Atherosclerotic Plaque Growth Research Articles

Pharmacological inhibition of fatty acid oxidation reduces atherosclerosis progression by suppression of macrophage NLRP3 inflammasome activation

BackgroundInflammation is a key process during atherosclerotic lesion development and propagation. Recent evidence showed clearly that especially the inhibition of interleukin (IL)-1β reduced atherosclerotic adverse events in human patients. Fatty acid oxidation (FAO) was previously demonstrated to interact with the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) pathway which is required for mature IL-1β secretion. To understand possible anti-inflammatory properties of FAO inhibition, we tested the effect of pharmacological FAO inhibition using the inhibitor for long-chain 3-ketoacyl coenzyme A thiolase trimetazidine on atherosclerotic plaque development and inflammation. Experimental ApproachThe effect of FAO inhibition was determined in LDL-R−/− male mice on a C57/BL6 background. In vitro effects of trimetazidine treatment were analyzed in human umbilical vein endothelial cells and human monocyte derived macrophages. Key ResultsWe were able to demonstrate that inhibition of FAO reduced atherosclerotic plaque growth. We did not find direct anti-inflammatory properties of trimetazidine in endothelial cells or macrophages in vitro. However, we found that the activation of the NLRP3 system and the secretion of IL-1β were significantly reduced in macrophages after FAO inhibition. These results were confirmed in atherosclerotic lesions of mice treated with trimetazidine as they showed a significant reduction of IL-1β and cleaved caspase-1 in the atherosclerotic lesion as well as of IL-1β and IL-18 in the circulation. ConclusionOverall, we therefore suggest that the main mechanism of reducing inflammation of trimetazidine and FAO inhibition is the reduction of the NLRP-3 activation leading to reduced levels of the proinflammatory cytokine IL-1β.

Deficiency of myeloid PHD proteins aggravates atherogenesis via macrophage apoptosis and paracrine fibrotic signalling

AimsAtherosclerotic plaque hypoxia is detrimental for macrophage function. Prolyl hydroxylases (PHDs) initiate cellular hypoxic responses, possibly influencing macrophage function in plaque hypoxia. Thus, we aimed to elucidate the role of myeloid PHDs in atherosclerosis.Methods and resultsMyeloid-specific PHD knockout (PHDko) mice were obtained via bone marrow transplantation (PHD1ko, PHD3ko) or conditional knockdown through lysozyme M-driven Cre recombinase (PHD2cko). Mice were fed high cholesterol diet for 6–12 weeks to induce atherosclerosis. Aortic root plaque size was significantly augmented 2.6-fold in PHD2cko, and 1.4-fold in PHD3ko compared to controls but was unchanged in PHD1ko mice. Macrophage apoptosis was promoted in PHD2cko and PHD3ko mice in vitro and in vivo, via the hypoxia-inducible factor (HIF) 1α/BNIP3 axis. Bulk and single-cell RNA data of PHD2cko bone marrow-derived macrophages (BMDMs) and plaque macrophages, respectively, showed enhanced HIF1α/BNIP3 signalling, which was validated in vitro by siRNA silencing. Human plaque BNIP3 mRNA was positively associated with plaque necrotic core size, suggesting similar pro-apoptotic effects in human. Furthermore, PHD2cko plaques displayed enhanced fibrosis, while macrophage collagen breakdown by matrix metalloproteinases, collagen production, and proliferation were unaltered. Instead, PHD2cko BMDMs enhanced fibroblast collagen secretion in a paracrine manner. In silico analysis of macrophage-fibroblast communication predicted SPP1 (osteopontin) signalling as regulator, which was corroborated by enhanced plaque SPP1 protein in vivo. Increased SPP1 mRNA expression upon PHD2cko was preferentially observed in foamy plaque macrophages expressing ‘triggering receptor expressed on myeloid cells-2’ (TREM2hi) evidenced by single-cell RNA, but not in neutrophils. This confirmed enhanced fibrotic signalling by PHD2cko macrophages to fibroblasts, in vitro as well as in vivo.ConclusionMyeloid PHD2cko and PHD3ko enhanced atherosclerotic plaque growth and macrophage apoptosis, while PHD2cko macrophages further activated collagen secretion by fibroblasts in vitro, likely via paracrine SPP1 signalling through TREM2hi macrophages.

Act Locally, Act Globally-Microbiota, Barriers, and Cytokines in Atherosclerosis.

Atherosclerosis is a lipid-driven chronic inflammatory disease that is characterized by the formation and progressive growth of atherosclerotic plaques in the wall of arteries. Atherosclerosis is a major predisposing factor for stroke and heart attack. Various immune-mediated mechanisms are implicated in the disease initiation and progression. Cytokines are key mediators of the crosstalk between innate and adaptive immune cells as well as non-hematopoietic cells in the aortic wall and are emerging players in the regulation of atherosclerosis. Progression of atherosclerosis is always associated with increased local and systemic levels of pro-inflammatory cytokines. The role of cytokines within atherosclerotic plaque has been extensively investigated; however, the cell-specific role of cytokine signaling, particularly the role of cytokines in the regulation of barrier tissues tightly associated with microbiota in the context of cardiovascular diseases has only recently come to light. Here, we summarize the knowledge about the function of cytokines at mucosal barriers and the interplay between cytokines, barriers, and microbiota and discuss their known and potential implications for atherosclerosis development.

A Novel Approach to Generate a Virtual Population of Human Coronary Arteries for In Silico Clinical Trials of Stent Design.

Goal: To develop a cardiovascular virtual population using statistical modeling and computational biomechanics. Methods: A clinical data augmentation algorithm is implemented to efficiently generate virtual clinical data using a real clinical dataset. An atherosclerotic plaque growth model is employed to 3D reconstructed coronary arterial segments to generate virtual coronary arterial geometries (geometrical data). Last, the combination of the virtual clinical and geometrical data is achieved using a methodology that allows for the generation of a realistic virtual population which can be used in in silico clinical trials. Results: The results show good agreement between real and virtual clinical data presenting a mean gof 0.1 ± 0.08. 400 virtual coronary arteries were generated, while the final virtual population includes 10,000 patients. Conclusions: The virtual arterial geometries are efficiently matched to the generated clinical data, both increasing and complementing the variability of the virtual population.

Association between Intraplaque Hemorrhage and Vascular Remodeling in Carotid Arteries: The Plaque at RISK (PARISK) Study

Introduction: Vascular remodeling is a compensatory enlargement of the vessel wall in response to atherosclerotic plaque growth. We aimed to investigate the association between intraplaque hemorrhage (IPH), vascular remodeling, and luminal dimensions in recently symptomatic patients with mild to moderate carotid artery stenosis in which the differences in plaque size were taken into account. Materials and Methods: We assessed vessel dimensions on MRI of the symptomatic carotid artery in 164 patients from the Plaque At RISK study. This study included patients with recent ischemic neurological event and ipsilateral carotid artery stenosis <70%. The cross section with the largest wall area (WA) in the internal carotid artery (ICA) was selected for analysis. On this cross section, the following parameters were determined: WA, total vessel area (TVA), and lumen area (LA). Vascular remodeling was quantified as the remodeling ratio (RR) and was calculated as TVA at this position divided by the TVA in an unaffected distal portion of the ipsilateral ICA. Adjustment for WA was performed to correct for plaque size. Results: Plaques with IPH had a larger WA (0.56 vs. 0.46 cm²; p < 0.001), a smaller LA (0.17 vs. 0.22 cm²; p = 0.03), and a higher RR (2.0 vs. 1.9; p = 0.03) than plaques without IPH. After adjustment for WA, plaques containing IPH had a smaller LA (B = −0.052, p = 0.01) than plaques without IPH, but the RR was not different. Conclusion: After correcting for plaque size, plaques containing IPH had a smaller LA than plaques without IPH. However, RR was not different.

In vitro and in silico testing of partially and fully bioresorbable vascular scaffold

Coronary artery disease (CAD), one of the leading causes of death globally, occurs due to the growth of atherosclerotic plaques in the coronary arteries, causing lesions which restrict the flow of blood to the myocardium. Percutaneous transluminal coronary angioplasty (PTCA), including balloon angioplasty and coronary stent deployment is a standard clinical invasive treatment for CAD. Coronary stents are delivered using a balloon catheter inserted across the lesion. The balloon is inflated to a nominal pressure, opening the occluded artery, deploying the stent and improving the flow of blood to the myocardium.All stent manufacturers have to perform standard in vitro mechanical testing under different physiological conditions. In this study, partially and fully bioresorbable vascular scaffolds (BVS) from Boston Scientific Limited have been examined in vitro and in silico for three different test methods: inflation, radial compression and crush resistance.We formulated a material model for poly-L-lactic acid (PLLA) and implemented it into our in-house software tool. A comparison of the different experimental results is presented in the form of graphs showing displacement-force curves, diameter – load curves or diameter - pressure curves. There is a strong correlation between simulation and real experiments with a coefficient of determination (R2) > 0.99 and a correlation coefficient (R) > 0.99.This preliminary study has shown that in-silico tests can mimic the applicable ISO standards for mechanical in vitro stent testing, providing the opportunity to use data generated using in-silico testing to partially or fully replacing the mechanical testing required for regulatory submission.

Simulation of atherosclerotic plaque growth using computational biomechanics and patient-specific data

Atherosclerosis is the one of the major causes of mortality worldwide, urging the need for prevention strategies. In this work, a novel computational model is developed, which is used for simulation of plaque growth to 94 realistic 3D reconstructed coronary arteries. This model considers several factors of the atherosclerotic process even mechanical factors such as the effect of endothelial shear stress, responsible for the initiation of atherosclerosis, and biological factors such as the accumulation of low and high density lipoproteins (LDL and HDL), monocytes, macrophages, cytokines, nitric oxide and formation of foams cells or proliferation of contractile and synthetic smooth muscle cells (SMCs). The model is validated using the serial imaging of CTCA comparing the simulated geometries with the real follow-up arteries. Additionally, we examine the predictive capability of the model to identify regions prone of disease progression. The results presented good correlation between the simulated lumen area (P < 0.0001), plaque area (P < 0.0001) and plaque burden (P < 0.0001) with the realistic ones. Finally, disease progression is achieved with 80% accuracy with many of the computational results being independent predictors.

Diagnostic efficacy of intravascular ultrasound combined with Gd2O3-EPL contrast agent for patients with atherosclerosis.

Atherosclerosis is a cardiovascular disease that is pathologically associated with the growth of atherosclerotic plaques and vascular vulnerability. Intravascular ultrasound (IVUS) has been used to evaluate and treat cardiovascular diseases. Accumulating evidence has demonstrated that Gd2O3-doped nanoparticles contrast can be applied for the diagnosis of human diseases. In the present study, eplerenone (EPL), a mineralocorticoid receptor antagonist, was first doped with Gd2O3 nanoparticles (Gd2O3-EPL), following which its diagnostic efficacy for use in IVUS measurements (Gd2O3-EPL-IVUS) was evaluated for patients suspected with atherosclerosis. Gd2O3-EPL-IVUS presented with higher accuracy and sensitivity compared with IVUS in diagnosing 188 patients with suspected atherosclerosis. Gd2O3-EPL-IVUS exhibited stronger signals associated with plaque morphology compared with aloe IVUS for patients with atherosclerosis. In addition, Gd2O3-EPL-IVUS application resulted in clearer arterial plaque images compared with IVUS by binding mineralocorticoid receptors. Atherosclerosis was subsequently confirmed in all patients using computerized tomography-coronary angiography. Gd2O3-EPL-IVUS showed more accuracy in measuring vessel size, plaque burden and minimal lumen area compared with IVUS analysis alone. In conclusion, these outcomes suggest that Gd2O3-EPL-IVUS is a reliable tool for the evaluation of coronary lesions in patients with atherosclerosis.

Is it worthwhile rethinking the positive experience of the last 50 years of using chondroitin sulfates against atherosclerosis?

Chondroitin sulfate (CS) and glucosamine sulfate (GS) are used in the treatment of osteoarthritis and exhibit a pronounced anti-inflammatory effect. CS/GS inhibit the NF-kB signaling cascade, which realizes the biological effects of tumor necrosis factor (TNF a ). Excessive activity of NF-kB also stimulates the development of atherosclerosis. The results of experimental and clinical studies show that inhibition of NF-kB by CS/GS will inhibit the formation and growth of atherosclerotic plaques also reducing levels of other markers of inflammation.

Novel Approaches to Anti-atherosclerotic Therapy: Cell-based Models and Herbal Preparations (Review of Our Own Data).

Atherosclerosis is a chronic arterial disease characterized by vascular inflammation, accumulation of lipids in the arterial wall, and formation and growth of atherosclerotic plaques followed by ischemia. In subclinical atherosclerosis, cholesterol retention in subendothelial cells leads to induction of local inflammation, generation of foam cells and lesion formation, followed by a chain of other pathogenic events. Atherosclerotic progression can frequently be fatal, since plaque rupture may lead to thrombosis and acute events, such as myocardial infarction, stroke and sudden death. Traditional anti-atherosclerotic therapy is mainly focused on improving the blood lipid profile and does not target various stages of plaque progression. Obviously, treating the disease at initial stages is better than beginning treatment at advanced stages and, in that regard, current atherosclerosis management can be improved. Cholesterol retention is an important component of atherogenesis that precedes plaque formation. Therapeutic targeting of cholesterol retention may be beneficial for preventing further atherogenic progression. For this purpose, we suggest using herbal preparations due to good tolerability and suitability for long-lasting treatment. We developed test systems based on cultured human intimal aortic cells for rapid screening of potential anti-atherogenic drugs. With the help of these test systems, we selected several natural substances with significant anti-atherogenic activity and further use these compounds to prepare herbal preparations for anti-atherosclerotic therapy. These preparations were clinically tested and showed good safety and a potent anti-atherogenic potential.

Three-Dimensional Imaging of Intraplaque Neovascularization in a Mouse Model of Advanced Atherosclerosis

Multiple lines of evidence suggest that intraplaque (IP) neovascularization promotes atherosclerotic plaque growth, destabilization, and rupture. However, pharmacological inhibition of IP neovascularization remains largely unexplored due to the limited number of animal models that develop IP neovessels and the lack of reliable methods for visualizing IP angiogenesis. Here, we applied 3D confocal microscopy with an optimized tissue-clearing process, immunolabeling-enabled three-dimensional imaging of solvent-cleared organs, to visualize IP neovessels in apolipoprotein E-deficient (ApoE^−/−) mice carrying a heterozygous mutation (C1039+/−) in the fibrillin-1 gene. Unlike regular ApoE^−/− mice, this mouse model is characterized by the presence of advanced plaques with evident IP neovascularization. Plaques were stained with antibodies against endothelial marker CD31 for 3 days, followed by incubation with fluorescently labeled secondary antibodies. Subsequent tissue clearing with dichloromethane (DCM)/methanol, DCM, and dibenzyl ether allowed easy visualization and 3D reconstruction of the IP vascular network while plaque morphology remained intact.

Associations of iron status with apolipoproteins and lipid ratios: a cross-sectional study from the China Health and Nutrition Survey

BackgroundIron overload has been found to be related with various cardiometabolic disorders, like dyslipidemia, metabolic syndrome, and diabetes. The disturbance of the iron status and lipid metabolism can contribute to organ damage such as atherosclerotic plaque growth and instability. An assessment on the associations of iron status with apolipoproteins and lipid ratios would be informative for maintenance of metabolic homeostasis and hinderance of disease progression. Hence, this study aims to establish the relationships of iron status with apolipoproteins and lipid ratios.MethodsA cross-sectional study of 7540 adult participants from the China Health and Nutrition Survey 2009 was conducted. Logistic regression analyses were used to investigate the relationships between indicators of iron status and the prevalence of unfavorable apolipoprotein profiles. Multivariate linear regression models were constructed to assess the dose-response correlations between serum ferritin and lipid parameters.ResultsAfter adjustment for confounding factors, in both sexes, the subjects in the top quartile of ferritin had the highest prevalence of an elevated apolipoprotein B (men: odds ratio (OR) 1.97, 95% confidence interval (CI) 1.50–2.62; women: OR 2.13, 95% CI 1.53–2.97) and an elevated apolipoprotein B/apolipoprotein A1 ratio (men: OR 2.00, 95% CI 1.50–2.66; women: OR 1.41, 95% CI 1.04–1.92) when compared with individuals in the lowest quartile. Hemoglobin were also independently associated with unfavorable apolipoprotein B and apolipoprotein B/apolipoprotein A1 ratio both in men and women. However, transferrin (men: OR 0.74, 95% CI 0.56–0.99; women: OR 0.73, 95% CI 0.56–0.95) and soluble transferrin receptor (men: OR 0.75, 95% CI 0.57–0.99; women: OR 0.71, 95% CI 0.55–0.91) were found to be negatively associated with a decreased apolipoprotein A1. Moreover, after controlling for potential confounders, the ferritin concentrations were significantly associated with the levels of lipid ratios including TG/HDL-C, non-HDL-C/HDL-C, TC/HDL-C, apoB/apoA1, and LDL-C/HDL-C ratio in men (β coefficient = 0.147, 0.061, 0.043, 0.038, 0.032, respectively, all P values < 0.001) and in women (β coefficient = 0.074, 0.034, 0.025, 0.020, 0.018, respectively, all P values < 0.05).ConclusionsThe indicators of iron status are significantly associated with unfavorable apolipoprotein profiles. Serum ferritin concentrations are positively correlated with the levels of lipid ratios. The management on the modifiable iron status and lipid metabolism has a clinical significance. The atherosclerotic lipid profiles of the patients with iron overload deserve special clinical concerns.

Endothelial-to-Mesenchymal Transition, Vascular Inflammation, and Atherosclerosis.

Atherosclerosis is a chronic progressive disease characterized by vascular inflammation and growth of atherosclerotic plaque that eventually lead to compromise of blood flow. The disease has proven to be remarkably resistant to multiple attempts at meaningful reversal including recent strategies targeting selective inflammatory mediators. Endothelial-to-mesenchymal transition (EndMT) has emerged as a key driver of both vascular inflammation and plaque growth. A deeper understanding of EndMT provides new insights into the underlying biology of atherosclerosis, suggests likely molecular mechanism of atherosclerotic resistance, and identifies potential new therapeutic targets.

Role of food and nutrition and prevention in pathogenesis of the arterial occlusive disease

Admission Atherosclerosis is a chronic inflammatory disease of complex etiopathogenesis. Improper diet, genetic predisposition, lack of physical activity, and smoking are just a few of the major factors contributing to the development of atherosclerotic plaque. Diet in atherosclerosis, treatment is based. Antiatherosclerotic diet is one of many components, which should provide not only the treatment of such a state, but primarily prevention. Accordingly, balanced nutrition regimen can reduce cholesterol synthesis in the liver, which contributes to the development of atherosclerosis. Limiting the intake of trans fatty acids and saturated fatty acids allows for inhibiting the development of atherosclerotic plaque.AimThe aim of the study is to analyze the role of food and nutrition in the prevention and pathogenesis of atherosclerosis of the lower extremities.Material and methodsA review of available literature.Results Adequate intake of potassium in the diet contributes significantly to reducing the risk of atherosclerosis and hypertension. Potassium determines many important functions in the body.Due to the fact that the monounsaturated fatty acids reduce LDL cholesterol levels, the proportion should be in the diet increased to 15% and for the secondary prevention of up to 20%. In the prevention of atherosclerosis is very important to maintain an appropriate ratio of omega-6 to omega-3 ratio is absolutely should be no more than 4. It is extremely important in the diet because distorted value for the benefit of omega-6 favors the formation of atherosclerotic lesions.respective supply of carbohydrates also has a huge impact on the development of atherosclerotic lesions. The recommended amount of antiatherosclerotic dietary up to 60% provided that the people do not apply to such ailments as hypertension, overweight or obesity, elevated fasting blood sugar levels, decreased HDL cholesterol and elevated triglycerides.ConclusionsGeneral nutritional recommendations play the role of a signpost, which you should use expecting to improve health. It should be noted, however, that is not all. Nutritional prevention is significant, but equally important is lifestyle modification. Atherosclerotic diet is an important part of the treatment of the disease and prevent further growth of atherosclerotic plaque. Atherosclerosis requires the use of low-fat diet that is necessary to beat high blood cholesterol levels.

Deficiency of cysteinyl cathepsin K suppresses the development of experimental intimal hyperplasia in response to chronic stress.

Chronic psychological stress (CPS) is linked to cardiovascular disease initiation and progression. Given that cysteinyl cathepsin K (CatK) participates in vascular remodeling and atherosclerotic plaque growth in several animal models, we investigated the role of CatK in the development of experimental neointimal hyperplasia in response to chronic stress. At first, male wild-type (CatK) mice that underwent carotid ligation injury were subjected to chronic immobilization stress. On postoperative and stressed day 14, the results demonstrated that stress accelerated injury-induced neointima hyperplasia. On day 4, stressed mice showed following: increased levels of monocyte chemoattractant protein-1, gp91phox, toll-like receptor-2 (TLR2), TLR4, and CatK mRNAs or/and proteins, oxidative stress production, aorta-derived smooth muscle cell (SMC) migration, and macrophage infiltration as well as targeted intracellular proliferating-related molecules. Stressed mice showed increased matrix metalloproteinase-2 (MMP-2) and MMP-9 mRNA expressions and activities and elastin disruption in the injured carotid arteries. Second, CatK and CatK deficiency (CatK) mice received ligation injury and stress to explore the role of CatK. The stress-induced harmful changes were prevented by CatK. Finally, CatK mice that had undergone ligation surgery were randomly assigned to one of two groups and administered vehicle or CatK inhibitor for 14 days. Pharmacological CatK intervention produced a vascular benefit. These data indicate that CatK deletion protects against the development of experimental neointimal hyperplasia via the attenuation of inflammatory overaction, oxidative stress production, and VSMC proliferation, suggesting that CatK is a novel therapeutic target for the management of CPS-related restenosis after intravascular intervention therapies.

State-of-the-Art Computational Models of Circle of Willis With Physiological Applications: A Review

Background: Various computational models of the circle of Willis (CoW) have been developed to non-invasively estimate the blood flow and hemodynamic parameters in intracranial arteries for the assessment of clinical risks such as aneurysms, ischemia, and atherosclerotic plaque growth. This review aims to categorize the latest computational models of CoW and summarize the innovative techniques. Summary of Review: In traditional computational models of CoW, the computational complexity increased from zero-dimensional models to one-dimensional and three-dimensional models. The applications extend from estimating certain hemodynamic parameters to simulating local flow field. The innovative techniques include the combination of models with different dimensions, the extension of vascular structure including heart and veins, as well as the addition of distal fractality, cerebral autoregulation, and intracranial pressure. There are some nontraditional models based on fluid-solid-interaction, control theory, and in-vitro experiments. In all kinds of models, the in-vivo data and non-Newtonian rheological models of blood have been widely applied to improve the accuracy of hemodynamic simulation. Conclusion: Firstly, the selection of model depends on its application scenario. The balance between computational complexity and physiological accuracy deserves further investigation. Secondly, the improvement of CoW models relies on the large-scale validations and the combination of various innovative modeling techniques.

Coronary artery plaque growth: A two-way coupled shear stress-driven model.

Atherosclerosis in coronary arteries can lead to plaque growth, stenosis formation, and blockage of the blood flow supplying the heart tissue. Several studies have shown that hemodynamics play an important role in the growth of coronary artery plaques. Specifically, low wall shear stress (WSS) appears to be the leading hemodynamic parameter promoting atherosclerotic plaque growth, which in turn influences the blood flow and WSS distribution. Therefore, a two-way coupled interaction exists between WSS and atherosclerosis growth. In this work, a computational framework was developed to study the coupling between WSS and plaque growth in coronary arteries. Computational fluid dynamics (CFD) was used to quantify WSS distribution. Surface mesh nodes were moved in the inward normal direction according to a growth model based on WSS. After each growth stage, the geometry was updated and the CFD simulation repeated to find updated WSS values for the next growth stage. One hundred twenty growth stages were simulated in an idealized tube and an image-based left anterior descending artery. An automated framework was developed using open-source software to couple CFD simulations with growth. Changes in plaque morphology and hemodynamic patterns during different growth stages are presented. The results show larger plaque growth towards the downstream segment of the plaque, agreeing with the reported clinical observations. The developed framework could be used to establish hemodynamic-driven growth models and study the interaction between these processes.

Chitinase-3-Like Protein 1 is an Inhibitor of Vascular Smooth Muscle Cell Dedifferentiation in Advanced Atherosclerosis

Introduction: Efforts have been devoted towards identifying the pathomechanisms of stroke - one of the leading causes for death and disability worldwide. Vascular smooth muscle cells (VSMCs) play an important role in both the growth and rupture of atherosclerotic plaques. A deeper understanding of their function will help in the development of novel diagnostic and therapeutic strategies to lower the burden of cardiovascular disease. By performing a Human Transcriptome Array of laser capture microdissections of the fibrous cap in ruptured plaques of symptomatic patients (n=20) vs stable plaques of asymptomatic patients (n=20), chitinase-3-like protein 1 (CHI3L1) was detected as the most significantly upregulated transcript in ruptured plaques. Hence, the aim of our research project was to investigate the function of CHI3L1 in VSMCs. Methods: To investigate the role of this gene, we used live-cell imaging analysis in VSMCs directly cultured from human carotid plaques (retrieved after carotid endarterectomy). Expression analysis was performed in primary cultured human VSMCs. Further, the carotid ligation model in C57Bl6 mice (reflecting intimal proliferation), and a plaque rupture model in ApoE-/- mice (reflecting lesion vulnerability) were used to investigate CHI3L1 function in vivo. The gene of interest was silenced with antisense oligonucleotides (GapmeRs). Sections of the ligated carotid artery were stained with H&E and immunohistochemistry for further quantitative analysis. Results: The live-cell imaging analyses indicated that CHI3L1 decreases the migration of cells primarily cultured from human carotid plaques. Further, in vitro knockdown of CHI3L1 in cultured human VSMCs increased CD68 and reduced alpha smooth muscle actin (αSMA) expression. In the carotid ligation model, silencing of CHI3L1 increased total vessel area and its individual components (media, intima and lumen). Further, silencing of this gene significantly reduced percentage of αSMA+ cells in the intima in this model. Silencing of CHI3L1 significantly reduced the percentage of αSMA+ cells in the fibrous cap of advanced lesions in the plaque rupture model, as well. Conclusion: In summary, CHI3L1 plays a role in VSMC-regulation in atherosclerotic plaques. It regulates VSMCs by altering the expression patterns of macrophage and VSMC markers. Differences in mouse vessel morphology and αSMA-expression indicate that CHI3L1 prevents VSMC dedifferentiation as well as transformation. Disclosure: No Disclosures

The role of cell proliferation in atherogenesis and in the destabilization of atherosclerotic plaque in human

The review examined of the processes of cell proliferation in human vascular wall and experimental animals during the formation of atherosclerotic plaques. Shows the types of actively proliferating cells: lymphocytes, macrophages, endotheliocytes and zones identified in the vascular wall, where this proliferation occurs. The factors that promote and hinder cell proliferation during the growth of atherosclerotic plaque are identified. The survey shows all the stages of the formation of atherosclerotic lesions, ranging from normal plots and lipid stains to pronounced fibrous plaques. Establishes a link between the cell proliferation and inflammation in the vascular wall man. Separately considered the role of cell proliferation in the destabilization of atherosclerotic plaque. If atherosclerosis this process still poorly studied, in the formation of unstable atherosclerotic plaques in humans it is completely unknown. Based on your own original data was finally on the important role of the processes of cell proliferation in the formation of unstable atherosclerotic plaques in humans.

Endothelial TGF-β signalling drives vascular inflammation and atherosclerosis.

Atherosclerosis is a progressive vascular disease triggered by interplay between abnormal shear stress and endothelial lipid retention. A combination of these and, potentially, other factors leads to a chronic inflammatory response in the vessel wall, which is thought to be responsible for disease progression characterized by a buildup of atherosclerotic plaques. Yet molecular events responsible for maintenance of plaque inflammation and plaque growth have not been fully defined. Here we show that endothelial TGFβ signaling is one of the primary drivers of atherosclerosis-associated vascular inflammation. Inhibition of endothelial TGFβ signaling in hyperlipidemic mice reduces vessel wall inflammation and vascular permeability and leads to arrest of disease progression and regression of established lesions. These pro-inflammatory effects of endothelial TGFβ signaling are in stark contrast with its effects in other cell types and identify it as an important driver of atherosclerotic plaque growth and show the potential of cell-type specific therapeutic intervention aimed at control of this disease.