[Adenovirus-mediated protein-kinase-GIalpha suppresses the hypoxia-induced proliferation and phenotype-switching of pulmonary arterial smooth muscle cell].

OBJECTIVE: To observe the proliferation and phenotype-switching of pulmonary arterial smooth muscle cell (PASMC) induced by hypoxia and interfered by Ad-PKGIα. And to investigate the potential regulative role of PKGIα gene in the molecule mechanism of hypoxia pulmonary vessel remodeling (HPVR). METHODS: To establish the pure PASMC cultured by tissue-sticking methods. Semi-quantitative reverse transcription and polymerase chain reaction (RT-PCR) and Western blot were used to examine the PKGIα mRNA and protein expression after PASMC were transfected by Ad-PKG. The mRNA and protein expressive change of smooth muscle alpha actin (SM-alpha-actin) determined the degree of cell phenotype-switching. The changes of PASMC proliferation were determined by flow cytometry and ³H-TdR incorporated way. RESULTS: Ad-PKGIα could transfect into PASMC and highly express. Hypoxia down-regulated the expression of SM-alpha-actin protein (44.25 ± 5.34 in normoxia, 32.18 ± 4.19 in 12 h hypoxia condition, 21.90 ± 2.44 in 24 h hypoxia condition, P < 0.05), that could be blocked by the transfection of Ad-PKGIα. Hypoxia could push PASMC mitosis and proliferating (³H-TdR incorporated way: 7570 ± 371 in normoxia, 12,020 ± 831 in 12 h hypoxia condition, 14,924 ± 1491 in 24 h hypoxia condition, P < 0.05), that could be blocked by the transfection of Ad-PKGIα, too. CONCLUSIONS: The results suggested that PKGIα signaling pathway might play an important role in the molecule mechanism of HPVR. And PKGIα gene might be a target point of gene therapy.