tbuckley/cabot-search huggingface dataset:
Abstract 5461 In vivo Knockdown of Aortic Nicotinic Acetylcholine Receptor Alpha1 (nAChR <i>α</i> 1) Diminishes Aortic Atherosclerosis and Valve Calcification
Authors: Guoqiang Zhang, Kelly A Kernan, Alison Thomas, Yanyuan Su, Yi Zheng, Renee C LeBoeuf, Allison A Eddy
Journal: Circulation (2009)

Urokinase plasminogen activator (uPA) contributes to atherosclerosis, restenosis and vascular remodeling. We have recently identified nAChR α 1 as a functional cell receptor for uPA in addition to its classic receptor, uPAR. Here, we test the hypothesis that nAChR α 1 plays a role in the pathogenesis of atherosclerosis. C57BL/6J ApoE −/− mice (male) were initially fed a Western diet for 8 wks. Plasmid DNA encoding scramble RNA ( pScr ) or siRNA ( pSir2 ) for nAChR α 1 was then injected into the mice (n=15) using an aortic hydrodynamic gene transfer protocol. Three mice from each group were sacrificed 7 days after DNA injection to confirm the nAChR α 1 gene silencing. The rest of the mice continued on the Western diet for an additional 16 wks. Aortas were harvested for paraffin-embedding (aorta root), protein (ascending aorta and aortic arch) and RNA (descending aorta) (n=8). Whole aortas were isolated for oil red staining in 4 mice of each group. The nAChR α 1 was highly up-regulated in aortic atherosclerotic lesions. Knockdown of the nAChR α 1 gene was achieved as early as day 7 (76%↓) after DNA injection, and aortic nAChR α 1 in pSir2 -treated mice remained lower (78%↓) at 16 wks compared to the pScr (n=8, P &lt;0.05). The nAChR α 1 reduction resulted in less severe aortic atheroslcerosis at 16 wks. The ratio of the intimal/medial thickness (I/M ratio) was smaller in the nAChR α 1-silenced aortas (3.1±1.8 versus 8.4±1.4, pSir2 versus pScr , n=8, P &lt;0.05). There were significantly fewer F4/80+ macrophages (60%↓) and α SMA+ myofibroblasts (80%↓) in the neointima of the pSir2 -treated mice compared to the pScr (both P &lt;0.05). The TGF- β 1 and α SMA mRNA levels were down-regulated by 80% and 72% respectively in the nAChR α 1-silenced aortas ( pSir2 vs pScr ; n=5, both P &lt;0.05). Since nAChR α 1 is a ligand-gated Ca 2+ channel that may be associated with osteopathic responses in aortic intimal myofibroblasts, aortic calcification was evaluated with the Von Kossa staining. The calcification was most prominent in the aortic valves; a 41% reduction in area stained was observed in the pSir2 -treated mice ( pSir2 vs pScr ; n=8 P &lt;0.05). These data suggest that the nAChR α 1 gene plays a significant role at the artery wall and reducing its expression serves to reduce aortic plaque development and valve calcification. This research has received full or partial funding support from the American Heart Association, National Center.
Abstract 4920: Endothelial-Targeted BMPR2 Loss-of-Function Mutations Cause Increased Apoptosis and Pulmonary Arterial Hypertension
Authors: Dominique Yelle, Yupu Deng, James West, Duncan J Stewart
Journal: Circulation (2009)

Introduction: Pulmonary arterial hypertension (PAH) is a rare and fatal disease caused by excessive remodelling of small pulmonary arterioles. Heterozygous loss-of-function mutations in the bone morphogenetic protein receptor 2 (BMPR2) have recently been implicated in patients with familial and idiopathic PAH. However, how mutations in this ubiquitously expressed receptor result in a specific abnormality of the lung microcirculation is unknown. We hypothesized that mutations in BMPR2 lead to PAH by increasing the susceptibility of ECs to apoptosis, particularly within fragile pulmonary arterioles. Aims: To examine the effect of endothelial targeted overexpression of a BMPR2 deletional mutation on EC apoptosis, pulmonary hemodynamics and arteriolar remodelling. Methods: We developed an endothelial-specific binary transgenic (BT) mouse model in which the driver mice express the tetracycline transactivator under the control of the endothelial-restricted V-cadherin promoter and the responder mice harbour a BMPR2 transgene containing an arginine-to-stop mutation in the receptor’s C-terminal domain driven by a tetracycline responsive promoter. Pulmonary artery pressure was evaluated by measuring right ventricular systolic pressure (RVSP). Fluorescent microangiography (FMA) was performed to visualize the 3D architecture of the pulmonary microcirculation. Results: RVSP was significantly increased in BT mice compared to non binary controls (p &lt; 0.05; n = 9), associated with increased muscularization of small pulmonary arterioles detected by α -smooth muscle actin immunostaining. In addition, FMA revealed decreased perfusion and distal pre-capillary discontinuity in BT mice. TUNEL staining also demonstrated a significant increase in the number of apoptotic cells in BT mice compared to non binary controls (5.8 ± 1.1, 1.0 ± 0.7 positive cells/HPF, respectively; p &lt; 0.05; n = 4). Conclusions: These data suggest that BMPR2 mutations increase the susceptibility to apoptosis, possibly leading to EC loss and pre-capillary arteriolar discontinuity. This new model will help elucidate the pathophysiological events leading to the development of PAH and provide a unique tool to evaluate novel potential treatments for this disease.
Abstract 5104: Direct Observation of Adipose Tissue-induced Leukocyte Recruitment to the Artery Wall: A Direct Link Between Obesity and Atherosclerosis
Authors: Sumihiko Hagita, Mizuko Osaka, Kentaro Shimokado, Masayuki Yoshida
Journal: Circulation (2009)

Background: Though inflammation within adipose tissues play a role in pathogenesis of metabolic syndrome, a causative connection between adipose tissue and atherosclerosis is not fully understood. The present study aimed to examine the direct effect of adipose tissue on macrovascular inflammation by intravital microscopic analysis of the femoral artery of mice after perivascular adipose tissue transplantation. Methods and Results Subcutaneous (SQ) or visceral (VIS) adipose tissue harvested from C57/BL6 mice was transplanted to the perivascular area of the femoral artery of recipient C57/BL6 mice. A quantitative intravital microscopic analysis was performed on the artery. The number of adherent leukocyte was increased after adipose tissue transplantation in a time-dependent manner (1day to 7days). VIS transplantation induced significantly more leukocyte accumulation than SQ at 7 days after transplantation. Simultaneous flow cytometry showed the expression of CD11b was significantly increased on peripheral neutrophils and monocytes. Interestingly, the amount of oxidative stress was not changed after transplantation. We found significant increase of MCP-1, MIP-1 β , and IL-6 in the recipient serum after transplantation. Further, the expression level of MCP-1 was significantly increased in the donor adipose tissues. Conclusion These data indicate that adipose tissue directly stimulates athero-prone vascular inflammation. The underlying mechanisms seem to involve induction of MCP-1 from adipose tissues.
Duffy Antigen Receptor for Chemokines (Darc) Polymorphism Regulates Circulating Concentrations of Monocyte Chemoattractant Protein-1 and Other Circulating Inflammatory Mediators
Authors: Renate B. Schnabel
Journal: Circulation (2009)

Abstract #1808 Renate B. Schnabel, Johannes Gutenberg Univ, Mainz, Germany; Jens Baumert, Helmholtz Zentrum München, German Res Ctr for Environmental Health, Neuherberg, Germany; Maja Barbalic, Human Genetics Ctr and Inst of Molecular Med, Univ of Texas Health Science Ctr, Houston, TX; Josée Dupuis, Dept of Biostatistics, Boston Univ Sch of Public Health, Boston, MA; Patrick T. Ellinor, Cardiovascular Res Ctr, Massachusetts General Hosp, Boston, MA; Peter Durda, Dept of Pathology, Univ of Vermont Coll of Med, Burlington, VT; Abbas Dehghan, Dept of Epidemiology, Erasmus Medical Ctr, Rotterdam, Netherlands; Joshua C. Bis, Dept of Med, Univ of Washington, Seattle, WA; Jacqueline C. Witteman, Dept of Epidemiology, Erasmus Medical Ctr, Rotterdam, Netherlands; Ron C. Hoogeveen, Human Genetics Ctr and Inst of Molecular Med, Univ of Texas Health Science Ctr, Houston, TX; Emelia J. Benjamin, Natl Heart, Lung, and Blood Inst’s and Boston Univ’s Framingham Heart Study, Framingham, MA; Wolfgang Koenig, Dept of Internal Med II –Cardiology, Univ of Ulm Medical Ctr, Ulm, Germany; Russell P. Tracy, Dept of Biochemistry, Univ of Vermont Coll of Med, Burlington, VT; CHARGE Consortium Renate B. Schnabel, 2009 Finalist and Presenting Author
Abstract 4874: Vascular Endothelial Barrier Compromise in Advanced Atherosclerosis: Novel in vivo Animal Models and Nanoparticle Characterization Methods
Authors: Samuel A Wickline, Huiying Zhang, Junjie Chen, Lei Zhang, Kristin Bibee, John Allen, Gregory Lanza
Journal: Circulation (2009)

To elucidate the functional consequences of advanced atherosclerosis on the vascular endothelial barrier, 8 NZW rabbits were fed a high fat diet for 9 –12 months (cholesterol: 1200 –1700 mg/dl). Control animals comprised 3 month-old rabbits on high fat or normal chow diets. Fluorescent perfluorocarbon-core nanoparticles (NP: ~250 nm) were given i.v. (2 ml/kg) and circulated for 1, 12, or 24 hours in selected animals. The aorta was then excised, imaged ex vivo with 12T MRI ( 1 H and 19 F) and whole mount fluorescence scanning, then fixed for histological and TEM/SEM analysis. Results: 6/8 of the older atherosclerotic rabbits exhibited massive penetration and persistence of NP into the intimal plaques extending upwards toward the IM junction. Most NP situated in the extracellular matrix in regions that co-stained for glycosaminoglycans and smooth muscle cell actin. Fewer NP penetrated plaques after 1 hour as compared with 12 or 24 hours, and even larger NP could be observed intact at high power Spin-dried SEM samples revealed extensive cholesterol crystal deposition penetrating the plaque endothelium. 19 F MRI/MRS revealed the presence of fluorinated NP core elements confirming the presence of intact NP. The 3 month fed animals exhibited far less NP penetration. Conclusion: These data suggest that disruption of the endothelial barrier in older atherosclerotic rabbits is a consequence of rapid (&lt;1 hr) passive (non receptor-mediated) diffusion and trapping of 19 F-detectable NP in plaque interstitium. If demonstrable in humans, this previously unrecognized mechanism for blood-intima communication could contribute to plaque vulnerability and disruption.
2006 Russell Ross Memorial Lectureship in Vascular Biology—Tissue Factor as a Mediator and Marker of Cardiovascular Disease: New Roles for an Old Molecule
Authors: Mark Taubman
Journal: Circulation (2006)

Tissue factor (TF) is a transmembrane glycoprotein that initiates coagulation and plays a critical role in hemostasis and thrombosis. TF expression is linked to inflammatory and proliferative responses, in part through the generation of thrombin, an important mediator of growth and inflammation. Recent data have implicated TF as an important mediator of angiogenesis, intimal hyperplasia, ischemia-reperfusion injury, and cardiac fibrosis. Our data also suggest that TF may mediate the intimal and proliferative responses in a rat model of pulmonary arterial hypertension. It is likely that the effects of TF on these processes are particularly related to its role in mediating inflammation. Although TF was once thought to act exclusively as a cell-associated molecule, TF is present in several forms in the circulation. The predominant form is in microparticles (MPs) that presumably bud from the surface of many cell types, such as endothelium, macrophages, and smooth muscle cells, as a part of normal cellular homeostasis or are released during cell death or injury. TF-containing MPs have been found in association with naturally occurring and experimental thrombi. In addition to MPs, there is a naturally occurring, soluble form of human TF generated by alternative splicing. This splice variant has a novel C-terminus, lacks a transmembrane domain, and is present in blood. There are conflicting data as to the role of TF-containing MPs in mediating thrombosis. However, recent studies have found that blood TF is elevated in a variety of cardiovascular diseases, and blood TF levels may have predictive value for secondary events in patients with previous myocardial infarction and for venous thromboembolism.
Abstract 5158: Opposite Effects of Salusins on the Development of Atherosclerotic Plaques
Authors: Takuya Watanabe, Masaharu Nagashima, Shigeko Arita, Shigeki Hongo, Masayoshi Shichiri, Tsutomu Hirano, Akira Miyazaki
Journal: Circulation (2009)

Background: Human salusin- α and - β are 2-related peptides processed from the same precursor, preprosalusin. Our previous studies in vitro showed that human macrophage foam cell formation is stimulated by salusin- β but suppressed by salusin- α ( Circulation 2008 ; 117 ; 638 – 48 ). Thus we assessed the effects of salusin- α and - β on atherosclerotic plaque formation in vivo in apoE-KO mice. Further, we investigated the relationship between serum salusin- α levels and carotid atherosclerosis in patients with essential hypertension. Methods and Results: Saline, salusin- α or - β (600 pmol/kg/h) was continously infused through osmotic minipumps into 13-week-old apoE-KO mice. Aortic atherosclerosis, oxidized LDL-induced cholesterol ester accumulation (foam cell formation), and its related gene expression in exudate peritoneal macrophages were determined. After 4-week infusion of salusin- β , atherosclerotic lesions were 2.6-times greater than vehicle controls, which paralleled 1.9-fold increase in foam cell formation and upregulation of scavenger receptors (CD36, scavenger receptor class A) and acyl-CoA:cholesterol acyltransferase-1 (ACAT1). In contrast, salusin- α decreased serum total cholesterol levels by 15% and foam cell formation by 68% partly due to ACAT1 downregulation. After 8-week infusion of salusin- α , atherosclerotic lesions were significantly suppressed by 54% compared with vehicle controls. Clinically, serum salusin- α levels were significantly lower in patients with essential hypertension than healthy volunteers (9.4±0.9 pM [n=70] vs 17.0±3.5 pM [n=20], P &lt;0.005). In all subjects, serum salusin- α levels became significantly lower in accordance with the severity of carotid plaque score and intima-media thickness ( P &lt;0.05). Immunoreactive salusin- α expression was at trace levels in human carotid plaques. Conclusins: We provided the first evidence that salusin- β accelerates atherosclerotic lesion development by upregulation of scavenger receptors and ACAT1 in apoE-KO mice. In contrast, salusin- α exerts anti-atherosclerotic effects by suppressing serum total cholesterol levels and ACAT1 expression. Decreased levels of salusin- α in circulating blood and vascular tissue have a close linkage with human atherosclerosis.
Abstract 561: A Cathepsin D-Cleaved 16kDa Form of Prolactin Mediates Postpartum Cardiomyopathy: Inhibition of Prolactin as a Novel Therapy Option
Authors: Denise Hilfiker-Kleiner, Ingrid Struman, Maren Luchtefeld, Olaf Forster, Karen Sliwa, Helmut Drexler
Journal: Circulation (2006)

Background: Postpartum cardiomyopathy (PPCM) is a disease of unknown etiology and exposes women to high risk of mortality after delivery despite optimal medical therapy. Mice with a cardiac specific knockout for STAT3 (KO: ∈±-MHC-Cretg/+; stat3flox/flox) develop PPCM. We used KO mice to investigate potential mechanisms behind PPCM and compared our findings to patients with acute PPCM. Methods: Cathepsin D (CD) expression was determined by Western blot and immunohistochemistry in left ventricles (LV) of wildtype (WT: stat3flox/flox) and KO mice after two subsequent pregnancies. In mouse LV supernatant CD activity was analyzed by ELISA and cleavage of recombinant prolactin (Prl) was determined by Western blot. Adenoviruses expressing either the16kDa Prl or as control the LacZ protein were injected into LVs of virgin WT mice. Prl secretion was inhibited by oral administration of bromocriptine in mice (BR, 4mg/kg/day 5 days before till 3 weeks postpartum). In serum samples collected from patients with acute PPCM (n=6) and from healthy nursing women (n=5) Prl isoform expression was analyzed by Western blot and CD activity was measured by ELISA. Results: In LVs from postpartum KO mice CD expression (3x, P&lt;0.05) and activity (4x, P&lt;0.05) was significantly enhanced and was associated with marked generation of the cleaved anti-angiogenic and pro-apoptotic 16kDa form of Prl compared with LVs from postpartum WT mice. Inhibition of Prl secretion by BR prevented the development of PPCM in KO mice completely. In contrast, the forced myocardial generation of 16kDa Prl by adenoviral transfection impaired the cardiac capillary network (−31Â±12%, P&lt;0.05) and the cardiac function (LacZ: 43Â±2% vs 16kDa : 33Â±7%, P&lt;0.05) while no such effect was observed in mice transfected with LacZ expressing adenovirus. In serum probes of patients (n=4) with acute PPCM enhanced CD activity (4x, P&lt;0.05) and elevated levels of 16kDa Prl (2 to 5 times; P&lt;0.05) were observed compared with serum probes of healthy nursing women (n=5). Conclusions: We propose that a biologically active, derivative of the pregnancy hormone, prolactin, mediates PPCM implying that inhibition of Prl release may represent a novel therapeutic strategy for PPCM.
Abstract 4937: A Novel Molecular Imaging Sensor of Cellular Oxidative Stress
Authors: Karen M Peterson, Ian Y Chen, Robert D Simari, Sanjiv S Gambhir, Amir Lerman, Martin Rodriguez-Porcel
Journal: Circulation (2009)

Increased oxidative stress has been suggested to play an important role in the biology of mesenchymal stem cells (MSCs). However, little is known of the effect of increased oxidative stress in-vivo, partly due to the lack of appropriate imaging technologies for monitoring of stem cell biology in the living subject. Recent developments in molecular imaging permit, for the first time, the longitudinal monitoring of stem cell biology in vivo. We hypothesize that changes in oxidative stress can be monitored using a reporter gene strategy (molecular imaging). Methods: We have developed a novel oxidative stress sensor, using a two-step transcriptional amplification strategy to enhance the expression of firefly luciferase (Fluc), driven by the pro-oxidant enzyme NAD(P)H promoter, and used to monitor oxidative stress in rMSCs. rMSCs was induced by hypoxia (1% O2 for 24 hours) and serum deprivation (SD) and confirmed using a dichlorofluorescein colorimetric assay (measures the production of hydrogen peroxide-H2O2-) and NAD(P)H protein expression. Results: Both serum deprivation and hypoxia led to a pro-oxidant state (Fig. A–B ). Most importantly, increased oxidative stress led to increased activity of the novel reporter gene sensor (Fig. C ) which was decreased in the presence of antioxidants (superoxide dismuatse mimetic Tempol, 5mM, SD+T, Fig D ). Results were reproduced in a different cell type (rat cardiomyoblast, data not shown). Conclusion: Changes in oxidative stress in MSCs can be monitored using molecular imaging. Reporter Gene-based Molecular Imaging, a strategy that is clinically applicable, provides the opportunity to monitor stem cell survival in the living subject.
Abstract 5265: Alternatively Spliced B-Type Natriuretic Peptide (ASBNP) is a Renal Selective Natriuretic and Diuretic Peptide Without Hypotensive Properties
Authors: Guido Boerrigter, Horng H Chen, Shuchong Pan, Robert D Simari, John C Burnett
Journal: Circulation (2009)

Background: B-type natriuretic peptide (BNP1–32) is a 32- amino acid cardiac peptide secreted in response to cardiac stress and plays an important compensatory role in cardiorenal homeostasis. Studies have recently reported that a mRNA encoding an alternatively spliced variant of BNP (ASBNP) exists in the human heart and like BNP1–32 is increased in the failing heart. While ASBNP and BNP1–32 have identical ring structures and amino termini, ASBNP and BNP1–32 differ in their carboxy terminus (34 vs. 6 amino acids, respectively). Studies have also reported that ASBNP activates cGMP, the second messenger of BNP1–32, in isolated glomeruli but not in endothelial cells. Also, unlike BNP1–32 ASBNP does not vasorelax isolated arteries or veins. The cardiorenal actions in vivo of ASBNP are unknown. We hypothesized that ASBNP in vivo would have selective renal actions yet as suggested by studies in isolated vessels would be devoid of blood pressure effects. Methods: We therefore determined for the first time the cardiorenal actions of three subsequent intravenous doses of ASBNP (10, 50, and 150 pmol/kg/min) in 5 healthy canines in an acute study under anesthesia in 30-minute clearances at baseline, during, and following infusion. Values provided are mean±SEM for baseline vs. 150 pmol/kg/min. *p&lt;0.05. Results: ASBNP dose-dependently increased plasma levels of cGMP (8.6±1.0 vs. 11.5±1.3* pmol/mL), and the same was true for urinary cGMP excretion (878±191 vs. 2028±551* pmol/min). Mean arterial pressure (p=0.83) and heart rate (p=0.43) remained unchanged. Urine flow increased (0.38±0.05 vs. 1.32±0.20* mL/min) as did urinary sodium excretion (38±15 vs. 133±38* μ Eq/min). Renal blood flow (p=0.51) and glomerular filtration rate (p=0.99) remained unchanged. BNP-immunoreactivity as measured by the Biosite BNP assay increased (5±4 vs. 3807±573* pg/mL). Conclusion: ASBNP, an alternatively spliced form of BNP produced in the human heart, activates cGMP and has diuretic and natriuretic actions but is without blood pressure lowering actions. Thus, ASBNP represents a novel renal selective, non-hypotensive, natriuretic, and diuretic peptide.