The beating cluster of adipose tissue-derived stromal cells

Adipose tissue-derived stromal vascular fraction (Ad-SVF) contains stem cells and rarely transdifferentiate into spontaneously beating cardiomyocyte-like cells (beating CMs). However, the factors that regulate the differentiation of Ad-SVF into the cardiac lineage is unknown. We developed a simple culture protocol under which the adult murine inguinal Ad-SVF reproducibly transdifferentiates into beating CMs without induction. We used microarray analyses to evaluate the global gene expressions of the beating CMs and investigated the mechanism underlying the transdifferentiation of SVF cells into CMs. To investigate the phenotype of the beating SVF cells, we performed a global transcriptome analysis. All of the beating SVF colonies in a dish on day 28 were manually picked up and combined, constituting the beating-SVF (beating) group. The other cells were collected as the non-beating SVF (non-beating) group. To test our hypothesis that the round cells were the progenitors of CMs, we performed a single-cell-based global gene expression analysis. At day 14 of primary SVF culture, six round cells were picked up using the ALS CellCelector system and combined for microarray analysis.