15-HETE protects rat pulmonary arterial smooth muscle cells from apoptosis via the PI3K/Akt pathway.
15-Hydroxyeicosatetraenoic acid (15-HETE), a metabolic product of arachidonic acid (AA), plays an important role in pulmonary vascular smooth muscle remodeling. Although its effects on the apoptotic responses are known, the underlying mechanisms are still poorly understood. Since Akt is a critical regulator of cell survival and vascular remodeling, there may be a crosstalk between 15-HETE anti-apoptotic process and PI3K/Akt survival effect in rat pulmonary arterial smooth muscle cells (PASMCs). To test this hypothesis, we studied the effect of 15-HETE on cell survival and apoptosis using Western blot, cell viability measurement, nuclear morphology determination, TUNEL assay and mitochondrial potential analysis. We found that activation of the PI3K/Akt signaling system was necessary for the 15-HETE to suppress PASMC apoptosis and improve cell survival. Our results indicated that 15-HETE inhibited the apoptotic responses of PASMCs, including morphological alterations, mitochondrial depolarization and the expression apoptosis-specific proteins. These effects were likely to be mediated through the activation of PI3K/Akt. Two downstream signal molecules of PI3K/Akt were identified. Both FasL and Bad were down-regulated by 15-HETE and 15-HETE phosphorylated Bad. These changes depended on the PI3K/Akt signaling pathway in PASMCs. Thus a signal transduction pathway was demonstrated which is necessary for the effects of 15-HETE in protection PASMCs from apoptosis.
Wang
Shuang
S
Institute of Biopharmaceutical Sciences, College of Pharmacy, Harbin Medical University, Harbin 157 Baojian Road, Nangang District, Harbin, Heilongjiang 150081, PR China.
Wang
Yali
Y
Jiang
Jing
J
Wang
Ruifang
R
Li
Lisa
L
Qiu
Zhaoping
Z
Wu
Hong
H
Zhu
Daling
D
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015687:Cell Hypoxia / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053222:Fas Ligand Protein / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006893:Hydroxyeicosatetraenoic Acids / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D010766:Phosphorylation / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D011651:Pulmonary Artery / Q000166:cytology*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects*; D051025:bcl-Associated Death Protein / Q000378:metabolism
D053222:Fas Ligand Protein; D006893:Hydroxyeicosatetraenoic Acids; D051025:bcl-Associated Death Protein; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D019869:Phosphatidylinositol 3-Kinases; D051057:Proto-Oncogene Proteins c-akt