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Inhibition of RELM-β prevents hypoxia-induced overproliferation of human pulmonary artery smooth muscle cells by reversing PLC-mediated KCNK3 decline.

Inhibition of RELM-β prevents hypoxia-induced overproliferation of human pulmonary artery smooth muscle cells by reversing PLC-mediated KCNK3 decline.

Authors :
Han, Linlin
Song, Nannan
Hu, Xiaomin
Zhu, Afang
Wei, Xin
Liu, Jinmin
Yuan, Shiying
Mao, Weike
Chen, Xiangdong
Source :
Life Sciences. Apr2020, Vol. 246, pN.PAG-N.PAG. 1p.
Publication Year :
2020

Abstract

Although resistin-like molecule β (RELM-β) is involved in the pathological processes of various lung diseases, such as pulmonary inflammation, asthma and fibrosis, its potential roles in hypoxic pulmonary arterial hypertension (PAH) remain largely unknown. The study aims to investigate whether RELM-β contributes to hypoxia-induced excessive proliferation of human pulmonary artery smooth muscle cells (PASMCs) and to explore the potential mechanisms of this process. Human PASMCs were exposed to normoxia or hypoxia (1% O 2) for 24 h. siRNA targeting RELM-β was transfected into cells. Protein levels of KCNK3, RELM-β, pSTAT3 and STAT3 were determined by immunoblotting. The translocation of NFATc2 and expression of KCNK3 were visualized by immunofluorescence. 5-ethynyl-2′-deoxyuridine assays and cell counting kit-8 assays were performed to assess the proliferation of PASMCs. (1) Chronic hypoxia significantly decreased KCNK3 protein levels while upregulating RELM-β protein levels in human PASMCs, which was accompanied by excessive proliferation of cells. (2) RELM-β could promote human PASMCs proliferation and activate the STAT3/NFAT axis by downregulating KCNK3 protein under normoxia. (3) Inhibition of RELM-β expression effectively prevented KCNK3-mediated cell proliferation under hypoxia. (4) Phospholipase C (PLC) inhibitor U-73122 could not only prevent the hypoxia/RELM-β-induced decrease in KCNK3 protein, but also inhibit the enhanced cell viability caused by hypoxia/RELM-β. (5) Both hypoxia and RELM-β could downregulate membrane KCNK3 protein levels by enhancing endocytosis. RELM-β activation is responsible for hypoxia-induced excessive proliferation of human PASMCs. Interfering with RELM-β may alleviate the progression of hypoxic PAH by upregulating PLC-dependent KCNK3 expression. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00243205
Volume :
246
Database :
Academic Search Index
Journal :
Life Sciences
Publication Type :
Academic Journal
Accession number :
142045735
Full Text :
https://doi.org/10.1016/j.lfs.2020.117419