MicroRNA-107 prevents amyloid-beta induced blood-brain barrier disruption and endothelial cell dysfunction by targeting Endophilin-1

Large-Scale Isolation of Milk Exosomes for Skincare

Exosomes are small membrane vesicles in a cell culture. They are secreted by most cells and originate from the endosomal pathway. A variety of proteins, lipids, and genetic materials have been shown to be carried by exosomes. Once taken up by neighboring or distant cells, the bioactive compounds in exosomes can regulate the condition of recipient cells. Typically, producing exosomes in large quantities requires cell culture, resulting in high production costs. However, exosomes are abundant in milk and can be isolated on a large scale at a low cost. In our study, we found that milk exosomes can promote the synthesis and reconstruction of stratum corneum lipids, enhance skin barrier function, and provide greater protection for the skin. Furthermore, milk exosomes have anti-inflammatory properties that can reduce skin irritation, redness, and other symptoms, giving immediate relief. They also exhibit antioxidant activity, which helps neutralize free radicals and slows down the skin aging process. Additionally, milk exosomes inhibit melanin production, aiding in skin whitening. Ongoing research has uncovered the benefits of milk exosomes for skin improvement and their application in cosmetics, skin healthcare, and other fields, and these applications are continuing to expand.

ω3-PUFA alleviates neuroinflammation by upregulating miR-107 targeting PIEZO1/NFκB p65

BACKGROUND

MiR-107 is reduced in sepsis and associated with inflammation regulation. Dietary supplementation with polyunsaturated fatty acids (ω3-PUFA) can increase the expression of miR-107; this study investigated whether the ω3-PUFA can effectively inhibit neuroinflammation and improve cognitive function by regulating miR-107 in the brain.

METHODS

The LPS-induced mouse model of neuroinflammation and the BV2 cell inflammatory model were used to evaluate the effects of ω3-PUFA on miR-107 expression and inflammation. Intraventricular injection of Agomir and Antagomir was used to modulate miR-107 expression. HE and Nissl staining for analyzing hippocampal neuronal damage, immunofluorescence analysis for glial activation, RT-qPCR, and Western blot were conducted to examine miR-107 expression and inflammation signalling.

RESULTS

The result shows that LPS successfully induced the mouse neuroinflammation model and BV2 cell inflammation model. Supplementation of ω3-PUFA effectively reduced the secretion of pro-inflammatory factors TNFα, IL1β, and IL6 induced by LPS, improved cognitive function impairment, and increased miR-107 expression in the brain. Overexpression of miR-107 in the brain inhibited the nuclear factor κB (NFκB) pro-inflammatory signalling pathway by targeting PIEZO1, thus suppressing microglial and astrocyte activation and reducing the release of inflammatory mediators, which alleviated neuroinflammatory damage and improved cognitive function in mice. miR-107, as an intron of PANK1, PANK1 is subject to PPAR α Adjust. ω3-PUFA can activate PPARα, but ω3-PUFA upregulates brain miR-107, and PPARα/PANK1-related pathways may not be synchronized, and further research is needed to confirm the specific mechanism by which ω3-PUFA upregulates miR-107.

CONCLUSION

The miR-107/PIEZO1/NFκB p65 pathway represents a novel mechanism underlying the improvement of neuroinflammation by ω3-PUFA.

Epigenetic modifications of DNA and RNA in Alzheimer's disease

Alzheimer's disease (AD) is a complex neurodegenerative disorder and the most common form of dementia. There are two main types of AD: familial and sporadic. Familial AD is linked to mutations in amyloid precursor protein (APP), presenilin-1 (PSEN1), and presenilin-2 (PSEN2). On the other hand, sporadic AD is the more common form of the disease and has genetic, epigenetic, and environmental components that influence disease onset and progression. Investigating the epigenetic mechanisms associated with AD is essential for increasing understanding of pathology and identifying biomarkers for diagnosis and treatment. Chemical covalent modifications on DNA and RNA can epigenetically regulate gene expression at transcriptional and post-transcriptional levels and play protective or pathological roles in AD and other neurodegenerative diseases.

Biology of endophilin and it's role in disease

Endophilin is an evolutionarily conserved family of protein that involves in a range of intracellular membrane dynamics. This family consists of five isoforms, which are distributed in various tissues. Recent studies have shown that Endophilin regulates diseases pathogenesis, including neurodegenerative diseases, tumors, cardiovascular diseases, and autoimmune diseases. In vivo, it regulates different biological functions such as vesicle endocytosis, mitochondrial morphological changes, apoptosis and autophagosome formation. Functional studies confirmed the role of Endophilin in development and progression of these diseases. In this study, we have comprehensively discussed the complex function of Endophilin and how the family contributes to diseases development. It is hoped that this study will provide new ideas for targeting Endophilin in diseases.

Vascular Ageing: Mechanisms, Risk Factors, and Treatment Strategies

Ageing constitutes the biggest risk factor for poor health and adversely affects the integrity and function of all the cells, tissues, and organs in the human body. Vascular ageing, characterised by vascular stiffness, endothelial dysfunction, increased oxidative stress, chronic low-grade inflammation, and early-stage atherosclerosis, may trigger or exacerbate the development of age-related vascular diseases, which each year contribute to more than 3.8 million deaths in Europe alone and necessitate a better understanding of the mechanisms involved. To this end, a large number of recent preclinical and clinical studies have focused on the exponential accumulation of senescent cells in the vascular system and paid particular attention to the specific roles of senescence-associated secretory phenotype, proteostasis dysfunction, age-mediated modulation of certain microRNA (miRNAs), and the contribution of other major vascular risk factors, notably diabetes, hypertension, or smoking, to vascular ageing in the elderly. The data generated paved the way for the development of various senotherapeutic interventions, ranging from the application of synthetic or natural senolytics and senomorphics to attempt to modify lifestyle, control diet, and restrict calorie intake. However, specific guidelines, considering the severity and characteristics of vascular ageing, need to be established before widespread use of these agents. This review briefly discusses the molecular and cellular mechanisms of vascular ageing and summarises the efficacy of widely studied senotherapeutics in the context of vascular ageing.

Blood-Brain Barrier Dysfunction in Normal Aging and Neurodegeneration: Mechanisms, Impact, and Treatments

Cerebral endothelial cells and their linking tight junctions form a unique, dynamic and multi-functional interface, the blood-brain barrier (BBB). The endothelium is regulated by perivascular cells and components forming the neurovascular unit. This review examines BBB and neurovascular unit changes in normal aging and in neurodegenerative disorders, particularly focusing on Alzheimer disease, cerebral amyloid angiopathy and vascular dementia. Increasing evidence indicates BBB dysfunction contributes to neurodegeneration. Mechanisms underlying BBB dysfunction are outlined (endothelium and neurovascular unit mediated) as is the BBB as a therapeutic target including increasing the uptake of systemically delivered therapeutics across the BBB, enhancing clearance of potential neurotoxic compounds via the BBB, and preventing BBB dysfunction. Finally, a need for novel biomarkers of BBB dysfunction is addressed.

RNA binding proteins in MLL-rearranged leukemia

RNA binding proteins (RBPs) have recently emerged as important post-transcriptional gene expression regulators in both normal development and disease. RBPs influence the fate of mRNAs through multiple mechanisms of action such as RNA modifications, alternative splicing, and miR-mediated regulation. This complex and, often, combinatorial regulation by RBPs critically impacts the expression of oncogenic transcripts and, thus, the activation of pathways that drive oncogenesis. Here, we focus on the major features of RBPs, their mechanisms of action, and discuss the current progress in investigating the function of important RBPs in MLL-rearranged leukemia.

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.

Molecular Insight Into the Therapeutic Potential of Long Non-coding RNA-Associated Competing Endogenous RNA Axes in Alzheimer's Disease: A Systematic Scoping Review

Alzheimer’s disease (AD) is a heterogeneous degenerative brain disorder with a rising prevalence worldwide. The two hallmarks that characterize the AD pathophysiology are amyloid plaques, generated via aggregated amyloid β, and neurofibrillary tangle, generated via accumulated phosphorylated tau. At the post-transcriptional and transcriptional levels, the regulatory functions of non-coding RNAs, in particular long non-coding RNAs (lncRNAs), have been ascertained in gene expressions. It is noteworthy that a number of lncRNAs feature a prevalent role in their potential of regulating gene expression through modulation of microRNAs via a process called the mechanism of competing endogenous RNA (ceRNA). Given the multifactorial nature of ceRNA interaction networks, they might be advantageous in complex disorders (e.g., AD) investigations at the therapeutic targets level. We carried out scoping review in this research to analyze validated loops of ceRNA in AD and focus on ceRNA axes associated with lncRNA. This scoping review was performed according to a six-stage methodology structure and PRISMA guideline. A systematic search of seven databases was conducted to find eligible articles prior to July 2021. Two reviewers independently performed publications screening and data extraction, and quantitative and qualitative analyses were conducted. Fourteen articles were identified that fulfill the inclusion criteria. Studies with different designs reported nine lncRNAs that were experimentally validated to act as ceRNA in AD in human-related studies, including BACE1-AS, SNHG1, RPPH1, NEAT1, LINC00094, SOX21-AS1, LINC00507, MAGI2-AS3, and LINC01311. The BACE1-AS/BACE1 was the most frequent ceRNA pair. Among miRNAs, miR-107 played a key role by regulating three different loops. Understanding the various aspects of this regulatory mechanism can help elucidate the unknown etiology of AD and provide new molecular targets for use in therapeutic and clinical applications.

MicroRNA-Target Interaction Regulatory Network in Alzheimer's Disease

Alzheimer’s Disease (AD) is a progressive neurodegenerative disorder and the most common cause of dementia; however, early diagnosis of the disease is challenging. Research suggests that biomarkers found in blood, such as microRNAs (miRNA), may be promising for AD diagnostics. Experimental data on miRNA–target interactions (MTI) associated with AD are scattered across databases and publications, thus making the identification of promising miRNA biomarkers for AD difficult. In response to this, a list of experimentally validated AD-associated MTIs was obtained from miRTarBase. Cytoscape was used to create a visual MTI network. STRING software was used for protein–protein interaction analysis and mirPath was used for pathway enrichment analysis. Several targets regulated by multiple miRNAs were identified, including: BACE1, APP, NCSTN, SP1, SIRT1, and PTEN. The miRNA with the highest numbers of interactions in the network were: miR-9, miR-16, miR-34a, miR-106a, miR-107, miR-125b, miR-146, and miR-181c. The analysis revealed seven subnetworks, representing disease modules which have a potential for further biomarker development. The obtained MTI network is not yet complete, and additional studies are needed for the comprehensive understanding of the AD-associated miRNA targetome.

Dysfunction of the blood-brain barrier in Alzheimer's disease: evidence from human studies

The pathological processes leading to synapse loss, neuronal loss, brain atrophy and gliosis in Alzheimer´s disease (AD) and their relation to vascular disease and immunological changes are yet to be fully explored. Amyloid-β (Aβ) aggregation, vascular damage and altered immune response interact at the blood-brain-barrier (BBB), affecting the brain endothelium and fuelling neurodegeneration. The aim of the present systematic literature review was to critically appraise and to summarise the published evidence on the clinical correlations and pathophysiological concepts of BBB damage in AD, focusing on human data. The PubMed, Cochrane, Medline and Embase databases were searched for original research articles, systematic reviews and meta-analyses, published in English language from 01/2000 to 07/2021, using the keywords Alzheimer*, amyloid-β or β-amyloid or abeta and brain-blood barrier or BBB. This review shows that specific changes of intercellular structures, reduced expression of transendothelial carriers, induction of vasoactive mediators and activation of both astroglia and monocytes/macrophages characterise blood-brain barrier damage in human AD and AD models. BBB dysfunction on magnetic resonance imaging takes place early in the disease course in AD-specific brain regions. The toxic effects of Aβ and apolipoprotein E (ApoE) are likely to induce a non-cerebral-amyloid-angiopathy-related degeneration of endothelial cells, independently of cerebrovascular disease; however, some of the observed structural changes may just arise with age. Small vessel disease, ApoE, loss of pericytes, pro-inflammatory signalling and cerebral amyloid angiopathy enhance blood-brain-barrier damage. Novel therapeutic approaches for AD, including magnetic resonance-guided focused ultrasound, aim to open the BBB, potentially leading to an improved drainage of Aβ along perivascular channels and increased elimination from the brain. In vitro treatments with ApoE-modifying agents yielded promising effects on modulating BBB function. Reducing cardiovascular risk factors represents one of the most promising interventions for dementia prevention at present. However, further research is needed to elucidate the connection of BBB damage and tau pathology, the role of pro-inflammatory mediators in draining macromolecules and cells from the cerebral parenchyma, including their contribution to cerebral amyloid angiopathy. Improved insight into these pathomechanisms may allow to shed light on the role of Aβ deposition as a primary vs. a secondary event in the complex pathogenesis of AD.

RNA Dynamics in Alzheimer's Disease

Alzheimer's disease (AD) is the most common age-related neurodegenerative disorder that heavily burdens healthcare systems worldwide. There is a significant requirement to understand the still unknown molecular mechanisms underlying AD. Current evidence shows that two of the major features of AD are transcriptome dysregulation and altered function of RNA binding proteins (RBPs), both of which lead to changes in the expression of different RNA species, including microRNAs (miRNAs), circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and messenger RNAs (mRNAs). In this review, we will conduct a comprehensive overview of how RNA dynamics are altered in AD and how this leads to the differential expression of both short and long RNA species. We will describe how RBP expression and function are altered in AD and how this impacts the expression of different RNA species. Furthermore, we will also show how changes in the abundance of specific RNA species are linked to the pathology of AD.

Non-coding RNAs: the extensive and interactive regulators of the blood-brain barrier permeability

The blood-brain barrier (BBB), which controls permeability into and out of the nervous system, is a tightly connected, structural, and functional separation between the central nervous system (CNS) and circulating blood. CNS diseases, such as Alzheimer’s disease, multiple sclerosis, traumatic brain injury, stroke, meningitis, and brain cancers, often develop with the increased BBB permeability and further leads to irreversible CNS injury. Non-coding RNAs (ncRNAs) are functional RNA molecules that generally lack the coding abilities but can actively regulate the mRNA expression and function through different mechanisms. Various types of ncRNAs, including microRNAs (miRNAs), long ncRNAs (lncRNAs), and circular RNAs (circRNAs), are highly expressed in brain microvascular endothelial cells and are potential mediators of BBB permeability. Here, we summarized the recent research progress on miRNA, lncRNA, and circRNA roles regulating the BBB permeability in different CNS diseases. Understanding how these ncRNAs affect the BBB permeability shall provide important therapeutic insights into the prevention and control of the BBB dysfunction.

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.

Analysis of regulatory effect of miR-149-5p on Sphingosine-1-phosphate receptor 2 of pericytes and its neuroprotective molecular mechanism after acute cerebral ischemia reperfusion in rats

To investigate the effect of miR-149-5p on sphingosine-1-phosphate receptor 2 (S1PR2) expression level and contents of matrix metalloproteinase (MMP-9) and superoxide dismutase (SOD) in the pericytes after acute cerebral ischemia reperfusion in rats, so as to clarify the neuroprotective molecular mechanism induced by miR-149-5p and provide references for the treatment of neurological diseases, 60 male SD rats aged 7-8 weeks were selected and divided randomly into test group (establishing middle cerebral artery occlusion (MCAO) model) and control group (no modeling). Rat pericytes and peripheral cerebral infarction tissues were collected 12 h, 1 d, 3 d, 5 d, and 7 d after MCAO modeling, respectively. The pericytes were identified by immunofluorescence assay (IFA) and transfected with miR-149-5p. Fluorescence quantitative PCR (FQPCR) and Western blot were adopted to detect S1PR2 expression level. The expression of S1PR2 in MCAO model rats was detected by IFA. Immunohistochemistry (IHC) and quantitative real-time PCR (qRT-PCR) were used to detect the changes of MMP9 protein and mRNA levels of SOD1, SOD2, and SOD3 in brain tissue. The results showed that mRNA level and protein expression level of S1PR2 in the test group were higher than those in the control group three days after MCAO modeling (P < 0.05); the expression of S1PR2 increased 12 h after MCAO modeling and returned to the normal level on the 5th day, and the content of MMP9 protein in brain tissue of the test group was significantly lower than that of the control group (P < 0.05); the mRNA levels and SODs activity of SOD1, SOD2, and SOD3 in the test group were higher than those in the control group (P < 0.05). Therefore, miR-149-5p played a neuroprotective role by regulating S1PR2 to change the expression levels of SODS and MMP9.

Targeting microRNAs to Regulate the Integrity of the Blood-Brain Barrier

The blood-brain barrier (BBB) is a highly specialized neurovascular unit that protects the brain from potentially harmful substances. In addition, the BBB also engages in the exchange of essential nutrients between the vasculature and brain parenchyma, which is critical for brain homeostasis. Brain diseases, including neurological disorders and cerebrovascular diseases, are often associated with disrupted BBB integrity, evidenced by increased permeability. Therefore, defining the mechanisms underlying the regulation of BBB integrity is crucial for the development of novel therapeutics targeting brain diseases. MicroRNAs (miRNA), a type of small non-coding RNAs, are emerging as an important regulator of BBB integrity. Here we review recent developments related to the role of miRNAs in regulating BBB integrity.

Cycloastragenol inhibits Aβ1-42-induced blood-brain barrier disruption and enhances soluble Aβ efflux in vitro

This study aimed to evaluate the effect Cycloastragenol (CAG), a triterpenoid saponin isolated from the Radix astragali, on Aβ-induced BBB damage. An immortalized endothelial cell line (bEnd.3) was employed to mimic a BBB. The Western blot, TUNEL staining, Flow cytometric analysis and Enzyme-linked immunosorbent assay were performed. The present results showed that CAG (10, 50, 75 μM) can alleviate oligomer Aβ_1-42 induced bEnd.3 cell apoptosis and increase tight junction scaffold proteins expression. The result also indicated that CAG increased soluble Aβ efflux across BBB via upregulation of the P-gp and downregulation of RAGE expression.[Formula: see text].

Epigenetics in blood-brain barrier disruption

The vessels of the central nervous system (CNS) have unique barrier properties. The endothelial cells (ECs) which comprise the CNS vessels contribute to the barrier via strong tight junctions, specific transporters, and limited endocytosis which combine to protect the brain from toxins and maintains brain homeostasis. Blood-brain barrier (BBB) leakage is a serious secondary injury in various CNS disorders like stroke, brain tumors, and neurodegenerative disorders. Currently, there are no drugs or therapeutics available to treat specifically BBB damage after a brain injury. Growing knowledge in the field of epigenetics can enhance the understanding of gene level of the BBB and has great potential for the development of novel therapeutic strategies or targets to repair a disrupted BBB. In this brief review, we summarize the epigenetic mechanisms or regulators that have a protective or disruptive role for components of BBB, along with the promising approaches to regain the integrity of BBB.

The Eminent Role of microRNAs in the Pathogenesis of Alzheimer's Disease

Alzheimer's disease (AD) is an irrevocable neurodegenerative condition characterized by the presence of senile plaques comprising amassed β-amyloid peptides (Aβ) and neurofibrillary tangles mainly comprising extremely phosphorylated Tau proteins. Recent studies have emphasized the role of microRNAs (miRNAs) in the development of AD. A number of miRNAs, namely, miR-200a-3p, miR-195, miR-338-5p, miR-34a-5p, miR-125b-5p, miR-132, miR-384, miR-339-5p, miR-135b, miR-425-5p, and miR-339-5p, have been shown to participate in the development of AD through interacting with BACE1. Other miRNAs might affect the inflammatory responses in the course of AD. Aberrant expression of several miRNAs in the plasma samples of AD subjects has been shown to have the aptitude for differentiation of AD subjects from healthy subjects. Finally, a number of AD-modifying agents affect miRNA profile in cell cultures or animal models. We have performed a comprehensive search and summarized the obtained data about the function of miRNAs in AD in the current review article.

Competing Endogenous RNA Networks as Biomarkers in Neurodegenerative Diseases

Protein aggregation is classically considered the main cause of neuronal death in neurodegenerative diseases (NDDs). However, increasing evidence suggests that alteration of RNA metabolism is a key factor in the etiopathogenesis of these complex disorders. Non-coding RNAs are the major contributor to the human transcriptome and are particularly abundant in the central nervous system, where they have been proposed to be involved in the onset and development of NDDs. Interestingly, some ncRNAs (such as lncRNAs, circRNAs and pseudogenes) share a common functionality in their ability to regulate gene expression by modulating miRNAs in a phenomenon known as the competing endogenous RNA mechanism. Moreover, ncRNAs are found in body fluids where their presence and concentration could serve as potential non-invasive biomarkers of NDDs. In this review, we summarize the ceRNA networks described in Alzheimer's disease, Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis and spinocerebellar ataxia type 7, and discuss their potential as biomarkers of these NDDs. Although numerous studies have been carried out, further research is needed to validate these complex interactions between RNAs and the alterations in RNA editing that could provide specific ceRNET profiles for neurodegenerative disorders, paving the way to a better understanding of these diseases.

MicroRNA-146a Is a Wide-Reaching Neuroinflammatory Regulator and Potential Treatment Target in Neurological Diseases

Progressive functional deterioration and loss of neurons underlies neurological diseases and constitutes an important cause of disability and death worldwide. The causes of various types of neurological diseases often share several critical nerve-related cellular mechanisms and pathological features, particularly the neuroinflammatory response in the nervous system. A rapidly growing body of evidence indicates that various microRNAs play pivotal roles in these processes in neurological diseases and might be viable therapeutic targets. Among these microRNAs, microRNA-146a (miR-146a) stands out due to the rapid increase in recent literature on its mechanistic involvement in neurological diseases. In this review, we summarize and highlight the critical role of miR-146a in neurological diseases. MiR-146a polymorphisms are associated with the risk of neurological disease. Alterations in miR-146a expression levels are crucial events in the pathogenesis of numerous neurological diseases that are spatially and temporally diverse. Additionally, the target genes of miR-146a are involved in the regulation of pathophysiological processes in neurological diseases, particularly the neuroinflammatory response. In summary, miR-146a mainly plays a critical role in neuroinflammation during the progression of neurological diseases and might be a prospective biomarker and therapeutic target. Understanding the mechanisms by which miR-146a affects the neuroinflammatory response in different neurological injuries, different cell types, and even different stages of certain neurological diseases will pave the way for its use as a therapeutic target in neurodegenerative diseases.

Mast cells-derived MiR-223 destroys intestinal barrier function by inhibition of CLDN8 expression in intestinal epithelial cells

Background

Mast cells (MCs) have been found to play a critical role during development of inflammatory bowel disease (IBD) that characterized by dysregulation of inflammation and impaired intestinal barrier function. However, the function of MCs in IBD remains to be fully elucidated.

Results

In our study, we used exosomes isolated from human mast cells-1 (HMCs-1) to culture with NCM460, HT-29 or CaCO2 of intestinal epithelial cells (IECs) to investigate the communication between MCs and IECs. We found that MCs-derived exosomes significantly increased intestinal epithelial permeability and destroyed intestinal barrier function, which is attributed to exosome-mediated functional miRNAs were transferred from HMCs-1 into IECs, leading to inhibit tight junction-related proteins expression, including tight junction proteins 1 (TJP1, ZO-1), Occludin (OCLN), Claudin 8 (CLDN8). Microarray and bioinformatic analysis have further revealed that a panel of miRNAs target different tight junction-related proteins. Interestingly, miR-223 is enriched in mast cell-derived exosome, which inhibit CLDN8 expression in IECs, while treatment with miR-223 inhibitor in HT-29 cells significantly reversed the inhibitory effect of HMCs-1-derived exosomes on CLDN 8 expression. Most importantly, enrichment of MCs accumulation in intestinal mucosa of patients with IBD compared with those healthy control.

Conclusions

These results indicated that enrichment of exosomal miR-223 from HMCs-1 inhibited CLDN8 expression, leading to destroy intestinal barrier function. These finding provided a novel insight of MCs as a new target for therapeutic treatment of IBD.

Overview of Crosstalk Between Multiple Factor of Transcytosis in Blood Brain Barrier

Blood brain barrier (BBB) conserves unique regulatory system to maintain barrier tightness while allowing adequate transport between neurovascular units. This mechanism possess a challenge for drug delivery, while abnormality may result in pathogenesis. Communication between vascular and neural system is mediated through paracellular and transcellular (transcytosis) pathway. Transcytosis itself showed dependency with various components, focusing on caveolae-mediated. Among several factors, intense communication between endothelial cells, pericytes, and astrocytes is the key for a normal development. Regulatory signaling pathway such as VEGF, Notch, S1P, PDGFβ, Ang/Tie, and TGF-β showed interaction with the transcytosis steps. Recent discoveries showed exploration of various factors which has been proven to interact with one of the process of transcytosis, either endocytosis, endosomal rearrangement, or exocytosis. As well as providing a hypothetical regulatory pathway between each factors, specifically miRNA, mechanical stress, various cytokines, physicochemical, basement membrane and junctions remodeling, and crosstalk between developmental regulatory pathways. Finally, various hypotheses and probable crosstalk between each factors will be expressed, to point out relevant research application (Drug therapy design and BBB-on-a-chip) and unexplored terrain.

Endothelial tight junctions and their regulatory signaling pathways in vascular homeostasis and disease

Endothelial tight junctions (TJs) regulate the transport of water, ions, and molecules through the paracellular pathway, serving as an important barrier in blood vessels and maintaining vascular homeostasis. In endothelial cells (ECs), TJs are highly dynamic structures that respond to multiple external stimuli and pathological conditions. Alterations in the expression, distribution, and structure of endothelial TJs may lead to many related vascular diseases and pathologies. In this review, we provide an overview of the assessment methods used to evaluate endothelial TJ barrier function both in vitro and in vivo and describe the composition of endothelial TJs in diverse vascular systems and ECs. More importantly, the direct phosphorylation and dephosphorylation of TJ proteins by intracellular kinases and phosphatases, as well as the signaling pathways involved in the regulation of TJs, including and the protein kinase C (PKC), PKA, PKG, Ras homolog gene family member A (RhoA), mitogen-activated protein kinase (MAPK), phosphatidylinositol 3-kinase (PI3K)/Akt, and Wnt/β-catenin pathways, are discussed. With great advances in this area, targeting endothelial TJs may provide novel treatment for TJ-related vascular pathologies.

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.

miR-424-5p maybe regulate blood-brain barrier permeability in a model in vitro with Abeta incubated endothelial cells

The blood-brain barrier (BBB) in AD patients and in animal models is changed. However, the mechanisms are still unclear. Here, we found that miR-424-5p was upregulated in Abeta-incubated microvascular endothelial cells. TEER and HRP exudation tests showed that miR-424-5p silencing significantly decreased BBB permeability in vitro BBB model with Abeta-incubated. MiR-424-5p silencing upregulated expression of the tight junction proteins, ZO-1 and occludin in Abeta-incubated microvascular endothelial cells. Furthermore, dual luciferase reporter gene assay results confirmed the presence of a potential binding site for miR-424-5p on the 3'UTR of Endophilin-1. Endophilin-1 was down-regulated in Abeta-incubated endothelial cells in which miR-424-5p was silenced. In conclusion, the present study demonstrates that miR-424-5p could affect the expression of tight junction proteins (ZO-1 and occludin) via Endophilin-1 and thereby maybe regulate BBB permeability in an BBB model in vitro with Abeta incubated endothelial cells. MiR-424-5p may thus serve as a protective target for AD and provide a new strategy for the prevention and treatment of AD.

Long Noncoding RNA NEAT1 Aggravates Aβ-Induced Neuronal Damage by Targeting miR-107 in Alzheimer's Disease

PURPOSE

Alzheimer's disease (AD) is the most common neurodegenerative disease, with a rising prevalence worldwide. Long noncoding RNAs (lncRNAs) have been found to play important roles in the development and treatment of AD. However, the exact role of lncRNA nuclear enriched abundant transcript 1 (NEAT1) in neuronal damage in AD is largely unknown.

MATERIALS AND METHODS

The AD model was established in SH-SY5Y and SK-N-SH cells via treatment with amyloid β1-42 (Aβ). The expression of NEAT1 and microRNA-107 (miR-107) was measured by quantitative real-time polymerase chain reaction. Cell viability and apoptosis were detected by MTT assay, immunocytochemistry, and flow cytometry. The expression of phosphorylated tau protein (p-Tau) was measured by Western blot. The interaction between NEAT1 and miR-107 was explored by bioinformatics analysis, luciferase activity, and RNA immunoprecipitation assays.

RESULTS

NEAT1 expression was enhanced in Aβ-treated SH-SY5Y and SK-N-SH cells, and its knockdown attenuated Aβ-induced inhibition of viability and promotion of apoptosis and p-Tau levels. NEAT1 was indicated as a decoy of miR-107. miR-107 abundance was reduced in Aβ-treated cells, and its overexpression reversed Aβ-induced injury. Moreover, interference of miR-107 abated silencing of NEAT1-mediated inhibition of neuronal damage in Aβ-treated SH-SY5Y and SK-N-SH cells.

CONCLUSION

LncRNA NEAT1 aggravated Aβ-induced neuronal damage by sponging miR-107, indicating a novel avenue for treatment of AD.

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.

MicroRNAs in Alzheimer's Disease

Alzheimer’s disease (AD) is a progressive and devastating neurodegenerative disorder. It is the leading cause of dementia in the world’s rapidly growing aging population. The characteristics of AD are memory loss and cognitive impairment, meaning patients cannot carry out their daily activities independently. The increase of AD cases poses heavy burdens on families, society and the economy. Despite frequent efforts being made to research the etiology of AD, the causes of AD remain unknown, and no curative treatments are available yet. The pathological hallmarks of AD are amyloid plaques and neurofibrillary tangles in the brain. MicroRNAs are endogenous ∼22 nucleotides non-coding RNAs that could regulate gene expression at a post-transcriptional level by transcript degradation or translation repression. MicroRNAs are involved in many biological processes and diseases, particularly multifactorial diseases, providing an excellent tool with which to research the mechanisms of these diseases. AD is a multifactorial disorder, and accumulating evidence shows that microRNAs play a critical role in the pathogenesis of AD. In this review, we will highlight the effect of microRNAs in different pathological processes throughout AD progression.

The role of LINC00094/miR-224-5p (miR-497-5p)/Endophilin-1 axis in Memantine mediated protective effects on blood-brain barrier in AD microenvironment

The dysfunction of the blood-brain barrier (BBB) is one of the main pathological features of Alzheimer's disease (AD). Memantine (MEM), an N-methyl-d-aspartate (NMDA) receptor antagonist, has been reported that been used widely for AD therapy. This study was performed to demonstrate the role of the MEM in regulating BBB permeability in AD microenvironment as well as its possible mechanisms. The present study showed that LINC00094 was dramatically increased in Abeta_1-42 -incubated microvascular endothelial cells (ECs) of BBB model in vitro. Besides, it was decreased in MEM-incubated ECs. Silencing LINC00094 significantly decreased BBB permeability, meanwhile up-regulating the expression of ZO-1, occludin and claudin-5. Furthermore, silencing LINC00094 enhance the effect of MEM on decreasing BBB permeability in AD microenvironment. The analysis of the mechanism demonstrated that reduction of LINC00094 inhibited Endophilin-1 expression by up-regulating miR-224-4p/miR-497-5p, promoted the expression of ZO-1, occludin and claudin-5, and ultimately alleviated BBB permeability in AD microenvironment. Taken together, the present study suggests that the MEM/LINC00094/miR-224-5p (miR-497-5p)/Endophilin-1 axis plays a crucial role in the regulation of BBB permeability in AD microenvironment. Silencing LINC00094 combined with MEM provides a novel target for the therapy of AD.

MiR-128-1-5p regulates tight junction induced by selenium deficiency via targeting cell adhesion molecule 1 in broilers vein endothelial cells

Vein endothelial cells (VECs) constitute an important barrier for macromolecules and circulating cells from the blood to the tissues, stabilizing the colloid osmotic pressure of the blood, regulating the vascular tone, and rapidly changing the intercellular connection, and maintaining normal physiological function. Tight junction has been discovered as an important structural basis of intercellular connection and may play a key role in intercellular connection injuries or vascular diseases and selenium (Se) deficiency symptoms. Hence, we replicated the Se-deficient broilers model and detected the specific microRNA in response to Se-deficient vein by using quantitative real time-PCR (qRT-PCR) analysis. Also, we selected miR-128-1-5p based on differential expression in vein tissue and confirmed its target gene cell adhesion molecule 1 (CADM1) by the dual luciferase reporter assay and qRT-PCR in VECs. We made the ectopic miR-128-1-5p expression for the purpose of validating its function on tight junction. The result showed that miR-128-1-5p and CADM1 were involved in the ZO-1-mediated tight junction, increased paracellular permeability, and arrested cell cycle. We presumed that miR-128-1-5p and Se deficiency might trigger tight junction. Interestingly, miR-128-1-5p inhibitor and fasudil in part hinder the destruction of the intercellular structure caused by Se deficiency. The miR-128-1-5p/CADM1/tight junction axis provides a new avenue toward understanding the mechanism of Se deficiency, revealing a novel regulation model of tight junction injury in vascular diseases.

MicroRNA-107 prevents amyloid-β-induced neurotoxicity and memory impairment in mice

The pathogenesis of Alzheimer's disease (AD) has still not been fully elucidated, however it is thought that the build up of amyloid plaque at least partially causes the symptoms of AD. MicroRNAs (miRNAs) are endogenous non‑coding small RNA molecules that regulate the expression and degradation of proteins. The present study induced symptoms of AD in mice via intraventricular injection of amyloid‑β 1‑42 (Aβ1‑42), which decreased levels of miR‑107. However, miR‑107 levels increased following administration of miR‑107 mimic, a double‑stranded RNA molecule designed to imitate the native miRNA. Intraventricular injection of Aβ1‑42 aggregates led to spatial memory impairments, inhibited hippocampal long‑term potentiation (LTP) and resulted in the loss of pyramidal cells in the CA1 region of the hippocampus. The miR‑107 mimic reversed the impairments of spatial memory and LTP and the loss of pyramidal neurons caused by Aβ neurotoxicity. Furthermore, the miR‑107 mimic reversed the Aβ‑induced increase in Aβ1‑42 and phosphorylated Tau levels. Critically, Aβ1‑42 injection decreased levels of brain‑derived neurotrophic factor and reduced the phosphorylation of tyrosine receptor kinase B and protein kinase B; these changes were reversed following treatment with the miR‑107 mimic. Collectively, these results demonstrated that miR‑107 may be a potential target for the treatment of AD.

Focusing on claudin-5: A promising candidate in the regulation of BBB to treat ischemic stroke

Claudin-5 is a tight junction (TJ) protein in the blood-brain barrier (BBB) that has recently attracted increased attention. Numerous studies have demonstrated that claudin-5 regulates the integrity and permeability of the BBB. Increased claudin-5 expression plays a neuroprotective role in neurological diseases, particularly in cerebral ischemic stroke. Moreover, claudin-5 might be a potential marker for early hemorrhagic transformation detection in ischemic stroke. In light of the distinctive effects of claudin-5 on the nervous system, we present the elaborate network of roles that claudin-5 plays in ischemic stroke. In this review, we first introduce basic knowledge regarding the BBB and the claudin family, the characterization and regulation of claudin-5, and association between claudin-5 and other TJ proteins. Subsequently, we describe BBB dysfunction and neuron-specific drivers of pathogenesis of ischemic stroke, including inflammatory disequilibrium and oxidative stress. Furthermore, we summarize promising ischemic stroke treatments that target the BBB via claudin-5, including modified rt-PA therapy, pharmacotherapy, hormone treatment, receptor-targeted therapy, gene therapy, and physical therapy. This review highlights recent advances and provides a comprehensive summary of claudin-5 in the regulation of the BBB and may be helpful for drug design and clinical therapy for treatment of ischemic stroke.

MicroRNA expression patterns in human anterior cingulate and motor cortex: A study of dementia with Lewy bodies cases and controls

OVERVIEW

MicroRNAs (miRNAs) have been implicated in neurodegenerative diseases including Parkinson's disease and Alzheimer's disease (AD). Here, we evaluated the expression of miRNAs in anterior cingulate (AC; Brodmann area [BA] 24) and primary motor (MO; BA 4) cortical tissue from aged human brains in the University of Kentucky AD Center autopsy cohort, with a focus on dementia with Lewy bodies (DLB).

METHODS

RNA was isolated from gray matter of brain samples with pathology-defined DLB, AD, AD + DLB, and low-pathology controls, with n = 52 cases initially included (n  = 23 with DLB), all with low (<4 h) postmortem intervals. RNA was profiled using Exiqon miRNA microarrays. Quantitative PCR for post hoc replication was performed on separate cases (n = 6 controls) and included RNA isolated from gray matter of MO, AC, primary somatosensory (BA 3), and dorsolateral prefrontal (BA 9) cortical regions.

RESULTS

The miRNA expression patterns differed substantially according to anatomic location: of the relatively highly-expressed miRNAs, 150/481 (31%) showed expression that was different between AC versus MO (at p < .05 following correction for multiple comparisons), most (79%) with higher expression in MO. A subset of these results were confirmed in qPCR validation focusing on miR-7, miR-153, miR-133b, miR-137, and miR-34a. No significant variation in miRNA expression was detected in association with either neuropathology or sex after correction for multiple comparisons.

CONCLUSION

A subset of miRNAs (some previously associated with α-synucleinopathy and/or directly targeting α-synuclein mRNA) were differentially expressed in AC and MO, which may help explain why these brain regions show differences in vulnerability to Lewy body pathology.

Linking deregulation of non-coding RNA to the core pathophysiology of Alzheimer's disease: An integrative review

The human genome encodes a vast repertoire of protein non-coding RNAs (ncRNA), some specific to the brain. MicroRNAs, which interfere with the translation of target mRNAs, are of particular interest since their deregulation has been implicated in neurodegenerative disorders like Alzheimer's disease (AD). However, it remains challenging to link the complex body of observations on miRNAs and AD into a coherent framework. Using extensive graphical support, this article discusses how a diverse panoply of miRNAs convergently and divergently impact (and are impacted by) core pathophysiological processes underlying AD: neuroinflammation and oxidative stress; aberrant generation of β-amyloid-42 (Aβ42); anomalies in the production, cleavage and post-translational marking of Tau; impaired clearance of Aβ42 and Tau; perturbation of axonal organisation; disruption of synaptic plasticity; endoplasmic reticulum stress and the unfolded protein response; mitochondrial dysfunction; aberrant induction of cell cycle re-entry; and apoptotic loss of neurons. Intriguingly, some classes of miRNA provoke these cellular anomalies, whereas others act in a counter-regulatory, protective mode. Moreover, changes in levels of certain species of miRNA are a consequence of the above-mentioned anomalies. In addition to miRNAs, circular RNAs, piRNAs, long non-coding RNAs and other types of ncRNA are being increasingly implicated in AD. Overall, a complex mesh of deregulated and multi-tasking ncRNAs reciprocally interacts with core pathophysiological mechanisms underlying AD. Alterations in ncRNAs can be detected in CSF and the circulation as well as the brain and are showing promise as biomarkers, with the ultimate goal clinical exploitation as targets for novel modes of symptomatic and course-altering therapy.

Development and Structural Modification of BACE1 Inhibitors

Alzheimer's disease (AD) is a progressive neurodegenerative disorder which usually occurs in the elderly. The accumulation of β-amyloid and the formation of neurofibrillary tangles are considered as the main pathogenies of AD. Research suggests that β-secretase 1 (BACE1) plays an important role in the formation of β-amyloid. Discovery of new BACE1 inhibitors has become a significant method to slow down the progression of AD or even cure this kind of disease. This review summarizes the different types and the structural modification of these new BACE1 inhibitors.

MicroRNA Regulation of Endothelial Junction Proteins and Clinical Consequence

Cellular junctions play a critical role in structural connection and signal communication between cells in various tissues. Although there are structural and functional varieties, cellular junctions include tight junctions, adherens junctions, focal adhesion junctions, and tissue specific junctions such as PECAM-1 junctions in endothelial cells (EC), desmosomes in epithelial cells, and hemidesmosomes in EC. Cellular junction dysfunction and deterioration are indicative of clinical diseases. MicroRNAs (miRNA) are ~20 nucleotide, noncoding RNAs that play an important role in posttranscriptional regulation for almost all genes. Unsurprisingly, miRNAs regulate junction protein gene expression and control junction structure integrity. In contrast, abnormal miRNA regulation of junction protein gene expression results in abnormal junction structure, causing related diseases. The major components of tight junctions include zonula occluden-1 (ZO-1), claudin-1, claudin-5, and occludin. The miRNA regulation of ZO-1 has been intensively investigated. ZO-1 and other tight junction proteins such as claudin-5 and occludin were positively regulated by miR-126, miR-107, and miR21 in different models. In contrast, ZO-1, claudin-5, and occludin were negatively regulated by miR-181a, miR-98, and miR150. Abnormal tight junction miRNA regulation accompanies cerebral middle artery ischemia, brain trauma, glioma metastasis, and so forth. The major components of adherens junctions include VE-cadherin, β-catenin, plakoglobin, P120, and vinculin. VE-cadherin and β-catenin were regulated by miR-9, miR-99b, miR-181a, and so forth. These regulations directly affect VE-cadherin-β-catenin complex stability and further affect embryo and tumor angiogenesis, vascular development, and so forth. miR-155 and miR-126 have been shown to regulate PECAM-1 and affect neutrophil rolling and EC junction integrity. In focal adhesion junctions, the major components are integrin β4, paxillin, and focal adhesion kinase (FAK). Integrin β4 has been regulated by miR-184, miR-205, and miR-9. Paxillin has been regulated by miR-137, miR-145, and miR-218 in different models. FAK has been regulated by miR-7, miR-138, and miR-135. Deregulation of miRNAs is caused by viral infections, tumorigenesis, and so forth. By regulation of posttranscription, miRNAs manipulate junction protein expression in all cellular processes and further determine cellular fate and development. Elucidation of these regulatory mechanisms will become a new alternative therapy for many diseases, such as cancers and inflammatory diseases.

Statins Inhibit Fibrillary β-Amyloid Induced Inflammation in a Model of the Human Blood Brain Barrier

Background

Astrocytes and cerebral endothelial cells are important components of the blood-brain barrier (BBB). Disruption to this barrier through inflammation is a major contributor to Alzheimer’s disease (AD) pathology. The amyloid beta (Aβ) protein is known to exist in several forms and is a key modulator of AD that is known to cause inflammation and changes to BBB function. While one of these forms, fibrillary Aβ (fAβ), is known to cause endothelial cell death at the BBB, no studies have looked specifically at its role on inflammation in a model of the human BBB.

Aims

To determine if fAβ is inflammatory to the human BBB. As statins have been shown to be anti-inflammatory and protective in AD, we also tested if these could inhibit the inflammatory effect of fAβ.

Methods

Using cultured cerebral endothelial cells and astrocytes we determined changes in cytokine release, cell toxicity and barrier function in response to fibrillary β-amyloid_1–42 (fAβ_1–42) alone and in combination with statins.

Results

fAβ_1–42 induced inflammatory cytokine release from endothelial cells in the absence of cell toxicity. It also induced astrocyte cytokine release and cell death and caused a loss of barrier integrity. Statin treatment inhibited all of these effects.

Conclusions

We conclude that fAβ_1–42 has both inflammatory and cytotoxic effects on the BBB and the protective effect of statins in AD may in part be through inhibiting these effects.