Prospective isolation of ISL1+ cardiac progenitors from human ESCs for myocardial infarction therapy

The LIM-homeodomain transcription factor ISL1 marks multipotent cardiac progenitors that give rise to cardiac muscle, endothelium, and smooth muscle cells. ISL1+ progenitors can be derived from human pluripotent stem cells, but the inability to efficiently isolate pure populations has limited their characterization. Using a genetic selection strategy, we were able to highly enrich ISL1+ cells derived from human embryonic stem cells. Comparative quantitative proteomic analysis of enriched ISL1+ cells identified ALCAM (CD166) as a surface marker that enabled the isolation of ISL1+ progenitor cells. ALCAM+/ISL1+ progenitors are multipotent and differentiate into cardiomyocytes, endothelial cells, and smooth muscle cells. Transplantation of ALCAM+ progenitors enhances tissue recovery, restores cardiac function and improves angiogenesis through activation of AKT-MAPK signaling in a rat model of myocardial infarction, based on cardiac MRI and histology. Our study establishes a new efficient method for scalable purification of human ISL1+ cardiac precursor cells for therapeutic applications. To investigate the effect of CD166+ cells, mRNA expression profiles of H9 hESCs, ALCAM-, ALCAM-/+, and ALCAM+ cells were generated using the Agilent-039494 Human 8x60k chip (Agilent, Santa Clara, CA, USA). In each condition, gene expression profiling was performed, according to the manufacturer's instructions, on two biological replicates obtained from independent cell cultures. Total RNA was extracted, and the integrity of the total RNA was analyzed using an Agilent 2100 Bioanalyzer. RIN numbers for all the samples were larger than 8. In vitro transcription was then performed to generate cRNA, which was hybridized onto each array. The array was scanned using a SureScan Microarray Scanner (Agilent).