Similar Datasets
Project description:The increased stiffness of the extracellular matrix is a key driver of liver fibrosis. The activated hepatic stellate cell (HSC) is the major producer of extracellular matrix (ECM) components. While little is known about the epigenomic changes that underlie the fibrogenic impact of ECM mechanics. In this study, we utilized a reliable in vitro system to mimic liver cirrhosis and integrated multi-omics analysis, which includes time-series RNA-seq and ATAC-seq as well as histone modification Cut&Tag, with imaging and biochemical essays to study the mechanism underlying the biomechanics function on fibrotic phenotype. We found that cells cultured in stiff matrix displayed more accessible chromatin sites, consisting of amount regions became accessible before stable fibrotic phenotype. We defined these regions as primed chromatin that chromatin accessibility foreshadows changes in gene expression. This kind of chromatin enriched in cytoskeleton organization and responding to mechanical stimulus biological process. Here, we depicted the AP-1 transcription factor family as being responsible for driving the construction of primed chromatin. Among AP-1 transcription factors, we confirmed JUN was critical to reconstruct chromatin accessibility to promote fibrogenic genotype. In addition, we described ERK contribute to the activation of JUN resulting in its binding on chromatin. Our results profiled a dynamic landscape of chromatin accessibility and defined the primed chromatin that contribute to fibrosis during responding to stiff matrix. We identified that AP-1 was capable of reorganizing the chromatin accessibility in mechanotransduction.
2023-08-05 | GSE240069 | GEO
Project description:Matrix stiffness modulates fibrogenesis in hepatic stellate cells through AP-1-induced chromatin priming
| PRJNA911197 | ENA
Project description:Matrix stiffness modulates fibrogenesis in hepatic stellate cells through AP-1-induced chromatin priming [ATAC-Seq]
| PRJNA1002239 | ENA
Project description:Liver fibrosis is characterised by a dense and highly cross-linked extracellular matrix (ECM) which promotes progression of diseases such as hepatocellular carcinoma. The fibrotic microenvironment is characterised by an increased stiffness, with rigidity associated with disease progression. External stiffness is known to promote hepatic stellate cell (HSC) activation through mechanotransduction, leading to increased secretion of ECM components. HSCs are key effector cells which maintain the composition of the ECM in health and disease, not only by regulating secretion of ECM proteins such as collagen, but also ECM-degrading enzymes called matrix metalloproteinases (MMPs) and their inhibitors (TIMPs). Uninhibited MMPs degrade ECM proteins to reduce external rigidity. Using fibronectin-coated polyacrylamide gels to alter substrate rigidity without altering ligand density, we show that fibrotic rigidities downregulate MMP-9 expression and secretion, and also upregulate secretion of TIMP-1, though not its expression. Using tissue immunofluorescence studies, we also report that the expression of MMP-9 is significantly decreased in activated HSCs in fibrotic tissues associated with hepatocellular carcinoma. This suggests the presence of a mechanical network that allows HSCs to maintain a fibrotic ECM, with external rigidity providing feedback which affects MMP-9 and TIMP-1 secretion, which may become dysregulated in fibrosis.
| S-EPMC6514003 | biostudies-literature
Project description:Hepatocytes are critical for the maintenance of liver homeostasis, but its involvement in hepatic fibrogenesis remains elusive. Hepatocyte nuclear factor 1? (HNF1?) is a liver-enriched transcription factor that plays a key role in hepatocyte function. Our previous study revealed a significant inhibitory effect of HNF1? on hepatocellular carcinoma. In this study, we report that the expression of HNF1? is significantly repressed in both human and rat fibrotic liver. Knockdown of HNF1? in the liver significantly aggravates hepatic fibrogenesis in either dimethylnitrosamine (DMN) or bile duct ligation (BDL) model in rats. In contrast, forced expression of HNF1? markedly alleviates hepatic fibrosis. HNF1? regulates the transcriptional expression of SH2 domain-containing phosphatase-1 (SHP-1) via directly binding to SHP-1 promoter in hepatocytes. Inhibition of SHP-1 expression abrogates the anti-fibrotic effect of HNF1? in DMN-treated rats. Moreover, HNF1? repression in primary hepatocytes leads to the activation of NF-?B and JAK/STAT pathways and initiates an inflammatory feedback circuit consisting of HNF1?, SHP-1, STAT3, p65, miR-21 and miR-146a, which sustains the deregulation of HNF1? in hepatocytes. More interestingly, a coordinated crosstalk between hepatocytes and hepatic stellate cells (HSCs) participates in this positive feedback circuit and facilitates the progression of hepatocellular damage. Our findings demonstrate that impaired hepatocytes play an active role in hepatic fibrogenesis. Early intervention of HNF1?-regulated inflammatory feedback loop in hepatocytes may have beneficial effects in the treatment of chronic liver diseases.
| S-EPMC4528057 | biostudies-literature
Project description:The hepatic stellate cells (HSCs) activation by myofibroblastic differentiation is critical for liver fibrosis. Crosstalk between stromal cells and tumor cells in the microenvironment alters the properties and facilitates the growth and metastasis of tumor cells. How mechanical stimuli originally stiffness of extracellular matrix (ECM) contribute to tumor development remains poorly understood. Here, we demonstrated that stiffness contributes to mechanosignal transduction in HSCs, which promotes hepatocellular carcinoma (HCC) cells growth and metastasis through secretion of FGF2. On stiffness matrix, HSCs activation was confirmed by immunofluorescence (IF) and Western blot (WB) for α-smooth muscle actin (SMA). Increasing matrix stiffness promoted HSCs activation by CD36-AKT-E2F3 mechanosignaling through shRNA-mediated E2F3 knockdown, AKT inhibitors, and CD36 shRNA. Moreover, ChIP-qPCR. Confirmed that E2F3 combined the promoter of FGF2, and stiffness promoted FGF2 expression. On a stiff matrix, HCC cells cultured with conditioned media (CM) from HSCs increased HCC cells growth and metastasis by binding FGFR1 to activate PI3K/AKT and MEK/ERK signaling pathways. Moreover, conditional E2F3 knockout mice were subjected to CCl4 treatment to assess the role of E2F3 in HSC activation. Additionally, the DEN-induced HCC model was also used to evaluate the role of E2F3 in liver fibrosis and HCC growth. In conclusion, we demonstrated that stiffness-induced HSC activation by E2F3 dependent. Stiffness activated CD36-AKT-E2F3 signaling and targeted FGF2 transcription, subsequently, activated HCC growth and metastasis by FGFR1-mediated PI3K/AKT and MEK/ERK signaling.
| S-EPMC8648844 | biostudies-literature
Project description:AimTo investigate the inhibitory effect of the natural product Leukamenin F on liver fibrosis and explore its potential underlying mechanisms.MethodsCarbon tetrachloride (CCl(4))-treated mouse model in vivo and in hepatic stellate cells (HSC) in vitro were used. The effect on CCl(4)-induced liver fibrosis was studied using histochemical and biochemical analysis, while the inhibition on HSC was assessed using cell proliferation/apoptosis assay and collagen I production using real-time PCR. The inhibitory effects of Leukamenin F on Akt/mTOR/p70S6K and TGFbeta/Smad pathways was studied using Western blot and cell image analysis.ResultsLeukamenin F (0.1-1 mg/kg, ip, q.d.x28) significantly reduced alpha-SMA and collagen specific Sirius red staining areas in CCl(4) -treated mouse livers. This compound at 1-2 micromol/L dose-dependently inhibited alpha-SMA expression, cell proliferation and type I procollagen mRNA expression in activated HSC. Furthermore it inhibited the Akt/mTOR/p70S6K pathway and suppressed TGFbeta -induced Smad2/Smad3 phosphorylation and nuclear translocation in HSC.ConclusionOur results demonstrated that Leukamenin F could attenuate CCl(4)-induced liver fibrogenesis in mice as an efficient inhibitor against both HSC proliferation and ECM production. This natural product provides a valuable structural hint for the development of anti-liver fibrosis reagents.
| S-EPMC4007723 | biostudies-literature
Project description:Understand mechanisms of NAFLD related liver fibrosis
2022-08-13 | GSE210966 | GEO
Project description:Liver fibrosis, the common response associated with chronic liver diseases, ultimately leads to cirrhosis, a major public health problem worldwide. Activation of hepatic stellate cells (HSCs) by transforming growth factor (TGF)-?1 is a key step in liver fibrosis. Here we report that Kindlin-2 expression is elevated in the livers of mice with experimental liver fibrosis and also in the livers of patients with liver fibrosis. TGF-?1 increases Kindlin-2 expression in cultured HSCs in a p38 and ERK mitogen-activated protein kinase (MAPK)-dependent manner, partly. More importantly, Kindlin-2 deficiency significantly attenuated mouse liver fibrosis and HSC activation. Mechanistically, Kindlin-2 promotes TGF-? signaling through upregulation of Smad2 and Smad3 phosphorylation. Our work demonstrates an important role for Kindlin-2 in liver fibrosis, and inhibiting Kindlin-2 in the livers may represent a novel strategy to treat liver fibrosis.
| S-EPMC6135746 | biostudies-literature
Project description:Background & aimsInterleukin-15 (IL-15) and its high affinity receptor interleukin-15 receptor alpha (IL-15Rα) are widely expressed in immune cells and hepatic resident cells. IL-15 signaling has important functions in homeostasis of natural killer (NK), natural killer T (NKT) and cytotoxic T (CD8(+) T) cells, and in liver regeneration. We hypothesized that IL-15 has a protective role in liver fibrosis progression by maintaining NK cell homeostasis.MethodsFibrosis was induced using two mechanistically distinct models. Congenic bone marrow transplantation was used to evaluate the contribution of IL-15 signaling from various compartments to NK, CD8(+) T and NKT cell homeostasis and fibrogenesis. The gene expression profile of hepatic stellate cell (HSC) from IL-15Rα knockout (IL-15RαKO) mice and wild-type mice were captured using microarray analysis and validated in isolated HSC. Quantitative real-time PCR was used to assess repressors of collagen transcription.ResultsIL-15RαKO mice exhibited more fibrosis in both models. IL-15 signaling from specific types of hepatic cells had divergent roles in maintaining liver NK, CD8(+) T and NKT cells, with a direct and protective role on radio-resistant non-parenchymal cells beyond the control of NK homeostasis. HSCs isolated from IL-15RαKO mice demonstrated upregulation of collagen production. Finally, IL-15RαKO HSC with or without transforming growth factor beta (TGF-β) stimulation exhibited increased expression of fibrosis markers and decreased collagen transcription repressors expression.ConclusionsIL-15Rα signaling has a direct anti-fibrotic effect independent of preserving NK homeostasis. These findings establish a rationale to further explore the anti-fibrotic potential of enhancing IL-15 signaling in HSCs.Lay summaryWe investigated how a cellular protein, Interleukin-15 (IL-15), decreases the amount of scar tissue that is formed upon liver injury. We found that IL-15 and its receptor decrease the amount of scar tissue that is created by specialized liver cells (called stellate cells) and increase the number of a specific subgroup of immune cells (natural killer cells) that are known to eliminate stellate cells.Transcript profiling accession numberGSE45612, GSE 68001 and GSE 25097.
| S-EPMC5048472 | biostudies-literature