Acute flares of inflammatory diseases of the intestine are characterized by the migration of neutrophils across the intestinal epithelium into the lumen to form 'crypt abscess'. Adenosine is generated during active intestinal inflammation by the conversion of neutrophil-derived 5'AMP into adenosine by the epithelial 5'ectonucleotidase. Adenosine, acting via the A2b receptor, not only mediates electrogenic chloride secretion but also induces an apically polarized secretion of the pro-inflammatory cytokine, interleukin-6 (IL-6). IL-6, in turn, induces a calcium flux in neutrophils, thus providing a paracrine signal to neutrophils. In this R01 application, we propose to investigate the hypothesis that the A2b receptors play a central role in orchestrating both the diarrheal and inflammatory components of the intestinal inflammatory response. If so, pharmacological manipulation of the A2b receptor may be therapeutic for intestinal inflammation. The overall goals of this proposal are to characterize the intestinal A2b receptor (specific aim 1), to examine the regulation of adenosine-induced IL-6 secretion (specific aim 2) and to determine the effect of IL-6 on neutrophil function (specific aim 3).
Specific aim 1 : We will use model intestinal cell line, T84, expressing native A2b receptor and Caco2-BBE (which do not express A2b receptor) overexpressing GFP-A2b to study: i) the recruitment of the A2b receptor to apical vs. basolateral membrane using domain-specific biotinylation and immunoflourescence ii) the molecular mechanism of interaction of A2b receptor with E3KARP will be studied using deletion constructs and site-directed mutagenesis iii) the role of A2b receptor recruitment in receptor signaling and function and desensitization.
Specific aim 2 : We will investigate: i) the mechanism of adenosine-mediated IL-6 induction using IL-6 promoter constructs with deletion and point mutations of the various nuclear factor binding sites, ii) the effect of IL-6 on intestinal epithelia by examining STAT-3 and NF-?B activation and expression of ICAM-1 and metalloproteinases, proteins regulated by STAT-3 and/or NF-?B and known to play key role in the pathogenesis of intestinal inflammation.
Specific aim 3 : We will study: i) the effect of IL-6 on degranulation of neutrophils and ii) the role of IL-6 in neutrophil adhesion and transmigration.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
3R01DK064711-05S1
Application #
7921152
Study Section
General Medicine A Subcommittee 2 (GMA)
Program Officer
Hamilton, Frank A
Project Start
2009-09-20
Project End
2010-08-31
Budget Start
2009-09-20
Budget End
2010-08-31
Support Year
5
Fiscal Year
2009
Total Cost
$99,906
Indirect Cost
Name
Emory University
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
066469933
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Titus, Jitto; Viennois, Emilie; Merlin, Didier et al. (2017) Minimally invasive screening for colitis using attenuated total internal reflectance fourier transform infrared spectroscopy. J Biophotonics 10:465-472
Pujada, Adani; Walter, Lewins; Patel, Aashka et al. (2017) Matrix metalloproteinase MMP9 maintains epithelial barrier function and preserves mucosal lining in colitis associated cancer. Oncotarget 8:94650-94665
Walter, Lewins; Pujada, Adani; Bhatnagar, Noopur et al. (2017) Epithelial derived-matrix metalloproteinase (MMP9) exhibits a novel defensive role of tumor suppressor in colitis associated cancer by activating MMP9-Notch1-ARF-p53 axis. Oncotarget 8:364-378
Viennois, Emilie; Zhao, Yuan; Merlin, Didier (2015) Biomarkers of Inflammatory Bowel Disease: From Classical Laboratory Tools to Personalized Medicine. Inflamm Bowel Dis 21:2467-74
Wang, Tanyu; Viennois, Emilie; Merlin, Didier et al. (2015) Microelectrode miRNA sensors enabled by enzymeless electrochemical signal amplification. Anal Chem 87:8173-80
Etienne-Mesmin, Lucie; Wang, Tanyu; Viennois, Emilie et al. (2015) Proceedings of the Second Shanthi V. Sitaraman Intestinal Pathobiology Symposium. Inflamm Bowel Dis 21:1942-7
Xiao, Bo; Si, Xiaoying; Zhang, Mingzhen et al. (2015) Oral administration of pH-sensitive curcumin-loaded microparticles for ulcerative colitis therapy. Colloids Surf B Biointerfaces 135:379-85
Xiao, Bo; Zhang, Mingzhen; Viennois, Emilie et al. (2015) Inhibition of MDR1 gene expression and enhancing cellular uptake for effective colon cancer treatment using dual-surface-functionalized nanoparticles. Biomaterials 48:147-60
Xiao, Bo; Laroui, Hamed; Viennois, Emilie et al. (2014) Nanoparticles with surface antibody against CD98 and carrying CD98 small interfering RNA reduce colitis in mice. Gastroenterology 146:1289-300.e1-19
Ghaleb, Amr M; Laroui, Hamed; Merlin, Didier et al. (2014) Genetic deletion of Klf4 in the mouse intestinal epithelium ameliorates dextran sodium sulfate-induced colitis by modulating the NF-?B pathway inflammatory response. Inflamm Bowel Dis 20:811-20

Showing the most recent 10 out of 29 publications