Effects of docosahexaenoic acid on expression of Ang-2 and VEGF in rat brain microvascular endothelial cells subjected to oxygen-glucose deprivation

Abstract

Objective To evaluate the effects of docosahexaenoic acid(DHA)on the expression of angiotensin-2(Ang-2)and vascular endothelial growth factor(VEGF)in rat brain microvascular endothelial cells(BMVECs)subjected to oxygen-glucose deprivation(OGD). Methods Primarily cultured rat BMVECs were divided into 3 groups(n=18 each)using a random number table: control group(group C), OGD group and DHA group.The cells were cultured with glucose-free and serum-free DMEM culture medium in OGD and DHA groups.In group DHA, DHA 40 μmol was added, and then the cells were exposed to 1%O2-5%CO2-94%N2 in an air-tight incubator.The cells were cultured in the normal glucose and normal oxygen conditions in group C. All the cells were cultured for 24 h. Cell apoptosis was detected using Annexin V/propidium iodide flow cytometry assay, and the apoptosis rate was calculated.The concentrations of Ang-2, VEGF, prostaglandin E2(PGE2)and prostacyclin(PGI2)in the supernatant of the culture medium were determined by enzyme-linked immunosorbent assay.The expression of Ang-2 mRNA and VEGF mRNA in cells was detected by real-time polymerase chain reaction.The expression of cyclooxygenase-2(COX-2)protein in cells was detected by Western blot. Results Compared with group C, the apoptosis rate and concentrations of Ang-2, VEGF, PGE2 and PGI2 in the supernatant were significantly increased, and the expression of Ang-2 mRNA, VEGF mRNA and COX-2 protein was significantly up-regulated in OGD and DHA groups(P<0.05). Compared with group OGD, the apoptosis rate and concentrations of Ang-2, VEGF, PGE2 and PGI2 in the supernatant were significantly decreased, and the expression of Ang-2 mRNA, VEGF mRNA and COX-2 protein was significantly down-regulated in group DHA(P<0.05). Conclusion DHA can inhibit the expression of Ang-2 and VEGF in rat brain BMVECs subjected to OGD and reduce cell apoptosis, and down-regulated expression of COX-2 protein is involved in the mechanism. Key words: Docosahexaenoic acids; Anoxia; Endothelial cells; Cerebrovascular trauma; Angiopoietin-2; Vascular endothelial growth factors