[Endothelin-1 overexpression inhibits rat pulmonary arterial microvascular smooth muscle cell apoptosis via Akt/PKB pathway].
OBJECTIVE
To investigate the effects of endothelin-1 (ET-1) overexpression on apoptosis of the rat pulmonary arterial microvascular smooth muscle cells (RPMC) in vitro.


METHODS
Primary RPMC obtained from the pulmonary artery and lung microvasculature were identified by immunofluorescence staining and electron microscope technique. The RPMC was transient transfected with the pMEXneo-ET1 and pCDNA5-FRT-TO-ET1-3'UTR plasmids as well as the empty vector respectively via lipofectamine. Flow cytometry was used to assess the cell cycle and apoptosis of RPMC. Akt and Caspase-3 expressions were detected by Western blot and real time RT-PCR.


RESULTS
The mRNA of ET(A) expression was significantly higher than that of ET(B) receptor in primary RPMC. Flow cytometry analysis revealed significantly reduced apoptosis in ET-1 transfected RPMC compared to that in vehicle transfected RPMC. Overexpression of ET-1 in RPMC also significantly increased the phosphorylation of Akt and reduced the cleaved Caspase-3 expression.


CONCLUSIONS
Overexpression of the ET-1 inhibited RPMC apoptosis and activated Akt/PKB-Caspase-3 signaling pathway, which might be responsible for ET-1 induced the pulmonary microvascular arteries remodeling.
Huang
Hai-qiong
HQ
Department of Anesthesiology, Zhong Shan Hospital, Fudan University, Shanghai 200032, China.
Wang
Zhen
Z
Jiang
Zhen
Z
Chen
Hao-zhu
HZ
D000818:Animals; D017209:Apoptosis; D001158:Arteries / Q000378:metabolism; D002478:Cells, Cultured; D019332:Endothelin-1 / Q000378:metabolism*; D005260:Female; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011651:Pulmonary Artery / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction
D019332:Endothelin-1; D051057:Proto-Oncogene Proteins c-akt