Fig. 7

3D cardiac microtissue for in vitro assessment of drug-induced cardiac fibrosis. a qRT-PCR analysis for mRNA expression for fibrosis-related collagen genes (Col1a1, Col1a2, and Col3a1) and TGF-β responsive genes (SERPINE1, CSNK2A, CSNK2, and CTGF) in CM-MSC cardiac microtissues independently treated with 10 μM concentration of each pro-fibrotic drug for 14 days. Data are the means±SD of three independent experimental replicates (n = 3). **p < 0.01, *p < 0.05. b Masson’s Trichrome staining to detect collagen deposition in CM-MSC cardiac microtissues following treatment with pro-fibrotic drugs for 14 days. Scale bars, 100 μm. c Immunoperoxidase staining of myofibroblast-specific marker (alpha-smooth muscle actin; α-SMA) in cardiac microtissues after treatment of pro-fibrotic drugs. Scale bars, 50 μm. d Average diameters of cardiac spheroids. Data are the means±SD of replicates (n ≥ 6). **p < 0.01. e Immunofluorescent staining of apoptotic CMs in cardiac microtissue with an apoptosis-specific marker (Cleaved caspase 3; Cl-Casp3) and cardiac-specific marker (sarcomeric-alpha actinin; SAA). White arrow indicates cells co-stained with SAA and Cl-Casp3. Scale bars, 50 μm. f Percentage of apoptotic CMs by quantifying ratio of Cl-Casp3 positive cells per number of DAPI-stained cells. Data are the means±SD of replicates (n = 4). **p < 0.01. g Immunofluorescence staining of mitochondrial-specific marker (TOM20). Nuclei were stained with DAPI (blue). Scale bars, 10 μm