Department of Gastroenterology, Shanghai Songjiang District Central Hospital, Shanghai, China.
Department of Gastroenterology, Songjiang Hospital Affiliated to Shanghai Jiao Tong University School of Medicine (Preparatory Stage), Shanghai, China.
Mol Cell Biochem. 2020 Feb;465(1-2):115-123. doi: 10.1007/s11010-019-03672-y. Epub 2019 Dec 21.
Increasing studies have indicated that hypoxia serves as a pivotal microenvironmental factor that facilitates activation of hepatic stellate cells (HSCs). However, the mechanism by which hypoxia activates HSCs is not clear. Here, we demonstrated that plasmacytoma variant translocation 1 (PVT1) and autophagy were overexpressed in liver fibrotic specimens. In primary mouse HSCs, both PVT1 and autophagy were induced by hypoxia. Further study showed that hypoxia-induced autophagy depended on expression of PVT1 and miR-152 in HSCs. Luciferase reporter assay indicated that autophagy-related gene 14 (ATG14) was a direct target of miR-152. In addition, inhibition of autophagy by 3-methyladenine and Beclin-1 siRNA impeded activation of HSCs cultured in 1% O. Taken together, autophagy induction via the PVT1-miR-152-ATG14 signaling pathway contributes to activation of HSCs under hypoxia condition.
越来越多的研究表明,缺氧作为一种关键的微环境因素,促进了肝星状细胞(HSCs)的激活。然而,缺氧激活 HSCs 的机制尚不清楚。在这里,我们证明了浆细胞瘤变异易位 1(PVT1)和自噬在肝纤维化标本中过度表达。在原代小鼠 HSCs 中,缺氧均可诱导 PVT1 和自噬。进一步的研究表明,缺氧诱导的自噬依赖于 HSCs 中 PVT1 和 miR-152 的表达。荧光素酶报告基因检测表明,自噬相关基因 14(ATG14)是 miR-152 的直接靶基因。此外,通过 3-甲基腺嘌呤和 Beclin-1 siRNA 抑制自噬可阻止在 1%O2 条件下培养的 HSCs 的激活。综上所述,通过 PVT1-miR-152-ATG14 信号通路诱导的自噬有助于缺氧条件下 HSCs 的激活。