Department of Liver Surgery, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu Province, China.
Key Laboratory of Living Donor Liver Transplantation of Ministry of Public Health, Nanjing, Jiangsu Province, China.
J Cell Mol Med. 2017 Dec;21(12):3679-3692. doi: 10.1111/jcmm.13278. Epub 2017 Aug 1.
We explored the role of microRNA-30a (miR-30a) and the mechanism involved in hepatic fibrosis. MiR-30a overexpression was achieved by miR-30a mimics transfection in hepatic stellate cells (HSCs) (HSC-T6, LX-2), and miR-30a agomir (ago-miR-30a) treatment in mice. MiR-30a levels were measured using TaqMan miRNA assay system, and the localization of miR-30a was detected by fluorescence in situ hybridization (FISH). The interaction of miR-30a and Beclin1 was confirmed by dual-luciferase reporter assay. Autophagic flux was analysed using tandem mRFP-GFP-LC3 fluorescence microscopy, electron microscopy and Western blot of LC3-II/I ratio. MiR-30a was notably down-regulated in activated HSCs and LX-2-exosomes induced by TGF-β1; overexpression of miR-30a down-regulated extracellular matrix (ECM), such as α-SMA, TIMP-1, and Collagen I expression, and suppressed cell viability in HSCs. MiR-30a was significantly down-regulated in hepatic fibrosis mice and overexpression of miR-30a prevented BDL-induced fibrogenesis, concomitant with the down-regulation of ECM. MiR-30a inhibited HSCs autophagy and increased lipid accumulation in HSCs and in mice fibrotic hepatic tissues. MiR-30a inhibited its downstream effector of Beclin1 by direct targeting its 3'-UTR region. Moreover, Knock-down of Beclin1 by small interfering RNA (siRNA) inhibited HSC autophagy and activation in LX-2 cells. In conclusion, miR-30a is down-regulated in hepatic fibrosis models and its overexpression prevents liver fibrogenesis by directly suppressing Beclin1-mediated autophagy; therefore, miR-30a may be a new potential therapeutic target for controlling hepatic fibrosis.
我们探索了 microRNA-30a(miR-30a)在肝纤维化中的作用及其相关机制。通过 miR-30a 模拟物转染肝星状细胞(HSCs)(HSC-T6、LX-2)实现 miR-30a 过表达,并用 miR-30a agomir(ago-miR-30a)处理小鼠。使用 TaqMan miRNA 分析系统测量 miR-30a 水平,并通过荧光原位杂交(FISH)检测 miR-30a 的定位。通过双荧光素酶报告基因检测证实 miR-30a 与 Beclin1 的相互作用。使用串联 mRFP-GFP-LC3 荧光显微镜、电子显微镜和 LC3-II/I 比值的 Western blot 分析自噬流。miR-30a 在 TGF-β1 诱导的活化 HSCs 和 LX-2-exosomes 中显著下调;miR-30a 的过表达下调细胞外基质(ECM),如α-SMA、TIMP-1 和 Collagen I 的表达,并抑制 HSCs 的细胞活力。miR-30a 在肝纤维化小鼠中显著下调,过表达 miR-30a 可预防 BDL 诱导的纤维化形成,同时下调 ECM。miR-30a 抑制 HSCs 自噬并增加 HSCs 和小鼠纤维化肝组织中的脂质堆积。miR-30a 通过直接靶向其 3'-UTR 区域抑制其下游效应物 Beclin1。此外,通过小干扰 RNA(siRNA)敲低 Beclin1 可抑制 LX-2 细胞中的 HSC 自噬和活化。总之,miR-30a 在肝纤维化模型中下调,其过表达通过直接抑制 Beclin1 介导的自噬来预防肝纤维化发生;因此,miR-30a 可能是控制肝纤维化的新的潜在治疗靶点。