bluuebunny/crossref_metadata_2025 huggingface dataset:
Occult Left Ventricular Mass Presenting as a Wide-Complex Tachycardia in a 47 Year Old Female
Authors: Kolski Brian C
Published: April 2024

Abstract #3083

Brian C Kolski, William D Ryan, Ahmed Shabaik, Gregory K Feld, Andrew Kahn, Univ of California, San Diego, San Diego, CA

Brian C Kolski, 2009 Finalist and Presenting Author
Novel Human and Canine Desmin Phosphorylations as Potential Regulators of Oligomer Formation and Disease in Heart Failure
Authors: Agnetti Giulio
Published: April 2024

Abstract #1809

Giulio Agnetti, Victoria Halperin-Kuhns, Yurong Guo, Shijun Sheng, Zongming Fu, Johns Hopkins Univ, Baltimore, MD; Francesco Nicolini, Tiziano Gherli, Univ of Parma, Parma, Italy; Carlo Guarnieri, Claudio M Caldarera, Univ of Bologna, Bologna, Italy; David A Kass, Gordon F Tomaselli, Jennifer E Van Eyk, Johns Hopkins Univ, Baltimore, MD

Giulio Agnetti, 2009 Finalist and Presenting Author
Abstract 4759: Endothelin-1: A Useful Prognostic Marker After Acute Myocardial Infarction
Authors: Freixa Xavier , Doltra Ada , Ortiz José Tomás , Argiró Sergio , Guasch Eduard , Heras Magda , Jiménez Marcelo , Betriu Amadeo , Masotti Mónica
Published: April 2024

INTRODUCTION: High Endothelin-1 (E-1) levels have been linked to poor clinical outcomes after myocardial infarction (MI). Vasoconstriction of the coronary microcirculation seems to be the underlying mechanism. However, the relationship between E-1 levels and microvascular integrity in the setting of MI has not been analyzed.

OBJECTIVES To assess the effect of E-1 on microvascular integrity, necrosis volume, left ventricular ejection fraction (LVEF) and myocardial savage (M-sav) in evolving MI.

METHODS: We measured E-1 levels in a consecutive series of 127 patients (pts) presenting with a first MI. Blood samples for E-1 measurements were taken 6 to 24 hours after MI onset. MRI was performed within 1 week following presentation and microvascular obstruction (MO), necrosis volume and LVEF was assessed by ce-CMR. M-sav was definded as the % of angiographic area at risk by the BARI score that spared necrosis on the MRI.

RESULTS: Mean age was 60.9±11,8 years and 94(80%) were males. MI location was anterior in 47.2%. As shown in table

, high E-1 levels were associated to admission Killip ≥2, higher prePCI TIMI 0, worse postPCI MBG and higher mortality at 30 days. MO was documented in 48%. High E-1 values were also associated with MO and worse M-sav while no significant correlation was obtained with necrosis volume and LVEF. Compared to Troponin I/CKMB peak values, E-1 levels showed better correlation with MO, M-sav, Killip on admission, MBG postPCI and mortality at 30 days.

CONCLUSIONS: In humans, high E-1 levels after MI are closely associated with the presence of MO and worse M-sav. E-1 assessment renders prognostic information, independent from that provided by LVEF and necrosis volume
Abstract 4760: Effect of Cyclosporine on Left Ventricle Remodeling After Reperfused Myocardial Infarction
Authors: Mewton Nathan , Croisille Pierre , Gahide Gerald , Rioufol Gilles , Bonnefoy Eric , Cung Thien Tri , Sportouch Catherine , Angoulvant Denis , Piot Christophe , Revel Didier , Ovize Michel
Published: April 2024

Introduction: In a human study, administration of cyclosporine A at the time of acute myocardial infarction (AMI) reperfusion was associated with a smaller infarct size. However, experimental data suggest that cyclosporine A has a detrimental effect on left ventricular remodeling. This study examined the effect of cyclosporine A used at the time of reperfusion, on LV remodeling and function by cardiac magnetic resonance (CMR) in the early days and several months after AMI. Material and

Methods: 28 patients of the original cyclosporine A study had an acute (day 5) and a follow-up (6 months) CMR study. Cine imaging was used to determine LV volumes, mass, ejection fraction and myocardial wall thickness in infarcted and remote non-infarcted myocardium, and late gadolinium imaging was used to determine infarct size.

Results: There was a persistent reduction of the absolute infarct size at 6 months in the cyclosporine A group compared with the control group of patients (29±15 grams VS 38±14 grams; P=0.04). There was a significant reduction of LV end-systolic volume (and a trend for LV end-diastolic volume; P=0.07) in the cyclosporine A group, compared with the control group, both at day 5 and at 6 months after infarction. There was no significant difference between the two groups in either global LV mass or regional wall thickness of the remote non-infarcted myocardium at day 5 or at 6 months. Attenuation of LV dilatation and improvement of LV ejection fraction by cyclosporine A at 6 months were correlated with infarct size reduction.

Conclusion: Cyclosporine A used at the moment of AMI reperfusion persistently reduces infarct size and does not have a detrimental effect on LV remodeling.
Abstract 4841: The Impact of Chronic Uremia on Ichemic Preconditioning of the Myocardium
Authors: Mccafferty Kieran , Byrne Conor , Kieswich Julius , Yaqoob Magdi
Published: April 2024

Background Ischemic Preconditioning (IPC) is a process by which brief non lethal periods of ischemia render the dependant tissue resistant to subsequent lethal injury. This process has been extensively studied in animal models and this has led to human clinical trials. There is evidence to suggest that additional co-morbidities may render hearts more resistant to the effects of IPC. There is no published data examining the effects of chronic uraemia on IPC. This is of clinical importance due to the burden of cardiovascular disease in CKD patients.

Hypothesises

Can uremic hearts respond to an IPC stimulus

Can uremic hearts respond to an IPC stimulus as well as non uremic hearts

Methods The 5/6 nephrectomy model (SNx) in male Wistar rats was used as a model of chronic uraemia. We performed 2 experiments to test the hypothesises. Expt 1: SNx rats were divided into 2 groups. The control group (n=15) underwent myocardial ischemia using reversible LAD artery ligation. The LAD was occluded for 25 minutes and reperfused for 2 hours. The IPC group (n=4) had 3 cycles of 5 minutes LAD ligation and 5 minutes reperfusion followed by 25 min occlusion and 120min reperfusion. Expt 2: SNX animals (n=8) and Sham controls (n=6) underwent x1 cycle of IPC as above with 35minutes ischemia 2 hours reperfusion. At the end of the experiment the animals were sacrificed and the infarct size was measured and expressed as a percentage of the area at risk (AAR).

Results Expt 1: Median Infarct size was 61.2% and 7.5% in the control and IPC groups respectively (P=0.003) Expt 2: Median infarct size was 16.8% and 43.7% in the SNX and sham SNx groups respectively. (P=0.008) The AAR was not significantly different in any of the groups studied.

Discussion This is the first evidence that unlike ‘old’ hypertensive rats and diabetic rats, uremic rats can respond to a preconditioning stimulus. Furthermore it appears that the preconditioning may confer greater protection in uremic animals than controls. We hypothesize that the significantly lower haemoglobin in the uremic animals reduces microvascular occlusion which may occur during IPC. Work is underway to quantify this finding.

Conclusion This study suggests that clinical trials using IPC in uremic patients could improve outcomes following cardiac interventions.
Abstract 4852: High Resting Velocity in Intramyocardial Coronary Artery is Related to Elevated Plasma Brain Natriuretic Peptide Levels in Patients With Hypertension
Authors: Doi Yasuji , Okada Ken-ichiro , Kaibe Shoji , Ito Noritoshi , Hayashi Tohru
Published: April 2024

Narrowings in intramyocardial coronary arteries (IMCA) and elevated plasma brain natriuretic peptide (BNP) levels have been demonstrated in hypertensive heart disease. To clarify the relation between abnormalities in IMCA and plasma BNP levels, 228 consecutive patients with hypertension were studied using high-frequency transthoracic Doppler echocardiography. We defined IMCA flow as abnormal one if acceleration flow in IMCA, indicating the presence of vessel narrowing, was detected by color flow mapping and the pulsed Doppler study demonstrated higher peak diastolic flow velocity than 32cm/sec (i.e. normal value + 2SD) in the site. Such abnormal flow in IMCA was demonstrated in 59 (56%) of 102 hypertensive patients with left ventricular hypertrophy (LVH) and in 36 (24%) of the other 126 hypertensive patients without LVH. Independent of LVH, the 95 hypertensive patients with abnormal IMCA flow had higher peak diastolic velocities in the IMCA (47.9±16.5 cm/s vs. 24.3±5.4 cm/s, p<0.01) and more elevated plasma BNP levels (131.0±24.4 pg/ml vs. 45.8±5.7 pg/ml, p<0.01) than those without abnormal IMCA flow. Furthermore, peak diastolic velocities had a significant correlation with log BNP values (p<0.01). The index of % area stenosis (IAS) estimated by the continuity equation was 46±14% at the site of acceleration flow, indicating the presence of mild to moderate lumen narrowing in the IMCA. The patients with the IAS of 50% and over had significantly higher log BNP values as compared to those with the IAS of less than 50% (p<0.05), indicating plasma BNP levels may be elevated by factors associated with lumen narrowing in the IMCA.

Conclusions: High resting velocity in IMCA is at least partly related to elevated BNP levels in patients with hypertension independent of LVH.
Abstract 4857: Relationship Between Arterial Stiffness and Cardiac Structure and Function in Patients With Hypertension and Diastolic Dysfunction: The VALIDD Trial
Authors: Verma Anil , Desai Akshay , Hung Chung-Lieh , Janardhanan Rajesh , Aurigemma Gerard , Thomas James , Zile Michael , Solomon Scott D
Published: April 2024

Background:
Although both vascular and ventricular stiffness are increased in hypertension, the degree to which these abnormalities are related has not been well characterized

Methods:
Echocardiographic measures of LV structure and function were assessed in 384 patients enrolled in the VALsartan In Diastolic Dysfunction (VALIDD) trial with mild hypertension (mean blood pressure 144±16/86±10 and LV hypertrophy < 4%), no heart failure and evidence of diastolic dysfunction, based on Doppler assessment of myocardial relaxation velocities (E′). Arterial compliance was calculated as stroke volume (SV)/pulse pressure (PP) with a lower ratio indicative of reduced compliance. Peak longitudinal systolic strain rate (SR) was measured in all 12 LV segments from 2 and 4 chamber views using speckle tracking.

Results:
Arterial compliance decreased with older age, female gender, and systolic pressure. In a multivariate model reduced arterial compliance was independently associated with lower E′ (r=0.22, p<0.001) and longitudinal systolic SR (r=−0.18, p<0.001) and with higher filling pressures (assessed either as E/E′ or as NTproBNP), increased end diastolic instantaneous operative LV stiffness (E/E′ ratio/LV EDV) and with increased LV mass and concentric remodeling [Table

].

Conclusion:
Even amongst patients with mild degree of hypertension, arterial stiffness is related to abnormalities in LV structure, and diastolic and systolic function. These results suggest that both diastolic dysfunction and arterial stiffness are pathophysiologically linked to end-organ consequences of hypertension.
Abstract 4858: Is Brachial Artery Diameter an Early Index of Organ Damage in Hypertension?
Authors: Schillaci Giuseppe , Pucci Giacomo , Mannarino Massimo R , Pirro Matteo , Pasqualini Leonella , Vaudo Gaetano , Mannarino Elmo
Published: April 2024

Objectives: Arteries can enlarge in response to a variety of hemodynamic and non-hemodynamic stimuli. The role of vascular remodeling in atherosclerosis-free arteries in hypertension is poorly understood. We investigated whether brachial artery diameter (BAD), an index of vascular remodeling,

is increased in hypertensive patients, and

has a relationship with left ventricular (LV) mass, an important marker of target-organ damege in hypertension.

Methods: 463 never-treated subjects with uncomplicated essential hypertension (283 men, 180 women; age 48+/−11 years, office blood pressure 155/96+/−17/9 mmHg) underwent M-mode echocardiography, 24-h BP monitoring, and ultrasound assessment of end-diastolic non-dominant BAD. 96 healthy normotensive subjects (40% women) served as controls. Analyses were performed separately in men and women.

Results: BAD had significant direct associations with age, male sex, systolic blood pressure and body mass index. BAD was larger in hypertensive subjects than in normotensive controls (4.62+/−0.8 vs 4.48+/−0.7 mm, p=0.02). In hypertensive subjects, age-adjusted BAD values were higher in subjects with LV hypertrophy (LV mass >51 g/m2.7; 4.46+/−0.6 vs 4.04+/−0.6 mm in women, 5.13+/−0.7 vs 4.81+/−0.7 mm in women, both p<0.0001). In sex-specific multiple linear regression analyses (Table), BAD predicted LV mass index in both men (beta=0.17, p=0.003) and women (beta=0.13, p=0.043), independently from the effects of age, 24-hour BP and body mass index (all p<0.05).

Conclusion: Diameter of the brachial artery is increased in untreated hypertensive subjects. In hypertension, larger brachial artery diameter is associated with left ventricular hypertrophy, and this relation is partly independent from the effect of common predictive factors. Brachial artery diameter is a potential early marker of organ damage in hypertension.
Abstract 4860: A Simple Electrocardiographic Criterion for Differentiating Tako-tsubo Cardiomyopathy From Anterior Acute Myocardial Infarction
Authors: Kosuge Masami , Ebina Toshiaki , Hibi Kiyoshi , Morita Satoshi , Iwahashi Noriaki , Okuda Jyun , Tsukahara Kengo , Uchino Kazuaki , Ishikawa Toshiyuki , Umemura Satoshi , Kimura Kazuo
Published: April 2024

Background:
Because clinical and ECG findings of Tako-tsubo cardiomyopathy (TC) mimic those of anterior acute myocardial infarction (ant AMI), differential diagnosis is crucial for deciding whether reperfusion therapy is required.

Methods:
We compared admission ECGs between 33 patients (pts) with TC and 342 with a first ant AMI due to the left anterior descending coronary artery occlusion as documented by emergency coronary angiography. All pts were admitted within 6 h after symptom onset. ST-segment deviation was considered present if deviation was >0.5 mm in limb leads and >1.0 mm in precordial leads.

Results:
Pts with TC were older (70±11 vs 61±11 yrs, p<0.01), more likely to be women (75 vs 15%, p<0.01), and had a lower initial left ventricular ejection fraction (39±11 vs 46±11%, p=0.08) than those with ant AMI. On admission ECG, TC was more frequently associated with the absence of abnormal Q waves (42 vs 26%, p<0.05) and of inferior ST-segment depression (ST↓) (94 vs 51%, p<0.01), and lesser maximal ST-segment elevation (ST ↑) (5±5 vs 7±3 mm, p<0.01). Distribution of ST↑ is shown in Figure

, using the Cabrera sequence for display of limb leads. In pts with TC, ST↑ most frequently occurred in lead -aVR, but was rare in lead V1. ST↑ in lead -aVR and no ST↑ in lead V1 was observed in 91% of pts with TC, as compared with only 4% of those with ant AMI (p<0.001). This finding identified TC with 91% sensitivity, 96% specificity, and 95% predictive accuracy, which were higher than those of other ECG variables.

Conclusions:
The presence of ST↑ in lead -aVR (i.e, ST↓ in lead aVR) and the absence of ST↑ in lead V1 strongly suggests TC. This ECG finding allows TC to be simply but accurately differentiated from ant AMI.
Abstract 4864: Electrocardiographic and Angiographic Correlations in Patients With Left Bundle Branch Block With Suspected Myocardial Infarction Undergoing Urgent Coronary Angiography
Authors: Ray Madhab , Ramic Dzanan , Kleaveland J P , Jacobs Larry E
Published: April 2024

Background:
The purpose of this study is to determine the accuracy of the Sgarbosa criteria to identify the presence of acute Myocardial Infarction (MI) diagnosed by biomarkers and to predict coronary occlusions in patients with new or presumed new Left Bundle Branch Block (LBBB) and suspected acute MI.

Methods:
We retrospectively reviewed the records of 1322 consecutive patients presenting to our institution with suspected acute transmural MI who underwent urgent coronary angiography between 2004 and 2008.

Results:
Thirty four patients (2.6%) had LBBB. Results of Sgarbosa criteria versus presence of an occluded coronary artery and troponin status are shown in the table

below.

Conclusions:
In our cohort of patients 26 out of 34 (76%) patients had MI as determined by elevated tropnin levels. Sgarbosa criteria, when applied with the weighted score of >/=2, could detect patients of myocardial infarction with a sensitivity of 62%, specificity of 63%, positive predictive value of 76% and negative predictive value of 23%. When the same criteria were applied to detect occlusion of any coronary artery the sensitivity was found to be 50% with a specificity of 32%, positive predictive value of 29% and negative predictive value of 54%. In conclusion, the incidence of MI among the patients of new or presumed new LBBB is high at 76%. The overall usefulness of Sgarbosa criteria to diagnose MI and occluded coronaries (which are most likely to benefit from early revascularization) in patients with LBBB is moderate but the negative predictive value is very low. Hence patients with new or presumed new LBBB with suspected myocardial infarction should get the benefit of early catheterization if clinically justified.

Occluded Coronary Artery and Troponin Status
Abstract 4871: Circulating Endothelial Microparticles: A Novel Biomarker for Prediction of Subsequent Death and Cardiovascular Events in End-stage Renal Disease
Authors: Amabile Nicolas , Boulanger Chantal M , Guérin Alain P , Tedgui Alain , London Gérard M
Published: April 2024

Background: Endothelial dysfunction is closely associated with increased circulating levels of endothelial microparticles (EMPs) in patients with end-stage renal disease (ESRD). As arterial damage is a major contributor to cardiovascular mortality, we examined whether or not circulating levels of EMPs could predict outcome in ESRD.

Methods: This prospective study included 81 stable hemodialyzed patients with ESRD (age 59±14 yr; 63% male; follow-up 57 months). Baseline plasma microparticles (MPs) levels, cell origin and reproducibility were analyzed by flow cytometry. The primary end-point was the occurrence of any death. Secondary end-points included cardiovascular death and occurrence of major adverse cardiovascular events (MACE).

Results: Non-survivors (n=19) were older (70.6±9.2, vs. 55.1±13.2 y, p<0.001) and were characterized by lower diastolic blood pressure (70.8±10.5 vs. 80±12.4 mmHg, p<0.01), higher levels of hsCRP (6.9±4.4 vs. 5.0±4.3 mg/L, p<0.05) and endothelial CD31+CD41- EMPs (1822±1516 vs. 934±207 ev/
μ
l, p<0.001), whereas other MPs subtypes were not different. Mutivariate Cox analysis demonstrated that baseline EMPs levels independently predicted all-cause death (HR=4.0 [1.2–13.0] per log unit, p=0.02), cardiovascular mortality (HR=8.81 [2.4 –31.8], p<0.001) and MACE (HR=3.28 [1.2 – 8.9], p<0.01) after adjustment for age, traditional cardiovascular risk factors, medications and biological parameters. ROC curve analysis showed that baseline EMPs levels correctly predicted all-causes and cardiovascular mortality (AUC: 0.80±0.008 and 0.83±0.008 respectively, p<0.001 for all). EMP baseline level > 710 event/
μ
L correctly identified subsequent death with a sensitivity of 92% and a specificity of 63%. Kaplan-Meier analysis revealed that survival of patients with EMPs levels above median was worse than other patients (p<0.01, log rank analysis), whereas platelet MPs levels did not affect outcome.

Conclusions: Increased circulating levels of endothelial microparticles is a robust independent predictor of all-causes and mainly cardiovascular mortality in patients with ESRD and could help identify asymptomatic patients at higher risk of developing cardiovascular diseases and adjust therapy.
Abstract 4875: Obstructive Sleep Apnea is Associated With Increased Aortic Stiffening, Microalbuminuria and Endothelial Dysfunction in Hypertensives: A Double Enemy to the Vasculature
Authors: Thomopoulos Costas , Tsioufis Costas , Kasiakogias Alexandros , Andrikou Eirini , Andrikou Ioannis , Mazaraki Anastasia , Alchanatis Manos , Makris Thomas , Stefanadis Christodoulos
Published: April 2024

Introduction:
Incriminating evidence of an adverse effect of obstructive sleep apnea (OSA) on the vasculature is increasing. We investigated the degree of vascular impairment in the high risk population of hypertensives with OSA by diverse atherosclerotic surrogates.

Methods
: We studied 62 consecutive patients [49 men, aged 48±7 years, 31 smokers, body mass index (BMI) 32±4kg/m
2
) with untreated hypertension and OSA diagnosed by polysomnography (PSG) [apnea/hypopnea index (AHI)≥5], and a control group of 70 untreated hypertensives without OSA (AHI<5) matched for age, sex, body mass index, smoking status and 24h systolic blood pressure (BP). All subjects underwent 24h ambulatory BP monitoring, echocardiography and aortic stiffness evaluation by means of carotid - femoral pulse wave velocity (PWV) using an automatic device (Complior SP). Metabolic profile, serum creatinine levels (sCr), glomerular filtration rate (eGFR), and asymmetric dimethyl-arginine (ADMA) were assessed from a morning blood sample. The albumin/creatinine excretion ratio (ACR) was calculated from two non consecutive urine morning samples.

Results
: Hypertensives with OSA had similar 24h systolic BP (140±9 vs. 138±6 mmHg, p=NS) but higher 24h diastolic BP levels (87±6 vs. 84±7 mmHg, p=0.03) compared to the control group. Left ventricle mass index was greater in the OSA group (109±23 vs. 100±25 gr/m
2
, p=0.04), while relative wall thickness (0.43±0.07 vs. 0.43±0.08) and metabolic profile did not differ (p=NS for all). Although sCr and eGFR were similar between the two groups (0.96±0.18 vs. 0.94±0.18mg/dl and 114±30 vs. 116±27 ml/min/1.73m
2
, p=NS for both), patients with OSA exhibited higher levels of logACR and logADMA compared to those without (1.07±0.31 vs. 0.66±0.38 mg/g, −0.25±0.1 vs. −0.31±0.1
μ
mol/l, respectively, p<0.0001 for both) even after adjustment for confounders. Furthermore, PWV was elevated in OSA patients compared to the control group. (8.2±0.7vs.7.2±0.9m/sec, p<0.001). In the entire study population logAHI was correlated with PWV (r=0.35, p<0.001), logADMA (r=0.30, p=0.001) and logACR (r=0.34, p<0.0001).

Conclusions
: Elevated values of ADMA, PWV and ACR in hypertensives with OSA reveal an atherosclerotic state enhanced by sleep disordered breathing.
Abstract 4880: Novel Role of P90RSK-mediated Sentrin/Sumo-specific Proteases 2 (SENP2) Phosphorylation on Disturbed Flow and H2O2-induced Apoptosis in Endothelial Cells
Authors: Heo Kyungsun , Le Nhat Tu , Lee Hakjoo , Woo Chang-Hoon , Nigro Patrizia , Chang Eugene , McClain Carolyn , Fujiwara Keigi , Abe Juni-ichi
Published: April 2024

The atheroprotective roles of steady laminar flow (s-flow) and its inhibition against pro-inflammatory responses and endothelial cells (EC) apoptosis has been extensively studied. Emerging evidence suggested that disturbed flow (d-flow) and reactive oxygen species (ROS) are critical factors to induce EC dysfunction, which includes changes in vasoregulation, inflammatory activation, and altered barrier function with EC apoptosis. However, it remains unclear how d-flow induces EC dysfunction. We performed a survey of which kinases can be activated by d-flow, but not s-flow. We found that two kinases, p90RSK and PKC
ζ
, were particularly activated under d-flow, but not s-flow in EC. D-flow and H2O2 (50
μ
M) significantly increased apoptosis in EC (5.79±0.5 fold compared with control; p<0.01). Interestingly, we found that H2O2 increased nuclear export of p53 and p53-Bcl2 binding. The contribution of p53-SUMOylation on p53 nuclear export has been reported, and cytosolic p53-Bcl2 binding inhibits Bcl2 anti-apoptotic effect and induces apoptosis. Overexpression of p90RSK increased p53-SUMOylation, and adenovirus containing dominant negative form of p90RSK (Ad-DN-p90RSK) transduction significantly inhibited H2O2-mediated p53-SUMOylation, p53 nuclear export, p53-Bcl2 binding, and apoptosis, suggesting the critical role of p90RSK in p53-SUMOylation and subsequent apoptosis. Since four isoforms of p90RSK have similar function in EC, we used DN-p90RSK instead of siRNA which may downregulated all the isoforms. In addition, we determined SENP2 as a novel target of p90RSK based on the following results;

depletion of SENP2 increased p53-SUMOylation and apoptosis in EC,

overexpression of p90RSK significantly decreased SENP2 de-sumoylation activity,

H2O2-mediated SENP2 nuclear export was significantly inhibited by Ad-DN-p90RSK transduction, and

in vitro kinase assay showed that SENP2 was a good substrate of p90RSK.

Finally, en face confocal microscopy analysis using apoE−/− mice also revealed the activation of p90RSK and the up-regulation of p53 expression at d-flow, but not at s-flow area, supporting the patho-physiological consequence of p90RSK-SENP2 and subsequent apoptosis on d-flow-mediated acceleration of atherosclerosis.
Abstract 4890: Telmisartan Decreases Sympathetic Nerve Activity via Reduction in Oxidative Stress Through the Blockade of AT1 Receptor in the Vasomotor Center in Dietary-induced Obesity Rat
Authors: Konno Satomi , Hirooka Yoshitaka , Kishi Takuya , Sunagawa Kenji
Published: April 2024

Background:
Activation of sympathetic nerve activity (SNA) is critically involved in the occurrence of hypertension in metabolic syndrome (MetS). However, the mechanism(s) involved remains unknown. Reactive oxygen species (ROS) generation in the brain may elicit sympathoexcitation in MetS. The rostral ventrolateral medulla (RVLM) is the vasomotor center that determines basal central sympathetic outflow. ROS in the RVLM is produced mainly by NAD (P) H oxidase via angiotensin II type 1 receptor stimulation (AT
1
R). The present study aimed to determine whether telmisartan decreases SNA via a reduction in ROS through the blockade of AT
1
R in the RVLM of MetS model rats.

Methods and Results:
Male Sprague-Dawley rats were fed a high-fat diet and segregated into obesity-prone (OP, n = 5) and obesity-resistant (OR, n = 5) groups based on their body weight (BW) after 13 weeks. The OP group was then divided into 2 groups, OP with telmisartan (5mg/kg/day for 12 weeks, TLM-OP, n = 3) and OP without telmisartan (VEH-OP, n = 3). At 13 weeks, body weight (BW), systolic blood pressure (SBP), heart rate (HR), and urinary norepinephrine excretion (uNE) as a parameter of SNA were significantly higher in OP than in OR (BW; 760 ± 46g vs 548 ± 13g, SBP; 151 ± 5mmHg vs 123 ± 7mmHg, HR; 375 ± 11bpm vs 333 ± 5bpm, uNE; 0.35 ± 0.05
μ
g/day/kg vs 0.25 ± 0.04
μ
g/day/kg, n = 5 for each,
P
< 0.05 for each). ROS in the RVLM, measured by the thiobarbituric acid-reactive substances (TBARS) method, was significantly higher in OP than in OR (7.2 ± 0.8
μ
mol/g vs 2.2 ± 1.9
μ
mol/g wet wt, n = 4 each,
P
< 0.05). Microinjection of AT
1
R blocker (ARB), candesartan, into the RVLM induced a significantly greater mean SBP reduction in OP than in OR. The expression of angiotensinogen, angiotensin-converting enzyme (ACE), and AT
1
R in the RVLM assessed by Affymetrix microarray was significantly higher in OP than in OR. TLM-OP had significantly lower BW, SBP, HR, uNE, and TBARS than VEH-OP. Microinjection of angiotensin II into the RVLM resulted in significantly lower pressor responses in TLM-OP than in VEH-OP.

Conclusion:
In MetS, increased ROS in the RVLM produced by upregulation of the local renin-angiotensin system increases SNA. Telmisartan inhibits SNA via a reduction of ROS through the blockade of AT
1
R in the RVLM.
Abstract 4904: Comparative Anti-atherogenic Effects of a Single Intravenous Injection of rAAV8 Or rAAV2 Encoding Apo A-IMilano Gene
Authors: Tian Fung , Wang Lai , Yang Mingjie , Sharifi Behrooz G , Shah Prediman K
Published: April 2024

Background: We previously reported potent anti-atherogenic effects of gene transfer of Apo A-IMilano through transplant of retrovirally transduced bone marrow. In anticipation of potential evaluation of Apo A-IMilano gene transfer in human atherosclerosis, we evaluated the comparative anti- atherogenic efficacy of Apo A-IMilano gene transfer using intravenous injection of type-2 and type-8 recombinant adeno-associated viruses (rAAV2 and rAAV8) as vectors in Apo A-I/apo E null mice.

Methods: Mice received one intravenous injection of 1.2×1012 vector genome copies of rAAV2 -Milano or rAAV2 -Control or rAAV8 -Milano or rAAV8 -Control (12 mice per group). Four weeks after injection mice were placed on high fat diet. Twenty weeks later mice were euthanized to analyze Apo A-IMilano gene expression and quantitative extent of aortic atherosclerosis after oil-red O staining. ELISA analysis of blood samples and real-time PCR analysis of target organs was used to determine the Apo A-IMilano gene expression. Blood was analyzed for cholesterol levels.

Results: The circulating cholesterol levels were comparably elevated among the 4 groups. Serum Apo A-IMilano levels were significantly higher in rAAV8 -Milano injected mice compared to rAAV2 -Milano injected mice at 4 weeks (71 ± 31 ng/ml vs. 31 ± 21ng/ml) 12 weeks (92 ± 61 ng/ml vs. 30 ± 27), and at 24 weeks (45 ± 32 ng/ml vs. 7.6 ± 6 ng/ml) (P <0.001 all groups). Real time PCR showed a significantly higher level of transgene expression in the heart (122 ± 36 fold), liver (32 ± 25 fold) and the brain (14 ± 0.39 fold) with rAAV8 -Milano compared to rAAV2 -Milano. Compared to rAAV8 -Control, the mean aortic lesion area was reduced by 42% by rAAV8 -Milano (7.7 ± 0.06% vs 13.4 ± 1.1 % of aorta; p = 0.001). Compared to rAAV2-Control, the mean aortic lesion area was reduced by 16% by rAAV2 -Milano (12.6 ± 0.8 vs 10.6 ± 0.8 % of aorta; p = NS). rAAV8 -Milano reduced lesion area by 27% compared to rAAV2 -Milano (p = 0.01).

Conclusions: Intravenous rAAV8 -Milano results in higher in-vivo transgene expression and a significantly greater reduction in aortic atherosclerosis compared to vector control or rAAV2 -Milano.
Abstract 4907: LDL-loaded Macrophages Convert Smooth Muscle Cells Into Foam Cell Like Cells by Direct Transport of LDL/cholesterol During Cell-cell-contact
Authors: Weinert Soenke , Poitz David M , Herold Joerg , Schmeisser Alexander , Strasser Ruth H , Braun-Dullaeus Ruediger
Published: April 2024

Lipid-loaded macrophages [MP] and vascular smooth muscle cells [VSMC] are key players of atherosclerotic plaque development. However, little is known about their interaction. We hypothesized that MP modulate VSMC behavior directly by cell cell contact. Monocyte-derived MP were exposed to fluorescence-labeled acetylated LDL [FL-LDL] prior co-culture. Semi-confluent VSMC were co-cultured with the FL-LDL-tagged MP in a ratio of 1:3, respectively. Immune cytochemistry revealed that up to 20% of sm-actin positive cells (VSMC) gained Fl-LDL particles. Transfer of the particles was abolished by cell separation in a trans-well co-culture system. Time-lapse microscopy demonstrated that the VSMC acquired the FL-LDL from MP within hours. No phagocytosis of apoptotic bodies was involved in this process. 3D high magnification microscopy demonstrated that, within 24 h, the entire cytosol of single VSMC was filled with FL-LDL. FL-LDL/FL-cholesterol complexes were also transferred and resulted in cholesterol positive lipid droplet formation in VSMC. Usage of the acidotropic fluorescence dye LysoTracker
™
demonstrated that some Fl-LDL was bioactive and reached the acidic lysosomes of VSMC. Marking all lysosomes with a fusion protein of LAMP1 and RFP demonstrated that the remaining FL-LDL was located in non acidic lysosomes. VSMC were then infected with a virus coding for a Rab5a-GFP fusion protein to mark all early endosomes. In contrast to endothelial cells (positive control) no co-localization of Rab5a-GFP and transported Fl-LDL in VSMC could be found, supporting a mechanism independent of phagocytosis. Rescue of the VSMC from co-culture and subsequent analysis demonstrated an increase in phagocytotic activity compared to VSMC co-cultured in a trans-well with MP. Xenogenic cell composure (rat VSMC, human MP) and subsequent quantitative RT-PCR with rat specific primers demonstrated induction of genes typical for MP (CD68 and Mac2) and a concomitant downregulation of cholersterol sensitve genes (HMG-CoA reductase) in VSMC. These results demonstrate an active and phagocytosis independent exchange of LDL/cholesterol from MP into VSMC and imply that MP are capable of transforming a plaque stabilizing VSMC into a plaque destabilizing foam cell like cell.
Abstract 4910: Forkhead Transcription Factor 3a (FOXO3a) is Involved in the Regulation of Functional Response to Aging and Stress in Murine Cardiomyocytes
Authors: Li Qun , Ma Heng , Thomas Paul , Kandadi Machender R , Ren Jun
Published: April 2024

Aging is a complicated but regulated process. Forkhead transcription factors (FOXO), the major substrates for the protein kinase Akt and AMP-activated protein kinase, play an important role in longevity. Our earlier studies suggested that deficiency in insulin-growth factor I (IGF-1) contribute to cardiomyocyte dysfunction but prolongs lifespan possibly through downregulation of FOXO3a signaling. Given that lifespan extension is closely associated with stress tolerance, our present study was set to examine the effect of FOXO3a inhibition on aging-/stress-induced cardiomyocyte contractility and survival. The dominant negative FOXO3a-GFP adenovirus was injected into adult and aged C57BL/6J murine hearts. Five days later, GFP positive cardiomyocytes (denoting successful Foxo3a transfection) isolated from in adult and old C57BL/6J mice were identified for assessment of contractile properties including peak shortening (PS), time-to-PS (TPS), time-to-relengthening (TR
90
), and maximal velocity of shortening/relengthening (+/−dL/dt). Dominant negative FOXO3a (FDN) transfection significantly reduced PS in adult group although it restored aging-induced dysfunction in PS, +/−dL/dt and TR
90
. Further study on MTT assay and western blot revealed that transfection of FDN in H9c2 myoblasts exhibited higher survival rate in response to paraquat and H
2
O
2
compared to control group. Inhibition of FOXO3a expression enhanced phosphorylation of Akt and AMPK in both normal and paraquat-treated conditions. Paraquat downregulated the “aging” protein-klotho, the effect of which was restored by FDN transfection. These data suggested that FOXO3a plays an important role in regulation of cardiomyocyte contractility and stress resistance under aging or oxidative stress.
Abstract 4912: Multidrug Resistance Associated Protein-1 (MRP-1) Regulates Endothelial Cell Apoptosis
Authors: Widder Julian D , Kruempel Christian , Fraccarollo Daniela , Ertl Georg , Bauersachs Johann
Published: April 2024

The multidrug resistance associated protein-1 (MRP-1) is the main transporter of oxidized glutathione in endothelial cells, and blockade of MRP-1 prevents endothelial cell dysfunction induced by reactive oxygen species (ROS). We therefore sought to investigate the effect of MRP-1 downregulation on TNF
α
-induced endothelial cell apoptosis. HAEC’s were either transfected with a siRNA against MRP-1 or a negative control siRNA and treated with TNF
α
/cycloheximide(CHX ) for 3h or 6h. TNF
α
/CHX lead to endothelial cell apoptosis as indicated by Annexin V staining (FACS analysis) and increased cleavage of caspase 3 (Western blot). Downregulation of MRP-1 via siRNA significantly diminished Annexin V staining and caspase 3 cleavage. TNF
α
/CHX augmented endothelial cell superoxide production which was significantly attenuated by siRNA against MRP-1. Further, pre-treatment with the glutathione precursor N-acetylcysteine prevented cleavage of caspase 3. TNF
α
/CHX mediated activation of caspases 7 and 8 were reduced when MRP-1 was downregulated, while no influence was found on phosphorylation levels of the Fas-Associated protein with Death Domain (FADD). TNF
α
/CHX induced phosphorylation of p38-, ERK- and JNK-MAP-kinases. While phosphorylation of p38 MAP kinase and ERK was not influenced by MRP-1 downregulation, TNF
α
/CHX induced JNK phosphorylation was significantly attenuated in HAEC’s transfected with MRP-1 siRNA. These data indicate a major role for MRP-1 in regulation of TNF
α
/CHX-induced endothelial cell apoptosis via modulation of ROS levels, caspase activation, and JNK phosphorylation.
Abstract 4915: IQGAP1 Expressed in Macrophage and Endothelial Cells Plays an Important Role in ROS-dependent Ischemia-induced Neovascularization
Authors: Urao Norifumi , McKinney Ronald D , Fukai Tohru , Ushio-Fukai Masuko
Published: April 2024

Not only endothelial cells (ECs) but also macrophage play a key role in ischemia-induced angiogenesis which is dependent on inflammation and reactive oxygen species (ROS). IQGAP1, an actin- and Rac1-binding scaffold protein, is a key regulator for actin cytoskeleton and motility. We demonstrated that IQGAP1 is involved in VEGF-induced ROS production and migration in cultured ECs; however, its role in post-ischemic neovascularization remains unknown. Using hindlimb ischemia model of mice, here we show that IQGAP1-expressing Mac3-positive macrophage and lectin-positive ECs (5.5 and 10.2-fold) are increased in ischemic limb tissues at 3 days and 7 days after ischemia, respectively. Ischemia-induced neovascularization is significantly impaired in IQGAP1 knockout (KO) mice as compared to wild-type (WT) mice as evaluated by laser Doppler blood flow (38% decrease), capillary density (48% decrease), and alpha-actin+ arterioles (68% decrease). In IQGAP1 KO mice, the number of infiltrated Mac3-positive macrophage and ROS production in ischemic muscles are significantly decreased (30% and 52%, respectively). In contrast, numbers of inflammatory cells and cKit+/Flk1+ endothelial progenitor cells (EPCs) in peripheral blood are not affected in these knockout mice. As compared to WT-BM transplantation to irradiated WT mice, WT-BM to irradiated KO mice inhibits ischemia-induced in blood flow recovery (22%) and CD31+ capillary density (5%), while KO-BM to irradiated WT mice shows decreases in flow recovery (48%) and capillary density (23%). These findings indicate that IQGAP1 KO mice impair function of BM derived cells without affecting their mobilization from BM. Furthermore, in vitro, BM-derived macrophages obtained from KO mice show defective polarization of actin (88% decrease), as visualized by phalloidin staining as well as inhibition of migration induced by SDF-1 (92%) or wound scratch (38%). VEGF- or wound scratch-induced EC migration is inhibited in IQGAP1-depleted ECs. In summary, IQGAP1 upregulated in macrophage and ECs after hindlimb ischemia plays an important role in ROS-dependent postnatal neovascularization. Thus, IQGAP1 is a potential therapeutic target for inflammation- and angiogenesis-dependent cardiovascular diseases.

This research has received full or partial funding support from the American Heart Association, Midwest Affiliate (Illinois, Indiana, Iowa, Kansas, Michigan, Minnesota, Missouri, Nebraska, North Dakota, South Dakota & Wisconsin).
Abstract 4923: Prostacyclin Analogues Activates Calcium-dependent Potassium (K
Ca
) Channels via PPAR
β
/
δ
in Pulmonary Artery
Authors: Li Yingji , Connolly Michelle , Tang Bi , Nagaraj Chandran , Bálint Zoltán , Smolle-Jüttner Freya , Popper Helmut , Olschewski Andrea
Published: April 2024

Pulmonary hypertension is associated with vasoconstriction, thrombosis and proliferation, and the lack of endogenous prostacyclin. Prostacyclin and its analogues are potent vasodilators, representing an important pillar of modern therapy of this devastating disease. Potassium channels determine the membrane potential of pulmonary artery smooth muscle cells (PASMCs) and are important controllers of their calcium homeostasis and consequently the pulmonary arterial tone. In the present study, we investigated the signaling pathway and effects of the stable prostacyclin analogues treprostinil and iloprost in primary human PASMCs and isolated rat pulmonary artery. We employed the whole-cell patch-clamp technique combined with small interfering (si)RNA and live-cell calcium imaging on human PASMCs and the myograph-mounted isolated intrapulmonary artery model. We found that treprostnil (10 nM) and iloprost (10 nM) hyperpolarized primary human PASMCs (13.1 ± 2.2 mV, p < 0.01 and 15.7 ± 2 mV, p < 0.01 respectively, n = 6 for each group) and activated K
Ca
(IC
50
= 0.2 ± 0.05 nM and IC
50
= 0.5 ± 0.2 nM respectively, n = 5 for each group) at clinically relevant concentrations. The IP receptor antagonist RO1138452 (10
μ
M) and PKA blocker KT5720 (1 mM) abolished these effects. In the siRNA-transfected cells no enhancement of K
Ca
current was detected. The novel PPAR
β
/
δ
antagonist GSK0660 (10 nM), abolished the activation of K
Ca
current by iloprost or treprostinil, whereas the selective PPAR
β
/
δ
agonist GW0742 (10 nM) activated the K
Ca
current. Calcium imaging measurements supported these data showing that GW0742 reduced the basal intracellular calcium concentration by 9.41±2.99 % (n = 25, p < 0.01) compared to the baseline in human PASMCs. Consequently, GW0742 caused relaxation in
U46619
-preconstricted rat intrapulmonary arteries (IC
50
= 9.42
μ
M, n = 5). This is the first study implicating K
Ca
in the prostacyclin analogue- mediated hyperpolarization via PPAR
β
/
δ
in human PASMCs. This might represent a novel pathway related to the vasodilating effects of prostanoids.
Abstract 4927: Thrombin Activation of Proteinase-Activated Receptor 1 (PAR1) Induces Ca
2+
-Independent Vasoconstriction by Activating the Production of Reactive Oxygen Species in the Pulmonary Artery
Authors: Maki Jun , Hirano Mayumi , Hirano Katsuya
Published: April 2024

Thrombotic pulmonary arteriopathy is associated with ~50% of primary pulmonary artery hypertension (PAH). Thrombin and its receptor PAR
1
are thus suggested to play a critical role in the pathogenesis and pathophysiology of PAH. However, the role of thrombin in the regulation of pulmonary artery contraction still remains largely unknown. This study thus aimed to elucidate the contractile mechanism of thrombin in the isolated porcine pulmonary artery. In the presence of extracellular Ca
2+
([Ca
2+
]
o
), thrombin induced a sustained contraction with a small sustained elevation of [Ca
2+
]
i
and an increase in myosin light chain (MLC) phosphorylation. The contractile effect of thrombin was abolished by either a protease inhibitor or a PAR
1
antagonist, while it was mimicked by an agonist peptide for PAR
1
, but not PAR
4
. In the absence of [Ca
2+
]
o
, thrombin induced a sustained contraction to an extent similar to that seen in the presence of [Ca
2+
]
o
, but no significant increase in [Ca
2+
]
i
or MLC phosphorylation was observed. A similar Ca
2+
-independent contraction was induced by H
2
O
2
. Pretreatment with
N
-acetyl cysteine substantially inhibited the Ca
2+
-independent contraction induced by thrombin and H
2
O
2
. The fluorescence imaging of reactive oxygen species (ROS) revealed the thrombin- induced production of ROS in the absence of [Ca
2+
]
o
. When a scavenger enzyme glutathione peroxidase was suppressed, the ROS production by thrombin was observed both in the presence and absence of [Ca
2+
]
o
, thus suggesting that thrombin is capable of producing ROS regardless of the presence or absence of [Ca
2+
]
o
, while this effect was veiled by the scavenger activity in the presence of [Ca
2+
]
o
. Rho kinase inhibitor inhibited not only the thrombin-induced contraction in the presence of [Ca
2+
]
o
, but also the Ca
2+
-independent contraction induced by thrombin and H
2
O
2
and the thrombin-induced ROS production, thus suggesting multiple roles of Rho kinase. This study thus provides the first evidence that the thrombin activation of PAR
1
induces pulmonary vasoconstriction via Ca
2+
-dependent as well as Ca
2+
-independent and ROS-mediated contractile mechanisms. PAR
1
is thus suggested to be useful as a novel therapeutic target for the treatment of PAH, especially when associated with thrombus.
Abstract 4937: A Novel Molecular Imaging Sensor of Cellular Oxidative Stress
Authors: Peterson Karen M , Chen Ian Y , Simari Robert D , Gambhir Sanjiv S , Lerman Amir , Rodriguez-Porcel Martin
Published: April 2024

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.