New Role for Interleukin-13 Receptor α1 in Myocardial Homeostasis and Heart Failure.

Background--The immune system plays a pivotal role in myocardial homeostasis and response to injury. Interleukins-4 and -13 are anti-inflammatory type-2 cytokines, signaling via the common interleukin-13 receptor alpha 1 chain and the type-2 interleukin-4 receptor. The role of interleukin-13 receptor a1 in the heart is unknown. Methods and Results--We analyzed myocardial samples from human donors (n=136) and patients with end-stage heart failure (n=177). We found that the interleukin-13 receptor alpha 1 is present in the myocardium and, together with the complementary type-2 interleukin-4 receptor chain Il4ra, is significantly downregulated in the hearts of patients with heart failure. Next, we showed that Il13ra1-deficient mice develop severe myocardial dysfunction and dyssynchrony compared to wild-type mice (left ventricular ejection fraction 29.7 +/- 9.9 versus 45.0 +/- 8.0; P=0.004, left ventricular end-diastolic diameter 4.2 +/- 0.2 versus 3.92 +/- 0.3; P=0.03). A bioinformatic analysis of mouse hearts indicated that interleukin-13 receptor a1 regulates critical pathways in the heart other than the immune system, such as extracellular matrix (normalized enrichment score=1.90; false discovery rate q=0.005) and glucose metabolism (normalized enrichment score=-2.36; false discovery rate q=0). Deficiency of Il13ra1 was associated with reduced collagen deposition under normal and pressure-overload conditions. Conclusions--The results of our studies in humans and mice indicate, for the first time, a role of interleukin-13 receptor alpha 1 in myocardial homeostasis and heart failure and suggests a new therapeutic target to treat heart disease.