Fig. 2
Histamine promotes the efficiency of cardiac differentiation. a Schematic timeline of the protocol used to direct human iPSCs into myocardial cells and the accompanying changes in cytokines. b The percentages of contracting CMs derived from hiPSCs under different concentrations of histamine treatment on day 10. c Gene expression of NKX2.5, cTnT, MYH6, and MYH7 in cardiomyocytes derived from hiPSCs under histamine (10−5 M) treatment. d The time required for the initial beating cardiomyocytes to appear. e Typical bright-field images of beating areas and immunofluorescence staining of cTNI in hiPSC-CMs on day 10. Scale bar 100 μM. The red dotted circles show the beating area. f Percentages of cTnT+ cardiomyocytes derived from hiPSCs on day 10 analyzed by FACS. g Immunofluorescence co-staining of α-actinin and cTnI (scale bar 100 μM) following histamine treatment. h Western blotting analysis of cTnT, α-actinin, and CX43 in hiPSC-CMs after histamine treatment. Data are expressed as the mean ± SEM. *p < 0.05, **p < 0.01, vs control (n = 3 for each group)