Endothelin and endothelial dysfunction

Adipocyte-endothelial cell interplay in adipose tissue physiology

Adipose tissue (AT) expansion through hyperplasia or hypertrophy requires vascular remodeling that involves angiogenesis. There is quite some evidence that obese white AT (WAT) displays altered vasculature. Some studies suggest that this is associated with hypoxia, which is thought to play a role in inducing inflammatory activation of the excessively expanding WAT. Increasing evidence, based on genetic manipulations or treatments with inhibitory or activator pharmaceuticals, demonstrates that AT angiogenesis is crucial for AT metabolic function, and thereby for whole body metabolism and metabolic health. Despite some contradiction between studies, disturbance of WAT angiogenesis in obesity could be an important factor driving WAT dysfunction and the comorbidities of obesity. Endothelial cells (ECs) contribute to healthy WAT metabolism via transport of fatty acids and other plasma components, secretory signaling molecules, and extracellular vesicles (EVs). This communication is crucial for adipocyte metabolism and underscores the key role that the AT endothelium plays in systemic energy homeostasis and healthy metabolism. Adipocytes communicate towards the neighboring endothelium through several mechanisms. The pro-inflammatory status of hypertrophic adipocytes in obesity is reflected in ECs activation, which promotes chronic inflammation. On the other hand, adiponectin secreted by the adipocytes is important for healthy endothelial function, and adipocytes also secrete other pro- or anti-angiogenic effector molecules and a wealth of EVs - however, their detailed roles in signaling towards the endothelium are yet poorly understood. To conclude, targeting AT angiogenesis and promoting the healthy communication between adipocytes and ECs represent potentially promising strategies to treat obesity and its comorbidities.

Sinomenine protects against atherosclerosis in apolipoprotein E-knockout mice by inhibiting of inflammatory pathway

Atherosclerosis, a multifaceted and persistent inflammatory condition, significantly contributes to the progression of cardiocerebrovascular disorders, such as myocardial infarctions and cerebrovascular accidents. It involves the accumulation of cholesterol, fatty deposits, calcium and cellular debris in the walls of arteries, leading to the formation of plaques. Our aim is to investigate the potential of sinomenine to counteract atherosclerosis in mice lacking Apolipoprotein E (ApoE-/-) Mice. We employed the high-fat diet-induced method to induce atherosclerosis in ApoE-/- mice, and the mice were treated with sinomenine (5, 10, and 15 mg/kg) and simvastatin (0.5 mg/kg) for 12 weeks. Body weight, water intake, and food intake were assessed. Lipid parameters, oxidative stress, inflammatory cytokines, and mRNA levels were estimated. Sinomenine treatment remarkably (P < 0.001) suppressed body weight, along with food and water intake. Sinomenine altered the levels of total cholesterol (TC), high-density lipoprotein (HDL), triglyceride (TG), low-density lipoprotein (LDL), and very low-density lipoprotein (VLDL), which were modulated in the atherosclerosis group. Sinomenine treatment also altered the levels of oxidative stress parameters such as glutathione peroxidase (GPx), catalase (CAT), malonaldehyde (MDA), superoxide dismutase (SOD) and glutathione (GSH). In addition, it modulated cardiac parameters like C-reactive protein (CRP), endothelin-1 (ET-1), thromboxane B2 (TXB2), nitric oxide (NO), cardiac troponin I (cTnI), lactate dehydrogenase (LDH), and creatinine kinase isoenzymes (CK-MB). Inflammatory cytokines interleukin (IL)-1α, IL-1β, TNF-α, IL-6, and IL-10 were also affected. Sinomenine further suppressed the mRNA expression of IL-6, IL-17, IL-10, tumor necrosis factor-α (TNF-α), Il-1β, monocyte chemoattractant protein-1 (MCP-1), MCP-2, MCP-3, transforming Growth Factor-1β (TGF-1β), vascular cell adhesion molecule 1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). The results suggest that sinomenine remarkably suppressed the development of atherosclerosis in the early stage.

Effect of Yoga on Endothelial Function: A Systematic Review and Meta-Analysis

Introduction: Endothelial dysfunction is the initial step in the pathogenesis of atherosclerosis; and it plays a central role in the development of cardiovascular diseases and many types of human diseases (diabetes, kidney failure, cancer, and viral infections). Strategies that are effective in protecting vascular endothelial function and retard or reversing endothelial dysfunction in the early stage appear to be potential in the prevention of vascular, cardiac, and many human diseases. Several studies have been carried out on the effects of yoga on endothelial function, but the results of these studies have not been synthesized. This study aimed at conducting a systematic review and meta-analysis to determine the effectiveness of yoga on endothelial function. Methods: A systematic review and meta-analysis of studies that assessed the effect of yoga practice on vascular endothelial function was done as per the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The PubMed, Scopus, Google Scholar, and Cochrane controlled register of trials (CENTRAL) were searched from inception to August 2022. The search strategy was constructed around yoga-based techniques and endothelial function. All the yoga-based interventional studies on endothelial function or dysfunction were included in this review. A narrative synthesis and descriptive analysis were done due to the diverse methodology of selected studies. We carried out a formal meta-analysis of controlled trials that assessed the effect of yoga on flow-mediated dilatation (FMD), a measure of endothelial function. Results: A total of 18 studies were included for review involving 1043 participants. Yoga training showed improved endothelial function in 12 studies, whereas 6 studies did not find any statistically robust effect. Meta-analysis (n = 395 participants, 6-studies, 7 comparisons) showed an increase in brachial FMD by yoga practice (mean difference = -1.23%; 95% confidence interval -2.23 to -0.23; p = 0.02). The heterogeneity between the studies was 43% (Tau2 = 0.70, χ2 = 10.49). The risk of bias was low to moderate in these studies. No adverse effects were reported. Conclusions: Yoga practice improved endothelial function. Yoga could be a safe and potential integrative medicine to improve endothelial function. However, as the statistical heterogeneity, that is, variation in the FMD among the studies was moderate, large clinical trials are necessary for its clinical recommendations.

Targeting Hypertension: A Review on Pathophysiological Factors and Treatment Strategies

Hypertension is one of the primary causes of cardiovascular diseases and death, with a higher prevalence in low- and middle-income countries. The pathophysiology of hypertension remains complex, with 2% to 5% of patients having underlying renal or adrenal disorders. The rest are referred to as essential hypertension, with derangements in various physiological mechanisms potentially contributing to the development of essential hypertension. Hypertension elevates the risk of cardiovascular disease (CVD) events (coronary heart disease, heart failure, and stroke) and mortality. First-line therapy for hypertension is lifestyle change, which includes weight loss, a balanced diet that includes low salt and high potassium intake, physical exercise, and limitation or elimination of alcohol use. Blood pressure-lowering effects of individual lifestyle components are partially additive, enhancing the efficacy of pharmaceutical treatment. The choice to begin antihypertensive medication should be based on the level of blood pressure and the existence of a high atherosclerotic CVD risk. First-line hypertension treatment includes a thiazide or thiazide-like diuretic, an angiotensin-converting enzyme inhibitor or angiotensin receptor blocker, and a calcium channel blocker. Addressing hypertension will require continued efforts to improve access to diagnosis, treatment, and lifestyle interventions.

Cardioprotective Effects of Solidago microglossa DC. in Nicotine-Treated Hypertensive Rats

Solidago microglossa DC. (Asteraceae), "arnica brasileira," is a Brazilian species popularly used to treat hypertension or renal ailments. This study investigated the cardioprotective effects of standardized S. microglossa extract (EESM) in nicotine-treated spontaneously hypertensive rats (SHRs). Moreover, the molecular mechanisms involved in the cardiovascular effects were also investigated. The acute toxicity was evaluated in female Wistar rats. Afterwards, six-month-old male spontaneously hypertensive rats received the EESM (14, 28, and 56 mg/kg), hydrochlorothiazide (25 mg/kg), and vehicle (filtered water; 0.1 mL/100 g) once daily for 28 days. All treatments were associated with 1.8 mg/kg of nicotine. At the end of the experimental period, the renal function, electrocardiographic profile, blood pressure, ventricular function, biochemical parameter, and mesenteric vascular bed reactivity were evaluated. Relative organ weights and cardiac morphometry were also investigated. Nicotine treatment in 6-month-old SHRs induced a significant reduction in renal function, with reduced urinary volume and lower renal elimination of sodium and creatinine. In addition, serum markers of the redox state and blood pressure levels remained significantly elevated, contributing to changes in vascular reactivity and left ventricular hypertrophy associated with reduced ventricular function. After 28 days of treatment, we found that the highest dose of EESM could mitigate all renal and cardiovascular changes developed by the nicotine-treated hypertensive rats. This study presented EESM as a possible cardioprotective drug that prevents cardiovascular dysfunctions in nicotine-treated hypertensive rats. Our data suggest EESM as a potential adjuvant therapy when cardioprotective effects are required.

HIV-Related Atherosclerosis: State-of-the-Art-Review

The infection caused by the Human Immunodeficiency Virus (HIV) has spread rapidly across the globe, assuming the characteristics of an epidemic in some regions. Thanks to the introduction of antiretroviral therapy into routine clinical practice, there was a considerable breakthrough in the treatment of HIV, that is now HIV is potentially well-controlled even in low-income countries. To date, HIV infection has moved from the group of life-threatening conditions to the group of chronic and well controlled ones and the quality of life and life expectancy of HIV+ people, with an undetectable viral load is closer to that of an HIV- people. However, unsolved issues still persist. For example: people living with HIV are more prone to the age-related diseases, especially atherosclerosis. For this reason, a better understanding of the mechanisms of HIV-associated destabilization of vascular homeostasis seems to be an urgent duty, that may lead to the development of new protocols, bringing the possibilities of pathogenetic therapies to a new level. The purpose of the article was to evaluate the pathological aspects of HIV-induced atherosclerosis.

Single-Cell Transcriptomics Reveals Evidence of Endothelial Dysfunction in the Brains of COVID-19 Patients with Implications for Glioblastoma Progression

BACKGROUND

Endothelial dysfunction is implicated in various inflammatory diseases such as ischemic stroke, heart attack, organ failure, and COVID-19. Recent studies have shown that endothelial dysfunction in the brain is attributed to excessive inflammatory responses caused by the SARS-CoV-2 infection, leading to increased permeability of the blood-brain barrier and consequently neurological damage. Here, we aim to examine the single-cell transcriptomic landscape of endothelial dysfunction in COVID-19 and its implications for glioblastoma (GBM) progression.

METHODS

Single-cell transcriptome data GSE131928 and GSE159812 were obtained from the gene expression omnibus (GEO) to analyze the expression profiles of key players in innate immunity and inflammation between brain endothelial dysfunction caused by COVID-19 and GBM progression.

RESULTS

Single-cell transcriptomic analysis of the brain of COVID-19 patients revealed that endothelial cells had undergone significant transcriptomic changes, with several genes involved in immune responses and inflammation upregulated. Moreover, transcription factors were observed to modulate this inflammation, including interferon-regulated genes.

CONCLUSIONS

The results indicate a significant overlap between COVID-19 and GBM in the context of endothelial dysfunction, suggesting that there may be an endothelial dysfunction link connecting severe SARS-CoV-2 infection in the brain to GBM progression.

Biomarkers Assessing Endothelial Dysfunction in Alzheimer's Disease

Alzheimer's disease (AD) is the most common degenerative disorder in the elderly in developed countries. Currently, growing evidence is pointing at endothelial dysfunction as a key player in the cognitive decline course of AD. As a main component of the blood-brain barrier (BBB), the dysfunction of endothelial cells driven by vascular risk factors associated with AD allows the passage of toxic substances to the cerebral parenchyma, producing chronic hypoperfusion that eventually causes an inflammatory and neurotoxic response. In this process, the levels of several biomarkers are disrupted, such as an increase in adhesion molecules that allow the passage of leukocytes to the cerebral parenchyma, increasing the permeability of the BBB; moreover, other vascular players, including endothelin-1, also mediate artery inflammation. As a consequence of the disruption of the BBB, a progressive neuroinflammatory response is produced that, added to the astrogliosis, eventually triggers neuronal degeneration (possibly responsible for cognitive deterioration). Recently, new molecules have been proposed as early biomarkers for endothelial dysfunction that can constitute new therapeutic targets as well as early diagnostic and prognostic markers for AD.

Multiple Sclerosis: Inflammatory and Neuroglial Aspects

Multiple sclerosis (MS) represents the most common acquired demyelinating disorder of the central nervous system (CNS). Its pathogenesis, in parallel with the well-established role of mechanisms pertaining to autoimmunity, involves several key functions of immune, glial and nerve cells. The disease's natural history is complex, heterogeneous and may evolve over a relapsing-remitting (RRMS) or progressive (PPMS/SPMS) course. Acute inflammation, driven by infiltration of peripheral cells in the CNS, is thought to be the most relevant process during the earliest phases and in RRMS, while disruption in glial and neural cells of pathways pertaining to energy metabolism, survival cascades, synaptic and ionic homeostasis are thought to be mostly relevant in long-standing disease, such as in progressive forms. In this complex scenario, many mechanisms originally thought to be distinctive of neurodegenerative disorders are being increasingly recognized as crucial from the beginning of the disease. The present review aims at highlighting mechanisms in common between MS, autoimmune diseases and biology of neurodegenerative disorders. In fact, there is an unmet need to explore new targets that might be involved as master regulators of autoimmunity, inflammation and survival of nerve cells.

Nitric oxide metabolites: associations with cardiovascular biomarkers and clinical parameters in patients with HFpEF

AIMS

Heart failure with preserved ejection fraction (HFpEF) is one of the most rapidly growing cardiovascular health burden worldwide, but there is still a lack of understanding about the HFpEF pathophysiology. The nitric oxide (NO) signalling pathway has been identified as a potential key element. The aim of our study was to investigate markers of NO metabolism [l-arginine (l-Arg), homoarginine (hArg), and asymmetric and symmetric dimethylarginine (ADMA and SDMA)], additional biomarkers [N-terminal pro-B-type natriuretic peptide (NT-proBNP), endothelin-1 (ET-1), mid-regional pro-adrenomedullin (MR-proADM), copeptin, and high-sensitivity C-reactive protein (hsCRP)], and the endothelial function in an integrated approach focusing on associations with clinical characteristics in patients with HFpEF.

METHODS AND RESULTS

Seventy-three patients, prospectively enrolled in the 'German HFpEF Registry', were analysed. Inclusion criteria were left ventricular ejection fraction (LVEF) ≥ 50%; New York Heart Association functional class ≥ II; elevated levels of NT-proBNP > 125 pg/mL; and at least one additional criterion for structural heart disease or diastolic dysfunction. All patients underwent transthoracic echocardiography, cardiopulmonary exercise testing, and pulse amplitude tonometry (EndoPAT™). Patients were categorized in two groups based on their retrospectively calculated HFA-PEFF score. Serum concentrations of l-Arg, hArg, ADMA, SDMA, NT-proBNP, ET-1, MR-proADM, copeptin, and hsCRP were determined. Patients had a median age of 74 years, 47% were female, and median LVEF was 57%. Fifty-two patients (71%) had an HFA-PEFF score ≥ 5 (definitive HFpEF), and 21 patients (29%) a score of 3 to 4 (risk for HFpEF). Overall biomarker concentrations were 126 ± 32 μmol/L for l-Arg, 1.67 ± 0.55 μmol/L for hArg, 0.74 (0.60;0.85) μmol/L for SDMA, and 0.61 ± 0.10 μmol/L for ADMA. The median reactive hyperaemia index (RHI) was 1.55 (1.38;1.87). SDMA correlated with NT-proBNP (r = 0.291; P = 0.013), ET-1 (r = 0.233; P = 0.047), and copeptin (r = 0.381; P = 0.001). ADMA correlated with ET-1 (r = 0.250; P = 0.033) and hsCRP (r = 0.303; P = 0.009). SDMA was associated with the left atrial volume index (β = 0.332; P = 0.004), also after adjustment for age, sex, and comorbidities. Biomarkers were non-associated with the RHI. A principal component analysis revealed two contrary clusters of biomarkers.

CONCLUSIONS

Our findings suggest an impaired NO metabolism as one possible key pathogenic determinant in at least a subgroup of patients with HFpEF. We argue for further evaluation of NO-based therapies. Upcoming studies should clarify whether subgroups of HFpEF patients can take more benefit from therapies that are targeting NO metabolism and pathway.

Hydroxychloroquine reduces hypertension and soluble fms-like kinase-1 in a Nω-nitro-l-arginine methyl ester-induced preeclampsia rat model

OBJECTIVE

Hydroxychloroquine, a drug used for malaria and autoimmune diseases reportedly has beneficial effects against preeclampsia in pregnant women with lupus. However, its mechanism against preeclampsia remains unclear. We investigated the effect of hydroxychloroquine on an Nω-nitro-l-arginine methyl ester-induced preeclampsia rat model.

METHODS

Pregnant Sprague-Dawley rats were divided into four groups based on treatment (administered on gestational days 7-18): control, Nω-nitro-l-arginine methyl ester, hydroxychloroquine, and Nω-nitro-l-arginine methyl ester plus hydroxychloroquine. All animals were sacrificed on gestational day 19. We assayed tube formation and determined reactive oxygen species levels using human umbilical vein endothelial cells.

RESULTS

Results showed that hydroxychloroquine significantly lowered mean systolic blood pressure (P  < 0.05) in Nω-nitro-l-arginine methyl ester-treated rats. Hydroxychloroquine did not affect their fetal and placental weights. Hydroxychloroquine mitigated Nω-nitro-l-arginine methyl ester-associated changes in proteinuria (P  < 0.05). It normalized plasma soluble fms-like kinase-1 (P  < 0.05) and endothelin-1 (P  < 0.01) levels. In the tube formation assay, hydroxychloroquine increased the total meshes area (P  < 0.05) and mitigated Nω-nitro-l-arginine methyl ester-induced reactive oxygen species formation (P  < 0.05) in human umbilical vein endothelial cells.

CONCLUSION

We conclude that hydroxychloroquine alleviated hypertension, proteinuria, and normalized soluble fms-like kinase-1 and endothelin-1 levels in our preeclampsia model and that these changes may involve the restoration of endothelial dysfunction; thus, hydroxychloroquine could potentially be used for preventing preeclampsia, even in the absence of lupus.

Essential Hypertension and Oxidative Stress: Novel Future Perspectives

Among cardiovascular diseases, hypertension is one of the main risk factors predisposing to fatal complications. Oxidative stress and chronic inflammation have been identified as potentially responsible for the development of endothelial damage and vascular stiffness, two of the primum movens of hypertension and cardiovascular diseases. Based on these data, we conducted an open-label randomized study, first, to evaluate the endothelial damage and vascular stiffness in hypertense patients; second, to test the effect of supplementation with a physiological antioxidant (melatonin 1 mg/day for 1 year) in patients with essential hypertension vs. hypertensive controls. Twenty-three patients of either gender were enrolled and randomized 1:1 in two groups (control and supplemented group). The plasmatic total antioxidant capacity (as a marker of oxidative stress), blood pressure, arterial stiffness, and peripheral endothelial function were evaluated at the beginning of the study and after 1 year in both groups. Our results showed that arterial stiffness improved significantly (p = 0.022) in supplemented patients. The endothelial function increased too, even if not significantly (p = 0.688), after 1 year of melatonin administration. Moreover, the supplemented group showed a significative reduction in TAC levels (p = 0.041) correlated with the improvement of arterial stiffness. These data suggest that melatonin may play an important role in reducing the serum levels of TAC and, consequently, in improving arterial stiffness.

Vanadyl sulphate ameliorates biomarkers of endothelial injury and coagulation and thrombosis in a rat model of hyperglycaemia

BACKGROUND

We sought to determine whether the insulin mimicking agent, vanadyl sulphate (Van) can inhibit biomarkers of endothelial injury and coagulation and thrombosis induced by a moderate level of hyperglycaemia.

MATERIAL AND METHODS

Hyperglycaemia was induced in rats by a single injection of streptozotocin (STZ, 50 mg/kg) two weeks after being fed on a high-fat diet (model group). The treatment group started Van (20 mg/kg/day) treatment one-week post STZ injection and continued on Van until being sacrificed at week 10.

RESULTS

Administration of Van to the model group significantly (p < .05) ameliorated dyslipidemia and biomarkers of inflammation (TNF-α, IL-6, and hsCRP) and endothelial injury (E-selectin, P-selectin, sICAM-1, sVCAM-1, and ET-1). Van also significantly inhibited hyperglycaemia-induced blood levels of coagulation (vWF) and thrombosis (PAI-1 and fibrinogen) biomarkers.

CONCLUSIONS

Vanadyl sulphate effectively suppresses hyperglycaemia-induced endothelial injury, coagulation and thrombosis, which is associated with the inhibition of inflammation and dyslipidemia.

Winery by-products as a valuable source for natural antihypertensive agents

Hypertension (HTN) is one of the leading causes of death in the world. Agri-food by-products are emerging as a novel source of natural antihypertensive agents allowing for their valorization and making food and agricultural industries more environmentally friendly. In this regard, wine making process generates large amounts of by-products rich in phenolic compounds that have shown potential to exert several beneficial effects including antihypertensive properties. The aim of this study was to review the blood pressure-lowering effects of winery by-products. In addition, molecular mechanisms involved in their bioactivity were also evaluated. Among the winery by-products, grape seed extracts have widely shown antihypertensive properties in both animal and human studies. Moreover, recent evidence suggests that grape stem, skin and pomace and wine lees may also have great potential to manage HTN, although more studies are needed in order to confirm their potential in humans. Improvement of endothelial dysfunction and reduction of oxidative stress associated with HTN are the main mechanisms involved in the blood pressure-lowering effects of these by-products.

COVID-19, the Pandemic of the Century and Its Impact on Cardiovascular Diseases

COVID-19 caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection likely ranks among the deadliest diseases in human history. As with other coronaviruses, SARS-CoV-2 infection damages not only the lungs but also the heart and many other organs that express angiotensin-converting enzyme 2 (ACE2), a receptor for SARS-CoV-2. COVID-19 has upended lives worldwide. Dietary behaviors have been altered such that they favor metabolic and cardiovascular complications, while patients have avoided hospital visits because of limited resources and the fear of infection, thereby increasing out-hospital mortality due to delayed diagnosis and treatment. Clinical observations show that sex, age, and race all influence the risk for SARS-CoV-2 infection, as do hypertension, obesity, and pre-existing cardiovascular conditions. Many hospitalized COVID-19 patients suffer cardiac injury, acute coronary syndromes, or cardiac arrhythmia. SARS-CoV-2 infection may lead to cardiomyocyte apoptosis and necrosis, endothelial cell damage and dysfunction, oxidative stress and reactive oxygen species production, vasoconstriction, fibrotic and thrombotic protein expression, vascular permeability and microvascular dysfunction, heart inflammatory cell accumulation and activation, and a cytokine storm. Current data indicate that COVID-19 patients with cardiovascular diseases should not discontinue many existing cardiovascular therapies such as ACE inhibitors, angiotensin receptor blockers, steroids, aspirin, statins, and PCSK9 inhibitors. This review aims to furnish a framework relating to COVID-19 and cardiovascular pathophysiology.

Involvement of multiple scavenger receptors in advanced glycation end product-induced vessel tube formation in endothelial cells

Toxic advanced glycation end products (toxic AGEs) derived from glycolaldehyde (AGE3) have been implicated in the development of diabetic vascular complications such as retinopathy characterised by excessive angiogenesis. Different receptor types, such as receptor for AGEs (RAGE), Toll like receptor-4 and scavenger receptors, are expressed in endothelial cells and contribute to AGE-elicited alteration of cell function. In the present study, we examined the involvement of AGE-related receptors on AGE-induced angiogenesis in endothelial cells. The effects of pharmacological inhibitors or receptor neutralizing antibodies on AGE3-induced tube formation were investigated using the in vitro Matrigel tube formation assay in b.End5 cells (mouse endothelial cells). AGE3-induced signalling pathways and receptor expression changes were analysed by Western blot analysis and flow cytometry, respectively. Both FPS-ZM1, a RAGE inhibitor, and fucoidan, a ligand for scavenger receptors, suppressed AGE3-induced tube formation. Cocktails of neutralizing antibodies against the scavenger receptors CD36, CD163 and LOX-1 prevented AGE3-induced tube formation. AGE3 activated mTOR signalling, resulting in facilitation of tube formation. Activation of the AGE-RAGE pathway also led to the upregulation of scavenger receptors. Taken together, our findings suggest that the scavenger receptors CD36, CD163 and LOX-1 in conjunction with the RAGE receptor work together to mediate toxic AGE-induced facilitation of angiogenesis.

Circulating Levels of Endothelin-1 and Big Endothelin-1 in Patients with Essential Hypertension

The role of endothelin-1 (ET-1) in the pathogenesis of hypertension (HTN) is not clearly established. There is evidence that its circulating levels are elevated in some forms of experimental and human HTN, but this was not a consistent finding. Based on these controversial data, we tested serum levels of ET-1 and Big ET-1 (the precursor of ET-1) in patients with essential HTN, comparing the results with those of healthy normotensive controls. The levels of ET-1 and Big ET-1 were measured by ELISA. Our results in patients with essential HTN showed that the mean levels of ET-1 (5.01 ± 2.1 pg/mL) were significantly higher (F = 6.34, p = 0.0144) than the mean levels in the control group (3.2 ± 1.0 pg/mL). The levels of Big ET-1 in patients with essential HTN (0.377 ± 0.1 pmol/L) were similar to those in the control group (0.378 ± 0.07 pmol/L) and did not differ significantly (F = 0.00, p = 0.9531). These data suggest that ET-1, but not Big ET-1, may play an important role in the pathogenesis of primary HTN.

Induced pluripotent stem cells can improve thrombolytic effect of low-dose rt-PA after acute carotid thrombosis in rat

Background

Intravenous thrombolysis using recombinant tissue plasminogen activator (rt-PA) is the standard treatment for acute ischemic stroke. Standard-dose rt-PA (0.9 mg/kg) is known to achieve good recanalization but carries a high bleeding risk. Lower dose of rt-PA has less bleeding risk but carries a high re-occlusion rate. We investigate if induced pluripotent stem cells (iPSCs) can improve the thrombolytic effect of low-dose rt-PA (0.45 mg/kg).

Methods

Single irradiation with 6 mW/cm² light-emitting diode (LED) for 4 h at rat common carotid artery was used as thrombosis model according to our previous report. Endothelin-1 (ET-1), intercellular adhesion molecule-1 (ICAM-1), and interleukin 1 beta (IL-1 beta) were used as the inflammatory markers for artery endothelial injury. Angiopoietin-2 (AP-2), brain-derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF) were examined in artery wall and iPSCs culture. Animal ultrasound was used to evaluate the stenosis degree of common carotid artery before and at 2 h, 24 h, 4 days and 7 days after LED irradiation.

Results

After LED irradiation alone, there was a persistent occlusion from 2 h to 7 days. Standard-dose rt-PA alone could recanalize the occluded artery from 24 h to 7 days to stenotic degree ≤ 50%. Low-dose rt-PA or 1 × 10⁶ mouse iPSCs alone could not recanalize the occluded arteries from 2 h to 7 days. Combination use of low-dose rt-PA plus 1 × 10⁶ mouse iPSCs caused better recanalization from 24 h to 7 days. ET-1, ICAM-1 and IL-1 beta were strongly expressed after LED irradiation but reduced after iPSCs treatment. AP-2, BDNF and VEGF were rarely induced after LED irradiation but strongly expressed after iPSCs treatment. In vitro study showed iPSCs could express AP-2, BDNF and VEGF.

Conclusion

The adjuvant use of iPSCs may help improving the thrombolytic effect of low-dose rt-PA by suppressing inflammatory factors and inducing angiogenic trophic factors. Stem cells could be a potential regimen in acute thrombolytic therapy to improve recanalization and reduce complications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02615-z.

Pulmonary vascular system: A vulnerable target for COVID-19

The number of coronavirus disease 2019 (COVID‐19) cases has been increasing significantly, and the disease has evolved into a global pandemic, posing an unprecedented challenge to the healthcare community. Angiotensin‐converting enzyme 2, the binding and entry receptor of severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) in hosts, is also expressed on pulmonary vascular endothelium; thus, pulmonary vasculature is a potential target in COVID‐19. Indeed, pulmonary vascular thickening is observed by early clinical imaging, implying a tropism of SARS‐CoV‐2 for pulmonary vasculature. Recent studies reported that COVID‐19 is associated with vascular endothelial damage and dysfunction along with inflammation, coagulopathy, and microthrombosis; all of these pathologic changes are the hallmarks of pulmonary vascular diseases. Notwithstanding the not fully elucidated effects of COVID‐19 on pulmonary vasculature, the vascular endotheliopathy that occurs after infection is attributed to direct infection and indirect damage mainly caused by renin‐angiotensin‐aldosterone system imbalance, coagulation cascade, oxidative stress, immune dysregulation, and intussusceptive angiogenesis. Degradation of endothelial glycocalyx exposes endothelial cell (EC) surface receptors to the vascular lumen, which renders pulmonary ECs more susceptible to SARS‐CoV‐2 infection. The present article reviews the potential pulmonary vascular pathophysiology and clinical presentations in COVID‐19 to provide a basis for clinicians and scientists, providing insights into the development of therapeutic strategies targeting pulmonary vasculature.

Silibinin augments the effect of clopidogrel on atherosclerosis in diabetic ApoE deficiency mice

BACKGROUND

Diabetes mellitus (DM) abolishes the antithrombotic effect of Clopidogrel. Here, we investigated the synergistic effect of Silibinin on Clopidogrel-mediated atherosclerosis treatment in diabetic mice.

METHODS

ApoE-/- mice were fed with high-fat diet (HFD) to establish the atherosclerotic model with diabetes. Animals were treated with Clopidogrel, Silibinin, or the combined to evaluate the protective effects on atherosclerosis and diabetes through Oil-red-O staining, qRT-PCR, Western blot, and metabolic measurements. Platelet activation and aggregation ex vivo assays were performed to detect the anti-thrombotic effect of different administrations.

RESULTS

Silibinin significantly enhanced the inhibitory effect of Clopidogrel on atherosclerosis in DM mice. Co-administration of Silibinin with Clopidogrel remarkedly reduced the aortic lesion, inflammation, and endothelial dysfunction in aorta roots, and diabetic symptoms were significantly improved by the Silibinin-Clopidogrel treatment in HFD-fed ApoE-/- mice. Interestingly, the anti-thrombotic effect of Clopidogrel was further augmented by the Silibinin treatment in atherosclerotic mice.

CONCLUSION

In atherosclerotic mouse model, Silibinin significantly improves the effect of Clopidogrel on atherosclerosis.

The Causal Relationship between Endothelin-1 and Hypertension: Focusing on Endothelial Dysfunction, Arterial Stiffness, Vascular Remodeling, and Blood Pressure Regulation

Hypertension (HTN) is one of the most prevalent diseases worldwide and is among the most important risk factors for cardiovascular and cerebrovascular complications. It is currently thought to be the result of disturbances in a number of neural, renal, hormonal, and vascular mechanisms regulating blood pressure (BP), so crucial importance is given to the imbalance of a number of vasoactive factors produced by the endothelium. Decreased nitric oxide production and increased production of endothelin-1 (ET-1) in the vascular wall may promote oxidative stress and low-grade inflammation, with the development of endothelial dysfunction (ED) and increased vasoconstrictor activity. Increased ET-1 production can contribute to arterial aging and the development of atherosclerotic changes, which are associated with increased arterial stiffness and manifestation of isolated systolic HTN. In addition, ET-1 is involved in the complex regulation of BP through synergistic interactions with angiotensin II, regulates the production of catecholamines and sympathetic activity, affects renal hemodynamics and water–salt balance, and regulates baroreceptor activity and myocardial contractility. This review focuses on the relationship between ET-1 and HTN and in particular on the key role of ET-1 in the pathogenesis of ED, arterial structural changes, and impaired vascular regulation of BP. The information presented includes basic concepts on the role of ET-1 in the pathogenesis of HTN without going into detailed analyses, which allows it to be used by a wide range of specialists. Also, the main pathological processes and mechanisms are richly illustrated for better understanding.

Endothelin-1 axes in the framework of predictive, preventive and personalised (3P) medicine

Endothelin-1 (ET-1) is involved in the regulation of a myriad of processes highly relevant for physical and mental well-being; female and male health; in the modulation of senses, pain, stress reactions and drug sensitivity as well as healing processes, amongst others. Shifted ET-1 homeostasis may influence and predict the development and progression of suboptimal health conditions, metabolic impairments with cascading complications, ageing and related pathologies, cardiovascular diseases, neurodegenerative pathologies, aggressive malignancies, modulating, therefore, individual outcomes of both non-communicable and infectious diseases such as COVID-19. This article provides an in-depth analysis of the involvement of ET-1 and related regulatory pathways in physiological and pathophysiological processes and estimates its capacity as a predictor of ageing and related pathologies,a sensor of lifestyle quality and progression of suboptimal health conditions to diseases for their targeted preventionand as a potent target for cost-effective treatments tailored to the person.

Mitochondrial dysfunction associated with autophagy and mitophagy in cerebrospinal fluid cells of patients with delayed cerebral ischemia following subarachnoid hemorrhage

Decreased mitochondrial membrane potential in cerebrospinal fluid (CSF) was observed in patients with subarachnoid hemorrhage (SAH) accompanied by delayed cerebral ischemia (DCI). However, whether abnormal mechanisms of mitochondria are associated with the development of DCI has not been reported yet. Under cerebral ischemia, mitochondria can transfer into the extracellular space. Mitochondrial dysfunction can aggravate neurologic complications. The objective of this study was to evaluate whether mitochondrial dysfunction might be associated with autophagy and mitophagy in CSF cells to provide possible insight into DCI pathogenesis. CSF samples were collected from 56 SAH patients (DCI, n = 21; and non-DCI, n = 35). We analyzed CSF cells using autophagy and mitophagy markers (DAPK1, BNIP3L, BAX, PINK1, ULK1, and NDP52) via qRT-PCR and western blotting of proteins (BECN1, LC3, and p62). Confocal microscopy and immunogold staining were performed to demonstrate the differentially expression of markers within dysfunctional mitochondria. Significant induction of autophagic flux with accumulation of autophagic vacuoles, increased expression of BECN1, LC3-II, and p62 degradation were observed during DCI. Compared to non-DCI patients, DCI patients showed significantly increased mRNA expression levels (2^-ΔCt) of DAPK1, BNIP3L, and PINK1, but not BAX, ULK1, or NDP52. Multivariable logistic regression analysis revealed that Hunt and Hess grade ≥ IV (p = 0.023), DAPK1 (p = 0.003), and BNIP3L (p = 0.039) were related to DCI. Increased mitochondrial dysfunction associated with autophagy and mitophagy could play an important role in DCI pathogenesis.

Low-to-Moderate-Intensity Resistance Exercise Is More Effective than High-Intensity at Improving Endothelial Function in Adults: A Systematic Review and Meta-Analysis

Aerobic exercise has been confirmed to improve endothelial function (EF). However, the effect of resistance exercise (RE) on EF remains controversial. We conducted this systematic review and meta-analysis on randomized controlled trials (RCTs) to determine the effect of RE and its intensities on EF. We searched Web of Science, PubMed/MEDLINE, Scopus, and Wiley Online Library, and included 15 articles (17 trials) for the synthesis. Overall, RE intervention significantly improved flow-mediated dilatation (FMD) in brachial artery (SMD = 0.76; 95% CI: 0.47, 1.05; p < 0.00001), which represents improved EF. Meta-regression showed that the RE intensity was correlated with changes in FMD (Coef. = −0.274, T = −2.18, p = 0.045). We found both intensities of RE improved FMD, but the effect size for the low- to moderate-intensity (30–70%1RM) was bigger (SMD = 1.02; 95% CI: 0.60, 1.43; p < 0.0001) than for the high-intensity (≥70%1RM; SMD = 0.48; 95% CI: 0.21, 0.74; p = 0.005). We further noticed that RE had a beneficial effect (SMD = 0.61; 95% CI: 0.13, 1.09; p = 0.01) on the brachial artery baseline diameter at rest (BAD_rest), and the age variable was correlated with the changes in BAD_rest after RE (Coef. = −0.032, T = −2.33, p = 0.038). Young individuals (<40 years) presented with a bigger effect size for BAD_rest (SMD = 1.23; 95% CI: 0.30, 2.15; p = 0.009), while middle-aged to elderly (≥40 years) were not responsive to RE (SMD = 0.07; 95% CI: −0.28, 0.42; p = 0.70). Based on our findings, we conclude that RE intervention can improve the EF, and low- to moderate-intensity is more effective than high-intensity.

An Outline of Renal Artery Stenosis Pathophysiology-A Narrative Review

Renal artery stenosis (RAS) is conditioned mainly by two disturbances: fibromuscular dysplasia or atherosclerosis of the renal artery. RAS is an example of renovascular disease, with complex pathophysiology and consequences. There are multiple pathophysiological mechanisms triggered in response to significant renal artery stenosis, including disturbances within endothelin, kinin-kallikrein and sympathetic nervous systems, with angiotensin II and the renin-angiotensin-aldosterone system (RAAS) playing a central and key role in the pathogenesis of RAS. The increased oxidative stress and the release of pro-inflammatory mediators contributing to pathological tissue remodelling and renal fibrosis are also important pathogenetic elements of RAS. This review briefly summarises these pathophysiological issues, focusing on renovascular hypertension and ischemic nephropathy as major clinical manifestations of RAS. The activation of RAAS and its haemodynamic consequences is the primary and key element in the pathophysiological cascade triggered in response to renal artery stenosis. However, the pathomechanism of RAS is more complex and also includes other disturbances that ultimately contribute to the development of the diseases mentioned above. To sum up, RAS is characterised by different clinical pictures, including asymptomatic disorders diagnosed in kidney imaging, renovascular hypertension, usually characterised by severe course, and chronic ischemic nephropathy, described by pathological remodelling of kidney tissue, ultimately leading to kidney injury and chronic kidney disease.

Vascular Manifestations of COVID-19 - Thromboembolism and Microvascular Dysfunction

The coronavirus pandemic has reportedly infected over 31.5 million individuals and caused over 970,000 deaths worldwide (as of 22nd Sept 2020). This novel coronavirus, officially named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), although primarily causes significant respiratory distress, can have significant deleterious effects on the cardiovascular system. Severe cases of the virus frequently result in respiratory distress requiring mechanical ventilation, often seen, but not confined to, individuals with pre-existing hypertension and cardiovascular disease, potentially due to the fact that the virus can enter the circulation via the lung alveoli. Here the virus can directly infect vascular tissues, via TMPRSS2 spike glycoprotein priming, thereby facilitating ACE-2-mediated viral entry. Clinical manifestations, such as vasculitis, have been detected in a number of vascular beds (e.g., lungs, heart, and kidneys), with thromboembolism being observed in patients suffering from severe coronavirus disease (COVID-19), suggesting the virus perturbs the vasculature, leading to vascular dysfunction. Activation of endothelial cells via the immune-mediated inflammatory response and viral infection of either endothelial cells or cells involved in endothelial homeostasis, are some of the multifaceted mechanisms potentially involved in the pathogenesis of vascular dysfunction within COVID-19 patients. In this review, we examine the evidence of vascular manifestations of SARS-CoV-2, the potential mechanism(s) of entry into vascular tissue and the contribution of endothelial cell dysfunction and cellular crosstalk in this vascular tropism of SARS-CoV-2. Moreover, we discuss the current evidence on hypercoagulability and how it relates to increased microvascular thromboembolic complications in COVID-19.

Vascular Manifestations of COVID-19 - Thromboembolism and Microvascular Dysfunction

The coronavirus pandemic has reportedly infected over 31.5 million individuals and caused over 970,000 deaths worldwide (as of 22nd Sept 2020). This novel coronavirus, officially named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), although primarily causes significant respiratory distress, can have significant deleterious effects on the cardiovascular system. Severe cases of the virus frequently result in respiratory distress requiring mechanical ventilation, often seen, but not confined to, individuals with pre-existing hypertension and cardiovascular disease, potentially due to the fact that the virus can enter the circulation via the lung alveoli. Here the virus can directly infect vascular tissues, via TMPRSS2 spike glycoprotein priming, thereby facilitating ACE-2-mediated viral entry. Clinical manifestations, such as vasculitis, have been detected in a number of vascular beds (e.g., lungs, heart, and kidneys), with thromboembolism being observed in patients suffering from severe coronavirus disease (COVID-19), suggesting the virus perturbs the vasculature, leading to vascular dysfunction. Activation of endothelial cells via the immune-mediated inflammatory response and viral infection of either endothelial cells or cells involved in endothelial homeostasis, are some of the multifaceted mechanisms potentially involved in the pathogenesis of vascular dysfunction within COVID-19 patients. In this review, we examine the evidence of vascular manifestations of SARS-CoV-2, the potential mechanism(s) of entry into vascular tissue and the contribution of endothelial cell dysfunction and cellular crosstalk in this vascular tropism of SARS-CoV-2. Moreover, we discuss the current evidence on hypercoagulability and how it relates to increased microvascular thromboembolic complications in COVID-19.

Extracellular Vesicles Attenuate Nitrofen-Mediated Human Pulmonary Artery Endothelial Dysfunction: Implications for Congenital Diaphragmatic Hernia

Congenital diaphragmatic hernia (CDH) leads to pathophysiologic pulmonary vasoreactivity. Previous studies show that mesenchymal stromal cell-derived extracellular vesicles (MSCEv) inhibit lung inflammation and vascular remodeling. We characterize MSCEv and human pulmonary artery endothelial cell (HPAEC) interaction, as well as the pulmonary artery (PA) response to MSCEv treatment. HPAECs were cultured with and without exposure to nitrofen (2,4-dichloro-phenyl-p-nitrophenylether) and treated with MSCEv. HPAEC viability, architecture, production of reactive oxygen species (ROS), endothelial dysfunction-associated protein levels (PPARγ, LOX-1, LOX-2, nuclear factor-κB [NF-κB], endothelial NO synthase [eNOS], ET-1 [endothelin 1]), and the nature of MSCEv-cellular interaction were assessed. Newborn rodents with and without CDH (nitrofen model and Sprague-Dawley) were treated with intravascular MSCEv or vehicle control, and their PAs were isolated. Contractility was assessed by wire myography. The contractile (KCL and ET-1) and relaxation (fasudil) responses were evaluated. HPAEC viability correlated inversely with nitrofen dose, while architectural compromise was directly proportional. There was a 2.1 × increase in ROS levels in nitrofen HPAECs (P < 0.001), and MSCEv treatment attenuated ROS levels by 1.5 × versus nitrofen HPAECs (P < 0.01). Nitrofen-induced alterations in endothelial dysfunction-associated proteins are shown, and exposure to MSCEv restored more physiologic expression. Nitrofen HPAEC displayed greater MSCEv uptake (80% increase, P < 0.05). Adenosine, a clathrin-mediated endocytosis inhibitor, decreased uptake by 46% (P < 0.05). CDH PA contraction was impaired with KCL (108.6% ± 1.4% vs. 112.0% ± 1.4%, P = 0.092) and ET-1 (121.7% ± 3.0% vs. 131.2% ± 1.8%, P < 0.01). CDH PA relaxation was impaired with fasudil (32.2% ± 1.9% vs. 42.1% ± 2.2%, P < 0.001). After MSCEv treatment, CDH PA contraction improved (125.9% ± 3.4% vs. 116.4 ± 3.5, P = 0.06), and relaxation was unchanged (32.5% ± 3.2% vs. 29.4% ± 3.1%, P = 0.496). HPAEC exposure to nitrofen led to changes consistent with vasculopathy in CDH, and MSCEv treatment led to a more physiologic cellular response. MSCEv were preferentially taken up by nitrofen-treated cells by clathrin-dependent endocytosis. In vivo, MSCEv exposure improved PA contractile response. These data reveal mechanisms of cellular and signaling alterations that characterize MSCEv-mediated attenuation of pulmonary vascular dysfunction in CDH-associated pulmonary hypertension.

Endothelial cells and angiogenesis in the horse in health and disease-A review

The cardiovascular system is the first functional organ in the embryo, and its blood vessels form a widespread conductive network within the organism. Blood vessels develop de novo, by the differentiation of endothelial progenitor cells (vasculogenesis) or by angiogenesis, which is the formation of new blood vessels from existing ones. This review presents an overview of the current knowledge on physiological and pathological angiogenesis in the horse including studies on equine endothelial cells. Principal study fields in equine angiogenesis research were identified: equine endothelial progenitor cells; equine endothelial cells and angiogenesis (heterogeneity, markers and assessment); endothelial regulatory molecules in equine angiogenesis; angiogenesis research in equine reproduction (ovary, uterus, placenta and conceptus, testis); angiogenesis research in pathological conditions (tumours, ocular pathologies, equine wound healing, musculoskeletal system and laminitis). The review also includes a table that summarizes in vitro studies on equine endothelial cells, either describing the isolation procedure or using previously isolated endothelial cells. A particular challenge of the review was that results published are fragmentary and sometimes even contradictory, raising more questions than they answer. In conclusion, angiogenesis is a major factor in several diseases frequently occurring in horses, but relatively few studies focus on angiogenesis in the horse. The challenge for the future is therefore to continue exploring new therapeutic angiogenesis strategies for horses to fill in the missing pieces of the puzzle.

Endothelium as a Therapeutic Target in Diabetes Mellitus: From Basic Mechanisms to Clinical Practice

Endothelium plays an essential role in human homeostasis by regulating arterial blood pressure, distributing nutrients and hormones as well as providing a smooth surface that modulates coagulation, fibrinolysis and inflammation. Endothelial dysfunction is present in Diabetes Mellitus (DM) and contributes to the development and progression of macrovascular disease, while it is also associated with most of the microvascular complications such as diabetic retinopathy, nephropathy and neuropathy. Hyperglycemia, insulin resistance, hyperinsulinemia and dyslipidemia are the main factors involved in the pathogenesis of endothelial dysfunction. Regarding antidiabetic medication, metformin, gliclazide, pioglitazone, exenatide and dapagliflozin exert a beneficial effect on Endothelial Function (EF); glimepiride and glibenclamide, dipeptidyl peptidase-4 inhibitors and liraglutide have a neutral effect, while studies examining the effect of insulin analogues, empagliflozin and canagliflozin on EF are limited. In terms of lipid-lowering medication, statins improve EF in subjects with DM, while data from short-term trials suggest that fenofibrate improves EF; ezetimibe also improves EF but further studies are required in people with DM. The effect of acetylsalicylic acid on EF is dose-dependent and lower doses improve EF while higher ones do not. Clopidogrel improves EF, but more studies in subjects with DM are required. Furthermore, angiotensin- converting-enzyme inhibitors /angiotensin II receptor blockers improve EF. Phosphodiesterase type 5 inhibitors improve EF locally in the corpus cavernosum. Finally, cilostazol exerts favorable effect on EF, nevertheless, more data in people with DM are required.

Sirtuins family as a target in endothelial cell dysfunction: implications for vascular ageing

The vascular endothelium is a protective barrier between the bloodstream and the vasculature that may be disrupted by different factors such as the presence of diseased states. Diseases like diabetes and obesity pose a great risk toward endothelial cell inflammation and oxidative stress, leading to endothelial cell dysfunction and thereby cardiovascular complications such as atherosclerosis. Sirtuins are NAD⁺-dependent histone deacetylases that are implicated in the pathophysiology of cardiovascular diseases, and they have been identified to be important regulators of endothelial cell function. A handful of recent studies suggest that disbalance in the regulation of endothelial sirtuins, mainly sirtuin 1 (SIRT1), contributes to endothelial cell dysfunction. Herein, we summarize how SIRT1 and other sirtuins may contribute to endothelial cell function and how presence of diseased conditions may alter their expressions to cause endothelial dysfunction. Moreover, we discuss how the beneficial effects of exercise on the endothelium are dependent on SIRT1. These mainly include regulation of signaling pathways related to endothelial nitric oxide synthase phosphorylation and nitric oxide production, mitochondrial biogenesis and mitochondria-mediated apoptotic pathways, oxidative stress and inflammatory pathways. Sirtuins as modulators of the adverse conditions in the endothelium hold a promising therapeutic potential for health conditions related to endothelial dysfunction and vascular ageing.

Potential therapeutic effects of endothelial cells trans-differentiated from Wharton's Jelly-derived mesenchymal stem cells on altered vascular functions in aged diabetic rat model

BACKGROUND

Diabetes mellitus in elderly represents an exceptional subset in the population vulnerable to cardiovascular events. As aging, diabetes mellitus and hypertension share common pathways, an ideal treatment should possess the ability to counter more than one of, if not all, the underlying mechanisms. Stem cells emerged as a potential approach for complicated medical problems. We tested here the possible role of trans-differentiated endothelial cells (ECs) in the treatment of diabetes mellitus in old rats.

METHODS

Mesenchymal stem cells where isolated from umbilical cord Wharton's Jelly and induced to differentiate into endothelial like-cells using vascular endothelial growth factor-enriched media. Thirty aged male Wistar albino rats were used in the present study. Rats were divided (10/group) into: control group (18-20 months old, weighing 350-400 g, received single intraperitoneal injection as well as single intravenous injection via tail vein of the vehicles), aged diabetic group (18-20 months old, weighing 350-400 g, received single intraperitoneal injection of 50 mg/kg streptozotocin, and also received single intravenous injection of saline via tail vein), and aged diabetic + ECs group (18-20 months old, weighing 350-400 g, received single intraperitoneal injection of 50 mg/kg streptozotocin, and also received single intravenous injection of 2*10⁶ MSC-derived ECs in 0.5 ml saline via tail vein) groups. Assessment of SBP, aortic PWV, and renal artery resistance was performed. Serum levels of ET1, ANG II, IL-6, TNF-α, MDA, ROS, and VEGF were evaluated, as well as the aortic NO tissue level and eNOS gene expression. Histopathological and immunostaining assessments of small and large vessels were also performed.

RESULTS

Induction of diabetes in old rats resulted in significant increase in SBP, aortic PWV, renal artery resistance, and serum levels of ET1, ANG II, IL-6, TNF-α, MDA, ROS, and VEGF. While there was significant decrease in aortic NO tissue level and eNOS gene expression in the aged diabetic group when compared to aged control group. ECs treatment resulted in significant improvement of endothelial dysfunction, inflammation and oxidative stress.

CONCLUSION

We report here the potential therapeutic role of trans-differentiated ECs in aged diabetics. ECs demonstrated anti-inflammatory, antioxidant, gene modifying properties, significantly countered endothelial dysfunction, and improved vascular insult.

Evidence that Nitric Oxide is Involved in the Blood Pressure Lowering Effect of the Peptide AVFQHNCQE in Spontaneously Hypertensive Rats

AVFQHNCQE is an antihypertensive nonapeptide obtained from a chicken foot protein hydrolysate. The present study aims to investigate the mechanisms involved in its blood pressure (BP)-lowering effect. Male (17⁻20 weeks old) spontaneously hypertensive rats (SHR) were used in this study. Rats were divided into two groups and orally administered water or 10 mg/kg body weight (bw) AVFQHNCQE. One hour post-administration, animals of both groups were intra-peritoneally treated with 1 mL of saline or with 1 mL of saline containing 30 mg/kg bw Nω-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthesis, or with 1 mL of saline containing 5 mg/kg bw indomethacin, which is an inhibitor of prostacyclin synthesis (n = 6 per group). Systolic BP was recorded before oral administration and six hours after oral administration. In an additional experiment, SHR were administered water or 10 mg/kg bw AVFQHNCQE (n = 6 per group) and sacrificed six hours post-administration to study the mechanisms underlying the peptide anti-hypertensive effect. Moreover, the relaxation caused by AVFQHNCQE in isolated aortic rings from Sprague-Dawley rats was evaluated. The BP-lowering effect of the peptide was not changed after indomethacin administration but was completely abolished by L-NAME, which demonstrates that its anti-hypertensive effect is mediated by changes in endothelium-derived NO availability. In addition, AVFQHNCQE administration downregulated aortic gene expression of the vasoconstrictor factor endothelin-1 and the endothelial major free radical producer NADPH. Moreover, while no changes in plasma ACE activity were observed after its administration, liver GSH levels were higher in the peptide-treated group than in the water group, which demonstrates that AVFQHNCQE presents antioxidant properties.

Neulasta Regimen for the Hematopoietic Acute Radiation Syndrome: Effects Beyond Neutrophil Recovery

PURPOSE

Understanding the physiopathology underlying the acute radiation syndrome (ARS) and the mechanism of action of drugs known to ameliorate ARS is expected to help identify novel countermeasure candidates and improve the outcome for victims exposed to radiation. Granulocyte colony-stimulating factor (G-CSF) has been approved by the US Food and Drug Administration for treatment of hematopoietic ARS (H-ARS) because of its ability to alleviate myelosuppression. Besides its role in hematopoiesis, G-CSF is known to protect the cardiovascular and neurologic systems, to attenuate vascular injury and cardiac toxicity, to preserve gap junction function, and to modulate inflammation and oxidative stress. Here, we characterized the protective effects of G-CSF beyond neutrophil recovery in minipigs exposed to H-ARS doses.

METHODS AND MATERIALS

Twenty male Göttingen minipigs were exposed to total body, acute ionizing radiation. Animals received either pegylated G-CSF (Neulasta) or dextrose at days 1 and 8 after irradiation. Survival was monitored over a 45-day period.

RESULTS

Neulasta decreased mortality compared with the control, reduced nadir and duration of neutropenia, and lowered prevalence of organ hemorrhage and frank bleeding episodes. Neulasta also increased plasma concentration of IGF-1 hormone, activated the cardiovascular protective IGF-1R/PI3K/Akt/eNOS/NO pathway, and enhanced membrane expression of VE-cadherin in the heart, improving vascular tone and barrier function. Expression of the acute phase protein CRP, a mediator of cardiovascular diseases and a negative regulator of the IGF-1 pathway, was also induced but at much lower extent compared with IGF-1. Activity of catalase and superoxide dismutase (SOD-1) was only marginally affected, whereas activation of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase was downregulated.

CONCLUSIONS

In addition to a neutrophilic effect, amelioration of endothelial homeostasis and barrier function and reduction in NADPH oxidase contribute to the beneficial effects of Neulasta for the treatment of H-ARS.

Total Hip Replacement Provokes Endothelial Dysfunction

Surgery represents an increased risk of different perioperative complications. Endothelial function (EF) is a key mechanism responsible for cardiovascular homeostasis and is involved in thromboembolic complications. We aimed to follow changes of EF in an early postoperative period in patients undergoing total hip replacement (THR). Endothelial function was assessed noninvasively in 70 consecutive patients who underwent an elective THR under spinal anesthesia. Flow-mediated dilation (FMD) and low flow-mediated constriction capability of the brachial artery, which are indicators of EF were measured before the operation (baseline), 24 hours after the operative procedure, and 5 to 7 days postoperatively. Baseline FMD was 12.3% and decreased a day after surgery to 7.3% ( P < .001). After 5 to 7 days, it gradually increased to 9.2%. However, on average, it was lower than before surgery ( P < .001). The median duration of THR was 85.0 (65.0-100.0) minutes, the average hospital length of stay was 7 days. Total hip replacement is associated with an immediate decrease in FMD which remains significantly decreased 5 to 7 days after the surgery compared with the preoperative value. These results indicate that surgery provokes endothelial dysfunction and deteriorates cardiovascular homeostasis. This effect could be involved in cardiovascular complications in the postoperative period.

Subclinical sleep apnoea and plasma levels of endothelin-1 among young and healthy adults

Objective

Obstructive sleep apnoea (OSA) is a risk factor for vascular disease and other adverse outcomes. These associations may be at least partly due to early endothelin-1 (ET-1)-mediated endothelial dysfunction (ED). Therefore, we assessed the relationships between subclinical sleep apnoea and plasma levels of ET-1.

Methods

We performed a population-based study among 1255 young and healthy adults aged 25–41 years. Cardiovascular disease, diabetes or a body mass index >35 kg/m² were exclusion criteria. Plasma levels of ET-1 were measured using a high-sensitivity, single-molecule counting technology. The relationships between subclinical sleep apnoea (OSA indices: respiratory event index (REI), oxygen desaturation index (ODI), mean night-time blood oxygen saturation (SpO₂)) and ET-1 levels were assessed by multivariable linear regression analysis.

Results

Median age of the cohort was 35 years. Median ET-1 levels were 2.9 (IQR 2.4–3.6) and 2.5 pg/mL (IQR 2.1–3.0) among patients with (n=105; 8%) and without subclinical sleep apnoea (REI 5–14), respectively. After multivariable adjustment, subclinical sleep apnoea remained significantly associated with plasma levels of ET-1 (β=0.13 (95% CI 0.06 to 0.20) p=0.0002 for a REI 5–14; β=0.10 (95% CI 0.03 to 0.16) p=0.003 for an ODI≥5). Every 1% decrease in mean night-time SpO₂ increased ET-1 levels by 0.1 pg/mL, an association that remained significant after multivariable adjustment (β=0.02 (95% CI 0.003 to 0.033) p=0.02).

Conclusions

In this study of young and healthy adults, we found that participants with subclinical sleep apnoea had elevated plasma ET-1 levels, an association that was due to night-time hypoxaemia. Our results suggest that ED may already be an important consequence of subclinical sleep apnoea.

Gene Expression of the Endothelin-1 in Vasospastic Flap Pedicle – an Experimental Study on a Porcine Model

The aim of this study was to evaluate the amount of Endothelin-1 (ET-1) gene expression in the vasospastic vessel of the flap pedicle to prove or disprove the role of ET-1 gene expression in pathogenesis of mechanically induced vasospasm. The vasospasm was induced by the tension on the pedicle of the pedicled caudal superficial epigastric flap on 8 pigs. Laser Doppler was used for peripheral blood flow measurement. Specimens from the vasospastic vessel (group of specimens B) and from the flap border with no vasospasm (control group A) were taken 2 h after the stimulus initiation. Detection of ET-1 mRNA by Quantitative Real-Time RT-PCR was performed. β-actin was selected as an acceptable reference gene. Relative gene expression data were given as the n-fold change in transcription of target genes normalized to the endogenous control. Relative gene expressions and time indicators of vasospasm were compared in both groups. No significant difference of the ET-1 gene expressions was found between groups A and B (p = 0.505). No correlation between the duration of vasospasm and ET-1 gene expression was found as well (p = 0.299). In conclusion, the expression of the ET-1 gene in the mechanically induced vasospastic vessel of the pedicled flap was not significantly increased. In this study, the causality of the vasospasm pathogenesis and gene expression of ET-1 was not proven.