Project description:Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia treatable with antiarrhythmic drugs, but patient responses are highly variable. Human induced pluripotent stem cell-derived atrial cardiomyocytes (iPSC-aCMs) are useful for discovering precision therapeutics, but current platforms yield an immature cellular phenotype and are not easily scalable for high-throughput screening. Here, we report that primary adult atrial, but not ventricular, fibroblasts induced greater functional iPSC-aCM maturation, partly through connexin-40 and ephrin-B1 signaling. We developed a protein patterning process within industry-standard multiwell plates to engineer patterned co-culture (PC) of iPSC-aCMs and atrial fibroblasts that significantly enhanced iPSC-aCM structural, electrical, contractile, and metabolic maturation for 6+ weeks versus conventional mono-/co-cultures. PC displayed greater sensitivity for detecting drug efficacy than monocultures, and enabled the modeling and pharmacological or gene editing treatment of an AF-like electrophysiological phenotype due to a sodium channel mutation. In conclusion, PC is useful to elucidate heterotypic cell signaling in the atria, drug screening, and to model AF.
Project description:Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia treatable with antiarrhythmic drugs, but patient responses are highly variable. Human induced pluripotent stem cell-derived atrial cardiomyocytes (iPSC-aCMs) are useful for discovering precision therapeutics, but current platforms yield an immature cellular phenotype and are not easily scalable for high-throughput screening. Here, we report that primary adult atrial, but not ventricular, fibroblasts induced greater functional iPSC-aCM maturation, partly through connexin-40 and ephrin-B1 signaling. We developed a protein patterning process within industry-standard multiwell plates to engineer patterned co-culture (PC) of iPSC-aCMs and atrial fibroblasts that significantly enhanced iPSC-aCM structural, electrical, contractile, and metabolic maturation for 6+ weeks versus conventional mono-/co-cultures. PC displayed greater sensitivity for detecting drug efficacy than monocultures, and enabled the modeling and pharmacological or gene editing treatment of an AF-like electrophysiological phenotype due to a sodium channel mutation. In conclusion, PC is useful to elucidate heterotypic cell signaling in the atria, drug screening, and to model AF.
Project description:To gain further insight into the mechanisms underlying the different response of atrial- and ventricular-like cardiomyocytes to ibrutinib, we performed RNA-seq in ibrutinib- or vehicle-treated atrial and ventricular cardiomyocytes and investigate the differential expression genes as well as enriched molecular pathways.
Project description:To investigate the chamber selective transcriptional programs, we performed RNA-seq on purified cardiomyocytes. Totally we have 5 replicates for atrial cardiomyocytes and 5 replicates for ventricular cardiomyocytes.
Project description:Central questions like cardiomyocyte subtype emergence during cardiogenesis or availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, characterization and implementation of pure cardiomyocyte subtypes is still challenging due to technical limitations. Our aim was to identify surface markers enabling the selective detection and purification of atrial and ventricular cardiomyocytes from mouse hearts. In a surface marker screen we found differential expression of CD49f in atrial and ventricular embryonic cardiomyocytes (E13.5). By flow cytometry we could correlate a high CD49f expression with MLC-2a on the single cell level; a low CD49f expression corresponded to MLC-2v. Based on the persisting differential CD49f expression we developed purification protocols for cardiomyocytes subtypes from the developing mouse heart. Flow sorting of E15.5 hearts into ErbB-2+/CD49flow and ErbB-2+/CD49fhigh cells led to a selective depletion (CD49flow) or enrichment of MLC-2a+ cells (CD49fhigh). We found a corresponding CD49f-dependent distribution of MLC-2a when pre-enriched neonatal cardiomyocytes (P2) were flow-sorted into CD49flow and CD49fhigh. Atrial and ventricular identity was confirmed by expression profiling and patch clamp analysis of sorted embryonic hearts, which unequivocally demonstrated that the sorted cells were viable and functional. For the first time, we introduce a non-genetic, antibody-based approach to specifically isolate atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This newly gained capability of obtaining highly pure, viable cells will facilitate in-depths characterization of the individual cellular subsets and will aid translational research and therapeutic applications. The dataset comprises four different cardiomyocytes subtypes from the developing mouse heart. Embryonic (E15.5) hearts were dissociated and flow-sorted into ErbB-2+/CD49flow and ErbB-2+/CD49fhigh cardiomyocytes. Neonatal (P2) hearts were dissociated, contaminating non-myocytes were removed by MACS depletion, and the purified cardiomyocytes were flow-sorted into CD49flow and CD49fhigh cardiomyocytes. Four biological replicates were available for each sample groups. Microarray analysis was conducted on the Agilent Whole Mouse Genome Oligo Microarray 8x60K platform.
Project description:Central questions like cardiomyocyte subtype emergence during cardiogenesis or availability of cardiomyocyte subtypes for cell replacement therapy require selective identification and purification of atrial and ventricular cardiomyocytes. However, characterization and implementation of pure cardiomyocyte subtypes is still challenging due to technical limitations. Our aim was to identify surface markers enabling the selective detection and purification of atrial and ventricular cardiomyocytes from mouse hearts. In a surface marker screen we found differential expression of CD49f in atrial and ventricular embryonic cardiomyocytes (E13.5). By flow cytometry we could correlate a high CD49f expression with MLC-2a on the single cell level; a low CD49f expression corresponded to MLC-2v. Based on the persisting differential CD49f expression we developed purification protocols for cardiomyocytes subtypes from the developing mouse heart. Flow sorting of E15.5 hearts into ErbB-2+/CD49flow and ErbB-2+/CD49fhigh cells led to a selective depletion (CD49flow) or enrichment of MLC-2a+ cells (CD49fhigh). We found a corresponding CD49f-dependent distribution of MLC-2a when pre-enriched neonatal cardiomyocytes (P2) were flow-sorted into CD49flow and CD49fhigh. Atrial and ventricular identity was confirmed by expression profiling and patch clamp analysis of sorted embryonic hearts, which unequivocally demonstrated that the sorted cells were viable and functional. For the first time, we introduce a non-genetic, antibody-based approach to specifically isolate atrial and ventricular cardiomyocytes from mouse hearts of various developmental stages. This newly gained capability of obtaining highly pure, viable cells will facilitate in-depths characterization of the individual cellular subsets and will aid translational research and therapeutic applications.
Project description:Our study aims to illustrate the potential use of atrial iPSC-CMs for modeling AF in a dish, elucidating the underlying cellular mechanisms, and identifying novel mechanism-based therapies custom-tailored for individual patients
Project description:Current differentiation protocols for human pluripotent stem cells produce a heterogeneous population of cardiomyocytes (CMs). Here, we identified CD151 as a marker of ventricular CMs (VCMs) and atrial CMs (ACMs) from 212 different cell surface markers. In the VCM induction, CD151high CMs were a homogeneous population of mature VCMs, including binuclear VCMs, and showed enriched cell cycle-related genes based on RNA-seq analysis. As for the ACM induction, CD151low CMs expressed high levels of atrial-related genes and exhibited atrial-type electrophysiological properties. According to RNA-seq analysis, CD151high CMs from the ACM induction had molecular signatures for cell-cell interactions and NOTCH signaling. When treated with a NOTCH signal inhibitor, the same cells showed mature electrophysiological properties consistent of ACMs with an increasing expression of atrial-related genes. Altogether, we found that CD151 is an indicator of subtype specification with distinct mechanisms between VCM and ACM differentiation and that NOTCH signaling inhibition enhances atrial specification.