The Roles of MicroRNAs in Asthma and Emerging Insights into the Effects of Vitamin D3 Supplementation.

Asthma is one of the most common chronic non-communicable diseases worldwide, characterized by variable airflow limitation secondary to airway narrowing, airway wall thickening, and increased mucus resulting from chronic inflammation and airway remodeling. Current epidemiological studies reported that hypovitaminosis D is frequent in patients with asthma and is associated with worsening the disease and that supplementation with vitamin D3 improves asthma symptoms. However, despite several advances in the field, the molecular mechanisms of asthma have yet to be comprehensively understood. MicroRNAs play an important role in controlling several biological processes and their deregulation is implicated in diverse diseases, including asthma. Evidence supports that the dysregulation of miR-21, miR-27b, miR-145, miR-146a, and miR-155 leads to disbalance of Th1/Th2 cells, inflammation, and airway remodeling, resulting in exacerbation of asthma. This review addresses how these molecular mechanisms explain the development of asthma and its exacerbation and how vitamin D3 may modulate these microRNAs to improve asthma symptoms.

Effect of Supplementation with Omega-3 Polyunsaturated Fatty Acids on Metabolic Modulators in Skeletal Muscle of Rats with an Obesogenic High-Fat Diet.

Previous studies provided evidence of the benefits of omega-3 polyunsaturated fatty acids (ω-3 PUFA) on the cardiovascular system and inflammation. However, its possible effect on skeletal muscle is unknown. This study aimed to evaluate whether ω-3 PUFA reverses the dysregulation of metabolic modulators in the skeletal muscle of rats on a high-fat obesogenic diet. For this purpose, an animal model was developed using male Wistar rats with a high-fat diet (HFD) and subsequently supplemented with ω-3 PUFA. Insulin resistance was assessed, and gene and protein expression of metabolism modulators in skeletal muscle was also calculated using PCR-RT and Western blot. Our results confirmed that in HFD rats, zoometric parameters and insulin resistance were increased compared to SD rats. Furthermore, we demonstrate reduced gene and protein expression of peroxisome proliferator-activated receptors (PPARs) and insulin signaling molecules. After ω-3 PUFA supplementation, we observed that glucose (24.34%), triglycerides (35.78%), and HOMA-IR (40.10%) were reduced, and QUICKI (12.16%) increased compared to HFD rats. Furthermore, in skeletal muscle, we detected increased gene and protein expression of PPAR-α, PPAR-γ, insulin receptor (INSR), insulin receptor substrate 1 (ISR-1), phosphatidylinositol-3-kinase (PI3K), and glucose transporter 4 (GLUT-4). These findings suggest that ω-3 PUFAs decrease insulin resistance of obese skeletal muscle.

Glycine: The Smallest Anti-Inflammatory Micronutrient.

Glycine is a non-essential amino acid with many functions and effects. Glycine can bind to specific receptors and transporters that are expressed in many types of cells throughout an organism to exert its effects. There have been many studies focused on the anti-inflammatory effects of glycine, including its abilities to decrease pro-inflammatory cytokines and the concentration of free fatty acids, to improve the insulin response, and to mediate other changes. However, the mechanism through which glycine acts is not clear. In this review, we emphasize that glycine exerts its anti-inflammatory effects throughout the modulation of the expression of nuclear factor kappa B (NF-κB) in many cells. Although glycine is a non-essential amino acid, we highlight how dietary glycine supplementation is important in avoiding the development of chronic inflammation.

Effect of omega-3 fatty acids supplementation combined with lifestyle intervention on adipokines and biomarkers of endothelial dysfunction in obese adolescents with hypertriglyceridemia.

Obesity in adolescents is considered a major public health problem; combined interventional approaches such as omega-3 supplementation with lifestyle intervention (LI) might exert synergistic effects and exceed the impact of each individual strategy. The purpose of the present study was to evaluate if the supplementation of omega-3 with LI could improve metabolic and endothelial abnormality in obese adolescents with hypertriglyceridemia. The study involved sixty-nine adolescents with normal weight and seventy obese adolescents with hypertriglyceridemia. All obese adolescents were applied to LI and randomly assigned to omega-3 supplementation or placebo group for 12 weeks. The obese adolescents with hypertriglyceridemia presented increased levels of leptin, retinol binding protein 4 (RBP4), selectin E (sE) and asymmetric dimethylarginine (ADMA) and decreased levels of adiponectin compared with control subjects. After 12-week intervention, omega-3 supplementation with LI decreased significantly in triglycerides, HOMA, leptin, RBP4, ADMA and sE. Moreover, omega-3 with LI displayed a significant reduction in triglycerides, ADMA and sE in comparison with LI alone. In subjects with omega-3 combined with LI assessed by multivariate regression model, the reduction in triglycerides was the only independent determinant of the decrease in ADMA. The reductions in triglycerides and HOMA were significantly contributed to the changes in sE. Our data indicated that omega-3 combined with LI in short duration significantly improved dyslipidemia, insulin resistance, abnormality of adipokines, endothelial dysfunction in comparison of LI alone, indicating the combined approach is an effective clinical and applicable strategy to control metabolic abnormality and decrease the risks of cardiovascular diseases in obese adolescents.