Proteoglycan core protein syndecan in bladder biopsies.

The etiology of interstitial cystitis (IC) may be related to a dysfunctional epithelium caused by an abnormal permeability barrier. The presence of deleterious urinary substances (quaternary amines) that alter an otherwise normal epithelium may also be contributory. IC disease could reflect an inability of the bladder to repair its protective surface-coat material (glycosaminoglycans and proteoglycans), which is constantly exposed to a toxic urine environment. Bladder biopsy tissue from IC patients and derived explant cells were investigated to determine if mRNA for a proteoglycan core protein could be extracted and evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). Syndecan was chosen for this investigation because the available sequence information permitted PCR primers to be synthesized. The results indicated that biopsy tissue and explant cells could be utilized for the isolation of syndecan core protein mRNA. This proteoglycan was also demonstrated in mouse bladders by immunostaining and immunoblotting (but not in human tissues) using a syndecan-specific monoclonal antibody (281-2). Quantitative differences in IC tissues versus normal bladder tissue with respect to gene expression for this proteoglycan core protein can now be determined.