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

• Published in: Acta pharmacologica Sinica 2021-07, Vol.42 (7), p.1090-1100
• Main Authors: Du, Jia-jia, Sun, Jia-chang, Li, Nan, Li, Xiu-qin, Sun, Wu-yi, Wei, Wei
• Format: Article
• Language: English
• Subjects: Actin; Angiotensin; Angiotensin II; Animals; Arrestin; beta-Arrestin 2 - deficiency; beta-Arrestin 2 - genetics; Biomedical and Life Sciences; Biomedicine; Carbon Tetrachloride; Cell activation; Collagen; Collagen - metabolism; Down-Regulation - physiology; Endocytosis; Extracellular matrix; Fibrosis; Gene Knockout Techniques; Immunology; Internal Medicine; Liver; Liver Cirrhosis - chemically induced; Liver Cirrhosis - metabolism; Liver Cirrhosis - pathology; Liver diseases; Matrix Metalloproteinase 13 - metabolism; Medical Microbiology; Mice; Mice, Inbred C57BL; Mice, Knockout; NAD(P)H oxidase; NADPH Oxidase 4 - metabolism; NOX4 protein; Oxidative stress; Oxidative Stress - physiology; Pharmacology/Toxicology; Reactive oxygen species; Reactive Oxygen Species - metabolism; Signal transduction; Signal Transduction - physiology; Smooth muscle; Stellate cells; Tissue Inhibitor of Metalloproteinase-1 - metabolism; Vaccine
• ISSN: 1671-4083; 1745-7254
• DOI: 10.1038/s41401-020-00545-9

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 ( Arrb 2 KO) mice and wild-type mice were intraperitoneally injected with carbon tetrachloride (CCl 4 ) to induce hepatic fibrosis. Arrb 2 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.