Objective: To investigate the signaling pathways involved in brain derived neurotrophic factor (BDNF) -induced angiogenesis and to provide a novel pathway to anti-angiogenesis in multiple myeloma.
Methods: The phosphorylation of AKT and endothelial NO synthase (eNOS) in human umbilical venous epithelial cells (HUVEC) were detected by Western blot. The angiogenic activity in vitro was evaluated by transwell migration assay and tube formation assay. BDNF-induced in vivo angiogenic activity was evaluated by Matrigel plug assay. The concentration of NO was detected by nitric acid deoxidizase assay. Cell apoptosis was detected by FITC-Annexin V/PI double staining and flow cytometry.
Results: BDNF activated the phosphatidylinositol-3-kinase (PI3K)/AKT/eNOS pathway in HUVEC in a time- and dose-dependent manner. BDNF-stimulated NO production was blocked by LY294002, a PI3K inhibitor. In vitro, BDNF induced HUVEC migration and tube formation on Matrigel, which could be significantly blocked by LY294002 and N(G)-nitro-L-arginine methyl ester (L-NAME) respectively; but BDNF induced HUVEC apoptosis could be blocked only by LY294002. In vivo, BDNF increased capillary ingrowth into subcutaneously implanted Matrigel plugs in mice, which could be significantly reduced in L-NAME treated mice.
Conclusion: BDNF induces angiogenesis through the AKT/eNOS signaling kinase pathway. It may be a novel target for the anti-angiogenesis therapy for multiple myeloma.