Molecular identification for epigallocatechin-3-gallate-mediated antioxidant intervention on the H2O2-induced oxidative stress in H9c2 rat cardiomyoblasts

Abstract

BackgroundEpigallocatechin-3-gallate (EGCG) has been documented for its beneficial effects protecting oxidative stress to cardiac cells. Previously, we have shown the EGCG-mediated cardiac protection by attenuating reactive oxygen species and cytosolic Ca2+ in cardiac cells during oxidative stress and myocardial ischemia. Here, we aimed to seek a deeper elucidation of the molecular anti-oxidative capabilities of EGCG in an H2O2-induced oxidative stress model of myocardial ischemia injury using H9c2 rat cardiomyoblasts.ResultsProteomics analysis was used to determine the differential expression of proteins in H9c2 cells cultured in the conditions of control, 400 μM H2O2 exposure for 30 min with and/or without 10 to 20 μM EGCG pre-treatment. In this model, eight proteins associated with energy metabolism, mitochondrial electron transfer, redox regulation, signal transduction, and RNA binding were identified to take part in EGCG-ameliorating H2O2-induced injury in H9c2 cells. H2O2 exposure increased oxidative stress evidenced by increases in reactive oxygen species and cytosolic Ca2+ overload, increases in glycolytic protein, α-enolase, decreases in antioxidant protein, peroxiredoxin-4, as well as decreases in mitochondrial proteins, including aldehyde dehydrogenase-2, ornithine aminotransferase, and succinate dehydrogenase ubiquinone flavoprotein subunit. All of these effects were reversed by EGCG pre-treatment. In addition, EGCG attenuated the H2O2-induced increases of Type II inositol 3, 4-bisphosphate 4-phosphatase and relieved its subsequent inhibition of the downstream signalling for Akt and glycogen synthase kinase-3β (GSK-3β)/cyclin D1 in H9c2 cells. Pre-treatment with EGCG or GSK-3β inhibitor (SB 216763) significantly improved the H2O2-induced suppression on cell viability, phosphorylation of pAkt (S473) and pGSK-3β (S9), and level of cyclin D1 in cells.ConclusionsCollectively, these findings suggest that EGCG blunts the H2O2-induced oxidative effect on the Akt activity through the modulation of PIP3 synthesis leading to the subsequent inactivation of GSK-3β mediated cardiac cell injury.

Epigallocatechin Gallate (EGCG) Inhibits Alpha-Synuclein Aggregation: A Potential Agent for Parkinson’s Disease

“…EGCG has shown to exert such activity by influencing cellular signal transduction pathways and reactive oxygen species [38,39]. Previous studies have shown that gallate esters are important for the association of polyphenols with proteins, probably because they mediate weak hydrophobic interactions with proline-rich regions in target proteins, which is a prerequisite for subsequent hydrogen bond formation [40].…”

Molecular targets for anti-oxidative protection of green tea polyphenols against myocardial ischemic injury

“…EGCG is the most physiologically potent compound, and primarily accounts for the biological effects of green tea [ 2 ]. Studies with a cell line of H9c2 rat cardiomyoblasts associated with H 2 O 2 - induced oxidative stress also demonstrated the protective role of EGCG against oxidative injury and cell death caused by ROS and cytosolic Ca 2+ overload in cardiac cells [ 29 - 31 ].…”

“…The convergence of these pathways via inhibition of GSK-3β on the end effector to limit mPTP induction is the general mechanism of cardiomyocyte protection [ 52 ]. Recent reports also provided evidence for that the cardio-protection of GTPs against oxidative stress associated with myocardial ischemic injury is caused by reducing cytosolic Ca 2+ overload and generation of ROS via the Akt/GSK-3β/β-catenine and caveolae signaling both in vivo myocardial ischemia injury [ 13 , 14 ] and In vitro H 2 O 2 -induced oxidative stress models [ 29 - 30 ].…”

“…Cx43) [ 13 ]. Evidence also suggested that GTPs pretreatment acts to protect heart from IR injury through PI3K/Akt survival pathway to limit GSK-3β activity in cardiac cells [ 13 , 29 , 30 ].…”

“…To identify the potential proteins for the GTPs-mediated cardioprotection, cardiac proteomics study was performed in an H 2 O 2 - induced oxidative stress model of myocardial ischemia injury [ 29 ]. In this model, 8 proteins associated with metabolism, electron transfer, redox regulation, signal transduction, RNA binding and transcription regulation were identified to take part in EGCGameliorating H 2 O 2 -induced injury to H9c2 cells.…”