Introduction: Leydig cells (LCs) are the principal source of testosterone in males, underpinning male reproductive health and androgendependent physiology. Precise isolation of viable human LCs is essential for mechanistic steroidogenesis research and cell-based therapeutic development. Existing protocols rely on density-gradient centrifugation, which is technically demanding and often compromises yield and viability. Here, we describe a simplified density-gradient-free approach using differential adhesion to enrich functional human LCs from testicular tissue. Methodology: Human testicular fragments (~5 mm³) were minced and enzymatically digested with collagenase IV (2 mg/mL) at 37°C for 20 min under gentle agitation (100 RPM). The suspension was filtered (45 µm) and plated onto poly-L-lysine-coated T25 flasks. After 24 hours, non-adherent cells were removed by PBS washing. Viability exceeded 90% by trypan blue exclusion. Cells were maintained in DMEM/F12 with 10% FBS, 1% Antibiotic-Antimycotic, and 10 ng/mL luteinizing hormone (LH) to preserve the mature LC phenotype. Characterization employed immunofluorescence and flow cytometry using antibodies against SF-1, StAR, LHCGR, PDGFRA, and TEM-1. Testosterone secretion was quantified by ELISA under basal conditions and LH-stimulated conditions (10 ng/mL). Results: The protocol yielded ~1.25 × 10⁶ LCs per gram of tissue with >80% purity. Adherent HLCs displayed dense cytoplasmic lipid granules and intercellular networks consistent with active steroidogenesis. Flow cytometry confirmed 84.7% StAR⁺ cells, indicative of a robust steroidogenic population. A distinct progenitor subpopulation (PDGFRα⁺/TEM-1⁺) comprising ~28% of primary cultures, suggests retention of regenerative capacity. Basal testosterone secretion averaged 8.88 ng/mL per 24 hours, confirming preserved functional activity post-isolation. Conclusion This differential-adhesion protocol efficiently isolates functional human LCs without density-gradient media. Multimodal validation integrating immunofluorescence, flow cytometry, and ELISA confirms both phenotypic identity and steroidogenic competence, providing a reproducible and accessible platform for LC research and translational applications in male hypogonadism and androgen replacement.
Leydig Cells

Introduction: Functioning gonadotroph adenomas, also known as follicle-stimulating hormone (FSH)-secreting pituitary adenomas (FSH-omas), are rare pituitary tumors characterized by the secretion of biologically active FSH. Unlike the more common clinically nonfunctioning gonadotroph adenomas, these tumors produce endocrine manifestations due to excessive FSH secretion. Clinical presentation may result from local mass effects such as headache, visual disturbances due to optic chiasmal compression, or from hormonal activity affecting reproductive function. The endocrine manifestations vary between males and females and can lead to diagnostic challenges. Cases: We report two patients with functioning gonadotroph adenomas presenting with distinct clinical manifestations. The first case involved a 23-year-old female who presented with secondary amenorrhea for 4 years, accompanied by personality changes. Abdominal ultrasound demonstrated bilaterally enlarged multicystic ovaries suggestive of ovarian hyperstimulation, which subsequently regressed postoperatively. Biochemical evaluation revealed inappropriately elevated FSH levels (3.5-fold increase), with suppressed luteinizing hormone (LH) and markedly elevated estradiol levels (11-fold increase). Pituitary magnetic resonance imaging (MRI) identified a large sellar–suprasellar mass with mass effect, consistent with a pituitary macroadenoma. The second case involved a 68-year-old male who presented with progressively worsening vision over 2 years. Hormonal evaluation demonstrated elevated FSH levels (4.5-fold increase), with relatively normal LH and low testosterone levels. Pituitary MRI revealed a sellar mass consistent with a pituitary adenoma. Both patients subsequently underwent pterional craniotomy with tumor debulking. Histopathological examination confirmed gonadotroph adenomas, with positive immunohistochemical staining for FSH. Conclusion Functioning gonadotroph adenomas are rare and may present with diverse clinical features related to gonadal hyperstimulation or mass effects. Early recognition of the characteristic hormonal profile and radiological findings is crucial for diagnosis and appropriate management. These cases highlight the importance of considering functioning gonadotroph adenoma in patients presenting with unexplained gonadal hyperstimulation or atypical reproductive hormonal profiles.
Gonadotrophs ; Adenoma

Introduction: Functioning gonadotroph adenomas (FGPAs) in males are rare and typically present with macroorchidism. In elderly patients, the presentation can be confounding. This case illustrates a unique scenario where a pituitary tumor masked the physiological decline of testosterone, maintaining the patient’s stamina despite Introduction testicular involution. Case: A 65-year-old male was referred for a pituitary macroadenoma (10.7 × 10.6 × 11.4 mm) following progressive headaches. Remarkably, the patient denied symptoms of andropause; his stamina, mood, and libido were wellpreserved. Investigations revealed elevated folliclestimulating hormone (15.42 mIU/mL) and luteinizing hormone (12.1 mIU/mL) with normal testosterone levels. Scrotal ultrasound showed bilateral testicular involution (right: 8.66 mL, left: 7.21 mL), contradicting the expected macroorchidism of FGPA. Although the patient felt his vision was normal, a confrontation test revealed temporal visual field defects, indicating chiasmatic compression. This case presents a striking clinical discordance where tumorinduced gonadotropin hypersecretion provided a supraphysiological drive to the involuting testes, maintaining testosterone levels and masking andropause. The primary indication for transsphenoidal surgery is the Introduction evidence of visual field defects. However, removing the adenoma will abruptly eliminate this “hormonal drive.” Postoperative management will focus on rigorous hormonal monitoring. Testosterone replacement therapy is not immediately indicated; rather, it will be carefully planned only if postoperative evaluations demonstrate a significant hormonal decline accompanied by symptomatic hypogonadism. This tailored approach ensures that the benefits of intervention outweigh the potential risks in an elderly patient. Conclusion In elderly patients, FGPAs can mask age-related hormonal decline. In this case, clinicians must treat the patient, not just the tumor. Anticipating a potential decline in postoperative stamina is as crucial as the surgery itself. Comprehensive hormonal evaluation and a personalized approach to therapy are essential to preserve quality of life after the “masking” effect is removed.
Male ; Andropause ; Gonadotrophs

Introduction: Pituitary macroadenomas may present with mass effects, hypopituitarism, or hormone hypersecretion. Hyperprolactinemia, resulting from a prolactin-secreting tumor or stalk compression, typically suppresses gonadotropins. Thus, elevated follicle-stimulating hormone (FSH) and luteinizing hormone (LH) with low testosterone in this context are unusual. We report a macroprolactinoma with a clinically non-functioning gonadotroph adenoma. Case: A 69-year-old male presented with acute giddiness and headache while in Vietnam. He reported reduced libido but no visual symptoms or galactorrhea. Examination showed no neurological deficits, normal visual fields, and secondary sexual characteristics; bilateral testes volume of 25 mL. Magnetic resonance imaging (MRI) brain revealed a 1.6 × 2.2 × 2.1 cm pituitary macroadenoma compressing the optic chiasm and pituitary stalk. Initial pituitary evaluation demonstrated hyperprolactinemia (prolactin >200 µg/L; normal 2.4–13.1), central hypothyroidism (T4 6.8 pmol/L [7.8–14.4], thyroid-stimulating hormone 2.3 mIU/L [0.38–5.3]), elevated FSH (21.5 IU/L [1.2–19.2]) and LH (191 IU/L [1.24–8.62]), low testosterone (8.88 nmol/L), normal insulin-like growth factor 1 (IGF-1) (68 µg/L [46.5–191.9]), and cortisol 237 nmol/L. Cabergoline was initiated at 0.25 mg twice weekly and titrated to 1 mg twice weekly over 4 months, alongside levothyroxine 25 µg daily. Repeated MRI brain 2 months after cabergoline initiation showed a persistent macroadenoma (1.7 × 2.2 × 2.2 cm) with bilateral cavernous sinus extension. Prolactin decreased to <170 µg/L, central hypothyroidism persisted; levothyroxine was optimized, and hydrocortisone was initiated. At the 5-month follow-up, prolactin further improved to 57 µg/L. Central hypothyroidism and borderline adrenal function persisted, requiring continued replacement therapy. Testosterone remained low-normal (10.2 nmol/L) despite elevated FSH (15.4 IU/L) and LH (92 IU/L). Followup MRI and hormonal reassessment were planned in May 2026. Conclusion Profoundly elevated prolactin level >200 µg/L and response to cabergoline reflect true prolactinoma rather than stalk effect. Persistently low testosterone with discordant high FSH/LH suggests a non-functioning gonadotroph component producing biologically inactive gonadotropins. Definitive diagnosis requires histopathological confirmation, while serial biochemical and radiological follow-up guides management and clarifies tumor subtype.
Gonadotrophs ; Hyperprolactinemia

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*

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*

The patient, assigned female at birth and aged 1 year and 7 months, presented with clinical manifestations of 46,XY disorders of sex development. The external genitalia exhibited a severely undermasculinized phenotype. Laboratory tests and gonadal biopsy indicated poor Leydig cell function and good Sertoli cell function. Genetic testing revealed compound heterozygous mutations of c.867-2A>C and c.547G>A (p.G183R) in the LHCGR gene. The patient was ultimately diagnosed with type II Leydig cell hypoplasia. Type II Leydig cell hypoplasia presents a broad spectrum of clinical phenotypes, characterized by a lack of parallel function between Leydig cells and Sertoli cells, and significant individual variability in spermatogenesis and gender assignment. This condition should be considered when there is poor Leydig cell function but good development of Wolffian duct derivatives.
Female ; Humans ; Infant ; Disorder of Sex Development, 46,XY/genetics* ; Leydig Cells/pathology* ; Mutation ; Receptors, LH/genetics* ; Testis/abnormalities*

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: To comprehensively evaluate the effect of icariin in alleviating reproductive function damage (RFD) in male mice via in vitro and in vivo experiments. METHODS: We isolated Leydig cells from 60 KM male mice in vitro, and examined the toxic effect of icariin on the Leydig cells using Cell Counting Kit-8 (CCK-8). We equally randomized the mice into six groups: normal control, RFD model control (made by intraperitoneal injection of busulfan at 10 mg/kg combined with cyclophosphamide (CP) at 120 mg/kg), positive control, and low-, medium- and high-dose icariin. After modeling, we treated the mice in the positive control group with Wuziyanzong Pills and those in the low-, medium- and high-dose icariin groups by intragastrical administration of icariin at 20, 40 and 80 mg/kg-1, respectively, for 30 successive days. Then we obtained the weight and visceral coefficients of the reproductive organs, calculated the sperm count, observed the pathological changes in the testis tissue by HE staining, measured the serum testosterone (T) level by ELISA, determined the indexes of testicular oxidative stress and nitric oxide (NO) signaling pathway by colorimetric assay, and detected the expression levels of the pro-apoptotic genes Fas and Bax by qRT-PCR. RESULTS: CCK-8 assay confirmed that icariin had no toxic effect on the isolated Leydig cells of the mice, and could effectively reduce busulfan- and CP-induced cytotoxicity and promote the secretion of serum T. Icariin at 80 mg/kg significantly increased the visceral coefficient of the testis and promoted spermatogenesis (P<0.05), but had little effect on the visceral coefficient of the epididymis in the RFD model mice. Testicular histomorphometric observation revealed significantly improved testis structure, intact boundary membrane of seminiferous tubules and increased numbers of various types of spermatogenic cells of the model mice after treated with icariin. Compared with the mice in the model control group, those treated with high-dose icariin showed a significantly reduced content of malondialdehyde (MDA) (by 35.3%, P<0.01), elevated total antioxidant capacity (TAOC) and superoxide dismutase (T-SOD) activity (P<0.05), and decreased NO content and nitric oxide synthase (NOS) activity in the testis tissue (P<0.01). In addition, icariin exhibited an evident inhibitory effect on the expressions of the pro-apoptotic genes Bax and Fas. CONCLUSION Icariin can ameliorate oxidative stress-induced damage to the testicular function and protect spermatogenesis of male mice by elevating TAOC, decreasing NOS activity, inhibiting the NO level in the testis, and suppressing busulfan- and CP-induced apoptosis of testicular cells.
Animals ; Male ; Cyclophosphamide/adverse effects* ; Mice ; Busulfan/adverse effects* ; Flavonoids/pharmacology* ; Leydig Cells/drug effects* ; Oxidative Stress/drug effects* ; Testis/drug effects* ; Apoptosis/drug effects* ; Testosterone/blood*

Trophoblast cells serve as the foundation for placental development. We analyzed published multiomics sequencing data and found that trophoblast cells highly expressed RRS1 compared to primitive endoderm and epiblast. We used HTR-8/SVneo cells for further investigation, and Western blot and immunofluorescence staining confirmed that HTR-8/SVneo cells highly expressed RRS1. RRS1 was successfully knocked down in HTR-8/SVneo cells using siRNA. Using IncuCyte S3 live-cell analysis system based on continuous live-cell imaging and real-time data, we observed that proliferation, migration, and invasion abilities were all significantly decreased in RRS1-knockdown cells. RNA-seq revealed that knockdown of RRS1 affected the gene transcription, and upregulated pathways in extracellular matrix organization, DNA damage response, and intrinsic apoptotic signaling, downregulated pathways in embryo implantation, trophoblast cell migration, and wound healing. Differentially expressed genes were enriched in diseases related to placental development. Consistent with these findings, human chorionic villus samples collected from spontaneous abortion cases exhibited significantly reduced RRS1 expression compared to normal controls. Our results highlight the functional importance of RRS1 in human trophoblasts and suggest that its deficiency contributes to early pregnancy loss.
Humans ; Trophoblasts/physiology* ; Cell Movement/genetics* ; Cell Proliferation/genetics* ; Female ; Pregnancy ; Abortion, Spontaneous/metabolism* ; Cell Line ; Placentation/genetics*