Mammalian testis exhibits remarkably high transcriptome complexity, and spermatogenesis undergoes two periods of transcriptional cessation. These make the RNA-binding proteins (RBPs) the utmost importance during male germ cell development. Heterogeneous nuclear ribonucleoproteins (hnRNPs) are a large family of RBPs implicated in many steps of RNA processing; however, their roles in spermatogenesis are largely unknown. Here, we investigated the expression pattern of 12 hnRNP family members in mouse testes and found that most detected members are highly expressed in the testis. Furthermore, we found that most of the detected hnRNP proteins (hnRNPD, hnRNPK, hnRNPQ, hnRNPU, and hnRNPUL1) display the highest signals in the nuclei of pachytene spermatocytes, round spermatids, and Sertoli cells, whereas hnRNPE1 exclusively concentrates in the manchette of elongating spermatids. The expression of these hnRNP proteins showed both similarities and specificity, suggesting their diverse roles in spermatogenesis.
Mice ; Male ; Animals ; Heterogeneous-Nuclear Ribonucleoproteins/metabolism* ; Spermatogenesis/genetics* ; Testis/metabolism* ; Spermatids/metabolism* ; Sertoli Cells ; Spermatocytes/metabolism* ; RNA-Binding Proteins/metabolism* ; Mammals

Microcystin-leucine arginine (MC-LR), a potentially carcinogenic toxin, is produced by Cyanobacteria such as Microcystis and Ananabacteria during water bloom. Increasing evidence demonstrated that MC-LR induces male reproductive toxicity, mainly by inducing germ cell apoptosis, destroying cell cytoskeleton, interfering with DNA damage repair pathway, and damaging blood-testicular barrier (BTB), which eventually lead to male sterility. Testicular Sertoli cells are the somatic cells that directly contact with spermatogenic cells in seminiferous tubules. They not only regulate immune response to maintain testicular immune homeostasis by secreting a variety of cytokines and immunosuppressive factors, but also provide the protective effects of spermatogenic cells by forming BTB. MC-LR induces inflammation and apoptosis of Sertoli cells, and destroys the integrity of the BTB, and then causes spermatogenesis dysfunction.
Male ; Humans ; Sertoli Cells ; Leucine/pharmacology* ; Arginine/pharmacology* ; Microcystins/metabolism* ; Immunity

Klinefelter syndrome (KS) is the most common genetic cause of human male infertility. However, the effect of the extra X chromosome on different testicular cell types remains poorly understood. Here, we profiled testicular single-cell transcriptomes from three KS patients and normal karyotype control individuals. Among the different somatic cells, Sertoli cells showed the greatest transcriptome changes in KS patients. Further analysis showed that X-inactive-specific transcript ( XIST ), a key factor that inactivates one X chromosome in female mammals, was widely expressed in each testicular somatic cell type but not in Sertoli cells. The loss of XIST in Sertoli cells leads to an increased level of X chromosome genes, and further disrupts their transcription pattern and cellular function. This phenomenon was not detected in other somatic cells such as Leydig cells and vascular endothelial cells. These results proposed a new mechanism to explain why testicular atrophy in KS patients is heterogeneous with loss of seminiferous tubules but interstitial hyperplasia. Our study provides a theoretical basis for subsequent research and related treatment of KS by identifying Sertoli cell-specific X chromosome inactivation failure.
Animals ; Humans ; Male ; Female ; Sertoli Cells/metabolism* ; Klinefelter Syndrome/genetics* ; Endothelial Cells ; Testis/metabolism* ; X Chromosome/metabolism* ; Mammals/genetics*

The testis is pivotal for male reproduction, and its progressive functional decline in aging is associated with infertility. However, the regulatory mechanism underlying primate testicular aging remains largely elusive. Here, we resolve the aging-related cellular and molecular alterations of primate testicular aging by establishing a single-nucleus transcriptomic atlas. Gene-expression patterns along the spermatogenesis trajectory revealed molecular programs associated with attrition of spermatogonial stem cell reservoir, disturbed meiosis and impaired spermiogenesis along the sequential continuum. Remarkably, Sertoli cell was identified as the cell type most susceptible to aging, given its deeply perturbed age-associated transcriptional profiles. Concomitantly, downregulation of the transcription factor Wilms' Tumor 1 (WT1), essential for Sertoli cell homeostasis, was associated with accelerated cellular senescence, disrupted tight junctions, and a compromised cell identity signature, which altogether may help create a hostile microenvironment for spermatogenesis. Collectively, our study depicts in-depth transcriptomic traits of non-human primate (NHP) testicular aging at single-cell resolution, providing potential diagnostic biomarkers and targets for therapeutic interventions against testicular aging and age-related male reproductive diseases.
Animals ; Male ; Testis ; Sertoli Cells/metabolism* ; Transcriptome ; Spermatogenesis/genetics* ; Primates ; Aging/genetics* ; Stem Cells

During spermatogenesis, developing germ cells that lack the cellular ultrastructures of filopodia and lamellipodia generally found in migrating cells, such as macrophages and fibroblasts, rely on Sertoli cells to support their transport across the seminiferous epithelium. These include the transport of preleptotene spermatocytes across the blood-testis barrier (BTB), but also the transport of germ cells, in particular developing haploid spermatids, across the seminiferous epithelium, that is to and away from the tubule lumen, depending on the stages of the epithelial cycle. On the other hand, cell junctions at the Sertoli cell-cell and Sertoli-germ cell interface also undergo rapid remodeling, involving disassembly and reassembly of cell junctions, which, in turn, are supported by actin- and microtubule-based cytoskeletal remodeling. Interestingly, the underlying mechanism(s) and the involving biomolecule(s) that regulate or support cytoskeletal remodeling remain largely unknown. Herein, we used an in vitro model of primary Sertoli cell cultures that mimicked the Sertoli BTB in vivo overexpressed with the ribosomal protein S6 (rpS6, the downstream signaling protein of mammalian target of rapamycin complex 1 [mTORC1]) cloned into the mammalian expression vector pCI-neo, namely, quadruple phosphomimetic and constitutively active mutant of rpS6 (pCI-neo/p-rpS6-MT) versus pCI-neo/rpS6-WT (wild-type) and empty vector (pCI-neo/Ctrl) for studies. These findings provide compelling evidence that the mTORC1/rpS6 signal pathway exerted its effects to promote Sertoli cell BTB remodeling. This was mediated through changes in the organization of actin- and microtubule-based cytoskeletons, involving changes in the distribution and/or spatial expression of actin- and microtubule-regulatory proteins.
Actins/metabolism* ; Animals ; Blood-Testis Barrier/metabolism* ; Cells, Cultured ; Male ; Mechanistic Target of Rapamycin Complex 1/metabolism* ; Permeability ; Rats ; Ribosomal Protein S6/metabolism* ; Seminiferous Epithelium/metabolism* ; Sertoli Cells/metabolism* ; Signal Transduction/physiology*

ObjectiveTo study the expression of CLAUDIN-11 in the testis tissue of non-obstructive azoospermia (NOA) patients with different severities and investigate its clinical significance.

METHODSSixty-two NOA patients were divided into a hypospermatogenesis (HS) group (n = 30) and a Sertoli cell only syndrome (SCO) group (n =32). The expression of CLAUDIN-11 in the testicular tissue of the patients was detected by immunohistochemistry, that of CLAUDIN-11 mRNA determined by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), and the levels of serum reproductive hormones measured by chemiluminescent immunoassay.

RESULTSImmunohistochemistry showed that the expression of CLAUDIN-11 was mainly in the cytoplasm of the Sertoli cells around the seminiferous tubule wall in the HS group, but diffusely distributed in the membrane of the Sertoli cells in the SCO group. RT-qPCR revealed a significantly lower expression of CLAUDIN-11 mRNA in the HS than in the SCO group (0.008 ± 0.001 vs 0.013 ± 0.002, t = 10.616, P<0.01). The level of serum luteotropic hormone (LH) was also markedly lower in the HS than in the SCO group (［3.62 ± 1.34］ vs ［4.96 ± 3.10］ IU/L, P<0.05) and so was that of follicle-stimulating hormone (FSH) (［5.36 ± 2.80］ vs ［10.65 ± 9.18］ IU/L, P<0.05).

CONCLUSIONSThe up-regulated expression of CLAUDIN-11 in Sertoli cells may play an important role in the development and progression of spermatogenic dysfunction in NOA patients.

Azoospermia ; genetics ; metabolism ; Claudins ; metabolism ; Follicle Stimulating Hormone ; metabolism ; Humans ; Male ; Oligospermia ; genetics ; metabolism ; RNA, Messenger ; metabolism ; Seminiferous Tubules ; metabolism ; Sertoli Cell-Only Syndrome ; genetics ; metabolism ; Sertoli Cells ; metabolism ; Spermatogenesis ; Testis ; metabolism

Inhibin B, a glycoprotein produced predominantly by Sertoli cells and preferentially suppressing the production and secretion of follicle-stimulating hormone (FSH) in the pituitary, is closely related to spermatogenesis. Varicocele is the abnormal dilatation and tortuosity of the pampiniform plexus veins, which may contribute to spermatogenic dysfunction and male infertility. More and more evidence has shown that the level of serum inhibin B is negatively correlated with the severity of varicocele. Determination of the inhibin B level may help assess the severity of spermatogenic dysfunction of the patient and predict the outcomes of varicocele repair and therefore has a potential application value in the diagnosis and treatment of varicocele.
Follicle Stimulating Hormone ; metabolism ; Humans ; Infertility, Male ; blood ; etiology ; Inhibins ; blood ; Male ; Sertoli Cells ; Spermatogenesis ; Varicocele ; blood

At present, there is no reliable in vitro assembled prepubertal testis-like biomimetic organ culture system designed to assess the functional effects of human gonadotropins on Sertoli and Leydig cells. Spermatogenesis is regulated by endocrine, paracrine, and juxtacrine factors (testicular cross-talk), mainly orchestrated by gonadotropins such as luteinizing hormone (LH) and follicle-stimulating hormone (FSH) that play a pivotal role by stimulating Leydig and Sertoli cells, respectively. The aim of our study was to set up an in vitro prepubertal porcine bioengineered construct as a new model for experimental studies on reassembled Sertoli and Leydig cells. We have evaluated Sertoli and Leydig cells obtained from 15- to 20-day-old neonatal pig testes in terms of purity and function. Subsequently, purified Sertoli and enriched Leydig cells were subjected to coincubation to obtain an in vitro prepubertal porcine testis-like culture system. We performed enzyme-linked immunosorbent assay (ELISA) for anti-Müllerian hormone (AMH), inhibin B, and testosterone secretion in the medium, and Real-Time PCR analysis of AMH, inhibin B, FSH-r, aromatase, LHr, and 3β-HSD mRNA expression levels. This in vitro testis-like system was highly responsive to the effects of human gonadotropins and testosterone. AMH mRNA expression and secretion declined, and inhibin-B increased, while FSH-receptor expression was downregulated upon FSH/LH exposure/treatment. Finally, the production of testosterone was increased selectively upon LH treatment. In summary, our proposed model could help to better determine the action of human gonadotropins on Sertoli and Leydig cells. The potential usefulness of the system for shedding light into male infertility-related issues is evident.
3-Hydroxysteroid Dehydrogenases/metabolism* ; Animals ; Animals, Newborn ; Anti-Mullerian Hormone/metabolism* ; Aromatase/metabolism* ; Cell Culture Techniques ; Enzyme-Linked Immunosorbent Assay ; Follicle Stimulating Hormone/pharmacology* ; Hormones/pharmacology* ; In Vitro Techniques ; Inhibins/metabolism* ; Leydig Cells/metabolism* ; Luteinizing Hormone/pharmacology* ; Male ; Models, Biological ; Real-Time Polymerase Chain Reaction ; Receptors, FSH/metabolism* ; Receptors, LH/metabolism* ; Sertoli Cells/metabolism* ; Swine ; Testis/metabolism* ; Testosterone/metabolism*

Objective: To explore the role of TGF-β1 in the proliferation and apoptosis of Sertoli cells and its effect on the expressions of tight junction-related proteins and genes in rats. METHODS: Rat Sertoli cells were isolated in vitro, primarily cultured, and divided into groups A (blank control), B (TGF-β1 receptor blocker), C (TGF-β1), and D (TGF-β1 + receptor blocker). The proliferation and apoptosis of the cells were detected by CCK-8 and flow cytometry, respectively. After establishment of the dual-chamber model for the primary culture of Sertoli cells, the trans-epithelia electrical resistance (TER) value was measured and the relative expressions of Occludin, ZO-1 and Claudin Ⅱ determined by RT-PCR and Western blot. RESULTS: The OD value of the proliferation of the Sertoli cells was markedly higher in group C than in groups A and D (0.79 ± 0.04 vs 0.66 ± 0.05 and 0.68 ± 0.02, P<0.05), with statistically significant differences among the four groups (F = 5.05, P <0.05). However, no remarkable difference with found among the four groups in the apoptosis rate of the cells (F = 1.13, P >0.05). The TER value was dramatically decreased in group C as compared with groups A and D (［176.37 ± 16.61］ vs ［281.42 ± 9.83］ and ［254.37 ± 13.55］ /cm2, P<0.01), with statistically significant differences among the four groups (F = 38.99, P<0.01). There were no remarkable differences among the four groups in the mRNA expressions of ZO-1 and Claudin Ⅱ (F = 0.49 and 0.93, P>0.05) or their protein expressions (F = 0.28 and 1.31, P>0.05). Both the mRNA and protein expressions of Occludin were markedly lower in group C than in A and D (P<0.01 and P<0.05), with statistically significant differences among the four groups (F = 6.86 and 6.87, P<0.01). CONCLUSIONS TGF-β1 can promote the proliferation of Sertoli cells in rats and act on the tight junction of the cells by regulating the expression of Occludin.
Animals ; Apoptosis ; Cell Proliferation ; Cells, Cultured ; Claudin-2 ; metabolism ; Male ; Occludin ; metabolism ; RNA, Messenger ; Rats ; Sertoli Cells ; cytology ; physiology ; Tight Junction Proteins ; metabolism ; Tight Junctions ; genetics ; metabolism ; Transforming Growth Factor beta1 ; physiology ; Zonula Occludens-1 Protein ; metabolism

Objective: To explore the mechanisms of oxidative stress-induced damage to TM4 Sertoli cells in the mouse using metabolomics techniques based on gas chromatography-mass spectrometry (GC-MS). METHODS: We established the model of oxidative stress-induced damage to mouse TM4 Sertoli cells by treatment with H₂O₂. Then, we detected the survival rate and apoptosis rate of the TM4 cells by MTT and flow cytometry respectively, measured the concentration of ROS in the TM4 cells with the DCFH-DA fluorescent probe, and determined the levels of endogenous metabolites in the TM4 cells by GC-MS after H₂O₂ intervention. RESULTS: After 2 hours of treatment with H₂O₂ at 600 μmol/L, the survival rate of the TM4 cells was reduced to about 50%, and the total apoptosis rates in the low- (100 μmol/L), medium- (300 μmol/L), and high-dose (600 μmol/L) groups were (19.45 ± 0.53), (20.12 ± 0.58), and (37.13 ± 0.35)%, respectively, increased in a dose-dependent manner as compared with (10.28 ± 0.35)% in the blank control (P <0.05). The ROS level was significantly higher in the medium- and high-dose groups than in the control (［1.27 ± 0.10］ vs ［1.00 ± 0.08］%, P <0.05; ［2.07 ± 0.09］ vs ［1.00 ± 0.08］%, P <0.01). Compared with the blank control group, the high-dose H₂O₂ group showed evident changes in the levels of amino acid and carbohydrates in the TM4 cells, more significantly in the levels of valine, norvaline, leucine, glutamic acid, arabinose, fructose, and 5-serotonin cholesterol (VIP >1, P <0.05). CONCLUSIONS Oxidative stress-induced damage and apoptosis of TM4 Sertoli cells are closely associated with the metabolism of amino acid, glucose, and energy in the cells.
Amino Acids ; metabolism ; Animals ; Apoptosis ; Cell Survival ; drug effects ; Dose-Response Relationship, Drug ; Energy Metabolism ; Gas Chromatography-Mass Spectrometry ; Glucose ; metabolism ; Hydrogen Peroxide ; pharmacology ; Male ; Metabolomics ; Mice ; Oxidative Stress ; Reactive Oxygen Species ; metabolism ; Sertoli Cells ; drug effects ; metabolism ; Time Factors