FGF1 receptor antagonist decreases biliary proliferation, fibrosis, and senescence in a mouse model of chronic cholestasis

Abstract

BackgroundAcute or chronic cholestasis is a hallmark for a wide variety of liver diseases such as primary sclerosing cholangitis (PSC), alcoholic liver disease (ALD) and cholestasis of pregnancy. Available treatments for cholestasis are few and the subsequent scarring often necessitates the patients undergo a costly and risky liver transplantion. Fibroblastic growth factor 1 (FGF1) is involved in a wide range of cellular activities and has been previously shown to act in both a protective and detrimental manner as it participates in the fibrotic process of various tissue systems. Therefore, we aimed to evaluate the role of FGF1 in the progression of senescence, inflammation and fibrosis in an MDR−/− mouse model of PSC.MethodsFVB and MDR−/− mice were treated with 100ng/kg/day for 7‐days with the FGF receptor inhibitor, AZD4547. Liver, serum, and pure cholangiocytes were obtained. Hepatic fibrosis was evaluated by H&E and Sirius Red staining, and qPCR for collagen‐1a. The inflammatory response was evaluated by qPCR in pure cells for IL1‐b, IL‐6, and IL‐33 and immunofluorescent staining of F4/80. Biliary proliferation was determined through IHC CK‐19 expression and qPCR for Ki67 and PCNA. Senescence was evaluated by qPCR for p53, p18 and p21. FGFR expression was determined by qPCR. FGF1 serum expression was measured using a commercially available ELISA kit and in OCT liver sections by immunofluorescence (IF). In vitro, human intrahepatic biliary epithelial cells (HIBepiC) were treated with 150ng/ml of either FGF1 or AZD4547 with or without the presence of 100ng/ml of LPS for 24 hr before evaluating inflammatory markers, biliary proliferation and markers of fibrosis.ResultsAs expected, MDR−/− mice had a significant increase in biliary proliferation and fibrosis when compared to the FVB control. MDR−/− animals treated with AZD4547 experienced a significant reduction in fibrosis, with a subsequent decrease in collagen 1a1 gene expression. Treatment with AZD4547 also decreased senescence and inflammatory markers in MDR−/− mice evaluated by IHC and IF. Serum analysis showed a dramatic increase in FGF1 levels that were significantly reduced upon treatment. In vitro studies also had significant reductions in inflammatory and fibrotic markers.ConclusionFGF1 receptor antagonist decreased biliary proliferation, senescence, inflammation and fibrosis in cholangiocytes and surrounding liver in a mouse model of PSC. Targeting the FGFR pathway may provide a therapeutic option for patients suffering from various forms of chronic cholestasis such as PSC.Support or Funding InformationNIH RO1 DK110035R01 DK115184