Objectives To review the literature and provide an updated summary on the role of reactive oxygen species (ROS) in male infertility. Methods A review of PubMed, Cochrane review, and Web of Science databases for full-text English-language articles published between 1943 and 2017 was performed, focusing on the aetiology of ROS, physiological role of ROS on spermatic function, pathological role of ROS in infertility, evaluation of ROS, and role of antioxidants in oxidative stress. Results ROS play a role in spermatic function and fertilisation. The literature describes both a physiological and a pathological role of ROS in fertility. A delicate balance between ROS necessary for physiological activity and antioxidants to protect from cellular oxidative injury is essential for fertility. Conclusion Although elevated levels of ROS are implicated as a cause of infertility, there is no consensus on selecting patients to test for ROS, which test to perform, or if treatment for ROS can have a positive impact on infertility rates and pregnancy.

Role of reactive oxygen species in male infertility: An updated review of literature.

European Association of Urology Guidelines on Male Sexual and Reproductive Health: 2021 Update on Male Infertility

Explanations for the high potency of HPV prophylactic vaccines

Sperm DNA integrity is crucial for fertilization and development of healthy offspring. The spermatozoon undergoes extensive molecular remodeling of its nucleus during later phases of spermatogenesis, which imparts compaction and protects the genetic content. Testicular (defective maturation and abortive apoptosis) and post-testicular (oxidative stress) mechanisms are implicated in the etiology of sperm DNA fragmentation (SDF), which affects both natural and assisted reproduction. Several clinical and environmental factors are known to negatively impact sperm DNA integrity. An increasing number of reports emphasizes the direct relationship between sperm DNA damage and male infertility. Currently, several assays are available to assess sperm DNA damage, however, routine assessment of SDF in clinical practice is not recommended by professional organizations. This article provides an overview of SDF types, origin and comparative analysis of various SDF assays while primarily focusing on the clinical indications of SDF testing. Importantly, we report four clinical cases where SDF testing had played a significant role in improving fertility outcome. In light of these clinical case reports and recent scientific evidence, this review provides expert recommendations on SDF testing and examines the advantages and drawbacks of the clinical utility of SDF testing using Strength-Weaknesses-Opportunities-Threats (SWOT) analysis.

Sperm DNA Fragmentation: A New Guideline for Clinicians.

This article addresses the importance of oxidative processes in both the generation of functional gametes and the aetiology of defective sperm function. Functionally, sperm capacitation is recognized as a redox-regulated process, wherein a low level of reactive oxygen species (ROS) generation is intimately involved in driving such events as the stimulation of tyrosine phosphorylation, the facilitation of cholesterol efflux and the promotion of cAMP generation. However, the continuous generation of ROS ultimately creates problems for spermatozoa because their unique physical architecture and unusual biochemical composition means that they are vulnerable to oxidative stress. As a consequence, they are heavily dependent on the antioxidant protection afforded by the fluids in the male and female reproductive tracts and, during the precarious process of insemination, seminal plasma. If this antioxidant protection should be compromised for any reason, then the spermatozoa experience pathological oxidative damage. In addition, situations may prevail that cause the spermatozoa to become exposed to high levels of ROS emanating either from other cells in the immediate vicinity (particularly neutrophils) or from the spermatozoa themselves. The environmental and lifestyle factors that promote ROS generation by the spermatozoa are reviewed in this article, as are the techniques that might be used in a diagnostic context to identify patients whose reproductive capacity is under oxidative threat. Understanding the strengths and weaknesses of ROS-monitoring methodologies is critical if we are to effectively identify those patients for whom treatment with antioxidants might be considered a rational management strategy.

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The Importance of Oxidative Stress in Determining the Functionality of Mammalian Spermatozoa: A Two-Edged Sword.

Summary
Male infertility can be responsible for up to 20% of the cases attending fertility consultation facilities; nonetheless, the underlying molecular mechanisms that could explain it are still elusive. Therefore, we aimed to evaluate conventional and functional parameters of semen samples from patients who presented with male infertility of unknown origin. Conventional semen parameters and functional parameters (i.e. intracellular reactive oxygen species production, mitochondrial membrane potential, sperm chromatin structure assay, sperm membrane lipid peroxidation and antioxidant capacity of seminal plasma) were evaluated on semen samples from 54 healthy donors, 23 patients with idiopathic infertility and 34 fertile controls. No significant differences were observed in the conventional seminal parameters between the fertile and infertile men. However, increased intracellular reactive oxygen species (ROS) production and DNA fragmentation were observed in the infertile patients compared to the fertile group. Alterations in intracellular ROS production and DNA fragmentation could be associated with male idiopathic infertility. These parameters could eventually distinguish both groups more accurately than the conventional parameters. Our current results are encouraging, and the efficacy of these parameters in the clinical settings needs to be further assessed to establish their predictive potential as a marker of unexplained male infertility.

Are oxidative stress markers associated with unexplained male infertility

/pdf/manual-de-procesamiento-de-semen-humano-de-la-organizacion-zux7lf1v0w.pdf

Manual de procesamiento de semen humano de la Organización Mundial de la Salud-2010

Resumen Objetivo Evaluar la importancia de los anticuerpos antiespermatozoides (AAE) y su relacion con la fertilidad humana mediante una revision de la literatura cientifica de los ultimos 45 anos. Metodos Se realizo una revision de la literatura cientifica basada en investigaciones realizadas sobre anticuerpos antiespermatozoides e infertilidad publicada en espanol e ingles en bases de datos del area de la salud, Pubmed, Medline, Scielo, libros y otra literatura gris que incluya informacion afin a la revision y que se encuentre publicada en los ultimos 45 anos . Resumen de evidencia Parejas infetiles padecen de infertilidad causada por mecanismos inmunologicos, principalmente por la presencia de AAE en sangre, semen o inclusive en secreciones cervicovaginales; la formacion de AAE en hombres y mujeres puede estar asociada a trastornos en mecanismos inmunomoduladores, que traen como consecuencia la alteracion funcional del espermatozoide y por ende su incapacidad para fecundar al oocito. Conclusion La infertilidad inmunologica causada por AAE es el resultado de la interferencia de estos anticuerpos en las diferentes etapas de la fecundacion, inhibiendo la capacidad de interaccion entre el espermatoozide y el oocito.

Anticuerpos antiespermatozoides y su asociación con la fertilidad

/pdf/world-health-organization-manual-for-the-processing-of-human-2guwqgiirp.pdf

[World Health Organization manual for the processing of human semen-2010].

Resumen Objetivo La impronta genomica es la modificacion epigenetica que ocurre de manera diferencial tanto en genes especificos del oocito como del espermatozoide de acuerdo con su origen paterno o materno, permitiendo asi una expresion monoalelica. En esta revision se realiza un analisis critico de la informacion relacionada con el papel que tiene la impronta masculina sobre el exito reproductivo. Metodologia Se hizo una busqueda bibliografica sobre algunos de los componentes que regulan la impronta geonomica masculina y el posible papel sobre los eventos reproductivos como la espermatogenesis y el desarrollo placentario y embrionario. Resultados Este analisis de la literatura permitio valorar que los cambios estructurales, geneticos y epigeneticos que ocurren durante la formacion del gameto masculino, pueden tener repercusiones en el desarrollo embrionario, principalmente en la formacion de tejidos extraembrionarios como la placenta. Conclusion Las alteraciones en los mecanismos moleculares implicados en el proceso de metilacion del ADN durante la espermatogenesis, pueden generar errores en el patron normal de expresion requerido para el adecuado desarrollo de los componentes feto-placentarios.

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W. Cardona Maya

Papers

Are oxidative stress markers associated with unexplained male infertility

Manual de procesamiento de semen humano de la Organización Mundial de la Salud-2010

Anticuerpos antiespermatozoides y su asociación con la fertilidad

[World Health Organization manual for the processing of human semen-2010].

Influencia de la impronta genómica masculina en la reproducción