Excitation-contraction coupling in ventricular myocytes is enhanced by paracrine signaling from mesenchymal stem cells

► Bone marrow derived mesenchymal stem cells enhance cardiomyocyte E-CC. ► Changes in E-CC and survival are mediated by paracrine signaling. ► MSCs activate the PI3K/Akt pathway and eNOS dependent NO production. ► MSCs increase Ca transient amplitude by increasing ICa,L and SERCA activity. ► Increased SERCA activity depends on eNOS activity.