Vascular Wall Remodeling Research Articles

Loss of Down syndrome critical region-1 leads to cholesterol metabolic dysfunction that exaggerates hypercholesterolemia in ApoE-null background

Down syndrome critical region (DSCR)-1 functions as a feedback modulator for calcineurin-nuclear factor for activated T cell (NFAT) signals, which are crucial for cell proliferation and inflammation. Stable expression of DSCR-1 inhibits pathological angiogenesis and septic inflammation. DSCR-1 also plays a critical role in vascular wall remodeling associated with aneurysm development that occurs primarily in smooth muscle cells. Besides, Dscr-1 deficiency promotes the M1-to M2-like phenotypic switch in macrophages, which correlates to the reduction of denatured cholesterol uptakes. However, the distinct roles of DSCR-1 in cholesterol and lipid metabolism are not well understood. Here, we show that loss of apolipoprotein (Apo) E in mice with chronic hypercholesterolemia induced Dscr-1 expression in the liver and aortic atheroma. In Dscr-1-null mice fed a high-fat diet, oxidative- and endoplasmic reticulum (ER) stress was induced, and sterol regulatory element-binding protein (SREBP) 2 production in hepatocytes was stimulated. This exaggerated ApoE−/−-mediated nonalcoholic fatty liver disease (NAFLD) and subsequent hypercholesterolemia. Genome-wide screening revealed that loss of both ApoE and Dscr-1 resulted in the induction of immune- and leukocyte activation-related genes in the liver compared with ApoE deficiency alone. However, expressions of inflammation-activated markers and levels of monocyte adhesion were suspended upon induction of the Dscr-1 null background in the aortic endothelium. Collectively, our study shows that the combined loss of Dscr-1 and ApoE causes metabolic dysfunction in the liver but reduces atherosclerotic plaques, thereby leading to a dramatic increase in serum cholesterol and the formation of sporadic vasculopathy.

Изменения эластичности сосудистой стенки артерий и маркеров ангиопатии на фоне длительной терапии статинами больных артериальной гипертонией с высоким сердечно-сосудистым риском

Objective. To determine the comparative effectiveness of atorvastatin and rosuvastatin in relation to individual biochemical and functional markers of vascular wall remodeling in patients with arterial hypertension of high cardiovascular risk. Materials and methods. The study included 140 patients with stage II of arterial hypertension (AH), II-III degree of severity with the duration of the disease from 5 to 12 years, who, against the background of antihypertensive therapy (enalapril 20-40 mg/day, indapamide retard 1.5 mg, metoprolol 100-150 mg/days) received atorvastatin 20 mg/day for 1 year, subsequently it was replaced by rosuvastatin 10, 20, 40 mg / day. The dose regimen was determined by achieving the target level of cholesterol (CS) and low density lipoprotein cholesterol (LDL-C). Results. Taking atorvastatin for 1 year was accompanied by a decrease in the value of the cardio-ankle vascular index (CAVI) by 14.4%, the augmentation index (AI) - by 10.3%. The replacement of atorvastatin with rosuvastatin was accompanied by a further decrease in the R-CAVI value: by 10.8% (20 mg/day) and 14.4% (40 mg/day). The use of atorvastatin for 1 year was accompanied by a decrease in both C-reactive protein (CRP) (by 26.0%) and osteopontin (OP) (by 22.8%). A further decrease in the concentration of CRP by 18 months of rosuvastatin therapy is recorded when using mean and high doses (20-40 mg/day). Differences in the severity of changes in CRP level between the groups were significant (p<0.05). The level of OP in comparison with the beginning of rosuvastatin decreased by 32.9%. Differences in the degree of reduction of OP when taking rosuvastatin between the groups were significant (P<0.05). Conclusion. Rosuvastatin in various dosage regimens with long-term use in patients with arterial hypertension with a high vascular risk reduces the content of CRP and OP in blood, reduces the CAVI and the AI, and is more effective than 20 mg atorvastatin a day.

Context-Dependent Regulation of Nrf2/ARE Axis on Vascular Cell Function during Hyperglycemic Condition.

Diabetes mellitus is associated with an increased risk of micro and macrovascular complications. During hyperglycemic conditions, endothelial cells and vascular smooth muscle cells are exquisitely sensitive to high glucose. This high glucose-induced sustained reactive oxygen species production leads to redox imbalance, which is associated with endothelial dysfunction and vascular wall remodeling. Nrf2, a redox-regulated transcription factor plays a key role in the antioxidant response element (ARE)-mediated expression of antioxidant genes. Although accumulating data indicate the molecular mechanisms underpinning the Nrf2 regulated redox balance, understanding the influence of the Nrf2/ARE axis during hyperglycemic condition on vascular cells is paramount. This review focuses on the context-dependent role of Nrf2/ARE signaling on vascular endothelial and smooth muscle cell function during hyperglycemic conditions. This review also highlights improving the Nrf2 system in vascular tissues, which could be a potential therapeutic strategy for vascular dysfunction.

Effects of smoking on the level of sp-a and sp-d surfactant proteins in the blood of patients without bronchopulmonary diseases

Every year, about six million people die from tobacco use. Respiratory epithelium is the first line of defense against exogenous invasion, in particular, harmful inhaled particles, pathogens and allergens. However, the epithelium of the respiratory tract is also a regulator of immunological and inflammatory reactions through secretion of inflammation and immune cell recruitment mediators. An important component of the pulmonary immune system is the surfactant, and, in particular, its proteins SP-A and SP-D, synthesized mainly by type II pneumocytes. Aim . To assess the levels of surfactant proteins SP-A and SP-D in the blood of smoking patients without bronchopulmonary diseases. Materials and мethods . The study included 59 patients admitted to the department of internal medicine with hypertension. The general group was divided into subgroups: non-smoking patients ( n = 31) and healthy smokers ( n = 28). All patients underwent clinical, functional, diagnostic and laboratory tests. The content of surfactant proteins SP-A and SP-D in the blood was determined by enzyme immunoassay. Results. The subgroups did not differ in sex, age, height, body weight, blood pressure, heart rate, respiratory rate, and the distribution of comorbidities. The subgroups differed in the platelet level; in other main parameters of complete blood count and blood biochemistry no differences were revealed. It was found that the blood levels of surfactant proteins SP-A and SP-D in the subgroup of healthy smokers were significantly higher in comparison with the subgroup of non-smoking patients. The correlation analysis revealed a direct relationship between surfactant proteins SP-A and SP-D and smoking ( R = 0.360, p = 0.006, R = 0.274, p = 0.037), a negative correlation between SP-D protein and age ( R = –0.315, p = 0.016), and a direct relationship between SP-A protein and diastolic blood pressure ( R = 0.271, p = 0.039). In the non-smoking subgroup, a negative correlation between SP-D and age ( R = –0.438, p = 0.016) and between SP-D and systolic blood pressure ( R = –0.433, p = 0.017) was identified. Conclusion. The direct relationship between higher levels of the surfactant proteins SP-A and SP-D and smoking in the group of healthy smokers is justified (inflammatory changes, structural abnormalities in the lung parenchyma under the influence of cigarette smoke). The SP-D protein is more significant in comparison with the SP-A protein in vascular wall remodeling, lung tissue matrix, oxidative lung tissue damage, and apoptosis, which explains its negative correlation with age and systolic blood pressure.

A Novel Neurovascular Liaison Governing the Blood-Brain Barrier

How circulating signals enter the median eminence to trigger homeostatic hypothalamic responses is not well understood. Jiang etal. describe a neural mechanism that increases endothelial fenestrations and enhances the hypothalamic response to the circulating hormone leptin, suggesting a novel way to regulate brain entry through vascular wall remodeling.

State of myocardium, stiffness of vascular wall and severity of emotional disorders in patients with myocardial infarction with atrial fibrillation

The widespread prevalence of myocardial infarction and the frequency of complications in the form of atrial fibrillation, makes it relevant to study its pathogenesis and effect on hemodynamics, significantly aggravating the patient’s condition, leading to a deterioration in hemodynamic parameters and the appearance of recurrent myocardial ischemia. At present, a large amount of data has been accumulated on the causes, electrophysiological mechanisms, and hemodynamic consequences of the development of atrial fibrillation during myocardial infarction. This circumstance necessitates both further study of the features of the development and course of atrial fibrillation, and the search for new approaches in organizing and optimizing the treatment of this complication. It is necessary to study in detail the structure of anxiety-depressive disorders, the state of the elastotonic properties of the vascular wall, endothelial function and heart remodeling in patients with myocardial infarction with various forms of atrial fibrillation.

Myristoylation of LMCD1 leads to its species‐specific derepression of E2F1 and NFATc1 in the modulation of CDC6 and IL‐33 expression during development of vascular lesions

Majority of translational research is focused on the use of rodent models to understand the pathophysiology of human disease. However, many experimental findings of rodent models fail to translate to human. In this regard, our previous studies show that LIM and cysteine‐rich domains 1 (LMCD1) plays a role in thrombin‐induced vascular smooth muscle cell (VSMC) proliferation and migration only in human but not rodents. Based on these findings, we asked the question whether LMCD1 exhibits any species‐specific role in the development of vascular lesions. A combination of genetic, molecular, cellular and disease models were used to test species‐specific role of LMCD1 in the pathogenesis of vascular lesions. Here, we report species‐specific regulation of LMCD1 expression in mediating VSMC proliferation and migration during vascular wall remodeling in human versus mice. Thrombin induced LMCD1 expression in human aortic smooth muscle cells (HASMCs) but not mouse aortic smooth muscle cells (MASMCs). We found association of ‘rapid promoter evolution’ in this expression divergence of LMCD1 in human versus mice. In exploring the mechanism, we found that Par1‐Gαq/11‐PLCβ3‐NFATc1 signaling axis mediates thrombin‐induced LMCD1 expression in HASMCs. Furthermore, although LMCD1 mediates thrombin‐induced proliferation and migration of both HASMCs and MASMCs via influencing CDC6 and IL‐33 expression, respectively, in humans it acts as an activator and in mice it acts as a repressor of their promoters. Interestingly, its repressor activity was revoked by its myristoylation in mouse. Besides, we found increased expression of LMCD1 in human stenotic arteries as compared to non‐stenotic arteries. On the other hand, LMCD1 expression was decreased in neointimal lesions of mouse injured arteries as compared to non‐injured arteries. Together, these observations reveal that LMCD1 acts as an activator and repressor of E2F1 and NFATc1 in human and mice, respectively, in the induction of CDC6 and IL‐33 expression during development of vascular lesions. Based on these findings, LMCD could be a potential target for drug development against restenosis and atherosclerosis in humans.Support or Funding InformationThis work was supported by a grant HL069908 from NIH to Dr. Gadiparthi N. Rao

Endothelial Cell Bulge Occludes the Vasa Vasorum in the Cerebellar Vascular Hyalinosis Lesions

BackgroundThe remodeling of the cerebral vascular wall contributes to the occurrence of ischemic stroke in systemic hypertension patients, representing a leading cause of death in the U.S. and worldwide. Cerebral vascular remodeling in systemic hypertension is characterized by progressive degradation of structural components of each layer of the vessel wall with the subsequent transformation to hyaline material leading to the thickening vascular wall and lumen narrowing. The vasa vasorum as a network of small blood vessels supplying the blood to the vascular wall tissues contributes to the damage vascular structure and results in the formation of hyalinosis. The occlusion of vasa vasorum contributes to development of cerebral vascular hyalinization in systemic hypertension. However, mechanisms of occlusion of vasa vasorum that contribute to the brain vascular remodeling events have not been well defined. Lack of such knowledge interferes with the development of therapeutic strategies to reduce the occurrence of ischemic stroke.Methods & ResultsLight microscopy and transmission electron microscopy (TEM) of hyalinized cerebral vessels from human patients who suffered from systemic hypertension and died by ischemic stroke visualized the occlusion of the vasa vasorum due to the formation of the “bulge” structure that protrude from the endothelial cells. Treatment of microvascular endothelial cell with adrenaline (a major biogenic amine that are increased in the blood due to disbalance of neurohumoral homeostasis in systemic hypertension) resulted in a cytoskeletal rearrangement that contributes to the formation of the bulge‐like structure in the vasa vasorum of the brain vessels with hyalinosis lesion. The adrenaline activated clathrin‐mediated endocytosis of endothelial cells that in turn elicited SNX9/N‐WASP‐dependent disruption of cytoskeleton. siRNA knockdown of SNX9 inhibited endocytosis and prevented the adrenaline‐induced bulge formation in human microvascular endothelial cells. TEM visualized the adrenaline‐induced an increase endocytosis of the endothelial cells. Immunofluorescence staining showed the actin filament structural reorganization and TEM confirmed myofilament damage within endothelial cells. Adrenaline treatment induced post‐translational modifications of N‐WASp as a regulator of actin polymerization.ConclusionsThis is the first demonstration that adrenaline contributes to the occlusion of vasa vasorum in the hyalinized cerebral vascular wall that will allow to the development new strategies that can be used to prevent ischemic stroke.Support or Funding InformationSupported by NIH

Ozanimod Protects Against Hypoxia plus Glucose Deprivation‐Induced Morphological Changes and Improves Cell Health in Human Brain Vascular Smooth Muscle

Vascular smooth muscle cells regulate arterial contractile tone, blood pressure, and flow in relation to specific metabolic demands during normal and pathophysiological (i.e. hypoxic or ischemic) conditions. The plasticity of vascular smooth muscle cells allows for phenotypic transitions from contractile to synthetic‐like dedifferentiated states during pathophysiological conditions which then can lead to the development and progression of vascular inflammation and blood vessel wall remodeling. Our previous studies demonstrated that hypoxia plus glucose deprivation (HGD), an in vitro model of ischemia, alters human vascular cell morphology and increases cell death. We further demonstrated that the selective sphingosine‐1‐phosphate receptor 1 (S1PR1) ligand, ozanimod, attenuated these HGD‐mediated responses. In this study, we characterized HGD mediated phenotypic transitions and assessed expression of proteins involved in contraction (myosin light chain kinase, MLCK) and structure formation (alpha‐smooth muscle actin, vimentin) following HGD exposure. We further investigated the effect of ozanimod HGD‐mediated phenotypic transitions by assessing protein levels and localization LC3B as an indicator of autophagocytosis. Using immunocytochemistry and standard immunoblotting, we determined the localization and expression levels of α‐smooth muscle actin, MLCK, vimentin, and LC3B protein during normoxia (21% O2, control) or HGD (1%O2) for 9 h in male human brain vascular smooth muscle cells (HBVSMC) at passage 6–7. We observed that LC3B protein, a vacuole marker associated with autophagy, is ubiquitously expressed in the cytoplasm of HBVSMC during normoxia. During HGD exposure, LC3B protein levels were increased and immunohistochemical staining demonstrated LC3B localization in what appears to be autophagic vacuole formation. Both responses were attenuated by ozanimod. Although alpha‐smooth muscle actin in HBVSMC was effective in visualization of morphological changes from spindle (contractile) to rhomboid (synthetic) shape following HGD, basal protein expression levels were not altered. Similarly, MLCK, an enzyme responsible for contractile protein phosphorylation, was not altered following HGD. Levels of the synthetic phenotype marker, vimentin, was basally expressed in HBVSMC, however, levels were not increased following HGD. In conclusion, although vacuole formation is prominent, indicating poor health, HBVSMCs retained a contractile phenotype during ischemic‐like conditions. Attenuation of HGD‐mediated LC3B via ozanimod suggests a novel mechanism associated with the beneficial effect of this selective S1PR1 ligand during ischemic‐like exposure.Support or Funding InformationAmerican Heart Association 19AIREA34480018 (RJG).

Tissue-specific relaxin-2 is differentially associated with the presence/size of an arterial aneurysm and the severity of atherosclerotic disease in humans.

Circulating or tissue-related biomarkers are of clinical value for risk stratification in patients with abdominal aortic aneurysms. Relaxin-2 (RL2) has been linked to the presence and size of arterial aneurysms, and to the extent of atherosclerosis in human subjects. Here, we assessed the expression levels of RL2 in aneurysmal (AA, n = 16) and atherosclerotic (ATH, n = 22) arteries, and established the correlation between RL2 levels and the presence/size of AA and the clinical severity of atherosclerosis. The expression levels of metalloproteinases (MMPs) and endothelial nitric oxide synthetase (eNOS) were also detected for correlations with different phenotypes of atherosclerosis and AA. Temporal artery biopsy specimens (n = 6) and abdominal aortic tissues harvested from accident victims during autopsy (n = 10) were used as controls. Quantitative tissue biomarker analysis revealed that tissue-specific RL2 was increased in patients with larger or symptomatic AA compared to subjects with atherosclerotic disease and healthy controls. In situ RL2 levels were proportional to the size and the severity of aneurysmatic disease, and were substantially elevated in patients with symptomatic aneurysm of any diameter or asymptomatic aneurysm of a diameter >350% of that of the normal artery. In contrast, tissue RL2 was inversely associated with the clinical severity of atherosclerotic lesions. Correlation between RL2 and MMP2 was different between ATH1 and ATH2, depending on atherosclerosis grade. Overall, tissue RL2 is differentially associated with discrete phenotypes of arterial disease and might exert multipotent biological effects on vascular wall integrity and remodeling in human subjects.

Cytoglobin overexpression facilitates proliferation and migration of vascular smooth muscle cells

Cytoglobin, a recently discovered globin, is expressed in vascular smooth muscle cells (VSMCs). Loss of cytoglobin provides a protective effect on vascular reconstruction but the effect of its overexpression is unclear. The aim of the study was to investigate the effect of cytoglobin overexpression on the migration and proliferation of VSMCs and possible mechanisms. We detected the expression of cytoglobin in hypertensive and normotensive rat aortas, with negative feedback regulation between cytoglobin and hypertension observed. The expression of cytoglobin was significantly decreased in hypertensive rats compared to normotensive rats, but VSMCs overexpressing cytoglobin displayed increased cell migration and proliferation, which led to a phenotypic switch. The increased expression of matrix metalloproteinase 9 and collagen Ia suggests a role for cytoglobin in extracellular matrix remodeling. Increased expression of proliferating cell nuclear antigen and decreased expression of p27 implies that cytoglobin is involved in modulating VSMC proliferation. Our findings indicate that cytoglobin may play an important role in vascular wall remodeling.

Small extracellular vesicles from rat plasma promote migration and proliferation of vascular smooth muscle cells.

Small extracellular vesicles (sEV) contain various molecules and mediate cell-to-cell communication under both physiological and pathological conditions. We have recently reported that sEV isolated from plasma of normotensive Wistar Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) regulate systemic blood pressure. The initiation and development of hypertension partly rely on proliferation and migration of vascular smooth muscle cells (SMCs) followed by the structural remodeling of vascular wall. In the present study, we examined the effects of plasma sEV in WKY and SHR on the proliferative and migratory functions of primary rat aortic SMCs. There was no difference in the concentration and size distribution of plasma sEV between WKY and SHR, while the protein expression of CD81 in plasma sEV from SHR was lower than that from WKY. Both plasma sEV from WKY and SHR were internalized into SMCs and stimulated the migration and proliferation with a similar potency. In summary, we, for the first time, demonstrated that plasma sEV in WKY and SHR are physiologically active in terms of proliferative and migratory functions, however, these effects do not seem to be related to the pathogenesis of hypertension development.

Possible mechanisms of renal denervation long-term cardiac effects

Background.The renin-angiotensin-aldosterone system (RAAS) plays a key role in target organ damage in arterial hypertension (HTN), initiating the development of left ventricular hypertrophy (LVH), as well as the heart and vascular wall fibrosis and remodeling. In addition, one of the mechanisms of the cardiovascular disease progression is the angiotensin II-induced inflammation.Objective.To study the changes in renin, aldosterone and high-sensitive C‑reactive protein (CRP) levels two years after sympathetic renal denervation (RDN), to compare these changes with antihypertensive efficacy of the intervention and LVH regression.Design and methods.We included 77 patients with drug-resistant hypertension in the absence of contraindications to renal denervation. All patients underwent renal radiofrequency ablation. The active renin, aldosterone and a high-sensitive CRP concentrations assessment, 24‑hour blood pressure (BP) measurement and echocardiography were performed before, at 6 months, one and two years after the intervention.Results.There was a gradual decrease in CRP levels (the difference was significant after 6 months), aldosterone (significant two years after surgical treatment), and active renin (the difference was the most pronounced after one year). At all follow-up assessments, plasma renin activity correlated with left ventricular mass. At the same time, there were no significant differences between responders and non-responders.Conclusions.RDN leads to a RAAS activity attenuation, manifested by the decrease in both renin and aldosterone and CRP, probably due to angiotensin II proinflammatory effects reduction. Given these effects are long-term, correlate with LVH degree and unrelated to the BP lowering, a direct cardioprotective effect of renal denervation should be considered.

Exome-chip association analysis of intracranial aneurysms.

To investigate to what extent low-frequency genetic variants (with minor allele frequencies <5%) affect the risk of intracranial aneurysms (IAs). One thousand fifty-six patients with IA and 2,097 population-based controls from the Netherlands were genotyped with the Illumina HumanExome BeadChip. After quality control (QC) of samples and single nucleotide variants (SNVs), we conducted a single variant analysis using the Fisher exact test. We also performed the variable threshold (VT) test and the sequence kernel association test (SKAT) at different minor allele count (MAC) thresholds of >5 and >0 to test the hypothesis that multiple variants within the same gene are associated with IA risk. Significant results were tested in a replication cohort of 425 patients with IA and 311 controls, and results of the 2 cohorts were combined in a meta-analysis. After QC, 995 patients with IA and 2,080 controls remained for further analysis. The single variant analysis comprising 46,534 SNVs did not identify significant loci at the genome-wide level. The gene-based tests showed a statistically significant association for fibulin 2 (FBLN2) (best p = 1 × 10-6 for the VT test, MAC >5). Associations were not statistically significant in the independent but smaller replication cohort (p > 0.57) but became slightly stronger in a meta-analysis of the 2 cohorts (best p = 4.8 × 10-7 for the SKAT, MAC ≥1). Gene-based tests indicated an association for FBLN2, a gene encoding an extracellular matrix protein implicated in vascular wall remodeling, but independent validation in larger cohorts is warranted. We did not identify any significant associations for single low-frequency genetic variants.

T-614 inhibits human aortic adventitial fibroblast proliferation and promotes interleukin-8 production in vitro.

The effect and underlying mechanism of T-614 (iguratimod) on Takayasu's arteritis (TA) are unknown. Here, we report the effects of T-614 on cell proliferation and interleukin-8 (IL-8) production in human aortic adventitial fibroblasts (HAAFs) in vitro and explore its initial benefit in terms of vascular wall inflammation and remodeling for patients with TA. HAAFs were cultured with 0, 5, 50, 100, or 250 μg/ml T-614 in the absence or presence of tumor necrosis factor-α (TNF-α) in vitro. Cell viability was determined by a modified MTT assay. Supernatant IL-8 levels were measured by enzyme-linked immunosorbent assays. In the presence of TNF-α, compared to that in the control group, cell viability of HAAFs significantly decreased in the 50, 100, and 250 μg/ml T-614 treatment groups (OD value: P < 0.01, P < 0.001, P < 0.001, respectively; survival fraction (SF): P < 0.05, P < 0.001, P < 0.001, respectively). However, there was no significant difference in cell viability between TNF-α-stimulated and unstimulated groups at the same concentration of T-614. In the absence or presence of TNF-α, T-614 suppressed HAAF cell viability dose-dependently (OD value: r = -0.915, P = 0.000; r = -0.926, P = 0.000, respectively; SF: r = -0.897, P = 0.000; r = -0.885, P = 0.000, respectively). Compared to that in the control group, in the absence of TNF-α, IL-8 levels in the 5 and 100 μg/ml T-614-treated groups were significantly higher (P < 0.05); in the presence of TNF-α, IL-8 levels in the 5, 50, and 100 μg/ml T-614-treated groups were significantly higher (P < 0.001, P < 0.001, P < 0.01, respectively). Further, there was a negative correlation between supernatant IL-8 levels and T-614 concentration in groups stimulated with TNF-α (r = -0.670, P = 0.000), but there was no significant correlation between these parameters in groups that were not stimulated with TNF-α. In the absence or presence of TNF-α, T-614 can inhibit HAAF proliferation and promote IL-8 production in vitro; therefore, it could be used to prevent adventitial thickening of the aorta and improve vascular remodeling in inflammatory environments in vitro and might provide a new immunotherapeutic intervention for TA.

New Absorbable Microvascular Anastomotic Devices Representing a Modified Sleeve Technique: Evaluation of Two Types of Source Material and Design

The purpose of this study was to create a new absorbable vascular anastomotic coupler and evaluate the patency and degradation degree. Vascular anastomosis was performed in the jugular vein in 31 New Zealand white female rabbits. The coupler consisted of an inner and outer ring. One side of the jugular vein was passed through and overlapped the inner ring. The opposite side of the jugular vein overlapped the everted jugular vein on the inner ring. Then, the outer ring engaged with the inner ring and completed the anastomosis. The outer rings were also constructed with two shapes including an O-type that had no slit and a C-type with a slit on the outer ring of the O-type coupler to allows expandability of the diameter. A Phase I experiment was performed to evaluate the degradability of the source materials, including the poly (lactic-co-glycolic acid) (PLGA) and polycaprolactone (PCL) couplers. A Phase II experiment was performed to evaluate the patency and anastomosis time of the O-type PLGA and PCL couplers. A Phase III experiment was performed to evaluate the patency and anastomosis time of suture anastomosis (control) and the C-type PLGA coupler. The patency was determined by ultrasonography and open exploration. Histological analysis was performed to determine the degradability of the couplers. In Phase I, the PLGA couplers were completely degraded with good vascular wall remodeling at 8 months, while the PCL couplers demonstrated incomplete degradation. In Phases II and III, the anastomosis time was significantly shorter in the coupler groups than that in the control group. All of the coupler groups demonstrated complete patency of the anastomoses on ultrasonography. In Phase III, the C-type PLGA coupler also demonstrated patency and complete degradation at 8 months. PLGA is a suitable source material for absorbable couplers due to its fast degradability. We devised the O-shaped outer ring for the C-shaped outer ring to increase flexibility, which also demonstrated complete patency during the experimental period. Our absorbable microvascular anastomosis devices could provide rapid and reliable microvascular anastomosis without anastomotic failure.

NFATc1-E2F1-LMCD1-Mediated IL-33 Expression by Thrombin Is Required for Injury-Induced Neointima Formation.

Objective- IL (interleukin)-33 has been shown to play a role in endothelial dysfunction, but its role in atherosclerosis is controversial. Therefore, the purpose of this study is to examine its role in vascular wall remodeling following injury. Approach and Results- Thrombin induced IL-33 expression in a time-dependent manner in human aortic smooth muscle cells and inhibition of its activity by its neutralizing antibody suppressed thrombin induced human aortic smooth muscle cell migration but not DNA synthesis. In exploring the mechanisms, we found that Par1 (protease-activated receptor 1), Gαq/11 (Gα protein q/11), PLCβ3 (phospholipase Cβ3), NFATc1 (nuclear factor of activated T cells), E2F1 (E2F transcription factor 1), and LMCD1 (LIM and cysteine-rich domains protein 1) are involved in thrombin-induced IL-33 expression and migration. Furthermore, we identified an NFAT-binding site at -100 nt that mediates thrombin-induced IL-33 promoter activity. Interestingly, we observed that NFATc1, E2F1, and LMCD1 bind to NFAT site in response to thrombin and found that LMCD1, while alone has no significant effect, enhanced either NFATc1 or E2F1-dependent IL-33 promoter activity. In addition, we found that guidewire injury induces IL-33 expression in SMC and its neutralizing antibodies substantially reduce SMC migration and neointimal growth in vivo. Increased expression of IL-33 was also observed in human atherosclerotic lesions as compared to arteries without any lesions. Conclusions- The above findings reveal for the first time that thrombin-induced human aortic smooth muscle cell migration and injury-induced neointimal growth require IL-33 expression. In addition, thrombin-induced IL-33 expression requires LMCD1 enhanced combinatorial activation of NFATc1 and E2F1.

Administration of endothelial progenitor cells accelerates the resolution of arterial thrombus in mice

BackgroundEndothelial progenitor cells (EPCs) are circulating progenitor cells that can play an essential role in vascular remodelling. In this work, we compared the role of two EPCs cultivated with different mediums in the resolution of the arterial thrombus induced by FeCl3 lesion and in vessel re-endothelization in the mouse carotid artery. MethodsMice mononuclear cells were differentiated into EPCs using Dulbecco's Modified Eagle's Medium (DMEM) and vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF) and IGF (Insulin Growth Factor) called EPCs--M1) or with EGM2(endothelial growth medium) (media supplemented with growth factors from Lonza called (EPCs-M2) for 30days and characterized using flow cytometry. The animals received three EPC injections post-lesion, and we analyzed thrombosis time, vessel re-endothelization, metalloproteinases activities, eNOS (endothelial Nitric oxide synthase) presence and SDF-1(Stromal Derived Factor- 1) levels in circulation. ResultsEPC-M1 presented a more immature progenitor profile than EPC-M2 cells. The injection of EPC-M1 prolonged the thrombosis time, and the treatment with the different EPCs increased eNOS expression and MMP2 (Metalloproteinase 2) activity and decreased SDF-1 in plasma. Only EPC-M1 treatment increased both MMP2 and MMP9 and reduced thrombus after 7days. Also, both EPCs decreased platelet aggregation in vitro. ConclusionsEPCs-M1 were more efficient in all of the analyzed assays. EPCsM2 may be a more mature EPC, proliferating less and promoting a less significant matrix remodelling. EPCs can promote vascular remodelling by inhibiting thrombosis and stimulating vascular wall remodelling and the treatment with a more immature progenitor may be more efficient in this process.

Endothelial dysfunction in patients with chronic obstructive pulmonary disease in combination with coronary heart disease.

The aim of this study was to evaluate the state of the vascular wall in patients with chronic obstructive pulmonary disease (COPD) combined with chronic coronary artery disease (CAD). The study included 108 patients: 37 patients with COPD and CAD and 71 patients with COPD without CAD. Endothelial function was studied in tests with reactive hyperemia and nitroglycerin. The number of blood plasma desquamated endotheliocytes were determined by the Hladovec method. In patients with COPD identified are signs of vascular wall remodeling: thickening wall of the brachial artery, reduction of the flow-mediated vasodilation. Patients with COPD in combination with CHD demonstrated higher impairments of the vasoregulatory dysfunction of endothelial of the vascular wall. In patients with COPD combined with chronic coronary heart disease more pronounced endothelial dysfunction with disturbance of endothelium-dependent vasomotor reactions.

Role of diet-related factors in cerebral aneurysm formation and rupture

Cerebral aneurysms (CAs) are dilations of the wall of an artery in the brain filled with blood. The prevalence of unrupted CA in general population is estimated at approximately 3%. Ruptured aneurysms are the cause of 85% of spontaneous subarachnoid hemorrhage (SAH) cases. The formation of cerebral aneurysms results from various factors, including chronic inflammation, hemodynamic stress and vascular wall remodeling. Reactive oxygen species may induce the endothelial dysfunction possibly through the activation of Nuclear Factor Kappa-B, which is a key regulator of the proinflammatory genes. Hypertension may additionally increase the hemodynamic stress and activate the local renin-angiotensin system. The aim of this review was to assess the role of selected diet-related factors in the formation and rupture of cerebral aneurysms. It appears that inadequate intake of dietary antioxidants, hyperhomocysteinemia, hypertension (including incidental elevated blood pressure) and alcohol consumption may increase the risk of intracranial aneurysms. Individuals at high risk of CA formation and/or rupture should consume adequate amounts of antioxidant vitamins (vitamin C, vitamin E and carotenoids), B vitamins (vitamin B6, vitamin B12 and folate), flavonoids and n-3 fatty acids, limit alcohol and caffeine consumption and regularly control their blood pressure. Vegetables, fruits, grains, pulses, nuts and fish, as well as herbs, spices and tea, should be the major components of the daily diet. Due to the synergistic effect of various dietary components on health, Mediterranean diet or Dietary Approach to Stop Hypertension (DASH) diet, as they meet abovementioned requirements and have high anti-inflammatory potential, are thus recommended for the prevention of cerebral aneurysm formation and rupture.