|Authors||Wang ZY, Wang P, Bjorling DE|
|Journal||Am. J. Physiol. Regul. Integr. Comp. Physiol. Volume: 297 Issue: 4 Pages: R1127-35|
|Publish Date||2009 Oct|
Mast cells have been shown to play a role in development and persistence of various inflammatory bladder disorders. Mast cell-derived tryptase specifically activates protease-activated receptor-2 (PAR-2), and PAR-2 is known to be involved in inflammation. We investigated whether mast cells participate in increase of cyclooxygenase-2 (COX-2) protein abundance in urothelium/suburothelium of bladders of mice subsequent to cyclophosphamide (CYP)-induced bladder inflammation. We also used primary cultures of human urothelial cells to investigate cellular mechanisms underlying activation of PAR-2 resulting in increased COX-2 expression. We found that treatment of mice with CYP (150 mg/kg ip) increased COX-2 protein abundance in bladder urothelium/suburothelium 3, 6, and 24 h after CYP (P < 0.01), and increased COX-2 protein abundance was prevented by treatment of mice with the mast cell stabilizer sodium cromolyn (10 mg/kg ip) for 4 consecutive days before CYP treatment. Incubation of freshly isolated mouse urothelium/suburothelium with a selective PAR-2 agonist, 2-furoyl-LIGRLO-amide (3 microM), also increased COX-2 protein abundance (P < 0.05). We further demonstrated that 2-furoyl-LIGRLO-amide (3 microM) increased COX-2 mRNA expression and protein abundance in primary cultures of human urothelial cells (P < 0.01), and the effects of PAR-2 activation were mediated primarily by the ERK1/2 MAP kinase pathway. These data indicate that there are functional interactions among mast cells, PAR-2 activation, and increased expression of COX-2 in bladder inflammation.
|Full Text||Full text available on PubMed Central|