P002 Glial cell line-Derived Neurotrophic Factor (GDNF) improves intestinal wound healing – A new target for IBD treatment?
Kelm, M.(1);Burkard, N.(1);Hoerner, M.(1);Germer, C.T.(1);Schlegel, N.(1);Flemming, S.(1);
(1)University Hospital of Wuerzburg, Department of Surgery, Würzburg, Germany;
Background
Due to the rising incidence and socioeconomic relevance of Inflammatory Bowel Disease (IBD) worldwide, new therapeutic strategies are necessary to improve patient care. Since immunosuppressants are partially insufficient with relevant rates of side effects, novel concepts of treatment need to be developed. Mucosal and/or histological healing represent potential criteria to measure disease activity and are mentioned in current guidelines as favorable prognostic factors regarding disease outcomes. In previous studies, the soluble factor Glial cell line-Derived Neurotrophic Factor (GDNF) has been shown to be significantly reduced in tissue specimens from IBD patients and to be critically involved in intestinal epithelial barrier maturation. Therefore, the goal of this study was to further analyze the potential role of GDNF in IBD.
Methods
Intestinal wound healing was assessed in endoscopic biopsy-based wound assays as well as dextran sodium sulphate (DSS)-induced colitis in vivo. During the experiments, C57Bl/6 mice were either injected with GDNF or sodium chloride intraperitoneal while tissue samples were used for detailed molecular analyses. Further, scratch wound assays were performed in Caco2 monolayers to identify molecular pathways and cell mechanisms in vitro.
Results
Intraperitoneal injection of GDNF resulted in significantly enhanced wound closure in vivo. During the DSS-induced colitis model, mice treated with GDNF demonstrated significantly improved recovery from colitis in comparison to mice injected with sodium chloride. Similarly, application of GDNF in a scratch wound assay significantly enhanced wound closure in vitro. Mechanistically, molecular analysis revealed that GDNF application resulted in significantly increased cell proliferation. The effect of GDNF on cell proliferation was based on upregulation of LGR5-positive cells with increased phosphorylation of pSrc. Further studies demonstrated that the effect of GDNF on wound healing and cell proliferation could be inhibited by application of a Src-inhibitor.
Conclusion
GDNF significantly improves intestinal mucosal healing in vivo and in vitro which results in significantly enhanced recovery from colitis. While this effect is driven by increased cell proliferation due to upregulation of LGR5-positive cells and increased phosphorylation of pSrc, previous studies already demonstrated the critical impact of GDNF on epithelial barrier function. Following that, GDNF might have great potential in IBD treatment and could be a new target for future therapeutic approaches.