Paternal Cyanidin-3-O-Glucoside Diet Improved High-Fat, High-Fructose Diet-Induced Intergenerational Inheritance in Male Offspring's Susceptibility to High-Fat Diet-Induced Testicular and Sperm Damage

High-fructose and high-fat diet (HFHFD) has been associated with impaired spermatogenesis, leading to decreased sperm quality and increased male infertility, with similar effects observed in offspring. Cyanidin-3-O-glucoside (C3G), a recognized food antioxidant, has shown promise in protecting in male reproduction and modulating epigenetic modifications. However, its potential role in ameliorating intergenerational inheritance induced by HFHFD remains underexplored. In this study, we investigated the effects of paternal HFHFD on reproductive injury of offspring and the protective effect of C3G. Paternal mice were subjected to 12 weeks of HFHFD induction and C3G treatment was conducted for 8 weeks. Offspring obtained via in vitro fertilization were fed either a normal diet (ND) or high-fat diet (HFD). Our findings indicate that while the paternal HFHFD did not result in observable reproductive impairments in paternal mice, it did affect offspring testicular function through intergenerational inheritance, rendering them more susceptible to testicular damage and reduced sperm counts when exposed to an HFD. Notably, C3G intervention significantly mitigated these effects, suggesting its potential as a therapeutic compound for alleviating the impact of paternal intergenerational inheritance on male fertility resulting from HFHFD. These results underscore the importance of further exploring the mechanisms underlying intergenerational inheritance and the potential of interventions such as C3G in mitigating its effects, with implications for both basic research and clinical practice.

A Case-Control Study of the Association Between GSTP1 Gene Polymorphisms (rs1695 and rs1138272) and the Susceptibility to Male Infertility in the Moroccan Population

Background: Infertility affects 10-15% of couples worldwide, with male factors accounting for half of cases. Environmental, behavioral, and genetic problems contribute to spermatogenic failure in 30% of idiopathic male infertility cases. Other factors, such as oxidative stress (OS), cause impaired spermatogenesis, abnormal sperm morphology, and reduced motility, eventually triggering male infertility. In the male reproductive tract, glutathione S-transferase (GST) family antioxidants are essential for preventing OS, detoxification, and DNA damage protection. Methods: GSTP1 isoenzyme, one of GST members, has previously been linked to male infertility, and this case-control study is the first to assess the possible association of GSTP1 gene polymorphisms (rs1695 and rs1138272) with nonobstructive azoospermia and severe oligospermia within 300 patients and 300 controls from the Moroccan population using an allele-specific PCR. The statistical analysis was performed with the R programming language. Results: Genotyping of GSTP1 polymorphisms fitted the Hardy-Weinberg equilibrium in both cases and controls (p > 0.05), but no significant association was found in rs1695 (odds ratio [OR] = 1.238, 95% confidence interval [CI] = 0.855 to 1.794, p = 0.258, power = 0.204) and in rs1138272 (OR = 1.192, 95% CI = 0.852 to 0.1668, p = 0.304, power = 0.176). Likewise, results from haplotype analysis (OR = 1.25, 95% CI = 0.61 to 2.57, p = 0.537) and SNP-SNP interactions (OR = 1.522, 95% CI = 0.838 to 2.762, p = 0.166) demonstrated no correlation with the risk of male infertility. Conclusion: The two SNPs (rs1695 and rs1138272) of the GSTP1 gene loci are not associated with male infertility susceptibility in Moroccan subjects. Yet, future investigations with a larger sample size may conclusively help to confirm this association.

Do Lifestyle Interventions Mitigate the Oxidative Damage and Inflammation Induced by Obesity in the Testis?

Obesity results from a disproportionate accumulation of fat and has become a global health concern. The increase in adipose tissue is responsible for several systemic and testicular changes including hormone levels (leptin, adiponectin, testosterone, estrogen), inflammatory cytokines (increase in TNF-α and IL-6 and decrease in IL-10), and redox state (increase in reactive oxygen species and reduction in antioxidant enzymes). This results in poor sperm quality and compromised fertility in men with obesity. Lifestyle modifications, particularly diet transition to caloric restriction and physical exercise, are reported to reverse these negative effects. Nevertheless, precise mechanisms mediating these benefits, including how they modulate testicular oxidative stress, inflammation, and metabolism, remain to be fully elucidated. The main pathway described by which these lifestyle interventions reverse obesity-induced oxidative damage is the Nrf2-SIRT1 axis, which modulates the overexpression of antioxidant defenses. Of note, some of the detrimental effects of obesity on the testis are inherited by the descendants of individuals with obesity, and while caloric restriction reverses some of these effects, no significant work has been carried out regarding physical exercise. This review discusses the consequences of obesity-induced testicular oxidative stress on adult and pediatric populations, emphasizing the therapeutic potential of lifestyle to mitigate these detrimental effects.

The Effect of Different Exercise Modalities on Sertoli-germ Cells Metabolic Interactions in High-fat Diet-induced Obesity Rat Models: Implication on Glucose and Lactate Transport, Igf1, and Igf1R-dependent Pathways

The study aimed to uncover a unique aspect of obesity-related metabolic disorders in the testicles induced by a high-fat diet (HFD) and explored the potential mitigating effects of exercise modalities on male fertility. Thirty mature male Wistar rats were randomly assigned to control, HFD-sole, moderate-intensity exercise with HFD (HFD+MICT), high-intensity continuous exercise with HFD (HFD+HICT), and high-intensity interval exercise with HFD (HFD+HIIT) groups (n=6/group). Intracytoplasmic carbohydrate (ICC) storage, expression levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R, and testicular lactate and lactate dehydrogenase (LDH) levels were assessed. ICC storage significantly decreased in HFD-sole rats, along with decreased mRNA and protein levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R. The HFD-sole group exhibited a notable reduction in testicular lactate and LDH levels (p<0.05). Conversely, exercise, particularly HIIT, upregulated ICC storage, expression levels of GLUT-1, GLUT-3, MCT-4, Igf1, and Igf1R, and enhanced testicular lactate and LDH levels. These results confirm that exercise, especially HIIT, has the potential to mitigate the adverse effects of HFD-induced obesity on testicular metabolism and male fertility. The upregulation of metabolite transporters, LDH, lactate levels, Igf1, and Igf1R expression may contribute to maintaining metabolic interactions and improving the glucose/lactate conversion process. These findings underscore the potential benefits of exercise in preventing and managing obesity-related male fertility issues.

Omega-3 fatty acids abrogates oxido-inflammatory and mitochondrial dysfunction-associated apoptotic responses in testis of tamoxifen-treated rats

BACKGROUND

Tamoxifen (TAM) is a widely used drug in patients with gynecomastia and breast cancer. TAM exerts its anticancer effects via its antiestrogenic activities. Unfortunately, TAM has been reported to exert gonadotoxic effects on male testes. Therefore, this study was designed to explore the possible associated mechanisms involved in TAM-induced testicular dysfunction and the possible ameliorative effects of omega-3 fatty acids (O3FA).

METHODOLOGY

Animals were randomly divided into control, O3FA, TAM, and TAM + O3FA. All treatment lasted for 28 days.

RESULTS

TAM exposure impaired sperm qualities (count, motility, and normal morphology) and decreased testicular 3β-HSD and 17β-HSD. It was accompanied by a decline in serum testosterone and an increase in estradiol, luteinizing and follicle-stimulating hormones. These observed alterations were associated with an increase in testicular injury markers, oxido-inflammatory response, and mitochondria-mediated apoptosis. These observed alterations were ameliorated by O3FA treatments.

CONCLUSIONS

O3FA ameliorated TAM-induced testicular dysfunction in male Wistar rats by modulating XO/UA and Nrf2/NF-kb signaling and cytochrome c-mediated apoptosis in TAM-treated rats.

Signatures of metabolic diseases on spermatogenesis and testicular metabolism

Diets leading to caloric overload are linked to metabolic disorders and reproductive function impairment. Metabolic and hormonal abnormalities stand out as defining features of metabolic disorders, and substantially affect the functionality of the testis. Metabolic disorders induce testicular metabolic dysfunction, chronic inflammation and oxidative stress. The disruption of gastrointestinal, pancreatic, adipose tissue and testicular hormonal regulation induced by metabolic disorders can also contribute to a state of compromised fertility. In this Review, we will delve into the effects of high-fat diets and metabolic disorders on testicular metabolism and spermatogenesis, which are crucial elements for male reproductive function. Moreover, metabolic disorders have been shown to influence the epigenome of male gametes and might have a potential role in transmitting phenotype traits across generations. However, the existing evidence strongly underscores the unmet need to understand the mechanisms responsible for transgenerational paternal inheritance of male reproductive function impairment related to metabolic disorders. This knowledge could be useful for developing targeted interventions to prevent, counteract, and most of all break the perpetuation chain of male reproductive dysfunction associated with metabolic disorders across generations.

Decreased Ubiquitination and Acetylation of Histones 3 and 4 Are Associated with Obesity-Induced Disorders of Spermatogenesis in Mice

BACKGROUND

Obesity, a chronic metabolic disorder, is related to cardiovascular diseases, diabetes, cancer, and reproductive disorders. The relationship between obesity and male infertility is now well recognized, but the mechanisms involved are unclear. We aimed to observe the effect of obesity on spermatogenesis and to investigate the role of histone ubiquitination and acetylation modifications in obesity-induced spermatogenesis disorders.

METHODS

Thirty male C57BL/6J mice were randomly divided into two groups. The control group was fed with a general maintenance diet (12% fat), while a high-fat diet (HFD) group was fed with 40% fat for 10 weeks; then, they were mated with normal females. The fertility of male mice was calculated, testicular and sperm morphology were observed, and the expression levels of key genes and the levels of histone acetylation and ubiquitination modification during spermatogenesis were detected.

RESULTS

The number of sperm was decreased, as well as the sperm motility, while the number of sperm with malformations was increased. In the testes, the mRNA and protein expression levels of gonadotropin-regulated testicular RNA helicase (GRTH/DDX25), chromosome region maintenance-1 protein (CRM1), high-mobility group B2 (HMGB2), phosphoglycerate kinase 2 (PGK2), and testicular angiotensin-converting enzyme (tACE) were decreased. Furthermore, obesity led to a decrease in ubiquitinated H2A (ubH2A) and reduced levels of histone H3 acetylation K18 (H3AcK18) and histone H4 acetylation K5, K8, K12, and K16 (H4tetraAck), which disrupted protamine 1 (Prm1) deposition in testis tissue.

CONCLUSION

These results suggest that low levels of histone ubiquitination and acetylation are linked with obesity-induced disorders during spermatogenesis, contributing to a better understanding of obesity-induced damage to male reproduction.

A ripple effect? The impact of obesity on sperm quality and function

Infertility affects approximately 15% of couples trying to conceive. Male-related causes account for roughly 50% of cases, with obesity emerging as a possible significant factor. Obesity, defined as a body mass index of 30.0 or higher, has become a widespread epidemic associated with numerous health issues, including a decrease of fertility. This review discusses the relationship between obesity and male infertility, particularly focusing on sperm quality and function. An overview of the literature suggests that obesity may influence the male reproductive system via disruptions in hormonal profiles, oxidative stress, and inflammation, leading to changes in sperm parameters. Several studies have discussed if obesity causes a decrease in sperm concentration, motility, and normal morphology, so far without a consensus being reached. However, available evidence suggests an impairment of sperm function in obese men, due to an increase in DNA damage and oxidative stress, impaired mitochondrial function and acrosome reaction in response to progesterone. Finally, the relationship between obesity and assisted reproductive technologies outcomes remains debatable, with conflicting evidence regarding the influence on fertilisation, pregnancy, and live birth rates. Therefore, the actual impact of obesity on human spermatozoa still needs to be clarified, due to the multiple factors potentially in play.

Naringin from sweet orange peel improves testicular function in high fat diet-induced diabetic rats by modulating xanthine oxidase/uric acid signaling and maintaining redox balance

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a metabolic disorder affecting many organs, including the testis. Naringin from orange peel extract (OPE) is a flavanone with fertility-enhancing properties. Hence, this study was designed to establish the effect of naringin on T2DM-induced testicular dysfunction. Thirty male (30) Wistar rats were randomized into five groups control, diabetes, diabetes + naringin, diabetes + OPE, and diabetes + metformin. The administrations were via the oral route and lasted for 28 days.

RESULTS

Naringin ameliorated T2DM-induced increase in FBS and decrease in serum insulin. It also abrogated T2DM-induced decrease in sperm quality, gonadotropin-releasing hormone, luteinizing hormone, follicle-stimulating hormone, testosterone, estradiol, prolactin, catalase, superoxide dismutase, and total antioxidant capacity. Furthermore, naringin prevented a T2DM-induced increase in malonaldehyde, tumor necrosis factor-alpha, C-reactive protein, xanthine oxidase (XO), and uric acid (UA), it was accompanied by the restoration of normal testicular histoarchitecture.

CONCLUSIONS

Naringin prevented T2DM-induced testicular dysfunction by modulating XO/UA and restoring redox balance. Also, while the animals treated with OPE exhibited better ameliorative effects than their counterparts treated with naringin, the findings from this study showed that naringin would be a promising supplement for treating T2DM-induced male infertility.

Dietary intervention in adult rats exposed to a high-sugar diet early in life permanently impairs sperm quality

Childhood obesity predicts the presence of adult obesity. Obesity is associated with poor sperm quality. We hypothesized that exposure to a high-sugar diet (HSD) in early life would cause permanent histomorphology damage to the testes, resulting in reduced sperm quality in adult life. Wistar rats (aged 21days) were divided into four groups (n=6). In the first experiment, the rats received tap water (control) and a 30% sucrose diet for two months (S30). In the second experiment, the control and 30% sucrose diets were fed for two months, followed by replacement with tap water for two months (IS30). Eating and drinking were monitored. Animals were then euthanized, visceral and gonadal fat tissue and testes were collected, and epididymal spermatozoa were excised. Testicular samples were used for morphological description by H&E staining and for quantifying triacylglycerol content, caspase activity, and oxidative stress. Serum testosterone concentration was evaluated. Spermatozoa were used to assess sperm quality. Our results show that sperm quality was impaired by consuming HSD and could not be restored by dietary intervention. HSD feeding induced hyperplasia of visceral adipose tissue, increased testicular weight, and serum testosterone levels. The dietary intervention increased visceral adipose tissue, serum, and testicular triacylglycerol levels and normalized serum testosterone levels. Overall, the HSD diet caused permanent changes in seminiferous tubule cross-sectional area, caspase activity, oxidative stress, and sperm quality. Therefore, a high-sugar diet in early life causes permanent damage to sperm quality in adulthood.

Pyrroloquinoline quinone inhibits PCSK9-NLRP3 mediated pyroptosis of Leydig cells in obese mice

Abnormal lipid metabolism and chronic low-grade inflammation are the main traits of obesity. Especially, the molecular mechanism of concomitant deficiency in steroidogenesis-associated enzymes related to testosterone (T) synthesis of obesity dominated a decline in male fertility is still poorly understood. Here, we found that in vivo, supplementation of pyrroloquinoline quinone (PQQ) efficaciously ameliorated the abnormal lipid metabolism and testicular spermatogenic function from high-fat-diet (HFD)-induced obese mice. Moreover, the transcriptome analysis of the liver and testicular showed that PQQ supplementation not only inhibited the high expression of proprotein convertase subtilisin/Kexin type 9 (PCSK9) but also weakened the NOD-like receptor family pyrin domain containing 3 (NLRP3)-mediated pyroptosis, which both played a negative role in T synthesis of Leydig Cells (LCs). Eventually, the function and the pyroptosis of LCs cultured with palmitic acid in vitro were simultaneously benefited by suppressing the expression of NLRP3 or PCSK9 respectively, as well the parallel effects of PQQ were affirmed. Collectively, our data revealed that PQQ supplementation is a feasible approach to protect T synthesis from PCSK9-NLRP3 crosstalk-induced LCs' pyroptosis in obese men.

Metabolomics profiling of seminal plasma in obesity-induced asthenozoospermia

BACKGROUND

Asthenozoospermia is one of the essential causes of male infertility, and its incidence is significantly higher in obese men. Due to its complex etiology and unknown pathomechanism, the diagnosis and treatment of obesity-induced asthenozoospermia is a prevalent problem in reproductive medicine.

OBJECTIVE

This study aims to explore major differential metabolites and metabolic pathways in seminal plasma and pathological mechanisms for obesity-induced asthenozoospermia.

MATERIALS AND METHODS

We performed non-target metabolomic studies on the seminal plasma of healthy men with normal semen parameters (HN group, n = 20), obese men with normal semen parameters (ON group, n = 20), and men with obesity-induced asthenozoospermia (OA group, n = 20) based on gas chromatography-mass spectrometry. Metabolic profilings and related pathway analyses were conducted to discriminate differential metabolites and metabolic pathways.

RESULTS

A total of 20 differential metabolites including fructose, succinic acid, aconitic acid, methylmaleic acid, glucopyranose, serine, valine, leucine, phenylalanine, glycine, glutamic acid, alanine, proline and threonine were identified in HN group and ON group; 24 differential metabolites including glucose, fructose, pyruvic acid, citric acid, succinic acid, aconitic acid, glucopyranose, glutamic acid, valine, leucine, glycine, phenylalanine, lysine, citrulline, proline and alanine were produced in OA group and ON group; and 28 differential metabolites including glucose, fructose, citric acid, succinic acid, glucopyranose, valine, glycine, serine, leucine, phenylalanine, alanine, threonine, proline, glutamic acid, citrulline, lysine and tyrosine were produced in OA group and HN group. In addition, abnormal energy metabolism including carbohydrate metabolism (TCA cycle, glycolysis/gluconeogenesis, and pyruvate metabolism) and amino acid metabolism (phenylalanine, tyrosine, and tryptophan biosynthesis, D-glutamine and D-glutamate metabolism; phenylalanine metabolism, etc.) were found in ON group and OA group.

CONCLUSION

Obesity could affect the metabolite composition in seminal plasma and abnormal energy metabolism in seminal plasma mainly including carbohydrate metabolism and amino acid metabolism were closely related to obesity-induced asthenozoospermia.

A North American study of anthropometric factors and semen quality

OBJECTIVE

To evaluate the association between anthropometric measures and semen parameters.

DESIGN

Cross-sectional study.

SUBJECTS

Male participants aged ≥21 years. We analyzed data from 659 males (1185 samples) participating in a semen testing substudy of the Pregnancy Online Study (PRESTO), a North American preconception cohort study. After enrollment, we invited males aged ≥21 years to perform at-home semen testing using the Trak system.

EXPOSURE(S)

Participants reported selected anthropometric variables (current weight, height, waist circumference, and weight at age 17 years) and covariate data via an online baseline questionnaire.

MAIN OUTCOME MEASURE(S)

We used generalized estimating equations models to estimate the percent difference in mean log-transformed semen parameter values and 95% confidence intervals (CI) for associations between selected anthropometric variables and semen volume (mL), sperm concentration (million/mL), and total sperm count (million), adjusting for sociodemographics, lifestyle factors, and medical history. We also evaluated World Health Organization-defined thresholds for low semen quality.

RESULT(S)

Percentage differences in mean log-transformed semen volume, sperm concentration, and total sperm count (95% CI) comparing current body mass index ≥35 vs. <25 kg/m2 were -6.3 (-15.8, 4.3), -6.4 (-24.6, 16.2), and -12.2 (-31.1, 11.8), respectively. Percentage differences (95% CIs) comparing waist circumferences of ≥42 vs. <31 inches were -4.2 (-15.0, 8.0), -6.4 (-27.6, 21.0), and -10.4 (-31.9, 17.9) for semen volume, sperm concentration, and total sperm count, respectively. Greater adult weight gain since age 17 years was associated with reduced semen volume (≥25 vs. <5 kg; percent difference, -9.7; 95% CI, -18.4, 0.1), but not sperm concentration or total sperm count. The highest categories of each anthropometric variable generally were associated with World Health Organization-defined low total sperm count (≤39 million).

CONCLUSION(S)

Selected anthropometric factors were associated modestly with poorer semen quality.

Molecular mechanisms regulating spermatogenesis in vertebrates: Environmental, metabolic, and epigenetic factor effects

The renewal of the natural resources is one of the most concerning aspects of modern farming. In animal production, there are many barriers breeders and researchers have to overcome to develop new practices to improve reproductive potential and hasten sexual maturation of the commercially viable species, while maintaining meat quality and sustainability. With the utilization of molecular biology techniques, there have been relevant advances in the knowledge of spermatogenesis, especially in mammals, resulting in new possibilities to control male fertility and the selection of desirable characteristics. Most of these discoveries have not been implemented in animal production. In this review, recent studies are highlighted on the molecular pathways involved in spermatogenesis in the context of animal production. There is also exploration of the interaction between environmental factors and spermatogenesis and how this knowledge may revolutionize animal production techniques. Furthermore, new insights are described about the inheritance of desired characteristics in mammals and there is a review of nefarious actions of pollutants, nutrition, and metabolism on reproductive potential in subsequent generations. Even though there are these advances in knowledge base, results from recent studies indicate there are previously unrecognized environmental effects on spermatogenesis. The molecular mechanisms underlying this interaction are not well understood. Research in spermatogenesis, therefore, remains pivotal as a pillar of animal production sustainability.

Obesity-Related Genes Expression in Testes and Sperm Parameters Respond to GLP-1 and Caloric Restriction

Aim: Calorie restriction (CR) diets and glucagon-Like Peptide-1 (GLP-1) analogs are known to alter energy homeostasis with the potential to affect the expression of obesity-related genes (ORGs). We hypothesized that CR and GLP-1 administration can alter ORGs expression in spermatozoa and testes, as well as the sperm parameters implicated in male fertility. Materials and Methods: Six-week-old adult male Wistar rats (n = 16) were divided into three groups, submitted either to CR (n = 6, fed with 30% less chow diet than the control rats), GLP-1 administration (n = 5, 3.5 pmol/min/kg intraperitoneal) for 28 days, or used as controls (n = 5, fed ad libitum). Selected ORGs expression, namely the fat mass and obesity-associated (FTO), melanocortin-4 receptor (MC4R), glucosamine-6-phosphate deaminase 2 (GNPDA2), and transmembrane protein 18 (TMEM18) were evaluated in testes and spermatozoa by a quantitative polymerase chain reaction (qPCR). Results: CR resulted in lower body weight gain and insulin resistance, but a higher percentage of sperm head defects. GLP-1 administration, despite showing no influence on body weight or glucose homeostasis, resulted in a lower percentage of sperm head defects. CR and GLP-1 administration were associated with a higher expression of all ORGs in the testes. Under CR conditions, the genes FTO and TMEM18 expression in the testes and the MC4R and TMEM18 transcripts abundance in sperm were positively correlated with the spermatozoa oxidative status. The abundance of FTO and TMEM18 in the spermatozoa of rats under CR were positively correlated with sperm concentration, while the testes’ TMEM18 expression was also positively correlated with sperm vitality and negatively correlated with insulin resistance. Testes GNPDA2 expression was negatively correlated with sperm head defects. Conclusions: CR and GLP-1 administration results in higher ORGs expression in testes, and these were correlated with several alterations in sperm fertility parameters.

Effects of Moderate-Intensity Continuous Training and High-Intensity Interval Training on Testicular Oxidative Stress, Apoptosis and m6A Methylation in Obese Male Mice

Exercise is an effective way to improve reproductive function in obese males. Oxidative stress and apoptosis are important pathological factors of obesity-related male infertility. Accumulating studies have demonstrated that N6-methyladenosine (m6A) methylation is associated with obesity and testicular reproductive function. Our study aimed to investigate and compare the effect of 8 weeks of moderate-intensity continuous training (MICT) and high-intensity interval training (HIIT) on testicular oxidative stress, apoptosis and m6A methylation in obese male mice. Male C57BL/6 mice were randomly allocated into the four groups: normal diet (ND) group, high-fat diet (HFD) group, high-fat diet with moderate-intensity continuous training (HFD-MICT) group and high-fat diet with high-intensity interval training (HFD-HIIT) group. Mice in the HFD-MICT and HFD-HIIT groups were subjected to 8 weeks of MICT or HIIT treadmill protocols after 12 weeks of HFD feeding. We found that MICT and HIIT increased the protein expression of Nrf2, HO-1 and NQO-1 in the testes of obese mice, and HIIT increased it more than MICT. The Bax/Bcl-2 ratio, Cleaved Caspase-3 protein expression and TUNEL-positive cells were consistently up-regulated in the testes of obese mice, but MICT and HIIT restrained these HFD-induced effects. In addition, HFDs increased m6A levels and the gene expression of METTL3, YTHDF2 and FTO in the testes, but these effects were reversed by MICT and HIIT. However, HIIT was more effective than MICT in reducing m6A methylation in the testes of obese mice. These results demonstrate that both MICT and HIIT protected against HFD-induced oxidative stress, apoptosis and m6A methylation in testicular tissues; as a result, testicular morphological and functional impairment improved. In particular, HIIT was more beneficial than MICT in increasing the mRNA expression of steroidogenic enzymes and testicular antioxidant capacity and decreasing m6A methylation in the testes of HFD-fed mice.

Follicle-stimulating hormone signaling in Sertoli cells: a licence to the early stages of spermatogenesis

Follicle-stimulating hormone signaling is essential for the initiation and early stages of spermatogenesis. Follicle-stimulating hormone receptor is exclusively expressed in Sertoli cells. As the only type of somatic cell in the seminiferous tubule, Sertoli cells regulate spermatogenesis not only by controlling their own number and function but also through paracrine actions to nourish germ cells surrounded by Sertoli cells. After follicle-stimulating hormone binds to its receptor and activates the follicle-stimulating hormone signaling pathway, follicle-stimulating hormone signaling will establish a normal Sertoli cell number and promote their differentiation. Spermatogonia pool maintenance, spermatogonia differentiation and their entry into meiosis are also positively regulated by follicle-stimulating hormone signaling. In addition, follicle-stimulating hormone signaling regulates germ cell survival and limits their apoptosis. Our review summarizes the aforementioned functions of follicle-stimulating hormone signaling in Sertoli cells. We also describe the clinical potential of follicle-stimulating hormone treatment in male patients with infertility. Furthermore, our review may be helpful for developing better therapies for treating patients with dysfunctional follicle-stimulating hormone signaling in Sertoli cells.

Testicular ultrastructure and hormonal changes following administration of tenofovir disoproxil fumarate-loaded silver nanoparticle in type-2 diabetic rats

Reproductive dysfunctions (RDs) characterized by impairment in testicular parameters, and metabolic disorders such as insulin resistance and type 2 diabetes mellitus (T2DM) are on the rise among human immunodeficiency virus (HIV) patients under tenofovir disoproxil fumarate (TDF) and highly active antiretroviral therapy (HAART). These adverse effects require a nanoparticle delivery system to circumvent biological barriers and ensure adequate ARVDs to viral reservoir sites like testis. This study aimed to investigate the effect of TDF-loaded silver nanoparticles (AgNPs), TDF-AgNPs on sperm quality, hormonal profile, insulin-like growth factor 1 (IGF-1), and testicular ultrastructure in diabetic rats, a result of which could cater for the neglected reproductive and metabolic dysfunctions in HIV therapeutic modality. Thirty-six adult Sprague–Dawley rats were assigned to diabetic and non-diabetic (n = 18). T2DM was induced by fructose-streptozotocin (Frt-STZ) rat model. Subsequently, the rats in both groups were subdivided into three groups each (n = 6) and administered distilled water, TDF, and TDF-AgNP. In this study, administration of TDF-AgNP to diabetic rats significantly reduced (p < 0.05) blood glucose level (268.7 ± 10.8 mg/dL) from 429 ± 16.9 mg/dL in diabetic control and prevented a drastic reduction in sperm count and viability. More so, TDF-AgNP significantly increased (p < 0.05) Gonadotropin-Releasing Hormone (1114.3 ± 112.6 µg), Follicle Stimulating Hormone (13.2 ± 1.5 IU/L), Luteinizing Hormone (140.7 ± 15.2 IU/L), testosterone (0.2 ± 0.02 ng/L), and IGF-1 (1564.0 ± 81.6 ng/mL) compared to their respective diabetic controls (383.4 ± 63.3, 6.1 ± 1.2, 76.1 ± 9.1, 0.1 ± 0.01, 769.4 ± 83.7). Also, TDF-AgNP treated diabetic rats presented an improved testicular architecture marked with the thickened basement membrane, degenerated Sertoli cells, spermatogenic cells, and axoneme. This study has demonstrated that administration of TDF-AgNPs restored the function of hypothalamic-pituitary–gonadal axis, normalized the hormonal profile, enhanced testicular function and structure to alleviate reproductive dysfunctions in diabetic rats. This is the first study to conjugate TDF with AgNPs and examined its effects on reproductive indices, local gonadal factor and testicular ultrastructure in male diabetic rats with the potential to cater for neglected reproductive dysfunction in HIV therapeutic modality.

Metabolic Syndrome and Male Fertility: Beyond Heart Consequences of a Complex Cardiometabolic Endocrinopathy

Metabolic syndrome (MetS) is a highly prevalent condition among adult males, affecting up to 41% of men in Europe. It is characterized by the association of obesity, hypertension, and atherogenic dyslipidemia, which lead to premature morbidity and mortality due to cardiovascular disease (CVD). Male infertility is another common condition which accounts for about 50% of cases of couple infertility worldwide. Interestingly, male infertility and MetS shares several risk factors (e.g., smoking, ageing, physical inactivity, and excessive alcohol consumption), leading to reactive oxygen species (ROS) production and increased oxidative stress (OS), and resulting in endothelial dysfunction and altered semen quality. Thus, the present narrative review aims to discuss the pathophysiological mechanisms which link male infertility and MetS and to investigate the latest available evidence on the reproductive consequences of MetS.

Lower Circulating Sertoli and Leydig Cell Hormone Levels During Puberty in Obese Boys: A Cross-sectional Study

CONTEXT

Alterations in semen characteristics and circulating Sertoli and Leydig cell hormones have been described in obese male adults. Whether hormonal alterations occur before adulthood has not been fully evaluated.

OBJECTIVE

We describe circulating Sertoli and Leydig cell hormone levels in overweight-obese (ow/ob) boys through childhood and adolescence in a cross-sectional study.

METHODS

Monocentric study in the Pediatric Endocrinology Unit of Angers University Hospital. Three hundred and fifty-one obese and overweight boys aged 5-19 years underwent physical examination, dual-energy X-ray absorptiometry for body composition, oral glucose tolerance test on insulin and glucose, and measurements of follicle-stimulating hormone, luteinizing hormone, anti-Müllerian hormone (AMH), inhibin B, testosterone, and estradiol. Hormonal levels were compared with normative data obtained from 652 healthy nonoverweight nonobese boys of similar age or Tanner stage.

RESULTS

Median inhibin B and testosterone levels during puberty were significantly lower in ow/ob than in healthy boys (1) from age >12 years and thereafter for inhibin B, and (2) from age >14 years and thereafter for testosterone. At Tanner stages 4 and 5, 26%, 31%, and 18% of inhibin B, testosterone, and AMH values were below the 5th percentile in ow/ob subjects (P < .01). In multiple regression analyses, estradiol and total bone mineral density Z-score were negative predictors of inhibin B, fat mass percentage was a negative predictor of testosterone, and insulin was a negative predictor of AMH.

CONCLUSION

Lower Sertoli and Leydig cell hormone levels during puberty were observed in the ow/ob boys.

Pregnancy Achievement by Medical Assisted Reproduction Is Correlated to the G Protein-Coupled Receptor 30 mRNA Abundance in Human Spermatozoa

Estrogens, specifically 17β-estradiol (E2), play an important role in male health, including male fertility. The G protein-coupled receptor for estrogen 30 (GPR30) is essential for mediating the rapid non-genomic effects of E2 on a variety of testicular cells, including spermatozoa, although its molecular effects remain largely unknown. In this work, we hypothesized that the GPR30 mRNA abundance in spermatozoa could be correlated to sperm quality. Sperm GPR30 mRNA could also be carried into the oocyte, potentially impacting embryo development and the success of a pregnancy. For this study, 81 sperm samples were collected from couples seeking fertility treatment and undergoing medically assisted reproduction treatments (ART), following the World Health Organization guidelines. GPR30 mRNA abundance in spermatozoa was assessed with a quantitative polymerase chain reaction. The resulting data show that there is no correlation between the abundance of the GPR30 transcript with paternal BMI, age, or sperm quality parameters. Interestingly, we observed that higher levels of GPR30 mRNA abundance in spermatozoa were related to the achievement of biochemical pregnancy and clinical pregnancy (p < 0.05) by couples undergoing treatment. These results highlight the role of the sperm’s RNA cargo in offspring development, suggesting that spermatozoa mRNA content can influence ART success.

Male Infertility in the XXI Century: Are Obesogens to Blame?

The permanent exposure to environmental contaminants promoting weight gain (i.e., obesogens) has raised serious health concerns. Evidence suggests that obesogens are one of the leading causes of the marked decline in male fertility and are key players in shaping future health outcomes, not only for those who are directly exposed to them, but also for upcoming generations. It has been hypothesized that obesogens affect male fertility. By using an interdisciplinary strategy, combining in silico, in vitro, in vivo and epidemiological findings, this review aims to contribute to the biological understanding of the molecular transformations induced by obesogens that are the basis of male infertility. Such understanding is shaped by the use of Adverse Outcomes Pathways, a new approach that may shift the paradigm of reproductive toxicology, contributing to the improvement of the diagnosis and management of the adverse effects of obesogens in male fertility.

Diet-induced maternal obesity and overnutrition cause a decrease in the sperm quality of the offspring

The present work aimed to study the changes caused by maternal obesity and overnutrition in both the quality and function of spermatozoa of the offspring. To this end, female rats received either a standard (SD) or cafeteria (CD) diet from 22 days of age until the weaning of their offspring, and the male offspring (OSD and OCD respectively) were used. Different endpoints in the offspring, as body weight, weight gain and glycemia were recorded and the testes were removed at 60 days of age. Different spermatozoa parameters, such as mitochondrial function, functional integrity of the sperm plasma membrane, capacitation, and acrosome status, were evaluated. The OCD group was heavier than the OSD group and exhibited lower testis and epididymal indices. The OCD group also showed a decrease in the ability of the sperm tail to react in the presence of a hypoosmotic solution, deficiency in sperm mitochondrial function, a lower percentage of spermatozoa without acrosome when exposed to a capacitation medium, and a higher number of abnormal metaphases. In addition, compared with OSD, OCD rats had a higher number of TUNEL-positive cells in the histological sections of the testis, and greater presence of reactive oxygen species in the spermatozoa, evaluated by a fluorescent probe. However, the OCD group displayed lower protein levels of cytochrome c and caspase-3 in testis tissue than the control group. These results suggest that maternal obesity and overnutrition program the offspring to develop poor sperm quality and function, which may imply a condition of subfertility.

Sperm Dysfunction in the Testes and Epididymides due to Overweight and Obesity Is Not Caused by Oxidative Stress

Obesity is a condition that has been linked to male infertility. The current hypothesis regarding the cause of infertility is that sperm are highly sensitive to reactive oxygen species (ROS) during spermatogenesis in the testes and transit through the epididymides, so the increase in ROS brought on by obesity could cause oxidative stress. The aim of this study was to evaluate whether the activity of the enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) is capable of counteracting oxidative stress in sperm. The male Wistar rat was used as an overweight and obesity model, and analysis of fertility in these groups was carried out including the control group. Serum testosterone levels were determined, and the scrotal fat, testes, and epididymides were extracted. The epididymides were separated ini0 3 principal parts (caput, corpus, and cauda) before evaluating sperm viability, sperm morphology, damage to desoxyribonucleic acid of the sperm, and ROS production. The protein content and specific activity of the three enzymes mentioned above were evaluated. Results showed a gain in body weight and scrotal fat in the overweight and obese groups with decreased parameters for serum testosterone levels and sperm viability and morphology. Fertility was not greatly affected and no DNA integrity damage was found, although ROS in the epididymal sperm increased markedly and Raman spectroscopy showed a disulfide bridge collapse associated with DNA. The specific activities of CAT and GPX increased in the overweight and obesity groups, but those of SOD did not change. The amounts of proteins in the testes and epididymides decreased. These findings confirm that overweight and obesity decrease concentrations of free testosterone and seem to decrease protein content, causing poor sperm quality. Implications. An increase in scrotal fat in these conditions fosters an increase of ROS, but the increase of GPX and CAT activity seems to avoid oxidative stress increase in the sperm without damaging your DNA.

Inherited Metabolic Memory of High-fat Diet Impairs Testicular Fatty Acid Content and Sperm Parameters

Exposure to a high-fat diet (HFD) from early-life is associated with a testicular metabolic signature linked to abnormal sperm parameters up to two generations after exposure in mice. Hereby, we describe a testicular lipid signature associated with "inherited metabolic memory" of exposure to HFD, persisting up to two generations in mice. Diet-challenged mice (n = 36) were randomly fed after weaning with standard chow (CTRL); HFD for 200 days or transient HFD (HFD_t ) (60 days of HFD+140 days of standard chow). Subsequent generations (36 mice per generation) were fed with chow diet. Mice were euthanized 200 days post-weaning. Glucose homeostasis, serum hormones, testicular bioenergetics and antioxidant enzyme activity were evaluated. Testicular lipid-related metabolites and fatty acids were characterized by ¹ H-NMR and GC-MS. Sons of HFD display impaired choline metabolism, mitochondrial activity and antioxidant defenses, while grandsons show a shift in testicular ω3/ω6 ratio towards a pro-inflammatory environment. Grandsons of HFDt raise 3-hydroxybutyrate levels with possible implications to testicular insulin resistance. Sperm counts decrease in grandsons of HFD-exposed mice, regardless of the duration of exposure. HFD-induced "inherited metabolic memory" alters testicular fatty acid metabolism with consequences to sperm parameters up to two generations. This article is protected by copyright. All rights reserved.

Influence of Risk Factors for Male Infertility on Sperm Protein Composition

Male infertility is a common health problem that can be influenced by a host of lifestyle risk factors such as environment, nutrition, smoking, stress, and endocrine disruptors. These effects have been largely demonstrated on sperm parameters (e.g., motility, numeration, vitality, DNA integrity). In addition, several studies showed the deregulation of sperm proteins in relation to some of these factors. This review inventories the literature related to the identification of sperm proteins showing abundance variations in response to the four risk factors for male infertility that are the most investigated in this context: obesity, diabetes, tobacco smoking, and exposure to bisphenol-A (BPA). First, we provide an overview of the techniques used to identify deregulated proteins. Then, we summarise the main results obtained in the different studies and provide a compiled list of deregulated proteins in relation to each risk factor. Gene ontology analysis of these deregulated proteins shows that oxidative stress and immune and inflammatory responses are common mechanisms involved in sperm alterations encountered in relation to the risk factors.

Metabolic syndrome and male fertility disorders: Is there a causal link?

Infertility is a global health problem affecting 10-15% of couples in reproductive age. Recent studies have provided growing evidence supporting that lifestyle factors can affect male fertility through alterations in endocrine profiles, spermatogenesis and/or sperm function. One of these critical factors could be the change in the food intake behavior in modern societies that produces metabolic alterations. Regarding this, metabolic syndrome (MetS) prevalence has increased in epidemic in the last 40-50 years. Although MetS is associated with advanced age, changes in lifestyles have accelerated the appearance of symptoms in the reproductive age. We review herein the current understanding of the relationship between MetS and the male reproductive status. For this purpose, in this narrative review a comprehensive literature search was made in both animal models and men, allowing us to evaluate such relationship. This analysis showed a high variability in the reproductive phenotypes observed in patients and mice suffering MetS, including sperm parameters, fertility and offspring health. In view of this, we proposed that the reproductive effects, which are diverse and not robust, observed among MetS-affected males, might depend on additional factors not associated with the metabolic condition and contributed not only by the affected male but also by his partner. With this perspective, this review provides a more accurate insight of this syndrome critical for the identification of specific diagnostic indicators and treatment of MetS-induced fertility disorders.

Pesticides and Male Fertility: A Dangerous Crosstalk

In recent decades, an increasing incidence of male infertility has been reported. Interestingly, and considering that pesticides have been used for a long time, the high incidence of this pathological state is concomitant with the increasing use of these chemicals, suggesting they are contributors for the development of human infertility. Data from literature highlight the ability of certain pesticides and/or their metabolites to persist in the environment for long periods of time, as well as to bioaccumulate in the food chain, thus contributing for their chronic exposure. Furthermore, pesticides can act as endocrine disrupting chemicals (EDCs), interfering with the normal function of natural hormones (which are responsible for the regulation of the reproductive system), or even as obesogens, promoting obesity and associated comorbidities, like infertility. Several in vitro and in vivo studies have focused on the effects and possible mechanisms of action of these pesticides on the male reproductive system that cause sundry negative effects, even though through diverse mechanisms, but all may lead to infertility. In this review, we present an up-to-date overview and discussion of the effects, and the metabolic and molecular features of pesticides on somatic cells and germinal tissues that affect germ cell differentiation.

Mitochondrial Uncoupling Proteins (UCPs) as Key Modulators of ROS Homeostasis: A Crosstalk between Diabesity and Male Infertility?

Uncoupling proteins (UCPs) are transmembrane proteins members of the mitochondrial anion transporter family present in the mitochondrial inner membrane. Currently, six homologs have been identified (UCP1-6) in mammals, with ubiquitous tissue distribution and multiple physiological functions. UCPs are regulators of key events for cellular bioenergetic metabolism, such as membrane potential, metabolic efficiency, and energy dissipation also functioning as pivotal modulators of ROS production and general cellular redox state. UCPs can act as proton channels, leading to proton re-entry the mitochondrial matrix from the intermembrane space and thus collapsing the proton gradient and decreasing the membrane potential. Each homolog exhibits its specific functions, from thermogenesis to regulation of ROS production. The expression and function of UCPs are intimately linked to diabesity, with their dysregulation/dysfunction not only associated to diabesity onset, but also by exacerbating oxidative stress-related damage. Male infertility is one of the most overlooked diabesity-related comorbidities, where high oxidative stress takes a major role. In this review, we discuss in detail the expression and function of the different UCP homologs. In addition, the role of UCPs as key regulators of ROS production and redox homeostasis, as well as their influence on the pathophysiology of diabesity and potential role on diabesity-induced male infertility is debated.

The Role of Citrate Transporter INDY in Metabolism and Stem Cell Homeostasis

I'm Not Dead Yet (Indy) is a fly gene that encodes a homologue of mammalian SLC13A5 plasma membrane citrate transporter. Reducing expression of Indy gene in flies, and its homologues in worms, extends longevity. Indy reduction in flies, worms, mice and rats affects metabolism by regulating the levels of cytoplasmic citrate, inducing a state similar to calorie restriction. Changes include lower lipid levels, increased insulin sensitivity, increased mitochondrial biogenesis, and prevention of weight gain, among others. The INDY protein is predominantly expressed in fly metabolic tissues: the midgut, fat body and oenocytes. Changes in fly midgut metabolism associated with reduced Indy gene activity lead to preserved mitochondrial function and reduced production of reactive oxygen species. All these changes lead to preserved intestinal stem cell homeostasis, which has a key role in maintaining intestinal epithelium function and enhancing fly healthspan and lifespan. Indy gene expression levels change in response to caloric content of the diet, inflammation and aging, suggesting that INDY regulates metabolic adaptation to nutrition or energetic requirements by controlling citrate levels.

Melatonin ameliorates endocrine dysfunction and defective sperm integrity associated with high-fat diet-induced obesity in male Wistar rats

Obesity (OBS) has been established as a link to male hypogonadism with consequent infertility. Previous studies have shown that melatonin (MEL) modulates hypothalamic-pituitary-gonadal function. The present study therefore investigated the hypothesis that MEL supplementation would attenuate spermatogenic and steroidogenic dysfunctions associated with obesity induced by high-fat diet (HFD). Twenty-four adult male Wistar rats (n = 6/group) were used: control group received vehicle (normal saline), obese group received 40% high-fat diet and distilled water, MEL-treated group received MEL (4 mg/kg), and OBS + MEL group received MEL and 40% HFD and the treatment lasted for 12 weeks. HFD caused increased body weight, glucose intolerance, plasma triglyceride and low-density lipoprotein cholesterol/ very low-density lipoprotein cholesterol and malondialdehyde, as well as decreased antioxidant capacity, high-density lipoprotein cholesterol, gonadotrophin-releasing hormone, follicle-stimulating hormone and testosterone and altered sperm parameters. However, all these alterations were attenuated when supplemented with MEL. Taken together, these results indicate that HFD exposure causes endocrine dysfunction and disrupted sperm parameters in obese animals, which are accompanied by lipid peroxidation/defective antioxidant capacity. In addition, the present results suggest that melatonin supplementation restores endocrine function and sperm integrity in obese rat model by suppression of oxidative stress-dependent mechanism.

Low protein diet and methyl-donor supplements modify testicular physiology in mice

The link between male diet and sperm quality has received significant investigation. However, the impact diet and dietary supplements have on the testicular environment has been examined to a lesser extent. Here, we establish the impact of a sub-optimal low protein diet (LPD) on testicular morphology, apoptosis and serum fatty acid profiles. Furthermore, we define whether supplementing a LPD with specific methyl donors abrogates any detrimental effects of the LPD. Male C57BL6 mice were fed either a control normal protein diet (NPD; 18% protein; n = 8), an isocaloric LPD (LPD; 9% protein; n = 8) or an LPD supplemented with methyl donors (MD-LPD; choline chloride, betaine, methionine, folic acid, vitamin B12; n = 8) for a minimum of 7 weeks. Analysis of male serum fatty acid profiles by gas chromatography revealed elevated levels of saturated fatty acids and lower levels of mono- and polyunsaturated fatty acids in MD-LPD males when compared to NPD and/or LPD males. Testes of LPD males displayed larger seminiferous tubule cross section area when compared to NPD and MD-LPD males, while MD-LPD tubules displayed a larger luminal area. Furthermore, TUNNEL staining revealed LPD males possessed a reduced number of tubules positive for apoptosis, while gene expression analysis showed MD-LPD testes displayed decreased expression of the pro-apoptotic genes Bax, Csap1 and Fas when compared to NPD males. Finally, testes from MD-LPD males displayed a reduced telomere length but increased telomerase activity. These data reveal the significance of sub-optimal nutrition for paternal metabolic and reproductive physiology.

Inheritable testicular metabolic memory of high-fat diet causes transgenerational sperm defects in mice

The consumption of energy-dense diets has contributed to an increase in the prevalence of obesity and its comorbidities worldwide. The adoption of unhealthy feeding habits often occurs at early age, prompting the early onset of metabolic disease with unknown consequences for reproductive function later in life. Recently, evidence has emerged regarding the intergenerational and transgenerational effects of high-fat diets (HFD) on sperm parameters and testicular metabolism. Hereby, we study the impact of high-fat feeding male mice (F₀) on the testicular metabolome and function of their sons (F₁) and grandsons (F₂). Testicular content of metabolites related to insulin resistance, cell membrane remodeling, nutritional support and antioxidative stress (leucine, acetate, glycine, glutamine, inosine) were altered in sons and grandsons of mice fed with HFD, comparing to descendants of chow-fed mice. Sperm counts were lower in the grandsons of mice fed with HFD, even if transient. Sperm quality was correlated to testicular metabolite content in all generations. Principal Component Analysis of sperm parameters and testicular metabolites revealed an HFD-related phenotype, especially in the diet-challenged generation and their grandsons. Ancestral HFD, even if transient, causes transgenerational "inherited metabolic memory" in the testicular tissue, characterized by changes in testicular metabolome and function.

Unbalance of Se and nutritional status in male infertility

OBJECTIVE

To evaluate the selenium status and oxidative stress in male infertility cases selected from a private human reproduction center in the state of Ceará, Brazil.

METHODS

The present study had a cross-sectional quantitative approach, carried out between January and October 2013 at a Human Reproduction Center. The studied population was composed of 49 male individuals seen at the clinic, aged between 18 and 60 years. Blood samples were collected to measure serum selenium concentrations, erythrocyte activity and glutathione peroxidase. After medical diagnosis, the participants were divided into fertile and infertile groups. Blood samples were collected for establishing Se concentrations in plasma and erythrocytes, and measurements of the enzymatic activity of glutathione peroxidase in the erythrocytes.

RESULT

it resulted in 53.1% of fertile men and 46.9% of infertile men. The average age of the fertile group was 34.1 years and the infertile group was 37.3 years. Regarding the assessment of nutritional status, the scatter diagram of the infertility group showed a higher body mass index and waist circumference, showing that this group has a higher risk of global and abdominal obesity compared to the fertile group (p<0.0001, respectively). There were similarities between the groups regarding caloric intake, macronutrient and selenium intake.

CONCLUSION

We can conclude that the serum values of selenium, in excess and in deficiency, can be harmful to male fertility.

Rearing system influences the testicular development, semen quality and spermatogenic cell apoptosis of layer roosters

The objective of this study was to compare the testicular development, semen quality, and spermatogenic cell apoptosis of roosters reared in colony, single, and large cages. Rohman parental layers (n = 540) were randomly allocated into cages of rearing system groups (135 males and 405 females). The experimental period was 70 to 210 d of age. We compared testicular development and plasma main reproductive hormones (Follicle-stimulating hormone; Luteinizing hormone; Testosterone; Estrogen2;) from d 70 to 210 of roosters among the three systems. In addition, routine semen quality indexes, apoptosis of testicular spermatogenic cells and sperm apoptosis of breeding roosters under three rearing systems on d 175 and d 210 were evaluated. Roosters during the growing period (from d 70 to 140) have rapid testis growth and increasing main reproductive hormones in plasma. At the peak of sexual maturity (d 210), in colony cage, the females have a positive effect and promote the testis development of males. However, the stocking density in colony cage has no effect on testicular development; compared with the single and large cage. Roosters reared in the natural mating system had better semen quality, particularly in semen volume, density, and viability; the hatching % of fertilized eggs and healthy chicks were higher for the colony than single and large cages. Furthermore, the sperm density was higher for colony than single and large cages, which was related to the apoptosis of spermatogonia and spermatocyte, not the apoptosis of mature sperm. This study provided the basic data for the reproductive performance research of chicken reared in the colony cages.

Lifestyle in urology: Benign diseases

Modifiable lifestyle-related risk factors are the object of increasing attention, with a view to primary and tertiary prevention, to limit the onset and development of diseases.Also in the urological field there is accumulating evidence of the relationship between urological diseases and lifestyle-related risk factors that can influence their incidence and prognosis. Risk factors such as nutrition, physical activity, sexual habits, tobacco smoking, or alcohol consumption can be modified to limit morbidity and reduce the social impact and the burdensome costs associated with diagnosis and treatment.This review synthesizes the current clinical evidence available on this topic, trying to satisfy the need for a summary on the relationships between the most important lifestyle factors and the main benign urological diseases, focusing on benign prostatic hyperplasia (BPH), infections urinary tract (UTI), urinary incontinence (UI), stones, erectile dysfunction, and male infertility.

Male obesity impacts DNA methylation reprogramming in sperm

BACKGROUND

Male obesity has profound effects on morbidity and mortality, but relatively little is known about the impact of obesity on gametes and the potential for adverse effects of male obesity to be passed to the next generation. DNA methylation contributes to gene regulation and is erased and re-established during gametogenesis. Throughout post-pubertal spermatogenesis, there are continual needs to both maintain established methylation and complete DNA methylation programming, even during epididymal maturation. This dynamic epigenetic landscape may confer increased vulnerability to environmental influences, including the obesogenic environment, that could disrupt reprogramming fidelity. Here we conducted an exploratory analysis that showed that overweight/obesity (n = 20) is associated with differences in mature spermatozoa DNA methylation profiles relative to controls with normal BMI (n = 47).

RESULTS

We identified 3264 CpG sites in human sperm that are significantly associated with BMI (p < 0.05) using Infinium HumanMethylation450 BeadChips. These CpG sites were significantly overrepresented among genes involved in transcriptional regulation and misregulation in cancer, nervous system development, and stem cell pluripotency. Analysis of individual sperm using bisulfite sequencing of cloned alleles revealed that the methylation differences are present in a subset of sperm rather than being randomly distributed across all sperm.

CONCLUSIONS

Male obesity is associated with altered sperm DNA methylation profiles that appear to affect reprogramming fidelity in a subset of sperm, suggestive of an influence on the spermatogonia. Further work is required to determine the potential heritability of these DNA methylation alterations. If heritable, these changes have the potential to impede normal development.

Chronic Exposure to Cadmium Induces Differential Methylation in Mice Spermatozoa

Cadmium exposure is ubiquitous and has been linked to diseases including cancers and reproductive defects. Since cadmium is nonmutagenic, it is thought to exert its gene dysregulatory effects through epigenetic reprogramming. Several studies have implicated germline exposure to cadmium in developmental reprogramming. However, most of these studies have focused on maternal exposure, while the impact on sperm fertility and disease susceptibility has received less attention. In this study, we used reduced representation bisulfite sequencing to comprehensively investigate the impact of chronic cadmium exposure on mouse spermatozoa DNA methylation. Adult male C57BL/J6 mice were provided water with or without cadmium chloride for 9 weeks. Sperm, testes, liver, and kidney tissues were collected at the end of the treatment period. Cadmium exposure was confirmed through gene expression analysis of metallothionein-1 and 2, 2 well-known cadmium-induced genes. Analysis of sperm DNA methylation changes revealed 1788 differentially methylated sites present at regulatory regions in sperm of mice exposed to cadmium compared with vehicle (control) mice. Furthermore, most of these differential methylation changes positively correlated with changes in gene expression at both the transcription initiation stage as well as the splicing levels. Interestingly, the genes targeted by cadmium exposure are involved in several critical developmental processes. Our results present a comprehensive analysis of the sperm methylome in response to chronic cadmium exposure. These data, therefore, highlight a foundational framework to study gene expression patterns that may affect fertility in the exposed individual as well as their offspring, through paternal inheritance.

Ameliorating Effect of Pineapple Juice on the Obesity-Induced Testicular Impairment in Male Wistar Rat

<b>Background and Objective:</b> Obesity exerts negative influences on male reproductive capacity via changing the molecular and physical structure of male germ cells. This study was conducted to evaluate the mitigating effects of raw juice of pineapple on obesity-associated testicular impairment in male Wistar rats. <b>Materials and Methods:</b> Rats included the control group (G_I, n = 6) who received a Normal Diet (ND) and the obese group (G_II, n = 18) who received a High-Fat Diet (HFD). Obese rats (G_II) were subdivided into 3 groups (6 rats each): G_II represents the untreated obesity group that continued to receive HFD with plain Drinking Water (DW), G_III received ND along with raw juice (15% v/v) in DW and G_IV continued to receive HFD with raw juice (15% v/v) in DW. Rats were sacrificed at the end of the trial and testis was processed for histopathology and immunohistochemistry. <b>Results:</b> Testis from obese rats revealed a significant increment in spermatogenic cell degeneration, pro-inflammatory Nuclear factor of kappa B (NF-κB) and pro-apoptotic Caspase-3 immunoreactivities. Yet, Proliferating Cell Nuclear Antigen (PCNA) displayed poor immunoreactivity in obese rats' testis relative to controls. Administration of raw juice of pineapple to obese rats significantly reduced degeneration of spermatogenic cells, NF-κB and Caspase-3 immunoreactivities. Additionally, treatment with the juice significantly increased immunoreactivity to PCNA in obese rats. These ameliorating effects were more obvious in rats who received juice along with ND (G_III) than in those who received it along with HFD (G_IV). <b>Conclusion:</b> Treatment of obese rats with pineapple juice restored testicular homeostasis, indicating its potential validity to overcome obesity-induced male fertility disorders.

Obesity-related genes are expressed in human Sertoli cells and modulated by energy homeostasis regulating hormones

The strong hormonal dysregulation associated with obesity is responsible for the disruption of several reproductive events. Sertoli cells (SCs) function is dependent on energetic homeostasis and thus, directly associated with energy homeostasis regulating hormones. To further understand the influence of those hormones with SCs function and obesity, we hypothesize that human SCs express obesity-related genes (ORG; MC4R, GNPDA2, TMEM18, and FTO) and that they respond to energy homeostasis regulating hormones (leptin, ghrelin, and glucagon-like protein 1 [GLP-1]) stimuli. To test our hypothesis, SCs were cultured with increasing doses of leptin (0, 5, 25, or 50 ng/ml, for 24 h), ghrelin (0, 20, 100, and 500 pM, for 24 h), and GLP-1 (10, 1000, or 1 × 105 pM, for 6 h). The presence and abundance of ORG transcripts and proteins in SCs were accessed by polymerase chain reaction techniques, Western blot analysis, and immunofluorescence staining. Our results show that human SCs express MC4R, GNPDA2, TMEM18, and FTO in specific cellular locations. MC4R and FTO expression in human SCs was not responsive to the treatments. However, GNPDA2 and TMEM18 expression increased after exposure to the highest concentration of leptin and ghrelin, respectively. We highlight for the first time that human SCs express ORG and that these are responsive to energy homeostasis hormonal stimuli. GNPDA2 and TMEM18 expression respond in opposite directions according to overall energy status, mediated by energy homeostasis regulating hormones. Leptin and ghrelin control of ORG expression by human SCs can be associated with overweight-related infertility and subfertility in males.

Metabolic diseases affect male reproduction and induce signatures in gametes that may compromise the offspring health

The most prevalent diseases worldwide are non-communicable such as obesity and type 2 diabetes. Noteworthy, the prevalence of obesity and type 2 diabetes is expected to steadily increase in the next decades, mostly fueled by bad feeding habits, stress, and sedentarism. The reproductive function of individuals is severely affected by abnormal metabolic environments, both at mechanical and biochemical levels. Along with mechanical dysfunctions, and decreased sperm quality (promoted both directly and indirectly by metabolic abnormalities), several studies have already reported the potentially harmful effects of metabolic disorders in the genetic and epigenetic cargo of spermatozoa, and the epigenetic inheritance of molecular signatures induced by metabolic profile (paternal diet, obesity, and diabetes). The inheritance of epigenetic factors towards the development of metabolic abnormalities means that more people in reproductive age can potentially suffer from these disorders and for longer periods. In its turn, these individuals can also transmit this (epi)genetic information to future generations, creating a vicious cycle. In this review, we collect the reported harmful effects related to acquired metabolic disorders and diet in sperm parameters and male reproductive potential. Besides, we will discuss the novel findings regarding paternal epigenetic inheritance, particularly the ones induced by paternal diet rich in fats, obesity, and type 2 diabetes. We analyze the data attained with in vitro and animal models as well as in long-term transgenerational population studies. Although the findings on this topic are very recent, epigenetic inheritance of metabolic disease has a huge societal impact, which may be crucial to tackle the 'fat epidemic' efficiently.

Diet during early life defines testicular lipid content and sperm quality in adulthood

Childhood obesity is a serious concern associated with ill health later in life. Emerging data suggest that obesity has long-term adverse effects upon male sexual and reproductive health, but few studies have addressed this issue. We hypothesized that exposure to high-fat diet during early life alters testicular lipid content and metabolism, leading to permanent damage to sperm parameters. After weaning (day 21 after birth), 36 male mice were randomly divided into three groups and fed with a different diet regimen for 200 days: a standard chow diet (CTRL), a high-fat diet (HFD) (carbohydrate: 35.7%, protein: 20.5%, and fat: 36.0%), and a high-fat diet for 60 days, then replaced by standard chow (HFD_t). Biometric and metabolic data were monitored. Animals were then euthanized, and tissues were collected. Epididymal sperm parameters and endocrine parameters were evaluated. Testicular metabolites were extracted and characterized by 1H-NMR and GC-MS. Testicular mitochondrial and antioxidant activity were evaluated. Our results show that mice fed with a high-fat diet, even if only until early adulthood, had lower sperm viability and motility, and higher incidence of head and tail defects. Although diet reversion with weight loss during adulthood prevents the progression of metabolic syndrome, testicular content in fatty acids is irreversibly affected. Excessive fat intake promoted an overaccumulation of proinflammatory n-6 polyunsaturated fatty acids in the testis, which is strongly correlated with negative effects upon sperm quality. Therefore, the adoption of high-fat diets during early life correlates with irreversible changes in testicular lipid content and metabolism, which are related to permanent damage to sperm quality later in life.

Mapping the past, present and future research landscape of paternal effects

BACKGROUND

Although in all sexually reproducing organisms an individual has a mother and a father, non-genetic inheritance has been predominantly studied in mothers. Paternal effects have been far less frequently studied, until recently. In the last 5 years, research on environmentally induced paternal effects has grown rapidly in the number of publications and diversity of topics. Here, we provide an overview of this field using synthesis of evidence (systematic map) and influence (bibliometric analyses).

RESULTS

We find that motivations for studies into paternal effects are diverse. For example, from the ecological and evolutionary perspective, paternal effects are of interest as facilitators of response to environmental change and mediators of extended heredity. Medical researchers track how paternal pre-fertilization exposures to factors, such as diet or trauma, influence offspring health. Toxicologists look at the effects of toxins. We compare how these three research guilds design experiments in relation to objects of their studies: fathers, mothers and offspring. We highlight examples of research gaps, which, in turn, lead to future avenues of research.

CONCLUSIONS

The literature on paternal effects is large and disparate. Our study helps in fostering connections between areas of knowledge that develop in parallel, but which could benefit from the lateral transfer of concepts and methods.

Lifestyle, metabolic disorders and male hypogonadism - A one-way ticket?

Hypogonadism is more frequent among men with common metabolic diseases, notably obesity and type 2 diabetes. Indeed, endocrine disruption caused by metabolic diseases can trigger the onset of hypogonadism, although the underlying molecular mechanisms are not entirely understood. Metabolic diseases are closely related to unhealthy lifestyle choices, such as dietary habits and sedentarism. Therefore, hypogonadism is part of a pathological triad gathering unhealthy lifestyle, metabolic disease and genetic background. Additionally, hypogonadism harbors the potential to aggravate underlying metabolic disorders, further sustaining the mechanisms leading to disease. To what extent does lifestyle intervention in men suffering from these metabolic disorders can prevent, improve or reverse hypogonadism, is still controversial. Moreover, recent evidence suggests that the metabolic status of the father is related to the risk of inter and transgenerational inheritance of hypogonadism. In this review, we will address the proposed mechanisms of disease, as well as currently available interventions for hypogonadism.

Effects of short-term exposure to high-fat diet on histology of male and female gonads in rats

Obesity, which reaches an epidemic, is characterized by alterations in metabolic and hormonal profiles. Moreover, uncontrolled obesity may lead to development of diabetes type 2, which accounts for about 90% of all diabetic cases. In obesity, besides changes in metabolism, numerous co-morbidities are reported, e.g. disruptions of reproductive functions. Additionally, sex differences in development of this disease occur. We hypothesized that short-term exposure to high-fat diet (HFD; containing 50% of total energy from fat) would alter histology of testes and ovaries, and thus contribute to reproductive disruptions in male and female rats. Adult rats were fed ad libitum with HFD for 6-7 weeks and its effects on histology of testes and ovaries (n = 4/sex and treatment group) were studied using hematoxylin-eosin staining followed by microscopic analysis and compared to control (laboratory chow fed) group. We have found that in male rats fed with HFD there were: 1) decrease in diameter of seminiferous tubules due to smaller luminar diameter, and no change in epithelium height; 2) decrease in number of Sertoli cells; 3) no changes in number of spermatogonia and in percentage of semen in seminiferous tubules. In female rats exposed to HFD we have seen: 1) decrease in diameters of corpora lutea; 2) decrease in diameter of ovarian follicles types 7 and 8, but no changes in their number; 3) no changes in number of early primary follicles, primary follicles, and secondary follicles. We concluded that relatively short-term exposure to HFD in rats leads to changes in histology of both testes and ovaries, thus affecting reproductive functions.

Sperm selection strategies and their impact on assisted reproductive technology outcomes

The application of assisted reproductive technologies (ART) has revolutionised the treatment of human infertility, giving hope to the patients previously considered incapable of establishing pregnancy. While semen analysis is performed to access whether a sample has an adequate number of viable, motile and morphologically normal sperm cells able to achieve fertilisation, sperm selection techniques for ART aim to isolate the most competent spermatozoon which is characterised by the highest fertilising potential. Based on the semen analysis results, the correct sperm selection technique must be chosen and applied. In this review, different sperm selection strategies for retrieving spermatozoa with the highest fertilising potential and their impact on ART outcomes are discussed. In addition, advantages and disadvantages of each method and the best suited techniques for each clinical scenario are described.

The effect of different types of exercise training on diet-induced obesity in rats, cross-talk between cell cycle proteins and apoptosis in testis

Obesity is associated with germ cell apoptosis, spermatogenesis arrest, and testicular endocrine suppression. The aim of the present study was to investigate the crosstalk between germ cell apoptosis and cell cycle machinery in sedentary and obese rats after moderate-intensity continuous (MICT), high-intensity continuous (HICT) and High-intensity interval (HIIT) exercise trainings. Male Wistar rats (n = 30) were randomly divided into 5 groups; the control, sedentary high-fat diet (HFD)-received (HFD-sole), MICT, HICT and HIIT-induced HFD-received groups. The serum levels of LDL-C, HDL-C, triglyceride, and testosterone, mRNA and protein levels of Cyclin D1, Cdk4, p21, apoptotic cell number/mm² of testicular tissue and testicular DNA fragmentation ratio were investigated. The obese animals in HFD-sole group represented a significant (p < 0.05) reduction in serum HDL-C and testosterone levels, Cyclin D1, Cdk4 expressions, and exhibited a remarkable (p < 0.05) increment in LDL-C, triglyceride, p21 expression, apoptotic cell number and DNA fragmentation ratio versus control animals. However, the animals in MICT, HICT, HIIT groups exhibited a significant (p < 0.05) increment in serum HDL-C and testosterone, Cyclin D1 and Cdk4 expressions and showed a significant (p < 0.05) reduction in serum LDL-C and triglyceride, p21 expression, apoptotic cell number and DNA fragmentation versus the HFD-sole group. In conclusion, a crosslink between cell cycle machinery and apoptosis of germ cells was revealed in the testicles of HFD-sole animals, and MICT, HICT and HIIT could ameliorate the obesity-induced impairments, respectively. This effect may be attributed to the effect of exercise training protocols on maintaining Cyclin D1 and Cdk4 and suppressing p21 expression levels in the testicles.