TY - JOUR
T1 - MiR-17/20 controls prolyl hydroxylase 2 (PHD2)/hypoxia-inducible factor 1 (HIF1) to regulate pulmonary artery smooth muscle cell proliferation
AU - Chen, Tianji
AU - Zhou, Qiyuan
AU - Tang, Haiyang
AU - Bozkanat, Melike
AU - Yuan, Jason X.J.
AU - Raj, J. Usha
AU - Zhou, Guofei
N1 - Funding Information:
The work is partly supported by an American Lung Association Biomedical Research Grant, a Pulmonary Hypertension Association/Pfizer Proof-of-Concept Award (in which American Thoracic Society provides administrative support), a Gilead Sciences Research Scholars Program in Pulmonary Arterial Hypertension Award (G. Zhou), NIH R01HL123804 (Raj and G. Zhou), R01HL115014 (Yuan), and American Lung Association Research Biomedical Research Grant RG-416135 (Chen). The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Publisher Copyright:
© 2016 The Authors.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Background-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). Methods and Results-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 HIF2a in vitro in PASMC. Overexpression of miR-17 in PASMC represses PHD2 expression, whereas miR-17/20a inhibitors induce PHD2 expression. The 30-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. Conclusions-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.
AB - Background-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). Methods and Results-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 HIF2a in vitro in PASMC. Overexpression of miR-17 in PASMC represses PHD2 expression, whereas miR-17/20a inhibitors induce PHD2 expression. The 30-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. Conclusions-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.
KW - Hypoxia
KW - Hypoxia-inducible factor 1
KW - MiR-17~92
KW - Prolyl hydroxylase 2
KW - Pulmonary artery smooth muscle cell
KW - Pulmonary hypertension
KW - Pulmonary hypertension
KW - Smooth muscle cell
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U2 - 10.1161/JAHA.116.004510
DO - 10.1161/JAHA.116.004510
M3 - Article
C2 - 27919930
AN - SCOPUS:85006507857
SN - 2047-9980
VL - 5
JO - Journal of the American Heart Association
JF - Journal of the American Heart Association
IS - 12
M1 - e004510
ER -