bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 186: Biopacemakers Induced by Gene Transfer of a Dual-Functional Kir2.1 Mutant
Authors: Kashiwakura Yuji , Chang Kuan-Cheng , Zhang Yiqiang , Barth Andreas , Cho Hee Cheol , Sasano Tetsuo , Marbán Eduardo
Published: April 2024

Previous efforts to engineer biopacemakers have focused either on overexpression of HCN, or on suppression of I
K1
to liberate endogenous pacemaker activity. Here we report a novel strategy designed to convert I
K1
into a nonselective “leak” current. The idea is to combine the key virtues of HCN (leak current) and I
K1
suppression (destabilization of the resting potential) in a single gene construct. We focused on the human Kir2.1ER mutation (E138R and R148E, KER) which can work as not only a functional non-selective channel in homotetramers but also as a dominant-negative suppressor for the Kir2.X gene family in heart. The plasmid CMV-KER-IRES-wtKir2.1 coexpresses the KER mutant and wild-type Kir2.1. In HEK cells transduced with CMV-KER-IRES-wtKir2.1, barium sensitive hyperpolarization-activated inward current (−5.5 pA/pF at −80mV) could be detected (n=5) with a reversal potential of −35.1± 2.1 mV in normal Tyrode external solution. These data demonstrate that overexpression of KER undermines the ability of Kir to produce functional I
K1
channels, while producing a cation-nonselective leak current. To probe the consequences of KER in primary tissues, we created the adenovirus AdKER in which KER expression is driven by the CMV promoter. Isolated guinea-pig myocytes transduced with AdKER exhibited spontaneous action potential oscillations with high reproducibility (n=10). Electrocardiograms performed 3 days after AdKER injection into guinea pig hearts showed idioventricular rhythms in virus injected-animals, while no such rhythms were seen in control (AdGFP) animals (n=6 each). These results show that KER mutants, if expressed in ventricular muscle, produce biopacemakers
in vitro
and
in vivo
. This study provides proof of principle for the notion that biological pacemakers can be readily induced by a single gene designed to destabilize I
K1
and to create a leak current.
Abstract 4174: The Association of Coffee Consumption With Wave Reflections in Hypertensive Patients
Authors: Vlachopoulos Charalambos , Alexopoulos Nikolaos , Vyssoulis Gregory , Pietri Panagiota , Zervoudaki Alexandra , Aznaouridis Konstantinos , Aggeli Konstantina , Stefanadis Christodoulos
Published: April 2024

Introduction: Wave reflections are important markers and prognosticators of cardiovascular risk, and have been implicated in the pathogenesis of systolic hypertension. Caffeine increases acutely wave reflections. Furthermore, chronic coffee consumption is associated with increased wave reflections in normotensive subjects. Hypothesis: In the present study we aimed to assess the association between chronic coffee consumption and wave reflections in hypertensive patients.

Methods: We examined 228 never treated hypertensives (age 50.7±11.9 years, 143 males) under no medication. Frequency of coffee consumption was assessed using a validated food frequency questionnaire. According to the distribution of coffee consumption, we categorized daily coffee consumption as:

none

low (<200 ml/day)

moderate (200 – 450 ml/day) and

high (>450 ml/day).

Augmentation Index (AIx) was measured non-invasively as an index of wave reflections, using SphygmoCor®. Analysis of covariance (ANCOVA) was applied to evaluate the association between AIx and coffee intake after adjusting for several potential confounders.

Results: AIx was found to be increased with increasing degree of daily coffee consumption when adjusted for gender, age, height, smoking status, heart rate, mean pressure, HDL cholesterol and hsCRP (p<0.02, Figure

). Systolic, diastolic, pulse and mean pressures were not different among the 4 groups of daily coffee consumption.

Conclusions: Increased daily coffee consumption is associated with enhanced wave reflections in hypertensive patients. This finding may have important implications for the management of these patients.
Abstract 4200: Does Homocysteine Lowering Impact Cardiovascular Outcomes? A Bayesian Meta-Analysis of NORVIT and HOPE-2 Trials
Authors: Kaul Sanjay , Zadeh Andrew A , Diamond George A , Shah Prediman K
Published: April 2024

Background:
In HOPE-2 trial, homocysteine lowering with B vitamins failed to reduce clinical outcomes compared to placebo except for a significant reduction in stroke (P=0.03). The stroke benefit was thought to “represent either an overestimate of the real effect or a spurious result due to play of chance, and that a meta-analysis should be able to clarify the issue”.

Objective:
To perform a Bayesian meta-analysis by integrating prior information from the NORVIT trial with the empirical evidence from HOPE-2 (the only 2 large completed placebo-controlled trials of homocysteine lowering).

Methods:
Posterior probabilities that the benefit (P
b
) or harm (P
h
) exceeds a specified difference (δ<0%, 10%) were estimated via the Bayes’ theorem: posterior α evidence x prior. Only data from comparison of combination vitamin therapy group vs placebo was utilized from NORVIT to match the HOPE-2 treatment groups for primary composite endpoint of cardiovascular death, myocardial infarction (MI) or stroke and the individual endpoints. Superiority or inferiority was inferred at a posterior probability of benefit or harm >0.950.

Results:
The P
h
exceeded P
b
for the primary composite endpoint and each of the individual components except for stroke where the probability of any benefit (δ>0%) was 0.992 and the probability of >10% risk reduction (δ>10%) was 0.930.

Conclusions:
Thus, a Bayesian meta-analysis helps clarify the issue, and suggests a low likelihood of coronary benefit and a high likelihood of stroke benefit with homocysteine-lowering therapy compared to placebo. These data are consistent with the epidemiologic observations of a stronger association of elevated homocysteine with stroke compared to CAD (adjusted odds ratio of 1.32 (1.18–1.49) vs 1.19 (1.12–1.25) for +5μmol/L increase in homocysteine level observed in prospective studies). Ongoing trials should further clarify the impact of homocysteine lowering.
Abstract 583: Identification of Target Proteins for Neuronal Calcium Sensor-1 (NCS-1) in the Heart
Authors: Telemaque Sabine , Wang Zhen
Published: April 2024

Introduction:
Changes in intracellular Ca
2+
concentration regulate numerous cellular functions that are mediated by Ca
2+
binding to a large family of EF-hand Ca
2+
sensor proteins. We previously reported that one of them, neuronal calcium sensor-1 (NCS-1) was present in both cytosol and membrane fractions of rat heart. Adenovirus-mediated gene delivery of NCS-1 to isolated ventricular myocytes results in an increase in myocardial contractile function, with a slight alteration of sarcoplasmic reticular function.

Aims and Methods:
To further investigate the role of NCS-1 in the regulation of cardiac contractility, we used the yeast two-hybrid system to identify novel protein interactions among cardiac E-C coupling-associated proteins and NCS-1. Human NCS-1 was used as a bait to screen a human heart cDNA library by yeast mating.

Results:
120 positive colonies were initially obtained under high stringency mating selection. DNA inserts of 47 true positive clones were sequenced; 27 clones contained unique DNA sequences, including 4 unknown genes. The remaining 23 identified proteins are primarily expressed in the cytoplasm, with fewer proteins localized at the plasma membrane. Cellular functions of these proteins include membrane transport, metabolism energy pathways, cell growth/maintenance, signal transduction/cell communication and structural/cytoskeletal-associated proteins. Interestingly, the yeast two hybrid studies show that NCS-1 interacts with Troponin I (cTnI), a key inhibitory protein involved in the regulation of E-C coupling in cardiac muscle. cTnI inhibits sarcomere contraction by interfering with actin-myosin interaction. Co-immunoprecipitation studies in cardiomyocytes also suggest an interaction between NCS-1 and Troponin I.

Conclusion:
Our results deonstrate that NCS-1 is involved in multiple aspects of Ca
2+
signaling in the heart. Furthermore, identification of a possible protein-protein interaction between Troponin I and NCS-1 provides novel insights into a cellular mechanism by which NCS-1 can augment cardiac contractile function.
Abstract 598: Activation of Volume-Sensitive Osmolyte/Anion Channels (
VSOACs
) Delays Progression from Myocardial Hypertrophy to Heart Failure
Authors: Liu Lihui , Wang Guanlei , Yuan Can , Xie Jiani , Hatton William J , Duan Dayue
Published: April 2024

Background:
In hypertrophied cardiac myocytes
VSOAC
s become constitutively activated. In this study, we used a murine line targeting ClC-3, a gene encoding native
VSOACs
in the heart, to explore the molecular mechanism for the potential role of
VSOACs
in pressure overload-induced myocardial hypertrophy and the progression to heart failure.

Methods:
A pressure overload model through a minimally invasive transverse aortic banding (MTAB) at the suprasternal notch level was established in age-matched
ClCn3
−/−
mice and their wild-type (WT) littermates. Echocardiography, whole-cell voltage-clamp technique, microarray (Affymetrix chips) and proteomic analysis were used to examine the changes in cardiac phenotype and in gene and protein expression profiles.

Results:

In 13/16 (81%) left ventricular myocytes isolated from WT mice subjected to MTAB for 5 weeks (wks) a large outwardly rectifying Cl
−
current was activated under isotonic conditions. Hypotonic cell swelling caused no changes in the current while it was significantly inhibited by hypertonic cell shrinkage or by intracellular dialysis of anti-ClC-3 antibody.

The increase in wall thickness (myocardial hypertrophy) peaked significantly faster in
ClCn3
−/−
mice (<1 wk) than in WT mice (>4 wks). After MTAB the hypertrophied changes remained at a similar level for >10 wks in WT mice, but heart failure accompanied by a significant decrease in wall thickness and increase in chamber dimensions developed in <6 wks in
ClCn3
−/−
mice.

Microarray and proteomic analyses in WT and
ClCn3
−/−
mouse myocardium pre and post MTAB for 1 and 5 wks revealed complex changes in gene and protein expression profiles involving not only ion channels but also cytoskeleton and signal transducer proteins.

Conclusion:
The constitutively activated
VSOACs
in hypertrophied heart may be due to ClC-3. Activation of
VSOACs
may delay the progression from myocardial hypertrophy to heart failure.
2006 George L. Duff Memorial Lecture—Familial Hypobetalipoproteinemia, a Unique Form of Fatty Liver
Authors: Schonfeld Gustav , Yue Pin , Averna Maurizio , Chen Zhouji
Published: April 2024

Several genetic forms of familial hypobetalipoproteinemia (FHBL) exist: (a) those due to premature stop-codon–specifying mutations or missense mutations of APOB; (b) those due to nonsense or missense mutations of PCSK9; (c) those due to certain mutations of MTP; and (d) those linked to none of the above-mentioned genes. “Knock-in” mouse models of apoB truncations (apoB38.9 and apoB27.6) resemble human FHBL phenotypes. In heterozygous crosses of apoB38.9 or apoB27.6 mice, homozygotes are born at <10% of expected frequencies, suggesting that homozygosity is lethal. In heterozygous apoB-defective FHBL, even the product of the normal allele, apoB100, is produced at only ~25% of the normal rate as a result of increased intracellular degradation. Furthermore, the lipid-ferrying capacities of the abnormal truncated apoBs are reduced. The net result is an impaired hepatic lipid export system via VLDL particles, resulting in increases of hepatic fat despite adaptive decreased synthesis of hepatic fatty acids and cholesterol. To assess the role of genetic factors in the fatty livers of mice, a 10-strain survey was performed. Six-fold differences in hepatic triglyceride levels were found, demonstrating the importance of genetic factors. Breeding of the apoB38.9 defect into low, medium, and high hepatic triglyceride strains yielded 3 congenic strains: the SWR/J-apoB
+/38.9
, C57BL/J-apoB
+38.9
, and BALBcByJ-apoB
+/38.9
, respectively. Significant effects on hepatic triglyceride levels were found by mouse strain, by the apoB38.9 gene, and there were strain–gene interactions. Thus, modifying genes affect the expression of the apoB38.9 defect.
2006 Laennec Clinician/Educator Lecture—The Contemporary Management of Patients Admitted to Hospital With Acute Decompensated Heart Failure
Authors: Francis Gary
Published: April 2024

René Laénnäc was an adolescent at the time of the French Revolution and went on to a career of lasting importance in the history of medicine. Among his many accomplishments was the invention of the stethoscope, but as with many new ideas, there was much early skepticism. Eventually it became widely accepted. In today’s world of high-tech medicine, some would opine that the usefulness of the stethoscope is again declining. Of the many cardiological conditions that we treat on a day-to-day basis, heart failure is one where the stethoscope is still quite useful. Heart failure remains a clinical diagnosis, requiring that the physician actually extract a history and examine the patient at the bedside. However, the treatment of acute decompensated heart failure has changed dramatically over the years, even though advances in treatment have been hampered to some extent by the lack of randomized clinical trials. Management of these patients can be extremely difficult, particularly when complicated by resistance to loop diuretics, refractory edema, hyponatremia, and oliguria. Strategies to date have primarily depended on previous observational studies and include the use of diuretics, vasodilators, inotropic agents for selected patients, ultrafiltration, and occasionally dialysis. Although there are both European and US guidelines for the treatment of acute heart failure, we are in need of further randomized controlled trials to guide us through the maze of therapeutic options. Future considerations should include an understanding of how the syndrome develops and how it can be prevented in its early stages.
2006 Lewis K. Dahl Memorial Lecture—Nitric Oxide Deficiency in Renal Disease
Authors: Baylis Christine
Published: April 2024

Nitric oxide (NO) production is reduced in renal disease, in part because of decreased endothelial production. Evidence indicates that NO deficiency contributes to cardiovascular events and progression of kidney damage. Two possible causes of NO deficiency are substrate (L-arginine) limitation and increased levels of circulating endogenous inhibitors of NO synthase (particularly asymmetric dimethylarginine [ADMA]). Decreased L-arginine availability in chronic kidney disease (CKD) is due to perturbed renal biosynthesis of this amino acid. In addition, inhibition of transport of L-arginine into endothelial cells and shunting of L-arginine into other metabolic pathways (eg, involving arginase) might also decrease availability. Elevated plasma and tissue levels of ADMA in CKD are functions of both reduced renal excretion and reduced catabolism by dimethylarginine dimethylamino-hydrolase (DDAH). The latter might be associated with loss-of-function polymorphisms of a DDAH gene and/or functional inhibition of the enzyme by oxidative stress in CKD and end-stage renal disease. An increase in ADMA has emerged as a major independent risk factor in end-stage renal disease (and probably CKD). Raising endogenous L-arginine and/or lowering ADMA concentration is a major therapeutic goal to reduce endothelial dysfunction, cardiovascular risk, and possibly progression in renal disease.
Abstract 4935:
Ex vivo
Acidic Preconditioning Modulates Bone Marrow-derived ckit
+
Cell Function
in vitro
and Enhances Their Therapeutic Potential in a Mouse Model of Hindlimb Ischemia
Authors: Cencioni Chiara , Melchionna Roberta , Straino Stefania , Romani Marta , Cappuzzello Claudia , Annese Valentina , Santoni Angela , Napolitano Monica , Capogrossi Maurizio C
Published: April 2024

Background and Objective
. Bone marrow-derived cell transplantation may provide a novel strategy for the treatment of cardiac and limb ischemia. However, in some cases cells appear to have lost their therapeutic potential and there is an interest in identifying interventions that are clinically applicable and may enhance cells’ ability to repair damaged tissues. The objective of the present work was to examine whether
ex vivo
acidic preconditioning (AP) may modulate bone marrow-derived ckit
+
cell functions
in vitro
and their regenerative properties in a mouse model of hindlimb ischemia.

Methods and results.
ckit
+
cells were obtained from 4-week old mice; AP was achieved by exposing cells to hypercarbic acidosis (buffer pH 7.0) for 24 hours and subsequently returning them to pH 7.4. Control ckit
+
cells (C) were always kept at pH 7.4. AP enhanced CXCR4 mRNA levels (2.5-fold vs C; n=6; p<0.05). In agreement with this result AP increased SDF-1-driven chemotaxis (2-fold vs C; n=6; p<0.02) and transendothelial migration (10-fold vs C; n=5; p<0.05) as well as SDF-1-driven differentiation toward the endothelial lineage as indicated by DiI-Ac-LDL uptake (2.2-fold vs C; n=10; p<0.005), vWF positivity (2.2-fold vs C; n=4; p<0.005) and KDR positivity (3-fold vs C; n=4; p<0.005). The effect of AP on ckit
+
cell therapeutic potential was examined in a mouse model of hindlimb ischemia. Either AP or C cells (5 × 10
5
) were injected into the adductor muscle at the time of femoral artery dissection. AP cells accelerated blood flow recovery vs C cells as determined by laser doppler perfusion imaging at different time points throughout the 14-day time course following acute ischemia (n=8; p<0.01 vs C). Further, 14 days after surgery, AP cells increased capillary (1.3-fold vs C; n=6; p<0.01) and arteriole number (4.6-fold vs C; n=6; p<0.01) as well as the number of regenerating muscle fibers measured 7 days after surgery (4.4-fold vs C; n=6; p<0.05).

Conclusions.
ckit
+
cells exposed to AP exhibit enhanced CXCR4 expression and SDF-1-directed cell responses
in vitro
and regenerative properties in a mouse model of hindlimb ischemia. Thus, AP may represent a simple, unexpensive and clinically applicable strategy to improve the therapeutic efficacy of bone marrow-derived cell transplantation.
Abstract 4939: Hypercholesterolemia Increases Microparticle Tissue Factor and Activates Coagulation in LDL Receptor Deficient Mice
Authors: Owens A. Phillip , Wang Jian-Guo , Manly David A , Daugherty Alan , Mackman Nigel
Published: April 2024

Objective:

Tissue factor (TF) is the initiator of the extrinsic pathway of coagulation and contributes to thrombosis. Previous studies demonstrated that the risk of arterial thrombosis is elevated in patients with increased plasma cholesterol concentrations. In addition, increased levels of circulating TF, bound to microparticles (MPs), may induce thrombosis. Therefore, we tested the hypothesis that hypercholesterolemia increases plasma levels of MP TF and activation of coagulation in low density lipoprotein receptor deficient (LDLr
−/−
) mice.

Methods and Results:

Male LDLr
−/−
mice were fed a high fat diet (HFD) consisting of 21% saturated fat, and 0.15% cholesterol for 0, 1, 2, 4, and 12 weeks (n=3–7 each time point). Mice were then euthanized, blood was collected from the inferior vena cava (into 3.8% sodium citrate), and plasma prepared. Mice had a sustained elevation in plasma cholesterol concentrations after 1 week of feeding HFD, which were unchanged in all subsequent feeding intervals (945±35 mg/dL). MP TF was analyzed by detection of Factor Xa generation in the presence or absence of an inhibitory rat anti mouse TF antibody. MP TF activity increased in a time-dependent manner at 1 (75%), 2 (112%), 4 (650%), and 12 (1140%) weeks (all times versus 0 week control; P<0.001). Importantly, a similar time-dependent increase in plasma thrombin-antithrombin (TAT) activity was observed at 2 (362%), 4 (1203%), and 12 (927%) weeks (all times versus 0 week control; P<0.001). Moreover, the levels of MP TF activity and TAT were linearly correlated (R=0.70, P<0.001). The inflammatory cytokine IL-6 was also increased in a time-dependent manner from 0 weeks (22.7±10.1 pg/ml) to 12 weeks (112.3±20.2 pg/ml; P<0.023).

Conclusion:

These data indicate that hypercholesterolemia results in increased MP TF activity and subsequently activates coagulation. Further studies are required to determine if TF positive MPs are required for hypercholesterolemia -induced coagulation.
Abstract 4952: Transplant Vasculopathy Response in CCR2 and NDST-1 Deficient Mice Aortic Transplant Model After Viral Anti-Inflammatory Chemokine Modulating Protein, M-T7, Treatment
Authors: Dai Mr Erbin , Liu Mrs Liying , Bartee Mrs Mee , McIvor Ms Dana , Sun Mr Yun ming , Macaulay Mr Colin , Esko Mr Jeffrey D , Charo Mr Israel , Lucas Mrs Alexandra R
Published: April 2024

Background:
Transplant vasculopathy impedes long-term organ transplant survival. Chemokines direct inflammatory cell migration, through binding to glycosaminoglycans (GAGs) on the surface of endothelial cells and in connective tissues. Chemokines bind GAGs via the C terminus and receptors via the N terminus. Both chemokine receptor and chemokine GAG interactions are important to inflammatory responses. Chemokines and chemokine receptors have been demonstrated to have important roles in transplant rejection. The relative roles of receptor and GAG interaction in transplant vasculopathy are not defined. Myxoma viral chemokine modulating protein (CMP) M-T7 interrupts C terminal GAG binding of C, CC and CXC chemokines. In prior work M-T7 reduced transplant vasculopathy in aortic and renal transplant models. We examine here the effects of CCR2 and GAG deficiency as well as M-T7 treatment in CCR2 and heparan sulfate (HS-GAG) deficient mouse aortic allograft transplant models.

Methods:

CCR2
−/−
or CCR2
+/+
donor Balb/C aorta was transplanted to C57BL/6 recipients

HS-GAG
+/+
and HS-GAG
−/−
aorta was transplanted to Balb/C.

WT to CCR2
−/−
or NDST-1
−/−
reverse aortic transplant was also examined.

All aortic transplant group were assessed with and without M-T7 treatment. Plaque growth and macrophage/T cell invasion were measured at 28 days.

Results:

Plaque growth was significantly decreased in both CCR2
−/−
and HS-GAG
−/−
transplants when compared to CCR2
+/+
(P = .021) or HS-GAG
+/+
(P = .032), respectively. Immunostaining demonstrated reduced CD3 T-cell and macrophage invasion.

Plaque was reduced in WT HS-GAG
+/+
when compared to WT Balb/C aortic transplant (P = .306).

Reverse Transplant of WT C57Bl/6 or Balb/C donor aorta to CCR2
−/−
or HS-GAG
−/−
mice, respectively, did not reduce plaque growth.

M-T7 treatment reduced plaque growth in both CCR2
+/+
(P < .047) and CCR2
−/−
(P = .017) aortic transplant, but had reduced inhibitory activity in HS-GAG
−/−
aortic transplants when compared to HS-GAG
+/+
.

Conclusion:

Heparan sulfate GAG is an important mediator in transplant vasculopathy development.

Interruption of chemokine: GAG binding provides a new therapeutic target for prevention of transplant vasculopathy.
Abstract 4962: Influence of Adiposity on Carotid Wave Reflection and Arterial Stiffness: A Longitudinal Study in Healthy Children
Authors: Sakuragi Satoru , Telford Richard D , Abhayaratna Walter P
Published: April 2024

Background:
The relationship between childhood obesity and adverse cardiovascular outcomes during adulthood may be mediated through the promotion of impaired vascular function. Wave reflection is an index of arterial function that is determined by arterial stiffness and is predictive of adverse cardiovascular events in adults. We hypothesized that baseline and changes in adiposity during childhood have an adverse influence on future levels of wave reflection and arterial stiffness.

Methods:
In 514 healthy children (mean age 8.3±0.4, 50% boys); percentage body fat (%BF) was quantitated by dual-energy x-ray absorptiometry during a baseline assessment in 2005 and during a follow-up assessment in 2007. Baseline insulin resistance was evaluated using a homeostasis model assessment (HOMA-IR). Cardiorespiratory fitness (CRF) was assessed using a 20 meter shuttle run. Carotid artery wave reflection and carotid-femoral pulse wave velocity (PWV) was assessed in 2007 using applanation tonometry (SphygmoCor, Atcor Medical, Sydney, Australia). The second peak of carotid systolic blood pressure (SBP2) was obtained from the carotid arterial waveform.

Results:
In univariable analysis, baseline %BF was positively associated with carotid SBP2 and PWV measured in 2007. In multivariable analysis, baseline %BF and change in %BF was associated with carotid SBP2 after adjustment for age, sex, baseline blood pressure, heart rate, height, HOMA-IR, total cholesterol and CRF (Table

). Baseline %BF was also independently associated with PWV (Table

).

Conclusion:
Baseline adiposity was positively related to future carotid wave reflection and arterial stiffness. In addition, subsequent increase in adiposity over a 2-year period was associated a greater degree of wave reflection.

Relationship between baseline and change in percent body fat and future wave reflection (carotid SBP2) and arterial stiffness (PWV) in multivariate models
Abstract 5012: Metabolic Syndrome Associates With Resistance to Aspirin in Patients With Coronary Artery Disease
Authors: Smith James P , Haddad Elias V , Boutaud Olivier , Oram Denise A , Blakemore Dana L , Chen Qingxia , Taylor Mary B , Oates John A
Published: April 2024

The ability of aspirin to acetylate cyclooxygenase (COX)
ex vivo
depends on the oxidation state of the enzyme. This suggests that clinical phenotypes associated with increased endogenous platelet activation, which generates lipid hydroperoxides in the platelet, may impair aspirin’s efficacy. Accordingly, we hypothesized that resistance to aspirin would be associated with metabolic syndrome based on evidence for increased
in vivo
platelet activation in this condition. We prospectively enrolled patients with coronary artery disease (CAD), who were taking aspirin as part of their outpatient regimen, and provided aspirin 81mg daily for 2 weeks. We optimized compliance with a telephone call mid-study and a pill count. The primary outcome was serum thromboxane B
2
(sTxB
2
) measured by GC/MS, which reflects aspirin’s pharmacological effect. Of 137 patients who completed the study with sufficient data for analysis, the mean age was 65±9 y, blood pressure 126/73, and body mass index 30±5.7 kg/m
2
; nearly all (99%) had a diagnosis of hypertension and 39 (29%) were diabetic. Ninety (66%) received enteric-coated aspirin (ECASA) and 47 (34%) received chewable aspirin. Twelve patients with sTxB
2
>13ng/ml were characterized as resistant to aspirin, as this represented <95% inhibition of the mean sTxB
2
levels determined in 60 aspirin-naïve healthy volunteers. All of these resistant patients had metabolic syndrome as defined by the AHA. Exploring this association further in a linear model, we found that the presence of metabolic syndrome significantly associated with higher sTxB
2
(log-transformed) (P=0.011), adjusted for age, sex, and formulation of aspirin. In a second linear model, no significant associations were found with the individual components of the metabolic syndrome, indicating that the presence of these components in concert was required to predict incomplete response to aspirin. Although the use of ECASA associated with higher sTxB
2
in both linear models (P=0.013), the formulation of aspirin did not correlate with sTxB
2
> 13ng/ml. These data suggest that the metabolic syndrome contributes to inadequate platelet inhibition by aspirin in patients with CAD.
Abstract 5019: Circulating MicroRNAs as New Biomarkers of Myocardial Infarction in Man
Authors: Alessandra Yuri d , Devanna Paolo , Limana Federica , Straino Stefania , Moro Franco , Micheli Barbara , Di Carlo Anna , Achilli Felice , Maggiolini Stefano , Pompilio Giulio , Capogrossi Maurizio Colognesi
Published: April 2024

Background and objective:
microRNAs (miRs) are small non-coding RNAs that regulate translation of messenger RNAs (mRNA) into proteins. Recently, it has been suggested that circulating miR may represent a novel class of biomarkers in cancer and liver disease, however no data are available in cardiovascular diseases. Our objective was to examine miR plasma levels in humans and mice with acute myocardial infarction (MI).

Results:
We analyzed the expression of 365 human miRs in plasma from healthy donors (n=9) and patients (n=11) with acute MI and ST-segment elevation (STEMI). In STEMI patients, during the initial 1 to 7 hours after the onset of MI symptoms, miR 1, 133a, 133b and 499 plasma levels increased over 10–190-folds (p<0.05) and at day 5 they were back to control values; in contrast, miR 122 and miR 375, at day 0 exhibited a 60 and 80 % decrease, respectively, and at day 30 they were still 50% lower than control (p<0.05). In 4 additional MI patients miR plasma levels were measured simultaneously and in the same blood samples with total CPK and TnI, at frequent intervals after reaching the hospital. All patients were reperfused within 4 hours after admission to the hospital. Both CPK and TnI had their peak expression 6 hours after reaching the hospital; in contrast miR 1, 133a and 133b peak increase was achieved within 3h whereas miR 499 peak occurred at 12 hours. Additional studies were performed in a mouse model of MI and miR plasma levels were measured at a single time point, i.e. 3 hr after coronary artery occlusion. Experiments in sham operated control (n=4) and MI (n=9) mice showed that circulating miR 1, 133a, 133b and 499 increased 10–18 folds (p< 0.01); this miR signature closely mimicked the results in humans.

Conclusions:
miR 1, 133a, 133b and 499 plasma levels are strongly upregulated after MI and may represent novel and sensitive biomarkers of cardiac damage. The negative regulation of miR 122 and 375 observed in humans raises the possibility that in man, during severe cardiac ischemia, miR release from cardiac cells may be due also to the modulation of active transport mechanisms and not only to cardiac necrosis.
Abstract 5022: The Relationship Between Plasma Pentraxin 3 and Coronary Plaque Morphologies in Patients With Acute Coronary Syndrome
Authors: Kimura Shigeki , Inagaki Hiroshi , Haraguchi Goh , Inaba Osamu , Miyazaki Toru , Sugiyama Tomoyo , Hatano Yu , Yoshikawa Shunji , hachiya Hitoshi , Hirao Kenzo , Isobe Mitsuaki
Published: April 2024

Background:
Inflammation is a significant factor contributing to atherosclerotic plaque development. Several inflammatory markers have been used to detect high risk patients with acute phase of ischemic heart disease. Recently, the long pentraxin family member, pentraxin 3 (PTX3) has been reported to be a significant predictor for clinical outcome in patients with acute coronary syndrome (ACS). However, the relationship between PTX3 and coronary plaque components has not been fully clarified. We tried to investigate the difference of plaque morphologies on intravascular ultrasound (IVUS) in ACS lesions among with elevating PTX3 or without.

Methods:
Eighteen target lesions in 18 ACS patients (ST-elevation MI (STEMI); 17 patients, non-STEMI; 1 patients), who underwent preintervention virtual histology (VH) - IVUS, were investigated. PTX3 was collected from all patients before percutaneous coronary intervention. The lesions were divided into two groups; group A with PTX3 ≥ 4ng/ml and group B with PTX3<4ng/ml. The differences of plaque morphologies on VH-IVUS were evaluated between the two groups. The presence of thin-cap fibroatheromas (TCFA), defined as a necrotic core ≥ 10% of plaque area at the minimal lumen area site without overlying fibrous tissue in the presence of >40% plaque burden characteristic. The presence of echo signal attenuation (EA) on IVUS, which recently has been reported to be related with no-reflow after PCI, was defined as atherosclerotic plaque showing ultrasound signal attenuation without very high intensity echo reflectors.

Results:
An elevation of PTX3 (≥4.0ng/ml) was detected in 10 lesions (55.6%). Lesion vessel area (20.1±3.3mm
2
vs. 14.8±4.9mm
2
, p<0.01) and plaque volume (312±118mm
3
vs. 200±93mm
3
, P<0.05) was significantly greater in group A than group B. Remodeling index was not significant but tended to be higher in lesion with group A than group B (1.19±0.19 vs. 1.06±0.17, p=0.13). The frequency of EA (60.0% vs. 0.0%, p<0.05) and TCFA (50.0% vs. 0 %, p<0.05) was significantly higher in lesions with group A than group B.

Conclusions:
In ACS lesions, pentraxin 3 might be a significant predictor for the presence of large amount of unstable and vulnerable plaque compositions, which might lead to a poor clinical outcome after PCI.
Abstract 5059: hHO-1 Overexpression in Transgenic Pigs is Cardioprotective After Acute Myocardial Ischemia and Reperfsuion
Authors: Hinkel Rabea , Petersen Björn , Thormann Michael , Horstkotte Jan , Wuchrer Alexander , Schmoeckel Michael , Niemann Heiner , Kupatt Christian
Published: April 2024

The inducible isoform of heme oxygenase (HO-1) responds to stress, such as hypoxia or cytokine activation, by reducing biliverdin to bilirubin, carbon monoxide (CO) and free iron. These have anti-inflammatory, anti-apoptotic potential and reduce free radical formation. During ischemia and even more during reperfusion these mechanisms play a major role for the extent of injury. Now, we investigated the cardio protective potential of a heme oxygenase-1 overexpression in transgenic pigs after acute myocardial ischemia and reperfusion.

Methods:
Transgenic pigs were generated through somatic nuclear transfer of the humane heme oxygenase 1 gene. In vivo, pigs (n=4 per group) underwent percutaneous LAD occlusion for 60 min, followed by 24 hours of reperfusion. Ejection fraction was obtained before ischemia and after 24 h of reperfusion. In addition regional myocardial function and infarct size were measured at day 1. PCR was performed to assure the HO-1 over expression in the transgenic pigs. Myeloperoxidase (MPO) levels were obtained to analyze inflammatory cell invasion.

Results:
The PCR analysis revealed overexpression of hHO-1 mRNA levels in the transgenic pigs compared to the wildtype control group. In vivo, hHO-1 overexpressing pigs a significant better global myocardial function compared to the control group (post-ischemic ejection fraction 41±2 vs. 24±4% in control). The analysis of the regional myocardial function showed an improved function in the infarct area of the transgenic group (50±4 % vs. 28±9% of the normoxic level at rest). Infarct size was reduced in hHO-1 overexpressing pigs, compared to controls (35±4 % vs. 63±4% of the area at risk), The evaluation of the leukocyte influx in the ischemic tissue via MPO assay displayed a clear reduction in the transgenic group compared to control (444±24 vs. 2817±831 in control group).

Conclusion:
We could demonstrate for the first time the cardioprotective potential of heme oxgenase-1 over expression in a transgenic pig model of ischemia and reperfusion. These results indicate a high therapeutic potential of HO-1 after acute myocardial infarction or other ischemia and reperfusion events (such as organ transplantation).
Abstract 5076: Differential Response of Renal Tubule Sodium Transporters in Salt Sensitive and Salt Resistant Mouse Strains to Salt Load
Authors: Wang Xiaoyan , Armando Ines , Escano Crisanto S , Asico Laureano , Jose Pedro A
Published: April 2024

We have reported that C57BL6 and SJL mice from Jackson laboratory have different responses to a chronic salt load: blood pressure increases in C57BL6 but not in SJL mice. We have suggested that the increase in blood pressure with NaCl loading in C57BL6 mice is due to a dysfunction of renal dopamine receptors caused by increased expression and activity of G protein-coupled receptor kinase 4. In order to determine if the salt sensitivity in C57BL6 mice can be related to increased expression of renal sodium transporters, we studied the effects of chronic NaCl loading on renal sodium transporters in these two mouse strains. C57BL6 and SJL mice (10 weeks old, male) were fed high NaCl (6%) or normal NaCl (0.8%NaCl) (n =5/group) diet. The blood pressures (measured by telemetry) were similar at baseline but increased in C57BL6 not in SJL mice after 1 and 3 weeks of salt loading. The urinary sodium excretions were also similar at baseline (2.34±0.27 vs 2.3±0.18,mEq/mg Cr, respectively) and increased to a lesser extent in C57BL6 than in SJL mice (1 wk: 4.39±0.9 vs 7.96±0.59, P<0.05; 3 wks: 3.5±0.4 vs 5.0±0.9, P =0.16, respectively). On normal NaCl diet, the renal protein expression (immunoblotting) of sodium hydrogen exchanger 3 (NHE3, 287±33, % of SJL) sodium chloride cotransporter (NCC, 167±24, %) and
β
-epithelial sodium channel (ENaC,169±9, % ) was greater in C57BL6 than in SJL mice. Urinary aldosterone excretion and renal
α
-ENaC expression (an aldosterone-induced protein) were decreased by the salt load to a similar extent in the two mouse strains. In contrast, one and three weeks of salt loading decreased renal NCC, another aldosterone-induced protein, in SJL but not in C57BL6 mice. There was a difference in the molecular size of the NCC upper band (SJL = 160 kDa; C57BL6 = 175 kDa) while the 110 kDa band was similar in the two strains. The upper band is glycosylated NCC (proved by N-glycosidase F studies) which may be the active transporter; it remains to be determined if glycosylation affects NCC activity in mice. We conclude that the increased renal NCC expression, which is independent of aldosterone levels, may be responsible for the decreased sodium excretion in C57B6 mice. Our studies provide a renal molecular mechanism to the salt sensitivity in C57BL6 mice.
Abstract 5078: Sustained Acting Atrial Natriuretic Peptide: A Novel Natriuretic Peptide With Potent Blood Pressure Lowering and Renal Enhancing Properties in a Canine Model of Acute Angiotensin Induced Hypertension
Authors: McKie Paul , Cataliotti Alessandro , Boerrigter Guido , Chen Horng , Martin Fernando , Burnett John
Published: April 2024

Background
Sustained Acting Atrial Natriuretic Peptide (SA-ANP) is a 40 AA peptide consisting of native ANP (1–28) with a 12 AA C-terminus extension which we synthesized based upon a familial ANP gene frameshift mutation. SA-ANP possesses markedly greater and more sustained mean arterial pressure (MAP) lowering, diuretic/natriuretic, angiotensin-aldosterone suppressing, and cGMP activating properties compared to ANP in normal dogs consistent with a super agonist of the ANP receptor (NPR-A) (
JACC in press
). Here we evaluated SA-ANP in a model of acute hypertension with the hypothesis that SA-ANP would have potent MAP lowering and renal enhancing properties.

Methods
Integrated physiological studies were performed in a canine model of ANG induced hypertension (20 ng/kg/min continuous infusion) before, during, and up to 3 hours following a 45 minute infusion of SA-ANP (30 pmol/kg/min) (n=6) or vehicle (n=6).

Results
MAP is shown in Figure 1

. SVR significantly decreased and despite a significant reduction in MAP both renal blood flow (RBF) and GFR were significantly increased following SA-ANP infusion. There were significant reductions in proximal and distal tubule sodium reabsorption resulting in a significant increase (>50 fold) in diuresis and natriuresis with SA-ANP. These renal actions were associated with significant increases in plasma and urine cGMP and a significant inhibition of aldosterone activation.

Discussion
We report for the first time in an acute model of hypertension that SA-ANP reduced MAP while enhancing RBF, GFR, and sodium/water excretion and thus may serve as a potential therapeutic agent in the treatment of hypertension in the setting of volume overload.
Abstract 5122: Hepatocyte Growth Factor Attenuates Renal Fibrosis Through Myofibroblasts Anoikis Induced by FAK/MMP Activaton
Authors: Iekushi Kazuma , Taniyama Yoshiaki , Azuma Junya , Sanada Fumihiro , Dosaka Norio , Okayama Keita , Kusunoki Hiroshi , Yokoi Toyohiko , Rakugi Hiromi , Moroshita Ryuichi
Published: April 2024

Progression of chronic kidney disease (CKD) is characterized by the accumulation of extracellular matrix. Especially,
α
-SMA positive myofibroblasts, which produce high amounts of TGF-
β
1, plays a key role in interstitial fibrosis. Previous studies demonstrated hepatocyte growth factor (HGF) improved kidney fibrosis, whereas mechanisms of HGF on prevention of renal fibrosis have not been fully understood. Since HGF may contribute to myofibroblasts apoptosis/anoikis, we tested whether HGF increased MMP expressions and contributed to myofibroblasts apoptosis/anoikis. When human mesangial cells were treated with TGF-
β
1, cells phenotypically changed to myofibroblasts, and this was associated with up-regulation of c-Met/HGF receptor (P<0.05). HGF significantly increased MMP-2/-9 expression (P<0.05) of myofibroblasts. Furthermore, HGF increased phosphorylation of Tyr925 FAK, suggesting the role of MMPs and FAK on HGF induced apoptosis. Indeed, when GM6001(GM;MMP inhibitor) or FAK siRNA were treated in combination with HGF, HGF-mediated myofibroblast apoptosis was significantly inhibited (HGF alone; 8.1±0.2%, HGF+GM; 3.4±0.2%, HGF+FAK siRNA; 3.6±0.3%, P<0.05). Next, we tested the anti-fibrotic effect of HGF using cardiac specific HGF over-expressing mice (HGF-Tg). Angiotensin II (Ang II) infusion induced renal fibrosis in litter mates control, while it was significantly inhibited in HGF-Tg accompanied with the significant depletion of interstitial myofibroblasts (P<0.05). TGF
β
-1, collagen type I and IV mRNA in HGF-Tg were significantly reduced compared to control (qPCR; P<0.05). Consistent with the in vitro studies, HGF-Tg significantly increased MMP-2/-9 expression (P<0.05). TUNEL and
α
-SMA double-positive cells induced by Ang II, which represents myofibroblasts apoptosis, was reduced in HGF-Tg compared to control (3.7±0.3 vs 1.7±0.4%, P<0.05). Furthermore, GM6001 injections in HGF-Tg with Ang II cancelled the anti-fibrotic effects of HGF accompanied with the depletion of myofibroblasts. In summary, increased activities of FAK-MMPs underlie the major mechanism of HGF mediated anoikis/apoptosis of myofibroblasts. Activation of MMPs by HGF might be a target to attenuate the progression of renal fibrosis in CKD.
Abstract 5140: The Transcription Factor Nrf2 is a Novel Target for the Treatment of Myocardial Ischemia-Reperfusion Injury
Authors: Calvert John W , Grinsfelder D. B , Elston Marah , Pattillo Christopher B , Kevil Christopher G , Lefer David J
Published: April 2024

Background:
Nuclear-factor-E2-related factor 2 (Nrf2), a member of the NF-E2 family of nuclear basic leucine zipper transcription factors, regulates the gene expression of a number of proteins that attenuate pro-oxidative and pro-apoptotic signaling pathways. The role of Nrf2 in myocardial ischemia-reperfusion (MI/R) injury has not been investigated. Therefore, we evaluated its role using an
in vivo
murine model of myocardial ischemia-reperfusion (MI/R) injury.

Methods:
Mice deficient in Nrf2 (Nrf2 KO; ICR background) were subjected to 30 minutes of MI followed by reperfusion for 24 hr, at which time the extent of myocardial infarction per area-at-risk (INF/AAR) or per left ventricle (INF/LV) was evaluated with TTC and serum troponin-I levels were measured. In separate studies, C57BL/6J mice were also subjected to MI followed by 24 hr of reperfusion. The known activator of Nrf2, sulforaphane (5 mg/kg) or vehicle was administered 30 min prior to myocardial ischemia.

Results:
Myocardial injury following I/R was found to be exacerbated in Nrf2 KO mice compared with Wild-Type mice, as evidenced by a 61% increase in infarct size relative to the area-at-risk (Inf/AAR; 43±7 vs. 27±0.1%, p<0.01), a 59% increase in INF relative to the entire left ventricle (Inf/LV; 25±4 vs. 14.9±1.6%, p<0.05), and an increase in circulating Troponin-I levels from 26±5.2 to 52.4±9 ng/mL (p<0.05). In contrast, the administration of sulforaphane induced myocardial Nrf2 nuclear translocation and reduced infarct size by 40%.

Conclusions:
These data reveal that Nrf2 is an endogenous cardioprotective-signaling molecule that represents a novel target for the treatment of acute myocardial infarction.
Abstract 5141: Guanylyl Cyclase Activation Using HMR1766 Improves Endothelial Function and Reduces Platelet Activation in Congestive Heart Failure
Authors: Schaefer Andreas , Fraccarollo Daniela , Bauersachs Johann
Published: April 2024

Background: Endothelial dysfunction and platelet activation are part of the cardiovascular phenotype of severe congestive heart failure(CHF). An association between reduced endothelium-dependent NO-bioavailability and platelet activation has been described in experimental CHF. We investigated, whether chronic activation of soluble guanylyl cyclase using HMR1766 increases vascular NO-bioavailability and reduces platelet activation in experimental CHF.

Methods and results: Chronic myocardial infarction was induced in male Wistar rats by coronary ligation. Rats were randomised to placebo or HMR1766 (10mg/kg twice daily). After 10 weeks, haemodynamics were measured and endothelial function was assessed in organ bath studies. Only animals were included in the CHF groups, when left-ventricular infarct size was >45% and left-ventricular end-diastolic pressure was >15 mmHg. Endothelium-dependent, acetylcholine-induced and NO-mediated relaxation of the aorta was significantly attenuated in CHF-Placebo compared to Sham-operated rats (Rmax: Sham 83.9±1.4%, CHF-Placebo 56.9±5.9%, p<0.01) and markedly improved in CHF-HMR1766 (Rmax 75.4±4.6% p<0.01 vs. CHF-Placebo). Basal NO-bioavailability in vivo was determined by the extent of phosphorylation of vasodilator-stimulated phosphoprotein (VASP) in platelets from whole blood fixed in formaldehyde immediately following collection. Platelet in vivo-VASP phosphorylation was attenuated in CHF-Placebo compared to Sham animals (mean fluorescence intensity: Sham 16.4±1.0%, CHF-Placebo 13.4±0.3%, p<0.05), and normalised by HMR1766 treatment (17.1±1.2% p<0.05 vs. CHF-Placebo). Activation of circulating platelets was determined measuring P-selectin surface-expression on platelets by flow-cytometry. P-selectin surface-expression was significantly increased in CHF-Placebo (mean fluorescence intensity: Sham 14.2±0.4%, CHF-Placebo 16.0±0.4%, p<0.05) and reduced following treatment with HMR1766 (14.5±0.3% p<0.05 vs. CHF-Placebo).

Conclusion: Chronic guanylyl cyclase activation using HMR1766 significantly improved endothelial function, enhanced systemic NO-bioavailability and reduced platelet activation in CHF rats.