Well-Known and Novel Players in Endothelial Dysfunction: Updates on a Notch(ed) Landscape

Association Between Arterial Stiffness, High Blood Pressure, and Hypertensive Phenotypes: Insights from the PAMELA Study

Hypertension is a clinical condition associated with structural alterations in small, medium, and large arteries, also affecting target organs due to the mechanical effects of high blood pressure and shear stress. However, these vascular changes are also influenced by various inflammatory and neurohumoral mediators originating from the endothelium, the renin-angiotensin-aldosterone system, the neuroadrenergic system, and the perivascular fat. Specifically, chronic hypertension leads to vascular stretching, which triggers complex signaling pathways that promote vascular remodeling. The endothelium plays a crucial role in this process, as its function is impaired in hypertensive patients, leading to reduced nitric oxide-mediated vasodilation, increased vascular tone, and a proinflammatory and prothrombotic state. Along with structural changes, hypertension also triggers dynamic alterations in arterial distensibility and arterial wall properties, leading to increased arterial stiffness, which is strongly linked to cardiovascular outcomes and associated disability, as well as subsequent rehabilitation needs. Several non-invasive and highly reproducible methods are currently used to assess arterial stiffness, one of which is the cardio-ankle vascular index (CAVI). This article examines the association between arterial stiffness and high blood pressure, with a particular focus on the results of the Pressioni Arteriose Monitorate e Loro Associazioni (PAMELA) study. This study analyzes the determinants of arterial stiffness in the general population, the different hypertensive phenotypes affecting diurnal and nocturnal blood pressure profiles, and the impact of blood pressure control through antihypertensive treatment on arterial stiffness.

Downregulation of microRNA‑221‑3p promotes angiogenesis of lipoprotein(a)‑injured endothelial progenitor cells by targeting silent information regulator 1 to activate the RAF/MEK/ERK signaling pathway

The present study aimed to investigate the role of microRNA (miR)‑221‑3p in endothelial progenitor cells (EPCs) treated with lipoprotein(a) [LP(a)]. EPCs were identified using immunofluorescence assays and miR‑221‑3p levels were measured using reverse transcription‑quantitative PCR. EPC migration was detected using Transwell assays, proliferation was measured by staining with 5‑ethynyl‑2'‑deoxyuridine and adhesion was assessed by microscopy. Flow cytometry was used to measure apoptosis and protein expression was detected using western blotting. A dual‑luciferase reporter assay was used to confirm the target interactions. The proliferation, migration, adhesion and angiogenesis of EPCs were decreased, and apoptosis was increased after treatment with LP(a). These effects were weakened by transfection with miR‑221‑3p inhibitor. The negative effects of LP(a) on EPCs were also weakened by overexpression of silent information regulator 1 (SIRT1). Inhibition of the RAF/MEK/ERK signaling pathway blocked the effects of SIRT1 overexpression. In conclusion, miR‑221‑3p inhibitor transfection activated the RAF/MEK/ERK signaling pathway through SIRT1, promoted the proliferation, migration, adhesion and angiogenesis of EPCs, and reduced apoptosis.

Berberine Inhibits Ferroptosis and Stabilizes Atherosclerotic Plaque through NRF2/SLC7A11/GPX4 Pathway

OBJECTIVE

To investigate potential mechanisms of anti-atherosclerosis by berberine (BBR) using ApoE-/- mice.

METHODS

Eight 8-week-old C57BL/6J mice were used as a blank control group (normal), and 56 8-week-old AopE-/- mice were fed a high-fat diet for 12 weeks, according to a completely random method, and were divided into the model group, BBR low-dose group (50 mg/kg, BBRL), BBR medium-dose group (100 mg/kg, BBRM), BBR high-dose group (150 mg/kg, BBRH), BBR+nuclear factor erythroid 2-related factor 2 (NRF2) inhibitor group (100 mg/kg BBR+30 mg/kg ML385, BBRM+ML385), NRF2 inhibitor group (30 mg/kg, ML385), and positive control group (2.5 mg/kg, atorvastatin), 8 in each group. After 4 weeks of intragastric administration, samples were collected and serum, aorta, heart and liver tissues were isolated. Biochemical kits were used to detect serum lipid content and the expression levels of malondialdehyde (MDA) and superoxide dismutase (SOD) in all experimental groups. The pathological changes of atherosclerosis (AS) were observed by aorta gross Oil Red O, aortic sinus hematoxylin-eosin (HE) and Masson staining. Liver lipopathy was observed in mice by HE staining. The morphology of mitochondria in aorta cells was observed under transmission electron microscope. Flow cytometry was used to detect reactive oxygen species (ROS) expression in aorta of mice in each group. The content of ferrous ion Fe2+ in serum of mice was detected by biochemical kit. The mRNA and protein relative expression levels of NRF2, glutathione peroxidase 4 (GPX4) and recombinant solute carrier family 7 member 11 (SLC7A11) were detected by quantitative real time polymerase chain reaction (RT-qPCR) and Western blot, respectively.

RESULTS

BBRM and BBRH groups delayed the progression of AS and reduced the plaque area (P<0.01). The characteristic morphological changes of ferroptosis were rarely observed in BBR-treated AS mice, and the content of Fe2+ in BBR group was significantly lower than that in the model group (P<0.01). BBR decreased ROS and MDA levels in mouse aorta, increased SOD activity (P<0.01), significantly up-regulated NRF2/SLC7A11/GPX4 protein and mRNA expression levels (P<0.01), and inhibited lipid peroxidation. Compared with the model group, the body weight, blood lipid level and aortic plaque area of ML385 group increased (P<0.01); the morphology of mitochondria showed significant ferroptosis characteristics; the serum Fe2+, MDA and ROS levels increased (P<0.05 or P<0.01), and the activity of SOD decreased (P<0.01). Compared with BBRM group, the iron inhibition effect of BBRM+ML385 group was significantly weakened, and the plaque area significantly increased (P<0.01).

CONCLUSION

Through NRF2/SLC7A11/GPX4 pathway, BBR can resist oxidative stress, inhibit ferroptosis, reduce plaque area, stabilize plaque, and exert anti-AS effects.

Serum from COVID-19 patients promotes endothelial cell dysfunction through protease-activated receptor 2

BACKGROUND

Endothelial dysfunction plays a central role in the pathophysiology of COVID-19 and is closely linked to the severity and mortality of the disease. The inflammatory response to SARS-CoV-2 infection can alter the capacity of the endothelium to regulate vascular tone, immune responses, and the balance between anti-thrombotic and pro-thrombotic properties. However, the specific endothelial pathways altered during COVID-19 still need to be fully understood.

OBJECTIVE

In this study, we sought to identify molecular changes in endothelial cells induced by circulating factors characteristic of COVID-19.

METHODS AND RESULTS

To this aim, we cultured endothelial cells with sera from patients with COVID-19 or non-COVID-19 pneumonia. Through transcriptomic analysis, we were able to identify a distinctive endothelial phenotype that is induced by sera from COVID-19 patients. We confirmed and expanded this observation in vitro by showing that COVID-19 serum alters functional properties of endothelial cells leading to increased apoptosis, loss of barrier integrity, and hypercoagulability. Furthermore, we demonstrated that these endothelial dysfunctions are mediated by protease-activated receptor 2 (PAR-2), as predicted by transcriptome network analysis validated by in vitro functional assays.

CONCLUSION

Our findings provide the rationale for further studies to evaluate whether targeting PAR-2 may be a clinically effective strategy to counteract endothelial dysfunction in COVID-19.

Endothelial, Vascular and Sympathetic Alterations as Therapeutic Targets in Chronic Heart Failure

Vascular and sympathetic abnormalities characterize chronic heart failure (CHF). Alterations include (1) a reduction in arterial distensibility, (2) endothelial dysfunction, (3) a decrease in arterial compliance and a parallel increase in arterial stiffness, and (4) sympathetic cardiovascular activation. Altogether, these alterations represent important targets in therapeutic interventions, because they display an independent negative impact on the disease prognosis, favouring disease progression and the development of cardiovascular complications with direct and indirect mechanisms. The present review will examine the effects of the different therapeutic interventions targeting the vascular/sympathetic alterations detected in CHF. Non-pharmacological, pharmacological and device-based treatments will be discussed in detail, highlighting the possible mechanisms responsible for the vascular/sympathetic effects of each intervention. Finally, the unmet goals in treatment in relation to endothelial and adrenergic targets will be also discussed.

Molecular Mechanisms and Therapeutic Implications of Endothelial Dysfunction in Patients with Heart Failure

Heart failure is a complex medical syndrome that is attributed to a number of risk factors; nevertheless, its clinical presentation is quite similar among the different etiologies. Heart failure displays a rapidly increasing prevalence due to the aging of the population and the success of medical treatment and devices. The pathophysiology of heart failure comprises several mechanisms, such as activation of neurohormonal systems, oxidative stress, dysfunctional calcium handling, impaired energy utilization, mitochondrial dysfunction, and inflammation, which are also implicated in the development of endothelial dysfunction. Heart failure with reduced ejection fraction is usually the result of myocardial loss, which progressively ends in myocardial remodeling. On the other hand, heart failure with preserved ejection fraction is common in patients with comorbidities such as diabetes mellitus, obesity, and hypertension, which trigger the creation of a micro-environment of chronic, ongoing inflammation. Interestingly, endothelial dysfunction of both peripheral vessels and coronary epicardial vessels and microcirculation is a common characteristic of both categories of heart failure and has been associated with worse cardiovascular outcomes. Indeed, exercise training and several heart failure drug categories display favorable effects against endothelial dysfunction apart from their established direct myocardial benefit.

Angiopoietin-like 2 is essential to aortic valve development in mice

Aortic valve (AoV) abnormalities during embryogenesis are a major risk for the development of aortic valve stenosis (AVS) and cardiac events later in life. Here, we identify an unexpected role for Angiopoietin-like 2 (ANGPTL2), a pro-inflammatory protein secreted by senescent cells, in valvulogenesis. At late embryonic stage, mice knocked-down for Angptl2 (Angptl2-KD) exhibit a premature thickening of AoV leaflets associated with a dysregulation of the fine balance between cell apoptosis, senescence and proliferation during AoV remodeling and a decrease in the crucial Notch signalling. These structural and molecular abnormalities lead toward spontaneous AVS with elevated trans-aortic gradient in adult mice of both sexes. Consistently, ANGPTL2 expression is detected in human fetal semilunar valves and associated with pathways involved in cell cycle and senescence. Altogether, these findings suggest that Angptl2 is essential for valvulogenesis, and identify Angptl2-KD mice as an animal model to study spontaneous AVS, a disease with unmet medical need.

Mechanistic Pathogenesis of Endothelial Dysfunction in Diabetic Nephropathy and Retinopathy

Diabetic nephropathy (DN) and diabetic retinopathy (DR) are microvascular complications of diabetes. Microvascular endothelial cells are thought to be the major targets of hyperglycemic injury. In diabetic microvasculature, the intracellular hyperglycemia causes damages to the vascular endothelium, via multiple pathophysiological process consist of inflammation, endothelial cell crosstalk with podocytes/pericytes and exosomes. In addition, DN and DR diseases development are involved in several critical regulators including the cell adhesion molecules (CAMs), the vascular endothelial growth factor (VEGF) family and the Notch signal. The present review attempts to gain a deeper understanding of the pathogenesis complexities underlying the endothelial dysfunction in diabetes diabetic and retinopathy, contributing to the development of new mechanistic therapeutic strategies against diabetes-induced microvascular endothelial dysfunction.

Inflammation and atherosclerosis: signaling pathways and therapeutic intervention

Atherosclerosis is a chronic inflammatory vascular disease driven by traditional and nontraditional risk factors. Genome-wide association combined with clonal lineage tracing and clinical trials have demonstrated that innate and adaptive immune responses can promote or quell atherosclerosis. Several signaling pathways, that are associated with the inflammatory response, have been implicated within atherosclerosis such as NLRP3 inflammasome, toll-like receptors, proprotein convertase subtilisin/kexin type 9, Notch and Wnt signaling pathways, which are of importance for atherosclerosis development and regression. Targeting inflammatory pathways, especially the NLRP3 inflammasome pathway and its regulated inflammatory cytokine interleukin-1β, could represent an attractive new route for the treatment of atherosclerotic diseases. Herein, we summarize the knowledge on cellular participants and key inflammatory signaling pathways in atherosclerosis, and discuss the preclinical studies targeting these key pathways for atherosclerosis, the clinical trials that are going to target some of these processes, and the effects of quelling inflammation and atherosclerosis in the clinic.

Fermentation of Vaccinium floribundum Berries with Lactiplantibacillus plantarum Reduces Oxidative Stress in Endothelial Cells and Modulates Macrophages Function

Accumulating evidence suggests that high consumption of natural antioxidants promotes health by reducing oxidative stress and, thus, the risk of developing cardiovascular diseases. Similarly, fermentation of natural compounds with lactic acid bacteria (LAB), such as Lactiplantibacillus plantarum, enhances their beneficial properties as regulators of the immune, digestive, and cardiovascular system. We investigated the effects of fermentation with Lactiplantibacillus plantarum on the antioxidant and immunomodulatory effects of Pushgay berries (Vaccinium floribundum, Ericaceae family) in human umbilical vein endothelial cells (HUVECs) and macrophage cell line RAW264.7. Polyphenol content was assayed by Folin–Ciocalteu and HPLC-MS/MS analysis. The effects of berries solutions on cell viability or proliferation were assessed by WST8 (2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium, monosodium salt and Lactate dehydrogenase (LDH) release, Trypan blue exclusion test, and Alamar blue assay. Antioxidant activity was evaluated by a cell-based chemiluminescent probe for the detection of intracellular H₂O₂ production in HUVECs. Heme oxygenase-1 (HO-1) expression levels were investigated by RT-qPCR. Glutathione reductase (GR), glutathione peroxidase (Gpx), superoxide dismutase (SOD), and catalase (CAT) activities, as markers of intracellular antioxidant defense, were evaluated by spectrophotometric analysis. The immunomodulatory activity was examined in RAW 264.7 by quantification of inducible nitric oxide synthase (iNOS) and Tumor Necrosis Factor—alpha (TNFα) by RT-qPCR. Data showed that fermentation of Pushgay berries (i) enhances the content of quercetin aglycone, and (ii) increases their intracellular antioxidant activity, as indicated by the reduction in H₂O₂-induced cell death and the decrease in H₂O₂-induced HO-1 gene expression in HUVECs treated for 24 h with fermented berries solution (10 µg/mL). Moreover, treatment with Pushgay berries for 72 h (10 µg/mL) promotes cells growth in RAW 264.7, and only fermented Pushgay berries increase the expression of iNOS in the same cell line. Taken together, our results show that LAB fermentation of Pushgay berries enhances their antioxidant and immunomodulatory properties.

Cardiac Calcifications: Phenotypes, Mechanisms, Clinical and Prognostic Implications

There is a growing interest in arterial and heart valve calcifications, as these contribute to cardiovascular outcome, and are leading predictors of cardiovascular and kidney diseases. Cardiovascular calcifications are often considered as one disease, but, in effect, they represent multifaced disorders, occurring in different milieus and biological phenotypes, following different pathways. Herein, we explore each different molecular process, its relative link with the specific clinical condition, and the current therapeutic approaches to counteract calcifications. Thus, first, we explore the peculiarities between vascular and valvular calcium deposition, as this occurs in different tissues, responds differently to shear stress, has specific etiology and time courses to calcification. Then, we differentiate the mechanisms and pathways leading to hyperphosphatemic calcification, typical of the media layer of the vessel and mainly related to chronic kidney diseases, to those of inflammation, typical of the intima vascular calcification, which predominantly occur in atherosclerotic vascular diseases. Finally, we examine calcifications secondary to rheumatic valve disease or other bacterial lesions and those occurring in autoimmune diseases. The underlying clinical conditions of each of the biological calcification phenotypes and the specific opportunities of therapeutic intervention are also considered and discussed.

The Role of Endothelial Progenitor Cells in Atherosclerosis and Impact of Anti-Lipemic Treatments on Endothelial Repair

Cardiovascular complications are associated with advanced atherosclerosis. Although atherosclerosis is still regarded as an incurable disease, at least in its more advanced stages, the discovery of endothelial progenitor cells (EPCs), with their ability to replace old and injured cells and differentiate into healthy and functional mature endothelial cells, has shifted our view of atherosclerosis as an incurable disease, and merged traditional theories of atherosclerosis pathogenesis with evolving concepts of vascular biology. EPC alterations are involved in the pathogenesis of vascular abnormalities in atherosclerosis, but many questions remain unanswered. Many currently available drugs that impact cardiovascular morbidity and mortality have shown a positive effect on EPC biology. This review examines the role of endothelial progenitor cells in atherosclerosis development, and the impact standard antilipemic drugs, including statins, fibrates, and ezetimibe, as well as more novel treatments such as proprotein convertase subtilisin/kexin type 9 (PCSK9) modulating agents and angiopoietin-like proteins (Angtpl3) inhibitors have on EPC biology.

Endothelial Dysfunction: From a Pathophysiological Mechanism to a Potential Therapeutic Target

The endothelium is considered the largest organ of the body, composed of a monolayer of endothelial cells (ECs) lining the interior surface of blood and lymphatic vessels [...].