Based On The Aβ Blood-brain Barrier Clearance Theory, The Effects Of Electroacupuncture On Brain LRP1 And Its Angiogenic Gene Expression In AD Model Were Investigated

1 ObjectiveAlzheimer’s disease(AD),also called senile dementia,is a kind of central nervous system degenerative disease mainly manifested by progressive cognition and memory ability disorders.AD is a great issue in public healthcare,and has been considered as the key disease in the field of central nervous system injuries.Therefore,the study of AD has become an urgent and important task both at home and abroad.Clinical research has shown that acupuncture can improve the mental and behavioral conditions of AD patients,as well as the cognitive function.Electro-acupuncture(EA)is a simple and effective modern acupuncture method used in the treatment of many diseases.More evidences have proved that acupuncture has a therapeutic effect on AD.However,the mechanism is still unclear and more exploration is needed.The amyloid cascade theory showed that the imbalance of Aβ generation and clearance was the reason that Aβ was sedimentated in the brain tissues and then formed amyloid plaques.The neuronal degeneration could be caused by the possible neurotoxic effect of the amyloid plaque,so that symptoms of AD were generated.So far,many research teams have studied and proved the existence of its neurotoxicity from multiple angles,and Aβ plays a very important role in the process of nerve degeneration and apoptosisIn this study,with the"Baihui,Yongquan"electroacupuncture,To observe Effect of Electro-Acupuncture on Behavioral Changes of different months APP/PS1 Transgenic Mice,and to explore the optimal time of the EA therapy for Alzheimer’s disease.According to the Aβacross Blood Brain Barrie(BBB),to observe the expression of brain and serum of Aβ1-40 and Aβ1-42 to in APP/PS1 transgenic mice after electro-acupuncture(EA).To observe whether Genes related to blood vessels of LRP1 can be adjusted by electro-acupuncture(EA)to strength the clearance of Apin hippocampus of APP/PS1 transgenic mice,and to explore the mechanism of the EA therapy for Alzheimer’s disease.2 MethodsFirst,Twenty 4-month-old APP/PS1 transgenic mice were randomly divided into model group and EA group,with Ten C57BL/6 wild type mice as the normal control group.The 6-month-old groups and the 9-month-old groups were grouped as the 4-month-old groups.The Morris water maze was used to assess learning-memorize ability after 6 weeks Electro-Acupuncture treatment.Furthermore,sixty-four 6-month-old APP/PS1 transgenic mice were randomly divided into model group and EA group,with thirty-two C57BL/6 wild type mice as the normal control group.The Morris water maze was used to assess learning-memorize ability.Immunohistochemistral method was used to observe the LRP1 and Aβ1-42 expression in the brain.The microvascular segment taken with quadratic sieve method,laser scanning confocal microscopy(LSCM)were used to observe LRP1 and Aβ1-42 expression in the hippocampus.Aβ1-42 was detected by Enzyme-linked immunosorbent assays(ELISA)method.and LRP1 hippocampal expression were also observed with Western Blotting and ELISA.MEOX2、MYOCD.SREBP2 were detected by Immunohistochemistry and RT-PCR method.3 Results3.1 The Morris water maze test showed that each month the escape latency of EA group were reduced compared with the model group.According to variance analysis of repeated measurement,the 5-month-old effect analysis of variance between groups have no statistically significant.The group,time and group xtime of 7-month-old and 10-month-old have statistically significant(P<0.01,P<0.05).The number of platform-site crossover and the swimming distance in platform quadrant of model group were reduced compared with the control group(P<0.05),while the EA group could revise them.3.2 The 7 monthsMorris water maze test showed the escape latency of model group increased,the number of platform-site crossover and the swimming distance in platform quadrant of model group were reduced compared with the control group(P<0.05,P<0.01)。According to Aβ1-42 immunohistochemistral and laser scanning confocal microscopy,the In model group,there were positive expressions of Aβ1-42 and sedimentations plaque.Compared with the model group,the expression of Aβ1-42 in EA group was significantly weakened.The LRP1 expression increased relatively around the blood vessels in EA group.3.3 The ELISA result showed that the Aiβn the cortex,hippocampus and serum of EA group obviously decreased compared with the model group(P<0.01).The level of LRP1 in the model group were lower than that in the control group(P<0.01),while the EA group could raise its expression.3.4 The RT-PCR result showed that The level of MEOX2 in the model group were lower than that in the control group(P<0.01),while the EA group could raise its expression(P<0.01).The MYOCD、SREBP2 in the hippocampus of EA group obviously decreased compared with the model group(P<0.01).These results consistent with the expressions of MEOX2,MYOCD and SREBP2 in the immunohistochemistry.4 Conclusions4.1 EA therapy can improve the learning-memorize ability of the APP/PS1 transgenic mice,the 6-month-old may be the optimal time for the EA treatment.4.2 The mechanism of EA therapy on Alzheimer’s disease should be explored further.EA therapy can decrease the level of Aβ in especial Aβ1-42 in brain and serum,which is the one way of EA mechanism on AD.4.3 EA therapy can improve the learning-memorize ability of the APP/PS1 transgenic mice,decrease the level of Apin brain,the mechanism may be related to the up-regulation of Aβtransport receptor LRP1.4.4 EA therapy can up-regulate MEOX2 and decrease the level of MYOCD、SREBP2 in hippocampus of them transport receptor LRP1,which is the one way of EA mechanism on AD base on the theory of Aβclearance via the BBB.