|
|
|
|
Institute of Biological Chemistry, Academia Sinica, Taiwan (P.-W.L.); and Department of Biological Science, National Taiwan University, Taiwan (Y.-M.L.)
The utility of morphine for the treatment of chronic pain is hindered by the development of tolerance. Fentanyl has been shown to be a potent analgesic with a lower propensity to produce tolerance and physical dependence in the clinical setting. Previous finding has shown that fentanyl induces µ opioid receptor gene expression in PC-12 cells (Brain Res 859:217-223, 2000). In this report, we aim to identify the molecular mechanism of µ-opioid receptor (MOR) gene regulation by fentanyl. We demonstrated that the 4.7-kilobase MOR promoter could be induced by fentanyl in PC-12 cells, and we defined a partial cAMP response element (CRE) located at -106/-111 in 5'-untranslated region of the MOR gene. In electrophoretic mobility shift assay, cAMP response element-binding protein (CREB) was found in the protein-DNA complex formed on the CRE box. CREB was phosphorylated after forskolin induction, and both CREB and CREB-binding protein (CBP) binding to the endogenous MOR promoter was increased by forskolin in chromatin immunoprecipitation assay. The functional role of CREB in the induction of MOR gene was further elucidated by an experiment in which a dominant-negative mutant CREB, CREB-S133A, abolished the forskolin-mediated MOR induction. Moreover, we found that this CRE box is conserved in mouse, rat, and human MOR gene, implying physiological relevance in different species. Collectively, this study demonstrated that fentanyl-triggered MOR gene induction was mediated by the sequential activation of CREB and the binding of CREB and CBP to MOR promoter, thus provides direct evidence for lower propensity of fentanyl to produce tolerance.
Address correspondence to: Yu-May Lee, Institute of Biological Chemistry, Academia Sinica, 128 Section 2, Academy Road, Nankang, Taipei 115, Taiwan. Email: yml6120{at}gate.sinica.edu.tw
This article has been cited by other articles:
![]() |
Q. Wu, C. K. Hwang, S. Yao, P.-Y. Law, H. H. Loh, and L.-N. Wei A Major Species of Mouse {micro}-opioid Receptor mRNA and Its Promoter-Dependent Functional Polyadenylation Signal Mol. Pharmacol., August 1, 2005; 68(2): 279 - 285. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. S. Choi, C. K. Hwang, C. S. Kim, K. Y. Song, P.-Y. Law, L.-N. Wei, and H. H. Loh Transcriptional Regulation of Mouse {micro} Opioid Receptor Gene: Sp3 Isoforms (M1, M2) Function as Repressors in Neuronal Cells to Regulate the {micro} Opioid Receptor Gene Mol. Pharmacol., May 1, 2005; 67(5): 1674 - 1683. [Abstract] [Full Text] [PDF] |
||||
![]() |
P.-W. Lee, S. Wu, and Y.-M. Lee Differential Expression of {micro}-Opioid Receptor Gene in CXBK and B6 Mice by Sp1 Mol. Pharmacol., December 1, 2004; 66(6): 1580 - 1584. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-M. Wu, W.-C. Kuo, W.-L. Hwu, K.-Y. Hwa, R. Mantovani, and Y.-M. Lee RNF4 Is a Coactivator for Nuclear Factor Y on GTP Cyclohydrolase I Proximal Promoter Mol. Pharmacol., November 1, 2004; 66(5): 1317 - 1324. [Abstract] [Full Text] [PDF] |
||||