RESUMO
Discrepancies between the measurement of body mass index (BMI) and metabolic health status have been described for the onset of metabolic diseases. Studying novel biomarkers, some of which are associated with metabolic syndrome, can help us to understand the differences between metabolic health (MetH) and BMI. A group of 1469 young adults with pre-specified anthropometric and blood biochemical parameters were selected. Of these, 80 subjects were included in the downstream analysis that considered their BMI and MetH parameters for selection as follows: norm weight metabolically healthy (MHNW) or metabolically unhealthy (MUNW); overweight/obese metabolically healthy (MHOW) or metabolically unhealthy (MUOW). Our results showed for the first time the differences when the MetH status and the BMI are considered as global MetH statures. First, all the evaluated miRNAs presented a higher expression in the metabolically unhealthy group than the metabolically healthy group. The higher levels of leptin, IL-1b, IL-8, IL-17A, miR-221, miR-21, and miR-29 are directly associated with metabolic unhealthy and OW/OB phenotypes (MUOW group). In contrast, high levels of miR34 were detected only in the MUNW group. We found differences in the SIRT1-PGC1α pathway with increased levels of SIRT1+ cells and diminished mRNA levels of PGCa in the metabolically unhealthy compared to metabolically healthy subjects. Our results demonstrate that even when metabolic diseases are not apparent in young adult populations, MetH and BMI have a distinguishable phenotype print that signals the potential to develop major metabolic diseases.
Assuntos
Índice de Massa Corporal , MicroRNAs , Feminino , Humanos , Masculino , Adulto Jovem , Biomarcadores/sangue , Leptina/sangue , Leptina/genética , Leptina/metabolismo , Síndrome Metabólica/genética , Síndrome Metabólica/metabolismo , MicroRNAs/genética , MicroRNAs/sangue , MicroRNAs/metabolismo , Obesidade/genética , Obesidade/metabolismo , Fenótipo , Sirtuína 1/genética , Sirtuína 1/metabolismoRESUMO
BACKGROUND: There has been a global increase in the prevalence of obesity in pregnant women in recent years. Animal studies have shown that intrauterine environment associated with maternal obesity leads to epigenetic changes. However, the effects of epigenetic changes occurring before birth in response to maternal conditions have not been clearly characterized in humans. OBJECTIVE: The aim of the study was to analyze peroxisome proliferator-activated receptor (PPAR)-γ expression in cell cultures from newborns from mothers with overweight and obesity, in response to in vitro metabolic challenges and their relationship with microRNA profile and cytokine expression. Methods/Study design: The profile of circulating microRNAs from 72 mother-child pairs (including healthy infants born to normal weight [n = 35], overweight [n = 25], and obese [n = 12] mothers) was determined through real-time PCR, and the PPAR-γ expression in peripheral blood mononuclear cell cultures from offspring was analyzed after in vitro challenges. RESULTS: miR-146a, miR-155, and miR-378a were upregulated in overweight mothers, while miR-378a was upregulated in obese mothers compared to normal weight mothers. In children from overweight mothers, miR-155 and miR-221 were downregulated and miR-146a was upregulated, while offspring of mothers with obesity showed downregulation of miR-155, miR-221, and miR-1301. These microRNAs have direct or indirect relation with PPAR-γ expression. In vitro exposure to high triglyceride and exposure to miR-378a induced a higher expression of PPAR-γ in cells from offspring of mothers with overweight and obesity. In contrast, cells from offspring of mothers with obesity cultured with high glucose concentrations showed PPAR-γ downregulation. IL-1ß, IL-6, and TNF-α expression in cells of offspring of overweight and obese mothers differed from that of offspring of normal weight mothers. Limitation of our study is the small sample size. CONCLUSION: The blood microRNA profile, and in vitro PPAR-γ and inflammatory cytokine expression in cells of newborn infants are associated with maternal obesity indicating that epigenetic marks may be established during intrauterine development. Key Message: Neonatal microRNA profile is associated with maternal weight. Neonatal microRNA profile is independent of maternal microRNA profile. PPAR-γ expression in newborn cell cultures is affected by maternal weight.
Assuntos
MicroRNAs , PPAR gama , Animais , Feminino , Desenvolvimento Fetal , Humanos , Leucócitos Mononucleares , MicroRNAs/genética , Obesidade/genética , Sobrepeso/genética , PPAR gama/genética , GravidezRESUMO
miRNAs are important immune regulators in the control of the CD4â¯+â¯T cells phenotype. miR-326 regulates the differentiation towards Th17 cells and the inhibition of miR-155 is associated with low levels of Treg cells. However, miRNAs expression and transcription factors associated with these lymphocyte subsets in obesity-induced adipose tissue inflammation is still unknown. The aim of this work was to identify Th17 cells in subcutaneous adipose tissue (SAT), proinflammatory cytokine production and their association with the miRNAs and transcription factors involved. We collected SAT samples obtained by lipoaspiration from individuals with normal weight, overweight and obesity. We obtained the stromal vascular fractions and then a Ficoll gradient was performed to obtain adipose tissue mononuclear cells (ATMC). Th17 cells were evaluated by flow cytometry and the expression of miR-326, miR-155, RORC2 and FOXP3 by qRT-PCR. We also analyzed cytokines from the supernatants of the ATMC culture and measured the FOXP3 methylation percentage by bisulfite conversion by PCR. According to the results, the frequency of Th17 cells and RORC2 expression was higher in individuals with obesity and associated with miR-326 expression. The ATMC from this group secreted a proinflammatory cytokine profile by in vitro assay. In contrast, lower levels of mRNA FOXP3 expression was detected in ATMC from individuals with obesity that correlated with methylation percentage of FOXP3 gene but no association with miR-155 was detected. Our results suggested that miR-326 participates in the polarization towards Th17 promoting the inflammatory state in the obesity-induced adipose tissue.