MicroRNA-194-5p Levels Decrease during Deep Hypothermic Circulatory Arrest

Hypothermia has been reported to be effective in protecting the brain in various clinical conditions, including resuscitation after cardiac arrest and complex cardiovascular surgery, and is considered to be a promising therapy for stroke. The present study aimed to confirm the pivotal role that miRNA-194-5p plays in deep hypothermia circulation arrest. On the basis of reductions in expression of miR-194-5p in the circulation of 21 aortic dissection patients who underwent deep hypothermia circulatory arrest, the specific expression, target, and function of miR-194-5p was investigated using primary neuron culture, polymerase chain reaction, in situ hybridization, and flow cytometry methods. Our results showed that miR-194-5p expression was significantly downregulated in hypothermia oxygen glucose deprivation-treated neurons in vitro. Cortical neurons transfected with miR-194-5p mimic exhibited increased death due to oxygen-glucose deprivation. MiR-194-5p mediated the regulation of neuronal death, which involves the downregulation of the specific target protein SUMO2, which is crucial to ischemia tolerance. Collectively, these data highlight the unique role of miR-194-5p in mediating the deep hypothermia circulation arrest response via the regulation of SUMO2. These findings suggest that miR-194-5p could be a potential therapeutic target for intervention in ischemic disease.