bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 395: Evaluation of Antibody Responses in Mice Toward Apolipoprotein A-I
Authors: Kline Robert H , Henson David , Venditto Vincent J
Published: July 2021

Antibodies targeting apolipoprotein A-I (ApoA-I) have been documented in patients suffering from chronic inflammation associated with obesity, autoimmunity and cardiovascular disease (CVD). Anti-ApoA-I antibodies are thought to be serum markers for CVD and not responsible for disease progression, but their exact role is poorly understood. We hypothesize that the antibody response to ApoA-I is highly nuanced with both protective and pathologic antibodies targeting modified or unmodified epitopes. We sought to induce ApoA-I specific autoantibodies in mice targeting specific modified and unmodified epitopes to study their nuanced role in disease progression. To achieve this goal we immunized mice with an immunogenic liposomal formulation containing modified or unmodified peptides derived from ApoA-I. The epitope-specific antibody response toward each epitope and the full length protein were quantified by ELISA. Mice immunized with formulations containing peptide were compared to control mice receiving either peptide or adjuvant alone. Furthermore, antibody responses toward ApoA-I from mice fed normal chow were compared to mice fed a western diet. Our vaccine strategy induced a robust immune response toward the peptide epitopes along with the full length protein. The oxidized peptide also appeared to be more immunogenic than the unmodified, but the mechanism of this observation is unclear. Antibody responses toward ApoA-I were observed after immunization with adjuvant alone suggesting that acute inflammation induces a response to ApoA-I. Studies are currently underway to evaluate the affinity of the anti-ApoA-I antibodies for HDL along with their role in cholesterol efflux and atherosclerosis progression. Correlating these findings with studies in human patients will generate insight into the nuanced antibody responses toward ApoA-I in CVD.
Abstract 400: Statin and Ezetimibe Differently Affect Spontaneous Atherothrombotic Occlusion in a Rabbit Model of Plaque Erosion
Authors: Matoba Tetsuya , Honda Katsuya , Koga Jun-ichiro , Nakano Kaku , Tsutsui Hiroyuki , Egashira Kensuke
Published: July 2021

Background:
Atherothrombosis of a coronary artery with plaque erosion is a major cause of acute coronary syndrome; however, its pathological mechanism and the effects of lipid-lowering therapy are unknown. We have recently reported the CuVIC Trial showing that ezetimibe added to statins improves coronary endothelial function associated with reductions in serum oxysterols in patients after coronary stenting (Takase, et al. ATVB 2017, in press).

Methods and Results:
We performed balloon injury in iliofemoral arteries in male Japanese white rabbits fed with high cholesterol diet and infused with angiotensin II. We examined the occurrence of atherothrombosis by echography 3 times/week, which were subsequently confirmed by angiography. Histochemical analysis revealed the lack of PECAM1-positive endothelial layer in the atherothrombotic sites. In treatment protocol, animals were divided into 3 groups; 1. Control, 2. Ezetimibe 0.6 mg/kg/day, and 3. Rosuvastatin 1.0 mg/kg/day, resulting total cholesterol 2514+/-179, 1716+/-111, and 1403+/-174, respectively after 8 weeks. Oral treatment with Ezetimibe significantly reduced atherothrombotic occlusion. Although there was no difference in the extent of arterial stenosis among 3 groups, treatment with ezetimibe was associated with better re-endothelialization and less tissue factor (TF)-positive areas in the intima. Serum oxysterols including 7-ketocholesterol (7KC) were lower in the Ezetimibe group. Serum from the model rabbits or 7KC induced TF in cultured SMCs. TF induction by the serum from the Ezetimibe group was significantly less compared with other groups.

Conclusions:
We established a valid animal model of spontaneous atherothromobotic occlusion in rabbits, which mimicked plaque erosion observed in human coronary arteries. Reduction in serum oxysterols with ezetimibe may prevent atherothrombosis from plaque erosion, by accelerating re-endothelialization and inhibiting TF expression in injured arteries.
Abstract 41: Transcriptional Networks Specifying Homeostatic and Pro-Inflammatory Programs of Gene Expression in Human Aortic Endothelial Cells
Authors: Romanoski Casey E , Hogan Nicholas T , Whalen Michael , Stolze Lindsey K , Lam Michael T , Springstead James R , Glass Christopher K
Published: July 2021

Endothelial cells are critical determinants of vascular homeostasis and inflammation, but transcriptional mechanisms specifying their identities and functional states remain poorly understood. Here, we report a genome-wide assessment of regulatory landscapes in primary human aortic endothelial cells (HAECs) under basal and activated conditions, enabling inference of transcription factor networks that direct homeostatic and pro-inflammatory programs of gene expression. We provide evidence that AP1, ETS, and GATA transcription factors play key roles in establishing HAEC identity by co-binding at many enhancers associated with EC-specific genes. We further demonstrate that exposure of HAECs to oxidized phospholipids or pro-inflammatory cytokines results in signal-specific alterations in enhancer landscapes that are associated with coordinated binding of CEBPD, IRF1 and NFkB. Collectively, these findings identify cis-regulatory elements and corresponding trans-acting factors that contribute to endothelial cell identity and their specific responses to pro-inflammatory stimuli.
Abstract 42: Control of Macrophage Cholesterol Efflux and Atherogenesis by the Noncoding RNA MeXis
Authors: Sallam Tamer , Jones Marius , Thomas Brandon J , Wu Xiaohui , Gilliland Thomas , Qian Kevin , Sandhu Jaspreet , Salisbury David , Casero David , Hong Cynthia , Ito Ayaka , Castrillo Antonio , Smale Stephen , Tontonoz Peter
Published: July 2021

The ligand-dependent nuclear receptor LXR regulates the expression of genes involved in responses to excess cholesterol including Abca1. Macrophage-specific cholesterol efflux driven by Abca1 has been causally linked to the prevention and reversal of heart disease, but therapeutic strategies for targeting efflux pathways in macrophages have been elusive. Here, we define a novel regulatory axis controlling macrophage responses to cholesterol overload. We identify the lncRNA MeXis as an amplifier of LXR-dependent Abca1 gene transcription in macrophages. MeXis interacts with and guides the promoter binding of nuclear receptor transcriptional coactivators. Loss of MeXis in murine immune cells has a marked impact on chromosome architecture at the Abca1 locus, impairs cellular responses to cholesterol overload, and accelerates the development of atherosclerosis. Our findings identify MeXis as a transcriptional gatekeeper that modifies the actions of LXR in lipid-dependent control of macrophage gene expression. It is conceivable that therapeutic approaches that enhance MeXis activity might augment reverse cholesterol transport and reduce foam cell formation.
Abstract 425: Is Adventitial Thickening a Pathogenic Factor in Aortic Atherosclerosis?: A Controlled Transesophageal Echocardiographic Study
Authors: Roldan Luis P , Roldan Paola C , Gibbs Brennan N , Snider Richard , Ratliff Michelle D , Qualls Clifford R , Roldan Carlos A
Published: July 2021

Background:
Aortic (Ao) atherosclerosis is common in systemic lupus erythematosus (SLE), is best assessed by transesophageal echocardiography (TEE), and is characterized by increased intima-media thickness (IMT) and plaques. Although TEE may also allow characterization of Ao adventitial thickness (AT), there is limited data on the pathogenic role of adventitial thickening in Ao atherosclerosis.

Methods:
68 SLE patients (62 women, age 36 ± 12 years) and 25 age-and-gender matched healthy controls (22 women, age 34 ± 11 years) underwent multiplane TEE. At a depth of 3-4 cm using narrow sector scan, 2-dimensional guided M-mode images were obtained to assess the presence of plaques, IMT outside of plaques, AT outside of plaques, and AT in plaques at three different levels of the thoracic Ao (proximal, mid, distal). At each aortic level, 3 IMT and 3 AT measurements were taken during end diastole using electronic calipers. These measurements were then averaged. Unaware of subjects’ clinical data, one observer assessed for IMT and plaques while a second observer assessed AT. For purpose of analysis, intima-media thickening was defined as >1 mm which is >2SD above the corresponding overall mean IMT in controls (0.66 ± 0.17 mm), and adventitial thickening as >1.07 mm which is >2SD above the corresponding overall mean AT in controls (0.81 ± 0.13 mm). Plaques were defined as focal-protruding IMT >50% of the surrounding vessel wall at any aortic level.

Results:
As shown in
Table 1A,
intima-media thickening and plaques were greater in patients than in controls. Similarly, adventitial thickening was more common in patients than in controls. In addition, AT was greater in patients with intima media thickening, plaques, and intima-media thickening or plaques (
Table 1B)
. Furthermore, AT was greater in plaques than AT outside of plaques (
Table 1C
).

Conclusion:
Adventitial thickening is a pathogenic factor of Ao atherosclerosis in SLE.
Abstract 426: Overexpression of Tissue-nonspecific Alkaline Phosphatase (TNAP) Accelerates Coronary Artery Disease in the Setting of Hypercholesterolemia in Mice
Authors: Romanelli Filippo , Corbo AnthonyMarco , Salehi Maryam , Yadav Manisha C , Salman Soha , Petrosian David , Rashidbaigi Omid J , Plummer Maria , Radichev Ilian , Pinkerton Anthony B , Millán José Luis , Savinov Alexei Y , Savinova Olga V
Published: July 2021

Objective:
Vascular calcification in asymptomatic individuals is an independent predictor of coronary heart disease (CHD). It is therefore plausible that vascular calcification plays a direct pathophysiological role in atherosclerosis, an underlying cause of CHD. The purpose of this study was to examine the contribution that vascular calcification has on the development of coronary atherosclerosis in a mouse model of familial hypercholesterolemia.

Approach and Results:
Calcification was induced by overexpression of tissue-nonspecific alkaline phosphatase (TNAP) in endothelial cells of mice harboring a point mutation in the low density lipoprotein receptor (
ldlr,
wicked high cholesterol, WHC). Mice were fed an atherogenic diet; echocardiographic and biochemical data were collected longitudinally. Atherosclerosis and vascular calcification were analyzed histologically in the aorta, aortic sinus and coronary arteries. TNAP mice were also treated with a combination of an atherogenic diet and a specific inhibitor of TNAP (SBI-425). Combined with the
ldlr
mutation and an atherogenic diet, TNAP-driven arterial calcification led to severe atherosclerosis with 100% morbidity characterized by occlusive coronary artery disease, pathological cardiac hypertrophy with dilated LV and reduced ejection fraction (EF). We detected an interaction between vascular calcification and atherosclerosis in mice with endothelial TNAP overexpression. This interaction was particularly prominent in coronary circulation. Targeting TNAP activity therapeutically helped improve survival and heart function of endothelial TNAP overexpressor mice, however the incomplete inhibition of TNAP by SBI-425 was a limitation of this study.

Conclusions:
Vascular calcification
via
TNAP overexpression in endothelial cells promotes coronary atherosclerosis and is pathogenic under conditions of hypercholesterolemia.
Abstract 430: Myeloid RANK Deletion Accelerate the Development of Atherosclerosis in ApoE Deficient Mice with Chronic Kidney Disease
Authors: Scatena Marta , Driscoll Will , Wigzell Luz , Striegel Heather , Rosenfeld Michael E
Published: July 2021

Objective:
Chronic kidney disease (CKD) greatly increases the risk of cardiovascular disease morbidity and mortality. Mounting data has identified the receptor activator of NF-κB (RANK) pathway as an important mediator of the accelerated atherosclerosis and vascular calcification observed in CKD. Here we investigated the role of myeloid RANK in a model of CKD accelerated atherosclerosis and vascular calcification in apolipoprotein E-deficient mice (apoE
-/-
).

Methods and Results:
We used the Lys M promoter to conditionally delete granulocyte and monocyte RANK in atherogenic apoE
-/-
mice. To induce CKD

RANK
(flox/flox)
LysM
(cre/+)
Apoe
(-/-)

(apoE
ΔRANK
) and

LysM
(cre/+)
Apoe
(-/-)

(apoE
CTL
) underwent a two-step surgical procedure to achieve 5/6
th
nephrectomy. Additional control animals underwent sham surgeries. Blood urea nitrogen (BUN) levels were elevated approximately two-fold in the CKD mice relative to sham-operated mice regardless of genotype. CKD was accompanied by a trend toward lower body weight, as well as slightly elevated circulating phosphate levels at the time of sacrifice. CKD induced a 47% elevation of plasma cholesterol levels in the apoE
ΔRANK
and apoE
CTL
mice, with no significant difference in cholesterol levels between the apoE
ΔRANK
and apoE
CTL
CKD mice. Interestingly, CKD resulted in elevated triglycerides in apoE
ΔRANK
mice, but not in apoE
CTL
mice. CKD mice age 22 and 34 weeks had larger average lesional cross-section areas in the root of the aorta as compared to sham operated mice (p<0.001 and p=0.03). Most importantly, the aortic root lesions in CKD apoE
ΔRANK
mice were significantly larger than those from apoE
CTL
CKD mice. In all genotypes and disease conditions we observed very little vascular calcification.

Conclusions:
These results suggest an atheroprotective role for myeloid RANK signaling in CDK-dependent lesion acceleration.
Abstract 44: Failure of Protective Autoimmunity in Mouse and Human Atherosclerosis
Authors: Wolf Dennis , Gerhardt Teresa , Anto Michel Nathaly , Hansen Bjarke , Sette Alessandro , Zirlik Andreas , Jenkins Marc K , Ley Klaus
Published: July 2021

Background:
In atherosclerosis, CD4
+
T helper cells recognize auto-antigens including ApoB, the main protein in low-density lipoprotein (LDL). However, atherosclerosis-specific, auto-reactive CD4
+
T cells have not been detected
in vivo
, and their function is unknown.

Methods and Results:
We have previously identified peptides derived from mouse ApoB that bind with high affinity to the MHC class II molecule of C57BL/6 mice (I-A
b
). We designed and validated a new multimer of a recombinant MHC-II molecule fused to one ApoB auto-epitopes, P6 (TGAYSNASSTESASY, P6:I-A
b
), that enabled detection of low-affinity, P6-reactive CD4
+
T cells. Using this P6:I-A
b
multimer, we identified ApoB-reactive CD4
+
T cells in healthy, young C57BL/6 mice that were predominately differentiated T-regulatory cells (T
regs
) and expressed IL-10, a known atheroprotective cytokine. This population was detectable in lymph nodes and already showed a memory phenotype in young animals without atherosclerosis. In
Apoe
-/-
mice, adoptively transferred ApoB P6-specific T
regs
accumulated in the aorta and draining lymph nodes and gave rise to pathogenic T
H
1 and T
H
17 cells. This phenotypic switch was caused by enhanced plasticity of antigen-specific T
regs
as evidenced by multiple clusters of intermediate T
reg
-T
eff
phenotypes in single cell RNA sequencing of 4485 antigen-specific CD4
+
T cells. In the plaque, many T cells were ex-T
regs
as identified by a FoxP3 lineage tracker mouse, suggesting that atherosclerosis-specific CD4
+
T cells lost their regulatory capacity. Vaccination with P6 maintained a protective phenotype in antigen-specific T
regs
and protected from atherosclerosis. In humans, ApoB-specific CD4
+
T cells from atherosclerotic patients showed the same cytokine patterns found in mouse CD4
+
T cells, suggesting that autoimmunity to ApoB is protective first, but later gives rise to a pathogenic CD4
+
T cell response that aggravates atherosclerosis.

Conclusion:
Protective T-regulatory cells recognizing peptide antigens of ApoB exist in naïve mice, protect against atherosclerosis, but convert into pathogenic T
H
1 and -17 cells during the natural course of disease in mice and humans. These results call for immunomodulatory therapies to maintain protective autoimmunity.
Abstract 447: Deep Transcriptomic Analysis of Human Vascular Cells Identifies Risk Genes for Common Vascular Diseases
Authors: Nurnberg Sylvia T , Park YoSon , Vaquero-Garcia Jordi , Pjanic Milos , Elwyn Susanna , Pluta John , Zhao Wei , Testa Stephanie , Barash Yoseph , Brown Christopher , Quertermous Thomas , Rader Daniel
Published: July 2021

The most recent Genome-wide Association Study (GWAS) meta-analysis has reported a total of 58 genomic loci to be statistically significantly associated with genetic susceptibility to Coronary Artery Disease (CAD) (Consortium, 2015). Many of these loci also associate with other phenotypes, with the majority being lipid traits (Tada et al., 2014). But also hypertension, stroke (Dichgans et al., 2014) and migraine (Pickrell et al., 2016) appear to share genetic determinants with CAD.

To functionally annotate the genomic loci harboring these association SNPs we sequenced the transcriptomes of 20 same donor human coronary artery endothelial (EC) and smooth muscle cell (SMC) lines. Deep RNA-Sequencing was used to assess Differential Gene Expression, Differential Splicing and Allele-Specific Expression. Focusing on GWAS loci for vascular phenotypes (CAD, stroke, migraine) we identified genes which display allele-specific differences in mRNA expression or splicing. We propose these genes as suitable targets for follow up studies.

Consortium, C.A.D. (2015). A comprehensive 1000 Genomes-based genome-wide association meta-analysis of coronary artery disease. Nature genetics 47, 1121-1130.

Tada, H., Won, H.H., Melander, O., Yang, J., Peloso, G.M., and Kathiresan, S. (2014). Multiple associated variants increase the heritability explained for plasma lipids and coronary artery disease. Circulation Cardiovascular genetics 7, 583-587.

Dichgans, M., Malik, R., Konig, I.R., Rosand, J., Clarke, R., Gretarsdottir, S., Thorleifsson, G., Mitchell, B.D., Assimes, T.L., Levi, C., et al. (2014). Shared genetic susceptibility to ischemic stroke and coronary artery disease: a genome-wide analysis of common variants. Stroke; a journal of cerebral circulation 45, 24-36.

Pickrell, J.K., Berisa, T., Liu, J.Z., Segurel, L., Tung, J.Y., and Hinds, D.A. (2016). Detection and interpretation of shared genetic influences on 42 human traits. Nature genetics 48, 709-717.
Abstract 450: Monocytic Glutaredoxin 1 Protects Mice Against Obesity, Hyperglycemia and Atherosclerosis
Authors: Downs Kevin , Tavakoli Sina , Short John D , Nguyen Huynh N , Asmis Reto
Published: July 2021

Overexpression of glutaredoxin 1 (Grx1) protects monocytes from metabolic stress-induced priming, i.e. dysregulation and hypersensitization to chemokines (Ullevig et al. ATVB 2012). To address the role of monocytic Grx1 in mice and in the development of atherogenesis and obesity, we transplanted bone marrow (BM) from either wild-type (WT) or Grx1
-/-
donor mice into atherosclerosis-prone LDLR
-/-
mice and fed these mice a high-fat diet (HFD) for up to 20 weeks. Grx1
Leuko
-/-
mice showed accelerated weight gain after 9 weeks followed by early onset of hyperglycemia. After 6 weeks on HFD, atherosclerotic lesions were slightly larger in Grx1
Leuko
-/-
mice than in WT mice, but the differences did not reach statistical significance. However, after 20 weeks, Grx1
Leuko
-/-
mice showed 36% larger lesions than WT-BM recipients, and monocyte chemotaxis
in vivo
was increased 1.6-fold. Furthermore, compared to WT-BM recipients, adipose tissues and livers of Grx1
Leuko
-/-
mice also showed increased macrophage content and elevated tissue inflammation as determined by IHC and qRT-PCR-based gene array. Adipose tissue in particular, showed significant increases in the expression of proinflammatory genes in addition to an increased abundance of proinflammatory “crown-like” structures. In contrast, genes associated with inflammation resolving macrophages were significantly suppressed. Macrophages isolated from Grx1
-/-
mice and stimulated with INFγ+TNFα also showed increased expression of pro-inflammatory M1-associated genes, whereas M2-associated genes were suppressed in Grx-1
-/-
macrophages activated with IL-4. Furthermore, macrophages from Grx1
-/-
mice exposed to metabolic stress also display increased protein
S
-glutathionylation, enhanced hypersensitization to chemokine, and impaired autophagy compared to macrophages from wild-type mice. Taken together, our data show that loss of monocytic Grx1 worsens monocyte priming in response to HFD-induced metabolic stress and accelerates the infiltration of dysfunctional monocyte-derived macrophages into tissues, such as aorta, liver and adipose tissues. We conclude that monocytic Grx1 is critical for maintaining metabolic homeostasis in mice and protects mice against obesity and atherogenesis.
Abstract 466: CX3CR1 Down Regulation Reduces Venous Neointimal Hyperplasia Formation in a Murine Hemodialysis Vascular Access Model
Authors: Yang Binxia , Kilari Sreenivaslisu , McCall Deborah L , Broadwater John , Kerr Steven , Pantages Lynn , Mcfarland Mary , Misra Sanjay
Published: July 2021

Introduction:
Venous neointimal hyperplasia (VNH) is a major cause of hemodialysis arteriovenous fistula (AVF) vascular access failure. CX3CR1 mediates macrophage infiltration into the vasculature. Mice were used which had been genetically engineered to knock in the human CX3CR1 gene.

Hypothesis:
The hypothesis to be tested is that increased CX3CR1 gene expression results in VNH formation associated with AVF.

Methods:
We used 50 CX3CR1 knock in mice which were divided into 2 groups: 1. CX3CR1 antibody (30 mg/kg administered intraperitoneally two times per week) or vehicle (equal amount of volume used for CX3CR1 antibody administered intraperitoneally). AVFs were created by connecting the carotid artery to ipsilateral jugular vein 28 days after nephrectomy was performed to induce chronic kidney disease. Histology and Immunohistochemistry analysis at the outflow vein of AVF were performed to assess the pathological changes.

Results:
There was a significant decrease in neointima area in the outflow veins of AVF in CX3CR1 antibody group compared to the vehicle group at day 28 (43085 ± 12678 vs. 58963.4 ± 9273 μm
2
, P<0.05). There was a significant decrease in the ratio of neointima/media+adventitia area in the outflow veins of AVF in CX3CR1 antibody group compared to the vehicle group at day 28 (0.34 ± 0.1 vs. 0.61 ± 0.1, P<0.05). Cell density in neointima area in CX3CR1 group outflow veins was significantly lower than the vehicle group at day 14 (9600 ± 1000 vs. 13000 ± 3000 /mm
2
, P<0.01). There was a significant decrease in the average CD68-positive cell density in the CX3CR1 group outflow veins compared to the vehicle group (0.96 ± 0.34 vs.15.9 ±10, P<0.001) at day 14.

Conclusion:
Decreasing CX3CR1 significantly reduces macrophages infiltration and results in a significant reduction in VNH. This study provides a rationale for using CX3CR1 antibody in reducing VNH formation.
Abstract 480: Aortic Microcalcification Associates With Aortic Elastin Fragmentation in Marfan Syndrome
Authors: Wanga Shaynah , Hibender Stijntje , Ridwan Yanto , van Roomen Cindy , Vos Mariska , van der Made Ingeborg , van Vliet Nicole , Franken Romy , Groenink Maarten , Zwinderman Aeilko H , Mulder Barbara J , de Vries Carlie J , Essers Jeroen , de Waard Vivian
Published: July 2021

Marfan syndrome (MFS) is a genetic connective tissue disorder, in which aortic rupture is the major cause of death. MFS patients with an aortic diameter below the advised limit for prophylactic surgery (<5cm) may unexpectedly experience an aortic dissection or rupture, despite yearly monitoring. Hence, there is a clear need for improved prognostic markers to predict such aortic events. We hypothesize that elastin fragments play a causal role in aortic calcification in MFS and that microcalcification serves as a novel marker for aortic disease severity. To address this hypothesis, we analyzed MFS patient and mouse aortas. MFS patient aortic tissue showed enhanced microcalcification in areas with extensive elastic lamina fragmentation in the media. A causal relationship between medial injury and microcalcification was revealed by studies in vascular smooth muscle cells (SMCs); elastin peptides were shown to increase the activity of the calcification marker alkaline phosphatase (ALP) and reduce the expression of the calcification inhibitor matrix gla protein (MGP) in human SMCs. In murine Fbn1
C1039G/+
MFS aortic SMCs, ALP mRNA and activity was upregulated when compared to wildtype SMCs. The elastin peptide-induced ALP activity was prevented by incubation with lactose as inhibitor of the elastin receptor complex, and a MEK1/2 kinase inhibitor, indicating downstream involvement of ERK1/2 phosphorylation. Histological analyses in MFS mice revealed macrocalcification in the aortic root, while the ascending aorta contained microcalcification, as identified with the near-infrared fluorescent bisphosphonate probe OsteoSense-800. Significantly, microcalcification correlated strongly with aortic diameter, aortic distensibility, elastin breaks and phosphorylated ERK1/2. In conclusion, microcalcification co-localizes with aortic elastin degradation in MFS aorta of man and mice, where elastin-derived peptides induce a calcification process in SMCs via the elastin receptor complex and ERK1/2 activation. We propose microcalcification as a novel imaging marker to monitor local elastin degradation and thus predict aortic events in MFS patients.
Abstract 487: Systemic Administration of Target-Seeking, Vessel Penetrating Recombinant Decorin Fusion Protein, Car-DCN, Reduces Severity of Abdominal Aortic Aneurysm in Mice
Authors: Shen Yue (Steve) , Russo Valerio , Zeglinski Matthew , Sellers Stephanie , Wu Zhengguo , Oram Cameron , Santacruz Stephanie , Merkulova Yulia , Turner Christopher , Tauh Keerit , Zhao Hongyan , Bozin Tatjana , Bohunek Lubos , Zeng Haishan , Seidman Michael , McManus Bruce , Bleackley R C , Ruoslahti Erkki , Järvinen Tero A , Granville David
Published: July 2021

Objective:
Decorin (DCN) is a small leucine-rich proteoglycan that mediates collagen fibrollogenesis, organization, and tensile strength. DCN is reduced in abdominal aortic aneurysm (AAA) through a Granzyme B-dependent mechanism resulting in vessel wall instability and aneurysm formation. A recombinant decorin fusion protein CAR-DCN was engineered with an extended C-terminus comprised of CAR homing peptide that recognizes inflammatory blood vessels and penetrates deep into the vessel wall. In the present study, we sought to evaluate the role of systemically administered CAR-DCN in AAA progression and rupture rate in a murine model.

Approach and Results:
To induce aneurysm, apolipoprotein E knockout (ApoE-KO) mice were infused with 28 days of angiotensin II (AngII). CAR-DCN or vehicle was systemically administrated until day 15. We observed a significant increase in the survival of CAR-DCN-treated mice (93%) compared to vehicle controls (60%). Although the incidence of AAA onset was similar between vehicle and CAR-DCN groups, the severity of aneurysm in the CAR-DCN group was significantly reduced. Furthermore, histological analysis revealed that CAR-DCN treatment significantly increased DCN and collagen levels in aortic walls compares to vehicle controls.

Conclusions:
CAR-DCN administration attenuated the severity of Ang II-induced AAA in mice by reinforcing the vessel wall. CAR-DCN may represent a novel therapeutic strategy to attenuate AAA progression and rupture.
Abstract 49: Adipose-Specific Knockout of
Trib1
Reduces Plasma Lipids and Diet-Induced Insulin Resistance, and Increases Circulating Adiponectin
Authors: Smith Mikhaila A , Cui Jian , Kheterpal Sumeet A , Rader Daniel J , Bauer Robert C
Published: July 2021

Tribbles-1 (TRIB1) was recently identified through genome-wide association studies as a novel mediator of plasma lipids and coronary artery disease in humans. While subsequent in vivo mouse work confirmed a role for hepatic TRIB1 in these associations, little is known about metabolic roles for extra-hepatic Trib1. Interestingly, SNPs near the
TRIB1
gene are significantly associated with circulating adiponectin levels in humans, suggesting a metabolic role for adipose
TRIB1
. To further investigate this, we generated adipose-specific
Trib1
KO mice (Trib1_ASKO) by crossing Trib1 cKO mice to transgenic Adiponectin-Cre mice. Chow-fed Trib1_ASKO mice exhibited no differences in adipose tissue mass and overall body mass as compared to control littermates (N=8/group). However, Trib1_ASKO mice had reduced total (-16.9%,
p
<0.01), HDL (-16.7%,
p
<0.01), and non-HDL cholesterol (-17.3%,
p
=0.068), as well as plasma triglycerides (-28.6%,
p
<0.001) as compared to WT mice. Trib1_ASKO mice also had increased plasma adiponectin levels, a finding more pronounced in female mice (+33.3%,
p
<0.001) than in males (+16.4%,
p
=0.072). Despite this increase, transcript levels of
adipoQ
were moderately decreased in Trib1_ASKO mice, suggesting a post-transcriptional mode of regulation. Transcript and protein levels of C/EBPα, the best described target of
Trib1
and a key regulator of adipogenesis, remained unchanged. To further investigate the metabolic consequences of adipose-specific KO of
Trib1
, WT and Trib1_ASKO mice were fed high-fat diet (HFD, 45% kCal fat) for 12 weeks to induce obesity. HFD-fed Trib1_ASKO mice had reduced fasting plasma glucose (-22.3%,
p
<0.05), insulin (-38.2%,
p
<0.05), and glucose tolerance (-19.8% AUC,
p
<0.05) compared to control mice. Body mass and fat mass of HFD-fed Trib1_ASKO mice remained unchanged from WT, and the reductions in plasma lipids and increase in plasma adiponectin persisted in the HFD-fed state. In summary, we present here the first in vivo validation of the human genetic association between
TRIB1
and plasma adiponectin, and provide evidence suggesting that adipose
TRIB1
contributes to the genetic associations observed in humans between
TRIB1
and multiple metabolic parameters.
Abstract 493: Correlation Between Cannabis Use and the Prevalence of Cerebrovascular Disease (Cva); Analysis From the National Inpatient Sample (NIS) 2012-2014
Authors: Alliu Samson E , Adejumo Adeyinka , Durojaiye Modupeolowa , Adegbala Oluwole , Ajayi Tokunbo , Onyeakusi Nnaemeka , Wolf Lawrence , Kamholz Stephan , Shani Jacob , Lichstein Edgar
Published: July 2021

Background:
With increasing legalization of cannabis, there is a growing number of cannabis users in the US. Cannabidiol - a component of cannabis with no psychoactive or cognitive effect has been proven in animal models to have vasodilatory and anti-inflammatory effect on the blood vessels. However, in clinical literature, the association between cerebrovascular accident (CVA) and cannabis remains inconclusive.

Objective:
To examine if there is a difference in the prevalence of CVA among patients who use cannabis and non-users.

Methods:
We identified patients > 18 years (N=12,114,360) from the 2012 -2014 National Inpatient Sample database. Using the ICD-9 code, we categorized patients using cannabis (non-dependent and dependent users) and non-users. Our outcome of interest was prevalence of CVA in this population. Logistic regression analysis was performed to assess the association between cannabis use and CVA. Using multivariate regression model, we adjusted for known confounders of CVA; age, gender, race, insurance type, socioeconomic status, tobacco use, cocaine use, alcohol abuse, amphetamine use, hyperlipidemia, diabetes, hypertension, renal failure, prior history of CVA and family history of CVA.

Results:
From our study sample (12,114,360 hospitalized patients), 2.1% (253,752) had a diagnosis of CVA, 1.48% (179,576) were non-dependent cannabis users and 0.21% (25,968) dependent users. Among hospitalized patient, non-dependent cannabis use was associated with an 8% increased odds of CVA (AOR 1.08 [1.03-1.13]) compared to non-users. However, dependent cannabis use was associated with a 60% decreased odds of CVA (AOR 0.40 [0.31-0.49]) compared to non-users. Also, In-group comparison shows a 60% decreased odds of CVA among dependent cannabis users (AOR 0.36[0.29-0.46]) compared to non-dependent cannabis users.

Conclusions:
Non-dependent cannabis use was associated with a slightly increased odd of CVA while dependent cannabis use was independently protective against CVA. Our study used the largest repository of clinical information to explore this association, however we recommend more clinical study to explore this correlation in other to maximize the pharmacological benefit of cannabidiol in cannabis for the prevention of CVA.
Abstract 5: The Contribution of Microbiome Alterations to Atherosclerotic Plaque Regression in Mice
Authors: Garshick Michael , Barrett Tessa , Zhou Felix , Blaser Martin , Fisher Edward
Published: July 2021

Objective:
The human microbiome represents an underexplored driver of atherosclerosis. Alterations to the intestinal microbiome are associated with, systemic inflammation and upregulation of M1 macrophages (Mϕ). Our study aims to determine if alterations to the intestinal microbiome by antibiotic treatment interferes with atherosclerotic plaque regression in mice.

Methods:
ApoE
-/-
mice were fed a western diet for 16 weeks to develop complex atherosclerosis in aortic arches. These arches were transplanted into the abdominal aorta of wild-type (WT) mice to model clinical aggressive lipid management and promote plaque regression. To assess the contribution of the microbiome to plaque regression, aortic arches were transplanted in WT mice (n=4), and WT mice pulsed with tylosin (antibiotic, n = 4) 3 days pre-transplant and the duration of the experiment (5 days). Arches were also transplanted into
ApoE
-/-
mice as a plaque progression control (n =4).

Results:
Antibiotic treatment of WT mice with tylosin compared to control WT mice did not change circulating total cholesterol (TC, 57 ± 21 mg/dl vs. 46 ± 24 mg/dl, p = 0.5), or HDL-C (42 ± 8 mg/dl vs. 34 ± 11 mg/dl, p = 0.32). No statistically significant difference in plaque size (117,801 ± 70,921 μm
2
vs. 133,286 ± 19,871 μm
2
vs. 132,976 ± 40,347 μm
2
, p = 0.88) or the absolute Mϕ content (44,672 ± 27,154 μm
2
vs. 32,546 ± 21,226 μm
2
vs. 54,154 ± 22,418 μm
2
, p = 0.47) was observed in WT mice which received tylosin, compared to control WT and
ApoE
-/-
mice, respectively. The composition of the plaques however did change: When compared to the control
ApoE
-/-
mice, WT recipient mice had a 26% reduction in the percent of the plaques occupied by Mϕ, while WT mice receiving tylosin had only a 4% reduction (p = 0.07). There was a 20% difference between the percent of plaque Mϕ content in the WT receiving tylosin, compared to WT controls (38% ± 4.3 vs. 30% ± 6.2, p = 0.07).

Conclusion:
Tylosin-treated WT mice undergoing regression had Mϕ enrichment in their plaques compared to WT controls. This study suggests that microbiome alterations can negatively influence plaque regression. Intestinal microbiome analysis and further studies are needed to confirm and extend this finding.
Abstract 500: Treatment of Arterial Embolization for Pulmonary Arteriovenous Malformations With and Without Osler Disease
Authors: Kawamura Yasutaka , Fukazawa Motoji , Hasegawa Shinya , Chiba Yukio
Published: July 2021

Purpose:
We report cases with pulmonary arteriovenous malformations (PAVM) treated with transcatheter arterial embolization. The clinical features of PAVM and the indication, techniques and longterm outcome of the embolization therapy were assessed.

Patients:
Six patients (age ranges from 44 to 67, five women and a man) had diagnosed as PAVM. Two patients diagnosed as definite HHT: Hereditary Hemorrhagic Telangiectasia (Rendu-Osler-Weber Syndrome) with epistaxis and family history and one as possible HHT associating hemorrhagic skin telangiectasias and abnormally enlarged the internal thoracic artery. Indication of the pulmonary arterial embolization therapy: Four patients had the episodes of cerebral infarction, one developed cerebellar ataxia, and another patient was proved the decreased PaO
2
. Two patients revealed the enlargement of PAVM. CT and 3-dimensional CT angiography (CTA) was obtained on 64-multi-detector row unit (Toshiba, Aquilion64, Japan) with bolus injection of contrast agent. The transcatheter pulmonary arterial embolization was performed with microcatheter system (TERUMO, Japan) and 0.035 coils of 6, 4, 3mm in diameter (Boston Scientific, USA).

Results:
After the selective catheterization for PAVM, all feeding arteries >3 mm in diameter was embolized. Since coil size selection was crucial for the safe and productive procedure, the size of feeding arteries had been carefully estimated on CTA date in advance. All patients were successfully treated without any problems during and after the procedure. One patient with HHT, three years after the treatment of 4.3cm PAVM, showed the recurrent PAVM of 0.5mm in diamete. The other patient showed a small vessel emerged distal to the embolized PAVM draining to the pulmonary vein. These lesions were too small to consider the clinical management and had been followed up with no change.

Conclusion:
The pulmonary arterial embolization therapy for PAVM was discussed. The treatments were successful, however, some recurrences were noted. We did not thoroughly embolized the distal side of PAVM because to minimize the normal lung damage and to avoid the migration of coils. Deliberate clinical follow-up should be required and should apply the additional treatment, if necessary.
Abstract 504: Regional Variations of Ischemic Stroke in The United States
Authors: Pati Prateeth , Khalif Adnan , Shanmugam Balaji
Published: July 2021

Geographic Distribution of Acute Ischemic Stroke admissions in the United States

Background:
The geographic distribution of acute ischemic stroke in the United States has not been evaluated, unlike the association shown with acute MI by Patel et al., (International Journal of Cardiology, 2014, 172.3). Our study looked at the geographic distribution and seasonal variation of acute ischemic stroke using the National Inpatient Sample (NIS) from 2011 - 2013.

Methods:
Adult admissions with a primary diagnosis of acute ischemic stroke were extracted from the NIS database using the ICD 9 code 434.91 from 2011 - 2013. Admission information included hospital region (West, South, Mid-Atlantic and Northwest) and seasonal admission rates (Winter=December-February, Spring=March-May, Summer=June-August, Fall=September-November). A Chi square analysis was used to analyze differences in categorical variables (we assumed a normal distribution of 25% per region).

Results:
A total of 120714 admissions were identified (weighted = 603361). There were more cases of acute ischemic stroke in the South (41.52 percent of admissions) compared to the mid Atlantic (21.4), Northwest (17.98) or West (19.08) with a p value < 0.0001. Each year between 2011 to 2013 showed a higher rate of admissions for acute ischemic stroke in the South. Taking the years into summation showed no statistically significant difference in seasonal variation in any of the regions.

Conclusion:
Our study shows a higher number of admissions for acute ischemic stroke in the South, but failed to show any seasonal differences. However, there are several studies that suggest a preponderance of admissions for acute myocardial infarction during the winter season, Spencer et al., (Journal of the American College of Cardiology, 1998, 31.2.) Further studies are needed to identify why there is a significant regional difference in the admission rates for acute ischemic stroke.
Abstract 517: Differential Redox Profiles Due to Endothelial Heterogeneity During Oxidative Stress
Authors: Shrestha Bandana , Pattillo Christopher B
Published: July 2021

Atherosclerosis, a chronic inflammatory disease characterized by plaque formation in vascular walls results in perfusion complications culminating in ischemia and induced angiogenesis. Interestingly, atherosclerosis is known largely to be an arterial disease with a preference in vascular beds, often affecting more arteries than veins. A significantly different pattern exists between the endothelial cells of these major blood vessels, highlighting the possibility of intrinsic differences between arterial and venous micro-environments including vascular endothelial cells themselves leading to variable responses during pathogenesis. Although isolated primary cells have been shown to lose some in-vivo characteristics under cell culture conditions, our data proves that these heterogeneous cell types retain the ability to differentially sense redox states. Oxidative stress is one of the key players associated with progression of atherosclerosis, marked by over-production of reactive oxygen species (ROS) and reduction in endogenous antioxidants such as glutathione (GSH). GSH, a major free radical scavenger prevents ROS damage by reducing ROS while being oxidized into glutathione disulfide (GSSG). GSSG is then recycled back to its reduced form under normal physiological conditions, hence maintaining an optimum GSH:GSSG ratio. This ratio is known to be deregulated during redox imbalance seen with oxidative stress during disease, due to decreasing GSH and increasing GSSG levels. Our experiments using Mouse Aorta Endothelial Cells (MAECs) and mouse Vena Cava Endothelial cells (VCECs) to represent arterial and venous endothelial cells display differences in this GSH:GSSG ratio as well, implicating differential redox states within these vessel types. Additionally, differences in oxidative stress related responses with regards to cell proliferation, migration, adhesion molecule expression and leukocyte recruitment in endothelial cells of arteries and veins further highlight the possibility of drastically different predispositions to atherosclerosis. Thus, endothelial cell heterogeneity between arteries and veins may lead to differential redox profiles and altered physiological functions during oxidative stress.
Abstract 522: Activated FXI Regulates the Catalytic Activity of Adamts13 by Removing the CUB Domains
Authors: Puy Cristina , Garland Kathleen S , Shirai Toshiaki , Reitsma Stephanie E. , Zilberman-Rudenko Jevgenia , Gruber András , McCarty Owen J
Published: July 2021

Background:
ADAMTS13 cleaves and inactivates von Willebrand factor (VWF), which binds collagen, facilitating platelet adhesion under vascular injury. But is still uncertain how ADAMTS13 activity is regulated. Thrombin and plasmin have been shown to cleave ADAMTS13. Based on the fact that elevated levels of FXI is an independent risk factor for deep vein thrombosis and ischemic stroke, we hypothesize that FXIa inactivates ADAMTS13 leading to platelet aggregation and thrombus formation.

Aim:
To determine the functional role of inactivation of ADAMTS13 by FXIa.

Methods and Results:
Recombinant ADAMTS13 (250 nM) was incubated with FXIa (50 nM) for increasing times (0-3 hours) at 37
o
C before being analyzed by western blot using an anti-ADAMTS13 antibody against the two CUB domains (C-terminal) or against the metalloproteinase (MET) domain (N-terminal). Our results show that FXIa caused the disappearance of the ADAMTS13 band (~200 kDa) and the appearance of a band at ~150 kDa when the samples were analyzed with the anti-MET antibody and a ~50 kDa band when the samples were analyzed with the anti-CUB antibody. The presence of aprotinin, which inhibits FXIa activity, blocked the degradation of ADAMTS13. Kallikrein or FXIIa were unable to cleave ADAMTS13. Using a cell surface immunoassay we observed that after incubation with FXIa, the detection of the CUB domain from ADAMTS13 was lost from endothelial cells surface. The incubation of ADAMTS13 with FXIa caused an increase in ADAMTS13 activity as measured by a fluorogenic substrate (FRETS).

Conclusion:
ADAMTS13 circulates in a closed conformation, which is maintained by a CUB-spacer domain binding interaction. ADAMTS13 becomes conformationally activated through interaction of its CUBs domains with VWF. Here we show that FXIa-mediated deletion of ADAMTS13-CUB domains enhances its capacity to cleave FRETS and blocks the interaction with VWF. Our results suggest that FXIa may limit ADAMTS13-mediated VWF inactivation.
Abstract 535: Gender Dictates the Relationship Between Clinical Markers of Lipid Metabolism and Immune Function
Authors: Andersen Catherine J , Vance Terrence M
Published: July 2021

Dyslipidemias and leukocytosis are associated with cardiovascular disease and immune disorders. Mechanistic studies have shown lipoprotein metabolism to play a significant role in the regulation of atherosclerosis development and leukocyte activation, whereas lipid-lowering treatments have been shown to exert beneficial anti-inflammatory and immunomodulatory effects in clinical trials. However, the relationship between clinical markers of lipid metabolism and immune function has not been extensively evaluated at the population level. Thus, we analyzed data from National Health and Nutrition Examination Surveys 1999-2004 to determine whether blood lipids could be used to predict clinical leukocyte counts, and whether there was a relationship between blood lipids, statin use, and prevalence of antinuclear antibodies (ANA) – the most common form of autoantibodies. After adjusting for age, serum cotinine, BMI, waist circumference, race/ethnicity, statin use, and survey cycle, we observed a strong positive linear trend between serum triglycerides vs. blood lymphocyte and basophil counts (cells/μL) in men and women (> 20 years old; n= 5,647), whereas a positive trend between monocytes vs. triglycerides and lymphocytes vs. total cholesterol and LDL-cholesterol was only detected in women. In multiple regression models, a 10% increase in total cholesterol, LDL-cholesterol, and triglycerides was associated with a predicted 1.6%, 0.6%, and 1.4% increase in blood lymphocyte counts in women, respectively, whereas no relationship was observed in men. In a population subsample (n = 1,526), we further found that women were more likely to be positive for ANA as compared to men (women: 17.4% vs. men: 11.7%); however, we did not observe significant associations between the odds of being ANA positive and serum levels of total cholesterol, LDL-cholesterol, or HDL-cholesterol in either men or women. Interestingly, we found that women who take statins have significantly lower odds of being ANA positive (OR 0.25; 95% CI 0.09-0.76), whereas no significant associations between statin use and ANA prevalence was observed in men. Together, these findings suggest blood lipids and statin usage may be better predictors of clinical markers of immune function in women.