Transcriptomic and phenotypic analysis of murine embryonic stem cell derived BMP2+ lineage cells:: an insight into mesodermal patterning

Background: Bone morphogenetic protein (BMP)2 is a late mesodermal marker expressed during vertebrate development and plays a crucial role in early embryonic development. The nature of the BMP2-expressing cells during the early stages of embryonic development, their transcriptome and cell phenotypes developed from these cells have not yet been characterized. Results: We generated a transgenic BMP2 embryonic stem (ES) cell lineage expressing both puromycin acetyltransferase and enhanced green fluorescent protein (EGFP) driven by the BMP2 promoter. Puromycin resistant and EGFP positive BMP2(+) cells with a purity of over 93% were isolated. Complete transcriptome analysis of BMP2(+) cells in comparison to the undifferentiated ES cells and the control population from seven-day-old embryoid bodies (EBs; intersection of genes differentially expressed between undifferentiated ES cells and BMP2(+) EBs as well as differentially expressed between seven-day-old control EBs and BMP2(+) EBs by t-test, p < 0.01, fold change > 2) by microarray analysis led to identification of 479 specifically upregulated and 193 downregulated transcripts. Transcription factors, apoptosis promoting factors and other signaling molecules involved in early embryonic development are mainly upregulated in BMP2(+) cells. Long-term differentiation of the BMP2(+) cells resulted in neural crest stem cells (NCSCs), smooth muscle cells, epithelial-like cells, neuronal-like cells, osteoblasts and monocytes. Interestingly, development of cardiomyocytes from the BMP2(+) cells requires secondary EB formation. Conclusion: This is the first study to identify the complete transcriptome of BMP2(+) cells and cell phenotypes from a mesodermal origin, thus offering an insight into the role of BMP2(+) cells during embryonic developmental processes in vivo.