MiR-126 and miR-126* regulate shear-resistant firm leukocyte adhesion to human brain endothelium

Network pharmacology and bioinformatics analysis reveals: NXC improves cardiac lymphangiogenesis through miR-126-3p/SPRED1 regulating the VEGF-C axis to ameliorate post-myocardial infarction heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Cardiac lymphangiogenesis disorder serves as a vital pathological mechanism in post-myocardial infarction heart failure (MI-HF). Nuanxin Capsule (NXC) has been applied in the treatment of MI-HF for more than 20 years and has shown clinical effectiveness in improving cardiac function in MI-HF patients. Nevertheless, the exact mechanisms through which NXC treats MI-HF are still unknown.

AIM OF THE STUDY

In this research, our aim was to investigate the influence of NXC on cardiac lymphangiogenesis and its mechanism in the treatment of MI-HF.

METHODS

The MI-HF mouse model was constructed by ligating the coronary artery. The protective impacts of NXC on cardiac function and fibrosis were appraised through echocardiography, Masson staining, and Western blotting. Cardiac lymphangiogenesis and inflammation were evaluated by RT-qPCR, immunohistochemistry, and Western blotting. UPLC-MS/MS, network pharmacology, and bioinformatics techniques were utilized to investigate the relevant targets and underlying mechanism of NXC in MI-HF. The regulatory effects of NXC on the miR-126-3p/SPRED1 and VEGF-C pathways were analyzed by RT-qPCR, Western blotting, and Dual-luciferase assay. Finally, AAV9-anti-miR-126-3p was injected into MI-HF mice via the tail vein to determine the molecular mechanism of NXC.

RESULTS

Our research results demonstrated that NXC notably improved cardiac function in MI-HF mice, facilitated the formation of cardiac lymphatic vessels, reduced the expression of inflammatory factors, and alleviated myocardial fibrosis. Network pharmacology and bioinformatics analyses further revealed that NXC exerted its cardioprotective effects by promoting cardiac lymphangiogenesis through the modulation of the VEGF-C pathway by miR-126-3p/SPRED1. Dual-luciferase test further confirmed that miR-126-3p has binding to SPRED1.The administration of anti-miR-126-3p effectively negated the cardioprotective effects of NXC in MI-HF mice, as well as its ability to promote lymphangiogenesis, reduce inflammation, and relieve myocardial fibrosis.

CONCLUSION

The findings of this research indicate that NXC can stimulate the VEGF-C pathway via miR-126-3p/SPRED1 to promote cardiac lymphangiogenesis, thus treating MI-HF. Additionally, the study initially revealed that miR-126-3p affects lymphangiogenesis in MI-HF by regulating the VEGF-C pathway. These results offer valuable insights for the development of cardiovascular drugs targeting MI-HF by leveraging the potential of NXC to enhance cardiac lymphangiogenesis.

Association of MicroRNA Expression and Serum Neurofilament Light Chain Levels with Clinical and Radiological Findings in Multiple Sclerosis

microRNAs (miRNAs) are promising biomarkers for many diseases, including multiple sclerosis (MS). The neurofilament light chain (NfL) is a biomarker that can detect axonal damage in different neurological diseases. The objective of this study was to evaluate the association of the expression profile of pre-selected miRNAs and NfL levels with clinical and radiological variables in MS patients. We conducted a 1-year longitudinal prospective study in MS patients with different clinical forms. We measured clinical disability using the expanded disability status scale (EDSS), the magnetic resonance imaging (MRI) volumetry baseline, and cognitive functioning using the processing speed test (PST) at baseline and 1 year later. Selected serum miRNAs and serum NfL (sNfL) levels were quantified. Seventy-three patients were recruited. MiR-126.3p correlated with EDSS and cognitive status at baseline and miR-126.3p and miR-9p correlated with cognitive deterioration at 1 year. Correlations with regional brain volumes were observed between miR-126.3p and the cortical gray matter, cerebellum, putamen, and pallidum; miR-146a.5p with the cerebellum and pallidum; miR-29b.3p with white matter and the pallidum; miR-138.5p with the pallidum; and miR-9.5p with the thalamus. sNfL was correlated with miR-9.5p. miR-146a.5p was also associated with the MS phenotype. These data justify future studies to further explore the utility of miRNAs (mirR-126.3p, miR-146.5p, and miR.9-5p) and sNfL levels as biomarkers of MS.

MicroRNA-126 (MiR-126): key roles in related diseases

In eukaryotes such as humans, some non-coding single-stranded RNAs (ncRNAs) help to regulate the pre- and post-transcriptional expression of certain genes, which in turn control many important physiological processes, such as cell proliferation, distinctions, invasion, angiogenesis, and embryonic development. microRNA-126 is an important member of these miRNAs that can be directly or indirectly involved in the control of angiogenesis. Recently, numerous studies have expounded that microRNA-126 can inhibit or promote angiogenesis as well as attenuate inflammatory responses through complex molecular mechanisms. As such, it serves as a biomarker or potential therapeutic target for the prediction, diagnosis, and treatment of relevant diseases. In this review, we present the advancements in research regarding microRNA-126's role in the diagnosis and treatment of related diseases, aiming to provide innovative therapeutic options for the diagnosis and treatment of clinically relevant diseases.

IQGAP1 and NWASP promote human cancer cell dissemination and metastasis by regulating β1-integrin via FAK and MRTF/SRF

Attachment of circulating tumor cells to the endothelial cells (ECs) lining blood vessels is a critical step in cancer metastatic colonization, which leads to metastatic outgrowth. Breast and prostate cancers are common malignancies in women and men, respectively. Here, we observe that β1-integrin is required for human prostate and breast cancer cell adhesion to ECs under shear-stress conditions in vitro and to lung blood vessel ECs in vivo. We identify IQGAP1 and neural Wiskott-Aldrich syndrome protein (NWASP) as regulators of β1-integrin transcription and protein expression in prostate and breast cancer cells. IQGAP1 and NWASP depletion in cancer cells decreases adhesion to ECs in vitro and retention in the lung vasculature and metastatic lung nodule formation in vivo. Mechanistically, NWASP and IQGAP1 act downstream of Cdc42 to increase β1-integrin expression both via extracellular signal-regulated kinase (ERK)/focal adhesion kinase signaling at the protein level and by myocardin-related transcription factor/serum response factor (SRF) transcriptionally. Our results identify IQGAP1 and NWASP as potential therapeutic targets to reduce early metastatic dissemination.

Hemocompatibility and biophysical interface of left ventricular assist devices and total artificial hearts

ABSTRACT

Over the past 2 decades, there has been a significant increase in the utilization of long-term mechanical circulatory support (MCS) for the treatment of cardiac failure. Left ventricular assist devices (LVADs) and total artificial hearts (TAHs) have been developed in parallel to serve as bridge-to-transplant and destination therapy solutions. Despite the distinct hemodynamic characteristics introduced by LVADs and TAHs, a comparative evaluation of these devices regarding potential complications in supported patients, has not been undertaken. Such a study could provide valuable insights into the complications associated with these devices. Although MCS has shown substantial clinical benefits, significant complications related to hemocompatibility persist, including thrombosis, recurrent bleeding, and cerebrovascular accidents. This review focuses on the current understanding of hemostasis, specifically thrombotic and bleeding complications, and explores the influence of different shear stress regimens in long-term MCS. Furthermore, the role of endothelial cells in protecting against hemocompatibility-related complications of MCS is discussed. We also compared the diverse mechanisms contributing to the occurrence of hemocompatibility-related complications in currently used LVADs and TAHs. By applying the existing knowledge, we present, for the first time, a comprehensive comparison between long-term MCS options.

Cladribine and ocrelizumab induce differential miRNA profiles in peripheral blood mononucleated cells from relapsing-remitting multiple sclerosis patients

Background and objectives

Multiple sclerosis (MS) is a chronic, progressive neurological disease characterized by early-stage neuroinflammation, neurodegeneration, and demyelination that involves a spectrum of heterogeneous clinical manifestations in terms of disease course and response to therapy. Even though several disease-modifying therapies (DMTs) are available to prevent MS-related brain damage-acting on the peripheral immune system with an indirect effect on MS lesions-individualizing therapy according to disease characteristics and prognostic factors is still an unmet need. Given that deregulated miRNAs have been proposed as diagnostic tools in neurodegenerative/neuroinflammatory diseases such as MS, we aimed to explore miRNA profiles as potential classifiers of the relapsing-remitting MS (RRMS) patients' prospects to gain a more effective DMT choice and achieve a preferential drug response.

Methods

A total of 25 adult patients with RRMS were enrolled in a cohort study, according to the latest McDonald criteria before (pre-cladribine, pre-CLA; pre-ocrelizumab, pre-OCRE, time T0) and after high-efficacy DMTs, time T1, 6 months post-CLA (n = 10, 7 F and 3 M, age 39.0 ± 7.5) or post-OCRE (n = 15, 10 F and 5 M, age 40.5 ± 10.4) treatment. A total of 15 age- and sex-matched healthy control subjects (9 F and 6 M, age 36.3 ± 3.0) were also selected. By using Agilent microarrays, we analyzed miRNA profiles from peripheral blood mononuclear cells (PBMC). miRNA-target networks were obtained by miRTargetLink, and Pearson's correlation served to estimate the association between miRNAs and outcome clinical features.

Results

First, the miRNA profiles of pre-CLA or pre-OCRE RRMS patients compared to healthy controls identified modulated miRNA patterns (40 and seven miRNAs, respectively). A direct comparison of the two pre-treatment groups at T0 and T1 revealed more pro-inflammatory patterns in the pre-CLA miRNA profiles. Moreover, both DMTs emerged as being capable of reverting some dysregulated miRNAs toward a protective phenotype. Both drug-dependent miRNA profiles and specific miRNAs, such as miR-199a-3p, miR-29b-3p, and miR-151a-3p, emerged as potentially involved in these drug-induced mechanisms. This enabled the selection of miRNAs correlated to clinical features and the related miRNA-mRNA network.

Discussion

These data support the hypothesis of specific deregulated miRNAs as putative biomarkers in RRMS patients' stratification and DMT drug response.

Irisin: A Potentially Fresh Insight into the Molecular Mechanisms Underlying Vascular Aging

Aging is a natural process that affects all living organisms, including humans. Aging is a complex process that involves the gradual deterioration of various biological processes and systems, including the cardiovascular system. Vascular aging refers to age-related changes in blood vessels. These changes can increase the risk of developing cardiovascular diseases, such as hypertension, atherosclerosis, and stroke. Recently, an exercise-induced muscle factor, irisin, was found to directly improve metabolism and regulate the balance of glucolipid metabolism, thereby counteracting obesity and insulin resistance. Based on a growing body of evidence, irisin modulates vascular aging. Adenosine monophosphate-activated protein kinase (AMPK) serves as a pivotal cellular energy sensor and metabolic modulator, acting as a central signaling cascade to coordinate various cellular processes necessary for maintaining vascular homeostasis. The vascular regulatory effects of irisin are closely intertwined with its interaction with the AMPK pathway. In conclusion, understanding the molecular processes used by irisin to regulate changes in vascular diseases caused by aging may inspire the development of techniques that promote healthy vascular aging. This review sought to describe the impact of irisin on the molecular mechanisms of vascular aging, including inflammation, oxidative stress, and epigenetics, from the perspective of endothelial cell function and vascular macroregulation, and summarize the multiple signaling pathways used by irisin to regulate vascular aging.

Flow-induced reprogramming of endothelial cells in atherosclerosis

Atherosclerotic diseases such as myocardial infarction, ischaemic stroke and peripheral artery disease continue to be leading causes of death worldwide despite the success of treatments with cholesterol-lowering drugs and drug-eluting stents, raising the need to identify additional therapeutic targets. Interestingly, atherosclerosis preferentially develops in curved and branching arterial regions, where endothelial cells are exposed to disturbed blood flow with characteristic low-magnitude oscillatory shear stress. By contrast, straight arterial regions exposed to stable flow, which is associated with high-magnitude, unidirectional shear stress, are relatively well protected from the disease through shear-dependent, atheroprotective endothelial cell responses. Flow potently regulates structural, functional, transcriptomic, epigenomic and metabolic changes in endothelial cells through mechanosensors and mechanosignal transduction pathways. A study using single-cell RNA sequencing and chromatin accessibility analysis in a mouse model of flow-induced atherosclerosis demonstrated that disturbed flow reprogrammes arterial endothelial cells in situ from healthy phenotypes to diseased ones characterized by endothelial inflammation, endothelial-to-mesenchymal transition, endothelial-to-immune cell-like transition and metabolic changes. In this Review, we discuss this emerging concept of disturbed-flow-induced reprogramming of endothelial cells (FIRE) as a potential pro-atherogenic mechanism. Defining the flow-induced mechanisms through which endothelial cells are reprogrammed to promote atherosclerosis is a crucial area of research that could lead to the identification of novel therapeutic targets to combat the high prevalence of atherosclerotic disease.

Exosomes Interactions with the Blood-Brain Barrier: Implications for Cerebral Disorders and Therapeutics

The Blood-Brain Barrier (BBB) is a selective structural and functional barrier between the circulatory system and the cerebral environment, playing an essential role in maintaining cerebral homeostasis by limiting the passage of harmful molecules. Exosomes, nanovesicles secreted by virtually all cell types into body fluids, have emerged as a major mediator of intercellular communication. Notably, these vesicles can cross the BBB and regulate its physiological functions. However, the precise molecular mechanisms by which exosomes regulate the BBB remain unclear. Recent research studies focused on the effect of exosomes on the BBB, particularly in the context of their involvement in the onset and progression of various cerebral disorders, including solid and metastatic brain tumors, stroke, neurodegenerative, and neuroinflammatory diseases. This review focuses on discussing and summarizing the current knowledge about the role of exosomes in the physiological and pathological modulation of the BBB. A better understanding of this regulation will improve our understanding of the pathogenesis of cerebral diseases and will enable the design of effective treatment strategies.

MicroRNAs Associated with Disability Progression and Clinical Activity in Multiple Sclerosis Patients Treated with Glatiramer Acetate

MicroRNAs (miRNAs) are promising biomarkers in multiple sclerosis (MS). This study aims to investigate the association between a preselected list of miRNAs in serum with therapeutic response to Glatiramer Acetate (GA) and with the clinical evolution of a cohort of relapsing-remitting MS (RRMS) patients. We conducted a longitudinal study for 5 years, with cut-off points at 2 and 5 years, including 26 RRMS patients treated with GA for at least 6 months. A total of 6 miRNAs from a previous study (miR-9.5p, miR-126.3p, mir-138.5p, miR-146a.5p, miR-200c.3p, and miR-223.3p) were selected for this analysis. Clinical relapse, MRI activity, confirmed disability progression (CDP), alone or in combination (No Evidence of Disease Activity-3) (NEDA-3), and Expanded Disability Status Scale (EDSS), were studied. After multivariate regression analysis, miR-9.5p was associated with EDSS progression at 2 years (β = 0.23; 95% CI: 0.04-0.46; p = 0.047). Besides this, mean miR-138.5p values were lower in those patients with NEDA-3 at 2 years (p = 0.033), and miR-146a.5p and miR-126.3p were higher in patients with CDP progression at 2 years (p = 0.044 and p = 0.05 respectively. These results reinforce the use of microRNAs as potential biomarkers in multiple sclerosis. We will need more studies to corroborate these data and to better understand the role of microRNAs in the pathophysiology of this disease.

MiR-126 and miR-146a as Melatonin-Responsive Biomarkers for Neonatal Brain Ischemia

Despite advances in obstetric and neonatal care, challenges remain in early identification of neonates with encephalopathy due to hypoxia-ischemia who are undergoing therapeutic hypothermia. Therefore, there is a deep search for biomarkers that can identify brain injury. The aims of this study were to investigate the serum and brain expressions of two potential biomarkers, miR-126/miR-146a, in a preclinical model of hypoxia-ischemia (HI)-induced brain injury, and to explore their modulation during melatonin treatment. Seven-day-old rats were subjected to permanent ligation of the right carotid artery followed by 2.5 h hypoxia (HI). Melatonin (15 mg/kg) was administered 5 min after HI. Serum and brain samples were collected 1, 6 and 24 h after HI. Results show that HI caused a significant increase in the circulating levels of both miR-126 and miR-146a during the early phase of ischemic brain damage development (i.e. 1 h), with a parallel and opposite pattern in the ischemic cerebral cortex. These effects are not observed 24 h later. Treatment with melatonin restored the HI-induced effects on miR-126/miR-146a expressions, both in the cerebral cortex and in serum. We conclude that miR-126/miR-146a are promising biomarkers of HI injury and demonstrate an associated change in concentration following melatonin treatment.

Tanshinone IIA and Cryptotanshinone Counteract Inflammation by Regulating Gene and miRNA Expression in Human SGBS Adipocytes

Inflammation of the adipose tissue contributes to the onset and progression of several chronic obesity-related diseases. The two most important lipophilic diterpenoid compounds found in the root of Salvia milthorrhiza Bunge (also called Danshen), tanshinone IIA (TIIA) and cryptotanshinone (CRY), have many favorable pharmacological effects. However, their roles in obesity-associated adipocyte inflammation and related sub-networks have not been fully elucidated. In the present study, we investigated the gene, miRNAs and protein expression profile of prototypical obesity-associated dysfunction markers in inflamed human adipocytes treated with TIIA and CRY. The results showed that TIIA and CRY prevented tumor necrosis factor (TNF)-α induced inflammatory response in adipocytes, by counter-regulating the pattern of secreted cytokines/chemokines associated with adipocyte inflammation (CCL2/MCP-1, CXCL10/IP-10, CCL5/RANTES, CXCL1/GRO-α, IL-6, IL-8, MIF and PAI-1/Serpin E1) via the modulation of gene expression (as demonstrated for CCL2/MCP-1, CXCL10/IP-10, CCL5/RANTES, CXCL1/GRO-α, and IL-8), as well as related miRNA expression (miR-126-3p, miR-223-3p, miR-124-3p, miR-155-5p, and miR-132-3p), and by attenuating monocyte recruitment. This is the first demonstration of a beneficial effect by TIIA and CRY on adipocyte dysfunction associated with obesity development and complications, offering a new outlook for the prevention and/or treatment of metabolic diseases.

Transplantation of Exercise-Induced Extracellular Vesicles as a Promising Therapeutic Approach in Ischemic Stroke

Clinical evidence affirms physical exercise is effective in preventive and rehabilitation approaches for ischemic stroke. This sustainable efficacy is independent of cardiovascular risk factors and associates substantial reprogramming in circulating extracellular vesicles (EVs). The intricate journey of pluripotent exercise-induced EVs from parental cells to the whole-body and infiltration to cerebrovascular entity offers several mechanisms to reduce stroke incidence and injury or accelerate the subsequent recovery. This review delineates the potential roles of EVs as prospective effectors of exercise. The candidate miRNA and peptide cargo of exercise-induced EVs with both atheroprotective and neuroprotective characteristics are discussed, along with their presumed targets and pathway interactions. The existing literature provides solid ground to hypothesize that the rich vesicles link exercise to stroke prevention and rehabilitation. However, there are several open questions about the exercise stressors which may optimally regulate EVs kinetic and boost brain mitochondrial adaptations. This review represents a novel perspective on achieving brain fitness against stroke through transplantation of multi-potential EVs generated by multi-parental cells, which is exceptionally reachable in an exercising body.

Interaction between endothelial cell-derived extracellular vesicles and monocytes: A potential link between vascular thrombosis and pregnancy-related morbidity in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease driven by a wide group of autoantibodies primarily directed against phospholipid-binding proteins (antiphospholipid antibodies). APS is defined by two main kinds of clinical manifestations: vascular thrombosis and pregnancy-related morbidity. In recent years, in vitro and in vivo assays, as well as the study of large groups of patients with APS, have led some authors to suggest that obstetric and vascular manifestations of the disease are probably the result of different pathogenic mechanisms. According to this hypothesis, the disease could be differentiated into two parallel entities: Vascular APS and obstetric APS. Thus, vascular APS is understood as an acquired thrombophilia in which a generalised phenomenon of endothelial activation and dysfunction (coupled with a triggering factor) causes thrombosis at any location. In contrast, obstetric APS seems to be due to an inflammatory phenomenon accompanied by trophoblast cell dysfunction. The recent approach to APS raises new issues; for instance, the mechanisms by which a single set of autoantibodies can lead to two different clinical entities are unclear. This review will address the monocyte, a cell with well-known roles in haemostasis and pregnancy, as a potential participant in vascular thrombosis and pregnancy-related morbidity in APS. We will discuss how in a steady state the monocyte-endothelial interaction occurs via extracellular vesicles (EVs), and how antiphospholipid antibodies, by inducing endothelial activation and dysfunction, may disturb this interaction to promote the release of monocyte-targeted procoagulant and inflammatory messages.

Therapeutic Potentials of MicroRNA-126 in Cerebral Ischemia

Stroke is a leading cause of death and disability worldwide. It is among the most common neurological disorders with an 8-10% lifetime risk. Ischemic stroke accounts for about 85% of all strokes and damages the brain tissue via various damaging mechanisms. Following cerebral ischemia, the disrupted blood-brain barrier (BBB) leads to cerebral edema formation caused by activation of oxidative stress, inflammation, and apoptosis, targeting primarily endothelial cells. Activation of the protective mechanisms might favor fewer damages to the neural tissue. MicroRNA (miR)-126 is an endothelial cell-specific miR involved in angiogenesis. MiR-126 orchestrates endothelial progenitor cell functions under hypoxic conditions and could inhibit ischemia-induced oxidative stress and inflammation. It alleviates the BBB disruption by preventing an augment in matrix metalloproteinase level and halting the decrease in the junctional proteins, including zonula occludens-1 (ZO-1), claudin-5, and occludin levels. Moreover, miR-126 enhances post-stroke angiogenesis and neurogenesis. This work provides a therapeutic perspective for miR-126 as a new approach to treating cerebral ischemia.

The expression of circulating hsa-miR-126-3p in dengue-infected Thai pediatric patients

Circulating hsa-miRNA-126 (CmiR-126) has been reported to involve in the pathogenesis of many infectious diseases including dengue virus infection. However, no prior study has been conducted to describe more details in dengue-infected pediatric patients. This study aimed to describe CmiR-126-3p in dengue-infected pediatric patients during the febrile and convalescent phases. Additionally, the correlations between CmiR-126-3p and other relevant clinical laboratory factors were investigated. Sixty paired-serum specimens collected during febrile and convalescent phases were retrieved from patients with dengue fever (DF) (n = 30) and dengue hemorrhagic fever (DHF) (n = 30). Thirty paired-serum specimens collected from non-dengue acute febrile illness patients (AFI) were included as the control group. CmiR-126-3p was determined using reverse transcription quantitative real-time polymerase-chain reaction (RT-qPCR). Relative miRNA expression was calculated as 2^-ΔCt using CmiR-16-5p for data normalization. CmiR-126-3p expression during febrile and convalescent phases in dengue-infected patients was significantly lower than AFI (p < 0.05). However, miRNA levels were not different (p > 0.05) compared between DF and DHF and between primary and secondary infection. CmiR-126-3p levels in DF in the convalescent were significantly higher than in the febrile phase (p = 0.025). No association between CmiR-126-3p and hematocrit, WBC level, platelet count, WBC differential count or dengue viral load was observed (p > 0.05). The data suggest that hsa-miR-126-3p involved in pathogenesis of dengue infection and may be a promising early and late biomarker for DENV infection. However, hsa-miR-126-3p alone cannot be used as a predictor for dengue severity.

The role of non-coding RNAs in neuroinflammatory process in multiple sclerosis

Multiple sclerosis (MS) is a central nervous system chronic neuroinflammatory disease followed by neurodegeneration. The diagnosis is based on clinical presentation, cerebrospinal fluid testing and magnetic resonance imagining. There is still a lack of a diagnostic blood-based biomarker for MS. Due to the cost and difficulty of diagnosis, new and more easily accessible methods are being sought. New biomarkers should also allow for early diagnosis. Additionally, the treatment of MS should lead to the personalization of the therapy. MicroRNAs (miRNAs) and long non-coding RNAs (lncRNAs) as well as their target genes participate in pathophysiology processes in MS. Although the detailed mechanism of action of non-coding RNAs (ncRNAs, including miRNAs and lncRNAs) on neuroinflammation in MS has not been fully explained, several studies were conducted aiming to analyse their impact in MS. In this article, we review up-to-date knowledge on the latest research concerning the ncRNAs in MS and evaluate their role in neuroinflammation. We also point out the most promising ncRNAs which may be promising in MS as diagnostic and prognostic biomarkers.

Non-coding RNAs in the regulation of blood–brain barrier functions in central nervous system disorders

The blood–brain barrier (BBB) is an essential component of the neurovascular unit that controls the exchanges of various biological substances between the blood and the brain. BBB damage is a common feature of different central nervous systems (CNS) disorders and plays a vital role in the pathogenesis of the diseases. Non-coding RNAs (ncRNAs), such as microRNAs (miRNAs), long non-coding RNA (lncRNAs), and circular RNAs (circRNAs), are important regulatory RNA molecules that are involved in almost all cellular processes in normal development and various diseases, including CNS diseases. Cumulative evidences have demonstrated ncRNA regulation of BBB functions in different CNS diseases. In this review, we have summarized the miRNAs, lncRNAs, and circRNAs that can be served as diagnostic and prognostic biomarkers for BBB injuries, and demonstrated the involvement and underlying mechanisms of ncRNAs in modulating BBB structure and function in various CNS diseases, including ischemic stroke, hemorrhagic stroke, traumatic brain injury (TBI), spinal cord injury (SCI), multiple sclerosis (MS), Alzheimer's disease (AD), vascular cognitive impairment and dementia (VCID), brain tumors, brain infections, diabetes, sepsis-associated encephalopathy (SAE), and others. We have also discussed the pharmaceutical drugs that can regulate BBB functions via ncRNAs-related signaling cascades in CNS disorders, along with the challenges, perspective, and therapeutic potential of ncRNA regulation of BBB functions in CNS diseases.

Alterations of the miR-126-3p/POU2AF1/Spi-B Axis and JCPyV Reactivation in Multiple Sclerosis Patients Receiving Natalizumab

Natalizumab (NTZ) can reactivate human polyomavirus John Cunningham polyomavirus (JCPyV) latent infection and lead to progressive multifocal leukoencephalopathy (PML). NTZ modulates the expression of microRNA-126-3p (miR-126-3p) and its target genes, Spi-B, POU2AF1, and vascular cell adhesion molecule-1 (VCAM-1); Spi-B protein binds the JCPyV regulatory region, initiating early gene transcription. This paper is aimed to evaluate the miR-126-3p and soluble (s)VCAM-1 concentration, Spi-B/POU2AF1 gene expression, and JCPyV activity in patients with multiple sclerosis (MS) before and during 2-years NTZ. Serum miR-126-3p and sVCAM-1 concentration was measured before NTZ and after 1, 12, and 24 months of treatment in 22 MS subjects, 1 patient who developed PML, and 29 healthy controls (HCs). The Spi-B and POU2AF1 expression in blood was analyzed at baseline and at month 24 in 13 patients with MS; results were clusterized based on JCPyV activity. miR-126-3p was significantly downregulated in MS before and during NTZ but was greatly increased in the PML patient. sVCAM-1 concentration was comparable in MS and HCs, and was reduced by NTZ in MS and PML. Spi-B/POU2AF1 expression was significantly increased in MS at baseline and was upregulated by NTZ, particularly in JCPyV-infected patients in whom JCPyV reactivation was detected. Taken together, the results suggest that the modulation of the miR-126-3p/POU2AF1/Spi-B axis associates with JCPyV activity in NTZ-treated patients with MS.

miR-27a-3p regulates expression of intercellular junctions at the brain endothelium and controls the endothelial barrier permeability

Background

The brain endothelial barrier permeability is governed by tight and adherens junction protein complexes that restrict paracellular permeability at the blood-brain barrier (BBB). Dysfunction of the inter-endothelial junctions has been implicated in neurological disorders such as multiple sclerosis, stroke and Alzheimer’s disease. The molecular mechanisms underlying junctional dysfunction during BBB impairment remain elusive. MicroRNAs (miRNAs) have emerged as versatile regulators of the BBB function under physiological and pathological conditions, and altered levels of BBB-associated microRNAs were demonstrated in a number of brain pathologies including neurodegeneration and neuroinflammatory diseases. Among the altered micro-RNAs, miR-27a-3p was found to be downregulated in a number of neurological diseases characterized by loss of inter-endothelial junctions and disruption of the barrier integrity. However, the relationship between miR-27a-3p and tight and adherens junctions at the brain endothelium remains unexplored. Whether miR-27a-3p is involved in regulation of the junctions at the brain endothelium remains to be determined.

Methods

Using a gain-and-loss of function approach, we modulated levels of miR-27a-3p in an in-vitro model of the brain endothelium, key component of the BBB, and examined the resultant effect on the barrier paracellular permeability and on the expression of essential tight and adherens junctions. The mechanisms governing the regulation of junctional proteins by miR-27a-3p were also explored.

Results

Our results showed that miR-27a-3p inhibitor increases the barrier permeability and causes reduction of claudin-5 and occludin, two proteins highly enriched at the tight junction, while miR-27a-3p mimic reduced the paracellular leakage and increased claudin-5 and occludin protein levels. Interestingly, we found that miR-27-3p induces expression of claudin-5 and occludin by downregulating Glycogen Synthase Kinase 3 beta (GSK3ß) and activating Wnt/ß-catenin signaling, a key pathway required for the BBB maintenance.

Conclusion

For the first time, we showed that miR-27a-3p is a positive regulator of key tight junction proteins, claudin-5 and occludin, at the brain endothelium through targeting GSK3ß gene and activating Wnt/ß-catenin signaling. Thus, miR-27a-3p may constitute a novel therapeutic target that could be exploited to prevent BBB dysfunction and preserves its integrity in neurological disorders characterized by impairment of the barrier’s function.

Endothelial Microparticles Derived from Primary Pulmonary Microvascular Endothelial Cells Mediate Lung Inflammation in Chronic Obstructive Pulmonary Disease by Transferring microRNA-126

Background

Extracellular vesicles (EVs) are considered to new types of intercellular communication media, and microRNA is one of the most common transferring components of EVs. This study aimed to explore the potential role of endothelial microparticles (EMPs) derived from primary pulmonary microvascular endothelial cells in regulating lung inflammation of chronic obstructive pulmonary disease (COPD) through transferring microRNA-126 (miR-126).

Methods

EMPs generated from primary pulmonary microvascular endothelial cells were isolated by gradient centrifugation and characterized by transmission electron microscopy, flow cytometry and Western blotting. EMPs were treated to in vitro and in vivo COPD models induced by cigarette smoke extract (CSE). miR-126 mimics or inhibitors were transfected into EMPs by calcium chloride. Pathological changes of lung tissue, mRNA and protein levels of inflammation-related factors were measured to explore the effect of EMPs transferring miR-126 on CSE-induced inflammation.

Results

Both in vitro and in vivo studies demonstrated that mRNA and protein levels of inflammation-related factors were significantly increased in COPD group, while EMPs could dramatically reverse these increases. In vitro, overexpression of miR-126 in EMPs decreased HMGB1 expression and magnified the decreasing effect of EMPs on inflammation-related factors.

Conclusion

The present study reveals that EMPs are capable of alleviating lung inflammation and transferring miR-126 can magnify the anti-inflammatory effect of EMPs, which may provide a novel therapeutic alternative for COPD.

The role of Exosomal miRNAs in cancer

Exosomal miRNAs have attracted much attention due to their critical role in regulating genes and the altered expression of miRNAs in virtually all cancers affecting humans (Sun et al. in Mol Cancer 17(1):14, 2018). Exosomal miRNAs modulate processes that interfere with cancer immunity and microenvironment, and are significantly involved in tumor growth, invasion, metastasis, angiogenesis and drug resistance. Fully investigating the detailed mechanism of miRNAs in the occurrence and development of various cancers could help not only in the treatment of cancers but also in the prevention of malignant diseases. The current review highlighted recently published advances regarding cancer-derived exosomes, e.g., sorting and delivery mechanisms for RNAs. Exosomal miRNAs that modulate cancer cell-to-cell communication, impacting tumor growth, angiogenesis, metastasis and multiple biological features, were discussed. Finally, the potential role of exosomal miRNAs as diagnostic and prognostic molecular markers was summarized, as well as their usefulness in detecting cancer resistance to therapeutic agents.

An In Vitro Blood-Brain Barrier Model to Study Firm Shear Stress-Resistant Leukocyte Adhesion to Human Brain Endothelial Cells

Adhesion between leukocytes and brain endothelial cells, which line cerebral blood vessels, is a key event in both physiological and pathological conditions such as neuroinflammatory diseases. Leukocyte recruitment from blood into tissues is described as a multistep process involving leukocyte rolling on endothelial cells, adhesion, crawling, and diapedesis under hemodynamic shear stress. In neuroinflammatory conditions, there is an increase in leukocyte adhesion to the brain endothelial cells, activated by proinflammatory molecules such as cytokines. Here, we describe an in vitro technique to study the interaction between human leukocytes with human brain endothelial cells under shear stress mimicking the blood flow in vivo, coupled to live-cell imaging.

Scavenging the hidden impacts of non-coding RNAs in multiple sclerosis

Multiple sclerosis (MS) is a chronic neuroinflammatory disease that causes severe neurological dysfunction leading to disabilities in patients. The prevalence of the disease has been increasing gradually worldwide, and the specific etiology behind the disease is not yet fully understood. Therapies aimed against treating MS patients have been growing lately, intending to delay the disease progression and increase the patients' quality of life. Various pathways play crucial roles in developing the disease, and several therapeutic approaches have been tackling those pathways. However, these strategies have shown several side effects and inconsistent efficacy. MicroRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) have been shown to act as key players in various disease pathogenesis and development. Several proinflammatory and anti-inflammatory miRNAs have been reported to participate in the development of MS. Hence, the review assesses the role of miRNAs, lncRNAs, and circRNAs in regulating immune cell functions better to understand their impact on the molecular mechanics of MS.

SARS-CoV-2, Cardiovascular Diseases, and Noncoding RNAs: A Connected Triad

Coronavirus Disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), is characterized by important respiratory impairments frequently associated with severe cardiovascular damages. Moreover, patients with pre-existing comorbidity for cardiovascular diseases (CVD) often present a dramatic increase in inflammatory cytokines release, which increases the severity and adverse outcomes of the infection and, finally, mortality risk. Despite this evident association at the clinical level, the mechanisms linking CVD and COVID-19 are still blurry and unresolved. Noncoding RNAs (ncRNAs) are functional RNA molecules transcribed from DNA but usually not translated into proteins. They play an important role in the regulation of gene expression, either in relatively stable conditions or as a response to different stimuli, including viral infection, and are therefore considered a possible important target in the design of specific drugs. In this review, we introduce known associations and interactions between COVID-19 and CVD, discussing the role of ncRNAs within SARS-CoV-2 infection from the perspective of the development of efficient pharmacological tools to treat COVID-19 patients and taking into account the equally dramatic associated consequences, such as those affecting the cardiovascular system.

Irisin: A Promising Target for Ischemia-Reperfusion Injury Therapy

Ischemia-reperfusion injury (IRI) is defined as the total combined damage that occurs during a period of ischemia and following the recovery of blood flow. Oxidative stress, mitochondrial dysfunction, and an inflammatory response are factors contributing to IRI-related damage that can each result in cell death. Irisin is a polypeptide that is proteolytically cleaved from the extracellular domain of fibronectin type III domain-containing protein 5 (FNDC5). Irisin acts as a myokine that potentially mediates beneficial effects of exercise by reducing oxidative stress, improving mitochondrial fitness, and suppressing inflammation. The existing literature also suggests a possible link between irisin and IRI, involving mechanisms similar to those associated with exercise. This article will review the pathogenesis of IRI and the potential benefits and current limitations of irisin as a therapeutic strategy for IRI, while highlighting the mechanistic correlations between irisin and IRI.

Endothelial-Derived Extracellular Vesicles Induce Cerebrovascular Dysfunction in Inflammation

Blood-brain barrier (BBB) dysfunction is a key hallmark in the pathology of many neuroinflammatory disorders. Extracellular vesicles (EVs) are lipid membrane-enclosed carriers of molecular cargo that are involved in cell-to-cell communication. Circulating endothelial EVs are increased in the plasma of patients with neurological disorders, and immune cell-derived EVs are known to modulate cerebrovascular functions. However, little is known about whether brain endothelial cell (BEC)-derived EVs themselves contribute to BBB dysfunction. Human cerebral microvascular cells (hCMEC/D3) were treated with TNFα and IFNy, and the EVs were isolated and characterised. The effect of EVs on BBB transendothelial resistance (TEER) and leukocyte adhesion in hCMEC/D3 cells was measured by electric substrate cell-substrate impedance sensing and the flow-based T-cell adhesion assay. EV-induced molecular changes in recipient hCMEC/D3 cells were analysed by RT-qPCR and Western blotting. A stimulation of naïve hCMEC/D3 cells with small EVs (sEVs) reduced the TEER and increased the shear-resistant T-cell adhesion. The levels of microRNA-155, VCAM1 and ICAM1 were increased in sEV-treated hCMEC/D3 cells. Blocking the expression of VCAM1, but not of ICAM1, prevented sEV-mediated T-cell adhesion to brain endothelia. These results suggest that sEVs derived from inflamed BECs promote cerebrovascular dysfunction. These findings may provide new insights into the mechanisms involving neuroinflammatory disorders.

Adding a "Notch" to Cardiovascular Disease Therapeutics: A MicroRNA-Based Approach

Dysregulation of the Notch pathway is implicated in the pathophysiology of cardiovascular diseases (CVDs), but, as of today, therapies based on the re-establishing the physiological levels of Notch in the heart and vessels are not available. A possible reason is the context-dependent role of Notch in the cardiovascular system, which would require a finely tuned, cell-specific approach. MicroRNAs (miRNAs) are short functional endogenous, non-coding RNA sequences able to regulate gene expression at post-transcriptional levels influencing most, if not all, biological processes. Dysregulation of miRNAs expression is implicated in the molecular mechanisms underlying many CVDs. Notch is regulated and regulates a large number of miRNAs expressed in the cardiovascular system and, thus, targeting these miRNAs could represent an avenue to be explored to target Notch for CVDs. In this Review, we provide an overview of both established and potential, based on evidence in other pathologies, crosstalks between miRNAs and Notch in cellular processes underlying atherosclerosis, myocardial ischemia, heart failure, calcification of aortic valve, and arrhythmias. We also discuss the potential advantages, as well as the challenges, of using miRNAs for a Notch-based approach for the diagnosis and treatment of the most common CVDs.

Involvement of noncoding RNA in blood-brain barrier integrity in central nervous system disease

Given the important role of the blood-brain barrier (BBB) in the central nervous system (CNS), increasing studies have been carried out to determine how the structural and functional integrity of the BBB impacts the pathogenesis of CNS diseases such as stroke, traumatic brain injuries (TBIs), and gliomas. Emerging studies have revealed that noncoding RNAs (ncRNAs) help to maintain the integrity and permeability of the BBB, thereby mediating CNS homeostasis. This review summarizes recent studies that focus on the effects of ncRNAs on the BBB in CNS diseases, including regulating the biological processes of inflammation, necrosis, and apoptosis of cells, affecting the translational dysfunction of proteins and regulating tight junctions (TJs). A comprehensive and detailed understanding of the interaction between ncRNAs and the BBB will lay a solid foundation for the development of early diagnostic methods and effective treatments for CNS diseases.

Effective silencing of miR-126 after ischemic stroke by means of intravenous α-tocopherol-conjugated heteroduplex oligonucleotide in mice

Brain endothelial cells (BECs) are involved in the pathogenesis of ischemic stroke. Recently, several microRNAs (miRNAs) in BECs were reported to regulate the endothelial function in ischemic brain. Therefore, modulation of miRNAs in BECs by a therapeutic oligonucleotide to inhibit miRNA (antimiR) could be a useful strategy for treating ischemic stroke. However, few attempts have been made to achieve this strategy via systemic route due to lack of efficient delivery-method toward BECs. Here, we have developed a new technology for delivering an antimiR into BECs and silencing miRNAs in BECs, using a mouse ischemic stroke model. We designed a heteroduplex oligonucleotide, comprising an antimiR against miRNA-126 (miR-126) known as the endothelial-specific miRNA and its complementary RNA, conjugated to α-tocopherol as a delivery ligand (Toc-HDO targeting miR-126). Intravenous administration of Toc-HDO targeting miR-126 remarkably suppressed miR-126 expression in ischemic brain of the model mice. In addition, we showed that Toc-HDO targeting miR-126 was delivered into BECs more efficiently than the parent antimiR in ischemic brain, and that it was delivered more effectively in ischemic brain than non-ischemic brain of this model mice. Our study highlights the potential of this technology as a new clinical therapeutic option for ischemic stroke.

A comprehensive review on the role of chemokines in the pathogenesis of multiple sclerosis

Multiple sclerosis (MS) as a chronic inflammatory disorder of the central nervous system (CNS) is thought to be caused by the abnormal induction of immune responses. Chemokines as molecules that can engage leukocytes into the location of inflammation, actively participate in the pathogenesis of MS. Several members of this family of chemo attractants have been shown to be dysregulated in the peripheral blood, cerebrospinal fluid or CNS lesions of MS patients. Studies in animal models of MS particularly experimental autoimmune encephalomyelitis have indicated the critical roles of chemokines in the pathophysiology of MS. In the current review, we summarize the data regarding the role of CCL2, CCL3, CCL4, CCL11, CCL20, CXCL1, CXCL2, CXCL8, CXCL10, CXCL12 and CXCL13 in the pathogenesis of MS.

Effect of silver nanoparticles (AgNPs) exposure on microRNA expression and global DNA methylation in endothelial cells EA.hy926

The aim of this study was to determine the effect of AgNPs on the epigenome of endothelial cells EA.hy926, including the levels of expression of microRNAs (miRNAs) and global DNA methylation patterns. In addition, evaluation of the expression of inflammatory genes and the levels of VCAM-1 protein (miRNA-126 target) was performed. The expression levels of analyzed miRNAs (microRNAs-126, 155 and 146) were reduced significantly and there were not observed changes in inflammatory gene expression. Regarding the levels of protein vascular cell adhesion molecule 1 (VCAM-1), they increase significantly to 0.5 μM AgNPs at 24 h of exposure. As far as DNA methylation is concerned, we found that AgNPs induce a state of global hyper-methylation. In conclusion, it was demonstrated that direct contact between AgNPs and endothelial cells resulted in the dysregulation of highly enriched and vastly functional miRNAs and DNA hypermethylation, that may have multiple effects on endothelium function and integrity.

The role of extracellular vesicles in neointima formation post vascular injury

Pathological neointimal growth can develop in patients as a result of vascular injury following percutaneous coronary intervention and coronary artery bypass grafting using autologous saphenous vein, leading to arterial or vein graft occlusion. Neointima formation driven by intimal hyperplasia occurs as a result of a complex interplay between molecular and cellular processes involving different cell types including endothelial cells, vascular smooth muscle cells and various inflammatory cells. Therefore, understanding the intercellular communication mechanisms underlying this process remains of fundamental importance in order to develop therapeutic strategies to preserve endothelial integrity and vascular health post coronary interventions. Extracellular vesicles (EVs), including microvesicles and exosomes, are membrane-bound particles secreted by cells which mediate intercellular signalling in physiological and pathophysiological states, however their role in neointima formation is not fully understood. The purification and characterization techniques currently used in the field are associated with many limitations which significantly hinder the ability to comprehensively study the role of specific EV types and make direct functional comparisons between EV subpopulations. In this review, the current knowledge focusing on EV signalling in neointima formation post vascular injury is discussed.

CSF microRNAs discriminate MS activity and share similarity to other neuroinflammatory disorders

Objective

To perform a comprehensive multicompartment analysis of microRNA (miRNA) expression in multiple sclerosis (MS) linked to disease activity and compared with other neuroinflammatory diseases through a retrospective cross-sectional study.

Methods

One hundred twenty-seven miRNAs were measured by PCR arrays on pooled CSF, serum, and peripheral blood mononuclear cell (PBMC) samples of 10 patients with relapsing MS and 10 controls. Sixty-four miRNAs were then measured by quantitative PCR on individual CSF samples of patients with relapsing or remitting MS and controls (n = 68). Fifty-seven miRNAs were analyzed in the CSF from a second cohort (n = 75), including patients with MS, neuroinfectious, or neuroinflammatory diseases and controls. MiRNAs significantly dysregulated in the CSF were analyzed on individual serum/PBMC samples (n = 59/48) of patients with relapsing or remitting MS and controls. Post hoc analysis consisted of principal component analysis (PCA), gene set, and pathway enrichment analysis.

Results

Twenty-one miRNAs were differentially expressed, mainly upregulated in the CSF during MS relapses. Relapsing MS and neuroinfectious/inflammatory diseases exhibited a partially overlapping CSF miRNA expression profile. Besides confirming the association of miR-146a-5p/150-5p/155-5p with MS, 7 miRNAs uncharacterized for MS emerged (miR-15a-3p/124-5p/149-3p/29c-3p/33a-3p/34c-5p/297). PCA showed that distinct miRNA sets segregated MS from controls and relapse from remission. In silico analysis predicted the involvement of these miRNAs in cell cycle, immunoregulation, and neurogenesis, but also revealed that the signaling pathway pattern of remitting MS is more akin to controls rather than patients with relapsing MS.

Conclusions

This study highlights the CSF-predominant dysregulation of miRNAs in MS by identifying a signature of disease activity and intrathecal inflammation among neuroinflammatory disorders.

MicroRNA-126-3p/-5p Overexpression Attenuates Blood-Brain Barrier Disruption in a Mouse Model of Middle Cerebral Artery Occlusion

Background and Purpose—

Blood-brain barrier (BBB) disruption is a critical pathological feature after stroke. MicroRNA-126 (miR-126) maintains BBB integrity by regulating endothelial cell function during development. However, the role of miR-126-3p and -5p in BBB integrity after stroke is unclear. Here, we investigated whether miR-126-3p and -5p overexpression regulates BBB integrity after cerebral ischemia.

Methods—

A lentivirus carrying genes encoding miR-126-3p or -5p was stereotactically injected into adult male Institute of Cancer Research mouse brains (n=36). Permanent middle cerebral artery occlusion was performed 2 weeks after virus injection. Brain infarct volume, edema volume, and modified neurological severity score were assessed at 1 and 3 days after ischemia. Immunostaining of ZO-1 (zonula occludens-1) and occludin was used to evaluate BBB integrity. IL-1β (interleukin-1β), TNF-α (tumor necrosis factor-α), VCAM-1 (vascular cell adhesion molecule-1), and E-selectin expression levels were determined by real-time polymerase chain reaction and Western blot analysis.

Results—

The expression of miR-126-3p and -5p decreased at 1 and 3 days after ischemia ( P <0.05). Injection of lentiviral miR-126-3p or -5p reduced brain infarct volume and edema volume ( P <0.05) and attenuated the decrease in ZO-1/occludin protein levels and IgG leakage at 3 days after stroke ( P <0.05). Injection of lentiviral miR-126-5p improved behavioral outcomes at 3 days after stroke ( P <0.05). miR-126-3p and -5p overexpression downregulated the expression of proinflammatory cytokines IL-1β and TNF-α and adhesion molecules VCAM-1 and E-selectin, as well as decreased MPO + (myeloperoxidase positive) cell numbers at 3 days after ischemia ( P <0.05).

Conclusions—

miR-126-3p and -5p overexpression reduced the expression of proinflammatory cytokines and adhesion molecules, and attenuated BBB disruption after ischemic stroke, suggesting that miR-126-3p and -5p are new therapeutic targets in the acute stage of stroke.

Hypoxia-Inducible Factor-1α: The Master Regulator of Endothelial Cell Senescence in Vascular Aging

Aging is one of the hottest topics in biomedical research. Advances in research and medicine have helped to preserve human health, leading to an extension of life expectancy. However, the extension of life is an irreversible process that is accompanied by the development of aging-related conditions such as weakness, slower metabolism, and stiffness of vessels. It also debated that aging can be considered an actual disease with aging-derived comorbidities, including cancer or cardiovascular disease. Currently, cardiovascular disorders, including atherosclerosis, are considered as premature aging and represent the first causes of death in developed countries, accounting for 31% of annual deaths globally. Emerging evidence has identified hypoxia-inducible factor-1α as a critical transcription factor with an essential role in aging-related pathology, in particular, regulating cellular senescence associated with cardiovascular aging. In this review, we will focus on the regulation of senescence mediated by hypoxia-inducible factor-1α in age-related pathologies, with particular emphasis on the crosstalk between endothelial and vascular cells in age-associated atherosclerotic lesions. More specifically, we will focus on the characteristics and mechanisms by which cells within the vascular wall, including endothelial and vascular cells, achieve a senescent phenotype.

MicroRNAs in central nervous system diseases: A prospective role in regulating blood-brain barrier integrity

Given the essential role of the blood-brain barrier (BBB) in the central nervous system (CNS), cumulative investigations have been performed to elucidate how modulation of BBB structural and functional integrity affects the pathogenesis of CNS diseases such as stroke, traumatic brain injuries, dementia, and cerebral infection. Recent studies have demonstrated that microRNAs (miRNAs) contribute to the maintenance of the BBB and thereby mediate CNS homeostasis. This review summarizes emerging studies that demonstrate cerebral miRNAs regulate BBB function in CNS disorders, emphasizing the direct role of miRNAs in BBB molecular composition. Evidence presented in this review will encourage a deeper understanding of the mechanisms by which miRNAs regulate BBB function, and facilitate the development of new miRNAs-based therapies in patients with CNS diseases.

MicroRNAs and the Genetic Nexus of Brain Aging, Neuroinflammation, Neurodegeneration, and Brain Trauma

Aging is a complex and integrated gradual deterioration of cellular activities in specific organs of the body, which is associated with increased mortality. This deterioration is the primary risk factor for major human pathologies, including cancer, diabetes, cardiovascular disorders, neurovascular disorders, and neurodegenerative diseases. There are nine tentative hallmarks of aging. In addition, several of these hallmarks are increasingly being associated with acute brain injury conditions. In this review, we consider the genes and their functional pathways involved in brain aging as a means of developing new strategies for therapies targeted to the neuropathological processes themselves, but also as targets for many age-related brain diseases. A single microRNA (miR), which is a short, non-coding RNA species, has the potential for targeting many genes simultaneously and, like practically all other cellular processes, genes associated with many features of brain aging and injury are regulated by miRs. We highlight how certain miRs can mediate deregulation of genes involved in neuroinflammation, acute neuronal injury and chronic neurodegenerative diseases. Finally, we review the recent progress in the development of effective strategies to block specific miR functions and discuss future approaches with the prediction that anti-miR drugs may soon be used in the clinic.

Role of flow-sensitive microRNAs and long noncoding RNAs in vascular dysfunction and atherosclerosis

Atherosclerosis is the primary underlying cause of myocardial infarction, ischemic stroke, and peripheral artery disease. The disease preferentially occurs in arterial regions exposed to disturbed blood flow, in part, by altering expression of flow-sensitive coding- and non-coding genes. In this review, we summarize the role of noncoding RNAs, [microRNAs (miRNAs) and long noncoding RNAs(lncRNAs)], as regulators of gene expression and outline their relationship to the pathogenesis of atherosclerosis. While miRNAs are small noncoding genes that post-transcriptionally regulate gene expression by targeting mRNA transcripts, the lncRNAs regulate gene expression by diverse mechanisms, which are still emerging and incompletely understood. We focused on multiple flow-sensitive miRNAs such as, miR-10a, -19a, -23b, -17~92, -21, -663, -92a, -143/145, -101, -126, -712, -205, and -155 that play a critical role in endothelial function and atherosclerosis by targeting inflammation, cell cycle, proliferation, migration, apoptosis, and nitric oxide signaling. Flow-dependent regulation of lncRNAs is just emerging, and their role in vascular dysfunction and atherosclerosis is unknown. Here, we discuss the flow-sensitive lncRNA STEEL along with other lncRNAs studied in the context of vascular pathophysiology and atherosclerosis such as MALAT1, MIAT1, ANRIL, MYOSLID, MEG3, SENCR, SMILR, LISPR1, and H19. Also discussed is the use of these noncoding RNAs as potential biomarkers and therapeutics to reduce and regress atherosclerosis.

miRNA-27a-3p and miRNA-222-3p as Novel Modulators of Phosphodiesterase 3a (PDE3A) in Cerebral Microvascular Endothelial Cells

Endothelial dysfunction is a key element in cerebral small vessel disease (CSVD), which may cause stroke and cognitive decline. Cyclic nucleotide signaling modulates endothelial function. The cyclic adenosine monophosphate-degrading enzyme phosphodiesterase 3 (PDE3) is an important treatment target which may be modulated by microRNAs (miRNAs) important for regulating gene expression. We aimed to identify PDE3-targeting miRNAs to highlight potential therapeutic targets for endothelial dysfunction and CSVD. PDE3-targeting miRNAs were identified by in silico analysis (TargetScan, miRWalk, miRanda, and RNA22). The identified miRNAs were ranked on the basis of TargetScan context scores and their expression (log2 read counts) in a human brain endothelial cell line (hCMEC/D3) described recently. miRNAs were subjected to co-expression meta-analysis (CoMeTa) to create miRNA clusters. The pathways targeted by the miRNAs were assigned functional annotations via the KEGG pathway and COOL. hCMEC/D3 cells were transfected with miRNA mimics miR-27a-3p and miR-222-3p, and the effect on PDE3A protein expression was analyzed by Western blotting. Only PDE3A is expressed in hCMEC/D3 cells. The in silico prediction identified 67 PDE3A-related miRNAs, of which 49 were expressed in hCMEC/D3 cells. Further analysis of the top two miRNA clusters (miR-221/miR-222 and miR-27a/miR-27b/miR-128) indicated a potential link to pathways relevant to cerebral and vascular integrity and repair. hCMEC/D3 cells transfected with miR-27a-3p and miR-222-3p mimics had reduced relative expression of PDE3A protein. PDE3A-related miRNAs miR-221/miR-222 and miR-27a/miR-27b/miR-128 are potentially linked to pathways essential for immune regulation as well as cerebral and vascular integrity/function. Furthermore, relative PDE3A protein expression was reduced by miR27a-3p and miR-222-3p.

Effect of exosomal miRNA on cancer biology and clinical applications

Exosomes, extracellular vesicles with diameters ranging from 30 to 150 nm, are widely present in various body fluids. Recently, microRNAs (miRNAs) have been identified in exosomes, the biogenesis, release, and uptake of which may involve the endosomal sorting complex required for transport (ESCRT complex) and relevant proteins. After release, exosomes are taken up by neighboring or distant cells, and the miRNAs contained within modulate such processes as interfering with tumor immunity and the microenvironment, possibly facilitating tumor growth, invasion, metastasis, angiogenesis and drug resistance. Therefore, exosomal miRNAs have a significant function in regulating cancer progression. Here, we briefly review recent findings regarding tumor-derived exosomes, including RNA sorting and delivering mechanism. We then describe the intercommunication occurring between different cells via exosomal miRNAs in tumor microenvironmnt, with impacts on tumor proliferation, vascularization, metastasis and other biological characteristics. Finally, we highlight the potential role of these molecules as biomarkers in cancer diagnosis and prognosis and tumor resistance to therapeutics.

Involvement of miR-126 in autoimmune disorders

BACKGROUND

Micro-RNA represent a great family of small non-condign ribonucleic acid molecules; in particular microRNA-126 is an important member of this family and is expressed in many human cells such as cardiomyocytes, endothelial and lung cells. Some studies have shown the implication of miR-126 in cancer, but recently significant progresses have also been made in determining the role of miR-126 regulating immune-related diseases; probably, in a near future, they could potentially serve as diagnostic biomarkers or therapeutic targets.

OBJECTIVE

The purpose of this review is to investigate the role of miR-126 in autoimmune diseases, so as to offer innovative therapies.

RESULTS

According literature, it was concluded that miRNAs, especially miR-126, are involved in many pathologies and that their expression levels increase in autoimmune diseases because they interfere with the transcription of the proteins involved. Since microRNAs can be detected from several biological sources, they may be attractive as potential biomarkers for the diagnosis, prognosis, disease activity and severity of various diseases. In fact, once confirmed the involvement of miR-126 in autoimmune diseases, it was speculated that it could be used as a promising biomarker. These discovers implicate that miR-126 have a central role in many pathways leading to the development and sustain of autoimmune diseases. Its key role make this microRNA a potential therapeutic target in autoimmunity.

CONCLUSION

Although miR-126 relevant role in several immune-related diseases, further studies are needed to clear its molecular mechanisms; the final step of these novel researches could be the blockage or the prevention of the diseases onset by creating of new targeted therapy.

MicroRNAs as Potential Mediators for Cigarette Smoking Induced Atherosclerosis

Smoking increases the risk of atherosclerosis-related events, such as myocardial infarction and ischemic stroke. Recent studies have examined the expression levels of altered microRNAs (miRNAs) in various diseases. The profiles of tissue miRNAs can be potentially used in diagnosis or prognosis. However, there are limited studies on miRNAs following exposure to cigarette smoke (CS). The present study was designed to dissect the effects and cellular/molecular mechanisms of CS-induced atherosclerogenesis. Apolipoprotein E knockout (ApoE KO) mice were exposed to CS for five days a week for two months at low (two puffs/min for 40 min/day) or high dose (two puffs/min for 120 min/day). We measured the area of atherosclerotic plaques in the aorta, representing the expression of miRNAs after the exposure period. Two-month exposure to the high dose of CS significantly increased the plaque area in aortic arch, and significantly upregulated the expression of atherosclerotic markers (VCAM-1, ICAM-1, MCP1, p22phox, and gp91phox). Exposure to the high dose of CS also significantly upregulated the miRNA-155 level in the aortic tissues of ApoE KO mice. Moreover, the expression level of miR-126 tended to be downregulated and that of miR-21 tended to be upregulated in ApoE KO mice exposed to the high dose of CS, albeit statistically insignificant. The results suggest that CS induces atherosclerosis through increased vascular inflammation and NADPH oxidase expression and also emphasize the importance of miRNAs in the pathogenesis of CS-induced atherosclerosis. Our findings provide evidence for miRNAs as potential mediators of inflammation and atherosclerosis induced by CS.

Endothelial microRNAs regulating the NF-κB pathway and cell adhesion molecules during inflammation

The surface of endothelial cells is covered with cell adhesion molecules, including E-selectin, intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM- 1) , that mediate the adhesion and extravasation of leukocytes and play pivotal roles in inflammatory response. microRNAs (miRNAs) regulate the expression of these important cell adhesion molecules through two distinct major mechanisms, namely via modulating the proinflammatory NF-κB pathway, which controls their transcription, and via directly targeting them. The present review highlights the role of various miRNAs in controlling the expression of E-selectin, ICAM-1, and VCAM-1: a type of regulation that can be harnessed for therapeutic prevention of inflammation-associated diseases such as atherosclerosis and sepsis. The roles of secreted miRNAs as paracrine regulators, and cell adhesion molecule-based miRNA delivery are also addressed.-Zhong, L., Simard, M. J., Huot, J. Endothelial microRNAs regulating the NF-κB pathway and cell adhesion molecules during inflammation.

Asiaticoside Attenuates Cell Growth Inhibition and Apoptosis Induced by Aβ1-42 via Inhibiting the TLR4/NF-κB Signaling Pathway in Human Brain Microvascular Endothelial Cells

Alzheimer's disease (AD) is a very common progressive neurodegenerative disorder with the highest incidence in the world. Dysfunction of the blood-brain barrier (BBB) may be responsible for the pathogenesis and pathology of AD for abnormally transporting amyloid-β (Aβ, the main component of the senile plaques) from the sera into the central nervous system. Aβ peptides induce apoptosis in human brain microvascular endothelial cells (hBMECs), the main component of BBB. Apoptosis in neuronal cells plays a critical role in the pathogenesis of AD. Asiaticoside, a natural glycoside extracted from Centella asiatica (L.) Urban, has an anti-apoptotic effect on hBMECs but the molecule mechanism remains unclear. Therefore, we investigate the protective effect of asiaticoside on Aβ_1-42-induced cytotoxicity and apoptosis as well as associated mechanism in hBMECs with commonly used in vitro methods for clinical development of asiaticoside as a novel anti-AD agent. In the present study, we investigated the effects of asiaticoside on cytotoxicity by Cell Counting Kit-8 assay, mitochondrial membrane potential by JC-1 fluorescence analysis, anti-apoptosis by Hoechst 33258 staining and Annexin V-FITC (fluorescein isothiocyanate) and propidium iodide (PI) analyses, the expressions of TNF-α and IL-6 by enzyme-linked immunosorbent assay (ELISA) and TLR4, MyD88, TRAF6, p-NF-κB p65, and total NF-κB p65 by Western blotting, and nuclear translocation of NF-κB p65 by immunofluorescence analysis in hBMECs. The results showed that pretreatment of asiaticoside (25, 50, and 100 μM) for 12 h significantly attenuated cell growth inhibition and apoptosis, and restored declined mitochondrial membrane potential induced by Aβ_1-42 (50 μM) in hBMECs. Asiaticoside also significantly downregulated the elevated expressions of TNF-α, IL-6, TLR4, MyD88, TRAF6, and p-NF-κB p65, as well as inhibited NF-κB p65 translocation from cytoplasm to nucleus induced by Aβ_1-42 in hBMECs in a concentration-dependent manner. The possible underlying molecular mechanism of asiaticoside may be through inhibiting the TLR4/NF-κB signaling pathway. Therefore, asiaticoside may be developed as a novel agent for the prevention and/or treatment of AD clinically.

miR-126-5p promotes retinal endothelial cell survival through SetD5 regulation in neurons

MicroRNAs are key regulators of angiogenesis, as illustrated by the vascular defects observed in miR-126-deficient animals. The miR-126 duplex gives rise to two mature microRNAs (miR-126-3p and -5p). The vascular defects in these mutant animals were attributed to the loss of miR-126-3p but the role of miR-126-5p during normal angiogenesis in vivo remains unknown. Here, we show that miR-126-5p is expressed in endothelial cells but also by retinal ganglion cells (RGCs) of the mouse postnatal retina and participates in protecting endothelial cells from apoptosis during the establishment of the retinal vasculature. miR-126-5p negatively controls class 3 semaphorin protein (Sema3A) in RGCs through the repression of SetD5, an uncharacterized member of the methyltransferase family of proteins. In vitro, SetD5 controls Sema3A expression independently of its SET domain and co-immunoprecipitates with BRD2, a bromodomain protein that recruits transcription regulators onto the chromatin. Both SetD5 and BRD2 bind to the transcription start site and to upstream promoter regions of the Sema3a locus and BRD2 is necessary for the regulation of Sema3A expression by SetD5. Thus, neuronally expressed miR-126-5p regulates angiogenesis by protecting endothelial cells of the developing retinal vasculature from apoptosis.

Current research into brain barriers and the delivery of therapeutics for neurological diseases: a report on CNS barrier congress London, UK, 2017

This is a report on the CNS barrier congress held in London, UK, March 22–23rd 2017 and sponsored by Kisaco Research Ltd. The two 1-day sessions were chaired by John Greenwood and Margareta Hammarlund-Udenaes, respectively, and each session ended with a discussion led by the chair. Speakers consisted of invited academic researchers studying the brain barriers in relation to neurological diseases and industry researchers studying new methods to deliver therapeutics to treat neurological diseases. We include here brief reports from the speakers.

Blood-brain barrier disruption in diabetic mice is linked to Nrf2 signaling deficits: Role of ABCB10?

Blood-brain barrier (BBB) damage is a critical neurovascular complication of diabetes mellitus that adversely affects the CNS health and function. Previously, we showed the protective role of NF-E2 related factor-2 (Nrf2), a redox sensitive transcription factor, in regulation of BBB integrity. Given the pathogenic role of mitochondrial oxidative stress in diabetes-related microvascular complications, we focused on assessing: 1) the impact of diabetes on brain Nrf2 in correlation with BBB permeability and 2) Nrf2-dependent regulation of the mitochondrial transporter ABCB10, an essential player in mitochondrial function and redox balance at BBB endothelium. Using live animal fluorescence imaging, we demonstrated a strong increase in BBB permeability to 70kDa dextran in db/db diabetic mice that correlated with significant down-regulation of brain Nrf2 protein. Further, Nrf2 gene silencing in human BBB endothelial cells markedly suppressed ABCB10 protein, while Nrf2 activation by sulforaphane up-regulated ABCB10 expression. Interestingly, ABCB10 knockdown resulted in a strong-induction of Nrf2 driven anti-oxidant responses as evidenced by increased expression of Nrf2 and its downstream targets. Nrf2 or ABCB10 silencing elevated endothelial-monocyte adhesion suggesting an activated inflammatory cascade. Thus, our results demonstrate a novel mechanism of ABCB10 regulation driven by Nrf2. In summary, Nrf2 dysregulation and ABCB10 suppression could likely mediate endothelial oxidative/inflammatory stress and BBB disruption in diabetic subjects.