Mechanism of Eph-ephrin Signaling in Intestinal Regeneration

Rutgers, The State Univ Of N.J., New Brunswick NJ

Investigators

Abstract

PROJECT SUMMARY Inflammatory bowel disease (IBD) affects approximately 3 million Americans. It is characterized by chronic inflammation of the gastrointestinal tract with flares (cycles of gastrointestinal damage and regeneration). Better understanding of the regenerative process can lead to more efficacious therapies to improve patient outcome and reduce the enormous healthcare burden of IBD. While elaborate cellular movements are required to transform an ulcerative lesion back into a homeostatic intestinal crypt pattern, the underlying molecular mechanism of epithelial re-patterning after damage is a major knowledge gap. A potential player in epithelial re- patterning is EPHB2, a receptor tyrosine kinase that binds to Ephrin-B ligands on neighboring cells to mediate cell-to-cell signaling. Disruption of EPHB2 function in transgenic mouse models leads to mis-localization of the crypt bottom cells towards the lumen. However, the role of EPHB2 in intestinal regeneration after tissue damage and its downstream mechanisms for inducing cell segregation in the intestine are unknown. The overarching hypothesis of the current proposal that EPHB2 is necessary for epithelial regeneration and re-patterning after tissue damage. The Aims of the current study will be to: 1) Determine if EPHB2 is required for epithelial re- patterning during intestinal regeneration. 2) Dissect the mechanisms of EphB2-dependent cell segregation in intestinal epithelial cells. The proposal will use transgenic mouse lines with spatial-temporal knockout of Ephb2 to study its role on epithelial re-patterning during regeneration. The mechanism of EPHB2- dependent cell segregation will be studied using innovative segregation assay that combines established wound healing assay using live cell imaging and 2D intestinal organoid monolayer cultures. The long-term goal is to utilize this knowledge to help promote intestinal regeneration and bring better treatments, such as organoid- based therapy, from bench to beside for patients suffering from IBD and other gastrointestinal diseases. The entire proposal will be conducted at Rutgers University, one of America's leading public research universities. Through this research, training RNA-sequencing and single cell RNA sequencing, mouse intestinal pathophysiology, and organoid culture and manipulation will be provided to Dr. Ping He. These techniques will prepare Dr. He for a future career as an academic physician-scientist in the field of intestinal biology and regenerative medicine. The ultimate goal of the research proposed is to address the knowledge gaps in intestinal regenerative processes and use what we learn about EPHB2 to help bring organoid-based therapy from the bench to the bedside.