RT Journal Article
SR Electronic
T1 Evaluation of expression and glycosylation status of UGT1A10 in Supersomes and intestinal epithelial cells with a novel specific UGT1A10 monoclonal antibody
JF Drug Metabolism and Disposition
JO Drug Metab Dispos
FD American Society for Pharmacology and Experimental Therapeutics
SP dmd.117.075291
DO 10.1124/dmd.117.075291
A1 Shingo Oda
A1 Yukiko Kato
A1 Masahiko Hatakeyama
A1 Atsushi Iwamura
A1 Tatsuki Fukami
A1 Toshiyuki Kume
A1 Tsuyoshi Yokoi
A1 Miki Nakajima
YR 2017
UL http://dmd.aspetjournals.org/content/early/2017/07/11/dmd.117.075291.abstract
AB UDP-Glucuronosyltransferases (UGTs) are major phase II drug-metabolizing enzymes. Each member of the UGT family exhibits a unique but occasionally overlapping substrate specificity and tissue-specific expression pattern. Earlier studies have reported that human UGT1A10 is expressed in the gastrointestinal tract at the mRNA level, but the evaluation at the protein level, especially tissue or cellular localization, has lagged behind because of the lack of a specific antibody. In this study, we prepared a monoclonal antibody against UGT1A10 to elucidate the tissue/cellular distribution and interindividual variability of UGT1A10 protein expression. Western blot analysis revealed that the prepared antibody does not cross-react with any other human UGTs. Using this specific antibody, we observed that UGT1A10 protein is expressed in the small intestine but not in the liver or kidney. Immunohistochemical analysis revealed the expression of UGT1A10 protein in epithelial cells of the crypts and villi of the duodenum. In the small intestine microsomes from six individuals, the UGT1A10 protein levels exhibited 16-fold variability. Dopamine 3- and 4-glucuronidation, which is mainly catalyzed by UGT1A10 and by other UGT isoforms marginally, exhibited 50- to 65-fold variability, and they were not correlated with the UGT1A10 protein levels. Interestingly, the enzymatic activities of recombinant UGT1A10 in insect cells that were normalized to the UGT1A10 protein level were markedly lower than those in pooled human small intestine microsomes. Thus, the UGT1A10 antibody we generated made it possible to assess the tissue/cellular distribution and interindividual variability of UGT1A10 protein expression for understanding the pharmacological and toxicological role of UGT1A10.