Perivascular adipose tissue as a source of therapeutic targets and clinical biomarkers

Obesity is a modifiable cardiovascular risk factor, but adipose tissue (AT) depots in humans are anatomically, histologically, and functionally heterogeneous. For example, visceral AT is a pro-atherogenic secretory AT depot, while subcutaneous AT represents a more classical energy storage depot. Perivascular adipose tissue (PVAT) regulates vascular biology via paracrine cross-talk signals. In this position paper, the state-of-the-art knowledge of various AT depots is reviewed providing a consensus definition of PVAT around the coronary arteries, as the AT surrounding the artery up to a distance from its outer wall equal to the luminal diameter of the artery. Special focus is given to the interactions between PVAT and the vascular wall that render PVAT a potential therapeutic target in cardiovascular diseases. This Clinical Consensus Statement also discusses the role of PVAT as a clinically relevant source of diagnostic and prognostic biomarkers of vascular function, which may guide precision medicine in atherosclerosis, hypertension, heart failure, and other cardiovascular diseases. In this article, its role as a 'biosensor' of vascular inflammation is highlighted with description of recent imaging technologies that visualize PVAT in clinical practice, allowing non-invasive quantification of coronary inflammation and the related residual cardiovascular inflammatory risk, guiding deployment of therapeutic interventions. Finally, the current and future clinical applicability of artificial intelligence and machine learning technologies is reviewed that integrate PVAT information into prognostic models to provide clinically meaningful information in primary and secondary prevention.

Mechanisms, therapeutic implications, and methodological challenges of gut microbiota and cardiovascular diseases: a position paper by the ESC Working Group on Coronary Pathophysiology and Microcirculation

The human gut microbiota is the microbial ecosystem in the small and large intestines of humans. It has been naturally preserved and evolved to play an important role in the function of the gastrointestinal tract and the physiology of its host, protecting from pathogen colonization, and participating in vitamin synthesis, the functions of the immune system, as well as glucose homeostasis and lipid metabolism, among others. Mounting evidence from animal and human studies indicates that the composition and metabolic profiles of the gut microbiota are linked to the pathogenesis of cardiovascular disease, particularly arterial hypertension, atherosclerosis, and heart failure. In this review article, we provide an overview of the function of the human gut microbiota, summarize, and critically address the evidence linking compositional and functional alterations of the gut microbiota with atherosclerosis and coronary artery disease and discuss the potential of strategies for therapeutically targeting the gut microbiota through various interventions.

Translating atherosclerosis research from bench to bedside: navigating the barriers for effective preclinical drug discovery

Cardiovascular disease (CVD) remains the leading cause of death worldwide. An ongoing challenge remains the development of novel pharmacotherapies to treat CVD, particularly atherosclerosis. Effective mechanism-informed development and translation of new drugs requires a deep understanding of the known and currently unknown biological mechanisms underpinning atherosclerosis, accompanied by optimization of traditional drug discovery approaches. Current animal models do not precisely recapitulate the pathobiology underpinning human CVD. Accordingly, a fundamental limitation in early-stage drug discovery has been the lack of consensus regarding an appropriate experimental in vivo model that can mimic human atherosclerosis. However, when coupled with a clear understanding of the specific advantages and limitations of the model employed, preclinical animal models remain a crucial component for evaluating pharmacological interventions. Within this perspective, we will provide an overview of the mechanisms and modalities of atherosclerotic drugs, including those in the preclinical and early clinical development stage. Additionally, we highlight recent preclinical models that have improved our understanding of atherosclerosis and associated clinical consequences and propose model adaptations to facilitate the development of new and effective treatments.

Single cell atlas of cd45+ cells in angiotensin II-induced hypertension

 

Hypertension has been recently identified as an inflammatory disease. Immune cell infiltration is a characteristic feature in the vasculature and the kidneys in experimental hypertension, but the unique nature of such inflammatory infiltrates has not yet been comprehensively characterised.

Accordingly, we aimed to provide in-depth characteristics of immune cells in the vasculature and the kidneys in experimental hypertension.

To achieve this, we used single-cell RNA-sequencing of leukocytes (CD45+ cells were sorted) using the 10x Genomics platform in the aortas and the kidneys of male 12-week-old C57BL/6J mice (n=16–17/group) upon AngII (490 ng/min/kg) or sham buffer 14-day infusion, using osmotic minipumps. Samples were pooled to analyse three independent replicates. Bioinformatics analysis used Seurat/R to identify immune cell subpopulations and characterise differentially expressed genes (DEGs), pathways, and interactions signatures.

Ang II infusion increases the total number of CD45+ leukocytes in the aorta (346.7±89.1 vs. 1210±214.3; p=0,048), while in the kidneys, this was much less pronounced (1.1±0.5 fold vs. sham). Fifteen leukocyte populations/clusters were identified in the aorta and kidney based on their unique markers. In the aorta, shifts in numerous populations were evident, with the most significant differences in tissue-resident macrophages and activated tissue-resident macrophages, monocyte-derived dendritic cells and NK cells (Figure 1). Kidneys did not display such profound changes. The transcriptomic profile analysis showed 767 significant DEGs in the aorta and only 35 in the kidney. CellChat analysis also indicated more robust interactions between the immune cells in the aorta than in kidneys. These included Ifitm1, Apoe, Il1b, and C1q a/b/c, which were shared between aorta and kidney and may play an immunoregulatory role, affecting smooth muscle cell proliferation and arterial vascular remodelling. Top up-regulated leukocyte genes in the aorta included Ccl8, Ccl3, Cxcl2, Lyz2, and Spp1, while in the kidney, Cd74, Cst3, Fos, Fcer1g, Tyrobp, and Ccl4. GO pathway signatures of aortic leukocyte DEGs revealed pathways related to leukocyte migration, cytokine production, T cell activation, and leukocyte activation and adhesion. Cell-specific analysis showed that macrophage subpopulations most strongly increased in Ang II-induced hypertension displayed the most pronounced changes in the transcriptome profiles and cell-cell interactions.

Comprehensive single-cell RNA sequencing identifies tissue-resident macrophages, monocyte-derived dendritic cells, and NK cells as most affected leukocyte subpopulations in hypertensive vasculature. Differentially expressed genes support the role of these cells in vascular remodelling and propagation of inflammation, further supporting the identification of these cells as potential future targets for therapeutic interventions in hypertension.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): European Research Council

Abstract 127: Nox5 Expression In A Vascular Smooth Muscle Cell-specific Manner Induces Fibroblast To Myofibroblast Differentiation

Mice expressing human Nox5 (hNox5) in VSMC exhibit cardfiovascular fibrosis, where mechanisms are unknown. We postulated that VSMC-Nox5 promotes fibroblast to myofibroblast differentiation that contributes to fibrosis. Fibroblasts were cultured from wildtype (WT) and hNOX5 mice. Mice (20 weeks old) were infused with Ang II (600 ng/Kg/day) for 28 days and renal fibrosis/inflammation studied. Markers of myofibroblasts (αSMA), and pro-fibrotic and inflammatory signaling molecules were assessed by qPCR and immunoblotting. Inflammatory infiltrate was assessed by FACS. Fibroblasts from Nox5 mice exhibited increased mRNA of markers of myofibroblast αSMA (2 -ddC :1.54±0.05 vs. WT 0.78±0.17) and Myocd (2 -ddC :1.36±0.17 vs. WT 0.39±0.22), as well as, pro-fibrotic markers, Col1A1 (2 -ddC :1.74±0.16 vs. WT 0.67±0.11), Col3A1 (2 -ddC :1.74±0.18 vs. WT 0.96±0.24) and TIMP3 (2 -ddC :2.65±0.25 vs. WT 0.38±0.07), p<0.05. mRNA expression of CD36 (2 -ddC :1.37±0.07 vs. WT 86±0.24), TNFα (2 -ddC :1.32±0.2 vs. WT 0.71±0.17) and TNFR1 (2 -ddC :1.26±0.04 vs. WT 1.02±0.10) were increased, while CD68 expression was decreased (2 -ddC :0.82±0.11 vs. WT 1.36±0.18) in fibroblasts from Nox5 mice (p<0.05). In Nox5 mice fibroblasts, ROS production and TGFβ protein expression (AU:1.8±0.05 vs. WT 1.4±0.06), as well as TGFβR2 gene expression (2 -ddC :2.04±0.17 vs. WT 0.57±0.12), were increased (p<0.05). mRNA of DNMT3a and TET2, DNA methylation regulatory enzymes, were also increased in fibroblasts from Nox5 mice, p<0.05. Kidneys from Ang II-infused Nox5 mice exhibited significant perivascular fibrosis and inflammatory cell infiltration compared to WT, as well as increased protein expression of TGFβ (AU: 3.59±0.8 vs. WT 1.54±0.2) and IL-11 (AU: 0.64±0.08 vs. WT 0.39±0.04), p<0.05; where levels of macrophage F4/80+ cells (%:24±2 vs WT 18±1, p<0.05) and levels of cytotoxic CD8+ T cells were increased, p<0.05. Kidney expression of vimentin (AU:1.01±0.05 vs WT 0.85±0.03) and αSMA (AU:0.44±0.03 vs WT 0.33±0.01), were increased in Nox5 mice (p<0.05). Nox5 regulates fibrosis by inducing fibroblast-to-myofibroblast differentiation, possibly through increased ROS. These processes may be important in Nox5-assocated cardiovascular-renal fibrosis.

Red blood cell distribution width is associated with increased interactions of blood cells with vascular wall

The mechanism underlying the association between elevated red cell distribution width (RDW) and poor prognosis in variety of diseases is unknown although many researchers consider RDW a marker of inflammation. We hypothesized that RDW directly affects intravascular hemodynamics, interactions between circulating cells and vessel wall, inducing local changes predisposing to atherothrombosis. We applied different human and animal models to verify our hypothesis. Carotid plaques harvested from patients with high RDW had increased expression of genes and proteins associated with accelerated atherosclerosis as compared to subjects with low RDW. In microfluidic channels samples of blood from high RDW subjects showed flow pattern facilitating direct interaction with vessel wall. Flow pattern was also dependent on RDW value in mouse carotid arteries analyzed with Magnetic Resonance Imaging. In different mouse models of elevated RDW accelerated development of atherosclerotic lesions in aortas was observed. Therefore, comprehensive biological, fluid physics and optics studies showed that variation of red blood cells size measured by RDW results in increased interactions between vascular wall and circulating morphotic elements which contribute to vascular pathology.

Rationale and Design for the LOnger-term effects of SARS-CoV-2 INfection on blood Vessels And blood pRessure (LOCHINVAR): an observational phenotyping study

Introduction

COVID-19 may lead to long-term endothelial consequences including hypertension, stroke and myocardial infarction. A pilot study ‘COVID-19 blood pressure endothelium interaction study’, which found that patients with normal blood pressure (BP) at the time of hospital admission with COVID-19 showed an 8.6 mm Hg higher BP ≥12 weeks after recovery, compared with a group without COVID-19. The ‘LOnger-term effects of SARS-CoV-2 INfection on blood Vessels And blood pRessure’(LOCHINVAR) study is designed to provide definitive evidence of the long-term impact of COVID-19 on BP.

Methods and analysis

The LOCHINVAR study is an observational clinical phenotyping study comparing longitudinal BP change between individuals with and without COVID-19 infection. 150 participants (30–60 years) with no history of hypertension and not on BP lowering medications will be recruited to the study to attend three visits (baseline, 12 months, 18 months). Cases will be patients who were admitted to the Queen Elizabeth University Hospital (QEUH), Glasgow, UK, with suspected/confirmed COVID-19 until 31 December 2021 and who were alive at discharge. Controls will be those who have never had confirmed COVID-19 infection. All participants will undergo clinical and vascular phenotyping studies which will include 24-hour ambulatory BP monitoring systolic BP (ABPM SBP), brachial flow-mediated dilatation urine and blood samples to assess the renin-angiotensin system, vascular inflammation and immune status. The primary outcome is the change in systolic 24-hour ABPM (ABPM SBP) between the cases and controls. Sample size was calculated to detect a mean difference of 5 mm Hg ABPM SBP at 80% power.

Ethics and dissemination

The protocol of this study has been approved by the West of Scotland Research Ethics Committee 5 (21/WS/0075), Scotland, UK. Written informed consent will be provided by all study participants. Study findings will be submitted to international peer-reviewed hypertension journals and will be presented at international scientific meetings.

Trial registration number

NCT05087290.

Cardiovascular and Renal Risk Factors and Complications Associated With COVID-19

The current COVID-19 pandemic, caused by the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) virus, represents the largest medical challenge in decades. It has exposed unexpected cardiovascular vulnerabilities at all stages of the disease (pre-infection, acute phase, and subsequent chronic phase). The major cardiometabolic drivers identified as having epidemiologic and mechanistic associations with COVID-19 are abnormal adiposity, dysglycemia, dyslipidemia, and hypertension. Hypertension is of particular interest, because components of the renin-angiotensin system (RAS), which are critically involved in the pathophysiology of hypertension, are also implicated in COVID-19. Specifically, angiotensin-converting enzyme-2 (ACE2), a multifunctional protein of the RAS, which is part of the protective axis of the RAS, is also the receptor through which SARS-CoV-2 enters host cells, causing viral infection. Cardiovascular and cardiometabolic comorbidities not only predispose people to COVID-19, but also are complications of SARS-CoV-2 infection. In addition, increasing evidence indicates that acute kidney injury is common in COVID-19, occurs early and in temporal association with respiratory failure, and is associated with poor prognosis, especially in the presence of cardiovascular risk factors. Here, we discuss cardiovascular and kidney disease in the context of COVID-19 and provide recent advances on putative pathophysiological mechanisms linking cardiovascular disease and COVID-19, focusing on the RAS and ACE2, as well as the immune system and inflammation. We provide up-to-date information on the relationships among hypertension, diabetes, and COVID-19 and emphasize the major cardiovascular diseases associated with COVID-19. We also briefly discuss emerging cardiovascular complications associated with long COVID-19, notably postural tachycardia syndrome (POTS).

The year in basic vascular biology research: from mechanoreceptors and neutrophil extracellular traps to smartphone data and omics

2020 has been an extraordinary year. The emergence of COVID-19 has driven urgent research in pulmonary and cardiovascular science and other fields. It has also shaped the way that we work with many experimental laboratories shutting down for several months, while bioinformatics approaches and other large data projects have gained prominence. Despite these setbacks, vascular biology research is stronger than ever. On behalf of the European Society of Cardiology Council for Basic Cardiovascular Science (ESC CBCS), here we review some of the vascular biology research highlights for 2020. This review is not exhaustive and there are many outstanding vascular biology publications that we were unable to cite due to page limits. Notwithstanding this, we have provided a snapshot of vascular biology research excellence in 2020 and identify topics that are in the ascendency and likely to gain prominence in coming years.

Progress in cardiac research - from rebooting cardiac regeneration to a complete cell atlas of the heart

We review some of the important discoveries and advances made in basic and translational cardiac research in 2020. For example, in the field of myocardial infarction (MI), new aspects of autophagy and the importance of eosinophils were described. Novel approaches such as a glycocalyx mimetic were used to improve cardiac recovery following MI. The strategy of 3D bio-printing was shown to allow the fabrication of a chambered cardiac organoid. The benefit of combining tissue engineering with paracrine therapy to heal injured myocardium is discussed. We highlight the importance of cell-to cell communication, in particular the relevance of extracellular vesicles such as exosomes, which transport proteins, lipids, non-coding RNAs and mRNAs and actively contribute to angiogenesis and myocardial regeneration. In this rapidly growing field, new strategies were developed to stimulate the release of reparative exosomes in ischaemic myocardium. Single-cell sequencing technology is causing a revolution in the study of transcriptional expression at cellular resolution, revealing unanticipated heterogeneity within cardiomyocytes, pericytes and fibroblasts, and revealing a unique subpopulation of cardiac fibroblasts. Several studies demonstrated that exosome- and non-coding RNA-mediated approaches can enhance human induced pluripotent stem cell (iPSC) viability and differentiation into mature cardiomyocytes. Important details of the mitochondrial Ca2+ uniporter and its relevance were elucidated. Novel aspects of cancer therapeutic-induced cardiotoxicity were described, such as the novel circular RNA circITCH, which may lead to novel treatments. Finally, we provide some insights into the effects of SARS-CoV-2 on the heart.

FC 062OBESITY AS A CAUSE OF KIDNEY DISEASE - INSIGHTS FROM MENDELIAN RANDOMISATION STUDIES

Background and Aims

Obesity and kidney diseases are common complex disorders with an increasing clinical and economic impact on healthcare around the globe. We aim to examine if modifiable anthropometric indices of obesity exert putatively causal effects on different measures of kidney health and disease.

Method

We performed conventional observational and Mendelian randomisation (MR) study to examine if modifiable anthropometric indices of obesity exert putatively causal effects on different kidney health and disease-related phenotypes. These analyses were conducted using approximately 300,000 participants of white-British ancestry from UK Biobank and up to 480,000 participants of predominantly European ancestry from genome-wide association studies.

Results

The Mendelian randomisation analysis indicated that increasing values of genetically predicted BMI and waist circumference were causally linked to changes in renal function indices including reduced estimated glomerular filtration (PeGFRcystatineC=5.96 × 10-59 for BMI and PeGFRcystatineC=1.72 × 10-69 for waist circumference) and increased blood urea nitrogen (PBUN=2.01 × 10-10 for BMI and PBUN=4.54 × 10-12 for waist circumference) in UK Biobank individuals. These associations were replicated using data from CKDGen Consortium individuals (PeGFRcystatineC=1.47 × 10-5 for BMI and PeGFRcystatineC=7.63 × 10-5 for waist circumference; PBUN=1.96 × 10-4 for BMI and PBUN=3.10 × 10-3 for waist circumference). One standard deviation increase in genetically-predicted BMI and waist circumference decreased the relative odds of kidney health index by 14% and 18% (OR=0.86; 95%CI: 0.82-0.92; P=9.18 × 10-6 for BMI and OR=0.82; 95%CI: 0.75-0.90; P=2.12 × 10-5 for waist circumference). Approximately 13-16% of the causal effect of obesity indices on kidney health was mediated by blood pressure. Obesity increased the risk of both acute and chronic kidney disease of several aetiologies including hypertensive renal disease (OR=1.79; 95%CI: 1.14-2.82; P=1.15 × 10-2 for BMI and OR=2.41; 95%CI: 1.30-4.45; P=5.03 × 10-3 for waist circumference), renal failure (OR=1.51; 95%CI: 1.25-1.83; P=2.60 × 10-5 for BMI and OR=1.86; 95%CI: 1.43-2.42; P=4.16 × 10-6 for waist circumference) and CKD (OR=1.50; 95%CI: 1.16-1.96; P=2.44 × 10-3 for BMI and OR=1.83; 95%CI: 1.28-2.63; P=9.49 × 10-4 for waist circumference) and diabetic nephropathy (OR=1.92; 95%CI: 1.44-2.54; P=6.86 × 10-6 for BMI).

Conclusion

These findings indicate that obesity is causally linked to indices of renal health and the risk of different kidney diseases. This evidence substantiates the value of weight loss as a strategy of preventing and/or counteracting a decline in kidney health as well as decreasing the risk of renal disease.

Immune spleen cells attenuate the inflammatory profile of the mesenteric perivascular adipose tissue in obese mice

The perivascular adipose tissue (PVAT) differs from other fat depots and exerts a paracrine action on the vasculature. The spleen has an important role in the immune response, and it was observed to have either a protective role or a contribution to obesity-related diseases. However, the relation between spleen and PVAT is elusive in obesity. We investigated the role of spleen in the inflammatory profile of the mesenteric PVAT (mPVAT) from mice fed a high-fat diet (HFD) for 16 weeks. Male C57Bl/6 mice were sham-operated or splenectomized (SPX) and fed a HFD for 16 weeks. mPVAT morphology was evaluated by hematoxylin and eosin staining, infiltrated immune cells were evaluated by flow cytometry, inflammatory cytokines were evaluated by ELISA and the splenic cell chemotaxis mediated by mPVAT was evaluated using a transwell assay. In SPX mice, HFD induced adipocyte hypertrophy and increased immune cell infiltration and proinflammatory cytokine levels in mPVAT. However, none of these effects were observed in mPVAT from sham-operated mice. Spleen from HFD fed mice presented reduced total leukocytes and increased inflammatory markers when compared to the spleen from control mice. Chemotaxis of spleen cells mediated by mPVAT of HFD fed mice was reduced in relation to standard diet fed mice. The spleen protects mPVAT against the effects of 16-week HFD. This information was missing, and it is important because PVAT is different from other fat depots and data cannot be extrapolated from any type of adipose tissue to PVAT.

Current progress in clinical, molecular, and genetic aspects of adult fibromuscular dysplasia

Fibromuscular dysplasia (FMD) is a non-atherosclerotic vascular disease that may involve medium-sized muscular arteries throughout the body. The majority of FMD patients are women. Although a variety of genetic, mechanical, and hormonal factors play a role in the pathogenesis of FMD, overall, its cause remains poorly understood. It is probable that the pathogenesis of FMD is linked to a combination of genetic and environmental factors. Extensive studies have correlated the arterial lesions of FMD to histopathological findings of arterial fibrosis, cellular hyperplasia, and distortion of the abnormal architecture of the arterial wall. More recently, the vascular phenotype of lesions associated with FMD has been expanded to include arterial aneurysms, dissections, and tortuosity. However, in the absence of a string of beads or focal stenosis, these lesions do not suffice to establish the diagnosis. While FMD most commonly involves renal and cerebrovascular arteries, involvement of most arteries throughout the body has been reported. Increasing evidence highlights that FMD is a systemic arterial disease and that subclinical alterations can be found in non-affected arterial segments. Recent significant progress in FMD-related research which has led to improved understandings of the disease's clinical manifestations, natural history, epidemiology, and genetics. Ongoing work continues to focus on FMD genetics and proteomics, physiological effects of FMD on cardiovascular structure and function, and novel imaging modalities and blood-based biomarkers that can be used to identify subclinical FMD. It is also hoped that the next decade will bring the development of multi-centred and potentially international clinical trials to provide comparative effectiveness data to inform the optimal management of patients with FMD.

Low-grade chronic inflammation and immune alterations in childhood and adolescent cancer survivors: A contribution to accelerated aging?

Background

The long‐term consequences of chemotherapy and radiotherapy result in a high prevalence and early onset of age‐related chronic diseases in survivors. We aimed to examine whether childhood and adolescent cancer survivors (CS) demonstrate biomarkers of accelerated aging.

Methods

We evaluated 50 young adult CS at 11 [8–15] years after cancer diagnosis, and 30 healthy, age and sex‐matched controls, who were unexposed to cancer therapy. Using a machine‐learning approach, we assessed factors discriminating CS from controls and compared selected biomarkers and lymphocyte subpopulations with data from the Framingham Heart Study (FHS) cohort and the Genotype Tissue Expression (GTEx) project.

Results

Survivors compared with controls had higher levels of C‐reactive protein and fibrinogen. The surface expression of CD38 on T cells was increased, and there was an increase in the percentage of memory T cells in survivors, compared with the unexposed group. The relationships between above cell subpopulations and age were consistent in CS, FHS, and GTEx cohorts, but not in controls.

Conclusions

Young pediatric cancer survivors differ from age‐related controls in terms of activation of the adaptive immune system and chronic, low‐grade inflammation. These changes resemble aging phenotype observed in older population. Further research in biomarkers of aging in young, adult childhood cancer survivors is warranted, as it may facilitate screening and prevention of comorbidities in this population.

Hypertension, the renin-angiotensin system, and the risk of lower respiratory tract infections and lung injury: implications for COVID-19

Systemic arterial hypertension (referred to as hypertension herein) is a major risk factor of mortality worldwide, and its importance is further emphasized in the context of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection referred to as COVID-19. Patients with severe COVID-19 infections commonly are older and have a history of hypertension. Almost 75% of patients who have died in the pandemic in Italy had hypertension. This raised multiple questions regarding a more severe course of COVID-19 in relation to hypertension itself as well as its treatment with renin–angiotensin system (RAS) blockers, e.g. angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs). We provide a critical review on the relationship of hypertension, RAS, and risk of lung injury. We demonstrate lack of sound evidence that hypertension per se is an independent risk factor for COVID-19. Interestingly, ACEIs and ARBs may be associated with lower incidence and/or improved outcome in patients with lower respiratory tract infections. We also review in detail the molecular mechanisms linking the RAS to lung damage and the potential clinical impact of treatment with RAS blockers in patients with COVID-19 and a high cardiovascular and renal risk. This is related to the role of angiotensin-converting enzyme 2 (ACE2) for SARS-CoV-2 entry into cells, and expression of ACE2 in the lung, cardiovascular system, kidney, and other tissues. In summary, a critical review of available evidence does not support a deleterious effect of RAS blockers in COVID-19 infections. Therefore, there is currently no reason to discontinue RAS blockers in stable patients facing the COVID-19 pandemic.

Immune cells as targets for cardioprotection: new players and novel therapeutic opportunities

New therapies are required to reduce myocardial infarct (MI) size and prevent the onset of heart failure in patients presenting with acute myocardial infarction (AMI), one of the leading causes of death and disability globally. In this regard, the immune cell response to AMI, which comprises an initial pro-inflammatory reaction followed by an anti-inflammatory phase, contributes to final MI size and post-AMI remodelling [changes in left ventricular (LV) size and function]. The transition between these two phases is critical in this regard, with a persistent and severe pro-inflammatory reaction leading to adverse LV remodelling and increased propensity for developing heart failure. In this review article, we provide an overview of the immune cells involved in orchestrating the complex and dynamic inflammatory response to AMI-these include neutrophils, monocytes/macrophages, and emerging players such as dendritic cells, lymphocytes, pericardial lymphoid cells, endothelial cells, and cardiac fibroblasts. We discuss potential reasons for past failures of anti-inflammatory cardioprotective therapies, and highlight new treatment targets for modulating the immune cell response to AMI, as a potential therapeutic strategy to improve clinical outcomes in AMI patients. This article is part of a Cardiovascular Research Spotlight Issue entitled 'Cardioprotection Beyond the Cardiomyocyte', and emerged as part of the discussions of the European Union (EU)-CARDIOPROTECTION Cooperation in Science and Technology (COST) Action, CA16225.

Controlled aerobic training improves endothelial function and modifies vascular remodeling in healthy adults with high normal blood pressure

The aim of the study was to assess endothelial function in adults with high normal blood pressure (HNBP) undergoing controlled aerobic training. The study was conducted among 31 volunteers with HNBP. Subjects underwent supervised cycle ergometer training for 12 weeks. Exercise intensity was assessed by monitoring the pulse with intention to keep the heart rate increase within the range of 40% to 65% of the heart rate reserve. The control group consisted of 14 healthy adults, not subjected to any intervention. The control group was examined twice at 12-week intervals (non-exercising time control). Vascular endothelial function was determined by flow-mediated dilation (FMD) and by measuring total nitric oxide products (NOx). The measurement of carotid intima-media complex thickness (IMT) was an indirect method of assessing vascular remodeling. Blood pressure (ABPM method), anthropological parameters and lipid profile were also assessed. There was a significant change in FMD after 3-month training in the study group: the average FMD training was 5.21 ± 2.17%, while after the program FMD increased to 9.46 ± 3.69% (P < 0.001). After training, the NO_x also increased from 1.01 ± 0.38 μmol/L to 1.27 ± 0.48 μmol/L (P < 0.001). Effects were observed irrespective of participants' sex. Interestingly, a modest but significant reduction of IMT was also observed, from 0.5 ± 0.06 mm to 0.46 ± 0.10 mm (P = 0.04). There was also a reduction in the percentage of body fat content from 25.01 ± 8.77% to 22.31 ± 8.79% (P < 0.001). No statistically significant changes were noted after 12 weeks of training in the blood pressure and lipid profile. In the control group no statistically significant changes of any parameter were observed. Regular aerobic exercise improves nitric oxide-dependent endothelial function of the vessels and can initiate regression of atherosclerosis in people with HNBP.

Serum rantes, transforming growth factor-β1 and interleukin-6 levels correlate with cardiac muscle fibrosis in patients with aortic valve stenosis

Regulated on Activation Normal T Expressed and Secreted (RANTES) chemokine is involved in the initiation of inflammation and immune-cell recruitment. Interleukin -6 (IL-6) is used as a general index of severity of the chronic inflammatory process. Finally, transforming growth factor-β (TGF-β) is an immune biomarker potentially involved in the regulation of valve fibrosis and calcification. The aim of this study was to analyze selected biomarkers associated with the different stages of immune-pathogenesis in aortic stenosis. Forty consecutive patients with moderate to severe aortic stenosis (AS) and without previous myocardial infarction history were included in the study and divided into two groups. Two imaging techniques, echocardiography and magnetic resonance, were used to estimate the degree of AS and left ventricular muscle function. Inflammatory biomarker serum levels including CCL5/RANTES, IL-6, and TGF-β1 were determined based on ELISA measurements. Mean levels of RANTES, IL-6, and TGF-β1 did not significantly differ between both groups. A negative correlation was found between RANTES serum level and left ventricle (LV) mass as assessed by MRI (r = -0.3358, P = 0.0341). A positive correlation (r = 0.3283, P = 0.0387) was found between IL-6 serum levels and LV mass as measured by MRI. In addition, a positive correlation (r = 0.6803, P = 0.01) was seen between IL-6 serum levels and LV muscle mass with positive late gadolinium enhancement (LGE). There was a positive correlation between TGF-β1 serum level and ejection fraction as measured by echocardiography (r = 0.3217, P = 0.043). The relationship between selected inflammatory biomarkers, LV ejection fraction, LV mass, and LV muscle mass with LGE appeared to be independent of valvular pathobiologic process severity, as we did not observe differences in IL-6, RANTES, or TGF-β1 between groups differing in severity. On the contrary, these markers appear to be linked to myocardial function and remodeling, which may provide valuable insights into the pathobiology of AS and provide a basis for future detection strategies of AS.

Abstract P338: Aging and Inhibition of Nox1/4 Modulate Perivascular Inflammation in Spontaneous Hypertension

Introduction: Hypertension is associated with enhanced oxidative stress and perivascular inflammation. Although, that aging and oxidative stress are major factors in the development of hypertension their effect on perivascular inflammation remains unclear.

Methods: Using flow cytometry we studied leukocytes infiltrating perivascular adipose tissue (PVAT) in 1-, 3-, 6- and 12-month-old SHR (Spontaneously Hypertensive Rats) and normotensive WKY (Wistar-Kyoto) rats. Additionally, 1-month-old rats were treated with GKT137831 (60mg/kg) or ML171 (NOX1/4 and NOX1 inhibitor, respectively) for 4 weeks. Blood pressure (PB) was measured by the tail cuff.

Results: Aging in SHRs was associated with elevation of BP (139±4 vs 180±4 vs 202±2 vs 208±2 mmHg; 1 vs 3 vs 6 vs 12-month-old, respectively) when this effect was not seen in WKY rats. While the total number of leukocytes infiltrating PVAT were comparable between 1-month-old WKY and SHR (p=0.8) aging escalated their numbers only in SHRs (2096±164 vs 1994±296 vs 2311±470 vs 3255±408 cell/mg; p int <0.001). Similar effect was observed among NK cells (p int <0.001) and macrophages (p int <0.001). Moreover, spontaneous hypertension was associated with 2-fold elevation of T cells residing in PVAT in comparison to WKY, however, aging did not affect their number in both groups. While the age-related increase of Nox4 mRNA was observed in both groups, this increase was more dynamic in SHRs, (p int <0.05). Furthermore, 5-, 6- and 9-fold induction of Nox1 mRNA was observed in the vessels of 3-, 6- and 12-months-old SHRs, respectively (p<0.01). GKT137831 treatment significantly increased BP (p<0.01, 2way ANOVA) in both WKY and SHR (150±2 vs 164±3 mmHg, 198±4 vs 209±3 mmHg, respectively). This was accompanied by elevation of the total number of leukocytes (988±180 vs 1471±88 cell/mg, 1487±945 vs 1878±164 cell/mg) and macrophages (107±14 vs. 153±14 cell/mg, 228±26 vs. 298±42) in PVAT of WKYs and SHRs treated with GKT137831. On the contrary, ML171 treatment protected against increased accumulation of CD45+ cells in PVAT, without affecting BP.

Conclusions: Aging in spontaneous hypertension is associated with elevation of BP and aggravation of perivascular inflammation which are hastened after NOX1/4 inhibitor treatment.

Endothelial dysfunction is independent of inflammation and altered CCR7 T cell expression in patients with ankylosing spondylitis

OBJECTIVES

The accumulation of CCR7 (chemokine receptor 7) positive cells in the vessel wall may be involved in endothelial dysfunction and subsequent accelerated atherogenesis. CCR7 plays a crucial role in T cell and monocyte migration/homing and in priming of naive T lymphocytes in non-lymphoid tissues in chronic inflammatory diseases. Our objective was to investigate the endothelial function and inflammation-driven expression of CCR7 on T lymphocytes in patients with ankylosing spondylitis (AS).

METHODS

We performed flow cytometry to assess the distribution of peripheral blood T cell subpopulations in the context of serum inflammatory markers (TNF-α, IL-6, sICAM-1) and asymmetric dimethylarginine (ADMA) in 38 patients with AS with active disease, and in 20 healthy controls.

RESULTS

Patients with AS demonstrated higher ADMA (0.74±0.2 μmol/l vs. 0.64±0.15 μmol/l; p=0.03), as well as elevated inflammatory markers (TNFα, IL-6, sICAM-1) and increased proportions of circulating CCR7-positive lymphocytes largely attributable to elevated CD8+ naive T cells (47.1±17 vs. 34.3±13.1%; p=0.005). However, ADMA did not correlate with either CCR7-positive lymphocytes or inflammatory markers.

CONCLUSIONS

We found an increased percentage of peripheral CCR7 T cells accompanied by endothelial dysfunction in patients with AS. The lack of direct associations between ADMA and inflammation may suggest the presence of other pathogenic mechanisms contributing to accelerated atherogenesis and increased cardiovascular risk in AS.

Treatment of denture-related stomatitis improves endothelial function assessed by flow-mediated vascular dilation

INTRODUCTION

The presence of oral inflammation has recently been linked with the pathogenesis of cardiovascular diseases. While numerous studies have described links between periodontitis and endothelial dysfunction, little is known about the influence of denture-related stomatitis (DRS) on cardiovascular risk. Therefore, the aim of this study was to determine whether the treatment of DRS can lead to improvement of the clinical measures of vascular dysfunction.

MATERIAL AND METHODS

The DRS patients were treated with a local oral antifungal agent for 3 weeks. Blood pressure, flow-mediated dilatation (FMD) and nitroglycerine-mediated vascular dilatation (NMD) were measured during three study visits: before treatment, one day and two months after conclusion of antifungal therapy.

RESULTS

Flow-mediated dilatation measurements showed significant improvement of endothelial function 2 months after treatment (FMD median 5%, 95 CI: 3-8.3 vs. 11%, 95% CI: 8.8-14.4; p < 0.01), while there was no difference in control, endothelium-independent vasorelaxations (NMD; median = 15.3%, 95% CI: 10.8-19.3 vs. 12.7%, 95% CI: 10.6-15; p = 0.3). Other cardiovascular parameters such as systolic (median = 125 mm Hg; 95% CI: 116-129 vs. 120 mm Hg, 95% CI: 116-126; p = 0.1) as well as diastolic blood pressure and heart rate (median = 65.5 bpm, 95% CI: 56.7-77.7 vs. 71 bpm, 95% CI: 66.7-75; p = 0.5) did not change during or after the treatment.

CONCLUSIONS

Treatment of DRS is associated with improvement of endothelial function. Since endothelial dysfunction is known to precede the development of severe cardiovascular disorders such as atherosclerosis and hypertension, patients should be more carefully screened for DRS in general dental practice, and immediate DRS treatment should be advised.

Abstract 046: The Role of Tumor Necrosis Factor α and Natural Killer Cells in Uterine Artery Function During Pregnancy in the Stroke Prone Spontaneously Hypertensive Rat

Objective: We have previously characterised the stroke prone spontaneously hypertensive rat (SHRSP) as a model of deficient uterine artery remodelling and identified an increase in pro-inflammatory TNFα relative to the normotensive WKY strain during pregnancy.

Method: SHRSP were treated with etanercept (0.8 mg/kg) or vehicle at gestational day (GD) 0, 6, 12 and 18. Animals were sacrificed at GD18.

Results: Etanercept reduced systolic blood pressure in the SHRSP after GD12 (ΔSBP GD 10-21 SHRSP 12.0 ± 4.17 vs. ETN 25.8 ± 4.27 mmHg; p<0.05). Uterine arteries from GD18 showed that etanercept reduced uterine artery contraction (SHRSP 57.3 ± 8.75 vs. ETN 35.2 ± 2.19 kPa; p<0.01) and increased carbachol response (SHRSP 13.8 ± 3.8 vs. ETN 40.1 ± 3.25 %; p<0.05). Uteroplacental blood flow analysed using Doppler showed that etanercept reduced uterine artery resistance index in SHRSP (SHRSP 0.79 ± 0.02 vs. ETN 0.61 ± 0.02 UARI; p<0.01). Etanercept increased litter size (SHRSP 7.80 ± 0.44 vs. ETN 12.75 ± 0.94 fetuses), reduced resorption frequency (SHRSP 66.7% vs. ETN 25.0% dams with resorption) and decreased glycogen cell loss from the placenta in SHRSP. We sought to identify the source of excess TNFα in the SHRSP. Natural killer (NK) cells (CD3-CD161+) were increased in the SHRSP relative to the WKY in the maternal circulation (WKY 1.5 ± 0.4 vs. SHRSP 6.06 ± 0.28 %; p<0.01) and placenta (WKY 11.6 ± 2.39 vs. SHRSP 659.8 ± 201.2 cells/mg; p<0.01). These NK cells produced excess TNFα in the SHRSP maternal circulation (SHRSP 6.5 ± 0.4 vs. WKY 2.5 ± 0.4 %; p<0.05) and placenta (SHRSP 65.7 ± 4.2 vs. WKY 16.9 ± 1.7 %; p<0.01) relative to the WKY. In the SHRSP placenta, etanercept treatment reduced the number of cytotoxic NK cells (SHRSP 659.8 ± 201.2 vs. ETN 148.0 ± 12.62 cells/mg; p<0.01) by down-regulating CD161 expression associated with a decrease in granzyme B production (CD161+ 71.47 ± 2.1 vs. CD161 Low 14.32 ± 0.77 % granzyme B+; p<0.01).

Conclusions: Excess TNFα plays a causative role in adverse pregnancy outcome in the SHRSP. One source of this TNFα is an increase in NK cells during gestation in the SHRSP. Etanercept targets NK cells in the SHRSP placenta and down-regulates cytotoxic granzyme B production.

Role and analysis of monocyte subsets in cardiovascular disease. Joint consensus document of the European Society of Cardiology (ESC) Working Groups "Atherosclerosis & Vascular Biology" and "Thrombosis"

Monocytes as cells of the innate immunity are prominently involved in the development of atherosclerotic lesions. The heterogeneity of blood monocytes has widely been acknowledged by accumulating experimental and clinical data suggesting a differential, subset-specific contribution of the corresponding subpopulations to the pathology of cardiovascular and other diseases. This document re-evaluates current nomenclature and summarises key findings on monocyte subset biology to propose a consensus statement about phenotype, separation and quantification of the individual subsets.

Thermographic assessment of skin prick tests in comparison with the routine evaluation methods

INTRODUCTION

The skin prick test is still the first and basic procedure in the diagnosis of allergic diseases. The possibility of using a sensitive thermographic method supported by the mathematical model for the assessment of skin test results will be highlighted in the studies.

AIM

To compare the proposed approach with routine planimetric and thermographic methods.

MATERIAL AND METHODS

A mathematical model of allergic reaction was developed. Simplifying assumptions of the IgE-mediated skin reaction is the essence of the model. Investigations were performed in a group of 40 patients.

RESULTS

Using the spatio-temporal evolution of temperature distributions, the ratios of the histamine released from mast cells to the control histamine were determined. The obtained values very well correlate with the standard evaluation of skin prick tests (correlation coefficient = 0.98).

CONCLUSIONS

The proposed method of skin test evaluation presents several advantages. The continuous acquisition of data provides the monitoring of time course of the allergic response. The transport of mediator and its concentration were distinctly discriminated, which may be diagnostically useful, especially for abnormal cases. The high sensitivity of the method enables studying patients regardless of age and skin sensitivity.

Systemic T Cells and Monocyte Characteristics in Patients with Denture Stomatitis

PURPOSE

Chronic inflammatory disorders of the oral cavity, such as periodontitis, were recently linked to systemic immune activation. Since fungal oral infections have not yet been studied in this respect, the aim of our study is to determine whether the local inflammation caused by oral fungal infection of the palatal tissue (denture stomatitis-DS) is associated with the systemic inflammatory response. This question is becoming essential as the population ages.

MATERIALS AND METHODS

Peripheral blood of DS patients (n = 20) and control patients (n = 24) was assessed with flow cytometry to determine lymphocyte and monocyte profiles. Intracellular cytometric analysis was carried out to establish cytokine production by T cells. DS was diagnosed based on clinical symptoms of DS such as swelling and redness of oral mucosa, confirmed by microbiological swabs for fungal colonization with Candida species. The control group was recruited from denture users without clinical and microbiological signs of oral infections.

RESULTS

Percentages of peripheral lymphocytes, T cells, monocytes, and their subpopulations were similar in both studied groups. The exception was median percentages of CD25+ T cell subsets, which were significantly lower in DS patients than in control subjects. This reduction was observed in both CD4 T cell subset (16.7% and 28.1%; p = 0.0006) and CD8 T cell subset (4.6% and 7.0%; p = 0.007) CONCLUSIONS: While DS and associated local fungal infection do not overtly affect activation of monocytes or lymphocytes, the number of CD 25+ T cells is significantly lower in the DS patients, possibly indicating limited potential for the infection clearance in denture-using aging patients.

Malignant hypertension: new aspects of an old clinical entity

Malignant hypertension (MHT), also known as accelerated-malignant hypertension or malignant-phase hypertension, is the most severe form of arterial hypertension. It is defined clinically as high blood pressure (BP) levels associated with lesions of the retinal fundus (flame-shaped hemorrhages, exudates, or cotton wool spots, with or without papilledema). Despite the availability of a vast range of antihypertensive agents, MHT continues to be a significant clinical challenge. Although its prevalence is very low, the absolute number of new cases has not changed over the past decades. While the role of the activation of the renin-angiotensin-aldosterone system and endothelial dysfunction in the pathogenesis of MHT has been well described, recent studies have indicated that the immune system may also play an important role in the development of this condition. Patients with MHT are characterized by pronounced target organ damage, including structural and functional cardiac abnormalities. MHT is frequently complicated by renal insufficiency and end-stage renal disease. The survival rates for patients with MHT have improved considerably with increased availability of antihypertensive treatment. However, renal insufficiency and end-stage renal disease still remain a significant cause of morbidity and mortality in this patient group. In conclusion, MHT is not a "vanishing disease" because there is a relatively stable number of new cases per year. Nonetheless, prognosis and survival rates in these patients have improved significantly owing to earlier detection, stricter BP control, lower BP targets, better choice of antihypertensive drugs, and availability of hemodialysis and renal transplantation.