HDAC Inhibitor Givinostat Targets HSC Activation To Prevent NASH And Liver Fibrosis

Background: Non-alcoholic steatohepatitis(NASH)and liver fibrosis are huge challenges facing clinical practice today,and there is currently no effective prevention and treatment method.Therefore,it is particularly important to explore new targets and strategies for the prevention and treatment of NASH and liver fibrosis.Based on the key role of targeted hepatic stellate cells(HSCs)in the treatment of liver fibrosis and the role of epigenetic mechanisms in HSC activation,a high-throughput screening method based on cells was used to screen small molecule compounds in the epigenetic inhibitor library Early screening studies have found that the HDAC inhibitor givinostat can strongly inhibit HSC activation,suggesting that givinostat may have a therapeutic effect on NASH and liver fibrosis.Objective:(1)To explore the effect and mechanism of givinostat on carbon tetrachloride(CCL4)-induced liver fibrosis in mice;(2)To explore the effect and mechanism of givinostat on NASH and related liver fibrosis in mice.Methods: Transforming growth factor-β(TGF-β)-induced hepatic stellate cell line LX2 was used as the HSC-activated cell model,and RAW 264.7 was used as the inflammatory cell model;CCL4 and choline / methionine-deficient feed(MCD)or high-fat diets,respectively(HFD)feeding to construct two mouse models of liver fibrosis;the effects and mechanisms of givinostat intervention on HSC activation,NASH,and liver fibrosis using biochemical detection,cell histopathology,highthroughput sequencing,and molecular biology detection.Results:(1)Compared with the model group,immunohistochemical and Western blot tests showed that givinostat significantly inhibited HSC a-SMA and col1 a gene expression in vitro and in vivo,and biochemical tests and histopathology showed that givinostat intervention can significantly improve CCL4-induced mice Liver fibrosis;high-throughput sequencing and RT-q PCR verified that DMKN,MSLN,and UPK3 B are the three genes that are most significantly down-regulated during blockade of HSC activation by givinostat.Knockdown DMKN,MSLN,and UPK3 B have also been shown to significantly inhibit TGF-β-induced HSC activation;(2)Compared with the model group,Western blot and RT-q PCR showed that givinostat intervention can significantly increase the levels of histone H3 and H4 acetylation of macrophages,and inhibit the expression of proinflammatory cytokines and chemokines in liver macrophages and NASH liver tissues;Decrease NAS score and improve NASH-related liver fibrosis;High-throughput sequencing shows that the most significant signaling pathways of givinostat intervention involve metabolism and inflammation,givinostat can inhibit inflammation-related genes such as TNF-a,MCP-1,IL-6,and CXCL2,CCL5 and fatty acid synthesis genes FAS,SREBP-1C,SCD1 expression;up-regulation of fatty acid β oxidation-related genes such as CYP7 A,ACOX1,COX5 a,UCP2 and PDK4 expression.Conclusion:(1)Givinostat can inhibit the expression of HSC DMKN,MSLN and UPK3 B by up-regulating the level of histone acetylation,inhibit HSC activation and improve the experimental liver fibrosis induced by CCL4 in mice;(2)givinostat can promote fatty acid β oxidation by inhibiting fatty acid synthesis in liver cells Inhibiting the expression of proinflammatory cytokines and chemokines in liver macrophages,reducing liver tissue inflammation and steatosis,and inhibiting HSC activation,thereby improving NASH and related liver fibrosis,suggesting that givinostat has the potential to become a prevention and treatment of NASH and liver fibrosis Innovative drugs.