Department of Gastroenterology/Hepatology, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuhan, 430071, Hubei, China.
The Hubei Clinical Center and Key Laboratory of Intestinal and Colorectal Diseases, Wuhan, 430071, Hubei, China.
Dig Dis Sci. 2021 Jan;66(1):143-150. doi: 10.1007/s10620-020-06174-w. Epub 2020 Mar 7.
The transformation of hepatic stellate cells (HSCs) into collagen-producing myofibroblasts is a key event in hepatic fibrogenesis. Recent studies have shown that microRNAs (miRNAs) play a critical role in the transformation of HSCs. However, the function of miR-489-3p in liver fibrosis remains unclear.
Here, we detected the levels of miR-489-3p and jagged canonical Notch ligand 1 (JAG1) in liver fibrosis by using CCl4-treated rats as an in vivo model and transforming growth factor-beta 1 (TGF-β1)-treated HSC cell lines LX-2 and HSC-T6 as in vitro models. The expression of profibrotic markers was affected by transfecting LX-2 cells with either miR-489-3p mimic or si-JAG1. A dual-luciferase reporter assay was carried out to study the interaction of JAG1 with miR-489-3p.
We found that miR-489-3p was remarkably decreased while JAG1 was increased in liver fibrosis models both in vivo and in vitro. Overexpression of miR-489-3p reduced the expression of profibrotic markers and the activation of LX-2 cells induced by TGF-β1. Moreover, miR-489-3p decreased the expression of jagged canonical Notch ligand 1 (JAG1) in LX-2 cells by interacting with its 3'-UTR. As JAG1 is a Notch ligand, decreased JAG1 by miR-489-3p inhibited the Notch signaling pathway. Moreover, the downregulation of JAG1 inhibited the expression of fibrotic markers.
Our results indicate that miR-489-3p can inhibit HSC activation by inhibiting the JAG1/Notch3 signaling pathway.
肝星状细胞（HSCs）向胶原产生的肌成纤维细胞的转化是肝纤维化发生的关键事件。最近的研究表明，微小 RNA（miRNA）在 HSCs 的转化中起着关键作用。然而，miR-489-3p 在肝纤维化中的功能尚不清楚。
在这里，我们使用 CCl4 处理的大鼠作为体内模型和转化生长因子-β1（TGF-β1）处理的 LX-2 和 HSC-T6 肝星状细胞系作为体外模型，检测了肝纤维化中 miR-489-3p 和 Jagged 经典 Notch 配体 1（JAG1）的水平。通过转染 miR-489-3p 模拟物或 si-JAG1 转染 LX-2 细胞来影响纤维化标志物的表达。进行双荧光素酶报告基因测定以研究 JAG1 与 miR-489-3p 的相互作用。
我们发现，miR-489-3p 在体内和体外的肝纤维化模型中均显著降低，而 JAG1 则增加。miR-489-3p 的过表达降低了 TGF-β1 诱导的 LX-2 细胞中纤维化标志物的表达和激活。此外，miR-489-3p 通过与其 3'-UTR 相互作用降低了 LX-2 细胞中 Jagged 经典 Notch 配体 1（JAG1）的表达。由于 JAG1 是 Notch 配体，因此 miR-489-3p 降低 JAG1 抑制了 Notch 信号通路。此外，JAG1 的下调抑制了纤维化标志物的表达。
我们的结果表明，miR-489-3p 通过抑制 JAG1/Notch3 信号通路抑制 HSC 激活。
