Laboratory of Liver Disease, Department of Infectious Disease, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China.
Central Laboratory, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China.
Life Sci. 2020 Jul 15;253:117572. doi: 10.1016/j.lfs.2020.117572. Epub 2020 Mar 19.
Liver fibrosis is a chronic liver disease characterized by hepatic stellate cell (HSC) activation. Peroxisome proliferator-activated receptor gamma (PPARγ) play an important role in HSC activation. This study aimed to investigate the role of PPARγ in the progression of human hepatic fibrosis and the mechanism by which microRNA-942 regulates HSC activation.
70 chronic hepatitis B (CHB) patients liver tissues were used to assess PPARγ, α-SMA and miR-942 levels by immunoblot and real-time PCR. Human primary HSCs or LX2 cells were used to perform multiple molecular experiments based on the transfection of small interfering RNA (siRNA) or co-transfection of microRNA inhibitor. Site-directed mutagenesis and luciferase reporter assays were used to identify miR-942 targets. miR-942 expression and localization in hepatic fibrosis and co-localization between α-SMA were determined by fluorescence in situ hybridization (FISH).
The mRNA expression of PPARγ was decreased in activated HSCs and CHB patients with liver fibrosis, which was negatively correlated with F stage and α-SMA. miR-942 negatively regulates PPARγ expression via targeting the PPARγ 3'UTR. Inhibiting PPARγ promoted TGFβ1 induced HSC activation, and this effect was blocked after inhibiting the miR-942. Moreover, miR-942 was mainly expressed in fibrous septa and negatively correlated with PPARγ in liver fibrosis.
PPARγ targeting by miR-942 and decreasing HSC activation in human hepatic fibrosis. Hence, regulating PPARγ may be a promising therapeutic strategy for hepatic fibrosis.
肝纤维化是一种以肝星状细胞（HSC）激活为特征的慢性肝病。过氧化物酶体增殖物激活受体γ（PPARγ）在 HSC 激活中起重要作用。本研究旨在探讨 PPARγ 在人肝纤维化进展中的作用以及 microRNA-942 调节 HSC 激活的机制。
采用免疫印迹和实时 PCR 检测 70 例慢性乙型肝炎（CHB）患者肝组织中 PPARγ、α-SMA 和 miR-942 的水平。根据转染小干扰 RNA（siRNA）或共转染 microRNA 抑制剂，用人原代 HSCs 或 LX2 细胞进行多项分子实验。通过定点突变和荧光素酶报告基因检测鉴定 miR-942 的靶标。采用荧光原位杂交（FISH）检测 miR-942 在肝纤维化中的表达和定位及其与 α-SMA 的共定位。
活化的 HSCs 和伴有肝纤维化的 CHB 患者中 PPARγ 的 mRNA 表达降低，与 F 分期和 α-SMA 呈负相关。miR-942 通过靶向 PPARγ 3'UTR 负调控 PPARγ 表达。抑制 PPARγ 促进 TGFβ1 诱导的 HSC 激活，而抑制 miR-942 可阻断此作用。此外，miR-942 主要在纤维间隔中表达，并在肝纤维化中与 PPARγ 呈负相关。
miR-942 靶向 PPARγ 并降低人肝纤维化中的 HSC 激活。因此，调节 PPARγ 可能是治疗肝纤维化的一种有前途的策略。
