The effects of angiotensin-converting enzyme inhibition on endothelial dysfunction: potential role in myocardial ischemia

The Different Impact of PM2.5 on Atherogenesis in Overseas vs. Native Chinese in the CATHAY Study

Air pollution (PM2.5) has been associated with cardiovascular disease (CVD) globally and with early atherosclerosis surrogate markers in modernized China. A sizeable number of Chinese have migrated overseas, with an increase in their vulnerability to CVD. To evaluate the impact of PM2.5 air pollution on atherogenesis in native vs. overseas Chinese, we recruited 756 asymptomatic native Chinese and 507 age- and gender-matched overseas Chinese from Sydney and San Francisco. Their cardiovascular profiles were evaluated. PM2.5 was derived from remote sensing technology; atherosclerosis surrogate markers, flow-mediated dilation (FMD) and carotid intima-media thickness (IMT) were measured by ultrasound. The native Chinese had a higher proportion of smokers as well as higher blood pressure, glucose, metabolic syndrome and PM2.5 exposure (p < 0.001), but lower lipids and folate than the overseas Chinese (p < 0.0001). Carotid IMT was lower in the native Chinese (p < 0.0001), but the other vascular parameters were similar. A multivariate regression revealed that FMD in the native Chinese was related to the male gender, age and location; in the overseas Chinese, it was related to age, but not to PM2.5. Carotid IMT in the native Chinese was related to PM2.5, independent of atherosclerotic risk factors and location (R2 = 0.384, F = 34.5, p < 0.0001) whereas in the overseas Chinese, IMT was related to the male gender and age, but not to PM2.5 or overseas location (R2 = 0.282, F = 19.7, p < 0.0001). PM2.5 had a greater impact on atherogenesis in the native Chinese, independent of traditional risk factors, with implications for preventive strategies.

Malaria infection promotes a selective expression of kinin receptors in murine liver

BACKGROUND

Malaria represents a worldwide medical emergency affecting mainly poor areas. Plasmodium parasites during blood stages can release kinins to the extracellular space after internalization of host kininogen inside erythrocytes and these released peptides could represent an important mechanism in liver pathophysiology by activation of calcium signaling pathway in endothelial cells of vertebrate host. Receptors (B1 and B2) activated by kinins peptides are important elements for the control of haemodynamics in liver and its physiology. The aim of this study was to identify changes in the liver host responses (i.e. kinin receptors expression and localization) and the effect of ACE inhibition during malaria infection using a murine model.

METHODS

Balb/C mice infected by Plasmodium chabaudi were treated with captopril, an angiotensin I-converting enzyme (ACE) inhibitor, used alone or in association with the anti-malarial chloroquine in order to study the effect of ACE inhibition on mice survival and the activation of liver responses involving B1R and B2R signaling pathways. The kinin receptors (B1R and B2R) expression and localization was analysed in liver by western blotting and immunolocalization in different conditions.

RESULTS

It was verified that captopril treatment caused host death during the peak of malaria infection (parasitaemia about 45%). B1R expression was stimulated in endothelial cells of sinusoids and other blood vessels of mice liver infected by P. chabaudi. At the same time, it was also demonstrated that B1R knockout mice infected presented a significant reduction of survival. However, the infection did not alter the B2R levels and localization in liver blood vessels.

CONCLUSIONS

Thus, it was observed through in vivo studies that the vasodilation induced by plasma ACE inhibition increases mice mortality during P. chabaudi infection. Besides, it was also seen that the anti-malarial chloroquine causes changes in B1R expression in liver, even after days of parasite clearance. The differential expression of B1R and B2R in liver during malaria infection may have an important role in the disease pathophysiology and represents an issue for clinical treatments.

Severe atherosclerosis of donor hepatic arteries is a salvageable condition in liver transplantation to optimise the graft utilisation: A case series and review of the literature

•

We showed how to manage sever atherosclerosis in liver transplant with special technique.

•

This case report will help not to discard donated liver graft.

•

Management of sever artherosclerosis, liver transplantation.

Introduction

The presence of atherosclerosis of the common hepatic artery (CHA) in donor livers potentially contributes to vascular complications after liver transplantation, thereby most of those organs are traditionally discarded. Herein, we describe the successful outcome of three patients transplanted with grafts that had severe atherosclerosis of the donor CHA up to the level of the gastroduodenal artery (GDA).

Presentation of case

In all three cases, endarterectomies were performed by dissection between the atheromatous core and the artery intima using a dissecting spatula, allowing to secure the lumen of the vessel. The native CHA/GDA patch was aligned with the corresponding CHA/GDA patch from the graft for the arterial reconstruction. No vascular complications were seen post-operatively.

Discussion

Endarterectomy and anatomical reconstitution of the arterial tree, without any redundancy or kinking, allowed for the successful transplantation of organs that would be otherwise discarded. Further, the straight alignment of the arteries may enhance flow dynamics, preventing thrombosis.

Conclusion

This report might guide future studies targeting means to increase the utility of donor livers discarded due to arterial atherosclerosis.

Specialized Pro-resolving Lipid Mediators: Modulation of Diabetes-Associated Cardio-, Reno-, and Retino-Vascular Complications

Diabetes and its associated chronic complications present a healthcare challenge on a global scale. Despite improvements in the management of chronic complications of the micro-/macro-vasculature, their growing prevalence and incidence highlights the scale of the problem. It is currently estimated that diabetes affects 425 million people globally and it is anticipated that this figure will rise by 2025 to 700 million people. The vascular complications of diabetes including diabetes-associated atherosclerosis and kidney disease present a particular challenge. Diabetes is the leading cause of end stage renal disease, reflecting fibrosis leading to organ failure. Moreover, diabetes associated states of inflammation, neo-vascularization, apoptosis and hypercoagulability contribute to also exacerbate atherosclerosis, from the metabolic syndrome to advanced disease, plaque rupture and coronary thrombosis. Current therapeutic interventions focus on regulating blood glucose, glomerular and peripheral hypertension and can at best slow the progression of diabetes complications. Recently advanced knowledge of the pathogenesis underlying diabetes and associated complications revealed common mechanisms, including the inflammatory response, insulin resistance and hyperglycemia. The major role that inflammation plays in many chronic diseases has led to the development of new strategies aiming to promote the restoration of homeostasis through the "resolution of inflammation." These strategies aim to mimic the spontaneous activities of the 'specialized pro-resolving mediators' (SPMs), including endogenous molecules and their synthetic mimetics. This review aims to discuss the effect of SPMs [with particular attention to lipoxins (LXs) and resolvins (Rvs)] on inflammatory responses in a series of experimental models, as well as evidence from human studies, in the context of cardio- and reno-vascular diabetic complications, with a brief mention to diabetic retinopathy (DR). These data collectively support the hypothesis that endogenously generated SPMs or synthetic mimetics of their activities may represent lead molecules in a new discipline, namely the 'resolution pharmacology,' offering hope for new therapeutic strategies to prevent and treat, specifically, diabetes-associated atherosclerosis, nephropathy and retinopathy.

Plant-based foods containing cell wall polysaccharides rich in specific active monosaccharides protect against myocardial injury in rat myocardial infarction models

Many cohort studies have shown that consumption of diets containing a higher composition of foods derived from plants reduces mortality from coronary heart disease (CHD). Here, we examined the active components of a plant-based diet and the underlying mechanisms that reduce the risk of CHD using three rat models and a quantitative proteomics approach. In a short-term myocardial infarction (MI) model, intake of wheat extract (WE), the representative cardioprotectant identified by screening approximately 4,000 samples, reduced myocardial injury by inhibiting apoptosis, enhancing ATP production, and maintaining protein homeostasis. In long-term post-MI models, this myocardial protection resulted in ameliorating adverse left-ventricular remodelling, which is a predictor of heart failure. Among the wheat components, arabinose and xylose were identified as active components responsible for the observed efficacy of WE, which was administered via ingestion and tail-vein injections. Finally, the food components of plant-based diets that contained cell wall polysaccharides rich in arabinose, xylose, and possibly fucose were found to confer protection against myocardial injury. These results show for the first time that specific monosaccharides found in the cell wall polysaccharides in plant-based diets can act as active ingredients that reduce CHD by inhibiting postocclusion steps, including MI and heart failure.

Treating coronary disease and the impact of endothelial dysfunction

Ischemic heart disease is the leading cause of morbidity and mortality throughout the world. Many clinical trials have suggested that lifestyle and pharmacologic interventions are effective in attenuating atherosclerotic disease progression and events development. However, an individualized approach with careful consideration to comprehensive vascular health is necessary to perform successful intervention strategies. Endothelial dysfunction plays a pivotal role in the early stage of atherosclerosis and is also associated with plaque progression and occurrence of atherosclerotic complications. The assessment of endothelial function provides us with important information about individual patient risk, progress and vulnerability of disease, and guidance of therapy. Thus, the application of endothelial function assessment might enable clinicians to innovate ideal individualized medicine. In this review, we summarize the current knowledge on the impact of pharmacological therapies for atherosclerotic cardiovascular disease on endothelial dysfunction, and argue for the utility of non-invasive assessment of endothelial function aiming at individualized medicine.

The effect of a periodontal intervention on cardiovascular risk markers in Indigenous Australians with periodontal disease: the PerioCardio study

Background

Indigenous Australians experience an overwhelming burden of chronic disease, including cardiovascular diseases. Periodontal disease (inflammation of the tissues surrounding teeth) is also widespread, and may contribute to the risk of cardiovascular diseases via pathogenic inflammatory pathways. This study will assess measures of vascular health and inflammation in Indigenous Australian adults with periodontal disease, and determine if intensive periodontal therapy improves these measures over a 12 month follow-up. The aims of the study are: (i) to determine whether there is a dose response relationship between extent and severity of periodontal disease and measures of vascular health and inflammation among Indigenous Australian adults with moderate to severe periodontal disease; and (ii) to determine the effects of periodontal treatment on changes in measures of vascular health and inflammation in a cohort of Indigenous Australians.

Methods/Design

This study will be a randomised, controlled trial, with predominantly blinded assessment of outcome measures and blinded statistical analysis. All participants will receive the periodontal intervention benefits (with the intervention delayed 12 months in participants who are randomised to the control arm). Participants will be Indigenous adults aged ≥25 years from urban centres within the Top End of the Northern Territory, Australia. Participants assessed to have moderate or severe periodontal disease will be randomised to the study's intervention or control arm. The intervention involves intensive removal of subgingival and supragingival calculus and plaque biofilm by scaling and root-planing. Study visits at baseline, 3 and 12 months, will incorporate questionnaires, non-fasting blood and urine samples, body measurements, blood pressure, periodontal assessment and non-invasive measures of vascular health (pulse wave velocity and carotid intima-media thickness). Primary outcome measures are pulse wave velocity and carotid intima-media thickness.

Discussion

The study will assess the periodontal-cardiovascular disease relationship among Indigenous Australian adults with periodontal disease, and the effectiveness of an intervention aimed at improving periodontal and cardiovascular health. Efforts to understand and improve Indigenous oral health and cardiovascular risk may serve as an important means of reducing the gap between Indigenous and non-Indigenous health in Australia.

Trial Registration

Australia and New Zealand Clinical Trials Register (ANZCTR): ACTRN12610000817044

Relation of candidate genes that encode for endothelial function to migraine and stroke: the Stroke Prevention in Young Women study

BACKGROUND AND PURPOSE

Migraine with aura is a risk factor for ischemic stroke, but the mechanism by which these disorders are associated remains unclear. Both disorders exhibit familial clustering, which may imply a genetic influence on migraine and stroke risk. Genes encoding for endothelial function are promising candidate genes for migraine and stroke susceptibility because of the importance of endothelial function in regulating vascular tone and cerebral blood flow.

METHODS

Using data from the Stroke Prevention in Young Women study, a population-based case-control study including 297 women aged 15 to 49 years with ischemic stroke and 422 women without stroke, we evaluated whether polymorphisms in genes regulating endothelial function, including endothelin-1 (EDN), endothelin receptor type B (EDNRB), and nitric oxide synthase-3 (NOS3), confer susceptibility to migraine and stroke.

RESULTS

EDN SNP rs1800542 and rs10478723 were associated with increased stroke susceptibility in whites (OR, 2.1; 95% CI, 1.1-4.2 and OR, 2.2; 95% CI, 1.1-4.4; P=0.02 and 0.02, respectively), as were EDNRB SNP rs4885493 and rs10507875, (OR, 1.7; 95% CI, 1.1-2.7 and OR, 2.4; 95% CI, 1.4-4.3; P=0.01 and 0.002, respectively). Only 1 of the tested SNP (NOS3 rs3918166) was associated with both migraine and stroke.

CONCLUSIONS

In our study population, variants in EDN and EDNRB were associated with stroke susceptibility in white but not in black women. We found no evidence that these genes mediate the association between migraine and stroke.

Peripheral artery disease: potential role of ACE-inhibitor therapy

Subjects with peripheral arterial disease (PAD) of the lower limbs are at high risk for cardiovascular and cerebrovascular events and the prevalence of coronary artery disease in such patients is elevated. Recent studies have shown that regular use of cardiovascular medications, such as therapeutic and preventive agents for PAD patients, seems to be promising in reducing long-term mortality and morbidity. The angiotensin-converting-enzyme (ACE) system plays an important role in the pathogenesis and progression of atherosclerosis, and ACE-inhibitors (ACE-I) seem to have vasculoprotective and antiproliferative effects as well as a direct anti-atherogenic effect. ACE-I also promote the degradation of bradykinin and the release of nitric oxide, a potent vasodilator; further, thay have shown important implications for vascular oxidative stress. Other studies have suggested that ACE-I may also improve endothelial dysfunction. ACE-I are useful for reducing the risk of cardiovascular events in clinical and subclinical PAD. Particularly, one agent of the class (ie, ramipril) has shown in many studies to able to significantly reduce cardiovascular morbidity and mortality in patients with PAD.

Physiology, Genetics, and Cardiovascular Disease: Focus on African Americans

The disproportionate impact of cardiovascular disease in African Americans is well recognized. Not only do risk factors such as obesity occur at a higher rate in the African-American community, but this population experiences a greater mortality from cardiovascular disease than their white counterparts. The cardiovascular system is regulated in part by two opposing mediators linking the risk factors of obesity, vascular dysfunction, and diabetes. One of these mediators--angiotensin II--increases blood pressure, impairs endothelial function, decreases peroxisome proliferator activated-receptor gamma, and is proinflammatory, growth stimulating, profibrotic, and proatherogenic. The other mediator, peroxisome proliferator activated-receptor gamma, lowers blood pressure, improves endothelial function, decreases angiotensin II type 1 receptor function, and is anti-inflammatory, growth-inhibiting, antifibrotic, and antiatherogenic. Genotypic variants have been discovered that affect the functioning of both of these important systems. Some of these variants--like some genotypic variants discovered in the adrenergic system--occur with different frequencies in African Americans than in Americans of European descent and may help to explain racial/ethnic differences in susceptibility to cardiovascular disease and aspects of the response to treatment. Recognition of these genotypic differences may permit the development of therapies tailored to individual patients.

Pathophysiology and therapeutic targets for ischemic stroke

The increased risk for stroke among those who have had a previous stroke or transient ischemic attack (TIA) and the tremendous burden of disability among stroke sufferers make both primary and secondary preventative strategies imperative. An understanding of the pathophysiology of stroke and TIA can help identify appropriate therapeutic targets.

Inflammatory pathways in atherosclerosis and acute coronary syndromes

Evidence from a broad range of studies demonstrates that atherosclerosis is a chronic disease that, from its origins to its ultimate complications, involves inflammatory cells (T cells, monocytes, macrophages), inflammatory proteins (cytokines, chemokines), and inflammatory responses from vascular cells (endothelial cell expression of adhesion molecules). Investigators have identified a variety of proteins whose levels might predict cardiovascular risk. Of these candidates, C-reactive protein, tumor necrosis factor-alpha, and interleukin-6 have been most widely studied. There is also the prospect of inflammation as a therapeutic target, with investigators currently debating to what extent the decrease in cardiovascular risk seen with statins, angiotensin-converting enzyme inhibitors, and peroxisome proliferator-activated receptor ligands derives from changes in inflammatory parameters. These advances in basic and clinical science have placed us on a threshold of a new era in cardiovascular medicine.

Angiotensin converting enzyme inhibitors: are they preferred first-line therapy?

In patients with hypertension, the primary goal is to reduce elevated blood pressure. All of the currently available and approved antihypertensive therapies are, by and large, equally efficacious. Some patient groups and individual patients may, however, respond differentially, and as a result one therapy may be more optimal than another. Overall, for uncomplicated hypertension and particularly for isolated systolic hypertension, diuretics should be considered for first-line therapy. However, comorbid conditions (which occur in > 50% of hypertensive patients) may prompt the need for a more ideal first-line therapy (eg, hypertension with diabetic nephropathy or with left ventricular dysfunction). Regardless, most patients with hypertension will require multidrug therapy to achieve the blood pressure goal, and an angiotensin converting enzyme (ACE) inhibitor may well be part of that therapy. Many going outcome trials comparing the newer therapies (such as ACE inhibitors) with diuretic-based therapy may redefine or clarify the use of different antihypertensive regimens.