Expression Of Adaptor Protein Complex-4 And AMPARs In Neonatal Rats With Hypoxia-Ischemic Brain Injury

ObjectiveWe established animal models of hypoxic-ischemic brain damage(HIBD) with neonate rats and then investigated the expression changes of AP4M1 and AMPA receptor in cortex, hippocampus, striatum and cerebellum at different time points after HIBD, in order to explore the hypoxic-ischemic mechanisms of brain injury. MethodsIn this study, 7 days old SD(Dawley Sprague) rats were selected as the experimental subjects and the HIBD model was made.In vivo level, we studied the expression of AP4M1, AMPA receptor m RNA and protein after HI 12 hours, 24 hours 72 hours in cortex, hippocampus, striatum and cerebellum by Real-time PCR, Western blot Result 1 Variation of AP4M1, Glu Rs in the cortex after HI1)After HI, AP4M1 m RNA in cortex appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F = 3.587, p = 0.043); AP4M1 protein in cortex appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F = 5.320, p = 0.022).2)After HI, Glu R1 m RNA in cortex appeared to be down-regulated in 12 hours, and to be upregulated in 24 hours, but still significantly lower than the control group in 72 hours(F=103.000, p=0.000); Glu R1 protein in cortex appeared to be down-regulated in 12 hours, and to be upregulated in 24 hours, but still significantly lower than the control group in 72 hours(F=574.711,p=0.000).3)After HI, Glu R2 m RNA in cortex appeared to have no changes in expression in 12 hours, and to be downregulated in 24 hours significantly, but still lower than the control group in 72 hours(F=7.823,p=0.005); Glu R2 protein in cortex appeared to be down-regulated in 12 hours slightly, to be downregulated in 24 hours significantly, regulated in 72 hours,but still lower than the control group(F=410.933,p=0.000). 2 Variation of AP4M1, Glu Rs in hippocampus after HI1)After HI, AP4M1 m RNA in hippocampus appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=154.327,p=0.000); AP4M1 protein in hippocampus appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=330.060,p=0.000).2)After HI, Glu R1 m RNA in hippocampus appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=9.074, p=0.003); Glu R1 protein in hippocampus appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=807.019,p=0.000).3)After HI, Glu R2 m RNA in hippocampus appeared to be down-regulated slighhtly in 12 hours, to be downregulated to minimization in 24 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=4.594,p=0.028); Glu R2 protein in hippocampus appeared to be down-regulated in 12 hours, to be downregulated to minimization in 24 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=425.574,p=0.000).3 Variation of AP4M1, Glu Rs in striatum after HI1)After HI, AP4M1 m RNA in striatum appeared to be down-regulated in 12 hours, and to be upregulated in 24 hours, but still significantly lower than the control group in 72 hours(F=8.556,p=0.003); AP4M1 protein in striatum appeared to be down-regulated in 12 hours, and to be upregulated in 24 hours, but still significantly lower than the control group in 72 hours(F=555.071,p=0.000).2)After HI, Glu R1 m RNA in striatum appeared to be down-regulated in 12 hours, and to be upregulated in 72 hours, but still significantly lower than the control group(F=161.996,p=0.000); AP4M1 protein in striatum appeared to have no significant change with control group in 72 hours(F=0.908,p=0.437).3)After HI, Glu R2 m RNA in striatum appeared to be down-regulated to minimization in 12 hours, and to be upregulated in 24 hours, but still significantly lower than the control group in 72 hours(F=18.483,p=0.000); Glu R2 protein in striatum appeared to be down-regulated in 12 hours to minimization, and to be upregulated in 24 hours, but still significantly lower than the control group in 72 hours(F=90.438,p=0.000). 4 Variation of AP4M1, Glu Rs in cerebellum after HI1)There was no difference in the expression of AP4M1 m RNA in 12 hours,24 hours and 72 hours in cerebellum after HI with control group(F=0.602,p=0.56);There was no difference in the expression of AP4M1 protein in 12 hours,24 hours and 72 hours in cerebellum after HI with control group(F=1.184,p=0.369)。2)There was no difference in the expression of Glu R1 m RNA in 12 hours,24 hours and 72 hours in cerebellum after HI with control group(F=0.102,p=0.903);There was no difference in the expression of Glu R1 protein in 12 hours,24 hours and 72 hours in cerebellum after HI with control group(F=312.032,p=0.000)。3)There was no difference in the expression of Glu R2 m RNA in 12 hours,24 hours and 72 hours in cerebellum after HI with control group(F=56.718,p=0.000);There was no difference in the expression of Glu R2 protein in 12 hours,24 hours and 72 hours in cerebellum after HI with control group(F=312.032,p=0.000)。 Conclusions:1.In different sites of Rat brains, the expression of Glu R1 and Glu R2 in m RNA and protein level was downregulated at different levels after HI.2. The expression of AP4M1 in m RNA and protein levels appear to be downregulated in cortex, hippocampus and striatum, but does not change significantly in cerebellum after HI.3.The expression of AP4M1 is downregulated relatively earlier than Glu R2 after HI.4.The effects of hypoxia ischemia on the expression of AP4M1 and Glu R2 in different parts of brain tissue are not consistent.