Protection Of CGRP On H₂O₂ Induced HUVEC Injury And Effection On P38 MAPK/Nox4 Pathway

Aim: H₂O₂ was used to stimulate HUVEC( Human umbilical vein endothelial cells ) to injury, and HUVEC vitality was observed treated with CGRP and H₂O₂, and which effection was evaluated on the regulation on phosphoration of p38 MAPK and Nox4, thus illustrate the protective mechanism of CGRP on HUVEC injury.Methods: The vitaility of HUVEC was observed by MTT; then the apoptosis rate of HUVEC was detected by Flow Cytometry; Western Blot was used to evaluate p-p38 MAPK and Nox4 protein expression , and real-time PCR to Nox4 mRNA.Results: The vitaility of HUVEC could be reduce H₂O₂ significantly in dose dependent manners, and reduced to 50% when treated with 500μM H₂O₂. The proportion of apoptosis was increased in H₂O₂ injuryed HUVEC. On the other hand, HUVEC vitality was increased by 10nM and 100nM CGRP, and 100nM CGRP could reduce HUVEC apoptosis rate significantly. p38 MAPK phosphorylation could be activated by 500μM H₂O₂ and Nox4 expression could be increased. And the increased Nox4 level could be reversed by CGRP partly via p38 MAPK. The effection of CGRP could be blockade by CGRP_8-37.Conclusion: p38 MAPK phosphorylation could be activated and Nox4 expression increased during HUVEC injury coursed by H₂O₂. And the protection mechanism of CGRP maybe related to the down-regulation of p38 MAPK phosphorylation and Nox4.