Effects of Acute Exposure to Methylglyoxal or/and A Diet Rich in Advanced Glycation End Products on Sperm Parameters in Mice.

BACKGROUND: Advanced glycation end products (AGEs) that accompany many metabolic disorders including diabetes, obesity, and a wide range of dyslipidemia conditions, are strongly associated with adverse effects on cell and tissue homeostasis. Accordingly, our objective was to investigate the impact of AGE-promoting diets on mouse models, considering both scenarios with and without methylglyoxal (MGO) as a primary precursor of AGEs. MATERIALS AND METHODS: In this experimental study, 5-week-old C57BL/6 mice were split into four groups as a control group (n=5), AGE (n=5), MGO (n=8), and AGE-MGO-diets (n=8). After five weeks the level of fasting blood sugar (FBS), body weight, food intake, sperm parameters, and functional tests were evaluated. Furthermore, testicular superoxide dismutase (SOD) activity, malondialdehyde, and total antioxidant capacity (TAC) were assessed. RESULTS: After five weeks, AGE, AGE-MGO, and MGO groups showed the highest level of body weight and FBS in comparison to the control group. Mean sperm concentration, sperm malondialdehyde, testicular lipid peroxidation, and TAC did not differ significantly among the study groups. While, AGE, MGO, and AGE-MGO groups showed a significant reduction in sperm motility and progressive motility compared to the control group (P<0.05). The greatest increases in abnormal sperm morphology and intracytoplasmic reactive oxygen species (ROS) were observed in the MGO and AGE-MGO groups than in the control group (P<0.05). Sperm protamine deficiency and residual histone were significantly increased in the three treatment groups compared to the control group (P<0.05). Regarding the DNA damage, the AGE and AGE-MGO groups showed the most severe damage. The lowest amount of testicular superoxide dismutases (SOD, P<0.001) was observed in the AGE-MGO group. CONCLUSION: AGEs and MGO have a negative influence on sperm function and reproductive potential. These effects could be possibly attributed to both increased oxidative stress (OS) and inflammation.

Effects of Streptozotocin Induced Diabetes on One-Carbon Cycle and Sperm Function.

In this article published in Cell J, Vol 26, No 1, 2024, on pages 81-90, the authors found that the affiliation of authors in address 1 and also the two corresponding authors had accidentally missed during the formatting of the paper. Therefore, we corrected them. The authors would like to apologize for any inconvenience.

Sperm Parameters and Chromatin Integrity in Men Suffering from Celiac Disease: Insights into Reproductive Health, Case-Control Study.

OBJECTIVE: Celiac disease is a common chronic inflammatory condition of the small intestine caused by permanent intolerance to gluten/gliadin. It has been demonstrated that oxidative stress is one of the mechanisms that is involved in gliadin toxicity, and there is a correlation between oxidative damage with this disease. Similarly, increased oxidative stress was repeatedly reported in infertile men which led to low-quality of sperm function. Therefore, we aimed to assess sperm parameters and chromatin status in men with Celiac disease. MATERIALS AND METHODS: In this case-control study, semen samples were collected from 11 fertile men without Celiac and 10 men with diagnostic Celiac disease. Basic semen analyses were performed according to the World Health Organization (WHO) 2010 protocol. The percentage of sperm with persistence histones, protamine deficiency, DNA fragmentation, malondialdehyde (MDA), and intracellular reactive oxygen species (ROS) were assessed using aniline blue, chromomycin A3, sperm chromatin structure assay, thiobarbituric acid reactive substances (TBARS) assay, and diacetyldichlorofluorescein staining, respectively. RESULTS: Unlike the sperm parameters, which did not show significant differences between men with Celiac disease and fertile individuals, sperm chromatin maturation (persistence histones and protamine deficiency) and sperm DNA damage in men with Celiac disease were significantly higher compared to fertile individuals (P<0.05). In addition, the percentage of sperm viability in these individuals was significantly lower than that in the fertile individuals (P<0.05). We did not observe any significant differences in sperm lipid peroxidation and intracellular ROS levels between the two study groups (P>0.05). CONCLUSION: Celiac disease affects sperm chromatin maturation and DNA fragmentation, emphasizing its impact on reproductive health.

Effect of Advanced Glycation end Products (AGEs) on Sperm Parameters and Function in C57Bl/6 Mice.

This study investigated the deleterious impact of advanced glycation end products (AGEs), commonly present in metabolic disorders like diabetes, obesity, and infertility-related conditions, on sperm structure and function using a mouse model where AGE generation was heightened through dietary intervention. Five-week-old C57BL/6 mice were divided into two groups, one on a regular diet (control) and the other on an AGE-rich diet. After 13 weeks, various parameters were examined, including fasting blood glucose, body weight, food consumption, sperm parameters and function, testicular superoxide dismutase levels, malondialdehyde content, total antioxidant capacity, Johnson score, AGE receptor (RAGE) content, and carboxymethyl lysine (CML) content. The results showed that mice in the AGE group exhibited increased body weight and elevated fasting blood glucose levels. Furthermore, the AGE group displayed adverse effects on sperm, including reduced sperm counts, motility, increased morphological abnormalities, residual histone, protamine deficiency, sperm DNA fragmentation, reduced testicular antioxidant capacity, and higher levels of RAGE and CML proteins. These findings underscore the negative impact of AGEs on male reproductive health, particularly within the context of metabolic disorders, emphasizing the crucial role of the AGE/RAGE axis in male infertility, especially in the context of Western dietary patterns.

Effects of Streptozotocin Induced Diabetes on One-Carbon Cycle and Sperm Function.

OBJECTIVE: Diabetic men suffer an increased risk of infertility associated with signs of oxidative damage and decreased methylation in sperm pointing to a deficit of the one-carbon cycle (1CC). We aimed to investigate this deficit using mice models (type 1 and 2) of streptozotocin-induced diabetes. MATERIALS AND METHODS: In this experimental study, 50 male mice, aged eight weeks, were divided randomly into four groups: sham, control, type 1 diabetes mellitus (DM1), and DM2. The DM1 group was fed a normal diet (ND) for eight weeks, followed by five consecutive days of intraperitoneal administration of Streptozotocin (STZ, 50 mg/kg body weight). The DM2 group was fed a high-fat diet (HFD) for eight weeks, followed by a single intraperitoneal injection of STZ (100 mg/kg). After twelve weeks, all the mice were euthanized, and study parameters assessed. In the sham group, citrate buffer as an STZ solvent was injected. RESULTS: Both types of diabetic animals had serious impairment of spermatogenesis backed by increased DNA damage (P=0.000) and decreased chromatin methylation (percent: P=0.019; intensity: P=0.001) and maturation (P=0.000). The 1CC was deeply disturbed with increased homocysteine (P=0.000) and decreased availability of carbon units [methionine (P=0.000), serine (P=0.088), folate (P=0.016), B12 (P=0.025)] to feed methylations. CONCLUSION: We have observed a distinct impairment of 1CC within the testes of individuals with diabetes. We speculate that this impairment may be linked to inadequate intracellular glucose and diminished carbon unit supply associated with diabetes. As a result, interventions focusing on enhancing glucose uptake into sperm cells and providing supplementary methyl donors have the potential to improve fertility issues in diabetic patients. However, additional clinical testing is required to validate these hypotheses.

The role of the transsulfuration pathway in spermatogenesis of vitamin D deficient mice.

Vitamin D deficiency is a global health problem and has been linked to defective spermatogenesis and male infertility. In this study, we aimed to investigate the main enzymes involved in the transsulfuration pathway of 1-carbon metabolism, and spermatogenesis function. Therefore, sixteen male C57 mice were addressed to a control (standard diet) or vitamin D deficient (VDD) diet for 14 weeks. The results show that compared to the standard diet, VDD increased final body weight and reduced sperm quality, caused damage to the testicular structure, and decreased the serum levels of testosterone. In addition, serum concentrations of homocysteine, vitamin B12, and sperm oxidative stress markers increased. In testicular tissues, the CBS and CSE protein levels were down-regulated whereas HO-1 was up-regulated at both mRNA and protein expression levels. Within a mice deprivation model, VDD deeply suppressed testosterone and impaired spermatogenesis with oxidative stress-mediated mechanisms. The effects of the deprivation appeared to be at least in part independent of genomic and receptor-mediated vitamin D actions and suggest a specific impairment of the alternative transsulfuration pathway.

Sperm chromatin structure assay (SCSA®) and flow cytometry-assisted TUNEL assay provide a concordant assessment of sperm DNA fragmentation as a function of age in a large cohort of approximately 10,000 patients.

BACKGROUND: Sperm DNA integrity is increasingly seen as a critical characteristic determining reproductive success, both in natural reproduction and in assisted reproductive technologies (ART). Despite this awareness, sperm DNA and nuclear integrity tests are still not part of routine examinations for either infertile men or fertile men wishing to assess their reproductive capacity. This is not due to the unavailability of DNA and sperm nuclear integrity tests. On the contrary, several relevant but distinct tests are available and have been used in many clinical trials, which has led to conflicting results and confusion. The reasons for this are mainly the lack of standardization between different clinics and between the tests themselves. In addition, the small number of samples analyzed in these trials has often weakened the value of the analyses performed. In the present work, we used a large cohort of semen samples, covering a wide age range, which were simultaneously evaluated for sperm DNA fragmentation (SDF) using two of the most frequently used SDF assays, namely the TUNEL assay and the sperm chromatin structure assay (SCSA®). At the same time, as standard seminal parameters (sperm motility, sperm morphology, sperm count) were available for these samples, correlations between age, SDF and conventional seminal parameters were analyzed. RESULTS: We show that the SCSA® and TUNEL assessments of SDF produce concordant data. However, the SDF assessed by TUNEL is systematically lower than that assessed by SCSA®. Regardless of the test used, the SDF increases steadily during aging, while the HDS parameter (High DNA stainability assessed via SCSA®) remains unchanged. In the cohort analyzed, conventional sperm parameters do not seem to discriminate with aging. Only sperm volume and motility were significantly lower in the oldest age group analyzed [50-59 years of age]. CONCLUSIONS: In the large cohort analyzed, SDF is an age-dependent parameter, increasing linearly with aging. The SCSA® assessment of SDF and the flow cytometry-assisted TUNEL assessment are well correlated, although TUNEL is less sensitive than SCSA®. This difference in sensitivity should be taken into account in the final assessment of the true level of fragmentation of the sperm nucleus of a given sample. The classical sperm parameters (motility, morphology, sperm count) do not change dramatically with age, making them inadequate to assess the fertility potential of an individual.

RéSUMé: CONTEXTE: l'intégrité de l'ADN des spermatozoïdes est de plus en plus considérée comme une caractéristique essentielle déterminant le succès de la reproduction, tant dans la reproduction naturelle que dans les techniques de reproduction assistée (AMP). Malgré cette prise de conscience, les tests d'intégrité nucléaire des spermatozoïdes ne font toujours pas partie des examens de routine pour les hommes infertiles ou fertiles souhaitant évaluer leur capacité de reproduction. Cette situation n'est pas due à l'indisponibilité des tests. Au contraire, plusieurs tests pertinents mais distincts sont disponibles et ont été utilisés dans de nombreux essais cliniques, ce qui a donné lieu à des résultats contradictoires et à une certaine confusion. Les raisons en sont principalement le manque de normalisation entre les différentes cliniques et entre les tests eux-mêmes. En outre, le petit nombre d'échantillons analysés dans ces essais a souvent affaibli la valeur des analyses effectuées. Dans le présent travail, nous avons utilisé une vaste cohorte d'échantillons, couvrant une large tranche d'âge, évalués simultanément pour la fragmentation de l'ADN des spermatozoïdes à l'aide de deux des tests les plus fréquemment utilisés, à savoir le test TUNEL et le test de la structure de la chromatine des spermatozoïdes (SCSA®). Parallèlement, comme les paramètres séminaux standard (motilité, morphologie, numération) étaient disponibles pour ces échantillons, les corrélations entre l'âge, le niveau de fragmentation et les paramètres séminaux conventionnels ont été analysées. RéSULTATS: Nous montrons que les évaluations SCSA® et TUNEL produisent des données concordantes. Cependant, le SDF évalué par TUNEL est systématiquement plus faible que celui évalué par SCSA®. Quel que soit le test utilisé, la fragmentation augmente régulièrement au cours du vieillissement, alors que le paramètre HDS (« High DNA stainability¼ évalué par le test SCSA®) reste inchangé. Dans la cohorte analysée, les paramètres spermatiques conventionnels ne semblent pas varier avec le vieillissement. Seuls le volume et la mobilité des spermatozoïdes étaient significativement plus faibles dans le groupe d'âge le plus élevé analysé [50­59 ans]. CONCLUSIONS: Dans la grande cohorte analysée, la fragmentation de l'ADN spermatique est un paramètre dépendant de l'âge, augmentant linéairement avec le vieillissement. L'évaluation du SDF par SCSA® et l'évaluation via le test TUNEL assistée par cytométrie de flux sont bien corrélées, bien que le TUNEL soit moins sensible que le SCSA®. Cette différence de sensibilité doit être prise en compte dans l'évaluation finale du niveau réel de fragmentation du noyau des spermatozoïdes d'un échantillon donné. Les paramètres classiques du sperme (motilité, morphologie, nombre de spermatozoïdes) ne changent pas de façon spectaculaire avec l'âge, ce qui les rend inadéquats pour évaluer le potentiel de fertilité d'un individu.

Aberrant Expression of TET2 Accounts for DNA Hypomethylation in Varicocele.

OBJECTIVE: Epigenetic modifications such as DNA methylation play a key role in male infertility etiology. This study aimed to explore the global DNA methylation status in testicular spermatogenic cells of varicocele-induced rats and consider their semen quality, with a focus on key epigenetic marks, namely 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC), as well as the mRNA and proteins of ten-eleven translocation (TET) methylcytosine dioxygenases 1-3. MATERIALS AND METHODS: In this experimental study, 24 mature male Wistar rats (8 in each group) were assigned amongst the control, sham, and varicocele groups. Sperm quality was assessed, and DNA methylation patterns of testicular spermatogenic cells were investigated using reverse transcription-polymerase chain reaction (RT-PCR), western blot, and immunofluorescence techniques. RESULTS: Sperm parameters, chromatin and DNA integrity were significantly lower, and sperm lipid peroxidation significantly increased in varicocele-induced rats in comparison with control rats. During spermatogenesis in rat testis, 5-mC and 5-hmC epigenetic marks, and TET1-3 mRNA and proteins were expressed. In contrast to the 5-mC fluorescent signal which was presented in all testicular cells, the 5-hmC fluorescent signal was presented exclusively in spermatogonia and a few spermatids. In varicocele-induced rats, the 5-mC signal decreased in all cells within the tubules, whereas a strong signal of 5-hmC was detected in seminiferous tubules compared to the control group. As well, the levels of TET2 mRNA and protein expression were significantly upregulated in varicocele-induced rats in comparison with the control group. Also, our results showed that the varicocele-induced animals exhibited strong fluorescent signals of TET1-3 in testicular cells, whereas weak fluorescent signals were identified in the seminiferous tubules of the control animals. CONCLUSION: Consequently, we showed TET2 upregulation and the 5-hmC gain at testicular levels are associated with varicocele and sperm quality decline, and therefore they can be exploited as potential biomarkers of spermatogenesis.

Omega 6/Omega 3 Ratio Is High in Individuals with Increased Sperm DNA fragmentation.

An imbalance between omega-6 and omega-3 fatty acids in sperm has been linked with lipid peroxidation and DNA damage in sperm, indicating a possible correlation to fertility potential. This cross-sectional study involved 56 infertile men (aged 25-45), and assessed the relationship between the omega-6 to omega-3 fatty acid ratio in sperm and seminal plasma with sperm DNA fragmentation. Individuals were categorized based on high or low levels of sperm DNA fragmentation according to two tests (TUNEL and SCSA assay less or greater than 10 and 30%, respectively), and their fatty acid composition, as well as sperm functional tests, were analyzed. Results showed that men with high DNA fragmentation exhibited higher percentages of total saturated, monounsaturated, and omega-6 to omega-3 fatty acid ratios in both sperm (P < 0.001) and seminal plasma (P < 0.001) compared to men with low DNA fragmentation. The percentage of sperm lipid peroxidation, and residual histone (P < 0.05) were higher, while the percentage of sperm motility (P < 0.001) was lower in the former compared to the latter group. Moreover, Pearson's correlation revealed positive associations between the omega-6 to omega-3 fatty acid ratio with sperm lipid peroxidation, DNA fragmentation, and residual histones in both sperm and seminal plasma. Overall, these observations suggest that consumption of omega-3 fatty acids may be related to male fertility potential, as it appears that individuals with a high percentage of omega-3 fatty acids have better sperm quality compared to men with a lower omega-3 fatty acid.

Role of Endoplasmic Reticulum Stress in The Male Reproductive System.

Testicular dysfunction, whether linked to varicocele, obesity, diabetes, aging, inflammation, or lifestyle or environmental issues, is frequently accompanied by an accumulation of unfolded or misfolded proteins, indicating impaired endoplasmic reticulum (ER) function. In this review, we examined the Google Scholar, Scopus and PubMed databases (from 2011 to 2022) to support the association of ER stress with defective spermatogenesis in animal models and humans. ER stress, whether in its pro-survival or pro-apoptotic aspect, appears to be closely linked to each studied situation. Several studies have demonstrated a significant increase in oxidative stress (OS) levels in infertile men compared to fertile individuals, which is associated with poor spermatogenesis quality. OS is likely the result of the interplay between ER stress and spermatogenesis defects. These findings suggest that therapeutic strategies aimed at mitigating both ER stress and OS could be of interest in restoring male reproductive function.

Enhancing the Accuracy of Measuring DEP Force Applied on Cells by Considering the Friction Effect.

The Dielectrophoresis (DEP) phenomenon has been widely used for cell separation in recent years. The experimental measurement of the DEP force is one of the concerns of scientists. This research presents a novel method for more accurately measuring the DEP force. The innovation of this method is considered the friction effect, which has been neglected in previous studies. For this purpose, first, the direction of the microchannel was aligned with the electrodes. As there was no DEP force in this direction, the release force of the cells caused by the fluid flow equaled the friction force between the cells and the substrate. Then, the microchannel was aligned perpendicular to the direction of the electrodes, and the release force was measured. The net DEP force was obtained by the difference between the release forces of these two alignments. In the experimental tests, the DEP force, when applied to the sperm and white blood cell (WBC), was measured. The WBC was used to validate the presented method. The experimental results showed that the forces applied by DEP to WBC and human sperm were 42 pN and 3 pN, respectively. On the other hand, with the conventional method, these figures were as high as 72 pN and 4 pN due to neglecting the friction force. The compression between the simulation results in COMSOL Multiphysics and the experiments determined the new approach to be valid and capable of use in any cell, such as sperm.

Assisted Oocyte Activation following Intracytoplasmic Sperm Injection: A Sensible Option for Infertile Couples with Severe Teratozoospermia.

The intracytoplasmic sperm injection (ICSI) has significantly improved male factor infertility treatment; however, complete fertilization failure still occurs in 1-5% of ICSI treatment cycles mainly due to oocyte activation failure. It is estimated that around 40-70% of oocyte activation failure is associated with sperm factors after ICSI. Assisted oocyte activation (AOA) as an effective approach to avoid total fertilization failure (TFF) has been proposed following ICSI. In the literature, several procedures have been described to overcome failed oocyte activation. These include mechanical, electrical, or chemical stimuli initiating artificial Ca2+ rises in the cytoplasm of oocytes. AOA in couples with previous failed fertilization and those with globozoospermia has resulted in varying degrees of success. The aim of this review is to examine the available literature on AOA in teratozoospermic men undergoing ICSI-AOA and determine whether the ICSI-AOA should be considered as an adjunct fertility procedure for these patients.

Oxidative Stress and Cell Cycle Arrest in Seminiferous Tubules Nearby Varicose Vessels: New Perspectives from Experimental Varicocele.

Varicocele (VCL) has been shown to induce severe oxidative stress in the testicular tissue resulting in 35% of males with primary infertility. To compare the exacerbating impacts of varicose on oxidative DNA damage and homeostatic antioxidant reactions in the seminiferous tubules (ST), enclosed and far from varicose vessels. Thirty mature Wistar rats were divided into control and VCL-induced groups. To approve VCL, the testicular diameters, volume, and blood circulation were measured using B-mode and Doppler ultrasonography. Next, to confirm oxidative stress (OS), the global homeostatic antioxidant biomarkers were evaluated. Moreover, the OS-induced oxidative DNA damage and homeostatic antioxidant reactions were compared between STs nearby and far from varicose vessels. Finally, to clarify the DNA damage-induced impact on the cell cycle progression, the global and local expressions of Cyclin D1, Cdk4, and p21 were examined. The VCL-induced group exhibited diminished global antioxidant status (marked with TAC, GPX, SOD, and CAT) and UNG and MPG expression levels. Moreover, the cross-sections of the VCL group represented a prominent reduction in the UNG, MPG, Cyclin D1, and cdk4, and upregulation in the p21 expression levels, more prominently in the STs nearby varicose vessels. Concerning severe oxidative DNA damage and intensive molecular changes in the STs nearby the varicose vessels, they can be considered the main cause of oxidative DNA damage in enclosed tubules. Thus, the varicose-mediated oxidative DNA damage negatively impacts the cell cycle progression in the tubules more intensively in the subcapsular area.

L-Carnitine and Pentoxifylline Supplementation Improves Sperm Viability and Motility at Low Temperature.

BACKGROUND: In infertility clinics, preserving high-quality spermatozoa for a long time is a necessity. Pentoxifylline (PT) and L-carnitine (LC) are effective in improving sperm motility as well as protecting the sperm membrane. The present study aimed to investigate the protective impacts of PT and LC on the quality of the normal sperm motility, protamine content, and viability on prolonged storage for 12 days at 4-6°C. MATERIALS AND METHODS: The present experimental work included 26 samples, which were first prepared based on the swim-up technique, of normozoospermic men. They were divided into three aliquots as untreated control, LC-treated, and PT-treated groups and incubated for up to 12 days at 4-6°C. Thereafter, chromatin maturity, sperm viability, and motility were assessed on 0, 1, 2, 5, 7, and 12 days. Data were analyzed using a one-way analysis of variance. RESULTS: The obtained data revealed that PT supplementation increased the percentage of motile spermatozoa in comparison with control and LC-treated specimens. On the other hand, LC supplementation increased the percentage of viable spermatozoa in comparison with the PT-treated and control samples. During the 12-day storage, the percentage of spermatozoa with a normal protamine content was nearly unchanged in the three groups (P>0.05). CONCLUSION: Although LC supplementation can be considered a better alternative than PT for preserving sperm viability, PT could better preserve sperm motility compared to LC during 12 days at 4-6°C.

Alpha-Lipoic Acid Supplementation for Male Partner of Couples with Recurrent Pregnancy Loss: A Post hoc analysis in Clinical Trial.

BACKGROUND: Increased sperm DNA damage is known as one of the causes of recurrent pregnancy loss (RPL) which can be due to increased levels of oxidative stress. Therefore, the aim of this study was to assess the effect of alpha-lipoic acid (ALA) on sperm parameters and sperm functions in couples with a history of RPL. MATERIALS AND METHODS: In this post hoc analysis in clinical trial study, a total of 37 couples with RPL (n=12 and n=25 for placebo and ALA groups, respectively) were considered. Men were treated with ALA (600 mg/day) or placebo for 80 days. Semen samples were acquired from the participants before initiation and after completion of the medication course and assessed regarding conventional sperm parameters, chromatin damage/integrity, intracellular oxidative stress, lipid peroxidation, and seminal antioxidant characteristics. Individuals were further followed up for twelve months for pregnancy occurrence and outcomes. Finally, after excluding patients with no history of RPL, the data was analyzed. RESULTS: No significant differences were observed between the baseline measures of the aforementioned parameters except for seminal volume. After the intervention, the mean sperm DNA damage, protamine deficiency, and persisted histones were significantly lower in the ALA group than in placebo receivers (P<0.05). A decrease in the mean of seminal total antioxidant capacity (P=0.03), malondialdehyde (P=0.02), and sperm DNA damage (P=0.004) as well as an increase in sperm total motility (P=0.04) after treatment with ALA was noticed. In addition, the mean of protamine deficiency and persisted histones were declined post-ALA therapy (P=0.003 and 0.002, respectively). The percentage of spontaneous pregnancy in the ALA group (4 of 25 cases; 16%) was higher than in the placebo group (1 of 12, 8.3%). CONCLUSION: ALA-therapy attenuates sperm DNA damage and lipid peroxidation while enhancing sperm total motility and chromatin compaction in the male partner of couples with PRL (registration number: IRCT20190406043177N1).

The effect of alpha-lipoic acid on sperm functions in rodent models for male infertility: A systematic review.

In this systematic review, we assessed different studies to evaluate the protective effect of alpha-lipoic acid (ALA), as a multifaceted antioxidant, on sperm functions in rodent models. Four databases were searched to find papers reporting the effect of ALA treatment on animal models of male infertility. Up to December 2022, 11,787 articles were identified to explain the ALA protective effects. The included studies were evaluated for eligibility and risk of bias (CRD42022341370). Finally, we identified 23 studies that explain the effect of ALA on sperm functions in rodents. Among them, 15 studies indicated that ALA could restore sperm parameters. Six studies showed a significant reduction in sperm DNA damage by ALA treatment. Seventeen papers displayed the ALA antioxidant ability, and four studies indicated the ALA anti-inflammatory effect. Besides, thirteen studies displayed that ALA could modulate androgenesis. Also, eighteen studies revealed that ALA restored the testicular architecture to normal, and was also effective in restoring reproductive performance in two included studies. This systematic review provided cogent evidence for the protective effect of ALA in rodent models for male infertility by re-establishing spermatogenesis and steroidogenesis and maintaining redox and immune systems homeostasis.

Oxidative versus reductive stress: a delicate balance for sperm integrity.

Despite the long-standing notion of "oxidative stress," as the main mediator of many diseases including male infertility induced by increased reactive oxygen species (ROS), recent evidence suggests that ROS levels are also increased by "reductive stress," due to over-accumulation of reductants. Damaging mechanisms, like guanidine oxidation followed by DNA fragmentation, could be observed following reductive stress. Excessive accumulation of the reductants may arise from excess dietary supplementation over driving the one-carbon cycle and transsulfuration pathway, overproduction of NADPH through the pentose phosphate pathway (PPP), elevated levels of GSH leading to impaired mitochondrial oxidation, or as a result NADH accumulation. In addition, lower availability of oxidized reductants like NAD+, oxidized glutathione (GSSG), and oxidized thioredoxins (Trx-S2) induce electron leakage leading to the formation of hydrogen peroxide (H2O2). In addition, a lower level of NAD+ impairs poly (ADP-ribose) polymerase (PARP)-regulated DNA repair essential for proper chromatin integrity of sperm. Because of the limited studies regarding the possible involvement of reductive stress, antioxidant therapy remains a central approach in the treatment of male infertility. This review put forward the concept of reductive stress and highlights the potential role played by reductive vs oxidative stress at pre-and post-testicular levels and considering dietary supplementation.

Paroxetine treatment in an animal model of depression improves sperm quality.

Depression in mammals is known to be associated with poor reproductive capacity. In males, it has been associated with decreased efficiency of spermatogenesis as well as the production of spermatozoa of reduced structural and functional integrity. Although antidepressants are effective in correcting depressive states, there is controversy regarding their effectiveness in restoring male reproductive function. Here, using an animal model of depression induced by a forced swim test, we confirmed that depression is accompanied by impaired male reproductive function. We further show that administration of a conventional antidepressant of the serotonin reuptake inhibitor class (paroxetine) impairs male reproductive performance in terms of sperm production and quality when administered to healthy animals. Intriguingly, when paroxetine is administered to "depressed" animals, it resulted in a complete restoration of the animal's ability to produce sperm that appears to be as capable of meeting the parameters evaluated here as those of control animals. The one-carbon cycle (1CC) is one of the most important metabolic cycles that include the methionine and folate cycles and plays a major role in DNA synthesis, amino acids, and also the production of antioxidants. Our results show that depression affects the main components of this cycle and paroxetine on healthy mice increases homocysteine levels, decreases glycine and vitamin B12, while in depressed mice, it increases folate levels and decreases vitamin B12. Thus, paroxetine exerts negative impacts on male reproductive function when administered to healthy animals and it well correlate with the altered sperm parameters and functions of depressed animals, and its mechanism remains to be explored.

Alpha-Lipoic Acid Ameliorates Sperm DNA Damage and Chromatin Integrity in Men with High DNA Damage: A Triple Blind Randomized Clinical Trial.

OBJECTIVE: Evidence suggests the contributory role of oxidative stress (OS) to sperm DNA damage and eventually, male infertility. Antioxidant supplementation has exhibited favorable results regarding seminal OS, sperm DNA damage, and chromatin integrity. We aimed to evaluate the effect of alpha-lipoic acid (ALA) supplementation on semen analysis, sperm DNA damage, chromatin integrity, and seminal/intracellular OS in infertile men with high sperm DNA damage. MATERIALS AND METHODS: In this randomized triple-blind placebo-controlled clinical trial study, we opted for a triple-blind controlled clinical trial design. Considering the study's inclusion criteria for the level of sperm DNA fragmentation (higher than the threshold of 30 and 15%), 70% of participants were selected for this clinical research study. Subjects were divided into case and control groups receiving oral ALA (600 mg/day) and placebo for eighty days, respectively. Sperm parameters and functional tests were examined and compared before and after treatment. The final sample size was 34 and 29 for ALA and placebo receivers, respectively. RESULTS: No significant differences were observed about anthropometrics and baseline measures of semen analysis, DNA damage, OS, and chromatin integrity between the two groups. Conventional semen parameters were enhanced insignificantly in both groups (P>0.05). DNA damage decreased significantly in the ALA group, as per sperm chromatin structure assay (SCSA, P<0.001). Moreover, chromomycin A3 (CMA3) staining results indicated a decrease in nuclear protamine deficiency post-ALA therapy (P=0.004). Lipid peroxidation decreased significantly after treatment with ALA (P=0.003). Further, seminal antioxidant capacity/activity did not differ significantly in either of the groups (registration number: IRCT20190406043177N1). CONCLUSION: An 80-day course of oral ALA supplementation (600 mg/day) alleviates sperm OS, DNA damage, and chromatin integrity in men with high sperm DNA damage.

Vulnerability of The Male Reproductive System to SARS-CoV-2 Invasion: Potential Role for The Endoplasmic Reticulum Chaperone Grp78/HSPA5/BiP.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) may adversely affect male reproductive tissues and male
fertility. This concern is elicited by the higher susceptibility and mortality rate of men to the SARS-CoV-2 mediated coronavirus disease-19 (COVID-19), compared to the women. SARS-CoV-2 enters host cells after binding to a functional receptor named angiotensin-converting enzyme-2 (ACE2) and then replicates in the host cells and gets released into the plasma. SARS-CoVs use the endoplasmic reticulum (ER) as a site for viral protein synthesis and processing, as well as glucose-regulated protein 78 (Grp78) is a key ER chaperone involved in protein folding by preventing newly synthesized proteins from aggregation.
Therefore, we analyzed Grp78 expression in various human organs, particularly male reproductive organs, using Broad
Institute Cancer Cell Line Encyclopedia (CCLE), the Genotype-Tissue Expression (GTEx), and Human Protein Atlas online
datasets. Grp78 is expressed in male reproductive tissues such as the testis, epididymis, prostate, and seminal vesicle. It can facilitate the coronavirus entry into the male reproductive tract, providing an opportunity for its replication. This link between the SARS-CoV-2 and the Grp78 protein could become a therapeutic target to mitigate its harmful effects on male fertility.