Homocysteine-impaired angiogenesis is associated with VEGF/VEGFR inhibition

This study investigated the effects of homocysteine (Hcy) on angiogenesis in cultured human umbilical vein endothelial cells (HUVEC) and zebrafish embryos. We found that Hcy (50 micromol/L) significantly decreased cell numbers, viability, and induced a G1/S arrest in HUVEC in the presence of adenosine (Ade, 50 micromol/L). Hcy, in combination with Ade, reduced migration and suppressed tube-like formation on Matrigel in HUVEC. Further, Hcy reduced subintestinal vessel formation in zebrafish embryos. Interestingly, Hcy-induced inhibitory effects on cell growth, migration, tube-like formation, and vessel formation in HUVEC and zebra fish embryos were abolished by the supplement of recombinant VEGF (10 ng/ml). Finally, Hcy in combination with Ade reduced the mRNA levels of VEGF, VEGFR-1, VEGFR-2, and attenuated protein levels of VEGF, ERK1/2 and Akt. The present study suggests that Hcy inhibits angiogenesis, and that the mechanism anti-angiogenic effects of Hcy may be through VEGF/VEGFR, Akt, and ERK1/2 inhibition.