Significance of changes in TNF-α and IL-10 levels in the progression of heart failure subsequent to myocardial infarction

Abstract

We tested whether a decrease in the ratio of interleukin-10 (IL-10) to tumor necrosis factor-α (TNF-α) correlates with the decrease in cardiac function in heart failure. It has been suggested that TNF-α plays a role in the progression of heart failure, and the effect of TNF-α in many tissues is modulated by IL-10. Any relation of these two cytokines to heart failure has never been examined. Cardiac function was assessed by echocardiographic and hemodynamic techniques in coronary artery-ligated rats at 1, 4, 8, and 16 wk after myocardial infarction (MI). Membrane-bound and soluble fractions of TNF-α and IL-10 proteins, the ratio of TNF-α to IL-10, and TNF-α and IL-10 mRNA levels were analyzed. Losartan was used to modify cardiac function in rats 4 wk after MI to further validate the relation between the IL-10-to-TNF-α ratio and cardiac function. Cardiac function deteriorated with time in all coronary artery-ligated groups, with severe failure at 16 wk after MI. Membrane-bound and soluble TNF-α protein fractions were increased 1 and 4 wk after MI, whereas TNF -α mRNA was increased 4 and 8 wk after MI. Membrane-bound IL-10 protein and mRNA levels were decreased 4, 8, and 16 wk after MI. The decrease in the IL-10-to-TNF-α protein ratio in all coronary artery-ligated groups correlated with the depressed cardiac function. Losartan improved cardiac function, membrane-bound and soluble TNF-α and IL-10 protein levels, the ratio of IL-10 to TNF-α, and IL-10 mRNA. This study suggests that a decrease in IL-10 and IL-10-to-TNF-α ratio correlates with depressed cardiac function.