The Expression Of MiR-101, APP And COX In The SAMP8Mice Hippocampus

Objective：miR-101have the potential rule of regulating both the expression ofAPP and COX-2. To investigate whether miR-101is expected to become a new drugtarget of prevention and treatment of Alzheimer’s disease(AD), we choose thesenescence-accelerated mouse prone8(SAMP8) as the research object, and detect thechanges of the expression of miR-101, APP and COX in different months old SAMP8mouse hippocampal tissue.Methods：We choose4,8,12months old SAMP8and SAMR1(senescence-accelerated resistance) mouse as the research objects.(1) Morris water maze wasapplied to detect SAMP8mouse space memory ability.(2) The mRNA level of APPand COX in SAMP8mouse hippocampal tissue was detected by semi-quantitativeRT-PCR.(3) Western Blot was utilized to measure the protein level of APP and COXin SAMP8mouse hippocampal tissue.(4) the expression of miR-101in SAMP8mouse hippocampal tissue was tested by real time RT-PCR.Results：Morris water maze results showed that8months old SAMP8mouseappeared age-early space memory disorders. It was more significant at12monthsgroup(p <0.01). However, SAMR1groups had no significant change (p>0.05).Western Blot results of Aβ42were conform.(2) Semi-quantitative RT-PCR resultsrevealed that APP mRNA is only slightly increased with increasing age in bothSAMP8and SAMR1mice hippocampal tissues, however, SAMP8group showed alittle higher expression than did SAMR1group and significant obvious changesappeared only at12months group.(3) Western Blot analysis showed that APP levels was highest in8months SAMP8mouse(p<0.01),12months group appeared a trendof decline, however, there is no significant alteration of APP protein level in SAMR1mice.(4) real time PCR results showed that miR-101level in SAMP8mouseincreased significantly with increasing age.(5) The change trend of COX-2mRNAand protein level was similar to APP level, however, COX-1mRNA and protein levelhad no significant changes in all groups.Conclusions：(1) SAMP8mice appeared early onset spontaneous spatialmemory disorders and Aβ deposition in hippocampal tissue.(2) The expression ofAPP and COX-2in SAMP8mouse hippocampal tissue is mainly affected bypost-transcription regulation.(3) MiR-101may regulate the expression of APP andCOX-2, but not affect the expression of COX-1.(4) MiR-101may be a new drugtarget of prevention and treatment of AD.