DNA methylation signatures in peripheral blood mononuclear cells from a lifestyle intervention for women at midlife: a pilot randomized controlled trial

Causal links between sedentary behavior, physical activity, and psychiatric disorders: a Mendelian randomization study

BACKGROUND

Studies suggest a correlation between excessive sedentary behavior, insufficient physical activity, and an elevated likelihood of experiencing psychiatric disorder. Nonetheless, the precise influence of sedentary behavior and physical activity on psychiatric disorder remains uncertain. Hence, the objective of this research was to investigate the possible causal relationship between sedentary behavior, physical activity, and the susceptibility to psychiatric disorder (depression, schizophrenia and bipolar disorder), utilizing a two-sample Mendelian randomization (MR) approach.

METHODS

Potential genetic instruments related to sedentary leisure behaviors were identified from the UK Biobank database, specifically a summary-level genome-wide association study (GWAS) involving 422,218 individuals of European descent. The UK Biobank database also provided the GWAS data for physical activity. Primary analysis was performed using inverse variance weighting (IVW) to assess the causal relationship between sedentary behavior, physical activity, and the risk of psychiatric disorder (depression, schizophrenia and bipolar disorder). Sensitivity analysis was conducted using Cochran's Q test, the MR-Egger intercept test, the MR-pleiotropy RESidual sum and outlier test, leave-one-out analysis, and funnel plot analysis.

RESULTS

According to the IVW analysis, there was a significant association between genetically predicted leisure television watching and an increased risk of depression (odds ratio [OR] = 1.027, 95% confidence interval [CI]: 1.001-1.053; P = 0.04). The IVW analysis also indicated that there was a decreased risk of depression associated with fraction accelerations of > 425 milligravities, as measured by accelerometers (OR = 0.951, 95%CI: 0.914-0.989; P = 0.013). The other MR methods obtained consistent but non-significant results in the same direction. However, there was no evidence of a causal association between genetic liability for moderate-to-vigorous physical activity, accelerometer-assessed physical activity, computer use, or driving and the risk of depression. Furthermore, IVW analysis has also found that driving has a slight effect in reducing the risk of schizophrenia (OR = 0.092, 95%CI: 0.010-0.827; P = 0.033), while leisure television viewing has a significant protective effect against the onset of bipolar disorder (OR = 0.719, 95%CI: 0.567-0.912; P = 0.006).

CONCLUSION

The study provides compelling evidence of a link between depression, bipolar disorder, and excessive TV watching. Furthermore, it suggests that higher accelerometer-assessed fraction accelerations of > 425 milligravities can serve as a genetic protective factor against depression. To mitigate the risk of developing depression, it is advisable to reduce sedentary activities, particularly television watching, and prioritize engaging in vigorous physical exercise.

Exercise mimetics: a novel strategy to combat neuroinflammation and Alzheimer's disease

Neuroinflammation is a pathological hallmark of Alzheimer's disease (AD), characterized by the stimulation of resident immune cells of the brain and the penetration of peripheral immune cells. These inflammatory processes facilitate the deposition of amyloid-beta (Aβ) plaques and the abnormal hyperphosphorylation of tau protein. Managing neuroinflammation to restore immune homeostasis and decrease neuronal damage is a therapeutic approach for AD. One way to achieve this is through exercise, which can improve brain function and protect against neuroinflammation, oxidative stress, and synaptic dysfunction in AD models. The neuroprotective impact of exercise is regulated by various molecular factors that can be activated in the same way as exercise by the administration of their mimetics. Recent evidence has proven some exercise mimetics effective in alleviating neuroinflammation and AD, and, additionally, they are a helpful alternative option for patients who are unable to perform regular physical exercise to manage neurodegenerative disorders. This review focuses on the current state of knowledge on exercise mimetics, including their efficacy, regulatory mechanisms, progress, challenges, limitations, and future guidance for their application in AD therapy.

DNA methylation signature in blood mirrors successful weight-loss during lifestyle interventions: the CENTRAL trial

BACKGROUND

One of the major challenges in obesity treatment is to explain the high variability in the individual's response to specific dietary and physical activity interventions. With this study, we tested the hypothesis that specific DNA methylation changes reflect individual responsiveness to lifestyle intervention and may serve as epigenetic predictors for a successful weight-loss.

METHODS

We conducted an explorative genome-wide DNA methylation analysis in blood samples from 120 subjects (90% men, mean ± SD age = 49 ± 9 years, body mass-index (BMI) = 30.2 ± 3.3 kg/m2) from the 18-month CENTRAL randomized controlled trial who underwent either Mediterranean/low-carbohydrate or low-fat diet with or without physical activity.

RESULTS

Analyses comparing male subjects with the most prominent body weight-loss (responders, mean weight change - 16%) vs. non-responders (+ 2.4%) (N = 10 each) revealed significant variation in DNA methylation of several genes including LRRC27, CRISP2, and SLFN12 (all adj. P < 1 × 10-5). Gene ontology analysis indicated that biological processes such as cell adhesion and molecular functions such as calcium ion binding could have an important role in determining the success of interventional therapies in obesity. Epigenome-wide association for relative weight-loss (%) identified 15 CpGs being negatively correlated with weight change after intervention (all combined P < 1 × 10- 4) including new and also known obesity candidates such as NUDT3 and NCOR2. A baseline DNA methylation score better predicted successful weight-loss [area under the curve (AUC) receiver operating characteristic (ROC) = 0.95-1.0] than predictors such as age and BMI (AUC ROC = 0.56).

CONCLUSIONS

Body weight-loss following 18-month lifestyle intervention is associated with specific methylation signatures. Moreover, methylation differences in the identified genes could serve as prognostic biomarkers to predict a successful weight-loss therapy and thus contribute to advances in patient-tailored obesity treatment.

The Influence of Physical Activity and Epigenomics On Cognitive Function and Brain Health in Breast Cancer

The risk of breast cancer increases with age, with the majority of women diagnosed with breast cancer being postmenopausal. It has been estimated that 25-75% of women with breast cancer experience changes in cognitive function (CF) related to disease and treatment, which compromises psychological well-being, decision making, ability to perform daily activities, and adherence to cancer therapy. Unfortunately, the mechanisms that underlie neurocognitive changes in women with breast cancer remain poorly understood, which in turn limits the development of effective treatments and prevention strategies. Exercise has great potential as a non-pharmaceutical intervention to mitigate the decline in CF in women with breast cancer. Evidence suggests that DNA methylation, an epigenetic mechanism for gene regulation, impacts CF and brain health (BH), that exercise influences DNA methylation, and that exercise impacts CF and BH. Although investigating DNA methylation has the potential to uncover the biologic foundations for understanding neurocognitive changes within the context of breast cancer and its treatment as well as the ability to understand how exercise mitigates these changes, there is a dearth of research on this topic. The purpose of this review article is to compile the research in these areas and to recommend potential areas of opportunity for investigation.

SOCS3 methylation mediated the effect of sedentary time on type 2 diabetes mellitus: The Henan Rural Cohort study

BACKGROUND AND AIMS

To assess the associations of sedentary time, suppressor of cytokine signaling (SOCS)-3 DNA methylation with type 2 diabetes mellitus (T2DM), and further identify the role of SOCS3 methylation in mediating the association of sedentary time with T2DM in a Chinese rural population.

METHODS AND RESULTS

A case-control study including 1032 participants from the Henan Rural Cohort study was conducted. Restricted cubic spline analysis and logistic regression model were performed to evaluate the associations between sedentary time, SOCS3 methylation and T2DM. The mediation effect of SOCS3 methylation on the association between sedentary time and T2DM was assessed. Sensitivity analysis was conducted by excluding individuals with diagnosed T2DM. Linear dose-response relationships were found between sedentary time, methylation level of Chr17:76356190 (one novel site on SOCS3) and T2DM. Compared with the first quartile (less than 5 h/d) of sedentary time, the adjusted odds ratio (OR, 95% confidence interval, 95%CI) for those in the third (7-10 h/d) and fourth (≥10 h/d) quartiles were 1.87 (1.22-2.85) and 3.54 (2.14-5.85), respectively. Participants in the fourth quartile of methylation level of Chr17:76356190 had lower risk of T2DM than those in the first quartile (OR (95%CI): 0.23 (0.14-0.38)). Mediation analysis showed 9.66% (6.38%-14.80%) of the association between sedentary time and T2DM was attributable to Chr17:76356190. The comparable effect estimates were observed between sedentary time, methylation level of Chr17:76356190 and undiagnosed T2DM.

CONCLUSION

Sedentary time and methylation level of Chr17:76356190 were both independently associated with T2DM in the Chinese rural population. Furthermore, Chr17:76356190 appeared to partially mediate the effect of sedentary time on T2DM.

CHINESE CLINICAL TRIAL REGISTRATION

ChiCTR-OOC-15006699 (URL: http://www.chictr.org.cn/showproj.aspx?proj=11375).

Impact of a diet and activity health promotion intervention on regional patterns of DNA methylation

BACKGROUND

Studies demonstrate the impact of diet and physical activity on epigenetic biomarkers, specifically DNA methylation. However, no intervention studies have examined the combined impact of dietary and activity changes on the blood epigenome. The objective of this study was to examine the impact of the Make Better Choices 2 (MBC2) healthy diet and activity intervention on patterns of epigenome-wide DNA methylation. The MBC2 study was a 9-month randomized controlled trial among adults aged 18-65 with non-optimal levels of health behaviors. The study compared three 12-week interventions to (1) simultaneously increase exercise and fruit/vegetable intake, while decreasing sedentary leisure screen time; (2) sequentially increase fruit/vegetable intake and decrease leisure screen time first, then increase exercise; (3) increase sleep and decrease stress (control). We collected blood samples at baseline, 3 and 9 months, and measured DNA methylation using the Illumina EPIC (850 k) BeadChip. We examined region-based differential methylation patterns using linear regression models with the false discovery rate of 0.05. We also conducted pathway analysis using gene ontology (GO), KEGG, and IPA canonical pathway databases.

RESULTS

We found no differences between the MBC2 population (n = 340) and the subsample with DNA methylation measured (n = 68) on baseline characteristics or the impact of the intervention on behavior change. We identified no differentially methylated regions at baseline between the control versus intervention groups. At 3 versus 9 months, we identified 154 and 298 differentially methylated regions, respectively, between controls compared to pooled samples from sequential and simultaneous groups. In the GO database, we identified two gene ontology terms related to hemophilic cell adhesion and cell-cell adhesion. In IPA analysis, we found pathways related to carcinogenesis including PI3K/AKT, Wnt/β-catenin, sonic hedgehog, and p53 signaling. We observed an overlap between 3 and 9 months, including the GDP-L-fucose biosynthesis I, methylmalonyl metabolism, and estrogen-mediated cell cycle regulation pathways.

CONCLUSIONS

The results demonstrate that the MBC2 diet and physical activity intervention impacts patterns of DNA methylation in gene regions related to cell cycle regulation and carcinogenesis. Future studies will examine DNA methylation as a biomarker to identify populations that may particularly benefit from incorporating health behavior change into plans for precision prevention.

Nutritional Factors, DNA Methylation, and Risk of Type 2 Diabetes and Obesity: Perspectives and Challenges

A healthy diet improves life expectancy and helps to prevent common chronic diseases such as type 2 diabetes (T2D) and obesity. The mechanisms driving these effects are not fully understood, but are likely to involve epigenetics. Epigenetic mechanisms control gene expression, maintaining the DNA sequence, and therefore the full genomic information inherited from our parents, unchanged. An interesting feature of epigenetic changes lies in their dynamic nature and reversibility. Accordingly, they are susceptible to correction through targeted interventions. Here we will review the evidence supporting a role for nutritional factors in mediating metabolic disease risk through DNA methylation changes. Special emphasis will be placed on the potential of using DNA methylation traits as biomarkers to predict risk of obesity and T2D as well as on their response to dietary and pharmacological (epi-drug) interventions.

DNA methylation markers in obesity, metabolic syndrome, and weight loss

The fact that not all individuals exposed to the same environmental risk factors develop obesity supports the hypothesis of the existence of underlying genetic and epigenetic elements. There is suggestive evidence that environmental stimuli, such as dietary pattern, particularly during pregnancy and early life, but also in adult life, can induce changes in DNA methylation predisposing to obesity and related comorbidities. In this context, the DNA methylation marks of each individual have emerged not only as a promising tool for the prediction, screening, diagnosis, and prognosis of obesity and metabolic syndrome features, but also for the improvement of weight loss therapies in the context of precision nutrition. The main objectives in this field are to understand the mechanisms involved in transgenerational epigenetic inheritance, and featuring the nutritional and lifestyle factors implicated in the epigenetic modifications. Likewise, DNA methylation modulation caused by diet and environment may be a target for newer therapeutic strategies concerning the prevention and treatment of metabolic diseases.