Loss of PBX1 function in Leydig cells causes testicular dysgenesis and male sterility.

Leydig cells are essential components of testicular interstitial tissue and serve as a primary source of androgen in males. A functional deficiency in Leydig cells often causes severe reproductive disorders; however, the transcriptional programs underlying the fate decisions and steroidogenesis of these cells have not been fully defined. In this study, we report that the homeodomain transcription factor PBX1 is a master regulator of Leydig cell differentiation and testosterone production in mice. PBX1 was highly expressed in Leydig cells and peritubular myoid cells in the adult testis. Conditional deletion of Pbx1 in Leydig cells caused spermatogenic defects and complete sterility. Histological examinations revealed that Pbx1 deletion impaired testicular structure and led to disorganization of the seminiferous tubules. Single-cell RNA-seq analysis revealed that loss of Pbx1 function affected the fate decisions of progenitor Leydig cells and altered the transcription of genes associated with testosterone synthesis in the adult testis. Pbx1 directly regulates the transcription of genes that play important roles in steroidogenesis (Prlr, Nr2f2 and Nedd4). Further analysis demonstrated that deletion of Pbx1 leads to a significant decrease in testosterone levels, accompanied by increases in pregnenolone, androstenedione and luteinizing hormone. Collectively, our data revealed that PBX1 is indispensable for maintaining Leydig cell function. These findings provide insights into testicular dysgenesis and the regulation of hormone secretion in Leydig cells.

Pulsatile gonadotropin releasing hormone therapy for spermatogenesis in congenital hypogonadotropic hypogonadism patients who had poor response to combined gonadotropin therapy.

Objective: Both pulsatile gonadotropin-releasing hormone (GnRH) and combined gonadotropin therapy are effective to induce spermatogenesis in men with congenital hypogonadotropic hypogonadism (CHH). This study aimed to evaluate the effect of pulsatile GnRH therapy on spermatogenesis in male patients with CHH who had poor response to combined gonadotropin therapy. Materials and methods: Patients who had poor response to combined gonadotropin therapy ≥ 6 months were recruited and shifted to pulsatile GnRH therapy. The rate of successful spermatogenesis, the median time to achieve spermatogenesis, serum gonadotropins, testosterone, and testicular volume were used for data analysis. Results: A total of 28 CHH patients who had poor response to combined gonadotropin (HCG/HMG) therapy for 12.5 (6.0, 17.75) months were recruited and switched to pulsatile GnRH therapy for 10.0 (7.25, 16.0) months. Sperm was detected in 17/28 patients (60.7%). The mean time for the appearance of sperm in semen was 12.0 (7.5, 17.5) months. Compared to those who could not achieve spermatogenesis during pulsatile GnRH therapy, the successful group had a higher level of LH60min (4.32 vs. 1.10 IU/L, P = 0.043) and FSH60min (4.28 vs. 1.90 IU/L, P = 0.021). Testicular size increased during pulsatile GnRH therapy, compared to previous HCG/ HMG therapy (P < 0.05). Conclusion: For CHH patients with prior poor response to one year of HCG/ HMG therapy, switching to pulsatile GnRH therapy may induce spermatogenesis.

Maternal high-fat diet during pregnancy and lactation affects factors that regulate cell proliferation and apoptosis in the testis of adult progeny.

Context A maternal high-fat diet is thought to pose a risk to spermatogenesis in the progeny. Aims We tested whether a maternal high-fat diet would affect Sertoli cell expression of transcription factors (insulin-like growth factor I (IGF-I); glial-cell line-derived neurotrophic factor (GDNF); Ets variant 5 (ETV5)) and cell proliferation and apoptotic proteins, in the testis of adult offspring. Methods Pregnant rats were fed ad libitum with a standard diet (Control) or a high-fat diet (HFat) throughout pregnancy and lactation. After weaning, male pups were fed the standard diet until postnatal day 160. Males were monitored daily from postnatal day 34 to determine onset of puberty. On postnatal day 160, their testes were processed for morphometry and immunohistochemistry. Key results The HFat diet increased seminiferous-tubule diameter (P P P P P P P P Conclusions A maternal high-fat diet alters the balance between spermatogonia proliferation and spermatid apoptosis. Implications A maternal high-fat diet seems to 'program' adult male fertility.

Adult Human, but Not Rodent, Spermatogonial Stem Cells Retain States with a Foetal-like Signature.

Spermatogenesis involves a complex process of cellular differentiation maintained by spermatogonial stem cells (SSCs). Being critical to male reproduction, it is generally assumed that spermatogenesis starts and ends in equivalent transcriptional states in related species. Based on single-cell gene expression profiling, it has been proposed that undifferentiated human spermatogonia can be subclassified into four heterogenous subtypes, termed states 0, 0A, 0B, and 1. To increase the resolution of the undifferentiated compartment and trace the origin of the spermatogenic trajectory, we re-analysed the single-cell (sc) RNA-sequencing libraries of 34 post-pubescent human testes to generate an integrated atlas of germ cell differentiation. We then used this atlas to perform comparative analyses of the putative SSC transcriptome both across human development (using 28 foetal and pre-pubertal scRNA-seq libraries) and across species (including data from sheep, pig, buffalo, rhesus and cynomolgus macaque, rat, and mouse). Alongside its detailed characterisation, we show that the transcriptional heterogeneity of the undifferentiated spermatogonial cell compartment varies not only between species but across development. Our findings associate 'state 0B' with a suppressive transcriptomic programme that, in adult humans, acts to functionally oppose proliferation and maintain cells in a ready-to-react state. Consistent with this conclusion, we show that human foetal germ cells-which are mitotically arrested-can be characterised solely as state 0B. While germ cells with a state 0B signature are also present in foetal mice (and are likely conserved at this stage throughout mammals), they are not maintained into adulthood. We conjecture that in rodents, the foetal-like state 0B differentiates at birth into the renewing SSC population, whereas in humans it is maintained as a reserve population, supporting testicular homeostasis over a longer reproductive lifespan while reducing mutagenic load. Together, these results suggest that SSCs adopt differing evolutionary strategies across species to ensure fertility and genome integrity over vastly differing life histories and reproductive timeframes.

Retinoic acid mitigates the NSC319726-induced spermatogenesis dysfunction through cuproptosis-independent mechanisms.

Copper ionophore NSC319726 has attracted researchers' attention in treating diseases, particularly cancers. However, its potential effects on male reproduction during medication are unclear. This study aimed to determine whether NSC319726 exposure affected the male reproductive system. The reproductive toxicity of NSC319726 was evaluated in male mice following a continuous exposure period of 5 weeks. The result showed that NSC319726 exposure caused testis index reduction, spermatogenesis dysfunction, and architectural damage in the testis and epididymis. The exposure interfered with spermatogonia proliferation, meiosis initiation, sperm count, and sperm morphology. The exposure also disturbed androgen synthesis and blood testis barrier integrity. NSC319726 treatment could elevate the copper ions in the testis to induce cuproptosis in the testis. Copper chelator rescued the elevated copper ions in the testis and partly restored the spermatogenesis dysfunction caused by NSC319726. NSC319726 treatment also decreased the level of retinol dehydrogenase 10 (RDH10), thereby inhibiting the conversion of retinol to retinoic acid, causing the inability to initiate meiosis. Retinoic acid treatment could rescue the meiotic initiation and spermatogenesis while not affecting the intracellular copper ion levels. The study provided an insight into the bio-safety of NSC319726. Retinoic acid could be a potential therapy for spermatogenesis impairment in patients undergoing treatment with NSC319726.

Spatially revealed roles for lncRNAs in Drosophila spermatogenesis, Y chromosome function and evolution.

Unlike coding genes, the number of lncRNA genes in organism genomes is relatively proportional to organism complexity. From plants to humans, the tissues with highest numbers and levels of lncRNA gene expression are the male reproductive organs. To learn why, we initiated a genome-wide analysis of Drosophila lncRNA spatial expression patterns in these tissues. The numbers of genes and levels of expression observed greatly exceed those previously reported, due largely to a preponderance of non-polyadenylated transcripts. In stark contrast to coding genes, the highest numbers of lncRNAs expressed are in post-meiotic spermatids. Correlations between expression levels, localization and previously performed genetic analyses indicate high levels of function and requirement. More focused analyses indicate that lncRNAs play major roles in evolution by controlling transposable element activities, Y chromosome gene expression and sperm construction. A new type of lncRNA-based particle found in seminal fluid may also contribute to reproductive outcomes.

The mechanoreceptor Piezo is required for spermatogenesis in Bombyx mori.

BACKGROUND: The animal sperm shows high diversity in morphology, components, and motility. In the lepidopteran model insect, the silkworm Bombyx mori, two types of sperm, including nucleate fertile eupyrene sperm and anucleate unfertile apyrene sperm, are generated. Apyrene sperm assists fertilization by facilitating the migration of eupyrene spermatozoa from the bursa copulatrix to the spermatheca. During spermatogenesis, eupyrene sperm bundles extrude the cytoplasm by peristaltic squeezing, while the nuclei of the apyrene sperm bundles are discarded with the same process, forming matured sperm. RESULTS: In this study, we describe that a mechanoreceptor BmPiezo, the sole Piezo ortholog in B. mori, plays key roles in larval feeding behavior and, more importantly, is essential for eupyrene spermatogenesis and male fertility. CRISPR/Cas9-mediated loss of BmPiezo function decreases larval appetite and subsequent body size and weight. Immunofluorescence analyses reveal that BmPiezo is intensely localized in the inflatable point of eupyrene sperm bundle induced by peristaltic squeezing. BmPiezo is also enriched in the middle region of apyrene sperm bundle before peristaltic squeezing. Cytological analyses of dimorphic sperm reveal developmental arrest of eupyrene sperm bundles in BmPiezo mutants, while the apyrene spermatogenesis is not affected. RNA-seq analysis and q-RT-PCR analyses demonstrate that eupyrene spermatogenic arrest is associated with the dysregulation of the actin cytoskeleton. Moreover, we show that the deformed eupyrene sperm bundles fail to migrate from the testes, resulting in male infertility due to the absence of eupyrene sperm in the bursa copulatrix and spermatheca. CONCLUSIONS: In conclusion, our studies thus uncover a new role for Piezo in regulating spermatogenesis and male fertility in insects.

Protective effects of Passiflora Incarnata on ischemia-reperfusion injury in testicular torsion: an experimental study in a rat model.

OBJECTIVE: The current study aimed to explore the potential protective effect of Passiflora Incarnata L., (PI) in treating IR injury after testicular torsion in rats. MATERIALS AND METHODS: This research investigated the impact of PI on IR damage in male Wistar albino rats. Animals were divided to three groups: group 1 (sham), group 2 (IR), and group 3 (IR+PI). RESULTS: The malondialdehyde (MDA), myeloperoxidase (MPO) and glutathione (GSH) levels did not significantly differ across the groups (p = 0.830, p = 0.153 and p=0.140, respectively). However, Group 3 demonstrated a superior total antioxidant status (TAS) value compared to Group 2 (p = 0.020). Concurrently, Group 3 presented a significantly diminished mean total oxidant status (TOS) relative to Group 2 (p = 0.009). Furthermore, Group 3 showed a markedly improved Johnsen score relative to Group 2 (p < 0.01). IR caused cell degeneration, apoptosis, and fibrosis in testicular tissues. PI treatment, however, mitigated these effects, preserved seminiferous tubule integrity and promoted regular spermatogenesis. Furthermore, it reduced expression of tumor necrosis factor-alpha (TNF-α), Bax, and Annexin V, signifying diminished inflammation and apoptosis, thereby supporting cell survival (p < 0.01, p < 0.01, p < 0.01, respectively). CONCLUSIONS: This study revealed that PI significantly reduces oxidative stress and testicular damage, potentially benefiting therapies for IR injuries.

OBJETIVO: Explorar el posible efecto protector de Passiflora incarnata L. (PI) en el tratamiento de la lesión por isquemia-reperfusión (IR) después de una torsión testicular en ratas. MÉTODO: Se estudió el impacto de Passiflora incarnata en el daño por IR en ratas Wistar albinas machos. Los animales se dividieron tres grupos: 1 (simulado), 2 (IR) y 3 (IR+PI). RESULTADOS: Los niveles de malondialdehyde (MDA), myeloperoxidase (MPO) y glutathione (GSH) no difirieron significativamente entre los grupos (p = 0.830, p = 0.153 y p = 0.140, respectivamente). Sin embargo, el grupo 3 tuvo un valor de estado antioxidante total (TAS) superior en comparación con el grupo 2 (p = 0.020). Al mismo tiempo, el grupo 3 presentó un estado oxidante total (TOS) medio significativamente disminuido en comparación con el grupo 2 (p = 0.009). El grupo 3 mostró una mejora notable en la puntuación de Johnsen en comparación con el grupo 2 (p < 0.01). La IR causó degeneración celular, apoptosis y fibrosis en los tejidos testiculares. El tratamiento con PI mitigó estos efectos, preservó la integridad de los túbulos seminíferos y promovió la espermatogénesis regular. Además, redujo la expresión de factor de necrosis tumoral alfa, Bax y anexina V, lo que significa una disminución de la inflamación y de la apoptosis, respaldando así la supervivencia celular (p < 0.01, p < 0.01 y p < 0.01, respectivamente). CONCLUSIONES: Este estudio reveló que PI reduce significativamente el estrés oxidativo y el daño testicular, beneficiando potencialmente las terapias para lesiones por IR.

CRISPR/Cas9 mediated validation of spermatogenesis-related gene, tssk2 as a component of genetic pest management of fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae).

Invasive insect pests, currently, pose a serious economic threat to several staple crops all over the world, one such being the fall armyworm, Spodoptera frugiperda. It was first observed in Africa since 2016, outside of its natural habitat in the Americas. Subsequently, it invaded several countries in South and South East Asia and also very recently in Australia. In all the newly invaded regions, maize is the principal crop attacked causing a serious economic concern to the poor farmers, particularly in the developing countries. Owing to the innate genetic ability, it defies many of the management options that include insecticides, Bt transgenics, and so forth. This is due to its high mobility, polyphagy and ability for quick development of resistance to several classes of insecticides. At this critical juncture, CRISPR/Cas9 mediated genome editing has shown a lot of promise in developing a novel area-wide pest management strategy called precision-guided sterile insect technique (pgSIT). pgSIT was initially demonstrated in Drosophila melanogaster which holds a greater promise for the environmentally friendly management of several globally significant agricultural pests such as S. frugiperda. Therefore, before developing both sgRNA and Cas9 transgenic lines, we have validated the target gene such as tssk2 through a non-transgenic approach by microinjecting ribo nucleo protein complex (Cas9 protein and tssk2 sgRNA) into G0 eggs of S. frugiperda. In the current investigation, we have obtained five edited males with distinct mutations which were further used for crossing studies to ascertain the effect of tssk2 editing affecting egg hatchability.

Cyto- and Histopographic Assessment of CPA3-Positive Testicular Mast Cells in Obstructive and Non-Obstructive Azoospermia.

Infertility is an important personal and society disease, of which the male factor represents half of all causes. One of the aspects less studied in male infertility is the immunological testicular microenvironment. Mast cells (MCs), having high potential for regulating spermatogenesis due to fine-tuning the state of the integrative buffer metabolic environment, are one of the most crucial cellular subpopulations of the testicular interstitium. One important component of the MC secretome is proteases that can act as proinflammatory agents and in extracellular matrix (ECM) remodeling. In the testis, MCs are an important cell component of the testicular interstitial tissue (TIT). However, there are still no studies addressing the analysis of a specific MC protease-carboxypeptidase A3 (CPA3)-in cases with altered spermatogenesis. The cytological and histotopographic features of testicular CPA3+ MCs were examined in a study involving 34 men with azoospermia. As revealed, in cases with non-obstructive azoospermia, a higher content of CPA3+ MCs in the TIT and migration to the microvasculature and peritubular tissue of seminiferous tubules were observed when compared with cases with obstructive azoospermia. Additionally, a high frequency of CPA3+ MCs colocalization with fibroblasts, Leydig cells, and elastic fibers was detected in cases with NOA. Thus, CPA3 seems to be of crucial pathogenetic significance in the formation of a profibrogenic background of the tissue microenvironment, which may have direct and indirect effects on spermatogenesis.

Interaction between Chromodomain Y-like Protein and Androgen Receptor Signaling in Sertoli Cells Accounts for Spermatogenesis.

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.

The ameliorative effects of curcumin nanomicelle on testicular damage in the mouse model of multiple sclerosis.

BACKGROUND: This study investigated the effect of curcumin nanomicelle (CUR-n) on the structure of testis tissue, the process of spermatogenesis, LH, FSH, testosterone, and oxidative stress in a model of multiple sclerosis. METHODS: Twenty-four male mice C57BL/6 were randomly allocated into 4 groups of 6 (1: group receiving 2% CPZ diet, 2: group receiving the diet of 2% CPZ + CUR-n with a dose of 50 mg/kg, 3: group receiving the diet of 2% CPZ + CUR-n with a dose of 100 mg/kg). The concentration of hormones (testosterone, LH and FSH), was measured by the special hormone assay ELISA kits. Measuring total antioxidant capacity (TAC) and Malondialdehyde (MDA) levels was done by spectrophotometry and calorimetric methods, respectively. Stereological analysis was done in order to explore the number of spermatogenesis cells, testis and sperm properties. RESULTS: The results indicated that CUR-n (100 mg/kg) significantly enhanced the concentration of LH, FSH, testosterone, and TAC but reduced MDA levels. It also notably increased the quantity of spermatogonia, spermatocyte, round spermatids, long spermatids and LCs, augmented testis weight and volume, and germinal epithelium volume, improved sperm count, morphology, viability, and motility. In addition, a considerable decrease in the amount of wrinkling and disruption of the germinal epithelium was observed after intervention with CUR-n (100 mg/kg). Furthermore, a significant increase in the number of germ cells compared to the group receiving CPZ was detected. CONCLUSION: This study proposes that CUR-n could be a therapeutic agent for decreasing the adverse effects of MS on testis.

Trim66's paternal deficiency causes intrauterine overgrowth.

The tripartite motif-containing protein 66 (TRIM66, also known as TIF1-delta) is a PHD-Bromo-containing protein primarily expressed in post-meiotic male germ cells known as spermatids. Biophysical assays showed that the TRIM66 PHD-Bromodomain binds to H3 N-terminus only when lysine 4 is unmethylated. We addressed TRIM66's role in reproduction by loss-of-function genetics in the mouse. Males homozygous for Trim66-null mutations produced functional spermatozoa. Round spermatids lacking TRIM66 up-regulated a network of genes involved in histone acetylation and H3K4 methylation. Profiling of H3K4me3 patterns in the sperm produced by the Trim66-null mutant showed minor alterations below statistical significance. Unexpectedly, Trim66-null males, but not females, sired pups overweight at birth, hence revealing that Trim66 mutations cause a paternal effect phenotype.

Effect of IL-1ß on the Development of Spermatogenesis In Vitro in Normal and Busulfan-Treated Immature Mice.

Gonadotoxic agents could impair spermatogenesis and may lead to male infertility. The present study aimed to evaluate the effect of IL-1ß on the development of spermatogenesis from cells isolated from seminiferous tubules (STs) of normal and busulfan-treated immature mice in vitro. Cells were cultured in a 3D in vitro culture system for 5 weeks. We examined the development of cells from the different stages of spermatogenesis by immunofluorescence staining or qPCR analyses. Factors of Sertoli and Leydig cells were examined by qPCR analysis. We showed that busulfan (BU) treatment significantly reduced the expression of testicular IL-1ß in the treated mice compared to the control group (CT). Cultures of cells from normal and busulfan-treated immature mice induced the development of pre-meiotic (Vasa), meiotic (Boule), and post-meiotic (acrosin) cells. However, the percentage of developed Boule and acrosin cells was significantly lower in cultures of busulfan-treated mice compared to normal mice. Adding IL-1ß to both cultures significantly increased the percentages of Vasa, Boule, and acrosin cells compared to their controls. However, the percentage of Boule and acrosin cells was significantly lower from cultures of busulfan-treated mice that were treated with IL-1ß compared to cultures treated with IL-1ß from normal mice. Furthermore, addition of IL-1ß to cultures from normal mice significantly increased only the expression of androgen receptor and transferrin but no other factors of Sertoli cells compared to their CT. However, the addition of IL-1ß to cultures from busulfan-treated mice significantly increased only the expression of androgen-binding protein and the FSH receptor compared to their CT. Adding IL-1ß to cultures of normal mice did not affect the expression of 3ßHSD compared to the CT, but it significantly reduced its expression in cultures from busulfan-treated mice compared to the CT. Our findings demonstrate the development of different stages of spermatogenesis in vitro from busulfan-treated mice and that IL-1ß could potentiate this development in vitro.

Zinc alleviates high fat diet-induced spermatogenic dysfunction in Wistar rats: role of oxidative stress, HMGB1 and inflammasome.

Whether chronic inflammation in the genital tract induced by obesity shares in spermatogenic dysfunction is not clearly known. We aimed to study the effect of high fat diet (HFD) on spermatogenesis, seminal oxidative stress (malondialdehyde (MDA)) and inflammatory markers (high mobility group box 1 (HMGB1), nucleotide-binding oligomerization domain, leucine rich repeat and pyrin-3 domain containing (NLRP3)) in the rat testes and the role of zinc on testicular dysfunction and chronic inflammation in high fat diet (HFD) fed rat testes. This parallel group comparative experimental study included 36 male wistar rats divided into 3 groups: group A (fed on normal control diet); group B (fed on high fat diet (HFD) only); and group C (fed on HFD with zinc supplementation 3.2 mg/kg/day orally). At the end of the 12th week, sperm count, viability and motility were assessed by computer-assisted seemen analysis (CASA), seminal malondialdehyde measured by calorimetry and histopathological examination of testicular sections was done. Immunohistochemical staining was done for HMGB1 and NLRP3 evaluation. Sperm count was lowest in group B. Groups A and C showed statistically significant higher mean sperm vitality, total and progressive motility scores (p < 0.001), while no difference was found between the groups A and C (p > 0.05). Seminal malondialdehyde level was significantly highest in group B. Tubular diameter, epithelial height and Johnsen score were significantly lowest in group B. Significantly higher HMGB1 and NLRP3 levels were demonstrated in group B (p < 0.001). Obesity is associated with testicular dysfunction, testicular oxidative stress and increased testicular HMGB1 and NLRP3. We suggest a beneficial effect of zinc on testicular function in HFD-rats.

USP11 regulates proliferation and apoptosis of human spermatogonial stem cells via HOXC5-mediated canonical WNT/ß-catenin signaling pathway.

Spermatogonial stem cells (SSCs) are capable of transmitting genetic information to the next generations and they are the initial cells for spermatogenesis. Nevertheless, it remains largely unknown about key genes and signaling pathways that regulate fate determinations of human SSCs and male infertility. In this study, we explored the expression, function, and mechanism of USP11 in controlling the proliferation and apoptosis of human SSCs as well as the association between its abnormality and azoospermia. We found that USP11 was predominantly expressed in human SSCs as shown by database analysis and immunohistochemistry. USP11 silencing led to decreases in proliferation and DNA synthesis and an enhancement in apoptosis of human SSCs. RNA-sequencing identified HOXC5 as a target of USP11 in human SSCs. Double immunofluorescence, Co-immunoprecipitation (Co-IP), and molecular docking demonstrated an interaction between USP11 and HOXC5 in human SSCs. HOXC5 knockdown suppressed the growth of human SSCs and increased apoptosis via the classical WNT/ß-catenin pathway. In contrast, HOXC5 overexpression reversed the effect of proliferation and apoptosis induced by USP11 silencing. Significantly, lower levels of USP11 expression were observed in the testicular tissues of patients with spermatogenic disorders. Collectively, these results implicate that USP11 regulates the fate decisions of human SSCs through the HOXC5/WNT/ß-catenin pathway. This study thus provides novel insights into understanding molecular mechanisms underlying human spermatogenesis and the etiology of azoospermia and it offers new targets for gene therapy of male infertility.

Non-invasive biomarkers for sperm retrieval in non-obstructive patients: a comprehensive review.

Recent advancements in reproductive medicine have guided novel strategies for addressing male infertility, particularly in cases of non-obstructive azoospermia (NOA). Two prominent invasive interventions, namely testicular sperm extraction (TESE) and microdissection TESE (micro-TESE), have emerged as key techniques to retrieve gametes for assisted reproduction technologies (ART). Both heterogeneity and complexity of NOA pose a multifaceted challenge to clinicians, as the invasiveness of these procedures and their unpredictable success underscore the need for more precise guidance. Seminal plasma can be aptly regarded as a liquid biopsy of the male reproductive tract, encompassing secretions from the testes, epididymides, seminal vesicles, bulbourethral glands, and prostate. This fluid harbors a variety of cell-free nucleic acids, microvesicles, proteins, and metabolites intricately linked to gonadal activity. However, despite numerous investigations exploring potential biomarkers from seminal fluid, their widespread inclusion into the clinical practice remains limited. This could be partially due to the complex interplay of diverse clinical and genetic factors inherent to NOA that likely contributes to the absence of definitive biomarkers for residual spermatogenesis. It is conceivable that the integration of clinical data with biomarkers could increase the potential in predicting surgical procedure outcomes and their choice in NOA cases. This comprehensive review addresses the challenge of sperm retrieval in NOA through non-invasive biomarkers. Moreover, we delve into promising perspectives, elucidating innovative approaches grounded in multi-omics methodologies, including genomics, transcriptomics and proteomics. These cutting-edge techniques, combined with the clinical and genetics features of patients, could improve the use of biomarkers in personalized medical approaches, patient counseling, and the decision-making continuum. Finally, Artificial intelligence (AI) holds significant potential in the realm of combining biomarkers and clinical data, also in the context of identifying non-invasive biomarkers for sperm retrieval.

Gene expression programs in mammalian spermatogenesis.

Mammalian spermatogenesis, probably the most complex of all cellular developmental processes, is an ideal model both for studying the specific mechanism of gametogenesis and for understanding the basic rules governing all developmental processes, as it entails both cell type-specific and housekeeping molecular processes. Spermatogenesis can be viewed as a mission with many tasks to accomplish, and its success is genetically programmed and ensured by the collaboration of a large number of genes. Here, I present an overview of mammalian spermatogenesis and the mechanisms underlying each step in the process, covering the cellular and molecular activities that occur at each developmental stage and emphasizing their gene regulation in light of recent studies.

Misregulation of bromotyrosine compromises fertility in male Drosophila.

Biological regulation often depends on reversible reactions such as phosphorylation, acylation, methylation, and glycosylation, but rarely halogenation. A notable exception is the iodination and deiodination of thyroid hormones. Here, we report detection of bromotyrosine and its subsequent debromination during Drosophila spermatogenesis. Bromotyrosine is not evident when Drosophila express a native flavin-dependent dehalogenase that is homologous to the enzyme responsible for iodide salvage from iodotyrosine in mammals. Deletion or suppression of the dehalogenase-encoding condet (cdt) gene in Drosophila allows bromotyrosine to accumulate with no detectable chloro- or iodotyrosine. The presence of bromotyrosine in the cdt mutant males disrupts sperm individualization and results in decreased fertility. Transgenic expression of the cdt gene in late-staged germ cells rescues this defect and enhances tolerance of male flies to bromotyrosine. These results are consistent with reversible halogenation affecting Drosophila spermatogenesis in a process that had previously eluded metabolomic, proteomic, and genomic analyses.

The lack of Tex44 causes severe subfertility with flagellar abnormalities in male mice.

By analyzing a mouse Interspecific Recombinant Congenic Strain (IRCS), we previously identified a quantitative trait locus (QTL), called Mafq1 on mouse chromosome 1, that is associated with male hypofertility and ultrastructural sperm abnormalities. Within this locus, we identified a new candidate gene that could be implicated in a reproductive phenotype: Tex44 (Testis-expressed protein 44). We thus performed a CRISPR/Cas9-mediated complete deletion of this gene in mice in order to study its function. Tex44-KO males were severely hypofertile in vivo and in vitro due to a drastic reduction of sperm motility which itself resulted from important morphological sperm abnormalities. Namely, Tex44-KO sperm showed a disorganized junction between the midpiece and the principal piece of the flagellum, leading to a 180° flagellar bending in this region. In addition, the loss of some axonemal microtubule doublets and outer dense fibers in the flagellum's principal piece has been observed. Our results suggest that, in mice, TEX44 is implicated in the correct set-up of the sperm flagellum during spermiogenesis and its absence leads to flagellar abnormalities and consequently to severe male hypofertility.