut, liver and brain, deliberating the probable therapeutic techniques against these disorders.