Akt and ERK1/2 are involved in brain derived neurotrophic factor-induced angiogenesis of endothelial cells
WANG Ya-dan; HU Yu；SUN Chun-yan
Institution of Hematology, Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, China. E-mail: huyu1964@163.net
Abstract：AIM: To investigate the role of PI3K/Akt and MEK1/ERK pathway in the brain derived neurotrophic factor(BDNF)-induced angiogenesis in vitro and to explore the further molecular mechanisms. METHODS: The phosphorylations of Akt and ERK1/2 were detected in human umbilical vein endothelial cells(HUVECs) by Western blotting. The angiogenic activity in vitro was evaluated by transwell migration assay and tubule formation assay. Cell proliferation was determined by crystal violet staining. Cell apoptosis was analysed by FITC-Annexin-V/PI double staining and flow cytometry. RESULTS: BDNF activated the PI3K/Akt and MEK1/ERK pathway in a time-dependent manner. Ly294002 and PD98059 blocked the activation of Akt and ERK1/2 in response to BDNF. BDNF at concentration of 100 μg/L significantly increased HUVECs tube formation, migration and proliferation in vitro to a degree similar to those induced by 25 μg/L VEGF. Furthermore, tube formation and migration of HUVECs toward BDNF were significantly inhibited by treatment with 20 μmol/L Ly294002 and 20 μmol/L PD98059. BDNF-induced survival was only blocked by Ly294002 and BDNF-induced proliferation was only inhibited by PD98059. CONCLUSION: BDNF promotes angiogenesis of HUVECs in vitro. The ERK and Akt are two crucial events in BDNF-mediated signal transduction leading to HUVECs angiogenesis by different mechanisms. Moreover, the latter is more important.
