Project description:Analysis of human hepatic stellate cell line LX2 stimulated for 24h in serum-free DMEM medium containing 0 or 50 ng/ml recombinant human GDF2 protein. Results provide insight into the activation effects of GDF2 on human hepatic stellate cell. We used microarrays to detail the global programme of gene expression underlying activation of hepatic stellate cells and identified liver-fibrosis-related genes genes during this process.
Project description:Expression of LIX1L is increased in fibrotic livers and associated with liver fibrosis stage. We investigated whether increased LIX1L expression promotes Hepatic stellate cells (HSCs) activation and liver fibrosis progression by interacting with Chemokine signaling pathway.
Project description:In this survey we effectively combined transcriptomics, proteomics and targeted-metabolomics to analyse the temporal relationship of alterations in liver preceding and accompanying the development of HFD-mediated hepatic insulin resistance. To assess HFD-mediated alterations in physiological parameters, insulin sensitivity, and molecular adaptations in liver male C3HeB/FeJ mice treated with a high-fat diet (HFD) for 7, 14, or 21 days and compared to age- matched controls fed low-fat diet (LFD). Data indicate early systemic increases in pro-inflammatory signals, in hepatic DAG but not hepatic TAG concentrations prior to development of hepatic insulin resistance. We propose a hypothesis via which a HFD-mediated increase in the hepatic long-chain acyl-carnitine moiety in liver alters mitochondrial membrane physiology and beta-oxidation rates, thereby contributing to oxidative stress and the development of insulin resistance in liver. Alterations in the enrichment of respiratory chain complex proteins, substrate transporters, VDACs, and long-chain carnitines in mitochondrial membranes likely affect mitochondrial membrane topology, membrane dynamics (fission and fusion) and bioenergetics as well as the cross-talk between the mitochondria and other cellular compartments. In conclusion, we emphasize a tight association between HFD-induced early modifications in the organisation of mitochondrial membranes paving the road for hepatic insulin resistance.
Project description:We study the effect of Treg cell-derived Areg on hepatic stellate cells. Here we look at the transcriptional effect of Areg on hepatic stellate cells in vitro.
Project description:Background & Aims: Rapid induction of beta-PDGF receptor (beta-PDGFR) is a core feature of hepatic stellate cell activation, the hallmark of liver fibrogenesis. However, biological consequences of the induction are not well characterized. We aimed to determine the involvement of beta-PDGFR-mediated molecular pathway activation on hepatic stellate cells in liver injury, fibrogenesis, and carcinogenesis in vivo. Methods: Loss and constitutive activation of beta-PDGFR were assessed in mouse models with either a stellate cell-specific beta-PDGFR knockout or the expression of an autoactivating mutation respectively. Liver injury and fibrosis were induced in two mechanistically distinct models: carbontetrachloride (CCl4) treatment and ligation of the common bile duct. Hepatocarcinogenesis with underlying liver injury/fibrosis was assessed by a single dose of diethylnitrosamine (DEN) followed by repeated injections of CCl4. Genome-wide expression profiling was performed isolated stellate cells from these models to determine deregulated pathways. Results: Depletion of beta-PDGFR in hepatic stellate cells led to decreased histological liver injury, serum transaminases, collagen alpha 1(I) and alpha smooth muscle actin expression, and collagen deposition. Stellate cell proliferation was significantly reduced after acute hepatic injury in vivo. In contrast, autoactivation of beta-PDGFR in stellate cells accelerated liver fibrosis, most prominently after 6 weeks of CCl4 induced injury. There was no difference in development of DEN-induced pre-neoplastic loci according to the status of beta-PDGFR. Conclusions: Depletion of beta-PDGFR in hepatic stellate cells attenuated the development of liver injury, fibrosis, and stellate cell proliferation in multiple animal models, whereas the constitutive activation of beta-PDGFR enhanced fibrosis. However, manipulation of beta-PDGFR alone did not reduce development of dysplastic nodules. These findings indicate that titration of receptor beta-PDGFR expression on stellate cells parallels fibrosis and injury, but may not impact the development of hepatic neoplasia alone. Hepatic stellate cells were isolated from liver of beta-PDGFR-wild-type or knockout mice, and treated with beta-PDGF ligand or vehicle control.
Project description:We report the effect of TGFβ vs PDGF 2h treatment in hepatic stellate cells. We also report the effect of TGFβ treatment for 48h in human hepatic stellate cells.
Project description:The activation of hepatic stellate cells (HSC) plays a crucial role in non-alcoholic fatty liver disease (NAFLD), which could further develop to non-alcoholic steatohepatitis (NASH) and liver fibrosis/cirrhosis. Since cGMP-dependent protein kinase 1 (cGK1) deficient (cGK1-KO) mice displayed hepatic insulin resistance we hypothesized that cGK1 modulates HSC activation and its metabolic consequences. First, retinol storage and gene expression were studied in cGK1-KO mice. Second, we investigated the effects of cGK1-silencing on gene expression in the human stellate cell line LX2. Finally, cGK1 expression was investigated in human liver biopsies covering a wide range of liver fat content. Retinyl-ester level in the liver of cGK1-KO mice was lower compared to wild-type animals, which was associated with increased inflammatory gene expression. mRNA regulation in cGK1-silenced LX2 cells showed stronger stellate cell activation profile, altered matrix degradation and elevated chemokine level. On the other hand, activation of LX2 cells suppressed cGK1 expression, which was associated with human data, showing a negative correlation between cGK1 mRNA and liver fat content in liver biopsies. These results suggest that the lack of cGK1 could possibly lead to stellate cell activation, which elevates chemokine expression and inflammatory processes, which in turn disturbs hepatic insulin sensitivity.
Project description:Background: The farnesoid X receptor (FXR) is a leading therapeutic target for MASH-related fibrosis. INT-767, a potent FXR agonist, has shown promise in preclinical models. We aimed to define the mechanisms of INT-767 activity in experimental MASH and dissect cellular and molecular targets of FXR agonism in human disease. Methods: Leptin-deficient ob/ob mice were fed a MASH-inducing diet for 15 weeks prior to study start. After baseline liver biopsy and stratification, mice were allocated to INT-767 (10 mg/kg/day) or vehicle treatment for 8 weeks, either alongside ongoing MASH diet (progression) or following conversion to normal chow (reversal). Effects on extracellular matrix remodelling were analyzed histologically and by RNA-sequencing. Serum fibrosis biomarkers were measured longitudinally. Human liver samples were investigated using bulk and single-cell RNA-sequencing, histology, and cell culture assays. Results: INT-767 treatment was antifibrotic during MASH progression but not reversal, attenuating accumulation of type I collagen and basement membrane proteins (type IV collagen, laminin). Circulating levels of PRO-C4, a type IV collagen formation marker, were reduced by INT-767 treatment and correlated with fibrosis. Expression of basement membrane constituents also correlated with fibrosis severity and adverse clinical outcomes in human MASH. Single-cell RNA-sequencing analysis of mouse and human livers, and immunofluorescence staining colocalized FXR and basement membrane expression to myofibroblasts within the fibrotic niche. Treatment of culture-activated primary human hepatic stellate cells with INT-767 decreased expression of basement membrane components. Conclusion: These findings highlight the importance of basement membrane remodelling in MASH pathobiology and as a source of circulating biomarkers. Basement membrane deposition by activated hepatic stellate cells is abrogated by INT-767 treatment and measurement of basement membrane molecules should be included when determining the therapeutic efficacy of FXR agonists.