The Biodistribution of Engineered MSCs
(A) The levels of CX3CL1 in different organs from control mice and mice with DSS-induced colitis. (B and C) Fluorescence quantitative analysis (B) and frozen sections of colon from mice with colitis 2 h, 24 h, and 8 days after fluorescently labeled LV-treated MSCs injection (C) (red indicates MSCs, and blue indicates DAPI nuclear staining; scale bars, 100 μm). (D) Fluorescence images of the colon from mice with colitis at 2 h, 24 h, and 8 days after the administration of different modified MSCs (MSCs 96 h post-LV infection, empty-LV-treated MSCs, or CX3CR1&IL-25-LV-MSCs). (E) Frozen sections of the colons from mice with DSS-induced colitis treated with DiI-labeled CX3CR1&IL-25-LV-MSCs 2 h post-injection were stained with endothelial cell markers (red indicates DiI-labeled CX3CR1&IL-25-LV-MSCs, green indicates CD31, and blue indicates DAPI nuclear staining). Scale bars: 200×, 100 μm; 1,000×, 20 μm. The white arrow represented extravascular DiI-labeled CX3CR1&IL-25-LV-MSCs. BV, blood vessel. Values are expressed as the mean ± SEM (n = 7 mice per group). **p < 0.01; ***p < 0.001; NS, no significant change.