POHaD: why we should study future fathers

Effects of semen inflammation on embryo implantation, placentation, pregnancy outcomes and offspring health

This review explores the critical role of semen inflammation in sperm quality, embryo implantation, placentation, and its broader implications on reproductive health. Chronic inflammation of the male genital tract has been increasingly recognized as a significant factor contributing to infertility. This inflammation not only impairs semen quality but also disrupts the intricate immune cross-talk between the male and female genital tracts, which is essential for successful implantation, placentation and pregnancy. The review synthesizes existing research on the mechanisms by which inflammatory mediators in semen influence the female immune environment, leading to altered uterine receptivity, placental formation, and embryo implantation. Furthermore, the impact of these disruptions on the health and development of the offspring is discussed, highlighting the transgenerational effects of male genital tract inflammation. Through an examination of both animal models and human studies, this review underscores the need for a deeper understanding of the immune interactions in reproductive biology and the potential for novel therapeutic interventions aimed at mitigating the adverse outcomes associated with semen inflammation.

Healthy Lifestyle in the First 1000 Days and Overweight and Obesity Throughout Childhood

OBJECTIVES

Investigate associations of different family healthy lifestyle scores (HLS) during the first 1000 days with childhood overweight and obesity (OWOB).

METHODS

Cohort-specific analyses were conducted on participants (n = 25 006) from 4 European birth cohorts (The study on the pre- and early postnatal determinants of child health and development [EDEN], Elfe, France; Generation R, the Netherlands; and Lifeways, Ireland). Three composite HLSs were calculated: a maternal pregnancy HLS based on prepregnancy body mass index (BMI) and diet quality, physical activity, smoking status, and alcohol consumption during pregnancy; a parental pregnancy HLS additionally considering paternal BMI and smoking status; and an infancy HLS based on breastfeeding duration, age of solid food introduction, and exposure to passive smoking. Associations with child BMI (primary outcome) and waist-to-height ratio (WHtR, available in 2 cohorts) in early (5-5.5 years), middle (7-8 years), and late childhood (9-12 years) were assessed using linear (BMI and WHtR z-scores) and robust Poisson (International Obesity Task Force [IOTF] categories) regression analyses adjusted for sociodemographic confounders.

RESULTS

Only a small proportion of families had favorable lifestyle factors during pregnancy and early infancy, with 3.4% to 10.0%, 1.9% to 3.7%, and 12.2% to 23.6% scoring maximum for maternal, parental, and infancy HLS, respectively. Associations between higher HLSs and a lower risk of OWOB when measured by BMI z-scores or IOTF categories were found for maternal HLS and early (3/4 cohorts with available data), middle (1/2), and late childhood (2/4); parental HLS and early (3/4), middle (2/2), and late childhood (4/4). Associations between infancy HLS and childhood OWOB were less consistent and did not remain significant after additional adjustment for parental HLS. Associations with WHtR were solely significant in EDEN at 5.5 years.

CONCLUSIONS

Greater maternal and parental adherence to healthy lifestyle behaviors during pregnancy was associated with a lower risk of offspring OWOB throughout childhood, illustrating the importance of promoting healthy lifestyle behaviors at the family level during pregnancy.

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

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

Investigating male factors and their relationships with reproductive health outcomes: a case-control study protocol for Towards Optimal Fertility, Fathering, and Fatherhood studY (TOFFFY) in Singapore

INTRODUCTION

Despite the global prevalence of low fertility rates, male contributions to fertility and reproductive health outcomes have been understudied. This study aims to investigate the male contribution to fertility and explore the underlying biological mechanisms. Specifically, we aim to (1) identify male factors associated with successful pregnancy, (2) develop a fertility index incorporating modifiable factors for both males and females to predict pregnancy rate and (3) explore the relationship of male modifiable factors with semen parameters and molecular characteristics.

METHODS AND ANALYSIS

We will conduct an unmatched case-control study involving 240 couples with impaired male fertility (cases) and 240 couples with normal male fertility (controls). Between July 2024 and June 2026, we will recruit 480 eligible couples from KK Women's and Children's Hospital, Singapore. Male and female participants will complete questionnaires on sociodemographics, general health and lifestyle factors, and their anthropometry and body fat composition will be measured. Blood and semen samples from the male participants will be collected for biochemical, molecular and semen analyses. Predictive male factors will be identified using the least absolute shrinkage and selection operator method, accounting for female factors. We will construct a logistic regression model incorporating both male and female factors to derive a fertility index, which will be evaluated using cross-validation on subsets of the study population. Multivariable linear regression will be used to explore relationships between male modifiable exposures and semen parameters.

ETHICS AND DISSEMINATION

The study protocol has received approval from the Centralised Institutional Review Board of SingHealth (2024/2120), Singapore. Participants will provide written informed consent. Study results will be disseminated through conferences and peer-reviewed scientific journals.

TRIAL REGISTRATION NUMBER

NCT06293235.

Associations between a paternal healthy lifestyle score and its individual components with childhood overweight and obesity

BACKGROUND

Maternal healthy lifestyle behaviors during pregnancy have been associated with reduced risk of offspring overweight and obesity (OWOB). However, there has been little investigation, in the context of the Paternal Origins of Health and Disease (POHaD) paradigm, of the potential influence of the paternal lifestyle on offspring OWOB.

OBJECTIVES

To describe paternal healthy lifestyle factors around pregnancy and investigate their associations, individually and combined, with offspring risk of OWOB during childhood.

MATERIALS AND METHODS

Participants included 295 father-child pairs from the Lifeways Cross-Generation Cohort Study. A composite paternal healthy lifestyle score (HLS) based on having a high dietary quality (top 40% of the Healthy Eating Index-2015), meeting physical activity guidelines (≥450 MET-min/week of moderate-to-vigorous physical activity), having a healthy body mass index (BMI) (18.5-24.9 kg/m2), being a non-smoker, and having no/moderate alcohol intake, was calculated (range 0-5). Paternal HLS (and individual components) associations with child BMI and waist-to-height ratio (WHtR) at age 5 and 9 years were assessed using linear (BMI z-scores and WHtR) and logistic (IOTF categories) regression analyses, adjusted for sociodemographic characteristics.

RESULTS

At age 5 and 9 years, 23.5% and 16.9% of children were classified as living with OWOB, respectively. Of the 160 pairs with a complete HLS, 45.0% of the fathers had unfavorable lifestyle factors, determined by a low HLS between 0 and 2 points. Although a low paternal HLS was not significantly associated with a higher risk of childhood OWOB measured using either BMI z-scores and IOTF categories, it was associated with a greater child WHtR, an indicator of central adiposity, at 9 years of age (β [95% CI] = 0.04 [0.01,0.07]).

DISCUSSION AND CONCLUSION

Almost half of the fathers had unfavorable lifestyle factors around pregnancy. A low paternal HLS was associated with a greater child WHtR at 9 years but not with a higher risk of childhood OWOB when measured by BMI z-scores or IOTF categories.

The role of ferroptosis in environmental pollution-induced male reproductive system toxicity

This article provides a comprehensive review of the toxic effects of environmental pollution on the male reproductive system, with a particular emphasis on ferroptosis, a form of programmed cell death. Research has shown that environmental pollutants, such as heavy metals, pesticide residues, and plastic additives, can disrupt oxidative stress, increasing the production of reactive oxygen species (ROS) in germ cells. This disruption damages cellular lipids, proteins, and DNA, culminating in cell dysfunction or death. Ferroptosis, a cell death pathway closely linked to oxidative stress, is characterized by the accumulation of intracellular iron ions and elevated levels of lipid ROS. This review also explores the role of ferroptosis in male reproductive disorders, including its contributions to reduced sperm count, decreased motility, and abnormal morphology. Environmental pollutants, particularly heavy metals, can induce ferroptosis by interfering with intracellular antioxidant systems, notably the NRF2, GSH, and GPX4 pathways, accumulating toxic lipid peroxides. Furthermore, the article examines the potential interplay between ferroptosis and other forms of cell death, such as apoptosis, autophagy, pyroptosis, and necrosis, in the context of male reproductive health. The review underscores the critical need for further research into the link between environmental pollutants and male fertility, particularly focusing on ferroptosis. It advocates for targeted research efforts to mitigate the adverse effects of ferroptosis and protect reproductive health, emphasizing that a deeper understanding of these mechanisms could lead to innovative preventive strategies against environmental threats to fertility.

Why do preconception and pregnancy lifestyle interventions demonstrate limited success in preventing overweight and obesity in children? A scoping review investigating intervention complexity, process evaluation components, and author interpretations

Preventing childhood obesity from early life is considered essential. However, evidence from recent systematic reviews has highlighted inconsistent results and limited effectiveness of preconception and pregnancy lifestyle interventions regarding offspring weight outcomes and adiposity. Therefore, to improve our understanding regarding the mixed success of these early life interventions, we conducted a scoping review examining intervention complexity, process evaluation components, and authors' statements. Eligible articles (preconception or pregnancy lifestyle trials with offspring data beyond 1 month of age) were identified by searching databases (PubMed, Embase, and CENTRAL), previous reviews, and performing CLUSTER searches. The Intervention Complexity Assessment Tool for Systematic Reviews (iCAT_SR) was used to evaluate intervention complexity. A thematic analysis provided insight into process evaluation components and authors' interpretations. Finally, an expert consultation on the results was conducted. We identified 40 eligible publications corresponding to 27 trials. Only two trials started before conception. Potential reasons for interventions' limited success included the late intervention initiation, short intervention duration, and insufficient sample size. Few studies reported process evaluations and included stakeholder involvement, which are essential according to the expert group. We discuss current limitations and outline suggestions for future interventions in this field of research.

Relationship between paternal excessive weight and neonatal anthropometry in a clinical trial of nutritional counseling for pregnant women with overweight

BACKGROUND/OBJECTIVES

Human studies suggest that fathers with obesity influence infant growth and development. This study aimed to evaluate the relationship between paternal body mass index (BMI) and waist circumference (WC) with neonatal anthropometry and adiposity.

METHODS

This study is a cohort nested in a randomized controlled clinical trial of nutritional counseling for pregnant women with overweight. In total, 89 partner-pregnant woman-neonate triads were included. Paternal anthropometric measurements were taken at the time of the interview. Secondary data related to birth were obtained through access to the health information systems. Neonatal skinfold thickness was assessed and the adiposity was estimated using a predictive anthropometric model. Pearson's correlation and adjusted multivariate linear regression models were employed to evaluate the relationship between paternal BMI and WC with neonatal anthropometric measurements and adiposity.

RESULTS

In total, 57.0% of the fathers presented a BMI ≥ 25 kg/m² and 14.6% a waist circumference ≥102 cm. The mean ± SD birth weight of the newborns (g) was 3357 ± 538. Paternal BMI and WC were inversely correlated with head circumference at birth [r = -0.31 (p = 0.004), r = -0.23 (p = 0.03), respectively]. Paternal BMI was also inversely correlated with the birth weight standardized by gestational age (z-score) [r = -0.23 (p = 0.03)]. In adjusted multivariate linear regression models, the paternal BMI (kg/m²) was inversely associated with the head circumference at birth (cm) [β = -0.07 (95% CI -0.15; -0.001) p = 0.04].

CONCLUSION

The data suggest that paternal excessive weight have a negative effect on fetal development, as assessed by anthropometric measurements. The inverse association between paternal BMI and the head circumference at birth was independent of confounders. Future studies with larger sample sizes are necessary to confirm or refute such hypotheses.

Impact of sperm sex sorting on sperm quality and in vitro embryo production in bovine

Increasing evidence suggests that environmental exposures can modify epigenetic marks in the germline, leading to the transmission of abnormal post-fertilization sperm epigenetic indicators and affecting embryonic development. Given the pivotal role of sperm cells in determining embryo quality, there is growing interest in understanding the potential effects of sperm sex sorting on embryo quality. This study aimed to investigate the impact of bovine sperm sexing on in vitro embryo production (IVP) and to associate molecular aspects of embryos analysis. Frozen semen samples from five Nellore bulls were used, with each bull contributing unsexed sperm (conventional semen - CV treatment) and female and male sexed sperm pooled after thawing (SX treatment). First, semen quality was assessed, including motility, morphology, acrosome integrity, and chromatin integrity to denaturation. Then, IVP was carried out, focusing on embryonic production and developmental kinetics. In the third experiment, embryo quality was evaluated by examining the gene expression of key markers (OCT4, NANOG, DNMT3A, TET1, and Fematrin-1) and the methylation pattern of the Satellite-1 and α-Satellite genes in blastocysts. Differences between CV and SX semen were only observed in motility, which was lower in SX compared with CV (P < 0.05). Although cleavage was similar, the SX groups showed lower blastocyst production than CV (P < 0.05). Of the genes evaluated, only NANOG showed high expression in the CV blastocysts compared with the SX blastocysts, but the methylation pattern revealed no differences. In conclusion, sex sorting markedly affects sperm motility and in vitro embryo production but showed no significant impact on embryo quality.

Orally Administered Silver Nanoparticles Are Absorbed and Migrate to Testes in Mice

Given that daily exposure to nanoparticles is now unavoidable, there are concerns that nanoparticles have unexpected biological effects due to their small size. Here, we examined the biodistribution of silver nanoparticles, which are the most frequently used nanoparticles owing to their antibacterial activity, with a diameter of 10 nm (nAg10) to the male genital tract, and the effects of paternal treatment with nAg10 on fetal development. Male Slc:ICR male mice were orally treated with nAg10 for 14 consecutive days. Inductively coupled plasma mass spectrometry analysis detected silver in the blood and testis of male mice, but no general toxicological effects were induced. Moreover, there were no significant changes in fetal development when these treated male mice were mated with nontreated female mice. This implies that although orally ingested nAg10 is distributed to the male genital tract, it does not affect fetal development under the present treatment conditions.

Sperm Metabolism

Bioenergetics plays a crucial role in sperm functions, including motility, capacitation-related protein modifications, oocyte recognition and interaction, all of which are essential for fertilization. Sperm metabolism is recognized as flexible, responding to environmental cues and energetic demands during ejaculation, the journey along the female tract, and until fertilization. Recent studies suggest that sperm metabolic functions are relevant beyond fertilization and may influence zygote and embryo development, impacting paternal-derived effects on offspring development and health. In recent years, sperm metabolic functions and homeostasis have gained increasing interest in male reproduction research. Given the crucial implications of sperm metabolism on fertility-related processes, this field is of interest not only in human male fertility but also in livestock research, semen conservation, and assisted reproductive techniques. Newly developed assessment tools are allowing a better understanding of sperm metabolism under different conditions and identifying species-specific peculiarities. This review aims to discuss the current knowledge of mammalian sperm metabolism, focusing on species-specific features, changes during the sperm journey, and potential contributions to translational research and reproductive biotechnologies. Furthermore, we propose future perspectives on sperm bioenergetics research.

Paternal preconception donepezil exposure enhances learning in offspring

BACKGROUND

Recent research has indicated that parental use of central nervous system-targeting medications during periconceptional periods may affect offspring across various developmental and behavioral domains. The present study sought to investigate the potential influence of paternal use of donepezil, a specific reversible central acetylcholinesterase inhibitor that activates the cholinergic system to promote cognition, on offspring.

RESULTS

In this study, male rats were bred after 21 days of oral donepezil administration at a dose of 4 mg/kg to generate F1 offspring. Both male and female F₁ offspring displayed enhanced performance in learning and short-term memory tests, including novel object recognition, Y maze, and operant learning. Transcriptomic analysis revealed notable alterations in genes associated with the extracellular matrix in the hippocampal tissue of the F1 generation. Integration with genes related to intelligence identified potential core genes that may be involved in the observed behavioral enhancements.

CONCLUSIONS

These findings indicate that prolonged paternal exposure to donepezil may enhance the learning and memory abilities of offspring, possibly by targeting nonneural, extracellular regions. Further research is required to fully elucidate any potential transgenerational effects.

Influence of substance use on male reproductive health and offspring outcomes

The prevalence of substance use globally is rising and is highest among men of reproductive age. In Africa, and South and Central America, cannabis use disorder is most prevalent and in Eastern and South-Eastern Europe, Central America, Canada and the USA, opioid use disorder predominates. Substance use might be contributing to the ongoing global decline in male fertility, and emerging evidence has linked paternal substance use with short-term and long-term adverse effects on offspring development and outcomes. This trend is concerning given that substance use is increasing, including during the COVID-19 pandemic. Preclinical studies have shown that male preconception substance use can influence offspring brain development and neurobehaviour through epigenetic mechanisms. Additionally, human studies investigating paternal health behaviours during the prenatal period suggest that paternal tobacco, opioid, cannabis and alcohol use is associated with reduced offspring mental health, in particular hyperactivity and attention-deficit hyperactivity disorder. The potential effects of paternal substance use are areas in which to focus public health efforts and health-care provider counselling of couples or individuals interested in conceiving.

Influence of paternal preconception health on pregnancy, intrapartum, postpartum and early childhood outcomes: protocol for a parallel scoping review

INTRODUCTION

Preconception care is the provision of behavioural, social or biomedical interventions to women and couples prior to conception. To date, preconception research has primarily focused on maternal health, despite the male partner's contribution before birth to both short-term and long-term child outcomes. The objectives of the reviews are: (1) to identify, consolidate and analyse the literature on paternal preconception health on pregnancy and intrapartum outcomes, and (2) to identify, consolidate and analyse the literature on paternal preconception health on postpartum and early childhood outcomes.

METHODS AND ANALYSIS

A scoping review will be conducted following the Joanna Briggs Institute methodology. MEDLINE, PsycINFO, Embase, Scopus and CINAHL databases will be searched for articles published in English. Two independent reviewers will screen titles and abstracts and then full text using Covidence, with conflicts resolved by a third reviewer. Data extraction will be performed using Covidence.

ETHICS AND DISSEMINATION

Ethics approval is not required for this scoping review. Results will be published in peer-reviewed journals as well as presented at relevant national and international conferences and meetings.

Paternal exposures to endocrine-disrupting chemicals induce intergenerational epigenetic influences on offspring: A review

Endocrine-disrupting chemicals (EDCs) are ubiquitous in ecological environments and have become a great issue of public health concern since the 1990 s. There is a deep scientific understanding of the toxicity of EDCs. However, recent studies have found that the abnormal physiological functions of the parents caused by EDCs could be transmitted to their unexposed offspring, leading to intergenerational toxicity. We questioned whether sustained epigenetic changes occur through the male germline. In this review, we (1) systematically searched the available research on the intergenerational impacts of EDCs in aquatic and mammal organisms, including 42 articles, (2) summarized the intergenerational genetic effects, such as decreased offspring survival, abnormal reproductive dysfunction, metabolic disorders, and behavioral abnormalities, (3) summarized the mechanisms of intergenerational toxicity through paternal interactions, and (4) propose suggestions on future research directions to develop a deeper understanding of the ecological risk of EDCs.

Intra-uterine programming of future fertility

The developmental origins of health and disease (DOHaD) shows that a relationship exists between parental environment at large, foeto-placental development and the risk for the offspring to develop non-transmittable disease(s) in adulthood. This concept has been validated in both humans and livestock. In mammals, after fertilization and time spent free in the maternal reproductive tract, the embryo develops a placenta that, in close relationship with maternal endometrium, is the organ responsible for exchanges between dam and foetus. Any modification of the maternal environment can lead to adaptive mechanisms affecting placental morphology, blood flow, foetal-maternal exchanges (transporters) and/or endocrine function, ultimately modifying placental efficiency. Among deleterious environments, undernutrition, protein restriction, overnutrition, micronutrient deficiencies and food contaminants can be outlined. When placental adaptive capacities become insufficient, foetal growth and organ formation is no longer optimal, including foetal gonadal formation and maturation, which can affect subsequent offspring fertility. Since epigenetic mechanisms have been shown to be key to foetal programming, epigenetic modifications of the gametes may also occur, leading to inter-generational effects. After briefly describing normal gonadal development in domestic species and inter-species differences, this review highlights the current knowledge on intra-uterine programming of offspring fertility with a focus on domestic animals and underlines the importance to assess transgenerational effects on offspring fertility at a time when new breeding systems are developed to face the current climate changes.

Paternal Prenatal and Lactation Exposure to a High-Calorie Diet Shapes Transgenerational Brain Macro- and Microstructure Defects, Impacting Anxiety-Like Behavior in Male Offspring Rats

Prenatal exposure to high-energy diets (HED) increases the susceptibility to behavioral alterations in the male offspring. We addressed whether prenatal HED primes the transgenerational inheritance of structural brain changes impacting anxiety/depression-like behavior in the offspring. For this, we used female Wistar rats exposed to a HED [cafeteria (CAF) diet, n = 6] or chow [control (CON) n = 6] during development. Anxiety and depression-like behavior were evaluated in filial 1 (F1), filial 2 (F2), and filial 3 (F3) male offspring using the open field (OFT), elevated plus maze, novelty suppressed feeding (NSFT), tail suspension (TST), and forced swimming tests. Structural brain changes were identified by deformation-based morphometry (DBM) and diffusion tensor imaging using ex vivo MRI. We found that the F1, F2, and F3 offspring exposed to CAF diet displayed higher anxious scores including longer feeding latency during the NSFT, and in the closed arms, only F1 offspring showed longer stay on edges during the OFT versus control offspring. DBM analysis revealed that CAF offspring exhibited altered volume in the cerebellum, hypothalamus, amygdala, and hippocampus preserved up to the F3 generation of anxious individuals. Also, F3 CAF anxious exhibited greater fractional anisotropy and axial diffusivity (AD) in the amygdala, greater apparent diffusion coefficient in the corpus callosum, and greater AD in the hippocampus with respect to the control. Our results suggest that prenatal and lactation exposure to HED programs the transgenerational inheritance of structural brain changes related to anxiety-like behavior in the male offspring.

Investigating the impact of paternal aging on murine sperm miRNA profiles and their potential link to autism spectrum disorder

Paternal aging has consistently been linked to an increased risk of neurodevelopmental disorders, including autism spectrum disorder (ASD), in offspring. Recent evidence has highlighted the involvement of epigenetic factors. In this study, we aimed to investigate age-related alterations in microRNA (miRNA) profiles of mouse sperm and analyze target genes regulated by differentially expressed miRNAs (DEmiRNAs). Microarray analyses were conducted on sperm samples from mice at different ages: 3 months (3 M), over 12 M, and beyond 20 M. We identified 26 miRNAs with differential expression between the 3 and 20 M mice, 34 miRNAs between the 12 and 20 M mice, and 2 miRNAs between the 3 and 12 M mice. The target genes regulated by these miRNAs were significantly associated with apoptosis/ferroptosis pathways and the nervous system. We revealed alterations in sperm miRNA profiles due to aging and suggest that the target genes regulated by these DEmiRNAs are associated with apoptosis and the nervous system, implying a potential link between paternal aging and an increased risk of neurodevelopmental disorders such as ASD. The observed age-related changes in sperm miRNA profiles have the potential to impact sperm quality and subsequently affect offspring development.

Uncovering the Hidden Dangers and Molecular Mechanisms of Excess Folate: A Narrative Review

This review delves into the intricate relationship between excess folate (vitamin B9) intake, especially its synthetic form, namely, folic acid, and its implications on health and disease. While folate plays a pivotal role in the one-carbon cycle, which is essential for DNA synthesis, repair, and methylation, concerns arise about its excessive intake. The literature underscores potential deleterious effects, such as an increased risk of carcinogenesis; disruption in DNA methylation; and impacts on embryogenesis, pregnancy outcomes, neurodevelopment, and disease risk. Notably, these consequences stretch beyond the immediate effects, potentially influencing future generations through epigenetic reprogramming. The molecular mechanisms underlying these effects were examined, including altered one-carbon metabolism, the accumulation of unmetabolized folic acid, vitamin-B12-dependent mechanisms, altered methylation patterns, and interactions with critical receptors and signaling pathways. Furthermore, differences in the effects and mechanisms mediated by folic acid compared with natural folate are highlighted. Given the widespread folic acid supplementation, it is imperative to further research its optimal intake levels and the molecular pathways impacted by its excessive intake, ensuring the health and well-being of the global population.

Insights from the maternal lineage of the F2 generation after exposure to an environmentally relevant dose of benzo(a)pyrene in the male rats of F0 generation

Benzo(a)pyrene (BaP) is a substance with the potential to induce endocrine disruption in the F0 generation and cause adverse multigenerational effects (F1 generation) for reproductive parameters in rats. The objective of this study was to investigate the occurrence of transgenerational inheritance in the reproductive aspects of male and female rats belonging to the F2 generation (MF2). This investigation was conducted following the exposure of male rats from the F0 generation to BaP to assess potential effects on subsequent generation from the maternal lineage (F1). For that, juvenile male Wistar rats (F0) were orally exposed to BaP (0.1 µg/kg/day) for 31 consecutive days. In adulthood, they were mated with untreated females to obtain female offspring (F1), which later produced the MF2. In the MF2 generation, both males and females exhibited increased body weight on postnatal day (PND) 1. In MF2 males, we observed delayed preputial separation, altered pup weight, reduced levels of follicle-stimulating hormone (FSH), increased intratesticular testosterone levels, decreased type A sperm, epididymal disturbances, reduced 5 α-reductase activity, increased testicular proliferation, and alterations in testicular antioxidant enzymes. In MF2 females, we noted morphological uterine enlargement, reduced sexual activity, and decreased progesterone levels. The findings suggest that the alterations observed in both MF2 males and females can be attributed to modifications in the sperm from F0 generation, which were subsequently transmitted to F1 females and MF2 generation due to BaP exposure.

Integrated transcriptome and proteome analysis indicates potential biomarkers of prostate cancer in offspring of pregnant rats exposed to a phthalate mixture during gestation and lactation

As the second leading cause of death for cancer among men worldwide, prostate cancer (PCa) prevention and detection remain a critical challenge. One aspect of PCa research is the identification of common environmental agents that may increase the risk of initiation and progression of PCa. Endocrine disrupting chemicals (EDCs) are strong candidates for risk factors, partially because they alter essential pathways for prostate gland development and oncogenesis. Phthalates correspond to a set of commercially used plasticizers that humans are exposed to ubiquitously. Here, we show that maternal exposure to a phthalate mixture interferes with the expression profile of mRNA and proteins in the ventral prostate of offspring and increases the susceptibility to prostate adenocarcinomas in aged animals. The data highlight Ubxn11, Aldoc, Kif5c, Tubb4a, Tubb3, Tubb2, Rab6b and Rab3b as differentially expressed targets in young and adult offspring descendants (PND22 and PND120). These phthalate-induced targets were enriched for pathways such as: dysregulation in post-translational protein modification (PTPM), cell homeostasis, HSP90 chaperone activity, gap junctions, and kinases. In addition, the Kif5c, Tubb3, Tubb2b and Tubb4a targets were enriched for impairment in cell cycle and GTPase activity. Furthermore, these targets showed strong relationships with 12 transcriptional factors (TF), which regulate the phosphorylation of eight protein kinases. The correlation of TF-kinases is associated with alterations in immune system, RAS/ErbB/VEGF/estrogen/HIF-1 signaling pathways, cellular senescence, cell cycle, autophagy, and apoptosis. Downregulation of KIF5C, TUBB3 and RAB6B targets is associated with poor prognosis in patients diagnosed with adenocarcinoma. Collectively, this integrative investigation establishes the post-transcriptional mechanisms in the prostate that are modulated by maternal exposure to phthalate mixture during gestation and lactation.

Developmental origins of health and disease knowledge is associated with diet quality in preconception young adult men and women

The Developmental Origins of Health and Disease (DOHaD) approach supports that nutritional exposures in early life affect an individual's later health and risk of disease. Dietary exposure during the preconception period may also influence individual, and inter- and transgenerational health and disease risk, in both men and women. This study aimed to describe knowledge of the DOHaD approach (DOHaDKNOWLEDGE) and diet quality in preconception young adults in Norway, to assess associations between DOHaDKNOWLEDGE and a Diet Quality Score (DQS), and to assess gender differences in those above. Data from 1362 preconception young adults was obtained from the PREPARED study baseline dataset. The sample had 88% women participants, a mean age of 27 years, 36% had overweight or obesity, and 77% had higher level of education. DOHaDKNOWLEDGE was assessed by the participants' agreement to five statements using a Likert scale. Diet quality was assessed using aspects of diet quality and a DQS derived from a dietary screener. We found moderate level of both DOHaDKNOWLEDGE (12/20 points) and diet quality (DQS: 60/100 points), indicating potential for improvements. Specifically, the greatest potential for diet quality improvements were observed for sugary foods, red and processed meats, legumes, and unsalted nuts and seeds. Gender differences were observed for both DOHaDKNOWLEDGE and diet quality. DOHaDKNOWLEDGE was positively associated with DQS, adjusted for sociodemographic factors, with little evidence of an interaction effect by gender. This study indicates that knowledge of the DOHaD approach is positively associated with diet quality in preconception young men and women. Future studies should consider incorporating pregnancy intentions, relationship status, and health literacy.

Preconception knowledge, beliefs and behaviours among people of reproductive age: A systematic review of qualitative studies

BACKGROUND

The health of parents before pregnancy influences the short- and long-term health of their offspring. This systematic review explored the preconception knowledge, beliefs and behaviours held by women and men of childbearing age.

METHODS

Databases were searched from 2009 to 2022 (MEDLINE, CINAHL Full-text, PsycINFO, EMBASE). Inclusion criteria specified qualitative research papers which recruited individuals of reproductive age (16-45 years) without existing chronic illnesses. Data were quality assessed and analysed using thematic synthesis.

RESULTS

Twelve papers met inclusion criteria. Six themes were identified (cultural context, pregnancy planning, knowledge, gender roles and responsibility, information seeking, prior health behaviours) which relate to individual, social, psychological and cultural factors. Cultural context was related to all other themes. Pregnancy planners had greater motivation to optimise their health whereas those not actively planning were focused more on becoming financially stable. Women and men's knowledge of how and why to engage in health protective behaviours was limited, with health risks and behaviour change discussed in the context of pregnancy rather than preconception. Gender roles influenced individual responsibility for preparation for pregnancy, which in turn influenced information seeking behaviours and engagement in health behaviours. Online sources of support and information were seen as desirable, regardless of pregnancy planning stage.

CONCLUSIONS

Our findings indicate that behaviour change interventions designed to support people to optimise health before conception should address cultural, individual, social and psychological factors to facilitate behaviour change. Development of online resources may help to increase accessibility for people across different cultural contexts and stages of pregnancy planning.

Paternal programming of fetoplacental and offspring metabolic disorders

The alarming increase in the prevalence of metabolic pathologies is of worldwide concern and has been linked not only to genetic factors but also to a large number of non-genetic factors. In recent years, there has been increasing interest in the study of the programming of metabolic diseases, such as type 2 diabetes mellitus (T2DM) and obesity, by paternal exposure, a paradigm termed "Paternal Origins of Health and Disease" (POHaD). This term derives from the better known "Developmental Origins of Health and Disease" (DOHaD), which focuses on the involvement of the maternal intrauterine environment and complications during pregnancy associated with the health and disease of the offspring. Studies on paternal programming have documented environmentally induced epigenetic modifications in the male germline and in seminal plasma, which lead to intergenerational and transgenerational phenotypes, evident already during fetoplacental development. Studies with animal models at both ends of the nutritional spectrum (undernutrition or overnutrition) have been performed to understand the possible mechanisms and signaling pathways leading to the programming of metabolic disorders by exploring epigenetic changes throughout the life of the offspring. The aim of this review was to address the evidence of the programming of fetoplacental developmental alterations and metabolic pathologies in the offspring of males with metabolic disorders and unhealthy exposures, highlighting the mechanisms involved in such programming and looking for paternal interventions to reduce negative health outcomes in the offspring.

Sperm Rhoa m6A modification mediates intergenerational transmission of paternally acquired hippocampal neuronal senescence and cognitive deficits after combined exposure to environmental cadmium and high-fat diet in mice

Little is currently known about the effect and mechanism of combined paternal environmental cadmium (Cd) and high-fat diet (HFD) on offspring cognitive ability. Here, using in vivo model, we found that combined paternal environmental Cd and HFD caused hippocampal neuronal senescence and cognitive deficits in offspring. MeRIP-seq revealed m6A level of Rhoa, a regulatory gene of cellular senescence, was significantly increased in combined environmental Cd and HFD-treated paternal sperm. Interestingly, combined paternal environmental Cd and HFD markedly enhanced Rhoa mRNA, its m6A and reader protein IGF2BP1 in offspring hippocampus. STM2457, the inhibitor of m6A modification, markedly mitigated paternal exposure-caused the elevation of hippocampal Rhoa m6A, neuronal senescence and cognitive deficits in offspring. In vitro experiments, Rhoa siR significantly reversed mouse hippocampal neuronal senescence. Igf2bp1 siR obviously reduced the level and stability of Rhoa in aging mouse hippocampal neuronal cells. In conclusion, combined paternal environmental Cd and HFD induce offspring hippocampal neuronal senescence and cognitive deficits by promoting IGF2BP1-mediated Rhoa stabilization in offspring hippocampus via elevating Rhoa m6A in paternal sperm.

The Impact of Microbiota on the Gut-Brain Axis: Examining the Complex Interplay and Implications

The association and interaction between the central nervous system (CNS) and enteric nervous system (ENS) is well established. Essentially ENS is the second brain, as we call it. We tried to understand the structure and function, to throw light on the functional aspect of neurons, and address various disease manifestations. We summarized how various neurological disorders influence the gut via the enteric nervous system and/or bring anatomical or physiological changes in the enteric nervous system or the gut and vice versa. It is known that stress has an effect on Gastrointestinal (GI) motility and causes mucosal erosions. In our literature review, we found that stress can also affect sensory perception in the central nervous system. Interestingly, we found that mutations in the neurohormone, serotonin (5-HT), would result in dysfunctional organ development and further affect mood and behavior. We focused on the developmental aspects of neurons and cognition and their relation to nutritional absorption via the gastrointestinal tract, the development of neurodegenerative disorders in relation to the alteration in gut microbiota, and contrariwise associations between CNS disorders and ENS. This paper further summarizes the synergetic relation between gastrointestinal and neuropsychological manifestations and emphasizes the need to include behavioral therapies in management plans.

Paternal low-dose benzo(a)pyrene exposure in rats impairs sexual development and fertility of the paternal lineage in F2 generation: A transgenerational study

The field of Paternal Origins of Health and Disease (POHaD) is highly relevant but remains under-explored. The F2 generation from males indirectly exposed (F1 - via germ cells) to benzo(a)pyrene (BaP), named PF2, was investigated in this study under parameters of sexual development and reproductive performance of male and female rats. Male Wistar rats (F0) were exposed to BaP (0.1µg/kg/day) for 31 consecutive days (gavage) during prepuberty. The F0 rats were mated with untreated females to produce male offspring (F1), which were exposed to BaP via germ cells. The F1 males were later mated with untreated females to obtain the PF2 generation, which was the focus of our investigation. Our findings showed that PF2 males exhibited a decrease in anogenital distance, fertility potential, testosterone levels, and type A sperm. Meanwhile, PF2 females had an earlier vaginal opening, lower lordosis scores, and decreased fertility. Furthermore, changes in the histomorphology of the testis/epididymis and ovary/uterus were observed. The repercussions of the PF2 generation indicate that these animals showed losses in both sexual development and fertility potential, and we can conclude that this damage remained due to paternal transgenerational inheritance caused by a low dose of BaP.

Benzo[a]pyrene-induced multigenerational changes in gene expression, behavior, and DNA methylation are primarily influenced by paternal exposure

Benzo[a]pyrene (BaP), a polycyclic aromatic hydrocarbon (PAH), is implicated in many developmental and behavioral adverse outcomes in offspring of exposed parents. The objective of this study was to investigate sex-dependent multigenerational effects of preconceptional effects of BaP exposure. Adult wild-type (5D) zebrafish were fed 708 μg BaP/g diet (measured) at a rate of 1% body weight twice/day (14 μg BaP/g fish/day) for 21 days. Fish were spawned using a crossover design, and parental (F0) behavior and reproductive indexes were measured. In offspring, behavioral effects were measured at 96 h post fertilization (hpf) in F1 & F2 larvae, and again when F1s were adults. Compared to controls, there was no significant effect on F0 adult behavior immediately following exposure, but locomotor activity was significantly increased in F1 adults of both sexes. Larval behavior (96 hpf, photomotor response assay) was significantly altered in both the F1 and F2 generations. To assess molecular changes associated with BaP exposure, we conducted transcriptome and DNA methylation profiling in F0 gametes (sperm and eggs) and F1 embryos (10 hpf) from all four crosses. Embryos resulting from the BaP male and control female cross had the most differentially expressed genes (DEGs) and differentially methylated regions (DMRs). Some DMRs were associated with genes encoding chromatin modifying enzymes suggesting regulation of chromatin conformation by DNA methylation. Overall, these results suggest that parental dietary BaP exposure significantly contributes to the multigenerational adverse outcomes.

Developmental origins of health and disease: Impact of paternal nutrition and lifestyle

Most epidemiological and experimental studies have focused on maternal influences on offspring's health. The impact of maternal undernutrition, overnutrition, hypoxia, and stress is linked to adverse offspring outcomes across a range of systems including cardiometabolic, respiratory, endocrine, and reproduction among others. During the past decade, it has become evident that paternal environmental factors are also linked to the development of diseases in offspring. In this article, we aim to outline the current understanding of the impact of male health and environmental exposure on offspring development, health, and disease and explore the mechanisms underlying the paternal programming of offspring health. The available evidence suggests that poor paternal pre-conceptional nutrition and lifestyle, and advanced age can increase the risk of negative outcomes in offspring, via both direct (genetic/epigenetic) and indirect (maternal uterine environment) effects. Beginning at preconception, and during utero and the early life after birth, cells acquire an epigenetic memory of the early exposure which can be influential across the entire lifespan and program a child's health. Potentially not only mothers but also fathers should be advised that maintaining a healthy diet and lifestyle is important to improve offspring health as well as the parental health status. However, the evidence is mostly based on animal studies, and well-designed human studies are urgently needed to verify findings from animal data.

Maternal and Paternal Dietary Quality and Dietary Inflammation Associations with Offspring DNA Methylation and Epigenetic Biomarkers of Aging in the Lifeways Cross-Generation Study

BACKGROUND

Early-life nutritional exposures may contribute to offspring epigenetic modifications. However, few studies have evaluated parental dietary quality effects on offspring DNA methylation (DNAm).

OBJECTIVES

We aim to fill this gap by elucidating the influence of maternal and paternal whole-diet quality and inflammatory potential on offspring DNAm in the Lifeways Cross-generation cohort.

METHODS

Families (n = 1124) were recruited around 16 weeks of gestation in the Republic of Ireland between 2001 and 2003. Maternal dietary intake during the first trimester and paternal diet during the 12 previous months were assessed with an FFQ. Parental dietary inflammatory potential and quality were determined using the energy-adjusted Dietary Inflammatory Index (E-DII), the Healthy Eating Index-2015 (HEI-2015), and the maternal DASH score. DNAm in the saliva of 246 children at age nine was measured using the Illumina Infinium HumanMethylationEPIC array. DNAm-derived biomarkers of aging, the Pediatric-Buccal-Epigenetic clock and DNAm estimator of telomere length, were calculated. Parental diet associations with the DNAm concentrations of 850K Cytosine-phosphate-guanine sites (CpG sites) and with DNAm-derived biomarkers of aging were examined using an epigenome-wide association study and linear regressions, respectively.

RESULTS

Maternal HEI-2015 scores were inversely associated with DNAm at CpG site (cg21840035) located near the PLEKHM1 gene, whose functions involve regulation of bone development (β = -0.0036, per 1 point increase in the score; P = 5.6 × 10-8). Higher paternal HEI-2015 score was related to lower methylation at CpG site (cg22431767), located near cell signaling gene LUZP1 (β = -0.0022, per 1 point increase in the score, P = 4.1 × 10-8). There were no associations with parental E-DII and DASH scores, and no evidence of major effects on biomarkers of aging.

CONCLUSIONS

Parental dietary quality in the prenatal period, evaluated by the HEI-2015, may influence offspring DNAm during childhood. Further research to improve our understanding of parental nutritional programming is warranted.

Parental exposure to famine in early life and child overweight in offspring in Chinese populations

BACKGROUND

Little is known about the transgenerational effect of nutrition deficiency in early life. This study aimed to evaluate the associations of fetal and childhood exposure to famine of parents with their offspring's risk of overweight during childhood.

METHODS

This analysis included a total of 3734 participants of the China Health and Nutrition Survey aged 1-17 years whose fathers and/or mothers were born in 1955-1966. These children were classified into subgroups according to parental famine exposure status (unexposed and exposed) and timing (fetal-exposed and childhood-exposed). Random effects models were applied to evaluate the associations of parental famine exposure with body mass index (BMI) and overweight of offspring. Fractional polynomial functions were adopted to describe trajectories of BMI against age.

RESULTS

Compared with children of unexposed parents, there was a lower risk of overweight among offspring of childhood-exposed fathers [OR (95%CI): 0.80 (0.61, 1.04)] or exposed parents [0.84 (0.68, 1.04)], particularly among male offspring, but not among those with exposed mothers only [0.98 (0.65, 1.47)]. For BMI, children with exposed mothers only had a slightly higher BMI [β(95%CI): 0.17 (-0.15, 0.49)], while those with exposed fathers only had no difference [-0.02 (-0.23, 0.19)] or exposed parents had a slightly lower BMI [-0.17 (-0.33, 0.00)] (p < 0.05 for interaction between maternal and paternal exposures). Stratified analysis showed little heterogeneity between male and female offspring, but the association between paternal childhood exposure to famine and lower overweight risk in offspring was more evident in high (vs low) paternal education group (p for interaction< 0.05).

CONCLUSIONS

The transgenerational associations of early-life exposure to famine with lower risks of child overweight may be via the paternal line and differ by the educational levels of parents. Further studies are warranted to confirm the results and reveal the biological mechanisms underlying.

Effects of paternal obesity on maternal-neonatal outcomes and long-term prognosis in adolescents

Objective

This study evaluated whether paternal body mass index (BMI) before pregnancy was a risk factor for maternal-neonatal outcomes and long-term prognosis in offspring.

Methods

This study included 29,518 participants from eight cities in Fujian, China using a stratified cluster random sampling method from May to September 2019. They were divided into four groups based on paternal BMI. Univariate and multivariate logistic regression were used to explore the relationship between paternal BMI groups, maternal-neonatal outcomes, and long-term prognosis in offspring. Further subgroup analysis was conducted to examine the stability of the risk.

Results

The incidences of hypertensive disorder complicating pregnancy (HDCP), cesarean delivery, gestational weight gain (GWG) over guideline, and macrosomia were significantly higher in the paternal overweight and obesity group. Importantly, this study demonstrated that the incidence of asthma, hand-foot-and-mouth disease (HFMD), anemia, dental caries, and obesity of adolescents in paternal obesity increased. Furthermore, logistic regression and subgroup analysis confirm paternal obesity is a risk factor for HDCP, cesarean delivery, and macrosomia. It caused poor long-term prognosis in adolescents, including asthma, dental caries, and HFMD.

Conclusions

Paternal obesity is a risk factor for adverse maternal-neonatal outcomes and poor long-term prognosis in adolescents. In addition to focusing on maternal weight, expectant fathers should pay more attention to weight management since BMI is a modifiable risk factor. Preventing paternal obesity can lead to better maternal and child outcomes. It would provide new opportunities for chronic diseases.

Paternal preconception modifiable risk factors for adverse pregnancy and offspring outcomes: a review of contemporary evidence from observational studies

BACKGROUND

The preconception period represents transgenerational opportunities to optimize modifiable risk factors associated with both short and long-term adverse health outcomes for women, men, and children. As such, preconception care is recommended to couples during this time to enable them to optimise their health in preparation for pregnancy. Historically, preconception research predominately focuses on maternal modifiable risks and health behaviours associated with pregnancy and offspring outcomes; limited attention has been given to inform paternal preconception health risks and outcomes. This systematic review aims to advance paternal preconception research by synthesising the current evidence on modifiable paternal preconception health behaviours and risk factors to identify associations with pregnancy and/or offspring outcomes.

METHODS

Medline, Embase, Maternity and Infant care, CINAHL, PsycINFO, Scopus, and ISI Proceedings were searched on the 5^th of January 2023, a date limit was set [2012-2023] in each database. A Google Scholar search was also conducted identifying all other relevant papers. Studies were included if they were observational, reporting associations of modifiable risk factors in the preconception period among males (e.g., identified as reproductive partners of pregnant women and/or fathers of offspring for which outcomes were reported) with adverse pregnancy and offspring outcomes. Study quality was assessed using the Newcastle-Ottawa Scale. Exposure and outcome heterogeneity precluded meta-analysis, and results were summarised in tables.

RESULTS

This review identified 56 cohort and nine case control studies. Studies reported on a range of risk factors and/or health behaviours including paternal body composition (n = 25), alcohol intake (n = 6), cannabis use (n = 5), physical activity (n = 2), smoking (n = 20), stress (n = 3) and nutrition (n = 13). Outcomes included fecundability, IVF/ISCI live birth, offspring weight, body composition/BMI, asthma, lung function, leukemia, preterm birth, and behavioural issues. Despite the limited number of studies and substantial heterogeneity in reporting, results of studies assessed as good quality showed that paternal smoking may increase the risk of birth defects and higher paternal BMI was associated with higher offspring birthweight.

CONCLUSION

The current evidence demonstrates a role of paternal preconception health in influencing outcomes related to pregnancy success and offspring health. The evidence is however limited and heterogenous, and further high-quality research is needed to inform clinical preconception care guidelines to support men and couples to prepare for a health pregnancy and child.

Preconception origins of asthma, allergies and lung function: The influence of previous generations on the respiratory health of our children

Emerging research suggests that exposures occurring years before conception are important determinants of the health of future offspring and subsequent generations. Environmental exposures of both the father and mother, or exposure to disease processes such as obesity or infections, may influence germline cells and thereby cause a cascade of health outcomes in multiple subsequent generations. There is now increasing evidence that respiratory health is influenced by parental exposures that occur long before conception. The strongest evidence relates adolescent tobacco smoking and overweight in future fathers to increased asthma and lower lung function in their offspring, supported by evidence on parental preconception occupational exposures and air pollution. Although this literature is still sparse, the epidemiological analyses reveal strong effects that are consistent across studies with different designs and methodologies. The results are strengthened by mechanistic research from animal models and (scarce) human studies that have identified molecular mechanisms that can explain the epidemiological findings, suggesting transfer of epigenetic signals through germline cells, with susceptibility windows in utero (both male and female line) and prepuberty (male line). The concept that our lifestyles and behaviours may influence the health of our future children represents a new paradigm. This raises concerns for future health in decades to come with respect to harmful exposures but may also open for radical rethinking of preventive strategies that may improve health in multiple generations, reverse the imprint of our parents and forefathers, and underpin strategies that can break the vicious circle of propagation of health inequalities across generations.

Intergenerational Inheritance of Hepatic Steatosis in a Mouse Model of Childhood Obesity: Potential Involvement of Germ-Line microRNAs

Childhood obesity increases the risk of developing metabolic syndrome later in life. Moreover, metabolic dysfunction may be inherited into the following generation through non-genomic mechanisms, with epigenetics as a plausible candidate. The pathways involved in the development of metabolic dysfunction across generations in the context of childhood obesity remain largely unexplored. We have developed a mouse model of early adiposity by reducing litter size at birth (small litter group, SL: 4 pups/dam; control group, C: 8 pups/dam). Mice raised in small litters (SL) developed obesity, insulin resistance and hepatic steatosis with aging. Strikingly, the offspring of SL males (SL-F1) also developed hepatic steatosis. Paternal transmission of an environmentally induced phenotype strongly suggests epigenetic inheritance. We analyzed the hepatic transcriptome in C-F1 and SL-F1 mice to identify pathways involved in the development of hepatic steatosis. We found that the circadian rhythm and lipid metabolic process were the ontologies with highest significance in the liver of SL-F1 mice. We explored whether DNA methylation and small non-coding RNAs might be involved in mediating intergenerational effects. Sperm DNA methylation was largely altered in SL mice. However, these changes did not correlate with the hepatic transcriptome. Next, we analyzed small non-coding RNA content in the testes of mice from the parental generation. Two miRNAs (miR-457 and miR-201) appeared differentially expressed in the testes of SL-F0 mice. They are known to be expressed in mature spermatozoa, but not in oocytes nor early embryos, and they may regulate the transcription of lipogenic genes, but not clock genes, in hepatocytes. Hence, they are strong candidates to mediate the inheritance of adult hepatic steatosis in our murine model. In conclusion, litter size reduction leads to intergenerational effects through non-genomic mechanisms. In our model, DNA methylation does not seem to play a role on the circadian rhythm nor lipid genes. However, at least two paternal miRNAs might influence the expression of a few lipid-related genes in the first-generation offspring, F1.

Phthalates impact on the epigenetic factors contributed specifically by the father at fertilization

BACKGROUND

Preconception exposure to phthalates such as the anti-androgenic dibutyl-phthalate (DBP) impacts both male and female reproduction, yet how this occurs largely remains unknown. Previously we defined a series of RNAs expressly provided by sperm at fertilization and separately, and in parallel, those that responded to high DBP exposure. Utilizing both populations of RNAs, we now begin to unravel the impact of high-DBP exposure on those RNAs specifically delivered by the father.

RESULTS

Enrichment of RNAs altered by DBP exposure within the Molecular Signature Database highlighted cellular stress, cell cycle, apoptosis, DNA damage response, and gene regulation pathways. Overlap within each of these five pathways identified those RNAs that were specifically (≥ fivefold enriched) or primarily (≥ twofold enriched) provided as part of the paternal contribution compared to the oocyte at fertilization. Key RNAs consistently altered by DBP, including CAMTA2 and PSME4, were delivered by sperm reflective of these pathways. The majority (64/103) of overlapping enriched gene sets were related to gene regulation. Many of these RNAs (45 RNAs) corresponded to key interconnected CRREWs (Chromatin remodeler cofactors, RNA interactors, Readers, Erasers, and Writers). Modeling suggests that CUL2, PHF10, and SMARCC1 may coordinate and mechanistically modulate the phthalate response.

CONCLUSIONS

Mediated through a CRREW regulatory network, the cell responded to exposure presenting stressed-induced changes in the cell cycle-DNA damage-apoptosis. Interestingly, the majority of these DBP-responsive epigenetic mediators' direct acetylation or deacetylation, impacting the sperm's cargo delivered at fertilization and that of the embryo.

Inheritance of paternal lifestyles and exposures through sperm DNA methylation

Many different lifestyle factors and chemicals present in the environment are a threat to the reproductive tracts of humans. The potential for parental preconception exposure to alter gametes and for these alterations to be passed on to offspring and negatively affect embryo growth and development is of concern. The connection between maternal exposures and offspring health is a frequent focus in epidemiological studies, but paternal preconception exposures are much less frequently considered and are also very important determinants of offspring health. Several environmental and lifestyle factors in men have been found to alter sperm epigenetics, which can regulate gene expression during early embryonic development. Epigenetic information is thought to be a mechanism that evolved for organisms to pass on information about their lived experiences to offspring. DNA methylation is a well-studied epigenetic regulator that is sensitive to environmental exposures in somatic cells and sperm. The continuous production of sperm from spermatogonial stem cells throughout a man's adult life and the presence of spermatogonial stem cells outside of the blood-testis barrier makes them susceptible to environmental insults. Furthermore, altered sperm DNA methylation patterns can be maintained throughout development and ultimately result in impairments, which could predispose offspring to disease. Innovations in human stem cell-based spermatogenic models can be used to elucidate the paternal origins of health and disease.

Transgenerational associations of parental famine exposure in early life with offspring risk of adult obesity in China

OBJECTIVE

The aim of this study was to investigate the transgenerational associations between exposure to famine in early life and obesity.

METHODS

This study used the longitudinal data from the China Health and Nutrition Survey from 1989 to 2015. A total of 1113 fathers and 1207 mothers (946 mother-father pairs) born in 1955 to 1966 and 1895 adult offspring were included. Offspring were classified into subgroups according to the famine exposure of their parents (unexposed, maternal exposed, paternal exposed, parental exposed) and exposure timing (during fetal development, childhood).

RESULTS

Maternal exposure to famine in early life was associated with elevated levels of BMI, waist circumference, overweight, and central obesity of their children, whereas paternal exposure was inversely associated with these measurements. Compared with children of unexposed parents (P0M0), the maternal exposed group (P0M1) had higher mean BMI, by 1.3 kg/m² (95% CI: 0.3 to 2.4); waist circumference, by 1.5 cm (-1.0 to 3.9); overweight (odds ratio [OR] [95% CI]: 3.1 [1.6 to 6.1]); and central obesity (OR [95% CI]: 1.9 [1.02 to 3.7]). No significant heterogeneity was observed in the associations by sex of offspring.

CONCLUSIONS

Fetal and early childhood exposure to famine in parents may be associated with their children's risk of obesity during adulthood. A better understanding of the transgenerational associations is important for developing strategies to reduce obesity risk in future generations.

Effects of paternal methionine supplementation on sperm DNA methylation and embryo transcriptome in sheep

Environmental effects on gene expression and offspring development can be mediated by epigenetic modifications. It is well established that maternal diet influences DNA methylation patterns and phenotypes in the offspring; however, the epigenetic effects of paternal diet on developing offspring warrants further investigation. Here, we examined how a prepubertal methionine-enriched paternal diet affected sperm DNA methylation and its subsequent effects on embryo gene expression. Three treatment and three control rams were bred to seven ewes, and blastocysts were flushed for RNA extraction. Semen was collected from all rams and submitted for reduced representation bisulfite sequencing analysis. In total, 166 differentially methylated cytosines were identified in the sperm from treatment versus control rams. Nine genes were found to be differentially expressed in embryos produced from treatment versus control rams, and seven differentially methylated cytosines in the sperm were found to be highly correlated with gene expression in the embryos. Our results demonstrate that sperm methylation differences induced by diet may influence fetal programming.

Paternal dietary ratio of n-6: n-3 polyunsaturated fatty acids programs offspring leptin expression and gene imprinting in mice

Background

This study determined the effects of the paternal dietary ratio of n-6: n-3 polyunsaturated fatty acids (PUFAs) on leptin expression in the offspring and associated gene imprinting in a mouse model.

Methods

Three- to four-week-old male C57BL/6J mice (F0) were fed an n-3 PUFA-deficient (n-3 D) diet, a diet with normal n-3 PUFA content (n-3 N; n-6: n-3 = 4.3:1), or a diet with a high n-3 PUFA content (n-3 H; n-6: n-3 = 1.5:1) for 8 weeks. Two subsequent generations were generated by mating F0 and F1 male mice with 10-week-old virgin female C57 BL/6J mice, to produce F1 and F2 offspring.

Results

Compared to the paternal n-3 D diet, paternal n-3 N and n-3 H diets reduced adipose mRNA expression of leptin (Lep) and its plasma concentrations in juvenile F1 male and female offspring, and adult F1 male and F2 female offspring, with upregulated Lep receptor mRNA expression in the hypothalamus. Meanwhile, paternal n-3 N and n-3 H diets altered the expression of the imprinted genes H19, Igf2, Igf2r, Plagl1, Cdkn1c, Kcnq1ot1, Peg3, and Grb10 in the adipose tissue of juvenile and adult F1 males, with almost no effects on F1 females, while more effects were observed in the adult F2 females than F2 males. Principal component analysis verified that Plagl1, Cdkn1c, and Kcnq1ot1 contributed the most to variation in adipose tissue expression in all offspring. Some of these genes (Plagl1, Cdkn1c, Kcnq1ot1, Peg3, and Grb10) were altered by the paternal n-3 N and n-3 H diets in the F1 and F2 generation testes as well. Furthermore, adipose Lep expression was positively correlated with expressions of H19, Igf2r, Plagl1, and Kcnq1ot1 in juvenile F1 males and females, negatively correlated with the Kcnq1ot1 expression in adult F1 males, and positively correlated with the Plagl1 expression in adult F2 females.

Conclusion

These data imply that paternal Plagl1, Cdkn1c, and Kcnq1ot1 might be part of the pathways involved in offspring leptin programming. Therefore, a lower ratio of n-6: n-3 PUFAs, with higher intake of n-3 PUFAs in paternal pre-conception, may help maintain the offspring's optimal leptin pattern in a sex-specific manner through multiple generations, and thereby, be beneficial for the offspring's long-term health.

Exploring adolescence as a key life history stage in bioarchaeology

Adolescence is a unique period in the life history of an individual. It is characterized by a myriad of changes that bioarchaeologists are only just coming to appreciate, related to sexual maturation, linear growth, immunological transformation, and emotional and cognitive development. New methods allow us to measure this age of transition through the stages of the adolescent growth, as a proxy for the physical development associated with sexual maturation (puberty). This review outlines ways bioarchaeologists may draw on research developments from the fields of human biology, evolutionary theory and neurobiology to advance a more holistic approach to the study of adolescence in the past. It considers current theoretical and analytical approaches to highlight the research potential of this critical stage of life history. This synthesis integrates the most recent research in the medical sciences concerned with body and brain development, and outlines the biological processes involved with sexual and physical maturation of the adolescent. The goal of this review is to help inform potentially rewarding areas of research that bioarchaeologists can contribute to and draw from, as well as the challenges and limitations, theoretical and methodological questions, and ways in which we can develop the study of adolescence in the discipline going forward.

Parental pre-pregnancy body mass index and risk of low birth weight in offspring: A prospective cohort study in central China

Background

Low birth weight (LBW) is one of the most common adverse pregnancy outcomes. Previous studies have consistently shown that maternal body mass index (BMI) status before and during pregnancy is associated with LBW. However, previous studies lacked an association between paternal BMI and the conjunction effect of a couple's BMI and LBW in the offspring. Therefore, we established a cohort of pre-pregnancy couples to prospectively assess the relationship between maternal and paternal pre-pregnancy BMI and offspring LBW, very low birth weight (VLBW), and extremely low birth weight (ELBW).

Methods

A prospective cohort study was established in Central China. A total of 34,104 pregnant women with singleton pregnancies at 8-14 gestational weeks and their husbands were finally enrolled and followed to 3 months postpartum. The multivariate logistic regression and restrictive cubic spline model were used to explore the relationship between parental pre-pregnancy BMI and the risk of LBW, VLBW, and ELBW in offspring.

Results

Of the 34,104 participants, maternal pre-pregnancy overweight and obesity were associated with a higher risk of LBW (overweight: OR = 1.720, 95% CI = 1.533 ~ 1.930; obesity: OR = 1.710, 95% CI = 1.360 ~ 2.151), VLBW (overweight: OR = 2.283, 95% CI = 1.839 ~ 2.834; obesity: OR = 4.023, 95% CI = 2.855 ~ 5.670), and ELBW (overweight: OR = 3.292, 95% CI = 2.151 ~ 5.036; obesity: OR = 3.467, 95% CI = 1.481 ~ 8.115), while underweight was associated with a higher risk of LBW (OR = 1.438, 95% CI = 1.294 ~ 1.599) and a lower risk of ELBW (OR = 0.473, 95% CI = 0.236 ~ 0.946). Paternal pre-pregnancy overweight and obesity were associated with a higher risk of LBW (overweight: OR = 1.637, 95% CI = 1.501 ~ 1.784; obesity: OR = 1.454, 95% CI = 1.289 ~ 1.641) and VLBW (overweight: OR = 1.310, 95% CI = 1.097 ~ 1.564; obesity: OR = 1.320, 95% CI = 1.037 ~ 1.681), while underweight was associated with a lower risk of LBW (OR = 0.660, 95% CI = 0.519 ~ 0.839). Parents who were both excessive-weights in pre-pregnancy BMI, as well as overweight mothers and normal-weight fathers before pre-pregnancy, were more likely to have offspring with LBW, VLBW, and ELBW. Dose-response relationship existed between parental pre-pregnancy and LBW, VLBW, and ELBW, except for paternal BMI and ELBW.

Conclusions

Parental pre-pregnancy BMI was associated with the risk of LBW in offspring. Management of weight before pregnancy for couples might help reduce their adverse pregnancy outcomes in future intervention studies.

A perspective on diet, epigenetics and complex diseases: where is the field headed next?

Dietary factors can regulate epigenetic processes during life, modulating the intracellular pools of metabolites necessary for epigenetic reactions and regulating the activity of epigenetic enzymes. Their effects are strong during the prenatal life, when epigenetic patterns are written, allowing organogenesis. However, interactions between diet and the epigenome continue throughout life and likely contribute to the onset and progression of various complex diseases. Here, we review the contribution of dietary factors to the epigenetic changes observed in complex diseases and suggest future steps to better address this issue, focusing on neurobehavioral, neuropsychiatric and neurodegenerative disorders, cardiovascular diseases, obesity and Type 2 diabetes, cancer and inflammatory skin diseases.

The Potential Role of PPARs in the Fetal Origins of Adult Disease

The fetal origins of adult disease (FOAD) hypothesis holds that events during early development have a profound impact on one’s risk for the development of future adult disease. Studies from humans and animals have demonstrated that many diseases can begin in childhood and are caused by a variety of early life traumas, including maternal malnutrition, maternal disease conditions, lifestyle changes, exposure to toxins/chemicals, improper medication during pregnancy, and so on. Recently, the roles of Peroxisome proliferator-activated receptors (PPARs) in FOAD have been increasingly appreciated due to their wide variety of biological actions. PPARs are members of the nuclear hormone receptor subfamily, consisting of three distinct subtypes: PPARα, β/δ, and γ, highly expressed in the reproductive tissues. By controlling the maturation of the oocyte, ovulation, implantation of the embryo, development of the placenta, and male fertility, the PPARs play a crucial role in the transition from embryo to fetus in developing mammals. Exposure to adverse events in early life exerts a profound influence on the methylation pattern of PPARs in offspring organs, which can affect development and health throughout the life course, and even across generations. In this review, we summarize the latest research on PPARs in the area of FOAD, highlight the important role of PPARs in FOAD, and provide a potential strategy for early prevention of FOAD.

Paternal preconceptional diet enriched with n-3 polyunsaturated fatty acids affects offspring brain function in mice

Recent studies demonstrate that paternal nutrition prior to conception may determine offspring development and health through epigenetic modification. This study aims to investigate the effects of paternal supplementation of n-3 polyunsaturated fatty acids (n-3 PUFAs) on the brain development and function, and associated gene imprinting in the offspring. Three to four-week-old male C57BL/6J mice (founder) were fed with an n-3 PUFA-deficient diet (n-3 D), and two n-3 PUFA supplementation diets – a normal n-3 PUFA content diet (n-3 N) and a high n-3 PUFA content diet (n-3 H) for 12 weeks. Then they were mated to 10-week-old virgin female C57BL/6J mice to generate the offspring. The results showed that paternal n-3 PUFA supplementation in preconception reduced the anxiety- and depressive-like behavior, and improved sociability, learning and memory in the offspring, along with increased synaptic number, upregulated expressions of neuron specific enolase, myelin basic protein, glial fibrillary acidic protein, brain-derived neurotrophic factor in the hippocampus and cerebral cortex, and altered expressions of genes associated with mitochondria biogenesis, fusion, fission and autophagy. Furthermore, with paternal n-3 PUFA supplementation, the expression of imprinted gene Snrpn was downregulated both in testes of the founder mice and their offspring, but upregulated in the cerebral cortex and hippocampus, with altered DNA methylation in its differentially methylated region. The data suggest that higher paternal intake of n-3 PUFAs in preconception may help to maintain optimal brain development and function in the offspring, and further raise the possibility of paternal nutritional intervention for mental health issues in subsequent generations.

The Legacy of Parental Obesity: Mechanisms of Non-Genetic Transmission and Reversibility

While a dramatic increase in obesity and related comorbidities is being witnessed, the underlying mechanisms of their spread remain unresolved. Epigenetic and other non-genetic mechanisms tend to be prominent candidates involved in the establishment and transmission of obesity and associated metabolic disorders to offspring. Here, we review recent findings addressing those candidates, in the context of maternal and paternal influences, and discuss the effectiveness of preventive measures.

Gene-environment interactions in Alzheimer disease: the emerging role of epigenetics

With the exception of a few monogenic forms, Alzheimer disease (AD) has a complex aetiology that is likely to involve multiple susceptibility genes and environmental factors. The role of environmental factors is difficult to determine and, until a few years ago, the molecular mechanisms underlying gene-environment (G × E) interactions in AD were largely unknown. Here, we review evidence that has emerged over the past two decades to explain how environmental factors, such as diet, lifestyle, alcohol, smoking and pollutants, might interact with the human genome. In particular, we discuss how various environmental AD risk factors can induce epigenetic modifications of key AD-related genes and pathways and consider how epigenetic mechanisms could contribute to the effects of oxidative stress on AD onset. Studies on early-life exposures are helping to uncover critical time windows of sensitivity to epigenetic influences from environmental factors, thereby laying the foundations for future primary preventative approaches. We conclude that epigenetic modifications need to be considered when assessing G × E interactions in AD.