Endothelium-dependent Vasodilation Research Articles

Adiponectin secretion by perivascular adipose tissue supports impaired vasodilation in a mouse model of accelerated vascular smooth muscle cell and adipose tissue aging

ObjectivePerivascular adipose tissue (PVAT) function during aging has not been investigated in detail so far and its effect on vasodilation remains to be fully elucidated. The aim of this study was to investigate endothelium-dependent vasodilation of thoracic aorta in a mouse model of accelerated, selective vascular smooth muscle and PVAT aging, induced by SM22α-Cre-driven genetic deletion of the endonuclease ERCC1 (SMC-KO mice) versus healthy littermates (LM). We hypothesized that PVAT enhances vasodilation in LM, possibly through adiponectin secretion, which might be compromised in SMC-KO animals. MethodsThoracic aorta was isolated from SMC-KO animals and LM and segments with and without PVAT were mounted in wire myography setups. The endothelium-dependent vasodilation was assessed via acetylcholine dose-response curves and pathway contribution was studied. Moreover, adiponectin secretion was measured after stimulating the aortic segments with PVAT with acetylcholine. ResultsAdiponectin, secreted by PVAT, led to increased NO-contribution to endothelium-dependent vasodilation in healthy LM, although this did not increase maximum relaxation due to loss of EDH. Endothelium-dependent vasodilation was decreased in SMC-KO animals due to reduced NO-contribution and complete EDH loss. Despite strong lipodystrophy the PVAT partially compensated for lost vasodilation in SMC-KO. LM PVAT contained acetylcholinesterase that attenuated acetylcholine responses. This was lost in SMC-KO. ConclusionsPVAT-derived adiponectin is able to partially compensate for age-related decline in NO-mediated vasodilation, even during strong lipodystrophy, in conditions of absence of compensating EDH. In aorta with healthy PVAT acetylcholinesterase modulates vascular tone, but this is lost during aging, further compensating for decreased acetylcholine responsiveness. Thus, preservation of adiponectin levels, through relatively increased production in lipodystrophic PVAT, and reduction of cholinesterase might be regulatory mechanisms of the PVAT to preserve cholinergic vasodilation during aging.

Inhalation of particulate matter containing environmentally persistent free radicals induces endothelial dysfunction mediated via AhR activation at the air-blood interface.

Particulate matter (PM) containing environmentally persistent free radicals (EPFR) is formed by the incomplete combustion of organic wastes, resulting in the chemisorption of pollutants to the surface of PM containing redox-active transition metals. In prior studies in mice, EPFR inhalation impaired endothelium-dependent vasodilation. These findings were associated with aryl hydrocarbon receptor (AhR) activation in the alveolar type-II (AT-II) cells that form the air-blood interface in the lung. We thus hypothesized that AhR activation in AT-II cells promotes the systemic release of mediators that promote endothelium dysfunction peripheral to the lung. To test our hypothesis, we knocked down AhR in AT-II cells of male and female mice and exposed them to 280 µg/m3 EPFR lo (2.7e + 16 radicals/g) or EPFR (5.5e + 17 radicals/g) compared with filtered air for 4 h/day for 1 day or 5 days. AT-II-AhR activation-induced EPFR-mediated endothelial dysfunction, reducing endothelium-dependent vasorelaxation by 59%, and eNOS expression by 50%. It also increased endothelin-1 mRNA levels in the lungs and peptide levels in the plasma in a paracrine fashion, along with soluble vascular cell adhesion molecule-1 and iNOS mRNA expression, possibly via NF-kB activation. Finally, AhR-dependent increases in antioxidant response signaling, coupled to increased levels of 3-nitrotyrosine in the lungs of EPFR-exposed littermate control but not AT-II AhR KO mice suggested that ATII-specific AhR activation promotes oxidative and nitrative stress. Thus, AhR activation at the air-blood interface mediates endothelial dysfunction observed peripheral to the lung, potentially via release of systemic mediators.

Absorbed Bioactive Compounds Replicate Guanxin II-Induced Endothelium-Associated in/ex vivo Vasodilation.

To develop an interference-free and rapid method to elucidate Guanxin II (GX II)'s representative vasodilator absorbed bioactive compounds (ABCs) among enormous phytochemicals. The contents of ferulic acid, tanshinol, and hydroxysafflor yellow A (FTA) in GX II/rat serum after the oral administration of GX II (30 g/kg) were detected using ultra-performance liquid chromatography-mass spectrometry. Totally 18 rats were randomly assigned to the control group (0.9% normal saline), GX II (30 g/kg) and FTA (5, 28 and 77 mg/kg) by random number table method. Diastolic coronary flow velocity-time integral (VTI), i.e., coronary flow or coronary flow-mediated dilation (CFMD), and endothelium-intact vascular tension of isolated aortic rings were measured. After 12 h of exposure to blank medium or 0.5 mmol/L H2O2, endothelial cells (ECs) were treated with post-dose GX II of supernatant from deproteinized serum (PGSDS, 300 µL PGSDS per 1 mL of culture medium) or FTA (237, 1539, and 1510 mg/mL) for 10 min as control, H2O2, PGSDS and FTA groups. Nitric oxide (NO), vascular endothelial growth factor (VEGF), endothelin-1 (ET-1), superoxide dismutase (SOD), malondialdehyde (MDA) and phosphorylated phosphoinositide 3 kinase (p-PI3K), phosphorylated protein kinase B (p-AKT), phosphorylated endothelial nitric oxide synthase (p-eNOS) were analyzed. PGSDS was developed as a GX II proxy of ex vivo herbal crude extracts. PGSDS effectively eliminates false responses caused by crude GX II preparations. When doses equaled the contents in GX II/its post-dose serum, FTA accounted for 98.17% of GX II -added CFMD and 92.99% of PGSDS-reduced vascular tension. In ECs, FTA/PGSDS was found to have significant antioxidant (lower MDA and higher SOD, P<0.01) and endothelial function-protective (lower VEGF, ET-1, P<0.01) effects. The increases in aortic relaxation, endothelial NO levels and phosphorylated PI3K/Akt/eNOS protein induced by FTA/PGSDS were markedly abolished by NG-nitro-L-arginine methyl ester (L-NA, eNOS inhibitor) and wortmannin (PI3K/AKT inhibitor), respectively, indicating an endothelium-dependent vasodilation via the PI3K/AKT-eNOS pathway (P<0.01). This study provides a strategy for rapidly and precisely elucidating GX II's representative in/ex vivo cardioprotective absorbed bioactive compounds (ABCs)-FTA, suggesting its potential in advancing precision ethnomedicine.

Testosterone modulates vasodilation in mesenteric arteries of hypertensive rats

AimsTo evaluate the effects of testosterone on endothelium-dependent vasodilation and oxidative stress in mesenteric resistance arteries. Main methodsSpontaneously hypertensive rats (SHR), aged 8 to 10 weeks, were divided into four groups: intact (SHAM), intact treated with testosterone (TTO; 3 mg/kg/day) via subcutaneous route (s.c.), intact treated with testosterone and anastrozole [aromatase enzyme inhibitor (TTO + ANA; 0.1 mg/kg/day, s.c.)] and intact treated with testosterone and finasteride [5 α-reductase enzyme inhibitor (TTO + FIN; 5 mg/kg/day, s.c.)] for four weeks. Concentration-response curves to acetylcholine (ACh, 0.1 nmol/L - 10 μmol/L) were obtained in mesenteric resistance arteries previously contracted with phenylephrine (PE, 3 μmol/L), before and after the use of selective inhibitors. Reactive oxygen species (ROS) levels were assessed in the vessels and the endothelium analyzed by scanning electron microscopy. Key findingsTTO group showed a lower participation of nitric oxide (NO), increased oxidative stress, and participation of prostanoids and endothelium-dependent hyperpolarization (EDH), possibly to maintain the vasodilator response. Lower participation of NO and prostanoids, combined to an increased participation of EDH, were observed in the TTO + ANA group, in addition to higher levels of ROS and altered endothelial morphology. The vasodilation to ACh was impaired in TTO + FIN, along increased participation of NO, reduction of prostanoids, and greater EDH-dependent vasodilation. SignificanceTestosterone contributes to endothelial vasodilation by enhancing EDH through an increased participation of epoxyeicosatrienoic acids. While the decrease in NO appears to involve the participation of dihydrotestosterone, 17 β-estradiol seems to stimulate the action of the NO pathway and prostanoids.

Influence of a Decrease in Blood Viscosity on Arterial Pressure in Normotensive and Spontaneously Hypertensive Rats.

We investigated the effect of a decrease in blood viscosity on the mean BP during isovolumic hemodilution and vasodilating activity of the endothelium in normotensive Wistar rats and spontaneously hypertensive rats (SHR). Blood viscosity was reduced by isovolumic hemodilution (replacement of 10% of circulating blood with an equal volume of plasma). Hemodilution caused the same reduction in blood viscosity by 16% in both groups of rats. In Wistar rats, a decrease in blood viscosity did not significantly change in the mean BP; no significant correlations between blood viscosity and mean BP were observed before and after hemodilution. In SHR, a decrease in blood viscosity led to a significant decrease in the mean BP by 18%. Correlations were found between the mean BP and blood viscosity in SHR before (r=0.63; p=0.028) and after (r=0.71; p=0.009) isovolumic hemodilution. In SHR, a decrease in the index of vasodilating activity of the endothelium due to a decrease in the vasodilatory response to intravenous administration of the endothelium-dependent vasodilator acetylcholine was revealed. In SHR, BP passively follows the change, in this case, the decrease in blood viscosity, which attests to impaired BP regulation in response to changes in shear stress on the vascular endothelium caused by the development of endothelial dysfunction in hypertensive animals.

Modification of Cardiovascular Risk Factors and the Evolution of The Cardiovascular Phenotype of Liver Transplant Recipients in the Long -Term Postoperative Period.

To evaluate the contribution of traditional and additional cardiovascular risk factors (CVRFs) to the development of chronic ischemic heart disease (CIHD) in liver transplant recipients during the long-term postoperative period. A single-center prospective cohort study was conducted. The study included 740 patients with chronic end-stage liver disease (CESLD) and cirrhotic cardiomyopathy (CCMP). During the observation period (5.4±2.29 years), patients were divided into two groups: liver transplant recipients (n=420) and patients with CESLD on the waiting list who did not receive a donor organ (n=320). In patients enrolled to the study upon inclusion in the waiting list, CVRFs, history, clinical and laboratory and instrumental data were studied at all stages of the hepato-cardiac continuum. During the long-term postoperative period, liver transplant recipients belonged to the group of high cardiovascular risk: over a 5-year observation period, 35.7% (n=150) of them developed metabolic syndrome (MS), 9.8% developed verified CIHD associated with MS. The incidence of traditional CVRFs was high (arterial hypertension, 88.6%; obesity, 36.6%; hypercholesterolemia, 77.8%; hypertriglyceridemia, 43.6%; reduced concentration of high-density lipoprotein cholesterol, 35.4%; increased concentrations of low-density lipoprotein cholesterol, 66.8% and very low-density lipoprotein cholesterol, 51.2%; increased atherogenic index, 61.5%). During the long-term postoperative period as compared to the period when patients were on the waiting list, additional CVRFs appeared: increases in body mass index, calcium index, nitric oxide metabolites, endothelin-1, homocysteine, intercellular adhesion molecules VCAM-1 and ICAM-1, and decreases in endothelium-dependent vasodilation and glomerular filtration rate to less than 60 ml/min/1.73 m2. A model for the development of CIHD was created. The model uses a complex of independent risk factors and demonstrates a predictive accuracy of 84.6%. The study results indicate a modification of CVRFs and a dynamic change in the cardiovascular phenotype of liver transplant recipients: progression of CCMP during their stay on the waiting list, regression of CCMP manifestations during the first 12 months after orthotopic liver transplantation, and increases in the total cardiovascular risk and likelihood of CIHD in the long-term postoperative period.

Histamine H2-receptor antagonism improves conduit artery endothelial function and reduces plasma aldosterone level without lowering arterial blood pressure in angiotensin II–hypertensive mice

Aldosterone through the mineralocorticoid receptor MR has detrimental effects on cardiovascular disease. It reduces the bioavailability of nitric oxide and impairs endothelium-dependent vasodilatation. In resistance arteries, aldosterone impairs the sensitivity of vascular smooth muscle cells to nitric oxide by promoting the local secretion of histamine which activates H2 receptors. The present experiments tested in vivo and ex vivo the hypothesis that systemic H2-receptor antagonism reduces arterial blood pressure and improves vasodilatation in angiotensin II–induced chronic hypertension. Hypertension was induced by intravenous infusion of angiotensin II (60 ng kg−1 min−1) in conscious, unrestrained mice infused concomitantly with the H2-receptor antagonist ranitidine (27.8 µg kg−1 min−1) or vehicle for 24 days. Heart rate and arterial blood pressure were recorded by indwelling arterial catheter. Resistance (mesenteric) and conductance (aortae) arteries were harvested for perfusion myography and isometric tension recordings by wire myography, respectively. Plasma was analyzed for aldosterone concentration. ANGII infusion resulted in elevated arterial blood pressure and while in vivo treatment with ranitidine reduced plasma aldosterone concentration, it did not reduce blood pressure. Ranitidine improved ex vivo endothelial function (acetylcholine 10−9 to 10−6 mol L−1) in mesenteric resistance arteries. This was abolished by ex vivo treatment with aldosterone (10−9 mol L−1, 1 h). In aortic segments, in vivo ranitidine treatment impaired relaxation. Activation of histamine H2 receptors promotes aldosterone secretion, does not affect arterial blood pressure, and protects endothelial function in conduit arteries but promotes endothelial dysfunction in resistance arteries during angiotensin II–mediated hypertension. Aldosterone contributes little to angiotensin II–induced hypertension in mice.

Nur77 mitigates endothelial dysfunction through activation of both nitric oxide production and anti-oxidant pathways

BackgroundNur77 belongs to the member of orphan nuclear receptor 4A family that plays critical roles in maintaining vascular homeostasis. This study aims to determine whether Nur77 plays a role in attenuating vascular dysfunction, and if so, to determine the molecular mechanisms involved. MethodsBoth Nur77 knockout (Nur77 KO) and Nur77 endothelial specific transgenic mice (Nur77-Tg) were employed to examine the functional significance of Nur77 in vascular endothelium in vivo. Endothelium-dependent vasodilatation to acetylcholine (Ach) and reactive oxygen species (ROS) production was determined under inflammatory and high glucose conditions. Expression of genes was determined by real-time PCR and western blot analysis. ResultsIn response to tumor necrosis factor alpha (TNF-α) treatment and diabetes, the endothelium-dependent vasodilatation to Ach was significantly impaired in aorta from Nur77 KO as compared with those from the wild-type (WT) mice. Endothelial specific overexpression of Nur77 markedly prevented both TNF-α- and high glucose-induced endothelial dysfunction. Compared with WT mice, after TNF-α and high glucose treatment, ROS production in aorta was significantly increased in Nur77 KO mice, but it was inhibited in Nur77-Tg mice, as determined by dihydroethidium (DHE) staining. Furthermore, we demonstrated that Nur77 overexpression substantially increased the expression of several key enzymes involved in nitric oxide (NO) production and ROS scavenging, including endothelial nitric oxide synthase (eNOS), guanosine triphosphate cyclohydrolase 1 (GCH-1), glutathione peroxidase-1 (GPx-1), and superoxide dismutases (SODs). Mechanistically, we found that Nur77 increased GCH1 mRNA stability by inhibiting the expression of microRNA-133a, while Nur77 upregulated SOD1 expression through directly binding to the human SOD1 promoter in vascular endothelial cells. ConclusionOur results suggest that Nur77 plays an essential role in attenuating endothelial dysfunction through activating NO production and anti-oxidant pathways in vascular endothelium. Targeted activation of Nur77 may provide a novel therapeutic approach for the treatment of cardiovascular diseases associated with endothelial dysfunction.

High dietary salt intake attenuates nitric oxide mediated endothelium-dependent vasodilation and increases oxidative stress in pregnancy.

This study aimed to investigate the impact of dietary salt intake during normal pregnancy on maternal microvascular and macrovascular endothelium-dependent reactivity and oxidative stress level. In this cross-sectional study, based on their 24-h urinary sodium excretion, pregnant women (37-40 weeks of gestation) were divided into three groups: normal salt (<5.75 g/day, N = 12), high salt (5.75-10.25 g/day, N = 36), and very high salt (VHS;>10.25 g/day, N = 17). Forearm skin microvascular reactivity in response to vascular occlusion, local heating (LTH) and iontophoresis of acetylcholine (AChID), as well as brachial artery flow mediated dilation (FMD) were measured. Serum nitric oxide, endocan, 8-iso-prostaglandin F2α (8-iso-PGF2α), thiobarbituric acid reactive substances (TBARS), and ferric-reducing ability of plasma assay were measured as biomarkers of endothelial function/activation and oxidative stress. Brachial artery FMD, microvascular AChID, and LTH were significantly decreased in VHS compared with NS group, while LTH was also decreased in normal salt compared with high salt group. Nitric oxide was significantly decreased in both high salt and VHS groups compared with normal salt. Endocan, 8-iso-PGF2α, and TBARS were significantly increased in VHS compared with the normal salt group. High dietary salt intake is associated with decreased nitric oxide mediated endothelium-dependent vasodilation in peripheral microcirculation and macrocirculation of healthy pregnant women due to increased oxidative stress.

The oxidized phospholipid PGPC impairs endothelial function by promoting endothelial cell ferroptosis via FABP3

Ferroptosis is a novel cell death mechanism that is mediated by iron-dependent lipid peroxidation. It may be involved in atherosclerosis development. Products of phospholipid oxidation play a key role in atherosclerosis. 1-palmitoyl-2-glutaroyl-sn-glycero-3-phosphocholine (PGPC) is a phospholipid oxidation product present in atherosclerotic lesions. It remains unclear whether PGPC causes atherosclerosis by inducing endothelial cell ferroptosis. In this study, human umbilical vein endothelial cells (HUVECs) were treated with PGPC. Intracellular levels of ferrous iron, lipid peroxidation, superoxide anions (O2•−), and glutathione were detected, and expression of fatty acid binding protein-3 (FABP3), glutathione peroxidase 4 (GPX4), and CD36 were measured. Additionally, the mitochondrial membrane potential (MMP) was determined. Aortas from C57BL6 mice were isolated for vasodilation testing. Results showed that PGPC increased ferrous iron levels, the production of lipid peroxidation and O2•−, and FABP3 expression. However, PGPC inhibited the expression of GPX4 and glutathione production and destroyed normal MMP. These effects were also blocked by ferrostatin-1, an inhibitor of ferroptosis. FABP3 silencing significantly reversed the effect of PGPC. Furthermore, PGPC stimulated CD36 expression. Conversely, CD36 silencing reversed the effects of PGPC, including PGPC-induced FABP3 expression. Importantly, E06, a direct inhibitor of the oxidized 1-palmitoyl-2-arachidonoyl-phosphatidylcholine IgM natural antibody, inhibited the effects of PGPC. Finally, PGPC impaired endothelium-dependent vasodilation, ferrostatin-1 or FABP3 inhibitors inhibited this impairment. Our data demonstrate that PGPC impairs endothelial function by inducing endothelial cell ferroptosis through the CD36 receptor to increase FABP3 expression. Our findings provide new insights into the mechanisms of atherosclerosis and a therapeutic target for atherosclerosis.

Diagnostic criteria of endothelial dysfunction, subclinical atherosclerosis and their relationship with NOS3 and HIF1A gene polymorphism in military personnel in extreme conditions of the arctic zone

The state of the arterial vascular endothelium against the background of subclinical atherosclerosis and its relationship with gene polymorphism in military personnel serving in the Arctic climatic zone, depending on the duration of service, was evaluated. In total, 251 male servicemen aged 28–40 years were examined. The group of servicemen of the Arctic climate zone included 99 people, who were divided into three groups according to the duration of military service in the Arctic: group 1 included 8 (8%) servicemen with up to 5 years of military service; group 2, 21 (21%) people with 5–10 years; group 3, 70 (71%) servicemen with 10 years. The control group included 152 military personnel aged 28–40 years from the temperate climate zone. All participants underwent a test with reactive hyperemia, elastography, measurement of the thickness of the intima–media complex on the brachial artery, ultrasound examination of the common carotid arteries, photoplethysmography, pulse oximetry, spirometry, anthropometry, biochemical blood analysis, and determination of gene polymorphism using polymerase chain reaction. The results revealed that endothelium-dependent vasodilation rats in groups 2 and 3 were 1. 7 and 2. 7 times less than that in group 1 (p 0. 05). In 11 (16%) military personnel of group 3, thickening of the intima–media complex was found in 50% of the adjacent areas of the common carotid arteries. In groups 2 and 3, the total blood cholesterol level exceeded the value by 10% and 14%, respectively, compared with group 1 (p 0. 05). The artery wall was rigid in carriers of the T/T genotypes of the HIF1A and NOS3 genes and was most elastic in the G/T genotypes of the NOS3 gene and C/C of the HIF1A gene. In general, military personnel serving in the Arctic climatic zone with a service duration of 10 years have endothelial dysfunction and peripheral vascular stiffness with subclinical atherosclerosis phenomena, particularly in military personnel with the T/T genotypes of HIF1A (rs11549465) and NOS3 (rs1799983). We believe that the leading pathogenetic link of endothelial dysfunction of arterial vessels is the resistance of myocytes to the effects of vasodilation factors expressed by the vascular endothelium, particularly nitric oxide. The longer the service experience of military personnel under conditions of polar hypoxia, the higher the probability of developing endothelial dysfunction.

Aging related decreases in NM myosin expression and contractility in a resistance vessel.

Introduction: Vasodilatation in response to NO is a fundamental response of the vasculature, and during aging, the vasculature is characterized by an increase in stiffness and decrease in sensitivity to NO mediated vasodilatation. Vascular tone is regulated by the activation of smooth muscle and nonmuscle (NM) myosin, which are regulated by the activities of myosin light chain kinase (MLCK) and MLC phosphatase. MLC phosphatase is a trimeric enzyme with a catalytic subunit, myosin targeting subunit (MYPT1) and 20kDa subunit of unknown function. Alternative mRNA splicing produces LZ+/LZ- MYPT1 isoforms and the relative expression of LZ+/LZ- MYPT1 determines the sensitivity to NO mediated vasodilatation. This study tested the hypothesis that aging is associated with changes in LZ+ MYPT1 and NM myosin expression, which alter vascular reactivity. Methods: We determined MYPT1 and NM myosin expression, force and the sensitivity of both endothelial dependent and endothelial independent relaxation in tertiary mesenteric arteries of young (6mo) and elderly (24mo) Fischer344 rats. Results: The data demonstrate that aging is associated with a decrease in both the expression of NM myosin and force, but LZ+ MYPT expression and the sensitivity to both endothelial dependent and independent vasodilatation did not change. Further, smooth muscle cell hypertrophy increases the thickness of the medial layer of smooth muscle with aging. Discussion: The reduction of NM myosin may represent an aging associated compensatory mechanism to normalize the stiffness of resistance vessels in response to the increase in media thickness observed during aging.

Physalis minima leaf extract improves endothelium-dependent vasodilation and decreases blood pressure in ovariectomized rats

This study examined the impact of methanol extract of Physalis minima leaf (MEP) on vascular function and blood pressure in ovariectomized (OVX) rats simulating postmenopausal syndrome. Thirty Wistar rats underwent bilateral ovariectomy. After five weeks, OVX rats were divided into groups, receiving MEP at doses of 500, 1,500, and 2,500 mg/kg BW for four weeks. Two groups served as OVX controls (5-week and 9-week OVX rats). Six sham-operated rats were included as a control. Thoracic aortic rings were isolated for endothelium-dependent vascular relaxation analysis. Endothelial cell count was determined via hematoxylin-eosin staining. Systolic blood pressure (SBP) was measured using a tail-cuff method. Results showed significant (p &lt; 0.01) vascular relaxation decline in 9-week OVX rats. MEP at 1,500 and 2,500 mg/kg BW restored vascular dilation. Endothelial cell number decreased significantly (p &lt; 0.0001) in 5-week and 9-week OVX rats. MEP at 2,500 mg/kg BW raised endothelial cell numbers significantly (p &lt; 0.0001). SBP increased significantly (p &lt; 0.0001) in 9-week OVX rats. MEP at 1,500 mg/kg BW lowered SBP, nearing sham levels, while 2,500 mg/kgBW further reduced SBP significantly (p &lt; 0.0001). Physalis minima extract has the potential to treat postmenopausal vascular issues and hypertension. The strong hypotensive effect at the highest dose emphasizes dosage determination and potential side effects investigation.

DNA-PKcs Phosphorylates Cofilin2 to Induce Endothelial Dysfunction and Microcirculatory Disorder in Endotoxemic Cardiomyopathy

The presence of endotoxemia is strongly linked to the development of endothelial dysfunction and disruption of myocardial microvascular reactivity. These factors play a crucial role in the progression of endotoxemic cardiomyopathy. Sepsis-related multiorgan damage involves the participation of the catalytic subunit of DNA-dependent protein kinase (DNA-PKcs). However, whether DNA-PKcs contributes to endothelial dysfunction and myocardial microvascular dysfunction during endotoxemia remains unclear. Hence, we conducted experiments in mice subjected to lipopolysaccharide (LPS)-induced endotoxemic cardiomyopathy, as well as assays in primary mouse cardiac microvascular endothelial cells. Results showed that endothelial-cell-specific DNA-PKcs ablation markedly attenuated DNA damage, sustained microvessel perfusion, improved endothelial barrier function, inhibited capillary inflammation, restored endothelium-dependent vasodilation, and improved heart function under endotoxemic conditions. Furthermore, we show that upon LPS stress, DNA-PKcs recognizes a TQ motif in cofilin2 and consequently induces its phosphorylation at Thr 25 . Phosphorylated cofilin2 shows increased affinity for F-actin and promotes F-actin depolymerization, resulting into disruption of the endothelial barrier integrity, microvascular inflammation, and defective eNOS-dependent vasodilation. Accordingly, cofilin2-knockin mice expressing a phospho-defective (T25A) cofilin2 mutant protein showed improved endothelial integrity and myocardial microvascular function upon induction of endotoxemic cardiomyopathy. These findings highlight a novel mechanism whereby DNA-PKcs mediates cofilin2 Thr25 phosphorylation and subsequent F-actin depolymerization to contribute to endotoxemia-related cardiac microvascular dysfunction.

Bioactive Flavonoids in Protecting Against Endothelial Dysfunction and Atherosclerosis.

Atherosclerosis is a common cardiovascular disease closely associated with factors such as hyperlipidaemia and chronic inflammation. Among them, endothelial dysfunction serves as a major predisposing factor. Vascular endothelial dysfunction is manifested by impaired endothelium-dependent vasodilation, enhanced oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, endothelial senescence, and endothelial-mesenchymal transition (EndoMT). Flavonoids are known for their antioxidant activity, eliminating oxidative stress induced by reactive oxygen species (ROS), thereby preventing the oxidation of low-density lipoprotein (LDL) cholesterol, reducing platelet aggregation, alleviating ischemic damage, and improving vascular function. Flavonoids have also been shown to possess anti-inflammatory activity and to protect the cardiovascular system. This review focuses on the protective effects of these naturally-occuring bioactive flavonoids against the initiation and progression of atherosclerosis through their effects on endothelial cells including, but not limited to, their antioxidant, anti-inflammatory, anti-thrombotic, and lipid-lowering properties. However, more clinical evidences are still needed to determine the exact role and optimal dosage of these compounds in the treatment of atherosclerosis.

The short-chain fatty acid propionate prevents ox-LDL-induced coronary microvascular dysfunction by alleviating endoplasmic reticulum stress in HCMECs.

Coronary microvascular dysfunction (CMD) is a critical pathogenesis of cardiovascular diseases. Lower endothelial nitric oxide synthase (eNOS) phosphorylation leads to reduced endothelium-derived relaxing factor nitric oxide (NO) generation, causing and accelerating CMD. Endoplasmic reticulum stress (ER stress) has been shown to reduce NO production in umbilical vein endothelial cells. Oxidized low-density lipoprotein (ox-LDL) damages endothelial cell function. However, the relationship between ox-LDL and coronary microcirculation has yet to be assessed. Short-chain fatty acid (SCFA), a fermentation product of the gut microbiome, could improve endothelial-dependent vasodilation in human adipose arterioles, but the effect of SCFA on coronary microcirculation is unclear. In this study, we found ox-LDL stimulated expression of ER chaperone GRP78. Further, we activated downstream PERK/eIF2a, IRE1/JNK, and ATF6 signaling pathways, decreasing eNOS phosphorylation and NO production in human cardiac microvascular endothelial. Furthermore, SCFA-propionate can inhibit ox-LDL-induced eNOS phosphorylation reduction and raise NO production; the mechanism is related to the inhibition of ER stress and downstream signaling pathways PERK/eIF2a, IRE1/JNK, and ATF6. In summary, we demonstrate that ox-LDL induced CMD by activating ER stress, propionate can effectively counteract the adverse effects of ox-LDL and protect coronary microcirculation function via inhibiting ER stress.

Роль корекції ендотеліальної дисфункції в комплексній профілактиці гіпертензивних ускладнень вагітності

Purpose - to study the effect of correction of endothelial dysfunction by the introduction of L-arginine in the comprehensive prevention of the development of severe hypertensive disorders in pregnant women. Materials and methods. The division into groups was carried out indiscriminately following the prescribed bath. 27 women reached the 1st group, who, in addition to basic prevention of preeclampsia (small doses of aspirin for 12 days, calcium supplement 1000 mg per dose for 16 years), took Tivortin until conception and p. It's an hour of urgency; up to the 2nd group - 54 women who did not receive basic prevention of preeclampsia. The control group (3) consisted of 16 healthy women with physiological changes in vagusity. Participants of the 1st group, during the hour of stay in the hospital, took L-arginine internally (iv) (4 g) + 2 teaspoons 2 times (4 g) per os per dose 40 minutes before admission, then 3 teaspoons spoons 2 times (6 g per dose). The average intensity of the droplets became 6. The function of the endothelium was evaluated according to the universally recognized non-invasive cuff test method, which is based on the principle of ultrasound assessment of the change in the diameter of the brachial artery in response to the restoration of blood flow in it after short-term compression of the upper limb with a cuff. Physical condition and endurance were assessed using the generally accepted 6-minute walk method. The quality of life in pregnant women who had experienced severe preeclampsia in the past was assessed in stages - according to the health-related quality of life (HRQoL) scale and the scale created by the World Health Organization (WHOQOL-BREF). Results. Arterial hypertension and preeclampsia are based on changes in endothelium-dependent vasodilatation. A positive effect on the function of the endothelium significantly improves indicators of physical well-being and quality of life. When conducting a test with a 6-minute walk in the Group 1, better indicators were found than in the Group 2 (respectively, 409±23 m vs. 381±32 m, p&lt;0.05), this indicator in the control group was 473±32 m (p&lt;0.05 according to the Groups 1 and 2). However, this indicator significantly improved in pregnant women of the Group 1 after intravenous administration of L-arginine: 441±12 m (p&lt;0.05 compared to the indicator before intravenous administration). According to the assessment of the quality of life of pregnant women of the studied groups, it should be noted that the quality of life indicators in all domains are significantly lower in women of the Group 1, which is associated with significantly worse anamnesis data of such women, significant concern about the results of the next pregnancy. When evaluating indicators of endothelium-dependent and endothelium-independent vasodilatation, it was found that in the group of women who received L-arginine preconceptionally, in the 1st trimester, the indicator before intravenous IV administration was 5.09±0.44, and after - 8.21±0.24, which indicates a significant improvement in endothelium-dependent vasodilation indicators (by 49.1%) 28-32 weeks, there are also no births of children with a body weight of less than 1500 g. Conclusions. In the group of high-risk pregnant women, the use of L-arginine in the complex prevention of preeclampsia allows to reduce the risks of early severe preeclampsia, to reduce the medication burden of two- and three-component hypotensive therapy. An increase in physical endurance, quality of life, and improvement in pregnancy outcomes are due to a positive effect on the function of the endothelium through the optimization of endothelium-dependent vasodilatation associated with the provision of the L-arginine substrate for the full synthesis of nitric oxide. The research was carried out in accordance with the principles of the Helsinki Declaration. The study protocol was approved by the Local Ethics Committee of the participating institution. The informed consent of the patient was obtained for conducting the studies. No conflict of interests was declared by the authors.

Chymase-independent vascular Ang-(1–12)/Ang II pathway and TXA2 generation are involved in endothelial dysfunction in the murine model of heart failure

The angiotensin (Ang)-(1–12)/Ang II pathway contributes to cardiac pathology. However, its involvement in the development of peripheral endothelial dysfunction associated with heart failure (HF) remains unknown. Therefore, this study aimed to characterise the effect of exogenous Ang-(1–12) and its conversion to Ang II on endothelial function using the murine model of HF (Tgαq*44 mice), focusing on the role of chymase and vascular-derived thromboxane A2 (TXA2).Ex vivo myographic assessments of isolated aorta showed impaired endothelium-dependent vasodilation in late-stage HF in 12-month-old Tgαq*44 mice. However, endothelium-dependent vasodilation was fully preserved in the early stage of HF in 4-month-old Tgαq*44 mice and 4- and 12-month-old FVB control mice. Ang-(1–12) impaired endothelium-dependent vasodilation in 4- and 12-month-old Tgαq*44 mice, that was associated with increased Ang II production. The chymase inhibitor chymostatin did not inhibit this response. Interestingly, TXA2 production reflected by TXB2 measurement was upregulated in response to Ang-(1–12) and Ang II in aortic rings isolated from 12-month-old Tgαq*44 mice but not from 4-month-old Tgαq*44 mice or age-matched FVB mice. Furthermore, in vivo magnetic resonance imaging showed that Ang-(1–12) impaired endothelium-dependent vasodilation in the aorta of Tgαq*44 mice and FVB mice. However, this response was inhibited by angiotensin I converting enzyme (ACE) inhibitor; perindopril, angiotensin II receptor type 1 (AT1) antagonist; losartan and TXA2 receptor (TP) antagonist-picotamide in 12-month-old-Tgαq*44 mice only.In conclusion, the chymase-independent vascular Ang-(1–12)/Ang II pathway and subsequent TXA2 overactivity contribute to systemic endothelial dysfunction in the late stage of HF in Tgαq*44 mice. Therefore, the vascular TXA2 receptor represents a pharmacotherapeutic target to improve peripheral endothelial dysfunction in chronic HF.

Endothelial Dysfunction and Heart Failure with Preserved Ejection Fraction-An Updated Review of the Literature.

Heart failure (HF) is a clinical syndrome consisting of typical symptoms and signs due to structural and/or functional abnormalities of the heart, resulting in elevated intracardiac pressures and/or inadequate cardiac output. The vascular system plays a crucial role in the development and progression of HF regardless of ejection fraction, with endothelial dysfunction (ED) as one of the principal features of HF. The main ED manifestations (i.e., impaired endothelium-dependent vasodilation, increased oxidative stress, chronic inflammation, leukocyte adhesion, and endothelial cell senescence) affect the systemic and pulmonary haemodynamic and the renal and coronary circulation. The present review is aimed to discuss the contribution of ED to HF pathophysiology-in particular, HF with preserved ejection fraction-ED role in HF patients, and the possible effects of pharmacological and non-pharmacological approaches. For this purpose, relevant data from a literature search (PubMed, Scopus, EMBASE, and Medline) were reviewed. As a result, ED, assessed via venous occlusion plethysmography or flow-mediated dilation, was shown to be independently associated with poor outcomes in HF patients (e.g., mortality, cardiovascular events, and hospitalization due to worsening HF). In addition, SGLT2 inhibitors, endothelin antagonists, endothelial nitric oxide synthase cofactors, antioxidants, and exercise training were shown to positively modulate ED in HF. Despite the need for future research to better clarify the role of the vascular endothelium in HF, ED represents an interesting and promising potential therapeutic target.

Use of Atherogenic Indices as Assessment Methods of Clinical Atherosclerotic Diseases.

Central illustration : Use of Atherogenic Indices as Assessment Methods of Clinical Atherosclerotic Diseases. The search for clinically useful methods to assess atherosclerotic diseases (ASCVD) with good accuracy, low cost, non-invasiveness, and easy handling has been stimulated for years. Thus, the atherogenic indices evaluated in this study may fit this growing demand. To assess the potential of atherogenic indices to evaluate patients with clinical atherosclerosis. Single-center cross-sectional study, through which the Castelli I and II indices, the atherogenic index of plasma (AIP), the lipoprotein combine index, and the variation in the peripheral perfusion index between 90 and 120 seconds after an endothelium-dependent (ΔPI90-120) vasodilator stimulus were evaluated in the prediction of atherosclerosis. Statistical significance was set at p < 0.05. The sample consisted of 298 individuals with an average age of 63.0±16.1 years, of which 57.4% were women. Paired comparisons of the ROC curve analysis of the indices that reached the area under the curve (AUC) > 0.6 show that ΔPI90-120 and AIP were superior to other indices, and no differences were observed between them (difference between AUC = 0.056; 95%CI -0.003-0.115). Furthermore, both the ΔPI90-120 [odds ratio (OR) 9.58; 95%CI 4.71-19.46)] and AIP (OR 5.35; 95%CI 2.30-12.45) were independent predictors of clinical atherosclerosis. The AIP and ΔPI90-120 represented better accuracy in discriminating clinical ASCVD. Moreover, they were independent predictors of clinical ASCVD, evidencing a promising possibility for developing preventive and control strategies for cardiovascular diseases. Therefore, they are markers for multicenter studies from the point of view of practicality, low cost, and external validity.