tbuckley/cabot-search huggingface dataset:
Abstract We135: Mechanistic Modeling Identifies Novel Regulators of Cardiac Hypertrophy
Authors: Lionel Watkins, Jeffrey Saucerman
Journal: Circulation Research (2024)

Introduction: Cardiac hypertrophy is a leading predictor of heart failure. The mechanisms that drive cardiac hypertrophy are poorly understood from a molecular and cellular perspective, due to the lack of knowledge of the governing signaling. Hypothesis and Aims: I hypothesize that there exist genes that regulate hypertrophy beyond the field’s current understanding that can be identified by combining the publicly available, high-throughput International Mouse Phenotyping Consortium (IMPC) database with network modeling. I aim to use a large-scale network model of cardiac hypertrophy to assess the IMPC genes’ effects on hypertrophic phenotypes and validate these findings in vitro to identify novel regulators. Materials &amp; Methods: The IMPC was established by worldwide mouse clinics using in vivo models to perform single gene knockout experiments with primary phenotyping, forming a database with ~9000 genes, ~1000 of which can be associated with cardiac hypertrophy. 1 st neighbors (genes directly interacting with the hypertrophy network model as evidenced by protein-protein interaction databases) were identified and effects on hypertrophy were assessed through the IMPC and network model knockdown simulations. When both methods suggested hypertrophic regulation, a gene was considered a candidate regulator. siRNA experiments are being performed in neonatal rat cardiomyocytes for validation. High-content imaging and qPCR are used to quantify changes in phenotype and confirm gene knockdown. Results: Combining the IMPC with protein-protein interaction data, 37 1 st neighbor genes were identified. Knockdown simulation identified 2 genes (LRIG1, CBL) as negative regulators. 3 genes (VAV2, LEPR, RASA1) were identified as positive regulators. These genes became candidates for in vitro validation given the network-wide hypertrophic effects enacted by their knockdowns. siRNA experiments are being optimized to fully validate modeling findings. Conclusions: Mechanistic modeling identified 5 genes as novel regulators of cardiac hypertrophy. Sensitivity analysis highlighted known influencers of hypertrophy in the knockdown context. siRNA knockdown experiments are being performed to validate the model predictions.
Abstract We115: Modified mRNA Therapeutics Inhibits Cardiomyocyte Apoptosis and Induces Cardiac Protection in Ischemic Heart Diseases
Authors: Ajit Magadum, Vandana Mallaredy, Rajika Roy, Charan Thej Gurrala, Darukeshwara Joladarashi, Maria Cimini, Carolina Gonzalez, May Truongcao, Cindy Benedict, Raj Kishore
Journal: Circulation Research (2024)

Introduction: Cardiovascular diseases are the leading cause of mortality worldwide. After myocardial infarction (MI), there is a permanent loss of cardiomyocytes (CMs), and as the mammalian heart has limited regenerative capacity, it leads to Heart Failure. Extracellular vesicles (EVs) derived from induced pluripotent stem cells (iPSCs) have emerged as potential therapeutic agents, yet their precise mechanism of CM survival and cardiac repair remains elusive. Hypothesis: The myocardial delivery of hiPSC-EV-specific protein improves cardiac function and mice survival post-MI by inhibiting CM apoptosis and oxidative stress molecular pathways. Methods and Results: Our preliminary studies confirmed that hiPSC-EVs promote CM survival post-MI in mice, and through proteomic analysis, we identified a novel protein uniquely expressed in hiPSC-EVs. We showed that the myocardial delivery of hiPSC-EVs specific protein in the form of modRNA inhibited CM apoptosis and induced CM survival post-MI. This increase in the CM's survival by hiPSC-EVs specific protein expression was associated with reduced scar size, improved cardiac function, and mice survival 28 days post-MI. Furthermore, using the siRNA and small molecule inhibition of hiPSC-EVs specific protein, we found enhanced MI-induced CM apoptosis post-MI. Mechanistic insights reveal the hiPSC-EVs specific protein induced STAT3 pathway, while STAT3 pathway inhibition by small molecule repressed hiPSC-EVs specific protein induced CM survival in vitro . Additionally, our preliminary study shows this protein translocates to the nucleus post-MI or ischemic injury. Conclusion: Taken together, the myocardial injection of hiPSC-EVs specific protein through a highly therapeutic modRNA tool improves cardiac function by inhibiting CMs apoptosis, and reactivating cardiac repair post-injury. Moreover, our studies demonstrate that the modRNA (protein) approach in mouse models is potentially adaptable for mRNA therapeutics in a clinical setup.
Abstract Mo081: Genetic Deletion of Histone Lysine Demethylase KDM5A in Cardiomyocytes Attenuates LMNA-associated Dilated Cardiomyopathy
Authors: Manisha Deogharia, Ali Marian, Priyatansh Gurha
Journal: Circulation Research (2024)

Background: Heart failure (HF) is a major cause of morbidity and mortality. Hereditary cardiomyopathies are the prototypic forms of HF. Notable among them is dilated cardiomyopathy (DCM) caused by mutations in the LMNA gene encoding Lamin A protein (LMNA-DCM). We have recently shown that KDM5A, a histone H3 lysine 4 demethylase, is activated in the hearts of human patients and mouse models of LMNA-DCM. Inhibition of the KDM5 family of proteins activates gene expression, including expression of genes involved in oxidative phosphorylation (OXPHOS) and fatty acid oxidation (FAO) in iPSC-derived cardiomyocytes. Thus, we hypothesized that activation of the KDM5A in the LMNA-DCM is pathogenic and contributes to cardiac dysfunction. Objective: The objective of this study is to determine the role of KDM5A in the pathogenesis of LMNA-DCM. Methods and Results: The Lmna and Kdm5a genes were concomitantly deleted in the cardiac myocytes (CMs) in mice using cre recombinase. CM-specific deletion of the Lmna gene ( Myh6-Cre:Lmna F/F ), representing a mouse model of LMNA-DCM, led to severe cardiac dysfunction, increased apoptosis, and premature death as published. The Myh6-Cre:Kdm5a F/F mice showed no discernible phenotype. Deletion of the Kdm5a gene in CMs in the LMNA-DCM mice (Myh6-Cre:Lmna F/F :Kdm5a F/F ) attenuated myocardial apoptosis, improved cardiac function, and prolonged survival. Specifically, left ventricular end-systolic and end-diastolic diameters (LVESD and LVEDD, respectively) were smaller and LV fractional shortening (LVFS) was greater in the Myh6-Cre: Lmna F/F :Kdm5a F/F mice as compared to the Myh6-Cre:Lmna F/F mice. Likewise, the median and maximum survival times were increased by ~ 40 to 50% in the Myh6-Cre:Lmna F/F :Kdm5a F/F . Analysis of the CM transcripts by RNA-sequencing showed dysregulation of 6609 genes in the Myh6-Cre: Lmna F/F CMs and 2791 genes were attenuated in the Myh6-Cre:Lmna F/F :Kdm5a F/F . Pathway analysis showed that genes involved in FAO and OXPHOS were the most suppressed in LMNA-DCM and were rescued upon Kdm5a deletion. Conclusions: Deletion of the Kdm5a gene in the LMNA-DCM mice imparts salubrious effects by prolonging survival and improving cardiac dysfunction, and upregulating genes involved in OXPHOS and FAO. Thus, activation of KDM5A is likely pathogenic and contributes to the phenotypic expression of LMNA-DCM.
Abstract We113: Intravascular Theranostic Photoactivation Guided By OCT-NIRF Dual-Modal Imaging Facilitates Inflammation Resolution of High-Risk Plaque
Authors: Jin Hyuk Kim, Yeon Hoon Kim, Hyun Jung Kim, Ryeong Hyun Kim, Ye Hee Park, Hyeong Soo Nam, Dong Oh Kang, Hongki Yoo, Kyeongsoon Park, Jin Won Kim
Journal: Circulation Research (2024)

Introduction and Hypothesis: Photoactivation eliminates inflammatory cells and promotes healing, paving the way for atherosclerosis intervention. We hypothesized that intravascular macrophage-targeted near-infrared fluorescence (NIRF) emitting photoactivation could facilitate inflammation resolution and stabilize the inflamed high-risk plaques. Method and Results: We newly fabricated a Dectin-1-targeted photoactivatable theranostic agent through the chemical conjugation of the NIRF-emitting photosensitizer chlorin e6 (Ce6) and the Dectin-1 ligand laminarin (LAM-Ce6). By intravascular OCT-NIRF structural-molecular imaging at 0- vs 4 weeks, LAM-Ce6 under light irradiation through a customized intravascular fiber effectively attenuated inflammatory NIRF signals, resulting in replacement of fibrotic composition in the targeted plaques (Figure A, P &lt;0.01). Mechanistically, one hour after the light irradiation, autophagy was strongly augmented with the formation of autophagolysosomes (Figure B, P &lt;0.001) and an increase of CD206-positive cells at 7 days. Furthermore, TUNEL/RAM11- and CD206/MerTK-positive cells were prominently increased at 1 day, suggestive of enhanced efferocytosis in the treated plaques (Figure C, the white arrow: macrophage associated apoptotic cells, P &lt;0.05). In line with inflammation resolution, photoactivation enhanced the cholesterol efflux regulatory protein ABCA1 and induced TGF-β in macrophages, which subsequently stimulated smooth muscle cells and produced collagen within the lesions (Figure D). Conclusions: The macrophage Dectin-1 targetable intravascular photoactivation assisted by OCT-NIRF catheter imaging could ultimately transit the plaque phenotype to collagen-rich fibrotic one by autophagy-mediated inflammation resolution with a fibrotic replacement. This novel targeted photoactivation is expected to offer new opportunity for the catheter-based theranostic strategy in patients with macrophage/lipid-rich inflamed coronary plaques.
Abstract We012: Sheet like extracellular matrix secreting single cell microvesicles for reprogrammed endothelial cell therapy towards vascular regeneration
Authors: Viola Morris, Sangho Lee, Simon He, Matthew Huang, Dandan Chen, Kyung Hee Kim, Seonggeon Cho, Laura Pencea, Divit Jain, Young-sup Yoon
Journal: Circulation Research (2024)

To enhance cell survival and engraftment for cell therapy, cell encapsulated injectable biomaterials have been widely used. However, the challenges were hypoxia and nutrient shortage in the core, inflammatory cell infiltration and limited distribution of cells from injection sites. Encapsulation of single cells in sub-100-micron microgels with higher surface to volume ratios provides more efficient oxygen and mass exchange. However, typical production of single-cell-laden microgels by microfluidics devices results in cell damage and compromised biological properties. We hypothesized that stimuli responsive amphiphilic copolymer bearing RGD peptides may self-assemble around single cells induced by cell adhesion moieties would result in single cell microvesicles (MV). A stimuli responsive amphiphilic copolymer GPM (Gelatin Poly glycerol sebacate Methacrylate) was synthesized by grafting hydrophobic synthetic polymer PGS into hydrophilic natural polymer gelatin via methacrylation followed by aza-Michael addition reaction. Single cell microvesicles of endothelial cells (EC-MVs) were fabricated by self-assembly of GPM at room temperature. For in vivo studies, sub-50-micron EC-MVs made of reprogrammed endothelial cells (rECs) were clustered into 200 micron spheres (mGPM) using sodium alginate and injected into a hindlimb ischemia model to investigate cell survival and biological function. The mGPM microspheres functioned as a barrier from immune cell infiltration and also enhanced cellular distribution. The encapsulated rECs were released over 2-4 wks in vivo and were shown robust engraftment, migration, and survival in limb tissues, promoting blood flow recovery and sustained vascular regeneration over 6 months. Interestingly, in in vitro culture, rEC-MVs secreted sheet like extra cellular matrix (ECM) which appeared to make an important role for vessel formation (neovascularization) in vivo (Figure 1). The current study clearly demonstrated the favorable biological applicability of GPM single cell MVs toward vascular regeneration by reprogrammed ECs.
Abstract We128: Effect of Coronavirus Disease 2019 on the Incidence of Stress-induced Cardiomyopathy; A Single Center Experience
Authors: Fawaz Mohammed, Zaina Ali Khan, Muna Mohammed, James Gubitosa, Anna H. Cox, Ahmed D. Kamaluldeen, Aisha A. Nour, Paige Long, Amanda M. Osborn, Kathryn Howard, Yub Raj Sedhai, Sameer Saleem, AKHTAR AMIN, Jacqueline Dawson Dowe, Mohammad Abdul Waheed, Muhammad Akbar, Mohammed Kazimuddin
Journal: Circulation Research (2024)

Introduction: Takotsubo Syndrome, or stress-induced cardiomyopathy (SIC) is a transient dysfunction of the left ventricle. Emerging data has shown a rise in the number of cases in recent times. In January of 2020 the Centers for Disease Control and Prevention (CDC) declared Coronavirus disease 2019 (COVID-19) a public healthcare emergency. Given the impact of the COVID-19 on economic and psychosocial factors in individuals across the globe, we sought to study the effect of COVID-19 on the incidence of SIC at our institution. Research Question: Has economic and psychosocial stress associated with COVID-19 led to an increase in the incidence of stress-induced cardiomyopathy? Aim: To study the impact of COVID-19 on the incidence of stress-induced cardiomyopathy. Methods: A retrospective review of cardiac catheterization laboratory data was performed from January 2011 to August 2022. We identified a total of (n=121) cases of stress induced cardiomyopathy. Diagnosis was adjudicated based on the findings on cardiac catheterization, left ventriculography, and echocardiography. Clinical and demographic data of interest was obtained from individual patient electronic medical records into a secure database management tool. Additional data of interest was obtained by performing a post-discharge questionnaire via a telephone survey. Results: The mean age of the population was 69 years (SD± 11.5). 93% (112) of the study population were females. A preceding physical stressor as a triggering factor was present in 59% (72) of individuals, 25% (31) individuals reported a preceding emotional stressor. An increase in the number of cases of SIC was noticed from January of 2020. Only 11% (8) of the patients who were admitted from Janurary 2020 had COVID-19 [Figure 1]. 36% (44) patients participated in the survery. Patients graded their disability from SIC as the following: Mild in 11% (4) , moderate in 7% (3) and severe in 2% (1) of the individuals [Figure 2]. All the patients were referred to Cardiac Rehabilitation at the Medical Center; a American Association of Cardiovascular and Pulmonary Rehabilitation (AACVPR) certified program that provides patients with educational, preventional and rehabilitative resources. Conclusion: A rise in the incidence of SIC was noted in our single center retrospective study when the CDC declared COVID-19 a healthcare emergency. This suggests an indirect economic and psychosocial stress related process from COVID-19; the "Long COVID" that is not talked about.
Abstract Mo080: Clinically Variable Penetrant MYH7 G256E Mutation Shows Gene-Dose-Dependent HCM Disease Phenotype on a Transcriptomic, Proteomic, and Functional Level
Authors: Paul Heinrich, Soah Lee, Carolin Sailer, Jonathan Achter, Raina Jung, Carissa Lee, Alison Vander Roest, Brock Roberts, Daniel Bernstein, Alicia Lundby, Sean Wu
Journal: Circulation Research (2024)

Introduction: Hypertrophic cardiomyopathy (HCM) is a monogenic disorder caused by heterozygous (HET) mutations in sarcomere genes such as MYH7 . Recently, human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) carrying HET HCM mutations have shed new insights into the molecular mechanisms of HCM. However, the cause of phenotype variability and the role of allelic imbalance in phenotype penetrance of HET missense mutations such as MYH7 G256E remain unclear. Hypothesis: We hypothesize that hiPSC CMs carrying clinically variable penetrant HCM missense mutations such as MYH7 G256E show a gene dose-dependent disease phenotype indicating their susceptibility for allelic imbalance as a cause for variable disease phenotype penetrance. Methods: We generated HET and homozygous (HOM) hiPSC-lines for variable penetrant HCM mutation MYH7 G256E. We performed multiplexed single-cell RNA sequencing and quantitative proteomics analyses on wildtype (WT), HET, and HOM iPSC-CMs at day 30 of cardiac differentiation. Additional Digital Droplet PCR studies were performed to investigate the MYH7 mutant allele expression. The functional contractile phenotype was assessed with Sony SI8000 Cell motion imaging system. Results: We detected a large clone-to-clone and batch-to-batch variability in HET iPSC-CMs on a transcriptomic and proteomic level that obscured the identification of a consistent mutant phenotype in HET MYH7 G256E vs WT CMs. These phenotypes correlated with a 1:1 bulk ratio of mutant vs WT mRNA and protein expression, while overall MYH7 gene and protein expression remained comparable. Transcriptomic and proteomic analyses of WT, HET, and HOM CMs show a gene dose-dependent regulation of known hypertrophy response markers such as NPPB (mRNA: HET vs WT: +1.76x p .adj=7.0*10 -7 , HOM vs WT: +5.42x p.adj=1.5*10 -48 ; protein: HET vs WT: +1.15x, 95% CI [0.86, 1.58]; HOM vs WT: +1.51x, 95% CI [1.12, 2.01]) which functionally correlated with enhanced contractility (contraction velocity in μm/s: WT: 5.84 +/-2.24, HET: 6.04 +/-2.89, HOM: 7.77 +/-3.352, p=0.3*10 -2 ANOVA) and the more frequent occurrence of arrhythmias (WT: 1/46, HET: 0/55, HOM: 5/41). Conclusions: Hypertrophic disease phenotype in MYH7 G256E mutation iPSC-CMs shows a gene dose-dependent penetrance on a transcriptomic, proteomic, and functional level. This indicates susceptibility to allelic imbalance as a potential cause for variable disease penetrance.
Abstract We121: Doxorubicin-Induced Cardiomyocyte Death is mediated by Lysosomal Membrane Permeabilization
Authors: Demarcus Nasef, Daniel Nasef, Younghee Hahn, Tamayo Kobayashi, Yuan Huang, Randy Stout, Qiangrong Liang, Satoru Kobayashi
Journal: Circulation Research (2024)

Doxorubicin (DOX) is a potent antineoplastic drug with broad-spectrum capabilities. However, its clinical use is hindered by dose-dependent cardiotoxicity, often leading to heart failure. This study investigates the connection between DOX-induced cardiotoxicity and lysosomal dysfunction, focusing on lysosomal membrane permeabilization (LMP) as a central mechanism in cardiomyocyte death. LMP occurs when there is a disruption in the integrity of the lysosomal membrane, releasing lysosomal enzymes into the cytoplasm. We tested the hypothesis that DOX induces LMP, contributing to cardiomyocyte death. Utilizing a tfGalectin3 LMP reporter and Lysosensor staining, we verified LMP occurrence in DOX-treated H9C2 cardiomyoblast cells, as indicated by compromised lysosomal acidity and increased release of lysosomal protease Cathepsin D (CTSD). Western blot analysis showed elevated CTSD expression following DOX exposure, while DQRed BSA staining demonstrated diminished lysosomal proteolysis, signifying lysosomal dysfunction. Intriguingly, downregulating CTSD via siRNA aggravates cardiomyocyte death, whereas enhancing CTSD expression through adenoviral delivery exerts opposite effects, suggesting a protective role of CTSD in DOX cardiotoxicity. In vivo study using a tfGalectin3 LMP reporter mouse validated the ability of DOX to induce LMP in cardiac tissue. CTSD heterozygous knockout mice exhibited deteriorated heart function compared to the wild type, underscoring CTSD's protective role against DOX-induced cardiotoxicity. In summary, our findings highlight the critical impact of DOX on lysosomal stability and protease activity, leading to cardiomyocyte death and cardiac dysfunction. Further studies are warranted to explore potential interventions, such as imidazolines and apolipoproteins, to reinforce LMP stability and safeguard against DOX-induced cardiotoxicity.
Abstract We016: Generative Artificial Intelligence for hPSC-derived Cardiac Organoid Florescence Generation
Authors: Huaxiao Yang, Arun Kumar Reddy Kandula, Tanakit Phamornratanakun, Angello Huerta Gomez, Marcel El-Mokahal, Zhen Ma, Yunhe Feng
Journal: Circulation Research (2024)

Background: Human pluripotent stem cell (hPSC)-derived cardiac organoids (COs) are extensively applied in modeling heart development and disease. COs are daily monitored by bright-field microscopic imaging for tracking organoid differentiation, morphology, and size, however, it does not provide important information on cell distribution and network in COs. Then, fluorescence microscopic imaging is required with extra steps of experiments when multiple hPSC lines are required. Recently, generative artificial intelligence (AI) has been increasingly applied for image colorization, which extends the possibility of colorizing COs with fluorescence from phase/contrast images. While the phase/contrast image is routinely applied and conveniently used in every biomedical lab daily, is it possible to generate accurate and useful fluorescence information or image colorization from the phase/contrast images of cardiac organoids under the same differentiation protocol is crucial for a broader characterization and analysis of hPSC-derived cardiac organoids and further applications? Hypothesis: We hypothesize that generative AI will generate accurate fluorescence images from phase/contrast images of COs. Approach: 1300 images from COs (differentiated from one reporter hPSC line) were used as the training dataset for the Pix2Pix Conditional Generative Adversarial Networks (GANs) model ( Fig.1a ) with the Convolution Block Attention Module (CBAM) in the U-Net generator ( Fig.1b ). Three models were designed: U-Net (Model 1), U-Net generator with CBAM (Model 2), and U-Net with CBAM and Generator Iteration (Model 3). Three different metrics were included: Peak Signal-to-Noise Ratio (PSNR), Structural Similarity Index (SSIM), and Weighted Patch Histogram to evaluate the prediction outcomes. Results: The predicted fluorescence images from phase/contrast images of different COs are very similar to the ground truths ( Fig.1c ). The similarities evaluated by all three metrics ( Fig.1d ) have the scores of PSNR over 30, SSIM over 0.92, and a Weighted Patch Histogram score over 0.75, which are the most accurate and similar to the ground truth. Conclusions: A generative AI model was established to colorize phase images of COs using cGANs and CBAM, which capture intricate fluorescence details to support the biomedical research of COs with enhanced interpretability and analysis of cardiac organoid morphology and structure in biomedical research and applications.