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The gut microbiota operates at the interface of host-environment interactions to influence human homoeostasis and metabolic networks 1-4 . Environmental factors that unbalance gut microbial ecosystems can therefore shape physiological and disease-associated responses across somatic tissues 5-9 . However, the systemic impact of the gut microbiome on the germline-and consequently on the F 1 offspring it gives rise to-is unexplored 10 . Here we show that the gut microbiota act as a key interface between paternal preconception environment and intergenerational health in mice. Perturbations to the gut microbiota of prospective fathers increase the probability of their offspring presenting with low birth weight, severe growth restriction and premature mortality. Transmission of disease risk occurs via the germline and is provoked by pervasive gut microbiome perturbations, including non-absorbable antibiotics or osmotic laxatives, but is rescued by restoring the paternal microbiota before conception. This effect is linked with a dynamic response to induced dysbiosis in the male reproductive system, including impaired leptin signalling, altered testicular metabolite profiles and remapped small RNA payloads in sperm. As a result, dysbiotic fathers trigger an elevated risk of in utero placental insufficiency, revealing a placental origin of mammalian intergenerational effects. Our study defines a regulatory 'gut-germline axis' in males, which is sensitive to environmental exposures and programmes offspring fitness through impacting placenta function., (© 2024. The Author(s).)

Glutathione synthetase (GSS) catalyzes the final step in the synthesis of glutathione (GSH), a well-established antioxidant. Research on the specific roles of the Gss gene during spermatogenesis remains limited due to the intricate structure of testis. In this study, we identified pachytene spermatocytes as the primary site of GSS expression and generated a mouse model with postnatal deletion of Gss using Stra8-Cre (S8) to investigate the role of GSS in germ cells. The impact of Gss knockout on reducing male fertility is age-dependent and caused by ferroptosis in the testis. The 2-month-old S8/Gss -/- male mice exhibited normal fertility, due to a compensatory increase in GPX4, which prevented the accumulation of ROS. With aging, there was a decline in GPX4 and an increase in ALOX15 levels observed in 8-month-old S8/Gss -/- mice, resulting in the accumulation of ROS, lipid peroxidation, and ultimately testicular ferroptosis. We found that testicular ferroptosis did not affect spermatogonia, but caused meiosis disruption and acrosome heterotopia. Then the resulting aberrant sperm showed lower concentration and abnormal morphology, leading to reduced fertility. Furthermore, these injuries could be functionally rescued by inhibiting ferroptosis through intraperitoneal injection of GSH or Fer-1. In summary, Gss in germ cells play a crucial role in the resistance to oxidative stress injury in aged mice. Our findings deepen the understanding of ferroptosis during spermatogenesis and suggest that inhibiting ferroptosis may be a potential strategy for the treatment of male infertility., (© 2023. The Author(s).)

Study Question: Is prior testicular torsion associated with testicular function (semen quality and reproductive hormones) in young men from the general population?, Summary Answer: In young men from the general population, no differences in semen parameters were observed in those who had experienced testicular torsion compared to controls and observations of higher FSH and lower inhibin B were subtle., What Is Known Already: Testicular function may be impaired after testicular torsion, but knowledge is sparse and based on studies with small sample sizes and no control group or a less than ideal control group., Study Design, Size, Duration: A cross-sectional population-based study was carried out including 7876 young Danish men with unknown fertility potential, examined from 1996 to 2020., Participants/materials, Setting, Methods: All men (median age 19.0 years) had a physical examination, provided a blood and semen sample, and filled in a questionnaire including information about prior testicular torsion, birth, lifestyle and current and previous diseases. Markers of testicular function, including testis volume, semen parameters and reproductive hormones, were compared between men operated for testicular torsion and controls, using multiple linear regression analyses., Main Results and the Role of Chance: The average participation rate was 24% for the entire study period. In total, 57 men (0.72%) were previously operated for testicular torsion (median age at surgery 13.4 years) of which five had only one remaining testicle. Men with prior testicular torsion were more often born preterm (25% versus 9.5% among controls), and they had significantly higher FSH and lower inhibin B levels, and a lower inhibin B/FSH ratio than controls in crude and adjusted models. The association was mainly driven by the subgroup of men who had undergone unilateral orchiectomy. No differences in semen parameters were observed., Limitations, Reasons for Caution: A limitation is the retrospective self-reported information on testicular torsion. Also, results should be interpreted with caution owing to the high uncertainty of the observed differences., Wider Implications of the Findings: Overall, the results of our study are reassuring for men who have experienced testicular torsion, especially when treated with orchiopexy, for whom reproductive hormone alterations were subtle and without obvious clinical relevance. Our study found no differences in semen parameters, but follow-up studies are needed to assess any long-term consequences for fertility., Study Funding/competing Interest(s): Financial support was received from the Danish Ministry of Health; the Danish Environmental Protection Agency; the Research fund of Rigshospitalet, Copenhagen University Hospital; the European Union (Contract numbers BMH4-CT96-0314, QLK4-CT-1999-01422, QLK4-CT-2002-00603, FP7/2007-2013, DEER Grant agreement no. 212844); A.P. Møller and wife Chastine Mckinney Møllers Foundation; Svend Andersens Foundation; the Research Fund of the Capital Region of Denmark; and ReproUnion (EU/Interreg). The authors have nothing to declare., Trial Registration Number: N/A., (© The Author(s) 2023. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Doxorubicin (DOX) is a chemotherapeutic agent that can disrupt testicular function leading to male infertility. This study examined the protective role of natural flavone, acacetin (ACA), and a protease of Bacillus cereus bacteria (B. cereus) as well as the potential role of miR-155/SIRT1/FOXO1 network in DOX-induced testicular injury. Twenty-four male Wistar rats were randomly allocated into four groups and treated as follows: Control, DOX (1 mg/kg, i.p) every other day for 21 days with a total dose equal to 10 mg/kg throughout the experiment, and pre-treated groups that received ACA (5 mg/kg/day, p.o) or B. cereus protease (36 mg/kg/day, p.o) for a week prior to DOX administration. DOX challenge reduced the testis weight coefficient, serum testosterone, and testicular 17β-hydroxysteroid dehydrogenase (17β-HSD). DOX caused a significant increase in testicular oxidative stress, inflammatory, and apoptotic markers. Aberrant testicular miR-34c, a germ-specific miRNA, and miR-155 expressions were observed, along with decreased protein expression of sirtuin1 (SIRT1) dependent forkhead box 1 (FOXO1) acetylation which induces apoptosis. Besides, abnormal histopathological architecture and a marked reduction in the testicular expression of proliferating cell nuclear antigen (PCNA) were observed. ACA or protease administration significantly improved the histopathological and immunohistochemical pictures compared with DOX alone and renovated testicular functions. Interestingly, treatment with protease was more significant than treatment with ACA in ameliorating DOX-induced testicular injury. Taken together, this study reveals the prophylactic role of these two regimens on male fertility by exhibiting antioxidant, anti-inflammatory, and anti-apoptotic effects against DOX-elicited testicular damage, possibly via modulating miR-155/SIRT1/FOXO1 network., (© 2022. The Author(s).)

Testicular-derived inhibin B (α/β B dimers) acts in an endocrine manner to suppress pituitary production of follicle-stimulating hormone (FSH), by blocking the actions of activins (β A/B/β A/B dimers). Previously, we identified a homozygous genetic variant (c.1079T>C:p.Met360Thr) arising from uniparental disomy of chromosome 2 in the INHBB gene (β B-subunit of inhibin B and activin B) in a man suffering from infertility (azoospermia). In this study, we aimed to test the causality of the p.Met360Thr variant in INHBB and testis function. Here, we used CRISPR/Cas9 technology to generate InhbbM364T/M364T mice, where mouse INHBB p.Met364 corresponds with human p.Met360. Surprisingly, we found that the testes of male InhbbM364T/M364T mutant mice were significantly larger compared with those of aged-matched wildtype littermates at 12 and 24 weeks of age. This was attributed to a significant increase in Sertoli cell and round spermatid number and, consequently, seminiferous tubule area in InhbbM364T/M364T males compared to wildtype males. Despite this testis phenotype, male InhbbM364T/M364T mutant mice retained normal fertility. Serum hormone analyses, however, indicated that the InhbbM364T variant resulted in reduced circulating levels of activin B but did not affect FSH production. We also examined the effect of this p.Met360Thr and an additional INHBB variant (c.314C>T: p.Thr105Met) found in another infertile man on inhibin B and activin B in vitro biosynthesis. We found that both INHBB variants resulted in a significant disruption to activin B in vitro biosynthesis. Together, this analysis supports that INHBB variants that limit activin B production have consequences for testis composition in males., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Although many studies have focused on SARS-CoV-2 infection in the lungs, comparatively little is known about the potential effects of the virus on male fertility. SARS-CoV-2 infection of target cells requires the presence of furin, angiotensin-converting enzyme 2 (ACE2) receptors, and transmembrane protease serine 2 (TMPRSS2). Thus, cells in the body that express these proteins might be highly susceptible to viral entry and downstream effects. Currently, reports regarding the expression of the viral entry proteins in the testes are conflicting; however, other members of the SARS-CoV family of viruses - such as SARS-CoV - have been suspected to cause testicular dysfunction and/or orchitis. SARS-CoV-2, which displays many similarities to SARS-CoV, could potentially cause similar adverse effects. Commonalities between SARS family members, taken in combination with sparse reports of testicular discomfort and altered hormone levels in patients with SARS-CoV-2, might indicate possible testicular dysfunction. Thus, SARS-CoV-2 infection has the potential for effects on testis somatic and germline cells and experimental approaches might be required to help identify potential short-term and long-term effects of SARS-CoV-2 on male fertility., (© 2021. Springer Nature Limited.)

The consumption of fructose has increased in children and adolescents and is partially responsible for the high incidence of metabolic diseases. The lifestyle during postnatal development can result in altered metabolic programming, thereby impairing the reproductive system and fertility during adulthood. Therefore, the aim of this study was to evaluate the effect of a high-fructose diet in the male reproductive system of pubertal and adult rats. Male Wistar rats (30 d old) were assigned to four different groups: Fr30, which received fructose (20%) in water for 30 d and were euthanized at postnatal day (PND) 60; Re-Fr30, which received fructose (20%) for 30 d and were euthanized at PND 120; and two control groups C30 and Re-C30, which received water ad libitum and were euthanized at PND 60 and 120, respectively. Fructose induced an increase in abnormal seminiferous tubules with epithelial vacuoles, degeneration, and immature cells in the lumen. Moreover, Fr30 rats showed altered spermatogenesis and daily sperm production (DSP), as well as increased serum testosterone concentrations. After discontinuing high-fructose consumption, DSP and sperm number decreased significantly. We observed tissue remodeling in the epididymis, with a reduction in stromal and epithelial compartments that might have influenced sperm motility. Therefore, we concluded that fructose intake in peripubertal rats led to changes in the reproductive system observed both during puberty and adulthood.

The HPG axis is critical in the maintenance of spermatogenesis and sexual function in males. The GnRH-releasing neurons of the hypothalamus are the axis's main hierarchical element. These neurons make connections with different areas of the brain to regulate the release of GnRH. Neurotransmitters have a critical in the connections between these neurons. So, neurotransmitters can inhibit or stimulate the release of GnRH by affecting GnRH-releasing neurons. In neurological disorders, neurotransmitter's activities inevitably change; therefore, these changes can affect the HPG axis via affecting GnRH-releasing neurons, just like in epilepsy. Many investigations have attracted attention to be decreased fertility potential in males with epilepsy. It has been stated that changes in the HPG axis hormone levels have been found in these patients. Moreover, it has also been observed that sperm quality decreased in patients. It has been emphasized that a decrease in sperm quality may be related to both epilepsy and AEDs. It has been shown that AEDs caused decreased sperm quality by impairing the HPG axis, so they act like endocrine-disrupting chemicals. AEDs can affect fertility and cause additive adverse effects in terms of sperm quality together with epilepsy. Therefore, it is crucial to investigate the adverse reproductive effects of AEDs, which are frequently used during reproductive ages, and determine the role of the HPG axis on potential reproductive pathologies., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Global sperm counts have declined in recent decades, coinciding with the proliferation of endocrine-disrupting chemicals, of which pesticides are some of the most common. Previous systematic reviews of epidemiologic studies published between 1991 through 2013 have reported associations between environmental and occupational pesticide exposure and reduced sperm quality, particularly associations with reduced sperm concentration. This systematic review used the Navigation Guide to critically evaluate the current body of evidence examining sperm quality and pesticide exposure in epidemiological studies. PubMed, Scopus, and Web of Science databases were searched for all English-language articles published after September 2012 until August 2021. Original observational studies that assessed human sperm quality parameters, defined as concentration, motility, morphology, and DNA integrity, and individual-level pesticide exposure were included. The risk of bias for each included study and the strength of evidence were evaluated using the Navigation Guide protocol. Nineteen studies assessing environmental or occupational pesticide exposure and sperm parameters were included. Eighteen studies were cross-sectional studies and one prospective cohort; sample sizes ranged from 42 to 2122 men from 14 different countries. Fifteen (79 %) studies found at least one significant association between pesticide exposure and reduced sperm quality. The overall risk of bias across studies was classified as low to moderate. The quality of evidence was determined to be moderate based on systematic evaluation criteria. There were consistent adverse associations between pesticide exposure and sperm motility (63 % of studies) and DNA integrity (80 % of studies). For sperm concentration and morphology, 42 % and 36 % of studies found significant negative associations, respectively. The strength of the body of evidence overall was rated as having sufficient evidence of toxicity. Regarding specific sperm endpoints, there was sufficient evidence that pesticides are toxic for sperm motility and DNA integrity; limited evidence of toxicity for sperm concentration; and inadequate evidence of toxicity for sperm morphology. The studies reviewed here showed consistent associations between pesticide exposure and diminished sperm parameters, particularly sperm motility and sperm DNA integrity. These findings are largely consistent with results of previous reviews, which have found significant negative associations between pesticide exposure and sperm quality in 13 of 20 (65 %) studies published between 1991 and 2008, and in 14 of 17 (82 %) studies published between 2008 and 2012. After thirty years of mounting evidence, actions are needed to reduce pesticide risks to testicular function and male fertility., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The hyperhomocysteinemia (HHcy) is toxic to the cells and associated with several diseases. Clinical studies have shown changes in plasma concentrations of Hcy after physical exercise. This study aimed to assess the effect of HHcy on testis, epididymis and sperm quality and to investigate whether voluntary exercise training protects this system against damage caused by HHcy in Swiss mice. In this study, 48 mice were randomly distributed in the control, HHcy, physical exercise, and HHcy combined with physical exercise groups. HHcy was induced by daily administration of dl-homocysteine thiolactone via gavage throughout the experimental period. Physical exercise was performed through voluntary running on the exercise wheels. The plasma concentrations of homocysteine (Hcy) and testosterone were determined. The testes and epididymis were used to assess the sperm count, histopathology, lipoperoxidation, cytokine levels, testicular cholesterol, myeloperoxidase, and catalase activity. Spermatozoa were analyzed for morphology, acrosome integrity, mitochondrial activity, and motility. In the testes, HHcy increased the number of abnormal seminiferous tubules, reduced the tubular diameter and the height of the germinal epithelium. In the epididymis, there was tissue remodeling in the head region. Ultimately, voluntary physical exercise training reduced plasma Hcy concentration but did not attenuate HHcy-induced testicular and epididymal disturbances., (© 2021. Society for Reproductive Investigation.)

Robinow syndrome (RS) is a rare, pleiotropic genetic disorder. While it has been reported that males with Robinow syndrome may have genitourinary atypicalities, these have not been systematically studied. We hypothesized that the underlying gene involved plays a role in the clinical variability of associated genital findings and that the phenotypic appearance of the genitalia in RS may have a psychological impact. Urologic-specific examination consisted of detailed examination and a questionnaire to investigate the psychological impact of the genital phenotype. Nine males agreed to a full evaluation. Average age was 19.9 years, penile length was 32.5 mm, stretched length 53 mm, and width 24.4 mm. Penile transposition occurred in all 9 male who allowed full examination. Undescended testicles were noted in 4/10, testicular atrophy in 5/9, buried penis in 7/9, hypospadias in 5/8, and a large penopubic gap (space between dorsum of penis base and pubic bone) in 5/6. In this cohort, 78% answered our semi-quantitative pilot questionnaire that identified diminished sexuality, sexual function, and self-perception. In conclusion, RS has unique, hallmark genital findings including penile transposition, buried penis, undescended testes, and large penopubic gaps. Genital phenotype in males was not shown to correlate with the specific gene involved for each patient. Surgical approaches and other interventions should be studied to address the findings of decreased sexuality and self-perception. It is the authors' opinion that intervention to provide the appearance of penile lengthening be postponed until puberty to allow for maximal natural phallic growth., (© 2020 Wiley Periodicals LLC.)

Background: Torsion of the testis is an urgent surgical condition that endangers the viability of the gonad and the fertility of the patient. Our aim was to assess potential autoimmune processes and hormonal abnormalities in boys operated on due to that illness., Methods: The authors evaluated the levels of antibodies against sperm and Leydig cells, concentrations of follicle-stimulating, luteinizing and anti-Müllerian hormone, testosterone, oestradiol and vascular endothelial growth factor in the serum in 28 boys operated on due to torsion of the testis. Patients' sexual maturity was assessed according the Tanner scale (group G1, G4 and G5)., Results: No antibodies against sperm or Leydig cells were found in the serum. Statistically significant differences in follicle-stimulating and anti-Müllerian hormone concentrations were observed in the G1, and they were higher in the study than in the control group. There were no statistically significant differences in luteinizing hormone, testosterone, oestradiol and vascular endothelial growth factor concentrations in the study group or control group. Testosterone concentration was unrelated to total testicular volume., Conclusions: Results did not confirm the autoimmune process in boys with torsion of the testis. The pituitary-testis axis seems to have sufficient compensation capabilities. However, study results suggest that primary gonadal dysfunction may predispose to torsion., Impact: Significant differences exist between the literature data and own results on the formation of antibodies and hormonal changes due to testicular torsion in boys. It is a novel, prospective study on antibodies against sperms and Leydig cells in the serum and on hormonal processes occurring as a result of the testicular torsion from the prenatal period to the adolescence with division into pubertal groups. The study has revealed sufficient compensation capabilities of the pituitary-testis axis and no autoimmune process in boys with torsion of the testis., (© 2021. The Author(s).)

Since the outbreak of the COVID-19, up to now, infection cases have been continuously rising to over 200 million around the world. Male bias in morbidity and mortality has emerged in the COVID-19 pandemic. The infection of SARS-CoV-2 has been reported to cause the impairment of multiple organs that highly express the viral receptor angiotensin-converting enzyme 2 (ACE2), including lung, kidney, and testis. Adverse effects on the male reproductive system, such as infertility and sexual dysfunction, have been associated with COVID-19. This causes a rising concern among couples intending to have a conception or who need assisted reproduction. To date, a body of studies explored the impact of SARS-CoV-2 on male reproduction from different aspects. This review aims to provide a panoramic view to understand the effect of the virus on male reproduction and a new perspective of further research for reproductive clinicians and scientists., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Guo, Sheng, Wu, Chen and Xu.)

The evolutionary theory of aging supports a trade-off relationship between reproduction and aging. Aging of the male reproductive system primarily affects the testes, leading to a decrease in the levels of sexual hormones, alterations in sperm quality and production, and a decline in fertility that does not necessarily involve a complete cessation of spermatogenesis. Inflammation, oxidation, and apoptosis are events considered as predictors of pathogenesis and the development of age-related diseases that are frequently observed in aged testes. Although the molecular mechanisms are still poorly understood, accumulating evidence points toward pro-inflammatory molecules and reactive oxygen species as primary contributing factors for testicular aging. However, the real impact of aging-related testicular alterations on fertility, reproductive health, and life span is far from being fully revealed. This work discusses the current knowledge on the impact of aging in the testis, particularly of aging-related dysregulated inflammation and oxidative damage on the functioning of its different cell populations. More interestingly, this review covers the potential benefits of anti-aging interventions and therapies using either pharmacological compounds (such as non-selective non-steroidal anti-inflammatory medication) or more natural alternatives (such as various nutraceuticals or even probiotics) that exhibit anti-inflammatory, antioxidant, and anti-apoptotic properties. Some of these are currently being investigated or are already in clinical use to delay or prevent testicular aging.

Triatomines are hematophagous insects of great epidemiological importance, since they are vectors of the protozoan Trypanosoma cruzi, the etiological agent of Chagas disease. Triatoma brasiliensis complex is a monophyletic group formed by two subspecies and six species: T. b. brasiliensis, T. b. macromelasoma, T. bahiensis, T. juazeirensis, T. lenti, T. melanica, T. petrocchiae and T. sherlocki. The specific status of several species grouped in the T. brasiliensis complex was confirmed from experimental crossing and analysis of reproductive barriers. Thus, we perform interspecific experimental crosses between T. lenti and other species and subspecies of the T. brasiliensis complex and perform morphological analysis of the gonads and cytogenetic analysis in the homeologous chromosomes of the hybrids of first generation (F1). Besides that, we rescue all the literature data associated with the study of reproductive barriers in this monophyletic complex of species and subspecies. For all crosses performed between T. b. brasiliensis, T. b. macromelasoma, T. juazeirensis and T. melanica with T. lenti, interspecific copulas occurred (showing absence of mechanical isolation), hybrids were obtained, none of the male hybrids presented the phenomenon of gonadal dysgenesis and 100% pairing between the chromosomes homeologous of the hybrids was observed. Thus, we demonstrate that there are no pre-zygotic reproductive barriers installed between T. lenti and the species and subspecies of the T. brasiliensis complex. In addition, we demonstrate that the hybrids obtained between these crosses have high genomic compatibility and the absence of gonadal dysgenesis. These results point to reproductive compatibility between T. lenti and species and subspecies of the T. brasiliensis complex (confirming its inclusion in the complex) and lead us to suggest a possible recent diversification of the taxa of this monophyletic group., Competing Interests: The authors have declared that no competing interests exist.

Metformin (Met) is widely used to control blood glucose levels and acts on various organs, including reproductive tissues, to improve reproductive and lifespan. This study evaluated whether neonatal Met exposure prevented male reproductive dysfunction caused by being overweight during adulthood. Randomized Wistar rat pups received an intraperitoneal injection from postnatal days (PNDs) 1 to 12of saline (Sal; 0.9% NaCl/day in 2mL/kg) or Met (100 mg/kg/day in 2 mL/kg). From PNDs 60 to 90, the animals received a regular (R; 4.5% fat; Sal R and Met R groups) or a high-fat (HF; 35% fat; Sal HF and Met HF groups) diet. At PND 90, all animals were euthanized to evaluate their biometric and reproductive parameters. The Sal and Met groups with R showed similar body weights, however, the HF diet increased the body weight in both groups. The Sal HF group showed testicular damage regarding in antioxidant status and inflammatory profile in the epididymal cauda. The HF diet reduced Leydig and Sertoli cells numbers, with lower sperm quality. The Met R animals showed positive reproductive programming, due to improved antioxidant defense, inflammatory biomarkers, and sperm morphology. Met HF prevented HF diet damage to reproductive organs and sperm morphology, but not to sperm motility. Early Met exposure positively affected the male reproductive system of adult rats, preventing reproductive HF disorders. STATEMENT OF NOVELTY AND SIGNIFICANCE: Metformin is used to control type 2 diabetes mellitus and can act to improve metabolism and lifespan. Metformin avoidance is recommended during pregnancy, but there is no information regarding its use when breastfeeding. For the first time, we showed in this current study that metformin positively acts in the male reproductive tissues and helps involved in later life. These data showed a better antioxidant defense and anti-inflammatory profile of Metformin animals than Saline animals and might directly improve reproductive organs morphophysiology and sperm morphology. Also, the neonatal Met application programs the male reproduction to counterbalance damages from an obesogenic environment in later life., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: The prospective, randomized AHL2011 trial demonstrated that the use of the doxorubicin, bleomycin, vinblastine, and dacarbazine regimen (ABVD) after two cycles of bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP escalated ) in early responders on the basis of a positron emission tomography (PET)-driven strategy was safe and minimized toxicity compared with standard 6 BEACOPP escalated cycles. This substudy investigated the benefit of this strategy in gonadal function and fertility in patients under 45 years old., Methods: Ovarian function was assessed by serum measurement of follicle-stimulating hormone (FSH), estradiol, and anti-müllerian hormone in women, and semen analysis, FSH, and testosterone levels were used to evaluate testicular function in men at baseline, end of treatment, and during 5 years of follow-up., Results: A total of 145 women and 424 men, enrolled between May 19, 2011, and April 29, 2014, were included. The risk of premature ovarian insufficiency (FSH > 24 IU/L) and of having a low ovarian reserve (anti-müllerian hormone < 0.5 ng/mL) was reduced after treatment in the PET-driven group (odds ratio [OR], 0.20; 95% CI, 0.08 to 0.50; P = .001 and OR, 0.15; 95% CI, 0.04 to 0.56, P = .005, respectively). Both parameters were correlated with age and dose of alkylating agents. However, no significant differences were observed in terms of pregnancy rates. Men in the PET-driven group had a higher recovery rate of sperm parameters after treatment compared with the standard BEACOPP escalated group, as well as a lower risk of severe testicular damage (OR, 0.26; 95% CI, 0.13 to 0.5; P < .0001) and a higher likelihood of achieving pregnancy (OR, 3.7; 95% CI, 1.4 to 9.3; P = .004)., Conclusion: Although both treatments affected ovarian reserve and spermatogenesis, the PET-driven strategy decreased the risk of gonadal dysfunction and infertility in advanced Hodgkin lymphoma., Competing Interests: Isabelle DemeestereConsulting or Advisory Role: RocheResearch Funding: Roche diagnosisTravel, Accommodations, Expenses: Ferring Jehan DupuisConsulting or Advisory Role: AstraZenecaTravel, Accommodations, Expenses: Gilead Sciences Franck MorschhauserConsulting or Advisory Role: Roche/Genentech, Gilead Sciences, Celgene, Bristol Myers Squibb, AbbVie, Epizyme, ServierSpeakers' Bureau: RocheExpert Testimony: Roche/Genentech Virginie De WildeConsulting or Advisory Role: Takeda, Janssen Oncology Julien LazaroviciTravel, Accommodations, Expenses: Roche, Novartis, Sandoz, Janssen-Cilag, Jazz Pharmaceuticals France, Daiichi Sankyo Oncology France, Mundipharma, Pfizer, AbbVie Hervé GhesquieresHonoraria: Gilead Sciences, Janssen, Celgene, RocheConsulting or Advisory Role: Gilead Sciences, Celgene, Roche, MundipharmaTravel, Accommodations, Expenses: Roche, Gilead Sciences, Celgene, Takeda Mohamed TouatiHonoraria: AmgenConsulting or Advisory Role: Janssen, Bristol Myers Squibb/Celgene David SibonConsulting or Advisory Role: Takeda, Iqone healthcare, Janssen, RocheTravel, Accommodations, Expenses: Takeda, Janssen Luc-Matthieu ForneckerConsulting or Advisory Role: Takeda, RocheTravel, Accommodations, Expenses: Takeda, Roche Marc AndréConsulting or Advisory Role: Takeda, BMSiResearch Funding: Takeda, RocheTravel, Accommodations, Expenses: Roche, Celgene, Gilead Sciences René-Olivier CasasnovasHonoraria: Roche/Genentech, Takeda, Gilead Sciences, Bristol Myers Squibb, Merck, AbbVie, Celgene, Janssen, AmgenConsulting or Advisory Role: Roche/Genentech, Takeda, Gilead Sciences, Bristol Myers Squibb, Merck, AbbVie, Celgene, Janssen, IncyteResearch Funding: Roche/Genentech, Gilead Sciences, TakedaTravel, Accommodations, Expenses: Roche/Genentech, Takeda, Gilead Sciences, JanssenNo other potential conflicts of interest were reported.

The World Health Organization has recognized that testicular function is temperature dependent. Testicular heat exposure caused by occupational factors, lifestyle, and clinical diseases can lead to different degrees of reproductive problems. The aim of this study was to reveal the transcriptional regulatory network and its potential crucial roles in mediating the effects of testicular heat exposure. Testicular tissue was collected from a group of mice subjected to scrotal heat exposure as well as a control group. RNA was isolated from both groups and used for high-throughput sequencing. Using differential transcriptome expression analysis, 172 circRNAs, 279 miRNAs, 465 lncRNAs, and 2721 mRNAs were identified as significantly differentially expressed in mouse testicular tissue after heat exposure compared with the control group. Through Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses, differentially expressed lncRNAs and mRNAs were found to have potentially important functions in meiotic cell cycle (GO:0051321), cytoplasm (GO:0005737), membrane raft (GO:0045121), MAPK signaling (mmu04010), purine metabolism (mmu00230), and homologous recombination (mmu03440). Some of the most upregulated and downregulated lncRNAs and circRNAs were predicted to be associated with numerous miRNAs and mRNAs through competing endogenous RNA regulatory network analysis, which were validated with molecular biology experiments. This research provides high-throughput sequencing data of a testicular heat exposure model and lays the foundation for further study on circRNAs, miRNAs, and lncRNAs that are involved in male reproductive diseases related to elevated testicular temperature., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Coronavirus disease 2019 (COVID-19), which resulted from the pandemic outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), causes a massive inflammatory cytokine storm leading to multi-organ damage including that of the brain and testes. While the lungs, heart, and brain are identified as the main targets of SARS-CoV-2-mediated pathogenesis, reports on its testicular infections have been a subject of debate. The brain and testes are physiologically synchronized by the action of gonadotropins and sex steroid hormones. Though the evidence for the presence of the viral particles in the testicular biopsies and semen samples from COVID-19 patients are highly limited, the occurrence of testicular pathology due to abrupt inflammatory responses and hyperthermia has incresingly been evident. The reduced level of testosterone production in COVID-19 is associated with altered secretion of gonadotropins. Moreover, hypothalamic pathology which results from SARS-CoV-2 infection of the brain is also evident in COVID-19 cases. This article revisits and supports the key reports on testicular abnormalities and pathological signatures in the hypothalamus of COVID-19 patients and emphasizes that testicular pathology resulting from inflammation and oxidative stress might lead to infertility in a significant portion of COVID-19 survivors. Further investigations are required to monitor the reproductive health parameters and HPG axis abnormalities related to secondary pathological complications in COVID-19 patients and survivors., (© 2020. Society for Reproductive Investigation.)

Purpose: Testicular temperature should remain low to maintain optimal function of germ cells; however, information regarding testicular temperature in infants and the effect of cryptorchidism and its correction, including laparoscopic staged Fowler-Stephens orchiopexy (LSFSO), is limited., Materials and Methods: A total of 82 infants with unilateral palpable cryptorchidism, 24 with nonpalpable testes who underwent unilateral LSFSO and 20 with scrotal hydrocele were included. Ultrasonographic determination of testicular volume and measurement of testicular temperature but not scrotal surface temperature using a Coretemp CTM204 ® (Terumo, Tokyo) were performed before and 12 months after orchiopexy. The effects of the route of testicular delivery, conventionally through a new hiatus medial to the inferior epigastric vessels or through the transinguinal approach, were investigated in the LSFSO cases., Results: Undescended testicular volume was significantly increased after orchiopexy (0.80 ml to 0.92 ml, p <0.0001). The preoperative testicular temperature (35.1C) was significantly higher than that of the control (34.4C, p <0.0001), and significant decreases in testicular temperature occurred after orchiopexy (34.3C, p <0.0001). A multivariate analysis showed that a decrease in testicular temperature was a factor associated with postoperative testicular development. Twelve months after LSFSO, transinguinal approach was shown to be more effective in decreasing the testicular temperature than the conventional approach (34.4 and 35.3C, respectively, p <0.05)., Conclusions: Orchiopexy is effective in correcting the high-temperature environment caused by cryptorchidism. In the case of nonpalpable testes treated by LSFSO, transinguinal fixation is more effective than the conventional approach in reducing testicular temperature, but a longer followup period is necessary to draw a final conclusion.

Introduction: Our study analysed previous studies employing positron emission tomography with co-registered computer tomography (PET/CT) in andrological patient evaluation and assessed the differences in 2-[ 18 F]F-fluoro-2'-deoxyglucose (FDG) uptake between three groups: healthy testes, benign and malignant testicular pathology., Methods: Medline and Embase were systematically searched for studies involving FDG-PET/CT imaging of testes with results expressed as mean standardised uptake value (SUV mean ). A one-way ANOVA was used to compare SUV mean between three groups. All papers assessing andrological parameters were pooled to compare fertility data., Results: Seventeen studies, including three relating to fertility diagnosis, with a total of 830 patients, were included in the review. One-way ANOVA showed a statistical difference between mean values of tracer SUV mean in healthy and malignant testes (Dif. = -2.77, 95% CI = -4.32 to 1.21, p < 0.01) as well as benign and malignant (Dif. = -2.95, 95% CI = -4.33 to -1.21, p < 0.01) but no difference between healthy and benign (Dif. = 0.19, 95% CI = -0.96 to 1.33, p = 0.90). There is some evidence to suggest that FDG uptake and testicular volume are positively correlated to total sperm count, sperm concentration and sperm motility and that germ cells are likely to account for the majority of testicular FDG accumulation., Conclusion: Our findings indicate that malignant testicular lesions demonstrate a significantly higher FDG uptake than benign testicular lesions or healthy testes. Some evidence also suggests that FDG-PET could visualise metabolic activity and thus spermatogenesis; however more studies are required to determine whether FDG-PET could also be used to diagnose infertility. Further studies should focus on correlating both sex hormone-serum levels and semen analysis results with imaging data., (© 2021 The Authors. Andrology published by Wiley Periodicals LLC on behalf of American Society of Andrology and European Academy of Andrology.)

Background: Cancer treatment of prepubertal patients impacts future fertility due to the abolition of spermatogonial stem cells (SSCs). In macaques, spermatogenesis could be regenerated by intratesticular transplantation of SSCs, but no studies have involved cytotoxic treatment before puberty and transplantation after puberty, which would be the most likely clinical scenario., Objectives: To evaluate donor-derived functional sperm production after SSC transplantation to adult monkeys that had received testicular irradiation during the prepubertal period., Materials and Methods: We obtained prepubertal testis tissue by unilaterally castrating six prepubertal monkeys and 2 weeks later irradiated the remaining testes with 6.9 Gy. However, because spermatogenic recovery was observed, we irradiated them again 14 months later with 7 Gy. Three of the monkeys were treated with GnRH-antagonist (GnRH-ant) for 8 weeks. The cryopreserved testis cells from the castrated testes were then allogeneically transplanted into the intact testes of all monkeys. Tissues were harvested 10 months later for analyses., Results: In three of the six monkeys, 61%, 38%, and 11% of the epididymal sperm DNA were of the donor genotype. The ability to recover donor-derived sperm production was not enhanced by the GnRH-ant pretreatment. However, the extent of filling seminiferous tubules during the transplantation procedure was correlated with the eventual production of donor spermatozoa. The donor epididymal spermatozoa from the recipient with 61% donor contribution were capable of fertilizing rhesus eggs and forming embryos. Although the transplantation was done into the rete testis, two GnRH-ant-treated monkeys, which did not produce donor-derived epididymal spermatozoa, displayed irregular tubular cords in the interstitium containing testicular spermatozoa derived from the transplanted donor cells., Discussion and Conclusion: The results further support that sperm production can be restored in non-human primates from tissues cryopreserved prior to prepubertal and post-pubertal gonadotoxic treatment by transplantation of these testicular cells after puberty into seminiferous tubules., (© 2021 American Society of Andrology and European Academy of Andrology.)

Background: Varicocele (VC) is present in 35 - 40% of men with infertility. However, current surgical and antioxidant treatments are not completely effective. In addition to oxidative stress, it is likely that other factors such as testicular immune microenvironment disorder contribute to irreversible testicular. Evidence suggests that VC is associated with anti-sperm antibodies (ASAs), spermatogenesis and testosterone secretion abnormalities, and testicular cytokine production. Moreover, inhibition of inflammation can alleviate VC-mediated pathogenesis. The normal function of the testis depends on its immune tolerance mechanism. Testicular immune regulation is complex, and many infectious or non-infectious diseases may damage this precision system., Results: The testicular immune microenvironment is composed of common immune cells and other cells involved in testicular immunity. The former includes testicular macrophages, T cells, dendritic cells (DCs), and mast cells, whereas the latter include Leydig cells and Sertoli cells (SCs). In animal models and in patients with VC, most studies have revealed an abnormal increase in the levels of ASAs and pro-inflammatory cytokines such as interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha in the seminal plasma, testicular tissue, and even peripheral blood. It is also involved in the activation of potential inflammatory pathways, such as the nucleotide-binding oligomerization domain-like receptor family pyrin domain containing (NLRP)-3 pathway. Finally, the development of VC-mediated infertility (VMI) may be facilitated by abnormal permeability of proteins, such as claudin-11, that constitute the blood-testis barrier (BTB)., Conclusions: The testicular immune response, including the production of ASAs and inflammatory factors, activation of inflammatory pathways, and destruction of the BTB may be involved in the pathogenesis of VMI it is necessary to further explore how patient outcomes can be improved through immunotherapy., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Fang, Su, Xu, Hu, Zhao, Liu and Zhang.)

Breeding bulls infected with Besnoitia besnoiti may develop sterility during either acute or chronic infection. The aim of this study was to investigate the molecular pathogenesis of B. besnoiti infection with prognosis value in bull sterility. Accordingly, five well-characterized groups of naturally and experimentally infected males were selected for the study based on clinical signs and lesions compatible with B. besnoiti infection, serological results and parasite detection. A broad panel of molecular markers representative of endothelial activation and fibrosis was investigated and complemented with a histopathological approach that included conventional histology and immunohistochemistry. The results indicated the predominance of an intense inflammatory infiltrate composed mainly of resident and recruited circulating macrophages and to a lesser extent of CD3+ cells in infected bulls. In addition, a few biomarkers were associated with acute, chronic or subclinical bovine besnoitiosis. The testicular parenchyma showed a higher number of differentially expressed genes in natural infections (acute and chronic infections) versus scrotal skin in experimental infections (subclinical infection). In subclinical infections, most genes were downregulated except for the CCL24 and CXCL2 genes, which were upregulated. In contrast, the acute phase was mainly characterized by the upregulation of IL-1α, IL-6 and TIMP1, whereas in the chronic phase, the upregulation of ICAM and the downregulation of MMP13, PLAT and IL-1α were the most relevant findings. Macrophages could be responsible for the highest level of gene regulation in the testicular parenchyma of severely affected and sterile bulls, and all these genes could be prognostic markers of sterility., (© 2021. The Author(s).)

Cryopreservation of testicular cells and tissues is useful for the preservation and restoration of fertility in pre-pubertal males expecting gonadotoxic treatment for cancer and genetic diseases causing impaired spermatogenesis. A number of freezing and vitrification protocols have thus been tried and variable results have been reported in terms of cell viability spermatogenesis progression and the production of fertile spermatozoa. A few studies have also reported the production of live offspring from cryopreserved testicular stem cells and tissues in rodents but their replication in large animals and human have been lacking. Advancement in in vitro spermatogenesis system has improved the possibility of producing fertile spermatozoa from the cryopreserved testis and has reduced the dependency on transplantation. This review provides an update on various cryopreservation strategies for fertility preservation in males expecting gonadotoxic treatment. It also discusses various methods of assessing and ameliorating cryoinjuries. Newer developments on in vitro spermatogenesis and testicular tissue engineering for in vitro sperm production from cryopreserved SSCs and testicular tissue are also discussed., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.)

This study explored treatment with Taif rosewater (RW) to protect against lead acetate-(PbAc) induced male testicular impairment. Male Wistar rats were divided into four groups and provided drinking water containing 4% Taif RW, PbAc, 4% Taif RW followed by PbAc or normal water (controls). Serum for hormonal assays and testicular tissue for histopathological and immunohistochemical examinations and molecular study were obtained. Epididymal spermatozoa were collected for analysis. PbAc significantly reduced serum levels of follicle-stimulating hormone (FSH), luteinising hormone (LH) and testosterone, as well as sperm count and motility percentage. It also caused a significant reduction in SOD and catalase activities, testicular CYTP450 SCC , CYP17α, StAR mRNA expressions and the percentage of Bcl-2 immunoreactivity. The percentage of caspase-3 and NF-ĸB immunoreactivities, as well as sperm abnormalities, was increased, as did the testicular degeneration associated with vacuolation and necrosis of spermatogenic cells. Pretreatment with Taif RW significantly reduced the negative effects of PbAc as shown by the increases in serum gonadotropins level, SOD and catalase activities, and percentage of Bcl-2 immunoreactivity, decreases in the percentage of caspase-3 and NF-ĸB immunoreactivities, and improved testicular histology and sperm parameters. These data provide evidence that Taif RW protects against testicular toxicity caused by PbAc., (© 2021 Wiley-VCH GmbH.)

Purpose: Higher grade aneuploidies (HGAs) of the male sex chromosomes are a rare genetic group of pathologies caused by nondisjunction meiotic events. The aim of this study was to evaluate the impact of early androgenic therapy on the testicular secretory hormone profile, and the pathophysiological implications., Patients and Methods: In this cross-sectional study, 18 HGA subjects aged 6-8 years were recruited. They were divided into two groups, based on whether or not they had previously undergone testosterone therapy (group 1: 11 untreated subjects; group 2: 7 treated subjects). Serum FSH, LH, testosterone (T), inhibin B (INHB) and anti-Müllerian hormone (AMH) were determined, and auxological parameters were assessed. Five group 1 patients and four group 2 patients were treated with hCG (human chorionic gonadotropin) for inguinal cryptorchidism; their hormone profile and auxological parameters were assessed both pre- and post-hCG treatment., Results: Group 1 subjects showed significantly higher testicular volume and higher levels of AMH and INHB (p < 0.0001). Subjects who had undergone hCG therapy showed a significantly higher testicular volume, penis length (respectively, p = 0.008 and p = 0.0005 for group 1 and p = 0.04 and p = 0.001 for group 2) and T (p = 0.005 for group 1 and p = 0.004 for group 2)., Conclusions: HGA patients undergoing early testosterone therapy show an earlier and persistent suppression of testicular secretory function. At this age, the testes are still responsive to stimulation with hCG. The selection of patients to be treated must be accompanied by a thorough clinical and hormonal evaluation.

To facilitate temperature adjustments, the testicles are located outside the body cavity. In most mammals, the temperature of the testes is lower than the body temperature to ensure the normal progression of spermatogenesis. Rising temperatures affect spermatogenesis and eventually lead to a decline in male fertility or even infertility. However, the testes are composed of different cell types, including spermatogonial stem cells (SSCs), spermatocytes, spermatozoa, Leydig cells, and Sertoli cells, which have different cellular responses to heat stress. Recent studies have shown that using different drugs can relieve heat stress-induced reproductive damage by regulating different signaling pathways. Here, we review the mechanisms by which heat stress damages different cells in testes and possible treatments., (© 2021 The Author(s).)

It is well established that maternal lifestyle during pregnancy and lactation affects the intrauterine programming of F1 offspring. However, despite the co-use of alcohol and nicotine is a common habit, the effects of exposure to both substances on the reproductive system of F1 male offspring and the underlying mechanisms of developmental programming have not been investigated. The present study aimed to examine pre- and postnatal concurrent exposure to these substances on genetic and epigenetic alterations of sperm cells as well as testis properties of F1 offspring compared with exposure to each substance alone. Pregnant dams in the F0 generation randomly received normal saline, nicotine, ethanol, and combinations throughout full gestation and lactation periods. Sperm cells and testes of F1 male offspring were collected at postnatal day 90 for further experiments. High levels of sperm DNA fragmentation were observed in all exposed offspring. Regarding epigenetic alterations, there was a significant increase in the relative transcript abundance of histone deacetylase 1 and 2 in all exposed sperm cells. Moreover, despite a decrease in the expression level of DNA methyltransferase (DNMT) 3A, no marked differences were found in the expression levels of DNMT1 and 3B in any of the exposed sperm cells compared to non-exposed ones. Interestingly, combined exposure had less prominent effects relative to exposure to each substance alone. The changes in the testicular and sperm parameters were compatible with genetic and epigenetic alterations. However, MDA level as an oxidative stress indicator increased in all exposed pups, which may be responsible for such outputs. In conclusion, maternal co-exposure to these substances exhibited epigenotoxicity effects on germline cells of F1 male offspring, although these effects were less marked relative to exposure to each substance alone. These counteracting effects may be explained by cross-tolerance and probably less impairment of the antioxidant defense system.

Background: Biological relevance of the major testis specific histone H2B variant (TH2B) in sperm is not fully understood. Studies in TH2A/TH2B double knockout male mice indicate its role in chromatin compaction and male fertility. Additionally, the presence of TH2B and TH2A reportedly generates more dynamic nucleosomes, leading to an open chromatin structure characteristic of transcriptionally active genome. Given that mature human sperm are transcriptionally and translationally inactive, the presence of TH2B in mature sperm is intriguing. To address its role in sperm, we investigated the genome-wide localization of TH2B in sperm of fertile men., Results: We have identified the genomic loci associated with TH2B in fertile human sperm by ChIP-seq analysis. Bioinformatic analysis revealed ~ 5% sperm genome and 5527 genes to be associated with TH2B. Out of these 105 (1.9%) and 144 (2.6%) genes showed direct involvement in sperm function and early embryogenesis, respectively. Chromosome wide analysis for TH2B distribution indicated its least distribution on X and Y chromosomes and varied distribution on autosomes. TH2B showed relatively higher percentage of gene association on chromosome 4, 18, 3 and 2. TH2B enrichment was more in promoter and gene body region. Gene Ontology (GO) analysis revealed signal transduction and associated kinase activity as the most enriched biological and molecular function, respectively. We also observed the enrichment of TH2B at developmentally important loci, such as HOXA and HOXD and on genes required for normal sperm function, few of which were validated by ChIP-qPCR. The relative expression of these genes was altered in particular subgroup of infertile men showing abnormal chromatin packaging. Chromatin compaction positively correlated with sperm- motility, concentration, viability and with transcript levels of PRKAG2 and CATSPER B., Conclusion: ChIP-seq analysis of TH2B revealed a putative role of TH2B in sperm function and embryo development. Altered expression of TH2B associated genes in infertile individuals with sperm chromatin compaction defects indicates involvement of TH2B in transcriptional regulation of these genes in post meiotic male germ cells. This altered transcriptome may be a consequence or cause of abnormal nuclear remodeling during spermiogenesis.

Objectives: To study the effect of combined gonadotropin therapy (CGT) on testicular descent ± spermatogenesis in congenital hypogonadotropic hypogonadism (CHH) patients with cryptorchidism beyond infancy., Methods: This retrospective cohort study included CHH patients with cryptorchidism [bilateral (n=5) or unilateral (n=1)] treated with CGT for testicular descent ± pubertal induction. All participants were treated with CGT [human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG)] with hMG pretreatment in three and monitored for changes in testicular volume (TV), serum total testosterone (T), serum inhibin-B, and sperm concentration., Results: Complete testicular descent to the scrotal position was achieved in 5/6 patients (10/11 testes) after 4.7 ± 1.6 months of treatment. There was 44 ± 18%, 97.5% (IQR: 44-195), 10-fold (IQR: 3-19.6), and two-fold (IQR: 1.7-9.3) increase in stretched penile length, ultrasound measured TV, T level, and serum inhibin-B from baseline, respectively. In two pediatric cases, testicular descent occurred with isolated hMG therapy. At the last follow up (median: 23.5, IQR: 10.5-38.7 months), all the descended testes remained in scrotal position. In four pubertal/postpubertal age patients, continuous CGT (18-60 months) yielded T and inhibin-B levels of 16.64 ± 1.46 nmol/l and 106 ± 32.6 pg/mL, respectively. All the three patients with available semen analysis had sperm concentration of ≥5 million/mL and one of them achieved paternity., Conclusions: A trial of CGT before orchiopexy may be considered in CHH males with cryptorchidism even beyond the narrow age-window of infancy. CGT may also have beneficial effects on future spermatogenesis and fertility outcomes in these patients., (© 2021 Walter de Gruyter GmbH, Berlin/Boston.)

The molecular mechanism underlying diabetes-induced testicular damage has not been thoroughly elucidated. The present study was conducted to elucidate the role of mitochondria-mediated apoptosis in diabetes-induced testicular dysfunction in rats and to explore the ameliorative effect of resveratrol. Diabetes suppressed sperm count, motility, and viability and increased sperm abnormalities. It decreased serum testosterone level and testicular mitochondrial membrane potential. The level of Bax and caspase-3 and -9 activities were increased in the testicular cytosol, while the level of Bcl-2 was decreased. Diabetes increased the Bax/Bcl-2 ratio. The cytochrome C level was decreased in the mitochondrial fraction, while its level was increased in the cytosol, a result that was supported by the immunohistochemistry of cytochrome C. Diabetes resulted in deleterious alterations in the architecture of testicular tissue, suppressed antioxidant enzymes, and increased H2O2 production, protein carbonyl content, and lipid peroxidation. However, administration of resveratrol at a dose of 50 mg kg/day for 4 successive weeks post diabetic induction, successfully ameliorated the testicular dysfunction. In conclusion, these findings strongly reveal that diabetes induces testicular damage, at least in part, by inducing mitochondrial-mediated apoptosis and oxidative stress. Administration of resveratrol to diabetic rats improves the diabetes-induced testicular damage. These impacts could be mediated through resveratrol antioxidant and anti-apoptotic effects., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Responsible for post-testicular maturation, concentration, protection and sperm storage, the epididymis is an organ that can be easily subdivided into three segments: caput, corpus and cauda. Each epididymal region displays different morphology and functions within the sperm maturation process. Despite the great importance of this organ, studies on its morphology and hormonal control in bats remain scarce. Thus, the aim of this study was to morphologically analyze the epididymis of the bat Molossus molossus (Chiroptera: Molossidae), in order to evaluate its morphological and morphometric variations, as well as some aspects of its hormonal control during the annual reproductive cycle. For this purpose, 60 sexually adult males were used in this study, comprising five specimens collected monthly for one year to form 12 sample groups. The epididymis was subjected to morphological, morphometric and immunohistochemical analyses. The results demonstrated that the processes of total testicular regression and posterior recrudescence suffered by M. molossus also impacts the physiology of the epididymis, however, a delay in the epididymal response is seen due to the storage of sperm. Similar to other mammals, the epididymis of M. molossus has a large predominance of principal and basal cells. The epididymal seasonal variations appear to be directly correlated to rainfall and photoperiod, but not to temperature. Meanwhile, epididymal physiology appears to be regulated, at least partially, by the expression of the androgen receptor in epithelial cells, which has agonist effects on cell proliferation., (Copyright © 2021 Elsevier GmbH. All rights reserved.)

Background: Literature has demonstrated that diabetes is associated with renal complication and testicular dysfunctions. The current study explored the potential of Tiliacora triandra extract and its major component against diabetic kidney and testicular damages in rats., Methods: Diabetes was induced by high fat diet/streptozotocin (HFD/STZ) and treated orally with Tiliacora triandra extract (TTE, 100 and 400 mg kg -1 body weight) and its major component, 5,7-dihydroxy-6-oxoheptadecanoic acid (DHA, 25 mg kg -1 body weight) for 30 consecutive days. Testicular activities of testicular enzymes, serum levels of testosterone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH), sperm parameters and urinalysis for protein and albumin levels were evaluated. Renal and testicular biomarkers of oxidative stress and pro-inflammation were analysed along with histology., Results: The experimental diabetes induced significant alterations in the levels and activities of indices evaluated compared to non-diabetic normal rats. The 28-day treatment of diabetic rats with TTE and DHA markedly improved activities of testicular enzymes, restored levels of testosterone, LH and FSH and sperm parameters compared to untreated diabetic rats. TTE and DHA abrogated proteinuria and reversed urine albumin level. Testicular and renal oxidative stress and pro-inflammation were attenuated in diabetic rats treated with TTE and DHA. The diabetes-mediated histopathological damage was alleviated in the kidney and testis., Conclusion: The protective effect of TTE and DHA against diabetes induced kidney and testicular damages may be related to its antioxidant and anti-inflammatory activities. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Background: The industrial revolution has resulted in increased synthesis and the introduction of a variety of compounds into the environment and their potentially hazardous effects have been observed in the biota. The present study was aimed to evaluate the potential endocrine-disrupting effects of chronic exposure to the low concentrations of bisphenol S (BPS) in male rats., Methods: Weaning male Sprague-Dawley rats (22 days old) were either exposed to water containing 0.1% ethanol for control or different concentrations of BPS (0.5, 5, and 50 μg/L) in drinking water for 48 weeks in the chronic exposure study. After completion of the experimental period, animals were dissected and different parameters (hormone concentrations, histology of testis and epididymis, oxidative stress and level of antioxidant enzymes in the testis, daily sperm production (DSP), and sperm parameters) were determined., Results: Results of the present study showed a significant alteration in the gonadosomatic index (GSI) and relative reproductive organ weights. Oxidative stress in the testis was significantly elevated while sperm motility, daily sperm production, and the number of sperm in epididymis were reduced. Plasma testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) concentrations were reduced and estradiol levels were high in the 50 μg/L-exposed group. Histological observations involved a significant reduction in the epithelial height of the testis along with disrupted spermatogenesis, an empty lumen of the seminiferous tubules, and the caput region of the epididymis., Conclusion: These results suggest that exposure to 5 and 50 μg/L of BPS for the chronic duration started from an early age can induce structural changes in testicular tissue architecture and endocrine alterations in the male reproductive system which may lead to infertility in males.

The effects of radiation exposure on germ cells and the gonads have been well studied at acute high-dose exposures, but the effects of chronic low-dose-rate (LDR) irradiation, particularly relevant for radiation protection, on germ cells and the gonads are largely unknown. Our previous study revealed that chronic exposure of mice to medium-dose-rate (MDR, 200 or 400 mGy/day) gamma-rays in utero for the entire gestation period (18 days) induced only a mild degree of general growth retardation, but with very drastic effects on the gonads and germ cells. In the current study, we further investigated the histomorphological changes in the gonads and the number of germ cells from gestation day (GD) 18 fetuses irradiated with MDR throughout the entire gestation period. The germ cells in the testes and ovaries of the MDR-irradiated fetuses were almost obliterated. Gestation day 18 fetuses exposed to LDR (20 mGy/day) radiation for the entire gestation period showed decreases in the number of the germ cells, which were not statistically significant or only marginally significant at most. Further investigations on the effects of LDR irradiation in utero using more sensitive methods are necessary., (©2021 by Radiation Research Society. All rights of reproduction in any form reserved.)

The association of exertional heat stroke (EHS) and testicular morphological changes affecting sperm quality, as well as the association of EHS and hypothalamic changes affecting sexual behavior, has yet to be elucidated. This study aimed to elucidate the effects of EHS on fertility, erectile function, and testicular morphology in male rats. Animals were exercised at higher room temperature (36 ℃ relative humidity 50%) to induce EHS, characterized by excessive hyperthermia, neurobehavioral deficits, hypothalamic cell damage, systemic inflammation, coagulopathy, and multiple organ injury. In particular, EHS animals had erectile dysfunction (as determined by measuring the changes of intracavernosal pressure and mean arterial pressure in response to electrical stimulation of cavernous nerves). Rats also displayed testicular temperature disruption, poorly differentiated seminiferous tubules, impaired sperm quality, and atrophy of interstitial Leydig cells, Sertoli cells, and peri-tubular cells in the testicular tissues accompanied by no spermatozoa and broken cells with pyknosis in their seminal vesicle and prostatitis. These EHS effects were still observed after 3 days following EHS onset, at least. Our findings provide a greater understanding of the effect of experimentally induced EHS on masculine sexual behavior, fertility, stress hormones, and morphology of both testis and prostate.

Invasion or damage of the male reproductive system is one of the reported outcomes of viral infection. Current studies have documented that SARS-CoV-2, which causes COVID-19, can damage the male reproductive system in large part by inflammatory damage caused by a cytokine storm. However, whether SARS-CoV-2 can infect the human testis directly and enter semen is controversial. Other adverse effects of SARS-CoV-2 on male reproduction are also of concern and require comprehensive evaluation. Here, we analyze the invasiveness of SARS-CoV-2 in the testis and examine reported mechanisms by which SARS-CoV-2 interferes with male reproduction. Long-term implications of SARS-CoV-2 infection on male reproduction are also discussed. It should be emphasized that although COVID-19 may induce testicular damage, a substantial decrease in male reproductive capacity awaits clinical evidence. We propose that there is an urgent need to track male COVID-19 patients during their recovery. The development of suitable experimental models, including human reproductive organoids, will be valuable to further investigate the viral impact on reproduction for current and future pandemics.

Cryopreservation of immature testicular tissue is an experimental strategy for the preservation of fertility in prepubertal boys that will be subjected to a gonadotoxic onset, as is the case of oncologic patients. Therefore, the objective of this study was to assess the impact of chemotherapeutic treatments on the testicular histologic phenotype in prepubertal patients. A total of 56 testicular tissue samples from pediatric patients between 0 and 16 years old (28 with at least one previous chemotherapeutic onset and 28 untreated controls) were histologically analyzed and age-matched compared. At least two 5-μm sections from testis per patient separated by a distance of 100 μm were immunostained for the germ cell marker VASA, the spermatogonial markers UTF1, PLZF, UCHL1, and SALL4, the marker for proliferative cells KI67, and the Sertoli cell marker SOX9. The percentage of tubule cross-sections positive for each marker and the number of positive cells per tubule cross-section were determined and association with the cumulative dose received of each chemotherapeutic drug was statistically assessed. Results indicated that alkylating agents, cyclophosphamide and ifosfamide, but also the antimetabolite cytarabine and asparaginase were associated with a decreased percentage of positive tubules and a lower number of positive cells per tubule for the analyzed markers. Our results provide new evidences of the potential of chemotherapeutic agents previously considered to have low gonadotoxic effects such as cytarabine and asparaginase to trigger a severe testicular phenotype, hampering the potential success of future fertility restoration in experimental programs of fertility preservation in prepubertal boys.

Spermatogenesis process is sensitive to heat stress because the testicular temperature is 2 to 4 °C lower than the core body temperature. The current study aimed to investigate the effects of iron oxide nanoparticles containing curcumin on spermatogenesis in mice induced by long-term scrotal hyperthermia. In this experimental study, 18 mice were equally divided into the following three groups: control, scrotal hyperthermia, and scrotal hyperthermia + curcumin-loaded iron particles (NPs) (240 μL) (mice were treated for 20 days). Hyperthermia was induced by exposure to the temperature of 43 °C for 20 min every other day for 5 weeks. Afterward, the animals were euthanized; sperm samples were collected for sperm parameters analysis, and testis samples were taken for histopathology experiments, evaluation of serum testosterone level, and RNA extraction in order to examine the expression of c-kit, STRA8 and PCNA genes. Our study showed that curcumin-loaded iron particles could notably increase the volume of testis, length of seminiferous tubules, sperm parameters, and stereological parameters (i.e., spermatogonia, primary spermatocyte, round spermatid, and Leydig cells) thereby increasing serum testosterone level; in addition, TUNEL-positive cells showed a significant decrease in curcumin-loaded iron particle group. Thus, based on the obtained results, the expression of c-kit, STRA8, and PCNA genes was significantly increased in treatment groups by curcumin-loaded iron particles compared with scrotal hyperthermia-induced mice. In conclusion, curcumin-loaded iron particles can be considered an alternative treatment for improving the spermatogenesis process in scrotal hyperthermia-induced mice.

The novel coronavirus was recognised in December 2019 and caught humanity off guard. The virus employs the angiotensin-converting enzyme 2 (ACE2) receptor for entry into human cells. ACE2 is expressed on different organs, which is raising concern as to whether these organs can be infected by the virus or not. The testis appears to be an organ enriched with levels of ACE2, while the possible mechanisms of involvement of the male reproductive system by SARS-CoV-2 are not fully elucidated. The major focus of the present studies is on the short-term complications of the coronavirus and gains importance on studying the long-term effects, including the possible effects of the virus on the male reproductive system. The aim of this review was to provide new insights into different possible mechanisms of involvement of male gonads with SARS-CoV-2 including investigating the ACE2 axis in testis, hormonal alterations in patients with COVID-19, possible formation of anti-sperm antibodies (ASA) and subsequently immunological infertility as a complication of SARS-CoV-2 infection. Finally, we suggest measuring the sperm DNA fragmentation index (DFI) as a determiner of male fertility impairment in patients with COVID-19 along with other options such as sex-related hormones and semen analysis. Invasion of SARS-CoV-2 to the spermatogonia, Leydig cells and Sertoli cells can lead to sex hormonal alteration and impaired gonadal function. Once infected, changes in ACE2 signalling pathways followed by oxidative stress and inflammation could cause spermatogenesis failure, abnormal sperm motility, DNA fragmentation and male infertility., (© 2020 Wiley-VCH GmbH.)

Purpose: The COVID-19 pandemic, caused by the SARS-CoV-2, represents an unprecedented challenge for healthcare. COVID-19 features a state of hyperinflammation resulting in a "cytokine storm", which leads to severe complications, such as the development of micro-thrombosis and disseminated intravascular coagulation (DIC). Despite isolation measures, the number of affected patients is growing daily: as of June 12th, over 7.5 million cases have been confirmed worldwide, with more than 420,000 global deaths. Over 3.5 million patients have recovered from COVID-19; although this number is increasing by the day, great attention should be directed towards the possible long-term outcomes of the disease. Despite being a trivial matter for patients in intensive care units (ICUs), erectile dysfunction (ED) is a likely consequence of COVID-19 for survivors, and considering the high transmissibility of the infection and the higher contagion rates among elderly men, a worrying phenomenon for a large part of affected patients., Methods: A literature research on the possible mechanisms involved in the development of ED in COVID-19 survivors was performed., Results: Endothelial dysfunction, subclinical hypogonadism, psychological distress and impaired pulmonary hemodynamics all contribute to the potential onset of ED. Additionally, COVID-19 might exacerbate cardiovascular conditions; therefore, further increasing the risk of ED. Testicular function in COVID-19 patients requires careful investigation for the unclear association with testosterone deficiency and the possible consequences for reproductive health. Treatment with phosphodiesterase-5 (PDE5) inhibitors might be beneficial for both COVID-19 and ED., Conclusion: COVID-19 survivors might develop sexual and reproductive health issues. Andrological assessment and tailored treatments should be considered in the follow-up.

Arsenic, a major environmental pollutant of global concern, is well-known for its reproductive toxicity. In this study, the protective potential of chlorogenic acid (CGA), a caffeoylquinic acid isomer abundantly found in many plants, was investigated against sodium arsenite (NaAsO 2 )-induced testicular dysfunctions. Adult male Swiss mice were either administered NaAsO 2 alone at 5 mg kg -1 or co-treated with CGA at 100 mg kg -1 or 200 mg kg -1 body weight for 4 weeks. Results showed that NaAsO 2 -treated mice exhibited marked declines in testes weight, sperm count, and viability accompanied by decreases in sexual hormonal levels. Moreover, NaAsO 2 toxicity evoked exhaustion of antioxidant markers (SOD, CAT, GPx, GR, and GSH), down-regulation of Nrf2 (nuclear factor erythroid 2-related factor 2) gene expression level, and elevations in malondialdehyde. Further, elevations in inflammatory cytokines (IL-1, TNF-α, and IL-6) together with the up-regulation of pro-apoptotic biomarkers (Bax and caspase- 3) and down-regulation of anti-apoptotic Bcl-2 were observed in NaAsO 2 intoxication. Immunohistochemical analysis of testis sections of NaAsO 2 -treated mice showed high caspase-3 expression. These findings were well supported with testicular histopathological examination. However, pretreatment of mice with CGA resulted in noteworthy improvements in testicular damage induced by arsenic in a dose-dependent manner possibly mediated by the Nrf2 signaling pathway. Conclusively, CGA counteracted arsenic-induced testicular injury through its antioxidant, anti-inflammatory, and anti-apoptotic properties. Therefore, CGA could serve as a favorable intervention in the alleviation of arsenic-induced reproductive toxicity., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: Klinefelter syndrome (KS) is a genetic disorder caused by the presence of an extra X chromosome in males. The aim of this study was to evaluate the hypothalamic-pituitary-gonadal (HPG) axis and the clinical profile of KS boys from mini-puberty to early childhood., Patients and Methods: In this retrospective, cross-sectional, population study, 145 KS boys and 97 controls aged 0-11.9 years were recruited. Serum FSH, LH, testosterone (T), Inhibin B (INHB), sex hormone binding globulin (SHBG) and anti-Müllerian hormone (AMH) were determined. Auxological parameters were assessed. To better represent the hormonal and clinical changes that appear in childhood, the entire population was divided into 3 groups: ≤ 6 months (group 1; mini-puberty); > 6 months and ≤ 8 years (group 2; early childhood); > 8 and ≤ 12 years (group 3; mid childhood)., Results: During mini-puberty (group 1), FSH and LH were significantly higher in KS infants than controls (p < 0.05), as were INHB and T (respectively p < 0.0001 and p < 0.005). INHB was also significantly higher in KS than controls in group 2 (p < 0.05). AMH appeared higher in KS than in controls in all groups, but the difference was only statistically significant in group 2 (p < 0.05). No significant differences were found in height, weight, testicular volume, and penile length., Conclusions: No hormonal signs of tubular or interstitial damage were found in KS infants. The presence of higher levels of gonadotropins, INHB and testosterone during mini-puberty and pre-puberty may be interpreted as an alteration of the HPG axis in KS infants.

Purpose: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is transmitted primarily via respiratory droplets and enters host cells through angiotensin-converting enzyme 2 (ACE-2) receptors. ACE-2 receptors have been identified in many tissues including testes. The aim of the study has been to investigate the long-term effects of SARS-CoV-2 infection (COVID-19) and its relative treatment on male reproductive health., Methods: Cross-sectional analysis has been performed on 49 recovered COVID-19 patients who had semen analysis prior to the COVID-19 pandemic. Those who had a recovery time lag of at least 3 months have been re-examined, and 29 eligible patients with no andrological problems have been enrolled in the study. Following a detailed physical examination and retrieval of medical history, the values of semen analysis and serum sex hormone parameters have been collected and compared before and after COVID-19 infection. The p value of <0.05 has been considered significant., Results: The average age of the 29 patients has been 31.21 ± 5.48 (range: 18-41) years. Favipiravir has been co-administered with hydroxychloroquine in 17 patients, while the remaining 12 received favipiravir treatment without hydroxychloroquine. The average time between clinical recovery from COVID-19 and collection of semen has been 4.52 ± 1.36 (range: 3-8) months. Before and after COVID-19, serum follicle-stimulating hormone, luteinizing hormone, total testosterone, and prolactin levels, as well as all semen parameters, have been comparable., Conclusion: Our study demonstrated that COVID-19 and its treatment with favipiravir and hydroxychloroquine did not affect spermatogenesis and serum androgen levels in the long-term period. Further clinical studies with larger sample size are needed to confirm and support our findings., (© 2021 S. Karger AG, Basel.)

The aim of this study was to determine whether, after 8 days of water-only fasting, there are changes in the efficiency of the lower urinary tract, the concentration of sex hormones, and the symptoms of prostate diseases in a group of middle-aged men ( n = 14). For this purpose, before and after 8 days of water-only fasting (subjects drank ad libitum moderately mineralized water), and the following somatic and blood concentration measurements were made: total prostate specific antigen (PSA-T), free prostate specific antigen (PSA-F), follicle stimulating hormone (FSH), luteotropic hormone (LH), prolactin (Pr), total testosterone (T-T), free testosterone (T-F), dehydroepiandrosterone (DHEA), sex hormone globulin binding (SHGB), total cholesterol (Ch-T), β-hydroxybutyrate (β-HB). In addition, prostate volume (PV), volume of each testis (TV), total volume of both testes (TTV), maximal urinary flow rate (Qmax), and International Prostate Symptom Score (IPSS) values were determined. The results showed that after 8 days of water-only fasting, Qmax and IPSS improved but PV and TTV decreased significantly. There was also a decrease in blood levels of PSA-T, FSH, P, T-T, T-F, and DHEA, but SHGB concentration increased significantly. These results indicate that 8 days of water-only fasting improved lower urinary tract functions without negative health effects.

Introduction: Leydig cell hypoplasia (LCH) is an autosomal recessive disease that causes 46, XY sex development disorder. The patients with LCH are usually in the female phenotype and are presented with the complaints of no breast development and primary amenorrhea. In this article, the cases of three siblings who presented with primary amenorrhea and who had LCH were presented., Case: A 16-year-old patient with female phenotype is presented with primary amenorrhea. Breast development was at Tanner stage 1, the external genitalia were completely in female phenotype. The karyotype was determined as 46, XY. The hormonal analyses revealed that the testosterone synthesis was insufficient despite the high level of luteinizing hormone (LH). Cortisol, ACTH, 17-Hydroxyprogesterone, and AMH levels were normal. LCH diagnosis was considered in the patient with elevated LH and no testosterone synthesis. A new mutation of homozygous c.161 + 4A > G was detected in LHCGR gene. The same mutation was detected in the patient's two siblings with female phenotype and 46, XY karyotype., Conclusion: In patients presenting with primary amenorrhea and karyotype 46, XY, there is no testosterone synthesis and if there is LH elevation, LCH should be considered. We found a novel variant in the LHCGR gene in three siblings with karyotype 46, XY and female phenotype.

Purpose: The purpose of this study was to determine quantitative testicular tissue stiffness values in normal and infertile men using shear wave elastography (SWE), and to evaluate the relationship between infertility and testicular stiffness value., Methods: In total, 100 testes of 50 infertile patients with abnormal semen parameters were classified as group A, and 100 testes of 50 control subjects were classified as group B. These two groups were compared in terms of age, testicular volume, and SWE values. The group B testes were randomly chosen from patients who had applied for ultrasonography for any reason, and who had no testis disease and no history of infertility., Results: The mean age of the patients was 27.83 years, and no significant difference in age was found between the groups (P = 0.133). No significant difference in testicular volume was found between the groups (P = 0.672). The SWE values were significantly higher in group A than in group B (P = 0.000 for both m/s and kPa values). SWE values had a negative correlation with mean testicular volume in group A (for m/s values: P = 0.043; for kPa values: P = 0.024)., Conclusion: SWE can be a useful technique for assessing testicular stiffness in infertile patients to predict parenchymal damage in testicular tissue that leads to an abnormality in sperm quantity. In addition, decreased testicular volume, together with increased SWE values, can reflect the degree of parenchymal damage.

Age-related changes in the human testis may include morphological alterations, disturbed steroidogenesis, and impaired spermatogenesis. However, the specific impact of cell age remains poorly understood and difficult to assess. Testicular peritubular cells fulfill essential functions, including sperm transport, contributions to the spermatogonial stem cell niche, and paracrine interactions within the testis. To study their role in age-associated decline of testicular functions, we performed comprehensive proteome and secretome analyses of repeatedly passaged peritubular cells from Callithrix jacchus . This nonhuman primate model better reflects the human testicular biology than rodents and further gives access to young donors unavailable from humans. Among 5095 identified proteins, 583 were differentially abundant between samples with low and high passage numbers. The alterations indicate a reduced ability of senescent peritubular cells to contract and secrete proteins, as well as disturbances in nuclear factor (NF)-κB signaling and a reduced capacity to handle reactive oxygen species. Since this in vitro model may not exactly mirror all molecular aspects of in vivo aging, we investigated the proteomes and secretomes of testicular peritubular cells from young and old donors. Even though the age-related alterations at the protein level were less pronounced, we found evidence for impaired protein secretion, altered NF-κB signaling, and reduced contractility of these in vivo aged peritubular cells.

Background: Late-onset hypogonadism (LOH) is a condition defined by low levels of testosterone (T), occurring in advanced age. LOH is promoted by senescence, which, in turn, has negative effects on male fertility. Interestingly, the impact of metabolic disorders on the male reproductive system has been the topic of several studies, but the association with LOH is still debatable., Objectives: Herein, we discuss the hypothesis that the prevalence of metabolic abnormalities potentiates the effects of LOH on the male reproductive system, affecting the reproductive potential of those individuals., Material and Methods: We analyzed the bibliography available, until June 2019, about LOH in relation to metabolic and hormonal dysregulation, sperm quality profiles and assisted-reproduction treatment outcomes., Results: LOH affects the hypothalamic-pituitary testis (HPT) axis. Additionally, metabolic disorders can also induce T deficiency, which is reflected in decreased male fertility, highlighting a possible connection. Indeed, T replacement therapy (TRT) is widely used to restore T levels. Although this therapy is unable to reverse all deleterious effects promoted by LOH on male reproductive function, it can improve metabolic and reproductive health., Discussion and Conclusions: Emerging new evidence suggests that metabolic disorders may aggravate LOH effects on the fertility potential of males in reproductive age, by enhancing T deficiency. These results clearly show that metabolic disorders, such as obesity and diabetes, have a greater impact on causing hypogonadotropic hypogonadism than tissue senescence. Further, TRT and off-label alternatives capable of restoring T levels appear as suitable to improve LOH, while also counteracting comorbidities related with metabolic diseases., (© 2020 American Society of Andrology and European Academy of Andrology.)