Down-regulation of CREB-binding protein expression inhibits thrombin-induced proliferation of endothelial cells: possible relevance to PDGF-B.
Thrombin acts as a potent mitogenic factor for ECs (endothelial cells) by the release of several growth factors, including PDGF-B (platelet-derived growth factor-B). CBP (CREB-binding protein), which functions as a transcriptional coactivator, links the changes in the extracellular stimuli with alterations in gene expression. Therefore, we hypothesized that CBP could mediate thrombin-induced proliferation of ECs via PDGF-B-dependent way. Short hairpin RNA was used to down-regulate the expression of CBP in ECs. CBP and PDGF-B levels were analysed by real-time RT-PCR and Western blot. To evaluate ECs proliferation, cell cycle and DNA synthesis were analysed by flow cytometry and BrdU (bromodeoxyuridine) incorporation assay, respectively. PDGF-B was involved in the mitogenic effect of thrombin on ECs. Down-regulation of CBP attenuated ECs proliferation and inhibited cell cycle progression induced by thrombin. Silencing CBP expression also suppressed thrombin-induced PDGF-B expression in ECs. Mitogenic activity of thrombin was impaired by silencing CBP expression in ECs. This inhibitory effect was, in part, related to the inability to up-regulate PDGF-B expression in ECs. CBP could be regarded as a potential therapeutic target for vascular injury.
Jiang
Hong
H
Department of Cardiology, Renmin Hospital of Wuhan University, Wuhan 430060, Peoples Republic of China. pyh_hongj@163.com
Chen
Jing
J
Wang
Lang
L
Zhu
Li-hua
LH
Wen
Hua-zhi
HZ
D000818:Animals; D050882:CREB-Binding Protein / Q000037:antagonists & inhibitors / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D015536:Down-Regulation / Q000187:drug effects / Q000502:physiology; D042783:Endothelial Cells / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D020574:Proto-Oncogene Proteins c-sis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D034622:RNA Interference / Q000502:physiology; D034741:RNA, Small Interfering / Q000494:pharmacology; D051381:Rats; D013917:Thrombin / Q000494:pharmacology*
D020574:Proto-Oncogene Proteins c-sis; D034741:RNA, Small Interfering; D050882:CREB-Binding Protein; D013917:Thrombin