Cases of reactive atypia showed similar CK20 reactivity to normal urothelium (Apparent only in the umbrella cell
layer), and p53 was at most patchy and weak, mostly in the basal cell layer.
Although outside the scope of the present study, findings with the rabbit primary culture system (29) suggest that further manipulation of the cell culture technique could modify the level of differentiation of the UROtsa cell cultures toward either the highly differentiated umbrella cell
or the undifferentiated basal cell.
The overlying urothelium was flat and appeared to be reactive rather than neoplastic, with cells with enlarged yet round nuclei with cleared chromatin and prominent nucleoli and a prominent umbrella cell
Roles of uroplakins in plaque formation, umbrella cell
enlargement, and urinary tract diseases.
(50) The normal urothelium shows CK20 positivity confined to the umbrella cell
layer, CD44 positivity in the basal cell layer, and a weak and patchy p53 nuclear staining.
In reactive urothelium, p53 is absent to focal staining, CD44 shows diffuse or patchy staining of all layers, and CK20 stains only the umbrella cell
(30,31) The surface or luminal cells are terminally differentiated umbrella cells
that express uroplakins and CK20.
In the urinary bladder, p-mTOR expression was exclusively stained in the umbrella cells
of fetal urothelium (Figure 1(f)) and extended to whole layer of the adult urothelium with still strongest staining in the umbrella cells
Due to slow turnover of the umbrella cells
, post-injury inflammation and hyperplasia, ethical drawbacks and animal cost, the in vivo study of urothelial differentiation and development is difficult.
Normal or reactive urothelium has been found to have a negative or weak Her2/Neu expression only in the superficial umbrella cells
in 93% of cases.
Stretch-regulated exocytosis/endocytosis in bladder umbrella cells
. Mol Biol Cell 2002;13:830-46http://dx.doi.org/10.1091/mbc.01-09-0435.
The biopsy specimens diagnosed as benign on H&E (Figure 1, A through D) showed multilayered urothelium along with surface umbrella cells
(cellular auto-flourescence; color-coded green) as identified on MPM.