The Role of Protamine 2 Gene Expression and Caspase 9 Activity in Male Infertility.

PURPOSE: Approximately 15% of couples are affected by infertility with the man responsible in almost half of the cases. PRMs (protamines) confer a higher order of DNA packaging in sperm than that in somatic cells. Because of the critical roles of PRMs in spermatid differentiation, aberrations in PRM expression or changes in protein structure could be causes of certain types of idiopathic human male infertility. The aim of this study was to give insight into the role of PRM2 gene expression and caspase 9 activity in the pathogenesis of male infertility. MATERIALS AND METHODS: The current study included 70 men with idiopathic infertility and 64 fertile men who attended the andrology outpatient clinic at Mansoura University Hospital. Semen sample analyses were done according to WHO recommendations. The acrosome reaction of spermatozoa recovered from each sample was assessed. Samples were separated using discontinuous gradient separation. From each semen sample mature sperm were separated from immature sperm. The resulting samples were divided into 2 parts, including one to determine caspase 9 activity and the other for RNA extraction and reverse transcriptase-polymerase chain reaction of PRM2 gene expression. The polymerase chain reaction product was electrophoresed on 2% agarose gel. RESULTS: PRM2 gene expression was significantly decreased in immature sperm extracted from the fertile and infertile groups. Caspase 9 activity was significantly increased in immature sperm extracted from both groups. CONCLUSIONS: Low levels of PRM2 may be associated with morphological abnormalities, initiation of the apoptotic pathway and decreasing sperm motility. PRM2 may be an important marker to better understand the key regulatory pathway of spermatogenesis and it may act as a crucial part of fertilization.

Androgen receptor expression relationship with semen variables in infertile men with varicocele.

PURPOSE: Androgen receptor, a member of the nuclear receptor superfamily, has important roles in male reproductive function. It is required for sexual differentiation, pubertal development, spermatogenesis regulation, meiosis completion and spermatocyte transition to haploid round spermatids. We assessed the association of androgen receptor expression and semen variables in infertile men with varicocele. MATERIALS AND METHODS: A total of 299 men were grouped into healthy, fertile controls, infertile men without varicocele and men with infertility associated with varicocele. A history was obtained, clinical examination and semen analysis were done and reproductive hormones were estimated. Androgen receptor expression and the acrosome reaction were determined in recovered spermatozoa. RESULTS: Androgen receptor expression was significantly decreased in infertile men with varicocele more than in infertile men without varicocele compared to fertile controls. Androgen receptor correlated positively with sperm count, motility, normal forms, velocity, linear velocity, acrosome reaction and α-glucosidase. It correlated negatively with serum follicle-stimulating hormone and estradiol. Multiple stepwise regression analysis of androgen receptor expression revealed that the sperm acrosome reaction and linearity index were the most affected independent variables. CONCLUSIONS: Androgen receptor expression was significantly decreased in infertile men with varicocele more than in infertile men without varicocele compared to fertile men. Androgen receptor expression correlated positively with sperm count, motility, normal forms, velocity, linear velocity and acrosome reaction.

ACE gene insertion/deletion polymorphism seminal associations in infertile men.

PURPOSE: We assessed seminal associations of the ACE gene insertion/deletion polymorphism in infertile men. MATERIALS AND METHODS: A total of 405 men were investigated, divided into healthy fertile men, and those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. They underwent semen analysis, and assessment of sperm acrosin activity, hypo-osmotic swelling, seminal 8-iso-prostaglandin-F(2α), total antioxidant capacity, α-glucosidase and ACE gene polymorphisms. RESULT: The ACE insertion/insertion genotype was noted in 182 men, including 76.5% of healthy fertile men, and 47.4%, 39.8% and 17.6% of those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. The ACE insertion/deletion genotype was noted in 133 men, including 13.7% of healthy fertile men, and 42.3%, 27.5% and 47.2% of those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. The ACE deletion/deletion genotype was identified in 90 men, including 9.8% of healthy fertile men, 10.3%, 32.70% and 35.2% of those with asthenozoospermia, asthenoteratozoospermia and oligoasthenoteratozoospermia, respectively. Men with the ACE deletion/deletion and insertion/deletion genotypes showed a significant decrease in sperm count, motility, linear velocity and normal forms, acrosin activity index, hypo-osmotic swelling test and seminal α-glucosidase, and significantly increased seminal 8-iso-prostaglandin-F(2α) than those with the ACE insertion/insertion genotype. CONCLUSIONS: ACE gene deletion polymorphism is associated with abnormal seminal variables, such that carriers of the ACE deletion/deletion genotype have higher seminal oxidative stress.

Relationship between acrosin activity of human spermatozoa and oxidative stress.

AIM: To study the association between seminal oxidative stress and human sperm acrosin activity. METHODS: It is a prospective study consisting of 30 infertile men and 12 fertile normozoospermic volunteers. A full history, clinical examination and scrotal ultrasound were done to exclude other related factors such as smoking and varicocele. Presence of white blood cells (WBCs) in semen samples was evaluated by peroxidase staining. Lipid peroxidation in spermatozoa was induced after incubating with ferrous sulphate (4 mmol/L) and sodium ascorbate (20 mmol/L). Induced peroxidation of spermatozoa was assessed by determining the production of thiobarbituric acid reactive substances (TBARS). Acrosin activity was measured using the gelatinolysis technique. The halo diameters around the sperm heads and the percentages of spermatozoa showing halo formation were evaluated. An acrosin activity index was calculated by multiplying the halo diameter by the halo formation rate. RESULTS: A significant difference was observed in acrosin activity parameters and TBARS levels between samples with WBCs (1 multiply 10(6)/mL of ejaculate) and those without. This difference was also noted between the normozoospermic and the oligoasthenoteratozoospermic semen samples. The TBARS production by spermatozoa had a significant negative correlation with the acrosin activity index (r = -0.89, P 0.001). CONCLUSION: The presence of oxidative stress in an individual with leukocytospermia and/or abnormal semen parameters is associated with impaired sperm function as measured by its acrosin activity.