Bisphenol A (BPA) is a recognized estrogenic endocrine disruptor that poses a threat to the reproductive health of fish. However, it remains unclear whether and how paternal BPA exposure can lead to developmental toxicity in offspring. To explore the potential paternal BPA exposure impacts on craniofacial cartilage growth in offspring, male rare minnows were subjected to BPA and subsequently mated with normal females to produce progeny. Our results demonstrated that paternal BPA exposure resulted in increased malformation and delayed craniofacial cartilage development in the F1 offspring. Furthermore, BPA exposure led to differential expression of 28 miRNAs in paternal sperm in F0 generation (13 upregulated and 15 downregulated), among which 7 miRNAs were involved in the regulation of bone development. BPA also downregulated the expression of bmp2a and Runx1 during F1 embryonic development. The inhibited bmp2a expression might derive from BPA's stimulation of one miRNA, aca-miR-16a-5P, due to bmp2a being one of its target genes. Notably, paternal BPA exposure did not affect craniofacial cartilage development or gonadal development in the F2 generation. Overall, our study sheds light on the molecular mechanisms underlying the impact of paternal BPA exposure on facial chondrogenesis in offspring and provides theoretical support for the ecological protection of fish populations.

Obesity is a major public health concern affecting millions of people globally. Early identification of individuals susceptible to obesity is crucial for reducing the burden of obesity. Obesity is often defined based on body-mass-index (BMI), and tracking BMI trajectories from early childhood offers a valuable tool for risk stratification. Although the role of mothers in shaping these trajectories is well-recognized, the paternal influence on childhood obesity development remains a knowledge gap. We hypothesize that children of fathers with obesity have higher odds of being in the rapid BMI growth trajectory with stronger estimates when the mother is also with overweight or obesity.

We analyzed data from the Canadian CHILD Cohort Study, a pregnancy cohort in which both parents were enrolled in early pregnancy when BMI was assessed. The child's BMI was repeatedly collected from birth to age five. We used group-based trajectory modeling to identify offspring BMI z-score (BMIz) trajectory groups (age-and-sex standardized) and weighted multinomial logistic regression analysis to determine the associations between prenatal paternal BMI and offspring growth trajectories, stratified by maternal weight categories.

Among 2 238 participants, the mean prenatal paternal BMI was 27.44 (SD = 4.77), and 22.83% of fathers were with obesity. The four identified offspring BMIz trajectories were: low stable (n = 220, 9.83%), normative (n = 1 356, 60.59%), high stable (n = 572, 25.56%), and rapid BMIz growth trajectory (n = 90, 4.02%). Children of normal-weight mothers and fathers with obesity had 1.86 higher odds (OR: 1.86; 95%CI: 1.22-2.84) of being classified in the rapid growth BMIz trajectory, compared to children of normal-weight fathers. The odds of being in the rapid growth BMIz trajectory were higher when both mothers and fathers were with obesity (OR: 4.35; 95%CI: 2.65-7.14).

Children of fathers with obesity had higher odds of being in the rapid BMI growth trajectory, particularly when also the mother was with overweight or obesity. These results support the need for preconception advice and interventions for couples to optimize their offspring's health.

The decline in male fertility correlates with the global rise in obesity and dyslipidaemia, representing significant public health challenges. High-fat diets induce metabolic alterations, including hypercholesterolaemia, hepatic steatosis and atherosclerosis, with detrimental effects on testicular function. Testicular tissue, critically dependent on lipids for steroidogenesis, is particularly vulnerable to these metabolic disruptions. Excessive lipid accumulation within the testes, including cholesterol, triglycerides and specific fatty acids, disrupts essential sperm production processes such as membrane formation, maturation, energy metabolism and cell signalling. This leads to apoptosis, impaired spermatogenesis, and abnormal sperm morphology and function, ultimately compromising male fertility. During spermiogenesis, round spermatids undergo extensive reorganization, including the formation of the acrosome, manchette and specialized filamentous structures, which are essential for defining the final sperm cell shape. In this Perspective, we examine the impact of high-fat diets on the cytoskeleton of spermatogenic cells and its consequences to identify the mechanisms underlying male infertility associated with dyslipidaemia. Understanding these processes may facilitate the development of therapeutic strategies, such as dietary interventions or natural product supplementation, that aim to address infertility in men with obesity and hypercholesterolaemia. The investigation of cytoskeleton response to lipid stress extends beyond male reproduction, offering insights with broader implications.

Paternal health and exposure to adverse environments in the period prior to conception have a profound impact on future generations. Adversities such as stress, diet, and toxicants influence offspring health. Emerging evidence indicates that epigenetic mechanisms including noncoding RNA, DNA methylation, and chromatin remodelling mediate these effects. Preclinical studies have contributed to advancing mechanistic understanding in the field; however, human research is limited and primarily observational. Here, we discuss the evidence linking paternal to offspring health and advocate for further research in this area, which may ultimately inform policy and healthcare guidelines to improve paternal preconception health and offspring outcomes.

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

Paternal lifestyle and environmental exposures can alter epigenetic changes in sperm and play a critical role in the offspring's future health, yet the underlying mechanisms remain elusive. The present study established a model of paternal obesity and found that the increased levels of H3K27me3 in sperm persist into the 8-cell embryo stage, resulting in a transgenerational decrease of Manf, which causes endoplasmic reticulum stress and activates the GRP78-PERK-EIF2α-ATF4-CHOP axis. This consequently leads to impaired glucose metabolism and apoptosis in the liver of female offspring. Based on these findings, the F0 mice are treated with 3-deazaneplanocin A, an EZH2 inhibitor, which successfully prevented metabolic dysfunction in F0 mice of the high-fat diet (HFD) group. Meanwhile, intravenous injection of recombinant human MANF in F1 female offspring can successfully rescue the metabolic dysfunction in the HFD-F1 group. These results demonstrate that paternal obesity triggers transgenerational metabolic dysfunction through sperm H3K27me3-dependent epigenetic regulation. The present study also identifies the H3K27me3-MANF pathway as a potentially preventive and therapeutic strategy for diabetes, although further studies are needed to validate its clinical applicability.

Disorders of the reproductive system, including hypogonadism and reduced fertility, are an under-recognized complication of diabetes. Based on experimental data in mice, hyperglycemia and obesity may modify epigenetic marks in sperm and impact health and development of offspring, but data are more limited in humans. Thus, we sought to study the impact of type 2 diabetes and glycemic control on sperm quality and DNA methylation.

In this prospective cohort study, we recruited 40 men with BMI greater than 25 kg/m2 including 18 with type 2 diabetes, 6 with prediabetes, and 16 normoglycemic controls. Assessments were repeated after 3 months in 9 men with type 2 diabetes and 7 controls. We analyzed reproductive hormones, sperm concentration and motility, and sperm DNA methylation (MethylationEPIC BeadChip).

Men with type 2 diabetes had higher levels of follicle-stimulating hormone (FSH), but similar testosterone levels and sperm quality as controls. Sperm DNA methylation was stable with repeat sampling at 3 months in men with and without type 2 diabetes. We identified differential methylation at 655 of 745,804 CpG sites in men with type 2 diabetes versus controls (FDR < 0.05). Of these, 96.5% showed higher methylation in type 2 diabetes, with a mean difference in DNA methylation (beta value, β) of 0.16 ± 0.004 (16 ± 0.4%). Ontology analysis of differentially methylated loci revealed annotation to genes regulating synaptic signaling, actin, cAMP-dependent pathways, and G protein-coupled receptor pathways. 24% of probes differentially regulated in men with type 2 diabetes versus control overlapped with probes associated with HbA1c, suggesting additional factors beyond glycemic control contributed to diabetes-associated differences in DNA methylation.

Men with type 2 diabetes showed higher DNA methylation levels in sperm relative to normoglycemic controls with similar BMI. Whether these differences are reversible with glucose-lowering treatment or may contribute to post-fertilization transcriptional regulation warrants further investigation.

NCT03860558.

Sperm cryopreservation is a complex process involving gene expression, protein synthesis, membrane stability, and metabolic adaptation. However, molecular alterations in sperm cryopreservation and the mechanisms defending against freezing damage remain poorly understood. This study investigates these changes and defense mechanisms using transcriptomics, proteomics, and metabolomics data. During sperm cryopreservation, the expression level of G protein subunit alpha i3 (GNAI3) was significantly downregulated in post-thaw sperm (P < 0.001), while matrix metallopeptidase 9 (MMP9) was upregulated compared to FS groups (P < 0.01). Additionally, interleukin 6 (IL6) expression in the CS group showed an approximate increase (P < 0.05), whereas ribosomal protein S27a (RPS27A) expression decreased markedly (P < 0.05). Other important molecules such as macrophage stimulating 1 receptor (MST1R), hypoxia-inducible factor 1 subunit alpha (HIF1A), fibroblast growth factor 8 (FGF8), CD9 molecule (CD9), peptidase D (PEPD) and terminal nucleotidyltransferase 5B (TENT5B) also exhibited significant changes in expression (P < 0.05). Moreover, the study revealed the regulatory roles of metabolites such as glucose and glutamic acid during sperm cryopreservation. The involvement of catalase (CAT) protein in antioxidant defense was also noted. The interactions among mRNAs, miRNAs, proteins, and metabolites highlight the critical role of the FoxO signaling pathway in modulating responses to freezing. Our study reveals the molecular regulatory mechanisms of sperm during cryopreservation, emphasizing the importance of the FoxO pathway and specific metabolites in response to cryo-injury. These findings provide deeper insights into the complexity of sperm cryobiology and offer practical guidance for optimizing sperm cryopreservation.

Offspring health outcomes are often linked with epigenetic alterations triggered by maternal nutrition and intrauterine environment. Strong experimental data also link paternal preconception nutrition with pathophysiology in the offspring, but the mechanism(s) routing effects of paternal exposures remain elusive. Animal experimental models have highlighted small non-coding RNAs (sncRNAs) as potential regulators of paternal effects. Here, we characterised the baseline sncRNA landscape of human sperm and the effect of a 6-week dietary intervention on their expression profile. This study involves sncRNAseq profiling, that was performed on a subset (n = 17) of the participants enrolled in the PREPARE trial: 9 from the control group and 8 from the intervention group. 5'tRFs, miRNAs and piRNAs were the most abundant sncRNA subtypes identified; their expression was associated with age, BMI, and sperm quality. Nutritional intervention with olive oil, vitamin D and omega-3 fatty acids altered expression of 3 tRFs, 15 miRNAs and 112 piRNAs, targeting genes involved in fatty acid metabolism and transposable elements in the sperm genome. PREPARE Trial registration number: ISRCTN50956936, Trial registration date: 10/02/2014.

Bisphenol A (BPA) is an "environmental obesogen" and this study aims to investigate the intergenerational impacts of BPA-induced metabolic syndrome (MetS), specifically focusing on unraveling mechanisms. Exposure to BPA induces metabolic disorders in the paternal mice, which are then transmitted to offspring, leading to late-onset MetS. Mechanistically, BPA upregulates Srebf1, which in turn promotes the Pparg-dependent transcription of Dicer1 in spermatocytes, increasing the levels of multiple sperm microRNAs (miRNAs). Several of these miRNAs are highly expressed in a synchronized manner in liver of the offspring. miR149-5p, miR150-5p, and miR700-5p target a specific region in the Lepr 3'UTR, termed "SMITE" ("Several MiRNAs Targeting Elements"), to negatively regulate Lepr. These inherited anti-Lepr miRNAs, also referred to inherited anti-Lepr miRNAs (IAL-miRs), modulate hepatic steatosis, and insulin signaling through the Lepr regulatory Igfbp2, Egfr, and Ampk. Furthermore, IAL-miRs inhibit Ccnd1 not only via binding to "SMITE" but also via Lepr-Igfbp2 axis, which contribute to hepatocyte senescence. These pathological processes interact in a self-reinforcing cycle, worsening MetS in the paternal BPA-exposed offspring. The findings reveal mechanism wherein lipid metabolism reprogramming in spermatocytes-induced perturbations of sperm miRNAs, triggered by BPA, leads to intergenerational inheritance of paternal MetS through suppression of the hepatic Lepr axis in the offspring.

Paternal dietary patterns and obesity can affect offspring through epigenetic signals in sperm RNA. By activating hypothalamic Agouti-related peptide (AgRP) neurons in mice to simulate obesity's effects, we observed changes in the small noncoding RNA payload of sperm. These alterations, particularly in transfer RNA-derived small RNAs (tsRNAs), are similar to those induced by short-term high-fat diets, suggesting a common upstream regulatory mechanism involving AgRP neurons that affects metabolic epigenetic inheritance.

Nutritional challenges and obesity can contribute to the transmission of metabolic diseases through epigenetic mechanisms. Among them, DNA methylation stands out as a potential carrier of information because germline cytosine methylation responds to environmental factors and can be transmitted across generations. Yet, it remains unclear whether inherited DNA methylation plays an active role in the inheritance of metabolic phenotypes or solely influences expression of a few genes that cannot recapitulate the whole metabolic spectrum in the next generation offspring. Previously, we established a mouse model of childhood obesity by reducing litter size at birth. Mice raised in small litters (SL) developed obesity, insulin resistance, and hepatic steatosis. The offspring (SL-F1) and grand-offspring (SL-F2) of SL males also exhibited hepatic steatosis. Here, we aimed to investigate whether germline DNA methylation could serve as a carrier of phenotypic information, hepatic steatosis, between generations. Litter size reduction significantly altered global DNA methylation profile in the sperm of SL-F0 males. Remarkably, 8% of these methylation marks remained altered in the sperm of SL-F1 mice and in the liver of SL-F2 mice. These data suggest that germline DNA methylation is sensitive to environmental challenges and holds significant heritability, either through direct germline transmission and/or through sequential erasure and reestablishment of the marks in the following generations. Yet, DNA methylation did not strongly correlate with the hepatic transcriptome in SL-F2 mice, suggesting that it does not directly drive phenotypes in the F2. As an alternative, germline DNA methylation could potentially influence the phenotype of the next generation by modulating the expression of a reduced number of key transcription factors that, through an amplification cascade, drive phenotypic outcomes in subsequent generations.

Environmental stressors can induce heritable traits in organisms across phyla, with distinct epigenetic alterations in gametes and phenotypic outcomes across several generations. However, the mechanisms underlying such intergenerational inheritance, mainly from the germline to the germline and from the germline to the soma, are enigmatic, given that postfertilization embryos and germline cells reprogram the epigenome in each generation to gain their cellular identity. Here, we report stable germline transmission of differential DNA methylation alterations (epimutations) and their associations with nonalcoholic fatty liver disease (NAFLD) in medaka exposed to a model estrogenic chemical but a ubiquitous environmental contaminant, bisphenol A (BPA).

Ancestral BPA exposure in the F0 generation led to advanced NAFLD in the unexposed grandchildren generation (F2) of medaka. The F2 liver transcriptome and histopathology revealed a severe NAFLD phenotype in females. Whole-genome bisulfite sequencing of the sperm and liver revealed a gradual shift in promoter methylation from F0 sperm (hypomethylated) to F1 sperm (mix of hypo- and hypermethylated) and F2 liver (predominantly hypermethylated). Many differentially methylated promoters (DMPs) overlapped in F0 sperm, F1 sperm, and F2 liver, regardless of sex. In females, stable transmission of 1511 DMPs was found across three generations, which are associated with protein-coding genes, miRNAs, and others and linked to NAFLD and nonalcoholic steatohepatitis (NASH). Among them, 27 canonical genes maintained consistently hypermethylated promoters across three generations, with significant downregulation of their expression and enrichment in NAFLD-related pathways, mainly fat digestion, glycerolipid metabolism, and steroid biosynthesis.

The present results demonstrate stable inter- and transgenerational germline-to-germline and germline-to-soma transmission of environmentally induced DNA epimutations with F0 and F1 gametic epimutations, predicting the F2 liver phenotype-a clear transgenerational passage of the disease phenotype in medaka.

Echoes of natural and anthropogenic stressors not only reverberate within the physiology, biology, and neurobiology of the generation directly exposed to them but also within the biology of future generations. With the intent of understanding this phenomenon, significant efforts have been made to establish how exposure to psychosocial stress, chemicals, over- and undernutrition, and chemosensory experiences exert multigenerational influences. From these studies, we are gaining new appreciation for how negative environmental events experienced by one generation impact future generations. In this review, we first outline the need to operationally define dimensions of negative environmental events in the laboratory and the routes by which the impact of such events are felt through generations. Next, we discuss molecular processes that cause the effects of negative environmental events to be initiated in the exposed generation and then perpetuated across generations. Finally, we discuss how legacies of flourishing can be engineered to halt or reverse multigenerational influences of negative environmental events. In summary, this review synthesizes our current understanding of the concept, causes, and consequences of multigenerational echoes of stress and looks for opportunities to halt them.

Dietary factors may regulate the epigenome. We aimed to explore whether a diet intervention, including excess sugar, affects the methylome in human sperm, and to describe the sperm methylome. We used Whole Genome Bisulfite Sequencing (WGBS) to analyze DNA methylation in sperm taken at three time points from 15 males during a diet intervention; i) at baseline, ii) after one week on a standardized diet, and iii) after an additional week on a high-sugar diet providing 150% of their estimated total energy expenditure.

We identified seven nominal diet-associated differentially methylated regions in sperm (p < 0.05). The diet was nominally associated with methylation of 143 sites linked to fertility (e.g. AHRR, GNAS, and HDAC4), 313 sites in imprinted genes (e.g. GLIS3, PEG10, PEG3, and SNURF), and 42 sites in top 1%-expressed genes (e.g. CHD2) (p < 0.05). In sperm, 3'UTRs and introns had the highest levels of methylation, while 5'UTRs and CpG islands had the lowest levels. Non-expressed genes in human sperm were hypomethylated in exons compared with transcribed genes.

In human sperm, DNA methylation levels were linked to gene expression, and excess sugar had modest effects on methylation on imprinted and highly expressed genes, and genes affecting fertility.

Over the past two decades, the study of sperm-borne small non-coding RNAs (sncRNAs) has garnered substantial growth. Once considered mere byproducts during germ cell maturation, these sncRNAs have now been recognized as crucial carriers of epigenetic information, playing a significant role in transmitting acquired traits from paternal to offspring, particularly under environmental influences. A growing body of evidence highlights the pivotal role of these sncRNAs in facilitating epigenetic inheritance across generations. However, the exact mechanisms through which these paternally supplied epigenetic carriers operate remain unclear and are under hot debate. This concise review presents the most extensive evidence to date on environmentally-responsive sperm-borne sncRNAs, encompassing brief summary of their origin, dynamics, compartmentalization, characteristics, as well as in-depth elaboration of their functional roles in epigenetic and transgenerational inheritance. Additionally, the review delves into the potential mechanisms by which sperm-delivered sncRNAs may acquire and transmit paternally acquired traits to offspring, modulating zygotic gene expression and influencing early embryonic development.

Recent studies support the influence of paternal lifestyle and diet before conception on the health of the offspring via epigenetic inheritance through sperm DNA methylation, histone modification, and small non-coding RNA (sncRNA) expression and regulation. Smoking may induce DNA hypermethylation in genes related to anti-oxidation and insulin resistance. Paternal diet and obesity are associated with greater risks of metabolic dysfunction in offspring via epigenetic alterations in the sperm. Metabolic changes, such as high blood glucose levels and increased body weight, are commonly observed in the offspring of fathers subjected to chronic stress, in addition to an enhanced risk of depressive-like behaviour and increased sensitivity to stress in both the F0 and F1 generations. DNA methylation is correlated with alterations in sperm quality and the ability to fertilise oocytes, possibly via a differentially regulated MAKP81IP3 signalling pathway. Paternal exposure to toxic endocrine-disrupting chemicals (EDCs) is also linked to the transgenerational transmission of increased predisposition to disease, infertility, testicular disorders, obesity, and polycystic ovarian syndrome (PCOS) in females through epigenetic changes during gametogenesis. As the success of assisted reproductive technology (ART) is also affected by paternal diet, BMI, and alcohol consumption, its outcomes could be improved by modifying factors that are dependent on male lifestyle choices and environmental factors. This review discusses the importance of epigenetic signatures in sperm-including DNA methylation, histone retention, and sncRNA-for sperm functionality, early embryo development, and offspring health. We also discuss the mechanisms by which paternal lifestyle and environmental factors (obesity, smoking, EDCs, and stress) may impact the sperm epigenome.

Evidence suggests that paternal diet can influence offspring metabolic health intergenerationally but whether dietary animal and plant proteins differ in their impact on fathers and their offspring is not known. Our objective was to examine the effects of a paternal diet high in casein versus pea protein on fathers and their offspring. Five-week-old male rats were fed: (1) control, (2) high animal protein (AP, 36.1% of energy as casein), or (3) high plant protein (PP, 36.1% of energy as pea protein with added methionine) diets for 8-11 weeks before being mated. Offspring were challenged with a high fat/sucrose diet (HFD) from 10 to 16 weeks of age. Metabolic and microbial outcomes were assessed in both generations. In fathers fed PP diet, enhanced insulin sensitivity and lower liver triglycerides were seen alongside altered hepatic microRNA expression and gut microbial profiles. Few changes were seen in their offspring. In contrast, the paternal AP diet influenced adult offspring hepatic microRNA expression and programmed a latent increase in adiposity, dysregulated satiety hormones, and modified gut microbial composition in their adult offspring that occurred following the HFD. Overall, a diet high in pea protein with added methionine demonstrated protective effects on biomarkers of metabolic health in the fathers but led to minimal effects on the offspring while a paternal diet high in casein led to evidence of an increase in characteristics of metabolic dysfunction in their adult offspring when unmasked by exposure to a HFD for 6 weeks.

Obesity leads to a number of health problems, including learning and memory deficits that can be passed on to the offspring via a developmental programming process. However, the mechanisms involved in the deleterious effects of obesity on cognition remain largely unknown. This study aimed to assess the impact of obesity on the production of sphingolipids (ceramides and sphingomyelins) in the brain and its relationship with the learning deficits displayed by obese individuals. We also sought to determine whether the effects of obesity on brain sphingolipid synthesis could be passed on to the offspring. Learning abilities and brain concentration of sphingolipids in male and female control and obese founder rats (F0) and their offspring (F1) were evaluated, respectively, by the novel object recognition test and by ultra-performance liquid chromatography tandem mass spectrometry. In addition, a global lipidome profiling of the cerebral cortex and hippocampus was performed. Both male and female F0 rats showed impaired learning and increased concentrations of ceramides and sphingomyelins in the hippocampus and frontal cortex compared to their control counterparts. However, the overall lipidome profile of these brain regions did not change with obesity. Remarkably, the alterations in brain sphingolipid synthesis, as well as the cognitive impairment induced by obesity, were also present in adult F1 male rats born to obese mothers or sired by obese fathers and were associated with enhanced expression of mRNAs coding for enzymes involved in the de novo synthesis of ceramides. These results show that the cognitive deficits and impaired sphingolipid metabolism induced by obesity can be transmitted to the offspring through both the maternal and paternal lineages and suggest that an increase in the brain concentration of sphingolipids could play a causal role in the cognitive deficits associated with obesity.

Recent evidence suggests that environmental factors experienced by sires can be transmitted through the ejaculate (seminal plasma + sperm) into the female reproductive tract, influencing fertilization, embryo development, and postnatal offspring outcomes. This concept is termed paternal programming. In rodents, sire nutrition was shown to directly alter offspring outcomes through sperm epigenetic signatures, DNA damage/oxidative stress, cytokine profiles, and/or the seminal microbiome. Response variables impacted in rodent models, including adiposity, muscle mass, metabolic responses, and reproductive performance, could have major productivity and financial implications for producers if these paternal programming responses are also present in ruminant species. However, a paucity of data exist regarding paternal programming in ruminants. The limited data in the literature mainly point to alterations in sperm epigenome as a result of sire diet or environment. Global nutrition has been implicated in ruminant models to alter seminal cytokine profiles, which could subsequently alter the uterine environment and immune response to mating. Several reports indicate that embryo development and epigenetic signatures can be impacted by sire plane of nutrition and inclusion of specific feed ingredients into diets (polyunsaturated fatty acids, folic acid, and rumen protected methionine). Models of sheep nutrition indicate that addition of rumen protected methionine can impact DNA methylation and offspring performance characteristics extending to the F3 generation, and that divergent planes of sire nutrition can cause altered hormone profiles and insulin/glucose metabolism in offspring. There are almost unlimited opportunities for discovery in this area, but researchers are encouraged to target critical questions such as whether and the extent to which paternal programming effects are present in common management scenarios, the mechanisms by which paternal programming is inherited in ruminants, and whether the effects of paternal nutrition interact with those of maternal nutrition to influence offspring physiology, whole animal outcomes, and herd or flock productivity.

Childhood obesity is a significant global health issue with complex and multifactorial origins, often beginning before conception and influenced by both maternal and paternal health. The increased prevalence of prepregnancy obesity and gestational diabetes mellitus in women of reproductive age contributes to a heightened risk of metabolic dysfunction in offspring. Current clinical practices often implement lifestyle interventions after the first trimester and have limited success, implying that they miss a critical window for effective metabolic adjustments. This review examines the limitations of lifestyle interventions during pregnancy in improving perinatal outcomes and highlights the importance of initiating such interventions before conception to positively impact parental health and fetal development. A re-evaluation of strategies is needed to enhance the metabolic health of prospective parents as a preventive measure against childhood obesity.

An increasing number of studies highlight the critical role of both maternal and paternal nutrition and body weight before conception in shaping offspring health. Traditionally, research has focused on maternal factors, particularly in utero exposures, as key determinants of chronic disease development. However, emerging evidence underscores the significant influence of paternal preconception health on offspring metabolic outcomes. While maternal health remains vital, with preconception nutrition playing a pivotal role in fetal development, paternal obesity and poor nutrition are linked to increased risks of metabolic disorders, including type 2 diabetes and cardiovascular disease in children. This narrative review aims to synthesize recent findings on the effects of both maternal and paternal preconception health, emphasizing the need for integrated early interventions. The literature search utilized PubMed, UNF One Search, and Google Scholar, focusing on RCTs; cohort, retrospective, and animal studies; and systematic reviews, excluding non-English and non-peer-reviewed articles. The findings of this review indicate that paternal effects are mediated by epigenetic changes in sperm, such as DNA methylation and non-coding RNA, which influence gene expression in offspring. Nutrient imbalances during preconception in both parents can lead to low birth weight and increased metabolic disease risk, while deficiencies in folic acid, iron, iodine, and vitamin D are linked to developmental disorders. Additionally, maternal obesity elevates the risk of chronic diseases in children. Future research should prioritize human studies to explore the influence of parental nutrition, body weight, and lifestyle on offspring health, ensuring findings are applicable across diverse populations. By addressing both maternal and paternal factors, healthcare providers can better reduce the prevalence of metabolic syndrome and its associated risks in future generations.

The transgenerational effects of exposing male mice to chronic social instability (CSI) stress are associated with decreased sperm levels of multiple members of the miR-34/449 family that persist after their mating through preimplantation embryo (PIE) development. Here we demonstrate the importance of these miRNA changes by showing that restoring miR-34c levels in PIEs derived from CSI stressed males prevents elevated anxiety and defective sociability normally found specifically in their adult female offspring. It also restores, at least partially, levels of sperm miR-34/449 normally reduced in their male offspring who transmit these sex-specific traits to their offspring. Strikingly, these experiments also revealed that inducing miR-34c levels in PIEs enhances the expression of its own gene and that of miR-449 in these cells. The same induction of embryo miR-34/449 gene expression likely occurs after sperm-derived miR-34c is introduced into oocytes upon fertilization. Thus, suppression of this miRNA amplification system when sperm miR-34c levels are reduced in CSI stressed mice can explain how a comparable fold-suppression of miR-34/449 levels can be found in PIEs derived from them, despite sperm containing ~50-fold lower levels of these miRNAs than those already present in PIEs. We previously found that men exposed to early life trauma also display reduced sperm levels of miR-34/449. And here we show that miR-34c can also increase the expression of its own gene, and that of miR-449 in human embryonic stem cells, suggesting that human PIEs derived from men with low sperm miR-34/449 levels may also contain this potentially harmful defect.

Paternal obesity has been implicated in adult-onset metabolic disease in offspring. However, the molecular mechanisms driving these paternal effects and the developmental processes involved remain poorly understood. One underexplored possibility is the role of paternally induced effects on placenta development and function. To address this, we investigated paternal high-fat diet-induced obesity in relation to sperm histone H3 lysine 4 tri-methylation signatures, the placenta transcriptome, and cellular composition. C57BL6/J male mice were fed either a control or high-fat diet for 10 weeks beginning at 6 weeks of age. Males were timed-mated with control-fed C57BL6/J females to generate pregnancies, followed by collection of sperm, and placentas at embryonic day (E)14.5. Chromatin immunoprecipitation targeting histone H3 lysine 4 tri-methylation (H3K4me3) followed by sequencing (ChIP-seq) was performed on sperm to define obesity-associated changes in enrichment. Paternal obesity corresponded with altered sperm H3K4me3 at promoters of genes involved in metabolism and development. Notably, altered sperm H3K4me3 was also localized at placental enhancers. Bulk RNA-sequencing on placentas revealed paternal obesity-associated sex-specific changes in expression of genes involved in hypoxic processes such as angiogenesis, nutrient transport, and imprinted genes, with a subset of de-regulated genes showing changes in H3K4me3 in sperm at corresponding promoters. Paternal obesity was also linked to impaired placenta development; specifically, a deconvolution analysis revealed altered trophoblast cell lineage specification. These findings implicate paternal obesity effects on placenta development and function as one potential developmental route to offspring metabolic disease.

The widespread use of microplastics and their harmful effects on the environment have emerged as serious concerns. However, the effect of microplastics on the immune system of mammals, particularly their offspring, has received little attention. In this study, polystyrene microplastics (PS-MPs) were orally administered to male mice during lactation. Flow cytometry was used to assess the immune cells in the spleens of both adult male mice and their offspring. The results showed that mice exposed to PS-MPs exhibited an increase in spleen weight and an elevated number of B and regulatory T cells (Tregs), irrespective of dosage. Furthermore, the F1 male offspring of the PS-MPs-exposed group had enlarged spleens; an increased number of B cells, T helper cells (Th cells), and Tregs; and an elevated ratio of T helper cells 17 (Th17 cells) to Tregs and T helper cells 1 (Th1 cells) to T helper cells 2 (Th2 cells). These results suggested a pro-inflammatory state in the spleen. In contrast, in the F1 female offspring exposed to PS-MPs, the changes in splenic immune cells were less pronounced. In the F2 generation of mice with exposed to PS-MPs, minimal alterations were observed in spleen immune cells and morphology. In conclusion, our study demonstrated that exposure to real human doses of PS-MPs during lactation in male mice altered the immune status, which can be passed on to F1 offspring but is not inherited across generations.

Numerous studies have suggested potential associations between maternal subclinical hypothyroidism (SCH) and adverse metabolic outcomes in offspring, however, the underlying mechanism remains unclear. In this study, we generated a maternal SCH mouse model by administering 50 ppm 6-propyl-2-thiouracil (PTU) in the drinking water of pregnant mice until delivery. This model was used to investigate the mechanisms influencing glucose metabolism in offspring. RNA sequencing (RNA-seq) revealed a substantial increase in ARRDC3 expression in the livers of the offspring of the SCH model mice, which may contribute to insulin resistance. Additionally, the phosphorylation levels of key proteins in the insulin signalling pathway, such as protein kinase B (Akt), glycogen synthase kinase 3 beta (GSK-3β), and Forkhead box protein O1 (FoxO1), were correspondingly reduced in the SCH offspring. Moreover, overexpression of ARRDC3 in Hepa1‒6 cells suppressed the Akt/GSK-3β/FoxO1 signalling pathway and increased the expression of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK), which was consistent with the molecular changes observed in SCH offspring. Our results also indicated that the upregulation of ARRDC3 in SCH offspring may result from increased H3K27 acetylation of the ARRDC3 promoter region, driven by elevated expression of P300. Importantly, adequate L-T4 supplementation during pregnancy improved insulin sensitivity and reversed the molecular alterations in the insulin signalling pathway observed in SCH offspring. In conclusion, exposure to intrauterine SCH resulted in altering the P300-ARRDC3 axis in offspring and impaired insulin sensitivity by disrupting the Akt/GSK-3β/FoxO1 signalling pathway. Timely L-T4 supplementation during pregnancy is an effective strategy to prevent insulin resistance in offspring of SCH mothers. This study elucidates potential molecular mechanisms behind insulin resistance in SCH offspring and suggests novel therapeutic targets for treating metabolic disorders related to maternal SCH.

The effects of chronically stressing male mice can be transmitted across generations by stress-specific changes in their sperm miRNA content that induce stress-specific phenotypes in their offspring. But how each stress paradigm alters the levels of distinct sets of sperm miRNAs is not known. We showed previously that exposure of male mice to chronic social instability (CSI) stress results in elevated anxiety and reduced sociability specifically in their female offspring across multiple generations because it reduces miR-34c levels in sperm of stressed males and their unstressed male offspring. Here we describe evidence that a strocyte-derived exos omes ( A-Exos ) carrying miR-34c mediate how CSI stress has this transgenerational effect on sperm. We found that CSI stress decreases miR-34c carried by A-Exos in the prefrontal cortex and amygdala, as well as in the blood of males. Importantly, miR-34c A-Exos levels are also reduced in these tissues in their F1 male offspring, who despite not being exposed to stress exhibit reduced sperm miR-34c levels and transmit the same stress-associated traits to their male and female offspring. Furthermore, restoring A-Exos miR-34c content in the blood of CSI-stressed males by intravenous injection of miR-34c-containing A-Exos restores miR-34c levels in their sperm. These findings reveal an unexpected role for A-Exos in maintaining sperm miR-34c levels by a process that when suppressed by CSI stress mediates this example of transgenerational epigenetic inheritance.

It is unclear whether parental consumption of non-nutritive sweetener (NNS) can affect subsequent generations. The aim of this study was to determine whether chronic parental consumption of sucralose and stevia in mice affects body weight gain and liver and intestinal expression of histone deacetylase 3 (Hdac3) in these animals and in the subsequent first filial (F1) and second filial (F2) generations.

Male and female mice (n = 47) were divided into three groups to receive water alone or supplemented with sucralose (0.1 mg/mL) or stevia (0.1 mg/mL) for 16 wk (parental [F0] generation). F0 mice were bred to produce the F1 generation; then, F1 mice were bred to produce the F2 generation. F1 and F2 animals did not receive NNSs. After euthanasia, hepatic and intestinal expression of Hdac3 was determined by quantitative reverse transcription polymerase chain reaction.

Body weight gain did not differ between the three groups in the F0 generation, but it was greater in the F1 sucralose and stevia groups than in the control group. Consumption of both NNSs in the F0 generation was associated with lower Hdac3 expression in the liver and higher in the intestine. Hepatic Hdac3 expression was normalized to the control values in the F1 and F2 animals of the sucralose and stevia groups. Intestinal expression was still higher in the F1 generations of the sucralose and stevia groups but was partially normalized in the F2 generation of these groups, compared with control.

NNS consumption differentially affects hepatic and intestinal Hdac3 expression. Changes in hepatic expression are not transmitted to the F1 and F2 generations whereas those in intestinal expression are enhanced in the F1 and attenuated in the F2 generations.

Obesity poses a public health threat, reaching epidemic proportions. Our hypothesis suggests that some of this epidemic stems from its transmission across generations via paternal epigenetic mechanisms. To investigate this possibility, we focused on examining the paternal transmission of CpG methylation. First-generation male Wistar rats were fed either a high-fat diet (HF) or chow and were mated with females fed chow. We collected sperm from these males. The resulting offspring were raised on a chow diet until day 35, after which they underwent a dietary challenge. Diet-induced obese (DIO) male rats passed on the obesogenic trait to both male and female offspring. We observed significant hypermethylation of the Pomc promoter in the sperm of HF-treated males and in the hypothalamic arcuate nucleus (Arc) of their offspring at weaning. However, these differences in Arc methylation decreased later in life. This hypermethylation is correlated with increased expression of DNMT3B. Further investigating genes in the Arc that might be involved in obesogenic transgenerational transmission, using reduced representation bisulfite sequencing (RRBS) we identified 77 differentially methylated regions (DMRs), highlighting pathways associated with neuronal development. These findings support paternal CpG methylation as a mechanism for transmitting obesogenic traits across generations.

Several studies have reported side effects of finasteride (FIN), such as anxiety/depression in young men. Obesity is also positively associated with anxiety/depression symptoms; however, the impacts of long-term FIN treatment and FIN withdrawal in young obese individuals are still elusive. The present study aimed to investigate the effect of long-term treatment and its withdrawal on anxiety/depression and brain pathologies in lean and obese adult male rats. Forty-eight male Wistar rats were equally divided into two groups and fed either a normal or high-fat diet. At age 13 weeks, rats in each dietary group were divided into three subgroups: 1) the control group receiving drinking water, 2) the long-term treatment group receiving FIN orally at 5 mg/kg/day for 6 weeks, and 3) the withdrawal group receiving FIN orally at 5 mg/kg/day for 2 weeks followed by a 4-week withdrawal period. Anxiety/depression-like behaviors, biochemical analysis, brain inflammation, oxidative stress, neuroactive steroids, brain metabolites, and microglial complexity were tested. The result showed that lean rats treated with long-term FIN and its withdrawal exhibited metabolic disturbances, depressive-like behavior, and both groups showed increased neurotoxic metabolites and reduced microglial complexity. Obesity itself led to metabolic disturbances and brain pathologies, including increased inflammation, oxidative stress, and quinolinic acid, as well as reduced microglial complexity, resulting in increased anxiety- and depression-like behaviors. Interestingly, the long-term FIN treatment group in obese rats showed attenuation of depressive-like behaviors, brain inflammation, and oxidative stress, along with increased brain antioxidants, suggesting the possible benefits of FIN in obese conditions.

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

The increasing global burden of metabolic disorders including obesity and diabetes necessitates a comprehensive understanding of their etiology, which not only encompasses genetic and environmental factors but also parental influence. Recent evidence has unveiled paternal obesity as a contributing factor to offspring's metabolic health via sperm epigenetic modifications. In this study, we investigated the impact of a Western diet-induced obesity in C57BL/6 male mice on sperm chromatin accessibility and the subsequent metabolic health of their progeny. Utilizing Assay for Transposase-Accessible Chromatin with sequencing, we discovered 450 regions with differential accessibility in sperm from obese fathers, implicating key developmental and metabolic pathways. Contrary to expectations, these epigenetic alterations in sperm were not predictive of long-term metabolic disorders in offspring, who exhibited only mild transient metabolic changes early in life. Both male and female F1 progeny showed no enduring predisposition to obesity or diabetes. These results underscore the biological resilience of offspring to paternal epigenetic inheritance, suggesting a complex interplay between inherited epigenetic modifications and the offspring's own developmental compensatory mechanisms. This study calls for further research into the biological processes that confer this resilience, which could inform interventional strategies to combat the heritability of metabolic diseases.

There have been many significant scientific advances in the diagnostics and treatment modalities in the field of male infertility in recent decades. Examples of these include assisted reproductive technologies, sperm selection techniques for intracytoplasmic sperm injection, surgical procedures for sperm retrieval, and novel tests of sperm function. However, there is certainly a need for new developments in this field. In this review, we discuss advances in the management of male infertility, such as seminal oxidative stress testing, sperm DNA fragmentation testing, genetic and epigenetic tests, genetic manipulations, artificial intelligence, personalized medicine, and telemedicine. The role of the reproductive urologist will continue to expand in future years to address different topzics related to diverse questions and controversies of pathophysiology, diagnosis, and therapy of male infertility, training researchers and physicians in medical and scientific research in reproductive urology/andrology, and further development of andrology as an independent specialty.

Diabetes constitutes a significant global public health challenge that is rapidly reaching epidemic proportions. Among the non-communicable diseases, the incidence of diabetes is rising at an alarming rate. The International Diabetes Federation has documented a 9.09% prevalence of diabetes among individuals aged between 20 and 79 years. The interplay of gonadal hormones and gender differences is critical in regulating insulin sensitivity and glucose tolerance, and this dynamic is particularly crucial because of the escalating incidence of diabetes. Variations in insulin sensitivity are observed across genders, levels of adiposity, and age groups. Both estrogen and testosterone are seen to influence glucose metabolism and insulin sensitivity. This chapter surveys the present knowledge of sex differences, sex hormones, and chromosomes on insulin imbalance and diabetes development. It further highlights the influence of metabolic traits in diabetes and changes in sex hormones during diabetic pregnancy. Notably, even stressful lifestyles have been acknowledged to induce hormonal imbalances. Furthermore, it discusses the potential of hormonal therapy to help stabilize sex hormones in diabetic individuals and focuses on the most recent research investigating the correlation between sex hormones and diabetes.

The prevalence of infertility among couples is estimated to range from 8 to 12%. A paradigm shift has occurred in understanding of infertility, challenging the notion that it predominantly affects women. It is now acknowledged that a significant proportion, if not the majority, of infertility cases can be attributed to male-related factors. Various elements contribute to male reproductive impairments, including aberrant sperm production caused by pituitary malfunction, testicular malignancies, aplastic germ cells, varicocele, and environmental factors.

The epigenetic profile of mammalian sperm is distinctive and specialized. Various epigenetic factors regulate genes across different levels in sperm, thereby affecting its function. Changes in sperm epigenetics, potentially influenced by factors such as environmental exposures, could contribute to the development of male infertility.

In conclusion, this review investigates the latest studies pertaining to the mechanisms of epigenetic changes that occur in sperm cells and their association with male reproductive issues.

Often associated with obesity, male infertility represents a widespread condition that challenges the wellbeing of the couple. In this article, we provide a comprehensive and critical analysis of studies exploring the association between obesity and male reproductive function, to evaluate the frequency of this association, and establish the effects of increased body weight on conventional and biofunctional sperm parameters and infertility. In an attempt to find possible molecular markers of infertility in obese male patients, the numerous mechanisms responsible for infertility in overweight/obese patients are reviewed in depth. These include obesity-related functional hypogonadism, insulin resistance, hyperinsulinemia, chronic inflammation, adipokines, irisin, gut hormones, gut microbiome, and sperm transcriptome. According to meta-analytic evidence, excessive body weight negatively influences male reproductive health. This can occurr through a broad array of molecular mechanisms. Some of these are not yet fully understood and need to be further elucidated in the future. A better understanding of the effects of metabolic disorders on spermatogenesis and sperm fertilizing capacity is very useful for identifying new diagnostic markers and designing therapeutic strategies for better clinical management of male infertility.