bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 12272: Sphingosine-1-phosphate Reverts the Mechanism of Flow Induced Dilation to Nitric Oxide in Diseased Human Arterioles
Authors: Freed Julie K , Hockenberry Joseph C , Gutterman David D
Published: April 2024

Impairment of flow-induced dilation (FID; the ability of the vasculature to dilate to increased shear stress in an endothelium-dependent manner) is predictive for future cardiovascular events. Recent discoveries in our laboratory have shown that increases in ceramide, through inhibiting its catabolism or exogenous administration, transitions the mediator of FID from NO to mitochondrial-derived H2O2, the same transition that occurs between health and disease. Ceramide can also undergo transformation to sphingosine, the backbone of all sphingolipids, and eventually phosphorylated to sphingosine-1-phosphate (S1P), known to have beneficial effects within the endothelial cell. We tested the hypothesis that exogenous administration of S1P will revert the mediator of FID back to NO in vessels from patients with CAD. Small adipose arterioles (100-200μm) from patients with CAD were prepared for videomicroscopy and constricted with endothelin-1. Changes in internal diameter to flow were recorded. The presence of PEG-Catalase (500U/ml) did not affect FID in CAD arterioles pre-treated with S1P (1μM, 16-20hrs) (82.4%±5.4 of maximal dilator capacity, n=7) compared to control (81.7%±2.9, n=4), however dilation was significantly impaired in the presence of L-NAME (100μM) (0.3%±2.0, n=8, p<0.01, one-way ANOVA). Dilation with S1P alone was no different from control (80.6%±3.8, n=8, versus 81.7%±2.9, n=4, respectively). Together these data suggest that S1P is critical in regulating the mediator of FID and promotes vasodilation through the NO pathway as opposed to H2O2. We conclude that the ceramide-sphinogsine-S1P balance has a significant influence in determining the primary mediator of FID.
Abstract 12281: Outcomes in Patients Treated With Transfemoral Aortic Valve Implantation After Admission to the Intensive Care Unit
Authors: Al-Rashid Fadi , Kahlert Philipp , Hildebrandt Heike , Selge Friederike , Patsalis Polykarpos-Christos , Wendt Daniel , Thielmann Matthias , Jakob Heinz , Heusch Gerd , Erbel Raimund , Janosi Rolf Alexander
Published: April 2024

Introduction:
Transcatheter aortic valve implantation (TAVI) has become established as a treatment option for patients with severe symptomatic aortic valve stenosis. Postoperative treatment of these old patients presents a new challenge for intensive care specialists. Although numerous studies have addressed perioperative anesthetic management, little is known about risk factors that lead to a longer intensive care unit (ICU) stay.

Hypothesis:
We retrospectively analyzed data focusing on the risk factors and indications for a prolonged ICU stay and their outcomes. We also compared predictive value of the SAPS II and EuroSCORE risk evaluation scales.

Methods:
From 2006 to 2012 a total of 214 consecutive patients (age: 80 ± 6 years) were admitted to the ICU after transfemoral TAVI.

Results:
Total 30-day mortality was 7%. Non-survivors differed from survivors in the rates of catecholamine therapy on ICU admission (93 vs. 29%; p<0.001), stroke (20 vs. 1%; p<0.001), and sepsis (27 vs. 2%; p<0.001). Acute kidney injury (83 vs. 56%; p < 0.001) and catecholamine therapy (88 vs. 61%; p < 0.001) significantly influenced 2-year survival. Mean SAPS II score was higher in non-survivors (38.1 ± 7.0 vs. 29.9 ± 6.2; p < 0.001), giving a predicted mortality of 23.1 ± 11.7% and 10.5 ± 8.2%, respectively, whereas the logistic EuroSCORE was not able to discriminate between the groups (p = 0.555) (figure 1). Among the biochemical parameters, the maximum values of creatinine (2.46±1.24 vs. 1.77±1.16 mg/dL; p <0.05), procalcitonin (1.44 ± 1.84 vs. 0.51 ± 1.65 ng/mL; p < 0.05), and troponin I (4.46 ± 4.19 vs. 2.02 ± 2.25 ng/mL; p < 0.001) during ICU admission were significantly higher in non-survivors.

Conclusions:
The SAPS II score was superior to the EuroSCORE in predicting ICU mortality and could be used for post-interventional risk stratification while distinct TAVI risk scores are lacking. Creatinine, procalcitonin, and troponin are strong predictors of 30-day and 2-year mortality after TAVI.
Abstract 12337: Platelet-neutrophil Complex Infiltration is Regulated by Serotonin in a Mouse Model of Myocardial Reperfusion Injury
Authors: Mauler Maximilian , Witsch Thilo , Dorner Ludwig , Blanz Kelly D , Koentges Christoph , Stallmann Daniela , Bugger Heiko , Bode Christoph , Duerschmied Daniel
Published: April 2024

Background:
Myocardial reperfusion injury leads to platelet neutrophil complex (PNCs) migration into cardiac tissue, which promotes post-infarction necrosis. Local serotonin levels are elevated during ischemia and platelet serotonin promotes recruitment of inflammatory cells. Tryptophan hydroxylase-1-deficient mice (Tph1-/-) lack peripheral serotonin and show attenuated inflammatory response. We evaluated PNC infiltration after myocardial ischemia reperfusion (I/R) in the absence of peripheral serotonin.

Methods:
C57Bl/6 (WT) and Tph1-/- mice underwent coronary artery ligation to induce myocardial infarction. Reperfusion was allowed after 30min, heart function determined by echocardiography after 24h. Hearts were excised to evaluate infarct size. PNC content was determined by flow cytometry and histology. The function of healthy WT and Tph1-/- hearts was analyzed in an ex vivo working heart model and compared to global flow/no flow/flow. Cardiomyocytes were isolated from healthy WT and Tph1-/- mice and their survival following different in vitro challenges was assessed over 48h.

Results:
Infarct size was 37±9% in Tph1-/- and 53±13% area at risk in WT mice (p<0.01). Fractional shortening in echocardiography was better in Tph1-/- mice (49±4% vs. 41±6%, p<0.05), whereas cardiac power after no flow in the ex vivo working heart assay was similar (33±4 vs. 31±3mW/gHW). Isolated cardiomyocytes of Tph1-/- and WT mice showed similar survival after 48h (11.5% vs. 8.8%). These data indicate that contractility and cardiomyocyte function were independent of serotonin in this setting. Histology displayed a reduced number of PNCs in Tph1-/- hearts (7±3) compared to WT (16±3/350μm2, p<0.01). This was confirmed by flow cytometry of homogenized heart tissue (4±2 vs. 13±1%leukocytes, p<0.05) and blood samples (24±8 vs. 41±15%leukocytes; p<0.05).

Conclusion:
Lack of peripheral, i.e. platelet serotonin did not influence the function of isolated hearts or cardiomyocytes in vitro. However, PNC formation and infiltration was reduced in the absence of serotonin, resulting in attenuated reperfusion injury in vivo. Serotonin appears to account for up to 30% of myocardial reperfusion injury by promoting PNC formation.
Abstract 12380: Preventing Tumor Formation Following iPS Cell-Derived Cardiomyocytes Transplantation Therapy by Carbohydrate Vaccine Therapy Targeting Undifferentiated iPS Cell-Specific Antigen
Authors: Kawamura Takuji , Miyagawa Shigeru , Fukushima Satsuki , Kashiyama Noriyuki , Kawamura Ai , Yoshida Shohei , Itou Emiko , Saito Atsuhiro , Maeda Akira , Eguchi Hiroshi , Toda Koichi , Miyagawa Shuji , Okuyama Hiroomi , Sawa Yoshiki
Published: April 2024

Introduction:
Cell transplantation therapy using induced pluripotent stem cell (iPSC)-derived cardiomyocyte (iPSC-CM) into damaged myocardium is a promising approach; however, the tumor formation from the remaining undifferentiated iPSCs in the graft is still a concern. We hypothesized that antigens specific to the undifferentiated iPSCs may provoke host immune response after transplantation, and that vaccine therapy targeting the antigen may minimize tumor formation following transplantation of iPSC-CMs.

Methods and Results:
Murine iPSCs or iPSC-CMs, were transplanted into syngeneic mice and then the antibodies against each cell in the serum were quantified as mean fluorescence intensity by flow cytometry. As a result, the anti-iPSC antibodies in the iPSC-immunized mice, but not the anti-iPSC-CM antibodies in the iPSC-CM-immunized mice, displayed significantly higher intensities (IgM, 1,400, IgG: 2,300) as compared to the normal (IgM: 180, IgG: 310). Of note, the antibodies against SSEA-1 were significantly increased in the serum of the iPSC-immunized mice (IgM: 219, IgG: 216), as compared to the normal (IgM: 59, IgG: 56), quantified by the enzyme-linked immunosorbent assay. It was thus indicated that SSEA-1 may be a target to induce undifferentiated iPSC-specific immune response. Then, we immunized mice with SSEA-1 conjugated CRM-197, which is reported to be an effective carrier protein to present carbohydrate antigens. In the serum of the SSEA-1-CRM-197-immunized mice, antibodies against the iPSCs (IgM: 1,600, IgG: 2,400) were significantly higher levels than those against the iPSC-CMs (IgM: 100, IgG: 200). In addition, CD4+ and CD19+ cells presented significantly higher proliferative responses against the transplanted iPSCs, resulting in depletion of more than 10^7 of the undifferentiated iPSCs in vivo. Finally, transplantation of the iPSC-CMs to the SSEA-1-CRM-197-immunized mice revealed the engraftment of the iPSC-CMs without the tumor formation (n=5).

Conclusions:
Carbohydrate vaccine targeting SSEA-1 induced the undifferentiated iPSC-specific immune response and enabled the iPSC-CMs to engraft without the tumor formation. This novel approach would be useful to ensure the safety of the iPSC transplantation therapy.
Abstract 12438: Efficacy and Safety Evaluation of a Platelet Glycoprotein Ib Inhibitor for Patients With Non-ST Segment Elevation Myocardial Infarction
Authors: Zheng Bo , Li Jianping , Jiang Jie , Xiang Dingcheng , Chen Yundai , Ge Junbo , Yu Zaixin , Dai Xiangrong , Li Benjamin , Huo Yong
Published: April 2024

Introduction:
Platelet receptor glycoprotein Ib (GPIb) plays a crucial role in the first step of platelet adhesion.

Hypothesis:
We hypothesized that GPIb inhibitor would attenuate platelet aggregation without increasing bleeding risk.

Methods:
This was a prospective, multicenter, double-blind, placebo controlled, randomized trial in 90 Chinese patients with non-ST segment elevation myocardial infarction (NSTEMI) undergoing percutaneous coronary intervention (PCI). GPIb inhibitor was initially administered via intravenous bolus injections at three dosing levels (low dose of 2IU/60kg, moderate dose of 3IU/60kg, and high dose of 5IU/60kg), followed by continuous intravenous infusion at 0.002IU/kg/h for up to 48 hours. Primary endpoint was the inhibition of platelet aggregation measured at baseline, 5 minutes, 24 hours and 48 hours from the beginning of infusion as well as 4 hours after withdrawal. Safety endpoint was in-hospital major bleeding.

Results:
Ninety patients were randomly assigned to low dose group (n=20), moderate dose group (n=20), high dose group (n=20), and placebo group (n=30). Overall, the median age was 57.7 and 14.4% were female. There was no significant difference among the 4 groups for demographic, clinical and procedural characteristics. Higher inhibition of platelet aggregation occurred in each GPIb inhibitor dosing group, compared with placebo at each time point, with strongest antiplatelet effect found in high-dose group (Figure 1). The TIMI flow and myocardial blush grade did not differ significantly among the 4 groups. The 30-day mortality (0% vs 3.3%, p=0.33), non-fatal MI (0% vs 3.3%, p=0.33) and major bleeding (1.7% vs 3.3%, p=1.00) were rare and comparable between the patients receiving GPIb inhibitor and placebo.

Conclusions:
The current study demonstrated that intravenous platelet receptor GPIb inhibitor could be feasible and safe with significant antiplatelet effect among patients with NSTEMI undergoing PCI.
Abstract 12452: Clinical Practice Patterns are Relatively Uniform Between Pediatric Heart Transplant Centers: A Survey Based Assessment
Authors: Castleberry Chesney , Ziniel Sonja , Almond Christopher , Auerbach Scott , Hollander Seth , Ashwin Lal , Fenton Matthew , Rossano Joseph , Everitt Melanie , Daly Kevin
Published: April 2024

Background:
Randomized control trials (RCT) of immunosuppression are needed in pediatric heart transplantation. However, variations in clinical practice could confound results. We surveyed centers to describe practice variations and understand willingness to modify protocols for the purpose of a RCT.

Hypothesis:
We hypothesized that though variability in practice exists, there would be a willingness to change protocols as part of a RCT.

Methods:
Pediatric heart transplant centers were identified based on participation in the Pediatric Heart Transplant Study. One member from each institution was sent an electronic request to complete a survey using a customized Qualtrics tool. Simple descriptive statistics were used.

Results:
The response rate was 72% (40 responses from 52 contacted centers, 37 complete). Respondents were from the United States (36, 90%), Great Britain (2, 5%), Canada (1, 2.5%), and Brazil (1, 2.5%). Mean center volume was 10 transplants/year (range of 1 to 25). A majority of centers use tacrolimus (36, 95%) and mycophenolate mofotil (36, 95%) as maintenance therapy. Other immunosuppression was cyclosporine (7, 18%), everolimus or sirolimus (3, 8%), and azathioprine (2, 5%). Responses for most clinical practices were over 70% similar except for steroid use and biopsy frequency (Table). Overall, willingness to change clinical practice was greater than 70%. A majority of respondents, 97% (36/37) responded that they would be willing to participate in a RCT and 100% (37/37) said they would be willing to participate in a RCT investigating everolimus or sirolimus.

Conclusion:
Though practice variations exist between pediatric heart transplant centers, most major components of clinical practice protocols are similar. Importantly, a majority of centers are willing to adopt a common protocol for a RCT and practice variations should not be considered a barrier to trial design. There is overwhelming support for a trial involving everolimus or sirolimus.
Abstract 12457: Carotid Intima-Media Thickness and Aortic Stiffness are Elevated in Chronic Obstructive Pulmonary Disease (COPD) Subjects Compared to Controls and Not Associated With Systemic Inflammation
Authors: Fisk Marie , Mäki Petäjä Kaisa , Gale Nichola , Mohan Divya , Cheriyan Joseph , Cockcroft John R , Forman Julia , Tal-Singer Ruth , Polkey Michael I , McEniery Carmel M , Wilkinson Ian B
Published: April 2024

Introduction:
COPD is associated with increased cardiovascular risk, independent of established risk factors. Carotid intima thickness (CIMT) and carotid-femoral aortic pulse wave velocity (aPWV) are surrogate measures of cardiovascular risk and small studies have suggested elevated CIMT and aPWV in COPD are associated with systemic inflammation. We investigated this further as part of the ERICA (Evaluation of Role of Inflammation in Chronic Airways disease) multi-centre UK study: the largest cohort study focussing on cardiovascular manifestations in COPD.

Hypothesis:
COPD subjects have increased CIMT and aPWV compared to controls and CIMT and aPWV are associated with systemic inflammation in COPD.

Methods:
Spirometry, cardiovascular history and assessment, CIMT and haemodynamic measures including aPWV were performed in 432 COPD patients recruited from Cambridge and Cardiff study centres only. Age and gender matched healthy controls (n=324) were evaluated for comparison. Possible determinants for CIMT and aPWV in COPD subjects were assessed by linear regression analysis.

Results:
Mean age of COPD and control subjects was 67 years (SEM±0.41), 61% were male. COPD subjects, when compared to controls had increased CIMT (0.85±0.01mm vs 0.70 ±0.08mm, p=0.0001) and aPWV (10.35±0.12m/s vs 8.22 ±0.1m/s, p=0.0001), which were maintained after adjustment for mean arterial pressure (MAP) and heart rate (HR). COPD subjects also had higher brachial systolic BP (Δ 12±0.2mmHg, p=0.0001), and central systolic BP (Δ 12±0.2mmHg, p=0.0001). COPD was an independent determinant of CIMT and aPWV in pooled analysis of COPD and controls (p=0.0001 respectively). In COPD, age and systolic BP were independently associated with CIMT; and age, MAP and HR were determinants of aPWV. Inflammatory markers (fibrinogen, CRP, WCC), smoking status and pack years smoked were not associated with CIMT or aPWV.

Conclusions:
These data support the theory of accelerated ageing in COPD subjects compared to matched controls, which may partly explain the excess cardiovascular risk seen. As systemic inflammatory biomarkers did not relate to CIMT or aPWV, consideration of novel therapeutic targets to ameliorate premature arterial stiffening in COPD, merits further investigation.
Abstract 12468: Efficacy and Safety of Lomitapide in Japanese Patients With Homozygous Familial Hypercholesterolemia on Concurrent Lipid-Lowering Therapy
Authors: Harada-Shiba Mariko , Yoshida Masayuki , Ikewaki Katsunori , Nohara Atsushi , Yanagi Koji , Otsubo Yoshihiko , Foulds Pamela , Sumeray Mark
Published: April 2024

Introduction:
Lomitapide is a microsomal triglyceride transfer protein inhibitor indicated as an adjunctive therapy for adults with homozygous familial hypercholesterolemia (HoFH). In a previous global Phase 3 study in non-Japanese patients with HoFH, lomitapide in combination with other lipid-lowering therapy resulted in a 50% reduction in LDL-C levels from baseline after 26 weeks of treatment. This open-label, multicenter, phase 3 study evaluated the efficacy and safety of lomitapide in adult Japanese patients with HoFH.

Methods:
Adult patients with HoFH added lomitapide to their maximally tolerated, stable lipid-lowering therapy. Lomitapide was initiated at 5 mg/day and escalated to each patient’s maximum tolerated dose (≤60mg/day) over 14 weeks. The primary endpoint was the mean % change from baseline in LDL-C at Week 26.

Results:
Nine patients (5 men, 4 women, mean age 50 [33-74] years) received lomitapide (mean dose 20 mg); 8 patients completed 26 weeks of treatment. Mean LDL-C was reduced from 199.3 mg/dL (95% CI: 148.6-250.0) at baseline to 117.9 mg/dL (95% CI: 70.2-165.6, last observation carried forward) at Week 26. Mean % LDL-C reduction was significant in patients with and without apheresis; significant reductions were also seen in key secondary endpoints (Table). A >50% reduction in LDL from baseline was achieved by 5/9 (56%) patients. Gastrointestinal symptoms were the most common adverse event (diarrhea in 7/9 [78%] patients). Abnormal liver function tests were reported in 3/9 (33%) patients; 1 patient discontinued treatment after 22 weeks due to persistent liver enzyme elevations. There were no serious adverse events.

Conclusions:
The efficacy and safety of 26 weeks of lomitapide in Japanese patients were consistent with results in the global phase 3 study, including a significant reduction in LDL-C and no new safety signals. Treatment in the safety phase (Weeks 26-56) is ongoing.
Abstract 12488: Spontaneous Beating of Cardiac Pacemaker Cells is Regulated by Basal Activation of Epidermal Growth Factor Receptor
Authors: Vinogradova Tatiana M , Tarasov Kirill V , Lakatta Edward G
Published: April 2024

Spontaneous firing of sinoatrial node cells (SANC) is controlled by sarcoplasmic reticulum (SR) generated local subsarcolemmal Ca
2+
releases (LCRs), which appear during diastolic depolarization (DD) and activate an inward Na
+
-Ca
2+
exchange current to regulate DD rate and spontaneous SANC beating rate. Therapy directed against the epidermal growth factor receptor (EGFR) pathway had improved outcomes for patients with different types of cancer. It was noted, however, that inhibition of EGFR might lead to sinus bradycardia and sick sinus syndrome. Until now neither expression nor possible role of EGFR for spontaneous beating of cardiac pacemaker was examined. Here we studied expression of EGFR in rabbit SANC; effects of EGFR inhibition on spontaneous SANC firing and possible mechanisms of EGFR-dependent regulation of cardiac pacemaker function.

We discovered that expression of EGFR (RNA-sequencing) in rabbit SANC exceeded that in ventricular myocytes by six-fold. Specific EGFR inhibitors erlotinib and AG1478 markedly decreased spontaneous SANC beating rate (perforated patch-clamp technique) and this effect was largely reversible upon drug washout. Both erlotinib and AG1478 suppressed SR Ca
2+
cycling (confocal microscopy, Ca
2+
indicator Fluo-3) in SANC, i.e. decreased LCR size and number per each spontaneous cycle and prolonged the LCR period (the interval between AP-induced Ca
2+
transient and subsequent LCR), which predicted the concomitant increase in the spontaneous cycle length. These data indicate basal activation of EGFR, which could activate other kinase cascades in rabbit SANC e.g. PKC-dependent phosphorylation through activation of PLC. Inhibition of either PLC activity by U-73122 or PKC activation by GF109203X or calphostin C suppressed LCRs and stopped spontaneous firing of rabbit SANC. We conclude that basal activation of EGFR regulates cardiac pacemaker function through PLC-PKC-dependent modulation of LCR characteristics. This might represent a novel pathway to control normal automaticity of SANC, which could be affected by cancer treatment therapy.
Abstract 12497: Regulation of Mitochondrial Biogenesis and Oxidative Phosphorylation by miR-1825 Promotes Proliferation and Survival of Quiescent Adult Cardiomyocytes
Authors: Pandey Raghav , Crocker Jeffrey S , Weller Benajmin , Ahmed Rafeeq P
Published: April 2024

Background:
Generation of reactive oxygen species (ROS) by mitochondrial oxidative phosphorylation is known to induce DNA Damage Response (DDR) pathway resulting in cell cycle arrest and apoptosis in a number of cell types including Adult Cardiomyocytes (ACMs). In our recent studies, we have identified miR-1825 to be the most robust ACM proliferation inducing miR. Here we hypothesize that miR-1825 promotes proliferation by regulating mitochondrial biogenesis and ROS production.

Methods and Results:
ACMs isolated from 10 week old male rats were transfected with hsa-miR-1825 and cel-miR-67 (control). EdU was added (5μM) each day for 6 days and cells were used for immuno-staining, RNA and protein analysis. In addition to EdU, TnI, and DAPI staining, Dihydro-rhodamine 123 was used as a marker for mitochondrial ROS production, VDAC immuno-staining was used to detect mitochondrial number. We identified 25% less mitochondrial ROS production in ACMs transfected with miR-1825. Moreover, when ACMs were administered H2O2 (10μM), along with miR-1825 a significant decrease in apoptosis was detected (TUNEL+ ACM 0.53±0.10 fold less than control). In addition to reduction of mitochondrial ROS, miR-1825 transfected ACMs also showed a significant reduction in total ROS. VDAC immuno-staining showed over 85% decrease in mitochondrial number in miR-1825 transfected ACMs compared to control. Our whole transcriptome micro-array analysis of ACMs transfected with miR-1825 identified down regulation of genes involved in oxidative phosphorylation and TCA cycle; while cell-cycle genes like Cyclin-D and Cyclin-B were up regulated. Our RNA sequencing data and in-silico analysis reveal miR-1825 regulates mitochondrial biogenesis indirectly through up-regulating miR-199a expression and by subsequent down regulation of miR-199a target SIRTUIN1 which is a known inhibitor of PGC-1α and mitochondrial biogenesis.

Conclusion:
We identified that the increase in proliferation of ACMs observed with miR-1825 is through miR-199a mediated inhibition of PGC-1α expression which inhibits mitochondrial biogenesis and ROS production. This is a novel mechanism and has translational potential for inducing proliferation of ACM post myocardial infarction.
Abstract 12601:
O
-Glycosylation of ApoB100 is Associated With Enhanced Sphingomyelinase Activity and Atherogenicity of Human Electronegative LDL
Authors: Ke Liang-Yin , Chan Hua-Chen , Chen Chih-Chieh , Lu Jonathan , Marathe Gopal K. , Chu Chih-Sheng , Chan Hsiu-Chuan , Wang Chung-Ya , Law Shi-Hui , Tung Yi-Ching , McIntyre Thomas M , Yen Jeng-Hsien , Chen Chu-Huang
Published: April 2024

Background:
Among the 5 (L1-L5) chromatographically resolved subfractions of human LDL, L5 is the most electronegative and atherogenic. L5’s atherogenicity may be attributed in part to its high ceramide content. Because ceramides can be converted from sphingomyelins by sphingomyelinase (SMase), we examined whether L5 has SMase-like properties.

Methods and Results:
The total lipid extract of L5 was as capable as L5 in inducing arterial endothelial cell (EC) apoptosis. LC/MS
E
analysis confirmed that L5 had a significantly greater ceramide content in the lipid extract than L1 (n=4;
P
<0.01). On Amplex Red SMase assays, L5 but not L1 exhibited a strong SMase-like activity (n=12). ECs treated with L5 increased intracellular ceramide concentrations; the associated cytotoxicity was significantly attenuated by SMase inhibitor desipramine. To identify the putative region of LDL with SMase activities, we compared human apolipoprotein B100 (apoB100) with
Bacillus cereus
,
Leptospira interrogans
, and
Staphylococcus aureus
SMases in amino acid sequences. The predicted catalytic site of human apoB-100 with activities similar to the bacterial SMases comprised N
2035
, E
2079
, F
2081
, N
2084
, E
2140
, N
2251
, D
2253
, D
2312
, and H
2366
in the α2 region. Post-translational analysis with LC/MS
E
and ProteinLynx Global SERVER (PLGS) revealed exclusive
O
-glycosylation of the amino acid residues S
1732
, S
1959
, S
2378
, S
2408
and S
2429
in the α2 region.

Conclusions:
The structural uniqueness of the α2 region of apoB-100 characterized by specific
O
-glycosylation may underlie L5’s atherogenicity through enhanced SMase activity and ceramide overproduction. Modifying this region may curtail L5’s atherogenicity.
Abstract 12686: Cariporide, a Selective Na+-H+ Exchange Inhibitor, Improves Cardiac Basal and β-Adrenergic Stimulated Functional Performance in Experimental Hypothyroidism
Authors: Li Tiankai , Zhang Xiaowei , Cheng Heng-Jie , Shao Qun , Li Wei-Min , Cheng Che Ping
Published: April 2024

Background:
Upregulation of Na
+
-H
+
exchanger 1 (NHE1) occurs during pathological insult and contributes to the deleterious consequence on the myocardium. Cariporide (CAR), a NHE1 selective inhibitor, exerts protective actions in various forms of heart disease, including heart failure (HF). Hypothyroidism (Hypo) causes cardiac injury. Recent studies link Hypo to the pathology of cardiomyopathy and HF. However the direct cardiac effects of CAR in Hypo are unknown. We tested the hypothesis that Hypo produces direct depressions in LV and myocyte basal function and β-adrenergic reserve. CAR would improve cardiac [Ca
2+
]
i
regulation and enhance myocyte basal and β-adrenergic stimulated contraction and relaxation.

Methods:
We simultaneously evaluated LV functional performance and compared myocyte contractile and [Ca
2+
]
i
transient ([Ca
2+
]
iT
) responses to isoproterenol (ISO) in 12 control (C) and 14 rats with Hypo induced by methimazole (30 mg/kg/day for 8 weeks in the drinking water) in the absence and presence of CAR.

Results:
Versus controls, Hypo caused LV dysfunction with significantly increased the time constant of LV relaxation (t) and decreased LV contractility (E
ES
) accompanied by concomitant significant depressed myocyte contraction (dL/dt
max
) (Hypo: 65.6 vs C: 135.9 μm/s), relaxation (dR/dt
max
) (52.8 vs 107.4 μm/s), and [Ca
2+
]
iT
(0.16 vs 0.25). Versus normal myocytes, in Hypo myocytes, ISO (10
-8
M) caused significantly less increases in dL/dt
max
(36% vs 65%), dR/dt
max
(26% vs 52%), and [Ca
2+
]
iT
(16% vs 31%). In Hypo, versus Hypo baselines, after CAR (0.5 mg/kg, ip), t (18.0 ms vs 22.8 ms) significantly decreased and the peak rate of mitral flow (4732 vs 3263 μl/s) and E
ES
(0.86 vs 0.60 mmHg/μl) were significantly augmented. Consistently, in Hypo myocytes, superfusion of CAR (10
-5
M) produced significant increases in dL/dt
max
(38%, 90.5 vs 65.6 μm/s), dR/dt
max
(27%, 67.1 vs 53.8 μm/s) and [Ca
2+
]
iT
(23%, 0.20 vs 0.16). Importantly, compared with Hypo baselines, with CAR superfusion, ISO also caused significantly greater increases in dL/dt
max
(57%), dR/dt
max
(46%), and [Ca
2+
]
iT
(29%).

Conclusions:
In hypothyroidism, clinically relevant dose of cariporide improves LV myocyte contraction, relaxation, [Ca
2+
]
iT
and β-adrenergic responsiveness.
Abstract 12746: Impaired Autophagic Flux in Ischemic/Reperfused Diabetic Heart and Its Reversal by a Novel Orally Active Adiponectin Receptor Agonist via AMPK-Mediated Autophagosome Formation and AMPK-Independent Autophagosome Clearance
Authors: Wang Yajing , Lau Wayne B , Gao Erhe , Koch Walter , Ma Xin
Published: April 2024

Autophagy is increasingly recognized as an important regulator of myocardial ischemia/reperfusion (MI/R) injury. However, whether and how autophagy is altered in the ischemic/reperfused diabetic heart remains unknown. Normal control (NC), high-fat-diet-induced diabetic (HFD), and adiponectin (APN) knockout (APNKO) mice were subjected to MI/R (30 minutes/3-24 hours) and treated with vehicle or AdipoRon (50 mg/kg gavage, 10 minutes before MI; or 10 mg/kg IP, 10 min before R). Compared to NC mice, autophagosome formation was significantly inhibited and autophagosome clearance was nearly completely blocked in the HFD heart after MI/R (P<0.01). APNKO largely reproduced the phenotypic alterations observed in the HFD heart, with both autophagosome formation and clearance inhibited after MI/R (P<0.01 vs. WT). Treatment of HFD and APKNO mice with AdipoRon stimulated autophagosome formation, increased autophagosome clearance, reduced infarct size, and improved cardiac function (P<0.01). Mechanistically, AdipoRon caused significant phosphorylation of AMPK, BeclineT119, and VPS34S16, and enhanced expression of lysosome protein LAMP2. Compound C pretreatment abolished AdipoRon-induced BeclineT119 and VPS34S164 phosphorylation without altering AdipoRon-induced LAMP2 expression. In vitro AdipoRon treatment of adult wild type cardiomyocytes enhanced phosphorylation of AMPK, BeclineT119, and VPS34S164. These effects are lost in cardiomyocytes isolated from cardiomyocyte-specific AMPK dominant negative mice (AMPK-DN). In contrast, AdipoRon-stimulated LAMP2 expression was preserved in AMPK-DN cardiomyocytes. Collectively, these results demonstrated for the first time that hypoadiponectinemia during diabetic conditions impairs autophagic flux in cardiomyocytes after MI/R via marked inhibition of both autophagosome clearance and formation. Administration of an orally active APN receptor agonist increased autophagosome formation via AMPK activation, and stimulated autophagosome clearance in an AMPK-independent fashion. Improving autophagic flux by restoring APN signaling systems might be a novel intervention against MI/R injury in diabetic conditions.
Abstract 12841: Mutations in the BMPR2 Gene Are Associated With Worse Survival in Patients With Pulmonary Arterial Hypertension
Authors: Evans Jonathan D , Girerd Barbara , Montani David , Jing Zhi-Cheng , Yan Yi , Wang Xiao-Jian , Galiè Nazzareno , Manes Alessandra , Palazzini Massimiliano , Austin Eric D , Wheeler Lisa A , Elliott Greg , Nakayama Ikue , Asano Koichiro , Grünig Ekkehard , Eichstaedt Christina , Hinderhofer Katrin , Wolf Matthias , Rosenzweig Erika B , Chung Wendy K , Soubrier Florent , Simonneau Gerald , Gräf Stefan , Kaptoge Stephen , Di Angelantonio Emanuele , Humbert Marc , Morrell Nicholas W
Published: April 2024

Introduction:
Mutations in the BMPR2 gene are the commonest genetic cause of pulmonary arterial hypertension (PAH), however the impact of BMPR2 mutations on clinical phenotype and outcomes remains uncertain.

Methods:
We collated individual participant-level data on 1550 patients with idiopathic, familial and anorexigen-associated PAH from 8 studies that had systematically tested for the presence of BMPR2 mutations. 1164 patients from 6 studies were included in the primary survival analysis. Associations of BMPR2 mutation status with risk of all cause death and death or transplant were assessed by calculating age and sex adjusted hazard ratios (95% CI) using Cox proportional-hazard regression models stratified by study.

Results:
Overall, 448 (28.9%) of 1550 patients had a BMPR2 mutation. BMPR2 mutation carriers were younger at diagnosis, (mean ±SD) 35 ±15 versus 42 ±18 years, p<0.001), had a higher mean pulmonary artery pressure (61 ±14 versus 56 ±15 mmHg, p<0.001) and pulmonary vascular resistance (17 ±8 versus 13 ±8 Wood units, p<0.001) and lower cardiac index (2.1 ±0.7 versus 2.5 ±0.9 L/min/m2, p<0.001) at diagnostic right heart catheterization. Patients with BMPR2 mutations were less likely to respond to acute vasodilator testing (2.7% versus 16.6%, p<0.001). Hazard ratios for those carrying a BMPR2 mutation for all cause death and death or transplant are shown in the figure below. In a complete case analysis, the increased risk of all cause death (HR 1.50 (1.07-2.12), p=0.02) and death or transplant (HR 1.76 (1.31-2.38), p<0.001) in those aged <50 at diagnosis persisted after adjusting for right atrial pressure, pulmonary vascular resistance and NYHA functional class at diagnosis.

Conclusions:
Patients with PAH and BMPR2 mutations are younger at diagnosis and present with more severe disease. Patients with BMPR2 mutations (particularly those diagnosed at a younger age) are at increased risk of death or transplantation compared with BMPR2 negative patients.
Abstract 12855: Circulating miRNA-30a, -30e, -188 as Early Biomarkers for CI-AKI diagnosis
Authors: Sun Shiqun , Zhang Tuo , Cai Zhaohua , Sun Zhe , Hu Liuhua , Nie Peng , Qin Shengying , Shen Linghong , He Ben
Published: April 2024

Background:
Contrast-induced acute kidney injury (CI-AKI) is typically defined as an increase in serum creatinine (SCr) within 3 days after intravascular administration of contrast medium. However, creatinine is an unreliable indicator for acute changes in kidney function. A reliable and early biomarker for CI-AKI diagnosis is needed.

Hypothesis:
Circulating miRNAs can serve as early diagnostic biomarkers for CI-AKI.

Methods and Results:
We utilized a previously described rat model of CI-AKI. The microRNA profiles of plasma and kidney tissue were determined using Agilent microarray platforms. Three individual miRNA species with >1.5-fold increases in plasma expression in CI-AKI rats as compared to wild-type rats were identified: miRNA-30a, miRNA-30e, and miRNA-188. These miRNAs were selected as potential candidate miRNA biomarkers for CI-AKI (Figure 1). TaqMan quantitative RT-PCR demonstrated that the plasma expression of these miRNAs peaked around 4h after contrast medium exposure. We screened for these candidate biomarkers in the peripheral circulation of 580 consecutive patients undergoing coronary angiography or percutaneous coronary intervention in Cardiovascular Center at Renji Hospital from July 2013 to June 2014. When compared with matched control patients without CI-AKI, the plasma levels of the three candidate miRNAs were significantly elevated post procedure in 71 patients diagnosed with CI-AKI (fold changes: miR-30a, 3.26±0.05 vs. 0.68±0.01, p<0.01; miR-30e, 3.03±0.04 vs. 0.74±0.01, p<0.01; miR-188, 2.36±0.03 vs. 0.77±0.01, p<0.01). Maximal sensitivity and specificity were found to be 71.83% and 88.73% respectively in this study, suggesting a limit of assay efficacy.

Conclusions:
Plasma expression levels of miRNA-30a, miRNA-30e, and miRNA-188 significantly differentiate patients with CI-AKI from those without CI-AKI. These miRNAs are potential biomarkers for the early detection of CI-AKI.
Abstract 12988: Intermittent Hypoxia and Hypercapnia Induce Pulmonary Artery Atherosclerosis in Low Density Lipoprotein Receptor Deficient Mice by an NF-kappa B-dependent Mechanism
Authors: Imamura Toshihiro , Haddad Gabriel G
Published: April 2024

Background:
Obstructive sleep apnea (OSA) is a common sleep disorder characterized by intermittent hypoxia and hypercapnia (IHH). Clinical studies have shown that OSA is an independent risk factor for atherosclerosis. In spite of its clinical importance and relevance, the contribution of IHH to atherogenicity has not yet been fully examined compared to the role of intermittent hypoxia exposure alone, which has been relatively well documented. We previously reported that IHH increased pulmonary artery (PA) but not aortic atherosclerosis in low-density lipoprotein receptor deficient (Ldlr-/-) mice. The mechanism of this IHH-induced PA atherosclerosis is unknown; however, previous studies have shown that various inflammatory mediators, particularly in the NF-kappa B (NF-kB) pathway, could cause atherosclerosis in OSA patients. Furthermore, it is known that the macrophages in atherosclerotic lesions play an important role as inflammatory cells involved in this process. Therefore, we hypothesized that IHH-induced PA atherosclerosis is caused by a macrophage NF-kB-dependent mechanism.

Methods:
Myeloid restricted IKK-beta deleted (Ikk-bΔMye) mice were generated by a Cre/lox recombination system to inactivate the NF-kB pathway in macrophages, and then crossed to Ldlr-/- mice to generate a double knockout animal (Ldlr-/-_Ikk-bΔMye). Male mice were fed with high-fat diet for 8 weeks while being exposed to IHH for 10 h/day. Plasma lipid levels, PA and aortic atherosclerotic lesions were then assayed.

Results:
The IKK-beta intact (Ldlr-/-_Ikk-bflox/flox) mice exposed to IHH developed more PA atherosclerotic lesions as compared to room air (RA) exposed mice (IHH 10.45%±5.07 vs. RA 5.68%±1.73). However, this IHH-induced PA atherogenicity was partially abolished in IKK-beta deleted mice (IHH 7.38%±4.71 and RA 4.58%±3.42). There was no significant difference in aortic atherogenicity among these four animal groups. Serum total cholesterol and triacylglycerol were increased after the implementation of high-fat diet but showed no difference among the groups during the course of this experiment.

Conclusion:
The macrophage NF-kB pathway plays a critical role in IHH-induced PA atherosclerosis and inactivation of NF-kB ameliorats such atheogenicity.
Abstract 13083: Multi-Center Study of Risk Factor Status on Entry to a Contemporary Phase 2 Cardiac Rehabilitation Program: Temporal Trends
Authors: Sandesara Pratik B , Eapen Danny J , Sperling Laurence , Salmon Richard D , Gordon Neil F
Published: April 2024

Introduction:
No comprehensive data are available on temporal trends in the percentage of participants who are not at recommended ASCVD risk factor goal levels on entry to a contemporary phase 2 cardiac rehabilitation (CR) program and, therefore, in need of intensified risk factor intervention. The purpose of this study was to determine whether improvements have occurred in recent years in the control of multiple risk factors in patients entering CR.

Methods:
In this multi-center registry, we compared the percentage of participants not at goal for select risk factors on entry to CR during 2000-2004 versus 2005-2009. Subjects were 26,956 consecutive patients (age=63.8
+
11.5 years; males=69.8%; females=30.2%) who enrolled in a phase 2 CR program at 35 centers in the US between 2000 and 2009 and completed an initial evaluation on program entry. Statistical significance of differences between groups was analyzed using chi-square and unpaired t-tests and statistical significance was established at p
<
0.05.

Results:
Percentages of patients with risk factors not at goal levels on entry to CR for the 2000-2004 (n=10,900) and 2005-2009 (n=16,056) cohorts are shown in
Figure 1 (*statistically significant difference)
. Compared to the 2000-2004 cohort, the percentage of the 2005-2009 cohort not at goal was lower (p<0.001) for BP (goal <120/80 mmHg) and LDL cholesterol (goal <100 mg/dl), higher (p<0.001) for BMI (goal <25 kg/m
2
), and not significantly different (p>0.05) for smoking (goal=no smoking), fasting glucose (goal <100 mg/dl) and physical activity (goal ≥150 min/wk).

Conclusions:
These data indicate that while the control of some risk factors has improved significantly over time, the control of others has remained unchanged or worsened. The data further demonstrate that multiple risk factors are often inadequately controlled on entry to contemporary phase 2 CR programs and serve to emphasize the need for intensive risk factor intervention during CR.
Abstract 13094: High Glucose/High Lipids Impair Vascular Adiponectin Function via Inhibition of Caveolin-1/AdipoR1 Signalsome Formation
Authors: Chen Yue , Lau Wayne , Christopher Theodore , Lopez Bernard , Ma Xin , Wang Yajing
Published: April 2024

Background and Aims:
Reduced levels of adiponectin (APN) contribute to cardiovascular injury in the diabetic population. Recent studies demonstrate elevated circulating APN levels are associated with endothelial dysfunction during pre-diabetes, suggesting the development of APN resistance. However, mechanisms leading to, and the role of, vascular APN resistance in endothelial dysfunction remain unidentified. The current study determined whether diabetes cause endothelial APN resistance, and by what mechanisms.

Methods and Results:
In HUVECs cultured under normal condition (control), APN caused eNOS, AMPK and Akt phosphorylation, increased nitric oxide (NO) production, and inhibited TNF-induced adhesion molecule expression. Under high glucose/high lipids (HG/HL), APN-stimulated nitric oxide production was decreased, phosphorylation of eNOS, AMPK, and Akt was attenuated (P<0.01 vs. control), and APN’s anti-TNFα effect was blunted (P<0.01). APN receptor expression remained normal, whereas Cav1 expression was reduced in HG/HL cells (P<0.01). The AdipoR1/Cav1 signaling complex was dissociated in HG/HL cells. Knock-down of Cav1 inhibited APN’s anti-oxidative and anti-inflammatory actions. Conversely, preventing HG/HL-induced Cav1 downregulation by Cav1 overexpression preserved APN signaling in HG/HL cells. Knock-in of a wild type Cav1 in Cav1 knock-down cells restored caveolae structure and rescued APN signaling. In contrast, knock-in of a mutated Cav1 scaffolding domain restored caveolae structure, but failed to rescue APN signaling in Cav1 knock-down cells. Finally, AdipoR1/Cav1 interaction was significantly reduced, and the vasorelaxative response to APN was impaired in vascular segments from diabetic animals.

Conclusion:
The current study demonstrates for the first time that the interaction between AdipoR1 and Cav1 is critical for adiponectin-mediated vascular signaling. The AdipoR1/Cav1 interaction is adversely affected by HG/HL, due largely to reduced Cav1 expression, supporting a potential mechanism for the development of APN resistance, contributing to diabetic endothelial dysfunction.
Abstract 13122: Hax1 Mediates Hippo Pathway to Enhance Therapeutic Effect of Sca1
+
Cardiac Stem Cell Against Myocardial Ischemia
Authors: Cai Wenfeng , Wang Lei , Huang Wei , Paul Christian , Xu Meifeng , Millard Ronald W , Wang Yigang
Published: April 2024

Background:
The Hippo pathway can regulate the fate and metabolic function of stem/progenitor cells through a kinase cascade that impinges on the transcription of growth-regulatory genes. This study investigates the role of HCLS-associated protein X-1 (HAX1) on the Hippo pathway with a goal of enhancing the therapeutic effects of sca1
+
cardiac stem cells (CSCs
sca1+
) in mouse ischemic hearts.

Methods and Results:
Western Blot assessment showed that phosphorylation levels of Yes-associated protein (Yap), the terminal effector of Hippo pathway, was increased in CSCs
sca1+
when endogenous HAX1 gene expression was silenced, whereas lentiviral over-expression of HAX1 maintained Yap activation by inhibiting its phosphorylation at Serine-397. ImageStream flow cytometry was then used to observe the enhanced nuclear translocation of Yap. Hypoxia exposure promoted this translocation to a greater extent in HAX1-overexpressing CSCs
sca1+
(CSCs
HAX1
) than non-encoding DNA sequence-transduced CSCs
sca1+
(CSCs
Null
) (
Fig 1A
). HAX-1 over-expression enhanced cardioprotective molecular mechanisms by restraining the dissipation of mitochondrial membrane potential
(Fig 1B)
, inhibiting endoplasmic reticulum stress response, promoting HIF-1α expression, and upregulating anti-fibrotic gene expression in CSCs
sca1+
response to hypoxia injury. Echocardiography and histological assessment demonstrated that contractile function was significantly improved and cardiac fibrosis was decreased in ischemic mouse hearts post engraftment of CSCs
HAX1
when compared with those of the CSCs
Null
-transplanted group (
Fig 1C
).

Conclusion:
HAX1 over-expression can regulate Hippo signal and promote nuclear translocation of Yap, upregulating intrinsic protective mechanisms of CSCs
sca1+
. This results in greater improvement of cardiac function in ischemic hearts post transplantation of HAX1 over-expressing CSCs
sca1+
.
Abstract 13165: Median Household Income and Rural Location Associated With Sudden Unexpected Death in Wake County, NC
Authors: Mounsey Louisa A , Lin Feng-Chang , Lewis Mary Elizabeth , Nanavati Parin , Mehta Neil , Nwosu Anthony , Hodonsky Chani J , Pursell Irion , Chung Eugene H , Simpson Ross J , Mounsey John P
Published: April 2024

Introduction:
The incidence of sudden unexpected death (SUD) in a racially and socioeconomically diverse population has been inadequately studied. We collated all SUDs among the 18 to 64 year population over a 12-month period in Wake County, North Carolina, a racially and socioeconomically diverse predominantly urban county, population c1 million. We investigated the socioeconomic differences in incidence of SUD to assist in future development of targeted interventions.

Methods:
Cases of possible SUD were identified from the Wake County EMS. Expected deaths were excluded and determination for cohort inclusion was made by independent cardiologists from review of medical records and medical examiner’s reports. SUD cases were geocoded to the level of census tract using death certificate residence address and the U.S Census Geocoder. Wake County includes 185 census tracts, population 5022 ± 2285 (M±SD). Median household income and other demographic data were obtained from the 2013 American Community Survey and 2010 U.S Census. Univariate and multivariable analysis were used to identify associates of SUD.

Results:
The 2013 incidence of SUD in Wake County was 19.5/100,000. A majority (107 of 185) of census tracts had at least one SUD, with 190 total. Census tracts with ≥1 SUD had a higher population of African Americans, a greater proportion unmarried, and a lower median household income than those with no SUDs (figure, p≤.001). After multivariable analysis, only median household income and rural tract location remained significantly associated with sudden death.

Conclusion:
This examination exemplifies the importance of studying sudden unexpected death in a racially and socioeconomically diverse population. Multivariable analysis suggests that low household income and rural location are important potential contributing factors to sudden death. Educational interventions to reduce the incidence of sudden death should be developed with these populations in mind.