Vascular Inflammatory Processes Research Articles

Blockage of the adenosine A2B receptor prevents cardiac fibroblasts overgrowth in rats with pulmonary arterial hypertension

Sustained pressure overload and fibrosis of the right ventricle (RV) are the leading causes of mortality in pulmonary arterial hypertension (PAH). Although the role of adenosine in PAH has been attributed to the control of pulmonary vascular tone, cardiac reserve, and inflammatory processes, the involvement of the nucleoside in RV remodelling remains poorly understood. Conflicting results exist on targeting the low-affinity adenosine A2B receptor (A2BAR) for the treatment of PAH mostly because it displays dual roles in acute vs. chronic lung diseases. Herein, we investigated the role of the A2BAR in the viability/proliferation and collagen production by cardiac fibroblasts (CFs) isolated from RVs of rats with monocrotaline (MCT)-induced PAH. CFs from MCT-treated rats display higher cell viability/proliferation capacity and overexpress A2BAR compared to the cells from healthy littermates. The enzymatically stable adenosine analogue, 5′-N-ethylcarboxamidoadenosine (NECA, 1–30 μM), concentration-dependently increased growth, and type I collagen production by CFs originated from control and PAH rats, but its effects were more prominent in cells from rats with PAH. Blockage of the A2BAR with PSB603 (100 nM), but not of the A2AAR with SCH442416 (100 nM), attenuated the proliferative effect of NECA in CFs from PAH rats. The A2AAR agonist, CGS21680 (3 and 10 nM), was virtually devoid of effect. Overall, data suggest that adenosine signalling via A2BAR may contribute to RV overgrowth secondary to PAH. Therefore, blockage of the A2AAR may be a valuable therapeutic alternative to mitigate cardiac remodelling and prevent right heart failure in PAH patients.

O-222 Functional characterization and clinical implications of patient-specific iPSC-derived endothelial cells to unravel the pathogenesis associated with androgen-mediated endothelial dysfunction in polycystic ovarian syndrome

Abstract Study question Whether and how the endothelial cell (EC) dysfunction is involved in the pathogenesis of PCOS revealed by iPSC-based disease modeling? Summary answer PCOS-specific iPSC-derived ECs were successfully established and the results showed that EC proliferation and function were impaired in PCOS through the androgen receptor(AR)-mediated signaling pathway. What is known already ECs have been shown to play critical biological roles in the regulation of vascular tone and inflammatory process and any injury to ECs or disturbance in their homeostasis is called EC dysfunction, which has been recognized as an early marker of atherosclerosis and cardiovascular diseases. Several studies have also revealed indirect evidence of EC dysfunction among women with PCOS, including elevated circulatory markers of endothelial damage and impaired vascular structure. But whether and how EC dysfunction is involved in the pathogenesis of PCOS is still unclear. Study design, size, duration This is an experimental study at tertiary university hospital. iPSCs were established from skin fibroblasts and peripheral blood mononuclear cells from two patients with PCOS and two control participants. Participants/materials, setting, methods iPSCs were differentiated into ECs through monoculture with chemically defined conditions. Single cell RNA sequencing (scRNA-seq) was performed on the iPSCs-derived ECs to compare the differences between PCOS and control. iPSCs-derived ECs were treated with different dosages (1, 10 and 100 nM) of dihydrotestosterone (DHT). Cell cycle phases were analyzed by flow cytometry with BrdU incorporation assay. The expression of AR, cyclin-dependent kinase 1 (CDK1) and vascular endothelial growth factor (VEGF) were analyzed using rtPCR. Main results and the role of chance Up to 90% of iPSC-derived ECs successfully expressed EC markers, including CD31, CD144 and von Willebrand Factor in both PCOS and control groups, showing a high differentiation efficiency in the present study. The pathway enrichment analysis of transcriptomic data of iPSC-derived ECs showed functional differences involving cell cycle process, VEGF signaling and apoptotic process between PCOS and control. Analysis using sc-RNA seq revealed decreased cellular proliferation in the PCOS iPSC-derived ECs compared to control group, which was due to cell cycle arrest revealed by flow cytometry. The modulating effects of androgen on the proliferation and gene expression of iPSC-derived ECs were further investigated. DHT at doses ranging from 1 to 100 nM stimulated iPSC-derived ECs proliferation in the control group through upregulation of AR, CDK1 and VEGF gene expression. In contrast, DHT did not promote the cellular proliferation of PCOS iPSC-derived ECs at physiological concentrations of 1 and 10 nM and the expression of AR, CDK1, and VEGF remained unchanged. These data suggest that DHT-induced cellular proliferation and the expression of associated genes were more sensitive and dose-dependent in the control iPSC-derived ECs and blunted in the PCOS iPSC-derived ECs. Limitations, reasons for caution One of the major limitations of our study was the limited number of cases during the establishment of iPSCs, which was unable to reflect the heterogeneity and complexity of PCOS. Wider implications of the findings Impaired cellular proliferation and differentially expressed genes involved in cell proliferation, immune responses, cardiovascular functions, and apoptosis were observed among PCOS iPSC-derived ECs. Additionally, androgen-induced ECs proliferation was blunted in PCOS through a diminished AR/VEGF/cyclin D1 signaling pathway, which might hinder VEGF-dependent vascular repair and probably increase cardiovascular risks. Trial registration number not applicable

Risk factors associated with glycated hemoglobin A1c trajectories progressing to type 2 diabetes

Background and objective The notion of prediabetes, defined by the ADA as glycated hemoglobin A1c (HbA1c) of 5.7–6.4%, implies increased vascular inflammatory and immunologic processes and higher risk for developing diabetes mellitus and major cardiovascular events. We aimed to determine the risk factors associated with rapid progression of normal and prediabetes patients to type 2 diabetes mellitus (T2DM). Methods Retrospective cohort study in a single 8-hospital health system in southeast Michigan, between 2006 and 2020. All patients with HbA1c <6.5% at baseline and at least 2 other HbA1c measurements were clustered in five trajectories encompassing more than 95% of the study population. Multivariate linear regression analysis was performed to examine the association of demographic and comorbidities with HbA1c trajectories progressing to diabetes. Results A total of 5,347 prediabetic patients were clustered based on their HbA1c progression (C1: 4,853, C2: 253, C66: 102, C12: 85, C68: 54). The largest cluster (C1) had a baseline median HbA1c value of 6.0% and exhibited stable HbA1c levels in prediabetic range across all subsequent years. The smallest cluster (C68) had the lowest median baseline HbA1c value and also remained stable across subsequent years. The proportion of normal HbA1c in each of the pre-diabetic trajectories ranged from 0 to 12.7%, whereas 81.5% of the reference cluster (C68) were normal HbA1c at baseline. The C2 (steady rising) trajectory was significantly associated with BMI (adj OR 1.10, 95%CI 1.03–1.17), and family history of DM (adj OR 2.75, 95%CI 1.32–5.74). With respect to the late rising trajectories, baseline BMI was significantly associated with both C66 and C12 trajectory (adj OR 1.10, 95%CI 1.03–1.18) and (adj OR 1.13, 95%CI 1.05–1.23) respectively, whereas, the C12 trajectory was also significantly associated with age (adj OR 1.62, 95%CI 1.04–2.53) and history of MACE (adj OR 3.20, 95%CI 1.14–8.93). Conclusions We suggest that perhaps a more aggressive preventative approach should be considered in patients with a family history of T2DM who have high BMI and year-to-year increase in HbA1c, whether they have normal hemoglobin A1c or they have prediabetes. KEY MESSAGES Progression to diabetes from normal or prediabetic hemoglobin A1c within four years is associated with baseline BMI. A steady rise in HbA1c during a four-year period is associated with age and family history of T2DM, whereas age and personal history of MACE are associated with a rapid rise in HbA1c. A more aggressive preventative approach should be considered in patients with a family history of T2DM who have high BMI and year-to-year increase in HbA1c.

Introducing Circulating Vasculature-Related Transcripts as Biomarkers in Coronary Artery Disease.

Atherosclerotic plaque is considered the hallmark of atherosclerotic lesions in coronary atherosclerosis (CAS), the primary pathogenesis in coronary artery disease (CAD), which develops and progresses through a complex interplay between immune cells, vascular cells, and endothelial shear stresses. Early diagnosis of CAS is critical for avoiding plaque rupture and sudden death. Therefore, identifying new CAD biomarkers linked to vessel wall functions, such as RNA molecules with their distinct signature, is a promising development for these patients. With this rationale, the present study investigated the expression level of the vascular-related RNA transcripts (lncRNA ANRIL, miRNA-126-5p, CDK4, CDK6, TGF-β, E-cadherin, and TNF-α) implicated in the cellular vascular function, proliferation, and inflammatory processes. A case-control study design with a total of 180 subjects classified participants into two groups; CAD and control groups. The relative expression levels of the seven transcripts under study-selected using online bioinformatics tools and current literature-were assessed in the plasma of all study participants using RT-qPCR. Their predictive significance testing, scoring of disease prioritization, enrichment analysis, and the miRNA-mRNA regulatory network was investigated. The relative expression levels of all seven of the circulating vascular-related transcripts under study were statistically significant between CAD patients and controls. Receiver operating characteristic (ROC) analysis results indicated the statistical significance of all the transcripts under study with CDK4 showing the highest area under the curve (AUC) equivalent to 0.91, followed by E-cadherin (0.90), miRNA-126-5p (0.83), ANRIL (0.82), TNF-α (0.63), TGF-β (0.62), and CDK6 (0.59), in descending order. A strong association was detected between most of the transcripts studied in CAD patients with a significant Spearman's correlation coefficient with a two-tailed significance of p<0.001. Network analysis revealed a strong relationship between the five circulating vasculature transcripts studied and their target miRNAs and miR-126-5p, but not for ANRIL. The seven circulating vascular-related RNA transcripts under study could serve as potential CAD biomarkers, reflecting the cellular vascular function, proliferation, and inflammatory processes in CAD patients. Therefore, blood transcriptome analysis opens new frontiers for the non-invasive diagnosis of CAD.

The effect of trehalose administration on miRNA-10a expression in patients with history of myocardial infarction (MI) and systemic inflammation

Abstract Background MicroRNAs (miRNAs) are small non-coding RNAs involved in the regulation of endothelial function, inflammatory cells, and cholesterol homeostasis, may cause the onset of vascular inflammation which plays an important role in the development of cardiovascular disease. Trehalose is a nonreducing disaccharide which anti-inflammatory properties have been indicated in different experimental models. Purpose This study aimed to evaluate the effectiveness of intravenous (IV) trehalose administration on the circulating level of miRNA-10a as a biomarker of coronary inflammation in patients with history of myocardial infarction (MI) and elevated C-reactive protein (CRP). Methods This was a randomized, double-blind trial comprised 15 men (aged 18–80) with history of MI and evidence of systemic inflammation. The patients were randomly allocated to 2:1 ratio and respectively underwent the injection of either IV trehalose (15 g/week) or placebo for 12 weeks. At baseline and at the end of study, the serum level of miRNA-10a was measured by SYBR Green qPCR, quantified by the comparative method, and normalized to U6 expression. Relative expression software tool (REST) was used to analyze the miRNA-10a fold change (FC) expression level. Results At the baseline, patients in trehalose group showed slightly lower level of miRNA-10a relative to the placebo group (FC: 0.272, P=0.052), while it was not statistically significant. Within-group analysis showed that miRNA-10a had a significantly lower level in placebo group at the end of the study in comparison with the baseline (FC; 0.19, P=0.029). Albeit, miRNA-10a level increased after trehalose administration in relation to the baseline, while it was not statistically significant (FC: 1.963, P=0.114), Moreover, these changes in miRNA-10a levels were statistically significant in trehalose group related to the placebo group (P=0.047). Conclusions Together these findings demonstrate that trehalose administration could effectively increase the circulating level of miRNA-10a and may contribute to the regulation of coronary inflammation in patients with a history of MI and elevated CRP levels. This anti-inflammatory effect of trehalose can be confirmed in the large-scale studies or by evaluating other miRNAs related to the vascular inflammatory processes. Funding Acknowledgement Type of funding sources: None.

Selective visuoconstructional impairment following mild COVID-19 with inflammatory and neuroimaging correlation findings.

People recovered from COVID-19 may still present complications including respiratory and neurological sequelae. In other viral infections, cognitive impairment occurs due to brain damage or dysfunction caused by vascular lesions and inflammatory processes. Persistent cognitive impairment compromises daily activities and psychosocial adaptation. Some level of neurological and psychiatric consequences were expected and described in severe cases of COVID-19. However, it is debatable whether neuropsychiatric complications are related to COVID-19 or to unfoldings from a severe infection. Nevertheless, the majority of cases recorded worldwide were mild to moderate self-limited illness in non-hospitalized people. Thus, it is important to understand what are the implications of mild COVID-19, which is the largest and understudied pool of COVID-19 cases. We aimed to investigate adults at least four months after recovering from mild COVID-19, which were assessed by neuropsychological, ocular and neurological tests, immune markers assay, and by structural MRI and 18FDG-PET neuroimaging to shed light on putative brain changes and clinical correlations. In approximately one-quarter of mild-COVID-19 individuals, we detected a specific visuoconstructive deficit, which was associated with changes in molecular and structural brain imaging, and correlated with upregulation of peripheral immune markers. Our findings provide evidence of neuroinflammatory burden causing cognitive deficit, in an already large and growing fraction of the world population. While living with a multitude of mild COVID-19 cases, action is required for a more comprehensive assessment and follow-up of the cognitive impairment, allowing to better understand symptom persistence and the necessity of rehabilitation of the affected individuals.

The Effect of Trehalose Supplementation on Macrovascular Inflammation Biomarker in Old Rats by Assessing NFκB-p65 Expression

Background: Vascular inflammation is one of contributing factors to the pathogenesis of arterial aging. Age-related activation of the inflammatory process can lead to various macro-and microvascular pathologies. The pro-inflammatory microenvironment generated in the vascular wall can lead to the pathogenesis of vascular diseases due to an increase in vascular dysfunction. Trehalose is a disaccharide that has several functions, protecting against stressors (one of them is reactive oxygen species/ROS) and preventing the inflammatory responses induced by endotoxic shock. Objectives: To analyze the effect of trehalose supplementation on macrovascular inflammatory processes related to the aging process. Methods: The experimental study used 28 male Wistar rats (Rattus novergicus) which were divided into 4 groups, young control group (Group A), old control group (Group B), 2% sucrose group (Group C), and 2% trehalose group (Group D); were then observed for 8 weeks. Results: The results showed that there were no significant differences in aortic tissue NFκB-p65 expression between old and young subjects (p=0.247). The 2% trehalose group had 40% lower aortic tissue NFkB-p65 expression compared to the old control group (p=0.012); while the group given 2% sucrose solution had a 30% higher aortic tissue NFkB-p65 expression compared to the trehalose group (p=0.018). Conclusion: Trehalose has a good effect on aging-associated vascular inflammatory processes that can be seen from the low aortic tissue NFκB-p65 expression in old rats.

The Modulation of Nrf-2/HO-1 Signaling Axis by Carthamus tinctorius L. Alleviates Vascular Inflammation in Human Umbilical Vein Endothelial Cells.

Carthamus tinctorius L., known as safflower, has been used in traditional treatment for cardiovascular, cerebrovascular, and diabetic vascular complications. We proposed to investigate how the ethanol extract of Carthamus tinctorius L. (ECT) can be used ethnopharmacologically and alleviate vascular inflammatory processes under cytokine stimulation in human vascular endothelial cells. Using the optimized HPLC method, six markers were simultaneously analyzed for quality control of ECT. Pretreatment with ECT (10–100 μg/mL) significantly reduced the increase of leukocyte adhesion to HUVEC by TNF-α in a dose-dependent manner. Cell adhesion molecules (CAMs) such as intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and endothelial cell selectin (E-selectin) are decreased by ECT. In addition, ECT significantly suppressed TNF-α-induced oxidative stress referring to reactive oxygen species (ROS) production. p65 NF-κB nuclear translocation and its activation were inhibited by ECT. Furthermore, pretreatment of ECT increased the HO-1 expression, and nuclear translocation of Nrf-2. These data suggest the potential role of ECT as a beneficial therapeutic herb in vascular inflammation via ROS/NF-kB pathway and the regulation of Nrf-2/HO-1 signaling axis is involved in its vascular protection. Thus, further study will be needed to clarify which compound is dominant for protection of vascular diseases.

A High-Cholesterol Diet Increases Toll-like Receptors and Other Harmful Factors in the Rabbit Myocardium: The Beneficial Effect of Statins.

Background: A high-cholesterol diet (HCD) induces vascular atherosclerosis through vascular inflammatory and immunological processes via TLRs. The aim of this study is to investigate the mRNA expression of TLRs and other noxious biomarkers expressing inflammation, fibrosis, apoptosis, and cardiac dysfunction in the rabbit myocardium during (a) high-cholesterol diet (HCD), (b) normal diet resumption and (c) fluvastatin or rosuvastatin treatment. Methods: Forty-eight male rabbits were randomly divided into eight groups (n = 6/group). In the first experiment, three groups were fed with HCD for 1, 2 and 3 months. In the second experiment, three groups were fed with HCD for 3 months, followed by normal chow for 1 month and administration of fluvastatin or rosuvastatin for 1 month. Control groups were fed with normal chow for 90 and 120 days. The whole myocardium was removed; total RNA was isolated from acquired samples, and polymerase chain reaction, reverse transcription PCR and quantitative real-time PCR were performed. Results: mRNA of TLRs 2, 3, 4 and 8; interleukin-6; TNF-a; metalloproteinase-2; tissue inhibitor of metalloproteinase-1; tumor protein 53; cysteinyl aspartate specific proteinase-3; and brain natriuretic peptide (BNP) increased in HCD. Statins but not resumption of a normal diet decreased levels of these biomarkers and increased levels of antifibrotic factors. Conclusions: HCD increases the levels of TLRs; inflammatory, fibrotic and apoptotic factors; and BNP in the rabbit myocardium. Atherogenic diets adversely affect the myocardium at a molecular level and are reversed by statins.

Heme induces significant neutrophil adhesion in vitro via an NFκB and reactive oxygen species-dependent pathway.

Intravascular hemolysis, a major manifestation of sickle cell disease (SCD) and other diseases, incurs the release of hemoglobin and heme from red blood cells, in turn triggering inflammatory processes. This study investigated the in vitro effects of heme, a major inflammatory DAMP, on the adhesive properties of isolated human neutrophils. Heme (20 and 50µM) significantly increased the adhesion of neutrophils to fibronectin and to recombinant ICAM-1, under static conditions, even more efficiently than the potent pro-inflammatory cytokine, tumor necrosis factor-α (TNF); a microfluidic assay confirmed that heme stimulated neutrophil adhesion under conditions of shear stress. Heme-induced neutrophil adhesion was associated with the increased activities, but not expressions, of the Mac-1 and LFA-1 integrin subunits, CD11b and CD11a, on the cell surface. Notably, heme (50µM) significantly induced NFκB translocation in neutrophils, and inhibition of NFκB activity with the BAY11-7082 molecule abolished heme-induced cell adhesion to fibronectin and significantly decreased CD11a activity. Flow cytometric analysis demonstrated major reactive oxygen species (ROS) generation in neutrophils following heme stimulation that could be inhibited by the antioxidant, α-tocopherol, and by BAY11-7082. Furthermore, co-incubation with α-tocopherol abrogated both heme-stimulated neutrophil adhesion and CD11a/CD11b activation. Thus, our data indicate that heme, at clinically relevant concentrations, is a potent activator of neutrophil adhesion, increasing the ligand affinity of the β2 integrins via a mechanism that may be partially mediated by an NFkB-dependent pathway and the generation of ROS. Given the fundamental role that the adhesion of neutrophils to the vascular wall plays in SCD vaso-occlusion and other vascular inflammatory processes, our findings provide further evidence that cell-free heme is a major therapeutic target in the hemolytic diseases.

Cardiovascular diseases and obesity: The concise systematic review in the context of SARS-CoV-2

Introduction: COVID-19 disease is associated with vascular inflammatory processes, myocarditis, and cardiac arrhythmias, worsening CVD, diabetes, and hypertension. In this scenario, SARS-CoV-2 is worsening the comorbidities of obesity. Objective: To conduct a summary systematic review on the main relationships of COVID-19 with cardiovascular diseases and obesity, highlighting the main physiometabolic and pathological mechanisms. Strategy: The search strategy was carried out in the PubMed, Embase, Ovid and Cochrane Library, Web of Science, and Scopus databases. After a complete analysis of these selected studies, in the scenario of cardiovascular diseases (CVD), obesity initially favors the development of inflammation in adipose tissue, by increasing the production of pro-inflammatory adipokines. Metainflammation leads to myocardial dysfunction by direct injury to inflammatory mediators, as well as by dysfunction to other organs. Thus, the endothelial dysfunction caused by SARS-CoV-2 justifies blood vessel-related comorbidities such as cardiovascular disease, hypertension, diabetes, and obesity are more likely to develop severe COVID-19. Conclusion: COVID-19 disease is associated with a high inflammatory load that can induce vascular inflammation, myocarditis, and cardiac arrhythmias. Cardiovascular disease and pharmacological inhibition of COVID-19 increase ECA2 levels, which can increase the virulence of the coronavirus in the lung and heart. Also, obesity is an important predictor of worsening SARS-CoV-2 pathology.

Perillyl alcohol suppresses monocrotaline-induced pulmonary arterial hypertension in rats via anti-remodeling, anti-oxidant, and anti-inflammatory effects

ABSTRACT Background: Pulmonary arterial hypertension (PAH) is a disastrous disease that current treatments cannot prevent its progression. The present study investigated the effects of perillyl alcohol (PA), a natural monoterpene, on the experimental PAH in male Wistar rats. Methods: Rats divided into eight groups of control, Monocrotaline (MCT), MCT+vehicle, and MCT+PA with doses of 20, 30, 40, 50, and 60 mg/kg. PAH was induced by a single injection of monocrotaline (60 mg/kg) on day 0. The animals in the groups of MCT+vehicle and MCT+PA received the vehicle or PA from day 22 to 42 once a day. On day 43, under general anesthesia, right ventricular systolic pressure (RVSP), as an index of pulmonary artery systolic pressure, and the ratio of the right ventricle to the left ventricle plus septum weight, as the right ventricular hypertrophy index (RVHI), were measured. Also, some histological and biochemical indices were assessed in the lung tissue. Results: MCT significantly (p < .001) enhanced the RVSP and RVHI compared to the control group (89.4 ± 8.2 vs 23 ± 3.3 mmHg & 0.63 ± 0.08 vs 0.26 ± 0.04 respectively). It also increased oxidative stress and inflammatory cytokines and reduced Bax/Bcl2 ratio. Treatment with PA significantly recovered RVSP and hypertrophy index and suppressed vascular cell proliferation, oxidant production, and inflammatory processes. Conclusion: PA exerted noticeable protective and curative effects against MCT-induced PAH and pulmonary vascular remodeling through inhibiting cellular proliferation, oxidative stress, and inflammation. Therefore, PA can be considered as a new therapeutic goal for the treatment of PAH.

Implications of diesel exhaust fumes exposure on vascular wall properties, endothelial function and inflammatory process

Background and Aims: Diesel exhaust fumes are toxic compounds, whose acute effects on the cardiovascular system are well known. However, their short term impact has not been thoroughly studied. Aim: Study acute and short-term (24 h) effects of diesel exhaust particles (DEPs) on endothelial function, vascular wall properties, inflammation and coagulation.

Preventive effect of cocoa flavanols against glucotoxicity-induced vascular inflammation in the arteria of diabetic rats and on the inflammatory process in TNF-α-stimulated endothelial cells

Hyperglycaemia induces a vascular inflammatory process that is a critical event in cardiovascular disease in type 2 diabetes. Cocoa and its flavanols have been widely investigated for its antioxidant and anti-inflammatory properties, and several clinical and pre-clinical studies support their vascular benefits. However, the effects of cocoa flavanols on vascular inflammation in diabetes remains to be elucidated. Herein, we evaluated the anti-inflammatory effect of a cocoa-rich diet on the aortas of Zucker diabetic fatty (ZDF) rats. Moreover, the potential role of flavanol-derived colonic metabolites to modulate the adhesion and inflammatory processes were also evaluated using TNF-α-stimulated endothelial cells. Results demonstrate that cocoa attenuates the levels of phospho-p65-nuclear factor-kappaB (NF-κB) and the expression of inflammatory factors including intercellular adhesion molecule-1 (ICAM-1), vascular adhesion molecule-1 (VCAM-1) and inducible nitric oxide synthase in the aortas of ZDF rats. Experiments with endothelial cells further confirm that a mix of flavanol-derived colonic metabolites effectively down-regulate the levels of p-p65-NF-κB and the cell adhesion molecules ICAM-1 and VCAM-1, preventing thus the increase of monocyte-endothelial adhesion induced by TNF-α. These novel data provide the first evidence of the relevant role of cocoa and their flavanol-derived metabolites to avoid the development of endothelial inflammation and diabetic complications.

Vasculo-Neuronal Coupling and Neurovascular Coupling at the Neurovascular Unit: Impact of Hypertension.

Components of the neurovascular unit (NVU) establish dynamic crosstalk that regulates cerebral blood flow and maintain brain homeostasis. Here, we describe accumulating evidence for cellular elements of the NVU contributing to critical physiological processes such as cerebral autoregulation, neurovascular coupling, and vasculo-neuronal coupling. We discuss how alterations in the cellular mechanisms governing NVU homeostasis can lead to pathological changes in which vascular endothelial and smooth muscle cell, pericyte and astrocyte function may play a key role. Because hypertension is a modifiable risk factor for stroke and accelerated cognitive decline in aging, we focus on hypertension-associated changes on cerebral arteriole function and structure, and the molecular mechanisms through which these may contribute to cognitive decline. We gather recent emerging evidence concerning cognitive loss in hypertension and the link with vascular dementia and Alzheimer’s disease. Collectively, we summarize how vascular dysfunction, chronic hypoperfusion, oxidative stress, and inflammatory processes can uncouple communication at the NVU impairing cerebral perfusion and contributing to neurodegeneration.

Markers of Endothelial Cells in Normal and Pathological Conditions.

Endothelial cells (ECs) line the blood vessels and lymphatic vessels, as well as heart chambers, forming the border between the tissues, on the one hand, and blood or lymph, on the other. Such a strategic position of the endothelium determines its most important functional role in the regulation of vascular tone, hemostasis, and inflammatory processes. The damaged endothelium can be both a cause and a consequence of many diseases. The state of the endothelium is indicated by the phenotype of these cells, represented mainly by (trans)membrane markers (surface antigens). This review defines endothelial markers, provides a list of them, and considers the mechanisms of their expression and the role of the endothelium in certain pathological conditions.

Differential Augmentation of Thrombin Generation by Andexanet Alfa in Lymphoma Patients

IntroductionThe prevalence of thrombosis in lymphoma patients is reportedly high and ranges from 3–10%. Vascular malfunction and inflammatory processes further contribute to the thrombotic activation processes in these patients. Andexanet alfa is an antidote for factor Xa inhibitors and its usage has been reported with thrombotic complications. This study was designed to compare effect of andexanet alfa (AA) on the thrombin generation potential and its relevance to the generation of thrombin.Materials and MethodCitrated blood samples from 78 patients with confirmed diagnosis of non‐Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL) and Chronic lymphocytic leukemia/Small lymphocytic lymphoma (CLL/SLL) were collected from the Clinic of Hematology Unit, University of Belgrade, Belgrade, Serbia. 50 samples of normal human plasma (NHP) was obtained from George King Biomedical (Overland park, KS). NHP was prepared for referencing purposes. Individual samples were supplemented with andexanet alfa at 100 ug/ml. Thrombin generation studies were carried out using a commercially available a kinetic fluorogenic substrate method (calibrated automated thrombogram; CAT). Thrombin generation parameters such as peak thrombin (PT), lag time (LT) and area under the curve (AUC) were compiled. Results were compiled in terms of mean ±SD.ResultsOn a cumulative basis, lymphoma patients showed an increase in LT (2.9 1.15) in comparison to NHP (2.06 .02) which decreases with AA (1.94 0.1). The PT levels were decreased (120.34 44.3) in comparison to NHP (159.20 4.8) and increases with AA (153.70 37.2). The AUC was also decreased (668.85 284.3) in comparison to NHP (756.46 34.5) which increases with AA (758.32 226.4). When the lymphoma patients were sub‐grouped, peak thrombin levels were similar in HL (128.16), NHL (113.99) and CLL (129.77) were decreased compared to normal human plasma (159.2) which increases with AA, in HL (180.75), NHL (154.16) and CLL (142.46) compared to AA control (153.7). The AUC was increased in the HL (769), decreased in NHL (642.4) and was comparable for CLL (715.4) compared to normal human plasma (756.46). However, with AA the AUC values increases for HL (938.31) and decreases for NHL (744.52) and CLL (725.26) in comparison with AA control (758.32). Variations in lag time were noted in the three groups.ConclusionLymphoma patients represent a heterogenous group of patients in which both the hypercoagulable state and inflammatory responses simultaneously occur. Thrombin is constantly generated in some of these patients leading to the formation of fibrin. The observed decrease in thrombin generation potential in these patients may be due to the consumption of prothrombin and other coagulation factors. Differential increase in thrombin generation in post andexxa supplemented samples suggest that the use of this agent may potentially be associated with thrombotic complications.

Endothelial sphingosine 1-phosphate receptors promote vascular normalization and antitumor therapy

Sphingosine 1-phosphate receptor-1 (S1PR1) is essential for embryonic vascular development and maturation. In the adult, it is a key regulator of vascular barrier function and inflammatory processes. Its roles in tumor angiogenesis, tumor growth, and metastasis are not well understood. In this paper, we show that S1PR1 is expressed and active in tumor vessels. Murine tumor vessels that lack S1PR1 in the vascular endothelium (S1pr1 ECKO) show excessive vascular sprouting and branching, decreased barrier function, and poor perfusion accompanied by loose attachment of pericytes. Compound knockout of S1pr1, 2, and 3 genes further exacerbated these phenotypes, suggesting compensatory function of endothelial S1PR2 and 3 in the absence of S1PR1. On the other hand, tumor vessels with high expression of S1PR1 (S1pr1 ECTG) show less branching, tortuosity, and enhanced pericyte coverage. Larger tumors and enhanced lung metastasis were seen in S1pr1 ECKO, whereas S1pr1 ECTG showed smaller tumors and reduced metastasis. Furthermore, antitumor activity of a chemotherapeutic agent (doxorubicin) and immune checkpoint inhibitor blocker (anti-PD-1 antibody) were more effective in S1pr1 ECTG than in the wild-type counterparts. These data suggest that tumor endothelial S1PR1 induces vascular normalization and influences tumor growth and metastasis, thus enhancing antitumor therapies in mouse models. Strategies to enhance S1PR1 signaling in tumor vessels may be an important adjunct to standard cancer therapy of solid tumors.

Diabetes-Induced Inflammation and Vascular Alterations in the Goto–Kakizaki Rat Retina

ABSTRACT Purpose Diabetic retinopathy is characterized by multiple microcirculatory dysfunctions and angiogenesis resulting from hyperglycemia, oxidative stress, and inflammation. In this study, the retina and retinal pigmented epithelium of non-insulin-dependent diabetic Goto–Kakizaki (GK) rats were examined to detect microvascular alterations, gliosis, macrophage infiltration, lipid deposits, and fibrosis. Emphasis was given to the distribution of kinin B1 receptor (B1R) and vascular endothelial growth factor (VEGF), two major factors in inflammation and angiogenesis. Materials and methods 30-week-old male GK rats and age-matched Wistar rats were used. The retinal vascular bed was examined using ADPase staining. The level of lipid accumulation was graded using triglyceride staining with Oil red O. Macrophage and retinal microglia activation, as well as other markers, were revealed by immunohistochemistry and studied with confocal laser scanning microscopy. Results Abundant lipid deposits were observed in the Bruch’s membrane of GK rats. Immunohistochemistry and quantitative analysis showed significantly higher B1R, VEGF, Iba1 (microglia), CD11 (macrophages), fibronectin, and collagen I labeling in the diabetic retina. B1R immunolabeling was detected in the vascular layers of the GK retina. A strong VEGF staining within different retinal cell processes was detected and a pattern of GFAP staining suggested strong Müller cells/astrocytes reactivity. Microgliosis was apparent in the GK retina. A greater tortuosity of the retinal microvessels (an index of endothelial dysfunction) and their increased number were also observed in GK retinas. Conclusions Data suggest retinal vascular bed alterations in spontaneous type 2 diabetic retinas at 30 weeks. Lipid and collagen accumulation in the retina and choroid, in addition to retinal upregulation of VEGF and B1R, microgliosis, and Müller cell reactivity, may contribute to vascular alterations and inflammatory processes.

Thrombin Generation Profile in Various Lymphoma Sub-Groups and Its Augmentation by Andexanet Alfa.

The prevalence of thrombosis in lymphoma patients is reportedly high and ranges from 3-10%. Vascular malfunction and inflammatory processes further contribute to the thrombotic activation process in these patients. Andexanet alfa (AA) is an antidote for factor Xa inhibitors and its usage has been reported with thrombotic complications. This study was designed to compare the effect of AA on the thrombin generation (TG) potential. Blood samples from 78 patients with confirmed diagnosis of non-Hodgkin lymphoma (NHL), Hodgkin lymphoma (HL) and Chronic lymphocytic leukemia (CLL) were collected from the University of Belgrade Clinic, Serbia. Normal human plasma (NHP) was used for referencing purposes. Individual samples were supplemented with AA at 100 ug/ml. TG studies were carried out using a commercially available fluorogenic substrate method. TG parameters such as peak thrombin (PT), lag time (LT) and area under the curve (AUC) were compiled. Cumulatively, lymphoma patients showed an increase in LT compared to NHP which decreases with AA. The PT and AUC levels were decreased compared to NHP and increases with AA. Upon sub-grouping of lymphoma patients, PT levels for all sub-groups were increased with AA. The AUC values increased for HL and NHL and decreased for CLL with AA. Variations in lag time were noted in all 3 sub-groups. Lymphoma represents a heterogenous group of patients where both the hypercoagulable state and inflammatory responses simultaneously occur. Increased thrombin generation in post AA supplemented samples suggest that the use of this agent may potentially be associated with thrombotic complications.