Fig. 5

IGBP1P1 is vital in cell size and contractility in human cardiac tissue mimetics. A Relative mRNA expression of RP11-98F14.11, COL3A1, MMP2, TGFb1, NPPA, NPPB, MYH7 and ratio MYH7/6 in MCOs transduced with either GM RP11-98F14.11 or GM Ctrl in both normoxia and hypoxia. Data are represented as Mean ± SEM; n = 3; *P < 0.05, **P < 0.01 vs. Normoxia GM Ctrl, %P < 0.05 vs. Hypoxia GM Ctrl. B Relative mRNA expression of RPL23AP92, COL3A1, MMP2, TGFb1, NPPA, NPPB, MYH7 and ratio MYH7/6 were detected. Data are represented as Mean ± SEM; n = 3; *P < 0.05, **P < 0.01 vs. Normoxia GM Ctrl, %P < 0.05 vs. Hypoxia GM Ctrl. C Relative mRNA expression of IGBP1P1, COL3A1, MMP2, TGFb1, NPPA, NPPB, MYH7 and ratio MYH7/6 in MCOs transduced with either GM IGBP1P1 or GM Ctrl in both normoxia and hypoxia. Data are represented as Mean ± SEM; n = 3; *P < 0.05, **P < 0.01 vs. Normoxia GM Ctrl, %P < 0.05 vs. Hypoxia GM Ctrl. D Representative images of α-actinin (red) and DAPI (blue) in 40-day-old human MCOs after GM IGBP1P1 or the GM Ctrl in normoxia or hypoxia for 3 days. Scale bar is 50 µm. E Cardiomyocyte cell size in the MCOs was assessed by the Image J. 50 cells were analyzed for each condition. Data are represented as Mean ± SEM; n = 3; **P < 0.01 vs. Normoxia GM Ctrl, %P < 0.05 vs. Hypoxia GM Ctrl. F Human MCOs were treated with GM IGBP1P1 or GM Ctrl in both normoxia and hypoxia for 3 days, and then the frequency of CMO contraction was determined by counting beats per minute. Data are represented as Mean ± SEM; 4–5 organoids per group; **P < 0.01 vs. Normoxia GM Ctrl, %P < 0.05 vs. Hypoxia GM Ctrl. G Representative traces of contractile MCOs. H The contractility assays were performed by determining the amplitude peak of contracting MCOs. Data are represented as Mean ± SEM; 4–5 organoids per group; *P < 0.05 vs. Normoxia GM Ctrl, %P < 0.05 vs. Hypoxia GM Ctrl. All by one-way ANOVA analyses followed by a Dunnett’s multiple comparison post-test. MCOs, monoculture cardiac organoids