The Experimental Study Of The Expression Changes Of Collapsin Response Mediator Protein 2 And Phosphorylation Collapsin Response Mediator Protein 2 In The Hippocampus Of A Rat Model Of Diffuse Axonal Injury

Objective To investigate the changes in the expression of collapsin response-mediator protein 2 (CRMP2) and phosphorylation collapsin response mediator protein 2 (p-CRMP2) in the hippocampus of the rat brain after diffuse axonal injury(DAI) by using immunofluorescence,Western blot and Real-time PCR technologies.Methods1. A rat model of DAI established by an experimental device independently designed (Patent No.:ZL200920067463.4) for inducing simultaneous linear and angular accelerations.2. Using immunofluorescence technique to qualitative research the expression of CRMP2 and p-CRMP2 in normal and DAI 7d groups of hippocampus in rats.3. Using Western blot technique to quantitative research the expression of the CRMP2 and p-CRMP2 in different time points after DAI and normal group of hippocampus in rats. Besides, the Real-time PCR technique is used to detect the expression of CRMP2 mRNA in the above-mentioned groups.Results1. Immunofluorescence:The expression of CRMP2 and p-CRMP2 are widespread in rat hippocampal neurons. The normal and DAI 7d groups demonstrate positive immunofluorescence reaction, both of the two proteins show green fluorescence and the nucleus emits blue fluorescence.2. Western blot and Real-time PCR:Both of CRMP2 and p-CRMP2 are expressed in different time points after DAI in hippocampus tissues. At the protein level:Compared with normal group, the CRMP2 expressed in the DAI 3day and 7day groups were significantly reduced(p<0.05),but after DAI 30 days, it is not change significantly. At the mRNA level:Compared with normal group, the CRMP2 expressed in the DAI 3day and 7day groups were significantly reduced(p<0.05),but after DAI 30 days, it is not change significantly. At the protein level, for the p-CRMP2, compared with normal group, it expressed in the DAI lday,3day and 7day groups were significantly increased(p<0.05),but after DAI 30 days, it is not change significantly.Conclusions Both CRMP2 and p-CRMP2 expressed in the hippocampus of rats before and after DAI. The expression of CRMP2 is decreasing while the p-CRMP2 is increasing at the early stage of DAI. At the 30th day after DAI, both of the two proteins reverse to the normal level.