15-Hydroxyeicosatetraenoic acid (15-HETE) protects pulmonary artery smooth muscle cells against apoptosis via HSP90.
OBJECTIVE
15-Hydroxyeicosatetraenoic acid (15-HETE), generated by hypoxia, is a product of arachidonic acid and mainly catalyzed by 15-lipoxygenase (15-LO) in pulmonary artery. As HSP90 is known to be involved in apoptosis in other tissues and cells, we aim to test whether anti-apoptotic effect of 15-HETE is regulated by the molecular chaperone in pulmonary artery smooth muscle cells.


METHODS
To test this hypothesis, we performed cell viability analysis, mitochondrial potential assay, caspase-3 activity measurement, Western blot, and terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling with and without HSP90 inhibitor.


RESULTS
Our results showed that both exogenous and endogenous 15-HETE up-regulated HSP90 expression and prevented PASMC from serum deprivation-induced apoptosis. Serum deprivation lead to mitochondrial membrane depolarization, decreased expression of Bcl-2 and enhanced expression of Bax, and activation of caspase-3 and caspase-9 in PASMCs. 15-HETE reversed all these effects in a HSP90-dependent manner.


CONCLUSIONS
This study establishes the factor involved in 15-HETE-protecting PASMC from apoptosis and the regulation of HSP90 by 15-HETE may be an important mechanism underlying the treatment of pulmonary artery hypertension and provide a novel therapeutic target in future.
Zhang
Lei
L
Institute of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, 157 Baojian Road, Nangang, Heilongjiang, PR China.
Ma
Jun
J
Li
Yaqian
Y
Guo
Lei
L
Ran
Yajuan
Y
Liu
Shulin
S
Jiang
Chun
C
Zhu
Daling
D
D000818:Animals; D017209:Apoptosis; D020169:Caspases / Q000235:genetics / Q000378:metabolism; D015687:Cell Hypoxia; D002478:Cells, Cultured; D053938:DNA Fragmentation; D005786:Gene Expression Regulation; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D006893:Hydroxyeicosatetraenoic Acids / Q000378:metabolism*; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism; D011651:Pulmonary Artery / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism
D018841:HSP90 Heat-Shock Proteins; D006893:Hydroxyeicosatetraenoic Acids; D019253:Proto-Oncogene Proteins c-bcl-2; D051028:bcl-2-Associated X Protein; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D020169:Caspases