Doxorubicin Induces Apoptosis in H9c2 Cardiomyocytes: Role of Overexpressed Eukaryotic Translation Initiation Factor 5A

Abstract

The cardiotoxicity of doxorubicin limits its clinical use in the treatment of a variety of solid tumors and malignant hematologic disease. Although the mechanism by which it causes cardiac injury is not yet known, apoptosis has been regarded as one of mechanisms underlying the cardiotoxic effects of doxorubicin. Eukaryotic translation initiation factor 5A (eIF5A) is a ubiquitously expressed multifunctional protein that interacts with a range of ligands and is implicated in cell signaling. However, there has been no direct evidence for the critical involvement of eIF5A in doxorubicin-induced apoptosis. Overexpression of eIF5A induced by doxorubicin in cardiomyocyte leads to growth perturbation along with initiation of apoptosis. Overexpression of eIF5A results in a gradual increase in reactive oxygen species (ROS) generation. This mitochondrial dysfunction is due to a gradual increase in ROS generation in eIF5A-overexpressing H9c2 cells. Along with ROS generation, increased Ca(2+) influx in mitochondria leads to loss of the mitochondrial transmembrane potential, release of cytochrome-c, and caspase activation. However, small interfering RNA (siRNA)-mediated suppression of eIF5A results in inhibition of apoptosis. Interestingly, upon overexpression of eIF5A induced by doxorubicin, cell apoptosis was shown to be significantly inhibited when cells were treated with SB202190 (p38 mitogen-activated protein kinase inhibitor) and SP600125 (anti-c-Jun N-terminal kinase inhibitor) for 18 h. The reduction in oxidant generation and reduction in the apoptotic cell population were the results of the disruption of eIF5A expression, corroborating the hypothesis that excess ROS generation with overexpression of eIF5A induced by doxorubicin leads to apoptosis due to the accumulation of eIF5A.

Telekin Induces Apoptosis Associated with the Mitochondria-Mediated Pathway in Human Hepatocellular Carcinoma Cells

“…32,33) excessive Ca 2+ load to the mitochondria may also induce RoS production and apoptosis by stimulating the release of apoptosis-promoting factors from the mitochondrial intermembrane space to the cytoplasm. [34][35][36] In the current work, telekin-treated HepG-2 cells showed an early increase in cellular RoS production and Ca 2+ overload before apoptosis, indicating that mitochondrial damage is possibly related to Ca 2+ release caused by oxidative stress.…”

Sulforaphane protects the heart from doxorubicin-induced toxicity

“…Activation of caspase-3 due to DOX-toxicity is the hallmark of apoptosis in mammalian cardiac cells [59, 60]. In order to analyze the protective effect of SFN on DOX-induced apoptosis, we compared the activity of caspase-3 in SFN-, DOX- and SFN+DOX-treated H9c2 cells.…”

The effect of a number of H9C2 rat cardiomyocytes passage on repeatability of cytotoxicity study results

“…Its parameters are particularly useful in preclinical tests of anticancer drugs, determining their cardiotoxicity, safety, and possibility of moving to subsequent stages of clinical tests. Drug effects on cardiomyocytes are evaluated by determining cytotoxicity of a given compound, changes in cardiomyocyte morphology, percentage of necrotic cells, and the effect on proliferation (Tan et al 2010). …”

“…This line is commonly used in numerous in vitro studies because morphological parameters of their cells resemble immature embryonic cardiomyocytes (Louch et al 2001; Tan et al 2010; Watkins et al 2011). However, these cells retain some components of the signalling pathway essential for their differentiation into mature cardiac muscle cells.…”