PT - JOURNAL ARTICLE AU - Lee, Chang-Lung AU - Moding, Everett J. AU - Cuneo, Kyle C. AU - Li, Yifan AU - Sullivan, Julie M. AU - Mao, Lan AU - Washington, Iman AU - Jeffords, Laura B. AU - Rodrigues, Rafaela C. AU - Ma, Yan AU - Das, Shiva AU - Kontos, Christopher D. AU - Kim, Yongbaek AU - Rockman, Howard A. AU - Kirsch, David G. TI - p53 Functions in Endothelial Cells to Prevent Radiation-Induced Myocardial Injury in Mice AID - 10.1126/scisignal.2002918 DP - 2012 Jul 24 TA - Science Signaling PG - ra52--ra52 VI - 5 IP - 234 4099 - http://stke.sciencemag.org/content/5/234/ra52.short 4100 - http://stke.sciencemag.org/content/5/234/ra52.full SO - Sci. Signal.2012 Jul 24; 5 AB - Radiation therapy, which is used for the treatment of some cancers, can cause delayed heart damage. In the heart, p53 influences myocardial injury that occurs after multiple types of stress. Here, we demonstrated that p53 functioned in endothelial cells to protect mice from myocardial injury after whole-heart irradiation. Mice with an endothelial cell–specific deletion of p53 succumbed to heart failure after whole-heart irradiation as a result of myocardial necrosis, systolic dysfunction, and cardiac hypertrophy. Moreover, the onset of cardiac dysfunction was preceded by alterations in myocardial vascular permeability and density, which resulted in cardiac ischemia and myocardial hypoxia. Mechanistic studies with primary cardiac endothelial cells irradiated in vitro indicated that p53 signaling caused mitotic arrest and protected cardiac endothelial cells from cell death resulting from abnormal mitosis or mitotic catastrophe. Furthermore, mice lacking the cyclin-dependent kinase inhibitor p21, which is a transcriptional target of p53, were also sensitized to myocardial injury after whole-heart irradiation. Together, our results demonstrate that the p53-p21 axis functions to prevent radiation-induced myocardial injury in mice.