aprepitant and Cystitis--Interstitial

To identify the effects of the neurokinin-1 receptor (NK1R) antagonist aprepitant in treating pelvic pain, micturition symptoms, and bladder inflammation in mice with experimental autoimmune cystitis (EAC) similar to bladder pain syndrome/interstitial cystitis (BPS/IC). Female C57BL/6 mice were divided into the following three groups: normal control, EAC, and EAC plus aprepitant. EAC was induced in mice by duplicate immunization with bladder homogenate. In the EAC model group, EAC mice were given PBS by gavage once a day during the fourth week. In the EAC plus aprepitant group, aprepitant was administered instead of PBS in the same way. After 4 weeks, pelvic pain threshold and urination habits of mice were analyzed, as well as the bladder weight to body weight ratio, and histologic assessment of the expression of IL-1β, TNF-α, intercellular adhesion molecule 1 (ICAM-1), and NK1R in bladder tissue. EAC mice mimicked the phenotype and pathophysiologic lesions of BPS/IC well. Compared to PBS-treated EAC mice, the mice treated with aprepitant exhibited higher pain threshold values, less number of total urine spots or small urine spots, lower bladder weight to body weight ratio, and reduced bladder inflammation with less mast cell infiltration and decreased expressions of IL-1β, TNF-α, and ICAM-1 in bladder tissue. There was no difference in NK1R expression in bladders treated with or without aprepitant. The NK1R antagonist aprepitant relieved pelvic pain, urinary symptoms, and bladder inflammation in EAC mice. This indicated that NK1R may be a novel therapeutic target in BPS/IC treatment.

Topics: Animals; Aprepitant; Autoimmune Diseases; Cystitis, Interstitial; Disease Models, Animal; Female; Inflammation; Mice; Mice, Inbred C57BL; Neurokinin-1 Receptor Antagonists; Pain; Urinary Bladder; Urination

The development and progression of bladder pain syndrome/interstitial cystitis (BPS/IC) is closely related to bladder inflammation. Intercellular adhesion molecule 1 (ICAM-1) is associated with bladder inflammation in BPS/IC. We investigated the effect of specific inhibition of ICAM-1 using an anti-ICAM-1 antibody (AIA) on bladder inflammation in a rat model of severe non-bacterial cystitis (NBC) resembling BPS/IC by evaluating the bladder inflammation grade, mast cell infiltration and related cytokines and receptors. We also compared the effects of AIA with the COX-2 inhibitor celecoxib and the neurokinin-1 receptor (NK1R) inhibitor aprepitant. Our NBC model was established by intraperitoneal injection of cyclophosphamide combined with intravesical protamine/lipopolysaccharide, which resulted in severe bladder inflammation and increased mast cell infiltration, similar to the pathological changes of BPS/IC. Inhibition of ICAM-1 by AIA significantly decreased the bladder inflammation grade and mast cell counts, which was accompanied by a reduction of purinergic receptors (P2X2/P2X3), prostaglandin E2, EP1/EP2 receptors, TNF-α, NK1R, and ICAM-1. Moreover, AIA showed superior effects to those of celecoxib and aprepitant treatment in improving the bladder inflammatory response. Our results suggest that ICAM-1 may play a critical role in bladder inflammation in severe NBC and may be used as a novel therapeutic target in non-bacterial bladder inflammation such as BPS/IC.

Topics: Animals; Antibodies; Aprepitant; Celecoxib; Cyclooxygenase 2 Inhibitors; Cyclophosphamide; Cystitis, Interstitial; Cytokines; Female; Immunotherapy; Intercellular Adhesion Molecule-1; Lipopolysaccharides; Mast Cells; Morpholines; Neurokinin-1 Receptor Antagonists; Protamines; Rats; Rats, Sprague-Dawley; Urinary Bladder