Septic cardiomyopathy is a life-threatening organ dysfunction caused by sepsis. Ribonuclease 1 (RNase 1) belongs to a group of host-defense peptides that specifically cleave extracellular RNA (eRNA). The activity of RNase1 is inhibited by ribonuclease-inhibitor 1 (RNH1). The role of RNase 1 in septic cardiomyopathy and associated cardiac apoptosis, however, is completely unknown. Here, we showed that sepsis resulted in a significant increase in RNH1 and eRNA serum levels compared to those of healthy subjects (p < 0.05). Treatment with RNase 1 resulted in a significant decrease of apoptosis, induced by the intrinsic pathway, and TNF expression in murine cardiomyocytes exposed to either necrotic cardiomyocytes or serum of septic patients for 16 h (p < 0.05). Furthermore, treatment of septic mice with RNase 1 resulted in a reduction in cardiac apoptosis, TNF expression and septic cardiomyopathy (p < 0.05). These data demonstrate that eRNA plays a crucial role in the pathophysiology of the organ (cardiac) dysfunction in sepsis and RNase and RNH1 may be new therapeutic targets/strategies to reduce the cardiac injury and dysfunction caused by sepsis.
Elisabeth Zechendorf, Caroline E O'Riordan, Lara Stiehler, Natalie Wischmeyer, Fausto Chiazza, Debora Collotta, Bernd Denecke, Sabrina Ernst, Gerhard Müller-Newen, Sina M. Coldewey, Bianka Wissuwa, Massimo Collino, Tim-Philipp Simon, Tobias Schuerholz, Christian Stoppe, Gernot Marx, Christoph Thiemermann, Lukas Martin