Fig. 3.

Histamine promotes the generation of cardiac progenitor cells from hiPSCs during directed cardiomyocyte differentiation. a Schematic diagram of the differentiation protocols (left panel); corresponding efficiency of cardiac differentiation of hiPSCs (right panel). b Gene expression of BRACHYURY, MESP1, and NKX2.5 respectively on days 2, 3, and 5 of differentiation. c Representative co-immunostaining views of GATA4 (green), NKX2.5 (red), and nuclei (blue) in cardiac progenitor cells on day 5 post-histamine administration. Scale bar 100 μM. d The protein levels of GATA4, MEF2C, and NKX2.5 in differentiated hiPSCs after 5 days of differentiation. The quantitative data are shown in the right panel. e The percentages of NKX2.5⁺ cells were analyzed by FACS. Data are expressed as mean ± SEM.*p < 0.05 vs control, **p < 0.01 vs control (n = 3 for each group)