Lack of phosphoenolpyruvate carboxykinase 1 in hepatic stellate cells causes liver fibrosis by fueling tricarboxylic acid cycle and increasing glycolysis
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE313667 | GEO | 2026/02/02
REPOSITORIES: GEO
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Project description:Neddylation is a post-translational mechanism that adds a ubiquitin-like protein, namely neural precursor cell expressed developmentally down-regulated protein 8, to target proteins, with yet-unknown consequences. Here we show in mice that neddylation in liver is modulated by nutrient availability. Inhibition of neddylation in mouse liver (either pharmacologically or genetically) reduces gluconeogenic capacity and the hyperglycemic actions of counterregulatory hormones (glucagon, adrenaline and glucocorticoids). Further, people with obesity and type 2 diabetes (compared to people with obesity and normoglycemia) display elevated hepatic neddylation levels that correlate positively with fasting glucose levels. Mechanistically, we determined that fasting or caloric restriction of mice leads to neddylation of phosphoenolpyruvate carboxykinase 1 (PCK1) at three lysine residues—K278, K342 and K387. PCK1 is a key control point for gluconeogenesis regulation that can be post-translationally modified by acetylation and phosphorylation, but to date no modifications are known to affect its gluconeogenic capacity. Of note, we find that mutating the three PCK1 lysines that are neddylated reduces its gluconeogenic activity rate. Molecular dynamics simulations show that neddylation of PCK1 could re-position two loops surrounding the catalytic center into an open configuration, rendering the catalytic center more accessible. Our study reveals that neddylation of PCK1 provides a finely-tuned mechanism of controlling glucose metabolism by linking whole nutrient availability to metabolic homeostasis.
2023-10-08 | PXD043054 | Pride
Project description:Liver fibrosis is characterized by the activation of perivascular hepatic stellate cells (HSCs), the release of fibrogenic nano-sized extracellular vesicles (EVs) and increased HSC glycolysis. Nevertheless, how glycolysis in HSCs coordinates fibrosis amplification through tissue zone-specific pathways remains elusive. Here, we demonstrate that HSC-specific genetic inhibition of glycolysis reduced liver fibrosis. Moreover, spatial transcriptomics revealed a fibrosis-mediated upregulation of EV-related pathways in the liver pericentral zone, which was abrogated by the glycolysis genetic inhibition. Mechanistically, glycolysis in HSCs upregulated the expression of EV-related genes such as RAB31 by enhancing histone-3-lysine-9 acetylation on the promoter region, which increased EV release. Functionally, these glycolysis-dependent EVs increased fibrotic gene expression in recipient HSC. Furthermore, EVs derived from glycolysis-deficient mice abrogated liver fibrosis amplification in contrast to glycolysis-competent mouse EVs. In summary, glycolysis in HSCs amplifies liver fibrosis by promoting fibrogenic EV release in the hepatic pericentral zone, which represents a potential therapeutic target.
2024-05-16 | PXD050337 | Pride
Project description:Liver fibrosis is characterized by the activation of hepatic stellate cells (HSCs) and the release of fibrogenic nano-sized extracellular vesicles (EVs). Activated HSCs increase their glucose metabolism via glycolysis to satisfy high energy demands. Nevertheless, the mechanism of how glycolysis in HSCs coordinates fibrosis amplification in the fibrogenic zones in the liver is elusive and is the scope of this study. Single cell RNA sequencing (scRNAseq) and bulk RNAseq demonstrated that several glycolysis enzymes, including hexokinase 2 (HK2), were upregulated in activated HSCs. HSC-selective glycolysis-deficient mice (HK2ΔHSC) showed abrogated CCl4-mediated fibrosis as compared to littermate controls (HK2fl/fl). Spatial transcriptomics revealed an upregulation of several EV-related pathways in the fibrotic pericentral zone during liver fibrosis in control HK2fl/fl mice. However, glycolysis-deficient HK2ΔHSC mice showed downregulation of these EV-related pathways in the pericentral zone. Consistently, induction of glycolysis in HSCs in vitro, either by glucose or platelet-derived growth factor B (PDGF), upregulated the expression of several extracellular vesicle (EV)-related genes, including RAB31. Glycolysis in HSCs epigenetically enhanced RAB31 expression through histone-3 lysine-9 acetylation (H3K9ac) on the promoter region, leading to increased EV release. Functionally, glycolysis-dependent EVs were enriched with fibrogenic molecules and increased the expression of fibrotic markers in recipient HSCs. Finally, EVs derived from glycolysis-deficient HK2ΔHSC mice abrogated liver fibrosis amplification as compared to EVs derived from littermate control HK2fl/fl mice. In summary, glycolysis in HSCs amplifies liver fibrosis by promoting fibrogenic EV release in the pericentral fibrotic regions in the liver.
2024-03-20 | GSE259363 | GEO
Project description:Hepatic stellate cells (HSCs) are pericytes of the liver and are responsible for liver fibrosis and cirrhosis, which are end stages of chronic liver diseases. TFG-β activates HSCs leading to differentiation of myofibroblasts in the process of liver fibrosis. While heterogeneity of HSCs is appreciated in the fibrotic liver, it remains elusive which HSC subsets mainly contribute to fibrosis. We here show that expression of pericyte marker, Foxd1, specifically marked a subset of HSCs in the Foxd1-fate tracer mice. HSCs fate-mapped by Foxd1 were preferentially localized in portal area and peripheral zone of normal liver and fibrotic liver induced by carbon tetrachloride. Furthermore, the deletion of Cbfβ, which is necessary for TGF-β signaling, in Foxd1-expressing cells ameliorated liver fibrosis. Thus, we identified an HSC subset which preferentially responds to liver injuries.
2025-06-17 | GSE270404 | GEO
Project description:Lack of phosphoenolpyruvate carboxykinase 1 in hepatic stellate cells causes liver fibrosis by fueling tricarboxylic acid cycle and increasing glycolysis
| PRJNA1380498 | ENA
Project description:Background/Aims: Sept4, a subunit of the septin cytoskeleton specifically expressed in quiescent hepatic stellate cells (HSCs), is downregulated through transdifferentiation to fibrogenic and contractile myofibroblastic cells. Since Sept4?/? mice are prone to liver fibrosis, we examined the unknown molecular network underlying liver fibrosis by probing the association between loss of Sept4 and accelerated transdifferentiation of HSCs. Methods: We compared the transcriptomes of Sept4+/+ and Sept4?/? HSCs by differential DNA microarray analysis and quantitative RT-PCR. Based on reduced dickkopf2 (Dkk2) gene expression in Sept4?/? HSCs, we tested whether supplementing Dkk2 could suppress myofibroblastic transformation of Sept4?/? HSCs. We used a lymphoid enhancer-binding factor/transcription factor-luciferase reporter assay to test whether Dkk2 can exert anti-fibrotic effects by interfering with the canonical Wnt pathway. Results: We observed consistent upregulation of Dkk2 in primary cultured HSCs and in a carbon tetrachloride hepatitis model in mice, which decreased with loss of Sept4. Supplementing Dkk2 suppressed the induction of pro-fibrotic genes (?-smooth muscle actin and 2 collagen genes) and induced an anti-fibrotic gene (Smad7) in Sept4?/? HSCs. In human liver specimens with inflammation and fibrosis, Dkk2 immunoreactivity appeared to be positively correlated with the degree of fibrotic changes. Conclusions: Pro-fibrotic transformation of HSCs through the loss of Sept4 is partly due to reduced expression of Dkk2 and its homologues, and the resulting disinhibition of the canonical Wnt pathway. We induced Liver Cirrhosis to SEPT4-KO or wild type mouse by CCl4, and examined mRNA expression profiling in hepatic stellate cell of these mouse.
2012-06-02 | E-GEOD-24588 | biostudies-arrayexpress
Project description:Liver fibrosis is a reversible wound-healing response to liver injury and hepatic stellate cells (HSCs) are central cellular players that mediate hepatic fibrogenesis. However, the molecular mechanisms that govern this process remain unclear. Here, we reveal a novel cistromic circuit in HSCs comprising the vitamin D receptor (VDR) and SMAD transcription factors that restrains the intensity of hepatic fibrogenesis. Ligand-activated VDR suppresses TGFβ1-induced pro-fibrotic gene expression in HSCs. Administration of a vitamin D analogue, calcipotriol, diminishes the fibrotic response in a mouse model of liver fibrosis, while VDR knockout mice spontaneous develop extensive hepatic fibrosis by age 6 months. Using ChIP-Seq, we find that the anti-fibrotic properties of VDR are due to crosstalk with SMAD, mediated by their co-occupancy of DNA-binding sites on pro-fibrotic genes. Specifically, SMAD binding potentiates local chromatin accessibility to enhance VDR recruitment at the same cis-regulatory elements, which reciprocally antagonizes the interaction between SMAD3 and chromatin and limits the assembly of transcriptional activation complexes at fibrotic genes, a process that is enhanced by the presence of VDR agonists. These results not only establish this coordinated VDR/SMAD cistromic circuit as a master regulator of hepatic fibrogenesis, but also support VDR as a potential drug target to ameliorate liver fibrosis. Identification of VDR, SMAD3 and H3 binding sites in human stellate LX2 cells that were pre-treated with calcipotriol (100nM) for 16 hrs (where calcipotriol treatment is indicated) followed by incubation of calcipotriol (100nM) or TGFβ1 (1ng/ml) for another 4 hours (where indicated).
2013-04-29 | E-GEOD-38103 | biostudies-arrayexpress
Project description:BACKGROUND & AIMS: Nonalcoholic steatohepatitis (NASH) is a chronic liver disease characterized by hepatic lipid accumulation, inflammation, and progressive fibrosis. Acetyl-CoA carboxylase (ACC) catalyzes the rate-limiting step of de novo lipogenesis and regulates fatty-acid beta-oxidation in hepatocytes. ACC inhibition reduces hepatic fat content and markers of liver injury in NASH patients; however, the effect of ACC inhibition on liver fibrosis has not been reported. METHODS: A direct role for ACC in fibrosis was evaluated by measuring de novo lipogenesis, procollagen production, gene expression, glycolysis, and mitochondrial respiration in hepatic stellate cells (HSCs) in the absence or presence of small-molecule inhibitors of ACC. ACC inhibitors were evaluated in rodent models of liver fibrosis induced by diet or the hepatotoxin, DEN. Fibrosis and hepatic steatosis were evaluated by histological and biochemical assessments. RESULTS: In TGF-beta-stimulated HSCs, ACC inhibition reduced activation and collagen production independent of mitochondrial beta-oxidation by blocking de novo lipogenesis. ACC inhibition prevented a metabolic switch necessary for induction of glycolysis and oxidative phosphorylation during HSC activation. Consistent with this direct anti-fibrotic mechanism in HSCs, ACC inhibition reduced liver fibrosis in a rat CDHFD model and in response to chronic DEN-induced liver injury that lacked hepatic lipid accumulation. CONCLUSIONS: In addition to reducing lipid accumulation in hepatocytes, ACC inhibition also directly impairs the pro-fibrogenic activity of HSCs. Small molecule inhibitors of ACC may reduce liver fibrosis by both reducing lipotoxicity in hepatocytes and directly reducing HSC activation, providing a mechanistic rationale for the treatment of patients with advanced liver fibrosis due to NASH.
2020-04-24 | GSE148849 | GEO
Project description:Liver fibrosis, characterized by the excessive deposition of extracellular matrix, presents a significant challenge due to its intricately complex and poorly understood mechanisms. In this study, we aimed to elucidate the roles of Minichromosome Maintenance Complex Component 7 (MCM7) and SHC SH2-Domain Binding Protein 1 (SHCBP1) in liver fibrosis, focusing on their regulatory networks and interactions. Stable hepatocyte cell lines with overexpression of MCM7 and SHCBP1 were constructed. Through targeted LC-MS analysis of MCM7, significant changes were observed in the protein interaction profiles, . MCM7 was found to interact with SHCBP1, which was further analyzed using LC-MS to detail its role in binding to RACGAP1. This interaction activates the SHCBP1-RACGAP1-STAT3 signaling axis, leading to increased IL11 expression. Elevated IL11 levels contribute to the activation of hepatic stellate cells (HSCs) and the progression of liver fibrosis. Our findings demonstrate that through mass spectrometry, MCM7 is identified as a crucial regulatory factor in liver fibrosis, promoting IL11 expression via the SHCBP1-RACGAP1-STAT3 signaling pathway. Both MCM7 and SHCBP1 involvement in driving HSC activation and fibrosis progression. Overall, our study highlights a mechanistic pathway where MCM7 and SHCBP1 collaborate to regulate IL11 expression, thereby influencing the progression of liver fibrosis. These insights emphasize the critical regulatory roles of MCM7 and SHCBP1, offering potential therapeutic targets for combating fibrotic liver diseases.
2025-08-09 | PXD055175 | Pride
Project description:Liver fibrosis has emerged as the primary determinant of outcomes in metabolic dysfunction associated steatohepatitis (MASH). Quiescent hepatic stellate cells (HSCs) differentiate into activated HSCs or myofibroblasts, which drives liver fibrosis and contribute to the progressive loss of hepatic function. However, the underlying mechanisms of autocrine signals driving and reversing HSC activation and fibrotic response within the liver microenvironment remains incompletely delineated. Here, through searching for cytokines highly enriched expression in HSCs compared to other liver cell types by single-cell transcriptomic analysis, we found that Gdf10 is specifically expressed in HSCs, whereas its protein levels were elevated during fibrosis associated with MASH and CCl4-induced liver injury. The functional importance of GDF10 in alleviating the progression of liver fibrosis was demonstrated using gain and loss of GDF10 function mice and cultured HSCs treated with GDF10. Furthermore, the novel HSC-targeted delivery strategy of Gdf10 mRNA in fibrosis mice reversed their fibrotic phenotypes. These results reveal a new regulatory pathway in MASH microenvironment, suggesting a promising strategy for delivering drugs that can shift HSC functions to restore HSC balance.
2025-12-04 | GSE303711 | GEO