miR-200a controls hepatic stellate cell activation and fibrosis via SIRT1/Notch1 signal pathway

• Published in: Inflammation research Vol. 66; no. 4; pp. 341 - 352
• Main Authors: Yang, Jing-Jing, Tao, Hui, Liu, Li-Ping, Hu, Wei, Deng, Zi-Yu, Li, Jun
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01.04.2017; Springer Nature B.V
• Subjects: Allergology; Animals; Biomedical and Life Sciences; Biomedicine; Cell Line; Cell Proliferation; Dermatology; Hepatic Stellate Cells - metabolism; Immunology; Liver - metabolism; Liver - pathology; Liver Cirrhosis - metabolism; Liver Cirrhosis - pathology; Male; MicroRNAs - genetics; Neurology; Original Research Paper; Pharmacology/Toxicology; Rats, Sprague-Dawley; Receptor, Notch1 - genetics; Receptor, Notch1 - metabolism; Rheumatology; RNA Interference; Signal Transduction; Sirtuin 1 - genetics; Sirtuin 1 - metabolism; Transforming Growth Factor beta1; MicroRNA-200a; Hepatic stellate cells; Liver fibrosis
• ISSN: 1023-3830; 1420-908X
• DOI: 10.1007/s00011-016-1020-4

Objectives miR-200a has been established as a key regulator of HSC activation processes in liver fibrosis. Epigenetic silencing of miR-200a contributing to SIRT1 over-expression has been discussed in breast cancer; however, whether miR-200a controls SIRT1 gene expression in hepatic fibrosis is still unknown. Methods and materials We analyzed miR-200a regulation of SIRT1 expression in CCl 4 -induced liver fibrosis and TGF-β1-mediated activation of HSC. miR-200a, SIRT1, α-SMA, Col1A1, Notch1 and NICD expression were estimated by Western blotting, qRT-PCR and Immunohistochemistry. HSCs were transfected with miR-200a mimic, miR-200a inhibitor and SIRT1-RNAi. Luciferase reporter assays further confirmed the interaction between miR-200a and the SIRT1 mRNA 3'-UTR. Cell proliferation ability was assessed by MTT and cell cycle. Results We found that treatment activated HSC with miR-200a mimics, restored miR-200a expression and reduced SIRT1 levels. Conversely, treatment activated HSC with miR-200a inhibitors, decreased miR-200a expression and up-regulated SIRT1 levels. Restoration of miR-200a or the knockdown of SIRT1 prevented HSC activation and proliferation. We have established the SIRT1 transcript as subject to regulation by miR-200a, through miR-200a targeting of SIRT1 3’-UTR. Finally, HSC transfected with SIRT1-siRNA increased the levels of Notch1 protein and mRNA expression. Conclusions Our study demonstrated that miR-200a regulates SIRT1/Notch1 expression during HSC activation and fibrosis.