Effects Of Human Cytomegalovirus Infection On The Exprssion Of Glucocorticoid Receptor And Mineralocortico Recepto Protein In The Hippocampus Of Offspring Rats In Early Pregnancy

Objective:Human cytomegalovirus(HCMV)is the most common virus in intrauterine infection.In infants,the main cause of moderate and severe mental retardation is TORCH series intraute rine infection represented by HCMV.The hippocampus is the key physiological basis for learning and memory,and is also the main target area of human cytomegalovirus(CMV).In order to explore the mechanism of human cytomegalovirus(HCMV)resulting in the gradual decline of the learning and memory function of the offspring,In this study,we used histopathology and molecular mechanism to investigate the effect of human cytomegalovirus infection on the expression of glucocorticoid receptor and mineralocorticoid receptor protein in hippocampus of newborn rats in early pregnancy,In order to provide new therapeutic targets for the treatment of HCMV intrauterine infection,the learning and memory function of the progeny of the offspring is gradually decreasing.Methods :20 SPF grade SD rats of 9-10 week old were mated by female and male 1:1(male rats could be copulated many times),,and pregnant rats were randomly divided into control group(10 rats)and experimental group(10 rats).In the experimental group,5 x 107 L-1 half of tissue cultured infection(TCID50)HCMV suspension was intraperitoneally injected at day 5 of gestation.Equal amount of human embryo fibroblast supernatant 0.8ml were intraperitoneally injected in the control group.Ten 15 days offspring were randomly selected from each group.(1)The Morris water maze experiment was used to test the learning and memory function of the offspring rats.(2)The brain tissues were collected after perfusion with 4% paraformaldehyde,and the histopathological HE staining was used to observe the morphological changes of hippocampus in neonatal rats.Indirect immunofluorescence staining was used to detect the expression of MR and GR protein in the hippocampal(CA1 area,CA3 region)of the offspring.SPSS 16 software was used for statistical processing.Results:1.Morris water maze experiment,in the navigation experiment,the escape latency of the control group and the experimental group showed a gradual decrease.The escape latency of the experimental group was longer than that of the control group,and the difference between the fourth days(t=-2.212,P<0.05)and the fifth day(t=-2.827,P<0.05)experimental group was statistically significant compared with the control group.In the space exploration experiment,the time in the target quadrant of the experimental group was less than that of the control group(t=2.390,P<O.05),and the number of crossing platform in the experimental group was less than that of the control group,and the difference was statistically significant(t=2.477,P<O.05).2.HE staining in CA1 and CA3 regions showed that the hippocampal neurons in In the control group,the neurons of the hippocampus were evenly arranged,the nuclei were round or oval,and the nucleolus were obvious,and the chromatin was uniform.In the experimental group,the hippocampal neurons were arranged in disorder,the number of the cells decreased,the edema of the cells became larger,the nuclei of some nuclei were condensed,and the giant cell changes were seen.3.Immunofluorescence staining showed that the average absorbance of GR(t=3.05,P<0.05),MR(t=2.23,P<0.05)and GR/MR(t=2.24,P<0.05)in hippocampus CA1 area of experimental group was lower than that of control group,and the difference was statistically significant.The average absorbance of GR(t=2.76,P<0.05),MR(t=2.67,P<0.05)and GR/MR(t=2.43,P<0.05)in hippocampus CA3 area of experimental group was lower than that of control group,the difference was statistically significant.Conclusion:The spatial learning-memory of rats was decreased with Human cytomegalovirus infection(HCMV)in early pregnancy.Hippocampal neurons was damaged in hippocampus CA1 and CA3 area of offspring rats,neuron edema and decrease,nuclear condensation,and some cells show giant cell changes.The expression level of nuclear receptor GR and MR in the CA1 and CA3 regions of the hippocampus in rats is decreased,and the ratio of GR/MR decreases.The dysfunction of HPA axis may be one of the mechanisms leading to impaired learning and memory function in the offspring.