Leydig Cell Function Research Articles

Germ Cell Dysfunction is Universal in Male Patients with β-Thalassemia Following Hematopoietic Stem Cell Transplantation During Childhood and Adolescence.

To assess gonadal function in adolescent male patients with β-thalassemia who underwent successful hematopoietic stem cell transplantation (HSCT) during childhood or adolescence. Fifty-two male patients with β-thalassemia, aged ≥10 years, who had undergone HSCT ≥2 years were included. Clinical data, such as age, genital Tanner (GT) stage at HSCT and enrollment, serum ferritin levels, and cumulative doses of alkylating agents, were collected. Gonadal function was evaluated through measurements of serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone, inhibin B levels, and semen analysis. Age at enrollment and HSCT were 17 (10-31) and 9 (1-19) years, respectively. The duration from HSCT to enrollment was 7.5 (2-20) years. Of 52 patients, 46 (88%) exhibited Sertoli cell dysfunction. Thirty-one patients had relatively small testes for their GT stage, 34 of 44 with GT V had elevated FSH of ≥5 IU/L, and 20 of 49 with GT stages II-V had low serum inhibin B levels. None of the patients with GT stage V showed Leydig cell dysfunction or gonadotropin deficiency. Serum FSH ≥8 IU/L showed the best diagnostic accuracy for detecting oligo- and azoospermia. All 39 patients who underwent semen analysis had >1 abnormal parameters. Having relatively small testes for GT stage and serum FSH ≥8 IU/L were associated with oligo- and azoospermia (p <0.01). Male patients with β-thalassemia after HSCT experienced universal spermatogenesis impairment and frequent Sertoli cell dysfunction but their Leydig cell function appears to be preserved. The high likelihood of future subfertility should be informed before HSCT.

12333 46 XX/XY Chimerism - Positive NIPT And Post-natal Karyotype Is It Real?

Abstract Disclosure: K.L. Del Rosario: None. N. Sheriden: None. N. Vijayakanthi: None. Introduction: Non-Invasive Prenatal Testing(NIPT) using cell free fetal DNA in plasma of pregnant women has become a routine part of prenatal care in screening for fetal aneuploidies including sex chromosome abnormalities in most regions around the world. False positive results are increasingly imposing challenges in pre-natal as well as post-natal care. Case Discussion: We report a neonate born at 32+2 weeks gestation to a 42-year-old G2 P2 mother. Pregnancy was complicated by insulin dependent maternal type 2 diabetes mellitus, maternal chronic hypertension and a positive NIPT for high-risk monosomy X. Prenatal ultrasound showed male anatomy. Interestingly on physical exam after birth, the neonate had typical male external genitalia with bilateral normal male gonads. Chromosome analysis done immediately after birth revealed the presence of two cell lines: 40 of the 50 cells (80%) had a normal female 46 XX karyotype and 10 of the 50 cells (20%) had a normal male 46 XY karyotype. These findings could be due to reabsorbed twin, Klinefelter syndrome with two trisomy rescue events, maternal cell contamination or true chimerism. In addition, fluorescence in situ hybridization (FISH) analysis for X and Y probes revealed the presence of two cell lines. The first cell line (70% of the cells) had two hybridization signals for chromosome X and the second cell line (∼25% of the cells) had one hybridization signal for chromosome X and one for chromosome Y. Postnatal ultrasound showed normal testicles with no evidence of Mullerian structures. Newborn screening was negative for congenital adrenal hyperplasia (CAH). Genetics was consulted and recommended repeat chromosomal analysis, parental testing to determine sex chromosome segregation, and follow-up with pediatric endocrinology. Repeat cytogenetic testing at 2 weeks of life resulted in a normal male chromosome complement of 46,XY. Previous abnormal cytogenetics were thought to be due to maternal cell contamination. Further endocrine labs showed LH(1.16 uIU/ml) and testosterone levels ( 87 ng/dL), appropriate levels for age indicating normal Hypothalamic Pituitary Gonadal (HPG) axis and testicular Leydig cell function. Since the family was previously counseled regarding the concept of maternal cell contamination, they expressed understanding and were happy with the update of the normal karyotype result. Conclusion: False-positive results concerning for rare chimerism on NIPT can occur and should prompt a thorough history, physical exam, ultrasound studies and repeat testing to confirm its presence. Careful consideration should be taken when counseling family about the implications of these results, especially communication about gender assignment of the infant. Presentation: 6/3/2024

Supplementing ageing male laying breeders with lycopene alleviates oxidative stress in testis and improves testosterone secretion

BackgroundReproductive performance is a crucial aspect of poultry production and is carefully controlled by endocrine, paracrine, and autocrine factors. This study aimed to investigate the effect of lycopene on testosterone synthesis in Leydig cells of laying breeder roosters, clarify the mechanism of lycopene improving Leydig cells function and promoting testosterone production, and explore the role of related signal transduction pathways in testosterone synthesis. ResultsA total of 96 healthy 55-week-old breeding roosters were randomly assigned to one of five dietary treatments. They were provided with a corn-soybean meal-based diet containing different levels of lycopene: 0 mg/kg (control), 50 mg/kg, 100 mg/kg, or 200 mg/kg. The experiment lasted for 6 weeks. With the increase in lycopene levels, the testosterone content in the plasma was significantly higher than in the control group. Testicular Leydig cells were isolated and cultured from fresh testicular tissue of 45-wk-old to 60-wk-old breeding roosters. Various doses of lycopene were administered to Leydig cells, and subsequently, cells were collected for the detection of cell viability and testosterone content. The optimal concentration of lycopene to be added was determined, and changes in mRNA expression and protein levels of key proteins involved in testosterone synthesis were investigated. The results showed that lycopene treatment significantly increased testosterone secretion, mRNA expression, and protein levels of steroid-producing enzymes. Cells were collected to measure the activity of antioxidant enzymes, the mRNA transcription level of apoptotic factors, and the protein expression of apoptotic factors after treatment with lycopene. The results showed that lycopene significantly increased the activities of antioxidant enzymes, and the ability to inhibit oxygen radicals, and decreased the content of malondialdehyde. Apoptosis was inhibited by regulating the expression of apoptosis-inducing and anti-apoptosis factors. After that, the MAPK signaling pathway and downstream SF-1, Nrf2 gene, and protein expression levels were detected. The results showed that lycopene treatment significantly increased the gene and protein expression of JNK, SF-1, and Nrf2, and significantly decreased the gene and protein expression of p38. ConclusionsLycopene treatment could promote testosterone synthesis of testicular Leydig cells by activating MAPK-SF-1 (increasing steroid-producing enzyme level) and MAPK-Nrf2 pathways (resisting oxidative damage).

Bisphenol H exposure disrupts Leydig cell function in adult rats via oxidative stress-mediated m6A modifications: Implications for reproductive toxicity

Bisphenol H (BPH) has emerged as a potential alternative to bisphenol A (BPA), which has been curtailed for use due to concerns over its reproductive and endocrine toxicity. This study investigates whether BPH exerts antiandrogenic effects by impairing Leydig cell function, a critical component in testosterone production. We administered orally BPH to adult male rats at doses of 0, 1, 10, and 100 mg/kg/day for 7 days. Notably, BPH treatment resulted in a dose-dependent reduction in testicular testosterone levels, with significant decreases observed at ≥ 1 mg/kg/day. Additionally, BPH affected the expression of key genes involved in steroidogenesis and cholesterol metabolism, including Nr5a1, Nr3c4, Lhcgr, Scarb1, and Star, at higher doses (10 and/or 100 mg/kg/day). The study also revealed alterations in antioxidant gene expression (Sod2 and Cat) and modulation of m6A-related genes (Ythdf1–3 and Foxo3) and their proteins. Through MeRIP-qPCR analysis, we identified increased m6A modifications in Scarb1 and Star genes following BPH exposure. In vitro experiments with primary Leydig cells confirmed that BPH enhanced oxidative stress and diminished testosterone production, which were partially mitigated by antioxidant vitamin E supplementation and Ythdf3 knockdown. Meanwhile, simultaneous administration of BPH and vitamin E to primary Leydig cells partially counteracted BPH-induced alterations in the Ythdf3 expression. Our findings underscore a novel mechanism by which BPH disrupts Leydig cell function through the oxidative stress-m6A modification-autophagy pathway, raising concerns about its potential reproductive toxicity.

Key role of CYP17A1 in Leydig cell function and testicular development in Qianbei Ma goats

Reproductive traits are vital economic parameters in goat production, and boosting the reproductive capacity of breeding rams is crucial for enhancing the profitability of goat farming. Currently, research on the reproductive performance of Qianbei Ma goats mainly centers on investigating mechanisms associated with prolificacy and estrous ovulation in ewes, with limited emphasis on ram reproductive aspects. This study used scanning electron microscopy and enzyme-linked immunosorbent assay (ELISA) to profile the morphology of testis and the dynamic changes of Luteinizing Hormone (LH), Follicle-Stimulating Hormone (FSH), and Testosterone (T) in serum at different developmental stages of Qianbei Ma goats. Meanwhile, transcriptome sequencing technology was used to investigate the mRNA expression patterns in testicular tissues at different developmental stages: newborn (0 M), puberty (6 M), sexual maturity (12 M), and physical maturity (18 M). The results showed that the diameter, circumference, and area of the testicular seminiferous tubules gradually increased with age. The levels of T and LH in serum significantly increased from 0 to 6 months after birth (p < 0.05), followed by a stabilization of T levels and a significant decrease in LH levels (p < 0.05). Meanwhile, FSH shows a decreasing trend between 0 and 18 months after birth. A total of 26,437 differentially expressed genes were identified in 6 comparison groups, which involve various biological processes such as immunity, growth, metabolism, development, and reproduction, and are significantly enriched in signaling pathways related to testicular development and spermatogenesis. WGCNA analysis identified 6 regions significantly associated with testicular development and spermatogenesis, and selected 320 genes for constructing a PPI network. Ten candidate genes related to testicular development and spermatogenesis were identified, including TP53, PLK4, RPS9, PFN4, ACTB, CYP17A1, GPX4, CLDN1, AMH and DHH. Of these, the CYP17A1 gene promotes interstitial cell proliferation, and promotes T synthesis. This study provides a theoretical basis and data support for promoting efficient breeding of goats and early breeding of excellent male goats.

P-003 Impact of SARS-CoV-2 infection on circulating male sex hormones and human semen quality: a systematic review and meta-analysis

Abstract Study question Does SARS-CoV-2 infection alter human male sex steroid hormones and semen quality? Summary answer SARS-CoV-2 infection reduced circulating testosterone but increased LH and prolactin levels. Also, SARS-CoV-2 infection reduced ejaculate volume, sperm count, concentration, viability, motility, and normal morphology. What is known already SARS-CoV-2 infection has been reported to be associated with a decline in semen quality, although this remains debatable given the novelty of the viral infection. In addition, available data on semen quality and circulating male reproductive hormones in association with SARS-CoV-2 infection is limited and inconsistent. Study design, size, duration This study provides a systematic review and meta-analysis of the impacts of SARS-CoV-2 infection on circulating male sex hormones and semen quality. Participants/materials, setting, methods This study was conducted according to PRISMA guidelines. Following a pre-defined strategic protocol, 852 studies were screened, and 40 articles were identified as eligible for this study. Included studies were from China (7), Germany (1), India (1), Indonesia (1), Iran (6), Iraq (2), Italy (5), Jordan (2), Russia (1), Turkey (12), UK (1), and USA (1). Main results and the role of chance A total of 4807 male subjects were included in the meta-analysis. SARS-CoV-2 infection significantly reduced circulating testosterone and testosterone/LH ratio (an index of Leydig cell function) but increased LH and prolactin levels even after sensitivity analysis when compared to SARS-CoV-2 uninfected patients. Also, SARS-CoV-2 infection significantly reduced ejaculate volume, sperm count, concentration, viability, total and progressive motility when compared to SARS-CoV-2 uninfected patients, although only ejaculate volume and sperm viability remained significant after sensitivity analysis. More so, ejaculate volume, sperm viability, and progressive motility were significantly reduced in SARS-CoV-2-infected patients before treatment when compared with after treatment; nonetheless, only sperm viability, and progressive motility remained significant after sensitivity analysis. Furthermore, ejaculate volume, sperm count, concentration, viability, total and progressive motility were significantly reduced in SARS-CoV-2-infected patients when compared with their pre-COVID state; these alterations, except sperm progressive motility, persisted after sensitivity analysis. Limitations, reasons for caution Although there is an increasing amount of data on the subject matter, SARS-CoV-2-infection is yet novel, and a continuous report and meta-analysis remains pertinent. Also, the included studies are from a few countries, which may not necessarily be a good global representation. Wider implications of the findings This study revealed that SARS-CoV-2-infection significantly reduced circulating testosterone, LH, and semen quality. SARS-CoV-2-induced reduction in semen quality is, at least in part, via a testosterone-dependent mechanism. These findings strengthen existing evidence in the literature on the negative impact of SARS-CoV-2-infection on male reproductive health. Trial registration number N/A

Triclosan inhibits testosterone biosynthesis in adult rats via inducing m6A methylation-mediated autophagy

Triclosan is a potent antibacterial compound widely used in everyday products. Whether triclosan affects Leydig cell function in adult male rats remains unknown. In this study, 0, 50, 100, or 200 mg/kg/day triclosan was gavaged to Sprague-Dawley male rats from 56 to 63 days postpartum. Triclosan significantly reduced serum testosterone levels at ≥ 50 mg/kg/day via downregulating the expression of Leydig cell gene Lhcgr, Scarb1, Star, Cyp11a1, Hsd3b1, Cyp17a1, and Hsd17b3 and regulatory transcription factor Nr3c2 at 100–200 mg/kg. Further analysis showed that triclosan markedly increased autophagy as shown by increasing LC3II and BECN1 and decreasing SQSTM1. The mRNA m6A modification analysis revealed that triclosan significantly downregulated Fto expression at 200 mg/kg while upregulating Ythdf1 expression at 100 and 200 mg/kg, leading to methylation of Becn1 mRNA as shown by MeRIP assay. Triclosan significantly inhibited testosterone output in rat R2C Leydig cells at ≥ 5 μM via downregulating Fto and upregulating Ythdf1. SiRNA Ythdf1 knockdown can reverse triclosan-mediated mitophagy in R2C cells, thereby reversing the reduction of testosterone output. In summary, triclosan caused Becn1 m6A methylation by downregulating Fto and upregulating Ythdf1, which accelerated Becn1 translation, thus leading to the occurrence of autophagy and the decrease of testosterone biosynthesis.

Radio frequency electromagnetic radiations interfere with the Leydig cell functions in-vitro.

A growing threat to male infertility has become a major concern for the human population due to the advent of modern technologies as a source of radiofrequency radiation (RFR). Since these technologies have become an integral part of our daily lives, thus, it becomes necessary to know the impression of such radiations on human health. In view of this, the current study aims to focus on the biological effects of radiofrequency electromagnetic radiations on mouse Leydig cell line (TM3) in a time-dependent manner. TM3 cells were exposed to RFR emitted from 4G cell phone and also exposed to a particular frequency of 1800 MHz and 2450 MHz from RFR exposure system. The cells were then evaluated for different parameters such as cell viability, cell proliferation, testosterone production, and ROS generation. A considerable reduction in the testosterone levels and proliferation rate of TM3 cells were observed at 120 min of exposure as compared to the control group in all exposure settings. Conversely, the intracellular ROS levels showed a significant rise at 60, 90 and 120 min of exposure in both mobile phone and 2450 MHz exposure groups. However, RFR treatment for different time durations (15, 30, 45, 60, 90, and 120 min) did not have significant effect on cell viability at any of the exposure condition (2450 MHz, 1800 MHz, and mobile phone radiation). Therefore, our findings concluded with the negative impact of radiofrequency electromagnetic radiations on Leydig cell's physiological functions, which could be a serious concern for male infertility. However, additional studies are required to determine the specific mechanism of RFR action as well as its long-term consequences.

Loss of PBX1 function in Leydig cells causes testicular dysgenesis and male sterility

Leydig cells are essential components of testicular interstitial tissue and serve as a primary source of androgen in males. A functional deficiency in Leydig cells often causes severe reproductive disorders; however, the transcriptional programs underlying the fate decisions and steroidogenesis of these cells have not been fully defined. In this study, we report that the homeodomain transcription factor PBX1 is a master regulator of Leydig cell differentiation and testosterone production in mice. PBX1 was highly expressed in Leydig cells and peritubular myoid cells in the adult testis. Conditional deletion of Pbx1 in Leydig cells caused spermatogenic defects and complete sterility. Histological examinations revealed that Pbx1 deletion impaired testicular structure and led to disorganization of the seminiferous tubules. Single-cell RNA-seq analysis revealed that loss of Pbx1 function affected the fate decisions of progenitor Leydig cells and altered the transcription of genes associated with testosterone synthesis in the adult testis. Pbx1 directly regulates the transcription of genes that play important roles in steroidogenesis (Prlr, Nr2f2 and Nedd4). Further analysis demonstrated that deletion of Pbx1 leads to a significant decrease in testosterone levels, accompanied by increases in pregnenolone, androstenedione and luteinizing hormone. Collectively, our data revealed that PBX1 is indispensable for maintaining Leydig cell function. These findings provide insights into testicular dysgenesis and the regulation of hormone secretion in Leydig cells.Graphical abstract

Prenatal diethylhexylphthalate exposure disturbs adult Leydig cell function via epigenetic downregulation of METTL4 expression in male rats

Prenatal exposure to diethylhexyl phthalate (DEHP) has been linked with a decline in testosterone levels in adult male rats, but the underlying mechanism remains unclear. We investigated the potential epigenetic regulation, particularly focusing on N6-methyladenosine (m6A) modification, as a possible mechanism. Dams were gavaged with DEHP (0, 10, 100, and 750 mg/kg/day) from gestational day 14 to day 21. The male offspring were examined at the age of 56 days. Prenatal DEHP administration at 750 mg/kg/day caused a decline in testosterone concentrations, an elevation in follicle-stimulating hormone, a downregulated expression of CYP11A1 HSD3B2, without affecting Leydig cell numbers. Interestingly, Methyltransferase Like 4 (METTL4), an m6A methyltransferase, was downregulated, while there were no changes in METTL3 and METTL14. Moreover, CYP11A1 showed m6A reduction in response to prenatal DEHP exposure. Additionally, METTL4 expression increased postnatally, peaking in adulthood. Knockdown of METTL4 resulted in the downregulation of CYP11A1 and HSD3B2 and an increase in SCARB1 expression. Furthermore, the increase in autophagy protection in adult Leydig cells induced by prenatal DEHP exposure was not affected by 3-methyladenosine (3MA) treatment, indicating a potential protective role of autophagy in response to DEHP exposure. In conclusion, prenatal DEHP exposure reduces testosterone by downregulating CYP11A1 and HSD3B2 via m6A epigenetic regulation and induction of autophagy protection in adult Leydig cells as a response to DEHP exposure.

Inter- and trans-generational impacts of real-world PM2.5 exposure on male-specific primary hypogonadism

Exposure to PM2.5, a harmful type of air pollution, has been associated with compromised male reproductive health; however, it remains unclear whether such exposure can elicit transgenerational effects on male fertility. Here, we aim to examine the effect of paternal exposure to real-world PM2.5 on the reproductive health of male offspring. We have observed that paternal exposure to real-world PM2.5 can lead to transgenerational primary hypogonadism in a sex-selective manner, and we have also confirmed this phenotype by using an external model. Mechanically, we have identified small RNAs (sRNAs) that play a critical role in mediating these transgenerational effects. Specifically, miR6240 and piR016061, which are present in F0 PM sperm, regulate intergenerational transmission by targeting Lhcgr and Nsd1, respectively. We have also uncovered that piR033435 and piR006695 indirectly regulate F1 PM sperm methylation by binding to the 3′-untranslated region of Tet1 mRNA. The reduced expression of Tet1 resulted in hypermethylation of several testosterone synthesis genes, including Lhcgr and Gnas, impaired Leydig cell function and ultimately led to transgenerational primary hypogonadism. Our findings provide insights into the mechanisms underlying the transgenerational effects of paternal PM2.5 exposure on reproductive health, highlighting the crucial role played by sRNAs in mediating these effects. The findings underscore the significance of paternal pre-conception interventions in alleviating the adverse effects of environmental pollutants on reproductive health.

Age-dependent changes in the expression and localization of LYZL4, LYZL6 and PCNA during testicular development in the Ashidan yak

Lysozyme like 4 (LYZL4), lysozyme like 6 (LYZL6) and proliferating cell nuclear antigen (PCNA) are implicated in the regulation of testicular function, but there was no research reported available on the expression patterns of LYZL4, LYZL6 and PCNA genes at different developmental stages of yak testes. In this study, we used the qRT-PCR, western blotting and immunohistochemistry estimated the LYZL4, LYZL6 and PCNA gene expression and protein lo-calization at different developmental stages of yak testes. The qPCR results showed that the mRNA expression of LYZL4, LYZL6 and PCNA genes significantly increased with age in the testes of yaks. Western blot results showed that the protein abundance of LYZL4, LYZL6 and PCNA in yak testes was significantly higher after puberty than before puberty. Furthermore, the results of immunohistochemistry indicated that LYZL4, LYZL6 and PCNA may be involved in the regulation of spermatogonia proliferation and Leydig cell function in immature testis. In adult yak testes, LYZL4, LYZL6 and PCNA may involve in the development of round spermatids and primary spermatocytes during testicular development. Our results indicated that LYZL4, LYZL6 and PCNA may be involved in the development of Sertoli cells, Leydig cells and gonocytes in yak testes.

Lower malathion concentrations reduce testosterone biosynthesis by Leydig TM3 cells in vitro by altering cellular redox profile and inducing oxidative damage

Malathion is an organophosphate pesticide used in agriculture and control of the Aedes aegypti mosquito. As previous reports have indicated the potential of malathion to compromise testosterone production in in vivo models, the objective of this study was to elucidate the mechanisms underlying the impairment of Leydig cell function, considering its critical role in male reproductive function. To this end, murine Leydig TM3 cells were exposed to concentrations of 1, 10, 100 or 1000 μM malathion for 24 h for evaluation of the compound on cell viability. Subsequently, concentrations of 1, 10, and 100 μM malathion were employed for a 24-h period to assess testosterone biosynthesis, levels of cytokines IL-1β, IL-6, IL-10, and TNF-α, as well as the redox profile. Malathion exerted a concentration-dependent impact on cell viability. Notably, the lower concentrations of malathion (1 and 10 μM) were found to impair testosterone biosynthesis in TM3 cells. While there were changes in IL-1 and TNF-α levels at specific concentrations, no direct correlation with altered hormone production was established. Our investigation revealed that varied malathion concentrations induced oxidative stress by increase in superoxide anion and a compensatory rise in antioxidants. In conclusion, the observed changes in the oxidative profile of TM3 cells were linked to functional impairment, evidenced by reduced testosterone biosynthesis at lower malathion concentrations.

Effects of superparamagnetic iron oxide nanoparticles (SPIONS) testicular injection on Leydig cell function and sperm production in a murine model

In the domain of medical advancement, nanotechnology plays a pivotal role, especially in the synthesis of biocompatible materials for therapeutic use. Superparamagnetic Iron Oxide Nanoparticles (SPIONs), known for their magnetic properties and low toxicity, stand at the forefront of this innovation. This study explored the reproductive toxicological effects of Sodium Citrate-functionalized SPIONs (Cit_SPIONs) in adult male mice, an area of research that holds significant potential yet remains largely unknown. Our findings reveal that Cit_SPIONs induce notable morphological changes in interstitial cells and the seminiferous epithelium when introduced via intratesticular injection. This observation is critical in understanding the interactions of nanomaterials within reproductive biological systems. A striking feature of this study is the rapid localization of Cit_SPIONs in Leydig cells post-injection, a factor that appears to be closely linked with the observed decrease in steroidogenic activity and testosterone levels. This data suggests a possible application in developing nanostructured therapies targeting androgen-related processes. Over 56 days, these nanoparticles exhibited remarkable biological distribution in testis parenchyma, infiltrating various cells within the tubular and intertubular compartments. While the duration of spermatogenesis remained unchanged, there were many Tunel-positive germ cells, a notable reduction in daily sperm production, and reduced progressive sperm motility in the treated group. These insights not only shed light on the intricate mechanisms of Cit_SPIONs interaction with the male reproductive system but also highlight the potential of nanotechnology in developing advanced biomedical applications.

Cryptorchidism and puberty.

Cryptorchidism is the condition in which one or both testes have not descended adequately into the scrotum. The congenital form of cryptorchidism is one of the most prevalent urogenital anomalies in male newborns. In the acquired form of cryptorchidism, the testis that was previously descended normally is no longer located in the scrotum. Cryptorchidism is associated with an increased risk of infertility and testicular germ cell tumors. However, data on pubertal progression are less well-established because of the limited number of studies. Here, we aim to review the currently available data on pubertal development in boys with a history of non-syndromic cryptorchidism-both congenital and acquired cryptorchidism. The review is focused on the timing of puberty, physical changes, testicular growth, and endocrine development during puberty. The available evidence demonstrated that the timing of the onset of puberty in boys with a history of congenital cryptorchidism does not differ from that of non-cryptorchid boys. Hypothalamic-pituitary-gonadal hormone measurements showed an impaired function or fewer Sertoli cells and/or germ cells among boys with a history of cryptorchidism, particularly with a history of bilateral cryptorchidism treated with orchiopexy. Leydig cell function is generally not affected in boys with a history of cryptorchidism. Data on pubertal development among boys with acquired cryptorchidism are lacking; therefore, more research is needed to investigate pubertal progression among such boys.

(106) Stem Cell Therapy Leads to an Increase in Testosterone Levels in Infertile Men

Abstract Introduction Sexual dysfunction is frequently encountered in infertile males. This may be related to psychosexual aspects of infertility and to some common factors of pathogenesis, such as hypogonadism. For example, many patients with non-obstructive azoospermia (NOA) have low testosterone levels, which may lead to low sex drive, erectile dysfunction and metabolic abnormalities later in life. Patients with NOA typically undergo surgical sperm retrieval procedures, which may lead to further decrease in androgen production, which may be transient or even permanent in some cases. Stem cell therapy is an investigative mode of treatment for patients with NOA, but its influence on Leydig cell function is currently unknown. Objective To assess the impact of stem cell therapy on testosterone levels in men. Methods Sixty patients with NOA were included in this study. All of them underwent unsuccessful MicroTESE more than 12 months prior to the inclusion in order to justify the use of stem cell therapy. Multipotent mesenchymal stromal cells (MMSC) were derived from healthy donor placenta following physiologic childbirth. MMSC product was used for systemic and local treatment via intravenous and intratesticular injection, respectively. Endocrine profiling was performed at baseline and 3 months after the procedure. Results Median testosterone level prior to MMSC therapy was 8.7 nmol/l (interquartile range [IQR]: 4.2–12.1), and 3 months after it was 12.3 nmol/l (IQR: 8.8–16.3) (p &amp;lt; 0.00001). This may be related to an increase in luteinizing hormone levels from 6.4 mIU/ml at baseline (IQR: 3.6–11.3) to 9.6 mIU/ml (IQR: 5.2–14.1) (p = 0.00026). Paradoxically, follicle-stimulating hormone levels declined from 12.5 mIU/ml (IQR: 4.7–24.7) to 7.4 mIU/ml (IQR: 4.2–12.3) (p &amp;lt; 0.00001). Prior to MMSC therapy 43 patients (71.7%) had testosterone levels lower than 12 nmol/l, after MMSC therapy 24 patients (40%) had testosterone levels lower than this threshold. Thirty patients (50%) and 14 patients (23.3%) had testosterone level below 8 nmol/l before and after MMSC therapy respectively. Conclusions MMSC therapy may increase testosterone levels in patients with NOA, though the exact mechanisms and its possible impact on quality of life should be elucidated. Disclosure No.

INSL3 Variation in Dogs Following Suppression and Recovery of the HPG Axis.

Insulin-like peptide 3 (INSL3) is a constitutive product of mature, adult-type Leydig cells of the testes and consequently in most mammals is an ideal biomarker with which to monitor pubertal development. A new heterologous time-resolved fluorescence immunoassay was developed and validated to measure circulating INSL3 in the blood of adult male dogs. Compared to other species, INSL3 concentration is low with marked variation between individuals, which appears to be independent of breed, age, or weight. A model system was then used in which a cohort of beagle dogs was subject to a GnRH-agonist implant to suppress the HPG axis and spermatogenesis, followed by implant removal and recovery. Unlike testosterone, INSL3 levels were not fully suppressed in all animals by the GnRH agonist, nor was the recovery of Leydig cell function following implant removal uniform or complete, even after several weeks. In dogs, and dissimilar from other species (including humans), Leydig-cell INSL3 appears to be quite variable between individual dogs and only weakly connected to the physiology of the HPG axis after its suppression by a GnRH-agonist implant and recovery. Consequently, INSL3 may be less useful in this species for the assessment of testis function.

Vitamin E and genistein generate a cytoprotective effect on polychlorinated biphenyl- induced oxidative stress in testicular Leydig cells

Polychlorinated biphenyls (PCBs) are industrial substances which were widely used in industrial applications starting from the 1930s until the mid-1970s. Aroclor 1242 (A1242) is a commercial PCB mixture with 42% chlorine manufactured by the Monsanto Chemical Company in St. Louis, Missouri, USA. Previous studies suggested that PCBs have inhibitory effect on reproductive function, developmental abnormality, and impaired reproductive ability. PCBs may also affect the endocrine system by reducing the testosterone synthesis and the activity of steroidogenic enzymes in Leydig cells. This study was performed to investigate the specific effects of A1242 on the viability of Leydig cells, oxidative damage, and the profile of steroidogenic enzymes in an in vitro culture. The therapeutic effects of vitamin E (VitE) and genistein (Gen), as two antioxidants, in mitigating the damage produced by A1242 were also evaluated. TM3 Leydig cells were exposed to 10-8 and 10-6 M of A1242 and VitE (50µM) and Gen (10µM) as antioxidant for 24 h. After the exposure period, the Leydig cells were assessed to determine their viability using a cell viability assay. Measurements were performed for lipid peroxidation, reactive oxygen species (ROS), and steroidogenic enzymes. The results showed that cell viability was reduced after A1242 exposure, while lipid peroxidation and ROS increased. Steroidogenesis was interrupted in a concentration-dependent manner. Following A1242 exposure, administrations of VitE or Gen as an antioxidant reduced hazardous effects of A1242 on Leydig cells. Our results showed that exposure to A1242 may impair Leydig cell function and cause toxicity in Leydig cells and that VitE and Gen treatment exhibited therapeutic effects against this toxicity.

In vitro and in vivo studies on the effect of a mitochondrial fusion promoter on Leydig cell integrity and function.

Background: The interstitial testicular Leydig cells are responsible for the production of testosterone, which functionally deteriorate with normal aging. Decreased expression of mitochondrial steroidogenic interactome proteins and diminished mitochondrial function in aging Leydig cells suggest that mitochondrial dynamics play a role in maintaining adequate levels of testosterone. Optic atrophy 1 (OPA1) protein regulates mitochondrial dynamics and cristae formation in many cell types. Previous studies showed that increasing OPA1 expression in dysfunctional Leydig cells restored mitochondrial function and recovered androgen production to levels found in healthy Leydig cells. These findings suggested that mitochondrial dynamics may be a promising target to ameliorate diminished testosterone levels in aging males. Methods: We used twelve-month-old rats to explore the relationship between mitochondrial dynamics and Leydig cell function. Isolated Leydig cells from aged rats were treated ex vivo with the cell-permeable mitochondrial fusion promoter 4-Chloro-2-(1-(2-(2,4,6-trichlorophenyl)hydrazono)ethyl) phenol (mitochondrial fusion promoter M1), which enhances mitochondrial tubular network formation. In parallel, rats were treated with 2mg/kg/day M1 for 6weeks before Leydig cells were isolated. Results: Ex vivo M1-treated cells showed enhanced mitochondrial tubular network formation by transmission electron microscopy, enhanced Leydig cell mitochondrial integrity, improved mitochondrial function, and higher testosterone biosynthesis compared to controls. However, in vivo treatment of aged rats with M1 not only failed to re-establish testosterone levels to that of young rats, it also led to further reduction of testosterone levels and increased apoptosis, suggesting M1 toxicity in the testis. The in vivo M1 toxicity seemed to be tissue-specific, however. Conclusion: Promoting mitochondrial fusion may be one approach to enhancing cell health and wellbeing with aging, but more investigations are warranted. Our findings suggest that fusion promoters could potentially enhance the productivity of aged Leydig cells when carefully regulated.

Effects of Varicocele Repair on Testicular Endocrine Function: A Systematic Review and Meta-Analysis.

The objective of this manuscript is to assess the effect of varicocele repair (VR) in patients with clinical varicoceles on serum total testosterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), and inhibin B serum levels. The study was performed in compliance with the Meta-Analysis and Systematic Reviews of Observational Studies (MOOSE) guidelines and the Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P). All eligible studies were selected following the PICOS (Population, Intervention, Comparison/Comparator, Outcomes, Study design) model. The values of each outcome measured after VR were compared to the before parameters and, when available, to the values on patients with unrepaired varicocele, and to those of healthy controls with no varicocele. For total testosterone, the values were sub-analyzed based on the mean total testosterone levels before VR (<300 ng/dL or >300 ng/dL), the fertility status, the time of follow-up and the technique used for VR. From a total of 460 abstracts retrieved, 48 articles were included in our meta-analysis. Serum total testosterone levels were significantly higher after VR compared to both pre-treatment levels (mean difference [MD] 82.45 ng/dL, 95% confidence interval [CI]: 64.14-100.76; p<0.00001) and to the levels of patients with unrepaired varicocele (MD 91.64 ng/dL, 95% CI: 62.30-120.99; p<0.00001). They did not differ from the levels of healthy controls with no varicocele (MD -22.01 ng/dL, 95% CI: -68.59-24.58; p=0.35). The increase resulted to be independent from the mean total testosterone levels before VR, fertility status, time of follow-up and type of VR. After VR, a trend toward lower serum LH levels was found compared to before values (MD -0.37 IU/L, 95% CI: -0.74-0.01; p=0.06). When compared to the levels of patients with unrepaired VR, LH levels after VR were significantly lower (MD -0.96 IU/L, 95% CI: -1.56 to -0.35; p=0.002). LH levels were not significantly higher than healthy men without varicocele (MD 0.84 IU/L, 95% CI: -0.68-2.36; p=0.28). Patients with VR had significantly lower FSH levels compared to their pre-treatment values (MD -1.43 IU/L, 95% CI: -1.82 to -1.04; p<0.00001), and also to those of patients with non-repaired varicocele (MD -2.35 IU/L, 95% CI: -4.06 to -0.65; p=0.007). When compared to healthy controls with no varicocele, FSH levels were significantly higher (MD 2.71 IU/L, 95% CI: 1.12-4.31; p=0.0009). Lastly, after VR no significant change in inhibin B serum levels was seen compared to pre-treatment levels (MD 11.76 pg/mL, 95% CI: -3.83-27.35; p=0.14). The present meta-analysis is the largest to date to assess the impact of VR on Leydig cell and Sertoli cell function using a before-after analysis for uncontrolled studies, and using data from patients with unrepaired varicoceles or healthy patients without varicocele as controls. VR was found to increase and restore to normality serum levels of total testosterone and LH. This evidence could be of value in considering the treatment of varicocele in patients with low testosterone or those who show a progressive decline in testosterone levels.