Optimized application of siRNA targeting aquaporin 4 with hypothermia treatment on cerebral edema following traumatic brain injury

Objective To optimize the treatment effect of siRNA targeting aquaporin 4 with hypothermia on cerebral edema following traumatic brain injury. Methods To construct siRNA targeting aquaporin 4, and establish the TBI models in rats. The animals were divided into four groups: TBI group, AQP-4 siRNA group, hypothermia group, and combined group. To extract the total mRNA and proteins on the 1st, 3rd, 5th, and 7th day for RT-PCR and western blot analysis. The changes of brain water content and permeability of blood-brain barrier were measured by the methods of wet and dry weight and Evans blue fluorometry. All the rats were given a mark for their nerve function on the 7th day. Results Hypothermia treatment can obtain better effect than AQP-4 siRNA in lessening brain edema level. Meanwhile, siRNA treatment can obtain better effect than hypothermia group in silencing AQP-4 mRNA and protein expression. When combining hypothermia treatment with AQP-4 siRNA, we can obtain an optimized result than the single application of above mentioned two groups. Conclusion The application of siRNA targeting aquaporin 4 may optimize the treatment effect of hypothermia on traumatic brain injury rats. Key words: Aquaporin;  RNA interference;  Craniocerebral trauma;  Hypothermia