Figure 4. XAV939 treatment promotes cardiomyogenesis at the expense of other mesoderm lineages.
XAV939 treatment decreased the expressions of mesoderm-derived cell lineage markers, including the hematopoietic marker Gata1 (A), the smooth muscle-specific myosin heavy chain gene Myh11 (B), and the endothelial markers Flk-1 and vascular endothelium-cadherin (VE-cad) (C, D). XAV treatment led to huge increase in expression of cardiac markers Myh6 and Nkx2.5. Q-PCR results represent relative expression normalized to that of DMSO-treated cells at Day 0. Measurements were obtained from at least three independent experiments for each time-point. Red bars, XAV939-treated. Gray bars, DMSO-vehicle treated. (E) DMSO-treated ES cells rarely formed cells that express the cardiac Nkx2.5 protein (red immunostaining, right panel), but rather formed large patches of cells that express the endothelial Pecam-1 protein (green immunostaining, middle panel). (F) By contrast, XAV939-treated ES cells formed large areas of Nkx2.5 expressing cardiomyocytes (left panel), and considerably smaller areas of Pecam-1 expressing endothelial cells (middle panel). (E, F) Right panels, merged images.
