Figure 4

Biological validation of cardiogenic network. (a) LIF cultured stem cells were left untreated for 48 h after LIF withdrawal or were treated with VEGF, IGF1 or IL6. Changes in expression of the cardiac transcription factor MEF2C were revealed through immunocytochemistry. Nuclei were counterstained with DAPI. Scale bar: 10 μm. (b) Stem cell-derived embryoid bodies were observed for the formation of beating areas (yellow circles) at day 9 (D9) in untreated, BMP4, LAP and NOG supplemented conditions, with treatments beginning at day zero (D0). Scale bar: 1 μm. (c) Measurement of contractile area activity using Metamorph software. Data reported as mean number of beating areas ± SEM, *P < 0.05, n = 40-50 embryoid bodies. (d) Visualization of beating areas in embryoid bodies treated at day 5 (D5) with LIF, involved in JAK/STAT signaling (left). Evaluation of beating area as a percentage of total area occupied by embryoid body (right). Data reported as mean number of beating areas ± SEM, *P < 0.05, n = 40-50 embryoid bodies.