Project description:Analysis of hepatic stellate cells isoltaed from wild-type, TLR4-/-, and CD44-/- mice. TLR4 and CD44 are major hyaluronic acid receptors. Results provide insight into the effects of TLR4 and CD44 loss in hepatic stellate cells.
Project description:Analysis of hepatic stellate cells (HSCs) isoltaed from ASMA-HAS2 transgenic and HSC-specific Has2 knockout mice. HAS2 synthesized hyaluronic acid, one of major extracellular matrix. Results provide insight into the role of HAS2 in hepatic stellate cells.
Project description:Gene expression of mouse hepatic stellate cells was characterized under the following conditions: Quiescent (isolated from normal mouse liver) and reverted (isolated from mouse liver treated with 4 injections of carbontetrachloride followed by 45 day rest period) Affymetrix Mouse 1.0ST gene expression measurements were used to characterize the transcriptomic basis in quiescent hepatic stellate cells, isolated from normal liver, and reverted hepatic stellate cells, isolated from liver treated with 4 injections of CCl4 followed by a 45 day rest period. Gene expression of mouse hepatic stellate cells was characterized under the following conditions: A. Quiescent control hepatic stellate cells (n=4). B. Reverted hepatic stellate cells (n=4).
Project description:Background: Advanced hepatic fibrosis is a pivotal event leading to cirrhosis and hepatocellular carcinoma (HCC). We identified osteopontin (SPP1) as a fibrosis-associated gene through transcriptome and immunohistochemical analyses and investigated its role in intratumoral fibrosis and HCC development. Methods: Gene expression analysis was conducted using publicly available datasets to screen for fibrosis-related genes. Immunohistochemical staining was performed on HCC samples to assess SPP1 expression and its correlation with fibrosis and prognosis. The biological effects of SPP1 overexpression (SPP1-OE) in HCC cells were examined in xenograft mouse models. Co-culture assay with hepatic stellate cells (HSCs) and single-cell RNA sequencing (scRNA-seq) analysis were used to explore HCC-HSC interactions. Results: Transcriptomic and prognostic analyses revealed that SPP1 was significantly upregulated in fibrotic HCC tissues and associated with unfavorable outcomes. Immunohistochemical analysis confirmed a strong correlation between SPP1 expression and intratumoral fibrosis. In xenograft models, SPP1-OE HCC cells exhibited enhanced tumor growth and extensive fibrosis. Co-culture assay demonstrated that SPP1-OE cells stimulated HSCs, and gene set enrichment analysis and differential gene expression analysis elucidated activation of the Hedgehog signaling pathway and upregulation of GLI1 in HSCs. scRNA-seq analysis discovered SPP1-CD44 signaling transduction as a key mediator of HSC activation. Pharmacological inhibition of GLI1 with the SMO inhibitor vismodegib suppressed HSC activation in vitro and reduced fibrosis and tumor growth in vivo. Conclusions: SPP1 promotes intratumoral fibrosis and HCC progression through the SPP1-CD44-GLI1 axis, highlighting its potential as a prognostic biomarker and therapeutic target. Inhibition of Hedgehog signaling may provide a promising strategy to mitigate fibrosis and improve HCC patient outcomes.
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:RNA sequencing of LX2 cell line (a human hepatic stellate cell line). METTL3 overexpression or downreguation were achieved by lenti-virus transduction.