Department of Pharmacy, Sanya Central Hospital (The Third People's Hospital of Hainan Province), Sanya City, Hainan Province, China.
Department of Pharmacy, The Second Affiliated Hospital of Hainan Medical University, Haikou City, Hainan Province, China.
Life Sci. 2019 Dec 15;239:116928. doi: 10.1016/j.lfs.2019.116928. Epub 2019 Nov 1.
The dysfunction of human pulmonary arterial smooth muscle cells (HPASMCs) has been suggested to participate in the pathophysiology of pulmonary arterial hypertension (PAH). This study determined miR-19a expression in hypoxia-induced HPASMCs and explored the mechanistic actions of miR-19a in hypoxia-induced HPASMC proliferation and migration.
QRT-PCR and western blot assays respectively determined the mRNA and protein expression of miR-19a, phosphatase and tensin homolog (PTEN) and hypoxia-inducible factor-1 alpha (HIF-1α). In vitro functional assays determined HPASMC proliferation and migration, respectively. Luciferase reporter assay determined interaction between miR-19a and PTEN. The knockdown effects of miR-19a on PAH were confirmed in in vivo mice model.
Hypoxia treatment time-dependently up-regulated miR-19a expression and enhanced cell proliferation in HPASMCs. MiR-19a overexpression increased cell proliferation and migration of HPASMCs, while repression of miR-19a reduced cell proliferative and migratory potentials of hypoxia-treated HPASMCs. Bioinformatics analysis and luciferase reporter assay showed that PTEN 3' untranslated region was targeted by miR-19a, and miR-19a repressed the mRNA and protein expression of PTEN in HPASMCs. Further rescue studies revealed that miR-19a regulated proliferative and migratory potentials of hypoxia-treated HPASMCs via suppressing PTEN expression. In addition, HIF-1α was identified as one of the mediators for the hypoxia-induced aberrant expression levels of miR-19a and PTEN. MiR-19a overexpression enhanced PI3K/AKT signaling, which was attenuated by enforced expression of PTEN in HPASMCs. More importantly, knockdown of miR-19 attenuated the chronic hypoxia-induced PAH in in vivo mice model.
This study presented a novel mechanistic action of miR-19a-mediated cell proliferation and migration of HPASMCs.
已有人提出，人肺动脉平滑肌细胞（HPASMC）功能障碍参与了肺动脉高压（PAH）的病理生理学过程。本研究测定了缺氧诱导的 HPASMC 中 miR-19a 的表达，并探讨了 miR-19a 在缺氧诱导的 HPASMC 增殖和迁移中的作用机制。
分别通过 QRT-PCR 和 Western blot 测定 miR-19a、磷酸酶张力蛋白同源物（PTEN）和缺氧诱导因子-1α（HIF-1α）的 mRNA 和蛋白表达。体外功能测定分别测定 HPASMC 增殖和迁移。荧光素酶报告测定 miR-19a 与 PTEN 之间的相互作用。在体内小鼠模型中验证 miR-19a 对 PAH 的敲低作用。
缺氧处理时间依赖性地上调 miR-19a 的表达并增强 HPASMC 的细胞增殖。miR-19a 过表达增加了 HPASMC 的细胞增殖和迁移，而 miR-19a 的抑制则降低了缺氧处理的 HPASMC 的增殖和迁移潜能。生物信息学分析和荧光素酶报告测定表明，PTEN 3'非翻译区是 miR-19a 的靶标，miR-19a 抑制了 HPASMC 中 PTEN 的 mRNA 和蛋白表达。进一步的挽救研究表明，miR-19a 通过抑制 PTEN 表达调节缺氧处理的 HPASMC 的增殖和迁移潜能。此外，HIF-1α 被鉴定为导致 miR-19a 和 PTEN 异常表达的缺氧诱导介质之一。miR-19a 过表达增强了 PI3K/AKT 信号通路，而在 HPASMC 中强制表达 PTEN 则减弱了该信号通路。更为重要的是，miR-19a 的敲低减弱了体内慢性缺氧诱导的 PAH。
本研究提出了 miR-19a 介导的 HPASMC 增殖和迁移的新机制。
