Abstract 15729: Neuregulin 1beta/erbb2 Signaling is Critical for Cardiac Recovery After Ischemic Injury

Introduction: ErbB2 plays a critical role in developing and adult heart. Neuregulin-1beta (Nrg) modulates PI3Kinase, MAPK, and Src/FAK signalling pathways in cardiac myocytes and thereby modulates cell survival and other phenotypes. Nrg is activated in the heart by ischemia/reperfusion injury, leading us to hypothesize that Nrg/ErbB modulates myocyte-matrix and myocyte-myocyte coupling and the response of the heart to ischemic injury at the intercalated disk. Methods: Co-immunoprecipitation assays were performed to assess interactions between ErbB receptors and components of the FAC. Isolated mouse hearts were perfused according to the Langerdorff method, and subjected 15 min ischemia followed by 30 min of reperfusion (I/R). Hearts were fixed and immunostaining, histological and electron microscopy analysis was performed. Results: Nrg induced ErbB2/ErbB4 co-immunoprecipitation with Src, FAK, p130CAS, and Paxilin in isolated myocytes. In isolated hearts subjected to I/R injury, phosphorylation of erbB2, FA...