Aim Acute injury and subsequent remodelling responses to ST-segment elevation myocardial infarction (STEMI) are major determinants of clinical outcome. Current imaging and plasma biomarkers provide delayed readouts of myocardial injury and recovery. Here, we sought to systematically characterize all microRNAs (miRs) released during the acute phase of STEMI and relate miR release to magnetic resonance imaging (MRI) findings to predict acute and late responses to STEMI, from a single early blood sample. Methods and results miRs were quantified in blood samples obtained from patients after primary PCI (PPCI) for STEMI. Cardiac MRI (cMRI) was performed to quantify myocardial edema, infarct size and salvage index. Regression models were constructed to predict these outcomes measures, which were then tested with a validation cohort. Transcoronary miR release was quantified from paired measurements of coronary artery and coronary sinus samples. A cell culture model was used to identify endothelial cell–derived miRs. A total of 72 patients undergoing PPCI for acute STEMI underwent miR analysis and cMRI. About >200 miRs were detectable in plasma after STEMI, from which 128 miRs were selected for quantification in all patients. Known myocardial miRs demonstrated a linear correlation with troponin release, and these increased across the transcoronary gradient. We identified novel miRs associated with microvascular injury and myocardial salvage. Regression models were constructed using a training cohort, then tested in a validation cohort, and predicted myocardial oedema, infarct size and salvage index. Conclusion Analysis of miR release after STEMI identifies biomarkers that predict both acute and late outcomes after STEMI. A novel miR-based biomarker score enables the estimation of area at risk, late infarct size and salvage index from a single blood sample 6 hours after PPCI, providing a simple and rapid alternative to serial cMRI characterization of STEMI outcome.

Background and aims: Imaging studies have relied on the ‘overall’ volumetric quantification of perivascular adipose tissue. We sought to assess the relationship of circumferential distribution between perivascular adipose tissue and adjacent wall thickness of carotid and aortic arteries using dedicated magnetic resonance imaging sequences. Methods: Vessel wall and perivascular adipose tissue were acquired using magnetic resonance imaging (1.5 T). Co-registered images were segmented separately, and measurements of both perivascular adipose tissue and vessel wall were obtained along radii of the vessel spaced at angles of 5° each. Results: In total, 29 patients were recruited. Perivascular adipose tissue thickness of the aorta was 3.34 ± 0.79 mm with specific pattern of ‘double peaks’ distribution, while carotid perivascular adipose tissue had no identifiable pattern with thickness of 0.8 ± 0.91 mm. Although statistically significant, the correlation between perivascular adipose tissue thickness and wall thickness in carotid arteries with normal (r = 0.040, p = 0.001) or with abnormal wall thickness (r = –0.039, p = 0.015) was merely nominal. Similarly, perivascular adipose tissue of the aorta had very weak correlation with normal aortic wall thickness (r = 0.010, p = 0.008) but not with the abnormal ones (r = −0.05, p = 0.29). Conclusion: Dissociation between the spatial distribution of perivascular adipose tissue and arterial wall thickening in the aorta and carotid arteries does not support that perivascular adipose tissue has a causal role in promoting atherosclerotic plaque via a paracrine route. Yet, perivascular adipose tissue functional properties were not examined in this study.

Early detection of vascular inflammation would allow deployment of targeted strategies for the prevention or treatment of multiple disease states. Because vascular inflammation is not detectable with commonly used imaging modalities, we hypothesized that phenotypic changes in perivascular adipose tissue (PVAT) induced by vascular inflammation could be quantified using a new computerized tomography (CT) angiography methodology. We show that inflamed human vessels release cytokines that prevent lipid accumulation in PVAT-derived preadipocytes in vitro, ex vivo, and in vivo. We developed a three-dimensional PVAT analysis method and studied CT images of human adipose tissue explants from 453 patients undergoing cardiac surgery, relating the ex vivo images with in vivo CT scan information on the biology of the explants. We developed an imaging metric, the CT fat attenuation index (FAI), that describes adipocyte lipid content and size. The FAI has excellent sensitivity and specificity for detecting tissue inflammation as assessed by tissue uptake of 18F-fluorodeoxyglucose in positron emission tomography. In a validation cohort of 273 subjects, the FAI gradient around human coronary arteries identified early subclinical coronary artery disease in vivo, as well as detected dynamic changes of PVAT in response to variations of vascular inflammation, and inflamed, vulnerable atherosclerotic plaques during acute coronary syndromes. Our study revealed that human vessels exert paracrine effects on the surrounding PVAT, affecting local intracellular lipid accumulation in preadipocytes, which can be monitored using a CT imaging approach. This methodology can be implemented in clinical practice to noninvasively detect plaque instability in the human coronary vasculature.

Background Following acute myocardial infarction (AMI), monocytes are rapidly mobilised from the spleen to peripheral blood, from where they undergo transcriptional activation and infiltrate injured tissue, with potential to contribute to both injury and repair. The mechanism by which the injured myocardium signals splenic-monocyte mobilisation remains poorly understood. Recent work shows extracellular vesicles (EV, which carry proteins, microRNA/mRNA) are a means of rapid cell-to-cell communication, which, combined with knowledge of their composition and propensity to be taken up by other cells, suggests a possible role in signalling. Here we show that AMI results in a net increase in circulating endothelial cell (EC)-EV that induce splenic monocyte motility in vivo and cellular transcription. Methods Platelet-poor plasma was collected from patients with ST-segment elevation-AMI (STEMI) and mice subjected to AMI. EV were isolated by ultra-centrifugation and analysed for size/number by Nanoparticle Tracking Analysis, western blot (EV-markers: ALIX, TSG101, CD69, CD9 and Hsp70), ELISA for EC markers (CD31, ICAM-1, P-selectin, E-selectin and VCAM-1), electron microscopy and for EV-miRNAs. Human and mouse EC were used in vitro to evaluate EV release, injected into wild-type or CD68GFP+ naïve mice to assess bio-distribution, splenic-monocyte mobilisation, uptake by monocytes, cellular mRNA transcription and cell motility. Results Acutely (24 hours) after AMI there is a significant increase in circulating EV in humans (p<0.01) and mice (p<0.001) that later subsides. Plasma EV number correlates with myocardial injury in humans (R2=0.52, p<0.01). Plasma EV display EC-surface markers and show enrichment for vascular cell adhesion moleculae-1 (VCAM-1) in AMI (p<0.05). In vitro pro-inflammatory cytokines significantly increase EV production by EC, whereas ‘anti-inflammatory’ IL-4 and IL-6 had no effect. Inflammatory-EC-EV displayed significant enrichment of VCAM-1 (p<0.05). In-vitro labelled EC-EV accumulate in monocytes. Inflammatory-EC-EV significantly enhanced macrophage chemokineses (p<0.05) and chemotaxis to MCP-1 (p<0.05), a response that was abolished by pre-incubating EC-EV with an anti-VCAM-1 antibody (p<0.05). Injected labelled EC-EV accumulate in the spleen, interact with splenic monocytes and induce splenic-monocyte mobilisation and peripheral monocytosis in-vivo (p<0.01). Human plasma-EV show enrichment for 12 miRNAs in AMI, including EC-associated miR-126–3p/5p. miRNA-mRNA target gene prediction and functional enrichment analysis show roles for these miRNAs in the positive regulation of chemotaxis, cellular growth and proliferation. EC-EV significantly induced alterations in mRNA of motility genes by reducing PLEXIN-B2 (p<0.001), a negative regulator of motility and increasing ITGB2 (p<0.001) expression in monocytes. In conclusion (1) AMI surges plasma EV; (2) Plasma-EV protein composition is consistent with EC origin. (3) Injected EV localise to the spleen and (4) mobilise splenic monocytes. (5) In culture, EC increase EV release, enhance monocyte motility and (6) regulate genes that are important in cellular movement. These demonstrate a novel role for EC-derived EV in monocyte activation after AMI.

Transcriptionally activated monocytes are recruited to the heart after acute myocardial infarction (AMI). After AMI in mice and humans, the number of extracellular vesicles (EVs) increased acutely. In humans, EV number correlated closely with the extent of myocardial injury. We hypothesized that EVs mediate splenic monocyte mobilization and program transcription following AMI. Some plasma EVs bear endothelial cell (EC) integrins, and both proinflammatory stimulation of ECs and AMI significantly increased VCAM-1-positive EV release. Injected EC-EVs localized to the spleen and interacted with, and mobilized, splenic monocytes in otherwise naive, healthy animals. Analysis of human plasma EV-associated miRNA showed 12 markedly enriched miRNAs after AMI; functional enrichment analyses identified 1,869 putative mRNA targets, which regulate relevant cellular functions (e.g., proliferation and cell movement). Furthermore, gene ontology termed positive chemotaxis as the most enriched pathway for the miRNA-mRNA targets. Among the identified EV miRNAs, EC-associated miRNA-126-3p and -5p were highly regulated after AMI. miRNA-126-3p and -5p regulate cell adhesion- and chemotaxis-associated genes, including the negative regulator of cell motility, plexin-B2. EC-EV exposure significantly downregulated plexin-B2 mRNA in monocytes and upregulated motility integrin ITGB2. These findings identify EVs as a possible novel signaling pathway by linking ischemic myocardium with monocyte mobilization and transcriptional activation following AMI.

Background: Non-invasive detection of vascular inflammation remains an unmet goal. We hypothesized that phenotypic changes in perivascular adipose tissue (PVAT) induced by vascular inflammation can be quantified using a new computed tomography angiography (CTA) methodology. Methods: In Arm 1, human PVAT adipocytes were cultured +/- inflammatory cytokines (n=7) or co-cultured with vascular tissue (+/-Angiotensin-II, n=6) to assess the effects of vascular inflammation on PVAT differentiation. In Arm 2, AT explants (epicardial, subcutaneous and thoracic AT) from 453 cardiac surgery patients were used in histology and gene expression studies to relate the ex vivo images with in vivo CT scan information (n=105) on the biology of the explants. In Arm 3, in 267 patients undergoing diagnostic CTA, PVAT attenuation (Fat Attenuation Index (FAI) defined as the average CT attenuation of AT), was analysed around the proximal right coronary artery. In Arm 4, PVAT FAI around unstable (culprit) and stable coronary plaques was calculated in 22 CAD patients undergoing CTA. Results: In Arm 1, Angiotensin-II (A) and proinflammatory cytokines (B) prevented lipid accumulation and adipocyte differentiation in cultured PVAT. In Arm 2, adipocyte size by histology was inversely correlated with FAI in vivo (C). Both FAI of AT explants (not shown) and FAI in-vivo (n=105) were negatively associated with epicardial AT differentiation as assessed by FABP4 expression (D). In Arm 3, PVAT FAI change over distance from RCA wall was significantly different in CAD compared to no CAD patients (E). In Arm 4, PVAT FAI was significantly increased around unstable plaques (F). Conclusions: Human vessels exert paracrine effects on surrounding PVAT, affecting local intracellular lipid accumulation in preadipocytes, which can then be monitored using a CT imaging approach. This novel methodology can be implemented in clinical practice to detect unstable plaques in the human coronary vasculature.

Background In acute myocardial infarction (MI), monocytes are rapidly mobilised from the spleen to peripheral blood, from where they infiltrate injured tissue, with potential to contribute to both injury and repair. The mechanism by which the injured myocardium signals splenic-monocyte mobilisation remains poorly understood. Recent work shows extracellular vesicles (EV, which carry proteins, microRNA/mRNA) are a means of rapid cell-to-cell communication, which, combined with knowledge of their composition and propensity to be taken up by other cells, suggests a possible role in signalling. Here we show that acute MI results in a net increase in circulating endothelial cell (EC)-EV that induce splenic monocyte motility in vivo. Methods MI was induced in mice. EV were isolated by ultra-centrifugation and analysed for size/number by Nanoparticle Tracking Analysis, western blot (EV-markers: Alix, TSG101, CD69, CD9 and Hsp70) and ELISA for EC markers (CD31, ICAM-1, P-selectin, E-selectin and VCAM-1). Primary cardiac mouse-EC (CM-EC) were used to produce EV in-vitro and were labelled fluorescently (PKH67) and transfected with cell-miR39-3p (C.elegans). EV were either tail vein injected into wild-type or CD68GFP+ naïve mice and/or exposed to macrophages (RAW 264.7) in-vitro. Results Acutely (24 hours) after MI there was a significant increase in circulating EV in mice (7.6 ± 1.7x108/ml vs 3.6 ± 1.5 x 108/ml, control,P < 0.01) that later subsided (4.6 ± 1.8 x 108/ml 4th day post-MI). Plasma EV displayed EC-surface markers, suggesting EC origin. Pro-inflammatory TNF-α (3.0 ± 0.1 x 109/ml vs 1.5 ± 0.1x108/ml control, P < 0.01) significantly increased EV production in CM-ECs in-vitro, whereas ‘anti-inflammatory’ IL-4 (1.3 ± 0.01 x 109/ml) and IL-6 (1.5 ± 0.1 x 109/ml) had no effect. Inflammatory-EC-EV displayed significant enrichment of VCAM-1 (P < 0.05). In-vitro there is a time-dependent accumulation of labelled EV in macrophages. Inflammatory-EC-EV significantly enhanced macrophage chemotaxis to MCP-1 in-vitro (2.2 ± 0.2 AU EV treated vs 1.7 ± 0.2AU untreated, P < 0.01), a response that was abolished by pre-incubating EC-EV with an anti-VCAM-1 antibody (1.8 ± 0.2AU, P < 0.05). Inflammatory EV significantly induced alterations in mRNA of motility genes by reducing PLEXIN-B2 (P < 0.001) and increasing ITGB2 (P < 0.001) expression in macrophages. Injected labelled EC-EV accumulate in the splenic red-pulp and injected inflammatory-EC-EV induced significant splenic monocyte mobilisation and peripheral monocytosis in-vivo in CD68GFP+ naïve mice (P < 0.05). In conclusion (1) In vivo EV are released acutely after MI; (2) Plasma-EV protein composition is consistent with endothelial cell origin. (3) Injected EV localise to the spleen and(4) mobilise splenic monocytes. (5) In culture, EV increase cell motility and (6) regulate genes that are important in motility. These findings are all suggestive of a role for EC-derived EV in monocyte activation after acute MI.

Oxidative stress plays a critical role in the vascular complications of type 2 diabetes. We examined the effect of type 2 diabetes on NADPH oxidase in human vessels and explored the mechanisms of this interaction. Segments of internal mammary arteries (IMAs) with their perivascular adipose tissue (PVAT) and thoracic adipose tissue were obtained from 386 patients undergoing coronary bypass surgery (127 with type 2 diabetes). Type 2 diabetes was strongly correlated with hypoadiponectinemia and increased vascular NADPH oxidase–derived superoxide anions (O2˙−). The genetic variability of the ADIPOQ gene and circulating adiponectin (but not interleukin-6) were independent predictors of NADPH oxidase–derived O2˙−. However, adiponectin expression in PVAT was positively correlated with vascular NADPH oxidase–derived O2˙−. Recombinant adiponectin directly inhibited NADPH oxidase in human arteries ex vivo by preventing the activation/membrane translocation of Rac1 and downregulating p22phox through a phosphoinositide 3-kinase/Akt-mediated mechanism. In ex vivo coincubation models of IMA/PVAT, the activation of arterial NADPH oxidase triggered a peroxisome proliferator–activated receptor-γ–mediated upregulation of the adiponectin gene in the neighboring PVAT via the release of vascular oxidation products. We demonstrate for the first time in humans that reduced adiponectin levels in individuals with type 2 diabetes stimulates vascular NADPH oxidase, while PVAT “senses” the increased NADPH oxidase activity in the underlying vessel and responds by upregulating adiponectin gene expression. This PVAT-vessel interaction is identified as a novel therapeutic target for the prevention of vascular complications of type 2 diabetes.

AIMS:Monocytes play critical roles in tissue injury and repair following acute myocardial infarction (AMI). Specifically targeting inflammatory monocytes in experimental models leads to reduced infarct size and improved healing. However, data from humans are sparse, and it remains unclear whether monocytes play an equally important role in humans. The aim of this study was to investigate whether the monocyte response following AMI is conserved between humans and mice and interrogate patterns of gene expression to identify regulated functions.METHODS AND RESULTS:Thirty patients (AMI) and 24 control patients (stable coronary atherosclerosis) were enrolled. Female C57BL/6J mice (n = 6/group) underwent AMI by surgical coronary ligation. Myocardial injury was quantified by magnetic resonance imaging (human) and echocardiography (mice). Peripheral monocytes were isolated at presentation and at 48 h. RNA from separated monocytes was hybridized to Illumina beadchips. Acute myocardial infarction resulted in a significant peripheral monocytosis in both species that positively correlated with the extent of myocardial injury. Analysis of the monocyte transcriptome following AMI demonstrated significant conservation and identified inflammation and mitosis as central processes to this response. These findings were validated in both species.CONCLUSIONS:Our findings show that the monocyte transcriptome is conserved between mice and humans following AMI. Patterns of gene expression associated with inflammation and proliferation appear to be switched on prior to their infiltration of injured myocardium suggesting that the specific targeting of inflammatory and proliferative processes in these immune cells in humans are possible therapeutic strategies. Importantly, they could be effective in the hours after AMI.

Preterm-born individuals have elevated blood pressure. We tested the hypothesis that this associates with an enhanced antiangiogenic circulating profile and that this association is mediated by variations in capillary density. We studied 204 adults aged 25 years (range, 20–30 years), of which 102 had been followed up prospectively since very preterm birth (mean gestational age, 30.3±2.5 weeks) and 102 were born term to uncomplicated pregnancies. A panel of circulating biomarkers, including soluble endoglin and soluble fms-like tyrosine kinase-1, were compared between groups and related to perinatal history and adult cardiovascular risk. Associations with cardiovascular phenotype were studied in 90 individuals who had undergone detailed assessment of microvascular, macrovascular, and cardiac structure and function. Preterm-born individuals had elevations in soluble endoglin (5.64±1.03 versus 4.06±0.85 ng/mL; P <0.001) and soluble fms-like tyrosine kinase-1 (88.1±19.0 versus 73.0±15.3 pg/mL; P <0.001) compared with term-born individuals, proportional to elevations in resting and ambulatory blood pressure, as well as degree of prematurity ( P <0.05). Maternal hypertensive pregnancy disorder was associated with additional increases in soluble fms-like tyrosine kinase-1 ( P =0.002). Other circulating biomarkers, including those of inflammation and endothelial activation, were not related to blood pressure. There was a specific graded association between soluble endoglin and degree of functional and structural capillary rarefaction ( P =0.002 and P <0.001), and in multivariable analysis, there were capillary density–mediated associations between soluble endoglin and blood pressure. Preterm-born individuals exhibit an enhanced antiangiogenic state in adult life that is specifically related to elevations in blood pressure. The association seems to be mediated through capillary rarefaction and is independent of other cardiovascular structural and functional differences in the offspring.

OBJECTIVE:To explore the role of systemic inflammation in the regulation of adiponectin levels in patients with ischemic heart disease.APPROACH AND RESULTS:In a cross-sectional study of 575 subjects, serum adiponectin was compared between healthy subjects, patients with coronary artery disease with no/mild/severe heart failure (HF), and patients with nonischemic HF. Adiponectin expression and release from femoral, subcutaneous and thoracic adipose tissue was determined in 258 additional patients with coronary artery bypass grafting. Responsiveness of the various human adipose tissue depots to interleukin-6, tumor necrosis factor-α, and brain natriuretic peptide (BNP) was examined by using ex vivo models of human fat. The effects of inducible low-grade inflammation were tested by using the model of Salmonella typhi vaccine-induced inflammation in healthy individuals. In the cross-sectional study, HF strikingly increased adiponectin levels. Plasma BNP was the strongest predictor of circulating adiponectin and its release from all adipose tissue depots in patients with coronary artery bypass grafting, even in the absence of HF. Femoral AT was the depot with the least macrophages infiltration and the largest adipocyte cell size and the only responsive to systemic and ex vivo proinflammatory stimulation (effect reversible by BNP). Low-grade inflammation reduced circulating adiponectin levels, while circulating BNP remained unchanged.CONCLUSIONS:This study demonstrates the regional variability in the responsiveness of human adipose tissue to systemic inflammation and suggests that BNP (not systemic inflammation) is the main driver of circulating adiponectin in patients with advanced atherosclerosis even in the absence of HF. Any interpretation of circulating adiponectin as a biomarker should take into account the underlying disease state, background inflammation, and BNP levels.

Introduction: Pro-inflammatory cytokines suppress adiponectin (AdN) expression in cultured adipocytes. However, it is unclear how systemic inflammation affects AdN biosynthesis in human adipose tissue (AT). Hypothesis: We hypothesised that inflammation differentially affects AdN biosynthesis in distinct AT depots of patients with ischaemic heart disease (IHD). Methods: Samples of femoral (FemAT), subcutaneous (ScAT) and thoracic (ThAT) AT collected from 258 patients undergoing coronary-artery bypass grafting (CABG), were used for gene expression and immunohistochemistry studies to determine macrophages infiltration (CD68+ cells) and M1/M2 polarization. AT from 13 additional CABG patients was incubated ex-vivo ± IL-6 (25ng/mL) and TNF-a (4ng/mL) for 24h and changes in gene expression profile and AdN release were determined. Results: Higher circulating IL-6 was related with lower AdN (A) and PPAR-γ (not shown) gene expression in FemAT but not in ScAT or ThAT. Incubation of AT with IL-6+TNFa, also reduced Ad...

Introduction: Obesity has been paradoxically associated with a better outcome of CAD patients, while anthropometic measures of obesity provide limited information on adipose tissue (AT) biology. We hypothesised that quantification of femoral AT (FemAT) deposition using U/S can provide mechanistic insights into the obesity paradox. Methods: FemAT biopsies from 185 pts undergoing coronary bypass surgery (CABG) were cultured ex vivo for secretome and gene expression studies. FemAT thickness was measured by U/S at both the anterior and exterior surface of the thigh, at the mid point of the distance between the iliac crest and the knee, and the average of both thighs was calculated. Malondialdehyde (MDA), a marker of oxidative stress, was measured in plasma and FemAT culture supernatants. Brachial artery (BA) flow mediated dilatation (FMD) and distensibility were assessed by U/S. Results: FemAT thickness was only weakly correlated with BMI (r=0.235, p<0.001) and waist-to-hip ratio (WHR, r=-0.179, p<0.05), suggesting that it provides different information to classic anthropometrics in obesity. Patients with increased FemAT thickness had lower plasma MDA (A), better FMD (B) and greater BA distensibility (C), despite of being more obese. On the contrary BMI did not predict systemic oxidative stress or vascular function, while WHR was weakly correlated only with FMD (rho=-0.156, p<0.05). Increased FemAT thickness was associated with lower MDA release from FemAT culture supernatants (D), and lower IL6-receptor (E) / CD68 (F) expression in FemAT samples, suggesting lower endogenous oxidative stress, and less macrophages’ infiltration. Conclusions: Femoral fat accumulation is associated with lower local AT inflammation and favourable systemic effects on vascular function in CAD. Combining imaging with AT biology could help to better understand the role of obesity-related vascular disease and provide an explanation to the “obesity paradox”.

Michael Demosthenous, Constantinos Bakogiannis, Dimitris Tousoulis, Christodoulos Stefanadis, Coutinho, Cheerag Shirodaria, Rana Sayeed, Mario Petrou, Ravi De Silva, Shapour Jalilzadeh, Marios Margaritis, Alexios S. Antonopoulos, Janet Digby, Regent Lee, Svetlana Reilly, Patricia Adiponectin in the Regulation of eNOS Function in Human Vessels Interactions between Vascular Wall and Perivascular Adipose Tissue Reveal Novel Roles for Print ISSN: 0009-7322. Online ISSN: 1524-4539 Copyright © 2013 American Heart Association, Inc. All rights reserved. is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Circulation published online April 26, 2013; Circulation. http://circ.ahajournals.org/content/early/2013/04/26/CIRCULATIONAHA.112.001133 World Wide Web at: The online version of this article, along with updated information and services, is located on the http://circ.ahajournals.org/content/suppl/2013/04/26/CIRCULATIONAHA.112.001133.DC1.html Data Supplement (unedited) at:

Acute myocardial infarction (AMI) results in the recruitment of leukocytes to injured myocardium. Additionally, myocardium remote to the infarct zone also becomes inflamed and is associated with adverse left ventricular remodelling. Renal ischaemic syndromes have been associated with remote organ inflammation and impaired function. Here, we tested the hypothesis that AMI results in remote organ (renal) inflammation.Mice were subjected to either AMI, sham procedure or no procedure and the inflammatory response in peripheral blood, injured and remote myocardium, and kidneys was studied at 24 h.AMI resulted in increased circulating neutrophils (P < 0.001) and monocytes (P < 0.001). mRNA for inflammatory mediators significantly increased in infarcted myocardium and in remote myocardium. VCAM-1 mRNA was increased in both infarcted and remote myocardium. VCAM-1 protein was also increased in the kidneys of AMI mice (P < 0.05) and immunofluorescence revealed localisation of VCAM-1 to glomeruli, associated with leukocyte infiltration and increased local inflammatory mRNA expression.We conclude that in addition to local inflammation, AMI results in remote organ inflammation evidenced by (1) increased expression of mRNA for inflammatory cytokines, (2) marked upregulation of VCAM-1 in renal glomeruli, and (3) the recruitment and infiltration of leukocytes in the kidney.

Background: Regulation of adiponectin (AdN) biosynthesis in human adipose tissue (AT) is poorly understood. Pro-inflammatory cytokines suppress AdN expression in cell models, while brain natriureti...

Background— Adiponectin is an adipokine with potentially important roles in human cardiovascular disease states. We studied the role of adiponectin in the cross-talk between adipose tissue and vascular redox state in patients with atherosclerosis. Methods and Results— The study included 677 patients undergoing coronary artery bypass graft surgery. Endothelial function was evaluated by flow-mediated dilation of the brachial artery in vivo and by vasomotor studies in saphenous vein segments ex vivo. Vascular superoxide (O2−) and endothelial nitric oxide synthase (eNOS) uncoupling were quantified in saphenous vein and internal mammary artery segments. Local adiponectin gene expression and ex vivo release were quantified in perivascular (saphenous vein and internal mammary artery) subcutaneous and mesothoracic adipose tissue from 248 patients. Circulating adiponectin was independently associated with nitric oxide bioavailability and O2− production/eNOS uncoupling in both arteries and veins. These findings were supported by a similar association between functional polymorphisms in the adiponectin gene and vascular redox state. In contrast, local adiponectin gene expression/release in perivascular adipose tissue was positively correlated with O2− and eNOS uncoupling in the underlying vessels. In ex vivo experiments with human saphenous veins and internal mammary arteries, adiponectin induced Akt-mediated eNOS phosphorylation and increased tetrahydrobiopterin bioavailability, improving eNOS coupling. In ex vivo experiments with human saphenous veins/internal mammary arteries and adipose tissue, we demonstrated that peroxidation products produced in the vascular wall (ie, 4-hydroxynonenal) upregulate adiponectin gene expression in perivascular adipose tissue via a peroxisome proliferator-activated receptor-&ggr;–dependent mechanism. Conclusions— We demonstrate for the first time that adiponectin improves the redox state in human vessels by restoring eNOS coupling, and we identify a novel role of vascular oxidative stress in the regulation of adiponectin expression in human perivascular adipose tissue.

Marios Margaritis MD 1* , Alexios S. Antonopoulos MD 1* , Janet Digby PhD 1 , Regent Lee MBBS MS 1 , Svetlana Reilly MD DPhil 1 , Patricia Coutinho PhD 1 , Cheerag Shirodaria MD MBA 1 , Rana Sayeed FRCS PhD 2 , Mario Petrou PhD 2 , Ravi De Silva PhD 2 , Shapour Jalilzadeh PhD 1 , Michael Demosthenous MD 3 , Costas Bakogiannis MD 3 , Dimitris Tousoulis MD 3 , Christodoulos Stefanadis MD 3 , Robin P Choudhury FRCP DM 1 , Barbara Casadei FRCP DPhil 1 , Keith M Channon FRCP MD 1 , Charalambos Antoniades MD PhD 1

Nicotinic acid (NA) regresses atherosclerosis in human imaging studies and reduces atherosclerosis in mice, mediated by myeloid cells, independent of lipoproteins. Since GPR109A is expressed by human monocytes, we hypothesized that NA may drive cholesterol efflux from foam cells. In THP-1 cells NA suppressed LPS-induced mRNA transcription of MCP-1 by 76.6±12.2% (P<0.01) and TNFα by 56.1±11.5% (P<0.01), yet restored LPS-induced suppression of PPARγ transcription by 536.5±46.4% (P<0.001) and its downstream effector CD36 by 116.8±19.8% (P<0.01). Whilst direct PPARγ-agonism promoted cholesterol efflux from THP-1 derived foam cells by 37.7±3.1% (P<0.01) and stimulated transcription of LXRα by 87.9±9.5% (P<0.001) and ABCG1 by 101.2±15.5% (P<0.01), NA showed no effect in foam cells on either cholesterol efflux or key RCT genes transcription. Upon foam cell induction, NA lost its effect on PPARγ and cAMP pathways, since its receptor, GPR109A, was down-regulated by foam cell transformation. This observation was confirmed in explanted human carotid plaques. In conclusion, despite NA's anti-inflammatory effect on human macrophages, it has no effect on foam cells in reverse cholesterol transport; due to GPR109A down-regulation.