Effects of electroacupuncture on microglia phenotype and epigenetic modulation of C/EBPβ in SAMP8 mice.

Backgroud: Alzheimer's disease (AD), an age-progressive neurodegenerative disease, is featured by a relentless deterioration of cognitive abilities. In parallel with the hypotheses of Aβ and tau, microglia-mediated neuroinflammation is a core pathological hallmark of AD. Promoting the transition of microglia from M1 to M2 phenotype and inhibition of neuroinflammatory response provide new insights into the treatment of AD. And substantial studies have confirmed that overexpression of C/EBPβ accelerates the progression of AD pathology. Acupuncture is renowned for its unique advantages including safety and effectiveness, which has gained wide application in geriatric diseases, and thoroughly exploring the mechanism for its treatment of AD will provide scientific basis for its clinical application.

Methods: In this study, SAMP8 mice were employed and EA therapy was performed as the main intervention. The combination of behavioural experiments (including water maze and novel objective recognition), Immunofluorescence, Western blot, and Chip-qPCR assay were performed to compare between different groups.

Results: EA therapy facilitates the polarization of microglia from M1 to M2 phenotype, reduces pro-inflammatory cytokines (IL-6, IL-1β and TNF-α) and promotes the expression of anti-inflammatory factors (IL-4 and IL-10), as well as attenuates neuroinflammation. Simultaneously, EA also inhibits the enrichment of H3K9ac at C/EBPβ promoter region and expression of C/EBPβ. Thus, it was evident that EA had a favorable effect on ameliorating cognitive decline in SAMP8 mice.

Conclusion: EA therapy may ameliorate cognitive deficits in AD via facilitating microglia shift from M1 to M2 phenotype and epigenetically regulating C/EBPβ. And further studies are required to better understand how the mechanisms between microglia and epigenetic modulation of C/EBPβ are effective in reversing AD.