RNase alleviates neurological dysfunction in mice undergoing cardiac arrest and cardiopulmonary resuscitation

Abstract

Cardiac arrest (CA) is one of the leading lethal factors. Despite cardiopulmonary resuscitation (CPR) procedure has been consecutively improved and lots of new strategies have been developed, neurological outcome of the patients experienced CPR is still disappointing. Ribonuclease (RNase) has been demonstrated to have neuroprotective effects in acute stroke and postoperative cognitive impairment, possibly through acting against endogenous RNA that released from damaged tissue. However, the role of RNase in post-cardiac arrest cerebral injury is unknown. In the present study, we investigated the role of RNase in neurological outcome of mice undergoing 5 minutes of CA and followed by CPR. RNase or the same dosage of normal saline was administrated. We found that RNase administration could: 1) improve neurologic score on day 1 and day 3 after CA/CPR performance; 2) improve memory and learning ability on day 3 after training in contextual fear-conditioning test; 3) reduce extracellular RNA (exRNA) level in plasma and hippocampus tissue, and hippocampal cytokines mRNA production on day 3 after CA/CPR procedure; 4) attenuate autophagy levels in hippocampus tissue on day 3 after CA/CPR procedure. In conclusion, RNase could improve neurological function by reducing inflammation response and autophagy in mice undergoing CA/CPR.