tbuckley/cabot-search huggingface dataset:
Abstract We076: Humoral profile of individuals with Chagas Cardiomyopathy
Authors: Gabriela Venturinida Silva, Tomasz Kula, Taniela Bes, Ellen Shrock, Stephen Elledge, Joshua Gorham, Ester Cerdeira Sabino, Alexandre Pereira, Jonathan Seidman, Christine Seidman
Journal: Circulation Research (2024)

Chronic Chagas cardiomyopathy (CCC) is the most severe manifestation of Chagas disease and one of the main causes of cardiomyopathy in Latin America. The number of individuals infected with Trypanosoma cruzi (T. cruzi), the causative parasite of Chagas disease, exceeds 6 million, with an increasing presence in non-endemic regions such as Europe, Japan, Canada, and the USA. While approximately 70% of infected individuals remain asymptomatic and are categorized as indeterminate (IND), the remaining 30% develop cardiac manifestations several decades after the initial infection. Despite extensive efforts to elucidate the triggers and predictors underlying the progression from IND to CCC, the exact causative factors remain elusive. Hypotheses have been proposed that focus on the specific humoral response, including the production of antibodies that effectively neutralize the parasite or demonstrate cross-reactivity between parasite and cardiac proteins. Here, using PhIP-seq technology we comprehensively characterized the IgG profile of 897 T. cruzi seropositive individuals. We identified 628 epitopes with increased IgG reactivity in chronic T. cruzi seropositive individuals. Mucin TcMUCII, trans-sialidase, and MASP emerged as the primary classes of proteins showing elevated IgG response. Remarkably, the serum of CCC individuals showed robustly elevated reactivity against 84 epitopes compared to IND individuals, while IgG response against 23 epitopes was increased in the serum of IND individuals. Trans-sialidase and mucin-like glycoproteins were the main classes of proteins distinguishing these two groups. Among all epitopes with increased reactivity in the serum of CCC individuals compared to IND, 36 epitopes showed linear sequence similarity to 210 human proteins highly expressed in human heart. These included sarcomere structural proteins, suggesting potential cross-reactions between the antibodies targeting T. cruzi epitopes and proteins with key roles in cardiac function. Overall, our study describes the humoral landscape of Chagas disease, expanding the pool of potential candidates for future vaccine development or as targets for infection/trials efficiency monitoring. Additionally, we identified potential sources of antibody cross-reaction that may contribute to CCC progression, including epitopes sharing sequence similarities with key proteins involved in cardiac structure.
Abstract We056: Hydroxychloroquine cures autoimmune myocarditis by inhibiting innate immune via the CXCL16-CXCR6 axis between macrophages and T cells
Authors: Yunling Xuan, Chen Chen, Dao Wen Wang
Journal: Circulation Research (2024)

Background: Myocarditis is a live-threatening inflammatory disease of the heart and is lack of effective treatment measures. Hydroxychloroquine (HCQ), a classic antimalarial drug, has been widely used in the treatment of rheumatic diseases. This study investigated whether HCQ can treat chronic autoimmune myocarditis. Methods and Results: Murine autoimmune myocarditis was induced, and therapeutic effects of oral HCQ on acute and chronic myocarditis were evaluated using echocardiography, cardiac catheterization, and analysis of inflammatory scores in cardiac tissue. Results showed that HCQ treatment significantly improved cardiac function, inhibited ventricle enlargement and reduced cardiac inflammation. Single-cell transcriptomic analysis in the heart showed that HCQ treatment significantly reduced infiltration of macrophage, neutrophiles and T-cells, inhibited inflammatory pathway, especially the secretion of CXCL16 from macrophages, thereby reducing the chemotaxis of T cells, especially NKT cells and Th17 cells. Finally, both in vitro and in vivo experiments confirm the inhibitory effect of HCQ on CXCL16-CXCR6 axis between macrophages and T cells. Additionally, treatment with anti-CXCL16 antibody can also improve cardiac function and attenuate cardiac fibrosis in myocarditis. Conclusions: HCQ treatments clinically cure mice with autoimmune myocarditis through inhibiting innate immune and infiltration of macrophages majorly via CXCL16-CXCR6 axis.
Abstract Tu109: Sirt1 inhibits the Sub1-induced RNA polymerase II recruitment to metabolic gene promoters during pressure overload
Authors: Shinichi Oka, Peiyong Zhai, Junichi Sadoshima
Journal: Circulation Research (2024)

Downregulation of genes involved in mitochondrial energy production is a hallmark of heart failure, which associates with inhibition of RNA polymerase II (Pol II) recruitment to the gene promoters. Sirt1 is a protein deacetylase regulating transcription of metabolic genes. However, how Sirt1 regulates metabolic genes in heart failure is controversial. Here we show that Sirt1 promotes pressure overload (PO)-induced downregulation of metabolic genes possibly through inhibition of the Pol II recruitment. Cardiac-specific Sirt1 overexpression in mice (Tg-Sirt1) promoted PO-induced cardiac dysfunction (Ejection fraction (%): wild type (WT) sham 76, WT PO 68, Tg-Sirt1 sham 76, Tg-Sirt1 PO 48*, p&lt;0.05 vs WT PO) and downregulation of metabolic genes, including Idh3a (relative Idh3a mRNA levels; WT Sham 1.0, WT PO 0.55, Tg-Sirt1 0.98, Tg-Sirt1 PO 0.41, p&lt;0.05 vs WT PO). In cultured cardiomyocytes, Sirt1 overexpression suppressed metabolic enzymes, reporter gene activity driven by endogenous metabolic gene promoters, and mitochondrial respiration. Chromatin immunoprecipitation and in vitro DNA binding assays, using 500bp of endogenous Idh3a promoter sequence, showed that Sirt1 inhibits the Pol II recruitment to the promoter. Unbiased screening using mass spectrometry identified Sub1 as a Sirt1 binding protein. Sub1 is an evolutionally conserved DNA binding protein that mediates the Pol II recruitment via the preinitiation complex formation. We confirmed direct binding of Sub1 to the Sirt1 catalytic domain (235-499aa) and Sub1-dependent Sirt1 recruitment to the Idh3a promoter using the in vitro reconstitution system. In vitro DNA binding assays with the Idh3a promoter sequence demonstrated that Sirt1 inhibits preinitiation complex formation, but not Sub1 recruitment. These results suggest that Sirt1 inhibits Sub1-induced preinitiation complex formation, thereby suppressing transcription of metabolic genes in the failing heart.
Abstract Mo071: Engineered Platform to Uncover Cellular Cross-Talk and Arrhythmogenesis in Idiopathic Ventricular Fibrillation (IVF)
Authors: Mitchell Josvai, Louise Reilly, Corey Anderson, Janay Walters, Haibo Ni, Jodi Lawson, Walter Stanwood, Jianhua Zhang, Timothy Kamp, Frederic SACHER, Alexey Glukhov, Eleonora Grandi, Wendy Crone, Lee Eckhardt
Journal: Circulation Research (2024)

Background: Idiopathic VF (IVF) represents an unmet clinical need with ~50% of patients having no known monogenic cause. This has resulted in the lack of an appropriate experimental model system, limiting effective treatment through an evidence-based approach. Within IVF, several subphenotypes have emerged through Deep Phenotyping. We recruited patients with Purkinje cell premature ventricular contraction-driven IVF (PVC-IVF) to generate induced pluripotent stem cells (iPSCs). Aim: To characterize PVC-IVF patient-specific iPSCs using a physiologically relevant engineered in vitro model. We hypothesize this model will allow for mechanistic characterization of PVC-IVF. Methods: Patient-specific iPSC-cardiomyocytes (CMs) and iPSC-cardiac fibroblasts (CFs) were plated on 10 kPa polydimethylsiloxane (PDMS) culture platform with Matrigel in either monolayers or interconnected 40 µm lanes ( Fig. 1A ). Optical mapping was used to characterize Ca 2+ handling and action potentials. Control cells were from non-diseased persons. Results: CM-CF coculture results in a monolayer yet maintains the underlying organization ( Fig. 1B-C ). Patterned constructs have increased conduction velocities and anisotropy. Custom stimulation protocols were developed to probe arrhythmia susceptibility and restitution kinetics ( Fig. 1D-E ). A genetic algorithm was used to optimize a biophysically detailed CM model which enabled identification of differential model parameters between IVF and control data ( Fig. 2A-B ). These data will be used to develop a Ca 2+ handling–conduction–contractility paradigm specific to PVC-IVF as well as a mechanistic-based understanding of the disorder. Conclusions: Topography informs CM structure, while CFs remodel the matrix to form a monolayer, enabling full field electrophysiological definition at the cell and tissue scale. The in vitro model provides a unique microenvironment to determine the arrhythmogenic mechanism of PVC-IVF.
Abstract Or117: JNK2-mediated gut-heart crosstalk in aging-associated AF pathogenesis.
Authors: Elena Carrillo, Saugat Khanal, Abigail Richardson, Nikola Ricchiuti, Jiajie Yan, Xun Ai
Journal: Circulation Research (2024)

Introduction: Aging is an independent risk factor for atrial fibrillation (AF). We recently revealed a critical role of activated cardiac stress kinase JNK2 in AF risk. Yet, the mechanisms underlying JNK2 activation in the aged heart remain unclear. Emerging evidence suggests that organ crosstalk critically contributes to the development of heart diseases. Interestingly, increased AF episodes were clinically observed in patients with active gastrointestinal (GI) diseases (with a hallmark of enhanced intestinal epithelial barrier permeability (‘leaky gut’), but reduced AF during remission. While both GI dysfunction and enhanced AF risk are seen in aged humans and animal models, whether aging-associated leaky gut leads to AF pathogenesis through activated JNK2 remains unknown. Methods: To assess the leaky gut and AF link, young (Yg, 2 mo) wildtype (WT) and JNK2dn mice (cardiac-specific overexpression of inactive dominant negative (dn) JNK2) were used for aged fecal matter transplant (FMT), while aged (Ag, 24 mo) mice were transplanted with Yg fecal matter to rescue aging-associated AF. Atrial tachycardia/fibrillation (AT/AF) incidence was measured using our well-established protocol, and GI permeability was measured using a serum dextran (4-kDa) FITC fluorescence assay 7 days post-FMT. Results: Aged WT mice had an elevated FITC level (4.9±1.5 µg/ml vs 0.98±0.04 µg/ml; n=11,8; p&lt;0.01) with increased AT/AF inducibility compared to Yg mice (n=7,10; p&lt;0.05). Interestingly, Yg WT recipients subjected to aged FMT (Ag-to-Yg) exhibited an ~3-fold increase in GI permeability (n=14; p&lt;0.01) and significantly enhanced AT/AF inducibility relative to Yg sham controls (8 of 13 vs 0 of 10; p&lt;0.05), while Yg-to-Yg FMT did not alter GI permeability and AT/AF inducibility in Yg recipients (0 of 5, p=NS). Strikingly, cardiac-specific JNK2 inhibition prevented aged-FMT-caused AT/AF in Yg JNK2dn recipient mice (0 of 10; p&lt;0.01), suggesting that activated cardiac JNK2 underlies leaky gut-evoked AF in aging. Further, Yg-to-Ag FMT eliminated aged-associated AT/AF inducibility in aged recipients (0 of 6). Conclusion: Aging-associated GI dysfunction enhances cardiac JNK2 activation, which in turn drives AF risk. Targeting cardiac JNK2 could be a novel anti-AF therapeutic strategy.
Abstract We099: Antisense Oligonucleotide Treatment of Calmodulinopathy
Authors: Raul Bortolin, FARINA NAWAR, Michael Trembley, Maksymilian Prondzynski, Mason Sweat, Peizhe Wang, park chaehyoung, Fujian Lu, Erin Keating, Daisuke Yoshinaga, Nikoleta Pavlaki, Cecilia B. Cavazzoni, Peter T. Sage, Robert D. Whitehill, Dominic Abrams, Chrystalle Carreon, Juan Putra, Sanda Alexandrescu, Shuai Guo, Owen Tsai, Michael Rubart, Dieter Kubli, Adam Mullick, Vassilios Bezzerides, William Pu
Journal: Circulation Research (2024)

Introduction: Antisense Oligonucleotides (ASOs) are an emerging class of drugs that target RNAs to impede their production, stability, and translation. Calmodulinopathies are severe cardiac arrhythmias caused by dominant mutations in CALM1 , CALM2 , or CALM3 . Each of these genes encodes the identical calmodulin (CaM) protein. Leveraging this genetic redundancy, we hypothesized that ASO-mediated knockdown of the affected CALM gene would treat arrhythmia while functional redundancy of the other CALM genes would maintain CaM protein level and prevent toxicity. Methods: Cells from a patient expressing the heterozygous CALM1 - F142L mutation were reprogrammed into induced pluripotent stem cells (iPSCs; P-CALM1 F142L/+ ). Additionally, the variant or a nonsense codon were introduced into the wild-type reference line, WTC11, to yield isogenic disease (E-CALM1 F142L/+ ) and CALM1 null ( CALM1 Δ/Δ ) lines respectively. iPSCs were differentiated into cardiomyocytes (iPSC-CMs) to assess their action potentials and Ca 2+ transients using multielectrode arrays and fluorescent voltage- and calcium-sensitive dyes. Calm1 N98S/+ mice, previously shown to develop catecholamine-induced ventricular tachycardia, were used for in vivo studies. Using these model systems, we tested ASOs that selectively depleted human or murine CALM1 . Results: Both E-CALM1 F142L/+ and P-CALM1 F142L/+ iPSC-CMs exhibited prolonged action potentials, consistent with QT prolongation observed in the proband. CALM1 Δ/Δ iPSC-CMs expressed normal levels of CaM protein and exhibited no change in action potential duration. ASO that selectively depleted CALM1 transcripts by ~50% did not alter CaM protein level but normalized action potential and Ca 2+ transient duration in CALM1 F142L/+ iPSC-CMs. In Calm1 N98S/+ mice, ASO selectively depleted Calm1 transcripts by ~90% and prevented catecholamine-induced ventricular tachycardia. Calm1 ASO did not alter CaM protein level, cardiac function, or treadmill endurance, or cause significant histopathological changes. Conclusion: ASO-based therapy safely and effectively treated arrhythmias caused by dominant CALM1 variants, suggesting that ASOs are a promising potential therapy for calmodulinopathy.
Abstract We072: Effects of electronic cigarettes on mouse cardiac lymphatic vessels after TAC surgery
Authors: Siqi Tao, Jiang Qian, Wei Shi, Jian Xu, Ching-Ling Lien
Journal: Circulation Research (2024)

Introduction: Heart failure is a public health concern worldwide. It is known that tobacco smoking is a risk factor of heart failure. Tobacco smoking also causes inflammation reaction and lymphatic dysfunction in the lung. However, the effects of electronic cigarettes (ECIG), as a new method of smoking, on the heart and cardiac lymphatic vessels (lymphatics) are not clear yet. The lymphatic vessels play an important role in maintaining cardiac function by modulating fluid homeostasis and transporting macromolecules. It has been reported that cardiac lymphatic vessel formation limits pressure overload-induced heart failure in C57Bl/6 but not in Balb/c mice. How cardiac lymphatics might contribute to the pathogenesis induced by ECIG is not known. Research Questions: The roles of cardiac lymphatic vessels in responses to ECIG exposure are not investigated. I hypothesize that the toxic effects of ECIG on the heart are partially caused by damaging the cardiac lymphatic vessels. Aim: To determine the effects of ECIG exposure on cardiac lymphatics after Transverse aortic constriction (TAC). Methods: I perform TAC surgery on mice as a heart hypertrophy and chronic heart failure model. Mice after TAC or Sham surgery are treated with different vaping components from ECIG: ECIG, propylene glycol and glycerin (PGVG) as vehicle, and air. After 4 weeks of treatment, hearts were harvested for histological analyses. The lymphatic vessel coverage percentage and morphology were examined by immunostaining. Results: Prior research suggested that genetic background in mice might affect the responses of cardiac lymphatic vessels to TAC-induced heart failure. I have established the TAC model using CD-1 mice. My results showed that CD-1 mice treated with PGVG after TAC do not show a significant difference in cardiac lymphatic vessel density compared to Sham group (p value=0.5951). ECIG treatment also did not affect the lymphatic density significantly compared to PGVG treated mice after sham operation (p value=0.8937). ECIG treated mice after TAC surgery showed a trend of increased lymphatic coverage and more mice are still being processed and will be presented at the conference. Conclusion: PGVG treated CD-1 mice do not show changes in lymphatic vessel density 4 weeks post TAC. Longer time points and more mouse numbers are needed to compare the effects of PGVG and ECIG after TAC induced hypertrophy and heart failure. This research is supported by California TRDRP grant.
Abstract Mo070: Metabolic Syndrome Alters cAMP Homeostasis and Contractile Function of Cardiomyocytes
Authors: Emanuele Pizzo, Daniel Cervantes, Valentina Ripa, Vineeta Jagana, harshada Ketkar, Kanwardeep Singh, Jason Jacobson, Sudhir Jain, Malik Bisserier, Marcello Rota
Journal: Circulation Research (2024)

Approximately one third of the population in the US has metabolic syndrome (MetS), a condition associated with increased risk for coronary artery disease and myocardial infarction. But whether MetS alters properties of the myocardium before the occurrence of ischemic insults remains to be fully elucidated. For this purpose, MetS was induced in C57Bl/6 female mice with a dietary paradigm recapitulating Western-style alimentary habits in humans. Animals on regular chow were used as control (Ctrl). Cardiac function was assessed by echocardiography and myocytes were studied under field stimulation, following enzymatic dissociation. From 3-12 months on the diet, MetS mice had increased body weight, impaired glucose metabolism, augmented left ventricular (LV) mass, but preserved cardiac function, with respect to Ctrl mice. Using ECGs, heart rate variability was attenuated in MetS mice, suggesting that metabolic disorders alter cardiac sympathovagal balance. At the cellular level, LV myocytes from MetS mice had increased volume (+24%), enhanced fractional cell shortening (+42%), and faster kinetics of relaxation (-27%), with respect to Ctrl myocytes. Because cAMP and protein Kinase A (PKA) modulates myocardial contractility upon activation of G-protein coupled receptors, including beta-adrenergic receptors (B-AR), levels of these molecules were assessed by ELISA assay. Consistent with enhanced cell shortening and faster relaxation, levels of cAMP and PKA activity were, respectively, 1.8-fold and 1.9-fold larger in MetS myocytes, in comparison to Ctrl cells. Interestingly, inhibition of PKA with H-89 reduced cell shortening (-30%) and delayed kinetics of relaxation (+50%) in MetS myocytes but had no major effects on Ctrl cells. To establish the contribution of the cAMP/PKA signaling in the functional behavior of the heart with MetS, mice were treated with the B-AR blocker propranolol. Under this condition, MetS mice had reduced ejection fraction and impaired indices of diastolic function, with respect to Ctrl animals. Interestingly, myocytes obtained from Ctrl and MetS mice treated with the B-AR blocker had comparable cell shortening and kinetics of relaxation. Collectively, these results indicate that metabolic syndrome alters the functional properties of the myocytes and heart by affecting cAMP homeostasis. These properties may increase myocardial oxygen demand predisposing the heart to ischemic insults.
Abstract Tu100: Multiscale Drug Screening for Cardiac Fibrosis Identifies MD2 as a Therapeutic Target
Authors: Hao Zhang, Phung Thai, Rabindra Shivnaraine, Lu Ren, Xuekun Wu, Dirk Siepe, Yu Liu, Chengyi Tu, Arianne Caudal, Souhrid Mukherjee, Jeremy Leitz, Wilson Wen, Hye Shin, Wenqiang Liu, Nipavan Chiamvimonvat, Joseph Wu
Journal: Circulation Research (2024)

Cardiac fibrosis impairs cardiac function, but no clinical therapies exist. To address this unmet need, we employed a high-throughput drug screening for antifibrotic compounds using human iPSC-derived cardiac fibroblasts (CFs) (Figure 1). Counter-screening of the initial candidates using iPSC-derived cardiomyocytes and endothelial cells excluded hits with toxicity. This screening process identified artesunate as the lead compound. Following profibrotic stimuli, artesunate inhibited proliferation, migration, gel contraction in human primary CFs, reduced collagen deposition and improved contractile function in 3D-engineered heart tissues. Artesunate also attenuated cardiac fibrosis and improved cardiac function in a heart failure mouse model. Mechanistically, artesunate molecularly targeted myeloid differentiation factor 2 (MD2) and inhibited MD2/toll-like receptor 4 (TLR4) signaling pathway, alleviating fibrotic gene expression in CFs (Figure 2). Our study is the first to use multiscale drug screening, which combines human iPSC platform, tissue engineering, animal models, in silico simulation, and multiomics to identify MD2 as a therapeutic target for cardiac fibrosis.
Abstract We088: Spatiotemporal analysis of cardiac progenitor cells reveals migratory characteristics during epithelial-mesenchymal transition
Authors: Jing Li, Ke Zhang
Journal: Circulation Research (2024)

Introduction: Congenital heart defects (CHD) are one of the most common types of birth defects, with a rising prevalence in mild types. The most frequent CHDs include anomalies in the cardiac outflow tract (OFT), which mainly derives from multipotent cardiac progenitor cells termed second heart field (SHF). Hence, dysregulation of highly synchronized, chronological sequence of proliferation and differentiation of SHF cells could lead to severe CHDs. As the SHF contributes entirely to the OFT, mutations in the SHF-related genes lead to major arterial pole defects which account for one third of CHDs in newborn children. Investigating how these genes regulate cell-cell behavior and communication is of vital importance. Hypothesis and Methods: In this study, we employed a multidimensional approach to assess the hypothesis that the dynamic behavior of SHFs is regulated by key genes implicated in CHD pathogenesis. Leveraging single-cell RNA sequencing (RNA-seq) data obtained from experimentally dissected mouse OFT, we delineated distinct epithelial-to-mesenchymal transition states within SHF cell populations. Additionally, we developed a quantitative metric to assess SHF cell’s migratory level and integrated it with spatial transcriptomic analyses to map the developmental trajectory of SHFs. Results and Conclusion: Through spatiotemporal analysis, we identified a panel of key genes associated with SHF migration, shedding light on the molecular mechanisms underlying OFT development during early embryonic stages. Furthermore, we leveraged the data from The Pediatric Cardiac Genomics Consortium (PCGC) study (phs001194.v3.p2) which comprises a large cohort of CHD patients (13716 participants) and a proportion of 21.68% identified with OFT obstruction in its sub-study. In conclusion, using these datasets and quantitative metric being developed, we validated the SHF-derived genes in the PCGC participants and revealed specific expression patterns of these genes associated with OFT-specific CHDs. These results would benefit the understanding of the genetic regulation of SHF proliferation and differentiation, which is crucial for early detection and precise surgical intervention in CHD patients.