Jing-Jing Yang1, Hui Tao2, Li-Ping Liu1, Wei Hu1, Zi-Yu Deng3, Jun Li4. 1. Department of Pharmacology, The Second Hospital of Anhui Medical University, Hefei, 230601, China. 2. Department of Cardiothoracic Surgery, The Second Hospital of Anhui Medical University, Hefei, 230601, China. 3. Department of Scientific, The Second Hospital of Anhui Medical University, Hefei, 230601, China. 4. School of Pharmacy, Anhui Medical University, Mei Shan Road, Hefei, Anhui, 230032, China. yncs01@hotmail.com.
Abstract
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 CCl4-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.
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 CCl4-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.
Authors: Thu Thao Pham; Jihye Ban; Yeojin Hong; Jiae Lee; Thi Hao Vu; Anh Duc Truong; Hyun S Lillehoj; Yeong Ho Hong Journal: Vet Res Date: 2020-02-03 Impact factor: 3.683