Local expression of inflammatory cytokines in human atherosclerotic plaques

IL1RAP Expression in Human Atherosclerosis: A Target of Novel Antibodies to Reduce Vascular Inflammation and Adhesion

BACKGROUND

Blockade of IL1RAP (interleukin 1 receptor associated protein) was recently shown to reduce atherosclerosis in mice, but the effect on human vascular cells is largely unknown. Targeting the IL1RAP coreceptor represents a novel strategy to block the IL1RAP-dependent cytokines IL (interleukin)-1, IL-33, and IL-36. In the present study, we aimed to evaluate the role of novel antibodies targeting IL1RAP to reduce the effects of IL-1β, IL-33, or IL-36γ in human vascular cells.

METHODS

Expression of IL1RAP was observed in human atherosclerotic plaques by immunohistochemistry and microarray and in endothelial cells by flow cytometry. Endothelial cells were cultured with IL-1β, IL-33, or IL-36γ cytokines with or without IL1RAP antibodies and analyzed with Olink proteomics, ELISA, Western blot, and real-time quantitative polymerase chain reaction. The functional effect of IL1RAP antibodies on endothelial cells were analyzed with adhesion and permeability assays.

RESULTS

Olink proteomics showed inhibition of the inflammatory proteins LIF (leukemia inhibitory factor), OPG (osteoprotegerin), CCL4 (C-C motif chemokine ligand 4), and MCP-3 (monocyte chemoattractant protein 3) by IL1RAP-blockade in endothelial cells after IL-1β stimulation. In addition, the IL1RAP antibodies inhibited IL-1β, and IL-33 induced IL-6 and IL-8 secretion. Secretion of MCP-1 (monocyte chemoattractant protein 1) was induced by IL-1β, IL-33, and IL-36γ, and subsequently was inhibited by IL1RAP antibodies. Similar effects were found on mRNA expression level. Endothelial expression of the adhesion markers ICAM1, VCAM1, and SELE were significantly reduced by IL1RAP antibodies, and neutrophil adhesion to endothelial cells induced by IL-1β and IL-33 was reduced by IL1RAP blockade. In human atherosclerotic lesions, IL1RAP expression correlated with markers of inflammation like IL6, IL8, and MCP1.

CONCLUSIONS

IL1RAP-targeting antibodies can reduce the expression of inflammatory cytokines and markers of adhesion in endothelial cells, which may be of importance for future putative targeted treatments against cardiovascular disease.

Dual-Function Nanoscale Coordination Polymer Nanoparticles for Targeted Diagnosis and Therapeutic Delivery in Atherosclerosis

Atherosclerosis is the primary cause of cardiovascular events such as heart attacks and strokes. However, current medical practice lacks non-invasive, reliable approaches for both imaging atherosclerotic plaques and delivering therapeutic agents directly therein. Here, a biocompatible and biodegradable pH-responsive nanoscale coordination polymers (NCPs) based theranostic system is reported for managing atherosclerosis. NCPs are synthesized with a pH-responsive benzoic-imine (BI) linker and Gd3+. Simvastatin (ST), a statin not used for lowering blood cholesterol but known for its anti-inflammatory and antioxidant effects in mice, is chosen as the model drug. By incorporating ST into the hydrophobic domain of a lipid bilayer shell on NCPs surfaces, ST/NCP-PEG nanoparticles are created that are designed for dual purposes: they diagnose and treat atherosclerosis. When administered intravenously, they target atherosclerotic plaques, breaking down in the mild acidic microenvironment of the plaque to release ST, which reduces inflammation and oxidative stress, and Gd-complexes for MR imaging of the plaques. ST/NCP-PEG nanoparticles show efficacy in slowing the progression of atherosclerosis in live models and allow for simultaneous in vivo monitoring without observed toxicity in major organs. This positions ST/NCP-PEG nanoparticles as a promising strategy for the spontaneous diagnosis and treatment of atherosclerosis.

Dengyinnaotong attenuates atherosclerotic lesions, gut dysbiosis and intestinal epithelial barrier impairment in the high fat diet-fed ApoE-/- mice

ETHNOPHARMACOLOGICAL RELEVANCE

Dengyinnaotong (DYNT) is a traditional Chinese medicine-based patent drug officially approved for the treatment of ischemic stroke primarily based on its indigenous application for the treatment of cardiovascular and cerebrovascular diseases in Southwest China. Atherosclerosis is the principal pathology underlying the pathogenesis of ischemic stroke and coronary artery disease. However, whether DYNT is effective at mitigating atherosclerosis remains unknown.

AIMS OF THE STUDY

The purpose of the current study is to evaluate the potential impact of DYNT treatment on the atherosclerotic lesions and associated pathological mechanisms.

MATERIALS AND METHODS

Histological, immunohistochemical, molecular biological approaches were adopted to investigate the pharmacological impact of DYNT treatment on atherosclerosis and associated pathophysiological alterations in the high fat diet (HFD)-fed ApoE gene deficient (ApoE-/-) mice.

RESULTS

DYNT treatment reduced the size of the atherosclerotic plaques, alleviated the necrotic core, lowered the lipid retention, mitigated the macrophagic burden and decreased the expression of proatherogenic chemokine Ccl2 in the atherosclerotic lesions. DYNT treatment also offered partial protection against atherogenic dyslipidemia and mitigated hepatic lipid content as well as fatty liver pathologies in the HFD-fed ApoE-/- mice. Furthermore, DYNT treatment protected against atherosclerosis-associated gut dysbiosis and impairment in the intestinal epithelial barrier.

CONCLUSIONS

Our work provides novel preclinical evidence that underpins the multifaceted effects of DYNT in the control of atherosclerosis.

m 6A methylation in cellular senescence of age-associated diseases

Cellular senescence is a state of irreversible cellular growth arrest that occurs in response to various stresses. In addition to exiting the cell cycle, senescent cells undergo many phenotypic alterations, including metabolic reprogramming, chromatin rearrangement, and senescence-associated secretory phenotype (SASP) development. Furthermore, senescent cells can affect most physiological and pathological processes, such as physiological development; tissue homeostasis; tumour regression; and age-associated disease progression, including diabetes, atherosclerosis, Alzheimer's disease, and hypertension. Although corresponding anti-senescence therapies are actively being explored for the treatment of age-associated diseases, the specific regulatory mechanisms of senescence remain unclear. N 6-methyladenosine (m 6A), a chemical modification commonly distributed in eukaryotic RNA, plays an important role in biological processes such as translation, shearing, and RNA transcription. Numerous studies have shown that m 6A plays an important regulatory role in cellular senescence and aging-related disease. In this review, we systematically summarize the role of m 6A modifications in cellular senescence with regard to oxidative stress, DNA damage, telomere alterations, and SASP development. Additionally, diabetes, atherosclerosis, and Alzheimer's disease regulation via m 6A-mediated cellular senescence is discussed. We further discuss the challenges and prospects of m 6A in cellular senescence and age-associated diseases with the aim of providing rational strategies for the treatment of these age-associated diseases.

Role of chemokine-like factor 1 as an inflammatory marker in diseases

Immunoinflammatory mechanisms have been incrementally found to be involved in the pathogenesis of multiple diseases, with chemokines being the main drivers of immune cell infiltration in the inflammatory response. Chemokine-like factor 1 (CKLF1), a novel chemokine, is highly expressed in the human peripheral blood leukocytes and exerts broad-spectrum chemotactic and pro-proliferative effects by activating multiple downstream signaling pathways upon binding to its functional receptors. Furthermore, the relationship between CKLF1 overexpression and various systemic diseases has been demonstrated in both in vivo and in vitro experiments. In this context, it is promising that clarifying the downstream mechanism of CKLF1 and identifying its upstream regulatory sites can yield new strategies for targeted therapeutics of immunoinflammatory diseases.

Anti-inflammatory and Immunomodulatory Therapies in Atherosclerosis

Hypercholesterolemia is a major risk factor in atherosclerosis development and lipid-lowering drugs (i.e., statins) remain the treatment of choice. Despite effective reduction of LDL cholesterol in patients, a residual cardiovascular risk persists in some individuals, highlighting the need for further therapeutic intervention. Recently, the CANTOS trial paved the way toward the development of specific therapies targeting inflammation, a key feature in atherosclerosis progression. The pre-existence of multiple drugs modulating both innate and adaptive immune responses has significantly accelerated the number of translational studies applying these drugs to atherosclerosis. Additional preclinical research has led to the discovery of new therapeutic targets, offering promising perspectives for the treatment and prevention of atherosclerosis. Currently, both drugs with selective targeting and broad unspecific anti-inflammatory effects have been tested. In this chapter, we aim to give an overview of current advances in immunomodulatory treatment approaches for atherosclerotic cardiovascular diseases.

Cross-sectional study of blood biomarkers of patients with moderate to severe alopecia areata reveals systemic immune and cardiovascular biomarker dysregulation

BACKGROUND

Although there is increased understanding of the alopecia areata (AA) pathogenesis based on studies in scalp tissues, little is known about its systemic profile.

OBJECTIVE

To evaluate the blood proteomic signature of AA and determine biomarkers associated with increased disease severity.

METHODS

In a cross-sectional study, we assessed 350 inflammatory and cardiovascular proteins using OLINK high-throughput proteomics in patients with moderate to severe AA (n = 35), as compared with healthy individuals (n = 36), patients with moderate to severe psoriasis (n = 19), and those with atopic dermatitis (n = 49).

RESULTS

Seventy-four proteins were significantly differentially expressed between AA and control individuals (false discovery rate, <.05) including innate immunity (interleukin [IL] 6/IL-8), T helper (Th) type 1 (interferon [IFN] γ/CXCL9/CXCL10/CXCL11), Th2 (CCL13/CCL17/CCL7), Th17 (CCL20/PI3/S100A12), and cardiovascular-risk proteins (OLR1/OSM/MPO/PRTN3). Eighty-six biomarkers correlated with AA clinical severity (P < .05), including Th1/Th2, and cardiovascular/atherosclerosis-related proteins, including SELP/PGLYRP1/MPO/IL-18/OSM (P < .05). Patients with AA totalis/universalis showed the highest systemic inflammatory tone, including cardiovascular risk biomarkers, compared to control individuals and even to patients with atopic dermatitis and those with psoriasis. The AA profile showed some Th1/Th2 differences in the setting of concomitant atopy.

LIMITATIONS

Our analysis was limited to 350 proteins.

CONCLUSION

This study defined the abnormalities of moderate to severe AA and associated circulatory biomarkers. It shows that AA has systemic immune, cardiovascular, and atherosclerosis biomarker dysregulation, suggesting the need for systemic treatment approaches.

Comparison of Diazeniumdiolated Dialkylhexanediamines as Nitric Oxide Release Agents on Nonthrombogenicity in an Extracorporeal Circulation Model

When blood from a patient is circulated through extracorporeal circuits (ECCs), such as in cardiopulmonary bypass or extracorporeal life support, platelets in the blood are activated and form a thrombus. This is prevented clinically with a range of different systemic anticoagulation agents (e.g., heparin); however, this increases a patient's risk of hemorrhage. Previous work with nitric oxide (NO) releasing materials using the combined diazeniumdiolated diamine, N-N-di-N'-butyl-1,6-hexanediamine (DBHD), and a polymer-linked thrombin inhibitor, argatroban (AG), showed significant nonthrombogenicity in ECCs using a 4 h rabbit model. Herein, we evaluated if diazeniumdiolated N-N-di-N'-propyl-1,6-hexanediamine (DPHDN₂O₂), which has a slightly lower degree of lipophilicity compared to DBHDN₂O₂, would provide similar nonthrombogenicity as the AG/DBHDN₂O₂-polymer-coated circuits. While DPHDN₂O₂ releases NO at a higher flux rate than DBHDN₂O₂ when coated (within CarboSil polymer) on the inner wall of polyvinyl chloride tubing, neither coated circuit significantly affected animal hemodynamics. Both diazeniumdiolated diamines, in combination with immobilized AG or alone, significantly reduced thrombus formation similarly in the 4 h rabbit model (vs uncoated control): AG/DBHDN₂O₂: 0.12 ± 0.03 cm²; DBHDN₂O₂: 2.57 ± 0.82 cm²; AG/DPHDN₂O₂: 0.68 ± 0.22 cm²; DPHDN₂O₂: 1.87 + 1.26 cm²; uncoated control: 6.95 ± 0.82 cm². AG/DPHDN₂O₂ was no different than AG/DBHDN₂O in preserving platelet count and function. In addition, AG did not leach into the systemic circulation as the total clotting times were insignificantly different from the baseline values (AG/DPHDN₂O₂: 12.7 + 0.5 s (n = 3); AG/DBHDN₂O₂: 12.3 + 0.7 s (n = 3); baseline: 13.9 + 0.3 s (n = 13)). Based on these results, both DPHDN₂O₂ and DPHDN₂O₂ are good candidates as NO donor molecules for creating nonthrombogenic polymer coatings for ECCs.

HTLV-1-host interactions facilitate the manifestations of cardiovascular disease

Atherosclerosis is a multifactorial life-threatening disease which an epidemiologic study in Northeastern Iran showed its association with HTLV-1 infection. Therefore, a cross-sectional study of 39 newly diagnosed subjects with angiography test in three groups including 14 coronary artery disease⁺HTLV-1⁺ (CAD⁺HTLV-1⁺), 8 CAD^-HTLV-1⁺, and 17 CAD⁺HTLV-1^- patients and 11 healthy subjects (CAD^-HTLV-1^-) were conducted. In the present study, Tax and proviral load (PVL) as HTLV-1 virulence factors, along with host chemokine receptor 1 (CCR1), and CCR2 were investigated. Real-time PCR TaqMan method was carried out for PVL measurement and HTLV-1-Tax, CCR1, and CCR2 expressions in peripheral blood mononuclear cells (PBMCs). Furthermore, the main risk factors, lipid profile, and complete blood count (CBC) were assessed. Expression of CCR1 in CAD⁺HTLV-1⁺ group was higher than CAD^-HTLV-1⁺ (P = 0.01) and healthy subjects (P = 0.02). Expression of CCR1 in CAD⁺HTLV-1⁺ was higher in comparison with CAD⁺HTLV-1^-group but did not meet 95% CI (P = 0.02), but meaningful at 91% CI. In addition, expression of CCR2 in CAD⁺HTLV-1⁺ subjects was higher than CAD^-HTLV-1⁺ and CAD⁺HTLV-1^- (P = 0.001, P = 0.005, respectively). In CAD⁺HTLV-1^- subjects, CCR2 was higher than CAD^-HTLV-1⁺ (P = 0.03). The mean PVL in CAD⁺HTLV-1⁺ group is more than CAD^-HTLV-1⁺ (P = 0.041). In HTLV-1⁺ patients Tax had a positive correlation with cholesterol (R = 0.59, P = 0.01), LDL (R = 0.79, P = 0.004) and a negative correlation with HDL (R = -0.47, P = 0.04). These correlations were stronger in CAD⁺HTLV-1⁺. Findings showed that HTLV-1 could alter the expression of CCR2 and, less effect, on CCR1. Moreover, the strong correlation between CCR2 and HTLV-1-Tax with cholesterol, LDL and HDL showed that Tax as the main HTLV-1 virulence factor in cytokine deregulation might be had indirect effects on cholesterol, LDL, and HDL levels.

Atherosclerosis: integration of its pathogenesis as a self-perpetuating propagating inflammation: a review

This review proposes that the development of the atherosclerotic plaque is critically dependent on its inflammatory components forming a self-perpetuating and propagating positive feedback loop. The components involved are: (1) LDL oxidation, (2) activation of the endothelium, (3) recruitment of inflammatory monocytes, (4) macrophage accumulation, which induces LDL oxidation, and (5) macrophage generation of inflammatory mediators, which also activate the endothelium. Through these stages, the positive feedback loop is formed, which generates and promotes expansion of the atherosclerotic process. To illustrate this dynamic of lesion development, the author previously produced a computer simulation, which allowed realistic modelling. This hypothesis on atherogenesis can explain the existence and characteristic focal morphology of the atherosclerotic plaque. Each of the components contributing to the feedback loop is discussed. Many of these components also contain subsidiary positive feedback loops, which could exacerbate the overall process.

Maraviroc Intensification Modulates Atherosclerotic Progression in HIV-Suppressed Patients at High Cardiovascular Risk. A Randomized, Crossover Pilot Study

Background

Experimental CCR5 antagonism with maraviroc in atherosclerosis-prone mice and preliminary data in humans suggest an anti-atherosclerotic effect of the drug. We assessed the impact of maraviroc treatment in persons living with HIV on subclinical indicators of atherosclerosis.

Methods

Persons living with HIV on effective antiretroviral therapy (ART) including only protease inhibitors were recruited if they had a Framingham risk score >20% and brachial flow-mediated dilation (bFMD) <4%, as indices of high cardiovascular risk. Maraviroc (300 mg per os for 24 weeks) was administered, in addition to ongoing ART, to all patients using a crossover design. Brachial FMD, carotid-femoral pulse wave velocity (cfPWV), and carotid intima-media thickness (cIMT) were measured as markers of atherosclerosis. Vascular competence—as expressed by the ratio of circulating endothelial microparticles (EMPs) to endothelial progenitor cells (EPCs)—and markers of systemic inflammation and monocyte and platelet activation were assessed.

Results

Maraviroc treatment significantly improved bFMD, cfPWV, and cIMT by 66%, 11%, and 13%, respectively (P = .002, P = .022, P = .038, respectively). We also found a beneficial effect of maraviroc on the EMP/EPC ratio (P < .001) and platelet/leucocyte aggregates (P = .013). No significant changes in markers of systemic inflammation, monocyte activation, and microbial translocation were observed.

Conclusions

Maraviroc led to significant improvements in several markers for cardiovascular risk, endothelial dysfunction, arterial stiffness, and early carotid atherosclerosis, which was accompanied by an increase of vascular competence, without seeming to affect systemic inflammation. Our data support the need for larger studies to test for any effects of maraviroc on preventing atherosclerosis-driven pathologies.

Potential of anti-inflammatory agents for treatment of atherosclerosis

Chronic inflammation is a central pathogenic mechanism of atherosclerosis induction and progression. Vascular inflammation is associated with accelerated onset of late atherosclerosis complications. Atherosclerosis-related inflammation is mediated by a complex cocktail of pro-inflammatory cytokines, chemokines, bioactive lipids, and adhesion molecules, and blocking the key pro-atherogenic inflammatory mechanisms can be beneficial for treatment of atherosclerosis. Therapeutic agents that specifically target some of the atherosclerosis-related inflammatory mechanisms have been evaluated in preclinical and clinical studies. The most promising anti-inflammatory compounds for treatment of atherosclerosis include non-specific anti-inflammatory drugs, phospholipase inhibitors, blockers of major inflammatory cytokines, leukotrienes, adhesion molecules, and pro-inflammatory signaling pathways, such as CCL2-CCR2 axis or p38 MAPK pathway. Ongoing studies attempt evaluating therapeutic utility of these anti-inflammatory drugs for treatment of atherosclerosis. The obtained results are important for our understanding of atherosclerosis-related inflammatory mechanisms and for designing randomized controlled studies assessing the effect of specific anti-inflammatory strategies on cardiovascular outcomes.

N-Caffeoyltryptamine, a Potent Anti-Inflammatory Phenolic Amide, Suppressed MCP-1 Expression in LPS-stimulated THP-1 Cells and Rats Fed a High-Fat Diet

Monocyte chemoattractant protein-1 (MCP-1) is a well-known chemokine critically involved in the pathophysiological progression of several inflammatory diseases including arthrosclerosis. N-caffeoyltryptamine is a phenolic amide with strong anti-inflammatory effects. Therefore, in this paper, the potential effect of N-caffeoyltryptamine on MCP-1 expression was investigated as a potential p38 mitogen-activated protein (MAP) kinase inhibitor in vitro and in vivo. At the concentration of 20 μM, N-caffeoyltryptamine significantly inhibited p38 MAP kinase α, β, γ and δ by 15-50% (p < 0.05), particularly p38 MAP kinase α (IC50 = 16.7 μM) and β (IC50 = 18.3 μM). Also, the pretreatment of the lipopolysaccharide (LPS)-stimulated THP-1 cells with N-caffeoyltryptamine (10, 20 and 40 μM) led to significant suppression of MCP-1 production by 10-45% (p < 0.05) in the cells. Additionally, N-caffeoyltryptamine was also able to significantly downregulate MCP-1 mRNA expression in the THP-1 cells (p < 0.05). On the basis of this strong inhibition in vitro, an animal study was conducted to confirm this inhibitory effect in vivo. Rats were divided into three groups (n = 8): a normal control diet (C), a high-fat diet (HF), or a high-fat diet supplemented with N-caffeoyltryptamine (2 mg per day) (HFS). After 16 weeks, blood samples were collected from the rats in each group, and MCP-1 levels were determined in plasma with other atherogenic markers (C-reactive protein and soluble E-selectin (sE-selectin)). As expected, the average MCP-1 levels of the HF group were found to be higher than those of the C group (p < 0.05). However, the MCP-1 levels of the HFS group were significantly lower than those of the HF group (p < 0.05), suggesting that N-caffeoyltryptamine could decrease MCP-1 expression in vivo. Related to other atherogenic markers such as C-reactive protein and sE-selectin, there was no significant difference in their levels between the HF and HFS groups. These data suggest that N-caffeoyltryptamine may specifically suppress MCP-1 expression in vitro and in vivo, possibly by inhibiting p38 MAP kinase.

CC chemokine ligand 2 and CXC chemokine ligand 8 as neutrophil chemoattractant factors in canine idiopathic polyarthritis

Canine idiopathic polyarthritis (IPA) is characterized by increased numbers of polymorphonuclear leukocytes (PMNs) in the synovial fluid (SF). In humans, CC chemokine ligand 2 (CCL2) and CXC chemokine ligand 8 (CXCL8) recruit monocytes and neutrophils, respectively, and are involved in various inflammatory disorders. The aim of this study was to assess the roles of these chemokines in driving PMNs infiltration into the joints of dogs with IPA. SF samples were collected from dogs with IPA (n=19) and healthy controls (n=8), and the concentrations of SF CCL2 and CXCL8 were determined by ELISA. Dogs with IPA had significantly higher concentrations of CCL2 (3316±2452pg/ml, mean±SD) and CXCL8 (3668±3879pg/ml) compared with the healthy controls (235±45pg/ml and <15.6pg/ml, respectively). Then, an in vitro chemotaxis assay was performed using a modified Boyden chamber (pore size: 3μm). SF from IPA dogs had a chemoattractant activity for PMNs that purified from the peripheral blood of a healthy dog. We subsequently found that combination treatment with MK-0812 (an antagonist of CCL2 receptor) and repertaxin (an antagonist of CXCL8 receptors) significantly inhibited the migration of PMNs to SF from IPA dogs. Thus, expression of the CCL2 receptor (chemokine (CC motif) receptor 2 (CCR2)) was examined using polymerase chain reaction and immunocytochemistry. Canine peripheral blood PMNs exhibited significantly higher CCR2 mRNA expression levels than those in monocytes. In addition, we observed strong CCR2 expression on PMNs obtained from healthy controls and IPA dogs, although mononuclear cells did not express CCR2. Taken together, the data suggest that CCL2 acts as a canine PMNs chemotactic factor as well as CXCL8 and both CCL2 and CXCL8 facilitate the infiltration of PMNs into the joints of dogs with IPA.

Polymorphism in the chemokine receptor 7 gene (CCR7) is associated with previous myocardial infarction in patients undergoing elective coronary angiography

Coronary artery disease (CAD) remains a major cause of death in developed countries. Both environmental and, less known, genetic factors contribute to progression of CAD to myocardial infarction (MI). Immune system is activated in patients with CAD through dendritic cells (DCs), which present plaque antigens to T lymphocytes. Production of proinflammatory cytokines by activated T cells contributes to plaque rupture in MI. Chemokine receptor 7 (CCR7) on DCs is required for their chemotaxis from plaque to lymph nodes. This makes possible an interaction of DCs with T lymphocytes and initiation of specific immune response. We hypothesized that single nucleotide polymorphisms (SNPs) in CCR7 gene locus are associated with previous MI in patients with CAD. To test this hypothesis, we genotyped six SNPs from the CCR7 gene locus in 300 consecutive patients, admitted for elective coronary angiography. We performed univariate-, multivariate- (including potential confounders) and haplotype-based tests of association of SNPs with previous MI and results of angiography. Allele A of rs17708087 SNP was associated with previous MI. This association remained significant after adjustment for age, sex, smoking, hypercholesterolaemia and drugs used by patients (odds ratio 2.13, 95% confidence interval: 1.13-3.86). Therefore, we conclude that CCR7 gene locus harbours a polymorphism that modifies risk of MI in patients with CAD. Replication of this association could be sought in a prospective cohort of initially healthy individuals.

Chlorella 11-peptide inhibits the production of macrophage-induced adhesion molecules and reduces endothelin-1 expression and endothelial permeability

The inflammation process in large vessels involves the up-regulation of vascular adhesion molecules such as endothelial cell selectin (E-selectin), intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) which are also known as the markers of atherosclerosis. We have reported that Chlorella 11-peptide exhibited effective anti-inflammatory effects. This peptide with an amino sequence Val-Glu-Cys-Tyr-Gly-Pro-Asn-Arg-Pro-Gln-Phe was further examined for its potential in preventing atherosclerosis in this study. In particular, the roles of Chlorella 11-peptide in lowering the production of vascular adhesion molecules, monocyte chemoattractant protein (MCP-1) and expression of endothelin-1 (ET-1) from endothelia (SVEC4-10 cells) were studied. The production of E-selectin, ICAM-1, VCAM-1 and MCP-1 in SVEC4-10 cells was measured with ELISA. The mRNA expression of ET-1 was analyzed by RT-PCR and agarose gel. Results showed that Chlorella 11-peptide significantly suppressed the levels of E-selectin, ICAM, VCAM, MCP-1 as well as ET-1 gene expression. The inhibition of ICAM-1 and VCAM-1 production by Chlorella 11-peptide was reversed in the presence of protein kinase A inhibitor (H89) which suggests that the cAMP pathway was involved in the inhibitory cause of the peptide. In addition, this peptide was shown to reduce the extent of increased intercellular permeability induced by combination of 50% of lipopolysaccharide (LPS)-activated RAW 264.7 cells medium and 50% normal SEVC cell culture medium (referred to as 50% RAW-conditioned medium). These data demonstrate that Chlorella 11-peptide is a promising biomolecule in preventing chronic inflammatory-related vascular diseases.

Efficacy of the CCR5 antagonist maraviroc in reducing early, ritonavir-induced atherogenesis and advanced plaque progression in mice

BACKGROUND

CCR5 plays an important role in atherosclerosis and ischemic cardiovascular diseases, as well as in HIV replication and diffusion. HIV infection is characterized by a high burden of cardiovascular diseases, particularly in subjects exposed to ritonavir-boosted protease inhibitors. Maraviroc, a CCR5 antagonist antiretroviral drug, might provide benefit for patients with M-tropic HIV infections at high risk for cardiovascular diseases.

METHODS AND RESULTS

Exposure to maraviroc limits the evolution and associated systemic inflammation of ritonavir-induced atherosclerotic in ApoE(-/-) mice and inhibits plaques development in a late model of atherosclerosis in which dyslipidemia plays the main pathogenic role. In ritonavir-treated mice, maraviroc reduced plaque areas and macrophage infiltration; downregulated the local expression of vascular cell adhesion molecule-1, intercellular adhesion molecule-1, monocyte chemoattractant protein-1, and interleukin-17A; and reduced tumor necrosis factor-α and RANTES (regulated on activation, normal T cell expressed, and secreted). Moreover, maraviroc counterregulated ritonavir-induced lipoatrophy and interlelukin-6 gene expression in epididymal fat, along with the splenic proinflammatory profile and expression of CD36 on blood monocytes. In the late model, maraviroc inhibited atherosclerotic progression by reducing macrophage infiltration and lowering the expression of adhesion molecules and RANTES inside the plaques. However, limited systemic inflammation was observed.

CONCLUSIONS

In a mouse model of genetic dyslipidemia, maraviroc reduced the atherosclerotic progression by interfering with inflammatory cell recruitment into plaques. Moreover, in mice characterized by a general ritonavir-induced inflammation, maraviroc reversed the proinflammatory profile. Therefore, maraviroc could benefit HIV-positive patients with residual chronic inflammation who are at a high risk of acute coronary disease despite a suppressive antiretroviral therapy. To determine these benefits, large clinical studies are needed.

Evaluation of 9 biomarkers for predicting 10-year cardiovascular risk in patients undergoing coronary angiography: findings from the LUdwigshafen RIsk and Cardiovascular Health (LURIC) study

BACKGROUND

Conventional factors do not fully explain the distribution of cardiovascular outcomes. Biomarkers are known to participate in well-established pathways associated with cardiovascular disease, and may therefore provide further information over and above conventional risk factors. This study sought to determine whether individual and/or combined assessment of 9 biomarkers improved discrimination, calibration and reclassification of cardiovascular mortality.

METHODS

3267 patients (2283 men), aged 18-95 years, at intermediate-to-high-risk of cardiovascular disease were followed in this prospective cohort study. Conventional risk factors and biomarkers were included based on forward and backward Cox proportional stepwise selection models.

RESULTS

During 10-years of follow-up, 546 fatal cardiovascular events occurred. Four biomarkers (interleukin-6, neutrophils, von Willebrand factor, and 25-hydroxyvitamin D) were retained during stepwise selection procedures for subsequent analyses. Simultaneous inclusion of these biomarkers significantly improved discrimination as measured by the C-index (0.78, P = 0.0001), and integrated discrimination improvement (0.0219, P<0.0001). Collectively, these biomarkers improved net reclassification for cardiovascular death by 10.6% (P<0.0001) when added to the conventional risk model.

CONCLUSIONS

In terms of adverse cardiovascular prognosis, a biomarker panel consisting of interleukin-6, neutrophils, von Willebrand factor, and 25-hydroxyvitamin D offered significant incremental value beyond that conveyed by simple conventional risk factors.

Characterization of CD4+CD28null T cells in patients with coronary artery disease and individuals with risk factors for atherosclerosis

Risk factors for atherosclerosis may contribute to chronic low-grade inflammation. A highly cytotoxic and inflammatory CD4(+) cell subset (CD4(+)CD28(null) cells) has been associated with inflammatory diseases, including acute coronary syndromes (ACS). The aim of this study was to quantify and characterize CD4(+)CD28(null) cells in individuals with risk factors for atherosclerosis and patients with coronary artery disease (CAD). In order to achieve this goal, peripheral blood mononuclear cells (PBMCs) from individuals with risk factors for atherosclerosis and patients with CAD were analyzed using flow cytometry to detect cytotoxic molecules and evaluate the expression of homing receptors and inflammatory cytokines in CD4(+) cell subsets. The cells were evaluated ex vivo and after stimulation in culture. We found no differences in the proportions of CD4(+)CD28(null) cells among the groups. Compared with the CD4(+)CD28(+) population, the ex vivo CD4(+)CD28(null) subset from all groups expressed higher levels of granzymes A and B, perforin, granulysin and interferon-γ (IFN-γ). Individuals with risk factors and patients with ACS showed the highest levels of cytotoxic molecules. After stimulation, tumor necrosis factor-α (TNF-α) expression in the CD4(+)CD28(null) subset from these groups increased more than in the other groups. Stimulation with LPS decreased the expression of cytotoxic molecules by CD4(+)CD28(null) cells in all groups. In conclusion, our results show that risk factors for atherosclerosis may alter the CD4(+)CD28(null) cells phenotype, increasing their cytotoxic potential. Our findings also suggest that CD4(+)CD28(null) cells may participate in the early phases of atherosclerosis.

Regulation of atherogenesis by chemokines and chemokine receptors

Atherosclerosis is a chronic inflammatory and metabolic disorder affecting large- and medium-sized arteries, and the leading cause of mortality worldwide. The pathogenesis of atherosclerosis involves accumulation of lipids and leukocytes in the intima of blood vessel walls creating plaque. How leukocytes accumulate in plaque remains poorly understood; however, chemokines acting at specific G protein-coupled receptors appear to be important. Studies using knockout mice suggest that chemokine receptor signaling may either promote or inhibit atherogenesis, depending on the receptor. These proof of concept studies have spurred efforts to develop drugs targeting the chemokine system in atherosclerosis, and several have shown beneficial effects in animal models. This study will review key discoveries in basic and translational research in this area.

Chemokines CCL3/MIP1α, CCL5/RANTES and CCL18/PARC are independent risk predictors of short-term mortality in patients with acute coronary syndromes

Cytokines play an important role in ischemic injury and repair. However, little is known about their prognostic value in cardiovascular disease. The aim of this study was to investigate the prognostic importance of chemokines CCL3/MIP-1α, CCL5/RANTES and CCL18/PARC for the risk of future cardiovascular events in patients with acute coronary syndromes (ACS). Baseline levels of CCL3/MIP-1α, CCL5/RANTES and CCL18/PARC were determined in ACS patients from the Bad Nauheim ACS II registry (n = 609). During the following 200 days, patients were monitored for the occurrence of fatal and non-fatal cardiovascular events. Patients with CCL3/MIP1α, CCL5/RANTES and CCL18/PARC concentrations in the highest tertile were associated with an increased risk of a fatal event during follow-up (HR: 2.19, 95%CI: 1.04–4.61 for CCL3/MIP1α, HR: 3.45, 95%CI: 1.54–7.72 for CCL5/RANTES and HR: 3.14, 95%CI: 1.33–7.46 for CCL18/PARC). This risk was highest for patients with all three biomarkers concentrations in the upper tertile (HR: 2.52, 95%CI: 1.11–5.65). Together with known risk predictors of cardiovascular events, CCL3/MIP-1α, CCL5/RANTES and CCL18/PARC combined improved the c-statistics from 0.74 to 0.81 (p = 0.007). In conclusion, CCL3/MIP-1α, CCL5/RANTES and CCL18/PARC are independently associated with the risk of short-term mortality in ACS patients. Combining all three biomarkers further increased their prognostic value.

Impact of macrophage inflammatory protein-1α deficiency on atherosclerotic lesion formation, hepatic steatosis, and adipose tissue expansion

Macrophage inflammatory protein-1α (CCL3) plays a well-known role in infectious and viral diseases; however, its contribution to atherosclerotic lesion formation and lipid metabolism has not been determined. Low density lipoprotein receptor deficient (LDLR^−/−) mice were transplanted with bone marrow from CCL3^−/− or C57BL/6 wild type donors. After 6 and 12 weeks on western diet (WD), recipients of CCL3^−/− marrow demonstrated lower plasma cholesterol and triglyceride concentrations compared to recipients of C57BL/6 marrow. Atherosclerotic lesion area was significantly lower in female CCL3^−/− recipients after 6 weeks and in male CCL3^−/− recipients after 12 weeks of WD feeding (P<0.05). Surprisingly, male CCL3^−/− recipients had a 50% decrease in adipose tissue mass after WD-feeding, and plasma insulin, and leptin levels were also significantly lower. These results were specific to CCL3, as LDLR^−/− recipients of monocyte chemoattractant protein^−/− (CCL2) marrow were not protected from the metabolic consequences of high fat feeding. Despite these improvements in LDLR^−/− recipients of CCL3^−/− marrow in the bone marrow transplantation (BMT) model, double knockout mice, globally deficient in both proteins, did not have decreased body weight, plasma lipids, or atherosclerosis compared with LDLR^−/− controls. Finally, there were no differences in myeloid progenitors or leukocyte populations, indicating that changes in body weight and plasma lipids in CCL3^−/− recipients was not due to differences in hematopoiesis. Taken together, these data implicate a role for CCL3 in lipid metabolism in hyperlipidemic mice following hematopoietic reconstitution.

CCR5Δ32 genotype leads to a Th2 type directed immune response in ESRD patients

Background

In patients with end stage renal disease (ESRD) we observed protection from inflammation-associated mortality in CCR5Δ32 carriers, leading to CCR5 deficiency, suggesting impact of CCR5Δ32 on inflammatory processes. Animal studies have shown that CCR5 deficiency is associated with a more pronounced Th2 type immune response, suggesting that in human CCR5Δ32 carriers the immune response may be more Th2 type directed. So, in the present study we determined the Th1-Th2 type directed immune response in ESRD patients carrying and not carrying the CCR5Δ32 genetic variant after stimulation.

Methodology/Principal Findings

We tested this hypothesis by determining the levels of IFN-γ and IL-4 and the distribution of Th1, Th2 and Th17 directed circulating CD4+ and CD8+ T cells and regulatory T cells (Tregs) after stimulation in ESRD patients with (n = 10) and without (n = 9) the CCR5Δ32 genotype. The extracellular levels of IFN-γ and IL-4 did not differ between CCR5Δ32 carriers and non carriers. However, based on their intracellular cytokine profile the percentages IL-4 secreting CD4+ and CD8+ T cells carrying the CCR5Δ32 genotype were significantly increased (p = 0.02, respectively p = 0.02) compared to non carriers, indicating a more Th2 type directed response. Based on their intracellular cytokine profile the percentages IFN-γ and IL-17 secreting T cells did not differ between carriers and non-carriers nor did the percentage Tregs, indicating that the Th1, Th17 and T regulatory response was not affected by the CCR5Δ32 genotype.

Conclusions/Significance

This first, functional human study shows a more pronounced Th2 type immune response in CCR5Δ32 carriers compared to non carriers. These differences may be involved in the previously observed protection from inflammation-associated mortality in ESRD patients carrying CCR5Δ32.

Polymorphisms in the CC-chemokine receptor-2 (CCR2) and -5 (CCR5) genes and risk of myocardial infarction among Tunisian male patients

OBJECTIVES

The aim of the present study was to investigate the association between CCR2-Val64Ile and CCR5-Δ32 variants and the estimation of haplotypes with MI in a sample of the Tunisian population.

DESIGN AND METHODS

A total of 290 unrelated MI patients and 282 healthy controls were studied. The CCR2-Val64Ile and CCR5-Δ32 variants were analyzed by PCR-RFLP.

RESULTS

Subjects carrying at least one copy of the CCR5-deletion allele were significantly more common in the control group, suggesting an atheroprotective effect (adjusted OR=0.44, 95% CI=0.28-0.72, p=0.001). Haplotype analysis showed that MI patients had significantly less 64Val-Del haplotype (9.9% vs. 21.3%, OR=0.30, 95% CI=0.21-0.43, p<0.001) and 64Ile-Ins haplotype (12.3% vs. 16.7%, OR=0.58, 95% CI=0.42-0.80, p<0.001).

CONCLUSION

A protective effect of the CCR5-Δ32 polymorphism against MI in the Tunisian population was found.

Chemokine receptor CCR5: from AIDS to atherosclerosis

There is increasing recognition of an important contribution of chemokines and their receptors in the pathology of atherosclerosis and related cardiovascular disease. The chemokine receptor CCR5 was initially known for its role as a co-receptor for HIV infection of macrophages and is the target of the recently approved CCR5 antagonist maraviroc. However, evidence is now emerging supporting a role for CCR5 and its ligands CCL3 (MIP-1α), CCL4 (MIP-1β) and CCL5 (RANTES) in the initiation and progression of atherosclerosis. Specifically, the CCR5 deletion polymorphism CCR5delta32, which confers resistance to HIV infection, has been associated with a reduced risk of cardiovascular disease and both CCR5 antagonism and gene deletion reduce atherosclerosis in mouse models of the disease. Antagonism of CCL5 has also been shown to reduce atherosclerotic burden in these animal models. Crucially, CCR5 and its ligands CCL3, CCL4 and CCL5 have been identified in human and mouse vasculature and have been detected in human atherosclerotic plaque. Not unexpectedly, CC chemokines have also been linked to saphenous vein graft disease, which shares similarity to native vessel atherosclerosis. Distinct roles for chemokine-receptor systems in atherogenesis have been proposed, with CCR5 likely to be critical in recruitment of monocytes to developing plaques. With an increased burden of cardiovascular disease observed in HIV-infected individuals, the potential cardiovascular-protective effects of drugs that target the CCR5 receptor warrant greater attention. The availability of clinically validated antagonists such as maraviroc currently provides an advantage for targeting of CCR5 over other chemokine receptors.

Genes and abdominal aortic aneurysm

Abdominal aortic aneurysm (AAA) is a multifactorial disease with a strong genetic component. Since the first candidate gene studies were published 20 years ago, approximately 100 genetic association studies using single nucleotide polymorphisms (SNPs) in biologically relevant genes have been reported on AAA. These studies investigated SNPs in genes of the extracellular matrix, the cardiovascular system, the immune system, and signaling pathways. Very few studies were large enough to draw firm conclusions and very few results could be replicated in another sample set. The more recent unbiased approaches are family-based DNA linkage studies and genome-wide genetic association studies, which have the potential of identifying the genetic basis for AAA, only when appropriately powered and well-characterized large AAA cohorts are used. SNPs associated with AAA have already been identified in these large multicenter studies. One significant association was of a variant in a gene called contactin-3, which is located on chromosome 3p12.3. However, two follow-up studies could not replicate this association. Two other SNPs, which are located on chromosome 9p21 and 9q33, were replicated in other samples. The two genes with the strongest supporting evidence of contribution to the genetic risk for AAA are the CDKN2BAS gene, also known as ANRIL, which encodes an antisense ribonucleic acid that regulates expression of the cyclin-dependent kinase inhibitors CDKN2A and CDKN2B, and DAB2IP, which encodes an inhibitor of cell growth and survival. Functional studies are now needed to establish the mechanisms by which these genes contribute toward AAA pathogenesis.

Chemokines as therapeutic targets for atherosclerotic plaque destabilization and rupture

Chemokines are instrumental in the initiation and progression of atherosclerosis. Recent advances in genomic technologies and the recognition of atherosclerosis as an inflammatory disease have given great impetus to studies addressing the relevance of chemokines for the clinically manifest stages of atherosclerosis and acute cardiovascular syndromes. In this paper, we will review the current status of these studies, highlighting those chemokines that have already been associated with plaque destabilization and rupture. We will recapitulate recent epidemiologic, genomic, histopathological and experimental support for the prominent role of particular chemokines in acute cardiovascular syndromes. Collectively, these data underpin the potential of chemokines as biomarkers and/or therapeutic targets, but also expose the lacunae in our understanding of the precise function of chemokines in the atherosclerosis-related disorders and in the efficacy of chemokine-targeted clinical trials.

Early Atherosclerosis Exhibits an Enhanced Procoagulant State

Background— Thrombin generation in vivo may be important in regulating atherosclerotic progression. In the present study, we examined for the first time the activity and presence of relevant coagulation proteins in relation to the progression of atherosclerosis.

Methods and Results— Both early and stable advanced atherosclerotic lesions were collected pairwise from each individual (n=27) during autopsy. Tissue homogenates were prepared from both total plaques and isolated plaque layers, in which the activity of factors (F) II, X, and XII and tissue factor was determined. Microarray analysis was implemented to elucidate local messenger RNA synthesis of coagulation proteins. Part of each specimen was paraffin embedded, and histological sections were immunohistochemically stained for multiple coagulation markers with the use of commercial antibodies. Data are expressed as median (interquartile range [IQR]). Tissue factor, FII, FX, and FXII activities were significantly higher in early atherosclerotic lesions than in stable advanced atherosclerotic lesions. Endogenous thrombin potential and thrombin-antithrombin complex values consolidated a procoagulant profile of early atherosclerotic lesions (endogenous thrombin potential, 1240 nmol/L · min [IQR, 1173 to 1311]; thrombin-antithrombin complex, 1045 ng/mg [IQR, 842.6 to 1376]) versus stable advanced atherosclerotic lesions (endogenous thrombin potential, 782 nmol/L · min [IQR, 0 to 1151]; thrombin-antithrombin complex, 718.4 ng/mg [IQR, 508.6 to 1151]). Tissue factor, FVII, and FX colocalized with macrophages and smooth muscle cells. In addition, multiple procoagulant and anticoagulant proteases were immunohistochemically mapped to various locations throughout the atherosclerotic vessel wall in both early and advanced atherosclerotic stages.

Conclusions— This study shows an enhanced procoagulant state of early-stage atherosclerotic plaques compared with advanced-stage plaques, which may provide novel insights into the role of coagulation during atherosclerotic plaque progression.

High-density lipoproteins suppress chemokines and chemokine receptors in vitro and in vivo

OBJECTIVE

To investigate whether high-density lipoproteins (HDLs) suppress chemokine (CCL2, CCL5, and CX(3)CL1) and chemokine receptor (CCR2 and CX(3)CR1) expression, a mechanism for the atheroprotective properties of HDLs.

METHODS AND RESULTS

Apolipoprotein (apo) E(-/-) mice were fed a high-fat diet for 12 weeks. Before being euthanized, the mice received 5 consecutive daily injections of lipid-free apoA-I, 40 mg/kg, or saline (control). The injection of apoA-I reduced CCR2 and CX(3)CR1 expression in plaques compared with controls (P<0.05). ApoA-I-injected mice had lower plasma CCL2 and CCL5 levels. Hepatic CCL2, CCL5, and CX(3)CL1 levels were also reduced (P<0.05). In vitro studies found that reconstituted HDL (rHDL) reduced monocyte CCR2 and CX(3)CR1 expression and inhibited their migration toward CCL2 and CX(3)CL1 (P<0.05). Preincubation with rHDL reduced CCL2, CCL5, and CX(3)CL1 expression in monocytes and human coronary artery endothelial cells. The stimulation of CX(3)CR1 with peroxisome proliferator-activated receptor gamma agonist CAY10410 was suppressed by preincubation with rHDL but did not affect the peroxisome proliferator-activated receptor gamma antagonist (GW9664)-mediated increase in CCR2. In monocytes and human coronary artery endothelial cells, rHDL reduced the expression of the nuclear p65 subunit, IkappaB kinase activity, and the phosphorylation of IkappaBalpha (P<0.05).

CONCLUSIONS

Lipid-free apoA-I and rHDL reduce the expression of chemokines and chemokine receptors in vivo and in vitro via modulation of nuclear factor kappaB and peroxisome proliferator-activated receptor gamma.

Exercise training versus diet-induced weight-loss on metabolic risk factors and inflammatory markers in obese subjects: a 12-week randomized intervention study

The purpose of this study was to investigate the effect of exercise training and diet-induced weight loss alone or in combination on inflammatory markers in circulation, in adipose tissue (AT) and in skeletal muscle (SM) in obese subjects. Seventy-nine obese subjects were randomized into a 12-wk intervention: 1) exercise only (EXO), 2) diet-induced weight loss using a very low energy diet (DIO), and 3) exercise and diet-induced weight-loss combined (DEX). Blood samples (metabolic and inflammatory markers) and AT and SM biopsies (mRNA expression) were collected at baseline and after 12 wk. In the EXO group the weight loss was 3.5 kg and in the DIO and DEX groups it was 12 kg in both. Vo(2max) was increased by 14-18% in the EXO and DEX groups with no changes in the DIO group. In the DIO and DEX groups, circulating levels of MCP-1, MIP-1alpha, IL-15, and IL-18 were decreased, and adiponectin was increased (P < 0.05 for all). In the EXO group, MCP-1 was decreased with 10% (P = 0.06). By combining the weight loss in all three groups, we found a correlation between the degree of weight loss and improvement in several of the inflammatory markers (P < 0.05). In AT biopsies, subjects in the DIO and DEX groups achieved a general beneficial but nonsignificant effect on the gene expression of inflammatory markers. In the EXO group, no changes in AT adipokine mRNA were found except for an increment of adiponectin (P < 0.05). In SM, the only observed change was that the gene expression of IL-6 was increased in all three groups (P < 0.05). In conclusion, rather large weight losses (>5-7%) were found to have beneficial effects on circulating inflammatory markers in these obese subjects. Aerobic exercise for 12 wk, which increased Vo(2max), was found to have no effects on circulating inflammatory markers in these obese patients. It is suggested that more intensive exercise may be necessary to affect systemic inflammation.

Effect of caffeic acid on tumor necrosis factor-alpha-induced vascular inflammation in human umbilical vein endothelial cells

Recruitment of specific leukocyte subpopulations at the site of inflammation requires a series of cell adhesion molecules (CAMs)-mediated interactions. The major CAMs, viz., intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin are expressed on endothelium in response to various cytokines. Caffeic acid (CA), a natural phenolic compound from herbs and other sources, has been shown to prevent cardiovascular diseases. We investigated the effect of CA on the expression of CAMs by human umbilical vein endothelial cells (HUVECs) stimulated with tumor necrosis factor (TNF-alpha). Adhesion of monocytes to CA-treated HUVECs was evaluated by co-culture experiments using 2,7-bis(2-carboxyethyl)-5(6)-carboxyfluorescein acetoxymethylester (BCECF-AM) labeling of U937 cells. The expression of adhesion and chemoattractant molecules was evaluated by Western blot and reverse transcription-polymerase chain reaction (RT-PCR), respectively. CA significantly inhibited the TNF-alpha-induced increase in U937 monocyte adhesion to HUVECs as well as decreased the protein and mRNA expression levels of CAMs on HUVECs. CA also inhibited the mRNA expression of monocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8). The involvement of nuclear factor (NF)-kappaB in the transcriptional control of CAMs protein was assessed by degradation of inhibitory (I)kappaB and nuclear translocation of NF-kappaB using Western blotting and immunofluorescence staining. CA attenuated TNF-alpha-induced IkappaB degradation and NF-kappaB translocation from cytosol to the nucleus. In conclusion, TNF-alpha-induced NF-kappaB-DNA complex formation was inhibited by CA. CA reduced TNF-alpha-induced endothelial adhesiveness to HUVECs by inhibiting transcription factor activation, and CAMs expression suggesting its potential role in atherosclerosis diseases.

Bee venom reduces atherosclerotic lesion formation via anti-inflammatory mechanism

The components of bee venom (BV) utilized in the current study were carefully scrutinized with chromatography. Despite its well documented anti-inflammatory property, there are no reports regarding the influence of BV on the expression of cellular adhesion molecules in the vascular endothelium. A great amount of information exists concerning the effects of an atherogenic diet on atherosclerotic changes in the aorta, but little is known about the molecular mechanisms and the levels of gene regulation involved in the anti-inflammatory process induced by BV. The experimental atherosclerosis was induced in mice by a lipopolysaccharide (LPS) injection and an atherogenic diet. The animals were divided into three groups, the NC groups of animals that were fed with a normal diet, the LPS/fat group was fed with the atherogenic diet and received intraperitoneal injections of LPS, and the LPS/fat + BV group was given LPS, an atherogenic diet and intraperitoneal BV injections. At the end of each treatment period, the LPS/fat + BV group had decreased levels of total cholesterol (TC) and triglyceride (TG) in their serum, compared to the LPS/fat group. The LPS/fat group had significant expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1β in the serum, compared with the NC group (p < 0.05). The amount of cytokines reduced consistently in the BV treatment groups compared with those in LPS/fat group. BV significantly reduced the amount of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), transforming growth factor-β1 (TGF-β1) and fibronectin in the aorta, compared with the LPS/fat group (p < 0.05). A similar pattern was also observed in the heart. In conclusion, BV has anti-atherogenic properties via its lipid-lowering and anti-inflammatory mechanisms.

The attenuation of platelet and monocyte activation in a rabbit model of extracorporeal circulation by a nitric oxide releasing polymer

Nitric oxide (NO) has been shown to reduce thrombogenicity by decreasing platelet and monocyte activation by the surface glycoprotein, P-selectin and the integrin, CD11b, respectively. In order to prevent platelet and monocyte activation with exposure to an extracorporeal circulation (ECC), a nitric oxide releasing (NORel) polymeric coating composed of plasticized polyvinyl chloride (PVC) blended with a lipophilic N-diazeniumdiolate was evaluated in a 4 h rabbit thrombogenicity model using flow cytometry. The NORel polymer significantly reduced ECC thrombus formation compared to polymer control after 4 h blood exposure (2.8 +/- 0.7 NORel vs 6.7 +/- 0.4 pixels/cm(2) control). Platelet count (3.4 +/- 0.3 NORel vs 2.3 +/- 0.3 x 10(8)/ml control) and function as measured by aggregometry (71 +/- 3 NORel vs 17 +/- 6% control) were preserved after 4 h exposure in NORel versus control ECC. Plasma fibrinogen levels significantly decreased in both NORel and control groups. Platelet P-selectin mean fluorescence intensity (MFI) as measured by flow cytometry was attenuated after 4 h on ECC to ex vivo collagen stimulation (27 +/- 1 NORel vs 40 +/- 2 MFI control). Monocyte CD11b expression was reduced after 4 h on ECC with NORel polymer (87 +/- 14 NORel vs 162 +/- 30 MFI control). These results suggest that the NORel polymer coatings attenuate the increase in both platelet P-selectin and monocytic CD11b integrin expression in blood exposure to ECCs. These NO-mediated platelet and monocytic changes were shown to improve thromboresistance of these NORel-polymer-coated ECCs for biomedical devices.

Anti-inflammatory properties of C-Peptide

C-peptide, historically considered a biologically inactive peptide, has been shown to exert insulin-independent biological effects on a number of cells proving itself as a bioactive peptide with anti-inflammatory properties. Type 1 diabetic patients typically lack C-peptide, and are at increased risk of developing both micro- and macrovascular complications, which account for significant morbidity and mortality in this population. Inflammatory mechanisms play a pivotal role in vascular disease. Inflammation and hyperglycemia are major components in the development of vascular dysfunction in type 1 diabetes. The anti-inflammatory properties of C-peptide discovered to date are at the level of the vascular endothelium, and vascular smooth muscle cells exposed to a variety of insults. Additionally, C-peptide has shown anti-inflammatory properties in models of endotoxic shock and type 1 diabetes-associated encephalopathy. Given the anti-inflammatory properties of C-peptide, one may speculate dual hormone replacement therapy with both insulin and C-peptide in patients with type 1 diabetes may be warranted in the future to decrease morbidity and mortality in this population.

CCR5Delta32 genotype is associated with outcome in type 2 diabetes mellitus

AIMS

To test whether the genetic variant CCR5Delta32 in the CC-chemokine receptor 5, which is known to lead to CCR5 deficiency, is associated with mortality in type 2 diabetes patients.

METHODS

We examined the effect of presence or absence of the CCR5Delta32 on overall and cardiovascular mortality risk in the Zwolle Outpatient Diabetes project Integrating Available Care (ZODIAC) cohort, a type 2 diabetes patient cohort.

RESULTS

We studied 756 patients with a mean duration of follow-up of 5.4 (+/- 1.4) years. 194 patients died during follow up of which 83 were cardiovascular deaths. 144 subjects (19%) carried the CCR5Delta32 deletion. CCR5Delta32 carriers had an adjusted hazard ratio of 0.62 (95%CI: 0.40-0.96; p=0.03) for all-cause mortality and 0.63 (95%CI: 0.33-1.19; p=0.16) for cardiovascular mortality.

CONCLUSIONS

The presence of CCR5Delta32 is associated with better survival in type 2 diabetes patients. These data suggest that it is worthwhile to explore the protective potential of pharmacological blockade of CCR5 in type 2 diabetic patients.

Local lentiviral short hairpin RNA silencing of CCR2 inhibits vein graft thickening in hypercholesterolemic apolipoprotein E3-Leiden mice

OBJECTIVE

Inflammatory responses to vascular injury are key events in vein graft disease and accelerated atherosclerosis, which may result in bypass failure. The monocyte chemoattractant protein-1 (MCP-1)/CC-chemokine receptor (CCR)-2 pathway is hypothesized to play a central role. A murine model for vein graft disease was used to study the effect of local application of lentiviral short hairpin RNA (shRNA) targeted against CCR2.

METHODS

A venous interposition was placed into the carotid artery of hypercholesterolemic apolipoprotein E3-Leiden (APOE*3-Leiden) mice to induce vein graft thickening with features of accelerated atherosclerosis. To demonstrate the efficacy of the lentiviral shRNA targeting murine CCR2 (shCCR2) in blocking vein graft disease in vivo, lentiviral shCCR2 or a control lentivirus was used to infect the vein graft locally (n = 8).

RESULTS

Vascular CCR2 and MCP-1 messenger RNA expression levels were significantly upregulated during lesion progression in the vein graft. Infection of smooth muscle cells (SMCs) with a lentiviral shRNA targeting shCCR2 completely abolished MCP-1-induced SMC migration and inhibited SMC proliferation in vitro (n = 3 per group). Morphometric analysis of sections of grafts showed a significant 38% reduction in vein graft thickening in the shCCR2-treated mice 4 weeks after surgery (control, 0.42 +/- 0.05 mm(2); shCCR2, 0.26 +/- 0.03 mm(2); P = .007).

CONCLUSION

Vascular CCR2 contributes to vein graft disease, and local application of shRNA against CCR2 to the vessel wall prevents vein graft thickening in hypercholesterolemic mice, suggesting that local overexpressing of shRNA using organ-targeted lentiviral gene delivery may be a promising therapeutic tool to improve vein graft disease in bypassed patients.

CLINICAL RELEVANCE

Vein graft disease is an important clinical issue that results from an inflammatory response. The monocyte chemoattractant protein (MCP)-1/CC-chemokine receptor (CCR)-2 pathway plays a key role in the initiation and development of vein graft disease. This study demonstrates that perivascular overexpression of short hairpin RNA, targeted against CCR2, inhibits vein graft thickening. These data show that organ-targeted gene therapy against CCR2 in the vessel wall could be a promising therapeutic tool to improve vein graft patency in bypassed patients.

Secretory products from human adipocytes stimulate proinflammatory cytokine secretion from human endothelial cells

Hyperplasia and hypertrophy of fat cells can be found in obesity and increased adiposity is associated with endothelial dysfunction as an early event of atherosclerosis. However, it is unclear whether human adipocytes directly influence endothelial protein secretion. To study the crosstalk between fat and endothelial cells, human umbilical venous endothelial cells (HUVECs) were cultured in infranatants (Adipo) of primary differentiated human adipocytes. Interestingly, significantly increased secretion of 23 cytokines and chemokines from HUVECs was detected in four independent experiments after Adipo stimulation by protein array analysis detecting a total of 174 different proteins. Among those, time-dependent Adipo-induced upregulation of cytokine secretion in HUVECs was confirmed by ELISA for interleukin (IL)-8, monokine induced by gamma interferon, macrophage inflammatory protein (MIP)-1beta, MIP-3alpha, monocyte chemoattractant protein-1, and IL-6. Factors besides adiponectin, leptin, resistin, and tumor necrosis factor alpha appear to mediate these stimulatory effects. Our findings suggest that endothelial cell secretion is significantly influenced towards a proinflammatory pattern by adipocyte-secreted factors.