title: Identification of telocytes in the upper lamina propria of the human urinary tract.
abstract: The upper lamina propria (ULP) area of interstitial cells (IC) has been studied extensively in bladder, but is rather unexplored in the rest of the urinary tract. This cell layer is intriguing because of the localization directly underneath the urothelium, the intercellular contacts and the close relationship with nerve endings and capillaries. In this study, we examine the ULP layer of IC in human renal pelvis, ureter and urethra, and we make a comparison with ULP IC in bladder. Tissue was obtained from normal areas in nephrectomy, cystectomy and prostatectomy specimens, and processed for morphology, immunohistochemistry and electron microscopy. A morphological and immunohistochemical phenotype for the ULP IC was assessed and region-dependent differences were looked for. The ULP IC in renal pelvis, ureter and urethra had a similar ultrastructural phenotype, which differed somehow from that of bladder IC, that is, thinner and longer cytoplasmic processes, no peripheral actin filaments and presence of dense core granules and microtubules. Together with their immunohistochemical profile, these features are most compatible with the phenotype of telocytes, a recently discovered group of stromal cells. Based on their global ultrastructural and immunohistochemical phenotype, ULP IC in human bladder should also be classified as telocytes. The most striking immunohistochemical finding was the variable expression of oestrogen receptor (ER) and progesterone receptor (PR). The functional relevance of ULP telocytes in the urinary tract remains to be elucidated, and ER and PR might therefore be promising pharmacological research targets.
authors.affiliation: Department of Urology, KU Leuven, University Hospitals Gasthuisberg, Leuven, Belgium. Thomas.Gevaert@med.kuleuven.be
authors.forename: Thomas
authors.initials: T
authors.lastname: Gevaert
authors.forename: Rita
authors.initials: R
authors.lastname: De Vos
authors.forename: Frank
authors.initials: F
authors.lastname: Van Der Aa
authors.forename: Steven
authors.initials: S
authors.lastname: Joniau
authors.forename: Joost
authors.initials: J
authors.lastname: van den Oord
authors.forename: Tania
authors.initials: T
authors.lastname: Roskams
authors.forename: Dirk
authors.initials: D
authors.lastname: De Ridder
mesh_terms: D000328:Adult; D006801:Humans; D007150:Immunohistochemistry; D056885:Interstitial Cells of Cajal / Q000166:cytology; D007682:Kidney Pelvis / Q000166:cytology / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D009092:Mucous Membrane / Q000166:cytology* / Q000648:ultrastructure; D010641:Phenotype; D011960:Receptors, Estrogen / Q000032:analysis*; D011980:Receptors, Progesterone / Q000032:analysis*; D014513:Ureter / Q000166:cytology* / Q000648:ultrastructure; D014521:Urethra / Q000166:cytology* / Q000648:ultrastructure; D001743:Urinary Bladder / Q000166:cytology; D019459:Urothelium / Q000166:cytology / Q000648:ultrastructure
chemical_list: D011960:Receptors, Estrogen; D011980:Receptors, Progesterone