Hypoxia activation IRE1a/JNK pathway regulates the proliferation and apoptosis of pulmonary artery smooth muscle cells in mice
10.3760/cma.j.issn.1671-0282.2023.08.013
- VernacularTitle:缺氧激活IRE1a/JNK通路调控小鼠肺动脉平滑肌细胞增殖和凋亡研究
- Author:
XinWei SHI
1
;
Jun QIAN
;
Chao YUAN
;
Yangyang SHI
;
Wei WANG
;
Kai SUN
Author Information
1. 南京医科大学第一附属医院急诊医学科，南京 210000
- Keywords:
Pulmonary hypertension;
Endoplasmic reticulum stress;
IRE1α;
JNK
- From:
Chinese Journal of Emergency Medicine
2023;32(8):1083-1089
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate whether hypoxia induces endoplasmic reticulum stress (ERS) through inositol-dependent enzyme 1α (IRE1α) and activates JNK pathway to participate in the proliferation and apoptosis of pulmonary artery smooth muscle cells in mice.Methods:Mouse pulmonary artery smooth muscle cell line (MPASMCs) was cultured in vitro to establish the hypoxic MPASMCs model. The expression of hypoxia-inducible factor-1α (HIF-1α), glucose-regulated protein 78 (GRP78) and JNK pathway genes were detected. The expression of IRE1α was knocked down by siRNA transfection, JNK pathway specific inhibitor 1, 9-pyrazoxanolone and pyrazoxanolone (SP600125) was used to inhibit JNK pathway, and XBP-1s plasmid was transfected to increase the expression of XBP-1s. CCK8 assay and proliferating cell nuclear antigen (PCNA) protein detection were used to observe the cell proliferation. Cell apoptosis was detected by flow cytometry and the expression of B-cell lymphoma-2 (BCL-2) and BCL-2 associated X protein (BAX) protein.Results:HIF-1αexpression was significantly up-regulated in MPASMCs cultured under hypoxia. The expression of GRP78, phosphorylated IRE1α (P-IRE1α) and phosphorylated JNK (P-JNK) increased after hypoxia, indicating that ERS and JNK pathways mediated by IRE1α were activated. When IRE1α expression was inhibited by si-IRE1a, the expression of P-JNK decreased, indicating that JNK pathway was inhibited. The expression of PCNA protein was up-regulated in the hypoxia group, and CCK8 assay indicated that the cell proliferation was up-regulated. The expression of BAX and BCL-2 protein were down-regulated in the hypoxia group, and the level of apoptosis was down-regulated. The above changes were delayed after SiIRE1a inhibited the expression of IRE1α. Treatment with SP600125 could also partially delay the pro-proliferation and anti-apoptosis changes induced by hypoxia. Overexpression of XBP-1s under normoxia activated the JNK pathway, accompanied by hypoxia-like changes.Conclusions:Hypoxia activates IRE1α-mediated endoplasmic reticulum stress, which promotes the proliferation and inhibits apoptosis of pulmonary artery smooth muscle cells through JNK pathway in mice.
