|
|
||||||||
Laboratory of Endocrine Pathophysiology and
1 Laboratory of Cellular Biology of Hypertension and Molecular Medicine, Department of Medicine, Centre Hospitalier de lUniversité de Montréal, Montreal, Quebec, Canada
(Requests for offprints should be addressed to A Lacroix, Hôtel-Dieu du Centre Hospitalier de lUniversité de Montréal, 3850 St Urbain Street, Montreal, Quebec, Canada, H2W 1T7; Email: andre.lacroix{at}umontreal.ca)
The best characterized effect of glucose-dependent insulinotropic polypeptide (GIP) is its stimulatory effect on insulin secretion by pancreatic ß-cells. Recently, it was demonstrated that some cases of primary adrenal Cushings syndrome were secondary to the ectopic expression of non-mutated GIP receptor (GIP-R) in bilateral adrenal hyperplasias or unilateral adrenal adenomas, resulting in food-dependent steroidogenesis. Using a human multiple-expression tissue array, GIP-R was found to be expressed in a large number of human adult and fetal tissues, but not in the adrenal gland. The analysis of the promoter region of human (h) GIP-R gene revealed six consensus sequences important in regulating the reporter gene activity and capable of binding to Sp1 and Sp3 transcription factors. Data obtained by gene array and semi-quantitative RT-PCR showed an increase in the expression of Sp3 and CRSP9 (co-regulator of Sp1 transcription factor, subunit 9) in the adrenal adenomas or bilateral macronodular hyperplasias of patients with GIP-dependent Cushings syndrome; they were, however, also increased in some patients with non-GIP-dependent cortisol-secreting adenomas or with ACTH-dependent Cushings disease. This study represents the first step in our understanding of the mechanisms involved in the regulation of the expression of the hGIP-R gene.
This article has been cited by other articles:
![]() |
Y. Yan, G. Dalmasso, S. Sitaraman, and D. Merlin Characterization of the human intestinal CD98 promoter and its regulation by interferon-{gamma} Am J Physiol Gastrointest Liver Physiol, February 1, 2007; 292(2): G535 - G545. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Lampron, I. Bourdeau, P. Hamet, J. Tremblay, and A. Lacroix Whole Genome Expression Profiling of Glucose-Dependent Insulinotropic Peptide (GIP)- and Adrenocorticotropin-Dependent Adrenal Hyperplasias Reveals Novel Targets for the Study of GIP-Dependent Cushing's Syndrome J. Clin. Endocrinol. Metab., September 1, 2006; 91(9): 3611 - 3618. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |