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

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*

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*

OBJECTIVE: This study investigated the effects of bis (2-butoxyethyl) phthalate (BBOP) on the onset of male puberty by affecting Leydig cell development in rats. METHODS: Thirty 35-day-old male Sprague-Dawley rats were randomly allocated to five groups mg/kg bw per day that were gavaged for 21 days with BBOP at 0, 10, 100, 250, or 500 mg/kg bw per day. The hormone profiles; Leydig cell morphological metrics; mRNA and protein levels; oxidative stress; and AKT, mTOR, ERK1/2, and GSK3β pathways were assessed. RESULTS: BBOP at 250 and/or 500 mg/kg bw per day decreased serum testosterone, luteinizing hormone, and follicle-stimulating hormone levels mg/kg bw per day (P < 0.05). BBOP at 500 mg/kg bw per day decreased Leydig cell number mg/kg bw per day and downregulated Cyp11a1, Insl3, Hsd11b1, and Dhh in the testes, and Lhb and Fshb mRNAs in the pituitary gland (P < 0.05). The malondialdehyde content in the testis significantly increased, while Sod1 and Sod2 mRNAs were markedly down-regulated, by BBOP treatment at 250-500 mg/kg bw per day (P < 0.05). Furthermore, BBOP at 500 mg/kg bw per day decreased AKT1/AKT2, mTOR, and ERK1/2 phosphorylation, and GSK3β and SIRT1 levels mg/kg bw per day (P < 0.05). Finally, BBOP at 100 or 500 μmol/L induced ROS and apoptosis in Leydig cells after 24 h of treatment in vitro (P < 0.05). CONCLUSION: BBOP delays puberty onset by increasing oxidative stress and apoptosis in Leydig cells in rats. UNLABELLED The graphical abstract is available on the website www.besjournal.com.
Rats ; Male ; Animals ; Leydig Cells/metabolism* ; Testosterone ; Glycogen Synthase Kinase 3 beta/pharmacology* ; Rats, Sprague-Dawley ; Sexual Maturation ; Testis ; Oxidative Stress ; TOR Serine-Threonine Kinases/metabolism* ; Apoptosis

Leydig cell tumor is a rare testicular neoplasm that can present as a non-palpable small testicular nodule. Here we present a case of a 36-year-old Filipino male who initially came in for fertility work-up. Semen analysis showed azoospermia. However, an incidental finding on ultrasound showed a well-circumscribed round tumor. The patient underwent radical orchiectomy. On histopathologic examination, a Leydig cell tumor was identified and supported by immunohistochemical staining. We discuss the clinical features pathogenesis, treatment, diagnosis and prognosis of this uncommon entity.
Leydig Cells ; Testis ; Orchiectomy ; Infertility

Animals ; Autophagy/genetics* ; Cholesterol/metabolism* ; Gene Expression Regulation ; Integrases/metabolism* ; Leydig Cells/metabolism* ; Male ; Mice, Knockout ; Multienzyme Complexes/metabolism* ; Phosphoproteins/metabolism* ; Primary Cell Culture ; Progesterone Reductase/metabolism* ; RNA Splicing Factors/metabolism* ; Scavenger Receptors, Class B/metabolism* ; Sequestosome-1 Protein/metabolism* ; Signal Transduction ; Sirtuin 1/genetics* ; Sodium-Hydrogen Exchangers/metabolism* ; Steroid 17-alpha-Hydroxylase/metabolism* ; Steroid Isomerases/metabolism* ; Testosterone/genetics*

PURPOSE: This study investigated the role of natriuretic peptide receptor 2 (NPR2) on cell proliferation and testosterone secretion in mouse Leydig cells. MATERIALS AND METHODS: Mouse testis of different postnatal stages was isolated to detect the expression C-type natriuretic peptide (CNP) and its receptor NPR2 by quantitative reverse transcription polymerase chain reaction (RT-qPCR). Leydig cells isolated from mouse testis were cultured and treated with shNPR2 lentiviruses or CNP. And then the cyclic guanosine monophosphate production, testosterone secretion, cell proliferation, cell cycle and cell apoptosis in mouse Leydig cells were analyzed by ELISA, RT-qPCR, Cell Counting Kit-8, and flow cytometry. Moreover, the expression of NPR2, cell cycle, apoptosis proliferation and cell cycle related gene were detected by RT-qPCR and Western blot. RESULTS: Knockdown of NPR2 by RNAi resulted in S phase cell cycle arrest, cell apoptosis, and decreased testosterone secretion in mouse Leydig cells. CONCLUSIONS: Our study provides more evidences to better understand the function of CNP/NPR2 pathway in male reproduction, which may help us to treat male infertility.
Animals ; Apoptosis ; Blotting, Western ; Cell Count ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Proliferation ; Enzyme-Linked Immunosorbent Assay ; Flow Cytometry ; Germ Cells ; Guanosine Monophosphate ; Humans ; Infertility, Male ; Lentivirus ; Leydig Cells ; Male ; Mice ; Natriuretic Peptide, C-Type ; Polymerase Chain Reaction ; Receptors, Peptide ; Reproduction ; Reverse Transcription ; RNA Interference ; S Phase ; Testicular Diseases ; Testis ; Testosterone

Male infertility (MI) is a complex multifactorial disease, and idiopathic infertility accounts for 30% of cases of MI. At present, the evidence for the effectiveness of empirical drugs is limited, and in vitro fertilization is costly and may increase the risk of birth defects and childhood cancers. Therefore, affected individuals may feel obliged to pursue natural remedies. Traditional Chinese medicine (TCM) may represent a useful option for infertile men. It has been demonstrated that TCM can regulate the hypothalamic-pituitary-testicular axis and boost the function of Sertoli cells and Leydig cells. TCM can also alleviate inflammation, prevent oxidative stress, reduce the DNA fragmentation index, and modulate the proliferation and apoptosis of germ cells. Furthermore, TCM can supply trace elements and vitamins, ameliorate the microcirculation of the testis, decrease the levels of serum anti-sperm antibody, and modify epigenetic markers. However, the evidence in favor of TCM is not compelling, which has hindered the development of TCM. This review attempts to elucidate the underlying therapeutic mechanisms of TCM. We also explore the advantages of TCM, differences between TCM and Western medicine, and problems in existing studies. Subsequently, we propose solutions to these problems and present perspectives for the future development of TCM.
Apoptosis ; Congenital Abnormalities ; DNA Fragmentation ; Epigenomics ; Fertilization in Vitro ; Germ Cells ; Humans ; Infertility ; Infertility, Male ; Inflammation ; Leydig Cells ; Male ; Male ; Medicine, Chinese Traditional ; Microcirculation ; Oxidative Stress ; Sertoli Cells ; Testis ; Trace Elements ; Vitamins

We investigated whether β-carotene (β-CA) or ellagic acid (EA), originating from various fruits and vegetables, has a preventive effect against male infertility induced by exogenous scrotal hyperthermia. ICR adult mice were intraperitoneally treated with 10 mg/kg of β-CA or EA daily for 13 days consecutively. During this time, mice were subjected to transient scrotal heat stress in a water bath at 43℃ for 20 min on day 7, and their testes and blood were obtained on day 14 for histopathologic and biochemical analyses. Heat stress induced significant testicular weight reduction, germ cell loss and degeneration, as well as abnormal localization of phospholipid hydroperoxide glutathione peroxidase (PHGPx) and manganese superoxide dismutase (MnSOD) in spermatogenic and Leydig cells. Heat stress also altered the levels of oxidative stress (lipid peroxidation, SOD activity, and PHGPx, MnSOD, and HIF-1α mRNAs), apoptosis (Bax, Bcl-xL, caspase 3, NF-κB, and TGF-β1 mRNAs), and androgen biosynthesis (serological testosterone concentration and 3β-hydroxysteroid dehydrogenase mRNA) in testes. These changes were all improved significantly by β-CA treatment, but only slightly improved by EA treatment. These findings indicate that β-CA, through modulations of oxidative stress, apoptosis, and androgen biosynthesis, is a potent preventive agent against testicular injuries induced by scrotal hyperthermia.
Adult ; Animals ; Apoptosis ; Baths ; beta Carotene ; Caspase 3 ; Ellagic Acid ; Fever ; Fruit ; Germ Cells ; Glutathione Peroxidase ; Hot Temperature ; Humans ; Hydrogen Peroxide ; Infertility, Male ; Leydig Cells ; Male ; Mice ; Oxidative Stress ; Oxidoreductases ; Superoxide Dismutase ; Testis ; Testosterone ; Vegetables ; Water ; Weight Loss