Role of PPAR-γ in diabetes-induced testicular dysfunction, oxidative DNA damage and repair in leptin receptor-deficient obese type 2 diabetic mice

The testis expresses peroxisome proliferator-activated receptor-γ (PPAR-γ), but its involvement in regulating diabetes-induced testicular dysfunction and DNA damage repair is not known. Pioglitazone-induced activation of PPAR-γ for 12 weeks in db/db obese diabetic mice increases bodyweights and reduces blood glucose levels, but PPAR-γ inhibition by 2-chloro-5-nitro-N-phenylbenzamide does not alter these parameters; instead, improves testis and epididymis weights and sperm count. Neither activation nor inhibition of PPAR-γ normalizes the diabetes-induced seminiferous epithelial degeneration. The PPAR-γ activation normalizes testicular lipid peroxidation, but its inhibition reduces lipid peroxidation and oxidative DNA damage (8-oxo-dG) in diabetic mice. As a response to diabetes-induced oxidative DNA damage, the base-excision repair (BER) mechanism proteins- 8-oxoguanine DNA glycosylases (OGG1/2) and X-ray repair cross-complementing protein-1 (XRCC1) increase, whereas the redox-factor-1 (REF1), DNA polymerase (pol) δ and poly (ADP-ribose) polymerase-1 (PARP1) show a tendency to increase suggesting an attempt to repair the oxidative DNA damage. The PPAR-γ stimulation inhibits OGG2, DNA pol δ, and XRCC1 in diabetic mice testes, but PPAR-γ inhibition reduces oxidative DNA damage and normalizes BER protein levels. In conclusion, type 2 diabetes negatively affects testicular structure and function and increases oxidative DNA damage and BER protein levels due to increased DNA damage. The PPAR-γ modulation does not significantly affect the structural changes in the testis. The PPAR-γ stimulation aggravates diabetes-induced effects on testis, including oxidative DNA damage and BER proteins, but PPAR-γ inhibition marginally recovers these diabetic effects indicating the involvement of the receptor in the reproductive effects of diabetes.

LncRNA Tug1 maintains blood-testis barrier integrity by modulating Ccl2 expression in high-fat diet mice

Sertoli cells are essential for spermatogenesis in the testicular seminiferous tubules by forming blood-testis barrier (BTB) and creating a unique microenvironment for spermatogenesis. Many lncRNAs have been reported to participate in spermatogenesis. However, the role of long noncoding RNAs (lncRNAs) in Sertoli cells has rarely been examined. Herein, we found that a high-fat diet (HFD) decreased sperm quality, impaired BTB integrity and resulted in accumulation of saturated fatty acids (SFAs), especially palmitic acid (PA), in mouse testes. PA decreased the expression of tight junction (TJ)-related proteins, increased permeability and decreased transepithelial electrical resistance (TER) in primary Sertoli cells and TM4 cells. Moreover, lncRNA Tug1 was found to be involved in PA-induced BTB disruption by RNA-seq. Tug1 depletion distinctly impaired the TJs of Sertoli cells and overexpression of Tug1 alleviated the disruption of BTB integrity induced by PA. Moreover, Ccl2 was found to be a downstream target of Tug1, and decreased TJ-related protein levels and TER and increased FITC-dextran permeability in vitro. Furthermore, the addition of Ccl2 damaged BTB integrity after overexpression of Tug1 in the presence of PA. Mechanistically, we found that Tug1 could directly bind to EZH2 and regulate H3K27me3 occupancy in the Ccl2 promoter region by RNA immunoprecipitation and chromatin immunoprecipitation assays. Our study revealed an important role of Tug1 in the BTB integrity of Sertoli cells and provided a new view of the role of lncRNAs in male infertility.

Reprotoxic Impact of Environment, Diet, and Behavior

Reproductive health is progressively declining due to multiples endogenous and exogenous factors, such as environmental contaminants, diet and behavior. Accumulated evidences confirm that fertility and reproductive function have been adversely affected by exposure to chemical contaminants released in the environment. Today, the impact of diet and behavior on reproductive processes is also receiving special attention from the scientific community. Indeed, a close relationship between diet and fertility has been proven. Furthermore, a combination of unhealthy behavior, such as exposure to hazardous compounds and stress factors, poses living organisms at higher risk of reprotoxic effects. In particular, it has been described that poor life behaviors are associated with reduced male and female fertility due to decreased gamete quality and function. Most of the erroneous behaviors are, furthermore, a source of oxidative stress that, leading to epigenetic alterations, results in an impaired reproductive fitness. This review reports the detrimental impact of the most common environmental chemical stressors, diet, and behavior on reproductive functionality and success. Although clear evidences are still scarce, reassuring data are provided that a healthy diet and reverting unhealthy lifestyles may be of help to recover physiological reproductive conditions.

Could Lower Testosterone in Older Men Explain Higher COVID-19 Morbidity and Mortalities?

The health scourge imposed on humanity by the COVID-19 pandemic seems not to recede. This fact warrants refined and novel ideas analyzing different aspects of the illness. One such aspect is related to the observation that most COVID-19 casualties were older males, a tendency also noticed in the epidemics of SARS-CoV in 2003 and the Middle East respiratory syndrome in 2012. This gender-related difference in the COVID-19 death toll might be directly involved with testosterone (TEST) and its plasmatic concentration in men. TEST has been demonstrated to provide men with anti-inflammatory and immunological advantages. As the plasmatic concentration of this androgen decreases with age, the health benefit it confers also diminishes. Low plasmatic levels of TEST can be determinant in the infection’s outcome and might be related to a dysfunctional cell Ca²⁺ homeostasis. Not only does TEST modulate the activity of diverse proteins that regulate cellular calcium concentrations, but these proteins have also been proven to be necessary for the replication of many viruses. Therefore, we discuss herein how TEST regulates different Ca²⁺-handling proteins in healthy tissues and propose how low TEST concentrations might facilitate the replication of the SARS-CoV-2 virus through the lack of modulation of the mechanisms that regulate intracellular Ca²⁺ concentrations.

High fat diet-induced obesity prolongs critical stages of the spermatogenic cycle in a Ldlr-/-.Leiden mouse model

Obesity can disturb spermatogenesis and subsequently affect male fertility and reproduction. In our study, we aim to elucidate at which cellular level of adult spermatogenesis the detrimental effects of obesity manifest. We induced high fat diet (HFD) obesity in low-density lipoprotein receptor knock-out Leiden (Ldlr^−/−.Leiden) mice, and studied the morphological structure of the testes and histologically examined the proportion of Sertoli cells, spermatocytes and spermatids in the seminiferous tubules. We examined sperm DNA damage and chromatin condensation and measured plasma levels of leptin, testosterone, cholesterol and triglycerides. HFD-induced obesity caused high plasma leptin and abnormal testosterone levels and induced an aberrant intra-tubular organisation (ITO) which is associated with an altered spermatids/spermatocytes ratio (2:1 instead of 3:1). Mice fed a HFD had a higher level of tubules in stages VII + VIII in the spermatogenic cycle. The stages VII + VII indicate crucial processes in spermatogenic development like initiation of meiosis, initiation of spermatid elongation, and release of fully matured spermatids. In conclusion, HFD-induced obese Ldlr^−/−.Leiden mice develop an aberrant ITO and alterations in the spermatogenic cycle in crucial stages (stages VII and VII). Thereby, our findings stress the importance of lifestyle guidelines in infertility treatments.

Restoring Impaired Fertility Through Diet: Observations of Switching From High-Fat Diet During Puberty to Normal Diet in Adulthood Among Obese Male Mice

BACKGROUND

Obesity is associated with a decrease in testicular function, yet the effects and mechanisms relative to different stages of sexual development remain unclear. The aim of this study is to determine whether high-fat diet-induced obesity impairs male fertility during puberty and in adulthood, and to ascertain its underlying mechanisms. This study aims to further reveal whether restoring to a normal diet can improve impaired fertility.

METHODS

Male mice were divided into 6 groups: the group N and H exposed to a normal diet or high-fat diet during puberty. The group NN or NH were further maintained a normal diet or exposed to high-fat diet in adulthood, the group HH or HN were further maintained high-fat diet or switched to normal diet in adulthood. Metabolic parameters, fertility parameters, testicular function parameters, TUNEL staining and testicular function-related proteins were evaluated, respectively.

RESULTS

The fertility of the mice in the high-fat diet group was impaired, which validated by declines in pregnancy rates and litter weight loss. Further analysis demonstrated the increased level of oxidative stress, the increased number of spermatogenic cell apoptosis and decreased number of sperm and decreased acrosome integrity. The expression of steroidogenic acute regulatory (StAR) and spermatogenesis related proteins (WT-1) decreased. Fertility among the HN group recovered, accompanied by the recovery of metabolism, fertility and testicular function parameters, StAR and WT-1 expression.

CONCLUSIONS

The findings suggest that high-fat diet-induced obesity impairs male fertility during puberty and in adulthood. The loss of acrosome integrity, the increase of oxidative stress, the increase of cells apoptosis and the down-regulation of StAR and WT-1 may be the underlying mechanisms. Switching from high-fat diets during puberty to normal diets in adulthood can improve male fertility.

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.

Cyantraniliprole impairs reproductive parameters by inducing oxidative stress in adult female wistar rats

Cyantraniliprole is a synthetic insecticide used to control pests of up to 23 different types of crops. It is able to modulate ryanodine-like calcium channels, which are widely found in the organism of insects and mammals. The objective of this research was to verify the possible reproductive effects of adult female Wistar rats exposure to cyantraniliprole. Animals (67 days old) were exposed to the chemical at doses of 10 or 150 mg/kg/day, orally, for 28 consecutive days (control animals received only the vehicle). Vaginal secretions were collected during the exposure period to assess the regularity of the estrous cycle; the liver, kidneys, pituitary gland, adrenal gland, uterus, and ovaries were collected and weighed; reproductive organs were assessed for histopathological evaluation and for biochemical markers of oxidative stress and progesterone plasma level was measured. Both doses caused negative changes in the morphology and redox system of the uterus and ovaries. Animals exposed to 10 mg/kg also exhibited higher level of plasma progesterone, elevated levels of lipid peroxidation in reproductive organs, increased superoxide dismutase activity in the uterus and glutathione peroxidase activity on the ovary, while the 150 mg/kg group exhibited an increment in estrous cycle length and diminished uterine glandular epithelium. Based on these results, we conclude that cyantraniliprole may have acted as an endocrine disruptor, and its effects are mediated by oxidative stress.

The relation between obesity, kisspeptin, leptin, and male fertility

Over the past decades, obesity and infertility in men increased in parallel, and the association between both phenomena have been examined by several researchers. despite the fact that there is no agreement, obesity appears to affect the reproductive potential of men through various mechanisms, such as changes in the hypothalamic-pituitary-testicular (HPT) axis, spermatogenesis, sperm quality and/or alteration of sexual health. Leptin is a hormone produced by the adipose tissue, and its production elevates with increasing body fat. Many studies have supported the relationship between raised leptin production and reproductive function regulation. In fact, Leptin acts on the HPT axis in men at all levels. However, most obese men are insensitive to increased production of endogenous leptin and functional leptin resistance development. Recently, it has been recommended that Kisspeptin neurons mediate the leptin's effects on the reproductive system. Kisspeptin binding to its receptor on gonadotropin-releasing hormone (GnRH) neurons, activates the mammal's reproductive axis and stimulates GnRH release. Increasing infertility associated with obesity is probably mediated by the Kisspeptin-GnRH pathway. In this review, the link between obesity, kisspeptin, leptin, and male fertility will be discussed.

Exploring the role of gut microbiome in male reproduction

BACKGROUND

The impact of the gut microbiome on the organism has become a growing research focus with the development of 16S rRNA sequencing. However, the effect of the gut microbiome in male reproduction has yet to be investigated.

OBJECTIVE

To overview on possible mechanisms by which gut microbiome could affect male reproduction and therapeutic opportunities related to the gut microbiome METHODS: Authors searched PubMed/MEDLINE, EMBASE, Web of Science, Cochrane Library for medical subject headings terms and free text words referred to "male infertility" "testis" "gut microbiome" "insulin resistance" "erectile dysfunction" "therapy" "sex hormones" "Genital Diseases." until Dec 2nd 2021.

RESULTS

Evidence suggests that immune system activation caused by the gut microbiome translocation not only leads to testicular and epididymal inflammation but can also induce insulin resistance together with gastrointestinal hormones such as leptin and ghrelin, which in turn affects the secretion of various sex hormones such as LH, FSH, and T to regulate spermatogenesis. In addition, the gut microbiome can influence spermatogenesis by controlling and metabolizing androgens as well as affecting the blood-testis barrier. It also promotes vascular inflammation by raising trimethylamine-N-oxide (TMAO) levels in the blood, which causes erectile dysfunction. Testicular microbiome and gut microbiome can interact to influence male reproductive function. This study discusses therapeutic options such as probiotics, prebiotics, and fecal microbiota transplantation, as well as the challenges and opportunities behind ongoing research, and emphasizes the need for additional research in the future to demonstrate the links and underlying mechanisms between gut microbiome and male reproduction. Therapeutic options such as probiotic, prebiotics and fecal microbiota transplantation are potential treatments for male infertility.

DISCUSSION AND CONCLUSION

Gut microbiota may have a causal role in male reproduction health, therapeutic strategies such as supplementation with appropriate probiotics could be undertaken as a complementary treatment. In the future, additional research is needed to demonstrate the links and underlying mechanisms between gut microbiome and male reproduction. This article is protected by copyright. All rights reserved.

Acetate supplementation restores testicular function by modulating Nrf2/PPAR-γ in high fat diet-induced obesity in Wistar rats

Purpose

Several studies have established impaired testicular function in obese male population, including the young males with childhood obesity, contributing to increased male infertility, which is a universal trend in the last few decades. Short chain fatty acids (SCFAs) have been recently demonstrated to inhibit progression to metabolic comorbidities. The present study therefore hypothesized that SCFAs, acetate attenuates testicular dysfunction in high fat diet (HFD)-induced obese rat model, possibly by modulating Nrf2/PPAR-γ.

Methods

Adult male Wistar rats weighing 160-190 g were randomly allotted into three groups (n = 6/group): The groups received vehicle (distilled water), 40% HFD and sodium acetate (200 mg/kg) plus 40% HFD respectively. The administration lasted for 12 weeks.

Results

HFD caused obesity, which is characterized with increased body weight and visceral adiposity and insulin resistance/hyperinsulinemia. In addition, it increased testicular lipid deposition, malondialdehyde, pro-inflammatory mediators, lactate/pyruvate ratio, γ-Glutamyl transferase, and circulating leptin as well as decreased testicular glutathione, nitric oxide, Nrf2, PPAR-γ and circulating follicle stimulating hormone and testosterone without a significant change in testicular lactate dehydrogenase, blood glucose and luteinizing hormone when compared to the control group. Nevertheless, administration of acetate reversed the HFD-induced alterations.

Conclusion

The present results demonstrates that HFD causes obesity-driven testicular dysfunction, associated with testicular lipid deposition, oxidative stress, and inflammation. The study in addition suggests the restoration of testicular function in obese animals by acetate, an effect that is accompanied by elevated Nrf2/PPAR-γ.

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.

Molecular Mechanisms Underlying the Relationship between Obesity and Male Infertility

In recent decades, the worldwide prevalence of obesity has risen dramatically and is currently estimated to be around 20%. Obesity is linked to an increased risk of comorbidities and premature mortality. Several studies have shown that obesity negatively impacts male fertility through various mechanisms. This review aims to investigate the molecular mechanisms through which obesity impairs male reproduction, including obesity-associated hypogonadism and its effects on spermatogenesis, chronic inflammation, and oxidative stress. Obesity negatively impacts both conventional and biofunctional sperm parameters, and it also induces epigenetic changes that can be transferred to offspring. Moreover, obesity-related diseases are linked to a dysregulation of adipocyte function and micro-environmental inflammatory processes. The dysregulated adipokines significantly influence insulin signaling, and they may also have a detrimental effect on testicular function. Sirtuins can also play an important role in inflammatory and metabolic responses in obese patients. Understanding the molecular mechanisms that are involved in obesity-induced male infertility could increase our ability to identify novel targets for the prevention and treatment of obesity and its related consequences.

Acupuncture for oligospermia and asthenozoospermia: A systematic review and meta-analysis

BACKGROUND

Acupuncture is widely used for oligospermia and asthenozoospermia in China, but its effect is unclear. We aimed to determine the effectiveness and safety of acupuncture in treating oligospermia and asthenozoospermia.

METHODS

An electronic search for randomized controlled trials evaluating acupuncture treatment in patients with oligospermia and asthenozoospermia published from database inception to October 2018 was conducted in PubMed, EMBASE, the Chinese Biomedical Literature Database, the Chinese Scientific Journal Database (VIP Database), the Wan-Fang Database, the China National Knowledge Infrastructure and the Cochrane Library. We established search terms related to 3 areas (oligospermia, asthenozoospermia, and acupuncture). Two authors independently screened all identified citations and extracted the data. The methodological quality of the included trials was assessed using the Cochrane criteria.

RESULTS

Seven studies with a total of 527 subjects were screened according to inclusion and exclusion standards, and most of the studies had significant methodological weaknesses. Seven randomized controlled trials tested the effects of acupuncture compared with placebo acupuncture and conventional medications in patients with oligospermia and asthenozoospermia. The results of this study suggest that acupuncture alone has no clear superiority in improving sperm motility (standard mean difference [SMD] = 1.13, 95% confidence interval [CI]: -0.64 to 2.89), the sperm concentration (SMD = 0.32, 95% CI: 0.27-0.92) or semen volume compared with placebo acupuncture. No significant difference was found between acupuncture alone and conventional medications in improving sperm motility (SMD = -0.53, 95% CI: -2.54 to 1.48), the sperm concentration (SMD = -1.10, 95% CI: -1.48 to -0.72) or semen volume. However, adjuvant acupuncture may enhance the effect of medications on improving sperm motility (SMD = 4.10, 95% CI: 1.09-7.12) and the sperm concentration (SMD = 1.07, 95% CI: 0.739-1.40), but the study heterogeneity was too high to establish robust conclusions.

CONCLUSION

These results suggest that the current evidence does not support acupuncture as an effective treatment for oligospermia and asthenozoospermia; therefore, acupuncture is not currently recommended as a treatment for these conditions. However, owing to the high risk of bias among the included studies, the evidence is limited, and more large-scale, high-quality clinical trials are needed in the future.

TRIAL REGISTRATION NUMBER

PROSPERO CRD42018083885.

Angiogenin mediates paternal inflammation-induced metabolic disorders in offspring through sperm tsRNAs

Paternal environmental inputs can influence various phenotypes in offspring, presenting tremendous implications for basic biology and public health and policy. However, which signals function as a nexus to transmit paternal environmental inputs to offspring remains unclear. Here we show that offspring of fathers with inflammation exhibit metabolic disorders including glucose intolerance and obesity. Deletion of a mouse tRNA RNase, Angiogenin (Ang), abolished paternal inflammation-induced metabolic disorders in offspring. Additionally, Ang deletion prevented the inflammation-induced alteration of 5'-tRNA-derived small RNAs (5'-tsRNAs) expression profile in sperm, which might be essential in composing a sperm RNA 'coding signature' that is needed for paternal epigenetic memory. Microinjection of sperm 30-40 nt RNA fractions (predominantly 5'-tsRNAs) from inflammatory Ang^+/+ males but not Ang^-/- males resulted in metabolic disorders in the resultant offspring. Moreover, zygotic injection with synthetic 5'-tsRNAs which increased in inflammatory mouse sperm and decreased by Ang deletion partially resembled paternal inflammation-induced metabolic disorders in offspring. Together, our findings demonstrate that Ang-mediated biogenesis of 5'-tsRNAs in sperm contributes to paternal inflammation-induced metabolic disorders in offspring.

Hope for male fecundity: clinically insignificant changes in semen parameters over 10 years at a single clinic while assessing an infertility population

PURPOSE

What is the trend in sperm parameters in a group of men attending a single reproductive center, over a 10-year period?

METHODS

A retrospective study was conducted on 12,188 semen samples obtained from unique individuals who attended a university reproductive clinic from 2009 to 2018, inclusively. Semen analysis was done using computer-assisted sperm analysis and verified by an andrologist. Analysis was done after dividing the dataset into two groups: above WHO 2010 lower reference limits (ARL) (N = 6325) and below the reference limits (BRL) (N = 5521).

RESULTS

Volume increased slightly (ARL, p = 0.049) before returning to baseline or was stable (BRL, p = 0.59). Sperm concentration and total count of the BRL and ARL group declined initially and then recovered slightly (p < 0.0001, in all cases). Although these changes were statistically significant, this was due to the large study population; clinically, these changes were quite mild and would not have been significant for fertility. Sperm total motility and progressive motility of both the BRL group and the ARL group increased slightly from 2009 until 2015 and then decreased back to baseline (p < 0.0001). This change offset the decrease in count seen in those years. A spurious change was observed with sperm morphology that declined after the first 2 years and remained stable thereafter (p < 0.0001, in both groups). However, this change was attributed to a contemporaneous change in the method of analyzing strict morphology which happened when the change occurred.

CONCLUSION

While statistically significant changes were found, clinically, these changes were quite mild and would not have been significant for fertility.

Association of diabetes and obesity with sperm parameters and testosterone levels: a meta-analysis

BACKGROUND

The present study performed two distinct meta-analyses with common outcomes (sperm parameters); one was performed in obese individuals (and non-obese controls) and the other in diabetic individuals (and non-diabetic controls).

METHODS

PubMed, Embase, The Cochrane library, Web of Science, Scopus databases were searched to collect clinical studies related to the effects of obesity and diabetes on male sperm from inception to on 1st February 2021. Statistical meta-analyses were performed using the RevMan 5.4 software. Stata16 software was used to detect publication bias. The methodological quality of the included studies was assessed with the Ottawa-Newcastle scale using a star-based system.

RESULTS

A total of 44 studies were finally included in the present study, which enrolled 20,367 obese patients and 1386 patients with diabetes. The meta-analysis results showed that both obesity and diabetes were associated with reduced semen volume (obese versus non-obese controls: mean difference (MD) = - 0.25, 95% CI = (- 0.33, - 0.16), p < 0.001; diabetes versus non-diabetic controls: MD = - 0.45, 95% CI = (- 0.63, - 0.27), p < 0.001), reduced sperm count (obese versus non-obese controls: MD = - 23.84, 95% CI = (- 30.36, - 17.33), p < 0.001; diabetes versus non-diabetic controls: MD = - 13.12, 95% CI = (- 18.43, - 7.82), p < 0.001), reduced sperm concentration (obese versus non-obese controls: MD = - 7.26, 95% CI = (- 10.07, - 4.46), p < 0.001; diabetes versus non-diabetic controls: MD = - 11.73, 95% CI = (- 21.44, - 2.01), p = 0.02), reduced progressive motility (obese versus non-obese controls: MD = - 5.68, 95% CI = (- 8.79, - 2.56), p < 0.001; diabetes versus non-diabetic controls: MD = - 14.37, 95% CI = (- 21.79, - 6.96), p = 0.001), and decreased testosterone levels (obese versus non-obese controls: MD = - 1.11, 95% CI = (- 1.92, - 0.30), p = 0.007; diabetes versus non-diabetic controls: MD = - 0.37, 95% CI = (- 0.63, - 0.12), p = 0.004).

CONCLUSIONS

Current evidence suggests that obesity and diabetes negatively affect sperm parameters in men and are associated with low testosterone levels. Due to the limitation of the number and quality of included studies, the above conclusions need to be verified by more high-quality studies.

Obesity Animal Models for Acupuncture and Related Therapy Research Studies

Obesity and related diseases are considered as pandemic representing a worldwide threat for health. Animal models are critical to validate the effects and understand the mechanisms related to classical or innovative preventive and therapeutic strategies. It is, therefore, important to identify the best animal models for translational research, using different evaluation criteria such as the face, construct, and predictive validity. Because the pharmacological treatments and surgical interventions currently used for treating obesity often present many undesirable side effects, relatively high relapse probabilities, acupuncture, electroacupuncture (EA), and related therapies have gained more popularity and attention. Many kinds of experimental animal models have been used for obesity research studies, but in the context of acupuncture, most of the studies were performed in rodent obesity models. Though, are these obesity rodent models really the best for acupuncture or related therapies research studies? In this study, we review different obesity animal models that have been used over the past 10 years for acupuncture and EA research studies. We present their respective advantages, disadvantages, and specific constraints. With the development of research on acupuncture and EA and the increasing interest regarding these approaches, proper animal models are critical for preclinical studies aiming at developing future clinical trials in the human. The aim of the present study is to provide researchers with information and guidance related to the preclinical models that are currently available to investigate the outcomes of acupuncture and related therapies.

Obesity induces morphological and functional changes in female reproductive system through increases in NF-κB and MAPK signaling in mice

BACKGROUND

Recently, human infertility incidence is increasing in obese women causing it to become an emerging global health challenge requiring improved treatment. There is extensive evidence that obesity caused female reproductive dysfunction is accompanied by an endocrinological influence. Besides, systemic and tissue-specific chronic inflammatory status are common characteristics of obesity. However, the underlying molecular mechanism is unclear linking obesity to infertility or subfertility.

METHODS

To deal with this question, we created an obese mouse model through providing a high fat diet (HFD) and determined the fertility of the obese mice. The morphological alterations were evaluated in both the reproductive glands and tracts, such as uterus, ovary and oviduct. Furthermore, to explore the underlying mechanism of these functional changes, the expressions of pro-inflammatory cytokines as well as the activations of MAPK signaling and NF-κB signaling were detected in these reproductive tissues.

RESULTS

The obese females were successful construction and displayed subfertility. They accumulated lipid droplets and developed morphological alterations in each of their reproductive organs including uterus, ovary and oviduct. These pathological changes accompanied increases in pro-inflammatory cytokine expression levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in all of these sites. Such effects also accompanied increases in nuclear factor kappa B (NF-kB) expression and mitogen-activated protein kinase (MAPK) signaling pathway stimulation based on uniform time dependent increases in the NF-κB (p-NF-κB), JNK (p-JNK), ERK1/2 (p-ERK) and p38 (p-p38) phosphorylation status.

CONCLUSIONS

These HFD-induced increases in pro-inflammatory cytokine expression levels and NF-κB and MAPKs signaling pathway activation in reproductive organs support the notion that increases of adipocytes resident and inflammatory status are symptomatic of female fertility impairment in obese mice.

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.

LncRNAs as Therapeutic Targets and Potential Biomarkers for Lipid-Related Diseases

Lipid metabolism is an essential biological process involved in nutrient adjustment, hormone regulation, and lipid homeostasis. An irregular lifestyle and long-term nutrient overload can cause lipid-related diseases, including atherosclerosis, myocardial infarction (MI), obesity, and fatty liver diseases. Thus, novel tools for efficient diagnosis and treatment of dysfunctional lipid metabolism are urgently required. Furthermore, it is known that lncRNAs based regulation like sponging microRNAs (miRNAs) or serving as a reservoir for microRNAs play an essential role in the progression of lipid-related diseases. Accordingly, a better understanding of the regulatory roles of lncRNAs in lipid-related diseases would provide the basis for identifying potential biomarkers and therapeutic targets for lipid-related diseases. This review highlighted the latest advances on the potential biomarkers of lncRNAs in lipid-related diseases and summarised current knowledge on dysregulated lncRNAs and their potential molecular mechanisms. We have also provided novel insights into the underlying mechanisms of lncRNAs which might serve as potential biomarkers and therapeutic targets for lipid-related diseases. The information presented here may be useful for designing future studies and advancing investigations of lncRNAs as biomarkers for diagnosis, prognosis, and therapy of lipid-related diseases.

Comparative protective effects of N-acetylcysteine and melatonin against obesity-induced testicular dysfunction in rats

N-acetylcysteine (NAC) and melatonin were reported to exert protective effects on testicular tissues. Thus, this study aimed to determine which of these is more efficient against obesity-induced testicular dysfunction in albino rats. A total of 32 adult male rats (195 ± 10 g) were divided into four groups: control, obese rats fed a high-fat diet (HFD), HFD+NAC (150 mg/kg per day, i.p.) and HFD+melatonin (10 mg/kg per day, i.p.), for 5 weeks. Testes and epididymis were weighed. Lipid profile, pituitary-testicular hormones, tumor necrosis factor α (TNFα), epididymal sperm parameters, testicular oxidant-antioxidant system, testicular and the epididymal histopathology and immunohistochemical localization for androgen receptors (AR) and Bax reaction were analyzed. Administration of NAC or melatonin significantly improved the lipid parameters, gonadal hormones, TNFα level, sperm count and abnormal morphology, oxidant-antioxidant system and the absolute testicular and epididymal mass with an enhancement of testicular architecture, AR expression and apoptosis as compared with that in the obese group. Additionally, as compared with the NAC group, the melatonin group had significantly reduced body mass index, total cholesterol, triglyceride, and TNFα and increased testosterone, sperm count, motility, superoxide dismutase activity, mitigated histomorphometrical changes, Bax expression, and increased testicular AR expression. Therefore, melatonin was more efficient than NAC in affording fortification against HFD-induced testicular dysfunction.

Pharmacological Exploration of Phenolic Compound: Raspberry Ketone-Update 2020

Raspberry ketone (RK) is an aromatic phenolic compound naturally occurring in red raspberries, kiwifruit, peaches, and apples and reported for its potential therapeutic and nutraceutical properties. Studies in cells and rodents have suggested an important role for RK in hepatic/cardio/gastric protection and as an anti-hyperlipidemic, anti-obesity, depigmentation, and sexual maturation agent. Raspberry ketone-mediated activation of peroxisome proliferator-activated receptor-α (PPAR-α) stands out as one of its main modes of action. Although rodent studies have demonstrated the efficacious effects of RK, its mechanism remains largely unknown. In spite of a lack of reliable human research, RK is marketed as a health supplement, at very high doses. In this review, we provide a compilation of scientific research that has been conducted so far, assessing the therapeutic properties of RK in several disease conditions as well as inspiring future research before RK can be considered safe and efficacious with limited side effects as an alternative to modern medicines in the treatment of major lifestyle-based diseases.

The Physics-Biology continuum challenges darwinism: Evolution is directed by the homeostasis-dependent bidirectional relation between genome and phenotype

The physics-biology continuum relies on the fact that life emerged from prebiotic molecules. Here, I argue that life emerged from the coupling between nucleic acid and protein synthesis during which proteins (or proto-phenotypes) maintained the physicochemical parameter equilibria (or proto-homeostasis) in the proximity of their encoding nucleic acids (or proto-genomes). This protected the proto-genome physicochemical integrity (i.e., atomic composition) from environmental physicochemical constraints, and therefore increased the probability of reproducing the proto-genome without variation. From there, genomes evolved depending on the biological activities they generated in response to environmental fluctuations. Thus, a genome maintaining homeostasis (i.e., internal physicochemical parameter equilibria), despite and in response to environmental fluctuations, maintains its physicochemical integrity and has therefore a higher probability to be reproduced without variation. Consequently, descendants have a higher probability to share the same phenotype than their parents. Otherwise, the genome is modified during replication as a consequence of the imbalance of the internal physicochemical parameters it generates, until new mutation-deriving biological activities maintain homeostasis in offspring. In summary, evolution depends on feedforward and feedback loops between genome and phenotype, as the internal physicochemical conditions that a genome generates ─ through its derived phenotype in response to environmental fluctuations ─ in turn either guarantee its stability or direct its variation. Evolution may not be explained by the Darwinism-derived, unidirectional principle (random mutations-phenotypes-natural selection) but rather by the bidirectional relationship between genome and phenotype, in which the phenotype in interaction with the environment directs the evolution of the genome it derives from.

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.

Effects of moderate intensity endurance training and high-intensity interval training on the reproductive parameters of wistar rats overfed in infancy

Studies indicate that rapid weight gain at critical development stages, such as the lactation period, is associated with the development of obesity, cardiovascular diseases, and diabetes in the long term. In addition to metabolic changes during adulthood, overweight/obesity may influence reproductive function. Human and animal studies suggest that lifestyle changes through exercise and/or controlled diet result in improved semen quality in obese individuals. However, the relationship between exercise volume/intensity and reproductive capacity effects remains inconclusive. The present study aimed to evaluate the effects of moderate intensity endurance training and high-intensity interval training (HIIT) on the reproductive parameters of lactating overfed male Wistar rats. Postnatal overfeeding was induced by applying the litter size reduction method. Forty males Wistar rats were used, divided into four groups: one with control litters (CLs) (10 animals/litter-sedentary) and three with small litters (SLs) (4 animals/litter), divided into sedentary, moderate endurance training, and HIIT. Morphologic, metabolic, and reproductive variables were analyzed. SL sedentary group showed increased body weight, adiposity, and decreased relative weight of the seminal vesicle, prostate, and epididymis as well as changes in the insulin tolerance and oral glucose tolerance tests glycemic tests compared to CL sedentary group. Endurance and HIIT protocols were efficient in improving the glycemic metabolism, central fat accumulation of trained groups and did not affect reproductive parameters. Endurance and HIIT protocols proved to be effective in reversing these metabolic changes without impairing the evaluated reproductive parameters.

Trans-resveratrol imparts disparate effects on transcription of DNA damage sensing/repair pathway genes in euglycemic and hyperglycemic rat testis

Prevention or repair of DNA damage is critical to inhibit carcinogenesis in living organisms. Using quantitative RT2 Profiler™ PCR array, we investigated if trans-resveratrol could modulate the transcription of DNA damage sensing/repair pathway genes in euglycemic and non-obese type 2 diabetic Goto-Kakizaki rat testis. Trans-resveratrol imparted disparate effects on gene expressions. In euglycemic rats, it downregulated 79% and upregulated 2% of genes. However, in diabetic rats, it upregulated only 2% and downregulated 4% of genes. As such, diabetes upregulated 16% and downregulated 4% of genes. Trans-resveratrol normalized the expression of 9 (60%) out of 15 upregulated genes in diabetic rats. In euglycemic rats, trans-resveratrol inhibited ATM/ATR, DNA damage repair, pro-cell cycle progression, and apoptosis signaling genes. However, it increased Cdkn1a and Sumo1, indicating cell cycle arrest, apoptosis, and cytostasis in conjunction with increased DNA double-strand breaks and apoptosis. Diabetes increased DNA damage and apoptosis but did not affect ATM/ATR and double-strand break repair genes, although it increased few single-strand repair genes. Diabetes increased Abl1 and Sirt1, which may be related to apoptosis, but their increase may well suggest the enhanced cell cycle progression and putative carcinogenicity. The transcription of Rad17 and Smc1a increased in diabetic rats indicating G2 phase arrest and increases in a few DNA single-strand breaks repair genes suggesting DNA damage repair. Trans-resveratrol inhibits the cell cycle and causes cell death in euglycemic rat testis but normalizes diabetes-induced genes related to DNA damage and cell cycle control, suggesting its usefulness in maintaining DNA integrity in diabetes.

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.

Obesity in childhood: how to improve male adolescence incoming

INTRODUCTION

Earlier or delayed puberty can be determined by numerous causes, but the exact mechanisms are not fully known. Anyway, those may be independent from the hypothalamicpituitary-gonadal axis involvement. Certainly, obesity is one of the main factors. In fact, obesity and infertility are strongly linked. For this reason, we want to analyse the relationship between puberty and obesity and give an updated state-of-the-art starting by discussing a 14-year-old obese boy's clinical case.

EVIDENCE ACQUISITION

Literature data are conflicting. Main criticisms are related to study design and evaluation criteria. Indeed, examined populations are not homogeneous by age, Tanner stage and BMI classification. The obesity epidemic is involved in earlier puberty, and puberty seems to be anticipated in all BMI groups. Very few studies evaluate the level of adiposity in the diagnosis of obesity. However, the role of the adipose tissue is crucial for hormone synthesis and regulation. Therefore, fat mass age-related and not simply BMI has to be considered by clinicians for appropriate diagnosis.

EVIDENCE SYNTHESIS

Regarding the clinical case, in three months our patient recovered delayed pubertal development following an anti-inflammatory and antioxidant Mediterranean Diet. Loss of weight, as in decrease of fat mass but saving of lean mass, increased testicular volume and testosterone levels occurred.

CONCLUSIONS

Puberty depends on several factors, including obesity. Further studies are needed to evaluate age groups, Tanner stage, diet and lifestyle, ethnicity and above all the fat/lean mass ratio. Lack of adequate tools could hinder a clinician's ability to recognize when or if therapeutic intervention is needed.

Male sexual function after weight-loss surgeries in a group of Saudi population

Introduction:

Obesity is associated with erectile dysfunction in many studies. This study aims to inspect the impact of weight-loss surgery on the erectile function in the Saudi male population.

Patients and Methods:

Forty-two consecutive male patients who underwent weight-loss surgery during a period from February 2013 to July 2016 were included in the study. Unmarried patients were excluded from the study. A designed questionnaire includes the short version of the International Index of Erectile Function (IIEF), usage of phosphodiesterase inhibitors, overall satisfaction before and after the intervention, marriage duration, and fertility postsurgery. All the participants were contacted through phone in July 2018, and then the questionnaire was mailed to them. All the data were analyzed and compared to a control group of married obese patients, who were waiting for the bariatric surgeries, using specific statistical tests.

Results:

Thirty patients responded and completed the survey. Their mean age was 41.9 years (range 26–62), and the mean preoperative body mass index (BMI) was 46.3 ± 7.5, with a significant reduction in the BMI postoperatively to a mean of 30 ± 5.5. The IIEF score improved, and the overall satisfaction and feelings were better (76.7%). Only 16.7% of cases needed PDEI before and after the operation. Thirteen (43.3%) patients got children after the surgery. Univariate and multivariate analysis showed that age was a significant factor in association with both erectile function and fertility after bariatric surgeries (P = 0.02). Fertility was better in patients who underwent laparoscopic sleeve gastrectomy than gastric bypass surgery (P = 0.01).

Conclusion:

The weight-loss surgeries have a significant effect on erectile function, and they improve patient sexual satisfaction. Most of these patients feel better sexual function after bariatric surgeries. Fertility outcome seems to have a positive correlation with this type of surgery. However, a larger sample size and more elaborate studies are warranted to substantiate this claim.

Evaluation of maternal high-fat diet and Quercetin-3-O-rutinoside treatment on the reproductive profile of diet naïve male offspring

BACKGROUND

Male infertility and reproductive dysfunctions have become major global health problems. Although several causative factors have been attributed to this challenge, of importance are alterations in maternal-foetal environment, diet-induced transcriptional changes and dysregulation in chemical signaling via hypothalamic-gonadal axis.

AIM

The present study investigated the impact of maternal high-fat diet (HFD) consumption and the putative role of Quercetin-3-O-rutinoside on reproductive functions of male offspring rats at critical developmental stages with a quest to unravel the underpinned molecular changes.

MATERIALS AND METHODS

Fifty-six pregnant rats (previously fed normal diet ND) or 45% HFD) were maintained on supplemented chow (150 mg/kg QR) - ND/QR, HFD/QR throughout gestation. Subsequently, dams (n = 7) and offspring (n = 6) were sacrificed at post-natal day (PND) 21, 28 and 35, respectively, and the blood, placenta, hypothalamus (HT), and testicular samples were processed for molecular analysis of Gonadotropin-releasing hormone (GnRH), Luteinizing hormone (LH), testosterone, chemerin, chemokine-like receptor 1 (CMKLR1), tumour necrosis factor α (TNF-α), interleukin 1β (IL-1β) and nuclear factor kappa B (NF-κB).

KEY FINDINGS

We observed a significant decrease in GnRH level in the HFD group at PND21 and PND28 in male offspring and treatment with QR significantly reduced GnRH. There was a significant reduction in LH levels in the HFD group at PND 21 in the male offspring accompanied by a significant decrease in testosterone level at PND 28 and PND35 which appears to be age dependent. In the HT, Chemerin and CMKLR1 was significantly upregulated in the HFD group at PND 21 and PND 35 respectively while CMKLR1 was significantly downregulated in the HFD group of the placenta and testis at PND 21. TNF-α, IL-1β and NF-κB were also expressed in the placenta, HT and testis at PND 21.

SIGNIFICANCE

Male fertility is affected by maternal HFD consumption while chemerin, CMKLR1 and TNF-α, may play a significant role in male steroidogenesis. Treatment with QR had little or no ameliorative effect on HFD induced alterations in male reproductive functions.

Research Progress on the Relationship between Obesity-Inflammation-Aromatase Axis and Male Infertility

Aromatase is a key enzyme in the transformation of androgen into estrogen. Its high expression will destroy the hormonal balance in the male body, and the excessive transformation of androgen into estrogen in the body will further damage the spermatogenic function of the testis, affect the normal development of the sperm, and cause spermatogenic disturbance. Adipose tissue has a high expression of aromatase and shows high enzymatic activity and ability to convert estrogen. Adipose tissue is the most estrogen-producing nongonadal tissue in the body because of its large size, accounting for about 20% of the body mass in healthy adults. PPARγ is recognized as the key adipose differentiation in the transcriptional regulation of the transcription factor. In the process of adipocyte differentiation, PPARγ regulate the expression of aromatase. The increase of aromatase is associated with the inflammatory response in adipose tissue caused by obesity. After obesity, the increase of proinflammatory factors in adipocytes will lead to enhanced transcription of the CYP19 gene encoding aromatase in adipocytes, which in turn will lead to increased expression of aromatase in adipocytes. This article reviews the regulation of male sterility from the angle of the "obesity-inflammation-aromatase" axis.

Paternal Methyl Donor Supplementation in Rats Improves Fertility, Physiological Outcomes, Gut Microbial Signatures and Epigenetic Markers Altered by High Fat/High Sucrose Diet

Increased consumption of high fat/sucrose (HF/S) diets has contributed to rising rates of obesity and its co-morbidities globally, while also negatively impacting male reproductive health. Our objective was to examine whether adding a methyl donor cocktail to paternal HF/S diet (HF/S+M) improves health status in fathers and offspring. From 3–12 weeks of age, male Sprague Dawley rats consumed a HF/S or HF/S+M diet. Offspring were followed until 16 weeks of age. Body composition, metabolic markers, gut microbiota, DNA methyltransferase (DNMT) and microRNA expression were measured in fathers and offspring. Compared to HF/S, paternal HF/S+M diet reduced fat mass in offspring (p < 0.005). HF/S+M fathers consumed 16% fewer kcal/day, which persisted in HF/S+M female offspring and was explained in part by changes in serum glucagon-like peptide-1 (GLP-1) and peptide tyrosine tyrosine (PYY) levels. Compared to HF/S, HF/S+M fathers had a 33% improvement in days until conception and 300% fewer stillbirths. In fathers, adipose tissue DNMT3a and hepatic miR-34a expression were reduced with HF/S+M. Adult male offspring showed upregulated miR-24, -33, -122a and -143 expression while females exhibited downregulated miR-33 expression. Fathers and offspring presented differences in gut microbial signatures. Supplementing a paternal HF/S diet with methyl-donors improved fertility, physiological outcomes, epigenetic and gut microbial signatures intergenerationally.

Male adiposity, sperm parameters and reproductive hormones: An updated systematic review and collaborative meta-analysis

The present updated systematic review and meta-analysis aims to summarize the evidence from published studies with low risk for any important bias (based on methodological quality assessment) investigating the potential associations of adiposity with sperm quality and reproductive hormones. We conducted a systematic search of the literature published in MEDLINE-PubMed and EMBASE through June 2019. Based on the criteria in our review, 169 eligible publications were used for data abstraction. Finally, 60 articles were included in the qualitative analysis and 28 in the quantitative analysis. Our systematic review results indicated that overweight and/or obesity were associated with low semen quality parameters (i.e., semen volume, sperm count and concentration, sperm vitality and normal morphology) and some specific reproductive hormones (e.g., inhibin B, total testosterone and sex hormone-binding globulin). Overweight and/or obesity were also positively associated with high estradiol concentrations. Meta-analysis indicated that overweight and/or obesity categories were associated with lower sperm quality (i.e., semen volume, sperm count and concentration, sperm vitality, total motility and normal morphology), and underweight category was likewise associated with low sperm normal morphology. In conclusion, our results suggest that maintaining a healthy body weight is important for increasing sperm quality parameters and potentially male fertility.

The Mechanisms Involved in Obesity-Induced Male Infertility

BACKGROUND

Obesity resulted by imbalance between the intake of energy and energy consumption can lead to growth and metabolic disease development in people. Both in obese men and animal models, several studies indicate that obesity leads to male infertility.

OBJECTIVE

This review has discussed some mechanisms involved in obesity-induced male infertility.

METHODS

Online documents were searched through Science Direct, Pubmed, Scopus, and Google Scholar websites dating from 1959 to recognize studies on obesity, kisspeptin, leptin, and infertility.

RESULTS

Obesity induced elevated inflammatory cytokines and oxidative stress can affect male reproductive functions, including spermatogenesis disorders, reduced male fertility power and hormones involved in the hypothalamus-pituitary-gonadal axis.

CONCLUSION

There is significant evidence that obesity resulted in male infertility. Obesity has a negative effect on male reproductive function via several mechanisms such as inflammation and oxidative stress.

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.

Seminal Plasma Proteomic Biomarkers of Oxidative Stress

The prevalence of idiopathic male infertility is high, up to 75% of patients with abnormal sperm parameters. Hence, the research of its causes is mandatory. Oxidative stress (OS) can be responsible for male infertility in 30–80% of cases. In recent years, seminal plasma (SP) proteomics has developed as a useful tool to provide biomarkers of specific diseases. This systematic review aims to collect the available evidence on the changes of SP proteome in patients exposed to OS to provide possible SP biomarkers of sperm OS. To accomplish this, the following keyterms “seminal fluid proteome”, “seminal plasma proteome”, “oxidative stress”, and “sperm oxidative stress” were used and 137 records were found. Among these, 17 were finally included. Nine proteins involved with OS were found overexpressed in patients with OS. Twenty-three proteins were found differentially expressed in patients with clinical conditions associated with OS, such as varicocele, male accessory gland infection/inflammation, cigarette smoke, and obesity. These proteins do not seem to overlap among the clinical conditions taken into account. We speculate that specific SP proteins may mediate OS in different clinical conditions. Altogether, these results suggest that proteomics could help to better understand some of the molecular mechanisms involved in the pathogenesis of infertility. However, further studies are needed to identify potential biomarkers of male infertility with valuable clinical significance.

Diet-induced obesity is associated with altered expression of sperm motility-related genes and testicular post-translational modifications in a mouse model

Obesity is a metabolic disease and its relation with male subfertility has aroused a growing concern. However, it is unclear whether gene expression and post-translational modifications (PTMs), two vital molecular mechanisms regulating cellular functions, are associated with obesity-induced male reproductive dysfunction. In this study, male obesity with compromised sperm motility was induced by a high-fat diet (HFD) using a mouse model. The expression of motility related-genes, the level of histone modifications, and the global profiles of post-translational modifications (PTMs), were examined in testes of HFD and control mice by quantitative real-time PCR and western blot, respectively. Outer dense fiber protein 2, a major component of outer dense fibers in the sperm tail, is the most obviously down-regulated gene out of 11 evaluated genes, showing a reduction of about 50% RNA level in testes of obese male mice compared with that in control mice. Semi-quantitative analysis of the western blot demonstrated that ∼56% enrichment of di-methylated histone (H)3 lysine (K)36, ∼59% enrichment of 2-hydroxyisobutyrylated H4K8, ∼32% decrease of propionylated H3K23, ∼33% decrease of crotonylated H4K8, and ∼45% decrease of acetylated H3K122 and H4K8 were detected in testes of male HFD mice compared with that in control mice. In addition, male obesity up-regulated the testicular levels of ubiquitination by ∼18%, tyrosine nitration by ∼20%, lysine succinylation by ∼25%, lysine benzoylation by ∼28%, lysine malonylation by ∼32%, lysine glutarylation by ∼36%, lysine propionylation by ∼42%, lysine 2-hydroxyisobutyrylation by ∼45%, and SUMO1 modification by ∼59%, and down-regulated the testicular levels of O-GlcNAcylation by ∼12%, lysine crotonylation by ∼22%, and lysine acetylation by 35%. These findings indicate that altered gene expression and PTMs are associated with the obesity-induced male reproductive dysfunction.

Dietary restriction and/or exercise training impairs spermatogenesis in normal rats

Dietary restriction and/or exercise has been shown to have multiple benefits for health. However, its effects on reproductive health and the mechanisms by which it regulates reproductive function remain unclear. Here, to evaluate its effects on spermatogenesis and sperm function, rats were divided into 4 groups: ad libitum-fed sedentary control, dietary restriction (DR), exercise training (ET), and dietary restriction plus exercise training (DR+ET) groups. Results indicated that body weight, epididymal fat pad weight, and sperm counts were significantly reduced in the DR, ET, and DR+ET groups. Moreover, sperm motility and capacitation-associated protein tyrosine phosphorylation were suppressed in the DR and DR+ET groups, but not the ET group. Microarray analysis revealed that the number of downregulated genes was higher than that of upregulated genes in the DR and/or ET groups. About half of the downregulated genes are common after exercise training and/or diet restriction. Gene ontology analysis showed that downregulated genes in the DR, ET, and DR+ET groups affected spermatogenesis through overlapping pathways, including glucocorticoid, corticosteroid, extracellular structure organization, and estradiol responses. Our findings suggest that diet restriction and/or exercise training may present potential risks to male reproductive dysfunction by disrupting normal gene expression patterns in the testis. Novelty: Dietary restriction and/or exercise can lead to the damage of spermatogenesis as well as sperm maturation. Sperm functional changes are more sensitive to dietary restriction than exercise training. Dietary restriction and exercise impair spermatogenesis through overlapping biological pathways in the testis.

Physical activity and sedentary time in relation to semen quality in healthy men screened as potential sperm donors

STUDY QUESTION

Is physical activity or sedentary time associated with semen quality parameters?

SUMMARY ANSWER

Among healthy men screened as potential sperm donors, higher self-reported physical activity was associated with increased progressive and total sperm motility.

WHAT IS KNOWN ALREADY

Despite the claimed beneficial effect of moderate physical activity on semen quality, results from epidemiological studies have been inconclusive. Previous studies were mostly conducted among endurance athletes or male partners of couples who sought infertility treatment.

STUDY DESIGN, SIZE, DURATION

Healthy men screened as potential sperm donors were recruited at the Hubei Province Human Sperm Bank of China. Between April 2017 and July 2018; 746 men completed the long-form International Physical Activity Questionnaire (IPAQ) and provided repeated semen samples (n = 5252) during an approximately 6-month period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Total metabolic equivalents (METs), moderate-to-vigorous METs and sedentary time were abstracted from the IPAQ. Sperm concentration, total sperm count, progressive motility and total motility in repeated specimens were determined by trained clinical technicians. Mixed-effect models were applied to investigate the relationships between physical activity and sedentary time and repeated measures of semen quality parameters.

MAIN RESULTS AND THE ROLE OF CHANCE

After adjusting for multiple confounders, total METs and moderate-to-vigorous METs were both positively associated with progressive and total sperm motility. Compared with men in the lowest quartiles, those in the highest quartiles of total and moderate-to-vigorous METs had increased progressive motility of 16.1% (95% CI: 6.4, 26.8%) and 17.3% (95% CI: 7.5, 27.9%), respectively, and had increased total motility of 15.2% (95% CI: 6.2, 24.9%) and 16.4% (95% CI: 7.4, 26.1%), respectively. Sedentary time was not associated with semen quality parameters.

LIMITATIONS, REASONS FOR CAUTION

The IPAQ was reported only once from study participants; measurement errors were inevitable and may have biased our results. Furthermore, although we have adjusted for various potential confounders, the possibility of unmeasured confounding cannot be fully ruled out.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that maintaining regular exercise may improve semen quality parameters among healthy, non-infertile men. Specifically, we found that higher self-reported total and moderate-to-vigorous METs were associated with improved sperm motility, which reinforces the existing evidence that physical activity may improve male reproductive health.

STUDY FUNDING/COMPETING INTEREST(S)

Y.-X.W was supported by the Initiative Postdocs Supporting Program (No. BX201700087). A.P. was supported by the National Key Research and Development Program of China (2017YFC0907504). C.-L.X. was supported by the National Key Research and Development Program of China (2016YFC1000206). The authors report no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

The Impact of Obesity on Various Semen Parameters and Sex Hormones in Iranian Men with Infertility: A Cross-Sectional Study

Objective

The aim of this study was to examine the correlations between body mass index (BMI) and waist circumference (WC) and semen parameters (semen volume, sperm count, motility, and morphology) and sex hormones in Iranian men with infertility.

Materials and Methods

In this cross-sectional study, a total of 119 male patients who had lived as a partner in an infertile couple for at least 1 year, after regular unprotected sexual intercourse in their married life were investigated. BMI and WC were assessed, and a morning blood sample was taken assessing serum levels of testosterone (T), sex hormone-binding globulin (SHBG), prolactin (PRL), luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2) and leptin. Semen-analysis parameters were also measured.

Results

Based on BMI and WC, the sperm count, total motility and progressive sperm were significantly lower in overweight and obese infertile males compared to that in normal weight infertile males and those with WC<102 cm. In addition, the fraction of sperm with abnormal morphology was significantly higher in infertile men with WC>102 cm compared to that in those with WC<102 cm. Moreover serum levels of LH, FSH, and leptin were significantly higher in overweight and obese infertile males compared to that in normal weight infertile males and those with WC<102 cm. Moreover serum level of E2 was significantly higher in obese infertile males compared to the normal weight infertile males and in those with WC>102 cm compared to the WC<102 cm. Furthermore, serum level of T was significantly lower in obese infertile males compared to the overweight infertile males and in those with WC>102 cm compared to the WC<102 cm. The mean of T/E2 ratio also was significantly lower in obese infertile males vs overweight and normal weight infertile males and in those with WC>102 cm compared to the WC<102 cm.

Conclusion

We concluded that overweight and obesity in infertile men compared to those with normal weight may worsen the infertility situation.

Male reproductive health and intergenerational metabolic responses from a small RNA perspective

The world has recently experienced a decline in male reproductive (e.g. sperm counts and motility) and metabolic (e.g. obesity and diabetes) health. Accumulated evidence from animal models also shows that the metabolic health of the father may influence the metabolic health in his offspring. Vectors for such paternal intergenerational metabolic responses (IGMRs) involve small noncoding RNAs (sncRNAs) that often increase in spermatozoa during the last days of maturation in the epididymis. We and others have shown that the metabolic state - depending on factors such as diet, obesity and physical exercise - may affect sperm quality and sperm sncRNA. Together, this suggests that there are overlapping aetiologies between the male metabolic syndrome, male factor infertility and intergenerational responses. In this review, we present a theoretical framework for an overlap of these aetiologies by exploring the advances in our understanding of the roles of sncRNA in spermatogenesis and offspring development. A special focus will lie on novel findings about tRNA-derived small RNA (tsRNA), rRNA-derived small RNA (rsRNA) and small mitochondrial RNA (mitoRNA), and their emerging roles in intergenerational metabolic and reproductive health.

Palmitic Acid Targets Human Testicular Peritubular Cells and Causes a Pro-Inflammatory Response

Palmitic acid (PA) is a major fatty acid, derived from diet and endogenous production, which is being linked to inflammation. While such actions of PA at the level of the testis remain difficult to examine, we reasoned that studies in human testicular cells may be instructive. Human testicular peritubular cells (HTPCs) can be isolated from men and cultured. They have contractile properties but also produce Interleukin 6 (IL6), express the inflammasome member NLRP3, and via glia cell line derived neurotrophic factor (GDNF), they contribute to the spermatogonial stem cell niche. We found that PA at 100 µM significantly increased the levels of IL6, while NLRP3 or the related Interleukin 1 beta (IL1beta) were not affected. The contractility marker calponin (CNN1) and the growth factor GDNF were likewise not affected. ELISA studies confirmed the stimulatory PA actions on IL6. Hence, PA derived from diet and/or endogenous sources may be able to foster a pro-inflammatory milieu in the testis. A possible link of these results to diet and high fat intake and obesity is indicated by the about 12-fold elevated testicular levels of IL6 in testes of obese rhesus monkeys (n = 3), fed with a Western Style diet. They had elevated 2–5-fold increased body fat and increased circulating triglyceride levels. Further consequences of PA and obesity for testicular functions remain to be evaluated.

The impact of metabolically healthy obesity in primary infertile men: Results from a cross-sectional study

BACKGROUND

A number of studies showed that obesity may negatively impact on sperm quality and consequently couple's fertility. Recently, specific attention was given to a clinical condition known as metabolically healthy obesity (MHO).

OBJECTIVES

To evaluate the effects of MHO on semen and hormonal parameters of men presenting for primary couple's infertility associated with pure male factor infertility (MFI).

MATERIALS AND METHODS

Data from a homogenous cohort of 512 white-European primary infertile men belonging to couples with pure MFI have been cross-sectionally analyzed. Semen analysis was based on 2010 WHO reference criteria. Patients were segregated into eugonadal, secondary hypogonadal, primary hypogonadal, and compensated hypogonadal. The Harmonized International Diabetes Federation criteria were used to define metabolic syndrome (MetS). Based on BMI and MetS, patients were further segregated into the following: (a) metabolically healthy non-obese (MHNO); (b) metabolically unhealthy non-obese (MUNO) (c) metabolically healthy obesity (MHO); and, (d) metabolically unhealthy obesity (MUHO). Main outcome measures were the prevalence of MHO and the impact of MHO on semen and hormonal parameters in this cohort of MFI primary infertile men.

RESULTS

Overall, MHNO, MUNO, MHO, and MUHO were found in 462 (90%), 13 (2.5%), 27 (5.2%), and 10 (1.9%) men, respectively. MHO patients had lower total testosterone and SHBG levels (all P < .05) but higher E₂ values (P < .005) compared with MHNO men. Groups did not differ in terms of semen parameters. At multivariable logistic regression, analysis MHO was associated with an increased risk of primary and secondary hypogonadism (all P ≤ .02) compared with MHNO, after accounting for age and comorbid conditions.

DISCUSSION AND CONCLUSIONS

Metabolically healthy obesity is threefold more prevalent than unhealthy obesity in primary infertile men. Despite semen parameters are comparable among groups, MHO patients show worse endocrine parameters and a higher risk of primary and secondary hypogonadism compared with metabolically healthy normal infertile men.

Potential Adverse Effects of Female and Male Obesity on Fertility: A Narrative Review

CONTEXT

Despite several studies documenting that obesity affects female and male fertility and leads to multiple adverse reproductive outcomes, the mechanisms involved are not elucidated. We aimed to summarize the potential adverse effects of female and male obesity, as well as the impact of weight loss on their fertility status.

EVIDENCE ACQUISITION

This review summarizes papers investigating the potential adverse effects of female and male obesity and the impact of weight-loss interventions on fertility among reproductive age populations. PubMed, Scopus, Web of Science, and Google Scholar databases were searched for retrieving studies published up to November 2019 on obesity/overweight among reproductive age populations.

RESULTS

The review of 68 studies revealed that female and male obesity/overweight increases the risk of sub-fecundity and infertility. The destructive effects of female obesity on reproduction are attributed to a variety of ovarian and extra-ovarian factors. In women with overweight or obesity, the time taken to conceive is longer, and they have a decreased fertility rate, increased requirement for gonadotropins, and higher miscarriage rate when compared to those with normal weight. Male obesity may lead to subfertility, mainly because of the disruption of the hypothalamus-pituitary-gonadal (HPG) axis, increased testicular temperature, impairment of the physical and molecular structure of sperm, decreased sperm quality, and erectile dysfunction due to peripheral vascular disease. Most studies recommend lifestyle interventions as first-line therapy in the general population of women and men with obesity and infertility.

CONCLUSIONS

This study shows the negative effects of female and male overweight and obesity on fertility. Therefore, educational interventions on the adverse effects of obesity and the benefits of weight reduction, such as increasing pregnancy rate, should be considered for couples seeking fertility.

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.

Effects of Lycium barbarum Polysaccharide on Endoplasmic Reticulum Stress and Oxidative Stress in Obese Mice

Background

The incidence of obesity-associated decline in male fertility has increased over the years. Lycium barbarum polysaccharide (LBP), a natural plant polysaccharide extracted from the Chinese herb L. barbarum has shown promising therapeutic effects in overcoming the same.

Aim

This study aimed to investigate the protective effect of LBP on the testes of obese mice.

Methods

Following administration of LBP to high-fat diet-induced obese mice for 35 days, serum, sperm, and testis samples were obtained for subsequent experiments. Biochemical analysis and sex hormone content determination were performed to observe changes in glycolipid metabolism and testosterone levels, respectively, in the blood. Hematoxylin and eosin staining were carried out to assess the pathological changes in the testicular tissue. Oxidative stress levels were detected using enzyme-linked immunosorbent assay and expression levels of endoplasmic reticulum stress markers were determined using western blot in the testicular tissue.

Results

Our results suggested that LBP reduced glucose levels and insulin resistance, increased testosterone levels and insulin sensitivity, and decreased testicular oxidative stress and pathological damage in obese mice. In addition, LBP down-regulated the expression of p-eIF2α, GRP78, and CHOP in the testicular tissues of obese mice.

Conclusion

Our results show that LBP is a potential novel drug for preventing male infertility caused by obesity.

Obesity and male infertility: Mechanisms and management

Obesity is considered a global health problem affecting more than a third of the population. Complications of obesity include cardiovascular diseases, type 2 diabetes mellitus, malignancy (including prostatic cancer), neurodegeneration and accelerated ageing. In males, these further include erectile dysfunction, poor semen quality and subclinical prostatitis. Although poorly understood, important mediators of obesity that may influence the male reproductive system include hyperinsulinemia, hyperleptinemia, chronic inflammation and oxidative stress. Obesity is known to disrupt male fertility and the reproduction potential, particularly through alteration in the hypothalamic-pituitary-gonadal axis, disruption of testicular steroidogenesis and metabolic dysregulation, including insulin, cytokines and adipokines. Importantly, obesity and its underlying mediators result in a negative impact on semen parameters, including sperm concentration, motility, viability and normal morphology. Moreover, obesity inhibits chromatin condensation, DNA fragmentation, increases apoptosis and epigenetic changes that can be transferred to the offspring. This review discusses the impact of obesity on the male reproductive system and fertility, including associated mechanisms. Furthermore, weight management strategies, lifestyle changes, prescription medication, and complementary and alternative medicine in the management of obesity-induced subfertility is discussed.

Diet and Nutritional Factors in Male (In)fertility-Underestimated Factors

In up to 50% of cases, infertility issues stem solely from the male. According to some data, the quality of human semen has deteriorated by 50%–60% over the last 40 years. A high-fat diet and obesity, resulting from an unhealthy lifestyle, affects the structure of spermatozoa, but also the development of offspring and their health in later stages of life. In obese individuals, disorders on the hypothalamic-pituitary-gonadal axis are observed, as well as elevated oestrogen levels with a simultaneous decrease in testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) levels. Healthy dietary models clearly correlate with better sperm quality and a smaller risk of abnormalities in parameters such as sperm count, sperm concentration and motility, and lower sperm DNA fragmentation. Apart from mineral components such as zinc and selenium, the role of omega-3 fatty acids and antioxidant vitamins should be emphasized, since their action will be primarily based on the minimization of oxidative stress and the inflammation process. Additionally, the incorporation of carnitine supplements and coenzyme Q10 in therapeutic interventions also seems promising. Therefore, it is advisable to have a varied and balanced diet based on vegetables and fruit, fish and seafood, nuts, seeds, whole-grain products, poultry, and low-fat dairy products.

Impacts of obesity, maternal obesity and nicotinamide mononucleotide supplementation on sperm quality in mice

Male fertility and sperm quality are negatively impacted by obesity. Furthermore, recent evidence has shown that male offspring from obese rat mothers also have reduced sperm quality and fertility. Here, we extend work in this area by comparing the effects of both maternal obesity and offspring post-weaning diet-induced obesity, as well as their combination, on sperm quality in mice. We additionally tested whether administration of the NAD⁺-booster nicotinamide mononucleotide (NMN) can ameliorate the negative effects of obesity and maternal obesity on sperm quality. We previously showed that intraperitoneal (i.p.) injection of NMN can reduce the metabolic deficits induced by maternal obesity or post-weaning dietary obesity in mice. In this study, female mice were fed a high-fat diet (HFD) for 6 weeks until they were 18% heavier than a control diet group. Thereafter, HFD and control female mice were mated with control diet males, and male offspring were weaned into groups receiving control or HFD. At 30 weeks of age, mice received 500 mg/kg body weight NMN or vehicle PBS i.p. for 21 days. As expected, adiposity was increased by both maternal and post-weaning HFD but reduced by NMN supplementation. Post-weaning HFD reduced sperm count and motility, while maternal HFD increased offspring sperm DNA fragmentation and levels of aberrant sperm chromatin. There was no evidence that the combination of post-weaning and maternal HFD exacerbated the impacts in sperm quality suggesting that they impact spermatogenesis through different mechanisms. Surprisingly NMN reduced sperm count, vitality and increased sperm oxidative DNA damage, which was associated with increased NAD⁺ in testes. A subsequent experiment using oral NMN at 400 mg/kg body weight was not associated with reduced sperm viability, oxidative stress, mitochondrial dysfunction or increased NAD⁺ in testes, suggesting that the negative impacts on sperm could be dependent on dose or mode of administration.