Evaluation the expression of insulin and insulin receptor-beta (IR-β) in sperm of infertile male with failed intracytoplasmic sperm injection (ICSI)

Introduction: Most infertility treatment centers are currently using semen analysis to differentiate between fertile and infertile individuals. Recent studies have evaluated the expression and secretion of independent insulin and related beta receptor (IR-β) in mammals’ ejaculated spermatozoa such as humans and pigs, and its effect on motility parameters capacitation and acrosomal reaction. Objectives: This study aimed to investigate the expression of insulin, IR-β and the parameters of sperm and DNA fragmentation index (DFI) in men with intracytoplasmic sperm injections (ICSI) failed. Patients and Methods: This study was conducted on 15 men with unknown infertility with a history of unsuccessful ICSI and 10 fertile men. After collecting samples, sperm parameters (concentration and motility), sperm DNA fragmentation and expression of insulin and IR-β genes were investigated. To assess DFI from SDFA kit and to review the expression, the genes were analyzed via RT-PCR method. Data were analyzed statistically by t-test and covariance tests. Results: Based on the findings of this research, the concentration and percentage of motility in infertile men with a history of unsuccessful ICSI was significantly lower than fertile individuals, moreover, the amount of DNA fragmentation significantly increased in infertile men with a history of unsuccessful ICSI compared to fertile men (P < 0.05). Insulin expression in the sperm of infertile men with a failed ICSI history was significantly lower than fertile men (P < 0.05); however, the IR-β expression rate was not significantly different between the two groups. Conclusion: Evaluation of insulin gene expression can be helpful as a good marker for identifying infertility with an unknown cause.