Genetic polymorphisms in the 5'-flanking region of human UDP-glucuronosyltransferase 2B7 affect the Nrf2-dependent transcriptional regulation.

フォーマット:

論文

責任表示:

Nakamura, Akiko ; Nakajima, Miki ; Higashi, Eriko ; Yamanaka, Hiroyuki ; Yokoi, Tsuyoshi

言語:

英語

出版情報:

Lippincott, Williams & Wilkins, 2008-08-01

著者名:

• Nakamura, Akiko
• Nakajima, Miki
• Higashi, Eriko
• Yamanaka, Hiroyuki
• Yokoi, Tsuyoshi

掲載情報:

Pharmacogenetics and genomics

ISSN:

1744-6872      

巻:

18

通号:

8

開始ページ:

709

終了ページ:

720

バージョン:

author

概要:

医薬保健研究域薬学系<br />OBJECTIVES: Human uridine diphosphate-glucuronosyltransferase 2B7 (UGT2B7) plays important roles in the metabolism of some clinical drugs, carcinogens, and steroid hormones. The molecular mechanisms of the inducible ex … pression of UGT2B7 in response to xenobiotics have not been fully clarified. We sought to investigate whether the UGT2B7 is under the control of NF-E2 p45-related factor 2 (Nrf2), a key transcriptional factor regulating the expression of cytoprotective enzymes. METHODS: HepG2, HuH7, HLE, and Caco-2 cells were treated with sulforaphane (SFN), and the UGT2B7 mRNA levels were determined by real-time reverse transcriptase PCR. These cells were genotyped for the UGT2B7*2 (H268Y) allele using the PCR-restriction fragment length polymorphism method. Luciferase analyses and gel shift analyses were performed to identify the responsive regions for Nrf2 signaling. RESULTS: The UGT2B7 mRNA was induced by SFN in HepG2 and HuH7 genotyped as UGT2B7*1/*1, but not in HLE and Caco-2 cells genotyped as UGT2B7*2/*2. In HepG2 cells, the UGT2B7 protein level and morphine glucuronosyltransferase activity were also significantly induced by SFN. The induction was prominently decreased with small interfering RNA for Nrf2. In the 5'-flanking region (-2.5 kb) of the UGT2B7*2 allele, a 324-base pair insertion at -2067 and 12 single nucleotide polymorphisms simultaneously existed. Luciferase analyses and gel shift analyses revealed that an antioxidant responsive element at -1170 was responsible for the transactivation by Nrf2. In addition, a region from -990 to -858 on the UGT2B7*1 allele was also responsible for the transactivation by Nrf2. Abrogation of the Nrf2-dependent transactivation of the UGT2B7*2 allele was owing to the single nucleotide polymorphism -900A>G. CONCLUSION: UGT2B7 is transcriptionally regulated by Nrf2, but the mechanism is hindered by polymorphisms in the promoter region of UGT2B7*2. The allele-specific mechanism may cause variability of the glucuronidation in response to oxidative stress.全文公開200908 続きを見る

URL:

http://hdl.handle.net/2297/12396