Novel Roles of Cdx Transcription Factors in Intestinal Homeostasis

Abstract

The transcription factor Cdx2 is essential for intestinal development and homeostasis. Recent research has demonstrated that Cdx regulates the NLRP3 (NOD-, LRR- and pyrin domain-containing protein 3) inflammasome, a critical driver of inflammation, in agreement with other literature suggesting a role for Cdx2 in inflammatory bowel disease. NLRP3 also induces pyroptosis, an inflammatory form of cell death, via processing of Gasdermin D (GSDMD). However, the effects of Cdx2 on GSDMD, the key executor of pyroptosis, remain undefined. This study investigated the role of Cdx in regulating GSDMD processing necessary to cause pyroptosis in intestinal epithelial cells. Our findings revealed elevated GSDMD cleavage in Cdx mutant cells, as well as increased cell death. Inhibition of the NLRP3 inflammasome significantly reduced GSDMD cleavage, consistent with an impact of Cdx on NLRP3 dependent pyroptosis. Additionally, subcellular fractionation and Western blot analyses demonstrated the translocation and oligomerization of cleaved GSDMD from the cytoplasm to the membrane, in Cdx mutant cells, indicative of formation of GSDMD pores which cause pyroptosis. These findings are consistent with a role for Cdx2 in regulating pyroptosis in the intestinal epithelium, and highlights the potential of Cdx and GSDMD as biomarkers and therapeutic targets for inflammatory conditions of the intestine such as inflammatory bowel disease (IBD) and colorectal cancer (CRC).