Abstract: Abstract: Objective To investigate whether lipopolysaccharide (LPS) can induce vascular endothelial cell growth factor(VEGF) expression in microglia regulated by hypoxia inducible factor-1α (HIF-1α). Methods The cultured BV2 cells were divided into four groups: control group, LPS (100 µg/L) simulated group, LPS (100 µg/L) + LPS antagonist (LRS, 200 µg/L)intervened group and LPS (100 µg/L) + HIF-1α inhibitors FM19G11 (10 mmol/L) intervened group. Immunofluorescence staining,Western blotting and ELISA were used to detect the expressions of VEGF and HIF-1α. Results Compared with the control group, the VEGF expression level was obvious high in LPS simulated group (P < 0.05). LRS inhibited this effect of LPS (P <0.05). The HIF-1α level was increased in LPS simulated group at 8 h post-injury (P < 0.05). FM19G11, the inhibitor of HIF- 1α reduced the expression of VEGF induced by LPS (P < 0.05). Conclusion LPS can up-regulate the expression of VEGF by HIF-1α.

Key words: lipopolysaccharides, microglia, vascular endothelial growth factors, hypoxia-inducible factor 1, alpha sub? unit