DECREASED SIRTUIN 1 GENE EXPRESSİON IN HUMAN EJACULATED SPERM IS ASSOCIATED WITH UNEXPLAINED INFERTILITY

Aims: The potential mechanisms underlying unexplained infertility, which is a condition in which couples experience infertility without an identifiable cause in both man and woman, have not yet been clarified. The present study aimed to investigate the role of Sirtuin 1 (SIRT1) gene in male infertility and unexplained infertility. Methods: A total of 50 couples who applied for infertility evaluation and treatment were included in the study. The couples' medical histories were taken and their fertility status was evaluated. Semen analysis results evaluated according to World Health Organization (WHO, 2010) criteria were divided into low and normal semen parameter groups in terms of sperm count and motility parameters. Couples were further categorized into three groups according to their fertility status; Non-infertility group (n=13): Couples without clinical infertility (no female and male factor (normal semen variables)). Male infertility group (n=19): Couples with clinical infertility (no female factor, with male factor (abnormal semen variables)). Unexplained infertility group (n=18): Couples with clinical infertility without an identifiable cause in male (normal semen variables) and female. Changes in SIRT1 gene expression between the groups were investigated using qPCR. Results: SIRT1 gene expression was not associated with sperm count and motility parameters. However, SIRT1 expression was observed to be significantly decreased in male infertility and, more importantly, in unexplained infertility groups, compared to the non-infertility group. Conclusions: Our study suggests that decreased SIRT1 may play a role in fertilization potential by affecting possibly different functions of sperm rather than count and motility parameters and may be one of the possible mechanisms underlying unexplained infertility.