Roles of cyclooxygenase-2 in microvascular endothelial cell proliferation induced by basic fibroblast growth factor.
BACKGROUND
The level of basic fibroblast growth factor (bFGF) increases rapidly after cerebral ischemia. However, the molecular mechanisms for the effects of bFGF on cerebral microvascular endothelial cells (cMVECs) have not yet been fully elucidated. In this study, a murine cMVEC line, bEnd.3, was employed to study the effects of bFGF on cyclooxygenase (COX) expression and its downstream effects in cMVECs.


METHODS
After treatment with bFGF, RT-PCR and Western blotting analyses were carried out to evaluate the changes in COX-2 mRNA and protein expression, respectively. MTT assays were performed to measure cell proliferation. The prostaglandin E2 (PGE2) and vascular endothelial growth factor (VEGF) concentrations in the culture medium were measured by enzyme-linked immunosorbent assay (ELISA).


RESULTS
COX-2 mRNA and protein expressions in bEnd.3 cells were induced by bFGF in time- and dose-dependent manners. The bFGF-induced COX-2 upregulation led to enhanced PGE2 production by bEnd.3 cells, and this effect was abolished by the selective COX-2 inhibitor NS-398. bFGF also increased VEGF production by bEnd.3 cells, and this effect was blocked by NS-398 and the EP1/2 (PGE2 receptors) antagonist AH6809. Furthermore, exogenous PGE2 increased VEGF production in bEnd.3 cells, and AH6809 blocked this effect.


CONCLUSIONS
bFGF increases VEGF production in an autocrine manner by increasing COX-2-generated PGE2 in cMVECs and subsequently stimulates MVEC proliferation and angiogenesis.
Qian
Rui-zhe
RZ
Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai 200032, China.
Yue
Fei
F
Zhang
Guo-ping
GP
Hou
Li-kun
LK
Wang
Xin-hong
XH
Jin
Hui-ming
HM
D015153:Blotting, Western; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects*; D051546:Cyclooxygenase 2 / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D015232:Dinoprostone / Q000378:metabolism / Q000494:pharmacology; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D006801:Humans; D018078:Receptors, Prostaglandin E / Q000037:antagonists & inhibitors; D020133:Reverse Transcriptase Polymerase Chain Reaction; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D044004:Xanthones / Q000494:pharmacology
D018078:Receptors, Prostaglandin E; D042461:Vascular Endothelial Growth Factor A; D044004:Xanthones; D016222:Fibroblast Growth Factor 2; C053876:6-isopropoxy-9-oxoxanthene-2-carboxylic acid; D051546:Cyclooxygenase 2; D015232:Dinoprostone