Effects of acupuncture on Nod-like receptor protein 3 inflammasome signal pathway in the prefrontal cortex of rat with depression

Abstract

To observe the influence of acupuncture on the expression of pivotal molecules of Nod-like receptor protein 3(NLRP3) inflammasome signal pathway in the prefrontal cortex of rats with depression, so as to explore the underlying mechanism of acupuncture on treatment of depression. SD rats were randomly divided into 4 groups (8 rats/group)，namely control, model, acupuncture and fluoxetine groups. The depression model was established by using chronic unpredictable mild stress for 6 weeks. During modeling, acupuncture (10 min)was applied to "Baihui"(GV20) and "Yintang"(EX-HN3) for rats of the acupuncture group once a day, with 1 day interval after consecutive 6 day-period for 36 days. Fluoxetine was given (10 mg/kg，1 mg/mL) by gavage to rats of the fluoxetine group every day during modeling for 42 days. The novelty-suppressed feeding test was used to observe feeding behavior of rats. The expressions of NLRP3 and apoptosis associated speck like protein containing a CARD (ASC), Caspase-1, and contents of IL-1β in the prefrontal cortex were detected by Western blot, immunohistoche-mistry and ELISA, separately. Compared with the control group, the latency of the novelty-suppressed feeding, and the expressions of NLRP3, ASC, Caspase-1 and IL-1β content in the prefrontal cortex of the model group were significantly increased (P<0.01). Following the interventions, the latency of the noveltysuppressed feeding，and the expressions of NLRP3, ASC, Caspase-1 and IL-1β content in the prefrontal cortex in the acupuncture and fluoxetine groups were significantly decreased (P<0.05，P<0.01). There was no significant differences in the above indicators between the acupuncture group and the fluoxetine group (P>0.05). Acupuncture could inhibit the expression of NLRP3 inflammasome signal pathway in the pre-frontal cortex, and reduce the inflammation in the brain, which may mediate the anti-depressant effect of acupuncture.