The Urothelial Transcriptomic Response to Interferon Gamma: Implications for Bladder Cancer Prognosis and Immunotherapy.

Interferon gamma (IFNγ) is central to the inflammatory immune response, such as that entrained by BCG immunotherapy for bladder cancer. However, immune-mediated tumour cell killing is subject to modulation by immunoinhibitory "checkpoint" receptors such as PD-L1. We investigated the effects of IFNγ on barrier-forming in vitro-differentiated normal human urothelium using mRNA-sequencing, and showed canonical upregulation of MHC class I/II and de novo expression of the T cell tropic CXCL9-11 chemokines.

The human urothelial tight junction: claudin 3 and the ZO-1α switch.

Objective: Tight junctions are multicomponent structures, with claudin proteins defining paracellular permeability. Claudin 3 is a candidate for the exceptional "tightness" of human urothelium, being localised to the terminal tight junction (TJ) of superficial cells. Our aim was to determine whether claudin 3 plays an instigating and/or a functional role in the urothelial TJ.

Differentiation-associated reprogramming of the transforming growth factor β receptor pathway establishes the circuitry for epithelial autocrine/paracrine repair.

Transforming growth factor (TGF) β has diverse and sometimes paradoxical effects on cell proliferation and differentiation, presumably reflecting a fundamental but incompletely-understood role in regulating tissue homeostasis. It is generally considered that downstream activity is modulated at the ligand:receptor axis, but microarray analysis of proliferative versus differentiating normal human bladder epithelial cell cultures identified unexpected transcriptional changes in key components of the canonical TGFβ R/activin signalling pathway associated with cytodifferentiation. Changes included upregulation of the transcriptional modulator SMAD3 and downregulation of inhibitory modulators SMURF2 and SMAD7.

Toll-like receptor responses of normal human urothelial cells to bacterial flagellin and lipopolysaccharide.

Purpose: We determined toll-like receptor expression in normal human urothelium and functional responses in normal human urothelial cell cultures to bacterial lipopolysaccharide via toll-like receptor-4 and to flagellin via toll-like receptor-5.

Materials And Methods: Toll-like receptor protein expression was examined immunohistochemically. Toll-like receptor transcript expression was determined in freshly isolated urothelium, and in proliferating and differentiated normal human urothelial cultured cells.

Differentiation potential of urothelium from patients with benign bladder dysfunction.

Objective: To develop a novel in vitro approach to test the hypothesis that failure of urothelial differentiation underlies the aetiopathology of interstitial cystitis (IC), where there is evidence of compromised urinary barrier function, as benign dysfunctional bladder disease encompass several poorly understood clinically defined conditions, including IC, idiopathic detrusor overactivity (IDO) and stress urinary incontinence (SUI).

Materials And Methods: Biopsy-derived urothelial cells from dysfunctional bladder biopsies were propagated as finite cell lines and examined for their capacity to differentiate in vitro, as assessed by the acquisition of a transitional cell morphology, a switch from a cytokeratin (CK)13(lo)/CK14(hi) to a CK13(hi)/CK14(lo) phenotype, expression of claudin 3, 4 and 5 proteins, and induction of uroplakin gene transcription.

Results: Two of 12 SUI cell lines showed early senescent changes in culture and were not characterized further; one of seven IC, one of five IDO and a further three SUI cell lines had some evidence of senescence at passage 3.