[Effect of insulin on VEGF expression in bovine retinal microvascular endothelial cells exposed to normal or high glucose].
OBJECTIVE
To investigate the effect of insulin or (and) high glucose on the vascular endothelial growth factor (VEGF) expression in bovine retinal microvascular endothelial cells (BREC).


METHODS
It was a experimental study. BREC were cultured with selective culture media. Passaged cells were cultured in normal (5 mmol/L) or high glucose (30 mmol/L) medium for 3 days. Equimolar mannitol was supplemented for osmotic controls. Cells were serum-deprived overnight in Dulbecco's modified Eagle's medium containing 0.2% w/v bovine serum albumin and then incubated in the absence or presence of 100 nmol/L insulin for 24 hrs. Cells were harvested and the expression of VEGF mRNA was analyzed by Real-time PCR. VEGF protein level was determined by HUVEC proliferation assay, immunofluorescence and western-blot


RESULTS
Insulin or (and) high glucose significantly increased VEGF mRNA (F = 5.67, 9.04; P <0.05) and protein (F = 5.50, 5.57; P <0.05) expression. However, the combined effect of insulin and high glucose is weak in contrast to insulin or high glucose alone.


CONCLUSIONS
High glucose attenuated insulin-induced VEGF expression. Therefore, VEGF may be not the major factor that lead to transient worsening of diabetic retinopathy after acute insulin therapy in diabetes.
Wu
Hai-Xiang
HX
Department of Ophthalmology, Shanghai Jiao Tong University Affiliated First People's Hospital, Shanghai, China.
Xia
Xin
X
Liu
Kun
K
Zheng
Zhi
Z
Zhu
Dong-Qing
DQ
Xu
Xun
X
Gu
Qing
Q
D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D007328:Insulin / Q000494:pharmacology*; D012171:Retinal Vessels / Q000166:cytology / Q000187:drug effects; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism*
D007328:Insulin; D042461:Vascular Endothelial Growth Factor A; D005947:Glucose