1. Academic Validation
  2. β-Arrestin2 deficiency attenuates oxidative stress in mouse hepatic fibrosis through modulation of NOX4

β-Arrestin2 deficiency attenuates oxidative stress in mouse hepatic fibrosis through modulation of NOX4

  • Acta Pharmacol Sin. 2021 Jul;42(7):1090-1100. doi: 10.1038/s41401-020-00545-9.
Jia-Jia Du  # 1 Jia-Chang Sun  # 1 Nan Li  # 1 Xiu-Qin Li 1 Wu-Yi Sun 2 Wei Wei 3
Affiliations

Affiliations

  • 1 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Hefei, 230032, China.
  • 2 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Hefei, 230032, China. [email protected].
  • 3 Institute of Clinical Pharmacology, Anhui Medical University, Key Laboratory of Anti-inflammatory and Immune Medicine, Ministry of Education, Anhui Collaborative Innovation Center of Anti-inflammatory and Immune Medicine, Hefei, 230032, China. [email protected].
  • # Contributed equally.
Abstract

Hepatic fibrosis is a disease characterized by excessive deposition of extracellular matrix (ECM) in the liver. Activation of hepatic stellate cells (HSCs) is responsible for most of ECM production. Oxidative stress and Reactive Oxygen Species (ROS) may be important factors leading to liver fibrosis. NADPH Oxidase 4 (NOX4) is the main source of ROS in hepatic fibrosis, but the mechanism by which NOX4 regulates oxidative stress is not fully understood. β-Arrestin2 is a multifunctional scaffold protein that regulates receptor endocytosis, signaling and trafficking. In this study, we investigated whether β-arrestin2 regulated oxidative stress in hepatic fibrosis. Both β-arrestin2 knockout (Arrb2 KO) mice and wild-type mice were intraperitoneally injected with carbon tetrachloride (CCl4) to induce hepatic fibrosis. Arrb2 KO mice showed significantly attenuated liver fibrosis, decreased ROS levels and NOX4 expression, and reduced collagen levels in their livers. In vitro, NOX4 knockdown significantly inhibited ROS production, and decreased expression of alpha-smooth muscle actin in angiotensin II-stimulated human HSC cell line LX-2. Through overexpression or depletion of β-arrestin2 in LX-2 cells, we revealed that decreased β-arrestin2 inhibited ROS levels and NOX4 expression, and reduced collagen production; it also inhibited activation of ERK and JNK signaling pathways. These results demonstrate that β-arrestin2 deficiency protects against liver fibrosis by downregulating ROS production through NOX4. This effect appears to be mediated by ERK and JNK signaling pathways. Thus, targeted inhibition of β-arrestin2 might reduce oxidative stress and inhibit the progression of liver fibrosis.

Keywords

NOX4; ROS; SP600125; U0126; hepatic stellate cells; liver fibrosis; oxidative stress; α-SMA; β-arrestin2.

Figures
Products