Biology subjects

Budan, A.

Publications and source records attributed to Budan, A..

3 recordsLinked to original sources

bioRxiv2025

SYNPO2L Isoforms Regulate the Action Potential Characteristics and Contractility of Atrial Cardiomyocytes via YAP Signaling to Modulate Atrial Fibrillation Risk

BackgroundSYNPO2L is a component of the sarcomere Z-disk with two distinct isoforms (SYNPO2L_A and SYNPO2L_B) described to regulate actin bundle size. Common and rare variations in SYNPO2L have been implicated in risk for heart failure and atrial fibrillation (AF); however, little is known about the function or pathophysiological mechanism upon disease risk. MethodsThe role of SYNPO2L was explored with human induced pluripotent stem cell cardiomyocyte (hiPSC-CM) models of a rare splicing mutation rs766868752 differentiated into both atrial and ventricular lineages. Electrophysiology was assessed via multi-electrode arrays (MEAs) and contractility was assessed using engineered heart tissues (EHTs). Genetic survival analyses were performed to explore the potential therapeutic role of the SYNPO2L_A isoform in AF risk after myocardial infarction. ResultshiPSC-CMs carrying the splice mutation rs766868752 resulted in preferential expression of the SYNPO2L_B isoform and absence of SYNPO2L_A isoform, and atrial hiPSC-CMs displayed significant differences in action potential durations when unpaced, and spontaneous extra-systolic beats when paced. Contractility of atrial hiPSC-CMs carrying the splice mutation was severely compromised. Electrophysiological differences were normalized and contractility was partially restored by overexpression with AAV:SYNPO2L_A. Absence of SYNPO2L_A in the mutant led to an observed decreased phosphorylation of YAP along with significant downstream transcriptional effects. A direct interaction between SYNPO2L_A and LATS2, a known regulator of YAP phosphorylation was found to occur in hiPSC-CMs. Additionally, a common variant time-to-event analysis may suggest a beneficial effect of the SYNPO2L_A isoform to lower the risk of atrial fibrillation after myocardial infarction. ConclusionsA rare splice mutation conferring isoform predominance of SYNPO2L_B appears to disturb the electrophysiology and contractility of atrial hiPSC-CMs via LATS2 phospho-regulatory effects upon YAP signaling. Supplementation of the SYNPO2L_A isoform can restore many functional deficits and supports a specific gene regulatory role for SYNPO2L in modulating the risk of AF and heart failure.

cell biology↗

bioRxiv2024

Gene Therapy Mediates Therapeutic Improvement in Cardiac Hypertrophy and Survival in a Murine Model of MYBPC3-Associated Cardiomyopathy

BackgroundHypertrophic cardiomyopathy (HCM) affects an estimated 600,000 people in the U.S. and is the leading cause of sudden cardiac arrest in those under 18. Loss-of-function mutations in Myosin Binding Protein C3, MYBPC3, are the most common genetic cause of HCM. The majority of MYBPC3 mutations causative for HCM result in truncations. The sarcomeric pathophysiology of the majority of HCM patients with MYBPC3 mutations appears to be due to haploinsufficiency, as the total amount of MYBPC3 protein incorporated into sarcomeres falls significantly below normal. MethodsA clear path for the treatment of haploinsufficiency is the restoration of the insufficient gene product; in this case wild-type MYBPC3. To achieve this, we engineered an AAV vector (TN-201) with superior properties for mediating cardiomyocyte-selective expression of MYBPC3 after systemic delivery. ResultsWe have demonstrated for the first time with AAV gene therapy the ability of both a mouse surrogate and TN-201, which encodes human MYBPC3 to reverse cardiac hypertrophy and systolic dysfunction and to improve diastolic dysfunction and survival in a symptomatic MYBPC3-deficient murine model of disease. Dose-ranging efficacy studies exhibited restoration of wild-type MYBPC3 protein levels and saturation of cardiac improvement at the clinically relevant dose of 3E13 vg/kg, outperforming a previously published construct. Further, we have established stable cardiac benefit for greater than one year post-injection, as well as reversal of cardiac dysfunction even in late-stage models of disease. ConclusionsOur data suggest that by restoring MYBPC3 to the sarcomere, TN-201 has the potential to slow and even reverse the course of the disease in patients with MYBPC3-associated HCM.

genetics↗

bioRxiv2021

Deep Learning Predicts Patterns of Cardiotoxicity in a High-Content Screen Using Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Drug-induced cardiotoxicity and hepatotoxicity are major causes of drug attrition. To decrease late-stage drug attrition, pharmaceutical and biotechnology industries need to establish biologically relevant models that use phenotypic screening to predict drug-induced toxicity. In this study, we sought to rapidly detect patterns of cardiotoxicity using high-content image analysis with deep learning and induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). We screened a library of 1280 bioactive compounds and identified those predicted to have cardiotoxic liabilities using a single-parameter score based on deep learning. Compounds with major predicted cardiotoxicity included DNA intercalators, ion channel blockers, epidermal growth factor receptor, cyclin-dependent kinase, and multi-kinase inhibitors. We also screened a diverse library of molecules with unknown targets and identified chemical frameworks with predicted cardiotoxic liabilities. By using this screening approach during target discovery and lead optimization, we can de-risk early-stage drug discovery. We show that the broad applicability of combining deep learning with iPSC technology is an effective way to interrogate cellular phenotypes and identify drugs that protect against diseased phenotypes and deleterious mutations. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=161 HEIGHT=200 SRC="FIGDIR/small/436666v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@695707org.highwire.dtl.DTLVardef@1d0980forg.highwire.dtl.DTLVardef@1af30e7org.highwire.dtl.DTLVardef@b3a312_HPS_FORMAT_FIGEXP M_FIG C_FIG CONTRIBUTION TO THE FIELDIn this article, Grafton and colleagues use induced pluripotent stem cell technology and deep learning to train a neural network capable of detecting patterns of cardiotoxicity. To identify bioactive and chemical classes that lead to cardiotoxicity, they combine the neural network with high-content screening of 2560 compounds. The methods described in this study can be used to de-risk early-stage drug development, triage hits, and identify drugs that protect against disease. This screening paradigm will serve as a useful resource for drug discovery and phenotypic interrogation of stem cells and stem cell-derived cell types.

cell biology↗