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Military Medical Research Nov 2023G-protein coupled receptors (GPCRs) are recognized as attractive targets for drug therapy. However, it remains poorly understood how GPCRs, except for a few chemokine...
BACKGROUND
G-protein coupled receptors (GPCRs) are recognized as attractive targets for drug therapy. However, it remains poorly understood how GPCRs, except for a few chemokine receptors, regulate the progression of liver fibrosis. Here, we aimed to reveal the role of GPR65, a proton-sensing receptor, in liver fibrosis and to elucidate the underlying mechanism.
METHODS
The expression level of GPR65 was evaluated in both human and mouse fibrotic livers. Furthermore, Gpr65-deficient mice were treated with either bile duct ligation (BDL) for 21 d or carbon tetrachloride (CCl) for 8 weeks to investigate the role of GPR65 in liver fibrosis. A combination of experimental approaches, including Western blotting, quantitative real-time reverse transcription‑polymerase chain reaction (qRT-PCR), and enzyme-linked immunosorbent assay (ELISA), confocal microscopy and rescue studies, were used to explore the underlying mechanisms of GPR65's action in liver fibrosis. Additionally, the therapeutic potential of GPR65 inhibitor in the development of liver fibrosis was investigated.
RESULTS
We found that hepatic macrophages (HMs)-enriched GPR65 was upregulated in both human and mouse fibrotic livers. Moreover, knockout of Gpr65 significantly alleviated BDL- and CCl-induced liver inflammation, injury and fibrosis in vivo, and mouse bone marrow transplantation (BMT) experiments further demonstrated that the protective effect of Gpr65 knockout is primarily mediated by bone marrow-derived macrophages (BMMs). Additionally, in vitro data demonstrated that Gpr65 silencing and GPR65 antagonist inhibited, while GPR65 overexpression and application of GPR65 endogenous and exogenous agonists enhanced the expression and release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and transforming growth factor-β (TGF-β), all of which subsequently promoted the activation of hepatic stellate cells (HSCs) and the damage of hepatocytes (HCs). Mechanistically, GPR65 overexpression, the acidic pH and GPR65 exogenous agonist induced up-regulation of TNF-α and IL-6 via the Gαq-Ca-JNK/NF-κB pathways, while promoted the expression of TGF-β through the Gαq-Ca-MLK3-MKK7-JNK pathway. Notably, pharmacological GPR65 inhibition retarded the development of inflammation, HCs injury and fibrosis in vivo.
CONCLUSIONS
GPR65 is a major regulator that modulates the progression of liver fibrosis. Thus, targeting GPR65 could be an effective therapeutic strategy for the prevention of liver fibrosis.
Topics: Animals; Humans; Mice; Inflammation; Interleukin-6; Liver Cirrhosis; NF-kappa B; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha
PubMed: 38001521
DOI: 10.1186/s40779-023-00494-4 -
Free Radical Biology & Medicine Jan 2021Liver fibrosis is a reversible wound-healing response to acute or chronic liver injury that can progress to cirrhosis and liver cancer. Finding new strategies for...
Liver fibrosis is a reversible wound-healing response to acute or chronic liver injury that can progress to cirrhosis and liver cancer. Finding new strategies for prevention and management of liver fibrosis is urgently needed. It is known that hepatic stellate cell (HSC) is the primary source of extracellular matrix that drives liver fibrosis progression. Herein, we carried out a comprehensive secretome profiling to identify NMN-induced changes in secretory proteins and found that NMN suppressed the secretion of profibrotic protein and oxidoreductase in activated HSC (LX-2) cells, while real-time quantitative PCR analysis revealed that NMN downregulated profibrotic gene expression, resulting in HSC inactivation. Next, we demonstrated that nicotinamide mononucleotide (NMN) reduced the accumulation of liver extracellular matrix in thioacetamide (TAA) and carbon tetrachloride (CCl) induced mouse models for liver fibrosis. Furthermore, we determined that NMN inhibited oxidation-mediated 15-PGDH degradation to promote prostaglandin E degradation and suppress HSC activation. In summary, our results propose that NMN supplementation is a new therapeutic approach for liver fibrosis prevention.
Topics: Animals; Dinoprostone; Hepatic Stellate Cells; Liver; Liver Cirrhosis; Mice; Nicotinamide Mononucleotide; Thioacetamide
PubMed: 33220424
DOI: 10.1016/j.freeradbiomed.2020.11.014 -
Frontiers in Endocrinology 2023The negative effects of obesity on hepatic steatosis and fibrosis have received considerable attention in recent years. The weight-adjusted-waist index (WWI) reflects...
BACKGROUND
The negative effects of obesity on hepatic steatosis and fibrosis have received considerable attention in recent years. The weight-adjusted-waist index (WWI) reflects weight-independent centripetal obesity. Herein, we provide the first investigation of a link between WWI, hepatic steatosis, and liver fibrosis.
METHODS
We used data from the National Health and Nutrition Examination Survey 2017-2020 to conduct a cross-sectional study. The linear relationship between WWI, controlled attenuation parameters, and liver stiffness measurements (LSM) was investigated using multivariate linear regression models. The nonlinear relationship was described using fitted smoothed curves and threshold effect analyses. Subgroup analyses were performed based on gender, age, body mass index, diabetes, hypertension, drinking, and smoking.
RESULTS
This population-based study included 7,594 people, 50.74% of whom were men and 49.26% of whom were women. Multivariate linear regression analysis revealed a significant positive relationship between WWI and hepatic steatosis [CAP, β=7.60, 95% confidence interval (CI) (4.42, 10.78), P<0.0001]. This positive association was stronger when excessive alcohol intake was present compared to when it was absent (P for interaction = 0.031), and when hypertension was present compared to when it was not (P for interaction = 0.014). The linear relationship between WWI and liver fibrosis was not statistically significant on multiple regression analysis [LSM, β=0.03, 95% CI (-0.26, 0.32), P=0.84]. However, a U-shaped association was seen between WWI and LSM, with a negative correlation when WWI< 10.92 and a positive correlation when WWI > 10.92.
CONCLUSION
We report a strong association between WWI and hepatic steatosis, and suggest that it may potentially be used as a simple anthropometric index to predict hepatic steatosis.
Topics: Male; Humans; Female; Cross-Sectional Studies; Nutrition Surveys; Elasticity Imaging Techniques; Prospective Studies; Fatty Liver; Liver Cirrhosis; Obesity; Hypertension
PubMed: 37274346
DOI: 10.3389/fendo.2023.1159055 -
Pharmacological Research Jan 2023Relevant studies have recognized the important role of hepatic stellate cell (HSC) senescence in anti-liver fibrosis. Cellular senescence is believed to be regulated by...
Relevant studies have recognized the important role of hepatic stellate cell (HSC) senescence in anti-liver fibrosis. Cellular senescence is believed to be regulated by the cGAS-STING signaling pathway. However, underlying exact mechanisms of cGAS-STING pathway in hepatic stellate cell senescence are still unclear. Here, we found that Oroxylin A could promote senescence in HSC by activating the cGAS-STING pathway. Moreover, activation of the cGAS-STING pathway was dependent on DNMT3A downregulation, which suppressed cGAS gene DNA methylation. Interestingly, the attenuation of DNMT activity relied on the reduction of methyl donor SAM level. Noteworthy, the downregulation of SAM levels implied the imbalance of methionine cycle metabolism, and MAT2A was considered to be an important regulatory enzyme in metabolic processes. In vivo experiments also indicated that Oroxylin A induced senescence of HSCs in mice with liver fibrosis, and DNMT3A overexpression partly offset this effect. In conclusion, we discovered that Oroxylin A prevented the methylation of the cGAS gene by preventing the production of methionine metabolites, which promoted the senescence of HSCs. This finding offers a fresh hypothesis for further research into the anti-liver fibrosis mechanism of natural medicines.
Topics: Animals; Mice; Cellular Senescence; DNA; DNA Methylation; Hepatic Stellate Cells; Liver Cirrhosis; Methionine; Nucleotidyltransferases
PubMed: 36464146
DOI: 10.1016/j.phrs.2022.106590 -
Cells Jul 2021Liver fibrosis is a potentially reversible pathophysiological event, leading to excess deposition of extracellular matrix (ECM) components and taking place as the net... (Review)
Review
Liver fibrosis is a potentially reversible pathophysiological event, leading to excess deposition of extracellular matrix (ECM) components and taking place as the net result of liver fibrogenesis, a dynamic and highly integrated process occurring during chronic liver injury of any etiology. Liver fibrogenesis and fibrosis, together with chronic inflammatory response, are primarily involved in the progression of chronic liver diseases (CLD). As is well known, a major role in fibrogenesis and fibrosis is played by activated myofibroblasts (MFs), as well as by macrophages and other hepatic cell populations involved in CLD progression. In the present review, we will focus the attention on the emerging pathogenic role of hypoxia, hypoxia-inducible factors (HIFs) and related mediators in the fibrogenic progression of CLD.
Topics: Animals; Basic Helix-Loop-Helix Transcription Factors; Humans; Hypoxia; Liver; Liver Cirrhosis; Neovascularization, Pathologic; Signal Transduction
PubMed: 34359934
DOI: 10.3390/cells10071764 -
Clinical and Translational Medicine Jul 2023As a central event during liver fibrosis, hepatic stellate cells (HSC) have been thought to be a potential therapeutic target for liver fibrosis. Previous studies have...
BACKGROUNDS AND AIMS
As a central event during liver fibrosis, hepatic stellate cells (HSC) have been thought to be a potential therapeutic target for liver fibrosis. Previous studies have shown that runt-related transcription factor 2 (Runx2) is associated with the development of non-alcoholic fatty liver disease, while its specific role in HSC activation and hepatic fibrosis remains elusive.
APPROACH AND RESULTS
In this study, we found that Runx2 expression was significantly upregulated in human liver fibrosis with different aetiologies. Runx2 expression was also gradually elevated in mouse liver during fibrosis, and Runx2 was mainly expressed in the activated HSC. Knockdown of Runx2 in HSC markedly alleviated CCl -induced, 3,5-diethoxycarbonyl-1,4-dihydrocollidine-induced or methionine-choline deficient (MCD)-induced liver fibrosis, while hepatic overexpression of Runx2 via HBAAV-Runx2 or VA-Lip-Runx2 injection exacerbated CCl -induced liver fibrosis. In vitro analysis demonstrated that Runx2 promoted HSC activation and proliferation, whereas Runx2 knockdown in HSC suppressed these effects. RNA-seq and Runx2 ChIP-seq analysis demonstrated that Runx2 could promote integrin alpha-V (Itgav) expression by binding to its promoter. Blockade of Itgav attenuated Runx2-induced HSC activation and liver fibrosis. Additionally, we found that cytokines (TGF-β1, PDGF, EGF) promote the expression and nuclear translocation of Runx2 through protein kinase A (PKA) in HSC.
CONCLUSIONS
Runx2 is critical for HSC activation via transcriptionally regulating Itgav expression during liver fibrosis, and may be a promising therapeutic target for liver fibrosis.
Topics: Mice; Animals; Humans; Hepatic Stellate Cells; Integrin alphaV; Core Binding Factor Alpha 1 Subunit; Cell Line; Liver Cirrhosis
PubMed: 37403784
DOI: 10.1002/ctm2.1316 -
Cell Stem Cell Jul 2018The development of complex in vitro hepatic systems and artificial liver devices has been hampered by the lack of reliable sources for relevant cell types, such as...
The development of complex in vitro hepatic systems and artificial liver devices has been hampered by the lack of reliable sources for relevant cell types, such as hepatic stellate cells (HSCs). Here we report efficient differentiation of human pluripotent stem cells into HSC-like cells (iPSC-HSCs). iPSC-HSCs closely resemble primary human HSCs at the transcriptional, cellular, and functional levels and possess a gene expression profile intermediate between that of quiescent and activated HSCs. Functional analyses revealed that iPSC-HSCs accumulate retinyl esters in lipid droplets and are activated in response to mediators of wound healing, similar to their in vivo counterparts. When maintained as 3D spheroids with HepaRG hepatocytes, iPSC-HSCs exhibit a quiescent phenotype but mount a fibrogenic response and secrete pro-collagen in response to known stimuli and hepatocyte toxicity. Thus, this protocol provides a robust in vitro system for studying HSC development, modeling liver fibrosis, and drug toxicity screening.
Topics: Cell Differentiation; Cells, Cultured; Coculture Techniques; Female; Hepatic Stellate Cells; Humans; Infant, Newborn; Liver Cirrhosis; Male; Models, Biological; Pluripotent Stem Cells; Thioacetamide; Wound Healing
PubMed: 30049452
DOI: 10.1016/j.stem.2018.05.027 -
Journal of Nanobiotechnology Jun 2023Lysyl oxidase-like 2 (LOXL2) is an extracellular copper-dependent enzyme that plays a central role in fibrosis by catalyzing the crosslinking and deposition of collagen....
Lysyl oxidase-like 2 (LOXL2) is an extracellular copper-dependent enzyme that plays a central role in fibrosis by catalyzing the crosslinking and deposition of collagen. Therapeutic LOXL2 inhibition has been shown to suppress liver fibrosis progression and promote its reversal. This study investigates the efficacy and underlying mechanisms of human umbilical cord-derived exosomes (MSC-ex) in LOXL2 inhibition of liver fibrosis. MSC-ex, nonselective LOX inhibitor β-aminopropionitrile (BAPN), or PBS were administered into carbon tetrachloride (CCl4)-induced fibrotic livers. Serum LOXL2 and collagen crosslinking were assessed histologically and biochemically. MSC-ex's mechanisms on LOXL2 regulation were investigated in human hepatic stellate cell line LX-2. We found that systemic administration of MSC-ex significantly reduced LOXL2 expression and collagen crosslinking, delaying the progression of CCl4-induced liver fibrosis. Mechanically, RNA-sequencing and fluorescence in situ hybridization (FISH) indicated that miR-27b-3p was enriched in MSC-ex and exosomal miR-27b-3p repressed Yes-associated protein (YAP) expression by targeting its 3' untranslated region in LX-2. LOXL2 was identified as a novel downstream target gene of YAP, and YAP bound to the LOXL2 promoter to positively regulate transcription. Additionally, the miR-27b-3p inhibitor abrogated the anti-LOXL2 abilities of MSC-ex and diminished the antifibrotic efficacy. miR-27b-3p overexpression promoted MSC-ex mediated YAP/LOXL2 inhibition. Thus, MSC-ex may suppress LOXL2 expression through exosomal miR-27b-3p mediated YAP down-regulation. The findings here may improve our understanding of MSC-ex in liver fibrosis alleviation and provide new opportunities for clinical treatment.
Topics: Humans; Collagen; In Situ Hybridization, Fluorescence; Liver Cirrhosis; Mesenchymal Stem Cells; MicroRNAs
PubMed: 37328872
DOI: 10.1186/s12951-023-01942-y -
Cells Jun 2023Fibrosis is an unavoidable consequence of chronic inflammation. Extracellular matrix deposition by fibroblasts, stimulated by multiple pathways, is the first step in the... (Review)
Review
Fibrosis is an unavoidable consequence of chronic inflammation. Extracellular matrix deposition by fibroblasts, stimulated by multiple pathways, is the first step in the onset of chronic liver disease, and its propagation promotes liver dysfunction. At the same time, chronic liver disease is characterized by alterations in primary and secondary hemostasis but unlike previously thought, these changes are not associated with an increased risk of bleeding complications. In recent years, the role of coagulation imbalance has been postulated as one of the main mechanisms promoting hepatic fibrogenesis. In this review, we aim to investigate the function of microvascular thrombosis in the progression of liver disease and highlight the molecular and cellular networks linking hemostasis to fibrosis in this context. We analyze the predictive and prognostic role of coagulation products as biomarkers of liver decompensation (ascites, variceal hemorrhage, and hepatic encephalopathy) and liver-related mortality. Finally, we evaluate the current evidence on the application of antiplatelet and anticoagulant therapies for prophylaxis of hepatic decompensation or prevention of the progression of liver fibrosis.
Topics: Humans; Esophageal and Gastric Varices; Gastrointestinal Hemorrhage; Liver Cirrhosis; Liver Diseases; Thrombosis
PubMed: 37443746
DOI: 10.3390/cells12131712 -
Matrix Biology : Journal of the... Aug 2018Liver fibrosis, a reversible wound-healing response to chronic cellular injury, reflects a balance between liver repair and progressive substitution of the liver... (Review)
Review
Liver fibrosis, a reversible wound-healing response to chronic cellular injury, reflects a balance between liver repair and progressive substitution of the liver parenchyma by scar tissue. Complex mechanisms that underlie liver fibrogenesis are summarized to provide the basis for generating targeted therapies to reverse fibrogenesis and improve the outcomes of patients with chronic liver disease. This minireview presents some pathophysiological aspects of liver fibrosis as a dynamic process and elucidates matrix metalloproteinases (MMPs) and their role within as well as beyond matrix degradation. Open questions remain, whether inhibition of fibrogenesis or induction of fibrolysis is the key mechanism to resolve fibrosis. And a point of principle might be whether regeneration of liver cirrhosis is possible. Will we ever cure fibrosis?
Topics: Animals; Humans; Liver Cirrhosis; Matrix Metalloproteinases; Regeneration; Wound Healing
PubMed: 29289644
DOI: 10.1016/j.matbio.2017.12.012