Project description:Over expression of PDGF-C in mouse liver resulted in the progression of hepatic fibrosis, steatosis and the development of HCC; this mouse model closely resembles the human HCC that is frequently associated with hepatic fibrosis. Peretinoin (generic name; code, NIK-333), developed by the Kowa Company, (Tokyo, Japan), is an oral acyclic retinoid (ACR) with a vitamin A-like structure that targets the retinoid nuclear receptor. Peretinoin effectively inhibits the progression of hepatic fibrosis and tumors in Pdgf-c Tg mice. Gene expression profiling was evaluated during the progression of hepatic fibrosis and tumors. After weaning at week 4, Pdgf-c Tg or non-transgenic WT mice were fed a basal diet or a diet containing+0.06% peretinoin respectively. At week 20, mice were sacrificed for the analysis of progression of hepatic fibrosis. At week 48, mice were sacrificed for the analysis of the development of hepatic tumors.
Project description:Over expression of PDGF-C in mouse liver resulted in the progression of hepatic fibrosis, steatosis and the development of HCC; this mouse model closely resembles the human HCC that is frequently associated with hepatic fibrosis. Peretinoin (generic name; code, NIK-333), developed by the Kowa Company, (Tokyo, Japan), is an oral acyclic retinoid (ACR) with a vitamin A-like structure that targets the retinoid nuclear receptor. Peretinoin effectively inhibits the progression of hepatic fibrosis and tumors in Pdgf-c Tg mice. Gene expression profiling was evaluated during the progression of hepatic fibrosis and tumors.
Project description:BCAA were administered to atherogenic and high-fat (Ath & HF) diet-induced nonalcoholic steatohepatitis (NASH) model mice and platelet-derived growth factor C transgenic mice (Pdgf-c Tg). Liver histology, tumor incidence, and gene expression profiles were evaluated. BCAA supplementation improved hepatic steatosis, inflammation, fibrosis, and tumors in the NASH mouse model, possibly through the modification of mTORC1 signaling.
Project description:Liver cirrhosis is a strong risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes patients to tumorigenesis are not well understood. Transgenic mice expressing platelet-derived growth factor C (Pdgf-c) under the control of the albumin promoter provide a unique animal model that mimics the step-wise disease progression in humans from fibrosis to HCC. The livers of Pdgf-c Tg mice show evidence of liver injury, including inflammation, proliferation, fibrosis and steatosis, and as the mice age, angiogenesis and dysplasia. Eighty-five percent of these mice develop HCC spontaneously, and have reduced survival that is related to their liver pathology. Through measurement of protein, RNA, and histological markers, we provide evidence to support the hypothesis that changes in liver stromal cells play an essential role in tumorigenesis in this model. A paracrine signaling model is proposed where ectopic expression of Pdgf-c in hepatocytes results in activation of hepatic stellate cells, which subsequently activates endothelial and Kupffer cells. Activation of these non-parenchymal cells promotes the release of hepatocyte growth factors that, together with changes in extracellular matrix, lead to the formation of HCC. Pdgf-c Tg mice provide a useful pre-clinical model in which to test novel drugs for chronic liver disease and HCC that focus on blocking the processes that alter the liver's fibrotic microenvironment. Two strains of mice, C57BL/6 and C57/BL6 Pdgf-c transgenic, were analyzed to see if liver stromal cells play an essential role in tumorigenesis.
Project description:Liver cirrhosis is a strong risk factor for the development of hepatocellular carcinoma (HCC), yet the mechanisms by which cirrhosis predisposes patients to tumorigenesis are not well understood. Transgenic mice expressing platelet-derived growth factor C (Pdgf-c) under the control of the albumin promoter provide a unique animal model that mimics the step-wise disease progression in humans from fibrosis to HCC. The livers of Pdgf-c Tg mice show evidence of liver injury, including inflammation, proliferation, fibrosis and steatosis, and as the mice age, angiogenesis and dysplasia. Eighty-five percent of these mice develop HCC spontaneously, and have reduced survival that is related to their liver pathology. Through measurement of protein, RNA, and histological markers, we provide evidence to support the hypothesis that changes in liver stromal cells play an essential role in tumorigenesis in this model. A paracrine signaling model is proposed where ectopic expression of Pdgf-c in hepatocytes results in activation of hepatic stellate cells, which subsequently activates endothelial and Kupffer cells. Activation of these non-parenchymal cells promotes the release of hepatocyte growth factors that, together with changes in extracellular matrix, lead to the formation of HCC. Pdgf-c Tg mice provide a useful pre-clinical model in which to test novel drugs for chronic liver disease and HCC that focus on blocking the processes that alter the liver's fibrotic microenvironment.
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:Rationale: RNA binding protein Apobec1 Complementation Factor (A1CF) regulates posttranscriptional ApoB mRNA editing but the range of RNA targets and long-term impact of altered A1CF expression on liver function are unknown. Objective: We studied hepatocyte-specific A1cf transgenic (A1cf +/Tg), A1cf+/Tg Apobec1– /– and A1cf –/– mice fed chow or high fat/high fructose diets using RNA-Seq, RNA-CLIP Seq and tissue microarrays from human hepatocellular cancer (HCC). Findings: A1cf +/Tg mice exhibited increased hepatic proliferation and steatosis, with increased lipogenic gene expression (Mogat1, Mogat2, Cidea, Cd36) associated with shifts in polysomal RNA distribution. Aged A1cf +/Tg mice developed spontaneous fibrosis, dysplasia and HCC, which was accelerated on a high fat/fructose diet and independent of Apobec1. RNA-Seq revealed increased expression of mRNAs involved in oxidative stress (Gstm3, Gpx3, Cbr3), inflammatory response (Il19, Cxcl14, Tnfα, Ly6c), extracellular matrix organization (Mmp2, Col1a1, Col4a1), proliferation (Kif20a, Mcm2, Mcm4, Mcm6) with a subset of mRNAs (including Sox4, Sox9, Cdh1) identified in RNA CLIP-Seq. Increased A1CF expression in human HCC correlated with advanced fibrosis and with reduced survival in a subset with nonalcoholic fatty liver disease. Conclusions: Hepatic A1CF overexpression selectively alters polysomal distribution and mRNA expression, promoting lipogenic, proliferative and inflammatory pathways leading to HCC.
Project description:Rationale: RNA binding protein Apobec1 Complementation Factor (A1CF) regulates posttranscriptional ApoB mRNA editing but the range of RNA targets and long-term impact of altered A1CF expression on liver function are unknown. Objective: We studied hepatocyte-specific A1cf transgenic (A1cf +/Tg), A1cf+/Tg Apobec1– /– and A1cf –/– mice fed chow or high fat/high fructose diets using RNA-Seq, RNA-CLIP Seq and tissue microarrays from human hepatocellular cancer (HCC). Findings: A1cf +/Tg mice exhibited increased hepatic proliferation and steatosis, with increased lipogenic gene expression (Mogat1, Mogat2, Cidea, Cd36) associated with shifts in polysomal RNA distribution. Aged A1cf +/Tg mice developed spontaneous fibrosis, dysplasia and HCC, which was accelerated on a high fat/fructose diet and independent of Apobec1. RNA-Seq revealed increased expression of mRNAs involved in oxidative stress (Gstm3, Gpx3, Cbr3), inflammatory response (Il19, Cxcl14, Tnfα, Ly6c), extracellular matrix organization (Mmp2, Col1a1, Col4a1), proliferation (Kif20a, Mcm2, Mcm4, Mcm6) with a subset of mRNAs (including Sox4, Sox9, Cdh1) identified in RNA CLIP-Seq. Increased A1CF expression in human HCC correlated with advanced fibrosis and with reduced survival in a subset with nonalcoholic fatty liver disease. Conclusions: Hepatic A1CF overexpression selectively alters polysomal distribution and mRNA expression, promoting lipogenic, proliferative and inflammatory pathways leading to HCC.
Project description:We used immunocompetent Fah-/- mice as the recipients and adoptively transferred HBsAg+ hepatocytes from HBs-Tg mice to replace the recipient hepatocytes (HBs-HepR). HBs-HepR mice maintained persistent HBsAg expression with chronic hepatitis and spontaneous liver fibrosis, and eventually developed HCC with a prevalence of 100%.
Project description:We used immunocompetent Fah-/- mice as the recipients and adoptively transferred HBsAg+ hepatocytes from HBs-Tg mice to replace the recipient hepatocytes (HBs-HepR). HBs-HepR mice maintained persistent HBsAg expression with chronic hepatitis and spontaneous liver fibrosis, and eventually developed HCC with a prevalence of 100%.