miR-17/20 Controls Prolyl Hydroxylase 2 (PHD2)/Hypoxia-Inducible Factor 1 (HIF1) to Regulate Pulmonary Artery Smooth Muscle Cell Proliferation.
miR-17/20 Controls Prolyl Hydroxylase 2 (PHD2)/Hypoxia-Inducible Factor 1 (HIF1) to Regulate Pulmonary Artery Smooth Muscle Cell Proliferation.
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DOI：
10.1161/jaha.116.004510
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发表时间：
2016-12-05
影响因子：
5.4
通讯作者：
Zhou G
中科院分区：
文献类型：
--
作者：
Chen T;Zhou Q;Tang H;Bozkanat M;Yuan JX;Raj JU;Zhou G
之前我们发现平滑肌细胞（SMC）特异性敲除 miR-17~92 可减轻缺氧引起的肺动脉高压。然而，miR-17~92介导的肺动脉平滑肌细胞（PASMC）增殖的机制仍不清楚。我们试图研究 miR-17~92 是否通过脯氨酰羟化酶 (PHD) 调节缺氧诱导因子 (HIF) 活性和 PASMC 增殖。我们发现缺氧的 sm-17~92−/− 小鼠的血细胞比容、红细胞计数和血红蛋白含量降低。 sm-17~92−/− 小鼠肺表达的 HIF 靶标 mRNA 水平降低，PHD2 水平升高。 miR-17~92 抑制剂在体外抑制 PASMC 中缺氧诱导的 HIF1α、VEGF、Glut1、HK2 和 PDK1 水平，但不抑制 HIF2α。 PASMC 中 miR-17 的过表达抑制 PHD2 表达，而 miR-17/20a 抑制剂则诱导 PHD2 表达。 PHD2 的 3'-UTR 包含功能性 miR-17/20a 种子序列。 PHD2 的沉默会诱导 HIF1α 和 PCNA 蛋白水平，而 PHD2 的过度表达会降低 HIF1α 和细胞增殖。 SMC 特异性敲除 PHD2 可增强小鼠缺氧诱导的血管重塑并加剧已形成的肺动脉高压。 PHD2 激活剂 R59949 可逆转现有高血压小鼠的血管重塑。从肺动脉高压患者分离出的 PASMC 中 PHD 失调。我们的结果表明，PHD2 是 miR-17/20a 的直接靶标，miR-17~92 通过抑制 PHD2 和诱导 HIF1α 促进 PASMC 增殖和红细胞增多。
Previously we found that smooth muscle cell (SMC)‐specific knockout of miR‐17~92 attenuates hypoxia‐induced pulmonary hypertension. However, the mechanism underlying miR‐17~92‐mediated pulmonary artery SMC (PASMC) proliferation remains unclear. We sought to investigate whether miR‐17~92 regulates hypoxia‐inducible factor (HIF) activity and PASMC proliferation via prolyl hydroxylases (PHDs). We show that hypoxic sm‐17~92−/− mice have decreased hematocrit, red blood cell counts, and hemoglobin contents. The sm‐17~92−/− mouse lungs express decreased mRNA levels of HIF targets and increased levels of PHD2. miR‐17~92 inhibitors suppress hypoxia‐induced levels of HIF1α, VEGF, Glut1, HK2, and PDK1 but not HIF2α in vitro in PASMC. Overexpression of miR‐17 in PASMC represses PHD2 expression, whereas miR‐17/20a inhibitors induce PHD2 expression. The 3′‐UTR of PHD2 contains a functional miR‐17/20a seed sequence. Silencing of PHD2 induces HIF1α and PCNA protein levels, whereas overexpression of PHD2 decreases HIF1α and cell proliferation. SMC‐specific knockout of PHD2 enhances hypoxia‐induced vascular remodeling and exacerbates established pulmonary hypertension in mice. PHD2 activator R59949 reverses vessel remodeling in existing hypertensive mice. PHDs are dysregulated in PASMC isolated from pulmonary arterial hypertension patients. Our results suggest that PHD2 is a direct target of miR‐17/20a and that miR‐17~92 contributes to PASMC proliferation and polycythemia by suppression of PHD2 and induction of HIF1α.