RESUMO
Varicocele can reduce male fertility potential through various oxidative stress mechanisms. Excessive production of reactive oxygen species may overwhelm the sperm's defenses against oxidative stress, damaging the sperm chromatin. Sperm DNA fragmentation, in the form of DNA strand breaks, is recognized as a consequence of the oxidative stress cascade and is commonly found in the ejaculates of men with varicocele and fertility issues. This paper reviews the current knowledge regarding the association between varicocele, oxidative stress, sperm DNA fragmentation, and male infertility, and examines the role of varicocele repair in alleviating oxidative-sperm DNA fragmentation in these patients. Additionally, we highlight areas for further research to address knowledge gaps relevant to clinical practice.
Assuntos
Fragmentação do DNA , Infertilidade Masculina , Estresse Oxidativo , Espermatozoides , Varicocele , Humanos , Masculino , Varicocele/fisiopatologia , Varicocele/complicações , Estresse Oxidativo/fisiologia , Infertilidade Masculina/etiologia , Infertilidade Masculina/genética , Infertilidade Masculina/fisiopatologia , Infertilidade Masculina/metabolismo , Espermatozoides/fisiologia , Espermatozoides/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Valosin-containing protein (VCP; aka p97), a member of the AAA (ATPases Associated with various cellular Activities) family, has been associated with a wide range of cellular functions. While previous evidence has shown its presence in mammalian sperm, our study unveils its function in mouse sperm. Notably, we found that mouse VCP does not undergo tyrosine phosphorylation during capacitation and exhibits distinct localization patterns. In the sperm head, it resides within the equatorial segment and, following acrosomal exocytosis, it is released and cleaved. In the flagellum, VCP is observed in the principal and midpiece. Furthermore, our research highlights a unique role for VCP in the cAMP/PKA pathway during capacitation. Pharmacological inhibition of sperm VCP led to reduced intracellular cAMP levels that resulted in decreased phosphorylation in PKA substrates and tyrosine residues and diminished fertilization competence. Our results show that in mouse sperm, VCP plays a pivotal role in regulating cAMP production, probably by the modulation of soluble adenylyl cyclase activity.
Assuntos
AMP Cíclico , Capacitação Espermática , Espermatozoides , Proteína com Valosina , Animais , Masculino , Capacitação Espermática/efeitos dos fármacos , Proteína com Valosina/metabolismo , Proteína com Valosina/genética , Espermatozoides/metabolismo , Camundongos , AMP Cíclico/metabolismo , Fosforilação , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Adenosina Trifosfatases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Proteínas de Ciclo Celular/genéticaRESUMO
Reproductive failure in dogs is often due to unknown causes, and correct diagnosis and treatment are not always achieved. This condition is associated with various congenital and acquired etiologies that develop inflammatory processes, causing an increase in the number of leukocytes within the female reproductive tract (FRT). An encounter between polymorphonuclear neutrophils (PMNs) and infectious agents or inflammation in the FRT could trigger neutrophil extracellular traps (NETs), which are associated with significantly decreased motility and damage to sperm functional parameters in other species, including humans. This study describes the interaction between canine PMNs and spermatozoa and characterizes the release of NETs, in addition to evaluating the consequences of these structures on canine sperm function. To identify and visualize NETs, May-Grünwald Giemsa staining and immunofluorescence for neutrophil elastase (NE) were performed on canine semen samples and sperm/PMN co-cultures. Sperm viability was assessed using SYBR/PI and acrosome integrity was assessed using PNA-FITC/PI by flow cytometry. The results demonstrate NETs release in native semen samples and PMN/sperm co-cultures. In addition, NETs negatively affect canine sperm function parameters. This is the first report on the ability of NETs to efficiently entrap canine spermatozoa, and to provide additional data on the adverse effects of NETs on male gametes. Therefore, NETs formation should be considered in future studies of canine reproductive failure, as these extracellular fibers and NET-derived pro-inflammatory capacities will impede proper oocyte fertilization and embryo implantation. These data will serve as a basis to explain certain reproductive failures of dogs and provide new information about triggers and molecules involved in adverse effects of NETosis for domestic pet animals.
Assuntos
Armadilhas Extracelulares , Neutrófilos , Espermatozoides , Animais , Cães , Armadilhas Extracelulares/metabolismo , Masculino , Espermatozoides/metabolismo , Neutrófilos/metabolismo , Motilidade dos Espermatozoides , Feminino , Elastase de Leucócito/metabolismo , Técnicas de Cocultura , Acrossomo/metabolismoRESUMO
To acquire the ability to fertilize the egg, mammalian spermatozoa must undergo a series of changes occurring within the highly synchronized and specialized environment of the female reproductive tract, collectively known as capacitation. In an attempt to replicate this process in vitro, various culture media for mouse sperm were formulated over the past decades, sharing a similar overall composition but differing mainly in ion concentrations and metabolic substrates. The widespread use of the different media to study the mechanisms of capacitation might hinder a comprehensive understanding of this process, as the medium could become a confounding variable in the analysis. In this context, the present side-by-side study compares the influence of four commonly used culture media (FD, HTF and two TYH versions) on mouse sperm capacitation. We evaluated the induction of protein kinase A phosphorylation pathway, motility, hyperactivation and acrosome reaction. Additionally, in vitro fertilization and embryo development were also assessed. By analyzing these outcomes in two mouse colonies with different reproductive performance, our study provides critical insights to improve the global understanding of sperm function. The results obtained highlight the importance of considering variations in medium composition, and their potential implications for the future interpretation of results.
Assuntos
Reação Acrossômica , Meios de Cultura , Fertilização in vitro , Capacitação Espermática , Espermatozoides , Animais , Capacitação Espermática/efeitos dos fármacos , Masculino , Camundongos , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Espermatozoides/metabolismo , Fertilização in vitro/métodos , Feminino , Reação Acrossômica/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Fosforilação , Fertilização , Desenvolvimento Embrionário/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismoRESUMO
As in most cells, intracellular pH regulation is fundamental for sperm physiology. Key sperm functions like swimming, maturation, and a unique exocytotic process, the acrosome reaction, necessary for gamete fusion, are deeply influenced by pH. Sperm pH regulation, both intracellularly and within organelles such as the acrosome, requires a coordinated interplay of various transporters and channels, ensuring that this cell is primed for fertilization. Consistent with the pivotal importance of pH regulation in mammalian sperm physiology, several of its unique transporters are dependent on cytosolic pH. Examples include the Ca2+ channel CatSper and the K+ channel Slo3. The absence of these channels leads to male infertility. This review outlines the main transport elements involved in pH regulation, including cytosolic and acrosomal pH, that participate in these complex functions. We present a glimpse of how these transporters are regulated and how distinct sets of them are orchestrated to allow sperm to fertilize the egg. Much research is needed to begin to envision the complete set of players and the choreography of how cytosolic and organellar pH are regulated in each sperm function.
Assuntos
Acrossomo , Citosol , Espermatozoides , Masculino , Concentração de Íons de Hidrogênio , Animais , Citosol/metabolismo , Humanos , Acrossomo/metabolismo , Espermatozoides/metabolismo , Mamíferos/metabolismo , Reação AcrossômicaRESUMO
OBJECTIVES: Bovine seminal plasma proteins perform several functions related to sperm function. Changes in the expression pattern or abundance of seminal proteins are related to changes in the fertilizing capacity of bulls. Considering the role of seminal plasma proteins in sperm function and animal reproduction, we investigated changes in the protein abundance profile in response to sperm morphological changes using a proteomic approach. DATADESCRIPTION: In our present investigation, we employed liquid chromatography coupled with mass spectrometry to elucidate the proteomic composition of seminal plasma obtained from Nellore bulls exhibiting varying percentages of sperm abnormalities. Following semen collection, seminal plasma was promptly isolated from sperm, and proteins were subsequently precipitated, enzymatically digested using porcine trypsin, and subjected to analysis utilizing the Acquity nano UHPLC System in conjunction with a mass spectrometer. This dataset encompasses a total of 297 proteins, marking the inaugural instance in which a comparative profile of seminal plasma proteins in young Nellore bulls, categorized by their sperm abnormality percentages, has been delineated using LC-MS/MS. The comprehensive nature of this dataset contributes pivotal proteomic insights, representing a noteworthy advancement in our understanding of the reproductive biology of the Nellore breed.
Assuntos
Proteoma , Sêmen , Espermatozoides , Animais , Masculino , Bovinos , Sêmen/metabolismo , Sêmen/química , Proteoma/metabolismo , Espermatozoides/metabolismo , Espectrometria de Massas em Tandem , Proteômica/métodos , Proteínas de Plasma Seminal/metabolismo , Proteínas de Plasma Seminal/genética , Cromatografia LíquidaRESUMO
Chlorothalonil is a broad-spectrum organochlorine fungicide widely employed in agriculture to control fungal foliar diseases. This fungicide enters aquatic environments through the leaching process, leading to toxicity in non-target organisms. Organic contaminants can impact organism reproduction as they have the potential to interact with the neuroendocrine system. Although there are reports of toxic effects of chlorothalonil, information regarding its impact on reproduction is limited. The aim of the present study was to evaluate the influence of chlorothalonil on male reproductive physiology using the zebrafish (Danio rerio) as ecotoxicological model. Zebrafish were exposed for 7 days to two concentrations of chlorothalonil (0.1 and 10 µg/L) along with a control group (with DMSO - 0.001%). Gene expression of hypothalamus-pituitary-gonad axis components (gnrh2, gnrh3, lhr, fshr, star, hsd17b1, hsd17b3, and cyp19a1), as well as hepatic vitellogenin concentration were assessed. In sperm cells, reactive oxygen species (ROS) content, lipid peroxidation (LPO), mitochondrial functionality, and membrane integrity and fluidity were evaluated. Results indicate that exposure to the higher concentration of chlorothalonil led to a reduction in brain gnr2 expression. In gonads, mRNA levels of lhr, star, and hsd17b1 were decreased at both chlorothalonil concentrations tested. Similarly, hepatic vitellogenin concentration was reduced. Regarding sperm cells, a decreased ROS level was observed, without significant difference in LPO level. Additionally, a higher mitochondrial potential and lower membrane fluidity were observed in zebrafish exposed to chlorothalonil. These findings demonstrate that chlorothalonil acts as an endocrine disruptor, influencing reproductive control mechanisms, as evidenced by changes in expression of genes HPG axis, as well as hepatic vitellogenin concentration. Furthermore, our findings reveal that exposure to this contaminant may compromise the reproductive success of the species, as it affected sperm quality parameters.
Assuntos
Disruptores Endócrinos , Fungicidas Industriais , Nitrilas , Poluentes Químicos da Água , Animais , Masculino , Peixe-Zebra/metabolismo , Disruptores Endócrinos/metabolismo , Eixo Hipotalâmico-Hipofisário-Gonadal , Espécies Reativas de Oxigênio/metabolismo , Fungicidas Industriais/metabolismo , Vitelogeninas/metabolismo , Sêmen , Gônadas , Espermatozoides/metabolismo , Reprodução , Poluentes Químicos da Água/metabolismoRESUMO
RESEARCH QUESTION: Can the addition of progesterone and neurotensin, molecular agents found in the female reproductive tract, after sperm washing increase the fertilization potential of human spermatozoa? DESIGN: (i) Cohort study of 24 men. Spermatozoa selected by swim-up were incubated in either progesterone or neurotensin (0.1-100 µM) for 1-4 h, and hyperactive motility and binding to hyaluronan (0.1-100 µM) were assessed. The effect of progesterone 10 µM on sperm function was assessed in a blinded manner, including: hyperactive motility, binding to hyaluronan, tyrosine phosphorylation, acrosome reaction and oxidative DNA damage. (i) Embryo safety testing [one-cell mouse embryo assay (MEA), endotoxin and sterility counts (nâ¯=â¯3)] in preclinical embryo models of IVF (murine and porcine, nâ¯=â¯7 each model) and a small preliminary human study (nâ¯=â¯4) of couples undergoing standard IVF with oocytes inseminated with spermatozoa ± 10 µM progesterone. RESULTS: Progesterone 10 µM increased sperm binding to hyaluronan, hyperactive motility and tyrosine phosphorylation (all P < 0.05). Neurotensin had no effect (P > 0.05). Progesterone 10 µM in human embryo culture media passed embryo safety testing (MEA, endotoxin concentration and sterility plate count). In preclinical models of IVF, the exposure of spermatozoa to progesterone 10 µM and oocytes to progesterone 1 µM was not detrimental, and increased the fertilization rate in mice and the blastocyst cell number in mice and pigs (all P ≤ 0.03). In humans, every transferred blastocyst that had been produced from spermatozoa exposed to progesterone resulted in a live birth. CONCLUSION: The addition of progesterone to sperm preparation media shows promise as an adjunct to current methods for increasing fertilization potential. Randomized controlled trials are required to determine the clinical utility of progesterone for improving IVF outcomes.
Assuntos
Infertilidade , Progesterona , Humanos , Masculino , Feminino , Animais , Camundongos , Suínos , Progesterona/farmacologia , Progesterona/metabolismo , Fertilização in vitro/métodos , Neurotensina/metabolismo , Neurotensina/farmacologia , Ácido Hialurônico/farmacologia , Estudos de Coortes , Sêmen , Espermatozoides/metabolismo , Infertilidade/metabolismo , Tirosina/metabolismo , Endotoxinas/metabolismo , Endotoxinas/farmacologiaRESUMO
BACKGROUND: Basal energetic metabolism in sperm, particularly oxidative phosphorylation, is known to condition not only their oocyte fertilising ability, but also the subsequent embryo development. While the molecular pathways underlying these events still need to be elucidated, reactive oxygen species (ROS) could have a relevant role. We, therefore, aimed to describe the mechanisms through which mitochondrial activity can influence the first stages of embryo development. RESULTS: We first show that embryo development is tightly influenced by both intracellular ROS and mitochondrial activity. In addition, we depict that the inhibition of mitochondrial activity dramatically decreases intracellular ROS levels. Finally, we also demonstrate that the inhibition of mitochondrial respiration positively influences sperm DNA integrity, most likely because of the depletion of intracellular ROS formation. CONCLUSION: Collectively, the data presented in this work reveals that impairment of early embryo development may result from the accumulation of sperm DNA damage caused by mitochondrial-derived ROS.
Assuntos
Mitocôndrias , Sêmen , Masculino , Humanos , Espécies Reativas de Oxigênio/metabolismo , Sêmen/metabolismo , Espermatozoides/metabolismo , Desenvolvimento Embrionário , Estresse OxidativoRESUMO
In this study we proposed to address the following question: "Are there differentially expressed sperm microRNAs related to fertility in bulls?". A systematic review of scientific literature until November 2022 was performed, in accordance with PRISMA guidelines. The main outcome was differentially expressed sperm microRNA from bulls with low versus high fertility profiles identified by using different methods such as field fertility evaluation and sperm laboratory analysis. Were identified 786 documents, of which 13 were selected for qualitative analysis. A total of 182 unique differentially expressed miRNAs were identified, among these, 49 miRNAs were found in common between at least two studies. It is believed that from these 49 miRNAs, it is possible that miRNAs such as miR-10a, -10b, -103, -15b, -122, -125b, -126-5p, -151-5p, -193a-5p, -196a, -27a-5p and -99b could be potential universal biomarkers to assess the reproductive potential of males.