Interstitial cystitis (IC) is a painful bladder syndrome of unknown etiology, characterized by chronic pelvic pain, urinary frequency and urgency. It affects an estimated 700,000 to one million people in the United States; approximately 90% of the reported sufferers are women. Diagnosis of IC is primarily based on symptoms, as there are no currently available blood or urine tests due to the lack of demonstrated biological markers. The nuclear matrix is the structural scaffolding of the cell nucleus and plays a central role in the regulation of important cellular processes. Specific nuclear matrix proteins (NMPs) have been identified as unique to certain cell types or states. Although the estimated number of different proteins in a cell might outnumber the estimated number of genes in the same cell, proteins are the functional players in cell pathophysiology. Therefore, we propose to use a proteomic approach to identify specific new markers related to chronic cystitis. Several agents, such as Nerve Growth Factor (NGF), nitric oxide (NO) and proinflammatory mediators, have been shown to exert an effect in bladder afferent pathways that could be related to frequent voiding and nociceptive responses in chronic cystitis. Thus, two hypotheses will be tested: 1) Alterations in NMPs are characteristic of the bladder with chronic irritation and can be developed into diagnostic markers and/or treatment targets for painful bladder syndrome such as IC. 2) Functional improvement of chronic cystitis after intervention on NGF, NO, and inflammatory pathways, is associated with changes in NMPs. To address these hypotheses, we propose the following Specific Aims: 1) to perform a comprehensive analysis of the nuclear matrix protein composition of the bladder with chronic irritation in comparison to normal controls to identify specific proteins associated with the disease. 2) to characterize and sequence specific nuclear matrix proteins associated with bladders with chronic irritation and to raise antibodies against these markers and to develop diagnostics tests in this regard. 3) to analyze the effect of several modulators of the bladder afferent pathway, NGF, NO and IPD-1151 T, on specific NMPs associated with the pathogenesis of chronic cystitic bladder. The long-term objectives of this research project are to identify new markers that can be used in sensitive, specific test/screens for IC and may prove of immense value in the accurate diagnosis, and even early prediction, of disease. The results of this research project could also identify new molecular targets of drug therapy for chronic bladder and/or pelvic pain associated with painful bladder syndromes, offering a better outcome for patients with IC.