Tumor necrosis factor‐alpha induces gp91phox, Nox1, Nox4 and eNos in rat myocardium and cardiomyocyte cell line

Abstract

Tumor necrosis factor-alpha (TNF-α) is a multifunctional cytokine that induces myocardial dysfunction, thereby contributing to the pathogenesis of cardiovascular disease. Pentoxifylline (PTX) is a xanthine derivative known to inhibit the production of TNF-α. In this study, we determined the in vivo and in vitro effects of TNF-α on oxidative stress in the left ventricle (LV) and in rat cardiomyocyte cultures. Methods In vivo: Rats were treated with TNF-α @ 30 μg/kg BW/day or saline for 5 days. One group of rats received TNF-α and PTX @ 20 mg/kg BW. LV function was measured at baseline and on day 5 using echocardiography. Subsequently, rats were sacrificed and the gene expression for gp91phox, Nox1, Nox4, and eNOS in the myocardium was measured using real-time PCR. In vitro: H9C2 rat cardiomyocyte cultures were treated with 5 ng/ml of TNF-α alone or 30 min pretreatment with PTX and TNF-α for 6h and the cells were harvested for gene expression studies. Results TNF-α treatment induced a significant increase in gp91phox, Nox1, Nox4 and eNOS in rat myocardium and in cardiomyocyte cultures. Pretreatment with PTX prevented TNF-α induced gene expression. Conclusions Both in vitro and in vivo treatment with TNF-α increases gene expression for eNOS, gp91phox, Nox1, and Nox4 in cardiomyocyte cultures and LV tissues. TNF-α modulate oxidative stress in vitro cardiomyocyte cultures and in the rat myocardium.