[Effect of pretreatment of acupuncture on learning-memory ability and related protein of NLRP3 inflammasome in hippocampus in Alzheimer's disease like rats].

OBJECTIVE

To observe the effect of pretreatment of acupuncture on the expression of nucleotide-binding oligomerization domain-like receptor 3(NLRP3), Caspase-1, interleukin1β(IL-1β) and the number of activated microglia (MG) in the hippocampus in Alzheimer's disease (AD) like rats, so as to explore the mechanism of pretreatment of acupuncture in preventing and treating AD.

METHODS

A total of 36 SD rats were randomly divided into a blank group, a model group and an electroacupuncture (EA) group, 12 rats in each group. The AD like rat model was established by 8-week continuous intraperitoneal injection of D-galactose (120 mg·kg·d) in the model group and the EA group. The rats in the EA group were intervened with EA at "Baihui" (GV 20) and "Zusanli" (ST 36), continuous wave, 5 Hz in frequency, 1 mA in intensity, 20 min each intervention, once a day, for 8 weeks. After the intervention, the spatial learning-memory ability was evaluated by the Morris water maze test. The expression levels of NLRP3, Caspase-1 and IL-1β protein in hippocampus were detected by Western blot method. The number of activated MG in hippocampus was detected by immunofluorescence labeling method.

RESULTS

Compared with the blank group, the average escape latency was prolonged (<0.01), the number of platform crossing was reduced (<0.01), and the exploration time of target quadrant was shortened (<0.01) in the model group. Compared with the model group, the average escape latency was shortened (<0.01), the number of platform crossing was increased (<0.01), and the exploration time of target quadrant was prolonged (<0.01) in the EA group. Compared with the blank group, the expression levels of NLRP3, Caspase-1, IL-1β protein in hippocampus were increased (<0.01), and the number of activated MG was increased (<0.01) in the model group. Compared with the model group, the expression levels of NLRP3, Caspase-1, IL-1β protein in hippocampus were decreased (<0.01), and the number of activated MG was decreased (<0.05) in the EA group.

CONCLUSION

Pretreatment of acupuncture could prevent and treat the learning-memory dysfunction in AD like rats, and its mechanism may be related to the inhibition of NLRP3 inflammatsome related protein and MG activation.