Noncoding RNAs Carried by Extracellular Vesicles in Endocrine Diseases

What is the role of the neutrophil extracellular traps in the cardiovascular disease burden associated with hemodialysis bioincompatibility?

Despite significant progress in dialysis modalities, intermittent renal replacement therapy remains an "unphysiological" treatment that imperfectly corrects uremic disorders and may lead to low-grade chronic inflammation, neutrophil activation, and oxidative stress due to repetitive blood/membrane interactions contributing to the "remaining uremic syndrome" and cardiovascular disease burden of hemodialysis patients. Understanding dialysis bioincompatibility pathways still remains a clinical and biochemical challenge. Indeed, surrogate biomarkers of inflammation including C-reactive protein could not discriminate between all components involved in these complex pathways. A few examples may serve to illustrate the case. Cytokine release during dialysis sessions may be underestimated due to their removal using high-flux dialysis or hemodiafiltration modalities. Complement activation is recognized as a key event of bioincompatibility. However, it appears as an early and transient event with anaphylatoxin level normalization at the end of the dialysis session. Complement activation is generally assumed to trigger leukocyte stimulation leading to proinflammatory mediators' secretion and oxidative burst. In addition to being part of the innate immune response involved in eliminating physically and enzymatically microbes, the formation of Neutrophil Extracellular Traps (NETs), known as NETosis, has been recently identified as a major harmful component in a wide range of pathologies associated with inflammatory processes. NETs result from the neutrophil degranulation induced by reactive oxygen species overproduction via NADPH oxidase and consist of modified chromatin decorated with serine proteases, elastase, bactericidal proteins, and myeloperoxidase (MPO) that produces hypochlorite anion. Currently, NETosis remains poorly investigated as a sensitive and integrated marker of bioincompatibility in dialysis. Only scarce data could be found in the literature. Oxidative burst and NADPH oxidase activation are well-known events in the bioincompatibility phenomenon. NET byproducts such as elastase, MPO, and circulating DNA have been reported to be increased in dialysis patients more specifically during dialysis sessions, and were identified as predictors of poor outcomes. As NETs and MPO could be taken up by endothelium, NETs could be considered as a vascular memory of intermittent bioincompatibility phenomenon. In this working hypothesis article, we summarized the puzzle pieces showing the involvement of NET formation during hemodialysis and postulated that NETosis may act as a disease modifier and may contribute to the comorbid burden associated with dialysis bioincompatibility.

Long Noncoding RNA: A Novel Insight into the Pathogenesis of Acute Lung Injury

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), represent an acute stage of lung inflammation where the alveolar epithelium loses its functionality. ALI has a devastating impact on the population as it not only has a high rate of incidence, but also has high rates of morbidity and mortality. Due to the involvement of multiple factors, the pathogenesis of ALI is complex and is not fully understood yet. Long noncoding RNAs (lncRNAs) are a group of non-protein-coding transcripts longer than 200 nucleotides. Growing evidence has shown that lncRNAs have a decisive role in the pathogenesis of ALI. LncRNAs can either promote or hinder the development of ALI in various cell types in the lungs. Mechanistically, current studies have found that lncRNAs play crucial roles in the pathogenesis of ALI via the regulation of small RNAs (e.g., microRNAs) or downstream proteins. Undoubtedly, lncRNAs not only have the potential to reveal the underlying mechanisms of ALI pathogenesis but also serve as diagnostic and therapeutic targets for the therapy of ALI.

Diagnosis of Extracellular Vesicles in Cardiovascular and Metabolic Diseases

Early detection and identification of those with or at increased risk for cardiovascular disease (CVD) and metabolic dysfunction is crucial for improving disease management and prognosis. Given the complex, multifactorial nature of the pathogenesis of the CVD and metabolic dysfunction, it is essential to have biomarkers that encompass the multiple facets of disease development. The uniquely ubiquitous nature and functionality of extracellular vesicles (EVs) in various disease pathologies can provide novel insight into both diagnosis and prognosis while further improving assessments used in clinical and research practice. Herein we summarize the use of EV count and content (including miRNA and protein) in diagnosis of CVD, obesity, metabolic syndrome, and type 2 diabetes (T2D), as well as highlight the potential utility for enhancing determination of prognosis and long-term complications in these clinical populations. Although the results are promising, future work is needed in both methodology and in relation to other factors such as sex and medications, in order to apply these findings in clinical practice.

The potential therapeutic role of extracellular vesicles in osteoarthritis

Osteoarthritis (OA) is a worldwide and disabling disease, which cause severe pain and heavy socioeconomic burden. However, pharmacologic or surgical therapies cannot mitigate OA progression. Mesenchymal stem cells (MSCs) therapy has emerged as potential approach for OA treatment, while the immunogenicity and ethical audit of cell therapy are unavoidable. Compared with stem cell strategy, EVs induce less immunological rejection, and they are more stable for storage and in vivo application. MSC-EVs-based therapy possesses great potential in regulating inflammation and promoting cartilage matrix reconstruction in OA treatment. To enhance the therapeutic effect, delivery efficiency, tissue specificity and safety, EVs can be engineered via different modification strategies. Here, the application of MSC-EVs in OA treatment and the potential underlying mechanism were summarized. Moreover, EV modification strategies including indirect MSC modification and direct EV modification were reviewed.

miRNAs: Regulators of immune system in diabetes

Diabetes, one of the most common multifactorial metabolic disorders, is a jeopardizing cause of human health worldwide. MicroRNAs (miRNAs) are a group of small non-coding RNAs that have been contributed to the regulation of gene expression through post-transcriptional mechanisms. The potential role of miRNAs has been studied in the most of biological processes and mechanisms underlying the progression of variety diseases including diabetes. In this review, we focus on the role of miRNAs in regulating pivotal molecular and cellular mechanisms associated with immune system that progress diabetic disorders.

Molecular Mechanisms of Nutrient-Mediated Regulation of MicroRNAs in Pancreatic β-cells

Pancreatic β-cells within the islets of Langerhans respond to rising blood glucose levels by secreting insulin that stimulates glucose uptake by peripheral tissues to maintain whole body energy homeostasis. To different extents, failure of β-cell function and/or β-cell loss contribute to the development of Type 1 and Type 2 diabetes. Chronically elevated glycaemia and high circulating free fatty acids, as often seen in obese diabetics, accelerate β-cell failure and the development of the disease. MiRNAs are essential for endocrine development and for mature pancreatic β-cell function and are dysregulated in diabetes. In this review, we summarize the different molecular mechanisms that control miRNA expression and function, including transcription, stability, posttranscriptional modifications, and interaction with RNA binding proteins and other non-coding RNAs. We also discuss which of these mechanisms are responsible for the nutrient-mediated regulation of the activity of β-cell miRNAs and identify some of the more important knowledge gaps in the field.

Islet Biology during COVID-19: Progress and Perspectives

The coronavirus-2019 (COVID-19) pandemic has had significant impact on research directions and productivity in the past 2 years. Despite these challenges, since 2020, more than 2,500 peer-reviewed articles have been published on pancreatic islet biology. These include updates on the roles of isocitrate dehydrogenase, pyruvate kinase and incretin hormones in insulin secretion, as well as the discovery of inceptor and signalling by circulating RNAs. The year 2020 also brought advancements in in vivo and in vitro models, including a new transgenic mouse for assessing beta-cell proliferation, a “pancreas-on-a-chip” to study glucose-stimulated insulin secretion and successful genetic editing of primary human islet cells. Islet biologists evaluated the functionality of stem-cell–derived islet-like cells coated with semipermeable biomaterials to prevent autoimmune attack, revealing the importance of cell maturation after transplantation. Prompted by observations that COVID-19 symptoms can worsen for people with obesity or diabetes, researchers examined how islets are directly affected by severe acute respiratory syndrome coronavirus 2. Herein, we highlight novel functional insights, technologies and therapeutic approaches that emerged between March 2020 and July 2021, written for both scientific and lay audiences. We also include a response to these advancements from patient stakeholders, to help lend a broader perspective to developments and challenges in islet research.

Engineered-extracellular vesicles as an optimistic tool for microRNA delivery for osteoarthritis treatment

Worldwide, osteoarthritis (OA) is one of the most common chronic diseases. In OA, profiling gene expression changes occur and cartilage tissue homeostasis is lost. Suggestions for OA treatment include regulation of gene expressions via the use of microRNAs (miRNAs). However, problems exist with the use of miRNAs, the most important of which is the delivery of sufficient amounts of effective miRNAs to save cartilage tissue. The engineering of extracellular vesicles (EVs) with the use of advanced techniques would be an efficient OA treatment. Therefore, we discuss the importance of miRNAs in terms of cartilage tissue regeneration and review recent advances in production of enriched EVs and miRNA delivery by EVs for future clinical applications.

Protein-driven mechanism of multiorgan damage in COVID-19

We propose a new plausible mechanism by mean of which SARS-CoV-2 produces extrapulmonary damages in severe COVID-19 patients. The mechanism consist on the existence of vulnerable proteins (VPs), which are (i) mainly expressed outside the lungs; (ii) their perturbations is known to produce human diseases; and (iii) can be perturbed directly or indirectly by SARS-CoV-2 proteins. These VPs are perturbed by other proteins, which are: (i) mainly expressed in the lungs, (ii) are targeted directly by SARS-CoV-2 proteins, (iii) can navigate outside the lungs as cargo of extracellular vesicles (EVs); and (iv) can activate VPs via subdiffusive processes inside the target organ. Using bioinformatic tools and mathematical modeling we identifies 26 VPs and their 38 perturbators, which predict extracellular damages in the immunologic endocrine, cardiovascular, circulatory, lymphatic, musculoskeletal, neurologic, dermatologic, hepatic, gastrointestinal, and metabolic systems, as well as in the eyes. The identification of these VPs and their perturbators allow us to identify 27 existing drugs which are candidates to be repurposed for treating extrapulmonary damage in severe COVID-19 patients. After removal of drugs having undesirable drug-drug interactions we select 7 drugs and one natural product: apabetalone, romidepsin, silmitasertib, ozanezumab, procaine, azacitidine, amlexanox, volociximab, and ellagic acid, whose combinations can palliate the organs and systems found to be damaged by COVID-19. We found that at least 4 drugs are needed to treat all the multiorgan damages, for instance: the combination of romidepsin, silmitasertib, apabetalone and azacitidine.

Therapeutic potential of extracellular vesicle-associated long noncoding RNA

Both extracellular vesicles (EVs) and long noncoding RNAs (lncRNAs) have been increasingly investigated as biomarkers, pathophysiological mediators, and potential therapeutics. While these two entities have often been studied separately, there are increasing reports of EV-associated lncRNA activity in processes such as oncogenesis as well as tissue repair and regeneration. Given the powerful nature and emerging translational impact of other noncoding RNAs such as microRNA (miRNA) and small interfering RNA, lncRNA therapeutics may represent a new frontier. While EVs are natural vehicles that transport and protect lncRNAs physiologically, they can also be engineered for enhanced cargo loading and therapeutic properties. In this review, we will summarize the activity of lncRNAs relevant to both tissue repair and cancer treatment and discuss the role of EVs in enabling the potential of lncRNA therapeutics.

Extracellular vesicles in metabolic disease

Extracellular vesicles (EVs) are submicron-sized lipid envelopes that are produced and released from a parent cell and can be taken up by a recipient cell. EVs are capable of mediating cellular signalling by carrying nucleic acids, proteins, lipids and cellular metabolites between cells and organs. Metabolic dysfunction is associated with changes in plasma concentrations of EVs as well as alterations in their EV cargo. Since EVs can act as messengers between parent and recipient cells, they could be involved in cell-to-cell and organ-to-organ communication in metabolic diseases. Recent literature has shown that EVs are produced by cells within metabolic tissues, such as adipose tissue, pancreas, muscle and liver. These vesicles have therefore been proposed as a novel intercellular communication mode in systemic metabolic regulation. In this review, we will describe and discuss the current literature that investigates the role of adipose-derived EVs in the regulation of obesity-associated metabolic disease. We will particularly focus on the EV-dependent communication between adipocytes, the vasculature and immune cells in type 2 diabetes.

miR-1185-1 and miR-548q Are Biomarkers of Response to Weight Loss and Regulate the Expression of GSK3B

The aim of the present investigation was to identify putative miRNAs involved in the response to weight loss. Reverse-transcribed RNA isolated from white blood cells (WBCs) of a subpopulation from the Reduction of the Metabolic Syndrome in Navarra-Spain (RESMENA-S) study (low-responders (LR) and high-responders (HR)) was hybridized in a gene expression microarray. Moreover, miRNAs were sequenced by miRNA-Seq. It was found that miR-548q and miR-1185-1 were overexpressed in HR, both in the microarray and in the miRNA-Seq. A bioinformatic prediction of putative target genes of the selected miRNAs found that GSK3B, a putative target for miR-548q and miR-1185-1, was downregulated in HR. Particular 3′-UTR binding regions of GSK3B were cloned downstream of the firefly luciferase gene. HEK-293T cells were co-transfected with either 0.25 μg of empty pmiR-GLO or pmiR-GLO-548q-3′-UTR/pmiR-GLO-1185-1-3′-UTR, and 7.5 pmol of miR-548q/miR-1185-1 mimics, demonstrating that miR-1185-1 bound to the 3′-UTR region of GSK3B. THP-1 cells were transfected with either 20/40 nM of miR-548q/miR-1185-1 mimics, evidencing that miR-1185-1inhibited the expression of the gene when transfected at doses of 20/40 nM, whereas miR-548q inhibited GSK3B expression at a dose of 40 nM. As a conclusion, miR-548q and miR-1185-1 levels in WBCs are biomarkers of response to weight-loss diets and could be involved in the regulation of the proinflammatory gene GSK3B.

The relationship between molecular content of mesenchymal stem cells derived exosomes and their potentials: Opening the way for exosomes based therapeutics

At least, more than half of our understanding of extracellular vesicles owes to the studies conducted over the past few years. When it became clear that the exosomes have various potentials in medicine, extensive research has focused on these potentials in a variety of areas including cancer, drug delivery and regenerative medicine. The growing understanding of molecular structure and functions of exosomes causes the vision to become brighter in the exosomes complexity, and our attitude toward these vesicles has undergone changes accordingly. Proteomic and transcriptomic studies on exosomes have highlighted their molecular diversity. In this review, we explicitly examine the exosomes composition, molecular structure and their therapeutic potentials in some diseases. Due to the very heterogeneous nature of exosomes, the process of their use as a therapeutic agent in the clinic has been challenged. We are still at the beginning of recognizing the molecular composition of exosomes and mechanisms that affect their physiology and biology. The growing trend of engineering of exosomes has shown a promising future to further utilize them in a different field. Molecular profiling of exosomes and their content for their related potentials in regenerative medicine should be done exactly for further defining a minimum content for specific therapeutic potentials.