Calcitonin gene-related peptide partly protects cultured smooth muscle cells from apoptosis induced by an oxidative stress via activation of ERK1/2 MAPK

Abstract

Oxidative stress induced by a glucose/glucose oxidase (G/GO) generator system dose-dependently decreased the viability of cultured vascular smooth muscle cells (VSMC) as estimated by MTT assay. Cell death was induced in 40% of cells exposed to 0.2 IU/ml of the free radical generating mixture. Annexin-V labeling, Hoechst staining together with DNA laddering demonstrated that apoptosis was responsible for this cell loss. Pretreatment of the cells with 10(-8) M calcitonin gene-related peptide (CGRP) significantly attenuated the damaging effect of the oxidative stress. Indeed, cell viability was estimated to be 80% in CGRP-treated group, instead of 60% in absence of CGRP treatment. This protective effect of CGRP was antagonized by 8-37 CGRP, an antagonist of CGRP-1 receptors, whereas it was not reproduced by amylin, a CGRP analogue. As indicated by the reduction in Hoechst staining and in DNA laddering, CGRP prevented the onset of apoptosis. We also demonstrated that the peptide significantly up-regulated the activation of ERK1/2 and P38 kinases. Inhibitors of the kinases prevented the protective effect of CGRP. We conclude that CGRP antagonizes oxidative stress-induced apoptosis by up-regulating MAP kinase activation and that activation of these kinases was necessary to protection.

High hydrostatic pressure enhances whey protein digestibility to generate whey peptides that improve glutathione status in CFTR‐deficient lung epithelial cells

“…This result concurs with the findings of Kent et al [3] who noted no significant decrease in cell viability following treatment of whey protein hydrolysates in cultured human prostate epithelial cells at a concentration of 500 lg/mL. Although the MTT assay detects mitochondrial activity rather than cell viability, these phenomena are intimately related and MTT has been widely used to assess cell injury [50].…”

TRPV1 Agonist Capsaicin Attenuates Lung Ischemia-Reperfusion Injury in Rabbits

“…CGRP has also been shown to inhibit type 1 cytokines (e.g., IL-12 and interferon) and enhance the production of IL-10 [30,31]. In addition, in H9c2 cardiomyocytes and cultured smooth muscle cells, CGRP protected cells from H 2 O 2 induced oxidative stress and reduced apoptosis [32,33]. These data suggest that capsaicin mitigated lung IR injuries possibly via activations of TRPV1-induced CGRP releases.…”

TRAIL promotes the survival, migration and proliferation of vascular smooth muscle cells

“…One such mechanism is certainly the activation of the ERK/MAPK pathway. In fact, the ERK1/2 pathway has previously been demonstrated to be involved in the inactivation of the pro-apoptotic protein Bad by phosphorylation and plays a positive role in VSMC survival following oxidant injury [28][29][30]. Of note, TRAIL activated the ERK/MAPK pathway in VSMCs, similarly to insulin and PDGF.…”