Male infertility has become a global concern, accounting for 20-70% of infertility. Dysfunctional spermatogenesis is the most common cause of male infertility; thus, treating abnormal spermatogenesis may improve male infertility and has attracted the attention of the medical community. Mitochondria are essential organelles that maintain cell homeostasis and normal physiological functions in various ways, such as mitochondrial oxidative phosphorylation (OXPHOS). Mitochondrial OXPHOS transmits electrons through the respiratory chain, synthesizes adenosine triphosphate (ATP), and produces reactive oxygen species (ROS). These mechanisms are vital for spermatogenesis, especially to maintain the normal function of testicular Sertoli cells and germ cells. The disruption of mitochondrial OXPHOS caused by external factors can result in inadequate cellular energy supply, oxidative stress, apoptosis, or ferroptosis, all inhibiting spermatogenesis and damaging the male reproductive system, leading to male infertility. This article summarizes the latest pathological mechanism of mitochondrial OXPHOS disorder in testicular Sertoli cells and germ cells, which disrupts spermatogenesis and results in male infertility. In addition, we also briefly outline the current treatment of spermatogenic malfunction caused by mitochondrial OXPHOS disorders. However, relevant treatments have not been fully elucidated. Therefore, targeting mitochondrial OXPHOS disorders in Sertoli cells and germ cells is a research direction worthy of attention. We believe this review will provide new and more accurate ideas for treating male infertility.
Male ; Humans ; Infertility, Male/metabolism* ; Oxidative Phosphorylation ; Mitochondria/metabolism* ; Spermatogenesis/physiology* ; Sertoli Cells/metabolism* ; Oxidative Stress/physiology* ; Animals ; Reactive Oxygen Species/metabolism*

One major challenge in male factor infertility is nonobstructive azoospermia (NOA), which is characterized by spermatozoa-deficient semen without physical duct blockage. This review offers a thorough overview of the histopathology of the testes in NOA cases, clarifying its complex etiology and emphasizing the possible value of histopathology inspection for both diagnosis and treatment. Variable histopathological findings have been linked to NOA, such as tubular hyalinization, Sertoli cell-only syndrome, hypospermatogenesis, and germ cell arrest. Understanding the pathophysiology and forecasting the effectiveness of treatment are further enhanced by both morphometric and ultrastructural analyses. The potential significance of testicular biopsy in forecasting reproductive outcomes is assessed, especially concerning assisted reproductive technologies like intracytoplasmic sperm injection (ICSI). Besides, testicular microlithiasis, serum hormone profiles, and testicular size are investigated concerning NOA histopathology. It is concluded that understanding the histopathological patterns in NOA is crucial for its accurate diagnosis and appropriate management. Further research is still warranted to improve understanding of the complex pathophysiology underlying NOA.
Humans ; Azoospermia/etiology* ; Male ; Testis/pathology* ; Sertoli Cell-Only Syndrome/pathology* ; Sperm Injections, Intracytoplasmic

Testicular histology based on testicular biopsy is an important factor for determining appropriate testicular sperm extraction surgery and predicting sperm retrieval outcomes in patients with azoospermia. Therefore, we developed a deep learning (DL) model to establish the associations between testicular grayscale ultrasound images and testicular histology. We retrospectively included two-dimensional testicular grayscale ultrasound from patients with azoospermia (353 men with 4357 images between July 2017 and December 2021 in The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China) to develop a DL model. We obtained testicular histology during conventional testicular sperm extraction. Our DL model was trained based on ultrasound images or fusion data (ultrasound images fused with the corresponding testicular volume) to distinguish spermatozoa presence in pathology (SPP) and spermatozoa absence in pathology (SAP) and to classify maturation arrest (MA) and Sertoli cell-only syndrome (SCOS) in patients with SAP. Areas under the receiver operating characteristic curve (AUCs), accuracy, sensitivity, and specificity were used to analyze model performance. DL based on images achieved an AUC of 0.922 (95% confidence interval [CI]: 0.908-0.935), a sensitivity of 80.9%, a specificity of 84.6%, and an accuracy of 83.5% in predicting SPP (including normal spermatogenesis and hypospermatogenesis) and SAP (including MA and SCOS). In the identification of SCOS and MA, DL on fusion data yielded better diagnostic performance with an AUC of 0.979 (95% CI: 0.969-0.989), a sensitivity of 89.7%, a specificity of 97.1%, and an accuracy of 92.1%. Our study provides a noninvasive method to predict testicular histology for patients with azoospermia, which would avoid unnecessary testicular biopsy.
Humans ; Male ; Azoospermia/diagnostic imaging* ; Deep Learning ; Testis/pathology* ; Retrospective Studies ; Adult ; Ultrasonography/methods* ; Sperm Retrieval ; Sertoli Cell-Only Syndrome/diagnostic imaging*

Researchers commonly use cyclization recombination enzyme/locus of X-over P1 (Cre/loxP) technology-based conditional gene knockouts of model mice to investigate the functional roles of genes of interest in Sertoli and Leydig cells within the testis. However, the shortcomings of these genetic tools include high costs, lengthy experimental periods, and limited accessibility for researchers. Therefore, exploring alternative gene silencing techniques is of great practical value. In this study, we employed adeno-associated virus (AAV) as a vector for gene silencing in Sertoli and Leydig cells. Our findings demonstrated that AAV serotypes 1, 8, and 9 exhibited high infection efficiency in both types of testis cells. Importantly, we discovered that all three AAV serotypes exhibited exquisite specificity in targeting Sertoli cells via tubular injection while demonstrating remarkable selectivity in targeting Leydig cells via interstitial injection. We achieved cell-specific knockouts of the steroidogenic acute regulatory ( Star ) and luteinizing hormone/human chorionic gonadotropin receptor (Lhcgr) genes in Leydig cells, but not in Sertoli cells, using AAV9-single guide RNA (sgRNA)-mediated gene editing in Rosa26-LSL-Cas9 mice. Knockdown of androgen receptor ( Ar ) gene expression in Sertoli cells of wild-type mice was achieved via tubular injection of AAV9-short hairpin RNA (shRNA)-mediated targeting. Our findings offer technical approaches for investigating gene function in Sertoli and Leydig cells through AAV9-mediated gene silencing.
Animals ; Male ; Leydig Cells/metabolism* ; Mice ; Dependovirus/genetics* ; Sertoli Cells/metabolism* ; Gene Silencing ; Genetic Vectors ; Testis/cytology*

Sertoli cells play an important role in the process of spermatogenesis, and the abnormalities in spermatogenesis are closely related to disruptions in glycolipid metabolism. The metabolic environment of Sertoli cells is hypoxic, with glycolysis and fatty acid β-oxidation being the primary metabolic pathways. In Sertoli cells, glycolysis produces lactate to provide energy for spermatogenic cells, while fatty acid β-oxidation generates ATP. Currently, the relationship between glycolipid metabolism in Sertoli cells and spermatogenic cell development, as well as the interplay between glucose and lipid metabolism remain unclear. Various hormones, including sex hormones, can affect glucose metabolism in Sertoli cells by endocrine regulation. The activation or inhibition of signaling pathways such as AMPK, mTOR, and Akt can alter the expression levels of glycolysis-related transporter genes and the synthesis of fatty acids, thereby affecting glycolipid metabolism in Sertoli cells. Some transcription factors such as PPARγ can regulate downstream fatty acid metabolism-related genes by directly binding to their response elements and promoting the oxidation of fatty acids in Sertoli cells. In this article we elaborate on the key factors influencing glycolipid metabolism in Sertoli cells and their interconnections, as well as their potential clinical implications, offering new insights for precisely targeted treatments of male infertility.
Sertoli Cells/cytology* ; Male ; Glycolipids/metabolism* ; Spermatogenesis/physiology* ; Humans ; Lipid Metabolism ; Animals ; Fatty Acids/metabolism* ; Signal Transduction ; Glycolysis

Objective： Varicocele (VC) induces male infertility by mediating changes in the testicular microenvironment, in which testicular hypoxia and high-pressure are important pathological conditions. This study aims to compare the mouse spermatogenesis (GC-2spd) cells and Sertoli (TM4) cells of mouse testis after hypoxic modeling and hypoxic and high-pressure combined modeling, and to explore the feasibility of establishing a hypoxic and high-pressure combined cell model. Methods： On the basis of cell hypoxia induced by CoCl2, the complex model of testicular cell hypoxia and high pressure was constructed by changing the osmotic pressure of GC-2 and TM4 cell medium with a high concentration of NaCl solution. After selecting the intervention concentration of CoCl2 by MTT test and detecting the expression level of HIF-1α for the determination of the optimal osmotic pressure conditions of the cell model, the cells were divided into normal group, hypoxia model group and composite model group. And the levels of OS, programmed cell death, inflammatory factors, and the expression levels of pyroptosis-related proteins were compared between the normal group and the groups with different modeling methods. Results： The optimal intervention concentration of CoCl2 in GC-2 and TM4 cells was 150 and 250μmol/L, respectively, and the expression of HIF-1α was the highest in both cells under osmotic pressure of 500 mOsmol/kg (P<0.05). Compared with the normal group, the SOD levels of GC-2 and TM4 cells decreased (all P<0.05), CAT level decreased (all P<0.05), and MDA level increased (all P<0.01), and the OS level of GC-2 and TM4 cells was more obvious than that of the hypoxia model group (all P<0.05). Compared with the normal group, apoptosis occurred in GC-2 and TM4 cells after composite modeling (all P<0.05). Compared with the normal group, the mRNA expressions of IL-1β, IL-18, TNF-α and COX-2 in GC-2 and TM4 cells significantly increased (P<0.01) and higher than those in hypoxia model group (P<0.05) and induced pyroptosis (P<0.01). The expression level of GSDMD increased (P<0.05). Conclusion： The cell model with hypoxia and high pressure combined modeling can not only induce oxidative stress and apoptosis of cells better than that with hypoxia alone, but also further cause inflammatory response damage and pyroptosis, which simulates the changes of testis microenvironment mediated by hypoxia and high pressure combined conditions in VC. This cell model can be used for studying the pathogenesis of VC-associated male infertility, evaluating drug efficacy, and exploring pharmacological mechanisms.
Male ; Animals ; Varicocele/pathology* ; Mice ; Testis/metabolism* ; Hypoxia-Inducible Factor 1, alpha Subunit/metabolism* ; Cell Hypoxia ; Cobalt ; Sertoli Cells/metabolism* ; Osmotic Pressure ; Spermatogenesis ; Cellular Microenvironment ; Infertility, Male ; Disease Models, Animal

A Sertoli-Leydig cell tumor (SLCT) is an extremely rare type of sex cord stromal tumor of the ovary, which mainly secretes testosterone, thus manifestations of hyperandrogenism commonly appear. This paper shall discuss a case of a postmenopausal woman who presented with pelvic organ prolapse, large left ovarian cyst and mild signs of hyperandrogenism. She underwent total abdominal hysterectomy with bilateral salpingo-oophorectomy, which on microscopic examination of the specimens, revealed a Mature cystic teratoma on the left ovary and an incidental finding of a well-differentiated SLCT, on the grossly normal-looking ovary. This histopathologic diagnosis of SLCT explained the patient’s hyperandrogenic characteristics. Authors likewise discussed the proper management of SLCT, including immunostaining and need for adjuvant chemotherapy.
Sertoli-Leydig Cell Tumor

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