C3G overexpression promotes the survival of rat‐derived H9C2 cardiomyocytes by p‐ERK1/2

Abstract

Integrin β1 subunit and its downstream molecules, such as integrin-linked kinase and focal adhesion kinase, are imperative for promotion of cell proliferation, survival and anti-apoptosis in cardiomyocytes by activation of their downstream pro-survival signalling molecules, such as the phosphorylated extracellular signal-regulated kinase1/2 (p-ERK1/2). As a component of the integrin pathway, C3G (Crk-SH3 domain guanine nucleotide exchange factor) protein may be involved in the promotion of cell proliferation and survival and anti-apoptosis in the H9C2 cardiomyocytes. Rat-derived H9C2 cardiomyocytes were transfected with pCXN2-flag-hC3G, a human C3G overexpression eukaryotic recombinant plasmid. Apoptosis, cell proliferation and survival were analysed in the H9C2 cardiomyocytes either treated with hypoxia/reoxygenation (H/R). Human C3G mRNA overexpression significantly elevated C3G protein expression in H9C2 cardiomyocytes whether treated with H/R or not. C3G overexpression promoted proliferation and survival and anti-apoptosis, and attenuated the proliferative and survival inhibition, and apoptosis induced by H/R by activation of its downstream pro-survival signalling molecule, p-ERK1/2. The results suggest that C3G acts as a pro-survival molecule in H9C2 cardiomyocytes by activation of p-ERK1/2.

Knockdown of CkrL by shRNA deteriorates hypoxia/reoxygenation‐induced H9C2 cardiomyocyte apoptosis and survival inhibition Via Bax and downregulation of P‐Erk1/2

“…[1][2][3] Increased apoptosis and cell survival inhibition in cardiomyocytes are the major causes of cardiomyocyte loss, ischemia/ reperfusion or H/R-induced myocardial injuries, postinfarction ventricular enlarged cardiomyopathy and systolic heart failure. [1][2][3] Increased apoptosis and cell survival inhibition in cardiomyocytes are the major causes of cardiomyocyte loss, ischemia/ reperfusion or H/R-induced myocardial injuries, postinfarction ventricular enlarged cardiomyopathy and systolic heart failure.…”

“…1,4,5 Targeting integrin pathway is a novel therapy measure for the previously mentioned cardiovascular diseases 6 because of its effects of cytoskeleton polymerisation and anti-apoptosis and prosurvival on the cardiomyocytes. 9 Integrin β1 subunit and its downstream molecules such as integrin-linked kinase (ILK), focal adhesion kinase (FAK), Dock180 (dedicator of cytokinesis 1) and C3G [v-crk avian sarcoma virus CT-10 oncogene homolog (Crk)-Src homology 3 (SH3) domain guanine nucleotide exchange factor] have been confirmed to be requisite to the inhibition of ischemia/reperfusion or H/R-induced myocardial injuries, postinfarction cardiac remodelling, ischemic cardiomyopathy and heart failure [10][11][12] because of their effects of actin cytoskeleton polymerisation and prosurvival and anti-apoptosis on the cardiomyocytes, 2,3,11,12 which are mediated possibly by regulating their downstream signalling molecules including Bax and phosphorylated extracellular signal-regulated kinase1/2 (p-ERK1/2). 9 Integrin β1 subunit and its downstream molecules such as integrin-linked kinase (ILK), focal adhesion kinase (FAK), Dock180 (dedicator of cytokinesis 1) and C3G [v-crk avian sarcoma virus CT-10 oncogene homolog (Crk)-Src homology 3 (SH3) domain guanine nucleotide exchange factor] have been confirmed to be requisite to the inhibition of ischemia/reperfusion or H/R-induced myocardial injuries, postinfarction cardiac remodelling, ischemic cardiomyopathy and heart failure [10][11][12] because of their effects of actin cytoskeleton polymerisation and prosurvival and anti-apoptosis on the cardiomyocytes, 2,3,11,12 which are mediated possibly by regulating their downstream signalling molecules including Bax and phosphorylated extracellular signal-regulated kinase1/2 (p-ERK1/2).…”

“…7,8 Integrin pathway links extracellular matrix substances to actin cytoskeleton in cardiomyocytes, and senses mechanical stretch, and translates it into intracellular biochemical signalling. 3,13 CrkL (Crk-like) is an adaptor protein in the integrin pathway and was found to be present in the periinfarct myocardium ( Figure 1). 3,13 CrkL (Crk-like) is an adaptor protein in the integrin pathway and was found to be present in the periinfarct myocardium ( Figure 1).…”

Silencing of C3G increases cardiomyocyte survival inhibition and apoptosis via regulation of p‐ERK1/2 and Bax

“…The CrkL effects on cell pro‐survival and anti‐apoptosis may be mediated via C3G. On the other hand, as a guanine nucleotide exchange factor in the integrin pathway, C3G was found to be expressed in H9C2 cardiomyocytes and rat peri‐infarct myocardium . We have also demonstrated that overexpression of C3G can promote cell survival and alleviate hypoxia and reoxygenation (H/R)‐induced survival inhibition and apoptosis in H9C2 cardiomyocytes .…”

“…Proposed molecular mechanisms are mediated by the upregulation of their downstream pro‐survival molecules such as phosphorylated extracellular signal‐regulated kinase1/2 (p‐ERK1/2) and the downregulation of pro‐apoptotic molecules such as Bax . Our previous study has shown that v‐crk avian sarcoma virus CT‐10 oncogene homolog‐like (CrkL), an adaptor protein which can bind Rap guanine nucleotide exchange factor 1 (C3G) in the integrin pathway, has the effects of cell pro‐survival and anti‐apoptosis on H9C2 cardiomyocytes . The CrkL effects on cell pro‐survival and anti‐apoptosis may be mediated via C3G.…”