superficial cell of bladder urothelium true EMAPA:36072 immature umbrella cell TS:22-TS:25 superficial cell of bladder urothelium (TS:22-28) (TS:22-25 synonym: immature umbrella cells of bladder urothelium , at TS:26 synonym: umbrella cells of bladder urothelium): the urothelial cell type lining the bladder lumen. Part of the superficial cell layer from E14 (TS:22) to adult (TS:28). During development immature umbrella cells become multinucleated large and oval shaped as they mature. Superficial cells are specialised for the syntheseis and transport of uroplakin proteins which make up the urothelial plaque. These cell express uroplakins (whereas genetic markers of other urothelial cell types including, Krt5, Trp63, Foxa2, Isl1 and Shh, are not expressed). At TS:22, superficial cells of bladder urothelium are immature umbrella cells which are mononucleated and similar in size to the other urothelial cell types. By TS:26 mature umbrella cells, are fully differentiated, they are multinucleated (polyploidy) and are enormous in size compared to the other urothelial cell types. Fully differentiated superficial cells uniquely express Krt20, from TS:26. In the adult, they make up ~5% of the urothelium of bladder. umbrella cell TS:26-TS:28 anatomical_structure