The gastrointestinal epithelium functions as a dynamic permeability barrier that separates luminal contents from underlying tissue compartments and is vital in maintaining mucosal homeostasis. Pathologic processes such as inflammatory bowel disease and ischemia induce epithelial injury and mucosal wounds that result in barrier disruption. In response to injury, intestinal epithelial cells (IECs) migrate as a cohesive sheet to rapidly cover denuded surfaces, close wounds and re-establish the critical epithelia barrier in a process termed restitution. Epithelial cell migration is critically dependent on actin cytoskeletal restructuring, directional polarization of cells into the wound and dynamic focal cell-matrix adhesion turnover. The long term goals of this proposal are to define mechanisms by which the intestinal epithelium migrates in response to injury and inflammation to efficiently reseal mucosal barrier defects. We recently determined that a multifunctional membrane associated and actin binding protein, Annexin 2 (AnxA2) and a secreted regulator of Wnt signaling, Dickkopf-1 (Dkk-1), play critical roles in controlling IEC migration and restitution. Thus our aims in this proposal are to define the mechanisms by which AnxA2 and Dkk-1 regulate IEC motility and wound closure. These studies will not only advance our understanding of AnxA2 and Dkk-1 function in the intestine, but will also aid in the development of new therapeutic strategies aimed at facilitating mucosal barrier recovery.

Public Health Relevance

The gastrointestinal epithelium functions as an important barrier that separates luminal contents from underlying tissue compartments. Disruption of the epithelial barrier in inflammatory bowel diseases and ischemia result in fluid &electrolyte loss and exposure of tissues to luminal antigens and pathogens. To rapidly reseal such wounds, epithelial cells migrate in a process termed restitution. Our studies are aimed at understanding mechanisms by which the intestinal epithelium migrates to rapidly cover denuded surfaces and reseal wounds. We recently determined that two proteins, annexin-2 and Dickkopf-1 control intestinal epithelial cell migration and wound recovery. The proposed studies will analyze the mechanisms by which these proteins regulate intestinal epithelial wound recovery. These investigations will not only define the mechanisms by which these proteins regulate wound resealing, but will also provide new ideas to identify therapeutic agents aimed at promoting intestinal epithelial wound closure and mucosal barrier recovery.

National Institute of Health (NIH)
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Research Project (R01)
Project #
Application #
Study Section
Special Emphasis Panel (ZRG1-DIG-C (02))
Program Officer
Carrington, Jill L
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Emory University
Schools of Medicine
United States
Zip Code
Mitchell, Leslie A; Ward, Christina; Kwon, Mike et al. (2015) Junctional adhesion molecule A promotes epithelial tight junction assembly to augment lung barrier function. Am J Pathol 185:372-86
Jiang, Kun; Rankin, Carl R; Nava, Porfirio et al. (2014) Galectin-3 regulates desmoglein-2 and intestinal epithelial intercellular adhesion. J Biol Chem 289:10510-7
Weber, D A; Sumagin, R; McCall, I C et al. (2014) Neutrophil-derived JAML inhibits repair of intestinal epithelial injury during acute inflammation. Mucosal Immunol 7:1221-32
Alam, A; Leoni, G; Wentworth, C C et al. (2014) Redox signaling regulates commensal-mediated mucosal homeostasis and restitution and requires formyl peptide receptor 1. Mucosal Immunol 7:645-55
Neumann, Philipp-Alexander; Koch, Stefan; Hilgarth, Roland S et al. (2014) Gut commensal bacteria and regional Wnt gene expression in the proximal versus distal colon. Am J Pathol 184:592-9
Leoni, Giovanna; Alam, Ashfaqul; Neumann, Philipp-Alexander et al. (2013) Annexin A1, formyl peptide receptor, and NOX1 orchestrate epithelial repair. J Clin Invest 123:443-54
Rankin, Carl R; Hilgarth, Roland S; Leoni, Giovanna et al. (2013) Annexin A2 regulates *1 integrin internalization and intestinal epithelial cell migration. J Biol Chem 288:15229-39
Brazil, Jennifer C; Liu, Renpeng; Sumagin, Ronen et al. (2013) *3/4 Fucosyltransferase 3-dependent synthesis of Sialyl Lewis A on CD44 variant containing exon 6 mediates polymorphonuclear leukocyte detachment from intestinal epithelium during transepithelial migration. J Immunol 191:4804-17
Koch, S; Capaldo, C T; Hilgarth, R S et al. (2013) Protein kinase CK2 is a critical regulator of epithelial homeostasis in chronic intestinal inflammation. Mucosal Immunol 6:136-45
McConnell, Beth B; Kim, Samuel S; Yu, Ke et al. (2011) Kruppel-like factor 5 is important for maintenance of crypt architecture and barrier function in mouse intestine. Gastroenterology 141:1302-13, 1313.e1-6

Showing the most recent 10 out of 15 publications