The Experimental Study Of DWI Monitoring Of The Treatment Effection For The Ischemic Brain Edema With The AQP4 MRNA Interference

Objective The aim of this study was to investigate siRNA-AQP4 interference of water channel protein-4 (AQP4) in early ischemic brain edema and the diagnostic values of diffusion-weighted imaging (DWI).Methods The 64 Wistar rats were randomly divided into 4groups:The normal group(n=1), sham operation group(n=3), the control group(MCAO) and treatment group (MCAO+SiRNA),After the two groups would be further divided into 6 groups (n=5 for each group). In after 15 min,30 min,1 h,2h,4h and 6 h time point were used immunohistochemistry, in situ hybridization, RT-PCR, Westen Blotting and MRI image analysis technique in determining the expression level of AQP4 infarct area and infarct size determination, and at the same time light and transmission electron microscopy (TEM) for the corresponding parts of the observation.Results Normal group and sham operation group of the MRI were normal, no pathological changes in brain tissue, AQP4 expression was not changed significantly. Control group:in ischemia and 15 min-6h after appearing in the DWI high signal rs-DWI is increasing rapidly, AQP4 protein expression was markedly increased, rs-DWI is a rapid increase, Treatment group:15 min-6 h after ischemia has also appeared on DWI high signal, with time, rs-DWI gradually increased, ADC value decreased gradually, Between treatment group with control group,30min-4-hour time segment rs-DWI, AQP4 protein expression between the two groups with significant difference (P<0.05). Within 15min arid 6h time points no significant difference between the two groups (P> 0.05).Conclusion The results imply that the up-regulating of the AQP4 expression is the molecular mechanism of the acute ischemic edema, which is result in the decreasing of the rADC. RANi might be effective technique for treat IP. But it become ineffectively With the progress of the time(4 h-6 h) after MCAO, which the pathologic changes in the stage was mixedema. The DWI could provide valuable imaging information for diagnostic the acute ischemic edema.RNA interference (RNAi) AQP4 in 30min, 1h,2h and 4h time can make brain tissue mRNA and AQP4 protein expression was decreased, and the corresponding time period in brain edema, the treatment group than the surgery group ischemic area of ischemic area reduced; 15min and 6h the impact on the brain edema was no significant change in the treatment group rs-DWI rs-DWI than the surgical group no significant change. AQP4 protein expression and rs-DWI was positively correlated. AQP4 protein expression was negatively correlated with the rADC.