The Function of Peroxisome Proliferator-Activated Receptor-Gamma in the Urothelium

The urothelium is a stratified epithelium that serves as a barrier between the urinary tract and blood. It consists of terminally differentiated umbrella cells, which are specialized for synthesizing and assembling uroplakins into a tough apical plaque and responsible for the barrier function; intermediate cells which are few in number but serve as umbrella cell progenitors; and unipotent basal cells, which populate the majority of the urothelium. The urothelium is one of the most quiescent epithelia in the body but can rapidly regenerate in response to damage. The urothelium is also a source of cells that give rise to bladder cancer. Patients with chronic inflammation caused by indwelling catheters or repeated urinary tract infections have a higher risk of developing bladder cancer. Bladder cancers with squamous histological features are considered to be more aggressive with poor prognosis and the majority are categorized as basal subtype. The expression of Peroxisome Proliferator-Activated Receptor-gamma (PPARG) is strongly down regulated in the basal subtype of bladder cancer, suggesting that its removal might be essential in tumorigenesis. PPARG is a nuclear hormone receptor th