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BSP-16
(P)
PERSISTANT HYPOXIA: BAD NEWS FOR THE UROTHELIUM
Anna RADFORD
1
, Ramnath SUBRAMANIAM
2
and Jennifer SOUTHGATE
3
1) Jack Birch Unit. University of York, Department of Biology, York, UNITED KINGDOM - 2) Leeds Teaching Hospitals
NHS Trust, Department of Paediatric Urology and Surgery, Leeds, UNITED KINGDOM - 3) Jack Birch Unit, University of
York, Department of Biology, York, UNITED KINGDOM
PURPOSE
End-stage bladder disease is characterised by fibrosis and loss of capacity. The contributing pathways are unknown, but
may include hypoxia as a consequence of recurrent infection and inflammation. Urothelial cells harvested from diseased
bladders have a compromised capacity to propagate or differentiate in vitro (Subramaniam et al. J.Urol 2011;186:2014-
20), potentially limiting autologous tissue engineering approaches.
MATERIAL AND METHODS
Sections of neuropathic and normal bladder urothelia were immunolabelled for hypoxia-inducible factor 1α
(HIF1α). Image analysis of nuclear labelling intensity was used to quantify hypoxia-induced pathway
activation. Hypoxic culture conditions were used to investigate the impact of hypoxia on urothelial cell proliferation and
differentiation, with urothelial barrier function monitored electrophysiologically. Organ cultures were maintained in
normoxic and hypoxic conditions before immunohistochemical evaluation of urothelial phenotype.
RESULTS
An increase in nuclear HIF1α was found in end-stage bladders (p<0.001, n=18912). Chronic hypoxia had a detrimental
impact on urothelial cell proliferation (p<0.001, n=9) and form a functional barrier (p<0.001, n=9). Organ cultures
demonstrated reduced urothelial thickness in hypoxia-exposed samples, with a diminution of urothelial Ki67 and CK20
immunolabelling.
CONCLUSIONS
The urothelium is not implicated directly in aetiopathologies that can result in terminal loss of bladder function, but yet
is compromised as a result. A role for hypoxia in end-stage bladder disease was indicated from nuclear HIF-1α
expression in situ. We have for the first time demonstrated that hypoxic conditions in vitro are able to replicate the
compromised phenotype seen in urothelial cells from end-stage bladders, which may offer new approaches for the
future.