MiR-551b-5p Contributes to Pathogenesis of Vein Graft Failure via Upregulating Early Growth Response-1 Expression

Downregulation of Exosomal hsa-miR-551b-3p in Obesity and Its Link to Type 2 Diabetes Mellitus

Obesity is a significant risk factor for the development of type 2 diabetes mellitus (T2DM). Adipose tissue dysfunction can affect the pool of circulating exosomal miRNAs, driving concomitant disease in obesity. These exosomal miRNAs can reflect adipose tissue functionality, thus serving as prognostic biomarkers for disease monitoring in case of T2DM. In the present study, we conducted NanoString microRNA profiling of extracellular vesicles (EVs) secreted by adipose tissue of obese patients (body mass index (BMI) > 35) without T2DM and nonobese individuals (BMI < 30) as a control group. Functional and pathway enrichment analysis showed that miRNAs associated with obesity in this study were implicated in insulin signaling and insulin resistance biological pathways. Further, these microRNAs were screened in serum EVs in the following groups: (1) obese patients with T2DM, (2) obese patients without T2DM, and (3) nonobese individuals as a control group. has-miR-551b-3p was shown to be downregulated in adipose tissue EVs, as well as in serum EVs, of patients with obesity without T2DM. At the same time, the serum exosomal hsa-miR-551b-3p content was significantly higher in obese patients with T2DM when compared with obese patients without T2DM and may be a potential biomarker of T2DM development in obesity.

MicroRNAs and obesity-induced endothelial dysfunction: key paradigms in molecular therapy

The endothelium plays a pivotal role in maintaining vascular health. Obesity is a global epidemic that has seen dramatic increases in both adult and pediatric populations. Obesity perturbs the integrity of normal endothelium, leading to endothelial dysfunction which predisposes the patient to cardiovascular diseases. MicroRNAs (miRNAs) are short, single-stranded, non-coding RNA molecules that play important roles in a variety of cellular processes such as differentiation, proliferation, apoptosis, and stress response; their alteration contributes to the development of many pathologies including obesity. Mediators of obesity-induced endothelial dysfunction include altered endothelial nitric oxide synthase (eNOS), Sirtuin 1 (SIRT1), oxidative stress, autophagy machinery and endoplasmic reticulum (ER) stress. All of these factors have been shown to be either directly or indirectly caused by gene regulatory mechanisms of miRNAs. In this review, we aim to provide a comprehensive description of the therapeutic potential of miRNAs to treat obesity-induced endothelial dysfunction. This may lead to the identification of new targets for interventions that may prevent or delay the development of obesity-related cardiovascular disease.

The Role of Immunomodulation in Vein Graft Remodeling and Failure

Obstructive arterial disease is a major cause of morbidity and mortality in the developed world. Venous bypass graft surgery is one of the most frequently used revascularization strategies despite its considerable short and long time failure rate. Due to vessel wall remodeling, inflammation, intimal hyperplasia, and accelerated atherosclerosis, vein grafts may (ultimately) fail to revascularize tissues downstream to occlusive atherosclerotic lesions. In the past decades, little has changed in the prevention of vein graft failure (VGF) although new insights in the role of innate and adaptive immunity in VGF have emerged. In this review, we discuss the pathophysiological mechanisms underlying the development of VGF, emphasizing the role of immune response and associated factors related to VG remodeling and failure. Moreover, we discuss potential therapeutic options that can improve patency based on data from both preclinical studies and the latest clinical trials. This review contributes to the insights in the role of immunomodulation in vein graft failure in humans. We describe the effects of immune cells and related factors in early (thrombosis), intermediate (inward remodeling and intimal hyperplasia), and late (intimal hyperplasia and accelerated atherosclerosis) failure based on both preclinical (mouse) models and clinical data.

Portable fluorescence-based microRNA detection system based on isothermal signal amplification technology

MicroRNAs (miRNAs) diagnostics can be useful for diagnosing or confirming miRNA abundance and are used in screening tests and to assess changes in miRNAs in vivo. At present, the use of traditional nucleic acid amplification assays to detect miRNAs has been limited in laboratory environment because of the time, equipment, and technical expertise required to perform these assays. A specialized, rapid affordable miRNA detection system is necessary when there are limited resources or point-of-care testing needs. We designed a portable and affordable fluorescence-based miRNA detection system based on isothermal signal amplification technology, using SYBR Green II as a fluorescent dye. To reduce costs, we chose LED as a light source and designed the corresponding optical path for LED. The portable detection system shows results consistent with those by real-time PCR, and can be used to detect miR-183 with a limit of detection of approximately 2 fmol. We used the system to detect miR-183 in tissues and blood from patients with hepatocellular carcinoma (HCC). The results from the portable detection device were compared with those from clinical trials and indicated that the miR-183 fluorescence signal could successfully identify HCC and provide information related to cancer progression.

Elevated Level of miR-551b-5p is Associated With Inflammation and Disease Progression in Patients With Severe Acute Pancreatitis

Circulating microRNAs have the potential to be noninvasive biomarkers for assessing disease progression. MicroRNA-551b-5p (miR-551b-5p) was previously reported to be differentially expressed in pancreatic patients. The serum miR-551b-5p level was measured in patients with mild acute pancreatitis (MAP), severe acute pancreatitis (SAP), and healthy controls using quantitative real-time polymerase chain reaction (RT-PCR) analysis to evaluate its impact on inflammatory response. Acute Physiology and Chronic Health Evaluation II (APACHE II), Multiple Organ Dysfunction Score (MODS), Sequential Organ Assessment Score (SOFA), and Ranson's scores were recorded. Inflammatory cytokines, IL-6, IL-17, IL-1β, and Tumor Necrosis Factor-α (TNF-α), were detected in serum samples obtained from MAP and SAP patients on admission day 1, day 3, and day 5 using Enzyme Linked Immunosorbent Assay (ELISA). Inflammatory cytokines were analyzed in peripheral blood mononuclear cells (PBMCs), which were transfected with miR-551b-5p-negative controls and inhibitors. The serum miR-551b-5p level was significantly higher in MAP and SAP patients compared to controls (P < 0.001). An elevated miR-551b-5p level is positively associated with APACHE II, MODS, SOFA, and Ranson's scores (P < 0.001). Serum cytokines levels were significantly elevated in MAP and SAP patients compared to controls (P < 0.05). In addition, the level of these inflammatory cytokines was increased in PBMCs of SAP patients in comparison with those of healthy controls (P < 0.05), and this rise was significantly reduced with the addition of an miR-551b-5p inhibitor. In conclusion, serum miR-551b-5p is elevated in patients with MAP and SAP and is involved in the regulation of inflammatory response. It may be a useful biomarker for assessing the severity of SAP.

Whole-Transcriptome Sequencing: a Powerful Tool for Vascular Tissue Engineering and Endothelial Mechanobiology

Among applicable high-throughput techniques in cardiovascular biology, whole-transcriptome sequencing is of particular use. By utilizing RNA that is isolated from virtually all cells and tissues, the entire transcriptome can be evaluated. In comparison with other high-throughput approaches, RNA sequencing is characterized by a relatively low-cost and large data output, which permits a comprehensive analysis of spatiotemporal variation in the gene expression profile. Both shear stress and cyclic strain exert hemodynamic force upon the arterial endothelium and are considered to be crucial determinants of endothelial physiology. Laminar blood flow results in a high shear stress that promotes atheroresistant endothelial phenotype, while a turbulent, oscillatory flow yields a pathologically low shear stress that disturbs endothelial homeostasis, making respective arterial segments prone to atherosclerosis. Severe atherosclerosis significantly impairs blood supply to the organs and frequently requires bypass surgery or an arterial replacement surgery that requires tissue-engineered vascular grafts. To provide insight into patterns of gene expression in endothelial cells in native or bioartificial arteries under different biomechanical conditions, this article discusses applications of whole-transcriptome sequencing in endothelial mechanobiology and vascular tissue engineering.