Background:Poor ovarian response (POR) reduces the success rate of in vitro fertilization
mainly because of fewer oocytes retrieved. Acupuncture (Ac) therapy can improve the number
of retrieved oocytes in the controlled ovarian stimulation program. The role of Ac in the corresponding
epigenetic mechanism of POR has not been studied.Objective:This study was conducted to determine the effect of Ac on the number of retrieved
oocytes and its role in DNA methylation in a mouse model of POR.Methods:Forty C57BL/6N female mice with normal estrous cycles were randomly classified into
4 groups of 10 each: control (Con) group, Ac-Con group, POR group, and Ac-POR group. Mice
in POR and Ac-POR groups received a gastric gavage of Tripterygium wilfordii polyglycoside
suspension of 50 mg/kg-1 once a day for 14 consecutive days. Ac was applied at “Shenting” (DU
24), “Guanyuan” (CV 4), “Zusanli” (ST 36), and “Shenshu” (BL 23) in the Ac-POR group for 10
min per session, once a day for 14 consecutive days. All four groups were stimulated with pregnant
mare serum gonadotropin and human chorionic gonadotropin, and the number of retrieved oocytes
and proportion of mature oocytes were recorded. The DNA methylation level in a single mouse
oocyte in each group was analyzed using single-cell genome-wide bisulfite sequencing (scBSseq),
and key pathways were identified using GO and KEGG enrichment analyses.Results:A dissecting microscope revealed that the Ac therapy improved the number of retrieved
oocytes compared with the POR group (p < 0.05). ScBS-seq showed that there was no significant
change in global DNA methylation levels between the POR model and control group mice. However,
differences were primarily observed in the differentially methylated regions (DMRs) of each
chromosome, and Ac decreased global DNA methylation. DMR analysis identified 13 genes that
may be associated with Ac treatment. Cdk5rap2 and Igf1r, which mediate germ cell apoptosis,
growth, and development, maybe most closely related to the Ac treatment of POR. KEGG analysis
revealed that differentially expressed genes were mainly enriched in Wnt, GnRH, and calcium
signaling pathways. The genes were closely related to the regulation of POR via Ac.Conclusion:The results suggest that DNA methylation in oocytes is related to the development
of POR and that the role of Ac in affecting DNA methylation in oocytes is associated with the
Wnt, GnRH, and calcium signaling pathways as well as Cdk5rap2 and Igf1r in POR mice.