miRNAs in vascular integrity

The association of microRNAs in the development of retinopathy of prematurity

INTRODUCTION

Retinopathy of prematurity (ROP) is one of the main reasons of preventable childhood blindness. In the development of ROP, MicroRNAs may be effective in the balance of factors that inhibit and activate angiogenic factors. We aimed to determine the changes in the blood levels of miR-146a, miR-143, miR-210, miR-21, miR-126, miR-211, miR-221, miR-106 and let 7f and to investigate their association with ROP. We hypothesed that the level of these miRNAs changed significantly in ROP cases.

MATERIALS AND METHODS

This observational study was conducted prospectively in preterm infants with ROP. Serum levels of 8 miRNAs were measured. The relationship between disease stage and progression with miRNA gene expression was analysed. Preterm infants without ROP were taken as the control group.

RESULTS

47 patients with ROP and 14 controls, were included in the study. In the ROP group, miR-210, miR-146a, miR-21 were statistically significantly lower. In the ROP group the expression level of miR-143 was insignificantly lower, miRNA-221 was insignificantly higher, and miR-106, miR-126 and let 7f were variable.

CONCLUSION

It was observed that miR-210, miR-146a, miR-21 and miR-143 were significantly lower in patients with ROP compared to the control group. However, no association could be established between the type of miRNA and stage of ROP. These miRNAs may be used as adjunctive biomarkers for diagnosis of ROP.

Peripheral Blood Mononuclear Cells Expression Levels of miR-196a and miR-100 in Coronary Artery Disease Patients

As a chronic inflammatory disease, coronary artery disease (CAD) is a common cause of death worldwide. Dysregulation of microRNA expression levels in peripheral blood mononuclear cells (PBMCs) may contribute to CAD and serve as a potential diagnostic biomarker. Here, we evaluated PBMC expression of two CAD-related inflammatory miRNAs, miR-196a and miR-100, in PBMCs of CAD patients with significant stenosis (CAD, n: 72), patients with insignificant coronary stenosis (ICAD, n: 30), and controls (n: 74) and checked whether they can segregate study groups. MiRNA expression was evaluated using the standard stem-loop RT-qPCR method. MiR-196a expression was downregulated in ICAD compared to CADs and healthy groups. MiR100 expression levels were not different between groups. The receiver operating characteristic (ROC) curve analysis acquainted that miR-196a expression levels in PBMC could segregate CAD individuals or any of its clinical manifestations (i.e. unstable angina, stable angina, acute myocardial infarction) from ICADs. In conclusion, this study reported a distinct miR-196a expression pattern in PBMCs of all patient groups and recommended a biomarker potential for miR-196a in discriminating ICADs from CADs or healthy controls.

Cholesterol transport system: An integrated cholesterol transport model involved in atherosclerosis

Atherosclerosis, the pathological basis of most cardiovascular disease (CVD), is closely associated with cholesterol accumulation in the arterial intima. Excessive cholesterol is removed by the reverse cholesterol transport (RCT) pathway, representing a major antiatherogenic mechanism. In addition to the RCT, other pathways are required for maintaining the whole-body cholesterol homeostasis. Thus, we propose a working model of integrated cholesterol transport, termed the cholesterol transport system (CTS), to describe body cholesterol metabolism. The novel model not only involves the classical view of RCT but also contains other steps, such as cholesterol absorption in the small intestine, low-density lipoprotein uptake by the liver, and transintestinal cholesterol excretion. Extensive studies have shown that dysfunctional CTS is one of the major causes for hypercholesterolemia and atherosclerosis. Currently, several drugs are available to improve the CTS efficiently. There are also several therapeutic approaches that have entered into clinical trials and shown considerable promise for decreasing the risk of CVD. In recent years, a variety of novel findings reveal the molecular mechanisms for the CTS and its role in the development of atherosclerosis, thereby providing novel insights into the understanding of whole-body cholesterol transport and metabolism. In this review, we summarize the latest advances in this area with an emphasis on the therapeutic potential of targeting the CTS in CVD patients.