RESUMO
Cardiovascular diseases (CVDs) have shown a high prevalence every year, presenting arterial hypertension as prime factor for their development, also driven by population growth, the aging of population and epidemiologic changes in disease. One of the main challenges in the study of CVD is the identification of reliable biomarkers that can be used in clinical practice and, in this context, microRNAs (miRNAs) have attracted much attention recently. MiRNAs are small non-coding RNAs, identified as post-transcriptional regulators of the expression of several genes both in physiologic and pathologic conditions. They have been studied as possible biomarkers, since they are highly expressed in the vascular system and are crucial modulators for the differentiation, contraction, migration and apoptosis of vascular cells, so modifications in their expression can cause several vascular alterations. Thus, this review aimed to compile the main studies regarding the role of miRNAs in the development of cardiac diseases, their potential applicability in the diagnosis, prognosis and treatment of these disorders. It was possible to verify that alterations in miRNAs expression are present in almost all cardiovascular diseases, such as the development of cardiac hypertrophy, coronary heart disease, heart failure and other conditions. Furthermore, growing evidence indicates that circulating miRNAs may become a potential tool for rapid and easy tests, since they are detected in peripheral blood, also allowing new therapeutic possibilities.
Assuntos
Biomarcadores/sangue , Doenças Cardiovasculares/genética , MicroRNA Circulante/genética , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/tratamento farmacológico , Diagnóstico Precoce , Regulação da Expressão Gênica , Humanos , Terapia de Alvo Molecular , PrognósticoRESUMO
Neuromedin B (NB) and gastrin-releasing peptide (GRP) are bombesin-like peptides, found in the gastrointestinal tube and pancreas, among other tissues. Consistent data proposed that GRP stimulates insulin secretion, acting directly in pancreatic cells or in the release of gastrointestinal hormones that are incretins. However, the role of NB remains unclear. We examined the glucose homeostasis in mice with deletion of NB receptor (NBR-KO). Female NBR-KO exhibited similar fasting basal glucose with lower insulinemia (48.4%) and lower homeostasis model assessment of insulin resistance index (50.5%) than wild type (WT). Additionally, they were more tolerant to oral glucose, demonstrated by a decrease in the area under the glucose curve (18%). In addition, 15 min after an oral glucose load, female and male NBR-KO showed lower insulin serum levels (45.6 and 26.8%, respectively) than WT, even though blood glucose rose to similar levels in both groups. Single injection of NB, one hour before the oral glucose administration, tended to induce higher serum insulin in WT (28.9%, p=0.3), however the same did not occur in NBR-KO. They showed no changes in fasting insulin content in pancreatic islets by immunohistochemistry, however, the fasting serum levels of glucagon-like peptide, a potent incretin, exhibited a strong trend to reduction (40%, p=0.07). Collectively, mice with deletion of NB receptor have lower insulinemia, especially in response to oral glucose, and females also exhibited a better glucose tolerance, suggesting the involvement of NB and its receptor in regulation of insulin secretion induced by incretins, and also, in insulin sensitivity.