bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 4905: High Density Lipoprotein is Dysfunctional in Primary Antiphospholipid Syndrome and is Associated With Impaired Vascular Function
Authors: Charakida Marietta , Besler Christian , Batuca Joanna , Sangle Shirish , Alves José , D’Cruz David , Tousoulis Dimitris , Mackworth-Young Charles , Lüscher Thomas , Deanfield John
Published: April 2024

Objectives: Antiphospholipid syndrome is characterised by increased thrombogenicity and/or pregnancy morbidity in the presence of raised levels of antiphospholipid antibodies (aPL). Increased oxidative properties of HDL (decreased activity of paraoxonase (PON) and accelerated atherosclerosis have been described in this syndrome. In this study, we assessed the functional properties of HDL and evaluated its impact on the vasculature in aPL positive patients and matched controls.

Methods: We studied 77 women with positive aPL (APL) aged 46.6 ± 1.2 yrs (mean ± SE) and matched Controls of 77 women aged 47.5 ± 1.2 yrs. In all subjects, carotid intima media thickness (IMT), flow mediated dilatation (FMD) and pulse wave velocity (PWV) were measured. PON activity was assessed by measuring p-nitrophenol formation. HDL was isolated in APL (N = 6) and Controls (N = 6). The impact of HDL on human aortic endothelial cell (HAEC) nitric oxide (NO) and superoxide production were determined. Anti-inflammatory properties of HDL were examined by analyzing the effect of HDL on endothelial cell VCAM-1 expression and monocyte adhesion to activated HAEC.

Results: APL had significantly increased IMT and PWV compared to Controls (0.75 ± 0.02mm vs 0.65 ± 0.01mm, p < 0.001 and 9.14 ± 0.18 m/s vs 8.56 ± 0.21m/s, p < 0.05 respectively) and decreased FMD (6.2 ± 0.5% vs 9.6 ± 0.5%, p < 0.001). PON activity was significantly reduced in APL compared to Controls (p = 0.006). PON activity was inversely associated with cIMT and PWV in APL (p < 0.05 for both) but not in Controls. HDL from Controls increased endothelial cell NO production, whereas in marked contrast HDL from APL reduced NO production by 20% (p < 0.0001). The beneficial effect of HDL on endothelial VCAM-1 expression, superoxide production and monocyte adhesion was diminished in APL (p < 0.05 for all).

Conclusions: APL is associated with impaired vascular function and structure. PON activity is decreased in APL and is inversely associated with IMT and PWV. HDL in APL is associated with decreased endothelial NO production and has impaired anti-inflammatory and anti-oxidant properties.

These findings suggest that HDL is dysfunctional in APL and support its role in promoting early vascular changes in antiphospholipid syndrome.
Abstract 4906: Systemic Nrf2 Expression Enhances Atherosclerosis Partially by Effects on Plasma Lipoproteins
Authors: Barajas Berenice , Gong Ke Wei , Orozco Luz D , Wang Xuping , Castellani Larry , Reue Karen , Lusis Aldons J , Araujo Jesus A
Published: April 2024

Background
: Nrf2 has been shown to be an important transcription factor and “master” orchestrator of the cellular anti-oxidant and anti-inflammatory response by regulating the expression of a variety of antioxidant genes such as Heme oxygenase 1, superoxide dismutase, catalase among many others. We have previously developed Nrf2 KO mice on the apoE null background to assess the role of Nrf2 on atherogenesis, resulting in Nrf2 homozygous (KO), heterozygous (HET) and wild-type (WT) littermates. Unexpectedly, we found that 14-week-old chow-fed KO males exhibited 47% and 53% lower lesions than HET and WT mice respectively, in agreement with a recently published report. The purpose of this work was to determine mechanisms that could explain Nrf2 proatherogenic effects.

Methods:
Male and female mice from all three genotypes underwent retroorbital bleeding at 14 weeks of age. Plasma lipoproteins were determined by enzymatic methods. Expression of lipid metabolic genes was assessed in the liver by qPCR. Atherosclerotic lesions were scored in the aortic root as
μ
m
2
/section.

Results: KO mice exhibited markedly decreased levels of plasma total cholesterol at the expense of the non-HDL fractions, decreased free fatty acids, unesterified cholesterol and glucose in a manner akin to the aortic atherosclerotic outcomes and in a sex-dependent fashion. Atherosclerotic lesion scores correlated positively with plasma total cholesterol levels in males (r = 0.47, p = 0.008) but not in females (r = −0.005, p = 0.98). These metabolic effects could be partially explained by the regulation of hepatic genes involved in lipogenesis. We found that as compared with WT controls, KO male livers displayed significant reduction (p < 0.05) in the mRNA levels of Me1 (malic enzyme 1), lipin1 and trends toward decreased levels of fatty acyl synthase (FAS), glucose 6-phosphate dehydrogenase (G6PDH), diacylglycerol acyl transferase (DGAT1) and HMG-CoA reductase. In addition, hepatic Me1 levels in male mice correlated positively with the levels of total plasma cholesterol levels (r = 0.43, p = 0.02) and free fatty acids (r = 0.54, p = 0.003).

Conclusions:
Nrf2 expression promotes atherosclerosis partly by effects on plasma lipoproteins, likely associated with increased hepatic lipogenesis.
Abstract 4913: Glutathione Peroxidase-1 Modulates the Effects of Tumor Necrosis Factor-alpha in Endothelial Cells by Regulating Dual Specificity Phosphatase 4
Authors: Lubos Edith , Kelly Neil J , Leopold Jane A , Zhang Ying-Yi , Loscalzo Joseph , Handy Diane E
Published: April 2024

Reactive oxygen species (ROS) have been implicated in pro-inflammatory signal transduction activated by tumor necrosis factor-
α
(TNF-
α
). For this reason, we examined the effect of glutathione peroxidase-1 (GPx-1), an important antioxidant enzyme, on TNF-
α
-induced changes in gene expression in endothelial cells. In human microvascular endothelial cells (HMVEC), we showed that suppression of GPx-1 mRNA by 96.6% (p<0.0001) with siRNA (siGPx-1) increases ICAM-1 mRNA (3.6-fold, p<0.01) and protein (7.1-fold, p = 0.0002) expression compared to siControl cells, and GPx-1 deficiency augments TNF-
α
-induced ICAM-1 mRNA (2.1-fold, p<0.0001) and protein (2.5-fold, p = 0.001) expression, in part, by enhancing ROS production and prolonging I
κ
B
α
degradation and phospho-ERK1/2 activation. The antioxidants,
N
-acetyl-L-cysteine and diphenyleneiodonium chloride, or adenoviral over-expression of GPx-1 significantly attenuated these TNF-
α
-mediated responses. Similarly, endothelial cells cultured from GPx-1 knockout mice had augmented TNF-
α
-mediated ICAM-1 expression, whereas cells from transgenic mice overexpressing GPx-1 showed blunted responses to TNF-
α
, confirming that GPx-1 modulates the inflammatory response to TNF-
α
. To analyze further signaling pathways, we performed microarray analysis of HMVEC treated with TNF-
α
in the presence and absence of GPx-1. Among the genes whose expression changed significantly, dual specificity phosphatase 4 (DUSP4), an antagonist of MAPK signaling, was downregulated 3.2-fold (p<0.005) by GPx-1 suppression. Quantitative real time PCR confirmed that GPx-1 deficiency enhanced DUSP4 suppression by TNF-
α
(p<0.01). Targeted knockdown of DUSP4 mRNA by 78.5% (p<0.0001) significantly increased TNF-
α
-mediated ICAM-1 and VCAM-1 gene expression (p<0.01 and p<0.012, respectively), suggesting that loss of DUSP4 is sufficient to augment TNF-
α
-mediated induction of adhesion molecule expression. Taken together, these data show that GPx-1 modulates endothelial cell activation by TNF-
α
, in part, by modulating DUSP4 expression. These results highlight a novel mechanism by which GPx-1 modulates ROS-dependent signaling in endothelial cells.
Abstract 4919: Contradictive Estrogen Effects on BMP Signaling in Pulmonary Artery Depend on Oxygen Concentration
Authors: Ichimori Hiroaki , Kogaki Shigetoyo , Takahashi Kunihiko , Ishida Hidekazu , Narita Jun , Nawa Nobutoshi , Uchikawa Toshiki , Maekawa Shu , Matsumoto Sayaka , Okada Yoko , Ozono Keiichi
Published: April 2024

Epidemiologic studies have shown that the female predominance in the morbidity of Idiopathic PAH (pulmonary arterial hypertension) in the world, which suggests a role of female sex hormones in the pathogenesis of PAH. Our previous study demonstrated the contradictory effects of estrogen on pulmonary arterial endothelial cells (PAEC) via BMP (Bone Morphogenetic Protein) signaling depend on cellular oxygen environment. This study is to investigate the mechanism of the contradictory effect of
β
-estradiol (E2) upon BMP signaling in PAEC.

 Human and rat PAEC were cultured and the expression of BMPR2, Smad1/5/8, and Id1 were examined under 21%O
2
(normoxic; N) or 1%O
2
(hypoxic; H) condition in the presence of E2. We investigated the effect of estrogen receptor antagonist (ICI 182.780.) and searched for an evidence of binding interaction between estrogen receptor (ER) and Smad. In the presence of E2 (10
−7
M), the expression of BMPR2, phosphorylated Smad (p-Smad)1/5/8 proteins, Id1 mRNA was augmented under N and suppressed under H. We confirmed same phenomena by using Id1 promoter assay. These alterations of BMPR signal expression were inhibited by ICI182.780. An Immunoprecipitation experiment demonstrated a direct binding interaction between ER and p-Smad1/5/8 proteins only under H, whereas estrogen response activity measured by luciferase assay was increased by E2 only under N. In addition, HIF-1
α
augmentation by cobalt chloride suppressed BMP signaling, whereas HIF-1
α
inhibition by YC-1 augmented those expression. By inhibiting de novo synthesis by administration of cycloheximide, p-Smad1/5/8 were suppressed under N, but could not change under H. We demonstrated that the alteration of BMP signaling in PAEC under different O
2
condition was associated with HIF-1
α
expression and the presence of E2. This alteration may also relate to an interaction between BMP signaling and receptor-mediated estrogen pathway under hypoxia, and to de novo synthesis under normoxia. Our observations provide the new mechanism how sex hormone affects on BMP signaling, a key signal pathway for PAH, which can offer novel therapeutic targets in the treatment of PAH.
Abstract 4928: Coronary Flow Reserve is Reduced in Pulmonary Arterial Hypertension Patients
Authors: Yamada Osamu , Tsuda Etsuko , Ohuchi Hideo
Published: April 2024

Background: Pump function of the right ventricle, which is a major determinant of prognosis in pulmonary arterial hypertension (PAH), is much influenced by coronary perfusion. Acute studies in animals exhibited paradoxical coronary flow decrease under excessive pressure overload. However, little is known about human or chronic coronary flow reserve (CFR) in PAH.

Methods: Coronary flow measurement with pulse Doppler was performed for 19 PAH consecutive patients (right ventricular systolic pressure RVSP 89.7±22.7 mmHg; age 22.0±5.5 year; 10 females, data are mean±SD). The control state blood velocity was recorded in distal right coronary artery (RCA). The maximal blood velocity was recorded at the same site, on continuous infusion of adenosine triphosphate (150ng/kg/min). CFR was defined as the ratio of peak adenosine/baseline flow velocity. RVSP was adopted from the most adjacent catheterization. Coronary arterial lesions were excluded with coronary angiogram.

Results: RCA flow signals were achieved in 17/19. Systolic flow signals were observed in 2/17. RCA diastolic peak velocity in basal condition was somewhat higher than reported in normal subjects (29.9±11.4 cm/sec) and positively correlated with right ventricular systolic pressure (RVSP) with significance (R^2 = .236; p<0.05). CFR of RCA ranged 1.55– 4.16 (2.46±0.82) and was below 2.0 in 7/17. It negatively correlated with RVSP (R^2 = .383; P < 0.01).

Conclusion: Peak flow velocity of RCA in PAH correlated with RVSP, in reply to greater energy demand of RV. CFR of RCA was low and negatively correlated with RVSP, which may suggest poor energy supply reserve in PAH patients.
Abstract 4936: Endovascular Perfusion of Pluripotent Mesenchymal Stem Cells Stabilizes Already-formed Aortic Aneurysms in a Rat Model
Authors: Schneider Fabrice , Dai Jian Ping , Taurel Marianne , Desgranges Pascal , Becquemin Jean-Pierre , Allaire Éric
Published: April 2024

Introduction:
Endovascular cell therapy using catheter-based delivery of Vascular Smooth Muscle Cells (VSMCs) has been shown to stabilize diameter of expanding Abdominal Aortic Aneurysms (AAAs) in rat. Mesenchymal Stem Cells (MSCs) are able to differentiate into VSMCs after stimulation by Platelet Derived Growth Factor-BB (PDGF-BB). Our goal was to assess the impact of MSCs endovascular perfusion with or without pre-differentiation by PDGF-BB stimulation on aneurysm growth.

Materials and methods:
After selection by plastic adhesion, bone marrow derived-MSCs were stimulated or not by PDGF-BB and phenotyped by immunohistochemistry. AAAs obtained by xenograft degeneration were perfused endovascularly with 1 million of VSMCs (n=5), MSCs (n=6), PDGF-MSCs (n=6) and medium culture as controls (n=4). Rats were euthanized 1 week later or 4 weeks later (non differentiated MSCs (n=6) and culture medium (n=5)) for diameter measurement and AAA harvesting for mRNA (MMP-9, TIMP-1) quantification.

Results:
MSCs were CD90
+
, CD44
+
, CD45
−
and CD11
b
−
and after PDGF stimulation strongly expressed calponin,
α
-actine and myosin. At 1 week, MSC infusion decreased aneurysm growth compared to SMCs and control group (% diameter increase: 6.5%+/−9.7, 25.5%+/−17.2 and 53.4%+/−14.4 respectively; p<0,05) whereas PDGF-MSCs increased aortic growth rate (55.6%+/−26.6; p<0,05) and induced rupture (n=3/6 AAAs). Perfusion of MSC decreased expression of MMP-9 and increased TIMP1 expression compared to controls. At 4 weeks, MSC signicantly decreased aneurysm growth compared to control group (9.2%+/−13.8 and 76.2%+/−17.4, respectively; p<0.05)

Conclusion:
Pluripotent MSCs stabilized growth of expanding AAAs more efficiently than VSMCs and decreased proteolytic activity in the aortic wall. Predifferentiation suppressed the stabilization properties of MSCs, suggesting the importance of pluripotency of progenitors in aneurysm repair.
Abstract 4943: Enhanced Stability of Plasminogen Activator Inhibitor-1 in Patients With Livedoid Vasculopathy
Authors: Agirbasli Mehmet , Eren Mesut , Vaughan Douglas E
Published: April 2024

Livedoid vasculopathy (LV) is a chronic, recurrent, painful cutaneous disease with distinctive clinical features and an uncertain etiology. The skin lesions are recognizable by focal purpura, depigmentation and shallow ulcers. Thrombophilic conditions occur frequently in patients with LV. While no definitive treatment exists for LV, smoking cessation, antiplatelet therapy, immunosuppressive treatment, anabolic steroids are often included in the therapeutic ladder. Recently, a possible link between LV and impaired fibrinolysis was suggested and cutaneous LV lesions responded to tissue plasminogen activator (t-PA) infusion. Hence, inhibition of the fibrinolysis through plasminogen activator inhibitor-1 (PAI-1) activity may determine the disease course in patients with LV. In this study, we investigated PAI-1 Ag and activity levels in 8 patients with biopsy proven LV (mean age 33±18, M/F = 1, median disease duration 5 years). All patients received antiplatelet treatment with aspirin and/or dipyrimadole and 6 patients received anabolic steroids or immunosuppressive treatment. Fasting PAI-1 antigen and activity levels were measured at 9 AM in all patients. Both PAI-1 Ag levels were 44±11 (ng/ml) and PAI activity levels were 16±9 (U/ng/ml) were moderately elevated compared to age-matched controls. However, PAI-1 kinetic studies demonstrated, markedly enhanced stability of PAI-1 activities in plasma from patients with LV. Specific activity at 16 hours were significantly higher than expected activity levels (0.1±0.1 versus 0.001±0.001 u/ng/ml, p=0.028). In conclusion, enhanced stability of PAI-1 may contribute to the pathophysiology of LV, mediated via either binding with stablizing co-factors or by post-translational modification in the PAI-1 protein. Systemic or local treatment with PAI-1 inhibitors may offer potential treatment alternative in patients with LV.
Abstract 4966: The High Mobility Group AT-hook 2 Gene Plays a Crucial Role in the Development of Aortic Rupture
Authors: Mohamed Salah A. , Meyer Anke , Stegen Isabel , Radtke Arlo , Richardt Doreen , Nimzyk Rolf , Nigam Vishal , Sievers Hans H. , Bullerdiek Joern , Belge Gazanfer
Published: April 2024

Introduction

The
high mobility group AT-hook 2
(
HMGA2
) gene has recently been shown to be a transcriptional organizer of transforming growth factor (TGF-β) signaling. It is proposed that
HMGA2
acts in a gene-specific manner to regulate factors involved in epithelial-mesenchymal-transition (EMT), known to be expressed only during embryogenesis. We analyzed the expression profile of the
HMGA2
gene in human aortic diseases.

Methods and Results

Aortic specimens were collected during surgery from 51 patients (mean age 56.8±15.3), 19 patients with acute aortic dissection (type A, 14m/5f), 26 samples obtained from aortic aneurysms (14 patients showed a bicuspid aortic valve, 12 patients tricuspid aortic valve), two Marfan syndrome samples, and aortic valves. Quantitative Real-Time-polymerase chain reaction (qRT-PCR) and immunohistochemical analysis were performed. The expression of let-7 microRNA, assumed to play a role in regulation of
HMGA2
in cancer cells, was quantified and measured in fetal RNA. The
HMGA2
gene was highly expressed in aortic type A dissection compared with all other samples (193.1 vs 8.7 fold,
p
= 2,4.10
−7
). In fetal RNA,
HMGA2
was expressed with 48-fold, however no significant expression of let-7 microRNA was detected among all investigated samples. Immunohistochemical investigation showed that HMGA2 protein was mainly detected in the endothelial cells of the
vasa vasorum
.

Discussion

The upregulation of
HMGA2
in acute aortic dissection may indicate an involvement in the pathogenesis of rupture. HMGA2 protein was mainly restricted to cells of the
vasa vasorum
. It seems that
HMGA2
-overexpression in aortic cells occurs in a let-7 independent manner, leading to increase angiogenesis of the
vasa vasorum
.
Abstract 5011: The Contribution of COX-1 and COX-2 to Platelet Activation in Essential Thrombocythemia: A Clinical Paradigm of Aspirin-resistant Thromboxane Biosynthesis
Authors: Rocca Bianca , Dragani Alfredo , Pascale Silvia , Recchiuti Antonio , Mattoscio Domenico , Lattanzio Stefano , Petrucci Giovanna , Mucci Luciana , Ferrante Elisabetta , Habib Aida , Ranelletti Franco Oreste , Davì Giovanni , Patrono Carlo
Published: April 2024

Low dose aspirin-resistant thromboxane (TX) A2 biosynthesis has been reported in different clinical settings, including acute coronary syndromes, myeloproliferative disorders and diabetes mellitus. Cyclooxygenase (COX)-2 expression in newly formed platelets and/or unacetylated COX-1, because of accelerated platelet regeneration, might explain this phenomenon. We tested this hypothesis in patients with essential thrombocythemia (ET), an extreme pathophysiological paradigm of accelerated thrombopoiesis. The study was approved by local Ethical Committee. Forty-one ET patients (21M, 20F, mean age 52±14 yr) on chronic aspirin therapy (100 mg/day) were studied on repeated occasions. COX-2 expression was detectable by immunocytochemistry in a significantly (p<0.001) higher percentage of circulating platelets from ET patients than healthy subjects: 19 [16–19] % vs. 6 [4–7] % (median [IQR]), respectively. Furthermore, COX-2 expression in platelets was significantly and positively correlated with the fraction of the youngest, RNA-expressing circulating platelets in ET patients (r=0.62, p<0.01). Urinary 11-dehydro-TXB2 (TXM) excretion, a non-invasive marker of platelet activation, was significantly higher in ET patients than in 48 aspirin-treated controls: 349 [257–484] pg/mg creatinine vs. 137 [105–187] pg/mg creatinine (p<0.01) (median [IQR]). ET patients were randomized to continuing low-dose aspirin alone or adding etoricoxib (90 mg/day), a highly selective COX-2 inhibitor, for 7 days. Etoricoxib significantly reduced TXM excretion by 25% (p=0.04), while TXM excretion was unaffected in the aspirin-alone arm. Whole blood TXB2 was similarly and significantly reduced following etoricoxib ex vivo or in response to NS-398 (a selective, in vitro COX-2 inhibitor), added to whole blood samples in vitro (by 22 and 30%, respectively, p<0.001). The addition of aspirin (50 microM) to ET platelets in vitro completely suppressed whole blood TXB2 production. We conclude that a variable fraction of both unacetylated COX-1 and COX-2 contribute to TXA2 biosynthesis that is resistant to a conventional once daily regimen of low-dose aspirin, in a clinical setting characterized by accelerated thrombopoiesis and increased thrombotic risk.
Abstract 5017: Osteoprotegerin and the Risk of Recurrent Events in Patients With Non-ST elevation Acute Coronary Syndromes (NSTE-ACS): Observations From MERLIN-TIMI 36
Authors: Bonaca Marc , Omland Torbjorn , Sabatine Marc S , Murphy Sabina A , Scirica Benjamin M , Rasmussen Lars M , Flyvbjerg Allan , Morrow David A
Published: April 2024

Osteoprotegerin (OPG) inhibits bone resorption and may also play a role in mediating vascular calcification. Recent studies have suggested that high plasma OPG is a strong predictor of cardiovascular disease (CV) and mortality. We hypothesized that OPG would be useful for risk assessment in patients presenting with NSTE-ACS.

METHODS:
We measured OPG at baseline in 4,463 pts with NSTE-ACS randomized to ranolazine or placebo in the MERLIN-TIMI 36 trial. Patients were followed for an average of one year. Endpoints were adjudicated by a blinded CEC.

RESULTS:
OPG at presentation showed a significant graded association with higher rates of recurrent CV events (Figure

). OPG > median (1632 pmol/L, IQR 1206–2242) was associated with a higher risk of CV death (HR 2.9; 95% CI 2.2 – 4.0), CV death or MI (HR 1.9; 95% CI 1.6 – 2.3), and CV death or CHF (HR 2.5; 95% CI 1.9 – 3.1). After adjustment for important covariates including age, gender, diabetes, smoking, HTN, index event, cTnI, CRP and BNP, OPG remained independently associated with the risk of death (adj HR 1.7; 95% CI 1.2 – 2.4), CVD or MI (adj HR 1.4; 95% CI 1.1 – 1.7) and CVD or CHF (adj HR 1.4; 95% CI 1.1 – 1.8).

CONCLUSIONS:
OPG was independently associated with long-term risk of recurrent CV events in patients with NSTE-ACS, adding to clinical predictors, cTnI, CRP and BNP. This finding in a large data set adds to the emerging evidence supporting OPG as a candidate prognostic marker in pts with ACS, and supports investigation of other therapies that might modify this risk.

Event Rates at 1 Year by Quartile of OPG
Abstract 5020: Effect of Rivaroxaban on Markers of Coagulation in Patients With Acute Coronary Syndromes: An ATLAS ACS-TIMI 46 Substudy
Authors: Gibson C. Michael , Mega Jessica L , Jennings Lisa K , Mohanavelu Satishkumar , Misselwitz Frank , Plotnikov Alexei , Sun Xiang , Zolynas Robert , Braunwald Eugene
Published: April 2024

Background:
Prothrombin fragments 1 and 2 (F1.2) and D-dimer (DD) are sensitive circulating markers of thrombin generation and fibrinolysis, respectively. Elevated concentrations of F1.2 and DD in ACS patients have been associated with adverse outcomes.

Methods:
In ATLAS ACS-TIMI 46, patients were randomized to placebo or the factor Xa inhibitor rivaroxaban (5–20 mg) twice daily (BID) or the same total daily dose once daily (QD). Blood samples were obtained at baseline, 8–24 hrs, and 180 days after drug administration.

Results:
1,006 subjects were included to date in this substudy. At baseline, F1.2 and DD levels were similar in the placebo, rivaroxaban BID, and rivaroxaban QD groups (F1.2: 241, 251, 259 pMol/L; DD: 0.69, 0.79, 0.76
μ
g/ml). Compared with placebo, rivaroxaban was associated with a significant reduction in F1.2 levels 8–24 hrs after administration in both the BID (240 vs 209 pMol/L, P<0.01) and QD (240 vs 177 pMol/L, P<0.001) groups. DD at baseline vs 8 –24 hrs was significantly increased in placebo patients (0.69 vs 0.75
μ
g/ml, P<0.05), but unchanged in patients receiving rivaroxaban. By day 180, F1.2 and DD were reduced in placebo patients, presumably because the previous thrombotic state had dissipated; however, patients receiving rivaroxaban continued to have even lower concentrations of both markers of coagulation (Figure

).

Conclusions:
In patients with ACS, rivaroxaban is associated with a significant, early reduction in F1.2 that persists throughout 180 days of treatment, as well as a reduction in DD evident at 180 days. These findings may explain, in part, the mechanism by which rivaroxaban reduces major cardiovascular events in patients following an ACS.
Abstract 5050: Wnt11 Enhances Mesenchymal Stem Cells Mediated Angiogenesis via Paracrine Signaling
Authors: Zuo Shi , Li Hongxia , He Zhisong , Wang Yigang , Ashraf Muhammad , Xu Meifeng
Published: April 2024

Neovascularization is essential for an organ repair. It has been previously reported that MSC transfected with Wnt11 (MSC
Wnt11
) promotes ischemic heart repair through protecting native cardiomyocytes. However, the mechanism of cardioprotection of MSC
Wnt11
remains unknown. Here, it is hypothesized that Wnt11 may enhance MSC mediated angiogenesis via the paracrine effects.

Methods:
MSCs were isolated from bone marrow of rats and transfected with Wnt11 using Clontech pMSCV retroviral expression system. MSCs transfected with GFP (MSC
GFP
) were used as control. MSC (2×10
6
/50
μ
l) were transplanted into the border area of ischemic rat hearts which have already underwent left anterior descending coronary artery (LAD) ligation. Four weeks post LAD ligation, regional myocardial blood flow in the ischemic and border zone was evaluated with a colored microsphere technique. The blood vessels were stained with von Willebrand factor (vWF) and counted in peri-infarct regions. Spontaneous capillary-like structure formation was monitored with Gelatin-coated Cytodex 3 microcarrier beads. The expression of growth factors was assayed by microarray and ELISA.

Results:
The blood flow was significantly increased and the density of blood vessel was higher in MSC
Wnt11
transplanted heart than that in MSC
GFP
transplanted hearts (Fig. A, B

). Microcarrier beads were completely covered by MSC
Wnt11
and formed a confluent monolayer and sprouts than MSC
GFP
(Fig. C

). Growth factors were highly expressed in MSC
Wnt11
(Table

and Fig. D

).

Conclusions:
Wnt11 promotes MSC mediated angiogenesis via up-regulating paracrine factors.
Abstract 5053: Deficiency of ASC (Apoptosis-associated Speck-like Protein Containing a Caspase Recruitment Domain) in Bone Marrow Cells Improved Myocardial Ischemia-Reperfusion Injury in Mice
Authors: Kawaguchi Masanori , Takahashi Masafumi , Hata Takeki , Kashima Yuichiro , Takahashi Yasuko , Sagara Junji , Taniguchi Shun’ichiro , Ikeda Uichi
Published: April 2024

Background:
Inflammatory responses play a key role in the pathophysiology of myocardial ischemia-reperfusion (I/R) injury. ASC is an adaptor protein that forms inflammasome whose activation leads to caspase-1-dependent interleukin (IL)-1
β
generation and subsequent inflammatory responses; however, the role of ASC in myocardial I/R injury remains to be determined.

Methods and Results:
ASC deficient (ASC
−/−
) and wild-type (WT) mice were subjected to 30 min LAD occlusion, followed by reperfusion. ASC
−/−
mice showed improved LV dysfunction (%FS: 34.0% vs. 25.7% at 14 days p<0.01), reduced infarct area/area at risk (IA/AAR: 18.7% vs. 28.6% at 48 h, p<0.01), and scar formation (scar/LV area: 9.7% vs. 14.6% at 14 days, p<0.01) after myocardial I/R. Immunostaining revealed decreased infiltration of macrophages (Mac3) and neutrophils (Gr-1), but not neovascularization (CD31), in the injured myocardium of the ASC
−/−
mice. Real-time RT-PCR and ELISA analyses demonstrated that the myocardial mRNA and protein expression of inflammatory cytokines, such as IL-1
β
, IL-6, and MCP-1, after I/R were significantly decreased in the ASC
−/−
mice. Further, improved myocardial I/R injury was also observed in the caspase-1
−/−
mice, compared with WT mice (IA/AAR: 20.2% vs. 28.6% at 48 h, p<0.05). Since double immunostaining revealed that ASC was expressed in the infiltrated macrophages and neutrophils, bone marrow-transplanted (BMT) mice were prepared. The IA/AAR was significantly decreased in the BMT
ASC−/−→WT
mice, compared with BMT
WT→WT
(IA/AAR: 17.8% vs. 27.9% at 48 h, p<0.01). Further,
in vitro
experiments showed that LPS-induced production of inflammatory cytokines such as IL-1
β
, IL-6, and MCP-1 in the ASC
−/−
-bone marrow cells was significantly decreased compared, with that in the WT-bone marrow cells.

Conclusion:
ASC deficiency improved myocardial I/R injury via inflammatory cell infiltration and cytokine expression. These results suggest that ASC is a novel therapeutic target for myocardial I/R injury.
Abstract 5066: Substance P Mediated Adventitial Mast Cell Activation Induces Intraplaque Hemorrhage in Advanced Atherosclerosis
Authors: Bot Ilze , de Jager Saskia C , Bot Martine , van Heiningen Sandra H , van Berkel Theo J , von der Thüsen Jan H , Biessen Erik A
Published: April 2024

Previously, we and others have shown that mast cells, present in intima and adventitia of advanced atherosclerotic lesions, play an important role in plaque progression and destabilization. However, the nature of the endogenous trigger for activation of these (peri)vascular cells during atherosclerosis is still unresolved. In this study, we show that perivascular mast cell content as demonstrated by CD117 staining correlates with the number of neurofilament
+
nerve fibers in the adventitia of human coronary atherosclerotic plaque specimens (P<0.05, r=0.42), suggestive of neural regulation of mast cell activation. Our attention turned to the neuropeptide substance P (SP) as mediator of mast cell activation via the neurokinin-1 receptor. Local perivascular administration of SP (0.1 nmol in 25% (w/v) F-127 pluronic gel) to advanced carotid artery plaques in apoE
−/−
mice did not affect plaque size at 3 days after challenge (SP: 67±14*10
3
μ
m
2
versus controls: 51±10*10
3
μ
m
2
, P=NS), however the number of adventitial mast cells was significantly enhanced in SP treated mice compared to PBS controls (4.9±0.8 versus 2.2±0.5 mast cells/mm
2
adventitial tissue, P<0.01). Also, mast cell activation status was increased in the SP challenged group (56±9% compared to 29±9% in controls, P<0.05). This was accompanied by a significant increase in the incidence of intraplaque hemorrhages (IPHs) in SP treated mice (5/12 compared to 0/15 in controls, P=0.01). SP mediated mast cell recruitment was inhibited by co-administration of the neurokinin-1 receptor antagonist Spantide-I (2.6±0.4 mast cells/mm
2
adventitial tissue, P<0.01), while in these mice hardly any IPHs occurred (1/16, P=0.06). Furthermore, SP was not effective in inducing IPHs in advanced carotid artery plaques of mast cell deficient apoE
−/−
Kit(W
−sh
/W
−sh
) mice (1/18, P<0.05), establishing the critical involvement of mast cells in SP elicited plaque destabilization. In conclusion, our data suggest that neurotransmitters such as SP are capable of promoting mast cell dependent plaque destabilization and our study thus provides a new, direct link between neural factors and vascular inflammation involving mast cells, which may be particularly relevant in acute cardiovascular syndromes.
Abstract 5074: The Rho Exchange Factor Arhgef1 in Vascular Smooth Muscle Cells is Essential for Angiotensin II-induced Hypertension
Authors: Guilluy Christophe , Brégeon Jérémy , Toumaniantz Gilles , Rolli-Derkinderen Malvyne , Retailleau Kevin , Loufrani Laurent , Henrion Daniel , Scalbert Elizabeth , Bril Antoine , Torres Raul M , Offermanns Stephan , Pacaud Pierre , Loirand Gervaise
Published: April 2024

Rho exchange factors (Rho-GEFs) are responsible for Rho protein activation by catalyzing the exchange of GDP for GTP. Although over-activation of RhoA and its effector Rho kinase is recognized as a critical component of the pathogenesis of hypertension in experimental models and in human, the molecular mechanisms and the RhoA-GEF(s) involved in this activation of RhoA signaling in vascular smooth muscle cells (VSMCs) are unknown. Among the Rho-GEFs family, Arhgef1 (p115) constitutes with Arhgef11 (PDZ-Rho GEF) and Arhgef12 (Larg) the subfamily of RGS-containing Rho-GEFs that have been suggested to couple G-protein associated receptors to RhoA activation. To establish the role of Arhgef1 in the regulation of vascular tone and hypertension
in vivo
, we generated mice lacking Arhgef1 specifically in SMCs (SM-Arhgef1-KO). We used Arhgef1
lox/lox
mice, which were mated to SMMHC-CreER
T2
. SM-Arhgef1-KO mice were then obtained by treatment with tamoxifen (1 mg/day, IP, 5 days). In VSMCs from SM-Arhgef1-KO mice, stimulation with angiotensin II (Ang II, 0.1
μ
M) was unable to induce RhoA/Rho kinase activation whereas that produced by U46619, phenylephrine (PhE), and endothelin-1 (ET1) was similar to that recorded in control mice.
Ex vivo
analysis of the contractile properties showed that, in aortic segments from SM-Arhgef1-KO mice, KCl-, PhE-, U46619- and ET1-induced contractions were similar to those obtained in control mice. In contrast, Ang II-induced contractions were severely reduced.
In vivo,
acute pressor responses to U46619 (3–100
μ
g/kg), ET1 (0.03–1
μ
g/kg) and PhE (0.1–100
μ
g/kg) were similar in control and SM-Arhgef1-KO mice, but responses to Ang II (0.1–30
μ
g/kg) were abolished. Basal blood pressure levels were similar in SM-Arhgef1-KO and control mice. In control mice, chronic infusion of Ang II (1 mg/kg/day) increased blood pressure whereas SM-Arhgef1-KO mice were resistant to the development of Ang II-induced hypertension. We therefore conclude that Arhgef1, as the molecular link between Ang II, RhoA activation and vascular tone regulation, provides an alternative target to reducing elevated vascular tone under hypertensive conditions without affecting normal blood pressure regulation by other vasoactive factors.
Abstract 5082: Interferon-
γ
Plays a Pivotal Role in Hypertension-Induced Cardiac Remodeling and Diastolic Heart Failure
Authors: Garcia Anthony G , Wilson Richard M , Heo Joline , Murthy Namita , De Silva Deepa S , Sam Flora
Published: April 2024

Background:
Diastolic heart failure (DHF) is clinical conundrum and accounts for ~50% of all HF admissions. There remains a paucity of therapies. Hypertension is
the
major cause of DHF and is associated with LV hypertrophy (LVH). Inflammatory cytokines are increased in hypertension but it is unknown if they mediate hypertension-induced cardiac remodeling. We tested the hypothesis that interferon-
γ
plays a pivotal role in the progression from hypertension-induced LVH to DHF.

Methods:
Twelve-week old BALB/c (WT) and interferon-
γ
deficient (IFN
γ
KO) mice underwent either saline (saline; n=10) or aldosterone-infusion (ALDO; n=20). All underwent uninephrectomy and drank 1% salt water for 4-weeks. Four-weeks after surgery, tail-cuff blood pressure (BP), echocardiogram and gene/protein analyses were performed. Isolated adult rat ventricular myocytes (ARVM) were treated with either interferon-
γ
(500nM) and/or aldosterone (50nM) for 30min.

Results:
BP was increased in WT-ALDO vs. WT-saline mice (P<0.01). Interestingly BP was not as increased in IFN
γ
KO-ALDO vs. WT-ALDO mice (127±5 vs. 136±4mmHg, P=NS). There was LVH in WT-ALDO vs. WT-saline mice (P<0.05). LVH was further increased in IFN
γ
KO-ALDO vs. WT-ALDO mice (HW/BW ratio: 4.9±0.1 vs. 4.3±0.1mg/g; P<0.01). LV end diastolic dimension was no different between IFNã KO-ALDO vs. WT-ALDO hearts. However, LV end systolic dimension (LVESD) was significantly smaller in IFNã KO-ALDO vs. IFNã KO-saline and WT-ALDO mice (1.12±0.1 vs. 1.4±0.1, and 2.1±0.3, respectively; P <0.05 for both). LVH was associated with an increase in myocardial ANP gene and protein expression in WT-ALDO hearts (P<0.05 vs. WT-sham). Intriguingly ANP gene and protein expression was not increased in IFNã KO-ALDO vs. WT-ALDO hearts. In ARVM pretreatment with interferon-ã prior to aldosterone significantly inhibited aldosterone-induced ERK1/2 phosphorylation, another marker of cardiomyocyte hypertrophy (P<0.05).

Conclusions:
Interferon-
γ
modulates cardiomyocyte hypertrophy partly independently of BP. There is a propensity to adverse cardiac remodeling with interferon-
γ
deficiency in this model of hypertension and DHF. Our findings suggest that interferon-
γ
may represent a novel target for hypertensive heart disease and DHF.
Abstract 5098: Clinical Presentation and Outcome of Early Postoperative Myocardial Infarction in Elderly Patients Following Hip Fracture Surgery
Authors: Gupta Bhanu , Huddleston Jeanne M , Kirkland Lisa L , Huddleston Paul M , Dirk Larson R , Gullerud Rachel E , Matthew Jensen R , Wright R Scott
Published: April 2024

Background:
Patients suffering post operative myocardial infarction (PMI) have higher mortality and morbidity rates than observed with non-PMI subsets. Little is known about the true incidence of PMI and how PMI differs from non-PMI with regard to clinical presentation, management and outcome.

Methods:
We examined the incidence and outcomes of patients with PMI in 1212 subjects (≥65 years) undergoing hip fracture surgery from 1988 – 2002 using a population-based retrospective cohort study from the Rochester Epidemiology Project in Olmstead County, Minnesota. PMI was defined on the basis of cardiac biomarker and/or electrocardiographic evidence of definitive MI within 7 days post operatively.

Results:
PMI occurred in 170 (14.0%) patients yet only 36 (21.2 %) patients had one or more clinical symptoms suggesting coronary ischemia. One or more classic symptoms of myocardial infarction were present in 26 (15.3%) including shortness of breath (SOB) in 18 (10.6%), chest/arm pain in 11 (6.5%), nausea/vomiting in 8 (4.7%) and diaphoresis in 1 (0.6%). Delirium was present in 15 (8.8%) patients. Median hospital length of stay was longer (10.0 vs. 8 days, p<0.01) and the in-hospital mortality rate was significantly higher (14.1% vs. 1.6%, p<0.001) among patients who had PMI within 7 days.

Conclusion:
The clinical presentation of PMI differs from non-PMI in the elderly undergoing hip fracture surgery. Most patients were asymptomatic or had atypical clinical presentations. We observed a significantly higher rate of hospital mortality among those experiencing a PMI. Further studies are necessary to better understand the presentation, optimal management and prevention of PMI.

Table 1.

Study Population

Table 2.

Clinical Presentation and Outcomes in Patients with and without Post Operative MI

This research has received full or partial funding support from the American Heart Association, National Center.
Abstract 5115: Purified Human Muscle-Derived Pericytes Support Formation of Vascular Structures and Promote Angiogenesis After Myocardial Infarction
Authors: Chen Chien-Wen , Tobita Kimimasa , Peault Bruno , Huard Johnny
Published: April 2024

We have recently shown that perivascular cells isolated from multiple human tissues represent stem cells endowed with mesodermal lineage potentials, and the injection of multipotent muscle-derived pericytes repair damaged skeletal muscle
in vivo
. Our current study further demonstrated that transplantation of human muscle-derived pericytes (3.0×10
5
cells/heart) into the ischemic myocardium of NOD/SCID mice sustains the cardiac function of the infarcted hearts. Here, we tested the hypothesis that purified CD34
−
/45
−
/56
−
/146
high
pericytes support formation of structures of blood vessels and promote angiogenesis post infarction. To illustrate the potential vessel-forming properties of purified pericytes, pericytes and endothelial cells were co-cultured in Matrigel
in vitro,
and co-formation of capillary-like structures was observed. To evaluate the angiogenic effect of pericytes
in vivo
, histological examination was performed two weeks after transplantation. Capillary density was measured by anti-CD31 staining on tissue sections. Capillary density within peri-infarct areas was 43% higher in the pericyte-injected group than in the saline-injected group (
P
<0.05). Myocardial fibrosis estimated by Masson’s trichrome staining revealed a 38% reduction of the scar area in pericyte-injected hearts when compared to saline-injected hearts. These findings indicated that transplantation of pericytes sustains the cardiac function of the infarcted left ventricle presumably through enhancement of angiogenesis and reduction of myocardial fibrosis. We further examined potential mediators of pericyte-induced cardiac repair in the ischemic micro-environment by culturing pericytes under hypoxic conditions (2.5% oxygen)
in vitro
for 24 hours. Real-time quantitative PCR analysis showed that vascular endothelial growth factor (VEGF)-related genes, including VEGF
165
and VEGF receptor 1 and 2, were significantly up-regulated in the pericyte population. Overall, the data suggested a role of VEGF-regulated angiogenesis on pericyte-mediated cardiac repair. Experiments are being performed to elucidate the potential of pericytes to differentiate into cardiac cell lineages and explore the regulatory mechanisms involved
in vivo
.
Abstract 5119: Von Willebrand Factor is Expressed Differently in Pathological Angiogenesis Models and Potentially Mediates Angiogenesis
Authors: Xie Yi , Chen Juhua
Published: April 2024

The objectives of this study were to assess von Willebrand factor (vWF) expression in different
in vivo
angiogenesis models, and also to investigate whether vWF plays a role in the regulation of angiogenesis. Basement membrane vWF is widely used as an endothelial cell marker for the analysis of physiological and pathological angiogenesis. In this study, we measured vWF expression in tumor xenografts, ischemic muscle, wound skin and matrigel implants. CD31 antibody, another routinely used endothelial cell marker, was used as an internal control. The sections of different tissues were immunofluorescently stained for vWF and CD31. The top five fields with the most microvessels in each section were acquired. The vWF- and CD31-positive vascular areas were quantified using Image-Pro Plus software and the ratios of vWF-/CD31-positive areas were compared. The ratios in normal muscle, skin and liver were 21.66%, 22.75% and 27.59%, respectively. In ischemic muscle and wound skin, the vWF/CD31 ratios were 23.10% and 21.73%, respectively, which were comparable with those in normal tissues. Matrigel implants had the highest ratio of vWF/CD31 (41.61%). However, tumor xenografts had the lowest ratios of vWF/CD31, which were 3.51% and 5.37% in breast cancer and melanoma, respectively. These data suggested that vWF expression is mediated by the micro-environment of distinct pathological processes. They also implied that the decreased expression of vWF in tumor vasculature might be a potential regulator of tumor growth and angiogenesis. We injected melanoma cells subcutaneously into wild type (WT) and vWF-deficient (vWF−/−) mice to examine tumor growth and vascular formation. Interestingly, the weight of tumors grown in vWF−/− mice was four times higher than that in WT counterparts. Importantly, the vascular area in the tumors from vWF−/− mice was significantly larger than that from the WT littermates. Taken together, these data demonstrate that vWF expression is different in distinct pathological angiogenesis models. Therefore, caution should be taken when using vWF as a vascular marker in different pathological angiogenesis models. Moreover, the decreased expression or deficiency of vWF might be implicated in the promotion of angiogenesis.

This research has received full or partial funding support from the American Heart Association, National Center.
Abstract 5120: Cardiac Sympathetic Nerve Activity is Associated With the Progression of Cardiorenal Syndrome in Patients With Chronic Heart Failure: 10-Year Follow up Study
Authors: Kawasaki Masato , Yamada Takahisa , Okuyama Yuji , Morita Takashi , Furukawa Yoshio , Tanaka Koji , Iwasaki Yusuke , Yasui Taku , Ueda Hiromichi , Okada Takeshi , Kuramoto Yuki , Fukunami Masatake
Published: April 2024

Background
: Chronic heart failure (CHF) and renal dysfunction (RD) frequently coexist. Cardiac sympathetic nerve activity (CSNA) influences the clinical outcomes in CHF patients (pts), but there is no information available on the relation between CSNA and RD in CHF pts, so-called cardiorenal syndrome (CRS).

Methods
: We studied 101 CHF patients with left ventricular ejection fraction (LVEF) < 40%. At the entry, I-123 MIBG imaging was performed, and washout rate (WR) was calculated from the chest anterior view images obtained at 20 and 200 min after isotope injection. Every year, estimated Glomerular Filtration Rate (GFR) by the MDRD equation was obtained in each patient.

Results
: GFR at the entry was significantly lower in pts with (n=49) than without abnormal WR (n=52) (more than 27%: the mean control WR +2SD) (59±18 vs 67±19 ml/min/1.73m
2
, p=0.029). With a mean follow-up of 7.3±3.5 yrs, GFR decreased from 64±19 to 50±21 ml/min/1.73m
2
, the median value of GFR depression rate (GFRdep) was 3.5%/year, and 31 of 101 pts died of cardiac death. GFRdep was also significantly greater in pts with than without abnormal WR (8.2 vs 2.5%/year, p<0.01). There were no significant differences in gender, age, NYHA class, LVEF, or the content of anti-heart failure therapy between pts with and without WR≥27%. Cardiac death was significantly more frequently observed in pts with than without GFRdep≥3.5%/year (44 vs 16%, p<0.01). The odds ratio of greater GFRdep for cardiac death was 3.8 (95%CI 1.7 to 8.5).

Conclusion:
In CHF pts, CSNA would be associated with the progression of RD. Furthermore, progression of RD had poor clinical outcome. Thus, CSNA might play an important role in the progression of CRS in CHF pts.