Oligoasthenoteratozoospermia is an important factor affecting male fertility and has been found to be associated with genetic factors. However, there are still a proportion of oligoasthenoteratozoospermia cases that cannot be explained by known pathogenic genetic variants. Here, we perform genetic analyses and identify bi-allelic loss-of-function variants of MFSD6L from an oligoasthenoteratozoospermia affected family. Mfsd6l knock-out male mice also present male subfertility with reduced sperm concentration, motility, and deformed acrosomes. Further mechanistic analyses reveal that MFSD6L, as an acrosome membrane protein, plays an important role in the formation of acrosome by interacting with inner acrosomal membrane protein SPACA1. Moreover, poor embryonic development is consistently observed after intracytoplasmic sperm injection treatment using spermatozoa from MFSD6L-deficient man and male mice. Collectively, our findings reveal that MFSD6L is required for the anchoring of sperm acrosome and head shaping. The deficiency of MFSD6L affects male fertility and causes oligoasthenoteratozoospermia in humans and mice.

BACKGROUND: PiRNA pathway factors, including evolutionarily conserved Tudor domain-containing proteins, play crucial roles in suppressing transposons and regulating post-meiotic gene expression. TDRD5 is essential for retrotransposon silencing and pachytene piRNA biogenesis; however, a causal link between TDRD5 variants and human infertility has not yet been established.
OBJECTIVE: To identify the likely pathogenic variants of TDRD5 in infertile men, characterised by azoospermia or severe oligozoospermia.
METHODS: Potential candidate variants were identified and confirmed using whole-exome and Sanger sequencing. Haematoxylin and eosin staining, immunofluorescence, and ultrastructural analyses were performed to investigate the structural and functional abnormalities of spermatozoa. The pathogenicity of the identified TDRD5 variants was verified using in vitro experiments. Functional effects of the C-terminal nonsense variant were assessed via histology, immunofluorescence staining, and small-RNA sequencing. Intracytoplasmic sperm injection (ICSI) was also performed to evaluate the efficacy of the clinical treatment.
RESULTS: We identified a homozygous missense variant (c.3043G > A, p.A1015T) and a homozygous nonsense variant (c.2293G > T, p.E765*) of TDRD5 in two unrelated infertile men. Both patients exhibited severe oligoasthenoteratozoospermia, characterised by the presence of spermatozoa with multiple heads and/or flagella, as well as acrosomal hypoplasia. In vitro experiments revealed that the p.A1015T variant caused a diffuse distribution of TDRD5 granules, whereas the p.E765* variant led to the production of a C-terminal truncated protein with nuclear localisation, instead of the typical cytoplasmic localisation observed for the wild-type protein. Functional investigations also revealed that truncation of the C-terminal region of TDRD5 could potentially lead to a decline in the expression levels of intermitochondrial cement and chromatoid body components, such as MIWI (PIWIL1) and UPF1, and a slight decrease in the abundance of pachytene piRNA, ultimately resulting in compromised spermiogenesis. ICSI may be an effective treatment for these deficiencies.
CONCLUSIONS: This study implicates TDRD5 as a novel candidate gene in the pathogenesis of human male infertility, emphasising the contribution of piRNA pathway genes to male infertility. In addition, our data suggest that ICSI could be a promising treatment for infertile men harbouring TDRD5 variants.

OBJECTIVE: Is the Tcte1 mutation causative for male infertility?
CONCLUSIONS: Our collected data underline the complex and devastating effect of the single-gene mutation on the testicular molecular network, leading to male reproductive failure.
BACKGROUND: Recent data have revealed mutations in genes related to axonemal dynein arms as causative for morphology and motility abnormalities in spermatozoa of infertile males, including dysplasia of fibrous sheath (DFS) and multiple morphological abnormalities in the sperm flagella (MMAF). The nexin-dynein regulatory complex (N-DRC) coordinates the dynein arm activity and is built from the DRC1-DRC7 proteins. DRC5 (TCTE1), one of the N-DRC elements, has already been reported as a candidate for abnormal sperm flagella beating; however, only in a restricted manner with no clear explanation of respective observations.
UNASSIGNED: Using the CRISPR/Cas9 genome editing technique, a mouse Tcte1 gene knockout line was created on the basis of the C57Bl/6J strain. The mouse reproductive potential, semen characteristics, testicular gene expression levels, sperm ATP, and testis apoptosis level measurements were then assessed, followed by visualization of N-DRC proteins in sperm, and protein modeling in silico. Also, a pilot genomic sequencing study of samples from human infertile males (n = 248) was applied for screening of TCTE1 variants.
METHODS: To check the reproductive potential of KO mice, adult animals were crossed for delivery of three litters per caged pair, but for no longer than for 6 months, in various combinations of zygosity. All experiments were performed for wild-type (WT, control group), heterozygous Tcte1+/- and homozygous Tcte1-/- male mice. Gross anatomy was performed on testis and epididymis samples, followed by semen analysis. Sequencing of RNA (RNAseq; Illumina) was done for mice testis tissues. STRING interactions were checked for protein-protein interactions, based on changed expression levels of corresponding genes identified in the mouse testis RNAseq experiments. Immunofluorescence in situ staining was performed to detect the N-DRC complex proteins: Tcte1 (Drc5), Drc7, Fbxl13 (Drc6), and Eps8l1 (Drc3) in mouse spermatozoa. To determine the amount of ATP in spermatozoa, the luminescence level was measured. In addition, immunofluorescence in situ staining was performed to check the level of apoptosis via caspase 3 visualization on mouse testis samples. DNA from whole blood samples of infertile males (n = 137 with non-obstructive azoospermia or cryptozoospermia, n = 111 samples with a spectrum of oligoasthenoteratozoospermia, including n = 47 with asthenozoospermia) was extracted to perform genomic sequencing (WGS, WES, or Sanger). Protein prediction modeling of human-identified variants and the exon 3 structure deleted in the mouse knockout was also performed.
RESULTS: No progeny at all was found for the homozygous males which were revealed to have oligoasthenoteratozoospermia, while heterozygous animals were fertile but manifested oligozoospermia, suggesting haploinsufficiency. RNA-sequencing of the testicular tissue showed the influence of Tcte1 mutations on the expression pattern of 21 genes responsible for mitochondrial ATP processing or linked with apoptosis or spermatogenesis. In Tcte1-/- males, the protein was revealed in only residual amounts in the sperm head nucleus and was not transported to the sperm flagella, as were other N-DRC components. Decreased ATP levels (2.4-fold lower) were found in the spermatozoa of homozygous mice, together with disturbed tail:midpiece ratios, leading to abnormal sperm tail beating. Casp3-positive signals (indicating apoptosis) were observed in spermatogonia only, at a similar level in all three mouse genotypes. Mutation screening of human infertile males revealed one novel and five ultra-rare heterogeneous variants (predicted as disease-causing) in 6.05% of the patients studied. Protein prediction modeling of identified variants revealed changes in the protein surface charge potential, leading to disruption in helix flexibility or its dynamics, thus suggesting disrupted interactions of TCTE1 with its binding partners located within the axoneme.
METHODS: All data generated or analyzed during this study are included in this published article and its supplementary information files. RNAseq data are available in the GEO database (https://www.ncbi.nlm.nih.gov/geo/) under the accession number GSE207805. The results described in the publication are based on whole-genome or exome sequencing data which includes sensitive information in the form of patient-specific germline variants. Information regarding such variants must not be shared publicly following European Union legislation, therefore access to raw data that support the findings of this study are available from the corresponding author upon reasonable request.
CONCLUSIONS: In the study, the in vitro fertilization performance of sperm from homozygous male mice was not checked.
CONCLUSIONS: This study contains novel and comprehensive data concerning the role of TCTE1 in male infertility. The TCTE1 gene is the next one that should be added to the \'male infertility list\' because of its crucial role in spermatogenesis and proper sperm functioning.
BACKGROUND: This work was supported by National Science Centre in Poland, grants no.: 2015/17/B/NZ2/01157 and 2020/37/B/NZ5/00549 (to M.K.), 2017/26/D/NZ5/00789 (to A.M.), and HD096723, GM127569-03, NIH SAP #4100085736 PA DoH (to A.N.Y.). The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.

Infertility is a widespread global issue that affects approximately 15% of sexually active and active couples, which contributes to about 50% of cases. Currently, the condition remains prevalent and often inadequately treated. This systematic review aims to evaluate existing studies investigating the effects of probiotic supplementation in men. A comprehensive search was conducted across major databases, including PubMed, Cochrane, Science Direct, and Scielo, using relevant keywords such as \'probiotic\' OR \'Lactobacillus\' OR \'Bifidobacterium\' AND \'Male infertility\' OR \'male fertility\' OR \'sperm quality\' OR \'sperm motility\' OR \'oligoasthenoteratozoospermia\' and their Portuguese equivalents. Four randomized clinical studies met the inclusion criteria, focusing on men diagnosed with idiopathic male infertility (oligozoospermia, teratozoospermia, and asthenozoospermia). The findings revealed that probiotic administration exhibited promising antioxidant properties by combating reactive oxygen species (ROS), consequently protecting sperm DNA from damage that correlates with declining sperm quality. Significant improvements were observed across all sperm parameters, with notable enhancement in motility. Consequently, probiotic supplementation emerges as a potential therapeutic alternative for men diagnosed with idiopathic infertility, demonstrating positive effects on sperm quality.

OBJECTIVE: Recently, oral antioxidants in combined forms have been used to treat men with idiopathic infertility. This study aimed to evaluate the effects of treatment with vitamin C, vitamin E, selenium, zinc, arginine, L-carnitine, and coenzyme Q10 on sperm quality parameters, DNA integrity, reproductive hormones, and pregnancy rates in men with infertility and idiopathic oligoasthenoteratozoospermia (OAT).
METHODS: A prospective study was conducted on 420 men with infertility and idiopathic OAT who took an oral supplement of antioxidant SP-Power tablets twice daily for 6 months. Semen quality, reproductive hormones, and the DNA fragmentation index (DFI) were evaluated at baseline and at 3 and 6 months after supplementation, using the World Health Organization 2021 guidelines.
RESULTS: No significant difference was observed in volume or the percentage of typical morphology during treatment. A significant improvement in sperm concentration was observed after supplementation (8.67±1.41, 12.17±1.91, and 19.01±0.86 at baseline, 3, and 6 months respectively, p<0.01). The total motility, progressive motility, and total motile sperm count also increased significantly (p<0.01), whereas the DFI decreased after 6 months. There was an increase in normal FSH levels and testosterone levels after 6 months of supplementation of antioxidant SP-Power but these differences were not statistically significant (p=not significant and p=0.06, respectively).
CONCLUSIONS: Supplementation with SP-Power tablets improved sperm quality parameters, sperm DFI, some reproductive hormones, and pregnancy rates in men with infertility and idiopathic OAT, which could be attributed to the supplement\'s synergistic antioxidant action. Further studies are needed to determine the effects of supplementation on oxidative stress markers.

Oligoasthenoteratospermia (OAT), characterized by abnormally low sperm count, poor sperm motility, and abnormally high number of deformed spermatozoa, is an important cause of male infertility. Its genetic basis in many affected individuals remains unknown. Here, we found that CCDC157 variants are associated with OAT. In two cohorts, a 21-bp (g.30768132_30768152del21) and/or 24-bp (g.30772543_30772566del24) deletion of CCDC157 were identified in five sporadic OAT patients, and 2 cases within one pedigree. In a mouse model, loss of Ccdc157 led to male sterility with OAT-like phenotypes. Electron microscopy revealed misstructured acrosome and abnormal head-tail coupling apparatus in the sperm of Ccdc157-null mice. Comparative transcriptome analysis showed that the Ccdc157 mutation alters the expressions of genes involved in cell migration/motility and Golgi components. Abnormal Golgi apparatus and decreased expressions of genes involved in acrosome formation and lipid metabolism were detected in Ccdc157-deprived mouse germ cells. Interestingly, we attempted to treat infertile patients and Ccdc157 mutant mice with a Chinese medicine, Huangjin Zanyu, which improved the fertility in one patient and most mice that carried the heterozygous mutation in CCDC157. Healthy offspring were produced. Our study reveals CCDC157 is essential for sperm maturation and may serve as a marker for diagnosis of OAT.

UNASSIGNED: Varicocele is a reversible cause of male infertility. However, there are conflicting data available concerning the benefit of varicocele repair for patients with nonobstructive azoospermia (NOA) and severe oligoasthenoteratozoospermia (OAT).
UNASSIGNED: To address the benefit of varicocelectomy in patients with severe OAT and NOA with regard to their semen parameters and surgical sperm retrieval rate in those who underwent testicular sperm extraction (TESE) or testicular sperm aspiration (TESA).
UNASSIGNED: This retrospective cohort study was conducted on a sample of 13 patients diagnosed with NOA and severe OAT who underwent varicocelectomy for infertility treatment with no prespecified exclusion criteria.
UNASSIGNED: Thirteen patients were enrolled. Five patients were diagnosed with NOA; eight were diagnosed with severe OAT. For improvements in the semen parameters postoperatively, the semen concentration of all patients was significantly increased compared to the preoperative concentration (3.59 ± 10.0.8 vs. 0.25 ± 0.31, P = 0.02) and the remaining parameters were unchanged. Regarding sperm retrieval, three patients underwent TESE and two patients underwent TESA, in which all had positive results.
UNASSIGNED: Varicocele repair was found to improve the semen parameters in patients with NOA and severe OAT and produced a successful surgical sperm retrieval rate in all patients who underwent TESA or TESE.

BACKGROUND: The impact of sexual abstinence on sperm quality, particularly in pathological cases, is a subject of debate. We investigated the link between abstinence duration and semen quality in both normal and pathological samples.
METHODS: We analyzed semen samples from 4423 men undergoing fertility evaluation, comprising 1256 samples from healthy individuals and 3167 from those with conditions such as oligozoospermia, asthenozoospermia, teratozoospermia, or a combination of these factors, namely oligoasthenoteratozoospermia (OAT). Parameters including sperm concentration, the percentage of progressively motile spermatozoa, total motile sperm count, and the percentage of spermatozoa with normal morphology were assessed at various abstinence durations (each day, 0-2, 3-7, and >7 days).
RESULTS: Extended abstinence correlated with higher sperm concentration overall (p < 0.001), except in oligozoospermia. Longer abstinence reduced progressive motility in normal (p < 0.001) and teratozoospermic samples (p < 0.001). Shorter abstinence was linked to higher morphologically normal sperm in normal samples (p = 0.03), while longer abstinence did so in oligoasthenoteratozoospermic samples (p = 0.013).
CONCLUSIONS: The findings suggest that a prolonged abstinence time is linked to higher sperm concentration, while optimal sperm motility is observed after shorter abstinence periods. However, results regarding morphology remain inconclusive. Recommendations on abstinence duration should be tailored based on the specific parameter requiring the most significant improvement.

Oligoasthenoteratozoospermia (OAT) is a common type of male infertility; however, its genetic causes remain largely unknown. Some of the genetic determinants of OAT are gene defects affecting spermatogenesis. BCORL1 (BCL6 corepressor like 1) is a transcriptional corepressor that exhibits the OAT phenotype in a knockout mouse model. A hemizygous missense variant of BCORL1 (c.2615T > G:p.Val872Gly) was reported in an infertile male patient with non-obstructive azoospermia (NOA). Nevertheless, the correlation between BCORL1 variants and OAT in humans remains unknown. In this study, we used whole-exome sequencing to identify a novel hemizygous nonsense variant of BCORL1 (c.1564G > T:p.Glu522*) in a male patient with OAT from a Han Chinese family. Functional analysis showed that the variant produced a truncated protein with altered cellular localization and a dysfunctional interaction with SKP1 (S-phase kinase-associated protein 1). Further population screening identified four BCORL1 missense variants in subjects with both OAT (1 of 325, 0.31%) and NOA (4 of 355, 1.13%), but no pathogenic BCORL1 variants among 362 fertile subjects. In conclusion, our findings indicate that BCORL1 is a potential candidate gene in the pathogenesis of OAT and NOA, expanded its disease spectrum and suggested that BCORL1 may play a role in spermatogenesis by interacting with SKP1.

Oligoasthenoteratozoospermia (OAT) decreases male fertility, seriously affecting the production of offspring. This study clarified the preventive impact of different moxibustion frequencies on OAT and selected the optimal frequency to elucidate the underlying mechanism. An OAT rat model was constructed by gavage of tripterygium glycosides (TGS) suspension. Daily moxibustion (DM) or alternate-day moxibustion (ADM) was administered on the day of TGS suspension administration. Finally, we selected DM for further study based on sperm quality and DNA fragmentation index, testicular and epididymal morphology, and reproductive hormone level results. Subsequently, the oxidative stress (OS) status was evaluated by observing the OS indices levels; malondialdehyde (MDA), 8-hydroxy-deoxyguanosine (8-OHdG), total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) in testicular tissue using colorimetry and enzyme-linked immunosorbent assay. Furthermore, heme oxygenase 1 (HO-1) and nuclear factor erythropoietin-2-related factor 2 (Nrf2) were evaluated using Western blotting. Immunohistochemistry was employed to locate and assess the expression of HO-1 and Nrf2 protein, while quantitative real-time polymerase chain reaction was utilized to detect their mRNA expression. MDA and 8-OHdG levels decreased following DM treatment, while T-SOD and T-AOC increased, suggesting that DM may prevent TGS-induced OAT in rats by decreasing OS in the testis. Furthermore, protein and mRNA expression of Nrf2 and HO-1 in the testis were elevated, indicating that DM may reduce OS by activating the signaling pathway of Nrf2/HO-1. Therefore, DM could prevent OAT in rats via the Nrf2/HO-1 pathway, thereby presenting a promising therapeutic approach against OAT.