AMPKα2 deficiency exacerbates hypoxia-induced pulmonary hypertension by promoting pulmonary arterial smooth muscle cell proliferation

• Published in: Journal of physiology and biochemistry Vol. 76; no. 3; pp. 445 - 456
• Main Authors: Wang, Hai-Long, Tang, Fu-Qin, Jiang, Yun-Han, Zhu, Yu, Jian, Zhao, Xiao, Ying-Bin
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.08.2020; Springer Nature B.V
• Subjects: Adenosine kinase; Adenosine monophosphate; AMP; AMP-Activated Protein Kinases - deficiency; AMP-Activated Protein Kinases - genetics; Animal Physiology; Animals; Biomedical and Life Sciences; Biomedicine; Cell Hypoxia; Cell Line; Cell Proliferation; Cyclin-dependent kinase inhibitor p27; Homeostasis; Human Physiology; Hypertension; Hypoxia; Hypoxia - pathology; Kinases; Male; Mice; Mice, Knockout; Muscle, Smooth, Vascular - cytology; Muscles; Myocytes, Smooth Muscle - cytology; Original Article; Pathogenesis; Protein kinase; Pulmonary Arterial Hypertension - metabolism; Pulmonary Artery - cytology; Pulmonary hypertension; Rapamycin; Rats; Smooth muscle; TOR protein; Hypoxia; Pulmonary arterial smooth muscle cells; Proliferation; AMPKα2; Pulmonary hypertension
• ISSN: 1138-7548; 1877-8755
• DOI: 10.1007/s13105-020-00742-4

Increased evidence indicates that adenosine monophosphate-activated protein kinase (AMPK) plays a vital role in vascular homeostasis, especially under hypoxia, and protects against the progression of pulmonary hypertension (PH). However, the role of AMPK in the pathogenesis of PH remains to be clarified. In the present study, we confirmed that a loss of AMPKα2 exacerbated the development of PH by using hypoxia-induced PH model in AMPKα2 −/− mice. After a 4-week period of hypoxic exposure, AMPKα2 −/− mice exhibited more severe pulmonary vascular remodeling and pulmonary vascular smooth muscle cell (SMC) proliferation when compared with wild type (WT) mice. In vitro, AMPKα2 knockdown promoted the proliferation of pulmonary arterial smooth muscle cells (PASMCs) under hypoxia. This phenomenon was accompanied by upregulated Skp2 and downregulated p27 kip1 expression and was abolished by rapamycin, an inhibitor of mTOR. These results indicate that AMPKα2 deficiency exacerbates hypoxia-induced PH by promoting PASMC proliferation via the mTOR/Skp2/p27 kip1 signaling axis. Therefore, enhanced AMPKα2 activity might underlie a novel therapeutic strategy for the management of PH.