Human sperm DNA damage has an effect on immunological interaction between spermatozoa and fallopian tube.

BACKGROUND: Toll-like receptors play a crucial role in the immunological interaction between the spermatozoa and fallopian tube and contribute to the ovulation, sperm capacitation, fertilization, and pregnancy. OBJECTIVES: To investigate the expression of toll-like receptors and their adaptor molecules and cytokines under the effect of spermatozoa with high DNA fragmentation (high DF) in human fallopian tube cell line (OE-E6/E7) and compare to those in normal spermatozoa. MATERIALS AND METHODS: Fresh semen samples were obtained from 10 unexplained infertile males with high DF (more than 20%) and from 10 healthy donors with a DF less than 3%. After sperm preparation, samples were co-cultured with OE-E6/E7. Toll-like receptors, myeloid differentiation factor 88 (MyD88), TIR domain-containing adapter protein (TIRAP), TIR domain-containing adapter-inducing IFN-b (TRIF), TRIF-related adapter molecule as well as IL-6, IL-8, IFN-ß, and TNFα mRNA expression were evaluated by quantitative real-time PCR. Protein levels of these cytokines and chemokines were measured using ELISA method. RESULTS: TLR 1-6 mRNA expression in OE-E6/E7 was significantly higher under the effect of spermatozoa with high DF compared to the spermatozoa with low DF. Furthermore, significantly increased mRNA expression of MyD88, TIRAP, and TRIF was observed in the high DF group compared to the low DF group, except TRIF-related adapter molecule. Moreover, the expression of IL-6 and IL-8 in the high DF group was significantly higher than low DF group, although there was no significant difference in IFN-ß and TNFα expression between the groups. DISCUSSION AND CONCLUSION: Damage-associated molecular patterns from DNA damage activate TLR signaling pathway in human fallopian tubes and result in the upregulation of inflammatory cytokines and chemokines. This situation may provide pathologic environment for capacitation, fertilization, embryo development, and implantation in female reproductive tract and can be one of the mechanisms of infertility in men with high DF.

Supplementation of sperm freezing medium with myoinositol improve human sperm parameters and protects it against DNA fragmentation and apoptosis.

The aim of this study is to evaluate the beneficial effect of Myoinositol (MYO) supplement in freezing media on the post thaw sperm quality. Semen samples from 40 normozoospermic men were divided into two aliquots and frozen with simple or 2 mg/mL MYO supplemented freezing medium. Post thaw process including, computer-assissted sperm analysis was used to analyze sperm motility and morphology. Reactive oxygen species was evaluated by the fluorometry of DCFH-DA, as well as total antioxidant capacity and lipid peroxidation were measured based on colorimetric assay by ELISA reader. Eventually, DNA fragmentation was assessed using TUNEL staining. MYO significantly improved progressive motility and normal morphology in treated samples (p < 0.05). Lipid peroxidation (malondialdehyde level) can be diminished in samples were frozen by MYO supplemented freezing media (p < 0.05). While MYO did not affect the amount of ROS (p > 0.05), it was associated with high values of total antioxidant capacity (p < 0.05). DNA integrity was significantly affected by MYO, as in MYO treated samples, DNA fragmentation was decreased compared to control ones (p < 0.001). The findings support the use of 2 mg/mL myoinositol supplemented freezing media in sperm cryopreservation to increase sperm quality after freezing-thawing procedures.

Evaluation of immunological interaction between spermatozoa and fallopian tube epithelial cells.

Toll-like receptors (TLR) are one of the major compartments of innate immune system. It was revealed that the TLR have relevance in ovulation, sperm capacitation and fertilisation. So, in this study, the expression of TLR, their adaptor molecules and cytokines in human fallopian tube cell line under the effect of human normal spermatozoa was evaluated. TLR mRNA and protein were evaluated in OE-E6/E7 cell line. Semen samples from 10 donors were collected and co-incubated with OE-E6/E7 cell line and used as sperm group, and cell line without spermatozoa was used as control group. Afterwards, the level of TLR, their adaptor molecule and cytokine mRNA expression was compared using qPCR in sperm and control groups, and supernatant was used for ELISA. To determine whether elevated cytokine reaction to spermatozoa in OE-E6/E7 cell line is mediated via TLR, TLR3 function-blocking antibody was used. OE-E6/E7 cell line expressed TLR1-6 genes and proteins. TLR expressions, especially TLR3 and TLR5, in OE-E6/E7 cell line under the effect of spermatozoa were significantly higher. Also, levels of adaptor molecules and cytokine production were increased in sperm group than in control group (P < 0.05). So, it may be hypothesised that TLR are essential for spermatozoa and fallopian tube immunological interaction and for preparing safe environment for important events in fallopian tube.