Dysregulations of Intestinal and Colonic UDP-glucuronosyltransferases in Rats with Type 2 Diabetes

Abstract

  Diabetes mellitus is a chronic disease of complex metabolic disorder associated with various types of complications. UDP-glucuronosyltransferases (UGTs), the major phase II conjugation enzymes, mediate the metabolism of both drugs and endogenous metabolites that may raise great concerns in the condition of diabetes. The aim of this study was to determine whether diabetes could affect UGTs in the intestinal and colonic tract. A high-fat diet combined with low-dose streptozotocin was used to induce a type 2 diabetic model in rats. The mRNA levels and enzymatic activities of UGT1A1, -1A6, and -1A7 in the diabetic intestine and colon were higher than those in nondiabetic rats. In contrast, both the activity and mRNA level of UGT2B1 in diabetic rats were lower than those in nondiabetic rats. Notably, the diabetic intestine and colon exhibited an inflammatory state with increased pro-inflammatory cytokines. Various transcriptional factors involved in UGT regulation were unanimously upregulated in the diabetic intestine and colon. These findings strongly suggest that the regulating pathways of the UGT1 family are adaptively upregulated in the diabetic gastrointestinal tract. Given the essential regulatory role of the gastrointestinal site in drug disposition, such changes in UGTs may have a dynamic and complex impact on therapeutic drugs and endogenous metabolomes.