Chrysophanol Prevents Lipopolysaccharide-Induced Hepatic Stellate Cell Activation by Upregulating Apoptosis, Oxidative Stress, and the Unfolded Protein Response.

Jiunn-Sheng Wu,Valeria Chiu,Ming-Chieh Wang,I.-Shiang Tzeng,Po-Chun Hsieh,Chan-Yen Kuo,Chou-Chin Lan

doi:10.1155/2020/8426051

Abstract

Hepatic stellate cell (HSC) activation is a vital driver of liver fibrosis. Recent research efforts have emphasized the clearance of activated HSCs by apoptosis, senescence, or reversion to the quiescent state. LPS induces human HSC activation directly and contributes to liver disease progression. Chrysophanol is an anthraquinone with hepatoprotective and anti-inflammatory effects. This study aimed to investigate the pharmacological effects and mechanisms of chrysophanol in an LPS-induced activated rat HSC cell line (HSC-T6). The fibrosis phenotype was identified from the expression of α-smooth muscle actin (α-SMA), connective tissue growth factor (CTGF), and integrin β1 by western blot analysis. We examined DNA fragmentation by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining. We detected the apoptotic markers p53 and cleaved caspase-3 by western blot analysis. Intracellular ROS were labeled with 2′,7′-dichlorofluorescein diacetate (DCF-DA) and the levels were measured by flow cytometry. Finally, we evaluated the ER stress markers binding immunoglobulin protein (BiP) and C/EBP homologous protein (CHOP) by Western blot analysis. Our results showed that chrysophanol decreased HSC-T6 cell viability in LPS-induced activated HSCs. Chrysophanol increased the expression of α-SMA, CTGF, integrin βI, p53, cleaved caspase-3, and DNA fragmentation. Chrysophanol also elevated ROS levels and increased the expression of BiP and CHOP. Pretreatment with chrysophanol prevented LPS-induced HSC-T6 cell activation by upregulating apoptosis, ROS accumulation, unfolded protein response (UPR) activation, and the UPR proapoptotic effect.

Highlights

Liver fibrosis is a global health burden that significantly elevates the risk of developing liver cirrhosis and hepatocellular carcinoma (HCC) [1]
We evaluated the expression of α-smooth muscle actin (α-SMA) by Western blot analysis
Our results indicated that LPS induced significantly increased expression of α-SMA in the LPS group compared with that in the control group (p < 0.05). e Cho + LPS group showed significantly decreased expression of α-SMA compared with the LPS group (p < 0.05) (Figure 1). e results suggested that chrysophanol pretreatment had a preventive effect on LPS-induced activation in Hepatic stellate cell (HSC)-T6 cells

Summary

Introduction

Liver fibrosis is a global health burden that significantly elevates the risk of developing liver cirrhosis and hepatocellular carcinoma (HCC) [1]. Hepatic stellate cell (HSC) activation is considered to be a vital driver of liver fibrosis [2]. Activated proliferative myofibroblast-like phenotype HSCs result from liver injury and show specific changes, including upregulated proliferation, contractility, fibrogenesis, altered matrix degradation, chemotaxis, and inflammatory signaling [2]. Ese processes accumulate extracellular matrix (ECM) (including α-smooth muscle actin (α-SMA) and type I and III collagens), leading to liver fibrosis [2,3,4]. Evidence-Based Complementary and Alternative Medicine factor-beta 1 (TGFβ1), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and connective tissue growth factor (CTGF)); (2) HSC-ECM interaction (integrin β1 and discoidin domain receptors (DDRs)); (3) the unfolded protein response (UPR); (4) oxidative stress; and (5) apoptosis signaling [2]. Several pharmacological agents have been demonstrated to target HSC activation, but none has been applied in clinical practice [2, 5]

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