Date of Award
Dr. Richard Rozmahel
Dr. Gilles Lajoie
Dr. Harvey Goldberg
The murine orthologue of the human calcium-activated chloride channel-1 protein (hCLCAl), mCLCA3, has been linked to regulating mucous properties due to its intimate association with mucin granule membranes of goblet cells. In particular, induced mCLCA3 expression via transgene introduction has been previously shown to significantly improve the intestinal Cystic Fibrosis (CF) phenotype in cystic fibrosis transmembrane conductance regulator- (Cftr) deficient mice, confirming its role as a modifier gene of CF. The specific biological or pathological function of the various CLCA members is unknown and their predicted role as ion channels has been disputed. The aim of this study was to investigate the effects of introducing and overexpressing the mCLCA3 gene on mucin synthesis, mucus composition and goblet cell development in the human colonic epithelial HT29 cell line. Results showed that expression of mCLCA3 significantly reduced gene expression of the mucin proteins, MUC1. Since MUC1 is expressed in all secretory epithelial cells, this indicates a potential role for the modulation of mucus composition by mCLCA3. Analysis of goblet cell morphometry by histological staining showed that almost two thirds of goblet cell populations contained mucus in HT29 cultures transfected with mCLCA3. This was a significant increase when compared to control FIT29 treatments and closely resembled the goblet cell population of untreated HT29 cells. This demonstrates that mCLCA3, and potentially hCLCAl, could have a regulatory role in goblet cell physiology by promoting mucus retention in HT29 cultures. Additional work is required to establish the mechanism of its action on goblet cell pathophysiology but mCLCA3, and hCLCAl, may be important therapeutic targets for mucous-based diseases.
Giakoumatos, Evangelos, "INVESTIGATING THE IN VITRO EFFECTS OF MURINE CLCA3 ON HT29 MUCUS AND GOBLET CELL PHYSIOLOGY" (2010). Digitized Theses. 4071.