Gene expression analysis of crypt base epithelial cells from WT and Nod2-/- mice

Nod2 has been extensively characterized as a bacterial sensor that induces an antimicrobial and inflammatory gene expression program. Therefore, it is unclear why Nod2 mutations that disrupt bacterial recognition are paradoxically among the highest risk factors for Crohn’s disease, which involves an exaggerated immune response directed at intestinal bacteria. Previous studies from our lab have shown that mice deficient in Atg16L1, another Crohns disease susceptibility gene, develop abnormalities in Paneth cells, specialized epithelial cells in the small intestine involved in antimicrobial responses. The goal of our study is to determine whether Nod2 deficiency leads to differences in the transcriptional profile of Paneth cells, ultimately leading to small intestinal inflammation. Small intestinal sections (ileum) of 8 week old WT and Nod2-/- mice were fixed in methacarn and embedded in paraffin. The Leica LMD6000 Laser Microdissection system was used to capture crypt base epithelial cells to enrich for Paneth cells. RNA was extracted from these cells, followed by cDNA synthesis and qPCR to confirm enrichment of Paneth cells using unique markers (a-defensins).