Sperm glyceraldehyde 3-phosphate dehydrogenase gene expression in asthenozoospermic spermatozoa

It has been suggested that the energy required for sperm motility is produced by oxidative phosphorylation while glycolysis seems to be an important source for ATP transmission along the flagellum. Some studies have investigated the chemical and kinetic properties of the enzyme glyceraldehyde 3‐phosphate dehydrogenase to identify any changes in the regulation of glycolysis and sperm motility. In contrast, there are few studies analyzing the genetic basis of hypokinesis. For this reason, we investigated the glyceraldehyde 3‐phosphate dehydrogenase gene in human sperm to evaluate whether asthenozoospermia was correlated with any changes in its expression. Semen examination and glyceraldehyde 3‐phosphate dehydrogenase gene expression studies were carried out on 116 semen samples divided into two groups – Group A consisted of 58 normokinetic samples and Group B of 58 hypokinetic samples. Total RNA was extracted from spermatozoa, and real‐time PCR quantification of mRNA was carried out using specific primers and probes. The expression profiles for the Groups A and B were very similar. The mean delta Ct was as follows – Group A, 5.79 ± 1.04; Group B, 5.47 ± 1.27. Our study shows that in human sperm, there is no difference in glyceraldehyde 3‐phosphate dehydrogenase gene expression between samples with impaired motility and samples with normal kinetics. We believe that this study could help in the understanding of the molecular mechanisms of sperm kinetics, suggesting that hypomotility may be due to a possible posttranscriptional impairment of the control mechanism, such as mRNA splicing, or to posttranslational changes

Testicular cancer and sperm DNA damage: short- and long-term effects of antineoplastic treatment

The aim of this study was to investigate sperm DNA damage induced by chemo- and radiotherapy in patients with testicular cancer to provide data on the extent and persistence of nuclear damage that might affect individual reproductive potential. We evaluated pre- and post-antineoplastic treatment sperm DNA integrity, expressed as DNA Fragmentation Index (DFI), in a large caseload of testicular cancer patients by sperm chromatin structure assay. The mean total DFI for all patients at T0 was 18.0 ± 12.5%. Sperm chromatin profile was markedly impaired at T3 (27.7 ± 17.4%) and T6 (23.2 ± 15.3%), improving considerably at T12 and T24 (14.0 ± 8.9% and 14.4 ± 10.3%). After chemotherapy, we found a marked increase in DFI at T3 and T6 and a significant reduction at T12 and T24 in comparison with the baseline. In contrast, DFI increased at T3 and T6 after radiotherapy but the subsequent reduction was far less marked, reaching baseline values at T12 and T24. Finally, post-treatment DNA damage was not age or histotype dependent, but was more marked in the advanced stage of cancer. In this study, we showed that the chromatin profile may be affected in the months immediately following the end of the treatment, improving after 12-24 months. Our results thus indicate that post-treatment DNA damage is influenced both by the type and intensity of the therapy and by the pathological and clinical stage of the disease. © 2014 American Society of Andrology and European Academy of Andrology

Protamine-1 and-2 polymorphisms and gene expression in male infertility: An Italian study

Background: Correct histone/protamine replacement is an important stage in chromatin condensation during spermiogenesis in humans. There are two types of protamines: protamine 1 (P1) and the protamine 2 family (P2, P3, and P4), coded by the genes PRM1 and PRM2. Aim: We analyze the sequences and gene expression of PRM1 and PRM2 and their relationship with defective spermatogenesis. Materials and methods: Sequence analysis was carried out on 163 patients attending our laboratory for analysis of seminal fluid. Patients were divided into three groups: normozoospermic (53), teratozoospermic (60), and azoospermic (50). Gene expression was analyzed in seven patients with azoospermia and one with cryptozoospermia. Results: Seven single nuclotide polymorphisms (SNP) were identified: G54A, G102T and C230A for PRM1, and C246T, G288C, G298C and C373A for PRM2. For C230A, the CA genotype was present in 38% of teratozoospermic vs 55% of normozoospermic and 64% of azoospermic patients; for C373A, CA was found in 37% of teratozoospermic vs 47% of normozoospermic and 64% of azoospermic patients. In contrast, for G298C, GC was more common in the teratozoospermic (63%) than in the normozoospermic (49%) or azoospermic (48%) groups. These differences could suggest a greater susceptibility of these patients to abnormal sperm morphology. In five patients the levels of transcripts were reduced with respect to the control. Conclusion: These data suggest that premeiotic arrest is associated with extremely reduced protamine expression. New studies of both PRM1 and PRM2 and their mRNA expression could help us better understand the molecular mechanisms underlying the protamine transcription and translation processes. (J. Endocrinol. Invest. 35: 882-888, 2012) (C) 2012, Editrice Kurti

Mitochondrial membrane potential profile and its correlation with increasing sperm motility

Objective: To investigate sperm mitochondrial integrity through analysis of mitochondrial membrane potential (Δψ) and to correlate the energy status with variations in sperm motility. Design: Experimental study. Setting: Seminology Laboratory, University of Rome, Italy. Patient(s): Two hundred thirteen semen samples from the same number of patients, divided into two groups on the basis of their motility: group A, 185 samples with linear motility and group B, 28 samples with nonlinear motility. Intervention(s): Evaluation of sperm motility. Main Outcome Measure(s): Sperm mitochondrial integrity evaluated with a fluorimetric method using the cationic lipophilic stain JC-1. Result(s): The mean FL2 (percentage of sperm with high and low ψ) for group A was 46.19 ± 23.25 and for group B, it was 48.32 ± 24.43. There was no significant difference between the groups. There was a positive correlation between both FL2 and linear motility and FL2 and sperm vitality in group A; both correlations were statistically significant. In group B, there was a positive correlation between FL2 and nonlinear motility and FL2 and sperm vitality; again, both correlations were statistically significant. Conclusion(s): Our data reveal a positive correlation between total motility and Δψ, suggesting that sperm motility may be dependent on the functional integrity of the mitochondria. © 2011 by American Society for Reproductive Medicine

Testicular tumors as a possible cause of antisperm autoimmune response

Objective: To evaluate the presence of antisperm antibodies in testicular cancer patients 1 month after orchiectomy and before radiotherapy or chemotherapy. Design: Clinical study. Setting: Department of andrology and seminology at a university hospital. Patient(s): One hundred ninety patients with testicular cancer. Intervention(s): Determination of semen parameters and autoimmune reaction evaluated on the sperm surface and in blood serum. Main Outcome Measure(s): Autoimmune reaction on the sperm surface by the direct immunobead test (IBT), and in blood serum by the indirect IBT and the gelatin agglutination test (GAT), was evaluated 1 month after orchiectomy and before beginning chemotherapy or radiotherapy. Result(s): Of the 190 patients, 11 (5.8%) were positive for antisperm antibody by GAT. On indirect IBT, 3 of the 11 GAT-positive patients were positive to IgG class only, with values of 22%, 24%, and 40%. Of the 11 GAT-positive patients, 4 showed no antibody bound to the sperm surface, and 3 were positive to IgG class only (28%, 21%, and 38%), with binding exclusively on the tail. Direct IBT could not be performed in the remaining 4 patients. Conclusion(s): Our data support the hypothesis that testicular cancer might not be a possible cause of antisperm autoimmunization and infertility. © 2009 American Society for Reproductive Medicine