Urothelial cell detachment and differentiation in urinary bladder

In developing and in repairing bladder, proliferation of the transitional u rothelium is followed by cell detachment - desquamation or apoptosis. Proli feration results in formation of terminally differentiated superficial cell s and this process may be followed by checking the cells on the presence of differentiation markers. The formation of an asymmetric unit membrane (AUM ) structure (plaque) on the cell surface is in correlation with urothelial differentiation. Thus, the microstructure of the luminal surface of the uri nary bladder provides a very convenient differentiation biomarker. The surf ace of immature cells showed a pattern of microvilli. The progress of diffe rentiation was associated with microvilli arranged in rows finally forming the characteristic pattern of ridges in terminally differentiated cells. Th ese results demonstrate that the characteristic surface pattern and the AUM plaque formation in the apical plasma membrane of superficial urothelial c ells are associated with specific morphology, and patterns and thus help de tect differentiation level of cell.