Search Results (20)

The Zinc Finger X-Linked Duplicate B (ZXDB) gene is one of a pair of replicated zinc finger genes on chromosome Xp11.21. The homologous gene of ZXDB in mice is Zxdb. Recent studies have found that Zxdb plays a role in the spermatogenic process of mice; however, its impact on the female reproductive system has not yet been explored. In our study, we found, for the first time, that the loss of function of Zxdb leads to reduced decidualization rates and a decrease in litter size in female mice. Secondly, we found that maternal loss of Zxdb is the determinant of these phenotypes. Thirdly, the transcriptional and proteomic differential expression genes in the uterine tissues of wild-type (WT) and Zxdb knockout (Zxdb-KO) mice were significantly enriched in signaling pathways such as adhesion molecules. Finally, we demonstrated that the disorder of expression and uneven distribution of adhesion molecules in mouse uterine tissue may be the main reason for the decline in embryo implantation rate. In conclusion, we have established for the first time a link between the Zxdb gene and reduced female fertility. This study will help provide guidance and genetic counseling for future common clinical complications such as Recurrent Spontaneous Abortion (RSA) or Recurrent Implantation Failure (RIF). Full article

Spermatogenesis is a tightly coordinated differentiation program that sustains male fertility while transmitting genetic and epigenetic information to the next generation. This review consolidates mechanistic evidence showing how RNA-centered regulation integrates with the epitranscriptome and three-dimensional (3D) genome architecture to orchestrate germ-cell fate transitions from spermatogonial stem cells through meiosis and spermiogenesis. Recent literature is critically surveyed and synthesized, with particular emphasis on human and primate data and on stage-resolved maps generated by single-cell and multi-omics technologies. Collectively, available studies support a layered regulatory model in which RNA-binding proteins and RNA modifications coordinate transcript processing, storage, translation, and decay; small and long noncoding RNAs shape post-transcriptional programs and transposon defense; and dynamic chromatin remodeling and 3D reconfiguration align transcriptional competence with recombination, sex-chromosome silencing, and genome packaging. Convergent nodes implicated in spermatogenic failure are highlighted, including defects in RNA metabolism, piRNA pathway integrity, epigenetic reprogramming, and nuclear architecture, and the potential of these frameworks to refine molecular phenotyping in male infertility is discussed. Finally, key gaps and priorities for causal testing in spatially informed, stage-specific experimental systems are outlined. Full article

During the COVID-19 pandemic, the prevalence of death in men was higher than in women. Using transgenic mice expressing the human angiotensin-converting enzyme 2 (hACE2), we demonstrated that SARS-CoV-2 infects Leydig cells and uses its steroidogenic machinery for replication. This study investigates the impact of SARS-CoV-2 in the seminiferous epithelium of K18-hACE2 mice, focusing on the immune response, junctional proteins, and spermatogenesis. The seminiferous tubules (STs) and epithelial (EA) areas were measured. The number of Sertoli cells (SCs), spermatocytes, and damaged ST was quantified. Ultrastructural analysis was performed under transmission electron microscopy. Angiotensin II levels and immunolocalization of hACE2, spike, and nucleocapsid were evaluated. TUNEL and immunoreactions for Ki-67, TNF-α, INF-γ, iNOS, NF-κB, and Conexin-43 were performed and correlated with Jam-α, Stat1, Stat3, and iNOS expressions. hACE2, spike, and nucleocapsid immunolabeling were detected in the epithelium along with high angiotensin II levels in the infected mice. The infection caused a significant reduction in ST, EA, spermatocytes, SCs, Ki-67+ cells, Cx43 immunoexpression, and Jam-a expression. In the epithelium, TNF-α, IFN-γ, iNOS, and nuclear NF-κB immunolabeling increased along with Stat1 upregulation. These findings, combined with the increased epithelial hACE2 and high angiotensin II levels, confirm epithelial responsiveness to the infection and explain the spermatogenic failure and impaired junctional proteins. The presence of viral particles, increased TNF-α immunolabeling, and apoptotic features in Sertoli cells suggests that these sustentacular cells are targets for viral infection in the epithelium, and, due to their extensive projections and ability to phagocytize dying infected germ cells, they may disseminate the viruses throughout the epithelium. Full article

Testosterone (T) produced by Leydig cells (LCs) is essential for male reproduction; yet, the regulatory mechanisms underlying steroidogenesis remain incompletely understood. Here, we investigated the role of cyclin-dependent kinase 5 regulatory subunit-associated protein 3 (CDK5RAP3) in Leydig cell development and steroidogenesis, based on its identification by immunoprecipitation-mass spectrometry (IP-MS) as a protein associated with steroidogenesis and cholesterol metabolism in mouse testicular tissue. Using human samples, we found that CDK5RAP3 expression was significantly reduced in Leydig cells from patients with spermatogenic failure (T < 10.4 nmol/L). Notably, CDK5RAP3 expression increased during mouse postnatal Leydig cell maturation and regeneration in an ethane dimethanesulfonate (EDS)-induced rat model. Functional analyses in primary LCs and MLTC-1 cells showed that hCG stimulation triggered CDK5RAP3 nuclear translocation without altering its overall expression, while CDK5RAP3 knockdown markedly impaired hCG-induced testosterone production and reduced the expression of the steroidogenic regulator steroidogenic acute regulatory (STAR) protein, as well as key steroidgenic enzymes, including cytochrome P450 family 11 subfamily A member 1 (CYP11A1), 17a-hydroxylase (CYP17A1), and 3β-hydroxysteroid dehydrogenase (HSD3B). Conversely, CDK5RAP3 overexpression enhanced testosterone production in the absence of hCG. In vivo, AAV2/9-mediated CDK5RAP3 silencing in adult mouse testes resulted in a significant reduction in serum testosterone levels compared with controls (3.60 ± 0.38 ng/mL vs. 1.83 ± 0.37 ng/mL). Mechanistically, CDK5RAP3 interacted with SMAD4 and CEBPB, and BMP pathway inhibition by Noggin rescued the testosterone deficit caused by CDK5RAP3 loss. Together, these findings identify CDK5RAP3 as an essential regulator of Leydig cell steroidogenesis and provide insight into its potential relevance to male infertility associated with low testosterone. Full article

Background: Reproductive performance is critical in the pig industry, and improved sow performance could lead to increased economic benefits. GWAS and ROH analyses based on SNP array data were conducted to identify the breed-specific genetic architecture underlying the variation in NBA and TNB. Methods: A total of 7488 breeding pigs with phenotypic data from 1586 Duroc, 2256 Landrace, and 3646 Yorkshire breeds, along with 76,756 SNP markers from Korean grand-grand-parent (GGP) breeding farms, were used. Results: In the Duroc breeds, SNPs on SSC 9 and 17 were found to be associated with the SIDT2 and TGM2 genes, respectively. In the Landrace breed, PPP1R9A, LMTK2, and GTF2H3 on SSCs 9, 3, and 14, respectively, were associated with both TNB and NBA. With the Yorkshire breed genome, GRID1, DLGAP2, ZZEF1, PARG, RNF17, and NDUFAF5 in SSCs 14, 15, 12, 14, 11, and 17, respectively, were associated with NBA and TNB traits. These genes have distinct functions, ranging from synaptic transmission and cytoskeletal organization to DNA repair and cellular energy production. In the Duroc breed, six genes identified in the ROH islands were associated with various biological pathways, molecular functions, and cellular components. NT5DC1 was associated with metaphyseal chondrodysplasia, CRTAC1 with ion binding, CFAP43 with spermatogenic failure, CASC3 with intracellular mRNA localization, ERC2 with cellular component organization, and FOCAD with Focadhesin. In the Landrace and Yorkshire breeds, PDE6D was associated with GTPase inhibitor activity. Conclusions: Through GWAS and ROH analyses, we identified breed-specific SNP markers associated with NBA and TNB in three breed genotypes, providing insights for improving reproductive performance efficiency and contributing to future breeding strategies. Full article

Non-obstructive azoospermia (NOA) is found in up to 15% of infertile men. While several causes for NOA have been identified, the exact etiology remains unknown in many patients. Advances in assisted reproductive technology, including intracytoplasmic sperm injection (ICSI) and testicular sperm retrieval, have provided hope for these patients. This review summarizes the chances of success with ICSI for NOA patients and examines preoperative factors and laboratory techniques associated with positive outcomes. Furthermore, we reviewed possible consequences for offspring by the use of ICSI with testicular sperm retrieved from NOA patients and the interventions that could potentially mitigate risks. Testicular sperm retrieved from NOA patients may exhibit increased chromosomal abnormalities, and although lower fertilization and pregnancy rates are reported in NOA patients compared to other forms of infertility, the available evidence does not suggest a significant increase in miscarriage rate, congenital malformation, or developmental delay in their offspring compared to the offspring of patients with less severe forms of infertility or the offspring of fertile men. However, due to limited data, NOA patients should receive specialized reproductive care and personalized management. Counseling of NOA patients is essential before initiating any fertility enhancement treatment not only to mitigate health risks associated with NOA but also to enhance the chances of successful outcomes and minimize possible risks to the offspring. Full article

Tumor cells display abnormal growth and division, avoiding the natural process of cell death. These cells can be benign (non-cancerous growth) or malignant (cancerous growth). Over the past few decades, numerous in vitro or in vivo tumor models have been employed to understand the molecular mechanisms associated with tumorigenesis in diverse regards. However, our comprehension of how non-tumor cells transform into tumor cells at molecular and cellular levels remains incomplete. The nematode C. elegans has emerged as an excellent model organism for exploring various phenomena, including tumorigenesis. Although C. elegans does not naturally develop cancer, it serves as a valuable platform for identifying oncogenes and the underlying mechanisms within a live organism. In this review, we describe three distinct germline tumor models in C. elegans, highlighting their associated mechanisms and related regulators: (1) ectopic proliferation due to aberrant activation of GLP-1/Notch signaling, (2) meiotic entry failure resulting from the loss of GLD-1/STAR RNA-binding protein, (3) spermatogenic dedifferentiation caused by the loss of PUF-8/PUF RNA-binding protein. Each model requires the mutations of specific genes (glp-1, gld-1, and puf-8) and operates through distinct molecular mechanisms. Despite these differences in the origins of tumorigenesis, the internal regulatory networks within each tumor model display shared features. Given the conservation of many of the regulators implicated in C. elegans tumorigenesis, it is proposed that these unique models hold significant potential for enhancing our comprehension of the broader control mechanisms governing tumorigenesis. Full article

Azoospermia is a form of male infertility characterized by a complete lack of spermatozoa in the ejaculate. Sertoli cell-only syndrome (SCOS) is the most severe form of azoospermia, where no germ cells are found in the tubules. Recently, FANCM gene variants were reported as novel genetic causes of spermatogenic failure. At the same time, FANCM variants are known to be associated with cancer predisposition. We performed whole-exome sequencing on a male patient diagnosed with SCOS and a healthy father. Two compound heterozygous missense mutations in the FANCM gene were found in the patient, both being inherited from his parents. After the infertility assessment, the patient was diagnosed with diffuse astrocytoma. Immunohistochemical analyses in the testicular and tumor tissues of the patient and adequate controls showed, for the first time, not only the existence of a cytoplasmic and not nuclear pattern of FANCM in astrocytoma but also in non-mitotic neurons. In the testicular tissue of the SCOS patient, cytoplasmic anti-FANCM staining intensity appeared lower than in the control. Our case report raises a novel possibility that the infertile carriers of FANCM gene missense variants could also be prone to cancer development. Full article

Spermatogenesis is a highly regulated process dependent on androgen receptor (AR) signaling in Sertoli cells. However, the pathogenic mechanisms of spermatogenic failure, by which loss of AR impairs downstream target genes to affect Sertoli cell function, remain incompletely understood. By using microarray analysis, we identified several AR-regulated genes involved in the maturation of spermatogenesis, including chromodomain Y-like protein (CDYL) and transition proteins 1 (TNP-1), that were significantly decreased in ARKO mouse testes. AR and CDYL were found to co-localize and interact in Sertoli cells. The AR–CDYL complex bound to the promoter regions of TNP1 and modulated their transcriptional activity. CDYL acts as a co-regulator of AR transactivation, and its expression is decreased in the Sertoli cells of human testes from patients with azoospermia. The androgen receptor–chromodomain Y-like protein axis plays a crucial role in regulating a network of genes essential for spermatogenesis in Sertoli cells. Disruption of this AR–CDYL regulatory axis may contribute to spermatogenic failure. These findings provide insights into novel molecular mechanisms targeting the AR–CDYL signaling pathway, which may have implications for developing new therapeutic strategies for male infertility. Full article

Teratozoospermia, a complex male fertility disorder affecting sperm morphology, has been linked to AURKC, SPATA16, and SUN5 gene defects. However, the sheer volume of SNPs in these genes necessitates prioritization for comprehensive analysis. This study focuses on the often-overlooked untranslated region (UTR) variants in these genes, aiming to assess their association with teratozoospermia and prioritize them. We employed a multi-step filtering process, including functional significance assessment (RegulomeDB, 3DSNP v2.0, SNPinfo (FuncPred)), evaluation of gene expression impacts in testis tissue using GTEx, and assessment of miRNA binding site effects (PolymiRTS Database 3.0, miRNASNP v3). Additionally, we used SNPnexus to evaluate their conservation and association with diseases. In AURKC, we identified six UTR SNPs (rs11084490, rs58264281, rs35582299, rs533889458, rs2361127, rs55710619), two of which influenced gene expression in testis, while others affected the binding sites of 29 miRNAs or were located in transcription-factor binding sites. Three of these SNPs were also found to be associated with spermatogenic failure according to previous studies indicating a potential regulatory role in teratozoospermia, too. For SPATA16, two 3′ UTR variants, rs146640459 and rs148085657, were prioritized, with the latter impacting miRNA binding sites. In SUN5, three 3′ UTR variants (rs1485087675, rs762026146, rs1478197315) affected miRNA binding sites. It should be noted that none of the above variants was identified in a conserved region. Our findings shed light on the potential regulatory roles of these SNPs in teratozoospermia and lay the foundation for future research directions in this area. Full article

GRTH/DDX25 is a testis-specific DEAD-box family of RNA helicase, which plays an essential role in spermatogenesis and male fertility. There are two forms of GRTH, a 56 kDa non-phosphorylated form and a 61 kDa phosphorylated form (pGRTH). GRTH-KO and GRTH Knock-In (KI) mice with R242H mutation (lack pGRTH) are sterile with a spermatogenic arrest at step 8 of spermiogenesis due to failure of round spermatids (RS) to elongate. We performed mRNA-seq and miRNA-seq analysis on RS of WT, KI, and KO to identify crucial microRNAs (miRNAs) and mRNAs during RS development by establishing a miRNA–mRNA network. We identified increased levels of miRNAs such as miR146, miR122a, miR26a, miR27a, miR150, miR196a, and miR328 that are relevant to spermatogenesis. mRNA–miRNA target analysis on these DE-miRNAs and DE-mRNAs revealed miRNA target genes involved in ubiquitination process (Ube2k, Rnf138, Spata3), RS differentiation, and chromatin remodeling/compaction (Tnp1/2, Prm1/2/3, Tssk3/6), reversible protein phosphorylation (Pim1, Hipk1, Csnk1g2, Prkcq, Ppp2r5a), and acrosome stability (Pdzd8). Post-transcriptional and translational regulation of some of these germ-cell-specific mRNAs by miRNA-regulated translation arrest and/or decay may lead to spermatogenic arrest in KO and KI mice. Our studies demonstrate the importance of pGRTH in the chromatin compaction and remodeling process, which mediates the differentiation of RS into elongated spermatids through miRNA–mRNA interactions. Full article

Removal of the 5′ cap structure of RNAs (termed decapping) is a pivotal event in the life of cytoplasmic mRNAs mainly catalyzed by a conserved holoenzyme, composed of the catalytic subunit DCP2 and its essential cofactor DCP1. While decapping was initially considered merely a step in the general 5′-3′ mRNA decay, recent data suggest a great degree of selectivity that plays an active role in the post-transcriptional control of gene expression, and regulates multiple biological functions. Studies in Caenorhabditis elegans have shown that old age is accompanied by the accumulation of decapping factors in cytoplasmic RNA granules, and loss of decapping activity shortens the lifespan. However, the link between decapping and ageing remains elusive. Here, we present a comparative microarray study that was aimed to uncover the differences in the transcriptome of mid-aged dcap-1/DCP1 mutant and wild-type nematodes. Our data indicate that DCAP-1 mediates the silencing of spermatogenic genes during late oogenesis, and suppresses the aberrant uprise of immunity gene expression during ageing. The latter is achieved by destabilizing the mRNA that encodes the transcription factor PQM-1 and impairing its nuclear translocation. Failure to exert decapping-mediated control on PQM-1 has a negative impact on the lifespan, but mitigates the toxic effects of polyglutamine expression that are involved in human disease. Full article

The aim of our study was to determine the type and frequency of chromosomal aberrations and polymorphisms in men with different degrees of spermatogenic failure in comparison to men with normozoospermia, in order to find correlations between cytogenetic findings and the abnormal results of semen analysis. In our study, we performed cytogenetic analysis in 901 infertile men, divided into five groups according to semen analysis—normozoospermia (86), asthenozoospermia (394), oligoasthenozoospermia (182), severe male factor (100), and azoospermia (139). The frequency of polymorphisms was similar in all groups (11–16%, without significant differences). The frequency of numerical and structural aberrations increases with the degree of the spermatogenic failure (3.5% in normozoospermia, 5.6% in asthenozoospermia, 9.8% in oligoasthenozoospermia, 9% in severe male factor, and 13.5% in azoospermia). We found a significantly higher incidence of numerical chromosomal aberrations in severe male factor (7%) and azoospermia (9.3%). Oligoasthenozoospermia occured in 45% of cases with translocation, compared to 20% in the group with a normal karyotype. We revealed that chromosomal translocations are tightly associated with oligoasthenozoospermia, whereas numerical chromosomal aberrations—with severe male factor and azoospermia. The impact of chromosome polymorphisms on male infertility should be studied in greater detail. Full article

We aimed to analyze the role of the common genetic variants located in the PIN1 locus, a relevant prolyl isomerase required to control the proliferation of spermatogonial stem cells and the integrity of the blood–testis barrier, in the genetic risk of developing male infertility due to a severe spermatogenic failure (SPGF). Genotyping was performed using TaqMan genotyping assays for three PIN1 taggers (rs2287839, rs2233678 and rs62105751). The study cohort included 715 males diagnosed with SPGF and classified as suffering from non-obstructive azoospermia (NOA, n = 505) or severe oligospermia (SO, n = 210), and 1058 controls from the Iberian Peninsula. The allelic frequency differences between cases and controls were analyzed by the means of logistic regression models. A subtype specific genetic association with the subset of NOA patients classified as suffering from the Sertoli cell-only (SCO) syndrome was observed with the minor alleles showing strong risk effects for this subset (OR_addrs2287839 = 1.85 (1.17–2.93), OR_addrs2233678 = 1.62 (1.11–2.36), OR_addrs62105751 = 1.43 (1.06–1.93)). The causal variants were predicted to affect the binding of key transcription factors and to produce an altered PIN1 gene expression and isoform balance. In conclusion, common non-coding single-nucleotide polymorphisms located in PIN1 increase the genetic risk to develop SCO. Full article

The steroidogenic cells in the testicle, Leydig cells, located in the interstitial compartment, play a vital role in male reproductive tract development, maintenance of proper spermatogenesis, and overall male reproductive function. Therefore, their dysfunction can lead to all sorts of testicular pathologies. Spermatogenesis failure, manifested as azoospermia, is often associated with defective Leydig cell activity. Spermatogenic failure is the most severe form of male infertility, caused by disorders of the testicular parenchyma or testicular hormone imbalance. This review covers current progress in knowledge on Leydig cells origin, structure, and function, and focuses on recent advances in understanding how Leydig cells contribute to the impairment of spermatogenesis. Full article