Doxorubicin induces autolysosome accumulation in mouse heart. (A) Representative fluorescence images of heart tissue sections from CAG-RFP-GFP-LC3 transgenic mice 24 hours after one-dose DOX injection. Bafilomycin A1 (1.5 mg/kg, BafA1) was injected intraperitoneally 2 hours before sacrifice. Autophagosome (yellow puncta) and autolysosome (red puncta) numbers in heart after DOX/NS treatment were calculated. N = 4–5 hearts per group with 6 microscopic fields (14,000 μm2) per heart section analyzed. Scale bar, 20 μm. NS, normal saline. DOX, doxorubicin. HPF, high-power field. One-way ANOVA and subsequent Tukey tests were performed for analyzing autophagosome numbers and autolysosome numbers respectively, among different groups. *, p < 0.05.