FIG. 4.

Blocking ITGB4 and/or ITGB5 reduced both the percentage of cardiomyocyte (CM) positive cells and p-FAK–expressing cells in differentiating hESC cultures. The reduced numbers of cTnI⁺ and Nkx2.5⁺ cells in differentiated hESC cultures (A) H7 and (B) H9 treated with ITGB4 and/or ITGB5 blocking antibodies at day 14 correlate with the reduction in p-FAK. Blocking MEK signaling inhibited cardiomyocyte differentiation from H7 (C) and H9 (D). The cTnI⁺, Nkx2.5⁺, and p-ERK⁺ cells in differentiation cultures were significantly much greater compared with cultures treated with MEK inhibitor U0126 at day 14. Bars indicate statistically significant differences between the indicated groups.