bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 16953: Effects of Exercise Training on PGC1α and Skeletal Muscle Function in Patients with Chronic Heart Failure - An Age-Stratified Study
Authors: Sandri Marcus , Adams Volker , Mangner Norman , Schuler Gerhard , Gielen Stephan
Published: April 2024

Introduction:
Despite its prognostic implications the mechanisms of skeletal muscle wasting in chronic heart failure (CHF) are still not completely understood. We have previously documented a catabolic activation and reduction of mitochondria in skeletal muscle biopsies of CHF patients. PGC1α is a key regulator in both processes and it is unclear, if PGC1α can be positively altered by exercise training and if beneficial training effects are diminished in older patients.

Methods:
60 CHF patients and 60 healthy subjects (HS) were randomized to 4 weeks of bicycle ergometer training at 70% of the heart rate reserve 4 x 20 min/day or to a control group (C). Before and after the intervention a spiroergometry, echocardiography, a force duration measurement and a muscle biopsy of the vastus lateralis muscle were performed. Expression of PGC1α was quantified by real-time PCR standardized for 18S-rRNA and Western blot.

Results:
(1) Clinical Training Effects: In younger CHF patients (n= 15, age 45±3 years, BMI 26.8±2.7, LV-EF 26.8±2.6%) training improved force duration from 31±3 to 45±4 seconds (p=0.004 vs. control). In elderly CHF patients (n=15, age 68±4 years, BMI 25.3±2.9, LV-EF 27.4±3.0%) training increased force duration from 35±4 to 47±7 seconds (p=0.01 versus control). (2) Molecular Training Effects: At baseline PGC1α mRNA expression in CHF patients was reduced versus HS at 201±19 versus 401±25 rel. units (p=0.007) confirmed by a reduced protein expression at 0.22±0.09 in CHF patients versus 0.97±0.04 rel. units in HS (p=0.01). Exercise training was associated with an increase of PGC1α mRNA expression by 39.3% (p=0.02) in younger CHF patients and an increase of 34.7% (p<0.05) in the elderly.

Conclusions:
Exercise training equally improves skeletal muscle function in younger and older patients with CHF. These clinical data underline the importance of exercise-based rehabilitation programs to prevent CHF related muscle wasting. On a molecular level, PGC1α is significantly increased on mRNA and protein level in both younger and older patients with CHF, implicating a reduced catabolic state and an improved oxidative capacity, both regulated by PGC1α.
Abstract 16959: Cardiac Grb2-associated Binder 1 Deficiency Causes Dilated Cardiomyopathy and Heart Failure Due to Severe Mitochondrial Damage and Cardiomyocyte Apoptosis
Authors: Zhao Jinjing , Jin Felix Q , Kim Ji Young , Wang Weiye , Liu Macrobin , Yang Ying , Wong Chelsea , Jin Zheng Gen
Published: April 2024

Background:
Receptor tyrosine kinase (RTK) inhibitors as novel anticancer therapy are associated with clinical heart failure. Better understanding molecular mechanisms underlying such a side effect may provide new strategies to prevent RTK inhibitors-induced heart failure. Grb2-associated binder 1 (Gab1), a member of the docking protein family, is a central mediator for RTK signaling. We hypothesized that the deletion of Gab1 causes dilated cardiomyopathy and heart failure.

Methods and Results:
Using alpha-MHC-Cre mice and Gab1 loxp mice, we generated cardiac-specific Gab1 knockout (Gab1-cKO) mice. Gab1-cKO mice were viable and born at the expected Mendelian ratio. With echocardiography, hemodynamic measurements and histological analysis, we found that cardiac Gab1 deficiency in mice caused progressive dilated cardiomyopathy and heart failure. At age 3-6 months, ejection fraction and dp/dt max in Gab1-cKO mice were considerably lower than those in Gab1 wild-type littermates. Moreover, under mechanical stress via transverse aortic constriction at young age (around 6 weeks) before onset of heart failure, Gab1-cKO mice suffered more severe dilated cardiomyopathy and induced lethality. The deletion of Gab1 in heart during adulthood by crossing Gab1-loxp mice with tamaxifen-inducible alpha-MHC-Cre mice also resulted in cardiac dysfunction and heart failure. Mechanistically, we observed loss of mitochondrial membrane potential and increase of cardiomyocyte apoptosis in Gab1-cKO heart. Transmission electronic microscopy studies showed frequent damaged mitochondria with cristae lysis and apparent abnormal internal membrane whorls in Gab1-cKO heart. Signaling studies revealed that proapoptotic genes including p38 and caspase 3 were overly activated in Gab1-cKO heart. Gene array and quantitative PCR analysis showed that antiapoptotic genes such as Bcl2 were downregulated, whereas proapopotic genes such Bnip3 were upregulated in Gab1-cKO heart.

Conclusion:
Gab1 is a crucial regulator of cardiac function through maintaining mitochondrial integrity and cell survival, suggesting that the preservation of Gab1 signaling could be one of therapeutic strategies to prevent heart failure induced by anticancer RTK inhibitors.
Abstract 16987: Genetic Deletion of DJ-1/Park7 Increases Myocardial Ischemia/Reperfusion Injury
Authors: Hood Rebecca L , Moody Bridgette F , Nicholson Chad K , Calvert John W
Published: April 2024

Background:
DJ-1/Park7 has classically been implicated in early onset Parkinson's disease, but has recently been identified to play a role in the cellular response to stress. For instance, in non-cardiac cells, DJ-1 has been shown to associate with and inactivate Daxx, a modulator of apoptosis. DJ-1 is expressed in the heart, but its role in mediating myocardial injury is currently unknown. Therefore, we examined how a deficiency in DJ-1 would affect myocardial ischemia/reperfusion (MI/R) injury.

Methods and Results:
Wild-type (WT) control and DJ-1 knockout (DJ-1 KO) mice were subjected to 45 min of left coronary artery I followed by 24 hr of R, at which time the extent of myocardial injury was evaluated. The deficiency of DJ-1 significantly increased the extent of myocardial injury as evidenced by a 45% increase in myocardial infarct size relative to the area-at-risk (INF/AAR), a 44% increase in INF relative to the left ventricle (LV) and a 155% increase in circulating troponin-I levels. In an effort to evaluate the signaling mechanism responsible for the increased injury in DJ-1 KO mice, WT and KO animals were subjected to 45 min of I followed by 1 hr R. Western blot analysis revealed that DJ-1 KO mice exhibited a higher baseline cytosolic protein expression of Daxx compared to WT. Following MI/R, Daxx expression was increased in WT mice and this increase was further augmented by the absence of DJ-1. DJ-1 is known to prevent the association of Daxx with ASK-1, leading to a decrease in the pro-apoptotic phosphorylation of Jnk (Jnk-P). Further analysis revealed that DJ-1 KO mice displayed both higher levels of Jnk-P and cleaved caspase-3 after MI/R when compared to WT mice.

Conclusions:
These data suggest for the first time that DJ-1 plays a protective role in the heart following MI/R injury as evidenced by the increase in Daxx-mediated apoptosis and exacerbated myocardial injury observed in DJ-1 deficient mice.
Abstract 16991: Endothelial Nitric Oxide Synthase is Essential for Hypoxia-Induced Progenitor Cell Mobilization and Homing
Authors: Everaert Bert R , Van Laere Steven J , Hoymans Vicky Y , Timmermans Jean-Pierre , Vrints Christiaan J
Published: April 2024

Introduction:
Acute myocardial infarction (AMI) is accompanied by induction of pro-angiogenic responses that lead to the recruitment of progenitor cells (PCs). Failure to induce PC mobilization, inefficient homing towards or limited survival in the ischemic microenvironment are all associated with loss in healing capacity and increased scar formation.

Hypothesis:
Both endothelial nitric oxide synthase (eNOS) and hypoxia-inducible factor-1 (HIF-1) have been implicated in PC biology, angiogenesis and vascular homeostasis. We investigated the effects of eNOS deficiency on HIF-1 and HIF-1 related gene expression, PC mobilization and peripheral PC homing conditions.

Methods & Results:
AMI was induced in wild-type (WT) (n=10) and eNOS knockout (KO) mice (n=10). One week post-AMI, bone marrow mobilization of early PCs (Lin
-
Sca-1
+
) was markedly attenuated under eNOS-deficient conditions (p<0.001), as assessed by flow cytometry. mRNA expression of Hif1a (p<0.001) and HIF-1-dependent chemotactic factors, such as Cxcl12 (p<0.001) and Ccl2 (p<0.05), and vascular adhesion molecules, such as Icam1 (p=0.002) and Vcam1 (p<0.001), displayed significantly lower expression in the infarction border zone in eNOS KO mice. eNOS activity was highly correlated with Hif1a expression in WT animals (r=0.876, p<0.0001), a relation that was completely lost in the absence of eNOS. Lin
-
Sca-1
+
PC mobilization was correlated with Hif1a (p=0.01), Cxcl12 (p=0.018) and Ccl2 (p=0.008). Histologically, eNOS KO showed decreased capillary formation in the infarction border zone, which correlated with Hif1a (p=0.007) and Cxcl12 (p<0.001) expression, vascular adhesion molecules Icam1 (p=0.003) and Vcam1 (p=0.018), and with mobilization of Lin
-
Sca-1
+
PCs (p=0.033).

Conclusions:
eNOS is essential for the mobilization of PCs out of the bone marrow and the expression of hypoxia-induced chemokines and vascular adhesion molecules. We provide evidence for the close relationship between eNOS and HIF-1 pathways and suggest a novel view on PC biology in which nitric oxide acts as an essential cofactor for normal HIF-1 activity, enhancing both PC mobilization and peripheral PC homing conditions.
Abstract 16995: Association Between Anthropometric Measures and Coronary Artery Calcium Score Progression in Multi-Ethnic Population
Authors: Zalawadiya Sandip K , Veeranna Vikas , Panaich Sidakpal S , Kommuri Naga V , Neeraj Ashutosh , Jacob Sony , Afonso Luis
Published: April 2024

Abstract:
No prior data is available for the comparative analyses on various anthropometric measures and coronary artery calcium score (CACS) progression in healthy low risk multiethnic population.

Methods:
The MESA (Multi-Ethnic Study of Atherosclerosis) study is a prospective cohort study of 6,814 self-identified White, African-American, Hispanic, or Chinese participants free of clinical cardiovascular disease at baseline. Incident CAC was defined as no CAC at baseline with development of CAC upon subsequent visits. CACS progression was defined as change in CAC volume score upon follow up visit in participants who had detectable CAC at baseline. Anthropometric measures at baseline were compared for their predictive value for incident CAC (analyzed using adjusted logistic regression analysis) and CACS progression (analyzed using adjusted median regression analyses). (See Table 1 for adjustments)

Results:
See Table 1

Conclusion:
Measures of central obesity (especially, waist circumference and waist-hip ratio) have stronger association with both incident CAC and CACS progression among low risk multiethnic population compared to other anthropometric measures.
Abstract 17000: Pre-Conditioning with an Apo-lipoprotein Mimetic Peptide Recruits Adiponectin Dependent p-AMPK and Prevents Ischemic Cardiac Injury
Authors: Peterson Stephen J , Cao Jian , Rodella Luigi F , Rezzani Rita , Piccolomini Francesco , Vanella Luca , L'Abbate Antonio
Published: April 2024

Objectives:
Heme-heme oxygenase (HO) system is one of the first line defenses against alterations in cellular redox, and, has been show to protect against vascular endothelial dysfunction in chronic diseased states, such as obesity and diabetes. We tested the hypothesis that pre-conditioning with L4F attenuates ischemia induced cardiac dysfunction in diabetic mice.

Methods:
db/db mice were treated with either L-4F (an apo-lipoprotein mimetic inducer of HO) or vehicle for 8 weeks. Glucose, insulin, adiponectin, and pro-inflammatory cytokines (IL-1beta, TNF-alpha, MCP-1) were measured in plasma so as to confirm a diabetic, inflammatory state. Trans-thoracic echocardiography was performed at the completion of the experiment after which, isolated hearts were subjected to ischemia/reperfusion (IR) while mounted on a Langendorff's preparation. Isolated hearts were then analyzed for HO-1, pAMPK, peNOS, iNOS, adiponectin and superoxide levels.

Results:
As shown before, db/db mice developed hyperglycemia with hyperinsulinemia and exhibited significantly increased (p<0.05) circulating levels of inflammatory cytokines including, TNFalpha, MCP-1 and IL1beta. Cardiac function was significantly compromised (p<0.05) in db/db mice with enhancement of coronary resistance (CR) and reduced LVDevp and reduced cardiac muscle shortening (dP/dT). L-4F treatment increased insulin sensitivity and adiponectin levels (p<0.05), while lowering inflammatory cytokines (p<0.05) in these mice. Also, L-4F normalized LV function by increasing (p<0.05) fractional shortening and decreasing (p<0.05) LV dimensions. In I/R experiments, L-4F prevented coronary microvascular resistance from increasing and LV function from deteriorating in the db/db mice (p<0.05). These changes were associated with increased cardiac expression of HO-1, pAMPK, peNOS and adiponectin and decreased levels of superoxide and iNOS (p<0.01).

Conclusion:
Attenuation of L-4F-induced myocardial and coronary functional abnormalities in db/db mice, involves HO induction and recruitment of adiponectin-dependent anti-inflammatory, anti-oxidative, and vasodilatory pathways; including activation of pAMPK and peNOS.
Abstract 17001: Safety and Efficacy of Balloon Atrial Septostomy for Advanced Pulmonary Hypertension in Patients Failing Prostanoid Therapy
Authors: Kuhn Brooks T , Javed Usman , Smith Thomas W , Bommer William J , Allen Roblee P , Rogers Jason H
Published: April 2024

Background:
Prostanoid therapy improves quality of life and may increase survival in patients with advanced pulmonary hypertension (PH). Balloon atrial septostomy (BAS) can palliate or a serve as a bridge to transplantation for patients resistant to medical therapy. The safety and efficacy of BAS in the era of prostanoid therapy has not previously been reported.

Methods:
All patients had progressive symptoms despite prostanoid therapy at the time of their first BAS. Eleven patients who underwent a total of 16 septostomies between 2004-11 were included in this retrospective analysis.

Results:
Baseline demographics are shown in Table 1. Survival at a mean of 739 days was 73%. No patient died within 24 hours post-procedure. Thirty-day and 1-year survival were both 82%. 4 subjects required repeat BAS due to shunt closure; 3 subjects were successfully bridged to transplant. 9 of 11 patients had improvement by one functional class. Hemodynamic and echocardiographic measurements are presented in Table 2. All non-survivors were male and had higher baseline serum creatinine, mean right atrial pressure, right ventricular (RV) end diastolic pressure and left ventricular filling pressures, and lower RV ejection fraction. Mortality was associated with unchanged post-septostomy cardiac output despite an increase in LVEDP. Tricuspid annular plane systolic excursion (TAPSE) and serum BNP were not different between the two groups.

Conclusions:
BAS appears to be a promising therapy for select PH patients who have symptomatic progression despite prostanoid therapy. Survival is comparable to prior reports of patients undergoing BAS in the pre-prostanoid era.
Abstract 17004: Genome-Wide Significant Findings for Endotoxin-Evoked but not Basal Inflammation in Americans of European and African Ancestry
Authors: Ferguson Jane F , Terembula Karen , Tabita-Martinez Jennifer , Hinkle Christine C , DerOhannessian Stephanie L , Shah Rhia , Patel Parth , Shah Rachana , Mehta Nehal N , Reilly Muredach P
Published: April 2024

Objective:
To assess variation in response to endotoxemia and investigate genome-wide SNP associations with inflammatory response in Americans of European and African ancestry.

Background:
Inflammation is a key component in the pathophysiology of cardiometabolic disease. We utilize a model of evoked endotoxemia (LPS) to explore differences in evoked inflammation. We hypothesized that inflammatory responses would differ by race and gender, and would be influenced by genetic background.

Methods:
The Genetics of Evoked-Responses to Niacin and Endotoxemia (GENE) Study recruited N=294 healthy volunteers (age 18-45, 52% Female, 35% African (Af) ancestry, 65% European (Eu) ancestry) to an inpatient endotoxin challenge (1ng/kg LPS). Anthropometric and clinical measurements were recorded; blood was collected for Affy 6.0 SNP genotyping, and measurement of cytokines, lipids, and insulin resistance.

Results:
LPS induced a robust inflammatory response characterized by increased temperature, heart rate and blood pressure (P< 0.0001). Cytokines increased significantly (TNFα ~50-fold, IL-6 ~150-fold P< 0.0001) peaking 2 hours post-LPS. Peak cytokine response varied by race and gender: IL-6 was higher in females than males (191 vs 145 pg/ml, P=0.01), while TNFα was higher in Eu compared to Af (54 vs 41 pg/ml, P=0.02). Decreased insulin sensitivity post-LPS (Si 4.4 to 2.8, P<0.0001) was observed in Eu, but not Af. Strikingly, 11 SNPs in moderate to high LD (r2 0.5-0.9) in an intergenic region on 7p11 were strongly associated at genome-wide significance with the change in temperature in Eu (best P=1x10-11). Several SNPs were associated with the change in TNFα in Eu (best P=1.7x10-10). Interestingly, we observed significant associations with SNPs in the LPS receptor TLR4 gene and both TNFα and temperature response in Eu (best P=0.009, P=0.004) and Af (best P=0.002, P=0.007).

Conclusion:
The degree of inflammatory response to LPS differs by gender and race, although individual response within groups is heterogeneous. We detected numerous genome-wide significant SNP associations with evoked inflammatory response, not detected at baseline, potentially representing novel genetic markers, of important relevance to inflammatory cardiometabolic disease.
Abstract 17012: Biochemical Parallelism to Decipher How the Endothelium Governs Monocyte Differentiation
Authors: Kibbie Jon , Wang Zhiming , Kwon Ohyun , Modlin Robert L , Cruz Daniel
Published: April 2024

The physiologic cues that skew circulating monocytes towards distinct macrophage (MF) subsets are not clearly defined. Since the endothelium is a gatekeeper for circulating monocytes entering tissues, it is poised to deliver differentiation signals to infiltrating monocytes. We hypothesized that the endothelial cell (EC), depending on its activation state, would give rise to distinct phenotypic and functional MF subsets. EC pre-treated with interferon gamma (IFNγ), but not other inflammatory cytokines, diverted MF differentiation away from a homeostatic MF subset and towards an inflammatory MF subset. Yet, deciphering the gene expression program in EC responsible for skewing monocyte differentiation presented a formidable task. This problem was solved by a novel approach we term biochemical parallelism. First, a high-throughput flow cytometry approach was developed to identify small molecules that “mimicked” IFNγ in regards to polarizing EC to trigger inflammatory MF. Subsequently, IFNγ and active small molecules - as well as structural analogues that were inactive- were compared by whole genome expression profiling. Of over 800 nuclear factors induced by IFNγ, this approach narrowed the candidate genes to 4 transcription factors (TF). Forced expression of the candidate TF revealed that only activating transcription factor 3 (ATF3) reprogrammed the EC to trigger inflammatory MF. Transcriptome analysis of EC with forced expression of ATF3 revealed that the transcriptome was highly enriched for IFNγ-related genes. Finally, we screened a small molecule library of FDA-approved compounds and found that tolfenamic acid - a non-steroidal anti-inflammatory drug - polarized the endothelium to trigger inflammatory MF. While such effects may contribute to host-protective effects in cancer prevention, it may also provide an explanation for the increased cardiovascular events associated with this class of drugs. In conclusion, we demonstrate that the activation state of the endothelium can govern MF subset differentiation, and outline how biochemical parallelism can help decipher complex biological processes, while providing a novel methodology to identify small compounds with potential therapeutic value or unanticipated risk.
Abstract 17023: PAI-1 Deficiency Protects Against Accelerated Aging in Klotho-Deficient Mice
Authors: Eren Mesut , Murphy Sheila B , Vaughan Douglas E
Published: April 2024

The
klotho
gene encodes a single-pass transmembrane protein and functions as an aging-suppressor gene, which extends life span when overexpressed and accelerates the development of aging-like phenotypes when disrupted in mice. Klotho protein and FGF receptor function as co-receptors for FGF23 and regulate phosphate and vitamin D metabolism. Klotho also plays a role in the regulation of calcium channel TRPV5, insulin, IGF-1, and Wnt.
Klotho
deficient (kl
-/-
) mice display a phenotype consistent with accelerated aging, including a markedly truncated lifespan (approx. 10 weeks), infertility, osteoporosis, renal sclerosis and obstructive pulmonary disease. The biochemical hallmarks of kl
-/-
include elevated plasma levels of FGF23, phosphate, calcium, vitamin D, and plasma PAI-1. Given the relationship between elevated PAI-1 and nephrosclerosis and tissue fibrosis, we hypothesized that PAI-1 deficiency would attenuate the phenotype of kl
-/-
mice. Partial or complete PAI-1 deficiency had no significant effects on serum levels of calcium, phosphate, and creatinine levels, while plasma levels of FGF23 were reduced more than 60-fold in kl
-/-
-pai-1
-/-
(P=0.01) and kl
-/-
-pai-1
+/-
(P=0.004) mice. Furthermore, both kl
-/-
-pai-1
-/-
and kl
-/-
-pai-1
+/-
mice exhibit normal fertility. Most importantly, partial and complete PAI-1 deficiency more than doubled the lifespan of kl
-/-
mice, with kl
-/-
-pai-1
-/-
living 148±79 days, (n=9, p=0.009)) and kl
-/-
-pai-1
+/-
surviving 208±155 days (n=17, p=0.002). These findings indicate that PAI-1 contributes to some of the critical components of the kl
-/-
phenotype. These results suggest that drugs that either directly or indirectly reduce PAI-1 might have beneficial effects in delaying age-related pathologies.
Abstract 17036: Flk1 Mediated Activation of ER71 and Specification of Cardiovascular Lineages
Authors: Rasmussen Tara L , Wallis Alicia , Shi Xiaozhong , Kweon Junghun , Koyano-Nakagawa Naoko , Garry Daniel J
Published: April 2024

We have previously demonstrated that Ets Related Protein 71 (ER71) is essential for primitive hematopoiesis and development of the endothelial/endocardial lineages. Lack of ER71 results in early (E8.0-E9.0) embryonic lethality. We generated an ER71-EYFP transgenic reporter mouse model using FACS and transcriptome analysis and determined that hematopoieitic and endothelial/endocardial molecular programs are restricted to the FACS sorted ER71-EYFP+ population. Using immunohistochemical techniques, we observed coexpression of EYFP (representing ER71 expression) and Flk1 between E7.0 and E9.5. However, Flk1 expression appears to precede ER71 expression in the primitive streak. Based on our observation that ER71 mutants phenocopy Flk1 null embryos at E8.0, we undertook a genetic analysis to determine whether Flk1 was upstream of ER71. We analyzed Flk1 expression in the ER71 mutant background by utilizing the Flk1-LacZ allele, FACS analysis, and qPCR. While Flk1-LacZ shows an aberrant spatial expression pattern, the frequency of cells expressing Flk1 is unchanged at E7.75 and is decreased modestly (two-fold) at E8.0. This demonstrates that Flk1 is not completely dependent on ER71 expression. In contrast, crossing the ER71-EYFP transgenic reporter allele into the Flk1 null background revealed that ER71 expression at E7.75 and E8.0 is dependent on Flk1. Furthermore, we have identified an evolutionarily conserved NFAT binding site in the essential ER71 promoter. NFAT is a family of transcription factors known to mediate a VEGF signalling cascade that involves the Flk1 receptor and Calcineurin. We have used ChIP and EMSA to verify that NFAT directly binds the ER71 promoter. Using transcriptional assays, we further demonstrate that ER71 is regulated by NFAT and Calcineurin. Collectively, these studies support the hypothesis that a Flk1-ER71 network specifies and coordinates the endothelial/endocardial lineages during cardiovascular development.
Abstract 17052: Multiparametric Noninvasive Assessment of Left Ventricular Filling Pressures: Are We There Yet?
Authors: Popovic Zoran , Negishi Kazuaki , Klein Alan L , Thomas Jamsed D , Marwick Thomas H
Published: April 2024

Background:
Several echo parameters have been proposed as surrogates of LV filling pressures, but their comparative and additive values are unknown. Recent American Society of Echocardiography/European Association of Echocardiography (ASE/EAE) recommendations have proposed a multiparametric algorithm to predict LV filling pressures in the setting of preserved or decreased LV ejection fraction (EF). Our aim was to compare discriminative ability of individual parameters used in ASE/ESE algorithm and validate its use in a large cohort of patients.

Methods:
We assessed 449 consecutive pts (181 women, age 63±13y) in whom echocardiography and invasive measurement of LV end-diastolic pressure (EDP) were performed within 24 hours. Elevated EDP was defined as ≥20 mmHg, and decreased EF was defined as <0.5. Predictive ability of individual parameters was compared by using area under the curve (AUC) obtained by receiver operator characteristic analysis. Finally, multiple parameters (see Table for list) were combined first in ASE/EAE algorithm, and then in a new Classification and Regression Tree (CART)-derived algorithm.

Results:
LV EDP was elevated in out 80/331 pts with normal EF, and in 47/118 pts with decreased EF. AUC values were higher in decreased EF pts, with E/E', LAVI, and PASP being significant in both groups (Table 1). Sensitivity and specificity of ASE/ESE algorithm to detect elevated EDP were 74% and 57% in patients with normal EF, and 78% and 59% in patients with decreased EF, while they were 73% and 76% in patients with normal EF and 77% and 80% in patients if CART-derived algorithm was used.

Conclusion:
While most echo parameters tested show discriminative ability to assess LV filling pressures, their predictive power is low. Their combined use in ASE/EAE algorithm shows moderate sensitivity but poor specificity in this series of pts. Specificity can be moderately improved by the use of the CART algorithm.
Abstract 17062: Adequacy of Primary Care Screening of Women with Adult Congenital Heart Disease
Authors: Castro-Zarraga Margarita , Patil Mitalee , Bhatt Ami B
Published: April 2024

Introduction:
Adults with congenital heart disease (ACHD) face non-cardiac healthcare challenges as the population ages. The 2008 ACC/AHA guidelines called for every ACHD patient to have a primary care physician and receive preventive screening, often underemphasized in chronic disease populations.

Hypothesis:
We assessed the hypothesis that women with ACHD have lower compliance rates for preventive screening compared with control subjects seen in a cardiac practice and with norms in the US population.

Methods:
IRB approved retrospective review of females over age 18 years seen in a cardiac care center in 2009-2011. Data on history, Pap smears, mammograms, colonoscopy, and bone densitometry were obtained from medical records. Adequacy of screening was defined according to US guidelines (as of November 2009).

Results:
We reviewed data of 164 women with ACHD, with 89 women meeting criteria with adequate data, and compared with 39 age-matched control subjects. Women with ACHD had lower rates of preventive screening compared with controls (p < 0.001 for comparison across 4 screening categories, see Table 1). Compliance rates of both groups with colonoscopies were better than nationwide statistics, surpassing the Healthy People 2010 target. Women with ACHD had low screening rates for cervical cancer, breast cancer, and osteoporosis, below national averages. Follow-up for abnormal results was adequate, with lowest rates of follow up for colonoscopies. Individuals with “moderate” ACHD per Bethesda conference guidelines had the lowest rates of adequate screening (37%) compared with simple (50%) or complex (47%) disease patients.

Conclusions:
Women with ACHD need increased primary care screening with Pap smears, mammograms, and DEXA scans. Primary care physicians, cardiologists, and gynecologists should collaborate to ensure appropriate health maintenance screening for this growing and aging patient population.
Abstract 17065: The Relationship Between Insulin-Like Growth Factor-1 and Augmentation Index, Independent of Pulse Wave Velocity
Authors: Oh Jaewon , Park Sungha , Son Nak Hoon , Shin Dong-Jik , Lee Sang-Hak , Kang Seok-Min , Jee Sun Ha , Jang Yangsoo
Published: April 2024

Introduction:
Insulin-like Growth Factor (IGF)-1 is associated with aging and recently linked to metabolic syndrome and cardiovascular disease. However, little is known about the relationship between IGF-1 and arterial stiffness such as augmentation index (AIx) and pulse wave velocity (PWV). We assessed the hypothesis that IGF-1 was independently associated with arterial stiffness.

Methods:
We measured the plasma IGF-1 level of 1114 subjects (724 males, 57.2 ±10.1 years old) using commercially available assays. Arterial stiffness parameters were assessed via VP-2000 pulse wave unit.

Results:
Our study included 875 (78.5%) hypertension, 580 (52.1%) coronary artery disease, and 177 (15.9%) diabetes mellitus patients. Elderly age group (age≥65 years, n=298) had lower IGF-1 (87.0 vs. 101.6ng/ml) but higher AIx (24.8 vs. 19.9%), heart to femoral PWV (hfPWV) (1110.3 vs. 936.0cm/s), brachial to ankle PWV (baPWV) (1583.2 vs. 1406.0 cm/s) compared with middle age group (age<65 years, n=816). IGF-1 was correlated with AIx (r=-0.211, p<0.001), hfPWV (r=-0.135, p<0.001) and baPWV (r=-0.157, p<0.001). Multiple linear regression analysis showed that IGF-1 was significantly associated with AIx after adjusting for age, gender, body mass index, systolic blood pressure, high sensitive C-reactive protein and hfPWV (p=0.019, r
2
=27.0%). This association strengthened in middle age group (p<0.001, total r
2
=31.7%) but disappeared in elderly age group.

Conclusion:
In conclusion, IGF-1 was associated with AIx independent of PWV especially in middle age group. The independent relationship between IGF-1 and AIx provides insight into the pathophysiologic mechanisms of arterial stiffness in cardiovascular disease.
Abstract 17072: Mitochondrial Import of miRNA as a Mechanism of Mitochondrial Gene Regulation
Authors: Das Samarjit , Ferlito Marcella , Wang Richard , Liu Delong , Raghavachari Nalini , Wheelan Sarah , Murphy Elizabeth , Steenbergen Charles
Published: April 2024

Mitochondria are semi-autonomous cellular organelles with their own genome, which not only act as the powerhouse of the cell by supplying energy through oxidative phosphorylation, but also play a destructive role through participation in cell death pathways. MicroRNAs (miRNAs) are usually 19-25 nt long, non-coding RNAs, involved in post-transcriptional gene regulation by binding to the 3'-untranslated regions (3'-UTRs) of target mRNA. Here we report a specific miRNA, miR-181c, in the mitochondrial fraction of rat heart. We find that miR-181c is encoded in the nucleus, assembled in the cytoplasm, and finally translocated into the mitochondria. Bioinformatics studies indicated that cytochrome c oxidase subunit 1 (mt-COX1) in the mitochondrial genome may be a target of miR-181c. To study whether miR-181c could regulate mt-COX1, we over-expressed precursor miR-181c (or scramble sequence) in rat neonatal ventricular cardiomyocytes (NRVM). Over-expression of miR-181c did not change mt-COX1 mRNA but significantly decreased mt-COX1 protein expression, suggesting that miR-181c acts primarily on translational regulation of mt-COX1. In addition to altering COX1, we also found that over-expression of miR-181c resulted in increased mt-COX2 mRNA and protein content. On the functional level, over-expression of miR-181c modulates mitochondrial respiration and ROS generation in NRVM. Thus, our data show for the first time that miR-181c can enter and target the mitochondrial genome, which ultimately causes electron transport chain complex IV remodeling and alters mitochondrial function. This unique observation may open a new dimension to our understanding of mitochondrial dynamics.
Abstract 17076: Attenuating Endoplasmic Reticulum (ER) Stress as a Novel Therapeutic Strategy in Pulmonary Arterial Hypertension
Authors: Dromparis Peter , Paulin Roxanne , Sutendra Gopinath , Kinnaird Adam S , Stenson Trevor H , Haromy Alois , Michelakis Evangelos
Published: April 2024

The poor prognosis associated with pulmonary arterial hypertension (PAH) is in part, due to the complex and poorly understood pathogenesis. ER stress is a potential common denominator among many of the seemingly unrelated molecular triggers of PAH, including BMPRII mutations and the misfolded protein response that follows, viruses, inflammation, Notch signaling and hypoxia. The ER forms a functional unit with the mitochondria (the ER-mito unit), allowing exchange of Ca2+, lipids and ATP between the organelles. Recently, we showed that disruption of the ER-mito unit was critical in PAH pathogenesis. ER stress-regulated induction of the reticulon protein Nogo caused structural/functional disruption of the ER-mito unit resulting in PAH. Chemical chaperones including the clinically studied 4-phenylbutyrate (PBA) can attenuate ER-stress and have been used in animals and patients to treat metabolic diseases and cancer. We hypothesized that attenuation of ER stress with PBA will prevent the disruption of the ER-mito unit and prevent/reverse PAH. We used two models of PAH associated with ER stress: hypoxia and monocrotaline (MCT). Mice exposed to chronic hypoxia and treated with PBA in the drinking water (~750mg/kg/day) in both prevention and reversal protocols had less distal pulmonary artery remodeling, improved hemodynamics, decreased right ventricular hypertrophy and better functional capacity (see table; data presented as mean±SEM). MCT-animals responded similarly. Mechanistic studies were performed in human cell lines and tissues from these animals. We showed that 2mM PBA decreased ER stress (decrease in the marker grp78), decreased Nogo and normalized the ER-mito unit (mitochondrial calcium and membrane potential). Both in vivo and in vitro, PBA suppressed proliferation (Ki67/PCNA) and induced apoptosis (TUNEL) in SMA+ cells. Metabolism and ER stress may be a common downstream effect of many diverse triggers of PAH and may expose a new therapeutic window.
Abstract 17084: Aspirin Influences Megakaryocytic Gene Expression Leading to Up-Regulation of Multidrug Resistance Protein 4 in Human Platelets
Authors: Pulcinelli Fabio M , Massimi Isabella , Trifirò Elisabetta , Lotti Lavinia Vittoria , Guerriero Raffaella
Published: April 2024

Recently, we demonstrated that MRP4 over-expression, an organic anion cellular detoxifier, has a role for the reduced aspirin action in patients after by-pass surgery (JACC in press). In other cell lines Mrp4 induction is an adaptive response necessary to reduce intracellular organic anion toxicity or cholestasis. To understand if aspirin treatment induces MRP4 up-regulation in human platelets we studied its quantitative variations in human megakacaryoblastic cell line, Dami, in platelets from megakaryocytic culture and from two different populations, aspirin treated patients (Asp-patients) and healthy volunteers (HV), in-vitro and in-vivo treated with aspirin. MRP4 expression was evaluated by mRNA intracellular expression (Real-time, PCR analysis), protein expression (immunofluorescence-WesternBlot). Aspirin in-vitro treatment (50 microM for 48 h) enhances of about 70% and 93% induction in MRP4 mRNA expression in Dami cells (5.3±0.2 vs 3.1±0.5 ΔΔCt) and in platelets from megakaryocytic culture (0.081±0.028 vs 0.042 ±0.013 ΔΔCt) respectively. In human platelets we found an association between in-vivo Aspirin treatment and MRP4 mRNA expression; which was higher than HV if the patients were treated for more than 2 months (HV 0.049±0.005 n=50; <1months 0.052±0.010 n=19; >2months 0.070±0.007 n=50 ΔΔCt respectively). In addition, platelets from in-vivo aspirin treated HV (330 mg/die n.=5) present an enhancement of induction in MRP4 mRNA expression after 15 days while, after 7 days, it is similar to those obtained before the treatment (HV 0.042±0.013; 7 days 0.048±0.022; 15 days 0.085±0.029ΔΔCt). Immunofluorescence and immunoblot analysis confirm that aspirin enhances MRP4 expression after either in-vitro or in-vivo treatment. Thus, MRP4 over-expression was associated with aspirin treatment. This is the first evidence that aspirin treatment induces a protein up-regulation in human platelets.
Abstract 17097: M2 Macrophage Polarization Promotes Neovascularization in vivo
Authors: Ismahil Mohamed Ameen , Kingery Justin R , Hamid Tariq , Prabhu Sumanth D
Published: April 2024

Following myocardial infarction (MI), resident and recruited macrophages remove necrotic and apoptotic cells, secrete cytokines, and modulate angiogenesis at the infarct site. In response to microenvironmental stimuli, macrophages adopt either pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes; however, the role of macrophage polarity in tissue neovascularization is unclear. We hypothesized that macrophage polarity with regard to activation state plays a critical role in neovascularization during wound healing. Peritoneal macrophages were isolated from adult C57Bl/6 mice (n = 7) using thioglycollate-elicitation, and polarization was induced to either M1, using LPS 1 μg/ml and IFN-γ 4 ng/ml, or M2, using IL-4 20 ng/ml or IL-10 20 ng/ml. Successful macrophage polarization was confirmed by immunofluorescence for M1- and M2-specific surface markers. In syngeneic mice, Matrigel plugs (0.6 ml/plug) were injected subcutaneously in vivo, either alone or with M1 or M2 macrophages (~20,000 cells/plug) or supernatant derived from M1 or M2 cultures (0.3 ml/plug) and plug neovascularization was assessed after 10 days. In addition, we also performed in vitro scrape wound healing assays using cultured mouse cardiac endothelial cells (MCECs) and human umbilical vein endothelial cells (HUVECs) and tube formation assays with HUVECs. Supernatant derived from M2 macrophages induced faster wound healing over 16 h in cultured MCECs or HUVECs, and increased HUVEC tube formation and tube length. However, in vitro wound closure and tube formation was delayed by supernatant derived from M1 cells (n = 5). In vivo neovascularization in the Matrigel plug was quantified morphologically and by flow cytometry. The presence of M2 macrophages, or supernatant derived from M2 macrophages, resulted in increased neovessel length and number, with recruitment of significantly greater numbers of CD31+ cells to the Matrigel plug, as compared with M1 or inactivated macrophages and their associate culture supernatant (p < 0.05, n = 6). We conclude that M2 macrophage polarization promotes angiogenesis in vivo via paracrine effects on vessel recruitment. Strategies to induce M2 polarization in vivo may augment wound healing after MI.
Abstract 17100: CaMKII Activity Modulates Basal Sarcoplasmic Reticulum Ca
2+
Cycling to Drive Normal Automaticity of Sinoatrial Node Cells
Authors: Vinogradova Tatiana M , Sirenko Syevda , Li Yue , Spurgeon Harold , Lakatta Edward G
Published: April 2024

Spontaneous beating of rabbit sinoatrial node cells (SANC) is linked to rhythmic, sarcoplasmic reticulum (SR) generated, submembrane local Ca
2+
releases (LCR) during diastolic depolarization (DD). LCRs activate inward Na
+
/Ca
2+
exchange current which imparts an exponential increase to the later part of DD and brings the membrane potential to threshold to fire an action potential. Although the crucial dependence of normal SANC automaticity on CaMKII signaling has previously been linked to an effect to facilitate recovery from inactivation of L-type Ca
2+
channels, there may also be direct CaMKII-dependent regulation of LCRs in SANC. Here we show that in freshly isolated rabbit SANC CaMKII inhibitor, KN-93 (0.3 μmol/L), but not its inactive analog KN-92, markedly suppresses LCRs (confocal microscopy, Ca
2+
indicator Fluo-3) reducing LCR number per each spontaneous cycle by 64% (from 1.1±0.1 to 0.4±0.1); LCR size by 32% (from 7.0±0.6 to 4.8±0.2 μm); and by markedly prolonging the LCR period (the interval between AP-induced Ca
2+
transient and subsequent LCR). Prolongation of the LCR period predicted the concomitant increase in spontaneous cycle length, indicating that CaMKII is vitally important for spontaneous SANC firing. To further delineate mechanism of CaMKII-dependent regulation of Ca
2+
cycling, avoiding interference of L-type Ca
2+
channels, we permeabilized SANC with saponin. Confocal linescan imaging of permeabilized SANC showed that KN-93, but not KN-92, decreased the LCR number by 62% (from 16.8±3.7 to 6.4±2.0 per 1sec×100μm) and LCR size by 25% (from 6.5±1.1 to 4.9±0.8 μm). The suppression of LCR parameters was associated with a ~12% reduction of the SR Ca
2+
load, assessed by a rapid application of caffeine on permeabilized SANC. The SR Ca
2+
load is controlled by phospholamban (PLB) which could be phosphorylated by CaMKII at Thr
17
site. Basal PLB phosphorylation at Thr
17
site, assessed by western blotting, is ~3 times greater in SANC than in ventricular myocytes, and KN-93, but not KN-92, markedly decreases PLB phosphorylation by ~40%. Thus, normal automaticity of SANC is regulated by basal CaMKII-dependent phosphorylation, in part, through modulation of SR Ca
2+
cycling, i.e. SR Ca
2+
load controlled by CaMKII-dependent phosphorylation of PLB.
Abstract 17106: Rapamycin Increases Infarct Size and is Detrimental During Acute Ischemia-Reperfusion
Authors: Lassaletta Antonio D , Chu Louis M , Sellke Frank W , Bianchi Cesario
Published: April 2024

Background:
The inflammatory response associated with myocardial ischemia and reperfusion has been shown to have both cardioprotective and damaging mechanisms. The effect of immunosuppression in this setting is unknown. We hypothesized that treatment with the immunosuppressant rapamycin prior to acute ischemia/reperfusion injury would be detrimental to cardiac function.

Methods/Results:
Male Yorkshire swine (16-19 kg) received either no drug (controls) or were given 4mg of rapamycin daily. After two weeks of treatment, all animals underwent sternotomy and the mid-LAD was occluded for 60 minutes followed by 120 minutes of reperfusion. Left ventricular pressure-volume data was collected throughout the operation. The ischemic and infarct areas were measured by triphenyltetrazolium chloride staining. Rapamycin levels were significantly higher in the treated animals compared to controls. Animals pre-treated with Rapamycin had significantly lower cardiac output (p=0.016), stroke work (p=0.022), and maximum power (p=0.017) compared to controls. There was nearly a two fold increase in infarct size in the treated animals compared to controls with no significant difference in the size of the ischemic territories between groups. Protein expression of p-SP6, p-P70S6K, and p-4E-BP1 were all significantly higher in the rapamycin treated group (Table).

Conclusions:
Pre-treatment with the immunosuppressant rapamycin, an inhibitor of mTOR, diminished cardiac function by several measures and increased infarct size after ischemia/reperfusion. Interestingly, the downstream substrates of mTOR were more highly expressed in the rapamycin treated animals. These results suggest that patients taking rapamycin, or carrying stents coated with rapamycin may not only be at higher risk for cardiac events but may also be predisposed to poorer outcomes after such events. The mechanism remains to be determined.
Abstract 17107: Induced Vascular Progenitor Cells Derived From Endothelial Cells Stimulate Coronary Collateral Growth
Authors: Yin Liya , Ohanyan Vahagn , Pung Yuh Fen , Delucia Angelo L , Bailey Erin , Enrick Molly , Stevanov Kelly , Kolz Christopher L , Guarini Giacinta , Chilian William
Published: April 2024

Although regenerative medicine has great potential in stimulating vascular growth in the heart, there have been mixed results and the ideal cell type for therapy has not been resolved. Induced pluripotent cells (iPSCs) show promise, because they can be autologous, but they suffer from the problem of potential tumor formation. To circumvent this problem, we reasoned that reprogramming cells to a progenitor-type cell, rather than to pluripotency, but would reduce the chances for tumor formation; yet still enable their application in stimulating coronary collateral growth in a rat model of repetitive ischemia. Accordingly, we reprogrammed endothelial cells (EC(s)) to “induced vascular progenitor cell(s)” (iVPC(s)), which should remain committed to a vascular lineage. We hypothesized that these cells would better stimulate coronary collateral growth than fully reprogrammed iPSCs because the latter can differentiate into various cell types other than vascular lineage. Rat vascular ECs were transduced with Oct4, Klf4, Sox2 and c-Myc. A population of reprogrammed cells expressing pluripotent markers, Oct4, SSEA-1, Rex1 and AP and markers of hemangioblasts, CD133, Flk1, c-kit were generated. These cells were named iVPCs, because they remained committed to vascular lineage and could differentiate into vascular ECs or vascular smooth muscle cells in vitro. iVPCs demonstrated better in vitro angiogenic potential (tube network on 2D culture, tube formation in serum reduced matrigel) than native ECs. In contrast to iPSCs, iVPCs had far less risk of teratoma formation. When iVPCs were implanted into rat myocardium, they engrafted into the blood vessels, increased coronary collateral flow measured by microspheres and improved cardiac function during coronary occlusion measured by echocardiography better than iPSCs or sham treatment (all difference were significant at P<0.05). Thus we successfully reprogrammed ECs into iVPCs. iVPCs had a better effect on coronary collateral growth and cardiac function during a coronary occlusion in vivo than iPS cells did. We conclude that “induced vascular progenitor cells,” generated by partial reprogramming of ECs, are an ideal cell type for regenerative therapy to stimulate coronary collateral growth.