RESUMO
OBJECTIVE: To explore the mechanism of electroacupunctureï¼EAï¼ in improving learning-memory ability in Alzheimer's disease ï¼ADï¼ mice from the perspective of endosomal-lysosomal system. METHODS: Male APP/PS1 transgenic mice were randomly divided into model group and EA group ï¼n=10 in each groupï¼ and 10 male C57BL/6 wild mice were taken as the normal group. EA ï¼1 Hz/50 Hz, 1 mAï¼ was applied at bilateral "Yongquan"ï¼KI1ï¼ and acupuncture was applied at "Baihui" ï¼GV20ï¼ for 15 min. The mice of the model and normal groups were subjected to restriction with the same method as those of the EA group for 15 min. The treatment was conducted once every other day for 6 weeks. The spatial learning-memory ability ï¼shown by escape latency of place navigation test and the time of crossing the target platform and total swimming distance in the target quadrant in 1 min of spatial probe test ï¼ was detected by Morris water maze test. The immunoactivity of senile plaques ï¼SPï¼ in the hippocampus tissue was detected by immunohistochemistry. The ultrastructural characters of hippocampal neurons were observed by transmission electron microscope, and the expression levels of Ras-related protein 5 ï¼Rab5ï¼, Ras-related protein 7 ï¼Rab7ï¼ and cathepsin D ï¼CTSDï¼ in the hippocampus were detected by Western blot, separately. RESULTS: Compared with the normal group, the escape latency, SP immunoactivity, and protein expression levels of Rab5, Rab7 and CTSD were significantly increased ï¼P<0.05, P<0.01ï¼, while the number of crossing the original platform and the total swimming distance in the platform quadrant were considerably reduced ï¼P<0.05ï¼ in the model group. In contrast to the model group, the EA group had a marked decrease in the escape latency, SP immunoactivity, and protein expression levels of Rab5, Rab7 and CTSD ï¼P<0.05, P<0.01ï¼, and a striking increase in the number of crossing the original platform and the swimming distance in the platform quadrant ï¼P<0.05ï¼. Results of transmission electron microscope showed an accumulation of endosome, lysosome, and endolysosomes in the hippocampal neurons in the model group, which was evidently milder in the EA group. CONCLUSION: EA of GV20 and KI1 can improve the learning-memory ability of AD mice, which may be related to its function in reducing hippocampal Aß deposition and down-regulating endosomal-lysosomal system activity.
Assuntos
Doença de Alzheimer , Eletroacupuntura , Masculino , Camundongos , Animais , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Doença de Alzheimer/genética , Doença de Alzheimer/terapia , Endossomos , Lisossomos/genética , Placa AmiloideRESUMO
OBJECTIVE: To investigate the effect of electroacupuncture (EA) on the expression of ß-amyloid (Aß) and autophagy-related proteins in hippocampal cells of Alzheimer's disease (AD) model mice, so as to explore its underlying mechanisms. METHODS: Eighteen male APP/PS1 transgenic mice (6 months old) were randomly divided into model and EA groups, with 9 mice in each group. Nine male C57BL/6 wild-type mice of the same age were chosen as the normal group. Mice in the EA group were treated with acupuncture on "Baihui" (GV20) and EA (1 Hz/50 Hz, 1 mA) on bilateral "Yongquan" (KI1), once every other day, 20 min each time for a total of 21 times. After the interventions, the spatial learning and memory ability were observed by Morris water maze test. The autophagy-related pathological changes in hippocampus were observed by transmission electron microscopy. The expressions of microtublue associated protein 1 light chain 3 (LC3) and Aß in hippocampus were observed by immunofluorescence and the expression levels of LC3 and p62 proteins were detected by Western blot. RESULTS: Compared with the normal group, the escape latency was prolonged (P<0.01), the residence time in the original quadrant platform was shor-tened (P<0.05), the positive expressions of LC3 and Aß, the expression levels of LC3â ¡ and p62 proteins, and the ratio of LC3â ¡/LC3â proteins in hippocampus were increased (P<0.01, P<0.05) in the model group. Compared with the model group, the escape latency was shortened (P<0.05), the residence time in the original quadrant platform was prolonged (P<0.05), the positive expressions of LC3 and Aß, the expression levels of LC3â ¡ and p62 proteins, and the ratio of LC3â ¡/LC3â proteins in hippocampus were decreased (P<0.05) in the EA group. The transmission electron microscopy showed that the structure of neurons was normal in the normal group, a large number of autolysosomes and autophagosomes existed in hip-pocampal nerve cells in the model group, and only a small number of autophagosomes were observed in the EA group. CONCLUSION: EA can reduce the expression levels of autophagy-related proteins LC3 and p62 in APP/PS1 transgenic mice, improve the hip-pocampal autophagy state, reduce intracellular Aß aggregation, and thus improve the learning and memory ability.