bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract P2010: Relationship between echocardiographic parameters and invasively measured left ventricular filling pressure in the persistent atrial fibrillation with preserved left ventricular systolic function
Authors: AHN JIHUN
Published: October 2023

Background:
Among patients with normal systolic function, elevated left ventricular end diastolic pressure (LVEDP) could represent early diastolic dysfunction or could be the main physiological consequence of diastolic dysfunction. However, the evaluation of LVEDP using classic echocardiographic assessment has been challenging in the setting of atrial fibrillation (AF). The aim of this study was to investigate the methods for predicting LVEPD in patients with persistent AF.

Methods:
Clinical data, laboratory data, and echocardiography findings were assessed in 90 patients with chronic AF who were undergoing diagnostic left-heart catheterization. LVEDP and standard echocardiographic measurements including pulmonary arterial systolic pressure (PASP) were evaluated.

Results:
E/e’ (r=0.448, p<0.001), E/Vp (r=0.471, p<0.001) and PASP (r=0.421, p<0.001) correlated well with LVEDP (figure 1). Using receiver operating characteristic analysis, the optimal cut-off for E/e’ was 13 (sensitivity, 88%; specificity, 65%) to predict LVEDP of >15 mmHg (figure ).

Conclusion:
E/e’, E/Vp and PASP were well correlated with LVEDP in patients with AF with preserved EF. E/e’ greater than 13 may suggest elevated LVEDP (>15 mmHg) in patients with persistent AF.
Abstract P2011: Reduced Activity Of Activin Like Kinase 1 (ALK1) Increases Mortality And Myocardial Rupture After Acute Myocardial Infarction
Authors: Bhave Shreyas , Esposito Michele , Swain Lija , Qiao Xiaoying , Martin Gregory , Everett Kay , Kapur Navin K
Published: October 2023

Introduction:
Acute myocardial infarction (AMI) is a primary cause of heart failure (HF). Transforming growth factor beta (TGFβ) plays a central role in cardiac remodeling after AMI. Reduced activity of the TGFβ Type I receptor, activin like kinase (ALK)-1 promotes cardiac fibrosis in murine models of heart failure. A functional role for ALK1 in post-infarct cardiac remodeling remains poorly understood. We hypothesize that reduced ALK1 activity reduces survival and promotes cardiac fibrosis after AMI.

Methods:
AMI was induced by left coronary ligation in wild type (WT), and ALK+/- mice. After 14 days, LV function was assessed using conductance catheters and myocardial ALK1 signaling was quantified. Using siRNAs targeting ALK1 in in human cardiac fibroblasts (H-CFs), we further tested the role of ALK1 in cardiac fibrosis.

Results:
Reduced ALK1 activity significantly reduced survival compared to WT (p= 0.008 respectively) after AMI. ALK1 mice demonstrated a higher rate of cardiac rupture compared to WT after AMI (0% vs 85.7%). Both WT ad ALK1+/- mice demonstrated reduced LV ejection fraction and stroke work compared to sham controls (p=0.001 and p=0.0001 respectively). Profibrotic SMAD3 signaling was increased and antifibrotic SMAD1 signaling decreased in ALK1-/+ (pSMAD3, p=0.03, pSMAD1, p=0.003) mice 14 days after AMI. Reduced SMAD1 signaling was directly associated with increased myocardial Type 1 collagen protein levels in ALK1-/+ (R2=0.42, p=0.01) mice compared to WT. Myocardial levels of the TGFb1 co-receptor, endoglin, were increased significantly in ALK+/- as compared to WT (p=0.001) after AMI. Activity of MMP9 was increased in ALK1+/- mice, but protein levels were not affected 2 weeks after MI.

Conclusion:
We identify for the first time that loss of ALK1 activity increases cardiac rupture and mortality after AMI. These findings identify a novel functional role for ALK1 as a determinant of post-infarct survival and cardiac remodeling and implicate ALK1 as a potential therapeutic target to improve survival after AMI.
Abstract P2024: Myofibroblast Ccn3 Contributes To Adverse Cardiac Outcomes Following Myocardial Infarction
Authors: Flinn Michael A , Alvarez Santiago , Knas Makenna , Moreno Caelan W , Buday Sydney L , Buddell Tyler , Taylor Reiauna , Drnevich Jenny , Patterson Michaela , Omeara Caitlin
Published: October 2023

Myofibroblast function is critical for initial scar formation and prevention of catastrophic rupture following myocardial infarction, however, extended myofibroblast activity promotes pathological remodeling through exacerbated scar formation, myocyte uncoupling, and regulation of immune cells. Therefore, there exists a need to identify molecular mediators of myofibroblast activity to therapeutically target these pathways and regulate the fibrotic response following cardiac injury. It has been demonstrated the suppression of the transcription factors Yap and Wwtr1 dramatically reduces myofibroblast activity, but the mechanisms by which these Hippo pathway factors mediate pathological remodeling remain relatively unknown. Recently, we have characterized the secreted matrix protein Ccn3 as an element of pathological remodeling. Regulated in part by the Hippo pathway, fibroblast expression of Ccn3 increases shortly after infarction. Administration of recombinant human CCN3 dramatically promoted cardiopathology in adult mice following injury, resulting in exacerbated injuries, reduced cardiac function, and expression of the pro-fibrotic Tgfβ1 pathway. Treatment of cultured cardiac fibroblasts with CCN3 resulted in increased expression of the fibrotic factors such as
Fn1, Serpine1, and Ccn2.
Conversely, genetic knockout of Ccn3 specifically in myofibroblasts promoted improved cardiac function following infarction as compared to injured control mice. Thus, Ccn3 is an enticing target for therapeutic strategies to suppress pathological remodeling.
Abstract P2032: Wnt5a Mediates Doxorubicin-induced Cardiomyopathy Through Induction Of Senescence
Authors: Sung Eun-Ah , Sadoshima Junichi
Published: October 2023

Heart failure and cancer are major causes of death in the United States. Doxorubicin (DOX) is a commonly used chemotherapeutic agent. However, its clinical use is restricted due to cardiotoxicity, which can cause cardiomyopathy as well as heart failure. Senescence is defined by irreversible cell cycle arrest, resistance to apoptosis, and a senescence-associated secretory phenotype (SASP). Elimination of senescent cells improves cardiac dysfunction, suggesting that senescent cardiomyocytes (CMs) contribute to impaired heart function. Although DOX-induced senescence has been shown to occur in CMs, little is known about the mechanisms mediating DOX-induced cardiomyopathy. Wnt5a, one of the most studied non-canonical Wnt ligands, has emerged as an important player in cardiac diseases. mRNA expression of Wnt5a is upregulated in induced pluripotent stem cells (iPSC)-derived CMs from patients with end-stage heart failure induced by DOX chemotherapy. However, the role of Wnt5a in mediating the progression of DOX-induced cardiomyopathy remains elusive. We found that Wnt5a protein expression is markedly increased in mouse hearts with DOX-induced cardiomyopathy. Upregulation of Wnt5a following DOX treatment was also observed in neonatal rat CMs (NRCMs), and the degree of upregulation was more prominent in CMs than in non-CMs. We tested whether Wnt5a induces the senescent phenotype in NRCMs. Wnt5a not only induced an increase in p16 protein levels but also increased the number of γH2AX foci per cell and SA-β-gal activity in NRCMs. Wnt5a knockdown markedly reduced DOX-induced increases in p16 protein levels in NRCMs. These results suggest that DOX may induce cardiomyopathy through Wnt5a-mediated induction of CM senescence. Wnt5a may be a novel therapeutic target for the prevention of DOX-induced cardiac dysfunction.
Abstract P2035: Rad Reduction Improves Heart Failure
Authors: Satin Jonathan , Elmore Garrett , Ahern Brooke , Levitan Bryana , Miller Jessica , Abouleisa Riham , Correll Robert N , Dupont Alec , Wen Yuan , Sebastian Andrea , Gao Erhe , Mohamed Tamer , Andres Douglas A
Published: October 2023

Background:
Heart failure with reduced ejection fraction (HFrEF) entails depressed systolic function. Targeting calcium handling provides a direct, restorative treatment for the loss of systolic function. We recently showed that induced, cardiomyocyte-restricted Rad knockout mice (cRadKO) show increased trigger Ca
2+
with improved contractility and no signs of pathological remodeling.

Hypothesis:
In the present study we tested the hypothesis that cRadKO provides inotropic support to hearts subjected to chronic pressure overload.

Results:
We first show that Rad-reduction in human myocardial slices provides an inotropic boost. We then performed transverse aortic constriction (TAC) in mice. cRadKO imposed either before TAC or 1-month after TAC promoted survival and attenuated cardiac remodeling. cRadKO induced after TAC reflects an interventional proof-of-principle that Rad reduction can attenuate heart failure progression. The intervention timeline group was further probed using bulk RNA sequencing. cRadKO attenuated key fetal gene program transcripts including NPPA, NPPB, and MYH7. RCAN1 levels were decreased with cRadKO consistent with reduced calcineurin-NFAT signaling, and BIN1 levels were restored in cRadKO, suggesting improved cardiac remodeling despite ongoing pressure overload.

Conclusions:
The prevention (cRadKO before TAC) and intervention (cRadKO after TAC) studies demonstrate that reduced Rad levels can provide an inotropic boost in HFrEF and stimulate transcriptional effects consistent with reparative remodeling.
Abstract P2068: β
Iv
-spectrin/stat3 Are Responsible For Concentric Versus Eccentric Cardiac Hypertrophy
Authors: Nassal Drew , Mohta Shivangi , Patel Nehal , xu Xianyao , Han Mei , Divekar Arnav , Leahy Nicholas , Mohler Peter J , Hund Thomas J
Published: October 2023

Hypertrophy is critical to development of heart failure following cardiac stress. In pressure overload, hypertrophy is divided by early concentric and chronic eccentric orientations, however, the mechanisms regulating this transition and the impact on heart function are largely unknown. Previous work identified the structural protein β
IV
-spectrin and its interaction with the transcription factor, STAT3, in coordinating hypertrophic profiles. Specifically, mice expressing truncated β
IV
-spectrin lacking interaction with the kinase CaMKII (

qv
3J

mice) resisted β
IV
-spectrin degradation and maintained concentric hypertrophy and systolic function compared to WT following 6 weeks transaortic constriction (TAC). Alternatively, mutant β
IV
-spectrin mice lacking the β
IV
-spectrin/STAT3 binding domain (

qv
4J

) expressed reduced EF and LV dilation, consistent with eccentric remodeling, suggesting β
IV
-spectrin/STAT3 is a regulator of cardiac profiles. This relationship was examined by adenoviral expression of the hypertrophic driver MEK1/2 on isolated myocytes, where MEK increased the width of WT cells but length in

qv
4J

. Notably, application of STAT3 inhibitor S3I-201 on

qv
4J

myocytes restored growth in width. Additionally,
in vivo
delivery of S3I-201 to WT mice after 6 weeks TAC reduced LV dilation and recovered systolic function. To enable hypertrophy, recent work identified the need for microtubules to traffic and locally translate sarcomeric transcripts. Therefore, we tested the hypothesis that β
IV
-spectrin/STAT3 direct orientation by altering microtubule stability and sarcomeric transcript trafficking. Isolated myocytes from WT and

qv
4J

mice were treated with the microtubule depolymerizing drug Nocodazole and then washed to evaluate microtubule repolymerization. Microtubules restored faster in

qv
4J

myocytes but could be reduced to WT levels by treating with S3I-201. Furthermore, localization of the sarcomeric gene,
actc1
(α-actinin) by RNAScope showed more peripheral localization in

qv
4J

myocytes, compared to WT, and was normalized by S3I-201. Together, these data identify β
IV
-spectrin/STAT3 as modulators of microtubule dynamics, sarcomeric transcript distribution, hypertrophic orientation, and systolic function.
Abstract P2076: Disrupting Nicotinamide Nucleotide Transhydrogenase Prevents Cardiometabolic Heart Failure With Preserved Ejection In Mice.
Authors: Pepin Mark E , Konrad Philipp , Nazir Sumra , Dewenter Matthias , Backs Johannes
Published: October 2023

Heart failure with preserved ejection fraction (HFpEF) represents a common clinical endpoint of cardiometabolic diseases which impair myocardial diastolic relaxation and/or stiffness. Although myocardial redox perturbations are known to accompany HFpEF, their contribution to its pathogenesis has not been clearly demonstrated. Therefore, our multi-cohort murine study sought to determine whether constitutive expression of NNT, a mitochondrial transhydrogenase that couples NADPH:NADP
+
to NADH:NAD
+
homeostasis, is required for the cardiometabolic manifestations of HFpEF in mice. Four cohorts of 12-week-old male and female mice with wild-type (NNT
+/+
) or mutant (NNT
-/-
) NNT were supplied a combined high-fat and 0.5% N(ω)-nitro-L-arginine methyl ester (HFD-LNAME) diet for 9 weeks (n = 6-10). Although male NNT
+/+
mice developed expected increases in body weight (23.2% Δ,
P
= 0.003), hypertension (24 ± 5 Δ mmHg,
P
= 0.02), impaired glucose tolerance (
P
= 0.006), and reduced maximal treadmill running distance (-172 ± 73.1 Δ m,
P
= 0.006) following 9 weeks HFD-LNAME, male NNT
-/-
mice were protected against such cardiometabolic dysfunction. As previously shown, female mice failed to develop cardiometabolic dysfunction independent of NNT genotype. Cardiac phenotyping via echocardiography and invasive PV-loop analysis revealed increased E/e’ (42.8 vs. 21.5,
P
< 0.001) and E/A (2.3 vs 1.4,
P
= 0.007) ratios, diastolic stiffness (0.09 vs 0.04 mmHg/μL,
P
= 0.02), and myocardial fibrosis (
P
= 0.02). Myocardial transcriptomic analysis via RNA-sequencing revealed robust unsupervised clustering of both genotypic and dietary groups, which ultimately showed disproportionate perturbations mitochondrial metabolic and redox signaling intermediate genes. Our search for putative transcriptional regulators identified NAD
+
deacetylase
Sirt3
as an NNT-dependent oxidative response gene that appears to underlie cardiometabolic HFpEF. Taken together, these observations support that the loss of NNT protects against nitrosative stress-induced cardiac and metabolic consequences of HFD-LNAME in mice, thus highlighting a novel therapeutic avenue for HFpEF.
Abstract P2077: FoxO3 Transcription Factor Regulates Myocyte Contractility And Calcium Homeostasis In Diabetic Cardiomyopathy
Authors: Bhardwaj Gourav , Penniman Christie , Tadinada Satya Murthy , Shi Qian , Chen Biyi , Nowers Colette , Weatherford Eric T , Abel Evan dale , Song Long-Sheng , O'Neill Brian
Published: October 2023

Diabetes is a risk factor for heart failure with preserved ejection fractions (HFpEF). Calcium (Ca
2+
) mishandling and diastolic abnormalities are the characteristics of diabetic cardiomyopathy (DCM), but the molecular mechanisms of these are elusive. FoxO transcription factors (FoxOs) are suppressed by insulin and this study evaluated the role of FoxO3 in myocardial contractility and Ca
2+
handling in the heart of a mouse model of type 1 diabetes. We show that cardiomyocyte-restricted deletion of FoxO3 (H-FoxO3 KO) prevented reduction in the peak rate of left ventricular (LV) pressure (dP/dt max) and prevented the increase in the minimum rate of fall in LV pressure (dP/dt min) that was evident after 4-7 weeks of Streptozotocin (STZ) diabetes. Time for pressure decay of LV while relaxation (Tau) was partially increased in STZ hearts and tended to decrease in STZ H-FoxO3 KO. Echocardiography showed LVEF was unchanged in control and H-FoxO3 KO animals treated with/without STZ. Ca
2+
imaging in perfused hearts found that Ca
2+
transient amplitude was decreased and decay kinetics prolonged (indicates decreased SERCA activity) in STZ hearts, but these changes were prevented in STZ H-FoxO3 KO. Phosphorylation of SERCA at Thr484 by SPEG (Striated muscle preferentially expressed protein kinase) controls Ca
2+
re-uptake and cardiac contractility. We show that STZ diabetes decreases SPEG protein and pSERCA2a
Thr484
, but levels of each were normalized or increased in STZ H-FoxO3 KO. Mechanistically, overexpression of FoxO3 in neonatal cardiomyocytes increases high-molecular weight SPEG adducts when proteasome degradation was inhibited with MG-132, suggesting that ubiquitin-mediated degradation of SPEG is a mechanism by which FoxO3 controls Ca
2+
handling via SERCA phosphorylation. SERCA function requires ATP, thus, we evaluated mitochondrial energetics in these animals. Respiratory capacity in saponin-permeabilized cardiac fibers was unchanged in hearts from controls and H-FoxO3 KO treated with/without STZ. ATP generation was decreased in STZ hearts but was not normalized in STZ-H FoxO3 KO. These data indicate FoxO3 regulates myocyte contractility via SPEG degradation to control intracellular Ca
2+
via pSERCA2a
Thr484
in the heart in a type 1 diabetes model.
Abstract P2091: Histone Deacetylase 6 (HDAC6) Inhibitor Improves Stress-Induced Cardiomyocyte Restructuring in Heart Failure with Preserved Ejection Fraction (HFpEF) in a Multimodal Manner Based on Single Nucleus RNA-seq (snRNA-seq) Analyses
Authors: Farshidfar Farshad , Kozubov Matthew , Shenwai Reva , Hosseinian Amir , Yang Jin , Zeng Aliya , Wu Iris , Greer-Short Amara , Mackay Charles , Priest James , Hoey Timothy
Published: October 2023

In the high fat diet (HFD)/L-NAME mouse model of HFpEF, Ranjbarvaziri
et al
from Tenaya Therapeutics have previously shown that pharmacological inhibition of HDAC6 improves functional and structural cardiac metrics, together with improved oxidative phosphorylation, improved contraction, and reduced fibrosis. Tissue level as well as single cell level transcriptional studies of control, HFD + L-NAME HFpEF, and HFD + L-NAME HFpEF treated with either HDAC6 inhibitor TYA-018 or SGLT2 inhibitor empagliflozin, demonstrated extensive reversal of disease phenotypes in mice treated with TYA-018. Based on snRNA-Seq analyses, we report characterization of cardiomyocyte (CM) subtypes in HFpEF that establish specific and substantial cell-cell interactions with their surrounding fibroblasts and endothelial cells. These interactions initiate CM-subtype-specific signaling cascades, leading to emergence of ‘stressed’ hypoxic CM and hypercontractile CM subtypes. We show that these cell types increase in the HFpEF disease state. The proportion of ‘stressed’ CMs at tissue level corresponds to the worsening cardiac functional measures, and their composing fractions in left ventricle tissue decline and normalize after TYA-018 treatment. These findings suggest HDAC6 inhibition may regulate undesirable HFpEF phenotype characteristics such as dysregulated metabolism, fibrosis and hypertrophy, and also present detailed cell-level evidence of HDAC6 inhibition’s favorable effects in metabolic syndrome.
Abstract P2113: Zdhhc7 Uniquely Influences Cardiac Fibroblast Activity Amongst Golgi-localized S-acyltransferases
Authors: Goldsmith Robert , Scissors Rachel , Brody Matthew
Published: October 2023

Cardiac fibroblasts (CF’s), the heart’s most critical regulators of the extra-cellular matrix, can undergo a continuum of activation states when stimulated that influence their proliferation, migration, collagen production, and cell-to-cell communication in response to injury. The signaling pathways that underlie this transformation though, are poorly understood. Previous studies have shown zDHHC3, an S-acyltransferase enzyme that mediates the reversible lipid modification, palmitoylation, to be important in cardiac remodeling in cardiomyocytes due to its ability to regulate intracellular signaling, though the role of zDHHC enzymes and palmitoylation in CF signaling are unknown. To investigate this, we deleted zDHHC3 or the closely related enzyme, zDHHC7, in cardiac fibroblasts to screen for changes in fibroblast activity and myocardial fibrosis. Loss of zDHHC7, but not zDHHC3, resulted in increased expression of the activated cardiac fibroblast marker α-smooth muscle actin in response to TGFb stimulation and a trend towards increased mRNA levels of fibrotic genes. More notably, zDHHC7 deletion significantly blunted migratory ability of adult cardiac fibroblasts in scratch assays. These data suggest zDHHC7 plays a critical role in CF signaling, and future experiments include analyzing the impact of zDHHC3/7 deletion alone or in combination on cardiac fibrosis and identifying key substrates and pathways being modified by these enzymes in CFs.
Abstract P2116: Role Of Cardiomyocyte Specific Pellino-1, An E3 Ligase On Therapeutic Angiogenesis And Attenuation Of Ventricular Remodeling In A Murine Myocardial Infarction Model
Authors: Kemerley Andrew , Pradeep Seetur R , Thirunavukkarasu Mahesh , Accorsi Diego , Swaminathan Santosh , Lim Sue Ting , Hubbard Jennifer , Yee Siu-Pok , Maulik Nilanjana
Published: October 2023

Ubiquitination plays a vital role in our system in controlling vascular inflammation, cellular protein quality control, and minimizing misfolded protein toxicity. Pellino1 (Peli1), a type of E3 ubiquitin ligase, has emerged as a critical regulator of the innate immune response; however, its role in the repair and regeneration of ischemic myocardium remains to be elucidated.

Materials:
Cardiomyocytes isolated from Wild type (WT), cardiomyocyte-specific Peli1 overexpressed (AMPEL1Tg/+), and cardiomyocyte specific Peli1 knockout (CP1KO) mice were cultured and exposed to 6 h hypoxia, and the conditioned media (CM) collected. CMs were used to treat mouse cardiac endothelial cells (MCECs) followed by H2O2 treatment. Cells were used for Western blot, Flow cytometry, and scratch analyses. For in vivo myocardial infarction (MI) model, animals were exposed to left anterior descending artery (LAD) ligation. Animals were divided into (a) WT, (b) AMPEL1Tg/+(c) CP1KO and subjected to sham (S) and MI.

Results:
In vitro study documented faster wound closure and increased expression of angiogenic factors (pFlk-1, Ang-1 and VEGF) with MCECs treated with CM obtained from AMPEL1 compared to the other CM obtained from CP1KO and WT. There was no change in cardiac functions between Sham groups. AMPEL1Tg/+ MI group, showed preserved systolic functions, represented by both EF [n=12-14, p<0.0001] and FS [n=12-14, p<0.0001] compared to WTMI. However, CP1KO MI showed loss of systolic function, as represented by EF [n=13, p=0.03] and FS [n=13, p=0.03] compared to WTMI. The extent of fibrosis is also reduced in AMPEL1MI [n=5, p=0.0031], but increased in CP1KOMI [n=6-7, p<0.0001] compared to WTMI. Capillary n=4-5, p=0.0010] and arteriolar density [n=5, p=0.0005] were increased in AMPEL1MI but reduced in CP1KOMI [n=6, p<0.0001]; [n=5-7, p=0.02] compared to WTMI. Western blot analysis documented increased survival and angiogenic factors (pAKT, VEGF, and Bcl2) in AMPEL1MI compared to CP1KOMI and WTMI.

Conclusion:
Our study uncovers the role of cardiomyocyte-specific Peli1 as a regulator of repair and regeneration of ischemic myocardium, as evidenced by preserved cardiac function, increased expression of angiogenic factors, and reduction of apoptotic markers in the MI model.
Abstract P2118: Intervention With The Adiponectin Mimetic Peptide ALY688 Protects Against Cardiac Dysfunction Induced By Ischemia Reperfusion Injury
Authors: Tang Jialing , Sung Hye Kyoung , Wu Jun , Li Ren-Ke , Pignalosa Angelica , Hsu Henry , Sweeney Gary
Published: October 2023

Cardiac ischemia reperfusion injury is associated with significant morbidity and mortality for which there remains a great clinical unmet for effective therapeutics. Adiponectin mediates numerous cardioprotective effects and there has been significant interest in developing adiponectin-based therapeutics. The objective of this study was to evaluate the cardioprotective effect of ALY688 on myocardial remodelling at 48 hours post ischemia reperfusion injury, and cardiac function after 28 days. We used a rat model of myocardial ischemia for 45 min followed by reperfusion ± intravenous ALY688 administration during either ischemia or reperfusion followed by daily subcutaneous injection for 28 days. Acute phase (48h) analysis indicated that, compared with vehicle, ALY688 intervention during ischemia or reperfusion reduced cardiac injury indicated by circulating troponin I level, myocardial DNA oxidation and lipid peroxidation and in tissue sections we observed lower TUNEL staining, neutrophil infiltration and macrophage 1 polarization. Further analysis of inflammation indicated an increase of the pro-resolution cytokine IL-10 and Treg content via Foxp3 detection in animals treated with ALY688. Importantly, echocardiography indicated that after 14 and 28 days ALY688-treated animals had significantly improved cardiac function as well as reduced infarct size. This was associated with reduced fibrosis by Masson trichrome, scanning electron microscopy and established markers of fibrosis at the protein and mRNA level. Overall, our data provide strong evidence for the cardioprotective effects of adiponectin mimetic peptide ALY688 as a novel therapeutic strategy in treating ischemia reperfusion injury.
Abstract P2125: Melatonin As A Strategy To Mitigate Late Doxorubicin-induced Cardiotoxicity
Authors: Fernandez Ortiz Marisol , Davis Logan , Gius David , Aune Gregory
Published: October 2023

There are more than 500,000 childhood cancer survivors in the USA. These patients have an elevated risk of developing life-threatening health problems, cardiovascular disease being the main cause of early mortality in this population. Most of these survivors received anthracyclines. These antitumor agents are the benchmark for treatment in pediatric and adult oncology. Doxorubicin (DOX) is the most used anthracycline due to its high efficacy against solid cancer and hematological malignancies. With the improvements in five-year survival rates and growing survivor population, the long-term wellbeing of these cancer survivors is a primary healthcare concern.The clinical utility of DOX is compromised by its link to cardiac disease development after a long asymptomatic period preceding cardiac dysfunction and irreversible heart failure. A mechanism proposed for this late
DOX
-
i
nduced
c
ardiotoxicity (
DOXIC
) is the accumulation of DOX in cardiac fibroblasts (CFs), a key cell type in cardiac maturation and injury response, which increases mitochondrial oxidative stress, declining heart function over decades. The use of a safe approach against DOXIC without impeding the antitumor activity of DOX is a major clinical challenge.Our study proposes melatonin (aMT) as a strategy against late DOXIC. This mitochondria-targeted antioxidant has been reported to enhance the efficacy of chemotherapy and has been used safely in patients even at high doses. Our
in vitro
results showed that young primary murine CFs presented higher proliferation and fewer dead cells with continuous exposure to aMT post-DOX treatment (% of death at 24h: 100% in DOX 3uM 3h, 86% DOX + 5uM aMT, 7% DOX + 10uM aMT, 0% DOX + 20uM aMT). Our i
n vivo
results proved that aMT protected against early DOXIC in young mice, with a fractional shortening (FS) similar to vehicle. Furthermore, aMT was used as a rescue strategy in mature mice with impaired cardiac function. This aMT intervention recovered FS from 28 to 39%, suggesting aMT could counteract late DOXIC. These experiments produce the first data of this kind using aMT as a preventive and rescue strategy to mitigate late DOXIC with an approach that is closely aligned with the cardiac outcomes noted in childhood cancer survivors decades after DOX exposure.
Abstract P2126: Role Of Microrna-98 In Myocardial Ischemia-reperfusion Injury In Late Pregnancy
Authors: Aryan Laila , Medzikovic Lejla , Li Min , Ruffenach Gregoire , Rahman Shadie , Bastanhagh Ehsan , Esdin Leana , Sun Wasila , Afshar Yalda A , Eghbali Mansoureh
Published: October 2023

Background:
We have shown that the late-pregnant (LP) rodent is more vulnerable to myocardial ischemia-reperfusion injury (IRI) compared to non-pregnant (NP). The molecular mechanisms are unknown. Several microRNAs (miRs) are dysregulated in IRI, making them promising therapeutic targets.

Methods:
The left anterior descending coronary artery (LAD) of female Sprague-Dawley rats (2-3 months old NP and LP, 20-21 days pregnant) was occluded for 45 minutes followed by 3 hours reperfusion. Myocardial necrosis was assessed using TTC staining. MicroRNA-microarray profiling was performed on hearts of NP and LP rats subjected to IRI. In vitro, female cardiomyocytes were transfected either miR98 mimic or inhibitor, followed by 3 hours hypoxia and 6 hours reoxygenation. Blood samples were collected from NP, LP, and coronary heart disease (CHD) patients. To assess therapeutic potential of miR, miR98 inhibitor was administered at the onset of reperfusion.

Results:
MicroRNA-microarray profiling revealed miR-98-5p (miR-98) is upregulated in the hearts of LP IRI rats compared to NP IRI by 2.3 folds, which we confirmed with qPCR. miR98 is significantly increased in the plasma of healthy LP compared to healthy NP women, and significantly increased in LP with CHD compared to healthy LP. TargetScan revealed STAT3 and PGC-1α to be targets of miR98. We confirmed significantly decreased expression of STAT3 and PGC-1α in LP IRI rat myocardium compared to NP IRI. MiR98 overexpression in female cardiomyocytes subjected to hypoxia/reoxygenation (H/R) decreased STAT3 and PGC-1α, and increased apoptosis, inflammation, and oxidative stress, while miR-98 knockdown resulted in the opposite effect. Therapeutic targeting of microRNA-98-5p in LP rats subjected to IRI reduced infarct size, apoptosis, oxidative stress, and inflammatory markers via upregulating Stat3 and Pgc-1α.

Conclusions:
MiR98 is upregulated in LP rats subjected to IRI compared to NP IRI and in LP human plasma samples with CHD compared to healthy NP and LP. miR98 promotes oxidative stress, inflammation, and apoptosis in the setting of H/R
in vitro
by targeting STAT3 and PGC-1α. Inhibition of miR-98 in LP rats reduces myocardial infarct size, apoptosis, oxidative stress, and inflammation via Stat3 and Pgc-1α.
Abstract P2131: Sialidase Neu3: A Novel Cardioprotective Target Against Ischemia And Reperfusion Injury
Authors: Piccoli Marco , Coviello Simona , Lavota Ivana , Ghiroldi Andrea , Cirillo Federica , Pappone Carlo , Anastasia Luigi
Published: October 2023

Coronary reperfusion techniques are life-saving approaches to restore blood flow to cardiac tissue after acute myocardial infarction. However, they also lead to what is known as ischemia and reperfusion injury (IRI), which causes additional damage and heart failure. Despite the urgent need for cardioprotective strategies against IRI, none has yet been introduced into clinical practice, suggesting that a more detailed characterization of the molecular mechanisms underlying the pathogenesis of IRI is essential. In this regard, our research group has shown that sialidase Neu3, an enzyme responsible for removing sialic acid from glycosphingolipids, is modulated during IRI in vivo and that its constitutive overexpression in rat cardiomyoblasts is sufficient to counteract the deleterious effects of IRI through activation of reperfusion injury salvage kinase (RISK) and the HIF-1α pathway.

Thus, in this study, we developed an inducible model of Neu3 overexpression in human cardiac cells (AC16) and in mice to further elucidate the role of this protein in promoting cardioprotection.

Inducible upregulation of Neu3 significantly increased cell resistance and reduced oxidative stress in AC16 exposed to IRI in vitro. These beneficial effects were related to Neu3-mediated maintenance of mitochondrial membrane potential, which was altered in control cells. Moreover, RNAseq data showed that Neu3 activation was associated with upregulation of the cellular responses to stress, whereas, in contrast, the pro-inflammatory signaling pathways of TNF-α and IL-22 were downregulated.

We also generated αMHC-Cre/LSL-Neu3 mice for the first time by crossing the tamoxifen-inducible αMHC-Cre mouse with a mouse carrying a floxed-transcriptional STOP sequence upstream of Neu3. These mice were characterized for cardiac morphology and functionality and showed no significant differences compared with wild-type mice. They will undergo surgical induction of IRI to test the beneficial effects of Neu3. Based on our findings, it can be hypothesized that Neu3 plays a significant role in the cardiac response to IRI. Consequently, targeting Neu3 may hold therapeutic promise in increasing cardioprotection and mitigating the incidence and severity of myocardial infarction.
Abstract P2144: Irisin, An Exercise-induced Myokine, Exhibits Protective Effects In Glucocorticoid-induced Cardiac Muscle Dysfunctions
Authors: Sheng Christina Y , Son Young Hoon , Park Sung J
Published: October 2023

Myocardial infarction caused by pharmacological substances, such as anti-inflammatory drugs, is a serious adverse drug effect in the cardiovascular system that often causes heart failure. Dexamethasone (DEX), a synthetic glucocorticoid, is commonly used as potent anti-inflammatory and immunosuppressive drugs, but is classified as one of the prime suspects of drug-induced acute myocardial infarction. High dose of DEX increased oxidative stress of the heart, induced myocardial degeneration and cardiomyocyte apoptosis and impaired cardiac contraction. Thus, therapeutic approaches are required to alleviate glucocorticoids-induced cardiotoxicity and prevent DEX-mediated cardiac complications. Exercise-induced secretion of irisin showed the beneficial effects against cardiovascular diseases on energy metabolism, anti-oxidant effects, and decreased inflammation and apoptosis by promoting mitochondria biogenesis, decreasing oxidative stress and inflammatory responses, and regulating intracellular calcium signaling. In this study, we investigate the endocrine effects of muscle-secreted irisin against DEX-induced cardiotoxicity. We engineered anisotropic human induced-pluripotent stem cell-derived cardiomyocyte tissues and designed three experimental groups: control, dex treatment, and dex plus irisin treatment. We then analyze the tissues with qPCR, immunostaining (muscle atrophy markers), contractility assay, and oxygen consumption assay to evaluate the protective effects of irisin on DEX-induced cardiac injury. Injured cardiac tissues showed systolic dysfunction by decreasing oxygen consumption, increasing muscle atrophy marker (MuRF-1), and significantly reducing systolic contractile force, but not diastolic stress. In contrast, these DEX-induced maladaptive responses was alleviated by irisin pretreatment by reducing proteolytic activity and muscle atrophy signaling pathways and promoting mitochondria biogenesis. In conclusion, our micro-physiological system showed the therapeutic effects of irisin against DEX-induced cardiotoxicity.
Abstract P2146: Endothelial Cell Specific Senescent Cell Clearance Alleviated Vascular Stiffness And Metabolic Dysfunction In Obese Mice
Authors: Suda Masayoshi , Huang Runqing , Roos Carolyn M , Leon Luisa , Tripathi Utkarsh , Miller Jordan D , Tchikonia Tamar , Kirkland James
Published: October 2023

Aging is the leading predictor of acquired cardiovascular disease (CVD), and emerging evidence suggests cellular senescence plays a causal role in development of clinically-significant CVD. While we previously reported that senescent cell elimination delays or prevents progression of several aging phenotypes in aging mice, the responsible types of senescent cells contributing to cardiovascular dysfunction
in vivo
are not yet elucidated. To test the hypothesis that senescent endothelial cells are a major contributor to cardiovascular dysfunction, we developed
Tie2-Cre;

p16
Ink4a
-
LOX-ATTAC

mice, which allows for specific elimination of

p16
Ink4a+

senescent endothelial cells upon administration of AP20187 (which only affects cells carrying the conditionally-expressed
ATTAC
construct). Using a mouse model of diabetic vascular disease (40% fat diet for 12 weeks , HFD), we found that biweekly selective removal of senescent endothelial cells alleviated HFD-induced endothelial dysfunction in aorta (assessed
ex vivo
using isolated organ baths). Additionally, ejection fraction (assessed using
in vivo
echocardiography) was preserved in AP20187-treated mice (driving ATTAC-dependent removal of senescent endothelial cells) compared to their vehicle-treated controls (76.6%±4.2, 63.2%±4.2). In addition to improvement in cardiovascular function, metabolic parameters (HbA1c and fasting glucose levels) were improved by senescent endothelial cell elimination. Collectively, these data suggest that elimination of

p16
Ink4a+

senescent endothelial cells may be a viable therapeutic strategy for alleviation of metabolic disease-induced cardiovascular dysfunction.
Abstract P2156: Endothelium-targeting Exosomes Ameliorate Cardiac Senescence Via Delivery Of Line1 Antisense Oligonucleotides In A Mouse Model Of Myocardial Infarction
Authors: Fu Enze , Liu Yue , Pan Kai , Li Rongrong , Li Zongjin
Published: October 2023

Transposable elements (TEs), which include long-interspersed element-1 (LINE1) retrotransposon, highly constitute the genome of mammals and their dysregulation is considered the stimulatory factor of genomic damage and innate interferon response and unnatural senescence. The objectives of this study are to determine the functions of LINE1 retrotransposon during myocardial infarction (MI). In this study, selectins, CD62E and CD62P, are identified as the biomarker of the injured endothelial cells in MI. Furthermore, selectin binding peptide (SBP)-engineered extracellular vesicles (SBP-EVs) with targeting functions are developed. We further investigated the SBP-EVs with therapeutic effects by packing LINE1 antisense oligonucleotides (SBP-LINE1-EVs). The results show that SBP-LINE1-EVs exhibit a selective targeting tendency to injured heart with an enhanced myocardium protection effect by LINE1 antisense oligonucleotides delivery. SBP-LINE1-EVs protected against myocardial senescence by inhibiting the reactivation of the innate immune cGAS-STING-TBK1-IRF3 pathway and further repressing the expressions of senescence-associated secretory phenotype (SASP) factors. In conclusion, our findings establish the causal relationship among LINE1, cardiac senescence, and myocardial infarction for the first time. Moreover, we demonstrate the enhanced therapeutic efficacy of the bifunctional SBP-LINE1-EVs system and provide preclinical evidence for targeted therapy of MI by LINE1 inhibition in future clinical applications.
Abstract P2170: Rescue Of Ctni Null Mice By Application Of Aav-9 Encoding Ctni Gene
Authors: Gerber Dustin , Gacitua John , Hackshaw Andrue , Prentice Howard M , Huang Xupei
Published: October 2023

Background:
Heart diastolic dysfunction can be caused by cardiac troponin I (cTnI) deficiencies or mutations. Our lab has created a unique cTnI gene knockout mouse model, demonstrating that homozygous cTnI null mice (-/-) die at postnatal day 18 (p18). In this study, we have applied gene therapy using adeno-associated virus serotype 9 (AAV9) carrying wild-type cTnI gene to rescue mice from a lethal cTnI knockout phenotype.

Methods:
The proposed gene therapy strategies involve novel approaches delivering AAV9 via intraperitoneal injection in newborn cTnI mice (-/-), employing a cardiac-specific promoter (chicken cTnT promoter) to express cTnI protein in myocardial cells.

Results:
Mice treated with doses ranging from 2e10
10
vg/g (vector genome per gram) to 8e10
10
vg/g at p10 displayed an increased life span compared to mice without treatment. 5e10
10
vg/g multi-injection two-dose treatment at p10 and p14 demonstrated 22 additional days of life past p18 (
Figure A)
. Using echocardiography, treated mice showed significant improvement in left ventricular diastolic function compared to mice without treatment. In addition, western blotting of cardiac samples demonstrated restored cTnI proteins in treated mice.

Conclusion:
The
in vivo
gene therapy approach shows that our mouse model can survive 2-3 weeks longer than untreated cTnI null mice. These data suggest AAV-9 serotype with a cardiac-specific promoter is a promising tool in treating cardiomyopathies by restoring cardiac proteins and reversing diastolic dysfunction.
Abstract P2195: SARS-CoV-2 Variants Divergently Infect And Damage Cardiomyocytes
Authors: Mok Bobo , Kwok Maxwell , Li Hung Sing , Ling Lowell , Lai Angel , Chan Paul , Yan Bryan , Chen Hong Lin , Poon Ellen
Published: October 2023

SARS-CoV-2 variants are known to exhibit different tropism and pathogenicity in respiratory cells, but their effect on cardiomyocytes (CMs) is unclear. Cardiac infection and damage induced by SARS-CoV-2 variants were examined using Golden Syrian hamsters and human induced pluripotent stem cell-derived (hiPSC-) CMs. Omicron BA.2 efficiently infected CMs
in vitr
o and
in vivo
, induced the most severe phenotype, and exhibited transcriptomic changes indicative of a more pro-inflammatory phenotype and increased cardiac dysfunction, compared to other variants. Increased infectivity of Omicron BA.2 is attributed to its ability to infect independently of TMPRSS2, which is absent in CMs. Our pilot study of patients infected with Omicron BA.2 in Hong Kong revealed significantly higher plasma troponin levels, consistent with severe myocardial injury. Here we reveal previously unknown differences in how different SARS-CoV-2 variants damage CMs, and that Omicron BA.2, which is generally considered mild, can induce severe CM damage
in vitro
,
in vivo
and in a subset of patients.
Abstract P3013: Rare Case Of Catheter-related Right Atrial Thrombosis In A Pediatric Multi-visceral Transplant Patient
Authors: Girish Akanksha , Noe Niki , De Marchi Lorenzo
Published: October 2023

Introduction:
There has been a recent increase in the use of intraoperative transesophageal echocardiography (TEE) in liver transplant surgeries to identify intracardiac thrombi and pulmonary embolism (PE). These are rare but serious complications of transplant surgery that carry a high mortality risk. However, there is a lack of literature supporting the use of TEE during liver transplants, especially in pediatric cases.

Case Presentation:
We present a rare case of intraoperative catheter-related right atrial thrombus (CRAT) in a nine-year-old multi-visceral transplant (MVT) patient. This patient’s medical history was notable for preterm birth and gastroschisis complicated by neonatal necrotizing enterocolitis resulting in short-gut syndrome. He had a significant surgical history, including intestinal resection, Hartmann Procedure, and cholecystectomy, after which he developed non-cholestatic liver disease. He was admitted for MVT for intestinal failure associated with ESLD. The procedure was complicated by massive hemorrhage during the dissection phase, significant coagulopathy after engrafting the donor liver, profound hemodynamic instability requiring inotropic drug support, and multiple instances of intraoperative CPR. Intraoperative TEE identified right atrial thrombi around the central venous line. The patient developed RV dysfunction and PEA secondary to PE on two occasions and received a total of 4 mg tissue plasminogen activator (tPA). In both cases, ROSC was achieved after thrombolysis. Due to profound coagulopathy and massive blood loss (70 liters), the completion of the surgery was postponed, and the patient left the operating room with an open abdomen. The patient’s postoperative course was complicated by hemodiafiltration, ureteral resection with reimplantation to bladder, pyloroplasty, appendectomy, small bowel resection, end colostomy and double-barrel ileostomy. The patient eventually developed a subarachnoid hemorrhage on POD3 and expired.

Conclusion:
This case highlights the importance of utilizing intraoperative TEE in pediatric liver transplant surgeries to diagnose intracardiac thrombi and PE.
Abstract P3016: Pathologic Matrix Markers Are Differentially Modulated By VSMC-Specific SGK-1 Activity In Hypertension And Abdominal Aortic Aneurysm
Authors: Mattia Victoria , Figueroa Mario , Gedney John , xiong Ying , Mukherjee Rupak , Jones Jeffrey A , Ruddy Jean Marie
Published: October 2023

Introduction:
The VSMC switch to synthetic phenotype promotes aortic pathology such as hypertension (HTN) and abdominal aortic aneurysm (AAA). Mechanical activation of serum and glucocorticoid inducible kinase-1 (SGK-1) alters the VSMC synthetic profile to promote remodeling. Plasma biomarkers may represent opportunities to assess VSMC function in aortic disease, and we hypothesize that analysis of a panel of plasma pathologic matrix markers (PMM) representing synthetic VSMC phenotype can reflect SGK-1-dependent activity.

Methods:
HTN was induced in wild-type C57Bl/6 (WT) and smooth muscle cell specific SGK-1 knockout (SMC-SGK-1KO
+/-
) mice with AngiotensinII infusion (1.46mg/kg/day, n=4-6). Separate mice underwent AAA induction by peri-adventitial CaCl
2
application (n=4-6). Terminal procedure included collecting systolic blood pressure (SBP), aortic diameter (AoD), and plasma. ELISA for PMMs included Interleukin-6 (IL-6), Matrix Metalloproteinase-9 (MMP-9), Cathepsin S (CtsS), and Cystatin C (CysC), Osteoprotegerin (OPG), and Tenascin C (TNC). Impact of the panel was evaluated by a composite T-score. Statistics included T-test and ANOVA.

Results:
WT+HTN had >30% increased SBP and elevation of IL-6, CtsS, CysC, and TNC (p<0.05). SMC-SGK-1KO
+/-
+HTN had equally elevated SBP, but no change in PMMs, suggesting that SGK-1 contributed to HTN-induced VSMC synthetic activity. WT+AAA had >65% increased AoD and elevation of all PMMs (p<0.05). Alternatively, SMC-SGK-1KO
+/-
+AAA had abrogated growth (29.4
+
3.6%, p<0.05 vs WT and WT+AAA) with IL-6, CtsS, CysC, and TNC returning to baseline, suggesting that SGK-1-dependent production of these PMMS was necessary for true AAA growth. Composite T-scores differed between Control, HTN, and AAA in WT mice (0.78
+
0.08 vs 2.91
+
0.29 vs 7.11
+
0.71 respectively, p<0.05). In SMC-SGK-1KO
+/-
mice, T-score normalized in HTN but remained elevated in AAA (2.19
+
0.21, p<0.05 vs Control and WT+AAA), attributable to the elevations in MMP-9 and OPG, peptides produced by inflammatory infiltrate.

Conclusion:
A panel of PMMs can be scored to reflect synthetic activity of VSMCs in aortic pathology, as well as response to inhibition, and warrants further investigation for the clinical care of patients with vascular disease.