bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 275: A New, Novel Shape Feature Space Classifier For Acute Type B Aortic Dissection
Authors: Jiang David , Khabaz Kameel , Yuan Karen , Milner Ross , Pocivavsek Luka
Published: October 2023

Background:
Early detection and treatment of acute type B aortic dissection (TBAD) is associated with improved morbidity and mortality. Artificial intelligence and machine-learning (ML) based approaches for expedited detection of TBAD have made strides in recent years with improving predictive power and accuracy. These deep-learning neural networks are trained with iterative exposure to patient imaging and clinical information of patients with aortic pathology to identify consistent patterns. AI-decision support tools can be improved with more focused feature selection, variables of particular interest. Here, we identify a novel shape variable to describe the highly complex topography of the aorta.

Methods:
46 patients with acute, complicated TBAD were identified from a now closed multi-center clinical trial of a conformable thoracic stent graft. An independent cohort of 87 patients without aortic pathology was obtained from a single center, retrospective database. Two-dimensional surface segmentations were generated from pre-operative CT angiography. Variance in total curvature, a size-independent shape measure, and inverse Casorati curvature, a size scalar, were calculated from the segmentations. Additional size measurements, including maximum diameter, were calculated using centerline methods.

Results:
44 pre-operative scans of acute TBAD were analyzed. Mean maximum diameter in the acute TBAD cohort was 39.20 ± 6.75 mm compared to 21.44 ± 3.28 mm in the non-pathologic aorta cohort (p = 2.50E-17). Mean fluctuation in total curvature, normalized, was 7.09 ± 3.58 versus 4.18 ± 2.32 in the non-pathologic aorta cohort (p = 4.36E-13). Mean inverse Casorati curvature was 0.043 ± 0.005 in acute TBAD compared to 0.06 ± 0.01 in non-pathologic aortas (p = 4.67E-21). Logistic regression classification accuracy was 91.6 ± 2.4%.

Conclusions:
Acute TBAD demonstrates a unique shape signature defined by fluctuation in total curvature, in addition to traditional size measures. This easily quantifiable and reproducible dimension of aortic geometry classification has significant potential as a new, anatomically derived feature space to improve AI/ML-based aortic dissection detection.
Abstract 278: Ccr2 Inhibition Impacts Abdominal Aortic Aneurysm Rupture In Rodents
Authors: Zaghloul Mohamed S , Elizondo-Benedetto Santiago , Arif Batool , Detering Lisa , Luehmann Hannah , Sultan Debbie , Heo Gyu Seong , Gropler Robert J , Liu Yongjian , Zayed Mohamed A
Published: October 2023

Background:
There is growing evidence that monocyte chemoattractant protein (MCP-1) / C-C chemokine receptor type 2 (CCR2) axis crucially affects the initiation and progression of abdominal aortic aneurysm (AAA). We hypothesize that inhibition of CCR2 may prevent AAA inflammation and rupture.

Methods:
40 Male and 49 female Sprague-Dawley rats underwent intraluminal infrarenal abdominal aortic exposure to elastase to induce AAA. Rats received daily β-aminopropionitrile to promote AAA rupture. On post-operative day 3 (POD3), a treatment group (15 males, 17 females) received daily oral gavage of a CCR2 inhibitor (CCR2i; RS-504393), and a control group (25 males, 32 females) received no CCR2i. On POD6, both groups underwent PET/CT with a CCR2 targeting radiotracer
64
Cu-DOTA-ECL1i. In addition, AAA tissue cytokine/chemokine arrays were evaluated. Incidence of AAA rupture was evaluated in the remaining surviving rats until POD14 (Figure 1A).

Results:
Compared with controls, the incidence of AAA rupture was reduced in treated male AAA rats (0% vs 56%,
p
<0.001; and tended to decreased in treated female AAA rats (18% vs 42%,
p
=0.09;). PET/CT demonstrated that male and female treatment groups had significantly decreased
64
Cu-DOTA-ECL1i uptake in AAAs (
p=
0.02 for male AAAs
, p
<0.001 for females, Figure 1B). All cytokines, including MCP-1, RANTES, IL-17A, IL-18, IL-1B, IL-6, IL-10, except TNF-a were significantly reduced in the male treatment group compared to control group (
p
<0.05; Figure 1C). Interestingly, in the female treatment group, IL-1B was significantly decreased (
p
<0.05), and RANTES was significantly increased (
p
<0.05).

Conclusion:
In rats, CCR2 appears to be a promising theranostic biomarker for AAAs. CCR2i can greatly impact AAA tissue inflammation and reduces the incidence of AAA rupture. Differences between male and female rats suggest that CCR2 signaling may be different in AAA between sexes and highlights future avenues of further investigation.
Abstract 290: Circulating FAS Is A Novel Serum-based Diagnostic Biomarker For PAD
Authors: Abu-Amer Wahid Y , Meade Rodrigo , Roberts Sophia , Belaygorod Larisa , Zaghloul Mohamed , Penrose Amanda , Arif Batool , Semenkovich Clay F , Zayed Mohamed A
Published: October 2023

A persistent challenge is the lack of reliable serum diagnostic tests for peripheral arterial disease (PAD). Serum cholesterol levels lack sensitivity for PAD and are not predictive of disease progression. Our team previously demonstrated that serum circulating Fatty Acid Synthase (cFAS) correlates with incidence of PAD and does not correlate with serum lipids. Therefore, we hypothesized that cFAS can be an independent diagnostic biomarker for PAD in a larger cohort, with or without diabetes.

An IRB-approved consecutive (2014-2018) cohort was used to identify individuals with PAD/diabetes, as well as healthy controls. Consented patients provided a serum sample, and total cFAS content was measured with ELISA. Demographics and incidence of PAD/diabetes were collected from chart review. Serum cFAS and demographics were compared, and regression was used to determine correlations with cFAS.

A total of 165 patients met inclusion criteria. Of these, 61 (37%) had PAD and diabetes (Group 1), 64 (38.8%) had PAD and no diabetes (Group 2), and 40 (24.2%) were healthy controls (Group 3). Compared to Group 3, Groups 1&2 were significantly older, had more males, and higher incidence of cardiovascular co-morbidities (p<0.001). Compared to Group 2, Group 1 had a higher incidence of cardiovascular/cerebrovascular disease, CHF, and HTN (p<0.05). Despite these differences, both Groups 1&2 had significantly higher serum cFAS content than Group 3 (p<0.01 and p=0.01, respectively). In the whole cohort, there were significant correlations between cFAS and PAD severity and between cFAS and smoking status. (p=0.02, p=0.01 respectively).

Our study suggests that cFAS can serve as an independent serum-based diagnostic biomarker for PAD, regardless of diabetes status. Future studies will further validate this serum biomarker and determine its predictive value for identifying individuals who are at highest risk of disease progression.
Abstract 297: FHL2 Deficiency Facilitates Tissue Plasminogen Activator-mediated Thrombolysis Without Further Prolonging Bleeding Time
Authors: Park Inyeong , Kim Nakyoung , Kim Jiwon , Lee Su-Kyoung , Hong Sung-Ha , Kim Eo Jin , Kim Dong-Eog E , Choi Seungbum
Published: October 2023

Introduction:
A recent study showed a relationship between Four-and-a-half-LIM-domains 2 (FHL2) and venous thromboembolism. Here, we investigated FHL2 deficiency-mediated effects on arterial thrombus formation, tissue plasminogen activator (tPA)-mediated thrombolysis, and bleeding time.

Methods:
First, arterial thrombosis was induced in twelve-week-old male FHL2
+/+
mice (n=17) and FHL2
-/-
mice (n=17) by applying FeCl
3
on the left common carotid artery (CCA) for 10 minutes. To measure thrombus volume at 30 minutes (n=10/group) or 3 hours (n=7/group) after the thrombus induction, microCT imaging was performed after intravenous injection of gold nanoparticles (2mg/kg in 200μL). Second, 32 mice (n=16/group) were treated with intravenous tPA (25 mg/kg) at 30 minutes (n=10/group) or 3 hours (n=6/group) after thrombosis, and microCT imaging was performed at baseline and post-tPA 0.5, 1, 3, and 24 hour time-points. Third, tail-bleeding test was performed with (n=6 and 8, respectively) or without (n=8/group) tPA treatment.

Results:
Thrombus volume at 30 minutes and 3 hours did not differ significantly between the groups. However, post-tPA 3-hour thrombus volume was significantly lower in FHL2
-/-
mice than in FHL2
+/+
mice (71% vs. 46% reduction from the baseline, respectively; p=0.03), when the thrombolytic therapy was initiated at 30 minutes after thrombosis. There were no significant inter-group differences in thrombus volumes when tPA treatment was delayed (ie., started at 3 hours after thrombosis). Lastly, bleeding time did not show significant inter-group differences, regardless of tPA therapy (all p>0.05).

Conclusions:
FHL2 deficiency does not reduce baseline arterial thrombus volume but facilitates tPA-mediated thrombolysis without prolonging bleeding time in mice.
Abstract 300: Physiologic Oxygen Conditions Preserve Ipsc-ec Progenitor Identity
Authors: Hekman Katherine , Scrivner Ottis , McLaughlin Dylan
Published: October 2023

Background:
Advanced peripheral artery disease (PAD) is characterized by disabling lower extremity pain at rest and non-healing wounds. Many patients are limited to palliation with major amputation. There remains a great need for improved therapeutic modalities to treat advanced PAD and prevent limb loss. Induced pluripotent stem cell-derived endothelial cells (iPSC-ECs) have improved limb perfusion without surgery in pre-clinical mouse models. iPSC-ECs lose angiogenic capacity under standard culture conditions, currently limiting scalability for larger animals and humans. Our prior work demonstrated that this is driven by accumulation of dysfunctional mitochondria. The current study evaluates the effect of oxygen metabolism on driving angiogenic capacity of iPSC-ECs in culture.

Methods and Results:
Purified ECs, differentiated from the Y6 iPSC line (Yale Stem Cell Core), were sub-cultured under standard (21% oxygen) or physiologic (4% oxygen) conditions. In the early phase, after 24 hours, Y6-ECs under physiologic conditions had significantly lower NO synthase activity (DAF-FM assay, Invitrogen) (p<0.05). There were no significant differences in the remaining EC function metrics: tubule formation on Matrigel to assess angiogenesis, beta galactosidase for senescence, or Edu-labeling for proliferation. All early phase cells expressed EC progenitor marker CD34. In the late phase, after 2 weeks, the physiologic conditions retained progenitor marker CD34 and EC marker CD31 while the normoxic conditions did not. Despite this, physiologic conditions demonstrated decreased tubule formation by some but not all measures but did not differ from normoxic conditions in the other EC function metrics. Additionally, late phase cells had a significant increase in senescence compared to early phase cells (p<0.05).

Conclusion:
In summary, physiologic culture conditions promoted retention of EC progenitor marker CD34 over serial passages in culture. However, some but not all in vitro metrics of angiogenic capacity appeared reduced in physiologic conditions. Future studies will be necessary to investigate the in vivo angiogenic capacity of iPSC-ECs grown under physiologic conditions.
Abstract 313: Finasteride Delays Atherosclerosis Progression and Reduces Hepatic Inflammation in Low-density Lipoprotein Receptor-deficient Mice
Authors: Molina Donald , McQueen Patrick , Pinos Ivan , Krug Samuel , Kane Maureen A , Amengual Jaume
Published: October 2023

Finasteride is commonly prescribed to treat benign hyperplasia and male-pattern baldness in cis men and, more recently, trans individuals. However, the effect of finasteride on cardiovascular disease remains elusive. We evaluated the role of finasteride on atherosclerosis using low-density lipoprotein receptor-deficient (
Ldlr
-/-
) mice fed a Western diet containing increasing doses of finasteride for 12 weeks. We did not observe changes in food intake, body weight, or liver markers for toxicity for any of our experimental conditions. At the highest dose, finasteride reduced plasma cholesterol and triglycerides to approximately 25% compared to the control group. Plaque content at the aortic arch and aortic root level showed a reduction in lesion burden. Finasteride reduced monocytosis, monocyte recruitment to the lesion, macrophage lesion content, and necrotic area. RNA sequencing analysis revealed a downregulation of inflammatory pathways and an upregulation of bile acid metabolism, oxidative phosphorylation, and cholesterol pathways in the liver of mice taking finasteride. Our data unveil finasteride as a potential treatment to delay cardiovascular disease by its effects on plasma lipid profile.
Abstract 325: Production Or Action Of Angiotensin II In Renal Proximal Tubules Does Not Affect Blood Pressure And Atherosclerosis In Hypercholesterolemic Mice
Authors: Amioka Naofumi , Kukida Masayoshi , Sawada Hisashi , Chen Hui , Liang Ching L , Ito Sohei , Moorleghen Jessica J , Howatt Deborah A , Daugherty Alan , Lu Hong S
Published: October 2023

Objective:
This study determined whether angiotensin-converting enzyme (ACE) or AngII type 1a receptor (AT1aR) in renal proximal tubule cells (PTCs) contributes to atherosclerosis.

Approach and Results:
To develop atherosclerosis, LDL receptor -/- mice were fed a Western diet for 12 weeks. We first determined whether global AT1R blockade has comparable effects between male and female mice on reducing atherosclerosis. Losartan (15 mg/kg/d), an AT1R blocker, was continuously administered via mini osmotic pumps for 12 weeks. Although losartan led to more profound reductions of blood pressure in females than in males, it attenuated atherosclerosis equivalently between males and females. We then determined whether the effects of global renin-angiotensin inhibition on atherosclerosis were attributed to the inhibition of AngII production or its action through AT1aR in PTCs. PTC-specific ACE or AT1aR deficient mice were developed using a tamoxifen-inducible Cre transgene containing the Ndrg1 promoter. Deletion of either gene occurred predominantly in S1 and S2 regions of PTCs, as verified using multiple approaches. Despite the profound genetic depletion, deletion of either ACE or AT1aR in PTCs did not affect atherosclerosis in either sex.

Conclusions:
Although global inhibition of AT1aR reduced atherosclerosis, PTC-specific blockade of either ACE or AT1aR had no effects on hypercholesterolemia-induced atherosclerosis, irrespective of sex.
Abstract 331: Clearance Of Senescent Cells Reduces Osteogenic And Fibrogenic Signaling In Fibrocalcific Aortic Valve Stenosis
Authors: Leon-Sanchez Luisa F , Roos Carolyn M , Hagler Michael A , Huang Runqing , Zhang Bin , Posada Eduardo , Kirkland James , Tchkonia Tamar , Miller Jordan D
Published: October 2023

Introduction:
Senescent cell accumulation and senescence-associated secretory phenotype (SASP) are putative major mechanisms of tissue aging, and growing evidence suggests that pharmacological clearance of senescent cells slows progression of multiple age-related diseases. Here, we hypothesized that treating with a known senolytic, Fisetin (FIS), would reduce molecular drivers of fibrosis and calcification and ultimately slow disease progression of fibrocalcific aortic valve stenosis (FCAVS) in mice when initiated in mild/moderate stages of disease.

Methods:
Male and female Ldlr
-/-
/ ApoB
100/100
mice were fed a western diet for 9 months and assigned to one of two treatment groups: FIS or vehicle, with treatment beginning at 6 months of diet.

Results:
Treatment with FIS reduced CDKN2A (p < 0.01) and SASP marker TNFα (p < 0.002) in both sexes, and consistent with our hypothesis was associated with reduced expression of the osteogenic markers RUNX2 (p < 0.021) and SPP1 (p < 0.006) in valve tissue from female mice. In contrast, expression of WNT5A was reduced in valves only from male mice (p < 0.004). In line with these molecular changes, valvular calcium burden (alizarin red staining) also tended to decrease in both sexes. Interestingly, TGFβ1 expression was significantly reduced (p < 0.018) in both sexes and was associated with reductions in collagen 3A1. These molecular changes in fibrogenic signaling manifested as a shift towards thinner collagen fibers only in male animals (p < 0.05). Functionally, slower progression of valvular dysfunction (declines in aortic valve cusp separation distance assessed with high-resolution echocardiography) was observed predominantly in females (p < 0.002).

Conclusions:
In conclusion, these data suggest that long-term, intermittent clearance of senescent cells robustly attenuates osteogenic and fibrogenic signaling in mild/moderate FCAVS, although the molecular, histopathological, and functional consequences of senolytic therapy may occur in a sex-specific manner. Future studies evaluating preclinical efficacy of senolytics should account for tissue and sex specificity and warrant longer-term treatment to assess the functional consequences of the biological and histopathological changes observed here.
Abstract 336: Endothelial Cells Communicate with Surrounding Vascular Cells Via Bidirectional and Polarized Secretion of Extracellular Vesicular Cargo: Implications for Atherosclerotic Plaque Development
Authors: Raju Sneha , Prajapati Kamalben , Blaser Mark C , Botts Steven R , Ho Tse Wing Winnie , Ching Crizza , Galant Natalie J , Fiddes Lindsey , Wu Ruilin , Clift Cassandra L , Pham Tan , Singh Sasha A , Lee Warren L , Aikawa Elena , Fish Jason , Howe Kathryn
Published: October 2023

Introduction:
Endothelial cells (EC) can release extracellular vesicle (EV)-encapsulated miRNAs and proteins to mediate cell-cell communication. We hypothesized that EC-EV release is altered by activation state and drives functional changes in surrounding cells via bidirectional release.

Methods:
EVs were isolated from supernatants of human aortic endothelial cells (HAECs; ± IL-1β, 100pg/ml) via serial ultracentrifugation and quantified as per MISEV2018 guidelines. Cargo was assessed (miRNA sequencing, proteomics). HAEC EVs were added to primary monocytes and vascular smooth muscle cells (VSMCs) at a physiological concentration and RNA-seq was performed. Bioinformatic analysis of EV contents and RNA-seq was performed. To assess polarized EV secretion, EVs were quantified from apical and basolateral compartments, and visualized with total internal reflection fluorescence (TIRF) and cryogenic transmission electron microscopy (cryo-TEM).

Results:
Activated HAECs have increased EV release (6.73±1.81X10
10
vs. 2.98±1.44 x10
11
particles/ml; p=0.028, N=3). In comparison to quiescent ECs, activated EC-EVs carry miRNA and protein cargo that play shared and distinct roles in several pro-atherogenic pathways. EC-EVs participate in cell-cell communication with circulating monocytes and resident VSMCs, and EVs from activated ECs lead to changes in pathways that are pro-inflammatory and atherogenic. Importantly, ECs are capable of bidirectional communication with luminal and abluminal cells via their unique ability to release EVs to the apical and basolateral compartments as determined by EV-quantification using nanoparticle tracking and western blot analysis, EV-visualization via cryo-TEM, and dynamic basolateral HAEC-EV release via TIRF microscopy. Intriguingly, ECs polarize and secrete compartment-specific cargo to the luminal and abluminal surfaces with
in silico
analysis implicating unique communication with circulating and resident vascular cells.

Conclusions:
ECs utilize EV contents to mediate cell-cell communication in quiescent and activated states. Importantly, they can polarize vesicle release bidirectionally, which may specifically govern functional changes in circulating and resident vascular cells.
Abstract 340: γ-carboxylated Growth Arrest Specific Protein 6 Differentially Induces Calcification In Human Aortic Valves
Authors: Turner Mandy E , Ito Shinsuke , Hoekstra Joost K , Blaser Mark C , Mikami Kentaro , Clift Cassandra L , Singh Sasha A , Aikawa Masanori , Aikawa Elena
Published: October 2023

Introduction:
Growth arrest specific protein 6 (GAS6) is a secreted γ-carboxylated vitamin K-dependent protein with roles in cell proliferation and migration. The role of GAS6 and post-translational γ-carboxylation in calcific aortic valve disease (CAVD) has yet to be evaluated.

Hypothesis:
Using proteomics, we identified GAS6 as a novel protein abundant in valve tissue and valvular interstitial cells (VICs), and assessed the hypothesis that γ-carboxylated GAS6 has a mechanistic role in the development of CAVD.

Methods:
Whole aortic valve and tissue extracellular vesicle (EV) label-free proteomics, valve histopathology, and valvular interstitial cell isolation was performed on human specimens collected from surgical aortic valve replacements for aortic stenosis at Brigham and Women’s Hospital. EVs were isolated from whole valves using ultracentrifugation and Optiprep density gradients. Mass-spectrometry will confirm γ-carboxylation.

Results:
GAS6 abundance was elevated in valvular areas of calcification compared to non-diseased regions (log2 FC=5, q=4.2E-10), and were enriched in GO terms associated with exosome and vesicular transport (N=18). Due to the role of EVs in ectopic cardiovascular calcification, tissue EVs were isolated from calcified aortic valves (N=9), and proteomics identified GAS6 in the vesicle-enriched fractions. Immunohistopathology of GAS6 in CAVD specimens identified co-localization of GAS6 with inflammation and calcification. Protein expression of GAS6 from VICs was significantly increased by media supplemented with organic phosphate (β-glycerophosphate) (N=5-8, p<0.05), but markedly decreased by supplementation with inorganic phosphate (NaH
2
PO
4
) (N=5-8, p<0.05), despite both conditions generating Alizarin red positive calcification. GAS6 knockdown prevented calcification only in the setting of organic phosphate stimulation.

Conclusions:
GAS6 is a novel protein of pathological significance in CAVD. EV enrichment of GAS6 and unappreciated differential mechanistic roles of phosphate sources impacts valvular calcification, potentially through γ-carboxylation regulation. GAS6 has an unrecognized role in CAVD, which may have important implications for future disease pharmacotherapy.
Abstract 361: Active Elastic Fiber Formation In The Vascular Wall Of Chronic Aortic Dissections
Authors: Ito Sohei , Liang Ching L , Lu Hong S , Daugherty Alan , Sawada Hisashi
Published: October 2023

Introduction:
Aortic dissection (AD) is a life-threatening disease with disruption of the extracellular matrix. Elastic fibers are a major component of the extracellular matrix and are vital for aortic integrity. Elastic fibers have a long half-life and are minimally synthesized in adulthood. Despite the important role in structural stability, it remains unknown whether new elastic fibers could be formed following ADs in adults.

Methods and Results:
To induce ADs, β-aminopropionitrile (BAPN, 0.5% wt/vol, in drinking water) was administered to male C57BL/6J mice at 4 weeks of age. Aortas were harvested at 4, 8, and 12 weeks of BAPN administration. BAPN administration for 4 weeks led to relatively fresh hematoma with modest luminal dilatation in the descending aorta, indicating development of acute ADs. Mice with BAPN administration for 8 or 12 weeks displayed severe aortic dilatation with thrombus and aortic wall remodeling, suggesting chronic ADs. Using these tissues, we then performed Verhoeff’s iron hematoxylin staining to evaluate the presence of elastic fibers during AD progression. As expected, elastic fibers adjacent to the true lumen were disrupted in both acute and chronic ADs. Of note, in chronic ADs, elastic fibers were observed surrounding the false lumen. Compared to elastic fibers surrounding the true lumen, these new fibers were thinner, denser, and less organized.
In situ
hybridization revealed
Eln
and
Fbn1
mRNA were distributed in proximity to new elastic fibers. In addition, immunostaining found the hyperplasia of αSMA-positive cells in the wall of the false lumen. Importantly, these cells were coincident with
de novo
elastic fibers. These results are consistent with smooth muscle cells being the primary cell type generating elastic fibers in chronic ADs. To investigate the molecular mechanism driving
de novo
elastic fiber formation, elastogenic genes were evaluated by RT-qPCR. Aortic
Eln
and
Fbn1
mRNA were increased significantly in the chronic phase, but not in the acute phase. Genes related to elastic fiber assembly, such as
Fbln5
,
Emilin1
, and
Lox
, were also upregulated in chronic ADs.

Conclusion:
Elastic fiber formation is reactivated, with enhanced expression of elastogenic genes and SMC hyperplasia, in response to AD progression.
Abstract 366: Endogenous Activation Of Cd45 Can Induce Endothelial To Mesenchymal Transition In Human Endothelial Cells
Authors: Nasim Sana , Wylie-Sears Jill , Gao Xinlei , Chen Kaifu , Zhu Bo , Peng Qianman , Chen Hong , Bischoff Joyce
Published: October 2023

Introduction:
Endothelial to Mesenchymal transition (EndMT) is an intricate process in which endothelial cells (ECs) loosen their cell-cell junctions, migrate into tissue matrix, and acquire mesenchymal phenotype. During embryonic development, EndMT is essential and yet re-occurrence postnatally is associated with cardiovascular diseases. In our previous study, we showed that CD45, a pan-leukocyte marker, is expressed in mitral valve endothelium at 6 months post-myocardial infarction. Additionally, transforming growth factor (TGF)b1 induced mitral valve ECs co-expressed CD45, but not CD11b or CD14. Pharmacological inhibition of CD45 protein tyrosine phosphatase domain in mitral valve ECs also blocked TGFb-induced EndMT. This led us to hypothesize that EndMT can be initiated with the expression of CD45 in human ECs.

Methods:
We used CRISPR/inactive Cas9 transcriptional activation system to activate endogenous CD45 expression in human endothelial colony forming cells (ECFCs). We carried out bulk RNA-Seq on control ECFCs and CD45-positve ECFCs to assess differential gene expression profiles. Additionally, we performed three functional assays to evaluate mesenchymal characteristics in the CD45 induced ECFCs – cell migration, collagen gel contraction and trans-endothelial electrical resistance (TEER) assay.

Results and Conclusion:
Activation of CD45 in ECFCs upregulated markers that implicate EndMT such as TAGLN, IL-1b, TGFb2, Col1a2, alpha-smooth muscle actin, and SNAIL2/SLUG. CD45-ECFCs showed significant increase in cell migration and collagen gel contraction, and decreased cell-cell barrier assessed by TEER assay. These results suggest that CD45 can lead ECs to decrease their endothelial phenotype and acquire mesenchymal properties.
Abstract 379: The Accuracy Of ICD-10 Discharge Diagnosis Codes For Identification Of Isolated Sub-Segmental Pulmonary Embolism: A PE-EHR+ Substudy
Authors: Bejjani Antoine , Khairani Candrika D , Lo Ying-Chih , Jimenez David , Barco Stefano , Mahajan Shiwani , Caraballo Cesar , Klok Erik , Secemsky Eric A , Aghayev Ayaz , Hunsaker Andetta , Hussain Mohamad A , Appah-Sampong Abena , Khera Rohan , Goldhaber Samuel , Zhou Li , Monreal Manuel , Krumholz Harlan M , Piazza Gregory , Bikdeli Behnood
Published: October 2023

Introduction:
International Classification of Diseases 10
th
revision (ICD-10) discharge diagnosis codes are widely used for research studies that use electronic databases. The accuracy of the codes for identifying patients with isolated sub-segmental pulmonary embolism (issPE) is unknown.

Methods:
We used data from the Mass General Brigham (MGB) health system (01/2016-12/2021) and included 1,000 patients randomly selected from 3 groups: Patients with ICD-10 Principal Discharge Diagnosis codes for PE, patients with secondary Discharge Diagnosis codes for PE, and patients with no ICD-10 codes for PE. Weighted estimates were obtained by considering the total number of hospitalizations in each category at MGB hospitals. Accuracy of the codes was assessed by two independent physicians who reviewed discharge summaries, daily notes, and radiology reports.

Results:
Of 1,000 records reviewed, 993 were included (age: 62.4±17.0 years, 54.8% female). Manual chart review found 493 patients with acute PE, including 59 (12.0%) with issPE. Of these 59 patients, 58 (98.3%) had ICD-10 codes for PE. However, only in 8 (13.6%) cases, PE codes were specified as being limited to subsegmental vessels (issPE). In turn, 23 additional cases with Principal-or-secondary ICD-10 codes for issPE did not have acute issPE during index hospitalization per review of records. The sensitivity and specificity for issPE codes in Principal or secondary discharge position were 13.6% and 99.5% (Table, panel A). Positive predictive value in the weighted sample was 26.2% (Table, panel B).

Conclusion:
Although specificity and negative predictive value of ICD-10 codes in Principal-or-secondary discharge diagnosis position for issPE are excellent, sensitivity and positive predictive value are low, highlighting the need for revised algorithms or use of natural language processing for data sources that include radiology reports.
Abstract 417: Effect Of Antiplatelets, Ace-i, And Statins On Post-covid-19 Cardiovascular Complications
Authors: Ho Huy , Nolan Johnny , Nerella Nishant K , Pasupuleti Suman , Oyesanmi Olugbenga
Published: October 2023

Post-COVID-19 patients are at increased risk of cardiovascular and stroke complications, especially the immediate period following infection. Beta-blockers, ACE-inhibitors, anticoagulants and antiplatelet agents are mainstay therapies for stroke patients and those with cardiovascular disease. This study aims to explore the potential benefit of these therapies in post-COVID-19 patients in prevention of cardiovascular and stroke complications. About 5134 cases were analyzed in this study. This study includes patients that were admitted for stroke of myocardial infarction who had history of COVID-19 infection within 4 weeks prior. These patients were then stratified based on their home medications including ACE-I, beta-blockers, antiplatelet and anticoagulant agents. Logistic regression and chi-square were used for analysis of data. There was no significant relationship between statin use and incident of readmission for myocardial infarction. Patients who were on antiplatelet agents were more likely to be readmitted for stroke at 1 and 4 weeks (odds ratio: 2.109 and 2.335, p value: 0.0204 and 0.0036). Patients who were on ACE-I were more likely to be readmitted for stroke at 1 and 4 weeks (odds ratio: 2.0331 and 1.945; p value: 0.0062 and 0.0055). The benefit of statin therapy in COVID-19 patients has been established previously. This is potentially due to two mechanisms: anti-inflammatory properties and lipid lowering. Our studies did not find significant relationship between statin use and incidence of re-admission for myocardial infarction. We deduce that this is due to the anti-inflammatory effect of statins in acute COVID-19, and not the lipid lowering effect. Patients who are on anti-platelet therapy are more likely to be readmitted for stroke. This is likely because they are at high risk for stroke, and COVID-19 increases their systemic inflammatory response and therefore increase stroke risk. Lastly, our study suggests there may be some relationship between ACE-I use and stroke post-COVID-19 infection.
Abstract 418: Sars-cov2 Infection Leads To Pulmonary Vascular Remodeling In Transgenic Mice Expressing Human ACE2 In Vascular Cells
Authors: Frisdal Angèle , Morosan Serban , Enond Christelle , Marot Stéphane Sylvain , Marcelin Anne-Geneviève , Hatem Stéphane , Nadaud Sophie
Published: October 2023

Introduction:
COVID-19 leads to multiple cardiovascular consequences that have been linked to the major inflammation observed in patients. As most cardiovascular cells express the SARS-Cov2 receptor ACE2, cell injury by direct viral infection could also be at play. However most experimental studies have been performed with mouse models expressing hACE2 only in epithelial cells.

Hypothesis:
Our hypothesis is that the vascular consequences of SARS-Cov2 infection are also dependent on the vascular expression of the receptor.

Methods:
We used mice expressing epithelial hACE2 (keratin 18 promoter) and mice with hACE2 replacing the endogenous mACE2 gene (hACE2-KI). K18-hACE2 and hACE2-KI mice were infected with two doses of SARS-Cov2 (New-York strain, 5 and 50 pfu) and sacrificed at 5 days or 21 days. Hearts and lung tissue were examined for SARS-Cov2 presence by immunofluorescence. We also determined pulmonary vessels muscularization using immunofluorescence and cardiac tissue alteration using collagen staining.

Results:
K18-hACE2 showed higher sensitivity to SARS-Cov2 infection than hACE2-KI, with rapid weakening and death of most K18-hACE2 mice before day 8 whereas hACE2-KI mice were very mildly affected. Viral protein was found in both cases in the lung but not in the heart at day 5. At day 21, hACE2-KI mice displayed a significant neomuscularization of pulmonary vessels (70% of muscularized vessels, x2 vs non infected control, p=0.03) whereas it was much weaker and not significant (48% of muscularized vessels, x1.4 vs non infected control, p=0.2) in lungs of surviving infected K18-hACE2 mice (n=4 in all groups). No cardiac alterations or fibrosis could be observed in surviving mice of both lines. In K18-hACE2 mice, hACE2 was only expressed in alveolar epithelial cells and not in the pulmonary vessels nor in the heart. In hACE2-KI mice, hACE2 was expressed in alveolar epithelial cells, vascular smooth muscle cells and cardiac epicardial cells.

Conclusion:
Our results suggest that pulmonary vascular remodeling associated with SARS-Cov2 infection is dependent on pulmonary vascular expression of hACE2 and that Covid-19 patients may be more susceptible to pulmonary hypertension development.
Abstract 424: Arachidonic Acid Synergizes With Aspirin In Cardioprotection Following Acute Myocardial Infarction
Authors: Talabieke Shaletanati , Yang Jianfeng , Wang Miao
Published: October 2023

Introduction:
Membrane-released arachidonic acid (AA) is metabolized via cyclooxygenase pathway to form prostanoids, including thromboxane, prostacyclin and prostaglandin E2. Aspirin suppresses platelet synthesis of thromboxane, rendering its first-line use for anti-thrombosis in patients with acute myocardial ischemia. We report that endogenous PGE2 protects against myocardial ischemia-reperfusion (MI/R) injury (Nat Commun. 2019;10(1):1888). The impact of AA administration while suppressing thromboxane on MI/R injury is unknown.

Methods and Results:
C57BL/6J mice were treated intravenously with vehicle, AA, aspirin, or their combination and then subjected to 30min coronary artery ligation and 24hr reperfusion. Cardiac function was assessed by ultrasonography and infraction size quantified by TTC staining. Cardiac microcirculation was assessed by laser doppler flow and vasomotor reactivity determined with isolated coronary arteries. Single treatment with AA at an optimized dose of 0.1mg/Kg, or combined with aspirin at a dose of 10mg/Kg that allowed sufficient suppressing of platelet activation over 24hr, decreased infarct size and improved heart function. Impressively, combination of AA with aspirin provided additional cardioprotection compared with either single treatment. While aspirin, not AA, ameliorated microvascular obstruction following MI/R injury, co-administration of AA and aspirin further increased coronary microcirculatory blood perfusion with improved vascular permeability compared with aspirin alone. MI/R impaired endothelium-dependent dilatation of coronary arteries, and the dual treatment, not AA or ASA alone, increased coronary artery relaxation. Cardiac infiltrated neutrophils and platelet-neutrophil aggregates were also reduced by the combination treatment, consistent with a suppressed leukocyte-ECs adhesion as assessed in vitro.

Conclusions:
AA and aspirin synergistically protect against MI/R injury and this is attributable to suppressed neutrophil inflammation and improved microvascular obstruction. AA might be used as an adjunct therapy to aspirin in patients with acute myocardial infarction.
Abstract 426: Genomic Structural Equation Modeling To Identify Shared And Distinct Genetic Drivers Of Cardiovascular Disease
Authors: Angueira Anthony , Levin Michael ,   VA Million Veteran Program, Bown Matt , Jones Greg , Roychowdhury Tanmoy , Tsao Philip S , Klarin Derek , Damrauer Scott M
Published: October 2023

Aneurysmal diseases of the aorta are among the most morbid cardiovascular diseases without effective medical therapies. Many genetic and environmental factors have been linked to thoracic and abdominal aortic aneurysmal disease; however, there is little data identifying shared and distinct genetic factors underlying aortic aneurysmal disease. In both diseases, degeneration of the medial smooth muscle layer leads to dilation of the vessel and predisposition to and rupture. Whether there are common and distinct genetic factors that function within the vasculature to predispose to aortic aneurysms is unknown. We utilized structural equation modeling to identify a common genetic signature associated with cardiovascular diseases and traits including: abdominal aortic aneurysms (AAA), thoracic aortic aneurysms (TAA), thoracic aortic diameter, peripheral arterial disease (PAD), and coronary artery disease (CAD) as a means to identify novel targets to study. We identified that AAA displays a positive genetic correlation with TAA as well as CAD and PAD. We then constructed a structural equation model that contained four novel factors: 1. Atherosclerotic factor, 2. Aneurysmal factor, 3. AAA-specific factor, 4. Aortic dimension factor. We identified that the atherosclerotic factor explained a large amount of genetic variance in CAD and PAD as well as a modest amount of variance in AAA. GWAS of the ‘atherosclerotic factor’ identified loci implicated in lipid homeostasis and inflammation. The ‘aneurysmal factor’ explained a large amount of genetic variance in TAA and aortic dimension as well as a modest amount in AAA. Notably GWAS for the ‘aneurysmal factor’ identified loci enriched in ECM components and smooth muscle contractile genes. Finally, we identified a factor explained the ‘residual’ genetic heritability underlying AAA. GWAS for this ‘residual factor’ identified a smaller number of hits enriched in matrix metalloprotease biology. Taken together, this study has highlighted the shared and distinct hereditability underlying aortic aneurysmal phenotypes and highlights a novel strategy for prioritizing loci for future study.
Abstract 428: O-GlcNAcylation Enhances Angiogenic Transdifferentiation And Vascular Regeneration
Authors: Lu Alexander J , Cooke John P , Lai Li
Published: October 2023

The ability to restore or enhance the microvasculature would be a major advancement in regenerative medicine and cardiovascular therapies. Angiogenic transdifferentiation from fibroblasts to endothelial cells has been shown to directly contribute to microvasculature repair and perfusion restoration after ischemia. Previous studies uncovered that regulating cell metabolism to facilitate angiogenic transdifferentiation could be a novel strategy to treat ischemic vascular diseases. To comprehensively characterize the metabolic contribution to the regulation of angiogenic transdifferentiation, we performed unbiased metabolomic profiling and discovered uridine diphosphate N-acetylglucosamine (UDP-GlcNAc), and O-GlcNAcylation may regulate epigenetic reprogramming in angiogenic transdifferentiation. O-GlcNAcylation is an essential post-translational protein modification (PTM), which uses UDP-GlcNAc as the substrate to directly alter protein activity. O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA) are the pair of enzymes that add or remove this protein modification, respectively. In vitro, the pharmacologic or genetic inhibition of OGT impairs transdifferentiation while inhibition of OGA enhances transdifferentiation. Lineage tracing studies
in vivo
showed that inhibition of O-GlcNAcylation attenuated angiogenic transdifferentiation
in vivo
. Fibroblast-specific knockout mice further showed that OGT KO impaired vascular recovery and OGA KO enhanced revascularization, supporting that O-GlcNAcylation is critical for angiogenic transdifferentiation and vascular regeneration. Mechanistically, we show evidence that O-GlcNAcylation of the H3.3 chaperone protein HIRA regulates angiogenic transdifferentiation and the de novo deposition of H3.3 into chromatin. In conclusion, O-GlcNAcylation regulates angiogenic transdifferentiation and vascular regeneration by regulating H3.3 deposition to facilitate cell fate plasticity and is a novel therapeutic target for treating ischemic vascular pathologies.
Abstract 429: Integrating Single-nuclei And Spatial Transcriptome Analysis To Identify Early Injury Pathways Following Arterial Venous Bypass
Authors: Mota Lucas , Michaud Marina E , Pilcher William J , Tomeo John N , Aridi Tarek , Thomas Beena E , Bakhtiari Mojtaba , Contreras Mauricio , Pradhan-Nabzdyk Leena , LoGerfo Frank W , Bhasin Manoj , Liang Patric
Published: October 2023

Vein graft failure (VGF) occurs in 20-40% of coronary and lower extremity bypasses within the first-year secondary to intimal hyperplasia. Despite previous work identifying the key genomic responses associated with implantation injury, the complex signaling pathways and biomolecular identities at the cellular and spatial levels have yet to be elucidated. We utilized integrated single-nuclei and spatial transcriptomics analysis to investigate the pathologic response to vein graft injury that occurs at 24hr after implantation of an autogenous cephalic vein in a canine carotid artery interposition bypass model. We identified upregulation of specific genes, including FNDC3B and VCAN, which have been implicated in smooth muscle cell (SMC) dysfunction, vascular injury and atherosclerosis, and downregulation of AHNAK, a gene known to promote vascular healing and accelerate re-endothelization (Figure 1). Interestingly, our spatial transcriptomics analysis revealed that the response to injury does not occur in a circumferential pattern in the vein graft. Genes associated with vascular dysfunction were more highly expressed in a distinct area of the graft that comprises approximately 25% of the entire circumference, representing a site of tear or mechanical injury. This area had a differential decrease in SMCs and increase in monocyte/macrophages compared to the remaining regions of the graft. These results highlight the feasibility and importance of single nuclei and spatial integrated analysis in understanding tissue architecture as well as genomic changes following vein graft implantation, to ultimately help identify novel targets for therapeutic intervention.
Abstract 440: Role Of Retinoid X Receptor In Regulating Pcsk9 Transcription In The Liver And Atherosclerosis
Authors: Choubey Mayank , Wang Xiang , Tirumalasetty Munichandra , Yadav Pradeep K , Ansari Abulaish , Rajan Sujith , Hu Wenquan , Hussain M M , Miao Qing R
Published: October 2023

Nonalcoholic fatty liver diseases (
NALFD)
are associated with high cardiovascular disease (
CVD
) risk. The demand for novel CVD treatments leads to the recent discovery of the Proprotein Convertase Subtilisin Kexin 9 (
PCSK9
), which promotes the degradation of low-density lipoprotein receptor (
LDLR
) to increase atherogenic lipoprotein LDL cholesterol (
LDL-C
) levels. Targeting PCSK9 shows promising benefits in mitigating CVD and NAFLD. However, the underlying mechanism causing the NAFLD-associated PCSK9 induction is still unclear.
Our findings fill the critical knowledge gap by elucidating that
Retinoid X Receptor alpha (

RXRα

) is essential to regulate the transcription of PCSK9 in the liver.
Our preliminary data showed that hepatic depletion of RXRα leads to hepatic steatosis. To reveal the underlying mechanism by which hepatic RXRα deficiency promotes NAFLD development, we carried out the RNA-seq analysis. The Gene Set Enrichment Analysis (
GSEA
) of RNA-seq data showed the expected downregulation of PPARα signaling genes and the unexpected upregulation of cholesterol pathway genes in the liver of RXRα hepatocyte-specific knockout (
hepKO
) mice. One of the significantly upregulated genes in the cholesterol pathway is PCSK9, which induction in the liver of RXRα hepKO mice can be abolished by AAV8-mediated overexpression of RXRα. Consistently, we observed the increased cholesterol and LDL-C in the plasma of RXRα hepKO mice, and hepatic overexpression of RXRα can significantly reduce the plasma cholesterol and LDL-C levels. Recently, we identified a previously unrecognized acetylation residue of RXRα, which controls the heterodimerization between RXRα and PPARα. The inhibitory effects of constitutively acetylated RXRα mutant further indicate that acetylation of RXRα is essential for preventing the induction of PCSK9 in the liver of RXRα hepKO mice. Interestingly, we also observed the decreased acetylation of RXRα in the liver of high-fat diet (
HFD
)-fed mice and human NAFLD patients. These results suggest
that
RXRα acetylation is required for regulating the PPARα-mediated repression of PCSK9 transcription in the liver, and impaired RXRα acetylation in the NAFLD liver results in increased PCSK9 and atherosclerosis risk.
Abstract 442: Anaconda Right Coronary Artery
Authors: Khan Muhammad S , Ahmed Owais , Nwaedozie Somto
Published: October 2023

Background:
Although coronary artery ectasia is documented in up to 5% of coronary angiograms, true coronary artery aneurysms are not common (<1% of all angiograms). The underlying mechanism of coronary ectasia is not well-known. In addition to atherosclerosis, trauma, systemic inflammatory disorders, genetic susceptibility may also play a role in the causation of coronary ectasia.

Case Presentation:
A 61-year-old male with a past medical history of dyslipidemia, hypothyroidism, cigarette smoking and obesity was brought to the hospital after levothyroxine overdose. While inpatient, he had chest discomfort and EKG showed inferior STEMI [Fig.1]. The coronary angiogram revealed a very ectatic right coronary artery (RCA) [Fig.2]. There was a total occlusion of distal RCA. Multiple unsuccessful attempts to perform a PCI at the site of distal occlusion were performed.

Discussion:
Coronary artery ectasia can sometimes lead to acute or sub-acute clinical presentations such as acute MI from distal embolization of proximal local thrombosis. This is likely what lead to acute MI in our patient. Other complications may include local compression of adjacent cardiovascular structure, and rupture leading to cardiac tamponade. It is important to note that the treatment of coronary ectasia should be individualized based on the fact of whether the ectasia is a culprit for the clinical presentation or simply represents an incidental finding. Potential treatment options can range from surgery, PCI or pharmacological medical therapy only.

Conclusion:
Since the pathophysiology of coronary artery ectasia is not well delineated and there are no obvious society guidelines regarding its management, therefore, it is of the utmost importance to take into account the location of coronary ectasia, its clinical presentation and underlying risk factors.