tbuckley/cabot-search huggingface dataset:
Abstract Tu116: Neurofibromin 2 regulates metabolic gene expression and cardiac responses to pressure overload stress
Authors: Yu Zhang, Satvik Mareedu, Wataru Mizushima, Jamie Francisco, Jin Guan, Zhi Yang, Shinichi Oka, Peiyong Zhai, Maha Abdellatif, Junichi Sadoshima, Dominic Del Re
Journal: Circulation Research (2024)

Background: Neurofibromin 2 (NF2) is a tumor suppressor that can engage multiple signaling pathways to modulate cell proliferation and survival. We previously demonstrated that NF2 mediates cardiomyocyte apoptosis and cardiac injury caused by acute myocardial infarction. Research Aim: The role of NF2 in heart failure remains uncharacterized. This study sought to determine whether NF2 modulates heart failure due to chronic stress. Approach: We generated cardiomyocyte-specific NF2 knockout (cKO) mice, and used transverse aortic constriction (TAC) to generate chronic pressure overload (PO) stress, which elicits cardiac remodeling and failure. Complementary cell-based experiments were performed in neonatal rat ventricular myocytes (NRVMs). We analyzed cardiac function by echocardiographic and hemodynamic analysis. We used RNAseq, ChIP, Seahorse metabolic profiling, and biochemical analyses to investigate underlying mechanisms. Results: We found that NF2 is transiently upregulated in wild-type mouse myocardium in response to early phase of PO, but is downregulated during heart failure. Following TAC, NF2 cKO hearts unexpectedly showed significantly worsened cardiac function, compared to controls. RNAseq analysis indicated downregulation of several metabolic pathways and impaired ERR activity in NF2 cKO hearts. qPCR confirmed significantly reduced ERRβ and ERRγ transcripts and decreased metabolic gene expression. Experiments employing NRMVs confirmed that NF2 promoted expression of ERRβ and ERRγ, and DNA pulldown assays demonstrated NF2 association with ERRβ and ERRγ proximal promoters. Analysis of NRVM bioenergetics demonstrated that NF2 depletion impaired mitochondrial respiration, which was reversed by concomitant expression of ERRγ. Moreover, AAV9-mediated restoration of ERRγ in NF2 cKO mice normalized cardiac function in response to PO. Because NF2 does not directly bind DNA, ongoing studies are leveraging a proteomics-based approach to identify the mediator linking NF2 to ERR isoform expression. Conclusion: Based on these findings, we conclude that transient upregulation of myocardial NF2 expression during PO stress is compensatory and regulates metabolic gene expression according to energy demand.
Proteomic Analysis of Asthma Airway Inflammation Post-Allergen Challenge: A Heterogeneous Response
Authors: Mats W Johansson, Stephane Esnault, Robert J Millikin, John W Steill, Kristine E. Lee, Heather L. Floerke, Loren C Denlinger, Ron Stewart, Nizar N Jarjour, Matthew C Tattersall
Journal: American Journal of Respiratory and Critical Care Medicine (2024)
Abstract Mo139: PDE1, 3 and 4 Inhibition and GPCR Agonism in the Regulation of cAMP Signaling
Authors: Michael Fitch, Evan Kelly, Grace Muller
Journal: Circulation Research (2024)

Modulators of cardiac cyclic adenosine 3’5’-monophosphate (cAMP) and/or its effector protein kinase A (PKA) are used to treat heart disease. Elucidating the mechanisms of endogenous and pharmacological modulators of cAMP, including phosphodiesterase (PDE) inhibitors, is key to predicating alternative drug therapies for heart failure (HF). PDEs regulate confined cAMP/PKA signaling pathways, depending on PDE isoform and localization. PDE3 regulates the SR and sarcolemmal membrane cAMP pools, controlling calcium influx and efflux at these domains. PDE1 regulates sarcolemmal cAMP/PKA signaling. Despite these differences, inhibitors of either increase heart contractility. However, inhibition of PDE3 is pro-arrhythmic, unlike that of PDE1. The regulation of localized cAMP signaling is key to controlled regulation of cell function, with ramifications for HF, and which GPCR lies upstream of PDE1 remains unknown. We hypothesized that the three cAMP-hydrolyzing cardiac PDEs (1, 3, 4) that are found in the human heart would regulate distinct cAMP signaling pathways. Using the cAMP biosensor EPAC-SH187, we performed fluorescence resonance energy transfer experiments in healthy guinea pig adult ventricular myocytes. Cells were treated with inhibitors of PDEs 1, 3, and 4 along with GPCR agonists isoproterenol, glucagon (gcg), and amthamine (amt), respectively for β-adrenergic, gcg and histamine H2 receptors at sub-maximal doses. Cell function and calcium data were obtained using IonOptix. We first asked if PDEi would synergistically regulate pools of cAMP, and found that PDE4i does at pools of cAMP generated by beta-agonism. PDE3i regulates that generated by amt at the H2R, with comparable effects observed in simultaneous or prior H2R stimulation. The combination of these sub-saturating doses exerted strong inotropic and lusitropic effects in paced myocytes. In neither of these domains, PDE1i changed cAMP levels. However, PDE1i intriguingly attenuated the level of gcg-stimulated cAMP production, suggesting a feedback loop mechanism. We conclude that PDEs 1, 3, and 4 regulate distinct pools of cAMP. Importantly, we demonstrate this in a species where the myocardial expression of these PDEs match that of humans as opposed to smaller rodent models.
Abstract Or122: Noncoding regulation of epicardial gene expression and epithelial-to-mesenchymal transition during heart development
Authors: Joaquim Nunes Vieira, Carolina Roque Silva, Mariana Valenzuela Sanchez, Hannah Scheucher, Tiago Dias, Jacinta Kalisch-Smith, Duncan Sparrow, Mauro Giacca, Paul Riley
Journal: Circulation Research (2024)

During organogenesis, epicardial cells undergo epithelial-to-mesenchymal transition (EMT), contributing essential cell types and paracrine signalling to the growing heart. The epicardium is integral to heart regeneration in lower vertebrates and neonatal mammalian injured hearts. That said, prospects to harness the epicardium for therapeutic applications to effect adult heart repair, heavily depend on improved insight into its intrinsic properties in development. Cell fate decisions underpinning EMT are directed by transcription factors such as Wilms’ tumour 1 (WT1). Whilst a requirement for Wt1 in heart development is established, the mechanisms underpinning its activation remain elusive. We identified two e volutionary c onserved r egions (ECRs) shared in mouse and human, located within intron 1 of Wt1 locus. We hypothesised these regulatory sequences direct locus activation and EMT to support normal heart development. Here, we used CRISPR/Cas9 gene-editing technology to generate mice carrying a sequence deletion containing one ECR or a deletion comprising both ECRs. Extensive survival analysis, high-resolution episcopic microscopy (HREM), qPCR, immunostaining, confocal microscopy and epicardial explants were used to characterise heart formation. Mendelian ratios indicated an overall underrepresentation of Wt1 ΔECR/ΔECR mutants in adulthood. HREM revealed smaller hearts, incidence of myocardial non-compaction and spongy interventricular septum with muscular and membranous defects, tricuspid hypoplasia and enlarged aortic valves, as well as abnormal patterning of coronary artery stems in mutant hearts. Expression of Wt1 was markedly reduced in Wt1 ΔECR/ΔECR hearts but not kidneys, suggesting intronic enhancers are cardiac-specific. Whole-mount and tissue immunostaining revealed abnormal coronary vessel and innervation patterning in the subepicardium, as well as reduced EMT and myocardial non-compaction/hyper-trabeculation in Wt1 ΔECR/ΔECR . Collectively, we demonstrated a requirement for novel Wt1 intronic enhancers regulating locus activity and essential epicardial EMT-associated biological processes in normal heart development. Importantly, observation of septum and semilunar valve defects in Δ ECR hearts suggests an hitherto unrecognised role for WT1-driven EMT, opening new avenues of research to improve our understanding of congenital heart disease affecting at least 1:150 live births, with remarkably two thirds of cases having unknown aetiology.
Abstract Mo012: Optimizing Mouse Models of Doxorubicin Cardiomyopathy
Authors: Casie Curtin, Jing Liu, Sandeep Basu, Benjamin Weitzman, Jakob Wieke, Aarti Asnani
Journal: Circulation Research (2024)

Introduction: Anthracyclines such as doxorubicin (Dox) are effective chemotherapies that treat various cancers, including breast, lymphoma, and leukemia. While effective, their use is limited due to cardiac toxicity, leading to cardiomyopathy and heart failure. Background: Several Dox treatment regimens in mice have been reported in the literature, from acute high-dose models to chronic low-dose models. Many of these regimens cause fulminant cardiomyocyte apoptosis and heart failure within days, and they do not accurately recapitulate the human toxicity phenotype. Objective: Our goal was to identify a Dox dosing regimen in mice that causes the most consistent subacute/chronic cardiomyopathy, as seen in patients, with the least systemic toxicity. Methods: We administered four different Dox dosing regimens to C57BL/6N female and male mice, based on published protocols and our laboratory’s prior studies ( Fig. 1 ): #1: Dox 3mg/kg intraperitoneally (IP) every other day for two weeks (cumulative dose of 24mg/kg) or saline #2: Dox 5mg/kg IP twice a week for two and a half weeks (cumulative dose of 25mg/kg) or saline #3: Dox 5mg/kg IP once a week for five weeks (cumulative dose of 25mg/kg) or saline #4: Dox 5mg/kg intravenously (IV) once a week for four weeks (cumulative dose of 20mg/kg) or saline Cardiac function was assessed after five to seven weeks by echocardiography, prior to sacrifice. Hearts and blood were isolated for molecular analyses. Regimens were compared using a one-way ANOVA and multiple comparisons analysis. Results: Protocol #3 (Dox 5mg/kg IP once a week for five weeks; cumulative dose of 25mg/kg) demonstrated the most consistent difference in fractional shortening between male mice treated with saline compared to those treated with Dox, as assessed by echocardiography ( Fig. 2 ). This protocol resulted in the lowest mortality, as well as the least amount of systemic toxicity ( Fig. 3 ). Protocol #1 (Dox 3mg/kg IP every other day for two weeks; cumulative dose of 24mg/kg) was the only protocol that elicited a decline in fractional shortening in female mice treated with Dox compared to those treated with saline, as assessed by echocardiography. Conclusion: Going forward, protocol #3 (5mg/kg IP once a week for five weeks) will be implemented as the standard dosing regimen in our laboratory. Ensuring consistency in cardiac phenotypes will allow us to better understand the effects of modulating cardioprotective pathways on the development of Dox cardiac toxicity.
Abstract Mo018: Using a mitochondria-rich hiPSC-CM model to investigate doxorubicin-induced cardiotoxicity
Authors: BinBin Wu, Jack Chen, Maxwell Kwok, Chloe Ma, Ellen Poon
Journal: Circulation Research (2024)

Doxorubicin (DOX) is commonly used to treat cancer but can induce severe cardiotoxicity by damaging the mitochondria. Dexrazoxane is clinically approved to protect against DOX-induced cardiotoxicity (DCT) but has been shown to reduce the anti-cancer efficacy of DOX and cause secondary neoplasm. Human induced pluripotent stem cell derived-cardiomyocyte (hiPSC-CMs) models have been used to study DOX-induced cardiotoxicity (DCT), but some do not correctly recapitulate patient response to dexrazoxane. This was previously attributed to the low mitochondrial abundance of these cells and is a hurdle against the identification of new therapeutics against DCT. Our aim is to use our patient-derived, mitochondria-rich hiPSC-CM model to identify compounds which can protect against DCT. We first checked that our hiPSC-CMs recapitulate the cardioprotective effects of dexrazoxane. Using this validated model, we showed that compound I1 suppressed both the mitochondrial and non-mitochondrial damage induced by DOX, at levels that are comparable to that of dexrazoxane. However, unlike dexrazoxane and contrary to its effects in CMs, compound I1 was cytotoxic to a panel of cancer cell lines. Mechanistic investigations indicated that the divergent effects of CMs vs cancer cells is due the ability of compound I1 to inhibit two distinct molecular targets in the two cell types. Lastly, we validated that compound I1 can protect the heart in an in vivo mouse model of DCT. In summary, compound I1 offers the dual benefits of cardioprotection and tumour suppression and is potentially superior to conventional treatment. Our results provide important proof of principle that a single compound can be used to simultaneously target both the heart and cancer via different targets/pathways to improve clinical outcome.
Abstract Mo021: Role of Estrogen and Testosterone in promoting Sex Dimorphism in Doxorubicin Cardiotoxicity.
Authors: Katy Trampel, Paloma De Melo Amaral, Igor Efimov, Sharon Ann George
Journal: Circulation Research (2024)

Background: Doxorubicin (DOX), a cancer chemotherapeutic agent, causes sex-specific cardiotoxicity. Lower cardiotoxicity in females compared to males is typically attributed to the cardioprotective effects of estrogen (E2). However, the role of the sex hormones, E2 and testosterone (T), in modulating DOX induced cardiac dysfunction and its underlying mechanisms are not known. Methods: C57BL/6J mice were divided into four groups, 1) Control, 2) DOX (5 mg/kg/week for 6 weeks), 3) Reverse hormone profile (RevH, castrated males+E2 and ovariectomized females+T), and 4) RevH + DOX. Mouse morbidity was tracked daily. Total body weight and cardiac function was assessed biweekly for 6 weeks by echocardiography, ECG and optical mapping. Dependence on fatty acid versus glucose for metabolism was measured by seahorse analysis. Results: DOX treatment reduced total body weight (11%) in males, and increased morbidity in males and females. This was associated with reduced mechanical function (15% decrease in stroke volume) in males and electrical remodeling (29% action potential duration prolongation) in females. In RevH mice, no changes in morbidity or cardiac function were observed compared to Control. In RevH+DOX males, the onset of morbidity was delayed by two weeks compared to DOX males. This cardioprotective effect was associated with preserved mechanical and electrical function. On the other hand, in RevH+DOX females, morbidity was increased, and this correlated with mechanical (20% reduction in cardiac output) and electrical remodeling (22% increase in action potential duration). Comparing RevH+DOX males to females, males had greater fatty acid dependency while females had greater glucose dependency for metabolism. Conclusions: These results suggest that sex hormones play a significant role in modulating specific aspects of DOX cardiotoxicity. While E2 has a critical role in preserving cardiac mechanics during DOX therapy, high T levels were associated with mechanical dysfunction in both males and RevH females. Switching of metabolic substrates with greater preference for fatty acid metabolism in mice with higher E2 could underlie cardiac mechanics preservation. Finally, DOX induced electrical remodeling was not altered by sex hormones.
Abstract Mo027: Impact of Ventricular Arrhythmias On Outcomes of Patients with Follicular Lymphoma
Authors: Hiral Amin, Fizan Khalid, Kirti Dasu, Yaser Khalid, Neethi Dasu
Journal: Circulation Research (2024)

Background: Follicular lymphoma (FL) is typically a slow-growing form of non-Hodgkin lymphoma (NHL) that arises from B-lymphocytes. Large-scale studies are lacking for the outcomes of patients with ventricular arrhythmias and FL. We retrospectively reviewed FL patients with ventricular tachycardia utilizing the National Inpatient Sample (NIS) database. Our analysis aimed to identify risk factors that worsen outcomes in patients with FL and ventricular arrhythmias and evaluate the impact of ventricular arrhythmias on in-hospital outcomes of patients with FL. Methods: Data were extracted from the National Inpatient Sample (NIS) 2016-2019 Database. The NIS was searched for hospitalizations for adult patients with FL as the principal discharge diagnosis with and without ventricular arrhythmias as a secondary diagnosis using ICD-10 codes. The primary outcome was inpatient mortality. Multivariate logistic and linear regression analysis was used accordingly to adjust for confounders. STATA software was used for analysis. Results: This study included 15,795 patients with FL of which 225 had ventricular arrhythmias. Patients with both FL and an associated ventricular arrhythmia had higher inpatient mortality (OR 5.44, CI 2.48-11.93, p&lt;0.0001), hospital length of stay (LOS) (+5.48 days, CI 3.27-7.68, p&lt;0.0001) and total hospital charges (TOTHCG) (+$109,117.3, CI $65,702.9- $152,531.7, p&lt;0.0001). In this patient population, the secondary analysis revealed that mortality was increased if patients had a cardiac arrest (OR 25.62, CI 1.36-484.48, p&lt;0.031). LOS was increased in the presence of an acute kidney injury (+0.34 days, 0.04-0.64, p&lt;0.026). Conclusions: Our study revealed that patients with FL and ventricular arrhythmias had increased mortality, hospital LOS, and TOTHCG, as well as much higher rates of complications, including cardiac arrest and acute kidney injury, compared to those without ventricular arrhythmias. Efforts to prevent, monitor, and aggressively manage ventricular arrhythmias in patients with FL will improve overall outcomes.
Abstract Mo130: Epigenetic Mechanisms Regulate Sex Differences in Cardiac Reparative Functions of Bone Marrow Progenitor Cells
Authors: Charan Gurrala, Rajika Roy, Zhongjian Cheng, Venkata Garikipati, MAY TRUONGCAO, Darukeshwara Joladarashi, Vandana Mallaredy, Maria Cimini, Carolina Gonzalez, Ajit Magadum, Jayashri Ghosh, Cindy Benedict, Walter Koch, Raj Kishore
Journal: Circulation Research (2024)

Historically, lower incidence of CVD and related deaths in women as compared with men of the same age has been attributed to female sex hormones, particularly estrogen and its receptors. Autologous Bone marrow stem cell (BMSC) clinical trials for cardiac cell therapy overwhelmingly included male patients; however, meta-analysis data on these trials suggest a better functional outcome in women as compared with men. A direct comparison of the mechanisms governing sex-specific cardiac reparative activity in bone marrow-derived mesenchymal stem cells (BMSCs), with and without the influence of sex hormones, remains unexplored. This study was designed to identify mechanisms that regulate superior reparative properties of female endothelial progenitor cells (EPCs) post-MI, particularly epigenetic mechanisms. Male (M), female (F), and ovariectomized female (OVX) mice-derived EPCs were subjected to a series of molecular and epigenetic analyses followed by in vivo functional assessments of cardiac repair. RNA sequencing and other quantitative assays showed a similar genetic profile between F-EPCs and OVX-EPCs, distinct from M-EPCs that displayed significant up-regulation of inflammation-related genes. F-EPCs and OVX EPCs secrete higher levels of proangiogenic factors, lower levels of proinflammatory cytokines and show better cardiac reparative activity after intra-cardiac injections in a male mouse model of myocardial infarction (MI). Epigenetic sequencing revealed a marked difference in the occupancy of the gene repressive H3K9me3 mark, particularly at transcription start sites of key angiogenic and proinflammatory genes in male EPCs compared with female and ovariectomized EPCs. Our study unveiled that functional sex differences in EPCs is, in part, mediated by differential epigenetic regulation of the proinflammatory and anti-angiogenic gene CCL3, orchestrated by the control of H3K9me3 by histone methyltransferase, G9a/Ehmt2. Our research highlights the importance of considering sex of donor cells for progenitor-based tissue repair.
Abstract Mo125: Translating ECG responses to drugs across sexes: model development and validation in the clinic
Authors: Roshni Shetty, Stefano Morotti, Vladimir Sobota, Jason Bayer, Haibo Ni, Eleonora Grandi
Journal: Circulation Research (2024)

Background: Sex-based differences in cardiac electrophysiology and their potential to impact susceptibility to cardiac arrhythmia and response to treatment are widely recognized. For example, female sex is an independent risk factor for drug-induced Long QT syndrome, Torsade de Pointes, and sudden cardiac death. However, arrhythmia studies have been predominantly performed in males, thus limiting our understanding of sex-specific arrhythmia mechanisms and the development of sex-specific metrics for arrhythmia risk. Computational tools are a powerful approach for integrating sex differences across scales and studying such multi-level phenomena, accelerating challenging and costly human and animal experiments. Aim: To develop a quantitative tool that predicts drug-induced responses in female electrocardiogram (ECG) features based on ECG data collected in males (and vice versa). Methods: Male and female 1D cable models of ventricular cardiomyocytes were constructed by incorporating transmural heterogeneity and sex-specific parameterizations. We constructed populations of male and female models by randomly perturbing baseline parameters, and derived pseudo-ECGs from computed extracellular potentials. We then utilized lasso regression to map ECG features (QRS duration, QT interval, T-peak-end duration, and T-wave amplitude) extracted from the male pseudo-ECG onto the female ECG features (and vice versa) ( Fig 1 ). Results: Our simulated data-driven translator accurately predicted female pseudo-ECG features from male data in an independent simulated test set (R 2 &gt;0.95). This predictive capability was further assessed in an independent dataset simulating the effects of 95 drugs at different concentrations ( Fig 2A ), exhibiting an average translation error &lt;1% for the QT interval ( Fig 2B ). Proof-of-concept application to ECG data sourced from publicly available FDA-approved datasets, in patients of both sexes under various anti-arrhythmic drugs and drug combinations, demonstrates high accuracy ( Fig 3 ) and validates the translator's applicability to the clinic. Conclusions: Our findings underscore the translator's potential in conducting sex-specific cardiac safety and efficacy assessments, enhancing the precision of evaluations in females. We plan to expand our translator capability to predict sex-specific effects of perturbations, including physiological and pathophysiological stressors.