Impacts of Eccentric Resistance Exercise on DNA Methylation of Candidate Genes for Inflammatory Cytokines in Skeletal Muscle and Leukocytes of Healthy Males.

Physical inactivity and a poor diet increase systemic inflammation, while chronic inflammation can be reduced through exercise and nutritional interventions. The mechanisms underlying the impacts of lifestyle interventions on inflammation remain to be fully explained; however, epigenetic modifications may be critical. The purpose of our study was to investigate the impacts of eccentric resistance exercise and fatty acid supplementation on DNA methylation and mRNA expression of TNF and IL6 in skeletal muscle and leukocytes. Eight non-resistance exercise-trained males completed three bouts of isokinetic eccentric contractions of the knee extensors. The first bout occurred at baseline, the second occurred following a three-week supplementation of either omega-3 polyunsaturated fatty acid or extra virgin olive oil and the final bout occurred after eight-weeks of eccentric resistance training and supplementation. Acute exercise decreased skeletal muscle TNF DNA methylation by 5% (p = 0.031), whereas IL6 DNA methylation increased by 3% (p = 0.01). Leukocyte DNA methylation was unchanged following exercise (p > 0.05); however, three hours post-exercise the TNF DNA methylation decreased by 2% (p = 0.004). In skeletal muscle, increased TNF and IL6 mRNA expression levels were identified immediately post-exercise (p < 0.027); however, the leukocyte mRNA expression was unchanged. Associations between DNA methylation and markers of exercise performance, inflammation and muscle damage were identified (p < 0.05). Acute eccentric resistance exercise is sufficient to induce tissue-specific DNA methylation modifications to TNF and IL6; however, neither eccentric training nor supplementation was sufficient to further modify the DNA methylation.

Health-related motivational and behavioral processes associated with DNA methylation of the TNF gene.

OBJECTIVE: Epigenetics has been described as one of the most exciting areas of contemporary biology, and research has begun to explore whether epigenetic modifications are influenced by psychological processes. The present research explored the associations of health-related motivation and behavior with the DNA methylation of tumor necrosis factor (TNF) gene. METHOD: Participants (N = 88) completed questionnaires examining engagement with health-related behavior (i.e., physical activity, diet, and smoking) and health-related motivation from the perspective of self-determination theory. They also provided a capillary blood sample for DNA extraction and analysis of four CpG sites via bisulfite conversion within Exon 1 of TNF. RESULTS: Health-related autonomous motivation was weakly but positively associated with TNF methylation (ß = .18, p = .08). Indirect effects were identified in a subsequent step; autonomous motivation was positively associated with fruit consumption (ß = .29, p = .004), negatively associated with smoking (ß = -.22, p = .03), but not associated with physical activity (ß = .10, p = .34). Moreover, TNF methylation was positively associated with lifetime physical activity (ß = .18, p = .08) and negatively associated with smoking (ß = -.23, p = .03). Direct effects of autonomous motivation on DNA methylation did not persist when these indirect effects were included (ß = .09, p = .43). CONCLUSIONS: Results support the idea that autonomous motivation is associated with DNA methylation, albeit indirectly through tobacco consumption. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Impact of aerobic exercise and fatty acid supplementation on global and gene-specific DNA methylation.

Lifestyle interventions, including exercise and dietary supplementation, can modify DNA methylation and exert health benefits; however, the underlying mechanisms are poorly understood. Here we investigated the impact of acute aerobic exercise and the supplementation of omega-3 polyunsaturated fatty acids (n-3 PUFA) and extra virgin olive oil (EVOO) on global and gene-specific (PPARGC1A, IL6 and TNF) DNA methylation, and DNMT mRNA expression in leukocytes of disease-free individuals. Eight trained male cyclists completed an exercise test before and after a four-week supplementation of n-3 PUFA and EVOO in a double-blind, randomised, repeated measures design. Exercise triggered global hypomethylation (Pre 79.2%; Post 78.7%; p = 0.008), alongside, hypomethylation (Pre 6.9%; Post 6.3%; p < 0.001) and increased mRNA expression of PPARGC1A (p < 0.001). Associations between PPARGC1A methylation and exercise performance were also detected. An interaction between supplement and trial was detected for a single CpG of IL6 indicating increased DNA methylation following n-3 PUFA and decreased methylation following EVOO (p = 0.038). Global and gene-specific DNA methylation associated with markers of inflammation and oxidative stress. The supplementation of EVOO reduced DNMT1 mRNA expression compared to n-3 PUFA supplementation (p = 0.048), whereas, DNMT3a (p = 0.018) and DNMT3b (p = 0.046) mRNA expression were decreased following exercise. In conclusion, we demonstrate that acute exercise and dietary supplementation of n-3 PUFAs and EVOO induce DNA methylation changes in leukocytes, potentially via the modulation of DNMT mRNA expression. Future studies are required to further elucidate the impact of lifestyle interventions on DNA methylation.

The Role of TLR4, TNF-α and IL-1ß in Type 2 Diabetes Mellitus Development within a North Indian Population.

This study investigated the role of IL-1ß-511 (rs16944), TLR4-896 (rs4986790) and TNF-α-308 (rs1800629) polymorphisms in type 2 diabetes mellitus (T2DM) among an endogamous Northern Indian population. Four hundred fourteen participants (204 T2DM patients and 210 nondiabetic controls) were genotyped for IL-1ß-511, TLR4-896 and TNF-α-308 loci. The C allele of IL-1ß-511 was shown to increase T2DM susceptibility by 75% (OR: 1.75 [CI 1.32-2.33]). Having two parents affected by T2DM increased susceptibility by 5.7 times (OR: 5.693 [CI 1.431-22.648]). In this study, we have demonstrated a conclusive association with IL-1ß-511 locus and IL-1ß-511-TLR4-896 diplotype (CC-AA) and T2DM, which warrants further comprehensive analyses in larger cohorts.

Genetic variation of MHC Class I polymorphic Alu insertions (POALINs) in three sub-populations of the East Midlands, UK.

BACKGROUND: Alu elements are highly researched due to their useful nature as markers in the study of human population genetics. Recently discovered Major Histocompatibility Complex (MHC) polymorphic Alu insertions (POALINs) have not been examined extensively for genetic variation and their HLA associations. AIMS: The aim of this study is to assess the genetic variation between three populations using five recently discovered POALINs. METHODS AND SUBJECTS: The study examined 190 healthy, unrelated subjects from three different populations in the East Midlands (UK) for the presence or absence of five Alu elements (AluHG, AluMICB, AluHJ, AluTF and AluHF) via the polymerase chain reaction followed by gel electrophoresis. Data were analysed for genetic variation and phylogenetic analyses. RESULTS: All Alus were polymorphic in study populations. Appreciable allele frequency variation was observed at a number of loci. The British population was significantly different from both the Punjabi Jat Sikh and Gujarati Patel populations, although showing a closer genetic relationship to the Punjabi Jat Sikh population than the Gujarati Patel population (Nei's DA = 0.0031 and 0.0064, respectively). CONCLUSIONS: MHC POALINs are useful markers in the investigation of genetic variation and the assessment of population relationships, and may have some bearing on disease associations due to their linkage disequilibrium with HLA loci; this warrants further studies.

Genetic analysis of novel Alu insertion polymorphisms in selected indian populations.

OBJECTIVES: Indian subpopulations (Chenchu, Koya, and Lobana Sikh) were analyzed at the genetic level for 12 Alu polymorphisms. These markers were then utilized to establish levels of genetic identity between the Indian populations and more widely between the Indian populations and a European population. METHODS: Previously collected blood samples were extracted using the phenol-chloroform method. The samples were utilized as templates for PCR using Alu specific primers and then analyzed by agarose gel electrophoresis for the presence and absence of the approximately 300 bp insertions. Allele frequencies were calculated by the gene counting method and were tested for Hardy-Weinberg equilibrium, heterozygosities, inbreeding coefficient, and GST to assess the level of genetic differentiation. RESULTS: All of the Alu loci were polymorphic in the three Indian populations studied and their average observed heterozygosity ranged from 0.294 (Lobana Sikh) to 0.357 (Koya). Allele and genotype frequency variation at the 2b, 9a, and ACE loci led to statistically significant pairwise differences among the three study populations. Overall population heterogeneity was observed for 7 out of 12 Alu polymorphisms. CONCLUSION: The overall results show that these Indian samples, though displaying significant genetic variation and differences among themselves, form an Indian cluster, which as expected, is distinct from the European sample (Russian). As Alus are easily analyzed and quantified by standard and cost-effective methodologies, this finding further reinforces their utility as effective population genetic markers. Am. J. Hum. Biol., 2016. © 2016 Wiley Periodicals, Inc. Am. J. Hum. Biol. 28:941-944, 2016. © 2016Wiley Periodicals, Inc.

n-3 Fatty acids and asthma.

Asthma is one of the most common and prevalent problems worldwide affecting over 300 million individuals. There is some evidence from observational and intervention studies to suggest a beneficial effect of n-3 PUFA in inflammatory diseases, specifically asthma. Marine-based n-3 PUFA have therefore been proposed as a possible complementary/alternative therapy for asthma. The proposed anti-inflammatory effects of n-3 fatty acids may be linked to a change in cell membrane composition. This altered membrane composition following n-3 fatty acid supplementation (primarily EPA and DHA) can modify lipid mediator generation via the production of eicosanoids with a reduced inflammatory potential/impact. A recently identified group of lipid mediators derived from EPA including E-series resolvins are proposed to be important in the resolution of inflammation. Reduced inflammation attenuates the severity of asthma including symptoms (dyspnoea) and exerts a bronchodilatory effect. There have been no major health side effects reported with the dietary supplementation of n-3 fatty acids or their mediators; consequently supplementing with n-3 fatty acids is an attractive non-pharmacological intervention which may benefit asthma.

Unity in diversity: an overview of the genomic anthropology of India.

CONTEXT: India is considered a treasure for geneticists and evolutionary biologists due to its vast human diversity, consisting of more than 4500 anthropologically well-defined populations (castes, tribes and religious groups). Each population differs in terms of endogamy, language, culture, physical features, geographic and climatic position and genetic architecture. These factors contributed to India-specific genetic variations which may be responsible for various common diseases in India and its migratory populations. As a result, interpretations of the origins and affinities of Indian populations as well as health and disease conditions require complex and sophisticated genetic analysis. Evidence of ancient human dispersals and settlements is preserved in the genome of Indian inhabitants and this has been extensively analysed in conventional and genomic analyses. OBJECTIVE AND METHODS: Using genomic analyses of STRs and Alu on a set of populations, this study estimates the level and extent of genetic variation and its implications. RESULTS: The results show that Indian populations have a higher level of unique genetic diversity which is structured by many social processes and geographical attributes of the country. CONCLUSION: This overview highlights the need to study the anthropological structure and evolutionary history of Indian populations while designing genomic and epigenomic investigations.

Influence of glutathione S-transferase polymorphisms (GSTT1, GSTM1, GSTP1) on type-2 diabetes mellitus (T2D) risk in an endogamous population from north India.

Glutathione S-transferases (GSTs) belong to a group of multigene and multifunctional detoxification enzymes, which defend cells against a wide variety of toxic insults and oxidative stress. Oxidative stress leads to cellular dysfunction which contributes to the pathophysiology of diseases such as cancer, atherosclerosis, and diabetes mellitus. It is important to assess whether the glutathione S-Transferase (GSTT1, GSTM1 and GSTP1) genotypes are associated with type 2 diabetes mellitus as deletion polymorphisms have an impaired capability to counteract the oxidative stress which is a feature of diabetes. GSTT1, GSTM1 and GSTP1 gene polymorphisms were analysed in 321 patients and 309 healthy controls from an endogamous population from north India. An association analysis was carried out at two levels (a) individual genes and (b) their double and triple combinations. The proportion of GSTT1 and GSTM1 null genotypes was higher in diabetics compared to controls (GSTT1 30.8 vs. 21.0 %; GSTM1 49.5 vs. 27.2 %). The frequency of the null genotype at both loci was higher in diabetics (19.6 vs. 7.8 %) leading to an odds ratio of 2.90 (CI 1.76-4.78, P < 0.0001). At GSTP1locus, patients had a higher frequency of the V/V genotype (15.6 vs. 7.5 %) and significant susceptible odds ratio (2.56, CI 1.47-4.48, P < 0.001). A combination of null genotypes at GSTT1 and GSTM1 loci and V/V genotype of GSTP1 locus showed highest odds ratio (9.64, CI 1.53-60.63, P < 0.01). Overall this study highlights that GST genes may play an important role in the pathogenesis of type 2 diabetes. The risk is higher in individuals carrying more than one susceptible genotype at these loci. The potential role of GST polymorphisms as markers of susceptibility to type 2 diabetes needs further investigations in a larger number of patients and populations.

Relationship of 2D:4D finger ratio with muscle strength, testosterone, and androgen receptor CAG repeat genotype.

This study aimed to examine the relationship between the ratio of the length of the second and fourth digits (2D:4D) and locomotor muscle strength. Furthermore, two putative mechanisms that might explain any relationship of 2D:4D with muscle strength, specifically serum total and free testosterone, and androgen receptor genotype CAG repeat number (AR CAGn) were investigated. Seventy-seven healthy young Caucasian men completed a thorough assessment of isometric and isokinetic knee extensor strength, with unilateral measurements averaged across both legs and repeated on two occasions. The lengths of the second and fourth fingers of each hand were measured to calculate 2D:4D ratio. Serum total testosterone (TT) and serum hormone binding globulin (SHBG) were measured by ELISA and used to calculate free testosterone (FT). AR CAGn was determined by PCR and microchip electrophoresis. There was no association between mean, left or right hand 2D:4D and isometric or isokinetic knee extensor strength (all, R < 0.12, P > 0.32). TT and FT were unrelated to mean, left or right hand 2D:4D ratio (all, R < 0.12, P > 0.34). Finally AR CAGn was not associated with mean, right or left hand 2D:4D ratio (all, R < 0.20, P > 0.10). This study found no evidence of 2D:4D being related to locomotor muscle strength, TT, FT, or AR CAGn. The reported association of 2D:4D with sports performance does not seem to be explained by an influence on locomotor muscle strength, and could be due to an effect on motor or cognitive skills.

Lack of association of bone morphogenetic protein 2 gene haplotypes with bone mineral density, bone loss, or risk of fractures in men.

Introduction. The association of bone morphogenetic protein 2 (BMP2) with BMD and risk of fracture was suggested by a recent linkage study, but subsequent studies have been contradictory. We report the results of a study of the relationship between BMP2 genotypes and BMD, annual change in BMD, and risk of fracture in male subjects. Materials and Methods. We tested three single-nucleotide polymorphisms (SNPs) across the BMP2 gene, including Ser37Ala SNP, in 342 Caucasian Englishmen, comprising 224 control and 118 osteoporotic subjects. Results. BMP2 SNP1 (Ser37Ala) genotypes were found to have similar low frequency in control subjects and men with osteoporosis. The major informative polymorphism, BMP2 SNP3 (Arg190Ser), showed no statistically significant association with weight, height, BMD, change in BMD at hip or lumbar spine, and risk of fracture. Conclusion. There were no genotypic or haplotypic effects of the BMP2 candidate gene on BMD, change in BMD, or fracture risk identified in this cohort.

The anti-inflammatory effects of exercise: mechanisms and implications for the prevention and treatment of disease.

Regular exercise reduces the risk of chronic metabolic and cardiorespiratory diseases, in part because exercise exerts anti-inflammatory effects. However, these effects are also likely to be responsible for the suppressed immunity that makes elite athletes more susceptible to infections. The anti-inflammatory effects of regular exercise may be mediated via both a reduction in visceral fat mass (with a subsequent decreased release of adipokines) and the induction of an anti-inflammatory environment with each bout of exercise. In this Review, we focus on the known mechanisms by which exercise - both acute and chronic - exerts its anti-inflammatory effects, and we discuss the implications of these effects for the prevention and treatment of disease.

Association analysis of TNFR2, VDR, A2M, GSTT1, GSTM1, and ACE genes with rheumatoid arthritis in South Asians and Caucasians of East Midlands in the United Kingdom.

Genetic associations of TNFR2, VDR (Bsm I and Fok I), A2M, GSTT(1), GSTM(1) and ACE in South Asian and Caucasian patients with rheumatoid arthritis (RA) were assessed in this study. DNA samples from South Asians (134 cases, 149 controls) and Caucasians (137 cases, 150 controls) from the East Midlands of the United Kingdom were genotyped for seven polymorphisms. All cases were rheumatoid-factor positive. Significant genetic associations were observed with TNFR2 R-R (OR = 3.16, CI 1.20-9.26, P < 0.05), A2M 1-1 (OR = 2.09, CI 1.21-3.64, P < 0.05) and GST T(1)null (OR = 1.97, CI 1.07-3.68, P < 0.05) among Caucasian patients. In South Asians, VDR Bsm I B-B genotype (OR = 2.08, CI 1.23-3.52, P < 0.05), A2M 2-2 genotype (OR = 3.99, CI 1.19-17.18, P < 0.05), and GST T(1)null genotype (OR = 2.81, CI 1.40-5.77, P < 0.002) genotypes were associated with RA. In the majority of cases, recessive and multiplicative modes of inheritance explained the observed associations. This study demonstrates that ethnicity affects the genetic associations in RA.

ACE I/D and ACTN3 R/X polymorphisms and muscle function and muscularity of older Caucasian men.

The progressive decline in strength and power with ageing leads to compromised mobility and an increased risk of falls. Angiotensin converting enzyme (ACE) I/D and alpha actinin 3 (ACTN3) R/X polymorphisms have been suggested to influence variations in skeletal muscle function and body composition. This study investigated the associations between these polymorphisms and knee extensor muscle function and muscularity in older Caucasian men. Strength was measured isometrically and isokinetically (at 30 and 240 degrees s(-1)), and the time course of the evoked twitch response recorded. A dual-energy X-ray absorptiometry scan measured thigh and whole body non-skeletal lean mass. ACE I/D and ACTN3 R/X polymorphisms were determined by polymerase chain reaction, and serum ACE activity using spectrophotometry. Whole body and thigh non-skeletal lean mass were independent of ACE and ACTN3 genotypes. Absolute and relative high velocity strength, and the time course of an evoked twitch were not associated with ACE or ACTN3 genotype. Serum ACE activity was negatively correlated with relative high velocity torque (R = -0.23, P = 0.03), and exhibited a positive trend with knee extensor isometric strength (R = 0.19, P = 0.07). ACE I/D and ACTN3 R/X polymorphisms were not associated with muscle function or muscularity phenotypes in older Caucasian men, although serum ACE activity appeared to have a small effect on muscle function.

Tumor necrosis factor alpha -308 gene locus promoter polymorphism: an analysis of association with health and disease.

Tumor necrosis factor-alpha (TNF-alpha) is a potent immunomediator and proinflammatory cytokine that has been implicated in the pathogenesis of a large number of human diseases. The location of its gene within major histocompatibility complex and biological activities has raised the possibility that polymorphisms within this locus may contribute to the pathogenesis of wide range of autoimmune and infectious diseases. For example, a bi-allelic single nucleotide substitution of G (TNFA1 allele) with A (TNFA2 allele) polymorphism at -308 nucleotides upstream from the transcription initiation site in the TNF-alpha promoter is associated with elevated TNF-alpha levels and disease susceptibilities. However, it is still unclear whether TNF-alpha -308 polymorphism plays a part in the disease process, in particular whether it could affect transcription factor binding and in turn influence TNF-alpha transcription and synthesis. Several studies have suggested that TNFA2 allele is significantly linked with the high TNF-alpha-producing autoimmune MHC haplotype HLA-A1, B8, DR3, with elevated serum TNF-alpha levels and a more severe outcome in diseases. This review discusses the genetics of the TNF-alpha -308 polymorphism in selected major diseases and evaluates its common role in health and disease.

Human angiotensin-converting enzyme I/D and alpha-actinin 3 R577X genotypes and muscle functional and contractile properties.

The angiotensin-converting enzyme (ACE) I/D and alpha-actinin 3 (ACTN3) R/X polymorphisms have been suggested to influence variations in skeletal muscle function. This study investigated the association between ACE I/D and ACTN3 R/X polymorphisms and muscle strength and contractile properties in young UK Caucasian men. Measurements of the knee extensor muscles were taken from 79 recreationally active but non-strength-trained males on two occasions. Isometric knee extensor strength was measured using a conventional strength-testing chair. Maximal twitches were electrically evoked by percutaneous stimulation to assess time-to-peak tension, half-relaxation time and peak rate of force development. The torque-velocity relationship was measured at four angular velocities (0, 30, 90 and 240 deg s(-1)) using isokinetic dynamometry, and the relative torque at high velocity was calculated (torque at 240 deg s(-1) as a percentage of that at 30 deg s(-1)). The ACE I/D and ACTN3 R/X polymorphisms were genotyped from whole blood by polymerase chain reaction. Serum ACE activity was assayed from serum using automated spectrophotometry. Physical characteristics were independent of either genotype. Absolute and relative high-velocity torque were not influenced by ACE or ACTN3 genotypes. Isometric strength and the time course of a maximal twitch were independent of ACE and ACTN3 genotypes. Serum ACE activity was significantly dependent on ACE genotype (P < 0.001), but was not associated with any measure of functional or contractile properties. Knee extensor functional and contractile properties, including high-velocity strength, were not influenced by ACE and ACTN3 polymorphisms in a cohort of UK Caucasian males. Any influence of these individual polymorphisms on human skeletal muscle does not appear to be of sufficient magnitude to influence function in free-living UK Caucasian men.

A variant of position -308 of the Tumour necrosis factor alpha gene promoter and the risk of coronary heart disease.

PURPOSE: The aim of this study was to investigate whether the variability between individuals with coronary heart disease (CHD) is related to the prevalence of TNF-alpha gene promoter -308 variant in un-matched British Caucasian population from East Midlands. PROCEDURES: Genotypes and allele frequencies were determined using restriction fragment length polymorphism analysis of polymerase chain reaction (PCR) products. Genomic DNA prepared from peripheral blood leukocytes of patients (n=97) and healthy controls (n=95) demonstrated two alleles TNF*1 (G) and TNF*2 (A). FINDINGS: The genotype distribution in patients was GG, n=59; GA, n=36; and AA, n=2 and in controls was GG, n=41; GA, n=40; and AA, n=14 (P=0.014). The association analysis demonstrated that TNF*1 allele in patients appears to be associated with greater incidences of CHD (OR 2.15; CI, 1.36-3.39; P=0.001). CONCLUSIONS: Our results suggest that TNF*1 allele (TNF-alpha -308 GG or GA) has a high prevalence among British Caucasian population that correlates with an increased CHD risk.

Genetic variation of apolipoproteins in North Indians.

Genetic variation at three apolipoprotein loci (APOA4, APOH, and APOE) has been examined in nine endogamous populations of Punjab, North India. The overall pattern of allele frequency variation at different loci is compatible with that of European populations, but observed microvariation differentiates the populations according to their position in the Indian caste structure. The most common allele at the APOA4 locus was APOA4*1 with a narrow frequency range (89%-92%). APOH*2 allele frequency was highest in these populations (0.852-0.914). APOE*E4 allele frequency was relatively low (6%-10%) in the North Indian populations compared to its frequency in many European populations. The anthropological usage of these polymorphisms was evaluated using multivariate analyses. Genetic distance analysis and principal correspondence analysis showed that the North Indian populations are closest to Europeans, followed by Chinese and African populations. Overall, this study highlights the usefulness of apolipoproteins as genetic markers for clinical, population, and anthropological studies.

Genetic heterogeneity of Apo CII locus in north India.

Apolipoprotein CII genotypes were determined in Brahmins, Banias, Jat Sikhs, Khatris, Ramgarhia, Ramdasia and Scheduled Castes of Punjab, North India (n = 930). The Apo CII exhibits three common polymorphic alleles CII*1, CII*2 and CII*3 with pooled frequencies 0.883, 0.114 and 0.003, respectively. CII*3 was absent in Brahmins. Distribution of Apo CII isoforms highlights a considerable variation among different ethnic groups across the world. The average heterozygosity of the Punjabi populations was 0.208. The gene diversity among these population groups was less than 0.1%.