Inhibitory Effects of Novel Oridonin Analog CYD0617‐2 on Hepatic Stellate Cell Activation through NF‐κB and Stat3 Pathways

Abstract

IntroductionInhibition of activated hepatic stellate cell (HSC) proliferation is recognized as a promising therapeutic strategy for liver fibrosis. Previously, we reported that natural compound oridonin exhibits potent anti‐hepatic fibrosis activity, and that NF‐κB and Stat3 signaling contribute to HSC activation. In this study, we determined the anti‐fibrotic effects of a novel oridonin analog CYD0617‐2 in activated HSCs and the underlying mechanism.MethodsThe activated human and rat HSC lines LX‐2 and HSC‐T6 were treated with CYD0617‐2. Cell viability was measured by alamarBlue assay. Apoptosis was determined by Cell death ELISA. Cellular proteins were analyzed with Western blot. Cytokines were determined with ELISA.ResultsCYD0617‐2 treatment significantly inhibited proliferation and induced apoptosis in both cell lines in a dose‐dependent manner approximately 10 fold more potent than the parent compound oridonin. CYD0617‐2 stimulated apoptotic proteins p21, p27, and cleaved‐PARP, while suppressing extracellular matrix proteins fibronectin and laminin. CYD0617‐2 blocked LPS‐induced NF‐κB p65 nuclear translocation and DNA binding activity, prevented LPS‐induced NF‐κB inhibitory protein IκBα phosphorylation and degradation, and suppressed LPS‐stimulated IKKα/β phosphorylation. LPS‐induced NF‐κB cytokines IL‐6, MCP‐1, and IL‐1β were attenuated by CYD0617‐2. The endogenous and LPS‐induced NF‐κB p65 S536 phosphorylation was inhibited by CYD0617‐2. Importantly, NF‐κB chemical inhibitor Bay‐11‐0782 was found to inhibit proliferation and promote apoptosis in both cell lines. Moreover, CYD0617‐2 attenuated Stat3 activation by suppressing pStat3/T705 phosphorylation and target gene c‐myc.ConclusionThe potent anti‐hepatic fibrogenetic effect of CYD0617‐2 may be through suppression of IKK/IκBα/NF‐κB and Stat3 pathway.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.