bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 382: Transgenic Overexpression of Dimethylarginine Dimethylaminohydrolase 1 Protects From Angiotensin II-induced Cardiac Hypertrophy
Authors: Rodionov Roman N , Brilloff Silke , Jarzebska Natalia , Kolouschek Anne , Martens-Lobenhoffer Jens , Bode-Böger Stefanie M , Weiss Norbert , Deussen Andreas , Kopaliani Irakli
Published: July 2021

Background:
ADMA (asymmetric dimethylarginine) is an endogenous inhibitor of nitric oxide synthase. ADMA can be metabolized to citrulline by dimethylarginine dimethylaminohydrolase (DDAH). DDAH1 overexpression lowers ADMA and protects from angiotensin II - induced renal interstitial fibrosis and vascular oxidative stress. The goal of the current study was to test the hypothesis that transgenic overexpression of DDAH1 protects from angiotensin II-induced cardiac hypertrophy.

Methods and Results:
DDAH1 transgenic mice grew and developed normally and had decreased plasma ADMA levels. Angiotensin II was infused for four weeks in the dose of 0.75 mg/kg/day in DDAH1 transgenic mice and wild type littermates via osmotic minipumps. Echocardiography was performed in the first and fourth week after start of the infusion on anaesthetized mice. After 4 weeks of angiotensin II infusion wild type mice developed cardiac hypertrophy. The DDAH1 transgenic mice had higher left ventricular lumen to wall ratio compared to the wild type mice (1.76 ± 0.18 vs 1.15 ± 0.22, P<0.01). They also had lower left ventricular posterior wall thickness in systole and diastole as compared to the wild type controls (1.18 ± 0.03 mm vs 1.95 ± 0.16 mm, P<0.001 and 0.81 ± 0.03 mm vs 1.62 ± 0.25 mm, P<0.001, respectively).

Conclusion:
We demonstrated that upregulation of DDAH1 protects from angiotensin II-induced cardiac hypertrophy. Our findings suggest that ADMA plays a role in angiotensin II - induced myocardial remodeling. Upregulation of DDAH1 might be a potential approach for protection from angiotensin II - induced end organ damage.
Abstract 390: The Absence of Abcg5 Abcg8 Reveals a Sexually Dimorphic Adaption to Impaired Biliary Cholesterol Secretion
Authors: Li Jianing , Ji Ailing , Temel Ryan E , van der Westhuyzen Deneys R , Graf Gregory A
Published: July 2021

Objective:
The ABCG5 ABCG8 (G5G8) sterol transporter is the primary mechanism for biliary cholesterol secretion, but mice maintain fecal sterol excretion in its absence. The mechanism by which mice maintain sterol excretion in the absence of this pathway is not known. Transintestinal cholesterol excretion (TICE) is an alternative pathway to hepatobiliary secretion. We investigated the impact of G5G8 deficiency on TICE in the absence of Sitosterolemia.

Methods and Results:
We compared both hepatobiliary and transintestinal cholesterol excretion rates in wild-type (WT) and G5G8 deficient mice of both sexes. WT and G5G8 were maintained on a plant-sterol free diet from the time of weaning to prevent the development of secondary phenotypes associated with Sitosterolemia. Biliary and intestinal cholesterol secretion rates were determined by biliary diversion with simultaneous perfusion of the proximal 10 cm of the small bowel. Among WT mice, biliary cholesterol secretion was greater in female mice compared to males. Conversely, male mice exhibited greater rates of TICE than females. As expected, WT mice had higher biliary cholesterol secretion rates than their G5G8 deficient littermates. However, the decline in biliary cholesterol secretion was far less in male mice compared to females in the absence of G5G8. In female mice, the absence of G5G8 resulted in a two-fold increase in TICE, whereas males were unaffected.

Conclusion:
Female mice are more dependent upon the biliary pathway for cholesterol excretion, whereas males are more dependent upon TICE. G5G8 independent pathways are present for both biliary and intestinal cholesterol secretion. Female and male mice differ in their adaptation to G5G8 deficiency in order to maintain fecal sterol excretion.
Abstract 402: Post-transcriptional Regulation of Bile Acid Metabolism by the RNA binding protein ZFP36L1
Authors: Tarling Elizabeth , Cheng Joan , Cheng Angela , Morand Pauline , Clifford Bethan , Sallam Tamer , Turner Martin , Vallim Thomas
Published: July 2021

Bile acids are detergents and important signaling molecules that activate the nuclear receptor FXR to control key metabolic processes, including feedback mechanisms to maintain bile acid homeostasis. Activation of FXR decreases the mRNA levels of several bile acid synthetic genes, including the rate-limiting enzyme
Cyp7a1
. Here we show that
Cyp7a1
mRNA levels are very rapidly reduced following FXR activation, indicative of a post-transcriptional mechanism. We identify the RNA binding protein
Zfp36l1
as an FXR target gene and show that hepatic overexpression of ZFP36L1 in mice decreases
Cyp7a1
mRNA levels. In contrast,

Zfp36l1
L

-KO
mice have increased levels of
Cyp7a1
mRNA and biliary bile acids as well as reduced plasma cholesterol levels.

Zfp36l1
L

-KO
mice fed a Western diet have reduced diet-induced obesity and steatosis, likely due to impaired lipid absorption, consistent with increased
Cyp7a1
levels. Thus, the ZFP36L1-dependent regulation of bile acid metabolism is an important metabolic contributor of dyslipidemia, obesity and hepatosteatosis.
Abstract 406: Flavocoxid a Dual Cox/Lox Inhibitor Reduces Atherosclerosis Development in ApoE KO Mice Fed With a Western High Fat Diet
Authors: Bitto Alessandra , Pizzino Gabriele , Pallio Giovanni , Mannino Federica , Irrera Natasha , Altavilla Domenica , Squadrito Francesco
Published: July 2021

Flavocoxid is composed by two flavonoids, baicalin and catechin and it exerts anti-inflammatory effect blocking the peroxidase activity of COX1/2 and 5-LOX. This balanced inhibition prevents the development of adverse effects as demonstrated in clinical trials. The antinflammatory effect of flavocoxid was tested in ApoE knock out mice fed with a high fat western diet. Mice (of both sex) were 5 weeks old at the beginning of the experiment and were fed with a high fat diet for 8 weeks. Mice were randomized to receive: vehicle, or simvastatin (40mg/kg/day by oral suspension), or flavocoxid by oral suspension at the human equivalent dose of 500 mg/day (20mg/kg/day) that was previously reported effective in other inflammatory conditions. The body weight, food intake, cholesterol, and triglyceride levels were recorded every week and at the time of sacrifice the thoracic aorta, liver, and blood samples were taken. Flavocoxid supplementation reduced blood levels of triglycerides and cholesterol and the extent of atherosclerotic plaques. In liver samples the mRNA expression of PPAR-alpha and SREBP-1 was significantly affected by flavocoxid supplementation (p less than 0.05 vs untreated ApoE mice), and the western blot analysis demonstrated an increased expression of the AMPK-alpha kinase demonstrating increased cellular metabolism in treated animals (p less than 0.05 vs untreated ApoE mice). The positive results obtained in this pre-clinical model further support the use of flavocoxid to reduce the atherosclerotic burden.
Abstract 414: Ath28 Congenic Mice Confirm Atherosclerosis Modifying Gene on the Distal End of Chromosome 2
Authors: Han Juying , Smith Jonathan D
Published: July 2021

Objective:
Strain intercrosses between apoE-deficient mice on the AKR (athero-resistant) and DBA/2 (athero-sensitive) strains identified the Ath28 quantitative trait locus (QTL) on the distal end of chromosome 2 (chr 2). We bred congenic mice on the DBA/2 background containing AKR alleles on chr 2 from 172.5 to 180 Mb in order to confirm the presence of atherosclerosis modifying genes in this region.

Methods and Results:
We used marker assisted backcrossing to generate DBA/2.AKR (chr 2) apoE-deficient congenic mice. High density genotyping using the MegaMuga array revealed that the AKR strain donated DNA on chr 2 from 171.5 Mb to the end of the chromosome, with the most distal marker tested at 180 Mb, while DBA/2 markers were found elsewhere in the genome. Mice heterozygote for the congenic interval were intercrossed to generate progeny homozygous for the AKR allele (AA) or the DBA/2 allele (DD). Female and male mice were fed a chow diet and sacrificed at 16 weeks of age. In the females, there was no effect on body weight; the total cholesterol levels trended 13% lower for the DD vs. AA mice (p=0.07); and, the HDL-C levels were 55% higher for the DD vs. AA mice (p=0.05). Despite having lower total cholesterol levels, the DD mice had 68% larger aortic root lesion areas (p=0.05, N=10 and 14 for AA and DD mice, respectively). In the males, the body weight was 12% higher in the DD vs. AA mice (p<0.01); the total cholesterol levels were similar in the DD and AA mice; and, the HDL-C levels were 73% higher for the DD vs. AA mice (p<0.05). The male DD mice had 27% larger aortic root lesion areas (NS), but we are adding more mice to this study to determine if this is significant (N=6 and 11 for AA and DD mice, respectively).

Conclusions:
Ath28 congenic mice confirm the presence of an atherosclerosis modifying gene on the distal end of chr 2 in chow-fed females. This interval in chr 2 contains over 100 genes. Our prior identification of missense variants between these strains, as well as transcriptomic and eQTL analyses have identified some candidate genes in this interval including
Cstf1, Ctcfl, Zbp1, Ankrd60, Gnas, Cdh4, Ctsz,
and
Rae1
. Further functional genomic studies and creating mice with smaller congenic intervals will be needed in order to narrow the list of candidate genes for in vivo testing.
Abstract 417: Trf2-Interacting Protein (Terf2ip) S205 Phosphorylation Mediates Atherosclerosis via Orchestrating Endothelial Senescence and Inflammation
Authors: Le Nhat Tu , Heo Kyung-Sun , Ko Kyung Ae , Tao Yunting , Thomas Tamlyn N , Quintana Quezada Raymundo A , Fujiwara Keigi , Abe Jun-ichi
Published: July 2021

Telomeric repeat-binding factor 2 (TRF2)-interacting protein (TERF2IP) S205 phosphorylation mediates atherosclerosis (AS) via orchestrating endothelial cell (EC) senescence (Sen) and inflammation. Nhat-Tu Le, Kyung-Sun Heo, Kyung Ae Ko, Yunting Tao,Tamlyn Thomas, Raymundo A Quintana Quezada, Keigi Fujiwara, and Jun-ichi Abe Department of Cardiology, UT MD Anderson Cancer Center

Objective:
Shortened telomere (TL) provokes EC Sen, which is associated with focalized EC inflammation and plaque formation in arteries exposed by disturbed blood flow (d-flow). Although d-flow is known to increase both EC inflammation and Sen, the exact mechanism by which d-flow induces these two different EC pathologies and subsequent AS is poorly understood.

Methods & Results:
TERF2IP, as a member of the sheltrin complex, is not only crucial for DNA double strand break repair at the TL, but also for activation of cytosolic IkB kinase (IKK) and subsequent NF-kB activity. TERF2IP and TRF2 form a stable heterodimer to protect the duplex region of TLs, while activating NF-kB, especially under the d-flow condition. We have discovered that inhibition of p90RSK reduces d-flow-induced EC Sen and inflammation via down-regulating TERF2IP S205 phosphorylation. The nuclear TERF2IP-TRF2 complex protects TLs by repairing DNA damages while the cytosolic complex plays a role in NF-kB activation. When we mutated the TERF2IP phosphorylation site (S205A) in ECs, the nuclear export of the TERF2IP-TRF2 complex was abolished, which inhibited d-flow-induced NF-kB activation and Sen. Both the depletion of TERF2IP by siRNA and S205A mutation inhibited d-flow-induced TERF2 nuclear export, and residual TRF2 at the TL inhibited d-flow-induced TL dysfunction. The mutation of TERF2IP S205A inhibited cytosolic IKK-NF-kB activation by eliminating the cytosolic TERF2IP-TERF2 complex. The inhibition of d-flow-induced inflammatory adhesion molecule expression and consequent AS were also confirmed in EC-specific TERF2IP knock out mice.

Conclusion:
These results suggest that S205 phosphorylation of TERF2IP induced by p90RSK activation is required for d-flow-induced TL shortening and NF-kB activation via regulating nuclear export of the TERF2IP-TERF2 complex.
Abstract 424: An IFNg-regulated Macrophage Protein Network Links Type 2 Diabetes to Atherosclerosis
Authors: Reardon Catherine A , Lingaraju Amulya , Schoenfelt Kelly Q , Zhou Guolin , Liu Ning-Chun , Babenko Ilona , Heinecke Jay , Vaiser Tomas , Hoofnagle Andrew , Becker Lev
Published: July 2021

Type 2 diabetics have a higher risk for atherosclerosis, but the mechanisms underlying the increased risk are poorly understood. Macrophages, which are activated in type 2 diabetes (T2D) and have a role in all stages of atherogenesis, are an attractive link. Our hypothesis is that T2D promotes macrophage dysfunction to promote atherosclerosis. To investigate the relationship between T2D and macrophage dysfunction, we used a proteomics approach to identify dysregulated proteins secreted from peritoneal macrophages in a diet induced mouse model of obesity and insulin resistance in the absence of hypercholesterolemia. Twenty-seven T2D responsive proteins were identified that predict defects in many of the critical functions of macrophages in atherosclerosis (e.g. decreased apoE- cholesterol efflux; decreased MFGE8 – efferocytosis, increased MMP12- matrix degradation). The macrophages from lean and obese mice were not lipid loaded, but the obese macrophages accumulated significantly more cholesterol when exposed to high levels of atherogenic lipoproteins in vitro suggesting that dysregulation of the T2D responsive proteins in diabetic mice render macrophages more susceptible to cholesterol loading. Importantly, many of these same protein changes, which were present in atherosclerotic
Ldlr-/-
mice with T2D, were normalized when these mice were fed non-diabetogenic hypercholesterolemic diets. Thus, foam cell formation in the presence and absence of T2D produces distinct effects on macrophage protein levels, and hence function. Further, we identify IFNγ as a mediator of the T2D responsive protein dysfunction. IFNγ, but not other cytokines, insulin or glucose, promote the T2D responsive protein dysregulation and increased susceptibility to cholesterol accumulation in vitro and the dysregulation is not observed in macrophage foam cells obtained from obese, diabetic IFNγ receptor 1 knockout animals. We also demonstrate that IFNγ can target these proteins in arterial wall macrophages
in vivo
. These studies suggest that IFNγ is an important mediator of macrophage dysfunction in T2D that may contribute to the enhanced cardiovascular risk in these patients.
Abstract 429: The Effects of Fluvastatin and Methyl-β-Cyclodextrin-Mediated Cholesterol Depletion on the Biomechanics of Vascular Smooth Muscle Cells in Atherosclerosis
Authors: Sanyour Hanna J , Hong Zhongkui
Published: July 2021

Atherosclerosis is a leading cause of death worldwide. Phenotypic shifting, alteration in cell adhesion, and migration toward inflammatory site of blood vessel wall are all critical contributions of vascular smooth muscle cells (VSMC) to the progression of atherosclerosis. Knowing that cholesterol is a main participant of fatty deposition in atherosclerotic lesions, cholesterol’s role in orchestrating cell migration, mechanics and spreading has grown more apparent. Growing evidences suggests that cholesterol loaded into VSMC in atherosclerosis is much larger than previously known, and about 40% of the total foam cells in the atherosclerotic plaque were VSMC-derived. Emerging studies have increasingly categorized cholesterol as major player in regulating VSMC stiffness and N-Cadherin mediated cell-cell adhesions. Modulating their activity or expression may block VSMC migration during the progression of atherosclerosis. In this study, the effects of a 3-hydroxy-3-methylglutaryl-coenzyme-A reductase inhibitor, fluvastatin and Methyl-β-Cyclodextrin-Mediated (MβCD) cholesterol depletion on VSMCs N-cadherin adhesion and cellular stiffness were addressed. VSMCs cholesterol quantification and lactate dehydrogenase assays demonstrated significant reduction in total cellular cholesterol content by approx. 67% for fluvastatin and 40% for MβCD. The atomic force microscope (AFM) was used to investigate real time adhesion and stiffness of living VSMCs. A proprietary software package written in Matlab was used to estimate Young’s modulus of the cell cortex. Cell adhesion was measured for 50-70% confluent cells with N-Cadherin coated stylus AFM probes on an AFM mounted on an inverted microscope. Our results suggested that fluvastatin and MβCD mediated cholesterol depletion increased N-cadherin mediated cell adhesion force by approx. 27% and 17% respectively. In addition, fluvastatin and MβCD respectively reduced VSMCs stiffness by approx. 24% and 29 % compared to control VSMCs. Altogether, the knowledge that we obtained in this project may lead to a novel therapeutic strategy that could potentially control and block VSMC migration and prevent atherosclerotic plaque formation by deciphering and regulating N-cadherin mediated adhesion
Abstract 454: Myeloid CD98hc Deficiency Reduces Atherosclerotic Plaque Development via Impaired Proliferation of Macrophages
Authors: McCurdy Sara , Boisvert William A
Published: July 2021

Macrophage accumulation is a key process affecting all stages of atherosclerosis. Whether these cells accumulate in plaque solely by recruitment of monocytes from circulation or by proliferation within the plaque is an important question that has garnered much interest in recent years. Originally identified as a lymphocyte activation marker, CD98hc (SLC3A2) is a transmembrane protein involved in cell proliferation and survival
via
integrin signaling and MAP kinase activation. We hypothesized that CD98hc deficiency in myeloid cells would have a protective effect on atherosclerosis development and plaque composition by limiting macrophage proliferation. For the studies described, we utilized mice with myeloid-specific deletion of the CD98hc (

CD98hc
fl/fl
LysMCre
+

) to determine the effects of CD98hc deficiency on macrophage function in the context of atherosclerosis
.
We performed
in vitro
assays to investigate the role of CD98hc in the proliferation and survival of primary mouse bone marrow derived macrophages. Although we found no differences in the number of bone marrow cells isolated from control or CD98hc
-/-
animals, after differentiation with MCS-F for 7 days, the number of macrophages obtained from CD98hc
-/-
mice was approximately 80% lower (7.2 ± 2.2 x 10
6
vs. 42.4 ± 4.6 x 10
6
per mouse) compared to control mice. Proliferation assays
in vitro
using EdU revealed approximately 50% (15.4 ± 2.5% vs. 7.5±1.8%) reduced cell proliferation in CD98hc
-/-
macrophages compared to control cells that could not be rescued with the addition M-CSF. In a 6-week atherosclerosis study using

Ldlr
-/-
CD98hc
fl/fl
LysMCre
+

mice, Oil-Red O staining of whole aortae as well as aortic sinus sections showed that atherosclerotic plaque development was reduced compared to

Ldlr
-/-
CD98hc
fl/fl
LysMCre
-

control mice. Additionally, immunohistochemical staining of atherosclerotic tissues revealed a reduction in macrophage abundance and proliferation within the plaque of

Ldlr
-/-
CD98hc
fl/fl
LysMCre
+

mice compared to control mice. These findings support an important role of CD98hc in macrophage proliferation within the plaque environment, and provide a novel target for reducing atherosclerosis.
Abstract 456: Rage Suppresses Angiogenesis and Blood Flow Recovery After Hind Limb Ischemia in Diabetic Mice Through Modulation of Macrophage Inflammation and Macrophage-endothelial Interactions
Authors: Lopez Diez Raquel , Li Qing , Li Huilin , Yan Shi Fang , Schmidt Ann Marie
Published: July 2021

Peripheral vascular disease is a condition characterized by atherosclerotic narrowed arteries distal to the aorta which triggers an acute or critical limb ischemia. Development of ischemic PVD has been considered one of the principal complications of diabetes, leading to amputation of digits and limbs. Advanced glycation end products (AGE) ligands and their receptor (RAGE) have been implicated in multiple key mechanisms underlying diabetes and diabetic complications, including hypoxia and ischemia/reperfusion injury. We tested the hypothesis that vascular recovery after hind limb ischemia would be rescued by deficiency of RAGE, at least in part through modulation of macrophage dysfunction. Wild type (WT) and
Ager
deficient mice were rendered diabetic with streptozotocin, and subjected to unilateral hind limb ischemia. Previous results showed an increased accumulation and expression of AGEs and RAGE in ischemic muscle, especially in diabetic WT mice. Attenuated angiogenesis and impaired blood flow recovery were also observed, in parallel with reduced early inflammatory macrophage infiltration into ischemic muscle in the WT diabetic mice. We performed flow cytometry to analyze circulating monocyte subsets: pro-inflammatory Ly6G/C
hi
and anti-inflammatory Ly6G/C
lo
. Work by others reported higher levels of monocytes in diabetes in the baseline state without injury; our data indicate that the increase is mostly attributed to the pro-inflammatory Ly6G/C
hi
population, being significantly lower in the
Ager
-/-
diabetic mice. After seven days of ischemia to the unilateral hind limb, lower levels of circulating pro-inflammatory Ly6G/C
hi
monocytes were found in both WT and
Ager
deficient diabetic mice. After four weeks of injury, the pro-inflammatory monocytes levels were significantly recovered to baseline levels in
Ager
-/-
mice, whereas WT mice failed to reacquire their baseline levels.
In vitro
studies using murine endothelial cells and murine macrophages revealed that RAGE suppressed macrophage-endothelial cell interaction, particularly in diabetes-relevant concentrations of D-glucose. These data suggest unique ischemia-dependent mechanisms in hind limb ischemia through RAGE down-regulation of the early adaptive immune response.
Abstract 459: O-Linked N-Acetylglucosamine Promotes Vascular Smooth Muscle Cell Dedifferentiation and Intimal Hyperplasia
Authors: Bauer Ashley J , Leslie Kristen L , Ostriker Allison C , Martin Kathleen A
Published: July 2021

Vascular smooth muscle cells (VSMCs) exhibit a unique phenotypic plasticity that underlies numerous cardiovascular pathologies. Platelet-derived growth factor (PDGF) promotes VSMC dedifferentiation characterized by proliferation and decreased contractile protein expression while the mTORC1 inhibitor and stent therapeutic rapamycin inhibits these effects. The enzyme O-linked N-Acetylglucosamine (O-GlcNAc) Transferase (OGT) adds O-GlcNAc modifications to serine or threonine in proteins and has been implicated in cardiovascular diseases. We hypothesized that OGT may regulate VSMC plasticity. We found that OGT and O-GlcNAc expression were associated with dedifferentiation, as both were decreased by rapamycin, but increased with PDGF treatment in human coronary artery SMCs. Knocking down OGT
in vitro
increased contractile marker expression at the mRNA and protein levels, including MYH11, CNN, TGLN, and ACTA2, while decreasing VSMC proliferation. Conversely, OGT overexpression inhibited expression of MHY11, CNN, and TGLN. Consistent with a role in dedifferentiation, immunostaining revealed that OGT and O-GlcNAc were increased following femoral artery endothelial denudation injury in C57BL/6 mice. Notably, smooth muscle-specific OGT knockout attenuated neointima formation relative to controls in a carotid artery ligation model of intimal hyperplasia. In conclusion, these findings indicate that PDGF and vascular injury increase OGT expression and O-GlcNAc modifications in SMCs in vitro and in vivo, leading to OGT-dependent transcriptional repression of contractile marker expression and promotion of intimal hyperplasia.
Abstract 461: A Novel Model of Spontaneous Arteriovenous Fistula Formation
Authors: Ito Yukinobu , Yoshida Makoto , Masuda Hirotake , Nanjo Hiroshi , Goto Akiteru
Published: July 2021

Aims:
Most In vivo angiogenesis studies have been performed by setting an ischemic condition, or by administrating angiogenic factors such as vascular endothelial growth factor. Unexpectedly, we discovered to spontaneously create new blood vessels by just suturing an arterial graft patch in the jugular vein, using a rabbit model. In general, arteriovenous malformations consist of tangles of arteries and veins that are often connected by a fistula. However, the causes and mechanisms of these clinical entities are not fully understood. The purpose of this study is to show the methods used to produce the model, and then to report the chronological processes involved in the development of this neovasculature and the change of endogenous angiogenic factors.

Methods and Results:
We performed to suture an arterial graft patch into the rabbit vein. Within a month after the surgery, dense (nidus-like) neovasculature was formed around the patch. Angiography and pulse-oximeter analyses demonstrated that the blood, which flew into the new vessels, was arterial blood. It means that arteriovenous shunt has been formed.. Pathological evaluation revealed multiple branching vessels sprouting out from the patch suture site, and numerous dilated vessels devoid of sphincter muscle in the surrounding connective tissue. We determined, by FISH analysis, that these branches had originated from the graft itself. The endogenous angiogenic factors, such as VEGF, have soared immediately after the surgery.

Conclusion:
This is the first
in vivo
model of spontaneous arteriovenous fistula formation via the creation of neovasculature. These findings exemplify the difference between the arterial and venous intima, and we believe that this difference could be key to understanding human vascular anomaly diseases and the basic principles of vascular network formation, angiogenesis and/or vasculogenesis.
Abstract 476: Exercise Induced Pulmonary Hypertension in Patient Presenting With Acute Cardiac Symptoms
Authors: Qutrio Baloch Zulfiqar A , Abbas Shabber , Ali Abbas , Imran Zaidi Syed , Bukhari Sumera
Published: July 2021

Introduction:
Patients presenting with symptoms of angina, dyspnea, and fatigue with negative cardiac and pulmonary test findings are often investigated with exercise right heart catheterization. Patients displaying pulmonary hypertension or exercise-induced pulmonary hypertension (EIPH) were isolated and studied further to elaborate upon similarities and differences with patients with normal pressures.

Hypothesis:
EIPH may be an under-recognized cause of cardiac complaints.

Methods:
Clinical data was obtained from 172 randomly and retrospectively selected patients including data on hemodynamics, cardiopulmonary exercise testing (CPET), and echocardiogram findings. Patients with EIPH had a resting mean pulmonary arterial pressure below 25 mmHg and on exercise above 25 mmHg. Patients with resting pulmonary hypertension were stratified into WHO group 1 (pulmonary arterial) and WHO group 2 (due to left heart). Prior response to treatment with long-acting nitrates was also reviewed.

Results:
27 patients had EIPH, 24 had WHO group 1 pulmonary hypertension, 37 had WHO group 2 pulmonary hypertension, 54 did not have pulmonary hypertension, and 30 did not have any exercise data. No significant differences were found across any groups in resting or exercise CPET performance. The mean age of those with pulmonary hypertension was 71.67 years and 58.89 for those without (p<0.01). Both had a mean left ventricular ejection fraction between 53-57%. The mean VO2 max for those with resting pulmonary hypertension or EIPH was below 20 ml/kg/min. For every 1-year increase in age the odds of developing EIPH increased by 1.08. The use of long-acting nitrate was associated with improvement of symptoms in symptomatic patients. Most of the EIPH patients were noted to have exercise-induced diastolic dysfunction and many also had concomitant chronotropic incompetance.

Conclusions:
EIPH represents those who have negative left-heart stress cardiac findings yet have underlying abnormalities significant enough to require symptomatic treatment during exercise. This includes diastolic dysfunction and chronotropic incompetency. Cardiovascular performance was found to be equally poor in patients with EIPH as compared to those with resting pulmonary hypertension.
Abstract 494: Safety of Chelation Therapy With Edta in Patients With Critical Limb Ischemia: A Pilot Trial of Limb Preservation in Diabetic Patients
Authors: Arenas Ivan A , Ergui Ian , Lamas Gervasio A
Published: July 2021

Critical limb ischemia (CLI) carries a one year 30% risk of amputation and 25% risk of mortality. Toxic metals are associated with peripheral artery disease and overall cardiac mortality. In The Trial to Assess Chelation Therapy (TACT), EDTA-based chelation improved outcomes in patients with coronary artery disease, with a particular benefit observed in diabetic patients. Here we present the preliminary findings of an open label study aimed at evaluating the safety of EDTA-based chelation, as used in TACT, in diabetic patients with CLI.

Methods:
Diabetic patients with CLI Rutherford stage 4 to 5, ≥ 75% stenosis in two or more infra-popliteal arteries and skin perfusion pressure of <40 mmHg in the affected limb were enrolled. Participants received 40 infusions of disodium EDTA over the course of a year, with the first 20 infusions administered bi-weekly and subsequent infusions administered weekly. Laboratory safety assessments were conducted at nine of the infusion visits. Lower extremity pressures and skin perfusion pressures were obtained at baseline and after 20 and 40 infusions using the SensiLase PAD-IQ. HIPAA compliant photographs along with clinical and quality of life questionnaires were also collected.

Results:
Three patients (2 women and 1 man) out of 10 planned patients have completed forty EDTA-based infusions. The mean (SD) age and creatinine clearance were 80(7) years and 55(3) mL/min, respectively. All patients had detectable levels of toxic metals in urine; lead was the most abundant toxic metal in the chelated urine. The lowest baseline tissue perfusion pressure in the affected limb was 22, 17 and 19 mmHg for each of the three patients, respectively. Patients have been followed up for an average of 61 (14) weeks. There have been no side effects related to therapy. No patient has been amputated or developed an acute cardiac event. One patient had a PTCA of her affected leg and underwent a debridement of a non-healing ulcer. No significant changes have been detected in skin perfusion pressures during follow up.

Conclusions:
Preliminary findings of this open label trial suggest that EDTA treatment in CLI patients is safe. Moreover, after more than a year of follow up, no patient has required any amputation or had any cardiovascular event.
Abstract 495: Mouse Model of Mesenteric Ischemia Secondary to Vascular Calcification and Atherosclerosis
Authors: Damiris Konstantinos , Romanelli Filippo , Savinov Alexei , Millan José Luis , Kuruvilla Jes , Savinova Olga V
Published: July 2021

Objective:
Atherosclerosis is a leading cause of chronic mesenteric ischemia (CMI), defined as intestinal hypoperfusion resulting from stenosis of mesenteric arteries. Symptoms of CMI range from non-specific abdominal pain and weight loss to aversion of food resulting in cachexia. In this study we aim to define intestinal ischemia and its effects on gastrointestinal structure and function in an
in vivo
model of atherosclerosis.

Hypothesis:
Overexpression of tissue-nonspecific alkaline phosphatase (TNAP) under conditions of hypercholesterolemia in a mouse model will lead to atherosclerosis causing intestinal ischemia.

Methods and Results:
We have previously established that endothelial TNAP overexpression (eTNAP) results in calcification of medium-sized arteries including mesenteric. In this study eTNAP was combined with a point mutation in the low-density lipoprotein receptor (
ldlr
^WHC). When fed an atherogenic diet (Paigen’s diet, starting at 8 weeks of age), WHC-eTNAP mice developed acute body weight loss (>15% from baseline), whereas WHC mice continued to gain weight. Examination of the mesenteries of WHC-eTNAP demonstrated eccentric vascular remodeling and stiffening, as well as calcification of atherosclerotic plaques (n=4). Mesenteric arteries of WHC were not affected (n=3). WHC-eTNAP (n=2) mice developed extensive atherosclerosis of submucosal arterioles in the colon where most vessels were narrowed or occluded. Examination of the small intestine in WHC-eTNAP mice showed structurally distressed villi accompanied with an increase in goblet cells and fragmentation of the epithelial layer possibly reflecting cell death. The colon demonstrated loss of goblet cells and signs of denuding of the epithelium.

Conclusion:
Atherosclerosis induced by overexpression of TNAP causes occlusion of mesenteric arteries as well as structural pathology in the small and large intestine
Abstract 497: Sex Differences in the Relationship Between Pro-Inflammatory Adipokines, Chemerin and Resistin, and Carotid Atherosclerotic Plaque Instability
Authors: Gasbarrino Karina , Yanofsky Russell , Sancho Carina , Jaunet Fanny , Zheng Huaien , Lai Chi , Veinot John , Daskalopoulou Stella S
Published: July 2021

Introduction:
Sex differences in plaque morphology and composition exist; men develop more unstable plaques than women. Yet, stroke kills more women than men. Despite these differences, no sex-specific guidelines for carotid disease management exist. Thus, markers that reflect sex-specific morphological features in the plaque should be explored for better prediction of stroke risk. Pro-inflammatory adipokines, chemerin and resistin, influence vascular function. Herein we are the first to investigate sex differences in the relationship between carotid plaque instability and the expression of these adipokines.

Methods:
Subjects with ≥50% carotid stenosis scheduled for a carotid endarterectomy were recruited from McGill-affiliated hospitals. Pre-operative plasma chemerin and resistin levels were measured using ELISA. Stability of carotid plaque specimens was assessed by two gold standard histological classifications. Stable and unstable plaques were immunostained for chemerin, chemerin’s receptor (ChemR23), and resistin. Digital and semi-quantifications assessed the % area of expression as well as staining intensity (mild to high) and % of positively stained macrophages/foam cells. Plaque mRNA expression was assessed by quantitative PCR. Sex-hormone analyses are ongoing.

Results:
Men (n=171) had more unstable plaque features, i.e., greater hemorrhage (P=0.022), lipid core size (P<0.001), inflammation (P=0.007), cap infiltration (P=0.006), and less fibrous tissue (P<0.001) than women (n=79). Circulating chemerin and resistin levels were similar between men and women and no sex differences were observed in relation to plaque instability. The % area of chemerin and resistin staining in the plaque was greater in unstable
vs
stable plaques in men only (P=0.040; P=0.005, respectively). Similarly, greater intensity in chemerin, ChemR23, and resistin staining was associated with plaque instability in men only (P<0.001; P=0.013; P=0.033, respectively). In contrast, lower resistin plaque mRNA expression was associated with plaque instability in women only (P=0.040).

Conclusion:
Our results suggest the possibility of a sex-dependent regulatory mechanism underlying the connection between these adipokines and plaque instability.
Abstract 501: Prevalence of Ascending Aorta Atherosclerosis as Detected by Echocardiography and Computed Tomography in Patients Referred for Atrial Fibrillation Ablation
Authors: Koutroumpakis Efstratios , Schwartz Benjamin , Espey John , Rau Elizabeth , Steckman David , Torosoff Mikhail
Published: July 2021

Introduction:
The prevalence and significance of thoracic aorta atherosclerosis in AF patients has not been clearly defined in the literature. There are scant reports supporting an association of atherosclerotic aortic plaque burden with embolic phenomena and recurrence of AF post ablation. Two modalities of aortic atherosclerosis detection include computed tomography (CT) and echocardiography.

Hypothesis:
The prevalence of ascending aorta atherosclerosis in AF patients is high and CT performs better than transthoracic echocardiography in its detection.

Methods:
We investigated prevalence of ascending aorta atherosclerosis by CT and transthoracic echocardiography in 76 consecutive patients referred for AF ablation (67.1% males, 62.9 +/- 9.8 years old, 6.6% active smokers, 75% paroxysmal AF, 13.1% with LV ejection fraction (EF) <50%, 61.8% with hyperlipidemia, 55.8% with hypertension, 10.5% with diabetes, 2.6% with chronic kidney disease, and 1 patient with peripheral artery disease). The pre-ablation echocardiograms and cardiac CT scans, originally performed for left atrial mapping and evaluation of left atrial appendage thrombus, were reviewed in a blinded fashion for the presence of aortic atherosclerosis.

Results:
Out of 76 AF ablation patients, 27 (35.5%) had evidence of ascending aorta atherosclerosis by CT and 43 (56.6%) by echocardiography. Using CT as the gold standard, echocardiography had a sensitivity of 70.4% and a specificity of 51% in identification of ascending aorta atherosclerosis. Positive and negative predictive values were 44.2% and 75.8%, respectively. A total of 16 patients (21.1%) had AF recurrence post ablation, out of which 6 (37.5%) had evidence of aortic atherosclerosis on CT (vs 21/49 [42.9%] in the non-recurrence group).

Conclusions:
Ascending aorta atherosclerosis is common in patients referred for AF ablation. Transthoracic echocardiography likely overestimates its prevalence. Aortic atherosclerosis as detected by CT was not significantly associated with AF recurrence post ablation. More studies investigating clinical implications and best treatment approach to subclinical aortic therosclerosis in patients with AF are needed.
Abstract 507: Glutamic Acid May Not Contribute to the Mechanism in Which Saccharina Japonica Attenuates Hypertension in 2-Kidney, 1-Clip Renovascular Hypertensive Rats
Authors: Segawa Yukiko , Hashimoto Hiroko , Maruyama Saki , Osera Tomoko , Kurihara Nobutaka
Published: July 2021

Objective:
Saccharina japonica (SJ), one of brown algae, is cultivated or grows wild in Japan and neighbor countries. The extract “dashi” is used for soup stock in Japan. We reported the decreases in blood pressure (BP) both by the intake of SJ diet and by dashi extracted from SJ (DASHI) in 2-kidney, 1-clip renovascular hypertensive (2K1C) rats. Some researchers have suggested that alginic acid (AA) may be involved in the mechanism of the SJ effect. However, DASHI contains AA as much as 5%(5 of 100) of what the original SJ contains. Thus, the antihypertensive effects by SJ in 2K1C may be through the other contents of SJ. SJ is rich in Glutamic acid (GA) which is one of the umami, the intake of which was reported to decrease BP in human in epidemiologic studies. GA is eluted from the SJ into the DASHI when extracting DASHI from SJ. Therefore, we hypothesized that GA in DASHI contributes to the mechanism of BP decreased by DASHI diet in 2K1C rats. In this study, we observed BP in 2K1C rats fed a diet containing GA as much as that in the SJ diet which had decreased BP in the previous study.

Methods:
Male Sprague-Dawley rats (6wks) were treated with sham operation (SHAM) or clipping the left renal artery (2K1C). After surgery, the rats started receiving a control diet (C) or a diet containing L-GA (G) for 6 weeks. The systolic BP (SBP) was measured by a tail-cuff method every week. At the end, mean arterial BP (MAP) was measured in each rat under anesthesia.

Result:
Six weeks after the surgery, SBP was significantly higher in 2K1C-C than in SHAM-C (163±2 vs 111±5 mmHg, p<0.05). In 2K1C-G (171±7), it showed no significant difference compared with 2K1C-C and was significantly higher than that in SHAM-C (p<0.05). At the end of the protocol, MAP showed the similar results to SBP.

Conclusion:
Glutamic acid may not contribute to the mechanism of alleviating hypertension by dietary SJ and SJ extract in 2K1C.
Abstract 512: Predictors of Mortality in Cancer-Associated Calf Deep Vein Thrombosis
Authors: Salazar Adum Juan P , Diaz-Quintero Luis , Fuentes Harry E , Tafur Alfonso , Lind Benjamin , Caprini Joseph
Published: July 2021

Background:
Venous thromboembolism (VTE) is a leading cause of mortality in cancer patients. The outcomes of patients with cancer-associated calf deep vein thrombosis (CDVT), including mortality data, are less understood compared with proximal thrombosis.

Aim:
To characterize predictors of mortality among cancer-associated CDVT patients.

Methods:
Single institution inception cohort of cancer-associated CDVT patients who presented with thrombosis distal to popliteal level confirmed objectively by ultrasound, computed tomography or VQ scan were independently reviewed. Active cancer was defined as metastatic disease or use of chemotherapy at diagnosis. The Khorana risk score (KRS) suggested for DVT and mortality prediction in cancer was abstracted based on laboratory tests and cancer type at diagnosis. Institutional review board approval was obtained prior to the analysis. Categorical variables are expressed as percentages and continuous variables as median (interquartile range). SPSS software version 22 was used and Chi-square, Mann–Whitney U and Cox proportional hazard were applied.

Results:
One hundred nine patients (Men=44 (40%), Age>65=89 (82%), BMI>30=25 (23%), Smoker=59 (54%)) were included. The majority had a low or intermediate KRS (30%-64% respectively). Forty-seven percent died during a median follow-up time of 2.5 years (0.5-3.1). After multivariate analysis, the predictors of mortality were found to be: smoking (Hazard Ratio 2.3; 95%CI 1.2-4.7), metastasis (HR 5.8; 95%CI 2.9-11.7), gastrointestinal cancer (HR 3.9; 95%CI 1.8-8.5), and lung cancer (HR 4.1 95%CI 1.7-10.3). VTE specific variables not associated with mortality included: bilateral CDVT, concomitant pulmonary embolism, multiple vein involvement, filter placement, or a surgery-associated event.

Conclusion:
Cancer-specific variables and smoking predicted mortality among CDVT patients in this cohort. Neither the KRS nor VTE specific characteristics were predictive of death. A larger study is necessary to further explore these findings.
Abstract 516: Chromosome 18p Deletion Inhibits Platelet Aggregation
Authors: Meyer Andrew D , Raghunath Anjana , Heard Patricia , Cody Jannine
Published: July 2021

Inappropriate platelet function is a significant risk factor for cardiovascular disease, the leading cause of death in the United States. Although abnormal platelet function has a strong genetic component, very few human genes have been linked to platelet function. Mice with a homozygous deletion of
EMILIN2
(Elastin Microfibril Interface Located Protein2) gene, located on Chromosome 18p, have a significant decrease in platelet function and clot formation. However, deletion or inactivation of only one copy of a gene is most relevant to human disease modeling. Our hypothesis is that blood samples from people with single 18p deletions that include
EMILIN2
will have decreased platelet function compared to healthy individuals. We conducted a case-control study of nine adult individuals with chromosome 18p deletions matched with healthy men and women (n=20). Routine coagulation measurements were performed on a STAGO STA-R instrument. Platelet aggregation was measured with whole blood impedance aggregometry and Thromboelastography with PlateletMapping using the manufacturers’ protocols. There was no significant difference in platelet count, prothrombin time, partial thromboplastin time, d-dimer, or fibrinogen between individuals with a single 18p gene copy number and normal controls. However, platelet aggregation was impaired in individuals with 18p deletions compared to normal controls in response to collagen and arachidonic acid (ASPI), respectively (
p
<0.0001, Figure 1). Moreover, Thromboelastography with PlateletMapping was decreased in individuals with 18p deletions compared to normal controls for ADP and ASPI, (
p
<0.001). Individuals with one copy of 18p have decrease platelet function compared to normal controls. These results identify a novel human genetic loci linked to a specific phenotype of platelet function. Future will studies will determine if this gene can be used for diagnostic or therapeutics for cardiovascular disease.
Abstract 526: Thromboembolic Phenomenon in a Patient With Unexplained Transverse Aortic Thrombus
Authors: Alhawasli Hazem , Brown Alan
Published: July 2021

A 55 year-old Caucasian male, with no known past medical history, presented to the ER complaining of left upper extremity pain with finger tingling and difficulty speaking that started 8 hours before presentation, while driving his car. In the ER, physical exam was remarkable for mild expressive aphasia with difficulty finding words. His left arm was tender without any edema or erythema and normal range of motion. His left hand fingertips appeared cyanotic (
Picture 1)
, however his radial and ulnar pulses were intact bilaterally. Laboratory evaluation revealed a platelet count 1,416,000/mcl, and normal PT/INR and PTT. CT of the brain showed no intracranial bleed. MRI of the brain showed multiple small sub-acute infarcts in the left occipital lobe, left basal ganglia and bilateral cerebellar hemispheres suggesting a shower of emboli. Because of a concern for possible aortic dissection by the ER physician, a CT angiogram of the chest was done. It revealed a large filling defect (up to 3.1 cm) in the distal transverse thoracic aorta, consistent with non-occlusive thrombus adjacent to the origin of the left subclavian artery (
Picture 2)
. Subsequently, TEE was done and again showed a large mobile thrombus attached to the inferior posterior wall of the transverse thoracic aorta (
Picture 3)
. Given the extremely mobile and large sized thrombus, with high risk for further embolization, the patient underwent surgery with excision of the aortic thrombus (
Picture 4)
. The patient had an uncomplicated post-operative course and warfarin was started empirically post-operatively.

Further Hematology work up was suggestive of Essential Thrombocytosis. The patient was started on hydroxyurea.

On his 3-week follow up appointment, his platelet count decreased to 202,000/mcl. Anti-coagulation was continued for 3 months. His neurologic symptoms significantly improved with only mild residual left hand finger tips claudication which resolved by 1 month post discharge.