The effects of type 1 diabetes on the hypothalamic, pituitary and testes axis

A preconception cohort study of sugar-sweetened beverage consumption and semen quality

BACKGROUND

Dietary factors, including high sugar intake, may have adverse effects on male reproduction. Studies of the association between sugar-sweetened beverage (SSB) intake and semen quality have reported inconsistent results.

OBJECTIVE

We estimated the effects of SSB consumption on semen quality in a North American preconception cohort study.

METHODS

We analyzed baseline data from 690 males (n = 1,247 samples) participating in Pregnancy Study Online (PRESTO) during 2015-2022. Participants aged ≥21 years completed a baseline questionnaire on which they reported information about intake of SSBs, including sodas, energy drinks, sports drinks, and fruit juices. After enrollment, we invited U.S. participants to a semen testing substudy, in which they collected and analyzed two samples using an at-home semen testing kit. We used linear regression models to estimate adjusted percent differences (%D) and 95% confidence intervals (CI) for associations of SSB intake with semen volume, sperm concentration, total sperm count (TSC), motility, and total motile sperm count (TMSC). We used modified Poisson regression models to estimate adjusted risk ratios (RRs) and 95% CIs for the association of SSB intake with World Health Organization semen parameter cut points.

RESULTS

Relative to non-consumers of SSBs, those who consumed ≥7 SSBs/week had lower semen volume (%D = -6, 95% CI: -13, 0), sperm concentration (%D = -22, 95% CI: -38, 0), TSC (%D = -22, 95% CI: -38, -2), motility (%D = -4, 95% CI: -10, 2), and TMSC (%D = -25, 95% CI: -43, -2). High SSB consumers also had greater risks of low sperm concentration (≤16 million/mL; RR = 1.89, 95% CI: 1.11, 3.21), low TSC (≤39 million; RR = 1.75, 95% CI: 0.92, 3.33), low motility (≤42%; RR = 1.23, 95% CI: 0.87, 1.75) and low TMSC (≤21 million; RR = 1.95, 95% CI: 1.12, 3.38). Associations were stronger among participants with body mass index ≥ 25 kg/m2 .

CONCLUSION

Greater SSB consumption was associated with reduced semen quality in a North American preconception cohort.

Roles of ferroptosis in type 1 diabetes induced spermatogenic dysfunction

Diabetes mellitus (DM) is a widespread metabolic disease presenting with various complications, including spermatogenic dysfunction. However, the underlying mechanisms are still unclear. Ferroptosis, a novel type of programmed cell death, is associated with much metabolic diseases. Here, we investigated the role of ferroptosis in spermatogenic dysfunction of streptozotocin (STZ)-induced type 1 diabetic mice (diabetic mice), high glucose (HG)-treated GC-2 cells (HG cells) as well as testicular tissues of diabetic patients. We found an accumulation of iron, elevated malondialdehyde level and reduced glutathione level in the testis tissues of diabetic mice and HG cells. Histological examination showed a decrease in spermatogenic cells and spermatids within the seminiferous tubules as well as mitochondrial shrinkage in the testis tissues of diabetic mice. Ferrostatin-1 (Fer-1), the inhibitor of ferroptosis, mitigated ferroptosis-associated iron overload, lipid peroxidation accumulation and spermatogenic dysfunction of diabetic mice. Furthermore, we observed a downregulation of GPX4, FTL and SLC7A11 in diabetic mice and HG cells. Fer-1 treatment and GPX4 overexpression counteracted the effects of HG on cell viability, reactive oxygen species, lipid peroxidation and glutathione via inhibition of ferroptosis. Moreover, we found an elevation of ferroptosis in testicular tissues of diabetic patients. Taken together, our results identify the crucial role of ferroptosis in diabetic spermatogenic dysfunction and ferroptosis may be a promising therapeutic target to improve spermatogenesis in diabetic patients.

Diabetes-induced male infertility: potential mechanisms and treatment options

Male infertility is a physiological phenomenon in which a man is unable to impregnate a fertile woman during a 12-month period of continuous, unprotected sexual intercourse. A growing body of clinical and epidemiological evidence indicates that the increasing incidence of male reproductive problems, especially infertility, shows a very similar trend to the incidence of diabetes within the same age range. In addition, a large number of previous in vivo and in vitro experiments have also suggested that the complex pathophysiological changes caused by diabetes may induce male infertility in multiple aspects, including hypothalamic-pituitary-gonadal axis dysfunction, spermatogenesis and maturation disorders, testicular interstitial cell damage erectile dysfunction. Based on the above related mechanisms, a large number of studies have focused on the potential therapeutic association between diabetes progression and infertility in patients with diabetes and infertility, providing important clues for the treatment of this population. In this paper, we summarized the research results of the effects of diabetes on male reproductive function in recent 5 years, elaborated the potential pathophysiological mechanisms of male infertility induced by diabetes, and reviewed and prospected the therapeutic measures.

Body composition and sexual hormones for the glucose control of autoimmune diabetes in males: are they necessary to predict diabetes-related complications?

Background

Glucose control in diabetes is essential for avoiding diabetes-related complications.

Aim

To determine the impact of body composition and sexual hormones in glucose control and diabetes-related complications, in males with autoimmune diabetes.

Patients and methods

Thirty-nine patients with autoimmune diabetes and flash glucose monitoring were included. A morphofunctional nutritional evaluation with bioelectrical impedance vector analysis (BIVA), abdominal adipose tissue ultrasound, rectus femoris ultrasound and biochemical parameters, was performed.

Results

Strong, positive correlations were observed between body composition parameters, biochemical variables and sexual hormones (p<0.05). Adipose tissue measured by BIVA and ultrasound was more significantly associated with glucose control (including time in range >70%, glucose variability <36% determined by flash glucose monitoring; p<0.05) and the presence of microvascular/macrovascular complications (p<0.05) than lean mass. After adjusting by the duration of diabetes, BMI, abdominal circumference, fat mass and phase angle increased the risk for microvascular complications (OR 1.32(1.00 - 1.73), OR 1.06(1.00 - 1.12), OR 1.14(1.01 - 1.20), 0R 0.3(0.10 - 0.91) respectively; for macrovascular complications: BMI OR 1.38(1.04 - 1.84) and fat mass OR 1.26(1.00 - 1.58)]. Sexual hormone levels did not influence on glucose control or the development of diabetes-related complications.

Conclusion

Anthrpometric parameters, especially adipose tissue, were associated with glucose control and variability determined by flash glucose monitoring. Furthermore, changes in fat and lean mass were associated with the presence of microvascular and macrovascular complications. Thus, a comprehensive nutritional evaluation might be useful for the evaluation of males with autoimmune diabetes, in order to identify patients with increased risk of complications.

Chromium Picolinate Protects against Testicular Damage in STZ-Induced Diabetic Rats via Anti-Inflammation, Anti-Oxidation, Inhibiting Apoptosis, and Regulating the TGF-β1/Smad Pathway

Chromium picolinate (CP) is an organic compound that has long been used to treat diabetes. Our previous studies found CP could relieve diabetic nephropathy. Thus, we speculate that it might have a positive effect on diabetic testicular injury. In this study, a diabetic rat model was established, and then the rats were treated with CP for 8 weeks. We found that the levels of blood glucose, food, and water intake were reduced, and body weight was enhanced in diabetic rats after CP supplementation. Meanwhile, in CP treatment groups, the levels of male hormone and sperm parameters were improved, the pathological structure of the testicular tissue was repaired, and testicular fibrosis was inhibited. In addition, CP reduced the levels of serum inflammatory cytokines, and decreased oxidative stress and apoptosis in the testicular tissue. In conclusion, CP could ameliorate testicular damage in diabetic rats, as well as being a potential testicle-protective nutrient in the future to prevent the testicular damage caused by diabetes.

Effect of saponin on spermatogenesis and testicular structure in streptozotocin-induced diabetic mice

About a third of human infertility is related to male factors. Of these, idiopathic-related infertility is not curable. Diabetes mellitus is a metabolic disorder affecting male impotence and fertility by increased production of free radicals and oxidative stress. Saponin, a glycosidic compound found in many plants, improves sperm parameters. The present study investigated the effect of saponin on sperm oxidative stress and testicular structure in streptozotocin (STZ)-induced diabetic mice. The diabetes was induced by the administration of 150 mg kg-1 STZ via a single intra-peritoneal injection. All experimental mice were allocated to the following groups: Control group, diabetic control group, diabetic group administrated 100 mg kg-1 saponin daily and one healthy group administrated saponin daily for 56 days. At the end of the treatment period, serum levels of insulin, glucose and oxidative stress markers were measured. A histological evaluation of testicles was performed. Treatment of diabetic mice with saponin ameliorated testicular tissue damage as well as serum glucose and insulin concentrations. Furthermore, in the diabetic group, the serum concentration of malondialdehyde was increased; while, the activity of superoxide dismutase and glutathione peroxidase enzymes was reduced. The mean Johnsen's score and the diameter and thickness of seminiferous tubules were lower in the diabetic mice than control ones. However, these parameters were higher in the saponin-treated mice than controls. Overall, saponin administration rectified all examined parameters. The anti-oxidant role of saponin improves sperm parameters and diabetes-induced testicular oxidative damage.

Dissecting mammalian reproduction with spatial transcriptomics

BACKGROUND

Mammalian reproduction requires the fusion of two specialized cells: an oocyte and a sperm. In addition to producing gametes, the reproductive system also provides the environment for the appropriate development of the embryo. Deciphering the reproductive system requires understanding the functions of each cell type and cell-cell interactions. Recent single-cell omics technologies have provided insights into the gene regulatory network in discrete cellular populations of both the male and female reproductive systems. However, these approaches cannot examine how the cellular states of the gametes or embryos are regulated through their interactions with neighboring somatic cells in the native tissue environment owing to tissue disassociations. Emerging spatial omics technologies address this challenge by preserving the spatial context of the cells to be profiled. These technologies hold the potential to revolutionize our understanding of mammalian reproduction.

OBJECTIVE AND RATIONALE

We aim to review the state-of-the-art spatial transcriptomics (ST) technologies with a focus on highlighting the novel biological insights that they have helped to reveal about the mammalian reproductive systems in the context of gametogenesis, embryogenesis, and reproductive pathologies. We also aim to discuss the current challenges of applying ST technologies in reproductive research and provide a sneak peek at what the field of spatial omics can offer for the reproduction community in the years to come.

SEARCH METHODS

The PubMed database was used in the search for peer-reviewed research articles and reviews using combinations of the following terms: 'spatial omics', 'fertility', 'reproduction', 'gametogenesis', 'embryogenesis', 'reproductive cancer', 'spatial transcriptomics', 'spermatogenesis', 'ovary', 'uterus', 'cervix', 'testis', and other keywords related to the subject area. All relevant publications until April 2023 were critically evaluated and discussed.

OUTCOMES

First, an overview of the ST technologies that have been applied to studying the reproductive systems was provided. The basic design principles and the advantages and limitations of these technologies were discussed and tabulated to serve as a guide for researchers to choose the best-suited technologies for their own research. Second, novel biological insights into mammalian reproduction, especially human reproduction revealed by ST analyses, were comprehensively reviewed. Three major themes were discussed. The first theme focuses on genes with non-random spatial expression patterns with specialized functions in multiple reproductive systems; The second theme centers around functionally interacting cell types which are often found to be spatially clustered in the reproductive tissues; and the thrid theme discusses pathological states in reproductive systems which are often associated with unique cellular microenvironments. Finally, current experimental and computational challenges of applying ST technologies to studying mammalian reproduction were highlighted, and potential solutions to tackle these challenges were provided. Future directions in the development of spatial omics technologies and how they will benefit the field of human reproduction were discussed, including the capture of cellular and tissue dynamics, multi-modal molecular profiling, and spatial characterization of gene perturbations.

WIDER IMPLICATIONS

Like single-cell technologies, spatial omics technologies hold tremendous potential for providing significant and novel insights into mammalian reproduction. Our review summarizes these novel biological insights that ST technologies have provided while shedding light on what is yet to come. Our review provides reproductive biologists and clinicians with a much-needed update on the state of art of ST technologies. It may also facilitate the adoption of cutting-edge spatial technologies in both basic and clinical reproductive research.

Withaferin-A attenuates diabetes mellitus induced male reproductive dysfunction mediated by ERα in brain and testes of Swiss albino mice

Diabetes mellitus (DM) is a chronic metabolic disease, characterized by persistent hyperglycemia resulting from diminished insulin secretion or insulin resistance. The present study evaluated the ameliorative effects of Withaferin-A (WA) on DM-induced reproductive dysfunction in mice. For the same, mice were intraperitoneally injected with Streptozotocin (STZ), (40 mg/kg/day) for 5 consecutive days to induce DM. Mice were then treated with WA (8 mg/kg/day) in normal and diabetic conditions (STZ + WA). Next, blood glucose levels, oral glucose tolerance, intraperitoneal insulin tolerance, oxidative stress and reproductive parameters were estimated. For reproductive performance, immunofluorescent localization of gonadotropin-releasing hormone (GnRH-I) and estrogen receptor alpha (ERα) in the preoptic area and paraventricular nucleus region of hypothalamus and ERα in testes was performed. STZ-induced diabetes triggered reproductive dysfunctions as mediated by low GnRH-I and ERα in the brain and ERα in the testes along with declined testosterone and estradiol levels. Treatment with WA significantly reduced the blood glucose levels and enhanced glucose clearance accompanied by reduced oxidative stress in the brain, pancreas and testes as indicated by the low levels of H2O2 and MDA in diabetic mice treated with WA (STZ + WA). This study reports, for the first time, that WA can efficiently ameliorate DM-induced reproductive dysfunctions by enhancing endogenous testosterone, estrogen and increased GnRH-I and ERα in the brain and ERα in the testes of DM-induced male mice.

Forskolin Improves Male Reproductive Complications Caused by Hyperglycemia in Type 2 Diabetic Rats

BACKGROUND

In many diabetic patients, spermatogenesis complications are frequent causing infertility problems. This study aimed to demonstrate the effect of Forskolin on male reproductive dysfunction caused by type 2 diabetes.

MATERIALS AND METHODS

In this experimental study, type 2 diabetes was induced by a high-fat diet (HFD) for one month and then a low single dose injection (35 mg/kg) of streptozotocin (STZ) in Wistar rats. After 72 hours, rats with more than 200 mg/dl of blood glucose were considered type 2 diabetic rats. Forty rats (200-250 g) were divided into four groups (n=10) including group 1 (G1): rats with normal diet and buffer citrate (STZ solvent) injection, group 2 (G2): control type 2 diabetic rats with HFD and STZ injection, group 3 (G3): type 2 diabetic rats received phosphate buffer saline (PBS) as Forskolin solvent, and group 4 (G4): Forskolin treated diabetic rats (10 mg/kg) for 1 month.

RESULTS

In comparison to control group, in diabetic groups (G2 and G3) some parameters are increased significantly: The blood glucose (P=0.00078), testicular malondialdehyde (MDA) level and body weight (P=0.00009) and Bax gene expression (P=0.00007). Unlike, some parameters are decreased significantly: The serum level of testosterone (P=0.0009), testicular superoxide dismutase (SOD, P=0.00007) and glutathione peroxidase (GPX) levels (P=0.00008), sperm concentration (P=0.00008), motility (P=0.00009), normal morphological sperm (P=0.00008) and Bcl-2 gene expression (P=0.00009). However, in Forskolin treated group (G4) the parameters stayed close to control values that was significantly (P=0.00007) higher than in G2 and G3 groups. Therefore, treatment with Forskolin significantly improved these abnormal changes in Forskolin-treated group.

CONCLUSION

Our study demonstrates that Forskolin is an effective antidiabetic agent, which significantly improves sperm concentration, testosterone levels, and antioxidant activity in diabetic rats.

New perspectives in functional hypogonadotropic hypogonadism: beyond late onset hypogonadism

Functional hypogonadotropic hypogonadism (FHH) is an increasingly frequent condition, whose pathological mechanisms are not yet fully clarified. The concept of FHH has now completely replaced that of late onset hypogonadism, that only concerned the ageing man. FHH is the result of an impairment of the hypothalamic-pituitary gonadal axis (HPG-A) function, resulting in decreased testosterone concentrations associated with low or inappropriately normal gonadotropin levels and infertility; it can be diagnosed once organic causes of hypogonadism are excluded. The growing occurrence of FHH derives from its association with widespread conditions, such as obesity and diabetes mellitus, but also to the increasing ease and frequency of use of several drugs, such as opioids, glucocorticoids, and sex steroids. Moreover, given the tendency of many subjects to excessive physical activity and drastic reduction in caloric intake, FHH may also be secondary to low energy availability. Finally, the association with HIV infection should not be overlooked. Therefore, there is an important variability in the diseases that can lead to FHH. Despite the heterogeneity of the underlying pathologies, the mechanisms leading to FHH would seem quite similar, with the initial event represented by the impairment at the HPG-A level. Nevertheless, many different biological pathways are involved in the pathogenesis of FHH, therefore the aim of the current paper is to provide an overview of the main relevant mechanisms, through a detailed analysis of the literature, focusing specifically on pathogenesis and clinical, diagnostic and therapeutic aspects.

The role of apelinergic system in metabolism and reproductive system in normal and pathological conditions: an overview

Lifestyle changes have made metabolic disorders as one of the major threats to life. Growing evidence demonstrates that obesity and diabetes disrupt the reproductive system by affecting the gonads and the hypothalamus-pituitary-gonadal (HPG) axis. Apelin, an adipocytokine, and its receptor (APJ) are broadly expressed in the hypothalamus nuclei, such as paraventricular and supraoptic, where gonadotropin-releasing hormone (GnRH) is released, and all three lobes of the pituitary, indicating that apelin is involved in the control of reproductive function. Moreover, apelin affects food intake, insulin sensitivity, fluid homeostasis, and glucose and lipid metabolisms. This review outlined the physiological effects of the apelinergic system, the relationship between apelin and metabolic disorders such as diabetes and obesity, as well as the effect of apelin on the reproductive system in both gender. The apelin-APJ system can be considered a potential therapeutic target in the management of obesity-associated metabolic dysfunction and reproductive disorders.

Diabetic Encephalopathy in a Preclinical Experimental Model of Type 1 Diabetes Mellitus: Observations in Adult Female Rat

Patients affected by diabetes mellitus (DM) show diabetic encephalopathy with an increased risk of cognitive deficits, dementia and Alzheimer's disease, but the mechanisms are not fully explored. In the male animal models of DM, the development of cognitive impairment seems to be the result of the concomitance of different processes such as neuroinflammation, oxidative stress, mitochondrial dysfunction, and aberrant synaptogenesis. However, even if diabetic encephalopathy shows some sex-dimorphic features, no observations in female rats have been so far reported on these aspects. Therefore, in an experimental model of type 1 DM (T1DM), we explored the impact of one month of pathology on memory abilities by the novel object recognition test and on neuroinflammation, synaptogenesis and mitochondrial functionality. Moreover, given that steroids are involved in memory and learning, we also analysed their levels and receptors. We reported that memory dysfunction can be associated with different features in the female hippocampus and cerebral cortex. Indeed, in the hippocampus, we observed aberrant synaptogenesis and neuroinflammation but not mitochondrial dysfunction and oxidative stress, possibly due to the results of locally increased levels of progesterone metabolites (i.e., dihydroprogesterone and allopregnanolone). These observations suggest specific brain-area effects of T1DM since different alterations are observed in the cerebral cortex.

Role of sex hormones in diabetic nephropathy

Diabetic nephropathy (DN) is the most common microvascular complication in diabetes and one of the leading causes of end-stage renal disease. The standard treatments for patients with classic DN focus on blood glucose and blood pressure control, but these treatments can only slow the progression of DN instead of stopping or reversing the disease. In recent years, new drugs targeting the pathological mechanisms of DN (e.g., blocking oxidative stress or inflammation) have emerged, and new therapeutic strategies targeting pathological mechanisms are gaining increasing attention. A growing number of epidemiological and clinical studies suggest that sex hormones play an important role in the onset and progression of DN. Testosterone is the main sex hormone in males and is thought to accelerate the occurrence and progression of DN. Estrogen is the main sex hormone in females and is thought to have renoprotective effects. However, the underlying molecular mechanism by which sex hormones regulate DN has not been fully elucidated and summarized. This review aims to summarize the correlation between sex hormones and DN and evaluate the value of hormonotherapy in DN.

Abnormalities in sex hormones and sexual dysfunction in males with diabetes mellitus: A mechanistic insight

Diabetes is a considerate metabolic disorder that can lead to a series of complications, involving the malfunctioning of the reproductive system of males. It has been observed that there is a gradual rise in male diabetic patients and almost half of the diabetic males have low semen quality and decrease reproductive function. In diabetic conditions, prolonged hyperglycemia leads to oxidative stress, diabetic neuropathy, and insulin resistance. Insulin resistance and its deficiency can impair the hypothalamus, pituitary gland, gonads, and perigonads. This causes a decrease in the secretion of gonadal steroids such as GnRH (gonadotropin-releasing hormone), FSH (follicle-stimulating hormone), LH (luteinizing hormone), and Testosterone. Moreover, it also causes damage to the testicles, spermatogenic and stromal cells, seminiferous tubules, and various structural injuries to male reproductive organs. During spermatogenesis, glucose metabolism plays an important role, because the fundamental activities of cells and their specific features, such as motility and mature sperm fertilization activity, are maintained by glucose metabolism. All these activities can influence the fertility and reproductive health of males. But the glucose metabolism is primarily disrupted in diabetic conditions. Until now, there has been no medicine focusing on the reproductive health of diabetic people. In this chapter, we review the consequences of diabetes on the reproductive system of males and all the pathways involved in the dysfunction of the reproductive system. This will help interpret the effects of DM on male reproductive health.

Synergistic properties of garlic and Citrullus colocynthis on reproductive injury caused by diabetes in male rats: Structural and molecular evidence

This study evaluates the synergistic effect of garlic and Citrullus colocynthis on diabetic reproductive damage by suppressing the AGEs/RAGE/Nox-4 signaling pathway. Thirty-five male Wistar rats were divided into five groups (n = 7/group): Control, Diabetic, Diabetic+G (Garlic, 1 mL/100 g b.w), Diabetic+C (C. colocynthis, 10 mg/kg b.w) and Diabetic+GC (Garlic, 1 mL/100 g b.w and C. colocynthis, 10 mg/kg b.w) groups. At the end of the experimental period (30 days), in diabetic rats, glucose increased, and body & testis weight, luteinizing hormone (LH) and testosterone levels, and sperm count decreased significantly and histopathological injuries were observed. In addition, they have increased testicular apoptosis and oxidative stress. Also, the mechanism based on advanced glycation end products (AGEs)/receptors for advanced glycation end products (RAGE)/NADPH oxidase-4 (Nox-4) was activated in diabetic rats. Separate consumption of garlic and C. colocynthis in Diabetic+G and Diabetic+C groups alleviated the negative adverse effect of diabetes to some extent, but when they were used in the combination form (Diabetic+GC) improvement was profound. Testis histopathology, increased body and testis weight, and enhanced capacity in protecting diabetic reproductive injury was seen. Decreases in testosterone and LH concentration and sperm count in diabetic rats were also reversed by combined administration of garlic and C. colocynthis. It regulated oxidative stress markers, meanwhile reducing caspase-3 immunoexpression. In addition, overexpression of RAGE, Nox-4 and nuclear transcription factor-κB (NF-κB) was inhibited by the combination of garlic and C. colocynthis. PRACTICAL APPLICATIONS: Diabetes mellitus is wide spread all around the world with variety of complications in body including reproductive system in which patients suffer from physical and psychological aspects. Despite many efforts in providing agents for controlling diabetes and its complications, economic conditions of some countries make it difficult for people to provide costly medicine and as a result, they have to bear the complications until they pass away. However, traditional medicine is still finding its way, especially in poor countries with emphasis on medicinal plants. There have been many studies on plants to alleviate diabetes or its side effects. But, using one plant for long term, may be not so effective. Here, we attempted to find whether two plants from two different species can show more efficacy than each one alone. We noticed garlic and Citrullus colocynthis despite having beneficial effects when used alone, they could show synergistic effects in combination.

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.

A systematic review on the role of melatonin and its mechanisms on diabetes-related reproductive impairment in non-clinical studies

BACKGROUND

Diabetes-induced reproductive complications can lead to subfertility and infertility, raising the need to protect reproductive organs. There are limited medications used to improve reproductive health in diabetic patients. Melatonin, mainly produced by the pineal gland, may improve diabetes-associated reproductive complications through various mechanisms and may be a preferred candidate to protect the reproductive system. The present review aims to elucidate the underlying mechanisms of melatonin's effect on the reproductive system adversely affected by diabetes mellitus (DM).

METHODS

A comprehensive systematic literature electronic search was done using the PRISMA guidelines. Web of Science, PubMed, Embase, and Scopus were searched for publications up to June 2022. Search terms were selected based on the study purpose and were explored in titles and abstracts. After screening, out of a total of 169 articles, 14 pertinent articles were included based on our inclusion and exclusion criteria.

RESULTS

The results of studies using rats and mice suggest that DM adversely affects reproductive tissues, including testes and epididymis, prostate, corpus cavernosum, and ovary leading to alterations in histological and biochemical parameters compared to the normal groups. Treatment with melatonin improves oxidative stress, blocks apoptosis induced by endoplasmic reticulum stress and caspase activation, reduces pro-inflammation cytokines, and enhances steroidogenesis.

CONCLUSION

Melatonin exerted a protective action on the impaired reproductive system in in-vivo and in-vitro models of DM. The topic has to be followed up in human pregnancy cases that will need more time to be collected and approved.

The impact of diabetes mellitus type 1 on male fertility: Systematic review and meta-analysis

BACKGROUND

Some evidence suggests that diabetes mellitus type 1 (DM1) could affect male fertility, gonadal axis, semen parameters, and spermatogenesis because of effects of hyperglycemia and insulin deficiency. Anyhow, the exact impact of DM1 on male fertility is unclear.

OBJECTIVES

To review the studies evaluating paternity rate, male gonadal axis, and semen parameters in men with DM1.

MATERIALS AND METHODS

A review of relevant literature from January 1980 to December 2020 was performed. Only studies published in English reporting data on fatherhood (rate of children by natural fertility), hormonal and seminal parameters were included. Out of 14 retrieved articles, the eight studies evaluating semen parameters were meta-analyzed.

RESULTS

The rate of children (four studies) was lower than controls among men affected by DM1, especially in men with a longer duration of disease. The data of gonadal hormonal profile in DM1 men (six studies) are very heterogeneous and a neutral effect of DM1 or a condition of subclinical hypogonadism could not be concluded. Meta-analysis showed that men with DM1 (n = 380), compared with controls (n = 434), have significantly lower normal sperm morphology [-0.36% (-0.66; -0.06), p < 0.05, six studies] and sperm progressive motility [33.62% (-39.13; -28.11), p < 0.001, two studies] and a trend toward a lower seminal volume [-0.51 (-1.03; 0.02), p = 0.06, eight studies], without difference in total sperm count and concentration. Data on scrotal ultrasound and sperm DNA fragmentation are too few. No study evaluated other factors of male infertility, such as transrectal ultrasound, semen infections, sperm auto-antibodies, and retrograde ejaculation.

DISCUSSION

DM1 might impair male fertility and testis functions (endocrine, spermatogenesis), but definition of its actual impact needs further studies.

CONCLUSION

Men with DM1 should be evaluated with a complete hormonal, seminal, and ultrasound workup to better define their fertility potential and need for follow up of testis functions.

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.

Association between intake of soft drinks and testicular function in young men

STUDY QUESTION

Is intake of sugar-sweetened beverages (SSB) or artificially sweetened beverages (ASB) associated with testicular function in young men?

SUMMARY ANSWER

Among young men unaware of their semen quality and reproductive hormone levels, intake of SSBs was associated with lower sperm concentration, lower total sperm count, and a lower ratio of serum inhibin-B/FSH.

WHAT IS KNOWN ALREADY

SSBs may adversely impact testicular function, but results are not consistent across studies. Moreover, the associations of ASB, energy-drinks or fruit juices with testicular function are unclear.

STUDY DESIGN, SIZE, DURATION

Young healthy men and unselected for fertility status men enrolled in a cross-sectional study between 2008 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2935 young (median age: 19 years) men enrolled in the study. Intake of SSBs, ASBs, fruit juices, and energy-drinks was assessed with a validated food frequency questionnaire. Testicular function was assessed through conventional semen quality parameters (semen volume, sperm concentration, total count, motility and morphology), testicular volume assessed with ultrasound, and serum reproductive hormone concentrations (total testosterone, free testosterone, E2, inhibin-B, LH, FSH, sex hormone-binding globulin) were measured.

MAIN RESULTS AND THE ROLE OF CHANCE

In multivariable-adjusted analyses, men in the highest category of SSB intake (median: 1.1 servings (∼220 ml)/day) had a 13.2 million/ml lower median sperm concentration (95% CI: -21.0, -5.5) than non-consumers. A similar pattern was observed with total sperm count (-28 million (95% CI: -48, -9)), serum inhibin-B (-12 pg/ml (95% CI: -21, -4)), and inhibin-B/FSH ratio (-9 (95% CI: -18, 0)). The adjusted median difference in sperm concentration and inhibin-B associated with increasing SSB intake by 1 serving (∼200ml)/day at the expense of water was -3.4 million sperm/ml (95% CI: -5.8, -1.0) and -7 pg/ml (95% CI: -11, -3), respectively.

LIMITATIONS, REASONS FOR CAUTION

Inferring causality is limited owing to the cross-sectional design. We adjusted for a number of potential confounders but cannot exclude that unmeasured lifestyle and behavior associated with soft drink intake is associated with testicular function in these young men.

WIDER IMPLICATIONS OF THE FINDINGS

In the largest study to date, intake of SSBs was associated with lower sperm concentration, total sperm count, and serum inhibin-B/FSH ratio, consistent with a direct suppressive effect of SSB intake on testicular function among otherwise healthy men, potentially affecting fertility. However, the observed association between higher SSB intake and lower semen quality does not necessarily imply a decrease in fertility.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by research from the Danish Council for Strategic Research (2101-08-0058), Independent Research Fund Denmark (8020-00218B), European Union (212844), the Kirsten and Freddy Johansen's Foundation (95-103-72087), the Research Fund of the Capital Region of Denmark (A6176), and the NIH (P30DK046200). The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Nobiletin protects against diabetes-induced testicular injury via hypophysis-gonadal axis upregulation and amelioration of oxidative stress

BACKGROUND

Testicular injury is one of the most serious problems associated with diabetes mellitus. The present study aimed to compare the effects of two different doses of nobiletin and analyze its mechanisms of action against diabetes-induced testicular impairment in rats.

METHODS AND RESULTS

Streptozotocin injection was used to induce diabetes. Diabetic rats received nobiletin orally at 10 or 25 mg/kg daily for 30 days. Diabetic rats displayed significant elevations in glucose, glycosylated hemoglobin (HbA1c), Homeostatic Model of Insulin Resistance (HOMA-IR), and pro-inflammatory cytokines, while the serum levels of insulin, testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) were significantly reduced. Histological changes to positivity for caspase-3 and decreased androgen receptors (AR) immunoexpression were observed in diabetic rats. Both doses of nobiletin improved hyperglycemia, reduced pro-inflammatory cytokines, and augmented insulin, testosterone, LH, and FSH levels. LH and FSH receptors and cytochrome P450 17 α-hydroxylase (CYP17A1) were markedly downregulated in terms of both gene and protein expression in testicular tissues of the diabetic group, effects that were markedly ameliorated with both doses of nobiletin. In addition, both doses significantly reduced lipid peroxidation and caspase-3 immunoexpression and improved the activity of the antioxidant enzymes and AR in testicular tissues of the diabetic group.

CONCLUSION

Both nobiletin doses showed protective effects against diabetes-induced testicular injury by reducing oxidative stress, hyperglycemia, inflammation, and caspase-3 and upregulating the hypophysis-gonadal axis and AR. The high dose of nobiletin was more effective than the lower one.

Testosterone Levels in Adolescents and Young Men with Type 1 Diabetes and Their Association with Diabetic Nephropathy

Simple Summary

Type 2 diabetes(T2D) has been known to be related with obesity, insulin-resistance, impaired glucose control. Low testosterone levels and hypogonadism are also known as clinical characteristics of T2D patients. On the contrary, type 1 diabetes(T1D) happens when insulin is insufficient rather than insulin-resistance. Relationship between T1D and testosterone has not been established enough. In the study, patients with T1D showed higher testosterone levels than the general population. We could also find that higher testosterone levels have positive relationship with nephropathy, one of complications in diabetic patients. Therefore, periodic check-up for testostrone levels may be helpful for preventing nephropathy in T1D.

Abstract

The association between serum testosterone levels and type 1 diabetes (T1D), especially in adolescents and young adults, has not been fully investigated. We aimed to compare testosterone levels between adolescents/young men with T1D and controls and to determine the factors affecting testosterone levels. We enrolled 47 men with T1D and 32 controls aged 15–29 years. We evaluated anthropometric measurements, lipid profiles, diabetic complications, and levels of serum luteinizing hormone, follicle-stimulating hormone, hemoglobin A1c, 24-h urine albumin, insulin autoantibody, and total serum testosterone. We assessed the correlation between serum testosterone levels and clinical characteristics. Total testosterone levels were higher in T1D patients than in controls (694.6 ± 182.2 vs. 554.1 ± 147.3 ng/dL, p = 0.001), and 24-h urine albumin level positively correlated with total testosterone levels (correlation coefficient 0.415, p = 0.004). T1D patients with nephropathy showed higher total testosterone levels than those without nephropathy (778.4 ± 198.9 vs. 655.4 ± 162.5 ng/dL, p = 0.029). However, diabetic nephropathy and testosterone levels were not significantly associated after adjusting for confounders (β ± SE 77.5 ± 55.2, p = 0.169). Further longitudinal studies are imperative to confirm a causal relationship between testosterone levels and T1D.

Mitochondria-Mediated Apoptosis Induced Testicular Dysfunction in Diabetic Rats: Ameliorative Effect of Resveratrol

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

Diabetes Type 1 Negatively Influences Leydig Cell Function in Rats, Which is Partially Reversible By Insulin Treatment

Type 1 diabetes mellitus (T1DM) is associated with impaired spermatogenesis and lower testosterone levels and epididymal weight. However, the underlying processes in the testis are unknown and remain to be elucidated. Therefore, the present study focused on the effects of T1DM on testicular function in a spontaneously diabetic rat model. BB/OKL rats after diabetes manifestation were divided into 3 groups: those without insulin treatment and insulin treatment for a duration of 2 and of 6 weeks. Anthropometrical data, circulating levels of gonadotrophins, testosterone, and inhibin B were measured. Intratesticular testosterone, oxidative stress, inflammation, and apoptosis were analyzed. Key enzymes of steroidogenesis were evaluated in the testis. Untreated diabetic rats had significantly lower serum follicle-stimulating hormone and luteinizing hormone levels. Serum and intratesticular testosterone levels significantly decreased in untreated diabetic rats compared to healthy controls. Key markers of Leydig cell function were significantly downregulated at the RNA level: insulin-like factor 3 (Insl3) by 53% (P = .006), Star by 51% (P = .004), Cyp11A1 by 80% (P = .003), 3Beta-Hsd2 by 61% (P = .005), and Pbr by 52% (P = .002). In the insulin-treated group, only Cyp11A1 and 3Beta-Hsd2 transcripts were significantly lower. Interestingly, the long-term insulin-treated group showed significant upregulation of most steroidogenic enzymes without affecting testosterone levels. Tumor necrosis factor α and apoptosis were significantly increased in the long-term insulin-treated rats. In conclusion T1DM, with a severe lack of insulin, has an adverse action on Leydig cell function. This is partially reversible with well-compensated blood glucose control. Long-term T1DM adversely affects Leydig cell function because of the process of inflammation and apoptosis.

Adiponectin/AdipoRs signaling as a key player in testicular aging and associated metabolic disorders

Aging undergoes serious worsening of peripheral organs and vital physiological processes including reproductive performances. Altered white adipose tissue and adipocyte functioning during aging results in ectopic lipid storage/obesity or metabolic derangements, leading to insulin resistance state. Eventually, accelerating cellular senescence thereby enhancing the high risk of age-associated metabolic alterations. Such alterations may cause derangement of numerous physiologically active obesity hormones, known as "adipokines." Specifically, adiponectin exhibits insulin sensitizing action causing anti-aging and anti-obesity effects via activation of adiponectin receptors (AdipoRs). The male reproductive physiology from reproductive mature stage to advanced senescent stage undergoes insidious detrimental changes. The mechanisms by which testicular functions decline with aging remain largely speculative. Adiponectin has also recently been shown to regulate metabolism and longevity signaling thus prolonging lifespan. Therefore, the strategy for activating adiponectin/AdipoRs signaling pathways are expected to provide a solid basis for the prevention and treatment of aging and obesity-associated reproductive dysfunctions, as well as for ensuring healthy reproductive longevity in humans.

Adverse effects of metabolic disorders in childhood on adult reproductive function and fertility in the male

Over the last 50 years, there has been a steady decline in fertility rates in humans, which has occurred in parallel with an increasing incidence of obesity and metabolic disorders. The potential impact of these disorders and plausible mechanisms by which they negatively influence male reproduction are only partly understood and published data are often controversial. Obesity is one of the most important health challenges worldwide and is becoming more prevalent in children and adolescents. Obesity, the metabolic syndrome and related co-morbidities can lead to impaired male reproductive function, including adverse effects on spermatogenesis and steroidogenesis as illustrated by reduced sperm number and quality, decreased testosterone levels and elevated inflammatory markers. The incidence of diabetes mellitus type I is also dramatically increasing and may negatively impact spermatogenesis and testicular function, resulting in decreased serum testosterone and epididymal weight. In this review, we summarize and discuss the effects of metabolic diseases that typically develop during childhood and adolescence on later reproductive function and fertility. While impact on reproductive health is likely observed in both sexes, we have chosen to focus on the male in the current review. Specifically, we illustrate adverse effects of obesity, type 1 diabetes, the metabolic syndrome and insulin resistance on sperm function and testosterone metabolism. Identification of pathophysiological mechanisms during childhood may open up new avenues for early prevention and treatment resulting in better reproductive outcomes and improved fertility rates during adulthood.

Male infertility due to testicular disorders

CONTEXT

Male infertility is defined as the inability to conceive following 1 year of regular unprotected intercourse. It is the causative factor in 50% of couples and a leading indication for assisted reproductive techniques (ART). Testicular failure is the most common cause of male infertility, yet the least studied to date.

EVIDENCE ACQUISITION

The review is an evidence-based summary of male infertility due to testicular failure with a focus on etiology, clinical assessment, and current management approaches. PubMed-searched articles and relevant clinical guidelines were reviewed in detail.

EVIDENCE SYNTHESIS/RESULTS

Spermatogenesis is under multiple levels of regulation and novel molecular diagnostic tests of sperm function (reactive oxidative species and DNA fragmentation) have since been developed, and albeit currently remain as research tools. Several genetic, environmental, and lifestyle factors provoking testicular failure have been elucidated during the last decade; nevertheless, 40% of cases are idiopathic, with novel monogenic genes linked in the etiopathogenesis. Microsurgical testicular sperm extraction (micro-TESE) and hormonal stimulation with gonadotropins, selective estrogen receptor modulators, and aromatase inhibitors are recently developed therapeutic approaches for men with the most severe form of testicular failure, nonobstructive azoospermia. However, high-quality clinical trials data is currently lacking.

CONCLUSIONS

Male infertility due to testicular failure has traditionally been viewed as unmodifiable. In the absence of effective pharmacological therapies, delivery of lifestyle advice is a potentially important treatment option. Future research efforts are needed to determine unidentified factors causative in "idiopathic" male infertility and long-term follow-up studies of babies conceived through ART.

Chitosan-Stabilized Selenium Nanoparticles and Metformin Synergistically Rescue Testicular Oxidative Damage and Steroidogenesis-Related Genes Dysregulation in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

BACKGROUND

this study examined the metformin (MF) and/or chitosan stabilized selenium nanoparticles (CH-SeNPs) efficacy to alleviate the male reproductive function impairment in a high-fat diet feed with low-dose streptozotocin (HFD/STZ) induced type 2 diabetes mellitus (T2DM) diabetic rat model.

METHODS

control non-diabetic, HFD/STZ diabetic, HFD/STZ+MF, HFD/STZ+CH-SeNPs, and HFD/STZ+MF+CH-SeNPs rat groups were used. After 60 days, semen evaluation, hormonal assay, enzymatic antioxidant, lipid peroxidation, testis histopathology, and the steroidogenesis-related genes mRNA expressions were assessed.

RESULTS

in the HFD/STZ diabetic rats, sperm count and motility, male sexual hormones, and testicular antioxidant enzymes were significantly reduced. However, sperm abnormalities and testicular malondialdehyde were significantly incremented. The steroidogenesis-related genes, including steroidogenic acute regulatory protein (StAr), cytochrome11A1 (CYP11A1), cytochrome17A1 (CYP17A1), and hydroxysteroid 17-beta dehydrogenase 3 (HSD17B3), and the mitochondrial biogenesis related genes, including peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGCα) and sirtuin (SIRT), were significantly downregulated in the HFD/STZ diabetic rats. However, CYP19A1mRNA expression was significantly upregulated. In contrast, MF and/or CH-SeNPs oral dosing significantly rescued the T2DM-induced sperm abnormalities, reduced sperm motility, diminished sexual hormones level, testicular oxidative damage, and steroidogenesis-related genes dysregulation. In the MF and CH-SeNP co-treated group, many of the estimated parameters differ considerably from single MF or CH-SeNPs treated groups.

CONCLUSIONS

the MF and CH-SeNPs combined treatment could efficiently limit the diabetic complications largely than monotherapeutic approach and they could be considered a hopeful treatment option in the T2DM.

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.

Momordica charantia Extract Protects against Diabetes-Related Spermatogenic Dysfunction in Male Rats: Molecular and Biochemical Study

More than 90% of diabetic patients suffer from sexual dysfunction, including diminished sperm count, sperm motility, and sperm viability, and low testosterone levels. The effects of Momordica charantia (MC) were studied by estimating the blood levels of insulin, glucose, glycosylated hemoglobin (HbA1c), testosterone (TST), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) in diabetic rats treated with 250 and 500 mg/kg b.w. of the total extract. Testicular antioxidants, epididymal sperm characteristics, testicular histopathology, and lesion scoring were also investigated. Testicular mRNA expression of apoptosis-related markers such as antiapoptotic B-cell lymphoma-2 (Bcl-2) and proapoptotic Bcl-2-associated X protein (Bax) were evaluated by real-time PCR. Furthermore, caspase-3 protein expression was evaluated by immunohistochemistry. MC administration resulted in a significant reduction in blood glucose and HbA1c and marked elevation of serum levels of insulin, TST, and gonadotropins in diabetic rats. It induced a significant recovery of testicular antioxidant enzymes, improved histopathological changes of the testes, and decreased spermatogenic and Sertoli cell apoptosis. MC effectively inhibited testicular apoptosis, as evidenced by upregulation of Bcl-2 and downregulation of Bax and caspase-3. Moreover, reduction in apoptotic potential in MC-treated groups was confirmed by reduction in the Bax/Bcl-2 mRNA expression ratio.

Comparative Study of the Steroidogenic Effects of Human Chorionic Gonadotropin and Thieno[2,3-D]pyrimidine-Based Allosteric Agonist of Luteinizing Hormone Receptor in Young Adult, Aging and Diabetic Male Rats

Low-molecular-weight agonists of luteinizing hormone (LH)/human chorionic gonadotropin (hCG) receptor (LHCGR), which interact with LHCGR transmembrane allosteric site and, in comparison with gonadotropins, more selectively activate intracellular effectors, are currently being developed. Meanwhile, their effects on testicular steroidogenesis have not been studied. The purpose of this work is to perform a comparative study of the effects of 5-amino-N-tert-butyl-4-(3-(1-methylpyrazole-4-carboxamido)phenyl)-2-(methylthio)thieno[2,3-d] pyrimidine-6-carboxamide (TP4/2), a LHCGR allosteric agonist developed by us, and hCG on adenylyl cyclase activity in rat testicular membranes, testosterone levels, testicular steroidogenesis and spermatogenesis in young (four-month-old), aging (18-month-old) and diabetic male Wistar rats. Type 1 diabetes was caused by a single streptozotocin (50 mg/kg) injection. TP4/2 (20 mg/kg/day) and hCG (20 IU/rat/day) were administered for 5 days. TP4/2 was less effective in adenylyl cyclase stimulation and ability to activate steroidogenesis when administered once into rats. On the 3rd–5th day, TP4/2 and hCG steroidogenic effects in young adult, aging and diabetic rats were comparable. Unlike hCG, TP4/2 did not inhibit LHCGR gene expression and did not hyperstimulate the testicular steroidogenesis system, moderately increasing steroidogenic proteins gene expression and testosterone production. In aging and diabetic testes, TP4/2 improved spermatogenesis. Thus, during five-day administration, TP4/2 steadily stimulates testicular steroidogenesis, and can be used to prevent androgen deficiency in aging and diabetes.

Diabetes mellitus and the impairment of male reproductive function: Possible signaling pathways

BACKGROUND AND AIMS

Today, it has been shown that diabetes mellitus (DM) can affect male fertility. Glucose metabolism is a vital process in spermatogenesis that is impacted by diabetes condition. But the mechanisms by which DM causes male infertility are not wholly clarified. The aim of this review is to provide brief information about the influence of hyperglycemia on male fertility and specific emphasis on the molecular signaling pathway that is involved.

METHODS

Broad literature search in the electronic database "Pubmed", "Google Scholar", the website of "World Health Organization" (WHO) and Control Disease and Prevention (CDC) took place. There was no time restriction. A key criterion for the selection of articles was English and language. Finally, one hundred thirty seven articles were included in the review.

RESULTS

Diabetes mellitus affects many signaling pathways that involved in the spermatogenesis. It seems that increased ROS and oxidative stress in the diabetes is the beginning of all fertility problems and affects all of involved signaling pathways in the spermatogenesis.

CONCLUSIONS

It seems that there was strong interconnected between oxidative stress and all of involved signaling pathways in the reproductive problems in diabetes. So, approaches that diminish oxidative stress in the testis can be effective in improving diabetes related infertility complications.

Green Coffea arabica Extract Ameliorates Testicular Injury in High-Fat Diet/Streptozotocin-Induced Diabetes in Rats

Diabetes mellitus (DM) is a chronic endocrine disease characterized by persistent hyperglycemia. Oxidative damage, inflammatory cytokines, and apoptotic cell death play a major role in the induction and progression of male testicular damage. Plant-derived phytochemicals such as green coffee (Coffea arabica) can possess antidiabetic effects with little toxicity. The current study is aimed at investigating the therapeutic roles of green coffee in diabetic testicular injury stimulated by high-fat diet/streptozotocin administration. Diabetes mellitus was induced by a high-fat diet and a single dose of streptozotocin (STZ) (35 mg kg-1) in male albino rats. Diabetic animals were orally given two different concentrations of green coffee (50 mg kg-1 and 100 mg kg-1) for 28 days. The levels of testosterone, luteinizing hormone, and follicle-stimulating hormone and parameters of oxidative stress, inflammation, and apoptosis were measured. mRNAs and protein levels were detected quantitatively by real-time PCR and ELISA, respectively. In the diabetic group, the levels of testosterone, luteinizing hormone, and follicle-stimulating hormone showed a significant reduction while they increased significantly after green coffee treatment. A significant increase of antioxidant markers glutathione, superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase along with decreased levels of lipid peroxides and nitric oxide was observed after green coffee treatment in the diabetic group. Finally, the levels of IL-1β, TNF-α, Bax, and caspase-3 were also decreased in both treated groups (metformin and green coffee) when compared to the diabetic group. We conclude that testicular oxidative impairment induced by a high-fat diet (HFD) and STZ can be reversed by green coffee. Administration of green coffee could represent a promising therapeutic agent which can help the treatment of type 2 DM-induced testicular dysfunction.

Zingiber officinale preserves testicular structure and the expression of androgen receptors and proliferating cell nuclear antigen in diabetic rats

The aim of this study was to assess the efficacy of Zingiber officinale, commonly referred to as ginger, in preserving the structural integrity of testis in streptozotocin (STZ)-induced diabetic rats compared to the efficacy of metformin, the traditional effective antidiabetic drug. STZ was utilised for the induction of diabetes mellitus in male Sprague Dawley rats. The study included five groups (n = 6 each), namely the normal control, ginger-treated normal, nontreated diabetic, metformin-treated diabetic and ginger-treated diabetic groups. Biochemical assessment of fasting blood glucose level (BGL) and total antioxidant capacity (TAC) was performed. Histopathological assessment of the testes was performed using routine and immunohistochemical techniques. Fasting BGL significantly (p = .01) reduced, whereas TAC significantly increased (p < .001) in metformin- and ginger-treated diabetic rats compared to those in untreated diabetic rats. Metformin and ginger reduced the degenerative changes observed in the testes of diabetic rats, significantly reduced (p < .001) caspase-3 immunoexpression, and significantly increased (p < .001) the immune-expression of androgen receptors and proliferating cell nuclear antigen. Ginger has antidiabetic effects and preserves testicular structural integrity and, thus, is recommended as an adjuvant therapy for male diabetic patients in the reproductive period.

Evaluation of carvacrol on pituitary and sexual hormones and their receptors in the testicle of male diabetic rats

Diabetes mellitus (DM) is a complex metabolic disease and it is also closely associated with a reduction in fertility in male patients. The purpose of the present study was to investigate the antidiabetic effect of carvacrol (CRV), as a potent antioxidant, on the numbers of germ cells and Sertoli cells in testicular tissue, and the messenger RNA (mRNA) and protein expression of some genes involved in spermatogenesis, including luteinizing hormone/choriogonadotropin receptor ( LHCGR), follicle-stimulating hormone receptor ( FSHR), and steroidogenic factor 1 ( SF-1), as well as hormones such as luteinizing hormone (LH), follicle-stimulating hormone (FSH), testosterone (T), and insulin. Adult male Wistar rats ( n = 32) were randomly divided into four groups (eight animals per group), including healthy control that received 0.2% Tween 80, diabetic control group, the diabetic group treated orally with CRV (75 mg/kg), and CRV group that received orally CRV (75 mg/kg). The duration of the treatment period lasted 8 weeks. In the diabetic group, the numbers of Sertoli cells and germ cells were significantly decreased, while the treatment with CRV prevented the degree of the damage to the cells mentioned earlier. CRV administration elevated the concentrations of insulin, T, FSH, and LH. Moreover, treatment with CRV significantly enhanced the levels of the mRNA and protein expression of SF-1, LHCGR, and FSHR. According to the obtained results, CRV administration could prevent the deleterious effects of DM on testicular germ cells, and it increases the levels of hormones and some essential genes, such as SF-1, LHCGR, and FSHR, involved in the process of spermatogenesis.

The effect of prolonged dietary sodium nitrate treatment on the hypothalamus-pituitary-gonadal axis and testicular structure and function in streptozotocin-induced diabetic male rats

The aim of this study was to evaluate the effect of prolonged dietary nitrate supplementation on the gonadotropin level, testicular histology and morphometry, expression of miR-34b and p53 mRNA, and spermatogenesis in streptozotocin-induced diabetic male rats.

METHODS

Fifty male Wistar rats were divided into 5 groups: Control (C), control + nitrate (CN), diabetes (D), diabetes + insulin (DI), and diabetes + nitrate (DN). Diabetes was induced using 45 mg kg^-1 of streptozotocin intraperitoneally. Rats in the CN and DN groups were administered sodium nitrate in drinking water (100 mg L^-1). NPH insulin (2-4 U d^-1) was injected subcutaneously in the DI group for 2 months. Nitrate and insulin supplementation was started one month after confirmation of diabetes.

RESULTS

Nitrate supplementation in the DN group significantly increased the body weight (p < 0.05), sperm parameters (p < 0.001), indices of spermatogenesis (p < 0.001), and testis histopathology as well as decreased the blood glucose level (p < 0.001) compared to the untreated diabetic group, although it had no significant effect on testicular parameters, LH and FSH levels. Nitrate administration in the DN group also decreased miR-34b (p < 0.001) and p53 mRNA (p < 0.001) expression, and increased serum insulin and NOx levels compared to the untreated diabetic rats.

CONCLUSIONS

Chronic nitrate supplementation in streptozotocin-induced diabetic rats improved fertility parameters, which may be associated with increased miR-34b and decreased p53 mRNA.

Can Antidiabetic Drugs Improve Male Reproductive (Dys)Function Associated with Diabetes?

The alarming increase in the number of diabetic patients worldwide raises concerns regarding the impact of the disease on global health, not to mention on social and economic aspects. Furthermore, the association of this complex metabolic disorder with male reproductive impairment is worrying, mainly due to the increasing chances that young individuals, at the apex of their reproductive window, could be affected by the disease, further contributing to the disturbing decline in male fertility worldwide. The cornerstone of diabetes management is glycemic control, proven to be effective in avoiding, minimizing or preventing the appearance or development of disease-related complications. Nonetheless, the possible impact of these therapeutic interventions on male reproductive function is essentially unexplored. To address this issue, we have made a critical assessment of the literature on the effects of several antidiabetic drugs on male reproductive function. While the crucial role of insulin is clear, as shown by the recovery of reproductive impairments in insulin-deficient individuals after treatment, the same clearly does not apply to other antidiabetic strategies. In fact, there is an abundance of controversial reports, possibly related to the various study designs, experimental models and compounds used, which include biguanides, sulfonylureas, meglitinides, thiazolidinediones/glitazones, bile acid sequestrants, amylin mimetics, as well as sodiumglucose co-transporter 2 (SGLT2) inhibitors, glucagon-like peptide 1 (GLP1), α-glucosidase inhibitors and dipeptidyl peptidase 4 (DPP4) inhibitors. These aspects constitute the focus of the current review.

Fucoxanthin-Rich Brown Algae Extract Improves Male Reproductive Function on Streptozotocin-Nicotinamide-Induced Diabetic Rat Model

Hypogonadism and oxidative stress are occurring commonly in men with diabetes and associated male infertility. This study aimed to investigate the capability of anti-oxidative and anti-inflammatory properties of fucoxanthin as well as to evaluate its protective effects on male reproduction in diabetic rats. The RAW 264.7 macrophage cells were used to evaluate the anti-oxidative and anti-inflammatory activity. Thirty male Sprague-Dawley rats were induced by streptozotocin-nicotinamide for a diabetes model and fed either with three different doses of fucoxanthin (13, 26, and 65 mg/kg) or rosiglitazone (0.571 mg/kg) for four weeks. The fucoxanthin significantly inhibited nitric oxide production and reduced reactive oxygen species level in lipopolysaccharide-induced RAW 264.7 cells. In the animal study, fucoxanthin administration improved insulin resistance, restored sperm motility, decreased abnormal sperm number, and inhibited lipid peroxidation. Moreover, it restored GPR54 and SOCS-3 mRNA expression in the hypothalamus and recovered luteinizing hormone level, as well as the testosterone level. In conclusion, fucoxanthin not only possessed antioxidant and anti-inflammatory properties but also decreased the diabetes signs and symptoms as well as improved spermatogenesis and male reproductive function.

Calorie Restriction Modulates Reproductive Development and Energy Balance in Pre-Pubertal Male Rats

The objective was to determine effects of feed restriction and refeeding on reproductive development and energy balance in pre-pubertal male rats. Sprague Dawley rats (n = 32, 24 days old, ~65 g), were randomly allocated into four treatments (n = 8/treatment): (1) Control (CON, ad libitum feed; (2) Mild Restriction (MR, rats fed 75% of CON consumption); (3) Profound Restriction (PR, 50% of CON consumption); or (4) Refeeding (RF, 50% restriction for 14 days, and then ad libitum for 7 days). Feed restriction delayed reproductive development and decreased energy balance and tissue accretion, with degree of reproductive and metabolic dysfunctions related to restriction severity. In RF rats, refeeding largely restored testis weight, sperm production (per gram and total), plasma IGF-1, leptin and insulin concentrations and energy expenditure, although body composition did not completely recover. On Day 50, more CON and RF rats than PR rats were pubertal (5/6, 4/5 and 1/6, respectively; plasma testosterone >1 ng/mL) with the MR group (4/6) not different. Our hypothesis was supported: nutrient restriction of pre-pubertal rats delayed reproductive development, induced negative energy balance and decreased metabolic hormone concentrations (commensurate with restriction), whereas short-term refeeding after profound restriction largely restored reproductive end points and plasma hormone concentrations, but not body composition.

Protective effects of catalpol on diabetes mellitus-induced male reproductive damage via suppression of the AGEs/RAGE/Nox4 signaling pathway

AIMS

Diabetes mellitus (DM)-induced reproductive damage is an important cause of infertility for male DM patients, we herein evaluated the effects of catalpol on diabetic reproductive damage through the suppression of the AGEs/RAGE/Nox4 signaling pathway.

METHODS

KK-Ay diabetic reproductive damage mice were administered with catalpol for 8 weeks, the testis/body weight ratio, testicular histopathology, the levels of endogenous hormone and the activity of testicular marker enzymes were determined. In vitro, the GC-2 cell injury model was induced by advanced glycation end-products (AGEs) and pretreated with catalpol. Cell viability, apoptosis, and oxidative stress markers were detected and the mechanism based on the AGEs/RAGE/Nox4 pathway was explored.

KEY FINDINGS

Catalpol showed remarkable capacity on protecting diabetic reproductive damage by improving the histomorphology of the testes, increasing the testis/body weight ratio and activity of acid phosphatase (ACP), lactate dehydrogenase (LDH), gamma-glutamyl transferase (γ-GT). The reduced testosterone (T), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in DM mice were also reversed with catalpol intervention. Moreover, catalpol showed markedly effects of anti-oxidative in vivo and in vitro, which significantly down-regulated reactive oxygen species (ROS) levels and restored superoxide dismutase (SOD) activity, meanwhile decreased GC-2 cell apoptosis and Bax/Bcl-2 ratio. Moreover, the over-expression of receptors for AGEs (RAGE), NADPH oxidase type 4 (Nox4) and phosphorylation of nuclear transcription factor-κB p65 (NF-κB p65) were suppressed by catalpol.

SIGNIFICANCE

Catalpol could alleviate DM-induced male reproductive damage by inhibiting oxidative stress-induced apoptosis and inflammation mediated by AGEs/RAGE/Nox4 signaling pathway.

Effects of noopept on cognitive functions and pubertal process in rats with diabetes

AIM

Type 1 diabetes (T1DM) is a common chronic disease in childhood. Increasing insulin resistance in puberty gives rise to higher doses of insulin usage in treatment. Of this reason new approaches in treatment are needed. Noopept researches suggest it to have anti-diabetic properties. We tried to determine the effects of noopept on pubertal diabetes.

MAIN METHOD

The research was made with 60 prepubertal, 28 day-old, male, Sprague Dawley rats. The rats were divided into randomised 6 groups (n = 10/group). i) Control, ii) Diabetes Control, iii) Noopept Control, iv) Diabetes + Noopept, v) Diabetes + Insulin, vi) Diabetes + Insulin + Noopept. T1DM model was induced by streptozotocin on postnatal 28th day. 0.5 mg/kg noopept and 1 IU insulin were administered intraperitoneally for 14 days. Blood glucose and body weight measurements, puberty follow-up and MWM tests were performed. Hippocampus, hypothalamus and testis were evaluated histologically. Hypothalamic GnRH and kisspeptin were studied immunohistochemically. Serum LH, FSH and insulin, hippocampal homogenate NGF and BDNF levels were determined by ELISA.

KEY FINDINGS

Delayed puberty was normalized by noopept (p < 0.05). Blood glucose levels were lower in noopept-administered diabetic groups (p < 0.05). Noopept decreased HOMA-IR in insulin administered diabetic group (p < 0.05). Number of degenerated cells in hippocampus and testis were higher in diabetes control group when compared with other groups (p < 0.05). GnRH immunoreactivity in Diabetes + Noopept group was increased when compared to insulin + noopept group (p = 0.018). There was no difference in kisspeptin, serum LH, FSH, hippocampal NGF-BDNF levels and spatial learning assessment among groups (p > 0.05).

SIGNIFICANCE

Noopept may have positive effect in treatment of pubertal diabetes.

Hyperglycemia and T Cell infiltration are associated with stromal and epithelial prostatic hyperplasia in the nonobese diabetic mouse

BACKGROUND

Prostatic inflammation and various proinflammatory systemic comorbidities, such as diabetes and obesity are associated with human benign prostatic hyperplasia (BPH). There is a paucity of in vivo models reflecting specific aspects of BPH pathogenesis. Our aim was to investigate the nonobese diabetic (NOD) mouse as a potential model for subsequent intervention studies.

MATERIALS AND METHODS

We used the NOD mouse, a model of autoimmune inflammation leading to type 1 diabetes to examine the effects of systemic inflammation and diabetes on the prostate. We assessed changes in prostatic histology, infiltrating leukocytes, and gene expression associated with aging and diabetic status.

RESULTS

Both stromal expansion and epithelial hyperplasia were observed in the prostates. Regardless of diabetic status, the degree of prostatic hyperplasia varied. Local inflammation was associated with a more severe prostatic phenotype in both diabetic and nondiabetic mice. Testicular atrophy was noted in diabetic mice, but prostate glands showed persistent focal cell proliferation. In addition, a prostatic intraepithelial neoplasia (PIN)-like phenotype was seen in several diabetic animals with an associated increase in c-Myc and MMP-2 expression. To examine changes in gene and cytokine expression we performed microarray and cytokine array analysis comparing the prostates of diabetic and nondiabetic animals. Microarray analysis revealed several differentially expressed genes including CCL3, CCL12, and TNFS10. Cytokine array analysis revealed increased expression of cytokines and proteases such as LDLR, IL28 A/B, and MMP-2 in diabetic mice.

CONCLUSION

Overall, NOD mice provide a model to examine the effects of hyperglycemia and chronic inflammation on the prostate, demonstrating relevance to some of the mechanisms present underlying BPH and potentially the initiation of prostate cancer.