Cold inducible RNA binding protein-regulated mitochondria associated endoplasmic reticulum membranes-mediated Ca2+ transport play a critical role in hypothermia cerebral resuscitation

Abstract

Cardiac arrest is a global health issue causing more deaths than many other diseases. Hypothermia therapy is commonly used to treat secondary brain injury resulting from cardiac arrest. Previous studies have shown that CIRP is induced in specific brain regions during hypothermia and inhibits mitochondrial apoptotic factors. However, the specific mechanisms by which hypothermia-induced CIRP exerts its anti-apoptotic effect are still unknown. This study aims to investigate the role of Cold-inducible RNA-binding protein (CIRP) in mitochondrial-associated endoplasmic reticulum membrane (MAM)-mediated Ca²⁺ transport during hypothermic brain resuscitation.We constructed a rat model of cardiac arrest and resuscitation and hippocampal neuron oxygen-glucose deprivation/reoxygenation model. We utilized shRNA transfection to interfere the expression of CIRP and observe the effect of CIRP on the structure and function of MAM.Hypothermia induced CIRP can reduce the apoptosis of hippocampal neurons, and improve the survival rate of rats. Hypothermia induced CIRP can reduce the expressions of calcium transporters IP₃R and VDAC1 in MAM, reduce the concentration of calcium in mitochondria, decrease the expression of ROS, and stabilize the mitochondrial membrane potential. Immunofluorescence and immunocoprecipitation showed that CIRP could directly interact with IP₃R-VDAC1 complex, thereby changing the structure of MAM, inhibiting calcium transportation and improving mitochondrial function in vivo and vitro.Both in vivo and in vitro experiments have confirmed that hypothermia induced CIRP can act on the calcium channel IP₃R-VDAC1 in MAM, reduce the calcium overload in mitochondria, improve the energy metabolism of mitochondria, and thus play a role in neuron resuscitation. This study contributes to understanding hypothermia therapy and identifies potential targets for brain injury treatment.