Figure 6. Simulated microgravity and 3D culture increase the proliferation of cardiac progenitors.

(A) Representative images, flow cytometry analysis and summary of cells at differentiation day 10 that were co-stained with EdU and an antibody against NKX2-5, a marker for cardiac progenitors. Scale bars = 100 μm. The quantitative summary was based on flow cytometry analysis. Data are presented as mean ± SD of 3 biological replicates. Scale bar = 100 μm. (B) Similar analyses to (A) except that Ki-67 instead of EdU was co-stained with NKX2-5. (C) Similar analyses to (A) except that IAK1 instead of EdU was co-stained with NKX2-5. (D) Relative expression levels of genes associated with proliferation and cell cycle in cells at differentiation day 8 according to qRT-PCR. Data are presented as mean ± SD of 8 biological replicates x 3 reactions/sample. *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001.