Author/Editor     Romih, Rok; Jezernik, Kristijan; Mašera, Andrej
Title     Uroplakins and cytokeratins in the regenerating rat urothelium after sodium saccharin treatment
Type     članek
Source     Histochem Cell Biol
Vol. and No.     Letnik 109
Publication year     1998
Volume     str. 263-9
Language     eng
Abstract     A sodium saccharin (NaSac) diet was used to induce cell damage and regeneration in the urothelium of the male rat urinary bladder. Foci of terminally differentiated superficial cell exfoliaton were detected after 5 weeks and their number increased after 10 and 15 weeks of the diet. At the sites of superficial cell loss, regenerative simple hyperplasia developed. Within 5 weeks of NaSac removal, regeneration re-established normal differentiated urothelium. In order to follow urothelial differentiation during regeneration we studied the expression of uroplakins and cytokeratins by means of immunocytochemistry and immunohistochemistry, respectively. Normal urothelium was characterised by terminally diffrentiated superficial cells which expressed uroplakins in their luminal plasma membrane and cytokeratin 20 (CK20( in the cytoplasm. Basal and intermediate cells were CK20 negative and cytokeratin 17 (CK17) positive. In hyperplastic urothelium all cells synthesised CK17, but not CK20. Differentiation of the superficial layer was reflected inthree successive cell types: cells with microvilli, cells with rounded microridges and those with a rigid-looking plasma membrane on the luminal surface. The cells with microvilli did not stain with anti-uroplakin antibody. When the synthesis of uroplakins was detected rounded microridges were formed. With the elevated expression of uroplakins the luminal plasma membrane becomes rigid-looking which is characteristic of asymmetric unit membrane of terminally differentiated cells. During differentiation, synthesis of CK17 ceased in superficial cells hile the synthesis of CK20 started. These results indicate that during urothelial regeneration after NaSac treatment, specific superficial cell types develop in which the switch to uroplakin synthesis and transition from CK17 to CK20 synthesis are crucial events for terminal differentation.
Descriptors     UROTHELIUM
SACCHARIN
REGENERATION
KERATIN
MEMBRANE GLYCOPROTEINS
RATS, WISTAR
CARCINOGENS
MEMBRANE PROTEINS