The expression and distribution of deoxyribonucleic acid repair and apoptosis markers in testicular germ cells of infertile varicocele patients resembles that of old fertile men

Abstract

To explore the expression and distribution of DNA damage repair and apoptosis marker proteins in human testicular germ cells of infertile varicocele patients; and to compare the expression and distribution with that of young and old fertile men. Retrospective case-control study. Academic institutions. Testicular specimens were obtained from 8 infertile varicocele patients aged 20-30 years and from 16 fertile volunteers aged 20-82 years. Testicular germ cell DNA repair markers were assessed using immunohistochemical staining for the cell proliferation marker (proliferating cell nuclear antigen), DNA repair markers [poly(ADP-ribose) polymerase-1 (PARP-1), poly(ADP-ribose), X-ray repair cross-complementing 1, and apurinic/apyrimidinic endonuclease 1], and apoptosis markers (caspase 9, active caspase 3, and cleaved PARP-1). The prevalence and cellular localization of the above markers in testicular tissues of varicocele patients and fertile men of varying ages. Statistically significant differences in DNA damage repair-associated proteins and apoptosis markers were observed in infertile men with varicocele compared with fertile young men. Old fertile men showed similar expression of the same markers when compared with infertile varicocele patients. The study demonstrates that there is an increase in human testicular germ cell DNA repair and apoptosis in infertile varicocele patients and that their profile resembles that of premature aging.