Endothelial nitric oxide gene haplotype reduces the effect of a single bout of exercise on the vascular reactivity in healthy subjects

Exercise training modifies the whole blood DNA methylation profile in middle-aged and older women

This is a longitudinal single-arm clinical trial aimed to investigate whether exercise training would modify the whole blood methylation profile in healthy women. A total of 45 subjects were engaged in an exercise training protocol during a 14-wk follow up, consisting of aerobic cardiorespiratory and muscle strength exercises. Subjects were evaluated at baseline (PRE), after 7 wk of exercise training (POST 7), and after 14 wk of exercise training (POST 14). Functional primary outcomes included anthropometric, blood pressure, biochemical measurements, physical tests, and global health assessments. Blood samples were collected at each time point to determine the methylation profile using a DNA methylation array technique screening up to 850k different sites. Exercise training decreased blood pressure and triglyceride levels and enhanced physical performance, including upper- and lower-body maximum strength. Moreover, exercise training improved markers of quality of life. In the array analysis, 14 wk of exercise training changed the methylation of more than 800 sites. Across these differentially methylated sites, we found that differentially methylated sites in the promoter region were more hypermethylated after exercise training, suggesting that this hypermethylation process may affect the transcription process. When inputting the differentially methylated sites in pathway analysis, we found several metabolic pathways, including AMPK signaling, TGF-β signaling, and insulin signaling. This study demonstrates that exercise training promotes a robust change in the whole blood methylation profile and provides new insights into the key regulators of exercise-induced benefits.NEW & NOTEWORTHY We have shown that exercise training lowers blood pressure and triglyceride levels, improves physical performance, and improves quality of life in middle-aged and elderly women. Regarding epigenetic data, we noticed that more than 800 sites are differentially methylated in whole blood after physical training. We emphasize that the differentially methylated sites in the promoter region are more hypermethylated after physical training. In addition, this study shows that key members of metabolic pathways, including AMPK signaling, TGF-β signaling, and insulin signaling, are among the genes hypermethylated after physical exercise in older women.

The VNTR polymorphism of the endothelial nitric oxide synthase gene and blood pressure in women at the end of pregnancy

OBJECTIVE

Examine the association of the 4a/4b polymorphism of endothelial nitric oxide synthase (eNOS) with blood pressure in women at late pregnancy.

MATERIALS AND METHODS

Blood pressure before pregnancy and at the end of gestation (37-40-week term) was measured in 588 women of the Russian ancestry. The women were divided into groups according to the body mass index and the presence of preeclampsia at late pregnancy. The 4a/4b polymorphism of the eNOS gene was genotyped using PCR with subsequent screening of amplified fragment length polymorphisms.

RESULTS

The 4a4a eNOS genotype was associated with higher levels of diastolic blood pressure in pregnant women and with more pronounced dynamics of the diastolic and mean arterial pressure in the development of pregnancy (p = 0.02-0.03). Pregnant women with the 4a4a genotype and increased body mass index had higher systolic, diastolic, and mean arterial pressure (p = 0.001-0.009). In pregnant women with preeclampsia, the 4a4a genotype was associated with higher level of diastolic blood pressure at the end of pregnancy (p = 0.04), whereas in the women without preeclampsia this genotype was associated with more pronounced changes of blood pressure at pregnancy (p = 0.02).

CONCLUSION

The results of our study suggest that the genotype 4a4a of the eNOS gene is associated with higher levels of blood pressure in women at the end of pregnancy.

Associations of the NOS3 rs1799983 polymorphism with circulating nitric oxide and lipid levels: a systematic review and meta-analysis

BACKGROUND

Circulating nitric oxide (NO) and lipid levels are closely associated with coronary artery disease (CAD). It is unclear whether the rs1799983 polymorphism in endothelial nitric oxide synthase (NOS3) gene is associated with plasma levels of NO and lipids. This systematic review and meta-analysis (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) aimed to clarify the relationships between the rs1799983 polymorphism and plasma levels of NO and lipids.

METHODS

Sixteen studies (2702 subjects) and 59 studies (14 148 subjects) were identified for the association analyses for NO and lipids, respectively. Mean difference (MD) and 95% CI were used to estimate the effects of the rs1799983 polymorphism on plasma NO and lipid levels. The primary outcome variable was NO, and the secondary outcomes included triglycerides, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C).

RESULTS

Carriers of the T allele had lower levels of NO (MD -0.27 μmol/L, 95% CI -0.42 to -0.12 μmol/L, p<0.001) and HDL-C (MD -0.07 mmol/L, 95% CI -0.14 to -0.00 mmol/L, p=0.04), and higher levels of TC (MD 0.13 mmol/L, 95% CI 0.06 to 0.20 mmol/L, p<0.001) and LDL-C (MD 0.14 mmol/L, 95% CI 0.05 to 0.22 mmol/L, p=0.002) than the non-carriers. Triglyceride levels were comparable between the genotypes.

CONCLUSION

The association between the NOS3 rs1799983 polymorphism and CAD may be partly mediated by abnormal NO and lipid levels caused by the T allele.

Effect of Multicomponent Training on Blood Pressure, Nitric Oxide, Redox Status, and Physical Fitness in Older Adult Women: Influence of Endothelial Nitric Oxide Synthase (NOS3) Haplotypes

The purpose of this study was to verify the influence of the genotype or haplotype (interaction) of the NOS3 polymorphisms [-786T>C, 894G>T (Glu298Asp), and intron 4b/a] on the response to multicomponent training (various capacities and motor skills) on blood pressure (BP), nitrite concentration, redox status, and physical fitness in older adult women. The sample consisted of 52 participants, who underwent body mass index and BP assessments. Physical fitness was evaluated by six-minute walk, elbow flexion, and sit and stand up tests. Plasma/blood samples were used to evaluate redox status, nitrite concentration, and genotyping. Associations were observed between isolated polymorphisms and the response of decreased systolic and diastolic BP and increased nitrite concentration and antioxidant activity. In the haplotype analysis, the group composed of ancestral alleles (H1) was the only one to present improvement in all variables studied (decrease in systolic and diastolic BP, improvement in nitrite concentration, redox status, and physical fitness), while the group composed of variant alleles (H8) only demonstrated improvement in some variables of redox status and physical fitness. These findings suggest that NOS3 polymorphisms and physical training are important interacting variables to consider in evaluating redox status, nitric oxide availability and production, and BP control.

Advances in exercise, fitness, and performance genomics in 2013

The most significant and scientifically sound articles in exercise genomics that were published in 2013 are reviewed in this report. No article on the genetic basis of sedentary behavior or physical activity level was identified. A calcineurin- and alpha actinin-2-based mechanism has been identified as the potential molecular basis for the observed lower muscular strength and power in alpha actinin-3-deficient individuals. Although baseline muscle transcriptomic signatures were found to be associated with strength training-induced muscle hypertrophy, no predictive genomic variants could be identified as of yet. One study found no clear evidence that the inverse relation between physical activity level and incident CHD events was influenced by 58 genomic variants clustered into four genetic scores. Lower physical activity level in North American populations may be driving the apparent risk of obesity in fat mass- and obesity-associated gene (FTO)-susceptible individuals compared with more active populations. Two large studies revealed that common genetic variants associated with baseline levels of plasma HDL cholesterol and triglycerides are not clear predictors of changes induced by interventions focused on weight loss, diet, and physical activity behavior. One large study from Japan reported that a higher fitness level attenuated the arterial stiffness-promoting effect of the Ala54 allele at the fatty acid binding protein 2 locus, which is a controversial finding because previous studies have suggested that Thr54 was the risk allele. Using transcriptomics to generate genomic targets in an unbiased manner for subsequent DNA sequence variants studies appears to be a growing trend. Moreover, exercise genomics is rapidly embracing gene and pathway analysis to better define the underlying biology and provide a foundation for the study of human variation.

eNOS gene haplotype is indirectly associated with the recovery of cardiovascular autonomic modulation from exercise

Polymorphisms in the endothelial nitric oxide synthase (eNOS) gene decrease expression and activation of eNOS in vitro, which is associated with lower post-exercise increase in vasodilator reactivity in vivo. However, it is unknown whether such polymorphisms are associated with other eNOS-related phenotypes during recovery from exercise. Therefore, we investigated the impact of an eNOS haplotype containing polymorphic alleles at loci -786 and 894 on the recovery of cardiovascular autonomic function from exercise. Sedentary, non-obese, healthy subjects were enrolled [n = 107, age 32 ± 1 years (mean ± SEM)]. Resting autonomic modulation (heart rate variability, systolic blood pressure variability, and spontaneous baroreflex sensitivity) and vascular reactivity (forearm hyperemic response post-ischemia) were assessed at baseline, 10, 60, and 120 min after a maximal cardiopulmonary exercise test. Besides, autonomic function was assessed by heart rate recovery (HRR) immediately after peak exercise. Haplotype analysis showed that vagal modulation (i.e., HF n.u.) was significantly higher, combined sympathetic and vagal modulation (i.e., LF/HF) was significantly lower and total blood pressure variability was significantly lower post-exercise in a haplotype containing polymorphic alleles (H2) compared to a haplotype with wild type alleles (H1). HRR was similar between groups. Corroborating previous evidence, H2 had significantly lower post-exercise increase in vasodilator reactivity than H1. In conclusion, a haplotype containing polymorphic alleles at loci -786 and 894 had enhanced recovery of autonomic modulation from exercise, along with unchanged HRR, and attenuated vasodilator reactivity. Then, these results suggest an autonomic compensatory response of a direct deleterious effect of eNOS polymorphisms on the vascular function.