Ureterovesical junction: a stem cell niche for ureteral urothelial renewal and bladder urothelial injury repair

Here we show that ureterovesical junction (UVJ) of urinary tract harbors a major cluster of label-retaining urothelial cells that exhibit organoid-forming activities. During lineage-tracing, these Foxa2-expressing UVJ urothelial cells renew ureteral urothelium, but do not migrate into the bladder during homeostasis or mild bladder injury.

Upon mechanical and chemical denudation of bladder urothelium, UVJ cells migrate rapidly into the bladder to replace bladder urothelium. This reepithelization also occurs during combination chemotherapies and severe bladder infection. Common to these injury repair processes is the early-phase and selective phosphorylation of TRKA and AKT which drives urothelial proliferation and differentiation.