Can circulating miR-7-1-5p, and miR-33a-5p be used as markers of T2D patients?

Selenium biomarkers and miR-7-5p in overweight/obese women

INTRODUCTION

Chronic low-grade inflammation and oxidative stress are pivotal contributors to the metabolic complications associated with obesity. Selenoprotein P (SELENOP) and glutathione peroxidase 1 (GPx1) are selenoproteins involved in the reduction of reactive oxygen species and pro-inflammatory cytokines levels. Nutritional epigenomics revealed the interaction of microRNAs and nutrients with an important impact on metabolic pathways involved in obesity. However, the knowledge regarding the influence of microRNA on selenium biomarkers and its impact on metabolic pathways related to obesity remains scarce. Thus, the aim of this study was to investigate the association of plasma miR-7-5p expression with selenium and inflammatory biomarkers in women with overweight/obesity.

MATERIAL AND METHODS

Anthropometric evaluations were performed and blood samples were collected for the analysis of fasting glucose, insulin, inflammatory and selenium biomarkers, and miR-7-5p expression in 54 women with overweight/obesity. Gene expression of SELENOP and GPX1 were evaluated in peripheral mononuclear blood cells.

RESULTS

This study observed a negative correlation between SELENOP levels and miR-7-5p (rho = -0.350; p = 0.018). Additionally, it was observed that body fat (OR = 0.737; p = 0.011), age (OR = 1.214; p = 0.007), and miR-7-5p (OR = 0.990; p = 0.015) emerged as significant predictors of SELENOP levels.

CONCLUSIONS

In conclusion, we observed a significant inverse association between miR-7-5p expression and SELENOP concentration in overweight/obese women, suggesting that age and percentage of body fat are also associated.

TRIAL REGISTRATION NUMBER

Brazilian Registry of Clinical Trials (ReBEC) number RBR-2nfy5q.

MiR-33a-5p in stored red blood cells regulates genes of innate immune response and promotes inflammation

BACKGROUND AND OBJECTIVES

Blood transfusion is a common therapeutic procedure in hospitalized patients. Red blood cell (RBC) units undergo various biochemical and morphological changes during storage (storage lesion). miRNAs have been studied intensively regarding cellular metabolic processes, but the effect of miRNAs on blood storage is not well defined.

MATERIALS AND METHODS

We performed bioinformatics analysis on the public data set of miRNA expression of RBC based on R language, and performed the Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis on the target genes of differentially expressed miRNA. The expression of miRNA differential genes in blood samples stored at different times was verified by qRT-PCR. Next, we used ELISA and qRT-PCR to verify the expression of IL-1β, IL-6, IL-12 and TNF-α in blood at day 1 and day 42. In addition, in vitro, we transfected macrophages with overexpressed miRNA, and the effects of overexpressed miRNA on macrophage polarization and the release of inflammatory factors were verified by flow cytometry and qRT-PCR and ELISA.

RESULTS

This study combined bioinformatics analysis and experiments to discover the differentially expressed miRNAs in long-term stored blood. The results showed that compared to fresh blood samples, the inflammatory factors were significantly doubled by ELISA, as well as the higher mRNA expression at 42 day. Experimentally verified that miR-33a-5p promoted the M1 type macrophage polarization and increased the release of related inflammatory factors through PPARα/ACC2/AMPK/CPT-1a axis regulation.

CONCLUSIONS

This study elucidates a potential mechanism of inflammatory factor accumulation in long-term stored blood, providing a theoretical basis and a potential target to prevent transfusion-related adverse reactions.

Identification of MicroRNAs Associated with Prediabetic Status in Obese Women

MicroRNAs (miRNAs) recently emerged as means of communication between insulin-sensitive tissues to mediate diabetes development and progression, and as such they present a valuable proxy for epigenetic alterations associated with type 2 diabetes. In order to identify miRNA markers for the precursor of diabetes called prediabetes, we applied a translational approach encompassing analysis of human plasma samples, mouse tissues and an in vitro validation system. MiR-652-3p, miR-877-5p, miR-93-5p, miR-130a-3p, miR-152-3p and let-7i-5p were increased in plasma of women with impaired fasting glucose levels (IFG) compared to those with normal fasting glucose and normal glucose tolerance (NGT). Among these, let-7i-5p and miR-93-5p correlated with fasting blood glucose levels. Human data were then compared to miRNome data obtained from islets of Langerhans and adipose tissue of 10-week-old female New Zealand Obese mice, which differ in their degree of hyperglycemia and liver fat content. Similar to human plasma, let-7i-5p was increased in adipose tissue and islets of Langerhans of diabetes-prone mice. As predicted by the in silico analysis, overexpression of let-7i-5p in the rat β-cell line INS-1 832/12 resulted in downregulation of insulin signaling pathway components (Insr, Rictor, Prkcb, Clock, Sos1 and Kcnma1). Taken together, our integrated approach highlighted let-7i-5p as a potential regulator of whole-body insulin sensitivity and a novel marker of prediabetes in women.

MicroRNAs as Biomarkers for Coronary Artery Disease Related to Type 2 Diabetes Mellitus-From Pathogenesis to Potential Clinical Application

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with still growing incidence among adults and young people worldwide. Patients with T2DM are more susceptible to developing coronary artery disease (CAD) than non-diabetic individuals. The currently used diagnostic methods do not ensure the detection of CAD at an early stage. Thus, extensive research on non-invasive, blood-based biomarkers is necessary to avoid life-threatening events. MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs that are stable in human body fluids and easily detectable. A number of reports have highlighted that the aberrant expression of miRNAs may impair the diversity of signaling pathways underlying the pathophysiology of atherosclerosis, which is a key player linking T2DM with CAD. The preclinical evidence suggests the atheroprotective and atherogenic influence of miRNAs on every step of T2DM-induced atherogenesis, including endothelial dysfunction, endothelial to mesenchymal transition, macrophage activation, vascular smooth muscle cells proliferation/migration, platelet hyperactivity, and calcification. Among the 122 analyzed miRNAs, 14 top miRNAs appear to be the most consistently dysregulated in T2DM and CAD, whereas 10 miRNAs are altered in T2DM, CAD, and T2DM-CAD patients. This up-to-date overview aims to discuss the role of miRNAs in the development of diabetic CAD, emphasizing their potential clinical usefulness as novel, non-invasive biomarkers and therapeutic targets for T2DM individuals with a predisposition to undergo CAD.

Circulating miR-148b-3p and miR-27a-3p can be potential biomarkers for diagnosis of pre-diabetes and type 2 diabetes: integrating experimental and in-silico approaches

BACKGROUND

In view of the growing global prevalence of type 2 diabetes (T2D), detection of prediabetes and type 2 diabetes in the early stages is necessary to reduce the risk of developing diabetes, prevent the progression of the disease, and dysfunction of different organs. Since miRNAs are involved in the initiation and progression of numerous pathogenic processes, including diabetes, in the present study, we aimed to investigate the expression of miR-148b-3p and miR-27a-3p in prediabetic and T2D patients and to evaluate the diagnostic potential of these miRNAs.

METHODS

We evaluated the expression of miR-148b-3p and miR-27a-3p in the plasma of three groups: 20 prediabetic patients, 20 T2D patients, and 20 healthy controls. The biochemical parameters were determined by the auto-analyzer. The possible target genes of these miRNAs were identified using an in-silico approach.

RESULTS

Our results showed that, as compared to the healthy controls, there was a significant up regulation and down regulation in the expression of miR-148b-3p and miR-27a-3p in the T2D patients, respectively. The results of receiver operating characteristic curve analysis also suggested that miR-148b-3p acted successfully in discriminating the prediabetic and diabetic patients from the control group. According to in-silico analysis, miRs influence biological pathways involved in T2DM development, such as insulin signaling.

CONCLUSIONS

The miR148b-3p and miR-27a-3p expression levels were deregulated in diabetes and pre-diabetes. Furthermore, miR-148b-3p showed significant ability in discriminating between diabetic and healthy individuals, suggesting a potential diagnostic use of miR-148b-3p in the detection of T2D.