The Establishment Of Rosa26-LSL-IE2/Cre Mouse Model And The Effects Of IE2 On The Cognitive Ability Of The Hippocampus

Objective:By constructing the Rosa26-LSL-IE2/Cre mouse model,the effects of HCMV IE2 on the cognitive function of the hippocampus and NMDARs/Ca MKIIα/CREB signal pathway were studied.The establishment of the model mice broke through the traditional practice of using mouse cytomegalovirus(MCMV)as an HCMV infection model,overcame the species limitation of HCMV,and laid a theoretical foundation for clarifying the pathogenic mechanism of nervous system development deformity caused by HCMV.Methods:In order to obtain the Rosa26-LSL-IE2/Cre(IE2~+/Cre~+)mouse,Rosa26-LSL-IE2(IE2~+/Cre~-)transgenic mice were mated with Ca MKIIα-Cre(IE2~-/Cre~+)mice.The tissue DNA of offspring mice was extracted,and the genotype of mice was identified by PCR.According to the PCR results,Rosa26-LSL-IE2/Cre(IE2~+/Cre~+)mice with IE2 and Cre genes were classified as the experimental group,and wild mice were used as the control group.We detected the expression of IE2 protein in the hippocampus of mice by Western Blot and IHC experimental techniques,and analyzed the overall structural changes and neuron cell status of the hippocampus of mice by HE staining technique.Then,the cognitive ability of the two groups of mice was tested by new object recognition and water maze test.Later,the m RNA expression levels of Glu N1,Glu N2A,Glu N2B and BDNF in the hippocampus of the two groups of mice were detected by q PCR,and the protein expression levels of Glu N1,Glu N2A and Glu N2B and the phosphorylation levels of Ca MKIIαand CREB were detected by Western Blot.Results:1.The mouse model was successfully constructed,and the mouse realized the stable inheritance and expression of IE2 protein in the hippocampus of the brain.2.The results of HE staining showed that the arrangement of hippocampal cell layer was disordered and the number decreased in the experimental group.3.Behavioral results showed that in the new object recognition test,the recognition index(RI)of the experimental group mice to recognize the new object C was significantly lower than that of the control group.And the results of water maze showed that in the training stage,the time for the experimental group mice to find and board the platform was longer than that of the control group,while in the testing stage,the times for the experimental group mice to cross the target platform and the percentage of time for them to swim in the quadrant where the platform was located were less than that of the control group.4.The q PCR results showed that the m RNA expression levels of Glu N1,Glu N2A,and Glu N2B decreased in the experimental group,and the Western Blot results showed that the expression levels of Glu N1,Glu N2A,and Glu N2B and the phosphorylation level of Ca MKIIαand CREB decreased in the experimental group.The above results were statistically significant.Conclusions:Rosa26-LSL-IE2/Cre mouse model was successfully constructed to achieve stable expression and inheritance of IE2.IE2 damaged the hippocampal formation of model mice and affected the expression of NMDARs/Ca MKIIα/CREB signal pathway,which was one of the mechanisms of cognitive impairment caused by HCMV IE2.