|
|
||||||||
MUCOSAL BIOLOGY
1Section of Digestive Disease and Nutrition, Department of Medicine, University of Illinois at Chicago, and Jesse Brown Veterans Affairs Medical Center, Chicago, Illinois, 2Division of Pediatric Gastroenterology, Hepatology and Nutrition, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, 3Department of Pathology, Emory University School of Medicine, Atlanta, Georgia; and 4Division of Gastroenterology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
Submitted 14 January 2007 ; accepted in final form 27 August 2007
Downregulated in adenoma (DRA), also referred to as SLC26A3, is an intestinal anion transporter essential for intestinal chloride absorption. Mutations in DRA result in congenital chloride diarrhea. DRA expression has been shown to be induced by differentiation and to be modulated by cytokines. However, mechanisms of DRA gene transcription and its tissue-specific targeting have not yet been investigated. In this study, we cloned a 3,765-bp promoter fragment of human DRA gene and characterized its activity in human colonic LS174T and Caco-2 human colon cell lines. Primer extension identified a single transcriptional initiation site that was identical in both colon cancer cell lines and normal colon. Although hepatic nuclear factor HNF-4 is involved in the basal activity of DRA promoter, sodium butyrate induces its activity in LS174T cells via the binding of Yin Yang 1 (YY1) and GATA transcription factors to their respective cis-elements in promoter region. We also demonstrated a reduction in DRA promoter activity in Caco-2 cells by IFN-
, suggesting that regulation of DRA promoter by IFN-
may contribute to the pathophysiology of intestinal inflammation. Furthermore, we showed that the DRA promoter fragment is sufficient to drive human growth hormone transgene expression specifically in villus epithelial cells of the small intestine and in differentiated upper crypt and surface epithelial cells of the colon. Our studies provide evidence for the involvement of HNF-4, YY1, and GATA transcription factors in DRA expression in intestinal differentiated epithelial cells.
SLC26A3; congenital chloride diarrhea; intestinal gene expression
This article has been cited by other articles:
![]() |
D. Borenshtein, K. A. Schlieper, B. H. Rickman, J. M. Chapman, C. W. Schweinfest, J. G. Fox, and D. B. Schauer Decreased Expression of Colonic Slc26a3 and Carbonic Anhydrase IV as a Cause of Fatal Infectious Diarrhea in Mice Infect. Immun., September 1, 2009; 77(9): 3639 - 3650. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. W. Musch, D. L. Arvans, G. D. Wu, and E. B. Chang Functional coupling of the downregulated in adenoma Cl-/base exchanger DRA and the apical Na+/H+ exchangers NHE2 and NHE3 Am J Physiol Gastrointest Liver Physiol, February 1, 2009; 296(2): G202 - G210. [Abstract] [Full Text] [PDF] |
||||
![]() |
F. J. Gennari and W. J. Weise Acid-Base Disturbances in Gastrointestinal Disease Clin. J. Am. Soc. Nephrol., November 1, 2008; 3(6): 1861 - 1868. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |