Fig. 6: Formation of stress vesicles in a human skin xenograft.

a Schematic representation of the experimental design to generate a human skin xenograft for intravital imaging. b Representative examples of a stable human skin xenograft in a mouse. Magnified views show the mounting (top) and the wide-field epifluorescence image of the xenograft, acquired by live imaging. c Representative low- and high-magnification serial optical sections and corresponding orthogonal views of the human skin xenograft, obtained by two-photon microscopy. Note the ridge-like structures at the epidermal-dermal junction (Second Harmonic Generation in red), the epithelial clonal columns (K14-GFP), and the distinct multilayered organization recapitulating the human skin epidermis. Scale bars: 200 µm and 20 µm. d Hematoxylin and eosin (H&E) stained histological section of the entire length of the human skin xenograft. Scale bar: 100 µm. e, f Representative images showing nuclear deformation (e) and stress vesicle formation (f) in basal epidermal cells of the human skin xenograft. Note the nuclear deformation recapitulates what was observed in mouse skin. Similar results were obtained from four independent experiments. Scale bar: 10 µm. g, h Quantifications of the number of cells with nuclear deformation (g) and stress vesicle formation (h). Data are from N = 4 mice, n = 2500 and 2276 cells analyzed from the stressed area. Mann-Whitney test, p = 0.0286. Data are presented as mean ± SEM.