The pseudogene PTENP1 regulates smooth muscle cells as a competing endogenous RNA
The pseudogene PTENP1 regulates smooth muscle cells as a competing endogenous RNA
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假基因 PTENP1 作为竞争性内源 RNA 调节平滑肌细胞
DOI：
10.1042/cs20190156
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发表时间：
2019-07-15
期刊：
影响因子：
6
通讯作者：
Bin, Jianping
中科院分区：
文献类型：
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作者：
Lai, Yanxian;Li, Jianyong;Bin, Jianping
长非编码 RNA (lncRNA) PTENP1 是十号染色体上删除的磷酸酶和张力蛋白同源物 (PTEN) 的假基因，与平滑肌细胞 (SMC) 增殖和凋亡有关。 PTENP1是PTEN的假基因。然而，目前尚不清楚PTENP1是否以及如何在人主动脉平滑肌细胞（HASMCs）的增殖和凋亡中发挥作用。在这里，我们假设 PTENP1 通过促进 PTEN 表达来抑制 HASMC 增殖并增强细胞凋亡。 PCR分析和Western blot分析分别显示PTENP1和PTEN在人主动脉夹层（AD）样本中表达上调。 PTENP1过表达显着增加PTEN蛋白表达，促进细胞凋亡并抑制HASMCs增殖。 PTENP1 沉默表现出相反的作用并减轻 H2O2 诱导的 HASMC 细胞凋亡。在血管紧张素 II (Ang II) 诱导的小鼠主动脉瘤 (AA) 模型中，PTENP1 过表达会增强主动脉 SMC 凋亡，加剧动脉瘤形成。从机制上讲，RNA Pull-down 测定和一系列使用 miR-21 模拟物或抑制剂的荧光素酶报告基因测定将 PTENP1 鉴定为 miR-21 的分子海绵，以内源性竞争 miR-21 和 PTEN 转录物之间的结合，释放 PTEN 表达。体外免疫荧光证据进一步支持了这一发现，显示在基线 PTENP1 过表达下，给予 miR-21 模拟物后细胞凋亡减少。 PTEN 的离体拯救显着减轻了 PTENP1 过表达诱导的 SMC 凋亡。最后，Western blot 检测显示 HASMC 中 Akt 磷酸化以及细胞周期蛋白 D1 和细胞周期蛋白 E 水平显着降低，同时 PTENP1 上调。我们的研究确定 PTENP1 是 HASMC 稳态的调节因子，并表明 PTENP1 是 AD 或 AA 干预的潜在靶点。
The long non-coding RNA (lncRNA) PTENP1 is a pseudogene of phosphatase and tensin homologue deleted on chromosome ten (PTEN), has been implicated in smooth muscle cell (SMC) proliferation and apoptosis. PTENP1 is the pseudogene of PTEN. However, it is unclear whether and how PTENP1 functions in the proliferation and apoptosis of human aortic SMCs (HASMCs). Here, we hypothesised that PTENP1 inhibits HASMC proliferation and enhances apoptosis by promoting PTEN expression. PCR analysis and Western blot assays respectively showed that both PTENP1 and PTEN were up-regulated in human aortic dissection (AD) samples. PTENP1 overexpression significantly increased the protein expression of PTEN, promoted apoptosis and inhibited the proliferation of HASMCs. PTENP1 silencing exhibited the opposite effects and mitigated H2O2-induced apoptosis of HASMCs. In an angiotensin II (Ang II)-induced mouse aortic aneurysm (AA) model, PTENP1 overexpression potentiated aortic SMC apoptosis, exacerbated aneurysm formation. Mechanistically, RNA pull-down assay and a series of luciferase reporter assays using miR-21 mimics or inhibitors identified PTENP1 as a molecular sponge for miR-21 to endogenously compete for the binding between miR-21 and the PTEN transcript, releasing PTEN expression. This finding was further supported by in vitro immunofluorescent evidence showing decreased cell apoptosis upon miR-21 mimic administration under baseline PTENP1 overexpression. Ex vivo rescue of PTEN significantly mitigated the SMC apoptosis induced by PTENP1 overexpression. Finally, Western blot assays showed substantially reduced Akt phosphorylation and cyclin D1 and cyclin E levels with up-regulated PTENP1 in HASMCs. Our study identified PTENP1 as a mediator of HASMC homeostasis and suggests that PTENP1 is a potential target in AD or AA intervention.