Inflammation‐regulatory microRNAs: Valuable targets for intracranial atherosclerosis

Platelet Microparticle-Derived MiR-320b Inhibits Hypertension with Atherosclerosis Development by Targeting ETFA

Hypertension and atherosclerosis often occur simultaneously. This study aimed to explore the role and mechanism of platelet microparticle (PMP) -derived microRNA-320b (miR-320b) in patients with hypertension accompanied by atherosclerosis.We collected samples from 13 controls without hypertension and atherosclerosis and 20 patients who had hypertension accompanied by atherosclerosis. In vitro, platelets were activated by Thrombin receptor-activating peptide to produce PMPs. HUVECs were induced by CoCl2 to mimic a hypoxic environment in vitro. RT-qPCR was employed to detect the expression levels of CD61, miR-320b, and ETFA. The protein expression level of ETFA was evaluated via Western blotting. Furthermore, 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide, 5-ethynyl-2'-deoxyuridine, and wound healing assays were employed to assess the proliferation and migration of HUVECs. Enzyme-linked immunosorbent assay was used to measure the oxidative stress and inflammation-related factor expression.The expression of miR-320b was reduced in both platelets and PMPs but increased in plasma. MiR-320b promoted CoCl2-induced HUVEC viability, proliferation, and migration. The levels of the oxidative stress factors SOD and GSH as well as the inflammatory factor IL-10 were elevated in the CoCl2 + miR-320b mimics group compared with both the CoCl2 + mimics NC and CoCl2 groups. Conversely, the levels of the oxidative stress factors MDA and ROS as well as the inflammatory factors IL-6, TNF-α, and IL-1β were decreased. These results were regulated by miR-320b targeting ETFA.PMP-derived miR-320b inhibits the development of hypertension accompanied by atherosclerosis by targeting ETFA.

High-Phosphate-Stimulated Macrophage-Derived Exosomes Promote Vascular Calcification via let-7b-5p/TGFBR1 Axis in Chronic Kidney Disease

Although macrophage infiltration has been proven to increase calcified artery media in chronic kidney disease (CKD) patients, the mechanism by which macrophages are involved in vascular calcification (VC) progression remains unclear. Taking advantage of miRNA-seq, RNA-seq, dual-luciferase reporter assay, qRT-PCR, and arteries from CKD patients as well as CKD mouse models, we identified that high-phosphate-stimulated macrophage-derived exosomes (Mexo-P) suppressed let-7b-5p expression in VSMCs, which further upregulated TGFBR1. Moreover, gain-and-loss-of-function assays were used to determine the regulatory effects and downstream mechanism of let-7b-5p and TGFBR1 on VC. Mechanically, Mexo-P induced VSMC TGFBR1 upregulation by suppressing let-7b-5p, which further amplifies SMAD3/RUNX2 signaling and thereby contributes to VC. Our findings indicate that macrophage-derived exosomes promote CKD-associated VC through the let-7b-5p/TGFBR1 axis in high-phosphate conditions. Our study provides insight into macrophages associated with VC, which might be potential therapeutical targets for VC.

Circulating MicroRNAs as Potential Biomarkers for Ischemic Stroke in Patients with Asymptomatic Intracranial Artery Stenosis

Circulating microRNAs have been shown to be biomarkers of various diseases. We aimed to investigate whether circulating microRNA can serve as a biomarker to predict ischemic stroke risk in asymptomatic intracranial artery stenosis. A total of 716 participants from the Asymptomatic Polyvascular Abnormalities Community study who had asymptomatic intracranial artery stenosis at baseline were enrolled (2010-11). Patients who suffered incident ischemic stroke were classified into the case group, and age- and sex-matched individuals without stroke were used as controls. MicroRNA microarrays were used to distinguish baseline circulating serum microRNA levels between the case and the control groups (GEO accession number GSE201860). The differentially expressed microRNAs were validated by real-time PCR. MicroRNA microarrays were performed in baseline serum samples from12 subjects who developed ischemic stroke and 12 age- and sex-matched subjects without stroke during the 2014-15 follow-up period. Twenty microRNAs were differentially expressed between the two groups (fold change > 1.3 and p < 0.05 for all). Hsa-miR-486-5p, hsa-miR-92a-3p, hsa-miR-6089 from them were selected and validated in the baseline serum samples of ten subjects with incident ischemic stroke and another ten age- and sex-matched subjects without stroke during the 2016-17 follow-up period. Hsa-miR-1225-5p, with a large fold change value and a reported relationship with cardiovascular or cerebrovascular diseases, was also validated. Ultimately, only hsa-miR-6089 was differentially downregulated among patients with intracranial artery stenosis who developed ischemic stroke (p < 0.05). In patients with asymptomatic intracranial artery stenosis, downregulated serum hsa-miR-6089 may be associated with the risk of ischemic stroke.

miR-146a contributes to atherosclerotic plaque stability by regulating the expression of TRAF6 and IRAK-1

BACKGROUND

Atherosclerosis is a chronic inflammatory disease. The vulnerable plaque of atherosclerotic can lead to the development of many diseases including acute coronary syndrome and coronary heart disease. It is well known that miR-146a is the key brake miRNA of the inflammatory signal transduction pathway. However, the effect of miR-146a on the stability of atherosclerotic plaque remains to be elucidated.

METHODS AND RESULTS

We constructed animal models of atherosclerosis and foam cell models, and overexpressed and knocked-down miR-146a in models. After staining with Hematoxylin-Eosin (HE), Oil Red O, immunocytochemistry (IHC) and Sirius Red, we used the proportion of (Lipids area + Macrophage area) and (SMCs area + collagen area) to evaluate atherosclerotic plaque stability. TUNEL and flow cytometry were performed to detect the apoptosis level of macrophages. Levels of inflammatory factors were detected via ELISA assay. The results showed that miR-146a, IRAK1 and TRAF6 were abnormally expressed in plaques of atherosclerotic animals. Overexpression of miR-146a contributed to the stability of plaques that inhibited plaque formation, macrophage apoptosis and levels of pro-inflammatory factors. The Dual-luciferase reporter gene assay, IF and FISH were used to verify the regulatory mechanism of miR-146a on IRAK1 and TRAF6. We found that IRAK1 and TRAF6 promoted lipid uptake, apoptosis, and release of pro-inflammatory factors of RAW264.7 macrophages, whereas miR-146a restored RAW264.7 macrophages phenotype by inhibiting IRAK1 and TRAF6 expression.

CONCLUSIONS

We display for the first time that miR-146a inhibits the formation of foam cells, RAW264.7 macrophage apoptosis and pro-inflammatory reaction through negative regulation of IRAK1 and TRAF6 expression, thereby enhancing the stability of atherosclerotic plaques.

miR-27a inhibits molecular adhesion between monocytes and human umbilical vein endothelial cells; systemic approach

OBJECTIVE

The endothelial cells overexpress the adhesion molecules in the leukocyte diapedesis pathway, developing vessel subendothelial molecular events. In this study, miR-194 and miR-27a were predicted and investigated on the expression of adhesion molecules in HUVEC cells. The SELE, SELP, and JAM-B adhesion molecules involved in the leukocyte tethering were predicted on the GO-enriched gene network. Following transfection of PEI-miRNA particles into HUVEC cells, the SELE, SELP, and JAM-B gene expression levels were evaluated by real-time qPCR. Furthermore, the monocyte-endothelial adhesion was performed using adhesion assay kit.

RESULTS

In agreement with the prediction results, the cellular data showed that miR-27a and miR-194 decrease significantly the SELP and JAM-B expression levels in HUVECs (P < 0.05). Moreover, both the miRNAs suppressed the monocyte adhesion to endothelial cells. Since the miR-27a inhibited significantly the monocyte-endothelial adhesion (P = 0.0001) through the suppression of SELP and JAM-B thus it might relate to the leukocyte diapedesis pathway.

MicroRNA-21 Is a Versatile Regulator and Potential Treatment Target in Central Nervous System Disorders

MicroRNAs (miRNAs) are a class of endogenous, non-coding, single-stranded RNAs with a length of approximately 22 nucleotides that are found in eukaryotes. miRNAs are involved in the regulation of cell differentiation, proliferation, invasion, apoptosis, and metabolism by regulating the expression of their target genes. Emerging studies have suggested that various miRNAs play key roles in the pathogenesis of central nervous system (CNS) disorders and may be viable therapeutic targets. In particular, miR-21 has prominently emerged as a focus of increasing research on the mechanisms of its involvement in CNS disorders. Herein, we reviewed recent studies on the critical roles of miR-21, including its dysregulated expression and target genes, in the regulation of pathophysiological processes of CNS disorders, with a special focus on apoptosis and inflammation. Collectively, miR-21 is a versatile regulator in the progression of CNS disorders and could be a promising biomarker and therapeutic target for these diseases. An in-depth understanding of the mechanisms by which miR-21 affects the pathogenesis of CNS disorders could pave the way for miR-21 to serve as a therapeutic target for these conditions.

Oxidative Stress and Inflammation Are Associated with Coexistent Severe Multivessel Coronary Artery Stenosis and Right Carotid Artery Severe Stenosis in Elderly Patients

Oxidative stress and inflammatory response are the main pathogenic pathways in atherosclerosis stenosis. This study is aimed at evaluating the roles of oxidative stress and inflammatory response in coexistent right carotid artery severe stenosis and severe multivessel coronary artery stenosis in elderly patients. Circulating levels of total oxidant status (TOS), lipid hydroperoxide (LHP), 8-isoprostane (8-IP), malondialdehyde (MDA), monocyte chemotactic protein-4 (MCP-4), amyloid A (AA), high-sensitivity C-reactive protein (hs-CRP), and tumor necrosis factor-α (TNF-α) were measured by standardised laboratory test methods. Markers of oxidative stress and inflammatory response: levels of TOS, LHP, 8-IP, MDA, MCP-4, AA, hs-CRP, and TNF-α, were increased (P < 0.001) in elderly patient. These results suggested that oxidative stress and inflammatory response may be involved in carotid artery severe stenosis and severe multivessel coronary artery stenosis and measuring oxidative stress and inflammation biomarkers may also be a promising step in the development of an effective method for monitoring the severity of right carotid artery stenosis and multivessel coronary artery stenosis in elderly patients.

Down-regulation of microRNA-342-5p or Up-regulation of Wnt3a Inhibits Angiogenesis and Maintains Atherosclerotic Plaque Stability in Atherosclerosis Mice

Evidence has demonstrated that microRNA-342-5p (miR-342-5p) is implicated in atherosclerosis (AS), but little is known regarding its intrinsic regulatory mechanisms. Here, we aimed to explore the effect of miR-342-5p targeting Wnt3a on formation of vulnerable plaques and angiogenesis of AS. ApoE^-/- mice were fed with high-fat feed for 16 w to replicate the AS vulnerable plaque model. miR-342-5p and Wnt3a expression in aortic tissues of AS were detected. The target relationship between miR-342-5p and Wnt3a was verified. Moreover, ApoE^-/- mice were injected with miR-342-5p antagomir and overexpression-Wnt3a vector to test their functions in serum lipid levels, inflammatory and oxidative stress-related cytokines, aortic plaque stability and angiogenesis in plaque of AS mice. miR-342-5p expression was enhanced and Wnt3a expression was degraded in aortic tissues of AS mice and miR-342-5p directly targeted Wnt3a. Up-regulating Wnt3a or down-regulating miR-342-5p reduced blood lipid content, inflammatory and oxidative stress levels, the vulnerability of aortic tissue plaque and inhibited angiogenesis in aortic plaque of AS mice. Functional studies show that depleting miR-342-5p can stabilize aortic tissue plaque and reduce angiogenesis in plaque in AS mice via restoring Wnt3a.

Knockdown of miR-26a in zebrafish leads to impairment of the anti-inflammatory function of TnP in the control of neutrophilia

Our recent data show the valuable potential of TnP for the development of a new and safe anti-inflammatory drug due to its ability to control the traffic and activation of leukocytes in response to inflammation. Although there is considerable knowledge surrounding the cellular mechanisms of TnP, less is known about the mechanistic molecular role of TnP underlying its immunomodulatory functions. Here, we conducted investigations to identify whether miRNAs could be one of the molecular bases of the therapeutic effect of TnP. Using a zebrafish model of neutrophilic inflammation with a combination of genetic gain- and loss-of-function approaches, we showed that TnP treatment was followed by up-regulation of only four known miRNAs, and mature dre-miR-26a-1, herein referred just as miR-26a was the first most highly expressed. The knockdown of miR-26a ubiquitously resulted in a significant reduction of miR-26a in embryos, accompanied by impaired TnP immunomodulatory function observed by the loss of the control of the removal of neutrophils in response to inflammation, while the overexpression increased the inhibition of neutrophilic inflammation promoted by TnP. The striking importance of miR-26a was confirmed when rescue strategies were used (morpholino and mimic combination). Our results identified miR-26a as an essential molecular regulator of the therapeutic action of TnP, and suggest that miR-26a or its targets could be used as promising therapeutic candidates for enhancing the resolution of inflammation.

Genistein alleviates chronic vascular inflammatory response via the miR‑21/NF‑κB p65 axis in lipopolysaccharide‑treated mice

Chronic vascular inflammatory response is an important pathological basis of cardiovascular disease. Genistein (GEN), a natural compound, exhibits anti‑inflammatory effects. The aim of the present study was to investigate the effects of GEN on lipopolysaccharide (LPS)‑induced chronic vascular inflammatory response in mice and explore the underlying anti‑inflammatory mechanisms. C57BL/6 mice were fed with a high‑fat diet combined with intraperitoneal injection of LPS to induce chronic vascular inflammation. The expression levels of TNF‑α, IL‑6 and microRNA (miR)‑21 in the vasculature were detected via reverse transcription‑quantitative (RT‑q)PCR. The protein levels of inducible nitric oxide synthase (iNOS) and NF‑κB p65 were detected via western blotting. NF‑κB p65 was also analyzed via immunohistochemistry and immunofluorescence (IF). In addition, after transfection with miR‑21 mimic or inhibitor for 24 h, vascular endothelial cells (VECs) were treated with GEN and LPS. RT‑qPCR and western blot analyses were performed to detect the expression of TNF‑α, IL‑6, miR‑21 and iNOS, and the protein levels of iNOS and NF‑κB p65, respectively. IF was used to measure NF‑κB p65 nuclear translocation. The results revealed that GEN significantly decreased the expression of inflammation‑associated vascular factors in LPS‑treated C57BL/6 mice, including TNF‑α, IL‑6, iNOS, NF‑κB p65 and miR‑21. Furthermore, miR‑21 antagomir enhanced the anti‑inflammatory effects of GEN. In LPS‑induced VECs, miR‑21 mimic increased inflammation‑associated factor expression and attenuated the anti‑inflammatory effects of GEN, whereas miR‑21 inhibitor induced opposing effects. Therefore, the results of the present study suggested that GEN inhibited chronic vascular inflammatory response in mice, which may be associated with the inhibition of VEC inflammatory injury via the miR‑21/NF‑κB p65 pathway.

MiR-10a, 27a, 34b/c, and 300 Polymorphisms are Associated with Ischemic Stroke Susceptibility and Post-Stroke Mortality

A recent study of the ischemic stroke described the roles played by miRNAs in the downregulation of specific cell-cycle gene expression and it is thought to require the development of biomarkers for the prognostic of ischemic stroke. Here, we hypothesized that four miRNA polymorphisms (miR-10a, miR-27a, miR-34b/c, and miR-300) may affect stroke susceptibility and mortality. Blood samples were collected from 530 patients and 403 controls. Genetic polymorphisms were detected by polymerase chain reaction (PCR)-restriction fragment length polymorphism analysis and real-time PCR. We found that the miR-300 rs12894467 TC genotype and the dominant model (AOR: 2.069, p-value: 0.017; AOR: 1.931, p-value: 0.027) were significantly associated with an increased risk for the ischemic stroke subtype. In Cox proportional hazard regression models, the miR-10a rs3809783 A>T and miR-34b/c rs4938723 T>C polymorphisms were associated with the mortality rates among ischemic stroke patients. We found that a miR-300 polymorphism was associated with increased ischemic stroke susceptibility among the Korean population. Additionally, polymorphisms in miR-10a and miR-34b/c were associated with the increased or decreased mortality of ischemic stroke patients. This study marks the first report of an association between ischemic stroke and miRNA polymorphisms (miR-10aA>T, miR-27aT>C, miR-34b/cT>C, and miR-300T>C) in the Korean population.

Mesenchymal stem cell-derived extracellular vesicle-based therapies protect against coupled degeneration of the central nervous and vascular systems in stroke

Stem cell-based treatments have been suggested as promising candidates for stroke. Recently, mesenchymal stem cells (MSCs) have been reported as potential therapeutics for a wide range of diseases. In particular, clinical trial studies have suggested MSCs for stroke therapy. The focus of MSC treatments has been directed towards cell replacement. However, recent research has lately highlighted their paracrine actions. The secretion of extracellular vesicles (EVs) is offered to be the main therapeutic mechanism of MSC therapy. However, EV-based treatments may provide a wider therapeutic window compared to tissue plasminogen activator (tPA), the traditional treatment for stroke. Exosomes are nano-sized EVs secreted by most cell types, and can be isolated from conditioned cell media or body fluids such as plasma, urine, and cerebrospinal fluid (CSF). Exosomes apply their effects through targeting their cargos such as microRNAs (miRs), DNAs, messenger RNAs, and proteins at the host cells, which leads to a shift in the behavior of the recipient cells. It has been indicated that exosomes, in particular their functional cargoes, play a significant role in the coupled pathogenesis and recovery of stroke through affecting the neurovascular unit (NVU). Therefore, it seems that exosomes could be utilized as diagnostic and therapeutic tools in stroke treatment. The miRs are small endogenous non-coding RNA molecules which serve as the main functional cargo of exosomes, and apply their effects as epigenetic regulators. These versatile non-coding RNA molecules are involved in various stages of stroke and affect stroke-related factors. Moreover, the involvement of aging-induced changes to specific miRs profile in stroke further highlights the role of miRs. Thus, miRs could be utilized as diagnostic, prognostic, and therapeutic tools in stroke. In this review, we discuss the roles of stem cells, exosomes, and their application in stroke therapy. We also highlight the usage of miRs as a therapeutic choice in stroke therapy.

TUG1 Represses Apoptosis, Autophagy, and Inflammatory Response by Regulating miR-27a-3p/SLIT2 in Lipopolysaccharide-Treated Vascular Endothelial Cells

BACKGROUND

The dysfunction of vascular endothelial cells is associated with sepsis development. Long noncoding RNAs take part in the regulation of vascular endothelial cell function. This study aimed to explore the role and mechanism of long noncoding RNA taurine-upregulated gene 1 (TUG1) in lipopolysaccharide (LPS)-induced endothelial cell injury.

METHODS

LPS-treated human umbilical vein endothelial cells (HUVECs) were used as a model of sepsis in vitro. Quantitative real-time polymerase chain reaction was performed to detect the expression of TUG1, microRNA-27a-3p (miR-27a-3p) and slit guidance ligand 2 (SLIT2) messenger RNA. Western blot was conducted to measure the protein levels of SLIT2 as well as those involved in apoptosis, autophagy, and inflammatory response. Flow cytometry was used to detect cell apoptotic rate. The targets of TUG1 and miR-27a-3p were predicted via starBase (http://starbase.sysu.edu.cn/index.php). Dual-luciferase reporter, RNA immunoprecipitation, and pull-down assays were carried out to validate the target correlation between miR-27a-3p and TUG1/SLIT2.

RESULTS

TUG1 expression was decreased after the treatment of LPS in HUVECs. Overexpression of TUG1 decreased LPS-induced apoptosis, autophagy, and inflammatory response. TUG1 was a sponge of miR-27a-3p. Upregulation of miR-27a-3p reversed the suppressive effect of TUG1 overexpression on LPS-induced apoptosis, autophagy, and inflammatory response. SLIT2 was a target of miR-27a-3p. Knockdown of miR-27a-3p could inhibit LPS-induced injury by increasing SLIT2 in HUVECs. TUG1 could enhance SLIT2 expression by competitively sponging miR-27a-3p.

CONCLUSIONS

TUG1 could repress cell apoptosis, autophagy, and inflammatory response in LPS-treated HUVECs by sponging miR-27a-3p to target SLIT2, providing a potential target for the treatment of sepsis.

Long non-coding RNA MIAT/miR-148b/PAPPA axis modifies cell proliferation and migration in ox-LDL-induced human aorta vascular smooth muscle cells

AIMS

Atherosclerosis (AS) performs the important pathogenesis which refers to coronaryheart and vascular diseases. Long non-coding RNAs (lncRNAs) was reported to be related to the AS progression. We aimed to probe the role and potential mechanism of Myocardial Infarction Associated Transcript (MIAT) in AS.

MATERIALS AND METHODS

Levels of MIAT, microRNA-148b (miR-148b) and pregnancy-associated plasma protein A (PAPPA) were detected by quantitative Real-time polymerase chain reaction (qRT-PCR) in oxidized low-density lipoprotein (ox-LDL)-induced human aorta vascular smooth muscle cells (HA-VSMCs). Proliferation and migration were examined by Cell counting kit-8 (CCK-8) and wound-healing assays, respectively. Protein levels of Ki-67, proliferating cell nuclear antigen (PCNA), matrix metalloproteinase (MMP)-2, MMP-9 and PAPPA were examined by western blot assay. Ki-67 and PCNA level was detected by flow cytometry. The interaction among MIAT, miR-148b and PAPPA was confirmed via dual-luciferase reporter and RNA immunoprecipitation (RIP). The biology role of MIAT was detected by an AS model in vivo.

KEY FINDINGS

The levels of MIAT and PAPPA were augmented, whereas mature miR-148b level was repressed in ox-LDL-induced AS model. The inhibitory effects of knockdown of MIAT on proliferation and migration were relieved by miR-148b inhibitor. Additionally, miR-148b regulated proliferation and migration by targeting PAPPA. Mechanically, MIAT functioned as sponge of miR-148b to impact PAPPA expression. MIAT knockdown protected AS mice against lipid metabolic disorders in vivo.

SIGNIFICANCE

Proliferation and migration were modified by MIAT/miR-148b/PAPPA axis in ox-LDL induced AS cell model, supplying a novel insight into the underlying application of MIAT in the clinical treatment of AS.

Deiminated proteins and extracellular vesicles as novel biomarkers in pinnipeds: Grey seal (Halichoerus gryptus) and harbour seal (Phoca vitulina)

Peptidylarginine deiminases (PADs) are phylogenetically conserved calcium-dependent enzymes which post-translationally convert arginine into citrulline in target proteins in an irreversible manner, leading to functional and structural changes in target proteins. Protein deimination can cause the generation of neo-epitopes, affect gene regulation and also allow for protein moonlighting and therefore facilitate multifaceted functions of the same protein. PADs are furthermore a key regulator of cellular release of extracellular vesicle (EVs), which are found in most body fluids and participate in cellular communication via transfer of cargo proteins and genetic material. In this study, post-translationally deiminated proteins and EVs were assessed in sera of two seal species, grey seal and harbour seal. We report a poly-dispersed population of serum-EVs, which were positive for phylogenetically conserved EV-specific markers and characterised by transmission electron microscopy. A number of deiminated proteins critical for immune and metabolic functions were identified in the seal sera and varied somewhat between the two species under study, while some targets were in common. EV profiles of the seal sera further revealed that key microRNAs for inflammation, immunity and hypoxia also vary between the two species. Protein deimination and EVs profiles may be useful biomarkers for assessing health status of sea mammals, which face environmental challenges, including opportunistic infection, pollution and shifting habitat due to global warming.

Adipose-derived mesenchymal stem cells-derived exosome-mediated microRNA-342-5p protects endothelial cells against atherosclerosis

Exosomes are reported to mediate several disease-related microRNAs (miRNAs) to affect the progression of diseases, including atherosclerosis. Here, we aimed to screen the atherosclerosis-associated miRNAs and preliminarily investigate the potential regulatory mechanism of atherosclerosis. First, the lesion model for human umbilical vein endothelial cells (HUVECs) was favorably constructed. Later, through RNA-sequencing and bioinformatics analyses, miR-342-5p was identified in lesion model for HUVECs. MiR-342-5p overexpression or knockdown evidently promoted or inhibited the apoptosis of HUVECs impaired by H₂O₂. Mechanistically, PPP1R12B was found to have great potential as a target of miR-342-5p in HUVECs impaired by H₂O₂, supported by RNA-sequencing and a series of bioinformatics analyses. Meanwhile, the effect of miR-342-5p on PPP1R12B expression in HUVECs’ lesion model was explored, revealing that miR-342-5p had an inhibitory role in PPP1R12B expression. Additionally, adipose-derived mesenchymal stem cells (ADSCs) in spindle-like shape and their derived exosomes with 30 to 150 nm diameter were characterized. Furthermore, results showed miR-342-5p was evidently decreased in the presence of ADSCs-derived exosomes. These findings indicated ADSCs-derived exosomes restrained the expression of miR-324-5p in lesion model. Collectively, this work demonstrates an atherosclerosis-associated miR-342-5p and reveals a preliminary possible mechanism in which miR-342-5p mediated by ADSCs-derived exosomes protects endothelial cells against atherosclerosis.

Deiminated proteins and extracellular vesicles - Novel serum biomarkers in whales and orca

Peptidylarginine deiminases (PADs) are a family of phylogenetically conserved calcium-dependent enzymes which cause post-translational protein deimination. This can result in neoepitope generation, affect gene regulation and allow for protein moonlighting via functional and structural changes in target proteins. Extracellular vesicles (EVs) carry cargo proteins and genetic material and are released from cells as part of cellular communication. EVs are found in most body fluids where they can be useful biomarkers for assessment of health status. Here, serum-derived EVs were profiled, and post-translationally deiminated proteins and EV-related microRNAs are described in 5 ceataceans: minke whale, fin whale, humpback whale, Cuvier's beaked whale and orca. EV-serum profiles were assessed by transmission electron microscopy and nanoparticle tracking analysis. EV profiles varied between the 5 species and were identified to contain deiminated proteins and selected key inflammatory and metabolic microRNAs. A range of proteins, critical for immune responses and metabolism were identified to be deiminated in cetacean sera, with some shared KEGG pathways of deiminated proteins relating to immunity and physiology, while some KEGG pathways were species-specific. This is the first study to characterise and profile EVs and to report deiminated proteins and putative effects of protein-protein interaction networks via such post-translationald deimination in cetaceans, revealing key immune and metabolic factors to undergo this post-translational modification. Deiminated proteins and EVs profiles may possibly be developed as new biomarkers for assessing health status of sea mammals.

The Epigenetic Landscape of Vascular Calcification: An Integrative Perspective

Vascular calcification (VC) is an important complication among patients of advanced age, those with chronic kidney disease, and those with diabetes mellitus. The pathophysiology of VC encompasses passive occurrence of physico-chemical calcium deposition, active cellular secretion of osteoid matrix upon exposure to metabolically noxious stimuli, or a variable combination of both processes. Epigenetic alterations have been shown to participate in this complex environment, through mechanisms including DNA methylation, non-coding RNAs, histone modifications, and chromatin changes. Despite such importance, existing reviews fail to provide a comprehensive view of all relevant reports addressing epigenetic processes in VC, and cross-talk between different epigenetic machineries is rarely examined. We conducted a systematic review based on PUBMED and MEDLINE databases up to 30 September 2019, to identify clinical, translational, and experimental reports addressing epigenetic processes in VC; we retrieved 66 original studies, among which 60.6% looked into the pathogenic role of non-coding RNA, followed by DNA methylation (12.1%), histone modification (9.1%), and chromatin changes (4.5%). Nine (13.6%) reports examined the discrepancy of epigenetic signatures between subjects or tissues with and without VC, supporting their applicability as biomarkers. Assisted by bioinformatic analyses blending in each epigenetic component, we discovered prominent interactions between microRNAs, DNA methylation, and histone modification regarding potential influences on VC risk.

Influence of miRNA Gene Polymorphism on Recurrence and Age at Onset of Ischemic Stroke in a Chinese Han Population

Polymorphisms in microRNAs (miRNAs) are associated with ischemic stroke occurrence and traditional risk factors for ischemic stroke such as atherosclerosis, hypertension, hyperlipidemia, and diabetes. However, few studies have examined recurrent ischemic stroke as an outcome. Thus, the aim of our study was to examine association of miRNA gene polymorphisms (namely, miR-126 rs4636297, miR-149 rs2292832, miR-124 rs531564, miR-499 rs3746444, miR-143 rs12655723, and miR-122 rs17669) with recurrence of ischemic stroke. miRNA gene polymorphisms were genotyped using the polymerase chain reaction-ligation detection reaction (PCR-LDR) method in 657 patients with ischemic stroke. Association of miRNA polymorphisms with prognosis outcomes was examined by the Kaplan-Meier method, log-rank test, and Cox proportional hazards models. miR-122 rs17669 was significantly associated with recurrence risk of ischemic stroke under the recessive model. Cox regression analysis showed that the CC genotype of rs17669 was associated with an increased risk of 1.9-fold for stroke recurrence (hazard ratio = 1.879; 95% confidence interval = 1.182-2.985; P = 0.008). Further, this effect was more evident among the non-drinker and male subgroups. We found no difference in risk of recurrent ischemic stroke among the other five miRNA polymorphisms. Furthermore, we identified a significant association between the miR-149 rs2292832 polymorphism and age at onset of first-ever stroke. Altogether, miR-122 rs17669 is a significant predictor for the risk of recurrent stroke, independent of traditional risk factors.

A combination of LCPUFAs regulates the expression of miRNA-146a-5p in a murine asthma model and human alveolar cells

BACKGROUND

LCPUFAs are suggestive of having beneficial effects on inflammatory diseases such as asthma. However, little is known about the modulative capacity of omega-(n)-3 and n-6 LCPUFAs within the epigenetic regulation of inflammatory processes.

OBJECTIVE

The aim of this study was to investigate whether a specific combined LCPUFA supplementation restores disease-dysregulated miRNA-profiles in asthmatic mice. In addition, we determined the effect of the LCPUFA supplementation on the interaction of the most regulated miRNA expression and oxygenase activity in vitro.

METHODS

Sequencing of miRNA was performed by NGS from lung tissue of asthmatic and control mice with normal diet, as well as of LCPUFA supplemented asthmatic mice. Network analysis and evaluation of the biological targets of the miRNAs were performed by DIANA- miRPath v.3 webserver software, TargetScanMouse 7.2, and tool String v.10, respectively. Expression of hsa-miRNA-146a-5p and activity of COX-2 and 5-LO in LCPUFA-treated A549 cells were assessed by qPCR and flow cytometry, respectively.

RESULTS

In total, 62 miRNAs were dysregulated significantly in murine allergic asthma. The LCPUFA combination restored 21 of these dysregulated miRNAs, of which eight (mmu-miR-146a-5p, -30a-3p, -139-5p, -669p-5p, -145a-5p, -669a-5p, -342-3p and -15b-5p) were even normalized compared to the control levels. Interestingly, six of the eight rescued miRNAs are functionally implicated in TGF-β signaling, ECM-receptor interaction and fatty acid biosynthesis. Furthermore, in vitro experiments demonstrated that upregulation of hsa-miRNA-146a-5p is accompanied by a reduction of COX-2 and 5-LO activity. Moreover, transfection experiments revealed that LCPUFAs inhibit 5-LO activity in the presence and absence of anti-miR-146a-5p.

CONCLUSION

Our results demonstrate the modulative capacity of LCPUFAs on dysregulated miRNA expression in asthma. In addition, we pointed out the high regulative potential of LCPUFAs on 5-LO regulation and provided evidence that miR-146a partly controls the regulation of 5-LO.

Post-Translational Deimination of Immunological and Metabolic Protein Markers in Plasma and Extracellular Vesicles of Naked Mole-Rat (Heterocephalus glaber)

Naked mole-rats are long-lived animals that show unusual resistance to hypoxia, cancer and ageing. Protein deimination is an irreversible post-translational modification caused by the peptidylarginine deiminase (PAD) family of enzymes, which convert arginine into citrulline in target proteins. Protein deimination can cause structural and functional protein changes, facilitating protein moonlighting, but also leading to neo-epitope generation and effects on gene regulation. Furthermore, PADs have been found to regulate cellular release of extracellular vesicles (EVs), which are lipid-vesicles released from cells as part of cellular communication. EVs carry protein and genetic cargo and are indicative biomarkers that can be isolated from most body fluids. This study was aimed at profiling deiminated proteins in plasma and EVs of naked mole-rat. Key immune and metabolic proteins were identified to be post-translationally deiminated, with 65 proteins specific for plasma, while 42 proteins were identified to be deiminated in EVs only. Using protein-protein interaction network analysis, deiminated plasma proteins were found to belong to KEEG (Kyoto Encyclopedia of Genes and Genomes) pathways of immunity, infection, cholesterol and drug metabolism, while deiminated proteins in EVs were also linked to KEEG pathways of HIF-1 signalling and glycolysis. The mole-rat EV profiles showed a poly-dispersed population of 50-300 nm, similar to observations of human plasma. Furthermore, the EVs were assessed for three key microRNAs involved in cancer, inflammation and hypoxia. The identification of post-translational deimination of critical immunological and metabolic markers contributes to the current understanding of protein moonlighting functions, via post-translational changes, in the longevity and cancer resistance of naked mole-rats.