Effects of growth-factor combinations on vascular endothelial cell growth in vitro.
Abnormal elevation of growth factors in ocular fluid and serum has been claimed to be a major positive regulator of diabetic retinopathy. In this study, we aimed to explore the individual and collective actions of insulin, insulinlike growth factor I (IGF-I), vascular endothelial growth factor (VEGF), and transforming growth factor-beta (TGF-beta) on the proliferation of vascular endothelial cells. Thus, primary human umbilical vein (HUVECs) endothelial cells (ECs) were used to examine their effects by direct viable cell counting and cell-proliferation assay. Insulin, IGF-I, and VEGF individually increased both cell number and proliferation status in a dose-dependent fashion. TGF-beta significantly potentiated the stimulatory effects of insulin and VEGF on EC proliferation, but revealed no synergism with double and triple growth-factor combinations. Our findings emphasize the complexity of the role of TGF-beta in the regulation of EC proliferation. TGF-beta plays an important role in the EC proliferation and the pathogenesis of diabetic retinopathy.
Wu
Wen-Chuan
WC
Department of Ophthalmology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan. wuoph@kmu.edu.tw
Kao
Ying-Hsien
YH
Chung
Chia-Hung
CH
D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects*; D016228:Endothelial Growth Factors / Q000494:pharmacology*; D006801:Humans; D007328:Insulin / Q000494:pharmacology; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D016212:Transforming Growth Factor beta / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A / Q000494:pharmacology
D016228:Endothelial Growth Factors; D007328:Insulin; D016212:Transforming Growth Factor beta; D042461:Vascular Endothelial Growth Factor A; D007334:Insulin-Like Growth Factor I