Role of DNA damage response in cyclophosphamide-induced premature ovarian failure in mice

Abstract

Aim: To investigate the DNA damage response (DDR) in a cyclophosphamide (CTX)-induced mouse model of premature ovarian failure (POF).

Methods: The POF model was established by injecting mice with CTX. The body, ovarian weights, the estrus cycle, and pathological changes of the ovaries were recorded. The serum levels of 17 β-estradiol (E2) and follicle-stimulating hormone (FSH) were measured. The expression of Ki67, β-galactosidase (β-gal), p21, p53, γH2AX, and pATM in ovarian tissues was detected by immunohistochemistry. The expression of β-gal, γH2AX, and pATM was analyzed by immunofluorescence staining of primary cultured granulosa cells (GCs).

Results: The body and ovarian weights decreased, the estrus cycles were erratic, and the FSH level increased, whereas the E2 level decreased in POF mice compared to controls. The pathological consequences of POF revealed an increase in atretic follicles, corpus luteum, and primordial follicles and a decrease in the number of primary, secondary, and tertiary follicles. Ki67 expression was reduced, β-gal, p21, p53, γH2AX, and pATM expression were elevated in the ovaries of POF mice. The expression of β-gal, γH2AX, and pATM increased in GCs with the concentration in a time-dependent manner.

Conclusion: In total, CTX induced POF in mice, which was mediated by the DDR pathway of ATM-P53-P21.

Keywords: ATM–P53–P21 signaling pathway; DNA damage response; cyclophosphamide; premature ovarian failure; γH2AX.