Physical exercise and microRNAs: new frontiers in heart failure

MicroRNA-146a polymorphism is not associated with cardiovascular disease in the elderly

Abstract Introduction: Cardiovascular diseases (CVD) figure among the most significant causes of morbidity and mortality in the world and, among genetic factors, the literature has demonstrated the crucial role of miRNAs and the relationship of physical activity with this pathology. Objective: To investigate the relationship between the functional capacity of exercise, the level of physical activity, and the polymorphism in the miRNA-146a gene in elderly individuals with and without CVD. Methods: This study, developed in a city in the southern region of Brazil, is characterized as cross-sectional. The sample for this study comprised 342 participants, aged 60 or over. The following aspects were analyzed: anthropometric characteristics, genetic profiles, diagnosis of CVD, functional capacity, and the level of physical activity. Results: A statistically significant association was observed between CVD and body mass index (BMI) (א² = 14.278; p = 0.0003), and 40.6% of elderly individuals with CVD were obese, while 31.5% of the normally developed elderly participants presented normal BMI. However, the genotype frequencies (p = 0.546; א² = 1.211) and 6MWT (p = 0.311; א² = 1.025) did not show a statistically signifi-cant association with CVD. Conclusion: Our results suggest that the polymorphism in the miRNA-146A (rs2910164) and functional capacity are not associated with CVD in the elderly. However, the BMI did demonstrate an association with this disease.

Effects of the exercise training on skeletal muscle oxygen consumption in heart failure patients with reduced ejection fraction

AIMS

Skeletal muscle dysfunction is a systemic consequence of heart failure (HF) that correlates with functional capacity. However, the impairment within the skeletal muscle is not well established. We investigated the effect of exercise training on peripheral muscular performance and oxygenation in HF patients.

METHODS AND RESULTS

HF patients with ejection fraction ≤40% were randomized 2:1 to exercise training or control for 12 weeks. Muscle tissue oxygen was measured noninvasively by near-infrared spectroscopy (NIRS) during rest and a symptom-limited cardiopulmonary exercise test (CPET) before and after intervention. Measurements included skeletal muscle oxygenated hemoglobin concentration, deoxygenated hemoglobin concentration, total hemoglobin concentration, VO₂ peak, VE/VCO₂ slope, and heart rate. Muscle sympathetic nerve activity by microneurography, and muscle blood flow by plethysmography were also assessed at rest pre and post 12 weeks. Twenty-four participants (47.5 ± 7.4 years, 58% men, 75% no ischemic) were allocated to exercise training (ET, n = 16) or control (CG, n = 8). At baseline, no differences between groups were found. Exercise improved VO₂ peak, slope VE/VCO₂, and heart rate. After the intervention, significant improvements at rest were seen in the ET group in muscle sympathetic nerve activity and muscle blood flow. Concomitantly, a significant decreased in Oxy-Hb (from 29.4 ± 20.4 to 15.7 ± 9.0 μmol, p = 0.01), Deoxi-Hb (from 16.3 ± 8.2 to 12.2 ± 6.0 μmol, p = 0.003) and HbT (from 45.7 ± 27.6 to 27.7 ± 13.4 μmol, p = 0.008) was detected at peak exercise after training. No changes were observed in the control group.

CONCLUSION

Exercise training improves skeletal muscle function and functional capacity in HF patients with reduced ejection fraction. This improvement was associated with increased oxygenation of the peripheral muscles, increased muscle blood flow, and decreased sympathetic nerve activity.

Orally administered pressure-blanched white saffron (Curcuma mangga Val.) improves antioxidative properties and lipid profiles in vivo

This research focused on studying the effects of orally administered pressure-blanched white saffron on the antioxidative properties and lipid profiles of wistar rats. White saffron was blanched in autoclave for 2.5, 5, 7.5, and 10 min at 100, 105, 110, 115, and 120 °C, which are equivalent to 14.71, 17.53, 20.79, 24.54, and 28.81 psia, respectively. A total of 30 male wistar rats aged four weeks were fed with a standard diet (N), oxidized peanut oil diet + unblanched white saffron (A), oxidized peanut oil diet + blanched white saffron (B), oxidized peanut oil diet + pressure-blanched white saffron (C), and oxidized peanut oil diet + aquadest (NC), for two weeks after pre-treatment with the standard diet for a week. Invivo study showed treatment with pressure-blanched white saffron could significantly improve SOD, Vitamin E, and HDL levels compared to the negative control (NC); 686.44 U/g Hb, 10.87 μg/mL, and 94.17 mg/dL versus 405.37 U/g Hb, 7.44 μg/mL, and 43.47 mg/dL, respectively. Meanwhile, treatment with pressure-blanched white saffron could significantly reduce MDA, total cholesterol, LDL, and triglyceride levels in the blood compared to the negative control (NC); 1.98 mmol/L, 108.74 mg/dL, 40.99 mg/dL, and 78.06 mg/dL versus 8.54 mmol/L, 232.46 mg/dL, 149.17 mg/dL, and 172.61 mg/dL, respectively. The results showed that pressurized blanching could significantly increase antioxidant levels of white saffron, and its dried form could improve antioxidative properties and lipid profiles in vivo.

Physical activity in the prevention of human diseases: role of epigenetic modifications

Epigenetic modification refers to heritable changes in gene function that cannot be explained by alterations in the DNA sequence. The current literature clearly demonstrates that the epigenetic response is highly dynamic and influenced by different biological and environmental factors such as aging, nutrient availability and physical exercise. As such, it is well accepted that physical activity and exercise can modulate gene expression through epigenetic alternations although the type and duration of exercise eliciting specific epigenetic effects that can result in health benefits and prevent chronic diseases remains to be determined. This review highlights the most significant findings from epigenetic studies involving physical activity/exercise interventions known to benefit chronic diseases such as metabolic syndrome, diabetes, cancer, cardiovascular and neurodegenerative diseases.

Exercise for the heart: signaling pathways

Physical exercise, a potent functional intervention in protecting against cardiovascular diseases, is a hot topic in recent years. Exercise has been shown to reduce cardiac risk factors, protect against myocardial damage, and increase cardiac function. This improves quality of life and decreases mortality and morbidity in a variety of cardiovascular diseases, including myocardial infarction, cardiac ischemia/reperfusion injury, diabetic cardiomyopathy, cardiac aging, and pulmonary hypertension. The cellular adaptation to exercise can be associated with both endogenous and exogenous factors: (1) exercise induces cardiac growth via hypertrophy and renewal of cardiomyocytes, and (2) exercise induces endothelial progenitor cells to proliferate, migrate and differentiate into mature endothelial cells, giving rise to endothelial regeneration and angiogenesis. The cellular adaptations associated with exercise are due to the activation of several signaling pathways, in particular, the growth factor neuregulin1 (NRG1)-ErbB4-C/EBPβ and insulin-like growth factor (IGF)-1-PI3k-Akt signaling pathways. Of interest, microRNAs (miRNAs, miRs) such as miR-222 also play a major role in the beneficial effects of exercise. Thus, exploring the mechanisms mediating exercise-induced benefits will be instrumental for devising new effective therapies against cardiovascular diseases.

Quercetin intake with exercise modulates lipoprotein metabolism and reduces atherosclerosis plaque formation

Study objectives

We proposed that mice supplemented with quercetin, a class of flavonoids known to have antioxidant and anti-inflammatory properties, will have profound effects on the pathophysiology of atherosclerosis when combined with exercise.

Study design

Forty C57BL6 LDLr −/− mice were divided into four groups (n = 10): control untreated (NN); control group supplemented with 100 μg/day of quercetin (NQ); exercise group (EN); and exercise group supplemented with 100 μg/day of quercetin (EQ). All animals were fed atherogenic diet. The exercise groups were run on a treadmill for 30 minutes, 15 m/min for 5 days/week for 30 days. After 30 day animals were sacrificed and tissues were harvested.

Results and conclusion

Mice supplemented with quercetin during exercise sessions had 78% atherosclerotic plaque reduction compared to control mice and 40% less atherosclerotic plaque formation compared to control group supplemented with quercetin. The manifestation of the combination of quercetin supplementation with exercise was more evident in the pro-reverse cholesterol transport genes, indicating a plausible mechanism for their combined beneficial effect.

The pathogenesis of atherosclerosis, the major cause of cardiovascular diseases (CVD), is multifactorial and therefore its treatment approaches and the ability to regress the plaque are complicated. Data from research on animal models and clinical studies have indicated that moderate daily exercise can alleviate the risk for the development of atherosclerotic plaques, while the same has not been true for the supplementation of antioxidants.

Endothelium and its alterations in cardiovascular diseases: life style intervention

The endothelium, which forms the inner cellular lining of blood vessels and lymphatics, is a highly metabolically active organ that is involved in many physiopathological processes, including the control of vasomotor tone, barrier function, leukocyte adhesion, and trafficking and inflammation. In this review, we summarized and described the following: (i) endothelial cell function in physiological conditions and (ii) endothelial cell activation and dysfunction in the main cardiovascular diseases (such as atherosclerosis, and hypertension) and to diabetes, cigarette smoking, and aging physiological process. Finally, we presented the currently available evidence that supports the beneficial effects of physical activity and various dietary compounds on endothelial functions.

Genomic and epigenomic insights into nutrition and brain disorders

Considerable evidence links many neuropsychiatric, neurodevelopmental and neurodegenerative disorders with multiple complex interactions between genetics and environmental factors such as nutrition. Mental health problems, autism, eating disorders, Alzheimer's disease, schizophrenia, Parkinson's disease and brain tumours are related to individual variability in numerous protein-coding and non-coding regions of the genome. However, genotype does not necessarily determine neurological phenotype because the epigenome modulates gene expression in response to endogenous and exogenous regulators, throughout the life-cycle. Studies using both genome-wide analysis of multiple genes and comprehensive analysis of specific genes are providing new insights into genetic and epigenetic mechanisms underlying nutrition and neuroscience. This review provides a critical evaluation of the following related areas: (1) recent advances in genomic and epigenomic technologies, and their relevance to brain disorders; (2) the emerging role of non-coding RNAs as key regulators of transcription, epigenetic processes and gene silencing; (3) novel approaches to nutrition, epigenetics and neuroscience; (4) gene-environment interactions, especially in the serotonergic system, as a paradigm of the multiple signalling pathways affected in neuropsychiatric and neurological disorders. Current and future advances in these four areas should contribute significantly to the prevention, amelioration and treatment of multiple devastating brain disorders.

MicroRNAs: new players in heart failure

MicroRNAs (miRNAs) are a class of non-coding small RNAs representing one of the most exciting areas of modern medical science. miRNAs modulate a large and complex regulatory network of gene expression of the majority of the protein-coding genes. Currently, evidences suggest that miRNAs play a crucial role in the pathogenesis of heart failure. Some miRNAs as miR-1, miR-133 and miR-208a are highly expressed in the heart and strongly associated with the development of cardiac hypertrophy. Recent data indicate that these miRNAs as well as miR-206 change their expression quickly in response to physical activity. The differential regulation of miRNAs in response to exercise suggests a potential value of circulating miRNAs (c-miRNAs) as biomarkers of physiological mediators of the cardiovascular adaptation induced by exercise. Likewise, serum levels of c-miRNAs such as miR-423-5p have been evaluated as potential biomarkers in the diagnosis and prognosis of heart failure. On the other hand, the manipulation of miRNAs levels using techniques such as 'miR mimics' and 'antagomiRs' is becoming evident the enormous potential of miRNAs as promising therapeutic strategies in heart failure.