Elevated Levels of Circulating lncRNAs LIPCAR and MALAT1 Predict an Unfavorable Outcome in Acute Coronary Syndrome Patients.

Coronary artery disease (CAD) is a leading cause of mortality worldwide. In this study, we aimed to assess the potential of plasma long non-coding RNAs (lncRNAs) LIPCAR and MALAT1 and microRNAs (miRNAs) miR-142-3p and miR-155-5p to discriminate unstable CAD patients from stable ones. 23 stable angina (SA), 21 unstable angina (UA), and 50 ST-segment elevation myocardial infarction (STEMI) patients were enrolled; their plasma was collected. ncRNA plasma levels were evaluated using RT-qPCR. All measured ncRNA levels were significantly increased in UA patients' plasma compared to SA patients' plasma and in STEMI-with major adverse cardiovascular event (MACE) patients' plasma vs. STEMI-without MACE patients' plasma. ROC analysis showed that increased levels of LIPCAR and MALAT1 were associated with UA, and the prognostic model improved with the addition of miR-155-5p levels. The assessed lncRNAs discriminated between hyperglycemic (HG) and normoglycemic (NG) UA patients, and they were associated with MACE incidence in STEMI patients; this prediction was improved by the addition of miR-142-3p levels to the ROC multivariate model. We propose LIPCAR and MALAT1 as effective diagnostic markers for vulnerable CAD, their association with HG in UA patients, and as robust predictors for unfavorable evolution of STEMI patients.

MiR-223-3p levels in the plasma and atherosclerotic plaques are increased in aged patients with carotid artery stenosis; association with HDL-related proteins.

BACKGROUND: Cardiovascular diseases are still the main cause of death worldwide. Our aim was to analyse the link between miR-223-3p levels, dysfunctional HDL and the age of patients with carotid artery stenosis (CAS). METHODS AND RESULTS: Thirty-two CAS patients enrolled for endarterectomy were divided in 2 groups: aged over 65 years (n = 19) and under 65 years (n = 13). Plasma samples and atherosclerotic plaques from the carotid artery were collected from all patients. Plaque levels of miR-223-3p and its primary transcript (pri-miR-223) were assessed, together with Drosha, Dicer, apolipoprotein (apo)A-I, apoE and myeloperoxidase (MPO) gene expression. In the plasma and plaques, miR-223-3p expression levels were significantly increased in CAS patients over 65 years. Positive correlations between plaque miR-223-3p and pri-miR-223 levels with Drosha, apoA-I and MPO expression were observed. Significantly increased miR-223-3p levels in the plasma of CAS patients over 65 years were measured. Significant correlations between plasma miR-223-3p levels and HDL-related proteins were determined. The variance of plasma miR-223-3p levels was predicted significantly by the multiple regression models using either age, clinical variables, blood lipids or oxidative and inflammatory parameters. Receiver operator characteristic analysis revealed that plasma miR-223-3p levels and HDL-related proteins (MPO activity/apoA-I ratio, MPO specific activity) were correlated with advanced age. CONCLUSIONS: Taken together, these data suggest that plasma levels of miR-223-3p are independently associated with ageing in CAS patients and that, correlated with parameters associated with dysfunctional HDL, could predict the aggravation of CAS in elderly patients.

Mitochondrial DNA Together with miR-142-3p in Plasma Can Predict Unfavorable Outcomes in Patients after Acute Myocardial Infarction.

Myocardial infarction is one of the leading causes of death worldwide, despite numerous efforts to find efficient prognostic biomarkers and treatment targets. In the present study, we aimed to assess the potential of six microRNAs known to be involved in cardiovascular diseases, cell-free DNA (cfDNA), and mitochondrial DNA (mtDNA) circulating in plasma to be used as prognostic tools for the occurrence of unfavorable outcomes such as major adverse cardiovascular events (MACE) after acute ST-segment elevation myocardial infarction (STEMI). Fifty STEMI patients were enrolled and monitored for 6 months for the occurrence of MACE. Plasma was collected at three time points: upon admission to hospital (T0), at discharge from hospital (T1), and 6 months post-STEMI (T6). Plasma levels of miR-223-3p, miR-142-3p, miR-155-5p, miR-486-5p, miR-125a-5p, and miR-146a-5p, as well as of cfDNA and mtDNA, were measured by RT-qPCR. Results showed that the levels of all measured miRNAs, as well as of cfDNA and mtDNA, were the most increased at T1, compared to the other two time points. In the plasma of STEMI patients with MACE compared to those without MACE, we determined increased levels of miRNAs, cfDNA, and mtDNA at T1. Hence, we used the levels of all measured parameters at T1 for further statistical analysis. Statistical analysis demonstrated that all six miRNAs and cfDNA plus mtDNA levels, respectively, were associated with MACE. The minimal statistical model that could predict MACE in STEMI patients was the combination of mtDNA and miR-142-3p levels, as evidenced by ROC analysis (AUC = 0.97, p < 0.001). In conclusion, the increased plasma levels of mtDNA, along with miR-142-3p, could be used to predict unfavorable outcomes in STEMI patients.

Increased miR-142 Levels in Plasma and Atherosclerotic Plaques from Peripheral Artery Disease Patients with Post-Surgery Cardiovascular Events.

There is an intensive effort to identify biomarkers to predict cardiovascular disease evolution. We aimed to determine the potential of microRNAs to predict the appearance of cardiovascular events (CVEs) in patients with peripheral artery disease (PAD) following femoral artery bypass surgery. Forty-seven PAD patients were enrolled and divided into two groups, without CVEs (n = 35) and with CVEs (n = 12), during 1 year follow-up. Intra-surgery atherosclerotic plaques from femoral arteries were collected and the levels of miR-142, miR-223, miR-155, and miR-92a of the primary transcripts of these microRNAs (pri-miRNAs), and gene expression of Drosha and Dicer were determined. Results showed that, in the plaques, miR-142, miR-223, and miR-155 expression levels were significantly increased in PAD patients with CVEs compared to those without CVEs. Positive correlations between these miRNAs and their pri-miRNAs levels and the Dicer/Drosha expression were observed. In the plasma of PAD patients with CVEs compared to those without CVEs, miR-223 and miR-142 were significantly increased. The multiple linear regression analyses revealed significant associations among several plasma lipids, oxidative and inflammatory parameters, and plasma miRNAs levels. Receiver operator characteristic (ROC) analysis disclosed that plasma miR-142 levels could be an independent predictor for CVEs in PAD patients. Functional bioinformatics analyses supported the role of these miRNAs in the regulation of biological processes associated with atherosclerosis. Taken together, these data suggest that plasma levels of miR-142, miR-223, miR-155, and miR-92a can significantly predict CVEs among PAD patients with good accuracy, and that plasma levels of miR-142 can be an independent biomarker to predict post-surgery CVEs development in PAD patients.

Inhibition of miR-486 and miR-92a decreases liver and plasma cholesterol levels by modulating lipid-related genes in hyperlipidemic hamsters.

In the present study we aimed to evaluate the potential of in vivo inhibition of miR-486 and miR-92a to reverse hyperlipidemia, then to identify and validate their lipid metabolism-related target genes. Male Golden-Syrian hamsters fed a hyperlipidemic (HL) diet (standard chow plus 3% cholesterol and 15% butter, 10 weeks) were injected subcutaneously with lock-nucleic acid inhibitors for either miR-486 or miR-92a. Lipids and miRNAs levels in liver and plasma, and hepatic expression of miRNAs target genes were assessed in all HL hamsters. MiR-486 and miR-92a target genes were identified by miRWalk analysis and validated by 3'UTR cloning in pmirGLO vectors. HL hamsters had increased liver (2.8-fold) and plasma (twofold) miR-486 levels, and increased miR-92a (2.8-fold and 1.8-fold, respectively) compared to normolipidemic hamsters. After 2 weeks treatment, liver and plasma cholesterol levels decreased (23 and 17.5% for anti-miR-486, 16 and 22% for miR-92a inhibition). Hepatic triglycerides and non-esterified fatty acids content decreased also significantly. Bioinformatics analysis and 3'UTR cloning in pmirGLO vector showed that sterol O-acyltransferase-2 (SOAT2) and sterol-regulatory element binding transcription factor-1 (SREBF1) are targeted by miR-486, while ATP-binding cassette G4 (ABCG4) and Niemann-Pick C1 (NPC1) by miR-92a. In HL livers and in cultured HepG2 cells, miR-486 inhibition restored the levels of SOAT2 and SREBF1 expression, while anti-miR-92a restored ABCG4, NPC1 and SOAT2 expression compared to scrambled-treated HL hamsters or cultured cells. In vivo inhibition of miR-486 and miR-92a could be a useful and valuable new approach to correct lipid metabolism dysregulation.

Oxidized LDL-Exposed Human Macrophages Display Increased MMP-9 Expression and Secretion Mediated by Endoplasmic Reticulum Stress.

Oxidatively modified low-density lipoproteins (oxLDL) alter the proper function of the endoplasmic reticulum (ER), inducing ER stress (ERS), which consequently activates inflammatory pathways in macrophages. Matrix metalloproteinase-9 (MMP-9) is the main protease acting on the degradation of the extracellular matrix and the ensuing destabilization of the atherosclerotic plaque. We aimed to investigate whether ERS induced by oxLDL or tunicamycin (TM) in human macrophages is associated with the stimulation of MMP-9 expression and secretion. The results showed that oxLDL induced in THP-1 macrophages: (i) increase of MMP-9 gene expression and its pro-form secretion, (ii) intracellular accumulation of 7-ketocholesterol, (iii) ERS activation (increased eIF2α phosphorylation, XBP1 and CHOP mRNA levels, and Grp78 protein expression), and (iv) oxidative stress (increased levels of reactive oxygen species and NADPH oxidase activity). Incubation of macrophages with ERS inducer, TM determined the secretion of both pro- and active-form of MMP-9 and oxidative stress. Treatment of oxLDL or TM-incubated cells with ERS inhibitor, sodium phenylbutyrate decreased MMP-9 gene expression, secretion, and activity. The inhibitor of NADPH oxidase, apocynin, decreased XBP-1 and CHOP mRNA levels, and MMP-9 gene expression and secretion in oxLDL-exposed cells. In conclusion, oxLDL stimulate MMP-9 expression and secretion in human macrophages by mechanisms involving ERS. J. Cell. Biochem. 118: 661-669, 2017. © 2016 Wiley Periodicals, Inc.

Glycated LDL increase VCAM-1 expression and secretion in endothelial cells and promote monocyte adhesion through mechanisms involving endoplasmic reticulum stress.

Type 2 Diabetes Mellitus is a worldwide epidemic, and its atherosclerotic complications produce morbidity and mortality in affected patients. It is known that the vascular cell adhesion molecule-1 (VCAM-1) levels are increased in the sera of diabetic patients. Our aim was to investigate the impact of the endoplasmic reticulum stress (ERS) in VCAM-1 expression and secretion in human endothelial cells (HEC) exposed to glycated low-density lipoproteins (gLDL). The results showed that 24 h incubation of HEC with gLDL induces (i) stimulation of VCAM-1 expression and secretion, determining increased monocyte adhesion to HEC; (ii) RAGE up-regulation and free cholesterol loading; (iii) ERS activation (increased eIF2α phosphorylation and CHOP mRNA levels, and decreased GRP78 protein expression); and (iv) oxidative stress [increased levels of reactive oxygen species (ROS) and glutamate cysteine ligase catalytic unit gene expression]. Treatment of gLDL-exposed HEC with ERS inhibitors, salubrinal (Sal) and sodium phenylbutyrate (PBA), decreased intracellular ROS. Incubation of gLDL-exposed cells with the anti-oxidant N-acetyl-cysteine (NAC) reduced ERS, revealed by decreased eIF2α phosphorylation and CHOP gene expression and increased GRP78 expression, thus validating the interconnection between ERS and oxidative stress. Sal, PBA, NAC and inhibitors of p38 MAP kinase and NF-kB induced the decrease of VCAM-1 expression and of the ensuing monocyte adhesion induced by gLDL. In conclusion, in HEC, gLDL stimulate the expression of cellular VCAM-1, the secretion of soluble VCAM-1, and the adhesion of monocytes through mechanisms involving p38 MAP kinase and NF-kB signalling pathways activated by RAGE, ERS and oxidative stress, thus contributing to diabetic atherosclerosis.

Oscillating Glucose Induces the Increase in Inflammatory Stress through Ninjurin-1 Up-Regulation and Stimulation of Transport Proteins in Human Endothelial Cells.

Clinical data implicate fluctuations of high levels of plasma glucose in cardiovascular diseases. Endothelial cells (EC) are the first cells of the vessel wall exposed to them. Our aim was to evaluate the effects of oscillating glucose (OG) on EC function and to decipher new molecular mechanisms involved. Cultured human ECs (EA.hy926 line and primary cells) were exposed to OG (5/25 mM alternatively at 3 h), constant HG (25 mM) or physiological concentration (5 mM, NG) for 72 h. Markers of inflammation (Ninj-1, MCP-1, RAGE, TNFR1, NF-kB, and p38 MAPK), oxidative stress (ROS, VPO1, and HO-1), and transendothelial transport proteins (SR-BI, caveolin-1, and VAMP-3) were assessed. Inhibitors of ROS (NAC), NF-kB (Bay 11-7085), and Ninj-1 silencing were used to identify the mechanisms of OG-induced EC dysfunction. The results revealed that OG determined an increased expression of Ninj-1, MCP-1, RAGE, TNFR1, SR-B1, and VAMP-3 andstimulated monocyte adhesion. All of these effects were induced bymechanisms involving ROS production or NF-kB activation. NINJ-1 silencing inhibited the upregulation of caveolin-1 and VAMP-3 induced by OG in EC. In conclusion, OG induces increased inflammatory stress, ROS production, and NF-kB activation and stimulates transendothelial transport. To this end, we propose a novel mechanism linking Ninj-1 up-regulation to increased expression of transendothelial transport proteins.

Dual role of lipoproteins in endothelial cell dysfunction in atherosclerosis.

The endothelium is a key constituent of the vascular wall, being actively involved in maintaining the structural integrity and proper functioning of blood vessels. Hyperlipidemia, diabetes, hypertension, smoking and aging are important risk factors for the dysfunction of endothelial cells (EC). Circulating lipoproteins (Lp) synthesized and secreted from the intestine or liver have an important role in supplying peripheral tissues with fatty acids from triglyceride rich lipoproteins (TGRLp) for energy production or storage, and cholesterol from low density lipoproteins (LDL) or high density lipoproteins (HDL) for the synthesis of cellular membranes and steroid hormones. Under pathological conditions, Lp may suffer alterations in concentration and composition and become aggressors for EC. Modified LDL, remnant Lp, TGRLp lipolysis products, dysfunctional HDL are involved in the changes induced in EC morphology (reduced glycocalyx, overdeveloped endoplasmic reticulum, Golgi apparatus and basement membrane), loose intercellular junctions, increased oxidative and inflammatory stress, nitric oxide/redox imbalance, excess Lp transport and storage, as well as loss of anti-thrombotic properties, all of these being characteristics of endothelial dysfunction. Normal HDL are able to counteract the harmful effects of atherogenic Lp in EC but under persistent pathological conditions they lose the protective properties and become pro-atherogenic. This review summarises recent advances in understanding the role of Lp in the induction of endothelial dysfunction and the initiation and progression of atherosclerotic lesions. Its main focus is the antagonistic role of atherogenic Lp (LDL, VLDL, dysfunctional HDL) versus anti-atherogenic Lp (HDL), also pointing out the potential targets for arresting or reversing this process.

Clusterin, paraoxonase 1, and myeloperoxidase alterations induce high-density lipoproteins dysfunction and contribute to peripheral artery disease; aggravation by type 2 diabetes mellitus.

Peripheral artery disease (PAD) is an atherosclerotic disorder affecting arteries of the lower limbs, the major risk factors including dyslipidemia and diabetes mellitus (DM). We aimed to identify alterations of the proteins in high-density lipoproteins (HDL) associated with HDL dysfunction in PAD patients. HDL2 and HDL3 were isolated from plasma of PAD patients with/without DM (PAD-DM/PAD) and healthy subjects (N). Apolipoprotein AI (ApoAI), ApoAII, ApoCIII, clusterin (CLU), paraoxonase 1 (PON1), myeloperoxidase (MPO), and ceruloplasmin (CP) were measured in HDL2 /HDL3 and plasma. Oxidation and glycation of the analyzed proteins were assessed as malondialdehyde-protein adducts (MDA) and advanced glycation end-products (AGE), respectively. The anti-inflammatory effect of HDL3 was estimated as its potential to reduce monocyte adhesion to tumor necrosis factor α-activated endothelial cells. We show that in PAD patients compared to N subjects: (i) HDL2 presented increased levels of MDA-PON1, AGE-PON1, AGE-ApoAI, ApoAII, ApoCIII, and CP levels, and decreased PON1 levels; (ii) HDL3 had increased levels of MDA- and AGE-CLU and -ApoAI, MDA-PON1, ApoCIII, CLU, MPO, CP, and reduced PON1 levels. All these alterations were exacerbated by DM. These changes were more pronounced in HDL3 , which had reduced anti-inflammatory potential in PAD and became pro-inflammatory in PAD-DM. In PAD patients' plasma, CLU levels and MPO specific activity increased, while PON1 specific activity decreased. In conclusion, HDL function is altered in PAD patients due to multiple modifications of associated proteins that are aggravated by DM. Plasma CLU, MPO, and PON1 could constitute indicators of HDL dysfunction and contribute to risk stratification in PAD patients.

Anti-oxidant and anti-inflammatory mechanisms of amlodipine action to improve endothelial cell dysfunction induced by irreversibly glycated LDL.

Amlodipine, alone or in combination with other drugs, was successfully used to treat hypertension. Our aim was to evaluate the potential of amlodipine (Am) to restore endothelial dysfunction induced by irreversibly glycated low density lipoproteins (AGE-LDL), an in vitro model mimicking the diabetic condition. Human endothelial cells (HEC) from EA.hy926 line were incubated with AGE-LDL in the presence/absence of Am and the oxidative and inflammatory status of the cells was evaluated along with the p38 MAPK and NF-κB signalling pathways. The cellular NADPH activity, 4-hydroxynonenal (4-HNE) and 3-nitrotyrosine levels in the culture medium and the adhesion of human monocytes to HEC were measured by chemiluminescence, UHPLC, Western Blot and spectrofluorimetric techniques. The gene expression of NADPH subunits (p22(phox), NOX4), eNOS and inflammatory molecules (MCP-1, VCAM-1) were determined by Real Time PCR, while the protein expression of p22(phox), MCP-1, iNOS, phospho-p38 MAPK and phospho-p65 NF-κB subunit were measured by Western Blot. Results showed that in HEC incubated with AGE-LDL, Am led to: (i) decrease of the oxidative stress: by reducing p22(phox), NOX4, iNOS expression, NADPH oxidase activity, 4-HNE and 3-nitrotyrosine levels; (ii) decrease of the inflammatory stress: by the reduction of MCP-1 and VCAM-1 expression, as well as of the number of monocytes adhered to HEC; (iii) inhibition of ROS-sensitive signalling pathways: by decreasing phosphorylation of p38 MAPK and p65 NF-κB subunits. In conclusion, the reported data demonstrate that amlodipine may improve endothelial dysfunction in diabetes through anti-oxidant and anti-inflammatory mechanisms.

CRISPR/dCas9 Transcriptional Activation of Endogenous Apolipoprotein AI and Paraoxonase 1 in Enterocytes Alleviates Endothelial Cell Dysfunction.

Atherosclerosis is the main cause of cardiovascular diseases with high prevalence worldwide. A promising therapeutic strategy to reverse atherosclerotic process is to improve the athero-protective potential of high-density lipoproteins (HDL). Since the small intestine is a source of HDL, we aimed to activate transcription of the endogenous HDL major proteins, apolipoprotein AI (ApoAI) and paraoxonase 1 (PON1), in enterocytes, and to evaluate their potential to correct the pro-inflammatory status of endothelial cells (EC). Caco-2 enterocytes were transfected with CRISPR activation plasmids targeting ApoAI or PON1, and their gene and protein expression were measured in cells and conditioned medium (CM). ATP binding cassette A1 and G8 transporters (ABCA1, ABCG8), scavenger receptor BI (SR-BI), and transcription regulators peroxisome proliferator-activated receptor γ (PPARγ), liver X receptors (LXRs), and sirtuin-1 (SIRT1) were assessed. Anti-inflammatory effects of CM from transfected enterocytes were estimated through its ability to inhibit tumor necrosis factor α (TNFα) activation of EC. Transcriptional activation of ApoAI or PON1 in enterocytes induces: (i) increase of their gene and protein expression, and secretion in CM; (ii) stimulation of ABCA1/G8 and SR-BI; (iii) upregulation of PPARγ, LXRs, and SIRT1. CM from transfected enterocytes attenuated the TNFα-induced inflammatory and oxidative stress in EC, by decreasing TNF receptor 1, monocyte chemoattractant protein-1, and p22phox. In conclusion, transcriptional activation of endogenous ApoAI or PON1 in enterocytes by CRISPR/dCas9 system is a realistic approach to stimulate biogenesis and function of major HDL proteins which can regulate cholesterol efflux transporters and reduce the inflammatory stress in activated EC.

Aggregated LDL turn human macrophages into foam cells and induce mitochondrial dysfunction without triggering oxidative or endoplasmic reticulum stress.

Uptake of modified lipoproteins by macrophages turns them into foam cells, the hallmark of the atherosclerotic plaque. The initiation and progression of atherosclerosis have been associated with mitochondrial dysfunction. It is known that aggregated low-density lipoproteins (agLDL) induce massive cholesterol accumulation in macrophages in contrast with native LDL (nLDL) and oxidized LDL (oxLDL). In the present study we aimed to assess the effect of agLDL on the mitochondria and ER function in macrophage-derived foam cells, in an attempt to estimate the potential of these cells, known constituents of early fatty streaks, to generate atheroma in the absence of oxidative stress. Results show that agLDL induce excessive accumulation of free (FC) and esterified cholesterol in THP-1 macrophages and determine mitochondrial dysfunction expressed as decreased mitochondrial membrane potential and diminished intracellular ATP levels, without generating mitochondrial reactive oxygen species (ROS) production. AgLDL did not stimulate intracellular ROS (superoxide anion or hydrogen peroxide) production, and did not trigger endoplasmic reticulum stress (ERS) or apoptosis. In contrast to agLDL, oxLDL did not modify FC levels, but stimulated the accumulation of 7-ketocholesterol in the cells, generating oxidative stress which is associated with an increased mitochondrial dysfunction, ERS and apoptosis. Taken together, our results reveal that agLDL induce foam cells formation and mild mitochondrial dysfunction in human macrophages without triggering oxidative or ERS. These data could partially explain the early formation of fatty streaks in the intima of human arteries by interaction of monocyte-derived macrophages with non-oxidatively aggregated LDL generating foam cells, which cannot evolve into atherosclerotic plaques in the absence of the oxidative stress.

Effect of irreversibly glycated LDL in human vascular smooth muscle cells: lipid loading, oxidative and inflammatory stress.

The major complication of diabetes is accelerated atherosclerosis, the progression of which entails complex interactions between the modified low-density lipoproteins (LDL) and the cells of the arterial wall. Advanced glycation end product-modified-LDL (AGE-LDL) that occurs at high rate in diabetes contributes to diabetic atherosclerosis, but the underlying mechanisms are not fully understood. The aim of this study was to assess the direct effect of AGE-LDL on human vascular smooth muscle cells (hSMC) dysfunction. Cultured hSMC incubated (24 hrs) with human AGE-LDL, native LDL (nLDL) or oxidized LDL (oxLDL) were subjected to: (i) quantification of the expression of the receptors for modified LDL and AGE proteins (LRP1, CD36, RAGE) and estimation of lipid loading, (ii) determination of NADPH oxidase activity and reactive oxygen species (ROS) production and (iii) evaluation of the expression of monocyte chemoattractant protein-1 (MCP-1). The results show that exposure of hSMC to AGE-LDL (compared to nLDL) induced: (a) increased NADPH oxidase activity (30%) and ROS production (28%) by up-regulation of NOX1, NOX4, p22phox and p67phox expression, (b) accumulation of intracellular cholesteryl esters, (c) enhanced gene expression of LRP1 (160%) and CD36 (35%), and protein expression of LRP1, CD36 and RAGE, (d) increased MCP-1 gene expression (160%) and protein secretion (300%) and (e) augmented cell proliferation (30%). In conclusion, AGE-LDL activates hSMC (increasing CD36, LRP1, RAGE), inducing a pro-oxidant state (activation of NADPHox), lipid accumulation and a pro-inflammatory state (expression of MCP-1). These results may partly explain the contribution of AGE-LDL and hSMC to the accelerated atherosclerosis in diabetes.

Ninjurin-1 upregulated by TNFα receptor 1 stimulates monocyte adhesion to human TNFα-activated endothelial cells; benefic effects of amlodipine.

AIMS: The objectives of the present study were to investigate the mechanisms of Ninj-1 regulation in TNFα-activated human endothelial cells (HEC), and to test if Amlodipine (AML) ameliorates the inflammatory stress by decreasing Ninj-1 expression. MAIN METHODS: TNFα-activated HEC with/without AML (0.1 µM and 1 µM) were used. TNFα-receptor 1 (TNFR1) was silenced and inhibitors for oxidative stress (N-acetyl cysteine), endoplasmic reticulum stress (salubrinal, 4-phenyl butyric acid), or NF-kB (Bay 11-7085) and p38 MAPK (SB203580) were used. Levels of Ninj-1, TNFR1, monocyte adhesion, endoplasmic reticulum stress (ERS) sensors, NADPH oxidase- and mitochondria-derived oxidative species were evaluated. KEY FINDINGS: The novel findings that we report here are: (i) silencing the endothelial TNFR1 leads to decreased Ninj-1 expression and diminished monocyte adhesion; (ii) increased oxidative stress, ERS and NF-kB activation enhance Ninj-1 expression and monocyte adhesion; (iii) up-regulation of endothelial Ninj-1 expression stimulates monocytes adhesion to TNFα - activated HEC; (iv) AML diminishes monocyte adhesion by reducing Ninj-1 expression through mechanisms involving the decrease of NADPH oxidase and mitochondria-dependent oxidative stress, ERS and NF-kB. In addition, AML alleviates apoptosis by reducing the pro-apoptotic CHOP expression and re-establishing the mitochondrial transmembrane potential. SIGNIFICANCE: The results of the present study suggest that Ninj-1 and the proteins involved in its regulation can be considered therapeutic targets for the alleviation of inflammation- dependent disorders. In addition, we demonstrate that some of the benefic effects of AML can be achieved through regulation of Ninj-1.

Regulation of microRNAs in high-fat diet induced hyperlipidemic hamsters.

Dyslipidemia is a documented risk factor for cardiovascular diseases and other metabolic disorders. Therefore, the analysis of hyperlipidemia (HL)-related miRNAs is a potential approach for achieving new prognostic markers in lipid-metabolism related diseases. We aimed to analyze specific distribution of miRNAs in different tissues from HL animals. Golden Syrian hamsters were fed either regular chow (NL) or high-fat diet (HL) for 12 weeks. Microarray miRNAs profiling was performed in liver, heart and small intestine and data analyzed by R-studio software. Functional enrichment bioinformatics analysis was performed using miRWalk and DAVID tools. We observed a dysregulation of miRNAs in HL tissues evidencing a discrete distribution in the heart-liver axis and three lipid metabolism-related miRNAs were identified: hsa-miR-223-3p, hsa-miR-21-5p, and hsa-miR-146a-5p. Expression levels of these miRNAs were increased in HL livers and hearts. Functional bioinformatics analysis showed involvement of these miRNAs in the regulation of biological processes altered in HL conditions such as lipid metabolic process, fat cell differentiation, regulation of smooth muscle cells and cardiac septum development. We identified a set of miRNAs dysregulated in different tissues of HFD-induced HL hamsters. These findings motivate further studies aiming to investigate novel molecular mechanisms of lipid metabolism and atherogenic HL.

Irreversibly glycated LDL induce oxidative and inflammatory state in human endothelial cells; added effect of high glucose.

In diabetes, hyperglycemia and the associated formation of advanced glycation end-products (AGE) and AGE-modified low density lipoproteins (AGE-LDL) can directly affect the cells of the vascular wall. We hypothesize that AGE-LDL may act directly and induce oxidant and inflammatory alterations in human endothelial cells (HEC), this effect being amplified by high glucose. To test this assumption, the activity of NADPH oxidase (NADPHox) was evaluated and the expression of its subunits (p22(phox), NOX4, and p67(phox)), of the AGE receptor (RAGE), and of the monocyte chemoattractant protein-1 (MCP-1) were assessed by real-time PCR and Western blot in confluent EA.hy926 cells incubated with AGE-LDL for 24 and 48h, in normal and high glucose conditions. Exposure of HEC for 48h to AGE-LDL in 5mM glucose induced an increase of RAGE expression (50%), NADPHox activity (107%), p22(phox) and NOX4 mRNA (50% and 188%, respectively) and MCP-1 expression (80%). AGE-LDL-stimulated p22(phox) expression by activating p38 MAP kinase and NF-kB, and MCP-1 expression by activating NF-kB, as demonstrated by the use of specific inhibitors (SB203580 and Bay11-7085). The addition of 25mM glucose in the culture medium enhanced the effect of AGE-LDL, but also of nLDL, on RAGE, p22(phox), NOX4, p67(phox), and MCP-1 gene expression. In conclusion, AGE-LDL induce an oxidative stress and a pro-inflammatory state in human endothelial cells. Both AGE-LDL and nLDL in the presence of high glucose amplify their effect, revealing a link between hyperlipidemia, diabetes, and endothelial cell dysfunction.

Vascular endothelium in atherosclerosis.

Their strategic location between blood and tissue and their constitutive properties allow endothelial cells (EC) to monitor the transport of plasma molecules, by employing bidirectional receptor-mediated and receptor-independent transcytosis and endocytosis, and to regulate vascular tone, cellular cholesterol and lipid homeostasis. These cells are also involved in signal transduction, immunity, inflammation and haemostasis. Cardiovascular risk factors, such as hyperlipaemia/dyslipidaemia trigger the molecular machinery of EC to respond to insults by modulation of their constitutive functions followed by dysfunction and ultimately by injury and apoptosis. The gradual activation of EC consists initially in the modulation of two constitutive functions: (1) permeability, i.e. increased transcytosis of lipoproteins, and (2) biosynthetic activity, i.e. enhanced synthesis of the basement membrane and extracellular matrix. The increased transcytosis and the reduced efflux of beta-lipoproteins (betaLp) lead to their retention within the endothelial hyperplasic basal lamina as modified lipoproteins (MLp) and to their subsequent alteration (oxidation, glycation, enzymatic modifications). MLp generate chemoattractant and inflammatory molecules, triggering EC dysfunction (appearance of new adhesion molecules, secretion of chemokines, cytokines), characterised by monocyte recruitment, adhesion, diapedesis and residence within the subendothelium. In time, EC in the athero-prone areas alter their net negative surface charge, losing their non-thrombogenic ability, become loaded with lipid droplets and turn into foam cells. Prolonged and/or repeated exposure to cardiovascular risk factors can ultimately exhaust the protective effect of the endogenous anti-inflammatory system within EC. As a consequence, EC may progress to senescence, lose their integrity and detach into the circulation.

Caffeic acid attenuates the inflammatory stress induced by glycated LDL in human endothelial cells by mechanisms involving inhibition of AGE-receptor, oxidative, and endoplasmic reticulum stress.

Type 2 diabetes mellitus is a worldwide epidemic and its atherosclerotic complications determine the high morbidity and mortality of diabetic patients. Caffeic acid (CAF), a phenolic acid present in normal diets, is known for its antioxidant properties. The aim of this study was to investigate CAF's anti-inflammatory properties and its mechanism of action, using cultured human endothelial cells (HEC) incubated with glycated low-density lipoproteins (gLDL). Levels of the receptor for advanced glycation end-products (RAGE), inflammatory stress markers (C reactive protein, CRP; vascular cell adhesion molecule-1, VCAM-1; monocyte chemoattractant protein-1, MCP-1), and oxidative stress and endoplasmic reticulum stress (ERS) markers were evaluated in gLDL-exposed HEC, in the presence/absence of CAF. RAGE silencing or blocking, specific inhibitors for oxidative stress (apocynin, N-acetyl-cysteine), and ERS (salubrinal) were used. The results showed that: (i) gLDL induced CRP synthesis and secretion through mechanisms involving NADPH oxidase-dependent oxidative stress and ERS in HEC; (ii) gLDL-RAGE interaction, oxidative stress, and ERS stimulated the secretion of VCAM-1 and MCP-1 in HEC; and (iii) CAF reduced the secretion of CRP, VCAM-1, and MCP-1 in gLDL-exposed HEC by inhibiting RAGE expression, oxidative stress, and ERS. In conclusion, CAF might be a promising alternative to ameliorate a wide spectrum of disorders due to its complex mechanisms of action resulting in anti-inflammatory and antioxidative properties. © 2017 BioFactors, 43(5):685-697, 2017.

Dysfunctional high-density lipoproteins have distinct composition, diminished anti-inflammatory potential and discriminate acute coronary syndrome from stable coronary artery disease patients.

There is a stringent need to find means for risk stratification of coronary artery diseases (CAD) patients. We aimed at identifying alterations of plasma high-density lipoproteins (HDL) components and their validation as dysfunctional HDL that could discriminate between acute coronary syndrome (ACS) and stable angina (SA) patients. HDL2 and HDL3 were isolated from CAD patients' plasma and healthy subjects. ApolipoproteinAI (apoAI), apoAII, apoCIII, malondialdehyde (MDA), myeloperoxidase (MPO), ceruloplasmin and paraoxonase1 (PON1) were assessed. The anti-inflammatory potential of HDL subfractions was tested by evaluating the secreted inflammatory molecules of tumor necrosis factor α-activated endothelial cells (EC) upon co-incubation with HDL2 or HDL3. We found in ACS versus SA patients: 40% increased MPO, MDA, apoCIII in HDL2 and HDL3, 35% augmented apoAII in HDL2, and in HDL3 increased ceruloplasmin, decreased apoAII (40%) and PON1 protein and activity (15% and 25%). Co-incubation of activated EC with HDL2 or HDL3 from CAD patients induced significantly increased levels of secreted inflammatory molecules, 15-20% more for ACS versus SA. In conclusion, the assessed panel of markers correlates with the reduced anti-inflammatory potential of HDL subfractions isolated from ACS and SA patients (mostly for HDL3 from ACS) and can discriminate between these two groups of CAD patients.