tbuckley/cabot-search huggingface dataset:
Abstract Mo045: The metabolic landscape of Fontan-associated liver disease
Authors: Rasheed Sule, Po Hu, Chris Petucci, Benjamin Wilkins, Jack Rychik, Liming Pei
Journal: Circulation Research (2024)

Introduction: Congenital heart diseases (CHDs) are the most common birth defects in the U.S. There are growing numbers of infants and children living with single ventricle congenital heart disease (SVCHD), a unique congenital cardiac anomaly in which there is only one functional ventricle. The Fontan surgery is the current standard of care for SVCHD. Although operative survival has improved over the years, it is now evident that these surviving patients are facing new life-threatening challenges: severe complications resulting from the Fontan operation, including one of the most evident consequences-hepatic fibrosis, which is now recognized as Fontan-Associated Liver Disease (FALD). Unfortunately, the mechanisms underlying FALD remain little understood. Improved understanding in this knowledge gap will offer crucial insights into FALD pathophysiology that can lead to targeted therapies for SVCHD patients. Goal: To determine if liver metabolism changes significantly in FALD and compare these liver metabolomics changes to metabolic gene expression (our snRNA-ATAC-seq data) and reported plasma metabolomics results, and validate the key findings. Methods: We recently generated the first single-cell transcriptomic landscape of human FALD using snRNA-ATAC-seq, which revealed profound metabolic reprogramming in FALD. Here we utilized metabolomics to further understand this. Liver samples/biopsies were collected from healthy donors and FALD patients. The extracted metabolites were analyzed using C18 and HILIC HPLC/MS columns. Raw data files were acquired by high resolution MS on Orbitrap and processed by Compound Discoverer. Further statistical and bioinformatics analyses were performed to identify altered metabolites and potential metabolic pathways involved in FALD. Results: Significant changes of metabolite levels of multiple metabolic pathways were observed in Fontan livers, often consistent with the gene expression results. Overall, these data unveiled profound metabolic abnormalities in livers of patients with early-stage FALD. Conclusions: In conclusion, our investigation revealed alterations in metabolites involved in glycolysis/gluconeogenesis, mitochondrial electron transport chain, and amino acids in early-stage FALD. The observed correlations between the metabolomics and gene expression results reveal new insights into the mechanisms underlying FALD. FALD is not only a hepatic fibrosis disease, but also features severe dysregulation of liver metabolism.
Abstract We049: Cell-Specific Metabolic Labelling Identifies hiPSC-CM Proteome In Vitro and In Vivo Post-Transplantation
Authors: Divya Sridharan, Julie Dougherty, Uzair Ahmed, Shridhar Sanghvi, Syed Baseeruddin Alvi, Ki Ho Park, Sue Knoblaugh, Harpreet Singh, Elizabeth Kirby, Mahmood Khan
Journal: Circulation Research (2024)

Background: Human induced pluripotent stem cells (hiPSCs) and their derived cardiomyocytes (hiPSC-CMs) have been used for cell-based therapies for myocardial regeneration. Underlying paracrine signals derived from these hiPSC-CMs have been shown to play a critical role in improving the function of the ischemic myocardium. However, characterization of the transplanted cell proteome in vivo has been challenging due to the lack of tools to distinguish cell-specific proteome in a complex multicellular microenvironment. Methods: To establish cell-specific proteome labelling, we adopted the biorthogonal non-canonical amino acid tagging (BONCAT) system in hiPSCs. We expressed the mutant mouse tRNA synthetase gene, “L274GmMetRS” in hiPSCs (L274G-hiPSCs) using lentiviral transduction to enable incorporation of the non-canonical amino acid azidonorleucine (Anl) in these cells. We assessed the pluripotency and trilineage differentiation potential of the L274G-hiPSCs in vitro and in vivo (teratoma formation assay). Furthermore, we validated the cell-specific Anl incorporation in the L274G-hiPSC-CMs both in vitro (co-culture) and in vivo (post-transplantation). Results: Our studies showed that the L274G-hiPSCs could efficiently differentiate into all the three germ lineages and can be used to track the cell-specific proteome in their differentiated progenies, including L274G-hiPSC-CMs. Furthermore, immunostaining and western blots showed cell-specific BONCAT in L274G-hiPSC-CMs both in co-cultures (in vitro) and post-transplantation (in vivo). Conclusion: The newly-established L274G-hiPSC line can be used to track cell-specific proteome of hiPSC-CMs in vitro and in vivo, to characterize cell-specific proteomic responses and delineate mechanisms underlying cell therapies.
Abstract Mo051: Phototherapy to stimulate carnosine activity and enhance global heart function: A promising adjunctive therapy for congestive heart failure (CHF)
Authors: James Kneller
Journal: Circulation Research (2024)

Background: The emerging field of cardiac optogenetics uses pulses of light to stimulate optically-sensitive proteins in the heart, influencing cellular physiology with unprecedented spatiotemporal resolution. Effects include increased glutathione and carnosine activity, and promotion of ATP synthesis. Clinical benefits include improved functional capacity, heart rhythm stability, and relief form congestive heart failure (CHF). Transcutaneous phototherapy devices are now available (LifeWave Inc, San Diego, USA), which may provide these benefits without the requirement for an external power source. Objective: To investigate whether upregulation of carnosine activity using a wearable cutaneous phototherapy device may improve echocardiographic measures of global heart function, cardiac contractility, and hemodynamics. Methods: The Carnosine ® adhesive skin patch (34 mm outside diameter) contain an organic crystalline material that reflects back specific frequencies of infra-red light known to activate carnosine dipeptides throughout the body. These function as a high-energy phosphate system known to enhance muscle function. Study participants (n=12 healthy volunteers (7 male, 5 female), 40-66 years of age) underwent a focused baseline echocardiogram, which included atrial (A) and early (E) mitral valve inflow, peak tissue velocity (E’) at both the lateral and septal mitral annulus, and left ventricular ejection fraction (LVEF). 10-14 patches were then applied along the sternum and across the left thorax (3 rd -5 th interspace), incorporating the anterior axilla. The echocardiogram was repeated 20-30 minutes after patch application. Results: LVEF was improved following application of the phototherapy device, increasing from 59.8±6.3% to 66.65±5.8% (Δ 6.3%, p&lt;0.05), indicating an improvement in overall cardiac function. Septal E’ also increased, from 7.3±0.7 cm/s to 8.2±0.6 cm/s (Δ 0.89 cm/s, p&lt;0.05), indicating a direct effect on contractility. E and A wave velocities increased from 63.7 cm/s to 66.1 cm/s (Δ 2.5±0.4 cm/s, p&lt;0.08) and from 56.8 cm/s to 62.6 cm/s (Δ 5.7±0.7 cm/s, p&lt;0.1), indicating augmented hemodynamics trending towards significance. Conclusion: Self-powered wearable phototherapy devices may enhance myocardial contractility and overall cardiac function. Such technologies represent a promising therapy for CHF.
Abstract Mo076: Combining Monogenic and Polygenic Analysis Improves Sudden Cardiac Death Risk Prediction
Authors: Tanner Monroe, Lorenzo pesce, Samuel Kearns, Lisa Dellefave-Castillo, Gregory Webster, Megan Puckelwartz, Elizabeth McNally
Journal: Circulation Research (2024)

Background: Nonischemic sudden cardiac death (SCD) is a catastrophic cardiac rhythm failure. Heritable arrhythmias and cardiomyopathies contribute significantly to SCD risk, and genetic markers can be used to identify and reduce risk, improving odds of survival. Clinically, genetic evaluation of known rare risk variants using gene panels often fails to identify a genetic etiology. These gene panels focus on genes affiliated with monogenic inheritance, and current genetic analysis is agnostic to polygenic disease architectures. Hypothesis: We hypothesized that cumulative rare and common variation scales with SCD risk. Approach: We established a diverse cohort of 1042 individuals at low or high SCD risk and classified them as cases (n=505) or controls (n=537). We then performed whole genome sequencing and analyzed variation centered around cardiomyopathy, arrhythmia, and epilepsy panel genes, as well as the regulatory variants that map to these genes. We also performed common variant analysis by computing polygenic scores for cardiac metrics including cardiac morphology, arrhythmia, and EKG intervals. We then created a risk stratification algorithm that incorporated each of those analyses. Results: We found a 3.4-fold enrichment for pathogenic or likely pathogenic (PLP) cardiomyopathy/arrhythmia variants (P&lt;1e-11) in the high risk group, with 23% of those individuals carrying at least one PLP variant. Rare high-effect epilepsy panel variants were also enriched in the high risk cohort (P=0.006). We also found a greater than two-fold enrichment of rare regulatory variants in the high risk group (P&lt;1e-7). Polygenic scores for blood pressure, QRS interval, and LV ejection fraction were all differentially distributed between the low and high risk groups (P&lt;0.05). The subsequent combined genomic analysis found those scoring in the highest decile of the total genetic risk scale had 13-fold higher odds of being a high-risk case and 73-fold higher odds compared to the lowest decile. Compared to using only the monogenic or only the polygenic analysis, the combined analysis was more predictive. Conclusions: Incorporating noncoding and polygenic analyses into sudden cardiac death genetic assessment improves risk stratification.
Abstract We080: Mapping the effect of Hedgehog signaling on cardiac differentiation and migration in space and time
Authors: Isaak Tarampoulous, Avryn Leo Justin, Kirthi Ponnuswamy, Patrick LaRiviere, Ivan Moskowitz
Journal: Circulation Research (2024)

Background: Organ morphogenesis requires precise control of organ-specific progenitor cell migration and differentiation. Hedgehog signaling is a major signaling pathway during animal development and is essential for proper cardiac development. Previous work demonstrated that Hedgehog signaling can regulate migration and the timing of differentiation of cardiac progenitors. However, how Hedgehog signaling integrates control of differentiation timing and migration in space to enable proper organ formation during development remains unclear. Hypothesis: We hypothesize that Hedgehog signaling explicitly controls cardiac morphogenesis by coordinating cellular migration and differentiation of cardiac progenitors to determining where and when they turn into cardiomyocytes. Methods: We combine mouse genetics, in-vivo lineage tracing, whole mouse embryo light-sheet imaging, and metanalysis of publicly available spatial transcriptomics datasets to address the hypothesis. Results: We identified the sites of active Hedgehog signaling by studying a reporter for Hedgehog signaling (GBS-GFP). Next, we determined the necessity of Hedgehog signaling for differentiation of cardiomyocytes at the right place and time by tracing the cardiac progenitors over developmental time in mutants in controls compared to Hedgehog signaling mutants. Conclusion and future directions: This work will establish the dual role of Hedgehog signaling in differentiation timing and migration control as a novel paradigm that may be generalizable to other organ systems dependent on Hedgehog signaling (e.g., neural cord and limb patterning).
Abstract We091: Maternal hyperglycemia disrupts human cardiac cell lineage differentiation
Authors: Javier Contreras, Cankun Wang, Shiqiao Ye, Yang Yu, Matthew Alonzo, Qin Ma, Mingtao Zhao
Journal: Circulation Research (2024)

Maternal diabetes is associated with a 4-fold increased risk of offspring developing congenital heart defects (CHDs). It remains unknown how maternal diabetes interferes with cardiac cell lineage determination and leads to malformations in the heart. In this study, we aim to elucidate the cellular mechanisms by which maternal hyperglycemia causes high risk of CHDs in newborns. Here we leverage an in vitro hyperglycemic model using human induced pluripotent stem cells (iPSCs), which could recapture cardiac differentiation and cell lineage commitment during embryonic heart development. We collected differentiating cells at D5 (cardiac mesoderm), D10 (cardiac progenitors), and D14 (early cardiomyocytes) during cardiac differentiation under normal and hyperglycemic conditions, and performed single-cell transcriptomic analysis. We found that hyperglycemia significantly impedes cardiac differentiation of human iPSCs as robust cardiac differentiation is rarely observed in multiple iPSC lines (n=10) under hyperglycemia. At the cellular level, hyperglycemia interferes with cardiac differentiation of human iPSCs in response to WNT signaling activation, which is manifested by reduced number of cardiac mesoderm (MESP1+ PDGFRA+) cells at D5 of differentiation. In contrast, neural differentiation is enhanced under hyperglycemia, with a high proportion of neural cell lineage (SOX2+ PAX6+). At D10, differentiated neural cell lineage dominates the cell population under hyperglycemia at the expense of cardiac progenitors and early cardiomyocytes. At D14, the prevalence of neural lineage persist whereas early cardiomyocytes only accounts for a small portion of cell population under hyperglycemia. Moreover, we treated D30 iPSC-derived cardiomyocytes (iPSC-CMs) with high glucose concentration (25 mM) for 7 days and found that iPSC-CMs show reduced mitochondria respiration and ATP production, but elevated apoptosis and reactive oxygen species (ROS) generation. Together, our data suggest that maternal hyperglycemia could interrupt human embryonic heart morphogenesis through overriding WNT-medicated cardiac differentiation and promoting neural cell lineage determination by default.
Abstract Or116: One Carbon Metabolism Defect In Failing Hearts
Authors: Jae Woo Jung, Emily Flam, Kenneth Bedi, Cholsoon Jang, Joshua Rabinowitz, Kenneth Margulies, Zoltan Arany
Journal: Circulation Research (2024)

Aberrant cardiac metabolism has long been hypothesized to contribute to heart failure (HF). However, understanding of cardiac metabolism in HF remains incomplete, especially in humans. To fill this gap, we performed metabolomic and RNA sequencing analysis of 48 non-failing (NF) and 39 dilated cardiomyopathy (DCM) hearts. Among many differences, metabolites from one-carbon metabolism were significantly reduced, especially in methionine cycle; methionine (Met) and S-adenosylmethionine (SAM), a universal methyl donor of methylation. We next studied the mechanism leading to decreased Met/SAM in DCM hearts. We first quantitatively defined methionine cycle in the heart: studies in neonatal rat ventricular myocytes (NRVMs), and in vivo steady-state infusions with isotope tracing, showed that Met was mostly imported or degraded from protein rather than recycled from homocysteine (~10%), suggesting that a defect in recycling is unlikely to explain low Met/SAM in DCM hearts. We next explored the impact of low SAM on cardiac function by generating mice with cardiac specific deletion of SAM synthase. Constitutive KO mice were largely embryonic lethal, and the few survivors showed dramatic systolic dysfunction and died within 12 weeks. Inducing loss of SAM synthase in adults led to 50% mortality after 2 weeks, again with marked cardiac dysfunction. Finally, we explored potential mechanisms by which low SAM can drive heart failure. In human DCM, numerous methylation products were low, including most notably creatine, a SAM methylation product and essential metabolite for cardiac energetics. Creatine is not thought to be synthesized in the heart, but we found that, to our surprise, NRVMs synthesized ~50% of their creatine pool when external supply was low, and synthesis was dependent on SAM availability. Moreover, in vivo steady state infusions revealed that in intact animals, even in the absence of stressors, ~10% of creatine in the heart is synthesized locally. In summary, we find that: (1) the majority of Met in cardiomyocyte is imported or derived from protein degradation, with rapid turnover; (2) Met and its product SAM are reduced in human DCM; (3) loss of SAM in murine heart leads to profound heart failure; (4) creatine is surprisingly synthesized from SAM in cardiomyocytes, and its levels are reduced in human DCM. Together, these findings suggest that a defective Met cycle may contribute to low creatine and ultimately HF.
Abstract We085: Origin and fate of CX3CR1 <sup>+</sup> cells in the heart: their unique contribution to cardiovascular cells
Authors: Kyuwon Cho, Mark Andrade, Seongho Bae, Christine Lee, Sangsung Kim, Jin Eyun Kim, Young-sup Yoon
Journal: Circulation Research (2024)

Introduction: During development, various cells intricately collaborate to form embryonic and fetal hearts. We can harness this naturally occurring generative mechanism to advance regenerative medicine for cardiac repair. Studies reported that C-X3-C Motif Chemokine Receptor 1 (CX3CR1) + cells play vital roles in cardiac development and disease. However, the origin and the fate of CX3CR1 + cells during cardiogenesis remain unclear. Specifically, the existence of CX3CR1 + cells before E8.5 and their commitment other than to macrophages have not been investigated. Methods: We investigated the origin and fate of CX3CR1 + cells using various knock-in reporter mice with CX3CR1 drivers for spatiotemporal genetic lineage tracing of CX3CR1 + cells. In addition, we developed a method to generate CX3CR1 + cells from differentiating mouse embryonic stem cells (mESCs). mESC-derived CX3CR1 + cells were characterized in vitro, in the fetal mouse heart ex vivo , and in the adult heart in vivo . Their heterogeneity and trajectory were analyzed via single cell RNA sequencing (scRNA-seq). Results: Genetic fate mapping of CX3CR1 + cells identified epiblasts at E6.5, the parietal endoderm at E7.0, yolk sac cells at E8.0, and cardiomyocytes at E9.5. Temporal genetic labeling (Cx3cr1-CreERT2;R26-tdTomato) showed that CX3CR1 + cells at E6.5 can contribute to cardiomyocytes (CMs) and endothelial cells (ECs) during prenatal development via both de novo differentiation and fusion with pre-existing CMs or ECs, respectively. In the adult heart, cells that have ever expressed Cx3cr1 comprised 13.5 ± 0.2% of CMs and 30.9 ± 1.3% of ECs. In addition, CX3CR1 + cells, which were differentiated from mESCs generated CMs, ECs and macrophages in vitro, in the fetal mouse heart ex vivo , and in the adult heart in vivo . Single cell RNA sequencing showed that Cx3cr1 + cells represent an intermediate cell population differentiating into the mesoderm from pluripotent stem cells. Conclusions: Our data demonstrate that CX3CR1 serves as a marker for a unique subset of progenitors that contribute to the formation of CMs and ECs as well as macrophages, providing new insights into the versatile role of CX3CR1 + cells in cardiogenesis.
Abstract We094: Acute Administration of The Novel Cardiac Sarcomere Modulator EDG-7500, Improves Ventricular Filling While Preserving LVEF In Dogs with Pacing Induced Left-Ventricular Systolic Dysfunction
Authors: Marc Evanchik, Craig Emter, carlos Del Rio, Steve Roof, Sydney St Clair, Alan Russell, Marcus Henze, marc Semigran
Journal: Circulation Research (2024)

Introduction: EDG-7500 is a cardiac sarcomere modulator that has been shown to slow early LV contraction and to improve diastolic filling, without directly inhibiting cardiac myosin. To assess the acute hemodynamic effects of EDG-7500 in a model of depressed systolic and diastolic LV function, we studied dogs with pacing-induced LV dysfunction before and after EDG-7500 administration. Methods: Beagle dogs (n = 7) underwent chronic RV pacing (180 to 240 ppm), and were studied, in sinus rhythm, at two levels of induced-dysfunction: mid-range EF (mEF, targeting 50%), and reduced EF (rEF, targeting 40%). At each level, animals were evaluated by echocardiography before and after administration of 0.3 mg/kg IV EDG-7500. Healthy beagle dogs served as disease controls (n = 7). Results: Post-pacing (Paced) dogs had depressed EF (mEF: 50 ± 4 and rEF: 40 ± 4 vs. 74 ± 1%, P &lt; 0.05) and short-axis global circumferential strain (mEF: -23 ± 2 and rEF: -14 ± 2 vs. -33 ± 1%, P &lt; 0.05), and elevated NT-proBNPs (mEF: 1,049 ± 319 and rEF: 4,236 ± 722 vs. 302 ± 27 pmol/L, P &lt; 0.05) when compared vs. healthy dogs. Paced dogs had slower early diastolic mitral annular velocity (mean e’, mEF: 11.0 ± 0.9 and rEF: 8.4 ± 0.8 vs. 14.2 ± 0.7 cm/s, P &lt; 0.05) and elevated E/e’ (mEF: 7.4 ± 0.7 and rEF: 8.4 ± 0.9 vs. 6.0 ± 0.2 n/u, P &lt; 0.05), at similar heart rates. Acute EDG-7500 increased e’ (mean e’, mEF: +9 ± 2 and rEF: +12 ± 3%, P&lt;0.05) and decreased E/e’ (mEF: -7 ± 2% and rEF: -9 ± 2%, P&lt;0.05), with no detectable effects on EF (mEF: +3 ± 6% and rEF: -5 ± 3%, P=NS). There were no adverse clinical observations. Conclusions: Treatment with EDG-7500 was well tolerated in dogs with tachycardia-induced mid-range (mEF) and reduced LV systolic function (rEF). In both cases, EDG-7500 improved echocardiographic indices of early ventricular filling and filling pressures, without observable effect on systolic performance. This data supports exploration of the effects of EDG-7500 in patient populations with LV diastolic dysfunction and mild to moderately reduced cardiac systolic performance.