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Glyphosate (GLY) is the most universally used herbicide worldwide and its application has caused extensive pollution to the ecological environment. Increasing evidence has revealed the multi-organ toxicity of GLY in different species, but its male reproductive toxicity in avian species remains unknown. Thus, in vivo and in vitro studies were conducted to clarify this issue. Data firstly showed that chronic GLY exposure caused testicular pathological damage. Intriguingly, we identified and verified a marked down-regulation gap junction gene Connexin 43 (Cx43) in GLY-exposed rooster testis by transcriptome analysis. Cx43 generated by Sertoli cells acts as a key component of blood-testis barrier (BTB). To further investigate the cause of GLY-induced downregulation of Cx43 to disrupt BTB, we found that autophagy activation is revealed in GLY-exposed rooster testis and primary avian Sertoli cells. Moreover, GLY-induced Cx43 downregulation was significantly alleviated by ATG5 knockdown or CQ administration, respectively, demonstrating that GLY-induced autophagy activation contributed to Cx43 degradation. Mechanistically, GLY-induced autophagy activation and resultant Cx43 degradation was due to its direct interaction with ER-α. In summary, these findings demonstrate that chronic GLY exposure activates autophagy to induce Cx43 degradation, which causes BTB damage and resultant reproductive toxicity in roosters., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Regenerative medicine and transplantation science continuously seek methods to circumvent immune-mediated rejection and promote tissue regeneration. Sertoli cells, with their inherent immunoprotective properties, emerge as pivotal players in this quest. However, whether Sertoli cells can play immunomodulatory role in tadpole tail regeneration and can thus benefit the regeneration process are needed to be discovered., Methods: Immature Sertoli cells from Xenopus tropicalis (XtiSCs) were transplanted into X. tropicalis tadpoles, followed by the amputation of the final third of their tails. We assessed the migration of XtiSCs, tail regeneration length, muscle degradation and growth, and macrophage counts across various regions including the entire tail, tail trunk, injection site, and regeneration site. The interactions between XtiSCs and macrophages were examined using a confocal microscope. To deplete macrophages, clodronate liposomes were administered prior to the transplantation of XtiSCs, while the administration of control liposomes acted as a negative control. Student's t-test was used to compare the effects of XtiSCs injection to those of a 2/3PBS injection across groups with no liposomes, control liposomes, and clodronate liposomes., Results: XtiSCs have excellent viability after transplantation to tadpole tail and remarkable homing capabilities to the regeneration site after tail amputation. XtiSCs injection increased macrophage numbers at 3 days post-amputation and 5 days post-amputation in the tail trunk, specifically at the injection site and at the regenerated tail, in a macrophage depleted environment (clodronate-liposome injection). What's more, XtiSCs injection decreased muscle fibers degradation significantly at 1 day post-amputation and facilitated new muscle growth significantly at 3 days post-amputation. In addition, whole-mount immunostaining showed that some XtiSCs co-localized with macrophages. And we observed potential mitochondria transport from XtiSCs to macrophages using MitoTracker staining in tadpole tail., Conclusions: Our study delineates the novel role of XtiSCs in facilitating muscle regeneration post tadpole tail amputation, underscoring a unique interaction with macrophages that is crucial for regenerative success. This study not only highlights the therapeutic potential of Sertoli cells in regenerative medicine but also opens avenues for clinical translation, offering insights into immunoregulatory strategies that could enhance tissue regeneration and transplant acceptance., Competing Interests: Declarations Ethics approval and consent to participate This study was carried out in strict accordance with the Act No. 246/1992 Coll., on the protection of animals against cruelty, the basic law related to animal protection governing the activities of all the state authorities of animal protection in the Czech Republic, such as the Ministry of Agriculture, including the Central Commission for Animal Welfare, and the veterinary administration authorities. The authorization to use experimental animals was issued to the Faculty of Science, Charles University, 37428/2019-MZE-18134. Study protocol was approved by the Ethical Committee of Faculty of Science, Charles University and the Ministry of Education, Youth and Sports. Title of the approved project: Cytological analysis of selected Pipidae species (Xenopus, Hymenochirus), Approval number: MSMT-20585/2022-4. Date of approval: November 3, 2022. No human cells/ tissues/ samples/ cell lines were used in this research. Consent for publication Not applicable. Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Spermatogenesis is a biological process within the testis that produces haploid spermatozoa for the continuity of species. Sertoli cells are somatic cells in the seminiferous epithelium that orchestrate spermatogenesis. Cyclic reorganization of the Sertoli cell actin cytoskeleton is vital for spermatogenesis, but the underlying mechanism remains largely unclear. Here, we report that the RNA-binding protein PTBP1 controls Sertoli cell actin cytoskeleton reorganization by programming alternative splicing of actin cytoskeleton regulators. This splicing control enables ectoplasmic specializations, the actin-based adhesion junctions, to maintain the blood-testis barrier and support spermatid transport and transformation. Particularly, we show that PTBP1 promotes actin bundle formation by repressing the inclusion of exon 14 of Tnik, a kinase present at the ectoplasmic specialization. Our results thus reveal a novel mechanism wherein Sertoli cell actin cytoskeleton dynamics are controlled post-transcriptionally by utilizing functionally distinct isoforms of actin regulatory proteins, and PTBP1 is a critical regulatory factor in generating such isoforms., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

Hexavalent chromium [Cr(VI)] has significant adverse effects on the environment and human health, particularly on the male reproductive system. Previously, we observed ferroptosis and autophagy in rat testicular injury induced by Cr(VI). In the present study, we focused on the association between ferroptosis and autophagy in mouse Sertoli cells (TM4) exposed to concentrations of 2.5 μМ, 5 μМ, and 10 μМ Cr(VI). Cr(VI) exposure altered mitochondrial ultrastructure; increased intracellular iron, malondialdehyde, and reactive oxygen species (ROS) levels; decreased glutathione content; increased TfR1 protein expression; and decreased GPX4, FPN1, and SLC7A11 protein expression, ultimately resulting in ferroptosis. Additionally, we observed ferritinophagy, increased expression of BECLIN1, LC3B, and NCOA4, and decreased expression of FTH1 and P62. Inhibition of autophagy and ferritinophagy via 3-MA and small interfering RNA (siRNA)-mediated silencing of NCOA4 ameliorated changes in ferritinophagy- and ferroptosis-associated protein expression, and reduced ROS levels. Rats exposed to Cr(VI) exhibited atrophy of testicular seminiferous tubules, a reduction in germ and Sertoli cells, and the occurrence of ferritinophagy and ferroptosis in cells of the rat testes. These results indicate that ferroptosis, triggered by NCOA4-mediated ferritinophagy, is one of the mechanisms that contribute to Cr(VI)-induced damage in Sertoli cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Resmethrin, a pyrethroid pesticide used to control insects, is toxic to non-target organisms and other mammals. However, little is known about the reproductive toxicity of resmethrin in the testes, or its mechanism of toxicity. In this study, we investigated the testicular toxicity of resmethrin on mouse Leydig (TM3) and Sertoli (TM4) cells, focusing on the mitochondria and endoplasmic reticulum (ER). We found that resmethrin inhibited proliferation and cell cycle progression and disrupted mitochondrial membrane potential (MMP; ΔΨ) in TM3 and TM4 cells. In particular, resmethrin exposure significantly reduced the expression of mitochondria-associated membranes (MAMs) proteins, such as Vapb, Vdac, and Grp75, in both cell lines. Resmethrin also disrupts calcium homeostasis in the mitochondrial matrix and cytoplasm. In addition, resmethrin activates oxidative stress-mediated ER stress signals. Finally, we confirmed that 4-PBA, an ER stress inhibitor, restored the growth of TM3 and TM4 cells, which was decreased by resmethrin. Therefore, we confirmed that resmethrin hampered MAMs and activated ER stress, thus suppressing TM3 and TM4 cell proliferation., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

Bisphenol A (BPA), a pervasive substance in our daily lives and livestock excreta, poses significant threats due to its infiltration into foods and water sources. BPA has adverse impacts on male reproductive function, particularly affecting the critical Sertoli (ST) cells that play a pivotal role in the process of spermatogonia differentiating into spermatozoa. In this study, we examined the prevalence of BPA within the pig industry and delved into the impact of BPA exposure on the motility of boar sperm, the function of pig ST cells, as well as the underlying molecular mechanisms involved. This study revealed spatial disparities in the global distribution of BPA and its analogue contamination, utilizing data compiled from 130 comprehensive studies. The average concentration of BPA found in pig feed ranges from 9.7 to 47.9 μg/kg, while in serum, it averages between 55.1 and 75.6 ng/L. The BPA concentration in feed exhibits a negative correlation with sperm viability and the percentage of progressive motile spermatozoa. Exposure to BPA reduced sperm motility in boar and ST cell activity at both 6 and 24 h. The transcriptome analysis revealed that, compared to untreated control cells, endoplasmic reticulum stress (ERS)-related genes were upregulated in ST cells exposed to BPA at 6 and 24 h. This activation of ERS in ST cells was mediated by receptor protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring protein-1α (IRE1α), and activating transcription factor 6 (ATF6). Additionally, BPA exposure triggered oxidative stress and a proinflammatory response mediated by the transcription factor NF-κB, accompanied by an increase in downstream proinflammatory cytokines. BPA exposure also led to apoptosis in ST cells and upregulated the expression levels of pro-apoptosis proteins. However, inhibiting ERS activity with 4-PBA attenuated the BPA-induced inflammatory response and apoptosis in ST cells. Our findings suggest that BPA induced apoptosis and inflammatory response in porcine ST cells through persistent activation of ERS, thereby compromising the normal function of these cells., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Study Question: Are Sertoli cells (SCs) from adult Klinefelter men (47,XXY) capable of proliferating in vitro and maintaining their main phenotypical and functional characteristics as do SCs from adult 46,XY patients?, Summary Answer: Isolated SCs from patients with Klinefelter syndrome (KS) can be expanded in vitro while maintaining their characteristics and a stable karyotype, similar to SCs from 46,XY patients., What Is Known Already: The mechanism leading to testicular tissue degeneration in KS is still unknown. A few recent studies highlight the main role played by SCs in the physiopathology of the disease, but new study models based on co-culture or testicular organoids are needed to further understand the SC's involvement in the mechanism of testicular degeneration and fibrosis, and to find therapeutical targets. KS SC expansion could be the first step towards developing such in vitro study models. SCs have been isolated from 46,XY men and expanded in vitro while maintaining the expression of phenotypical and functional markers, but propagation of SCs from KS men has not been achieved yet., Study Design, Size, Duration: Testicular tissue was obtained during a testicular sperm extraction procedure for infertility treatment between 2019 and 2021 from three azoospermic adult KS (47,XXY) men (33±3.6 years old) and from three control patients (46,XY) (36±2 years old) presenting with obstructive azoospermia. SCs isolated from frozen-thawed tissue of KS and 46,XY patients were cultured for 60 days and compared. All patients signed an informed consent according to the ethical board approval of the study protocol., Participants/materials, Setting, Methods: Testicular biopsies obtained from KS (n = 3) and 46,XY (n = 3) adult patients were slow-frozen. After tissue thawing SCs were isolated using a double-step enzymatic digestion and differential plating, and cultured for 60 days in DMEM medium containing FBS. Analyses were performed at different culture times (passages 5 (P5) and 10 (P10)). Quantification of cells using immunofluorescence (IF) for cell type-specific markers (Sox9, GATA4, ACTA2, INSL3, MAGEA4), SCs characterization using both IF and quantitative real-time PCR for GDNF, BMP4, AR and CLDN11 and cells karyotyping were performed., Main Results and the Role of Chance: We demonstrate for the first time that a small population of human SCs isolated from frozen-thawed testis of adult KS patients can be expanded in vitro while retaining expression of characteristic markers of SCs and the 47,XXY karyotype, and exhibiting cell-specific functional proteins and gene expression (GDNF, BMP4, AR, and CLDN11) after 60 days in culture. At P10, 83.39 ± 4.2% of cultured cells from KS men and 85.34 ± 4.1% from 46,XY men expressed Sox9, and 88.8 ± 3.9% of KS cells versus 82.9 ± 3.2% of the control cells were positive for GATA4 without any differences between two groups; both Sox9 and GATA4 are typical SC markers. No differences were found between KS and 46,XY SCs in vitro in terms of cells expansion (exponential growth between P1 and P10 with an average cell count of 2.8±1.5×107 versus 3.8±1.2×107 respectively for the KS and control groups at P10). There was no significant statistical difference for functional proteins and genes expressions (GDNF, BMP4, AR, and CLDN11) neither between KS SCs and control SCs nor between P5 and P10., Limitations, Reasons for Caution: The small number of donor samples is a limitation but it is due to limited availability of tissue for research in KS populations. Although no differences were observed in SCs function in the culture of isolated SCs after 60 days, the possibility of a SCs dysfunction needs to be investigated in more complex 3-dimensional models allowing the establishment of a proper cell organization and further analyses of cell functions and interactions during longer culture periods., Wider Implications of the Findings: The demonstration of the possibility to propagate KS SCs in vitro could be useful to build new in vitro models for deciphering testicular cell interactions, determining deficient signalling pathways involved in impaired spermatogenesis, and identifying targets for infertility treatment in KS. As the cell numbers achieved in this study are higher than cell numbers used to develop testicular organoids, we may expect to be able to understand the behaviour and physiopathology of SCs in the disease during the long-term culture of these organoids. Such models could be further applied to understand other causes of deficiencies in seminiferous tubules., Study Funding/competing Interest(s): M.G.G is funded by a grant from the Cliniques Universitaires Saint-Luc (FRC) for the research project on Klinefelter Syndrome Physiopathology. The authors declare no conflicts of interest., Trial Registration Number: NCT05997706., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Long noncoding RNAs (lncRNAs) are important regulatory biomolecules responsible for many cellular processes. The aging of mammals is manifested by a slow and gradual decline of physiological functions after adulthood, progressively resulting in age-related diseases. Testis comprises different cell-types with defined functions for producing haploid gametes and androgens in males, contributing gene-pool to the next generation with genetic variations to species for evolutionary advantage. The LINC-RBE (long intergenic noncoding-rat brain expressed) RNA showed highest expression in the Leydig cells, responsible for steroidogenesis and production of testosterone; higher expression in primary spermatocytes (pachytene cells), responsible for generation of haploid gametes and high expression in Sertoli cells, the nursing cells of the testes. Testes of immature (4-weeks), adult (16- and 44-weeks), and nearly-old (70-weeks) rats showed low, high, and again low levels of expression, respectively. This along with the nuclear-cytoplasmic localization of LINC-RBE RNA showed age-related expression and function. Thus, expression of LINC-RBE is involved in the molecular physiology of testes, especially Leydig cells, primary spermatocytes, and Sertoli cells. The decline in its expression correlates with diminishing reproductive function of the testes during aging of the rat., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The human immunodeficiency virus continues to pose a significant global public health challenge, affecting millions of individuals. The current treatment strategy has incorporated the utilization of combinations of antiretroviral drugs. The administration of these drugs is associated with many deleterious consequences on several physiological systems, notably the reproductive system. This study aimed to assess the toxic effects of abacavir sulfate, ritonavir, nevirapine, and zidovudine, as well as their combinations, on TM3 Leydig and TM4 Sertoli cells. The cell viability was gauged using 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) and neutral red uptake (NRU) assays. Reactive oxygen species (ROS) production was assessed via the 2',7'-dichlorofluorescein diacetate (DCFDA) test, and DNA damage was determined using the comet assay. Results indicated cytotoxic effects at low drug concentrations, both individually and combined. The administration of drugs, individually and in combination, resulted in the production of ROS and caused damage to the DNA at the tested concentrations. In conclusion, the results of this study suggest that the administration of antiretroviral drugs can lead to testicular toxicity by promoting the generation of ROS and DNA damage. Furthermore, it should be noted that the toxicity of antiretroviral drug combinations was shown to be higher compared to that of individual drugs.

Tri (2-Ethylhexyl) phosphate (TEHP), widely used as a fire retardant and plasticizer, has been commonly found in the environment. Its potential health-related risks, especially reproductive toxicity, have aroused concern. However, the potential cellular mechanisms remain unexplored. In this study, we aimed to investigate the molecular mechanisms underlying TEHP-caused cell damage in Sertoli cells, which play a crucial role in supporting spermatogenesis. Our findings indicate that TEHP induces apoptosis in 15P-1 mouse Sertoli cells. Subsequently, we conducted RNA sequencing analyses, which suggested that ER stress, autophagy, and MAPK-related pathways may participate in TEHP-induced cytotoxicity. Furthermore, we demonstrated that TEHP triggers ER stress, activates p38 MAPK, and inhibits autophagy flux. Then, we showed that the inhibition of ER stress or p38 MAPK activation attenuates TEHP-induced apoptosis, while the inhibition of autophagy flux is responsible for TEHP-induced apoptosis. These results collectively reveal that TEHP induces ER stress, activates p38, and inhibits autophagy flux, ultimately leading to apoptosis in Sertoli cells. These shed light on the molecular mechanisms underlying TEHP-associated testicular toxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Numerous variables that regulate the metabolism of Sertoli cells and sperm have been identified, one of which is sex steroid hormones. These hormones play a vital role in maintaining energy homeostasis, influencing the overall metabolic balance of the human body. The proper functioning of the reproductive system is closely linked to energy status, as the reproductive axis responds to metabolic signals. The aim of this study was to investigate the gene expression patterns of metabolite interconversion enzymes in testicular cells (Sertoli cells and spermatogonia) of non-obstructive azoospermia (NOA) patients, as compared to normal controls, to understand the molecular mechanisms contributing to NOA. We used microarray and bioinformatics techniques to analyze 2912 genes encoding metabolite interconversion enzymes, including methyltransferase, monooxygenase, transmembrane reductase, and phosphohydrolase, in both testicular cells and normal samples. In sperm, the upregulation of MOXD1, ACAD10, PCYT1A, ARG1, METTL6, GPLD1, MAOA, and CYP46A1 was observed, while ENTPD2, CPT1C, ADC, and CYB5B were downregulated. Similarly, in the Sertoli cells of three NOA patients, RPIA, PIK3C3, LYPLA2, CA11, MBOAT7, and HDHD2 were upregulated, while NAA25, MAN2A1, CYB561, PNPLA5, RRM2, and other genes were downregulated. Using STRING and Cytoscape, we predicted the functional and molecular interactions of these proteins and identified key hub genes. Pathway enrichment analysis highlighted significant roles for G1/S-specific transcription, pyruvate metabolism, and citric acid metabolism in sperm, and the p53 signaling pathway and folate metabolism in Sertoli cells. Additionally, Weighted Gene Co-expression Network Analysis (WGCNA) and single-cell RNA sequencing (scRNA-seq) were performed to validate these findings, revealing significant alterations in gene expression and cellular distribution in NOA patients. Together, these results provide new insights into the molecular mechanisms underlying NOA and identify potential therapeutic targets., (© 2024. The Author(s).)

Liraglutide, an analog of the incretin hormone glucagon-like peptide 1 (GLP-1), is widely used for obesity and type 2 diabetes treatment. However, there is scarce information about its effects on testicular function. Within the testis, Sertoli cells (SCs) provide nutritional support for germ cells; they metabolize glucose to lactate, which is delivered to germ cells to be used as a preferred energy substrate. Besides, SCs use fatty acids (FAs) as an energy source and store them as triacylglycerols (TAGs) within lipid droplets (LDs), which serve as an important energy reserve. In the present study, 20-day-old rat SC cultures were used to assess whether liraglutide affects their metabolic functions related to nutritional support and lipid storage. The results show that liraglutide does not modify glucose consumption or lactate production. However, it increases TAG levels and LD content. These effects are accompanied by an increase in the mRNA levels of the fatty acid transporter FAT/CD36, glycerol-3-phosphate-acyltransferase 3, and perilipins 1 and 4. The participation of the cAMP/PKA signaling pathway was explored. We observed that H89 (a PKA inhibitor) decreases the LD upregulation elicited by liraglutide, and that dibutyryl cAMP increases LD content and the expression of related genes. In summary, liraglutide promotes lipid storage in SCs through the regulation of key regulatory genes involved in FA transport, TAG synthesis, and LD formation. Considering the importance of lipid storage in SC energetic homeostasis maintenance, we postulate that liraglutide might improve the overall energetic status of the seminiferous tubule.

2,2',4,4'-Tetrabromodiphenyl ether (PBDE-47), being the most prevalent congener of polybrominated diphenyl ethers (PBDEs), has been found to accumulate greatly in the environment and induce spermatogenesis dysfunction. However, the specific underlying factors and mechanisms have not been elucidated. Herein, male Sprague-Dawley (SD) rats were exposed to corn oil, 10 mg/kg body weight (bw) PBDE-47 or 20 mg/kg bw PBDE-47 by gavage for 30 days. PBDE-47 exposure led to blood-testis barrier (BTB) integrity disruption and aberrant spermatogenesis. Given that Sertoli cells are the main toxicant target, to explore the potential mechanism involved, we performed RNA sequencing (RNA-seq) in Sertoli cells, and the differentially expressed genes were shown to be enriched in ferroptosis and lysosomal pathways. We subsequently demonstrated that ferroptosis was obviously increased in testes and Sertoli cells upon exposure to PBDE-47, and the junctional function of Sertoli cells was restored after treatment with the ferroptosis inhibitor ferrostatin-1. Since glutathione peroxidase 4 (GPX4) was dramatically reduced in PBDE-47-exposed testes and Sertoli cells and considering the RNA-sequencing results, we examined the activity of chaperone-mediated autophagy (CMA) and verified that the expression of LAMP2a and HSC70 was upregulated significantly after PBDE-47 exposure. Notably, Lamp2a knockdown not only inhibited ferroptosis by suppressing GPX4 degradation but also restored the impaired junctional function induced by PBDE-47. These collective findings strongly indicate that PBDE-47 induces Sertoli cell ferroptosis through CMA-mediated GPX4 degradation, resulting in decreased BTB-associated protein expression and eventually leading to BTB integrity disruption and spermatogenesis dysfunction., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Background: Androgens are essential hormones for testicular development and the maintenance of male fertility. Environmental factors, stress, aging, and psychological conditions can disrupt androgen production, impacting the androgen signaling pathway and consequently spermatogenesis. Within the testes, testosterone is produced by Leydig cells and acts on Sertoli cells by activating the androgen receptor (AR), which then translocates to the nucleus to function as a transcription factor. Despite clinical correlations between low testosterone levels and diminished sperm quality, the precise mechanism remains unclear., Methods: This study explores the hypothesis that reduced androgen levels impair Sertoli cell function by disrupting AR transcriptional regulation. Using an androgen blockade model with enzalutamide, we investigated the impact of low androgen levels on AR target genes in Sertoli cells through ChIP-seq and RNA-seq assays., Results: Our results reveal that androgen blockage increases AR enrichment on the promoter region of Wee1, promoting Wee1 expression, while decreasing binding to the promoter region of Lfng, inhibiting its expression. Increased WEE1 protein inhibits Sertoli cell proliferation, whereas reduced LFNG affects Notch modification, leading to decreased production of glial cell line-derived neurotrophic factor (GDNF), a key growth factor for spermatogonial stem cell self-renewal., Conclusions: These findings provide new insights into the molecular mechanisms by which low androgen levels interfere with Sertoli cell functions, offering novel perspectives for the clinical treatment of male reproductive disorders., (© 2024. The Author(s).)

Sperm production depends on proper Sertoli-germ cell interaction, and we hypothesized that receptor activator of nuclear factor κB ligand (RANKL) activity in Sertoli cells may influence spermatogenesis. Treatment with the RANKL inhibitor denosumab, normally used to treat osteoporosis, increased testicular weight, inhibin B, and germ cell proliferation in ex vivo testis cultures and in vivo in a humanized RANKL mouse. The effect on germ cell proliferation was positively associated with baseline serum concentrations of anti-müllerian hormone (AMH). In accordance, denosumab increased germ cell proliferation in ex vivo human testis cultures with low/moderate but not severe impairment of Sertoli cell function. In a placebo-controlled randomized clinical trial, denosumab had no effect on semen quality but increased sperm concentration in a subgroup of infertile men with serum AMH ≥38 pmol/L at baseline. In conclusion, high serum AMH may increase the probability of a beneficial response to denosumab treatment in infertile men, thus suggesting a possible venue for precision medicine in male infertility., Competing Interests: Declaration of interests M.B.J. holds two patents on the use of RANKL inhibitors to treat male infertility and founded the spin-out company XY Therapeutics., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)

Cadmium (Cd) has garnered significant attention due to reproductive toxicity in inducing ferroptosis. However, the specific mechanisms underlying Cd-induced germ cell ferroptosis remain poorly understood. This study aimed to systematically explore the molecular mechanisms of germ cell ferroptosis by investigating differential changes in transcription factors and proteins in male mice treated orally with CdCl 2 (0.5 g/L) reaching postnatal day 60, alongside Leydig cell (TM3) and Sertoli cell (TM4) lines. Results demonstrated that Cd exposure led to increased iron overload and oxidative stress in mouse testes, disrupted intracellular mitochondrial morphology characteristic of ferroptosis. RNA sequencing revealed significant upregulation of Atf3 and Hmox1 in Cd-exposed germ cells, along with increased expression of ATF3 and HO-1. Intervention in ferroptosis or HO-1 effectively rescued cells from Cd-induced mortality by breaking the detrimental cycle between lipid peroxidation and HO-1 activation. Further findings showed that NRF2 and HO-1 expression was notably elevated upon ATF3 overexpression in TM3 and TM4 cells, activating the Keap1-Nrf2 pathway and triggering ferroptosis in testes, whereas NRF2 and HO-1 expression levels were reversed when ATF3 was silenced. This study provides novel insights into ATF3-mediated NRF2/HO-1 signaling in Cd-induced mitochondrial ferroptosis in testes, shedding light on the mechanisms underlying Cd-induced ferroptosis and testicular injury., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Excess exogenous supplementation of D-galactose (D-gal), a monosaccharide and reducing sugar, generates reactive oxygen species (ROS), leading to cell damage and death. ROS accumulation is critical in aging. Therefore, D-gal-induced aging mouse models are used in aging studies. Herein, we evaluated D-gal's effect on neonatal testis development using an in vitro organ culture method. Mouse testicular fragments (MTFs) derived from neonatal testes (postnatal day 5) were cultured with 500 mM D-gal for 5 days. D-gal-treated MTFs showed a significantly increased and decreased expression of undifferentiated and differentiated germ cell markers, respectively, with a substantial reduction in meiotic cells. In D-gal-exposed MTFs, expression levels of Sertoli cell markers (Sox9 and Wt1) increased, while those of StAR and 17β-HSD3, whose expressions are abundant in D-Gal treated adult Leydig cells, decreased. Additionally, the enzyme 3 β-HSD1, essential for steroidogenesis in Leydig cells, was significantly reduced in D-gal-exposed MTFs compared to that in controls.D-gal significantly increased the expression of Bad, Bax, and cleaved caspase-3 and -8. Via oxidative stress in MTF. Overall, D-gal negatively regulates germ cell and Leydig cell development in neonatal testes through pro-apoptotic mechanisms and ROS., (© 2024. The Author(s).)

Several models of maternal undernutrition reveal impairment of testicular development and compromise spermatogenesis in male offspring. The expansion of the litter size model, valuable for studying the impact of undernutrition on early development, has not yet been used to evaluate the consequences of early undernutrition in the adult male reproductive system. For this purpose, pups were raised in either normal litter (ten pups/dam) or large litter (LL; sixteen pups/dam). On postnatal day 90, sexual behaviour was evaluated or blood, adipose and reproductive tissues were collected for biochemical, histological and morphological analysis. Adult LL animals were lighter and thinner than controls. They showed increased food intake, but decrease of retroperitoneal white adipose tissue weight, glycaemia after oral glucose overload and plasma concentration of cholesterol. Reproductive organ weights were not altered by undernutrition, but histopathological analysis revealed an increased number of abnormal seminiferous tubules and number of immature spermatids in the tubular lumen of LL animals. These animals also showed reduction in total spermatic reserve and daily sperm production in the testes. Undernutrition decreased the number of Sertoli cells, and testosterone production was increased in the LL group. Mitochondrial activity of spermatozoa remained unchanged between experimental groups, suggesting no significant impact on the energy-related processes associated with sperm function. All animals from both experimental groups were considered sexually competent, with no significant difference in the parameters of sexual behaviour. We conclude that neonatal undernutrition induces histological and physiological testicular changes, without altering sperm quality and sexual behaviour of animals.

Sertoli cells, omnipresent, somatic cells within the seminiferous tubules of the mammalian testis are essential to male fertility. Sertoli cells maintain the integrity of the testicular microenvironment, regulate hormone synthesis, and of particular importance, synthesize the active derivative of vitamin A, all trans retinoic acid (atRA), which is required for germ cell differentiation and the commitment of male germ cells to meiosis. Stages VIII-IX, when atRA synthesis occurs in the testis, coincide with multiple germ cell development and testicular restructuring events that rely on Sertoli cell gene products to proceed normally. In this study, we have synchronized and captured the mouse testis at four recurrent points of atRA synthesis to observe transcriptomic changes within Sertoli cells as mice age and the Sertoli cells are exposed to increasingly developed germ cell subtypes. This work provides comprehensive, high-resolution characterization of the timing of induction of functional Sertoli cell genes across the first wave of spermatogenesis, and outlines in silico predictions of germ cell derived signaling mechanisms targeting Sertoli cells. We have found that Sertoli cells adapt to their environment, especially to the needs of the germ cell populations present and establish germ-Sertoli cell and Sertoli-Sertoli cell junctions early but gain many of their known immune-regulatory and protein secretory functions in preparation for spermiogenesis and spermiation. Additionally, we have found unique patterns of germ-Sertoli signaling present at each endogenous pulse of atRA, suggesting individual functions of the various germ cells in germ-Sertoli communication., (© The Author(s) 2024. Published by Oxford University Press on behalf of Society for the Study of Reproduction. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: While polystyrene microplastics (PS-MPs) are emerging as potentially significant health threats, linked to cancer and reproductive dysfunction, their precise effects on human health remain largely unknown. We aimed to investigate the underlying mechanisms promoting microplastic-induced damage in the reproductive system., Methods: Thirty C57BL/6 male mice were randomly allocated into six equal-sized groups. Mice were exposed to fluorescent PS-MPs (5 µm, < 18%, green) at a dose of 1 and 3 mg/dL via oral gavage for 28 and 56 days, respectively (control, 0 mg/dL). The presence of antibodies and inflammatory and oxidative stress markers were evaluated using western blotting. Sperm analysis was also performed. Mouse testis Sertoli TM4 cells were divided into two groups: control (medium only) and PS-MPs (medium containing, 1,000 μg/mL) groups and cultured in vitro for 1, 24, 48, or 72 hours. The cells were cultured in a Ham's F12: Dulbecco's Modified Eagle Medium medium with 0.25% fetal bovine serum at 37°C with humidified atmosphere of 5% carbon dioxide in the air. Protein analyses for interleukin (IL)-6, IL-10, NADPH-oxidase (NOX)-2, NOX-4, hypoxia-inducible transcription factor (HIF)-2α, monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor (TNF)-α, and transforming growth factor (TGF)-β were performed using western blotting., Results: The testes were evaluated after 28 and 56 days of exposure. Varying sizes of PS-MPs were detected in the testes (ranging from 5.870 to 7.768 µm). Significant differences in sperm concentration, motility, and the proportion of normal sperm were observed between the two groups. An increase in TGF-β, HIF-2α, and NOX-4 levels was observed using western blot analysis. However, no dose-dependent correlations were observed between the two groups. In vitro evaluation of the PS-MPs group displayed PS-MP penetration of the lumen of Sertoli cells after 1 hour. Further PS-MP aggregation within Sertoli cells was observed at 24, 48, and 72 hours. A significant increase in inflammatory protein expressions (IL-10, TGF-β, MCP-1, IL-6, TNF-α, and HIF-2α) was observed through western blotting, although oxidative agents did not show a significant increase., Conclusion: PS-MPs induced reproductive dysfunction in male mice provide new insights into PS-MPs-associated toxicity in mammals., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2024 The Korean Academy of Medical Sciences.)

Spermatogenesis constitutes a complex and intricate cascade of differentiation, indispensable for the male reproductive competence. The intercellular communication conduits of Sertoli cells (SCs) are pivotal in orchestrating this cascade ensuring sustenance and development of germ cells. Single cells and bioinformatics recently demonstrated articles are used for the regulatory modalities through which SCs modulate spermatogenesis, specifically via androgen receptors (ARs), the transforming growth factor-beta/Smad axis, mitogen-activated protein kinases, cAMP/protein kinase A (PKA), phosphatidylinositol 4,5-bisphosphate 3-kinase (PI3k)/AKT serine threonine kinase (Akt), AMP-activated protein kinase, and AR pathways. Within this framework, homeostasis of gap junction dynamics, cryptic sites and the activities at tight junctions and adherens junctions, with the integrity of the testicular barrier, glucose assimilation, lactate distribution, being governed also along with SC maturation. Disruptions in activities or abnormal concentration in derangements in AR, cAMP/PKA, and PI3k/Akt pathways, and as well as the molecules that comprise them, would present male infertility.

Study Question: Do testis-specific cells have a normal karyotype in non-mosaic postpubertal Klinefelter syndrome (KS) patients with focal spermatogenesis and in non-mosaic prepubertal KS boys?, Summary Answer: Spermatogonia have a 46, XY karyotype, and Sertoli cells surrounding these spermatogonia in postpubertal patients also have a 46, XY karyotype, whereas, in prepubertal KS boys, Sertoli cells surrounding the spermatogonia still have a 47, XXY karyotype., What Is Known Already: A significant proportion of patients with non-mosaic KS can have children by using assisted reproductive techniques thanks to focal spermatogenesis. However, the karyotype of the cells that are able to support focal spermatogenesis has not been revealed., Study Design, Size, Duration: Testicular biopsy samples from non-mosaic KS patients were included in the study. Karyotyping for sex chromosomes in testis-specific cells was performed by immunohistochemical analysis of inactive X (Xi) chromosome and/or fluorescent in situ hybridization (FISH) analysis of chromosomes 18, X, and Y., Participants/materials, Setting, Methods: A total of 22 KS patients (17 postpubertal and 5 prepubertal) who were non-mosaic according to lymphocyte karyotype analysis, were included in the study. After tissue processing, paraffin embedding, and sectioning, the following primary antibodies were used for cell-specific analysis and Xi detection; one section was stained with MAGE A4 for spermatogonia, SOX9 for Sertoli cells, and H3K27me3 for Xi; the other one was stained with CYP17A1 for Leydig cells, ACTA2 for peritubular myoid cells, and H3K27me3 for Xi. Xi negative (Xi-) somatic cells (i.e. Sertoli cells, Leydig cells, and peritubular myoid cells) were evaluated as having the 46, XY karyotype; Xi positive (Xi+) somatic cells were evaluated as having the 47, XXY. FISH stain for chromosomes 18, X, and Y was performed on the same sections to investigate the karyotype of spermatogonia and to validate the immunohistochemistry results for somatic cells., Main Results and the Role of Chance: According to our data, all spermatogonia in both postpubertal and prepubertal non-mosaic KS patients seem to have 46, XY karyotype. However, while the Sertoli cells surrounding spermatogonia in postpubertal samples also had a 46, XY karyotype, the Sertoli cells surrounding spermatogonia in prepubertal samples had a 47, XXY karyotype. In addition, while the Sertoli cells in some of the Sertoli cell-only tubules had 46, XY karyotype, the Sertoli cells in some of the other Sertoli cell-only tubules had 47, XXY karyotype in postpubertal samples. In contrast to the postpubertal samples, Sertoli cells in all tubules in the prepubertal samples had the 47, XXY karyotype. Our data also suggest that germ cells lose the extra X chromosome during embryonic, fetal, or neonatal life, while Sertoli cells lose it around puberty. Peritubular myoid cells and Leydig cells may also be mosaic in both postpubertal patients and prepubertal boys, but it requires further investigation., Limitations, Reasons for Caution: The number of prepubertal testicle samples containing spermatogonia is limited, so more samples are needed for a definitive conclusion. The fact that not all the cell nuclei coincide with the section plane limits the accurate detection of X chromosomes by immunohistochemistry and FISH in some cells. To overcome this limitation, X chromosome analysis could be performed by different techniques on intact cells isolated from fresh tissue. Additionally, there is no evidence that X chromosome inactivation reoccurs after activation of the Xi during germ cell migration during embryogenesis, limiting the prediction of X chromosome content in germ cells by H3K27me3., Wider Implications of the Findings: Our findings will lay the groundwork for new clinically important studies on exactly when and by which mechanism an extra X chromosome is lost in spermatogonia and Sertoli cells., Study Funding/competing Interest(s): This study was funded by The Scientific and Technological Research Council of Türkiye (TUBITAK) (2219 - International Postdoctoral Research Fellowship Program for Turkish Citizens) and the Strategic Research Program (SRP89) from the Vrije Universiteit Brussel. The authors declare no competing interests., Trial Registration Number: N/A., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Mimicking the microenvironment of seminiferous tubules plays an indispensable role in directing differentiation of stem cells toward germ cells in vitro. In this work, we fabricated electrospun gelatin (EG) mats (i.e., with diameter <500 nm) conditioned with Sertoli cells' extracellular matrix (ECM) to simulate both 3D structures and composition of normal testis tissue. Sertoli cells were isolated from mice testis and represented through immunocytochemistry (ICC) staining for expression of vimentin, a specific marker of Sertoli cells. The morphological characteristics of ECM-coated scaffold were investigated under scanning electron microscope (SEM). The efficient elimination of cells was confirmed by MTT assay. Furthermore, the cyto/biocompatibility of ECM-conditioned EG scaffold was determined for Sertoli cells and embryonic stem cells (ESCs), alone and as in co-culture. According to the results, the designed scaffold provided a mat for cell proliferation with negligible toxicity (almost 100% cell viability). SEM micrographs displayed cells with elongated shape and complete stretching morphology when compared with those cultured on scaffold without ECM. Moreover, an enhanced differentiation of ESCs toward sperm-generating cells was obtained through co-culturing of Sertoli cells and ESCs, where cell viability was found almost 100%. Our findings introduce the ECM-conditioned EG scaffold as a potentially influential engineered substrate for in vitro guidance of stem cells differentiation by mimicking the native microenvironment., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Although bitter receptors, known as Tas2Rs, have been identified in the testes and mature sperm, their expression in testicular Sertoli cells (SCs) and their role in recognizing harmful substances to maintain the immune microenvironment remain unknown. To explore their potential function in spermatogenesis, this study utilized TM4 cells and discovered the high expression of the bitter receptor Tas2R143 in the cells. Interestingly, when the Tas2R143 gene was knocked down for 24 and 48 h, there was a significant downregulation (P < 0.05) in the expression of tight junction proteins (occludin and ZO-1) and NF-κB. Additionally, Western blot results demonstrated that the siRNA-133+NF-κB co-treatment group displayed a significant downregulation (P < 0.05) in the expression of occludin and ZO-1 compared to both the siRNA-133 transfection group and the NF-κB inhibitors treatment group. These findings suggest that Tas2R143 likely regulates the expression of occludin and ZO-1 through the NF-κB signaling pathway and provides a theoretical basis for studying the regulatory mechanism of bitter receptors in the reproductive system, aiming to attract attention to the chemical perception mechanism of spermatogenesis., Competing Interests: Declaration of competing interest The authors declare that the research was conducted without any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024. Published by Elsevier Inc.)

The aim of this study was to investigate the signaling pathways involved in the proliferation and differentiation of pig Sertoli cells (SCs) mediated by thyroid hormone (T3) to provide a theoretical and practical basis for enhancing pig semen production. The effects of different concentrations of T3 on the proliferation of pig SCs were evaluated using the CCK8 assay. The impact of T3 on the proliferation and differentiation of pig SCs was further examined using RNA-seq, qPCR, and Western Blotting techniques. Additionally, the involvement of the p38 MAPK and NFκB pathways in mediating the effects of T3 on SCs proliferation and differentiation was investigated. Our findings revealed a strong correlation between the dosage of T3 and the inhibition of pig SCs proliferation and promotion of maturation. T3 regulated the activation state of the NFκB signaling pathway by upregulating IKKα, downregulating IKKβ, and promoting IκB phosphorylation. Furthermore, T3 facilitated SCs maturation by upregulating AR and FSHR expression while downregulating KRT-18. In conclusion, T3 inhibits pig SCs proliferation and promote pig SCs maturation through the IKK/NFκB and p38 MAPK pathways. These findings provide valuable insights into the mechanisms by which T3 influences the proliferation and maturation of pig SCs., (Copyright © 2024 Elsevier Inc. All rights reserved.)

HSP47, a chaperone whose main function is the maturation of collagen molecules, is considered a marker of fibrotic diseases. Increased collagen synthesis in the testis has been associated with various pathologies leading to seminiferous tubule regression. Our aim was to study whether HSP47 is expressed in hamster Sertoli cells both in the adult and in two physiological situations of seminiferous tubule atrophy: irreversible testicular ageing and testicular regression due to short photoperiod (reversible). Eighteen animals were divided as follows: a group of 6 young animals aged 6 months, a group of 6 animals aged 24 months, which were exposed to a long photoperiod, and a final group of 6 young animals subjected to a short photoperiod. Testicular samples were fixed in methacarn and an immunohistochemical technique was used to detect HSP47. A semiquantitative study of of this protein expresion was performed between tubular sections of aged animals with complete spermatogenesis and arrested spermatogenesis and tubular sections with arrest spermatogenesis of photoinhibited testes. Sertoli cells were positive for HSP47, the intensity being greater in tubular sections with arrested spermatogenesis in both aged and photoinhibited animals. Semiquantitative analysis corroborated this observation in the sense that the expression of this protein differed according to the functional state of the seminiferous tubules. Thus, the radio of immunoreactivity was significantly higher in tubular sections with arrested spermatogenesis in aged animals compared with regressed animals, and in the latter compared with those whose tubular sections showed complete spermatogenesis. In conclusion, HSP47 expression in Sertoli cells was found for the first time in mammals. Moreover, increased expression seemed to be related to the degree of atrophy of the seminiferous epithelium and to the reversible or non-reversible physiological state of the seminiferous epithelium., (©The Author(s) 2024. Open Access. This article is licensed under a Creative Commons CC-BY International License.)

Vitamin C (Ascorbic acid, AA), as vital micro-nutrient, plays an essential role for male animal reproduction. Previously, we showed that vitamin C reprogrammed the transcriptome and proteome to change phenotypes of porcine immature Sertoli cells (iSCs). Here, we used LC-MS-based non-targeted metabolomics to further investigate the metabolic effects of vitamin C on porcine iSCs. The results identified 43 significantly differential metabolites (DMs) (16 up and 27 down) as induced by vitamin C (L-ascorbic acid 2-phosphate sesquimagnesium salt hydrate, AA2P) treatment of porcine iSCs, which were mainly enriched in steroid related and protein related metabolic pathways. ELISA (Enzyme-Linked ImmunoSorbent Assay) showed that significantly differential metabolites of Dehydroepiandrosterone (DHEA) (involved in steroid hormone biosynthesis) and Desmosterol (involved in steroid degradation) were significantly increased, which were partially consistent with metabolomic results. Further integrative analysis of metabolomics, transcriptomics and proteomics data identified the strong correlation between the key differential metabolite of Dehydroepiandrosterone and 6 differentially expressed genes (DEGs)/proteins (DEPs) (HMGCS1, P4HA1, STON2, LOXL2, EMILIN2 and CCN3). Further experiments validated that HMGCS1 could positively regulate Dehydroepiandrosterone level. These data indicate that vitamin C could modulate the metabolism profile, and HMGCS1-DHEA could be the pathway to mediate effects exerted by vitamin C on porcine iSCs., Competing Interests: Conflict of interest The authors declare that there are no conflicts of interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

In this study, we have explored the role of the KATNB1 gene, a microtubule-severing protein, in the seminiferous epithelium of the rat testis. Our data have shown that KATNB1 expressed in rat brain, testes, and Sertoli cells. KATNB1 was found to co-localize with α-tubulin showing a unique stage-specific distribution across the seminiferous epithelium. Knockdown of KATNB1 by RNAi led to significant disruption of the tight junction (TJ) permeability barrier function in primary Sertoli cells cultured in vitro with an established functional TJ-barrier, as well as perturbations in the microtubule and actin cytoskeleton organization. The disruption in these cytoskeletal structures, in turn, led to improper distribution of TJ and basal ES proteins essential for maintaining the Sertoli TJ function. More importantly, overexpression of KATNB1 in the testis in vivo was found to block cadmium-induced blood-testis barrier (BTB) disruption and testis injury. KATNB1 exerted its promoting effects on BTB and spermatogenesis through corrective spatiotemporal expression of actin- and microtubule-based regulatory proteins by maintaining the proper organization of cytoskeletons in the testis, illustrating its plausible therapeutic implication. In summary, Katanin regulatory subunit B1 (KATNB1) plays a crucial role in BTB and spermatogenesis through its effects on the actin- and microtubule-based cytoskeletons in Sertoli cells and testis, providing important insights into male reproductive biology., (© 2024 Federation of American Societies for Experimental Biology.)

In Brief: FSH leads to glutamine dependence, which is required for mTORC1 activation and in consequence Sertoli cell proliferation., Abstract: The spermatogenic capacity of adult individuals depends on, among other factors, the number of Sertoli cells (SCs) that result from the proliferative waves during development. FSH upregulates SC proliferation at least partly, through the activation of the PI3K/Akt/mTORC1 pathway, among other mechanisms. It is widely known that mTORC1 is a sensor of amino acids. Among amino acids, glutamine acquires relevance since it might contribute to cell cycle progression through the modulation of mTORC1 activity. It has not been studied yet whether glutamine intervenes in FSH-mediated regulation of SC proliferation and cell cycle progression, or if FSH has any effect on glutamine metabolism. Eight-day-old rat SCs were incubated in culture media without glutamine or with glutamine in the absence or presence of a glutamine transporter inhibitor or a glutaminase activity inhibitor under basal conditions or stimulated with FSH. The results obtained show that FSH does not promote SC proliferation and mTORC1 activation in the absence of glutamine. Also, FSH modulates glutamine metabolism increasing glutaminase isoform 2 and reducing glutamine synthetaseexpression. FSH did not promote SC proliferation and mTORC1 activation when glutaminase activity was inhibited. The results suggest that glutamine or its metabolites might cooperate with FSH in the upregulation of SC proliferation through mTORC1. In addition, as FSH modulates glutamine metabolism through the induction of glutaminase isoform 2, the hormonal control of glutamine metabolism might be part of the intricate signaling network triggered by FSH, which is crucial to establish the population of mature SCs that supports the reproductive function.

Over the past several decades, a trend toward delayed childbirth has led to increases in parental age at the time of conception. Sperm epigenome undergoes age-dependent changes increasing risks of adverse conditions in offspring conceived by fathers of advanced age. The mechanism(s) linking paternal age with epigenetic changes in sperm remain unknown. The sperm epigenome is shaped in a compartment protected by the blood-testes barrier (BTB) known to deteriorate with age. Permeability of the BTB is regulated by the balance of two mTOR complexes in Sertoli cells where mTOR complex 1 (mTORC1) promotes the opening of the BTB and mTOR complex 2 (mTORC2) promotes its integrity. We hypothesized that this balance is also responsible for age-dependent changes in the sperm epigenome. To test this hypothesis, we analyzed reproductive outcomes, including sperm DNA methylation in transgenic mice with Sertoli cell-specific suppression of mTORC1 ( Rptor KO) or mTORC2 ( Rictor KO). mTORC2 suppression accelerated aging of the sperm DNA methylome and resulted in a reproductive phenotype concordant with older age, including decreased testes weight and sperm counts, and increased percent of morphologically abnormal spermatozoa and mitochondrial DNA copy number. Suppression of mTORC1 resulted in the shift of DNA methylome in sperm opposite to the shift associated with physiological aging - sperm DNA methylome rejuvenation and mild changes in sperm parameters. These results demonstrate for the first time that the balance of mTOR complexes in Sertoli cells regulates the rate of sperm epigenetic aging. Thus, mTOR pathway in Sertoli cells may be used as a novel target of therapeutic interventions to rejuvenate the sperm epigenome in advanced-age fathers., Competing Interests: SA, OA, EM, JM, OO, OS, JP No competing interests declared, AS Reports a relationship with ReGENE LLC that includes board membership, equity or stocks, and funding grants, (© 2024, Amir, Arowolo et al.)

The increased LH levels resulting from the absence of negative feedback after castration has been linked to long-term health issues. A need exists for an alternative contraceptive agent that functions without interfering the LH pathways. This study aimed to develop antibody fragments against the follicular-stimulating hormone receptor (anti-FSHr) using phage-display technology and evaluate its effects on Sertoli cell functions. Phage clones against the extracellular domain of dog and cat FSHr selected from an antibody fragment phagemid library were analyzed for binding kinetics by surface plasmon resonance. Sertoli cells were isolated from testes of adult animals (five dogs and five cats). Efficacy test was performed by treating Sertoli cell cultures (SCCs) with anti-FSHr antibody fragments compared with untreated in triplicates. Expressions of androgen binding protein (ABP), inhibin subunit beta B (IHBB) and vascular endothelial growth factor A (VEGFA) mRNA in SCCs were quantified by RT-qPCR. The results demonstrated that the molecular weight of the purified dog and cat anti-FSHr antibody fragment was 25 kDa and 15 kDa, respectively. Based on protein molecular weight, the antibody fragment of dogs and cats was therefore, so-called single-chain variable fragments (scFv) and nanobody (nb), respectively. The binding affinity with dissociation constant (K D ) was 2.32 × 10 -7  M and 2.83 × 10 -9  M for dog and cat anti-FSHr antibody fragments, respectively. The cross-binding kinetic interactions between the dog anti-FSHr scFv and the cat ECD of FSHr could not be fitted to the curves to determine the binding kinetics. However, the cross-binding affinity K D between the cat anti-FSHr nb and the dog ECD FSHr was 1.75 × 10 -4  M. The mRNA expression of ABP, IHBB and VEGFA in SCCs was less (P < 0.05) in both dogs (12.26, 4.07 and 5.11 folds, respectively) and cats (39.53, 14.07 and 20.29 folds, respectively) treated with anti-FSHr antibody fragments, indicating the Sertoli cell functions were suppressed. In conclusion, this study demonstrated the establishment of species-specific antibody fragments against FSHr in SCCs for dogs and cats. The fragment proteins illustrate potential to be developed as non-surgical contraceptive agent targeting FSHr in companion animals., Competing Interests: Declaration of competing interest None of the authors have any conflict of interest to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Background: The Axl gene is a receptor tyrosine kinase essential for male fertility. With other Tyro3 family members, it regulates cell apoptosis and preserves the organization of seminiferous tubules. However, the regulation of the expression of Axl in testicular Sertoli cells is not entirely understood. The transcription factors NR5A1 and JUNB are involved in several male fertility mechanisms such as sex development and steroidogenesis. We hypothesize that Axl promoter activity is regulated by cooperation between JUNB and NR5A1 in Sertoli cells., Methods and Results: Following transfections of TM4 Sertoli cells with DsiRNA interference against Axl, our results show that cell morphology may be regulated by AXL. Using transfections of expression plasmids and reporter plasmids containing the Axl promoter, we report that Axl expression is highly activated by cooperation between NR5A1 and JUNB in TM4 and 15P-1 Sertoli cells. Chromatin immunoprecipitation and luciferase reporter assays with 5' promoter deletions demonstrate that JUNB and NR5A1 are being recruited to DNA regulatory elements in the proximal region of the Axl promoter. The fourth intronic region of Axl also participates in the recruitment of JUNB., Conclusion: Thus, Axl expression is regulated by a cooperation between the transcription factors JUNB and NR5A1 and influences the morphology of TM4 Sertoli cells., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Blood-testis barrier (BTB) genes are crucial for the cellular mechanisms of spermatogenesis as they protect against detrimental cytotoxic agents, chemicals, and pathogens, thereby maintaining a sterile environment necessary for sperm development. BTB proteins predominantly consist of extensive tight and gap junctions formed between Sertoli cells. These junctions form a crucial immunological barrier restricting the intercellular movement of substances and molecules within the adluminal compartment. Epithelial tight junctions are complex membrane structures composed of various integral membrane proteins, including claudins, zonula occludens-1, and occludin. Inter-testicular cell junction proteins undergo a constant process of degradation and renewal. In addition, the downregulation of genes crucial to the development and preservation of cell junctions could disrupt the functionality of the BTB, potentially leading to male infertility. Oxidative stress and inflammation may contribute to disrupted spermatogenesis, resulting in male infertility. L-cysteine is a precursor to glutathione, a crucial antioxidant that helps mitigate damage and inflammation resulting from oxidative stress. Preclinical research indicates that L-cysteine may offer protective benefits against testicular injury and promote the expression of BTB genes. This review emphasizes various BTB genes essential for preserving its structural integrity and facilitating spermatogenesis and male fertility. Furthermore, it consolidates various research findings suggesting that L-cysteine may promote the expression of BTB-associated genes, thereby aiding in the maintenance of testicular functions.

Background: Inflammation-induced testicular damage is a significant contributing factor to the increasing incidence of infertility. Traditional treatments during the inflammatory phase often fail to achieve the desired fertility outcomes, necessitating innovative interventions such as cell therapy., Methods: We explored the in vivo properties of intravenously administered Sertoli cells (SCs) in an acute lipopolysaccharide (LPS)-induced inflammatory mouse model. Infiltrating and resident myeloid cell phenotypes were assessed using flow cytometry. The impact of SC administration on testis morphology and germ cell quality was evaluated using computer-assisted sperm analysis (CASA) and immunohistochemistry., Results: SCs demonstrated a distinctive migration pattern, importantly they preferentially concentrated in the testes and liver. SC application significantly reduced neutrophil infiltration as well as preserved the resident macrophage subpopulations. SCs upregulated MerTK expression in both interstitial and peritubular macrophages. Applied SC treatment exhibited protective effects on sperm including their motility and kinematic parameters, and maintained the physiological testicular morphology., Conclusion: Our study provides compelling evidence of the therapeutic efficacy of SC transplantation in alleviating acute inflammation-induced testicular damage. These findings contribute to the expanding knowledge on the potential applications of cell-based therapies for addressing reproductive health challenges and offer a promising approach for targeted interventions in male infertility., (© 2024. The Author(s).)

Organophosphate pesticides have potent endocrine disrupting effects, hence banned in many countries. However, many organophosphates like chlorpyrifos, malathion et cetera continue to be used in some countries (Wołejko et al., 2022; Wołejko et al., 2022)including India. Fodder mediated ingestion of these substances may be harmful for livestock fertility. We have investigated the effect of the widely used organophosphate pesticide chlorpyrifos (CPF) and its metabolite, 3,5,6-trichloropyridinol (TCPy) on the expression of genes essential for spermatogenesis in goat testicular tissue. The testicular Sertoli cells (Sc) regulate germ cell division and differentiation under the influence of follicle stimulating hormone (FSH) and testosterone (T). Impaired FSH and T mediated signalling in Sc can compromise spermatogenesis leading to sub-fertility/infertility. As Sc express receptors (R) for FSH and T, they are highly susceptible to the endocrine disrupting effects of pesticides affecting fertility by dysregulating the functioning of Sc. Our results indicated that exposure to different concentrations of CPF and TCPy can compromise Sc function by downregulating the expression of FSHR and AR which was associated with a concomitant decline in the expression of genes essential for germ cell division and differentiation, like KITLG, INHBB, CLDN11 and GJA1. CPF also induced a significant reduction in the activity of acetylcholinesterase in the testes and increased the total testicular antioxidant capacity. Our results suggested that CPF and its metabolite TCPy may induce reproductive toxicity by dysregulating the expression of Sc specific genes essential for spermatogenesis., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2024 Elsevier Inc. All rights reserved.)

4-methylimidazole (4-MI), a derivative of imidazole, is a widely used component in caramel-colored food products such as soy sauce, beer and other soft drinks. The present study is aimed to investigate the effects of 4-MI on the male reproduction. The results revealed that 8 weeks of 4-MI exposure did not significantly alter the body weight and testicular weight of male mice. However, testicular morphology and computer-assisted sperm analysis showed that exposed to 4-MI caused irregular arrangement of spermatogenic cells in the testes and weakened sperm motility. Consistently, we observed the decreased fertilization ability in vivo of 4-MI-treated male mice. We further demonstrated that 4-MI disrupted the blood-testis barrier (BTB) integrity by decreasing the protein expression of BTB-related junction with permeability assay and western blot. In addition, the apoptosis of Sertoli cells (TM4) occurred in 4-MI treated mice, which might be caused by the generation of oxidative stress. Collectively, our findings document that 4-MI exposure damages the sperm mobility via disruption of BTB integrity., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier B.V. All rights reserved.)

Atrazine is currently one of the most commonly used agrochemicals in the United States and elsewhere. Here, we studied the immunoexpression of molecular markers of mammalian testicular functions: androgen receptor (AR), promyelocytic leukemia zinc finger (PLZF), GDNF family receptor alpha-1 (GFRA1), VASA/DDX4 (DEAD-Box Helicase 4) as well as the levels of intratesticular and intra-epididymal estradiol (E2) and dihydrotestosterone (DHT), tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), interleukins (IL-1β and IL-6, IL-10) and testicular chemokines (CXCL-1, CCL-2 and CCL3) in BalB/c mice after a sub-acute gavage treatment with a gonado-toxin, atrazine (50 mg/kg body wt.) for three days. We found high numbers of AR immunopositive Sertoli cells and low numbers of GFRA1, PLZF and VASA/DDX4-positive germ cells in the seminiferous tubule regions of the testes. While TNF-α level in the testes fell and remained unchanged in the epididymides, IFN-γ levels in the testes remained constant but increased in the epididymides. E2 and DHT concentrations remained unaltered in the testes but were changed in the epididymides. There were no significant changes in the levels of interleukins in the testis and epididymis. Intratesticular chemokines were also not significantly altered, except for CCL-4, which was increased in the testis. Light microscopy of the epididymis showed detached epithelium and some detached cells in the lumen. It is concluded that atrazine changed the inflammatory status of the gonads and highlighted Sertoli and undifferentiated spermatogonia as important targets for atrazine's toxic effects in the testis of mice. Concerning the epididymis, atrazine altered the epididymal hormonal concentrations and promoted histopathological modifications in its parenchyma., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Reactive oxygen species causes oxidative stress, which oxidizes polyunsaturated fatty acids (PUFAs) to form oxidative metabolites. Sertoli cell is an important cellular metabolism of PUFA in testicular cells, and it regulates the testis development and spermatogenesis. However, the oxylipins generated in testes with different developmental statuses are lacking. In this study, twelve 6-month-old Hu sheep were selected and divided into large testicular group (L) and the small testicular group (S) (n=6). UPLC-MS/MS was conducted to screen oxylipins in the testis, and the total oxylipin and ω-3 PUFA-derived oxylipin contents in the S group were higher. A total of 20 differential oxylipins between the two groups were screened. Among them, the contents of ω-3 PUFA, DHA-derived oxylipins were increased in the S group. The arachidonic acid-derived oxylipin was lower in the S group. The mRNA expression levels of genes related to oxylipin regulation (AKR1B1, PTGER2, and PTGDS) were higher in the S group (P < 0.05). In vitro, 200 µM α-linolenic acid alleviated oxidative stress damage to Sertoli cells and improved cell viability by increasing the superoxide dismutase contents and mRNA expression levels of GPX4 and Bcl2. These results indicate that ω-3 PUFA is more susceptible to lipid oxidation in the S group under oxidative stress, which might alleviate the damage of oxidative stress to testis. Moreover, ALA could stimulate the proliferation of Sertoli cells by increasing the capacity of antioxidants. This work may provide a theoretical basis for further studies on the antioxidant properties of the testis for Hu sheep., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Titanium dioxide nanoparticles (TiO 2 NPs) can reduce sperm number, but the mechanisms of defective spermatogenesis induced by TiO 2 NPs have not been studied through cell-cell interactions at present. A kind of biomimetic three-dimensional blood-testis barrier microfluidic chip capable of intercellular communication was constructed with soft lithography techniques, including Sertoli cell (TM4), spermatogonia (GC-1) and vascular endothelial cell units, to study the mechanisms of TiO 2 NPs-induced defective spermatogenesis. TM4 and GC-1 cells cultured in TiO 2 NPs exposure and control chips were collected for transcriptomics and metabonomics analysis, and key proteins and metabolites in changed biological processes were validated. In TM4 cells, TiO 2 NPs suppressed glucose metabolism, especially lactate production, which reduced energy substrate supply for spermatogenesis. TiO 2 NPs also decreased the levels of key proteins and metabolites of lactate production. In GC-1 cells, TiO 2 NPs disturbed chemokine signaling pathways regulating cell proliferation and interfered with glutathione metabolism. The Cxcl13, Stat3 and p-Stat3 levels and cell proliferation rate were decreased, and the GSR, GPX4 and GSH contents were increased in GC-1 cells in chips under TiO 2 NPs treatment. The decrease in energy substrate supply for spermatogenesis and inhibition of spermatogonia proliferation could be the main mechanisms of defective spermatogenesis induced by TiO 2 NPs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Ethnopharmacological Relevenace: Sertoli cells are vital to maintain spermatogenesis and their function decline during aging. Epimedium has the effects of tonifying kidney-yang, strengthening bones and muscles, and expelling wind and dampness, and is commonly used in the treatment of kidney-yang deficiency, impotence and spermatorrhea. Icariin is the main active ingredients from Epimedium exhibiting delaying aging effects and improving male reproductive dysfunction. Whereas, it remains poorly understood how icariin alleviates age-associated decline in testicular function by protecting against the damage of junction function of Sertoli cells., Aim of the Study: This study aimed to evaluate the improvement effect of icariin on Sertoli cell junction function damage and explore the underlying mechanisms., Materials and Methods: Male C57BL/6 mice and mouse Sertoli cell line TM4 cells were utilized to assess the improvement effect of icariin on aging-associated Sertoli cell junction function injury. H&E staining, transmission electron microscopy, qPCR, Western blot, molecular docking, siRNA transfection, and immunofluorescence were performed in this study., Results: Dietary administration of icariin remarkly attenuated age-associated deterioration in spermatogenic function as evidenced by elevated testicular weight and index, sperm concentration and sperm viability. In addition, icariin protected Sertoli cell junction function from age-associated damage as proven by increased Sertoli cell numbers, improved tight junction ultrastructure, and upregulated junction-related proteins (ZO-1, Occludin and β-Catenin). Moreover, icariin significantly upregulated ERα/c-fos signaling and PKR pathway in testicular Sertoli cells. Similarly, in vitro studies revealed that deletion of ERα, c-fos or PKR abolished the improvement effects of icariin on Sertoli cell junction function damage., Conclusions: Icariin effectively mitigates age-associated decline in testicular function by diminished Sertoli cell junction function damage through upregulating PKR pathway via ERα/c-fos signaling. Therefore, attenuating Sertoli cell junction function injury by the upregulation of PKR pathway via ERα/c-fos signaling probably indicates an effective target for the prevention and treatment of testicular spermatogenic function with aging., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Cryptorchidism, a condition where the testis fails to fully descend into the scrotum during development, is associated with elevated environmental temperatures and pressures, leading to male infertility and germ cell tumors. Factors such as oxidative stress and high temperatures contribute to infertility in cryptorchidism. This study aims to explore how external pressure affects Sertoli cells and discover new mechanisms affecting spermatogenesis in cryptorchidism. Sertoli cells were subjected to various pressure levels (0 mmHg, 25 mmHg, 50 mmHg, 100 mmHg) and durations (0 h, 2 h, 4 h) using an enzyme-linked immunosorbent assay (ELISA) to measure androgen binding protein (ABP) and inhibin B (INH B) secretion. Cell morphology changes were observed using immunofluorescence; apoptosis rates were measured with terminal-deoxynucleotidyl transferase mediated nick end labelling (TUNEL) assay and flow cytometry; ultrastructural variations were examined via transmission electron microscopy; and the expression of apoptosis-related proteins ( Fas , FasL , caspase 3 , and caspase 8 ) was analyzed through immunohistochemistry, real-time polymerase chain reaction (real-time PCR), and western blotting. The results showed that elevated pressure suppressed ABP and INH B secretion from Sertoli cells. Structural changes were observed under pressure, including cytoskeleton loosening and nuclear fragmentation. Apoptosis rates increased with higher pressure levels. Ultrastructural analysis revealed chromatin changes, apoptotic bodies, and mitochondrial alterations. Increased expressions of Fas and FasL were detected, along with elevated levels of caspase 3 and caspase 8 . The caspase 8 inhibitor blocked pressure-induced apoptosis and caspase 3 activation, while the cytochrome C inhibitor did not show the same effect. Our findings suggested that external pressure induces apoptosis of Sertoli cells via the Fas / FasL signaling pathway, potentially contributing to male infertility associated with cryptorchidism.

Chloroquine (CQ) is widely used in the therapy against malarial, tumor and recently the COVID-19 pandemic, as a lysosomotropic agent to inhibit the endolysosomal trafficking in the autophagy pathway. We previously reported that CQ (20 μM, 36 h) could reprogram transcriptome, and impair multiple signaling pathways vital to porcine immature Sertoli cells (iSCs). However, whether CQ treatment could affect the metabolomic compositions of porcine iSCs remains unclear. Here, we showed that CQ (20 μM, 36 h) treatment of porcine iSCs induced significant changes of 63 metabolites (11 up and 52 down) by the metabolomics method, which were involved in different metabolic pathways. Caffeic acid and esculetin, the top two up-regulated metabolites, were validated by ELISA. The combined analysis of metabolomics and transcriptome showed caffeic acid and esculetin to be highly correlated with multiple differentially expressed genes (DEGs), including Ndrg1, S100a8, Sqstm1, S100a12, S100a9, Ill1, Lif, Ntn4 and Peg10. Furthermore, esculetin treatment (53 nM, 36 h) significantly decreased the viability and proliferation, suppressed the mitochondrial function, whereas promoted the apoptosis of porcine iSCs, similar to those by CQ treatment (20 μM, 36 h). Collectively, our results showed that CQ treatment induces metabolic changes, and its effect on porcine iSCs could be partially mediated by esculetin., Competing Interests: Declaration of competing interest The authors declare that there are no conflicts of interests., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Porcine reproductive and respiratory syndrome virus (PRRSV) causes a highly contagious disease that threatens the global swine industry. Recent studies have focused on the damage that PRRSV causes to the reproductive system of male pigs, although pathological research is lacking. Therefore, we examined the pathogenic mechanisms in male piglets infected with PRRSV. Gross and histopathological changes indicated that PRRSV affected the entire reproductive system, as confirmed via immunohistochemical analysis. PRRSV infected Sertoli cells and spermatogonia. To test the new hypothesis that PRRSV infection in piglets impairs blood - testis barrier (BTB) development, we investigated the pathology of PRRSV damage in the BTB. PRRSV infection significantly decreased the quantity and proliferative capacity of Sertoli cells constituting the BTB. Zonula occludens-1 and β-catenin were downregulated in cell - cell junctions. Transcriptome analysis revealed that several crucial genes and signalling pathways involved in the growth and development of Leydig cells, Sertoli cells, and tight junctions in the testes were downregulated. Apoptosis, necroptosis, inflammatory, and oxidative stress-related pathways were activated, whereas hormone secretion-related pathways were inhibited. Many Sertoli cells and spermatogonia underwent apoptosis during early differentiation. Infected piglets exhibited disrupted androgen secretion, leading to significantly reduced testosterone and anti-Müllerian hormone levels. A cytokine storm occurred, notably upregulating cytokines such as tumour necrosis factor-α and interleukin-6. Markers of oxidative-stress damage (i.e. H 2 O 2 , malondialdehyde, and glutathione) were upregulated, whereas antioxidant-enzyme activities (i.e. superoxide dismutase, total antioxidant capacity, and catalase) were downregulated. Our results demonstrated that PRRSV infected multiple organs in the male reproductive system, which impaired growth in the BTB.

Yaks live in the Qinghai-Tibet Plateau for a long time where oxygen is scarce, but can ensure the smooth development of testis and spermatogenesis. The key lies in the functional regulation of the Sertoli cells under hypoxia. In this study, we sequenced yak Sertoli cells cultured in normal oxygen concentration (Normoxia) and treated with low oxygen concentration (Hypoxia) by whole transcriptomics, and screened out 194 differentially expressed mRNAs (DEmRNAs), 934 differentially expressed LncRNAs (DELncRNAs) and 129 differentially expressed miRNAs (DEmiRNAs). GO and KEGG analysis showed that these differential genes were mainly concentrated in PI3K-AKT, MAPK, RAS, and other signaling pathways, and were associated with glucose metabolism, tight junction, steroid hormone synthesis, cell fusion, and immunity of yak Sertoli cells. We constructed the gene interaction network of yak Sertoli cells in hypoxia and screened out the relationship pairs related to glucose metabolism and tight junction. The results suggested that the changes in energy metabolism, tight junction, and immune regulation of yak Sertoli cells under hypoxia might provide favorable conditions for spermatogenesis. This study provides data for further study on the role of non-coding RNA in testis development and spermatogenesis of yak., (© 2024. The Author(s).)

Fumonisin B1 (FB1), a mycotoxin produced by Fusarium species, is prevalent in crops and animal feed, posing significant health risks to livestock and humans. FB1 induces oxidative stress in Sertoli cells, destroys testicular structure, and affects spermatogenesis. However, methods to mitigate the reproductive toxicity of FB1 in testes remain unknown. Quercetin, a natural flavonoid antioxidant, may offer protective benefits. This study investigated the protective effects and mechanisms of quercetin against FB1-induced reproductive toxicity in TM4 cells (a Sertoli cell line). The results indicated that 40 μM quercetin improved cell viability, reduced apoptosis, and preserved cell functions. Quercetin also decreased reactive oxygen species (ROS) levels in TM4 cells exposed to FB1, enhanced the expression of antioxidant genes, and improved mitochondrial membrane potential. Compared with FB1 alone, the combination of quercetin and FB1 increased ATP levels, as well as pyruvate and lactic acid, the key glycolysis products. Furthermore, this combination elevated the mRNA and protein expression of glycolysis-related genes, including glucose-6-phosphate isomerase 1 ( Gpi1 ), hexokinase 2 ( Hk2 ), aldolase ( Aldoa ), pyruvate kinase, muscle ( Pkm ), lactate dehydrogenase A ( Ldha ) and phosphofructokinase, liver, B-type ( Pfkl ). Quercetin also boosted the activity of PKM and LDHA, two crucial glycolytic enzymes. In summary, quercetin mitigates FB1-induced toxicity in TM4 cells by reducing ROS levels and enhancing glycolysis. This study offers new insights into preventing and treating FB1-induced toxic damage to the male reproductive system and highlights the potential application of quercetin.

Plastic pollution is an emerging environmental issue, with microplastics and nanoplastics raising health concerns due to bioaccumulation. This work explored the impact of polystyrene nanoparticle (PS-NPs) exposure during prepuberty on male reproductive function post maturation in rats. Rats were gavaged with PS-NPs (80 nm) at 0, 3, 6, 12 mg/kg/day from postnatal day 21 to 95. PS-NPs accumulated in the testes and reduced sperm quality, serum reproductive hormones, and testicular coefficients. HE staining showed impaired spermatogenesis. PS-NPs disrupted the blood-testis barrier (BTB) by decreasing junction proteins, inducing inflammation and apoptosis. Transcriptomics identified differentially expressed genes related to metabolism, lysosome, apoptosis, and TLR4 signaling. Molecular docking revealed Cordycepin could compete with polystyrene for binding to TLR4. Cordycepin alleviated oxidative stress and improved barrier function in PS-NPs treated Sertoli cells. In conclusion, prepubertal PS-NPs exposure induces long-term reproductive toxicity in male rats, likely by disrupting spermatogenesis through oxidative stress and BTB damage. Cordycepin could potentially antagonize this effect by targeting TLR4 and warrants further study as a protective agent. This study elucidates the mechanisms underlying reproductive toxicity of PS-NPs and explores therapeutic strategies., (© 2024. The Author(s).)

Bacterial testicular inflammation is one of the important causes of male infertility. Using plant-derived compounds to overcome the side effects of antibiotics is an alternative treatment strategy for many diseases. Schizandrin B (SchB) is a bioactive compound of herbal medicine Schisandra chinensis which has multiple pharmacological effects. However its effect and the mechanism against testicular inflammation are unknown. Here we tackled these questions using models of lipopolysaccharide (LPS)-induced mice and -Sertoli cells (SCs). Histologically, SchB ameliorated the LPS-induced damages of the seminiferous epithelium and blood-testicular barrier, and reduced the production of pro-inflammatory mediators in mouse testes. Furthermore, SchB decreased the levels of pro-inflammatory mediators and inhibited the nuclear factor kB (NF-κB) and MAPK (especially JNK) signaling pathway phosphorylation in LPS-induced mSCs. The bioinformatics analysis based on receptor prediction and the molecular docking was further conducted. We targeted androgen receptor (AR) and illustrated that AR might bind with SchB in its function. Further experiments indicate that the AR expression was upregulated by LPS stimulation, while SchB treatment reversed this phenomenon; similarly, the expression of the JNK-related proteins and apoptotic-related protein were also reversed after AR activator treatment. Together, SchB mitigates LPS-induced inflammation and apoptosis by inhibiting the AR-JNK pathway., (© 2024. The Author(s).)

The yak (Bos grunniens) is a valuable livestock animal endemic to the Qinghai-Tibet Plateau in China with low reproductive rates. Cryptorchidism is one of the primary causes of infertility in male yaks. Compared with normal testes, the tight junctions (TJs) of Sertoli cells (SCs) and the integrity of the blood-testis barrier (BTB) in cryptorchidism are both disrupted. MicroRNAs are hairpin-derived RNAs of about 19-25 nucleotides in length and are involved in a variety of biological processes. Numerous studies have shown the involvement of microRNAs in the reproductive physiology of yak. In this study, we executed RNA sequencing (RNA-seq) to describe the expression profiles of mRNAs and microRNAs in yaks with normal testes and cryptorchidism to identify differentially expressed genes. GO and KEGG analyses were used to identify the biological processes and signaling pathways which the target genes of the differentially expressed microRNAs primarily engaged. It was found that novel-m0230-3p is an important miRNA that significantly differentiates between cryptorchidism and normal testes, and it is down-regulated in cryptorchidism with p < 0.05. Novel-m0230-3p and its target gene CSF1 both significantly contribute to the regulation of cell adhesion and tight junctions. The binding sites of novel-m0230-3p with CSF1 were validated by a dual luciferase reporter system. Then, mimics and inhibitors of novel-m0230-3p were transfected in vitro into SCs, respectively. A further analysis using qRT-PCR, immunofluorescence (IF), and Western blotting confirmed that the expression of cell adhesion and tight-junction-related proteins Occludin and ZO-1 both showed changes. Specifically, both the mRNA and protein expression levels of Occludin and ZO-1 in SCs decreased after transfection with the novel-m0230-3p mimics, while they increased after transfection with the inhibitors, with p < 0.05. These were achieved via the CSF1/CSF1R/Ras signaling pathway. In summary, our findings indicate a negative miRNA-mRNA regulatory network involving the CSF1/CSF1R/Ras signaling pathway in yak SCs. These results provide new insights into the molecular mechanisms of CSF1 and suggest that novel-m0230-3p and its target protein CSF1 could be used as potential therapeutic targets for yak cryptorchidism.

Per- and polyfluoroalkyl substances (PFASs) are a family of "forever chemicals" including perfluorooctane sulfonate (PFOS). These toxic chemicals do not break down in the environment or in our bodies. In the human body, PFOS and perfluoroctanoic acid (PFOA) have a half-life ( T 1/2 ) of about 4-5 yr so low daily consumption of these chemicals can accumulate in the human body to a harmful level over a long period. Although the use of PFOS in consumer products was banned in the United States in 2022/2023, this forever chemical remains detectable in our tap water and food products. Every American tested has a high level of PFAS in their blood (https://cleanwater.org/pfas-forever-chemicals). In this report, we used a Sertoli cell blood-testis barrier (BTB) model with primary Sertoli cells cultured in vitro with an established functional tight junction (TJ)-permeability barrier that mimicked the BTB in vivo. Treatment of Sertoli cells with PFOS was found to perturb the TJ-barrier, which was the result of cytoskeletal disruption across the cell cytoplasm, disrupting actin and microtubule polymerization. These changes thus affected the proper localization of BTB-associated proteins at the BTB. Using RNA-Seq transcriptome profiling, bioinformatics analysis, and pertinent biochemical and cell biology techniques, it was discovered that PFOS -induced Sertoli cell toxicity through the c-Jun N-terminal kinase (JNK; also known as stress-activated protein kinase, SAPK) and its phosphorylated/active form p-JNK signaling pathway. More importantly, KB-R7943 mesylate (KB), a JNK/p-JNK activator, was capable of blocking PFOS-induced Sertoli cell injury, supporting the notion that PFOS-induced cell injury can possibly be therapeutically managed. NEW & NOTEWORTHY PFOS induces Sertoli cell injury, including disruption of the 1 ) blood-testis barrier function and 2 ) cytoskeletal organization, which, in turn, impedes male reproductive function. These changes are mediated by JNK/p-JNK signaling pathway. However, the use of KB-R7943, a JNK/p-JNK activator was capable of blocking PFOS-induced Sertoli cell injury, supporting the possibility of therapeutically managing PFOS-induced reproductive dysfunction.

Ribavirin, an antiretroviral agent targeting the hepatitis C virus, causes male reproductive toxicity. This study investigated the mechanism of ribavirin transport at the blood-testis barrier (BTB). In vivo mouse integration plot analysis after intravenous administration revealed that the net influx clearance of [ 3 H]ribavirin in the testis was 3.6-fold greater than that of [ 14 C]D-mannitol, a paracellular transport marker, implying transcellular transport of ribavirin across the BTB. Moreover, [ 3 H]ribavirin uptake by TM4 cells, mouse-derived Sertoli cells, was time- and concentration-dependent, with a K m value of 2.49 mM. S-[(4-nitrophenyl)methyl]-6-thioinosine, an inhibitor of Na + -independent equilibrative nucleoside transporters (ENTs), strongly inhibited the [ 3 H]ribavirin uptake by TM4 cells at 100 µM. Compared to the uptake of [ 3 H]adenosine, a typical endogenous nucleoside, [ 3 H]ribavirin uptake was relatively similar to ENT2 transport. [ 3 H]Ribavirin uptake was also observed in mouse ENT2-expressing Xenopus laevis oocytes, and gene silencing via the transfection of ENT2 small interfering RNA significantly reduced the [ 3 H]ribavirin transport into TM4 cells by 13%. Taken together, these results suggest that ENT2 partially contributes to ribavirin transport at the BTB., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)