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Background: Semen hyperviscosity is a threatening cause of abnormal spermatozoa and infertility in men. We aimed to evaluate oxidative stress, antioxidants depletion and sperm apoptosis as main reasons for poor quality of spermatozoa in men with hyperviscous semen. Materials and Methods: In this cross-sectional study, ejaculate specimens were collected from fertile (n=102) and infertile men with hyperviscous semen (n=123) and without semen hyperviscosity (n=143). Total antioxidant capacity (TAC), glutathione (GSH), malondialdehyde (MDA), protein carbonyl (PC), 8-hydroxydeoxyguanosine (8-OHdG), and were measured in semen samples to estimate oxidative stress status. Gene expression pattern of BAX, CASPASE-9, CASPASE-3, and BCL2 was assessed to estimate sperm apoptosis. Results: The average of sperm count, normal morphology, normal motility, and sperm vitality in men with hyperviscous semen was significantly lower than infertile subjects without hyperviscous semen (P<0.01). Men with hyperviscous semen exhibited higher levels of PC (8.34 ± 1.03 nmol/mg vs. 6.01 ± 0.93 nmol/mg, P=0.008), MDA (1.14 ± 0.27 nmol/ ml vs. 0.89 ± 0.22 nmol/ml, P=0.031), 8-OHdG (259.71 ± 24.59 ng/ml vs. 197.13 ± 18.47 ng/ml, P=0.009), but lower TAC contents (1250.44 ± 66.23 μM/L vs. 1784.31 ± 89.87 μM/L, P=0.018) and GSH (3.82 ± 1.05 μM vs. 5.89 ± 0.87 μM, P=0.021) than men with non-viscous semen. The expression of BAX, CASPASE-3 and CASPASE-9 genes in men with hyperviscous semen was significantly increased by 1.39-fold (P=0.041), 1.47-fold (P=0.046), 1.29-fold (P=0.048), respectively, as compared with the infertile subjects without hyperviscous semen. However, BCL2 expression in infertile men without hyperviscous semen was higher compared to those with hyperviscous semen (1.36-fold, P=0.044). Conclusion: Hyperviscous semen is markedly associated with depletion of seminal plasma antioxidants, sperm membrane lipid peroxidation, DNA and protein oxidation, and sperm apoptosis. Antioxidant therapy might be considered as a valuable strategy to protect sperm cells against oxidative damage in cases with seminal fluid hyperviscosity. [ABSTRACT FROM AUTHOR]

Recent studies have indicated that epigenetic alterations are critical for normal function and development of spermatozoa during the fertilization process. This review will focus on the latest advances in epigenome profiling of the chromatin modifications during sperm development, as well as the potential roles of epigenetic mechanisms in the context of male infertility. In this review, all data were collected from published studies that considered the effect of epigenetic abnormalities on human spermatogenesis, sperm parameters quality, fertilization process, embryo development and live births. The database PubMed was searched for all experimental and clinical studies using the Keywords "epigenetic modifications", "male infertility", "spermatogenesis", "embryo development" and "reproductive function". Post-translational modifications of histone, DNA methylations and chromatin remodeling are among the most common forms of epigenetic modifications that regulate all stages of spermatogenesis and fertilization process. Incorrect epigenetic modifications of certain genes involved in the spermatogenesis and sperm maturation may be a main reason of male reproductive disorder and infertility. Most importantly, abnormal patterns of epigenetic modifications or transgenerational phenotypes and miRNAs expression may be transmitted from one generation to the next through assisted reproductive techniques (ART) and cause an increased risk of birth defects, infertility and congenital anomalies in children. Epigenetic modifications must be considered as a one of the main factors of unexplained male infertility etiology. Due to high risk of transmitting incorrect primary imprints to offspring, there is a need for more research into epigenetic alterations in couples who benefit of ART support. [ABSTRACT FROM AUTHOR]

Calcium (Ca) is a significant element that acts as an intracellular second messenger. It is necessary for many physiological processes in spermatozoa including spermatogenesis, sperm motility, capacitation, acrosome reaction and fertilization. Although influences of Ca deficiency on sperm function and male infertility have been widely studied, mechanisms for these abnormalities are not well considered. Poor sperm motility, impairment of chemotaxis, capacitation, acrosome reaction and steroidogenesis are the major mechanisms by which Ca deficiency induces male infertility. Therefore, an optimal seminal Ca concentration is required to strengthen sperm function and all steps leading to successful fertilization. Furthermore, identification of these mechanisms provides valuable information regarding the mechanisms of Ca deficiency on male reproductive system and the way for developing a better clinical approach. In this review, we aim to discuss the proposed cellular and molecular mechanisms of Ca deficiency on male reproductive system, sperm function and male fertility. Also we will discuss the valuable information currently available for the roles of Ca in male reproduction. [ABSTRACT FROM AUTHOR]