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Cyclo-oxygenase (COX) inhibitors are among the most commonly used drugs in the western world for their anti-inflammatory and analgesic effects. However, they are also well-known to increase the risk of coronary events. This area is of renewed significance given alarming new evidence suggesting this effect can occur even with acute usage. This contrasts with the well-established usage of aspirin as a mainstay for cardiovascular prophylaxis, as well as overwhelming evidence that COX inhibition induces vasodilation and is protective for vascular function. Here, we present an updated review of the preclinical and clinical literature regarding the cardiotoxicity of COX inhibitors. While studies to date have focussed on the role of COX in influencing renal and vascular function, we suggest an interaction between prostanoids and T cells may be a novel factor, mediating elevated cardiovascular disease risk with NSAID use. [ABSTRACT FROM AUTHOR]

It is now becomingly increasingly evident that the functions of the mammalian Y chromosome are not circumscribed to the induction of male sex. While animal studies have shown variations in the Y are strongly accountable for blood pressure (BP), this is yet to be confirmed in humans. We have recently shown modulation of adaptive immunity to be a significant mechanism underpinning Y-chromosome-dependent differences in BP in consomic strains. This is paralleled by studies in man showing Y chromosome haplogroup is a significant predictor for coronary artery disease through influencing pathways of immunity. Furthermore, recent studies in mice and humans have shown that Y chromosome lineage determines susceptibility to autoimmune disease. Here we review the evidence in animals and humans that Y chromosome lineage influences hypertension and cardiovascular disease risk, with a novel focus on pathways of immunity as a significant pathway involved. [ABSTRACT FROM AUTHOR]

The acute phase protein serum amyloid A (SAA) is associated with endothelial dysfunction and early-stage atherogenesis. Stimulation of vascular cells with SAA increases gene expression of pro-inflammation cytokines and tissue factor (TF). Activation of the transcription factor, nuclear factor kappa-B (NFκB), may be central to SAA-mediated endothelial cell inflammation, dysfunction and pro-thrombotic responses, while targeting NFκB with a pharmacologic inhibitor, BAY11-7082, may mitigate SAA activity. Human carotid artery endothelial cells (HCtAEC) were pre-incubated (1.5 h) with 10 μM BAY11-7082 or vehicle (control) followed by SAA (10 μg/mL; 4.5 h). Under these conditions gene expression for TF and Tumor Necrosis Factor (TNF) increased in SAA-treated HCtAEC and pre-treatment with BAY11-7082 significantly (TNF) and marginally (TF) reduced mRNA expression. Intracellular TNF and interleukin 6 (IL-6) protein also increased in HCtAEC supplemented with SAA and this expression was inhibited by BAY11-7082. Supplemented BAY11-7082 also significantly decreased SAA-mediated leukocyte adhesion to apolipoprotein E-deficient mouse aorta in exvivo vascular flow studies. In vascular function studies, isolated aortic rings pre-treated with BAY11-7082 prior to incubation with SAA showed improved endothelium-dependent vasorelaxation and increased vascular cyclic guanosine monophosphate (cGMP) content. Together these data suggest that inhibition of NFκB activation may protect endothelial function by inhibiting the pro-inflammatory and pro-thrombotic activities of SAA. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article on maternal adiposity and newborn vascular health.

Comments on how coronary heart disease accounts for more than a quarter of all deaths in the United Kingdom. Costs associated with the disease and care of its patients; Recommendations for the use of lipid-lowering drugs; Statistics; Ambivalence doctors have towards treating elderly patients with lipid-lowering drugs.

The Y chromosome accounts for 15-20mmHg difference in arterial pressure; the gene(s) and mechanism(s) underlying this effect remain unknown. One candidate gene, the Sry3 gene, expressed exclusively on the hypertensive SHR Y chromosome has been shown in vitro to interact with the renin angiotensin system (RAS). Using a reciprocal Y consomic rat approach, we investigated the functional consequences of this interaction in vivo; examining the interaction of the Y chromosome with the renal vasculature. 16 week old normotensive rats (WKY), hypertensive rats (SHRSP) and two reciprocal Y consomic rat strains; one comprising the WKY autosomes and X chromosome with the hypertensive Y chromosome (WKY.SPGlaY) and vice versa (SP.WKYGlaY) were examined. We confirmed via radiotelemetry that systolic blood pressure (SBP) was Y chromosome dependent; SP.WKYGlaY had lower SBP than SHRSP (195±5mmHg vs 227±8mmHg, P<0.03) and was higher in WKY.SPGlaY compared to WKY (157±3mmHg vs 148±3mmHg, P<0.05). Compared to WKY rats, the vasodilator arm of the RAS was enhanced in SHRSP as evidenced by a higher plasma Ang(1-7):Ang II ratio (WKY:0.13±0.01 vs SHRSP:1.33±0.4, P<0.005) and a blunted renal blood flow (RBF) response to graded intrarenal Ang I and Ang(1-7) infusions. In response to 10ng/kg we observed a reduction in RBF of WKY:58±6% and 16±6% vs SHRSP: 17±6%, P<0.01 and 1±4%, P<0.05 respectively. Introgression of the normotensive Y chromosome into the SHRSP background (SP.WKYGlaY) resulted in a reduction in plasma Ang(1-7):AngII ratio (SP.WKYGlaY: 0.24±0.02, P<0.01) and an increased vasoconstrictor response to intrarenal Ang I and Ang(1-7) infusion. In response to 10ng/kg bolus RBF in SP.WKYGlaY reduced by 45±14%, P<0.01 and 41±18%, P<0.005, respectively compared to SHRSP, demonstrating the blunted responsiveness in the SHRSP is Y chromosome dependent. Investigation of the interlobular arteries via wire myography revealed increased sensitivity to Ang II in SHRSP compared to WKY which was reduced following introgression of the WKY Y chromosome (SP.WKYGlaY) confirming that the Y chromosome influences the RAS in the renal vasculature. This study provides novel evidence that the Y chromosome influences the vasodilatory arm of the RAS and intrarenal vascular function. [ABSTRACT FROM AUTHOR]

Vascular inflammation, involving the recruitment, adhesion and infiltration of monocytes to the sub-endothelial space, is a critical early event in the development of atherosclerosis. The renin angiotensin system plays an important role in inflammation via activation of the angiotensin type I receptor (AT1R), which induces pro-inflammatory effects. The angiotensin II type 2 receptor (AT2R) counter-regulates the effects of the AT1R, including AT1R-mediated pro-inflammatory cytokine expression. We investigated the anti-inflammatory effects of AT2R stimulation in vascular inflammation by examining leukocyte to endothelial adhesion. We quantified the effect of AT2R stimulation (Compound 21: C21, 100μM) on TNFα (10ng/mL)-induced monocyte adhesion to cultured human umbilical vascular endothelial cells in vitro. AT2R stimulation attenuated TNFα-induced monocyte adhesion (unstimulated: 8±4% of TNFα: 100%, C21+TNFα: 59±12% of TNFα-induced adhesion). Adhesion of monocytes to the endothelial monolayer following incubation with TNFα+C21+AT2R antagonism (PD 123319, 10μM) was not different to TNFα-induced monocyte adhesion (93±5% of TNFα); demonstrating that the anti-inflammatory effects of C21 are mediated by the AT2R. Furthermore, C21 treatment attenuated TNFα-induced upregulation of adhesion molecules ICAM-1 and E-selectin and abolished TNFα-induced ROS production (unstimulated: 2±2, TNFα: 55±16, TNFα+C21: -3±5 dihydroethidium fluorescence intensity units). We quantified TNFα-induced leukocyte adhesion in intact mouse thoracic aorta ex vivo in real time in the presence and absence of AT2R activation. Consistent with our in vitro findings, we observed that direct AT2R activation (C21, 10μM) abolished TNFα-induced leukocyte adhesion (TNFα: 30±4, vs TNFα+C21: 11±4 adhered leukocytes/field of view (FOV), P<0.01) an effect which was abolished by co-incubation with PD 123319 (10μM: 31±5 adhered leukocytes/FOV). This study provides the first functional evidence that direct AT2R stimulation prevents TNFα-induced leukocyte adhesion, ICAM-1 and E-selectin expression and ROS production revealing the anti-inflammatory and therapeutic potential of the AT2R in the treatment of inflammation-induced cardiovascular disease. [ABSTRACT FROM AUTHOR]

Background and Purpose: Monocyte-derived macrophages are critical in the development of atherosclerosis and can adopt a wide range of functional phenotypes depending on their surrounding milieu. High-density lipoproteins (HDLs) have many cardio-protective properties including potent anti-inflammatory effects. We investigated the effects of HDL on human macrophage phenotype and the mechanisms by which these occur.Experimental Approach: Human blood monocytes were differentiated into macrophages in the presence or absence of HDL and were then induced to either an inflammatory macrophage (M1) or anti-inflammatory macrophage (M2) phenotype using LPS and IFN-γ or IL-4, respectively.Key Results: HDL inhibited the induction of macrophages to an M1-phenotype, as evidenced by a decrease in the expression of M1-specific cell surface markers CD192 and CD64, as well as M1-associated inflammatory genes TNF-α, IL-6 and MCP-1 (CCL2). HDL also inhibited M1 function by reducing the production of ROS. In contrast, HDL had no effect on macrophage induction to the M2-phenotype. Similarly, methyl-β-cyclodextrin, a non-specific cholesterol acceptor also suppressed the induction of M1 suggesting that cholesterol efflux is important in this process. Furthermore, HDL decreased membrane caveolin-1 in M1 macrophages. We confirmed that caveolin-1 is required for HDL to inhibit M1 induction as bone marrow-derived macrophages from caveolin-1 knockout mice continued to polarize into M1-phenotype despite the presence of HDL. Moreover, HDL decreased ERK1/2 and STAT3 phosphorylation in M1 macrophages.Conclusions and Implications: We concluded that HDL reduces the induction of macrophages to the inflammatory M1-phenotype via redistribution of caveolin-1, preventing the activation of ERK1/2 and STAT3. [ABSTRACT FROM AUTHOR]

Background and Purpose: Angiotensin AT2 receptors are upregulated in disease states such as atherosclerosis and blockade of the AT2 receptors exacerbates plaque formation. Direct stimulation of these receptors is anti-atherogenic but the mechanisms and pathways involved remain unknown. We examined the effect of direct AT2 receptor stimulation with Compound 21 (C21) on the leukocyte adhesion cascade in vitro, right through to plaque formation in vivo.Experimental Approach: Effects of C21 on TNFα-induced inflammation were assessed in human umbilical vein endothelial cells (HUVECs), activation of monocytes, polarisation of monocyte-derived macrophages and in intact mouse aortae.Key Results: C21 attenuated TNFα-induced: monocyte adhesion to cultured HUVECs, adhesion molecule expression and abolished TNFα-induced ROS production. TNFα-induced NFκB translocation from the cytoplasm to the nucleus, essential for cytokine production, was prevented by C21. C21 did not influence monocyte activation or macrophage polarisation but did reduce TNFα and IL-6 mRNA expression in M1 macrophages. The anti-inflammatory effects of C21 were abolished by an AT2 receptor antagonist confirming that the effects of C21 were AT2 receptor-mediated. Also, leukocyte adhesion and cytokine gene expression, induced by high-fat diet (HFD), was attenuated in ApoE(-/-) mice treated with C21. Plaque size and stability were improved with C21 treatment with increased smooth muscle cell composition and decreased lipid size, compared with HFD-saline treated mice.Conclusion and Implications: C21 prevented TNFα-induced and HFD-induced vascular inflammation in vitro and in vivo. Our data provide strong evidence that the anti-atherosclerotic actions of C21 were due to vascular anti-inflammatory effects, mediated by AT2 receptors. [ABSTRACT FROM AUTHOR]

1. The endothelium is critical in the control of vascular haemodynamics and haemostasis. Endothelial dysfunction, typically characterized by decreased nitric oxide bioavailability and response to endothelium-dependent agonists, is well accepted as a defining characteristic of early atherosclerosis. 2. Numerous epidemiological studies have reported that increased levels of circulating HDL are vasculoprotective and reduce the incidence of adverse cardiovascular events. Traditionally, these effects have been attributed to the ability of HDL to remove cholesterol from cells via reverse cholesterol transport. However, there is increasing evidence that the beneficial effects on the endothelium by HDL encompass its anti-inflammatory, antithrombotic and anti-oxidative properties, which include the release of nitric oxide (NO). 3. This review highlights recent findings on the importance of HDL in reducing atherosclerotic risk. We focus on the beneficial effects of HDL-induced NO release and how this relates to endothelial dysfunction and on the effect of HDL on vascular repair via endothelial progenitor cells. [ABSTRACT FROM AUTHOR]

Background and Aim: Patients with liver cirrhosis exhibit peripheral vasodilatation and decreased vasoconstrictor responsiveness. We investigated the role of the endothelium in these patients. Methods: Nine patients with cirrhosis and seven controls were recruited. Responses to acetylcholine, bradykinin and sodium nitroprusside were obtained using forearm plethysmography. Responses to norepinephrine (100 ng/min) were obtained in the absence and combined presence of the cyclo-oxygenase inhibitor, indomethacin, and the nitric oxide (NO) synthase inhibitor, NG-monomethyl-L-arginine. Results: Responses to acetylcholine (area under curve: controls vs cirrhotic, 10326 ± 1400 vs 18490 ± 2787 units; P = 0.036), but not to bradykinin (15619 ± 3557 vs 12415 ± 3823 units) or sodium nitroprusside, were significantly higher in patients with cirrhosis. Responses to norepinephrine were significantly dampened in cirrhotics (percentage increase in forearm blood flow; controls vs cirrhotics, −50.50 ± 2.69 vs−26.39 ± 5.44; P = 0.036) but this blunted response was no longer apparent following the administration of both blockers. Conclusions: We conclude that: (i) there is an increased response to acetylcholine but not to bradykinin; and (ii) that an enhanced production of prostacyclin and/or NO is responsible for the dampened response to norepinephrine. [ABSTRACT FROM AUTHOR]

The aetiology and progression of hypertension involves various endogenous systems, such as the renin angiotensin system, the sympathetic nervous system, and endothelial dysfunction. Recent data suggest that vascular inflammation may also play a key role in the pathogenesis of hypertension. This study sought to determine whether high intraluminal pressure results in vascular inflammation. Leukocyte adhesion was assessed in rat carotid arteries exposed to 1 h of high intraluminal pressure. The effect of intraluminal pressure on signaling mechanisms including reactive oxygen species production (ROS), arginase expression, and NFĸB translocation was monitored. 1 h exposure to high intraluminal pressure (120 mmHg) resulted in increased leukocyte adhesion and inflammatory gene expression in rat carotid arteries. High intraluminal pressure also resulted in a downstream signaling cascade of ROS production, arginase expression, and NFĸB translocation. This process was found to be angiotensin II-independent and mediated by the mechanosensor caveolae, as caveolin-1 (Cav1)-deficient endothelial cells and mice were protected from pressure-induced vascular inflammatory signaling and leukocyte adhesion. Cav1 deficiency also resulted in a reduction in pressure-induced glomerular macrophage infiltration in vivo. These findings demonstrate Cav1 is an important mechanosensor in pressure-induced vascular and renal inflammation. [ABSTRACT FROM AUTHOR]

Despite its well-known antithrombotic properties, the effect of aspirin on blood pressure (BP) and hypertension pathology is unclear. The hugely varying doses used clinically have contributed to this confusion, with high-dose aspirin still commonly used due to concerns about the efficacy of low-dose aspirin. Because prostaglandins have been shown to both promote and inhibit T-cell activation, we also explored the immunomodulatory properties of aspirin in hypertension. Although the common preclinical high dose of 100 mg/kg/d improved vascular dysfunction and cardiac hypertrophy, this effect was accompanied by indices of elevated adaptive immunity, renal T-cell infiltration, renal fibrosis, and BP elevation in stroke-prone spontaneously hypertensive rats and in angiotensin II-induced hypertensive mice. The cardioprotective effects of aspirin were conserved with a lower dose (10 mg/kg/d) while circumventing heightened adaptive immunity and elevated BP. We also show that low-dose aspirin improves renal fibrosis. Differential inhibition of the COX-2 isoform may underlie the disparate effects of the 2 doses. Our results demonstrate the efficacy of low-dose aspirin in treating a vast array of cardiovascular parameters and suggest modulation of adaptive immunity as a novel mechanism underlying adverse cardiovascular profiles associated with COX-2 inhibitors. Clinical studies should identify the dose of aspirin that achieves maximal cardioprotection with a new awareness that higher doses of aspirin could trigger undesired autoimmunity in hypertensive individuals. This work also warrants an evaluation of high-dose aspirin and COX-2 inhibitor therapy in sufferers of inflammatory conditions who are already at increased risk for cardiovascular disease. [ABSTRACT FROM AUTHOR]

The essential role of the Y chromosome in male sex determination has largely overshadowed the possibility that it may exert other biologic roles. Here, we show that Y-chromosome lineage is a strong determinant of perivascular and renal T-cell infiltration in the stroke-prone spontaneously hypertensive rat, which, in turn, may influence vascular function and blood pressure (BP). We also show, for the first time to our knowledge, that augmented perivascular T-cell levels can directly instigate vascular dysfunction, and that the production of reactive oxygen species that stimulate cyclo-oxygenase underlies this. We thus provide strong evidence for the consideration of Y-chromosome lineage in the diagnosis and treatment of male hypertension, and point to the modulation of cardiovascular organ T-cell infiltration as a possible mechanism that underpins Y-chromosome regulation of BP. [ABSTRACT FROM AUTHOR]

Vascular dysfunction is a hallmark of hypertension and the strongest risk factor to date for coronary artery disease. As Y chromosome lineage has emerged as one of the strongest genetic predictors of cardiovascular disease risk to date, we investigated if Y chromosome lineage modulated this important facet in the stroke-prone spontaneously hypertensive rat (SHRSP) using consomic strains. Here, we show that vascular dysfunction in the SHRSP is attributable to differential cyclooxygenase (COX) activity with nitric oxide (NO) levels playing a less significant role. Measurement of prostacyclin, the most abundant product of COX in the vasculature, confirmed the augmented COX activity in the SHRSP aorta. This was accompanied by functional impairment of the vasodilatory prostacyclin (IP) receptor, while inhibition of the thromboxane (TP) receptor significantly ameliorated vascular dysfunction in the SHRSP, suggesting this is the downstream target responsible for constrictor prostanoid activity. Importantly, Y chromosome lineage was shown to modulate vascular function in the SHRSP through influencing COX activity, prostacyclin levels and IP dysfunction. Vascular dysfunction in the renal and intrarenal arteries was also found to be prostanoid and Y chromosome dependent. Interestingly, despite no apparent differences in agonist-stimulated NO levels, basal NO levels were compromised in the SHRSP aorta, which was also Y chromosome dependent. Thus, in contrast with the widely held view that COX inhibition is deleterious for the vasculature due to inhibition of the vasodilator prostacyclin, we show that COX inhibition abolishes vascular dysfunction in three distinct vascular beds, with IP dysfunction likely being a key mechanism underlying this effect. We also delineate a novel role for Y chromosome lineage in regulating vascular function through modulation of COX and basal NO levels. [ABSTRACT FROM AUTHOR]

Background and aims Monocyte levels predict cardiovascular outcomes and play a causal role in atherogenesis. Monocytes can be produced in the spleen and track to the atherosclerotic lesion in significant numbers. The cholinergic system has been shown to have anti-inflammatory actions in the spleen. We aimed to explore whether therapeutic stimulation of the nicotinic acetylcholine receptor alpha 7 (nAChRα7) can suppress atherogenesis. Methods Apoe −/− mice were placed on a Western-type diet and treated with bi-daily injections of the nAChRα7 agonist GTS-21 or vehicle every 2–3 days for 8 weeks. Results GTS-21 caused a reduction in atherosclerosis in the aortic arch and proximal aorta. This also resulted in less plaque macrophages. Moreover, GTS-21 reduced the abundance of blood monocytes, which was caused by inhibition of inflammatory cytokines and extramedullary hematopoiesis in the spleen, along with splenic monocytes. Conclusions Stimulation of nAChRα7 with GTS-21 reduced atherosclerosis, which was associated with dampened splenic myelopoiesis. [ABSTRACT FROM AUTHOR]

Platelets play a critical role in atherogenesis and thrombosis-mediated myocardial ischemia, processes that are accelerated in diabetes. Whether hyperglycemia promotes platelet production and whether enhanced platelet production contributes to enhanced atherothrombosis remains unknown. Here we found that in response to hyperglycemia, neutrophil-derived S100 calcium-binding proteins A8/A9 (S100A8/A9) interact with the receptor for advanced glycation end products (RAGE) on hepatic Kupffer cells, resulting in increased production of IL-6, a pleiotropic cytokine that is implicated in inflammatory thrombocytosis. IL-6 acts on hepatocytes to enhance the production of thrombopoietin, which in turn interacts with its cognate receptor c-MPL on megakaryocytes and bone marrow progenitor cells to promote their expansion and proliferation, resulting in reticulated thrombocytosis. Lowering blood glucose using a sodium-glucose cotransporter 2 inhibitor (dapagliflozin), depleting neutrophils or Kupffer cells, or inhibiting S100A8/A9 binding to RAGE (using paquinimod), all reduced diabetes-induced thrombocytosis. Inhibiting S100A8/A9 also decreased atherogenesis in diabetic mice. Finally, we found that patients with type 2 diabetes have reticulated thrombocytosis that correlates with glycated hemoglobin as well as increased plasma S100A8/A9 levels. These studies provide insights into the mechanisms that regulate platelet production and may aid in the development of strategies to improve on current antiplatelet therapies and to reduce cardiovascular disease risk in diabetes. [ABSTRACT FROM AUTHOR]

Objective To determine whether a clinically-utilised IL-1 receptor antagonist, anakinra, reduces renal inflammation, structural damage and blood pressure (BP) in mice with established hypertension. Methods Hypertension was induced in male mice by uninephrectomy, deoxycorticosterone acetate (2.4 mg/d, s.c. ) and replacement of drinking water with saline (1K/DOCA/salt). Control mice received uninephrectomy, a placebo pellet and normal drinking water. 10 days post-surgery, mice commenced treatment with anakinra (75 mg/kg/d, i.p. ) or vehicle (0.9% saline, i.p. ) for 11 days. Systolic BP was measured by tail cuff while qPCR, immunohistochemistry and flow cytometry were used to measure inflammatory markers, collagen and immune cell infiltration in the kidneys. Results By 10 days post-surgery, 1K/DOCA/salt-treated mice displayed elevated systolic BP (148.3 ± 2.4 mmHg) compared to control mice (121.7 ± 2.7 mmHg; n = 18, P < 0.0001). The intervention with anakinra reduced BP in 1K/DOCA/salt-treated mice by ∼20 mmHg (n = 16, P < 0.05), but had no effect in controls. In 1K/DOCA/salt-treated mice, anakinra modestly reduced (∼30%) renal expression of some (CCL5, CCL2; n = 7–8; P < 0.05) but not all (ICAM-1, IL-6) inflammatory markers, and had no effect on immune cell infiltration (n = 7–8, P > 0.05). Anakinra reduced renal collagen content (n = 6, P < 0.01) but paradoxically appeared to exacerbate the renal and glomerular hypertrophy (n = 8-9, P < 0.001) that accompanied 1K/DOCA/salt-induced hypertension. Conclusion Despite its anti-hypertensive and renal anti-fibrotic actions, anakinra had minimal effects on inflammation and leukocyte infiltration in mice with 1K/DOCA/salt-induced hypertension. Future studies will assess whether the anti-hypertensive actions of anakinra are mediated by protective actions in other BP-regulating or salt-handling organs such as the arteries, skin and brain. [ABSTRACT FROM AUTHOR]

Nitroxyl anion (HNO) donors are currently being assessed for their therapeutic utility in several cardiovascular disorders including heart failure. Here, we examine their effect on factors that precede atherosclerosis including endothelial cell and monocyte activation, leucocyte adhesion to the endothelium and macrophage polarization. Similar to the NO donor glyceryl trinitrate (GTN), the HNO donors Angeli's salt (AS) and isopropylamine NONOate (IPA/NO) decreased leucocyte adhesion to activated human umbilical vein endothelial cells (HUVECs) and mouse isolated aorta. This reduction in adhesion was accompanied by a reduction in intercellular adhesion molecule-1 (ICAM-1) and the cytokines monocyte chemoattractant protein 1 (MCP-1) and interleukin 6 (IL-6) which was inhibitor of nuclear factor κB (NFκB) α (IκBα)- and subsequently NFκB-dependent. Intriguingly, the effects of AS on leucocyte adhesion, like those on vasodilation, were found to not be susceptible to pharmacological tolerance, unlike those observed with GTN. As well, HNO reduces monocyte activation and promotes polarization of M2 macrophages. Taken together, our data demonstrate that HNO donors can reduce factors that are associated with and which precede atherosclerosis and may thus be useful therapeutically. Furthermore, since the effects of the HNO donors were not subject to tolerance, this confers an additional advantage over NO donors. [ABSTRACT FROM AUTHOR]

New Findings What is the central question of this study? What is the potential role of endothelial NO production via overexpression of the l-arginine transporter, CAT1, as a mitigator of cardiac hypertrophy?, What is the main finding and its importance? Augmentation of endothelium-specific l-arginine transport via CAT1 can attenuate pressure-overload-dependent cardiac hypertrophy and fibrosis. Our findings support the conclusion that interventions that improve endothelial l-arginine transport may provide therapeutic utility in the setting of myocardial hypertrophy. Such modifications may be introduced by exercise training or locally delivered gene therapy, but further experimental and clinical studies are required., Endothelial dysfunction has been postulated to play a central role in the development of cardiac hypertrophy, probably as a result of reduced NO bioavailability. We tested the hypothesis that increased endothelial NO production, mediated by increased l-arginine transport, could attenuate pressure-overload-induced cardiac hypertrophy. Echocardiography and blood pressure measurements were performed 15 weeks after transverse aortic constriction (TAC) in wild-type (WT) mice ( n = 12) and in mice with endothelium-specific overexpression of the l-arginine transporter, CAT1 (CAT+; n = 12). Transverse aortic constriction induced greater increases in heart weight to body weight ratio in WT (by 47%) than CAT+ mice (by 25%) compared with the respective controls ( P ≤ 0.05). Likewise, the increase in left ventricular wall thickness induced by TAC was significantly attenuated in CAT+ mice ( P = 0.05). Cardiac collagen type I mRNA expression was greater in WT mice with TAC (by 22%; P = 0.03), but not in CAT+ mice with TAC, compared with the respective controls. Transverse aortic constriction also induced lesser increases in β-myosin heavy chain mRNA expression in CAT+ mice compared with WT ( P ≤ 0.05). Left ventricular systolic pressure after TAC was 36 and 39% greater in WT and CAT+ mice, respectively, compared with the respective controls ( P ≤ 0.001). Transverse aortic constriction had little effect on left ventricular end-diastolic pressure in both genotypes. Taken together, these data indicate that augmenting endothelial function by overexpression of l-arginine transport can attenuate pressure-overload-induced cardiac hypertrophy. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a progressive disease, involving the build-up of lipid streaks in artery walls, leading to plaques. Understanding the development of atherosclerosis and plaque vulnerability is critically important since plaque rupture can result in heart attack or stroke. Plaques can be divided into two distinct types: those likely to rupture (vulnerable) or less likely to rupture (stable). In the last decade, researchers have been interested in studying the influence of the mechanical effects (blood shear stress, pressure forces and structural stress) on the plaque formation, progression and rupture processes but no general agreement has been found. The purpose of the present work is to include more realistic conditions for the numerical calculations of the blood flow by implementing real geometries with plaques in the numerical model. Hemodynamical parameters are studied in both diseased and healthy configurations. The healthy configuration is obtained by removing numerically the plaques from three dimensional geometries obtained by micro-computed tomography. A new hemodynamical parameter is also introduced to relate the location of plaques to the characteristics of the flow in the healthy configuration. [ABSTRACT FROM AUTHOR]

Background/Aims: Neointimal thickening results from inflammation in association with vascular smooth muscle cell (VSMC) proliferation. We studied the role of perivascular adipose tissue (PVAT) on VSMC proliferation and intima-media thickening (IMT) in a rodent model of chronic inflammation. Methods: The abdominal aorta and surrounding PVAT of tumour necrosis factor (TNF)-α-injected mice were examined 28 days after administration. Plasma and PVAT cytokines were measured with Milliplex™ assays. Inflammatory cells were examined with immunofluorescence. Expression of transforming growth factor (TGF)-β1, matrix metalloproteinase (MMP)-2, MMP-9 and MMP-12 was examined with immunohistochemistry, immunoblotting and zymography. IMT was determined. Cell proliferation and TGF-β1 mRNA levels were examined after treating VSMC with PVAT homogenates ± MMP-2 inhibitors (batimastat, ARP 100 or TIMP-2) and SB-431542, a selective inhibitor of the TGF-β-type 1 receptor. Results: Significant increases in CD3, CD68, neutrophils, vascular cell adhesion molecule-1 and MMP-2 in PVAT, and TGF-β1 and IMT of the aorta of TNF-α-injected mice were observed. PVAT of TNF-α-injected mice significantly up-regulated TGF-β1 and increased cell proliferation in a dose-dependent manner and was attenuated by SB-431542, batimastat, ARP 100 and TIMP-2. Conclusions: Our study shows that chronic PVAT inflammation leads to MMP-mediated increase in TGF-β1 and hence VSMC proliferation. Copyright © 2013 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Aims Plaque rupture partly results from inadequate collagen synthesis due to lower smooth muscle cell numbers in fibrous caps. Fibrocytes are bone-marrow-derived circulating mesenchymal progenitors and have recently been identified in fibrous caps. This study hypothesized that reduced fibrocyte numbers would be associated with plaque instability. Methods and results Patients with acute myocardial infarction (MI) (n = 22), stable angina (SA) (n = 20), or healthy controls (n = 22) were recruited. Circulating fibrocytes (CD45+/CD34+/collagen I+) were measured by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were isolated from blood and cultured for 2 weeks, and fibrocytes were quantified by morphology (spindle-shaped) and flow cytometry (CD45+/collagen I+). Another set of PBMCs was stimulated with macrophage colony-stimulating factor (M-CSF) for 72 h and the expression of several macrophage markers was measured by flow cytometry. Acute MI patients had decreased circulating fibrocyte numbers compared with healthy controls or SA patients. Following 2 weeks' culture, both the number of spindle-shaped fibrocytes counted under the microscope and the percentage of fibrocytes of the remaining adherent cells in culture measured by flow cytometry were reduced in acute MI patients. Expression of macrophage markers CD68, CD36, and EMR in M-CSF-stimulated PBMCs was enhanced in acute MI patients compared with the other two groups. SA patients with previous MI had decreased circulating fibrocyte numbers and a lower yield of fibrocytes from PBMCs than those without previous MI. Conclusions This is the first report of decreased fibrocyte numbers in patients with MI. Reduced fibrocytes and preferential differentiation of PBMCs into macrophages may contribute to plaque instability. [ABSTRACT FROM AUTHOR]

Objectives: Our aim was to investigate the effects of reconstituted high-density lipoprotein (rHDL) infusions on plasma high-density lipoprotein (HDL) anti-inflammatory properties and ex vivo cholesterol efflux in patients with type 2 diabetes. Background: The anti-inflammatory effects of HDL contribute to protection from cardiovascular events. Individuals with type 2 diabetes are at elevated risk for cardiovascular disease, and typically have low HDL with reduced anti-inflammatory properties. Methods: Thirteen fasting male patients (mean age 52 years) with type 2 diabetes mellitus received both rHDL (80 mg/kg of apolipoprotein A-I) and a saline placebo on separate occasions in a randomized cross-over design study. Changes in the ability of isolated HDL to influence the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in human coronary artery endothelial cells was the main outcome measure. Other outcome measures included expression of the key integrin, CD11b on patient monocytes, adhesiveness of patient neutrophils to fibrinogen, and the ability of plasma to promote cholesterol efflux to THP-1 macrophages. Results: Four and 72 h post-rHDL infusion, the anti-inflammatory properties of isolated HDL increased in parallel to their concentration in plasma (by up to 25%, p < 0.01). Participants'' peripheral blood monocyte CD11b expression and neutrophil adhesion to a fibrinogen matrix was also reduced 72 h post-rHDL, compared with that seen in placebo (p = 0.02). rHDL increased the capacity of plasma to receive cholesterol from THP-1 macrophages by 1 h up to 72 h post-infusion (by 40% to 60%, p < 0.05). Conclusions: rHDL infusions have significant, potentially atheroprotective effects in individuals with diabetes, including suppression of inflammation and enhancement of cholesterol efflux. [Copyright &y& Elsevier]

Background: While selective intestinal decontamination (SID) can alter the hyperdynamic circulatory state of cirrhosis, the impact of SID on portal pressure remains unclear especially in the setting of clinically significant portal hypertension. Aims: To examine the impact of SID with norfloxacin on portal pressure in subjects with clinically significant portal hypertension and explore the potential mechanisms by which norfloxacin exerts its haemodynamic effects. Methods: Randomised, double blind, placebo-controlled, crossover trial of norfloxacin 400 mg twice daily for 4 weeks. The portal pressure was assessed by hepatic venous pressure gradient (HVPG). Endotoxaemia was assessed by the Limulus amebocyte lysate (LAL) assay.l-arginine (l-Arg) transporter function was assessed in peripheral blood mononuclear cells (PBMCs). Plasma levels of urotensin II (UII) and tumour necrosis factor were measured before and after therapy. Results: Sixteen subjects with clinically significant portal hypertension (16.5±1.1 mmHg) completed the study. Norfloxacin therapy was not superior to placebo in reducing HVPG (13.8±1.0 mmHg vs 13.6±1.2 mmHg, P=0.3). Furthermore, no alteration inl-Arg transport was detected after 4 weeks of norfloxacin therapy. Plasma UII levels correlated positively with HVPG ( P=0.01) and the Child–Pugh score ( P<0.05). However, UII levels following therapy did not parallel HVPG changes. Conclusions: Norfloxacin is not superior to placebo in reducing HVPG in subjects with clinically significant portal hypertension. Furthermore, norfloxacin does not appear to modulate thel-Arg transporter mechanism in this patient population. Although plasma UII correlates positively with HVPG, UII does not appear to have a direct role in modulating HVPG. [ABSTRACT FROM AUTHOR]

Background: Peripheral vasodilatation is central to the pathogenesis of the accompanying hyperkinetic circulatory state and portal hypertension in cirrhotic patients. Selective intestinal decontamination with norfloxacin has been demonstrated to partially correct nitric oxide production in the forearm vasculature of cirrhotic patients.Objective: To examine the effects of selective intestinal decontamination on regional and systemic hemodynamics in cirrhotic patients.Design: Randomized, double-blind, placebo-controlled, crossover study.Setting: Alfred Hospital, Melbourne, Australia.Patients: 14 patients with alcohol-related cirrhosis and 14 matched healthy controls.Intervention: Norfloxacin, 400 mg twice daily, for 4 weeks.Measurements: Venous occlusion plethysmography was used to determine forearm blood flow. Cardiac output and the hepatic venous pressure gradient were determined after cardiac catheterization. Glomerular filtration rate was assessed by measuring inulin clearance. Serum levels of endotoxin were determined by chromogenic Limulus amebocytelysate assay.Results: Norfloxacin significantly diminished serum endotoxin levels (average change, -2.14 EU/mL [95% CI, -3.6 to -0.68 EU/mL]). Derived systemic vascular resistance increased significantly with norfloxacin (2.94 units [CI, 0.74 to 5.11 units]) and was accompanied by an increase in mean arterial pressure (8.70 mm Hg [CI, 2.65 to 14.73]), a trend toward decreased cardiac output (-1.207 L/min [range, 0.05 to -2.37 L/min]), a decrease in forearm blood flow (-0.99 mL/100 mL per min [CI, -1.80 to -0.17 mL/100 mL per min]), and a trend toward reduced hepatic venous pressure gradient (-2.43 mm Hg [CI, -5.2 to 0.34 mm Hg]). Norfloxacin did not significantly alter glomerular filtration rate.Conclusion: Selective intestinal decontamination with norfloxacin partially reverses the hyperdynamic circulatory state in cirrhotic patients without harming splanchnic or renal hemodynamics. [ABSTRACT FROM AUTHOR]

Elevated serum amyloid A (SAA) levels may promote endothelial dysfunction, which is linked to cardiovascular and renal pathologies. We investigated the effect of SAA on vascular and renal function in apolipoprotein E-deficient (ApoE -/- ) mice. Male ApoE -/- mice received vehicle (control), low-level lipopolysaccharide (LPS), or recombinant human SAA by i.p . injection every third day for 2 weeks. Heart, aorta and kidney were harvested between 3 days and 18 weeks after treatment. SAA administration increased vascular cell adhesion molecule (VCAM)-1 expression and circulating monocyte chemotactic protein (MCP)-1 and decreased aortic cyclic guanosine monophosphate (cGMP), consistent with SAA inhibiting nitric oxide bioactivity. In addition, binding of labeled leukocytes to excised aorta increased as monitored using an ex vivo leukocyte adhesion assay. Renal injury was evident 4 weeks after commencement of SAA treatment, manifesting as increased plasma urea, urinary protein, oxidized lipids, urinary kidney injury molecule (KIM)-1 and multiple cytokines and chemokines in kidney tissue, relative to controls. Phosphorylation of nuclear-factor-kappa-beta (NFκB- p -P65), tissue factor (TF), and macrophage recruitment increased in kidneys from ApoE -/- mice 4 weeks after SAA treatment, confirming that SAA elicited a pro-inflammatory and pro-thrombotic phenotype. These data indicate that SAA impairs endothelial and renal function in ApoE -/- mice in the absence of a high-fat diet.

Hypertension is a major, independent risk factor for atherosclerotic cardiovascular disease. However, this pathology can arise through multiple pathways, which could influence vascular disease through distinct mechanisms. An overactive sympathetic nervous system is a dominant pathway that can precipitate in elevated blood pressure. We aimed to determine how the sympathetic nervous system directly promotes atherosclerosis in the setting of hypertension. We used a mouse model of sympathetic nervous system-driven hypertension on the atherosclerotic-prone apolipoprotein E-deficient background. When mice were placed on a western type diet for 16 weeks, we showed the evolution of unstable atherosclerotic lesions. Fortuitously, the changes in lesion composition were independent of endothelial dysfunction, allowing for the discovery of alternative mechanisms. With the use of flow cytometry and bone marrow imaging, we found that sympathetic activation caused deterioration of the hematopoietic stem and progenitor cell niche in the bone marrow, promoting the liberation of these cells into the circulation and extramedullary hematopoiesis in the spleen. Specifically, sympathetic activation reduced the abundance of key hematopoietic stem and progenitor cell niche cells, sinusoidal endothelial cells and osteoblasts. Additionally, sympathetic bone marrow activity prompted neutrophils to secrete proteases to cleave the hematopoietic stem and progenitor cell surface receptor CXCR4. All these effects could be reversed using the β-blocker propranolol during the feeding period. These findings suggest that elevated blood pressure driven by the sympathetic nervous system can influence mechanisms that modulate the hematopoietic system to promote atherosclerosis and contribute to cardiovascular events., (Copyright© 2019 Ferrata Storti Foundation.)

The acute phase protein serum amyloid A (SAA) is associated with endothelial dysfunction and early-stage atherogenesis. Stimulation of vascular cells with SAA increases gene expression of pro-inflammation cytokines and tissue factor (TF). Activation of the transcription factor, nuclear factor kappa-B (NFκB), may be central to SAA-mediated endothelial cell inflammation, dysfunction and pro-thrombotic responses, while targeting NFκB with a pharmacologic inhibitor, BAY11-7082, may mitigate SAA activity. Human carotid artery endothelial cells (HCtAEC) were pre-incubated (1.5 h) with 10 μM BAY11-7082 or vehicle (control) followed by SAA (10 μg/mL; 4.5 h). Under these conditions gene expression for TF and Tumor Necrosis Factor (TNF) increased in SAA-treated HCtAEC and pre-treatment with BAY11-7082 significantly (TNF) and marginally (TF) reduced mRNA expression. Intracellular TNF and interleukin 6 (IL-6) protein also increased in HCtAEC supplemented with SAA and this expression was inhibited by BAY11-7082. Supplemented BAY11-7082 also significantly decreased SAA-mediated leukocyte adhesion to apolipoprotein E-deficient mouse aorta in ex vivo vascular flow studies. In vascular function studies, isolated aortic rings pre-treated with BAY11-7082 prior to incubation with SAA showed improved endothelium-dependent vasorelaxation and increased vascular cyclic guanosine monophosphate (cGMP) content. Together these data suggest that inhibition of NFκB activation may protect endothelial function by inhibiting the pro-inflammatory and pro-thrombotic activities of SAA.

Aim: Rheumatoid arthritis (RA) is associated with an approximately two-fold elevated risk of cardiovascular (CV)-related mortality. Patients with RA present with systemic inflammation including raised circulating myeloid cells, but fail to display traditional CV risk-factors, particularly dyslipidaemia. We aimed to explore if increased circulating myeloid cells is associated with impaired atherosclerotic lesion regression or altered progression in RA., Methods and Results: Using flow cytometry, we noted prominent monocytosis, neutrophilia, and thrombocytosis in two mouse models of RA. This was due to enhanced proliferation of the haematopoietic stem and progenitor cells (HSPCs) in the bone marrow and the spleen. HSPCs expansion was associated with an increase in the cholesterol content, due to a down-regulation of cholesterol efflux genes, Apoe, Abca1, and Abcg1. The HSPCs also had enhanced expression of key myeloid promoting growth factor receptors. Systemic inflammation was found to cause defective cellular cholesterol metabolism. Increased myeloid cells in mice with RA were associated with a significant impairment in lesion regression, even though cholesterol levels were equivalent to non-arthritic mice. Lesions from arthritic mice exhibited a less stable phenotype as demonstrated by increased immune cell infiltration, lipid accumulation, and decreased collagen formation. In a progression model, we noted monocytosis, enhanced monocytes recruitment to lesions, and increased plaque macrophages. This was reversed with administration of reconstituted high-density lipoprotein (rHDL). Furthermore, RA patients have expanded CD16+ monocyte subsets and a down-regulation of ABCA1 and ABCG1., Conclusion: Rheumatoid arthritis impairs atherosclerotic regression and alters progression, which is associated with an expansion of myeloid cells and disturbed cellular cholesterol handling, independent of plasma cholesterol levels. Infusion of rHDL prevented enhanced myelopoiesis and monocyte entry into lesions. Targeting cellular cholesterol defects in people with RA, even if plasma cholesterol is within the normal range, may limit vascular disease.

Obesity enhances the risk of developing myelodysplastic syndromes. However, the effect of obesity on survival is unclear. Obese people present with monocytosis due to inflammatory signals emanating from obese adipose tissue. We hypothesized that obesity-induced myelopoiesis would promote the transition of myelodysplastic syndrome to acute myeloid leukemia and accelerate mortality in obesity. Obese Ob/Ob mice or their lean littermate controls received a bone marrow transplant from NUP98-HOXD13 transgenic mice, a model of myelodysplastic syndrome. The metabolic parameters of the mice were examined throughout the course of the study, as were blood leukocytes. Myeloid cells were analyzed in the bone, spleen, liver and adipose tissue by flow cytometry halfway through the disease progression and at the endpoint. Survival curves were also calculated. Contrary to our hypothesis, transplantation of NUP98-HOXD13 bone marrow into obese recipient mice significantly increased survival time compared with lean recipient controls. While monocyte skewing was exacerbated in obese mice receiving NUP98-HOXD13 bone marrow, transformation to acute myeloid leukemia was not enhanced. Increased survival of obese mice was associated with a preservation of fat mass as well as increased myeloid cell deposition within the adipose tissue, and a concomitant reduction in detrimental myeloid cell accumulation within other organs. The study herein revealed that obesity increases survival in animals with myelodysplastic syndrome. This may be due to the greater fat mass of Ob/Ob mice, which acts as a sink for myeloid cells, preventing their accumulation in other key organs, such as the liver., (Copyright© 2018 Ferrata Storti Foundation.)

Background and Aims: Monocyte levels predict cardiovascular outcomes and play a causal role in atherogenesis. Monocytes can be produced in the spleen and track to the atherosclerotic lesion in significant numbers. The cholinergic system has been shown to have anti-inflammatory actions in the spleen. We aimed to explore whether therapeutic stimulation of the nicotinic acetylcholine receptor alpha 7 (nAChRα7) can suppress atherogenesis., Methods: Apoe -/- mice were placed on a Western-type diet and treated with bi-daily injections of the nAChRα7 agonist GTS-21 or vehicle every 2-3 days for 8 weeks., Results: GTS-21 caused a reduction in atherosclerosis in the aortic arch and proximal aorta. This also resulted in less plaque macrophages. Moreover, GTS-21 reduced the abundance of blood monocytes, which was caused by inhibition of inflammatory cytokines and extramedullary hematopoiesis in the spleen, along with splenic monocytes., Conclusions: Stimulation of nAChRα7 with GTS-21 reduced atherosclerosis, which was associated with dampened splenic myelopoiesis., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Fibrosis is a process of dysfunctional wound repair, described by a failure of tissue regeneration and excessive deposition of extracellular matrix, resulting in tissue scarring and subsequent organ deterioration. There are a broad range of stimuli that may trigger, and exacerbate the process of fibrosis, which can contribute to the growing rates of morbidity and mortality. Whilst the process of fibrosis is widely described and understood, there are no current standard treatments that can reduce or reverse the process effectively, likely due to the continuing knowledge gaps surrounding the cellular mechanisms involved. Several cellular targets have been implicated in the regulation of the fibrotic process including membrane domains, ion channels and more recently mechanosensors, specifically caveolae, particularly since these latter contain various signaling components, such as members of the TGFβ and MAPK/ERK signaling pathways, all of which are key players in the process of fibrosis. This review explores the anti-fibrotic influences of the caveola, and in particular the key underpinning protein, caveolin-1, and its potential as a novel therapeutic target.

Objective: Apolipoprotein A-I (apoA-I) mimetic peptides have antiatherogenic properties of high-density lipoprotein in vitro and have been shown to inhibit atherosclerosis in vivo. It is unclear, however, if each in vitro antiatherogenic property of these peptides translates to a corresponding activity in vivo, and if so, which of these contributes most to reduce atherosclerosis., Approach and Results: The effect of 7 apoA-I mimetic peptides, which were developed to selectively reproduce a specific component of the antiatherogenic properties of apoA-I, on the development of atherosclerosis was investigated in apolipoprotein E-deficient mice fed a high-fat diet for 4 or 12 weeks. The peptides include those that selectively upregulate cholesterol efflux, or are anti-inflammatory, or have antioxidation properties. All the peptides studied effectively inhibited the in vivo development of atherosclerosis in this model to the same extent. However, none of the peptides had the same selective effect in vivo as they had exhibited in vitro. None of the tested peptides affected plasma lipoprotein profile; capacity of plasma to support cholesterol efflux was increased modestly and similarly for all peptides., Conclusions: There is a discordance between the selective in vitro and in vivo functional properties of apoA-I mimetic peptides, and the in vivo antiatherosclerotic effect of apoA-I-mimetic peptides is independent of their in vitro functional profile. Comparing the properties of apoA-I mimetic peptides in plasma rather than in the lipid-free state is better for predicting their in vivo effects on atherosclerosis., (© 2017 American Heart Association, Inc.)

Vascular inflammation and disease progression, such as atherosclerosis, are in part a consequence of haemodynamic forces generated by changes in blood flow. The haemodynamic forces, such as shear stress or stretch, interact with vascular endothelial cells, which transduce the mechanical stimuli into biochemical signals via mechanosensors, which can induce an upregulation in pathways involved in inflammatory signaling. However, it is unclear how these mechanosensors respond to shear stress and most significantly what cellular mechanisms are involved in sensing the haemodynamic stimuli. This review explores the transition from shear forces, stretch and pressure to endothelial inflammation and the process of mechanotransduction, specifically highlighting evidence to suggest that caveolae play as a role as mechanosensors.

An elevated level of tumor necrosis factor (TNF)-α is implicated in several cardiovascular diseases including heart failure. Numerous reports have demonstrated that TNF-α activates nuclear factor (NF)-kappaB, resulting in the upregulation of several genes that regulate inflammation, proliferation, and apoptosis of cardiomyocytes. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, a major source of reactive oxygen species (ROS), is also activated by TNF-α and plays a crucial role in redox-sensitive signaling pathways. The present study investigated whether NADPH oxidase mediates TNF-α-induced NF-kappaB activation and NF-kappaB-mediated gene expression. Human cardiomyocytes were treated with recombinant TNF-α with or without pretreatment with diphenyleneiodonium (DPI) and apocynin, inhibitors of NADPH oxidase. TNF-α-induced ROS production was measured using 5-(and-6)-chloromethyl-2', 7'-dichlorodihydrofluorescein diacetate assay. TNF-α-induced NF-kappaB activation was also examined using immunoblot; NF-kappaB binding to its binding motif was determined using a Cignal reporter luciferase assay and an electrophoretic mobility shift assay. TNF-α-induced upregulation of interleukin (IL)-1β and vascular cell adhesion molecule (VCAM)-1 was investigated using real-time PCR and immunoblot. TNF-α-induced ROS production in cardiomyocytes was mediated by NADPH oxidase. Phosphorylation of IKK-α/β and p65, degradation of IkappaBα, binding of NF-kappaB to its binding motif, and upregulation of IL-1β and VCAM-1 induced by TNF-α were significantly attenuated by treatment with DPI and apocynin. Collectively, these findings demonstrate that NADPH oxidase plays a role in regulation of TNF-α-induced NF-kappaB activation and upregulation of proinflammatory cytokines, IL-1β and VCAM-1, in human cardiomyocytes.

Background: Near-infrared spectroscopy of the thenar eminence (NIRSth) can be used at the bedside to assess tissue oxygenation (StO2), the reperfusion response to ischaemia and the tissue haemoglobin index (THI). Its ability to estimate forearm blood flow (FBF) has not previously been assessed., Objectives: We aimed to test whether short-lived venous occlusion-induced changes in NIRSth-derived THI (ΔTHI/ minute) correlate with strain gauge plethysmography (SGP) measurements., Methods: We measured FBF in nine volunteers with SGP by venous occlusion, while estimating ΔTHI. Measurements were obtained in two forearm positions (elevated and horizontal) at baseline and during induced hyperaemia., Results: We performed 246 paired measurements at rest and after occlusion-induced hyperaemia. At rest, mean SGP-estimated FBF was 3.5-3.6 mL/dL/minute at baseline, compared with 12.9-13.6 mL/dL/minute during hyperaemia. At rest, ΔTHI was 6.1-8.2/minute, compared with 29.7-32.5/minute during hyperaemia. ΔTHI was a significant predictor of SGP FBF (P < 0.01), with stronger correlation during hyperaemia (P < 0.01). An equation was developed to convert ΔTHI/minute into FBF at mL/dL/minute (FBF = 0.362 ΔTHI/minute + 0.864)., Conclusions: NIRSth can be used to estimate FBF. Given its portability and its ability to also measure StO2 and vascular reactivity, NIRSth can assist in providing a comprehensive bedside assessment of the forearm circulation in critically ill patients.

Background: Fibrocytes are bone marrow-derived mesenchymal progenitors that have been linked to various fibrotic disorders. This study was undertaken to investigate whether fibrocytes are increased in diffuse myocardial fibrosis in humans., Methods and Results: Thirty-seven patients with hypertrophic cardiomyopathy (HCM) and 20 healthy controls were recruited. Cardiac magnetic resonance imaging with postcontrast T1 mapping was performed to non-invasively quantify diffuse myocardial fibrosis and these patients were classified into 2 groups (T1 < 470 ms or T1 ≥ 470 ms, as likely or unlikely to have diffuse fibrosis, respectively). Circulating fibrocytes (CD45+/CD34+/collagen I+) were measured by flow cytometry. Peripheral blood mononuclear cells (PBMCs) were cultured for 13 days and fibrocytes were quantitated by flow cytometry (CD45+/collagen I+) and real-time PCR (gene expression of matrix proteins). Plasma cytokines/chemokines mediating fibrocyte trafficking and differentiation were measured by multiplex assays. Circulating fibrocytes were decreased in HCM patients compared to controls. The proportion of fibrocytes derived from PBMCs was increased in patients with diffuse fibrosis compared with those without or controls (31.1 ± 4.1% versus 18.9 ± 3.9% and 10.9 ± 2.0%, P < 0.05 and P < 0.001, respectively), and the proportion of fibrocytes was inversely correlated with T1 time (r = -0.37, P = 0.03). Plasma levels of stromal cell-derived factor-1 were elevated in patients with diffuse fibrosis compared with those without or controls (5131 ± 271 pg/mL versus 3893 ± 356 pg/mL and 4172 ± 185 pg/mL, respectively, both P < 0.05)., Conclusions: HCM patients with diffuse fibrosis as assessed by postcontrast T1 mapping have elevated plasma SDF and an enhanced ability of PBMCs to differentiate into fibrocytes, suggesting that fibrocytes may contribute to the pathogenesis of myocardial fibrosis.

Essential hypertension is the leading risk factor for mortality worldwide, accountable for 13% of deaths globally. Despite numerous therapies available uncontrolled hypertension is still very prevalent today and a large subset are shown to have treatment resistant hypertension. Several cardiovascular diseases including hypertension result in endothelial dysfunction and inflammation. Once thought of as a passive barrier between blood flow and tissue the endothelium is now considered a main hub for maintaining vascular tone, structure and haemostasis. Several pathways occur in the endothelium that can result in dysfunction and altered vascular stasis. Such pathways include the impairment of the vasodilator nitric oxide (NO), increases in pro-inflammatory pathways such as ROS (reactive oxygen species) production and also recent reports suggest that the enzyme arginase, associated with the L-arginine-urea cycle, may be an important factor that is increased in hypertension. These pathways may offer alternative mechanisms to treat the complications associated with hypertension rather than the conventional therapies that aim to lower blood pressure.

Inflammation plays a fundamental role in many chronic diseases, including atherosclerosis associated cardiovascular disease. Adhesion of immune cells plays a critical role in the inflammatory response and indeed the pathophysiology of inflammatory related diseases. P-selectin is an inflammatory adhesion molecule, enabling the recruitment of leukocytes to the endothelium and to activated platelets involved with the growing thrombus. P-selectin is critical in the progression of atherosclerosis as evidenced by knockout animal models where P-selectin knockout mice crossed with apoE deficient mice exhibit significantly reduced atherosclerosis and leukocyte recruitment in the plaque. A soluble form of P-selectin also exists, which may have pro-atherogenic and pro-thrombotic effects. Thus targeting of P-selectin remains a strong clinical candidate for developing novel therapeutic strategies in inflammatory diseases. This review will discuss the role of P-selectin and describe the function of P-selectin antagonists as clinical targets.

Structural and functional properties of high-density lipoprotein (HDL) after short-term freezing in the presence or absence of 10% sucrose were compared with HDL stored at 4 degrees C. Freezing did not affect the size of HDL particles or their antiinflammatory and antioxidant properties. Freezing slightly impaired the ability of HDL to support cholesterol efflux from human macrophages, but this property was preserved when HDL was frozen in the presence of sucrose. Freezing also resulted in approximately 10% loss of HDL in the samples. We conclude that freezing HDL in the presence of 10% sucrose preserves its structural and functional properties.