Extended Data Fig. 4: Bladder assembloids mimic the pathophysiology and represent tissue dynamics during urinary tract infection.
From: Creation of bladder assembloids mimicking tissue regeneration and cancer
a, Schematic diagram for establishment of in vivo and in vitro models of UTI. b, UTI89 labelled with the fluorescent protein, AmCyan, was microinjected into the lumen bladder assembloids. Scale bars, 100 μm. c, d, Wild-type bladders (c) and bladder assembloids (d) were analysed by immunostaining. Scale bars, 50 μm. e, Wild-type bladders and bladder assembloids were analysed by immunostaining (white arrowheads, intracellular bacterial aggregates within superficial cells). Scale bars, 50 μm. f, Wild-type bladders and bladder assembloids were immunostained for KRT5, KRT18 and vimentin to highlight basal epithelial cells, luminal epithelial cells, and stromal cells, respectively. Scale bars, 100 μm. g, h, Bladder assembloids reconstituted with different cell types from Col1a2CreER;Smofl/fl mice (g, wild-type Smo; h, Smo ablated) analysed by immunostaining. The quantification of epithelial and stromal cell proliferations is shown in the right panels. Scale bars, 100 μm. i, Schematic representation of the Rainbow allele. After Cre-mediated excision of three lox sites (lox2272, loxN, and loxP) induced by tamoxifen (TM), each cell expresses either EGFP (before recombination) or mCerulean, mOrange, or mCherry (after recombination). j, Single-cell-labelled normal bladder or bladder organoid from Rainbow mouse after TM treatment. Scale bars, 100 μm. k, Experimental scheme for in vivo and in vitro lineage tracing of KRT5-expressing basal epithelial cells. l, Bladders from TM-injected Krt5CreERT2;Rosa26Rainbow/WT mice and bladder assembloids derived from Krt5CreERT2;Rosa26Rainbow/WT mice treated with 4-OHT were analysed before (UPEC day 0) and after (UPEC day 7) bacterial injection using four-colour fluorescence. Scale bars, 100 μm. m, Model for clonal relationship during UTI-induced urothelial regeneration. For details on statistics, sample sizes (n), and numbers of replications, see ‘Statistics and reproducibility’ (Methods).
