Abstract 6: Novel Tools for Generation, Purification, and Analysis of Pluripotent Stem Cell Derived Cardiomyocytes
Pure and well-characterized cardiac cells derived from human pluripotent stem cells (hPSCs) are of high interest for cardiovascular disease modeling, drug safety studies and development of cell replacement strategies. Although several protocols for cardiac differentiation of hPSCs have been developed, major limitations are clone-to-clone variations in differentiation efficacy as well as heterogeneity of generated cardiomyocyte populations. Therefore, we have developed novel tools for cardiomyocyte differentiation, magnetic cell sorting-based purification and cell analysis using new antibody-conjugates enabling for flow cytometry- and immunofluorescence-based identification of cardiomyocytes and subtypes.
hPSCs were maintained under xeno-free conditions in our recently developed StemMACS iPS-Brew XF medium to keep pluripotency for more than >20 passages and enable for efficient cardiac differentiation. We chose a monolayer differentiation protocol based on the timely regulated activation and inhibition of Wnt signaling by small molecules.
In order to identify antibodies suitable for cardiomyocyte enrichment or depletion of non-myocytes, we performed a surface marker screen with more than 400 antibodies between days 10-20 of differentiation. Besides identification of new surface markers, our screen confirmed expression of recently published markers like CD172a and CD106. In order to evaluate kinetics of their expression and correlation with intracellular markers of cardiomyocytes and subtypes, we performed a flow cytometry-based analysis of marker expression. Our data indicate a dynamic expression pattern for both CD172a and CD106, either completely or partially overlapping with intracellular cardiomyocyte marker expression. Based on these data we developed magnetic cell separation procedures for the isolation of cardiomyocytes. Magnetically enriched cardiomyocytes initiated contractions after replating and could be stably maintained in culture.
Taken together, we have developed novel tools supporting the workflow for efficient generation of PSC-derived cardiomyocytes, magnetic purification and flow cytometry or immunofluorecence-based characterization of cardiomyocytes.
Author Disclosures: D. Eckardt: 1. Employment; Significant; Miltenyi Biotec GmbH. K. Noack: 1. Employment; Significant; Miltenyi Biotec GmbH. A. Bosio: 1. Employment; Significant; Miltenyi Biotec GmbH.
- © 2015 by American Heart Association, Inc.