17? Estradiol Inhibits The Proliferation Of Human Pulmonary Smooth Muscle Cells Through The ERR?/PGC-1?Pathway

Objective:In recent years,studies have shown that 17 ? estradiol(E2)has important protective effects on pulmonary vasculature,mainly mediated by estrogen receptor ?(ERa),and plays a role in inhibiting the proliferation of smooth muscle cells.Estrogen related receptor(ERR alpha),one of the member of the nuclear receptor subgroup,is highly homologous with ER alpha,and can interfere with and interact with the DNA binding site and the co activating factor in different cells and ER alpha in the conduction pathway,thereby interfering with the signal estrogen-estrogen receptor.The ERR?/PGC-1?(peroxisome proliferator receptor ? coactivating factor-1?)signaling pathway has been studied to mainly regulate cell metabolism,mitochondrial biosynthesis,and thus regulate cell proliferation.However,whether ERR? participates in the protection of E2 against pulmonary hypertension has not been studied.The aim of this study is to investigate whether ERR? participates in the regulation of proliferation of human pulmonary artery smooth muscle cells and whether ERR? can mediate the protective effect of E2 on pulmonary vessels in hypoxia environment.Methods: Human pulmonary artery smooth muscle cells(hPASMC)were cultured and randomly assigned to normoxic,hypoxic,hypoxia + ERR?inverse agonist XCT790 and hypoxia + 17 ? estradiol(E2)groups.CCK-8assay was used to detect cell proliferation in each intervention group;RT-PCR method was used to measure mRNA levels of ERR-?,PGC-1? and PCNA in hPASMCs;Western blot was used to measure ERR-? and PGC in hPASMCs.-1?,PCNA protein expression levels.Results: The results of CCK-8 assay showed that the proliferation of hypoxic group was significantly higher than that of normoxic group(P<0.05).and the proliferation activity of hypoxia+E2 group and hypoxia+XCT790group was significantly inhibited than that of hypoxia group(P<0.05).The mRNA and protein expressions of ERR?,PGC-1?,and PCNA in the hypoxic group were significantly higher than those in the normoxic group(P<0.05).And the three gene in the hypoxia+E2 group and the hypoxia+XCT790 group were simultaneously reduced by RT-PCR and Western blot(P<0.05).There was no statistically significant difference between the hypoxia+E2 group and the hypoxia+XCT790 group.Conclusions:1.Hypoxia significantly stimulated the proliferation of hPASMCs.2.E2 inhibits ERR? expression in hypoxic environment.3.XCT790 inhibits hPASMCs proliferation by inhibiting ERR alpha activity.4.E2 inhibits proliferation of human pulmonary artery smooth muscle cells through ERR? /PGC-1? signaling pathway,which may play an important role in protecting pulmonary vessels in hypoxic pulmonary hypertension.