The mediating effect of DNA methylation in the association between maternal sleep during pregnancy and offspring adiposity status: a prospective cohort study

Epigenetics in metabolic dysfunction-associated steatohepatitis

Metabolic dysfunction-associated steatohepatitis (MASH) is a complex disease involving genetics, environment, and lifestyle, with the potential to progress to liver fibrosis, cirrhosis, and even hepatocellular carcinoma (HCC). Although the pathogenesis of MASH is not fully clear, increasing evidence has indicated that epigenetics plays an important role in the genesis and progression of MASH, during which, as drastic changes in metabolites, epigenetics undergo drastic changes. Roles of chromatin structure, chromatin accessibility, DNA methylation, histone modification, and non-coding RNAs were considered as bridges of pathogenic factors and MASH. In this review, the research progress on the epigenetics of MASH was summarized, and indepth research and therapeutic strategies based on epigenetics is expected to bring new hope to MASH patients.

The impact of maternal sleep during pregnancy on childhood health: A systematic review

The impact of maternal gestational sleep on pregnancy complications and birth outcomes has been well established by several systematic reviews/meta-analyses. However, the long-term health effect on children has not been summarized. Given the emerging evidence in maternal sleep is revealing new significant insights into this research field, the present review was particularly designed to systematically review and critically appraise existing population-based studies on the association between maternal sleep during pregnancy and childhood health. Available full-text studies that focused on the association were taken into account in this review; 6462 titles and abstracts and 36 full articles were screened from three databases, PubMed, Embase, and Web of Science, among which 24 studies were ultimately included in the synthesis. Based on childhood health indicators these studies covered, four areas of outcomes including metabolism, neurocognition, sleep, and allergy were categorized and summarized. Our analyses show that maternal gestational poor sleep and sleep disturbance negatively impact multiple aspects of childhood health, though the quality of the studies should be improved. The results inform future studies that should ideally reach out touching on broader health concerns and draw out longer follow-up periods, accompanying adopting more specific methods of assessing maternal sleep and children's health outcomes.

Maternal high-fat diet alters the transcriptional rhythm in white adipose tissue of adult offspring

A maternal high-fat diet (HFD) deteriorates the long-term metabolic health of offspring. Circadian rhythms are crucial for regulating metabolism. However, the impact of maternal HFD on the circadian clock in white adipose tissue (WAT) remains unexplored. This study aimed to identify transcriptional rhythmic alterations in inguinal WAT of adult male offspring induced by maternal HFD. To this end, female mice were fed an HFD and their male offspring were raised on a standard chow diet until 16 weeks of age. Transcriptome was performed and the data was analyzed using CircaCompare. The results showed that maternal HFD before and throughout pregnancy significantly altered the circadian rhythm of inguinal WAT while slightly modifying the WAT clock in adult male offspring. Specifically, maternal HFD contributed to gaining rhythmicity of Cry2, resulted in the elevated amplitude of Nr1d2, and led to increased midline estimating statistic of rhythm (MESOR) of Clock and Nr1d2. Furthermore, maternal HFD changed the rhythmic pattern of metabolic genes, such as Pparγ, Hacd2, and Acsl1, which are significantly enriched in metabolic regulation pathways. In conclusion, a maternal HFD before and throughout pregnancy altered the circadian rhythm of inguinal WAT in adult offspring. These alterations may play a significant role in disturbing metabolic homeostasis, potentially leading to metabolic dysfunction in adult male offspring.

Sleep During Pregnancy and Offspring Outcomes From Infancy to Childhood: A Systematic Review

OBJECTIVE

Prenatal sleep problems have been previously linked to poor birth outcomes. However, much less is known about the associations between poor prenatal maternal sleep and offspring outcomes after birth. The purpose of this systematic review was to synthesize the findings linking prenatal maternal sleep health and offspring health and development during infancy and childhood.

METHODS

A total of 4650 nonduplicate articles were identified via PsycInfo and PubMed databases. After screening and full-text review, 34 articles met the inclusion criteria and were extracted for information.

RESULTS

The bulk of studies in this review (n = 19; 76.5%) were published between 2019 and 2024. Measures of prenatal sleep included sleep timing, quality, sleep disorders and/or symptoms of disorders, and daytime sleepiness. Offspring outcomes were categorized as follows: a) sleep health (e.g., nighttime sleep duration, night wakings), b) physical health (e.g., body mass index, hospitalizations), c) child developmental outcomes (e.g., global development, negative affect, executive functioning), and d) brain structure and function (e.g., brain volume, event-related potentials). Evidence consistently links poor prenatal sleep health to poorer offspring sleep, higher body mass index, higher prevalence of physical health conditions, poorer global development, and more behavioral problems. Emerging evidence also links prenatal sleep to differences in offspring brain structure and function.

CONCLUSIONS

Poor prenatal maternal sleep health may be an environmental signal that informs offspring health. Future studies are needed to fully understand the pervasive, intergenerational, and long-lasting effects of sleep across pregnancy.

The Effect of Maternal Diet and Lifestyle on the Risk of Childhood Obesity

Background/Objectives: Childhood obesity is a global health problem that affects at least 41 million children under the age of five. Increased BMI in children is associated with serious long-term health consequences, such as type 2 diabetes, cardiovascular disease, and psychological problems, including depression and low self-esteem. Although the etiology of obesity is complex, research suggests that the diet and lifestyle of pregnant women play a key role in shaping metabolic and epigenetic changes that can increase the risk of obesity in their children. Excessive gestational weight gain, unhealthy dietary patterns (including the Western diet), and pregnancy complications (such as gestational diabetes) are some of the modifiable factors that contribute to childhood obesity. The purpose of this narrative review is to summarize the most important and recent information on the impact of the diet and lifestyle of pregnant women on the risk of childhood obesity. Methods: This article is a narrative review that aims to summarize the available literature on the impact of pregnant women's diet and lifestyle on the risk of obesity in their offspring, with a focus on metabolic and epigenetic mechanisms. Results/Conclusions: Current evidence suggests that a pregnant woman's lifestyle and diet can significantly contribute to lowering the risk of obesity in their offspring. However, further high-quality research is needed to understand better the metabolic and epigenetic relationships concerning maternal factors that predispose offspring to obesity.

Mediation analysis in longitudinal study with high-dimensional methylation mediators

Mediation analysis has been widely utilized to identify potential pathways connecting exposures and outcomes. However, there remains a lack of analytical methods for high-dimensional mediation analysis in longitudinal data. To tackle this concern, we proposed an effective and novel approach with variable selection and the indirect effect (IE) assessment based on both linear mixed-effect model and generalized estimating equation. Initially, we employ sure independence screening to reduce the dimension of candidate mediators. Subsequently, we implement the Sobel test with the Bonferroni correction for IE hypothesis testing. Through extensive simulation studies, we demonstrate the performance of our proposed procedure with a higher F$_{1}$ score (0.8056 and 0.9983 at sample sizes of 150 and 500, respectively) compared with the linear method (0.7779 and 0.9642 at the same sample sizes), along with more accurate parameter estimation and a significantly lower false discovery rate. Moreover, we apply our methodology to explore the mediation mechanisms involving over 730 000 DNA methylation sites with potential effects between the paternal body mass index (BMI) and offspring growing BMI in the Shanghai sleeping birth cohort data, leading to the identification of two previously undiscovered mediating CpG sites.

The Importance of Sleep in Overcoming Childhood Obesity and Reshaping Epigenetics

The development of childhood obesity is a complex process influenced by a combination of genetic predisposition and environmental factors, such as sleep, diet, physical activity, and socioeconomic status. Long-term solutions for decreasing the risk of childhood obesity remain elusive, despite significant advancements in promoting health and well-being in school and at home. Challenges persist in areas such as adherence to interventions, addressing underlying social determinants, and individual differences in response to treatment. Over the last decade, there has been significant progress in epigenetics, along with increased curiosity in gaining insights into how sleep and lifestyle decisions impact an individual's health. Epigenetic modifications affect the expression of genes without causing changes to the fundamental DNA sequence. In recent years, numerous research studies have explored the correlation between sleep and the epigenome, giving a better understanding of DNA methylation, histone modification, and non-coding RNAs. Although significant findings have been made about the influence of sleep on epigenetics, a notable gap exists in the literature concerning sleep-related genes specifically associated with childhood obesity. Consequently, it is crucial to delve deeper into this area to enhance our understanding. Therefore, this review primarily focuses on the connection between sleep patterns and epigenetic modifications in genes related to childhood obesity. Exploring the interplay between sleep, epigenetics, and childhood obesity can potentially contribute to improved overall health outcomes. This comprehensive review encompasses studies focusing on sleep-related genes linked to obesity.

Mediating effects of DNA methylation in the association between sleep quality and infertility among women of childbearing age

BACKGROUND

This study aims to investigate the association between sleep quality and infertility among women and to explore the mediating effects of DNA methylation in this association.

METHODS

This study is a population-based case-control study. The relationship between sleep quality and infertility was investigated in women with anovulatory infertility (n = 43) and healthy controls (n = 43). Genome-wide DNA methylation was profiled from peripheral blood samples using the Illumina Infinium Human Methylation 850k BeadChip. Differentially methylated CpGs between cases and controls were identified using the ChAMP R package. The mediating effect of DNA methylation between sleep quality and infertility among women was investigated using the Bayesian estimation method provided by the R package "mediation".

RESULTS

The survey included 86 women of reproductive age, with 43 participants each in the case and control groups. The average age of the women was 27.6 ± 2.8 years (case group: 27.8 ± 3.0 years, control group: 27.4 ± 2.7 years). A total of 262 differentially methylated CpGs corresponding to 185 genes were identified. Difficulty falling asleep was a risk factor for infertility in women (OR = 3.69, 95%CI = 1.14, 11.99), and a causal mediation effect of DNA methylation CpGs was found. The mediating effect coefficient for cg08298632 was 0.10 (95%CI = 0.01-0.22), and the proportion of the total effect mediated by this methylation site increased to 64.3%.

CONCLUSION

These results suggest that DNA methylation CpGs (cg08298632) play a significant role in the relationship between difficulty falling asleep and infertility in females. These findings contribute to our understanding of the underlying mechanisms that connect difficulty falling asleep and infertility in women. Further studies are necessary to fully understand the biological significance and potential therapeutic applications of these findings. The identified DNA methylation sites provide new and valuable insights and potential targets for future studies aiming to prevent and treat female infertility.

Early-to-mid pregnancy sleep and circadian markers in relation to birth outcomes: An epigenetics pilot study

Maternal sleep and circadian health during pregnancy are emerging as important predictors of pregnancy outcomes, but examination of potential epigenetic mechanisms is rare. We investigated links between maternal leukocyte DNA methylation of circadian genes and birth outcomes within a pregnancy cohort. Women (n = 96) completed a questionnaire and provided a blood sample at least once during early-to-mid pregnancy (average gestation weeks = 14.2). Leukocyte DNA was isolated and DNA methylation (average percent of methylation) at multiple CpG sites within BMAL1, PER1, and MTNR1B genes were quantified by pyrosequencing. Birth outcomes including gestational age at delivery, birthweight, and head circumference were abstracted from medical charts. Linear regression analyses were run between each CpG site with birth outcomes, adjusting for important confounders. Sleep duration and timing were assessed as secondary exposures. Higher methylation of a CpG site in PER1 was associated with smaller log-transformed head circumference (β=-0.02 with 95% CI -0.02 to 0.01; P, trend = 0.04). Higher methylation of MTNR1B (averaged across sites) was associated with lower log-transformed birthweight (-0.08 with 95% CI -0.16 to -0.01; P, trend = 0.0495). In addition, longer sleep duration was associated with higher birthweight (0.10 with 95% CI 0.02 to 0.18 comparing > 9 h to < 8 h; P, trend = 0.04). This pilot investigation revealed that higher methylation of PER1 and MTNR1B genes, and sleep duration measured in early-to-mid pregnancy were related to birth outcomes.

Maternal circadian disruption before pregnancy impairs the ovarian function of female offspring in mice

Circadian disturbance brought on by shift employment, nighttime light pollution, and other factors is quite prevalent in contemporary culture. However, the effect of maternal circadian disruption before pregnancy on the reproduction of offspring in mice requires further research. Herein, we exposed female ICR mice to constant light to establish a model of preconceptional circadian disruption and then checked the ovarian function of female offspring (named the CLE group below). Our results revealed obesity, abnormal lipid metabolism and earlier puberty onset in the CLE group. Additionally, impaired ovarian follicle development, oocyte quality and preimplantation embryo development were shown in the CLE group. Moreover, the expression levels of Gnrh1 in the hypothalamus and Cyp17a1, Bmper, Bdnf and Lyve1 in ovaries, as well as circadian clock genes, including Clock, Cry1, Nr1d2 and Per2, were significantly downregulated in the CLE group. Mechanistically, immune responses, including the interleukin-17 (IL-17) signalling pathway, cytokine-cytokine receptor interaction and the chemokine signalling pathway, were altered in the CLE group, which may be responsible for the damaged ovarian function.

Effects of prenatal and postnatal melatonin supplementation on overall performance, male reproductive performance, and testicular hemodynamics in beef cattle

Melatonin has been documented to alleviate compromised pregnancies and enhance livestock performance traits. The objective of this study was to determine the effect of prenatal and postnatal melatonin supplementation on overall calf performance and dam milking traits in relation to calves, molecular factors involved in growth and metabolism of calves, along with testicular physiology and fertility traits in subsequent bulls. On days 190, 220 and 250 of gestation, dams (N = 60) were administered either two subdermal ear melatonin implants (preMEL) or no implants (preCON). After parturition, birth weights were recorded and calves were blocked based on prenatal treatment and sex. Calves received either melatonin implants (posMEL) or none (posCON) on days 0, 30, and 60 of age. On day 60 of lactation, a subset of dams (N = 32) were selected based on age, weight, and calf sex for milk collection and analysis. At weaning, (day 210 postnatally) calf weight, morphometric data, liver samples, and loin samples were collected. At 12 mo of age, bull (N = 30) scrotal circumference, scrotal temperature, and testicular artery measurements were recorded. Milk yield and fat percent from dams tended to decrease in the preMEL group (P < 0.07) compared with preCON group. Prenatal melatonin administration did not affect (P = 0.95) calf birth weight and similarly calf weaning weight was unaffected (P < 0.10) by prenatal or postnatal melatonin supplementation. Blood analysis demonstrated that plasma concentrations of melatonin were not different (P = 0.12) in dams; however, an increase (P < 0.001) in plasma concentrations of melatonin was observed in posMEL vs. posCON calves. A tendency (P < 0.10) for decreased MYF5 and MYOD1 expression in loin muscle was observed in the posMEL calves. Prenatal and postnatal melatonin administration did not affect subsequent bull scrotal measurements or testicular hemodynamics (P ≥ 0.14). Administering supplemental melatonin via implants during the prenatal and postnatal phase did not alter performance characteristics in offspring. In this study, dams were implanted in winter months, whereas calves were implanted in the spring months. Seasonal differences involving photoperiod and ambient temperature might have attributed to a lack of differences in melatonin levels during the prenatal phase. In the postnatal period, the level of developmental plasticity appears to be too low for melatonin properties to be effective.