[Effect of protein kinase C-nuclear factor-kappa B signal transduction pathway on proliferation and expression of vascular endothelial growth factor in human pulmonary artery smooth muscle cells].
OBJECTIVE
To investigate the effect of protein kinase C (PKC)-nuclear factor-kappa B (NF-kappaB) signal transduction pathway on proliferation and expression of vascular endothelial growth factor (VEGF) in human pulmonary artery smooth muscle cells (HPASMCs).


METHODS
Cultured HPASMCs in normoxia or hypoxia conditions were divided into three groups and stimulated with or without phorbol 12-myristate 13-acetate (PMA) and pyrrolidine dithiocarbamate (PDTC) in vitro. The three groups were the control group, the PMA group and the PMA + PDTC group. Reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect VEGF mRNA expression, and the expression of VEGF protein and the inhibitor protein IkappaBalpha were observed by Western blot, while the location and expression of NF-kappaB p65 were observed by immunocytochemical staining, and cell cycle phases were analyzed by flow cytometry.


RESULTS
(1) As for the positive rate of nucleolar staining for NF-kappaB p65, the relative expression of IkappaBalpha protein, and the percentage of G(2)/M phases of cell cycle, there were significant differences between the PMA group and the control group or PMA + PDTC group, both in normoxia and hypoxia conditions (P < 0.05, respectively), and there was also a significant difference between the normoxia and hypoxia PMA groups (P < 0.05). (2) There were no significant differences in VEGF mRNA and protein expression among the three groups (P > 0.05, respectively) in normoxia, but the expression was higher in hypoxia PMA group than in hypoxia control and hypoxia PMA + PDTC or normoxia PMA group (P < 0.05, respectively). (3) There was a positive correlation between the positive rate of nucleolar staining for NF-kappaB p65, the relative expression of VEGF protein and the percentage of G(2)/M phases of cell cycle in hypoxia PMA group (r = 0.587 - 0.710, P < 0.05, respectively).


CONCLUSIONS
There is a signal transduction pathway of PKC-NF-kappaB in HPASMCs. The activity of PKC can be enhanced in hypoxia, concomitant NF-kappaB activation or VEGF overexpression to be involved in the proliferation. These results suggest that the activation of NF-kappaB can be considered as a downstream of PKC signal transduction pathway, and the activation of PKC-NF-kappaB signal transduction pathway and VEGF overexpression may contribute to the process of hypoxic pulmonary hypertension.
Zhang
Huan-ping
HP
Department of Respiratory Medicine, Tongji Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China.
Xu
Yong-jian
YJ
Zhang
Zhen-xiang
ZX
Ni
Wang
W
Chen
Shi-xin
SX
D002453:Cell Cycle / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D015687:Cell Hypoxia; D002478:Cells, Cultured; D006801:Humans; D020672:I-kappa B Proteins / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000378:metabolism*; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D011392:Proline / Q000031:analogs & derivatives* / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D011651:Pulmonary Artery / Q000166:cytology; D012333:RNA, Messenger / Q000235:genetics; D015398:Signal Transduction; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D013859:Thiocarbamates / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics
D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606204:NFKBIA protein, human; D012333:RNA, Messenger; D013859:Thiocarbamates; D042461:Vascular Endothelial Growth Factor A; C066229:prolinedithiocarbamate; D000072000:NF-KappaB Inhibitor alpha; D011392:Proline; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate