RESUMEN
Infertility represents a significant health concern, with sperm quantity and quality being crucial determinants of male fertility. Oligoasthenoteratozoospermia (OAT) is characterized by reduced sperm motility, lower sperm concentration, and morphological abnormalities in sperm heads and flagella. Although variants in several genes have been implicated in OAT, its genetic etiologies and pathogenetic mechanisms remain inadequately understood. In this study, we identified a homozygous nonsense mutation (c.916C>T, p.Arg306*) in the coiled-coil domain containing 146 ( CCDC146) gene in an infertile male patient with OAT. This mutation resulted in the production of a truncated CCDC146 protein (amino acids 1-305), retaining only two out of five coiled-coil domains. To validate the pathogenicity of the CCDC146 mutation, we generated a mouse model ( Ccdc146 mut/mut ) with a similar mutation to that of the patient. Consistently, the Ccdc146 mut/mut mice exhibited infertility, characterized by significantly reduced sperm counts, diminished motility, and multiple defects in sperm heads and flagella. Furthermore, the levels of axonemal proteins, including DNAH17, DNAH1, and SPAG6, were significantly reduced in the sperm of Ccdc146 mut/mut mice. Additionally, both human and mouse CCDC146 interacted with intraflagellar transport protein 20 (IFT20), but this interaction was lost in the mutated versions, leading to the degradation of IFT20. This study identified a novel deleterious homozygous nonsense mutation in CCDC146 that causes male infertility, potentially by disrupting axonemal protein transportation. These findings offer valuable insights for genetic counseling and understanding the mechanisms underlying CCDC146 mutant-associated infertility in human males.
Asunto(s)
Astenozoospermia , Proteínas Asociadas a Microtúbulos , Animales , Humanos , Masculino , Ratones , Astenozoospermia/genética , Codón sin Sentido , Homocigoto , Infertilidad Masculina/genética , Mutación , Oligospermia/genética , Motilidad Espermática/genética , Espermatozoides , Proteínas Asociadas a Microtúbulos/genéticaRESUMEN
Male infertility is a complex multifactorial reproductive disorder with highly heterogeneous phenotypic presentations. Azoospermia is a medically non-manageable cause of male infertility affecting â¼1% of men. Precise etiology of azoospermia is not known in approximately three-fourth of the cases. To explore the genetic basis of azoospermia, we performed whole exome sequencing in two non-obstructive azoospermia affected siblings from a consanguineous Pakistani family. Bioinformatic filtering and segregation analysis of whole exome sequencing data resulted in the identification of a rare homozygous missense variant (c.962G>C, p. Arg321Thr) in YTHDC2, segregating with disease in the family. Structural analysis of the missense variant identified in our study and two previously reported functionally characterized missense changes (p. Glu332Gln and p. His327Arg) in mice showed that all these three variants may affect Mg2+ binding ability and helicase activity of YTHDC2. Collectively, our genetic analyses and experimental observations revealed that missense variant of YTHDC2 can induce azoospermia in humans. These findings indicate the important role of YTHDC2 deficiency for azoospermia and will provide important guidance for genetic counseling of male infertility.
Asunto(s)
Azoospermia , Secuenciación del Exoma , Homocigoto , Mutación Missense , Linaje , Hermanos , Adulto , Animales , Humanos , Masculino , Ratones , Azoospermia/genética , Azoospermia/patología , Consanguinidad , Infertilidad Masculina/genética , Infertilidad Masculina/patología , Pakistán , ARN Helicasas/genéticaRESUMEN
Male infertility due to asthenozoospermia is quite frequent, but its etiology is poorly understood. We recruited two infertile brothers, born to first-cousin parents from Pakistan, displaying idiopathic asthenozoospermia with mild stuttering disorder but no ciliary-related symptoms. Whole-exome sequencing identified a splicing variant (c.916+1G>A) in ARMC3, recessively co-segregating with asthenozoospermia in the family. The ARMC3 protein is evolutionarily highly conserved and is mostly expressed in the brain and testicular tissue of human. The ARMC3 splicing mutation leads to the exclusion of exon 8, resulting in a predicted truncated protein (p.Glu245_Asp305delfs*16). Quantitative real-time PCR revealed a significant decrease at mRNA level for ARMC3 and Western blot analysis did not detect ARMC3 protein in the patient's sperm. Individuals homozygous for the ARMC3 splicing variant displayed reduced sperm motility with frequent morphological abnormalities of sperm flagella. Transmission electron microscopy of the affected individual IV: 2 revealed vacuolation in sperm mitochondria at the midpiece and disrupted flagellar ultrastructure in the principal and end piece. Altogether, our results indicate that this novel homozygous ARMC3 splicing mutation destabilizes sperm flagella and leads to asthenozoospermia in our patients, providing a novel marker for genetic counseling and diagnosis of male infertility.
Asunto(s)
Astenozoospermia , Consanguinidad , Homocigoto , Linaje , Empalme del ARN , Cola del Espermatozoide , Adulto , Humanos , Masculino , Astenozoospermia/genética , Astenozoospermia/patología , Secuenciación del Exoma , Infertilidad Masculina/genética , Infertilidad Masculina/patología , Mutación , Empalme del ARN/genética , Motilidad Espermática/genética , Cola del Espermatozoide/patología , Cola del Espermatozoide/ultraestructura , Cola del Espermatozoide/metabolismo , Espermatozoides/ultraestructura , Espermatozoides/patologíaRESUMEN
As the most abundant small RNAs, piwi-interacting RNAs (piRNAs) have been identified as a new class of non-coding RNAs with 24-32 nucleotides in length, and they are expressed at high levels in male germ cells. PiRNAs have been implicated in the regulation of several biological processes, including cell differentiation, development, and male reproduction. In this review, we focused on the functions and molecular mechanisms of piRNAs in controlling spermatogenesis, including genome stability, regulation of gene expression, and male germ cell development. The piRNA pathways include two major pathways, namely the pre-pachytene piRNA pathway and the pachytene piRNA pathway. In the pre-pachytene stage, piRNAs are involved in chromosome remodeling and gene expression regulation to maintain genome stability by inhibiting transposon activity. In the pachytene stage, piRNAs mediate the development of male germ cells via regulating gene expression by binding to mRNA and RNA cleavage. We further discussed the correlations between the abnormalities of piRNAs and male infertility and the prospective of piRNAs' applications in reproductive medicine and future studies. This review provides novel insights into mechanisms underlying mammalian spermatogenesis and offers new targets for diagnosing and treating male infertility.
Asunto(s)
Infertilidad Masculina , ARN Interferente Pequeño , Espermatogénesis , Espermatogénesis/genética , Masculino , Humanos , Animales , ARN Interferente Pequeño/metabolismo , ARN Interferente Pequeño/genética , Infertilidad Masculina/genética , Infertilidad Masculina/metabolismo , Medicina Reproductiva , Mamíferos/genética , Mamíferos/metabolismo , ARN de Interacción con PiwiRESUMEN
Azoospermia (the complete absence of spermatozoa in the semen) is a common cause of male infertility. The etiology of azoospermia is poorly understood. Whole-genome analysis of azoospermic men has identified a number of candidate genes, such as the X-linked testis-expressed 11 (TEX11) gene. Using a comparative genomic hybridization array, an exonic deletion (exons 10-12) of TEX11 had previously been identified in two non-apparent azoospermic patients. However, the putative impact of this genetic alteration on spermatogenesis and the azoospermia phenotype had not been validated functionally. We therefore used a CRISPR/Cas9 system to generate a mouse model (Tex11Ex9-11del/Y) with a partial TEX11 deletion that mimicked the human mutation. Surprisingly, the mutant male Tex11Ex9-11del/Y mice were fertile. The sperm concentration, motility, and morphology were normal. Similarly, the mutant mouse line's testis transcriptome was normal, and the expression of spermatogenesis genes was not altered. These results suggest that the mouse equivalent of the partial deletion observed in two infertile male with azoospermia has no impact on spermatogenesis or fertility in mice, at least of a FVB/N genetic background and until 10 months of age. Mimicking a human mutation does not necessarily lead to the same human phenotype in mice, highlighting significant differences species.
Asunto(s)
Azoospermia , Meiosis , Espermatogénesis , Animales , Masculino , Ratones , Espermatogénesis/genética , Meiosis/genética , Azoospermia/genética , Azoospermia/patología , Infertilidad Masculina/genética , Eliminación de Secuencia , Humanos , Testículo/metabolismo , Testículo/patología , Sistemas CRISPR-CasRESUMEN
Male infertility can be caused by chromosomal abnormalities, mutations and epigenetic defects. Epigenetic modifiers pre-program hundreds of spermatogenic genes in spermatogonial stem cells (SSCs) for expression later in spermatids, but it remains mostly unclear whether and how those genes are involved in fertility. Here, we report that Wfdc15a, a WFDC family protease inhibitor pre-programmed by KMT2B, is essential for spermatogenesis. We found that Wfdc15a is a non-canonical bivalent gene carrying both H3K4me3 and facultative H3K9me3 in SSCs, but is later activated along with the loss of H3K9me3 and acquisition of H3K27ac during meiosis. We show that WFDC15A deficiency causes defective spermiogenesis at the beginning of spermatid elongation. Notably, depletion of WFDC15A causes substantial disturbance of the testicular protease-antiprotease network and leads to an orchitis-like inflammatory response associated with TNFα expression in round spermatids. Together, our results reveal a unique epigenetic program regulating innate immunity crucial for fertility.
Asunto(s)
Homeostasis , Espermátides , Espermatogénesis , Masculino , Animales , Espermatogénesis/genética , Ratones , Espermátides/metabolismo , Testículo/metabolismo , Histonas/metabolismo , Péptido Hidrolasas/metabolismo , Péptido Hidrolasas/genética , Epigénesis Genética , Infertilidad Masculina/genética , Ratones Endogámicos C57BL , Meiosis/genética , Células Madre Germinales Adultas/metabolismo , Ratones Noqueados , Inmunidad Innata/genética , Espermatogonias/metabolismoRESUMEN
BACKGROUND: Spermatogenic failure is one of the leading causes of male infertility and its genetic etiology has not yet been fully understood. METHODS: The study screened a cohort of patients (n = 167) with primary male infertility in contrast to 210 normally fertile men using whole exome sequencing (WES). The expression analysis of the candidate genes based on public single cell sequencing data was performed using the R language Seurat package. RESULTS: No pathogenic copy number variations (CNVs) related to male infertility were identified using the the GATK-gCNV tool. Accordingly, variants of 17 known causative (five X-linked and twelve autosomal) genes, including ACTRT1, ADAD2, AR, BCORL1, CFAP47, CFAP54, DNAH17, DNAH6, DNAH7, DNAH8, DNAH9, FSIP2, MSH4, SLC9C1, TDRD9, TTC21A, and WNK3, were identified in 23 patients. Variants of 12 candidate (seven X-linked and five autosomal) genes were identified, among which CHTF18, DDB1, DNAH12, FANCB, GALNT3, OPHN1, SCML2, UPF3A, and ZMYM3 had altered fertility and semen characteristics in previously described knockout mouse models, whereas MAGEC1,RBMXL3, and ZNF185 were recurrently detected in patients with male factor infertility. The human testis single cell-sequencing database reveals that CHTF18, DDB1 and MAGEC1 are preferentially expressed in spermatogonial stem cells. DNAH12 and GALNT3 are found primarily in spermatocytes and early spermatids. UPF3A is present at a high level throughout spermatogenesis except in elongating spermatids. The testicular expression profiles of these candidate genes underlie their potential roles in spermatogenesis and the pathogenesis of male infertility. CONCLUSION: WES is an effective tool in the genetic diagnosis of primary male infertility. Our findings provide useful information on precise treatment, genetic counseling, and birth defect prevention for male factor infertility.
Asunto(s)
Secuenciación del Exoma , Infertilidad Masculina , Humanos , Masculino , Infertilidad Masculina/genética , Adulto , Variaciones en el Número de Copia de ADNRESUMEN
BACKGROUND: Bi-allelic variants in DNAH11 have been identified as causative factors in Primary Ciliary Dyskinesia, leading to abnormal respiratory cilia. Nonetheless, the specific impact of these variants on human sperm flagellar and their involvement in male infertility remain largely unknown. METHODS: A collaborative effort involving two Chinese reproductive centers conducted a study with 975 unrelated infertile men. Whole-exome sequencing was employed for variant screening, and Sanger sequencing confirmed the identified variants. Morphological and ultrastructural analyses of sperm were conducted using Scanning Electron Microscopy and Transmission Electron Microscopy. Western Blot Analysis and Immunofluorescence Analysis were utilized to assess protein levels and localization. ICSI was performed to evaluate its efficacy in achieving favorable pregnancy outcomes for individuals with DNAH11 variants. RESULTS: In this study, we identified seven novel variants in the DNAH11 gene in four asthenoteratozoospermia subjects. These variants led the absence of DNAH11 proteins and ultrastructure defects in sperm flagella, particularly affecting the outer dynein arms (ODAs) and adjacent structures. The levels of ODA protein DNAI2 and axoneme related proteins were down regulated, instead of inner dynein arms (IDA) proteins DNAH1 and DNAH6. Two out of four individuals with DNAH11 variants achieved clinical pregnancies through ICSI. The findings confirm the association between male infertility and bi-allelic deleterious variants in DNAH11, resulting in the aberrant assembly of sperm flagella and contributing to asthenoteratozoospermia. Importantly, ICSI emerges as an effective intervention for overcoming reproductive challenges caused by DNAH11 gene variants.
Asunto(s)
Astenozoospermia , Dineínas Axonemales , Secuenciación del Exoma , Infertilidad Masculina , Humanos , Masculino , Astenozoospermia/genética , Astenozoospermia/patología , Dineínas Axonemales/genética , Femenino , Infertilidad Masculina/genética , Infertilidad Masculina/patología , Adulto , Cola del Espermatozoide/patología , Cola del Espermatozoide/ultraestructura , Cola del Espermatozoide/metabolismo , Inyecciones de Esperma Intracitoplasmáticas , Embarazo , Espermatozoides/ultraestructura , Espermatozoides/patología , Dineínas/genéticaRESUMEN
Microtubules, polymers of αß-tubulin heterodimers, are essential for various cellular processes. The incorporation of different tubulin isotypes, each encoded by distinct genes, is proposed to contribute to the functional diversity observed in microtubules. However, the functional roles of each tubulin isotype are not completely understood. In this study, we investigated the role of the ß4B-tubulin isotype (Tubb4b) in spermatogenesis, utilizing a Tubb4b knockout mouse model. We showed that ß4B-tubulin is expressed in the germ cells throughout spermatogenesis. ß4B-tubulin was localized to cytoplasmic microtubules, mitotic spindles, manchette, and axonemes of sperm flagella. We found that the absence of ß4B-tubulin resulted in male infertility and failure to produce sperm cells. Our findings demonstrate that a lack of ß4B-tubulin leads to defects in the initial stages of spermatogenesis. Specifically, ß4B-tubulin is needed for the expansion of differentiating spermatogonia, which is essential for the subsequent progression of spermatogenesis.
Asunto(s)
Diferenciación Celular , Ratones Noqueados , Microtúbulos , Espermatogénesis , Espermatogonias , Tubulina (Proteína) , Animales , Masculino , Tubulina (Proteína)/metabolismo , Tubulina (Proteína)/genética , Espermatogonias/metabolismo , Espermatogonias/citología , Espermatogénesis/genética , Ratones , Microtúbulos/metabolismo , Infertilidad Masculina/genética , Infertilidad Masculina/metabolismo , Infertilidad Masculina/patologíaRESUMEN
Transmembrane channel-like (TMC) proteins are a highly conserved ion channel family consisting of eight members (TMC1-TMC8) in mammals. TMC1/2 are components of the mechanotransduction channel in hair cells, and mutations of TMC1/2 cause deafness in humans and mice. However, the physiological roles of other TMC proteins remain largely unknown. Here, we show that Tmc7 is specifically expressed in the testis and that it is required for acrosome biogenesis during spermatogenesis. Tmc7-/- mice exhibited abnormal sperm head, disorganized mitochondrial sheaths, and reduced number of elongating spermatids, similar to human oligo-astheno-teratozoospermia. We further demonstrate that TMC7 is colocalized with GM130 at the cis-Golgi region in round spermatids. TMC7 deficiency leads to aberrant Golgi morphology and impaired fusion of Golgi-derived vesicles to the developing acrosome. Moreover, upon loss of TMC7 intracellular ion homeostasis is impaired and ROS levels are increased, which in turn causes Golgi and endoplasmic reticulum stress. Taken together, these results suggest that TMC7 is required to maintain pH and ion homeostasis, which is needed for acrosome biogenesis. Our findings unveil a novel role for TMC7 in acrosome biogenesis during spermiogenesis.
Asunto(s)
Acrosoma , Infertilidad Masculina , Ratones Noqueados , Espermatogénesis , Animales , Masculino , Acrosoma/metabolismo , Ratones , Infertilidad Masculina/genética , Infertilidad Masculina/metabolismo , Espermatogénesis/genética , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Proteínas de la Membrana/deficiencia , Aparato de Golgi/metabolismo , Testículo/metabolismoRESUMEN
Background: In recent years, the decline in sperm quality in men has become a global trend. There is a close relationship between sperm quality and pregnancy outcome. There is a large body of literature supporting the role of plasma lipidome in male infertility, while the complex mechanisms between them and male infertility are still less clear. Systematic study of the causal relationship between plasma lipidome and MI can help to provide new therapeutic ideas and targets for male infertility. Methods: In this study, we used a two-sample Mendelian randomization analysis based on Genome-wide association studies pooled data of 179 causal relationships between plasma lipidome and male infertility. We used employed the inverse variance weighted method as the main analysis to assess causality between exposure and outcome, in addition to MR-Egger, Weighted median as complementary methods, and tests for multiplicity and heterogeneity. Results: We identified 13 plasma lipidome comprising 4 types of plasma lipidome that were associated with male infertility. Among these, 9 plasma lipidome were found to be protective factors, while 4 were risk factors. Notably, the largest proportion of these plasma lipidome were triglyceride types, with Sphingomyelin (d40:1) exhibiting the strongest association with male infertility. Conclusion: These findings contribute to the current better understanding of male infertility and provide new perspectives on the underlying etiology of male infertility as well as prevention and treatment strategies. In addition, clinical trial validation is needed to assess the potential of these plasma lipidome as biomarkers.
Asunto(s)
Estudio de Asociación del Genoma Completo , Infertilidad Masculina , Lipidómica , Análisis de la Aleatorización Mendeliana , Humanos , Masculino , Infertilidad Masculina/sangre , Infertilidad Masculina/genética , Infertilidad Masculina/epidemiología , Lípidos/sangre , Factores de RiesgoRESUMEN
Male infertility affects approximately 7% of the male population, and about 15% of these cases are predicted to have a genetic etiology. One gene implicated in autosomal dominant male infertility, SYCP2, encodes a protein critical for the synapsis of homologous chromosomes during meiosis I, resulting in impaired spermatogenesis. However, the clinical validity of the gene-disease pair was previously categorized as on the border of limited and moderate due to few reported cases. This study investigates the genetic cause of infertility for three unrelated Chinese patients with oligoasthenozoospermia. Whole exome sequencing (WES) and subsequent Sanger sequencing revealed novel heterozygous loss-of-function (LOF) variants in SYCP2 (c.89dup, c.946_947del, and c.4378_4379del). These cases, combined with the previously reported cases, provide strong genetic evidence supporting an autosomal dominant inheritance pattern. The experimental evidence also demonstrates a critical role for SYCP2 in spermatogenesis. Collectively, this updated assessment of the genetic and experimental evidence upgrades the gene-disease association strength of SYCP2 and autosomal dominant male infertility from on the border of limited and moderate to strong. The reclassification improves SYCP2 variant interpretation and qualifies it for the inclusion on diagnostic male infertility gene panels and prioritization in whole exome or genome studies for related phenotypes. These findings therefore improve the clinical interpretation of SYCP2 LOF variants.
Asunto(s)
Secuenciación del Exoma , Infertilidad Masculina , Masculino , Humanos , Infertilidad Masculina/genética , Adulto , Secuenciación del Exoma/métodos , Espermatogénesis/genética , Mutación con Pérdida de Función , Proteínas de Unión al ADN/genética , Proteínas de Ciclo Celular/genética , LinajeRESUMEN
piRNAs are crucial for transposon silencing, germ cell maturation, and fertility in male mice. Here, we report on the genetic landscape of piRNA dysfunction in humans and present 39 infertile men carrying biallelic variants in 14 different piRNA pathway genes, including PIWIL1, GTSF1, GPAT2, MAEL, TDRD1, and DDX4. In some affected men, the testicular phenotypes differ from those of the respective knockout mice and range from complete germ cell loss to the production of a few morphologically abnormal sperm. A reduced number of pachytene piRNAs was detected in the testicular tissue of variant carriers, demonstrating impaired piRNA biogenesis. Furthermore, LINE1 expression in spermatogonia links impaired piRNA biogenesis to transposon de-silencing and serves to classify variants as functionally relevant. These results establish the disrupted piRNA pathway as a major cause of human spermatogenic failure and provide insights into transposon silencing in human male germ cells.
Asunto(s)
Elementos Transponibles de ADN , Infertilidad Masculina , ARN Interferente Pequeño , Espermatogénesis , Testículo , Masculino , Humanos , Espermatogénesis/genética , Infertilidad Masculina/genética , Infertilidad Masculina/metabolismo , Infertilidad Masculina/patología , ARN Interferente Pequeño/metabolismo , ARN Interferente Pequeño/genética , Elementos Transponibles de ADN/genética , Animales , Testículo/metabolismo , Ratones , Adulto , Silenciador del Gen , Ratones Noqueados , Proteínas Argonautas/metabolismo , Proteínas Argonautas/genética , Elementos de Nucleótido Esparcido Largo/genética , Espermatogonias/metabolismo , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/metabolismo , ARN de Interacción con PiwiRESUMEN
Background: Previous observational studies have reported a possible association between circulating lipids and lipid-lowering drugs and male infertility (MIF), as well as the mediating role of circulating vitamin D. Then, due to issues such as bias, reverse causality, and residual confounding, inferring causal relationships from these studies may be challenging. Therefore, this study aims to explore the effects of circulating lipids and lipid-lowering drugs on MIF through Mendelian randomization (MR) analysis and evaluate the mediating role of vitamin D. Method: Genetic variations related to lipid traits and the lipid-lowering effect of lipid modification targets are extracted from the Global Alliance for Lipid Genetics Genome-Wide Association Study. The summary statistics for MIF are from the FinnGen 9th edition. Using quantitative expression feature loci data from relevant organizations to obtain genetic variations related to gene expression level, further to explore the relationship between these target gene expression levels and MIF risk. Two-step MR analysis is used to explore the mediating role of vitamin D. Multiple sensitivity analysis methods (co-localization analysis, Egger intercept test, Cochrane's Q test, pleiotropy residuals and outliers (MR-PRESSO), and the leave-one-out method) are used to demonstrate the reliability of our results. Result: In our study, we observed that lipid modification of four lipid-lowering drug targets was associated with MIF risk, the LDLR activator (equivalent to a 1-SD decrease in LDL-C) (OR=1.94, 95% CI 1.14-3.28, FDR=0.040), LPL activator (equivalent to a 1-SD decrease in TG) (OR=1.86, 95% CI 1.25-2.76, FDR=0.022), and CETP inhibitor (equivalent to a 1-SD increase in HDL-C) (OR=1.28, 95% CI 1.07-1.53, FDR=0.035) were associated with a higher risk of MIF. The HMGCR inhibitor (equivalent to a 1-SD decrease in LDL-C) was associated with a lower risk of MIF (OR=0.38, 95% CI 0.17-0.83, FDR=0.39). Lipid-modifying effects of three targets were partially mediated by serum vitamin D levels. Mediation was 0.035 (LDLR activator), 0.012 (LPL activator), and 0.030 (CETP inhibitor), with mediation ratios of 5.34% (LDLR activator), 1.94% (LPL activator), and 12.2% (CETP inhibitor), respectively. In addition, there was no evidence that lipid properties and lipid modification effects of six other lipid-lowering drug targets were associated with MIF risk. Multiple sensitivity analysis methods revealed insignificant evidence of bias arising from pleiotropy or genetic confounding. Conclusion: This study did not support lipid traits (LDL-C, HDL-C, TG, Apo-A1, and Apo-B) as pathogenic risk factors for MIF. It emphasized that LPL, LDLR, CETP, and HMGCR were promising drug targets for improving male fertility.
Asunto(s)
Estudio de Asociación del Genoma Completo , Infertilidad Masculina , Análisis de la Aleatorización Mendeliana , Humanos , Masculino , Infertilidad Masculina/genética , Lípidos/sangre , Vitamina D/sangre , Polimorfismo de Nucleótido Simple , Proteínas de Transferencia de Ésteres de Colesterol/genética , Hipolipemiantes/uso terapéutico , Receptores de LDL/genética , Hidroximetilglutaril-CoA Reductasas/genéticaRESUMEN
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.
Asunto(s)
Fragmentación del ADN , Infertilidad Masculina , Estrés Oxidativo , Espermatozoides , Varicocele , Humanos , Masculino , Varicocele/fisiopatología , Varicocele/complicaciones , Estrés Oxidativo/fisiología , Infertilidad Masculina/etiología , Infertilidad Masculina/genética , Infertilidad Masculina/fisiopatología , Infertilidad Masculina/metabolismo , Espermatozoides/fisiología , Espermatozoides/metabolismo , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Gut bacteria might play an important role in male reproductive disorders, such as male infertility and sperm abnormalities; however, their causal role is unclear. Herein, Mendelian randomization (MR)-Egger, weighted median, inverse variance weighting, Simple mode, and Weighted mode were used to test the causal relationship between gut microbes and male reproductive diseases. The MR results were validated using various metrics. The MR results were also consolidated using reverse causality speculation, conducted using two-way MR analysis and Steiger filtering. Biological function was analysed using enrichment analyses. The results suggested that eight intestinal microflorae were causally associated with male infertility. The Eubacterium oxidoreducens group was associated with an increased risk of male infertility, while the family Bacteroidaceae was negatively associated with male reproductive diseases. Eight intestinal microflorae were causally associated with abnormal spermatozoa. The family Streptococcaceae was associated with a high risk of abnormal spermatozoa, whereas the family Porphyromonadaceae was associated with a low risk of abnormal spermatozoa. No pleiotropy was observed, this study identified a high correlation between the gut flora and the likelihood of male reproductive diseases. Future research will attempt to advance microbial-focused treatments for such diseases.
Asunto(s)
Microbioma Gastrointestinal , Infertilidad Masculina , Análisis de la Aleatorización Mendeliana , Masculino , Humanos , Microbioma Gastrointestinal/genética , Infertilidad Masculina/microbiología , Infertilidad Masculina/genética , Espermatozoides/microbiologíaRESUMEN
BACKGROUND: The complete absence of the azoospermia factor A (AZFa) region typically results in nonobstructive azoospermia. Partial deletions of the AZFa region are particularly noteworthy due to the limited and enigmatic reports of partial deletions in the AZFa region. Here, we present a rare case report of partial deletion of sY84 in the AZFa region but exhibiting normal sperm quality. The aim of this case report is to gain a deeper insight into the impact of AZFa region deletion on male fertility and to guide future clinical decisions and treatment strategies. METHODS AND RESULTS: A 25-year-old man presented to the hospital with his 25-year-old wife due to recurrent spontaneous abortions. Routine semen analysis, sperm morphology analysis, acrosomal enzyme analysis, sperm DNA fragmentation indexed, and peripheral blood karyotype analysis revealed no abnormalities. Y chromosome microdeletion was detected by real-time fluorescence polymerase chain reaction, which showed that sY84 could not be amplified and sY86 was amplified nonspecifically. The man was diagnosed with partial deletions in the AZFa region. The wife underwent in vitro fertilization treatment for tubal infertility and recurrent spontaneous abortions. The couple successfully delivered a healthy daughter weighing 2.7 kg at 39 weeks of gestation, following 2 assisted reproductive pregnancies. CONCLUSION: Our findings contribute to expanding our knowledge of the AZFa region. A sY84 deficiency in the AZFa region may not lead to spermatogenesis failure and may potentially be one of the factors causing recurrent miscarriages, which needs to be confirmed by further data.
Asunto(s)
Azoospermia , Deleción Cromosómica , Cromosomas Humanos Y , Adulto , Femenino , Humanos , Masculino , Embarazo , Azoospermia/genética , Cromosomas Humanos Y/genética , Infertilidad Masculina/genética , Análisis de Semen , Proteínas de Plasma Seminal/genética , Aberraciones Cromosómicas Sexuales , Trastornos de los Cromosomas Sexuales del Desarrollo Sexual/genética , Espermatozoides/anomalías , Aborto HabitualRESUMEN
Ciliary beat and intraflagellar transport depend on dynein and kinesin motors. The kinesin-9 family members Kif6 and Kif9 are implicated in motile cilia motilities across protists and mammals. How they function and whether they act redundantly, however, remain unclear. Here, we show that Kif6 and Kif9 play distinct roles in mammals. Kif6 forms puncta that move bidirectionally along axonemes, whereas Kif9 appears to oscillate regionally on the ciliary central apparatus. Consistently, only Kif6 displays microtubule-based motor activity in vitro, and its ciliary localization requires its ATPase activity. Kif6 deficiency in mice disrupts coordinated ciliary beat across ependymal tissues and impairs cerebrospinal fluid flow, resulting in severe hydrocephalus and high mortality. Kif9 deficiency causes mild hydrocephalus without obviously affecting the ciliary beat or the lifespan. Kif6-/- and Kif9-/- males are infertile but exhibit oligozoospermia with poor sperm motility and defective forward motion of sperms, respectively. These results suggest Kif6 as a motor for cargo transport and Kif9 as a central apparatus regulator.
Asunto(s)
Cilios , Cinesinas , Ratones Noqueados , Animales , Cinesinas/metabolismo , Cinesinas/genética , Cilios/metabolismo , Masculino , Ratones , Transporte de Proteínas , Motilidad Espermática/genética , Hidrocefalia/metabolismo , Hidrocefalia/genética , Hidrocefalia/patología , Ratones Endogámicos C57BL , Axonema/metabolismo , Infertilidad Masculina/genética , Infertilidad Masculina/metabolismo , Infertilidad Masculina/patología , Humanos , Microtúbulos/metabolismoRESUMEN
OBJECTIVE: To clarify the causal relationship between obesity and male infertility through Mendelian randomization (MR) study. METHODS: We assessed the causal effect of genetically predicted body mass index (BMI) on the risk of male infertility via a two-sample MR analysis, with the BMIs of 99 998 cases and 12 746 controls as the exposure factor and genetic information on male infertility obtained from a genome-wide association study of 73 479 Europeans. In the univariable MR (UVMR) analysis of the causal relationship, we mainly used inverse variance weighting (IVW), with MR-Egger regression and weighted median filtering as the supplementary methods. Sensitivity analyses including the Cochran's Q test, Egger intercept test, MR-PRESSO, leave-one-out analysis and funnel plot were performed to verify the robustness of the MR results. To evaluate the direct causal effects of BMI on MI risk, multivariable MR (MVMR) was performed. RESULTS: UVMR indicated a causal relationship between genetically predicted BMI and an increased risk of male infertility (OR: 1.237, 95% CI: 1.090ï¼1.404, P = 0.001). Sensitivity analysis revealed little evidence of bias in the current study (P> 0.05). With such risk factors as type 2 diabetes, alcohol consumption and smoking adjusted, MVMR confirmed a direct causal effect of genetically predicted BMI on the risk of male infertility (P<0.05). CONCLUSION: Genetically predicted BMI may be associated with an increased risk of male infertility. Further studies are expected to explore the underlying mechanisms of this association and provide some new strategies for the prevention and treatment of BMI-related male infertility.
Asunto(s)
Índice de Masa Corporal , Estudio de Asociación del Genoma Completo , Infertilidad Masculina , Análisis de la Aleatorización Mendeliana , Obesidad , Humanos , Masculino , Infertilidad Masculina/genética , Obesidad/genética , Factores de Riesgo , Polimorfismo de Nucleótido SimpleRESUMEN
Ribonucleoprotein (RNP) granules are membraneless electron-dense structures rich in RNAs and proteins, and involved in various cellular processes. Two RNP granules in male germ cells, intermitochondrial cement and the chromatoid body (CB), are associated with PIWI-interacting RNAs (piRNAs) and are required for transposon silencing and spermatogenesis. Other RNP granules in male germ cells, the reticulated body and CB remnants, are also essential for spermiogenesis. In this study, we disrupted FBXO24, a testis-enriched F-box protein, in mice and found numerous membraneless electron-dense granules accumulated in sperm flagella. Fbxo24 knockout (KO) mice exhibited malformed flagellar structures, impaired sperm motility, and male infertility, likely due to the accumulation of abnormal granules. The amount and localization of known RNP granule-related proteins were not disrupted in Fbxo24 KO mice, suggesting that the accumulated granules were distinct from known RNP granules. Further studies revealed that RNAs and two importins, IPO5 and KPNB1, abnormally accumulated in Fbxo24 KO spermatozoa and that FBXO24 could ubiquitinate IPO5. In addition, IPO5 and KPNB1 were recruited to stress granules, RNP complexes, when cells were treated with oxidative stress or a proteasome inhibitor. These results suggest that FBXO24 is involved in the degradation of IPO5, disruption of which may lead to the accumulation of abnormal RNP granules in sperm flagella.