Protective role of ABCC drug subfamily resistance transporters (ABCC1-7) in intestinal inflammation.

The ABCC subfamily contains thirteen members. Nine of these transporters are called multidrug resistance proteins (MRPs). The MRPs have been associated with developing ulcerative colitis (UC). This study aimed to evaluate the ABCC expression in UC patients and its role in a dextran sulfate sodium (DSS)-induced colitis mice model under 5-aminosalicylates or methylprednisolone treatment and compared with control without inflammation. DSS-induced colitis mice were treated with 5-aminosalicylates (50 mg/kg 24 h) or methylprednisolone (2 mg/kg 24 h). Human rectal biopsies were obtained from UC patients. The abcc-relative mRNA levels and protein expression were determined by RT-PCR and immunohistochemistry. abcc4, abcc5, and abcc6 mRNA levels were significantly increased in DSS-induced colitis compared to the other groups. The 5-aminosalicylate treatment dramatically increased the abcc2 and abcc3 mRNA levels vs. control. Methylprednisolone treatment increased abcc1 vs. DSS-induced colitis and colitis treated with 5-aminosalicylate. Immunohistochemical analysis revealed down-regulation of ABCC1/ABCC2/ABCC5/ABCC7 in mice colitis vs. control. Treatment with 5-aminosalicylate restored ABCC5 levels, while methylprednisolone restored ABCC2/ABCC5/ABCC7 in colitis mice at similar control levels. Relative mRNA levels of mrp1-5 were increased in active UC patients vs. control. ABCC2/ABCC4/ABCC7 were conspicuously expressed in the mucosa of 5-aminosalicylate and/or methylprednisolone-treated UC patients, while ABCC2/ABCC4/ABCC5/ABCC7 in submucosa, ABCC1/ABCC5/ABCC7 in muscular, and ABCC1/ABCC4/ABCC5/ABCC7 in serosa were expressed vs. controls. This is the first report about the differential up-regulation of the ABCC subfamily gene and protein expression in DSS-induced colitis under aminosalicylates or methylprednisolone treatment.