Browsing by Subject "Atherosclerosis"
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Item Embargo Atherosclerotic Risk of Branched Chain Amino Acids in a Tissue Engineered Blood Vessel Model(2023) Jones, Ellery JensenThe purpose of this work is to determine if branched chain amino acids (BCAA) could have a causative role in the development of atherosclerosis. Atherosclerotic lesions occur in the vasculature and mediate the progression of cardiovascular disease (CVD). Advanced atherosclerotic lesions can lead to heart attacks or strokes. Conflicting evidence from previous studies has made it difficult to understand if BCAA help or hurt cardiovascular health, and it is not known if other pro-atherosclerotic factors cooperate with BCAA to accelerate atherosclerosis. While studies in human patients have shown that there is a correlation between BCAA levels in the blood and the development of diseases like metabolic syndrome and CVD, we cannot conclude that BCAA cause these diseases from association studies alone. Additionally, some studies in animals have shown that supplementation with BCAA supports cardiovascular health. Therefore, we need to determine if there is a mechanistic link between BCAA levels and atherosclerotic disease processes in human cells. This will also help us determine if BCAA could be a mechanistic link between metabolic syndrome and CVD.
In this work, we use a tissue engineered blood vessel (TEBV) model to determine the role of BCAA in the development of atherosclerosis. The TEBV model is an artificial blood vessel made of a collagen-based scaffold and populated with vascular cells, using similar tissue architecture and environmental stimuli of an artery in the human body. The TEBV system models the processes that occur in atherosclerosis, such as inflammation, loss of vasomotor tone, and interactions between white blood cells and vascular cells. Measuring these processes then allows us to predict what effect a novel risk factor, such as BCAA, would have on vascular health in the human body.
In chapter 2, we develop an “intermediate stage” lesion model in the TEBV system. Atherosclerotic lesions develop over many years, and since metabolic syndrome is often diagnosed in adults, many patients will have existing lesions. Therefore, it is important to expand upon existing models of early atherogenesis to include features that occur in later disease stages, such as remodeling of the vessel wall. We recapitulate the increase of a carbohydrate-based molecule called chondroitin sulfate (CS) that occurs in the atherosclerotic extracellular matrix in our TEBV model. While many studies have shown that CS enhances the development of atherosclerosis by affecting processes like lipid retention in the vessel wall and inflammation, there have not been many in vitro disease models that include the effects of CS-remodeling that occurs in the body In our work, we demonstrated that enriching the TEBV extracellular matrix with pathological levels of CS leads to an enhanced atherosclerotic response to treatment with modified low-density lipoprotein (LDL), including increased VCAM expression, a marker of inflammation in endothelial cells, and increased white blood cell adhesion to the vessel wall.
In chapter 3, we tested the effects of BCAA treatment on endothelial cell and TEBV health. We cultured cells and TEBVs in a low-BCAA medium that reflected the BCAA levels that occur in human serum. While a few other studies have looked at the effects of BCAA on human vascular cells, they did not use physiologically relevant levels of BCAA in their untreated controls, and used much higher levels of BCAA doses to test their effects. In our studies, we found that BCAA affect several key processes related to endothelial health, inducing oxidative stress in the mitochondria, inducing increased expression of redox-balancing enzymes, and slowing autophagy. This was consistent with results in TEBV experiments, where we saw that BCAA cooperate with another pro-atherosclerotic agent, oxidized LDL, to induce vasodilation dysfunction and increased white blood cell adhesion to the vessel wall.
In chapter 4, we evaluated the hypothesis that slowing BCAA catabolism is sufficient to induce buildup of BCAA in vascular cells, leading to an atherosclerotic phenotype. To slow BCAA catabolism, we used a dCas9-KRAB construct to repress the gene PPM1K. PPM1K plays a critical regulatory role in modulating BCAA levels in the cell by activating the rate-limiting enzyme in the BCAA metabolic pathway and stimulating BCAA breakdown. We found that repressing PPM1K effectively alters the active state of its target enzyme, BCKDH, and increases glutamine and serine levels in iPSC-derived endothelial cells. In TEBVs, we found that PPM1K repressed-endothelium induces a differential response to oxLDL treatment in causing vasodilation dysfunction, compared to the vehicle control. Thus, there may be a role for BCAA metabolism in enhancing an atherosclerotic phenotype induced by other pro-atherosclerotic factors.
In summary, we determined that BCAA can contribute to an atherosclerotic phenotype, specifically by affecting endothelial cell health. This conclusion is supported by our observations that BCAA affect several key molecular and functional markers of endothelial health, including mitochondrial oxidative stress, autophagy, vasodilation function, and white blood cell adhesion to the endothelium. Importantly, in TEBVs, the presence of other pro-inflammatory factors, such as oxLDL, enhanced these effects. Future research should aim to identify which of these processes may be a suitable target to interrupt the atherosclerotic risk of BCAA.
Item Open Access Beta-arrestins regulate atherosclerosis and neointimal hyperplasia by controlling smooth muscle cell proliferation and migration.(Circ Res, 2008-07-03) Kim, Jihee; Zhang, Lisheng; Peppel, Karsten; Wu, Jiao-Hui; Zidar, David A; Brian, Leigh; DeWire, Scott M; Exum, Sabrina T; Lefkowitz, Robert J; Freedman, Neil JAtherosclerosis and arterial injury-induced neointimal hyperplasia involve medial smooth muscle cell (SMC) proliferation and migration into the arterial intima. Because many 7-transmembrane and growth factor receptors promote atherosclerosis, we hypothesized that the multifunctional adaptor proteins beta-arrestin1 and -2 might regulate this pathological process. Deficiency of beta-arrestin2 in ldlr(-/-) mice reduced aortic atherosclerosis by 40% and decreased the prevalence of atheroma SMCs by 35%, suggesting that beta-arrestin2 promotes atherosclerosis through effects on SMCs. To test this potential atherogenic mechanism more specifically, we performed carotid endothelial denudation in congenic wild-type, beta-arrestin1(-/-), and beta-arrestin2(-/-) mice. Neointimal hyperplasia was enhanced in beta-arrestin1(-/-) mice, and diminished in beta-arrestin2(-/-) mice. Neointimal cells expressed SMC markers and did not derive from bone marrow progenitors, as demonstrated by bone marrow transplantation with green fluorescent protein-transgenic cells. Moreover, the reduction in neointimal hyperplasia seen in beta-arrestin2(-/-) mice was not altered by transplantation with either wild-type or beta-arrestin2(-/-) bone marrow cells. After carotid injury, medial SMC extracellular signal-regulated kinase activation and proliferation were increased in beta-arrestin1(-/-) and decreased in beta-arrestin2(-/-) mice. Concordantly, thymidine incorporation and extracellular signal-regulated kinase activation and migration evoked by 7-transmembrane receptors were greater than wild type in beta-arrestin1(-/-) SMCs and less in beta-arrestin2(-/-) SMCs. Proliferation was less than wild type in beta-arrestin2(-/-) SMCs but not in beta-arrestin2(-/-) endothelial cells. We conclude that beta-arrestin2 aggravates atherosclerosis through mechanisms involving SMC proliferation and migration and that these SMC activities are regulated reciprocally by beta-arrestin2 and beta-arrestin1. These findings identify inhibition of beta-arrestin2 as a novel therapeutic strategy for combating atherosclerosis and arterial restenosis after angioplasty.Item Open Access Carotid intima-media thickness progression and risk of vascular events in people with diabetes: results from the PROG-IMT collaboration.(Diabetes care, 2015-10) Lorenz, Matthias W; Price, Jackie F; Robertson, Christine; Bots, Michiel L; Polak, Joseph F; Poppert, Holger; Kavousi, Maryam; Dörr, Marcus; Stensland, Eva; Ducimetiere, Pierre; Ronkainen, Kimmo; Kiechl, Stefan; Sitzer, Matthias; Rundek, Tatjana; Lind, Lars; Liu, Jing; Bergström, Göran; Grigore, Liliana; Bokemark, Lena; Friera, Alfonsa; Yanez, David; Bickel, Horst; Ikram, M Arfan; Völzke, Henry; Johnsen, Stein Harald; Empana, Jean Philippe; Tuomainen, Tomi-Pekka; Willeit, Peter; Steinmetz, Helmuth; Desvarieux, Moise; Xie, Wuxiang; Schmidt, Caroline; Norata, Giuseppe D; Suarez, Carmen; Sander, Dirk; Hofman, Albert; Schminke, Ulf; Mathiesen, Ellisiv; Plichart, Matthieu; Kauhanen, Jussi; Willeit, Johann; Sacco, Ralph L; McLachlan, Stela; Zhao, Dong; Fagerberg, Björn; Catapano, Alberico L; Gabriel, Rafael; Franco, Oscar H; Bülbül, Alpaslan; Scheckenbach, Frank; Pflug, Anja; Gao, Lu; Thompson, Simon GObjective
Carotid intima-media thickness (CIMT) is a marker of subclinical organ damage and predicts cardiovascular disease (CVD) events in the general population. It has also been associated with vascular risk in people with diabetes. However, the association of CIMT change in repeated examinations with subsequent CVD events is uncertain, and its use as a surrogate end point in clinical trials is controversial. We aimed at determining the relation of CIMT change to CVD events in people with diabetes.Research design and methods
In a comprehensive meta-analysis of individual participant data, we collated data from 3,902 adults (age 33-92 years) with type 2 diabetes from 21 population-based cohorts. We calculated the hazard ratio (HR) per standard deviation (SD) difference in mean common carotid artery intima-media thickness (CCA-IMT) or in CCA-IMT progression, both calculated from two examinations on average 3.6 years apart, for each cohort, and combined the estimates with random-effects meta-analysis.Results
Average mean CCA-IMT ranged from 0.72 to 0.97 mm across cohorts in people with diabetes. The HR of CVD events was 1.22 (95% CI 1.12-1.33) per SD difference in mean CCA-IMT, after adjustment for age, sex, and cardiometabolic risk factors. Average mean CCA-IMT progression in people with diabetes ranged between -0.09 and 0.04 mm/year. The HR per SD difference in mean CCA-IMT progression was 0.99 (0.91-1.08).Conclusions
Despite reproducing the association between CIMT level and vascular risk in subjects with diabetes, we did not find an association between CIMT change and vascular risk. These results do not support the use of CIMT progression as a surrogate end point in clinical trials in people with diabetes.Item Open Access Clinician's guide to the updated ABCs of cardiovascular disease prevention.(Journal of the American Heart Association, 2014-09) Kohli, Payal; Whelton, Seamus P; Hsu, Steven; Yancy, Clyde W; Stone, Neil J; Chrispin, Jonathan; Gilotra, Nisha A; Houston, Brian; Ashen, M Dominique; Martin, Seth S; Joshi, Parag H; McEvoy, John W; Gluckman, Ty J; Michos, Erin D; Blaha, Michael J; Blumenthal, Roger STo facilitate the guideline-based implementation of treatment recommendations in the ambulatory setting and to encourage participation in the multiple preventive health efforts that exist, we have organized several recent guideline updates into a simple ABCDEF approach. We would remind clinicians that evidence-based medicine is meant to inform recommendations but that synthesis of patient-specific data and use of appropriate clinical judgment in each individual situation is ultimately preferred.Item Open Access G protein-coupled receptor kinase-5 attenuates atherosclerosis by regulating receptor tyrosine kinases and 7-transmembrane receptors.(Arteriosclerosis, thrombosis, and vascular biology, 2012-02) Wu, Jiao-Hui; Zhang, Lisheng; Fanaroff, Alexander C; Cai, Xinjiang; Sharma, Krishn C; Brian, Leigh; Exum, Sabrina T; Shenoy, Sudha K; Peppel, Karsten; Freedman, Neil JObjective
G protein-coupled receptor kinase-5 (GRK5) is a widely expressed Ser/Thr kinase that regulates several atherogenic receptors and may activate or inhibit nuclear factor-κB (NF-κB). This study sought to determine whether and by what mechanisms GRK5 affects atherosclerosis.Methods and results
Grk5(-/-)/Apoe(-/-) mice developed 50% greater aortic atherosclerosis than Apoe(-/-) mice and demonstrated greater proliferation of macrophages and smooth muscle cells (SMCs) in atherosclerotic lesions. In Apoe(-/-) mice, carotid interposition grafts from Grk5(-/-) mice demonstrated greater upregulation of cell adhesion molecules than grafts from wild-type mice and, subsequently, more atherosclerosis. By comparing Grk5(-/-) with wild-type cells, we found that GRK5 desensitized 2 key atherogenic receptor tyrosine kinases: the platelet-derived growth factor receptor-β in SMCs, by augmenting ubiquitination/degradation; and the colony-stimulating factor-1 receptor (CSF-1R) in macrophages, by reducing CSF-1-induced tyrosyl phosphorylation. GRK5 activity in monocytes also reduced migration promoted by the 7-transmembrane receptor for monocyte chemoattractant protein-1 CC chemokine receptor-2. Whereas GRK5 diminished NF-κB-dependent gene expression in SMCs and endothelial cells, it had no effect on NF-κB activity in macrophages.Conclusions
GRK5 attenuates atherosclerosis through multiple cell type-specific mechanisms, including reduction of SMC and endothelial cell NF-κB activity and desensitization of receptor-specific signaling through the monocyte CC chemokine receptor-2, macrophage CSF-1R, and the SMC platelet-derived growth factor receptor-β.Item Open Access Gene by stress genome-wide interaction analysis and path analysis identify EBF1 as a cardiovascular and metabolic risk gene.(European journal of human genetics : EJHG, 2015-06) Singh, Abanish; Babyak, Michael A; Nolan, Daniel K; Brummett, Beverly H; Jiang, Rong; Siegler, Ilene C; Kraus, William E; Shah, Svati H; Williams, Redford B; Hauser, Elizabeth RWe performed gene-environment interaction genome-wide association analysis (G × E GWAS) to identify SNPs whose effects on metabolic traits are modified by chronic psychosocial stress in the Multi-Ethnic Study of Atherosclerosis (MESA). In Whites, the G × E GWAS for hip circumference identified five SNPs within the Early B-cell Factor 1 (EBF1) gene, all of which were in strong linkage disequilibrium. The gene-by-stress interaction (SNP × STRESS) term P-values were genome-wide significant (Ps = 7.14E-09 to 2.33E-08, uncorrected; Ps = 1.99E-07 to 5.18E-07, corrected for genomic control). The SNP-only (without interaction) model P-values (Ps = 0.011-0.022) were not significant at the conventional genome-wide significance level. Further analysis of related phenotypes identified gene-by-stress interaction effects for waist circumference, body mass index (BMI), fasting glucose, type II diabetes status, and common carotid intimal-medial thickness (CCIMT), supporting a proposed model of gene-by-stress interaction that connects cardiovascular disease (CVD) risk factor endophenotypes such as central obesity and increased blood glucose or diabetes to CVD itself. Structural equation path analysis suggested that the path from chronic psychosocial stress to CCIMT via hip circumference and fasting glucose was larger (estimate = 0.26, P = 0.033, 95% CI = 0.02-0.49) in the EBF1 rs4704963 CT/CC genotypes group than the same path in the TT group (estimate = 0.004, P = 0.34, 95% CI = -0.004-0.012). We replicated the association of the EBF1 SNPs and hip circumference in the Framingham Offspring Cohort (gene-by-stress term P-values = 0.007-0.012) as well as identified similar path relationships. This observed and replicated interaction between psychosocial stress and variation in the EBF1 gene may provide a biological hypothesis for the complex relationship between psychosocial stress, central obesity, diabetes, and cardiovascular disease.Item Open Access Identifying Vulnerable Plaques with Acoustic Radiation Force Impulse Imaging(2014) Doherty, Joshua RyanThe rupture of arterial plaques is the most common cause of ischemic complications including stroke, the fourth leading cause of death and number one cause of long term disability in the United States. Unfortunately, because conventional diagnostic tools fail to identify plaques that confer the highest risk, often a disabling stroke and/or sudden death is the first sign of disease. A diagnostic method capable of characterizing plaque vulnerability would likely enhance the predictive ability and ultimately the treatment of stroke before the onset of clinical events.
This dissertation evaluates the hypothesis that Acoustic Radiation Force Impulse (ARFI) imaging can noninvasively identify lipid regions, that have been shown to increase a plaque's propensity to rupture, within carotid artery plaques in vivo. The work detailed herein describes development efforts and results from simulations and experiments that were performed to evaluate this hypothesis.
To first demonstrate feasibility and evaluate potential safety concerns, finite-element method simulations are used to model the response of carotid artery plaques to an acoustic radiation force excitation. Lipid pool visualization is shown to vary as a function of lipid pool geometry and stiffness. A comparison of the resulting Von Mises stresses indicates that stresses induced by an ARFI excitation are three orders of magnitude lower than those induced by blood pressure. This thesis also presents the development of a novel pulse inversion harmonic tracking method to reduce clutter-imposed errors in ultrasound-based tissue displacement estimates. This method is validated in phantoms and was found to reduce bias and jitter displacement errors for a marked improvement in image quality in vivo. Lastly, this dissertation presents results from a preliminary in vivo study that compares ARFI imaging derived plaque stiffness with spatially registered composition determined by a Magnetic Resonance Imaging (MRI) gold standard in human carotid artery plaques. It is shown in this capstone experiment that lipid filled regions in MRI correspond to areas of increased displacement in ARFI imaging while calcium and loose matrix components in MRI correspond to uniformly low displacements in ARFI imaging.
This dissertation provides evidence to support that ARFI imaging may provide important prognostic and diagnostic information regarding stroke risk via measurements of plaque stiffness. More generally, the results have important implications for all acoustic radiation force based imaging methods used clinically.
Item Open Access Inflammatory markers and extent and progression of early atherosclerosis: Meta-analysis of individual-participant-data from 20 prospective studies of the PROG-IMT collaboration.(European journal of preventive cardiology, 2016-01) Willeit, Peter; Thompson, Simon G; Agewall, Stefan; Bergström, Göran; Bickel, Horst; Catapano, Alberico L; Chien, Kuo-Liong; de Groot, Eric; Empana, Jean-Philippe; Etgen, Thorleif; Franco, Oscar H; Iglseder, Bernhard; Johnsen, Stein H; Kavousi, Maryam; Lind, Lars; Liu, Jing; Mathiesen, Ellisiv B; Norata, Giuseppe D; Olsen, Michael H; Papagianni, Aikaterini; Poppert, Holger; Price, Jackie F; Sacco, Ralph L; Yanez, David N; Zhao, Dong; Schminke, Ulf; Bülbül, Alpaslan; Polak, Joseph F; Sitzer, Matthias; Hofman, Albert; Grigore, Liliana; Dörr, Marcus; Su, Ta-Chen; Ducimetière, Pierre; Xie, Wuxiang; Ronkainen, Kimmo; Kiechl, Stefan; Rundek, Tatjana; Robertson, Christine; Fagerberg, Björn; Bokemark, Lena; Steinmetz, Helmuth; Ikram, M Arfan; Völzke, Henry; Lin, Hung-Ju; Plichart, Matthieu; Tuomainen, Tomi-Pekka; Desvarieux, Moise; McLachlan, Stela; Schmidt, Caroline; Kauhanen, Jussi; Willeit, Johann; Lorenz, Matthias W; Sander, Dirk; PROG-IMT study groupBackground
Large-scale epidemiological evidence on the role of inflammation in early atherosclerosis, assessed by carotid ultrasound, is lacking. We aimed to quantify cross-sectional and longitudinal associations of inflammatory markers with common-carotid-artery intima-media thickness (CCA-IMT) in the general population.Methods
Information on high-sensitivity C-reactive protein, fibrinogen, leucocyte count and CCA-IMT was available in 20 prospective cohort studies of the PROG-IMT collaboration involving 49,097 participants free of pre-existing cardiovascular disease. Estimates of associations were calculated within each study and then combined using random-effects meta-analyses.Results
Mean baseline CCA-IMT amounted to 0.74 mm (SD = 0.18) and mean CCA-IMT progression over a mean of 3.9 years to 0.011 mm/year (SD = 0.039). Cross-sectional analyses showed positive linear associations between inflammatory markers and baseline CCA-IMT. After adjustment for traditional cardiovascular risk factors, mean differences in baseline CCA-IMT per one-SD higher inflammatory marker were: 0.0082 mm for high-sensitivity C-reactive protein (p < 0.001); 0.0072 mm for fibrinogen (p < 0.001); and 0.0025 mm for leucocyte count (p = 0.033). 'Inflammatory load', defined as the number of elevated inflammatory markers (i.e. in upper two quintiles), showed a positive linear association with baseline CCA-IMT (p < 0.001). Longitudinal associations of baseline inflammatory markers and changes therein with CCA-IMT progression were null or at most weak. Participants with the highest 'inflammatory load' had a greater CCA-IMT progression (p = 0.015).Conclusion
Inflammation was independently associated with CCA-IMT cross-sectionally. The lack of clear associations with CCA-IMT progression may be explained by imprecision in its assessment within a limited time period. Our findings for 'inflammatory load' suggest important combined effects of the three inflammatory markers on early atherosclerosis.Item Open Access Infusion of Reconstituted High-Density Lipoprotein, CSL112, in Patients With Atherosclerosis: Safety and Pharmacokinetic Results From a Phase 2a Randomized Clinical Trial.(Journal of the American Heart Association, 2015-08-25) Tricoci, Pierluigi; D'Andrea, Denise M; Gurbel, Paul A; Yao, Zhenling; Cuchel, Marina; Winston, Brion; Schott, Robert; Weiss, Robert; Blazing, Michael A; Cannon, Louis; Bailey, Alison; Angiolillo, Dominick J; Gille, Andreas; Shear, Charles L; Wright, Samuel D; Alexander, John HBackground
CSL112 is a new formulation of human apolipoprotein A-I (apoA-I) being developed to reduce cardiovascular events following acute coronary syndrome. This phase 2a, randomized, double-blind, multicenter, dose-ranging trial represents the first clinical investigation to assess the safety and pharmacokinetics/pharmacodynamics of a CSL112 infusion among patients with stable atherosclerotic disease.Methods and results
Patients were randomized to single ascending doses of CSL112 (1.7, 3.4, or 6.8 g) or placebo, administered over a 2-hour period. Primary safety assessments consisted of alanine aminotransferase or aspartate aminotransferase elevations >3× upper limits of normal and study drug-related adverse events. Pharmacokinetic/pharmacodynamic assessments included apoA-I plasma concentration and measures of the ability of serum to promote cholesterol efflux from cells ex vivo. Of 45 patients randomized, 7, 12, and 14 received 1.7-, 3.4-, and 6.8-g CSL112, respectively, and 11 received placebo. There were no clinically significant elevations (>3× upper limit of normal) in alanine aminotransferase or aspartate aminotransferase. Adverse events were nonserious and mild and occurred in 5 (71%), 5 (41%), and 6 (43%) patients in the CSL112 1.7-, 3.4-, and 6.8-g groups, respectively, compared with 3 (27%) placebo patients. The imbalance in adverse events was attributable to vessel puncture/infusion-site bruising. CSL112 resulted in rapid (T(max)≈2 hours) and dose-dependent increases in apoA-I (145% increase in the 6.8-g group) and total cholesterol efflux (up to 3.1-fold higher than placebo) (P<0.001).Conclusions
CSL112 infusion was well tolerated in patients with stable atherosclerotic disease. CSL112 immediately raised apoA-I levels and caused a rapid and marked increase in the capacity of serum to efflux cholesterol. This potential novel approach for the treatment of atherosclerosis warrants further investigation.Clinical trial registration
URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01499420.Item Open Access Kruppel-like factor 15 is critical for vascular inflammation.(The Journal of clinical investigation, 2013-10) Lu, Yuan; Zhang, Lisheng; Liao, Xudong; Sangwung, Panjamaporn; Prosdocimo, Domenick A; Zhou, Guangjin; Votruba, Alexander R; Brian, Leigh; Han, Yuh Jung; Gao, Huiyun; Wang, Yunmei; Shimizu, Koichi; Weinert-Stein, Kaitlyn; Khrestian, Maria; Simon, Daniel I; Freedman, Neil J; Jain, Mukesh KActivation of cells intrinsic to the vessel wall is central to the initiation and progression of vascular inflammation. As the dominant cellular constituent of the vessel wall, vascular smooth muscle cells (VSMCs) and their functions are critical determinants of vascular disease. While factors that regulate VSMC proliferation and migration have been identified, the endogenous regulators of VSMC proinflammatory activation remain incompletely defined. The Kruppel-like family of transcription factors (KLFs) are important regulators of inflammation. In this study, we identified Kruppel-like factor 15 (KLF15) as an essential regulator of VSMC proinflammatory activation. KLF15 levels were markedly reduced in human atherosclerotic tissues. Mice with systemic and smooth muscle-specific deficiency of KLF15 exhibited an aggressive inflammatory vasculopathy in two distinct models of vascular disease: orthotopic carotid artery transplantation and diet-induced atherosclerosis. We demonstrated that KLF15 alters the acetylation status and activity of the proinflammatory factor NF-κB through direct interaction with the histone acetyltransferase p300. These studies identify a previously unrecognized KLF15-dependent pathway that regulates VSMC proinflammatory activation.Item Open Access Neuropeptide Y gene polymorphisms confer risk of early-onset atherosclerosis.(PLoS Genet, 2009-01) Shah, SH; Freedman, NJ; Zhang, L; Crosslin, DR; Stone, DH; Haynes, C; Johnson, J; Nelson, S; Wang, L; Connelly, JJ; Muehlbauer, M; Ginsburg, GS; Crossman, DC; Jones, CJ; Vance, J; Sketch, MH; Granger, CB; Newgard, CB; Gregory, SG; Goldschmidt Clermont, PJ; Kraus, WE; Hauser, ERNeuropeptide Y (NPY) is a strong candidate gene for coronary artery disease (CAD). We have previously identified genetic linkage to familial CAD in the genomic region of NPY. We performed follow-up genetic, biostatistical, and functional analysis of NPY in early-onset CAD. In familial CAD (GENECARD, N = 420 families), we found increased microsatellite linkage to chromosome 7p14 (OSA LOD = 4.2, p = 0.004) in 97 earliest age-of-onset families. Tagged NPY SNPs demonstrated linkage to CAD of a 6-SNP block (LOD = 1.58-2.72), family-based association of this block with CAD (p = 0.02), and stronger linkage to CAD in the earliest age-of-onset families. Association of this 6-SNP block with CAD was validated in: (a) 556 non-familial early-onset CAD cases and 256 controls (OR 1.46-1.65, p = 0.01-0.05), showing stronger association in youngest cases (OR 1.84-2.20, p = 0.0004-0.09); and (b) GENECARD probands versus non-familial controls (OR 1.79-2.06, p = 0.003-0.02). A promoter SNP (rs16147) within this 6-SNP block was associated with higher plasma NPY levels (p = 0.04). To assess a causal role of NPY in atherosclerosis, we applied the NPY1-receptor-antagonist BIBP-3226 adventitially to endothelium-denuded carotid arteries of apolipoprotein E-deficient mice; treatment reduced atherosclerotic neointimal area by 50% (p = 0.03). Thus, NPY variants associate with atherosclerosis in two independent datasets (with strong age-of-onset effects) and show allele-specific expression with NPY levels, while NPY receptor antagonism reduces atherosclerosis in mice. We conclude that NPY contributes to atherosclerosis pathogenesis.Item Open Access Nurse-Led Strategy to Improve Blood Pressure and Cholesterol Level Among People With HIV: A Randomized Clinical Trial.(JAMA network open, 2024-03) Longenecker, Christopher T; Jones, Kelley A; Hileman, Corrilynn O; Okeke, Nwora Lance; Gripshover, Barbara M; Aifah, Angela; Bloomfield, Gerald S; Muiruri, Charles; Smith, Valerie A; Vedanthan, Rajesh; Webel, Allison R; Bosworth, Hayden BImportance
Despite higher atherosclerotic cardiovascular disease (ASCVD) risk, people with HIV (PWH) experience unique barriers to ASCVD prevention, such as changing models of HIV primary care.Objective
To test whether a multicomponent nurse-led strategy would improve systolic blood pressure (SBP) and non-high-density lipoprotein (HDL) cholesterol level in a diverse population of PWH receiving antiretroviral therapy (ART).Design, setting, and participants
This randomized clinical trial enrolled PWH at 3 academic HIV clinics in the US from September 2019 to January 2022 and conducted follow-up for 12 months until January 2023. Included patients were 18 years or older and had a confirmed HIV diagnosis, an HIV-1 viral load less than 200 copies/mL, and both hypertension and hypercholesterolemia. Participants were stratified by trial site and randomized 1:1 to either the multicomponent EXTRA-CVD (A Nurse-Led Intervention to Extend the HIV Treatment Cascade for Cardiovascular Disease Prevention) intervention group or the control group. Primary analyses were conducted according to the intention-to-treat principle.Intervention
The EXTRA-CVD group received home BP monitoring guidance and BP and cholesterol management from a dedicated prevention nurse at 4 in-person visits (baseline and 4, 8, and 12 months) and frequent telephone check-ins up to every 2 weeks as needed. The control group received general prevention education sessions from the prevention nurse at each of the 4 in-person visits.Main outcomes and measures
Study-measured SBP was the primary outcome, and non-HDL cholesterol level was the secondary outcome. Measurements were taken over 12 months and assessed by linear mixed models. Prespecified moderators tested were sex at birth, baseline ASCVD risk, and trial site.Results
A total of 297 PWH were randomized to the EXTRA-CVD arm (n = 149) or control arm (n = 148). Participants had a median (IQR) age of 59.0 (53.0-65.0) years and included 234 males (78.8%). Baseline mean (SD) SBP was 135.0 (18.8) mm Hg and non-HDL cholesterol level was 139.9 (44.6) mg/dL. At 12 months, participants in the EXTRA-CVD arm had a clinically significant 4.2-mm Hg (95% CI, 0.3-8.2 mm Hg; P = .04) lower SBP and 16.9-mg/dL (95% CI, 8.6-25.2 mg/dL; P < .001) lower non-HDL cholesterol level compared with participants in the control arm. There was a clinically meaningful but not statistically significant difference in SBP effect in females compared with males (11.8-mm Hg greater difference at 4 months, 9.6 mm Hg at 8 months, and 5.9 mm Hg at 12 months; overall joint test P = .06).Conclusions and relevance
Results of this trial indicate that the EXTRA-CVD strategy effectively reduced BP and cholesterol level over 12 months and should inform future implementation of multifaceted ASCVD prevention programs for PWH.Trial registration
ClinicalTrials.gov Identifier: NCT03643705.Item Open Access Phosphorylation of USP20 on Ser334 by IRAK1 promotes IL-1β-evoked signaling in vascular smooth muscle cells and vascular inflammation.(The Journal of biological chemistry, 2023-07) Zhang, Lisheng; Wu, Jiao-Hui; Jean-Charles, Pierre-Yves; Murali, Pavitra; Zhang, Wenli; Jazic, Aeva; Kaur, Suneet; Nepliouev, Igor; Stiber, Jonathan A; Snow, Kamie; Freedman, Neil J; Shenoy, Sudha KReversible lysine-63 (K63) polyubiquitination regulates proinflammatory signaling in vascular smooth muscle cells (SMCs) and plays an integral role in atherosclerosis. Ubiquitin-specific peptidase 20 (USP20) reduces NFκB activation triggered by proinflammatory stimuli, and USP20 activity attenuates atherosclerosis in mice. The association of USP20 with its substrates triggers deubiquitinase activity; this association is regulated by phosphorylation of USP20 on Ser334 (mouse) or Ser333 (human). USP20 Ser333 phosphorylation was greater in SMCs of atherosclerotic segments of human arteries as compared with nonatherosclerotic segments. To determine whether USP20 Ser334 phosphorylation regulates proinflammatory signaling, we created USP20-S334A mice using CRISPR/Cas9-mediated gene editing. USP20-S334A mice developed ∼50% less neointimal hyperplasia than congenic WT mice after carotid endothelial denudation. WT carotid SMCs showed substantial phosphorylation of USP20 Ser334, and WT carotids demonstrated greater NFκB activation, VCAM-1 expression, and SMC proliferation than USP20-S334A carotids. Concordantly, USP20-S334A primary SMCs in vitro proliferated and migrated less than WT SMCs in response to IL-1β. An active site ubiquitin probe bound to USP20-S334A and USP20-WT equivalently, but USP20-S334A associated more avidly with TRAF6 than USP20-WT. IL-1β induced less K63-linked polyubiquitination of TRAF6 and less downstream NFκB activity in USP20-S334A than in WT SMCs. Using in vitro phosphorylation with purified IRAK1 and siRNA-mediated gene silencing of IRAK1 in SMCs, we identified IRAK1 as a novel kinase for IL-1β-induced USP20 Ser334 phosphorylation. Our findings reveal novel mechanisms regulating IL-1β-induced proinflammatory signaling: by phosphorylating USP20 Ser334, IRAK1 diminishes the association of USP20 with TRAF6 and thus augments NFκB activation, SMC inflammation, and neointimal hyperplasia.Item Open Access Rationale and design of a nurse-led intervention to extend the HIV treatment cascade for cardiovascular disease prevention trial (EXTRA-CVD).(American heart journal, 2019-10) Okeke, Nwora Lance; Webel, Allison R; Bosworth, Hayden B; Aifah, Angela; Bloomfield, Gerald S; Choi, Emily W; Gonzales, Sarah; Hale, Sarah; Hileman, Corrilynn O; Lopez-Kidwell, Virginie; Muiruri, Charles; Oakes, Megan; Schexnayder, Julie; Smith, Valerie; Vedanthan, Rajesh; Longenecker, Chris TPersons living with human immunodeficiency virus (PLHIV) are at increased risk of atherosclerotic cardiovascular disease (ASCVD). In spite of this, uptake of evidence-based clinical interventions for ASCVD risk reduction in the HIV clinic setting is sub-optimal. METHODS: EXTRA-CVD is a 12-month randomized clinical effectiveness trial that will assess the efficacy of a multi-component nurse-led intervention in reducing ASCVD risk among PLHIV. Three hundred high ASCVD risk PLHIV across three sites will be randomized 1:1 to usual care with generic prevention education or the study intervention. The study intervention will consist of four evidence-based components: (1) nurse-led care coordination, (2) nurse-managed medication protocols and adherence support (3) home BP monitoring, and (4) electronic health records support tools. The primary outcome will be change in systolic blood pressure and secondary outcome will be change in non-HDL cholesterol over the course of the intervention. Tertiary outcomes will include change in the proportion of participants in the following extended cascade categories: (1) appropriately diagnosed with hypertension and hyperlipidemia (2) appropriately managed; (3) at treatment goal (systolic blood pressure <130 mm Hg and non-HDL cholesterol < National Lipid Association targets). CONCLUSIONS: The EXTRA-CVD trial will provide evidence appraising the potential impact of nurse-led interventions in reducing ASCVD risk among PLHIV, an essential extension of the HIV care continuum beyond HIV viral suppression.Item Open Access Relationship between Smoking and Abdominal Aorta Calcification on Computed Tomography.(Korean journal of family medicine, 2019-07) Jung, Jin-Gyu; Wu, Li-Tzy; Kim, Jong-Sung; Kim, Eung-Du; Yoon, Seok-JoonBackground
Cigarette smoking increases the risk of atherosclerosis, which often develops as vascular calcification on radiologic examinations. This study evaluated the relationship between smoking-related factors and incidental abdominal aorta calcification (AAC) detected by computed tomography (CT) among middle-aged and elderly men.Methods
We assessed the abdominal CT findings of 218 men aged 40 to 81 years who underwent health checkups. The associations between smoking factors and AAC were analyzed using logistic regression analysis to adjust for confounding variables such as age, lifestyle factors, and chronic diseases.Results
Adjusting for confounding variables, the risk of AAC was significantly increased in association with smoking for at least 20 years (adjusted odds ratio [AOR], 5.22; 95% confidence interval [CI], 1.82-14.93), smoking 10+ pack-years (10-20 pack-years: AOR, 4.54; 95% CI, 1.07-5.68; >20 pack-years: AOR, 5.28; 95% CI, 2.10-13.31), and a history of smoking (former smoker: AOR, 2.10; 95% CI, 1.07-5.68; current smoker: AOR, 5.05; 95% CI, 2.08-12.26). In terms of the daily smoking amount, even a low smoking level increased the risk of AAC.Conclusion
These findings suggest that smoking for 20+ years, smoking 10+ pack-years, and even a low level of smoking daily increases the likelihood of developing AAC. Clinicians should recommend that patients quit smoking and stress the importance of smoking duration when promoting health in middle-aged and elderly patients.Item Open Access Targeting phosphorylation of eukaryotic initiation factor-2α to treat human disease.(Progress in molecular biology and translational science, 2012-01) Fullwood, Melissa J; Zhou, Wei; Shenolikar, ShirishThe unfolded protein response, also known as endoplasmic reticulum (ER) stress, has been implicated in numerous human diseases, including atherosclerosis, cancer, diabetes, and neurodegenerative disorders. Protein misfolding activates one or more of the three ER transmembrane sensors to initiate a complex network of signaling that transiently suppresses protein translation while also enhancing protein folding and proteasomal degradation of misfolded proteins to ensure full recovery from ER stress. Gene disruption studies in mice have provided critical insights into the role of specific signaling components and pathways in the differing responses of animal tissues to ER stress. These studies have emphasized an important contribution of translational repression to sustained insulin synthesis and β-cell viability in experimental models of type-2 diabetes. This has focused attention on the recently discovered small-molecule inhibitors of eIF2α phosphatases that prolong eIF2α phosphorylation to reduce cell death in several animal models of human disease. These compounds show significant cytoprotection in cellular and animal models of neurodegenerative disorders, highlighting a potential strategy for future development of drugs to treat human protein misfolding disorders.Item Open Access The Actin-Binding Protein Drebrin Inhibits Neointimal Hyperplasia.(Arteriosclerosis, thrombosis, and vascular biology, 2016-05) Stiber, Jonathan A; Wu, Jiao-Hui; Zhang, Lisheng; Nepliouev, Igor; Zhang, Zhu-Shan; Bryson, Victoria G; Brian, Leigh; Bentley, Rex C; Gordon-Weeks, Phillip R; Rosenberg, Paul B; Freedman, Neil JObjective
Vascular smooth muscle cell (SMC) migration is regulated by cytoskeletal remodeling as well as by certain transient receptor potential (TRP) channels, nonselective cation channels that modulate calcium influx. Proper function of multiple subfamily C TRP (TRPC) channels requires the scaffolding protein Homer 1, which associates with the actin-binding protein Drebrin. We found that SMC Drebrin expression is upregulated in atherosclerosis and in response to injury and investigated whether Drebrin inhibits SMC activation, either through regulation of TRP channel function via Homer or through a direct effect on the actin cytoskeleton.Approach and results
Wild-type (WT) and congenic Dbn(-/+) mice were subjected to wire-mediated carotid endothelial denudation. Subsequent neointimal hyperplasia was 2.4±0.3-fold greater in Dbn(-/+) than in WT mice. Levels of globular actin were equivalent in Dbn(-/+) and WT SMCs, but there was a 2.4±0.5-fold decrease in filamentous actin in Dbn(-/+) SMCs compared with WT. Filamentous actin was restored to WT levels in Dbn(-/+) SMCs by adenoviral-mediated rescue expression of Drebrin. Compared with WT SMCs, Dbn(-/+) SMCs exhibited increased TRP channel activity in response to platelet-derived growth factor, increased migration assessed in Boyden chambers, and increased proliferation. Enhanced TRP channel activity and migration in Dbn(-/+) SMCs were normalized to WT levels by rescue expression of not only WT Drebrin but also a mutant Drebrin isoform that binds actin but fails to bind Homer.Conclusions
Drebrin reduces SMC activation through its interaction with the actin cytoskeleton but independently of its interaction with Homer scaffolds.Item Open Access Tissue Engineered Blood Vessels to Study Endothelial Dysfunction in Hutchinson-Gilford Progeria Syndrome(2022) Abutaleb, Nadia OsamaHutchinson-Gilford Progeria Syndrome (HGPS) is a rare, fatal genetic disease that causes progressive atherosclerosis and accelerated aging in children resulting in fatality at an average of 14.6 years of age. With a limited pool of HGPS patients, clinical trials face unique challenges and require reliable preclinical testing. Preclinical studies to date have relied on 2D cell culture using HGPS fibroblasts which does not accurately model the 3D physiological microenvironment and limits the scope many studies to only the fibroblast response, which may not translate to a vascular benefit. Further, only two HGPS murine models develop atherosclerosis and these exhibit symptoms that are not present in HGPS patients. An ideal model would incorporate human cells in a microenvironment mimicking in vivo conditions and replicate key aspects HGPS vascular pathology. Such a model would contribute significantly to the ability to study HGPS mechanisms and test therapies. One significant area of research that requires further study is the contribution of endothelial cells to HGPS pathology. The endothelium plays a critical atheroprotective role in maintaining vascular homeostasis. When it is damaged, dysfunctional endothelium becomes inflammatory and proatherogenic, contributing significantly to atherosclerosis and cardiovascular disease. Progressive atherosclerosis is the most severe symptom of HGPS and is the common underlying cause of mortality in HGPS patients, yet only a few studies have investigated the HGPS endothelial phenotype. The goal of our work was to develop and characterize a tissue engineered model of HGPS vasculature that could be used to study endothelial dysfunction in HGPS and test therapies to alleviate HGPS vascular pathology.In Aim 1, we developed and characterized a tissue engineered blood vessel (TEBV) model of HGPS using vascular smooth muscle cells (viSMCs) and endothelial cells (viECs) differentiated from induced pluripotent stem cells (iPSCs) from two HGPS patients. HGPS viSMCs and viECs exhibited manifestations consistent with typical symptoms of HGPS including progerin expression, abnormal nuclear morphology, and premature senescence. HGPS viECs exhibited cell responses consistent with endothelial dysfunction including impaired tube formation, elevated reactive oxygen species (ROS) levels, reduced proliferation, and increased levels of DNA damage compared with healthy viECs. HGPS viECs also displayed a blunted response to shear stress including limited flow-sensitive gene expression and reduced nitric oxide production. TEBVs fabricated with HGPS cells exhibited reduced vasoactivity compared with healthy TEBVs and replicated HGPS vascular pathology including SMC loss, excess extracellular matrix (ECM) protein deposition, inflammation, and vascular calcification. In Aim 2, we tested the effects of HGPS therapeutics the farnesyltransferase inhibitor Lonafarnib and mTOR inhibitor Everolimus, currently in Phase I/II clinical trial, on endothelial dysfunction and HGPS TEBVs phenotype. Everolimus decreased reactive oxygen species levels, increased proliferation, and reduced DNA damage in HGPS vascular cells. Lonafarnib improved flow-sensitive gene expression of HGPS viECs exposed to physiological shear stress. Both Lonafarnib and Everolimus were able to restore nitric oxide production to healthy levels in HGPS viECs exposed to physiological shear stress. While Everolimus improved vasoconstriction, Lonafarnib increased vasodilation, ECM deposition, inflammation, and calcification in HGPS TEBVs. Combination treatment with Lonafarnib and Everolimus maintained the benefits of each monotherapy and also resulted in additional benefits such as improved endothelial marker expression and reduced apoptosis. The 3D TEBV model was critical to reveal the benefit of Lonafarnib and Everolimus combination treatment which was more limited in 2D studies but became clear in the TEBVs. In Aim 3, we tested a recently developed targeted gene therapy for HGPS known as adenine base editing (ABE). ABE corrects the genetic heterozygous point mutation that causes HGPS with high efficiency and minimal off-target effects. ABE ameliorated all the dysfunctional endothelial phenotypes that we tested in HGPS viECs including elevated ROS levels, reduced proliferation, and increased DNA damage. Most critically for endothelial function, ABE restored nitric oxide production and flow-sensitive gene expression to healthy levels in HGPS viECs. In TEBVs, ABE restored healthy levels of vasoconstriction and vasodilation, improved SMC retention, increased proliferation, and inhibited excess ECM protein expression. In summary, this work contributes data supporting the hypothesis that progerin induces endothelial dysfunction in HGPS endothelial cells which could contribute to the vascular pathology observed in HGPS. This work also tests current and novel therapies in the first 3D tissue engineered model of HGPS, validating the model as a valuable platform for preclinical testing that can supplement and improve information gathering from current 2D and animal models.