Abstract
Evidence link bacterial enterotoxins to apparent crypt-cell like cells (CCLCs), and Alpha Defensin 5 (DEFA5) expansion in the colonic mucosa of Crohn’s colitis disease (CC) patients. These areas of ectopic ileal metaplasia, positive for Paneth cell (PC) markers are consistent with diagnosis of CC. Retrospectively, we: 1. Identified 21 patients with indeterminate colitis (IC) between 2000–2007 and were reevaluation their final clinical diagnosis in 2014 after a followed-up for mean 8.7±3.7 (range, 4–14) years. Their initial biopsies were analyzed by DEFA5 bioassay. 2. Differentiated ulcer-associated cell lineage (UACL) analysis by immunohistochemistry (IHC) of the CC patients, stained for Mucin 6 (MUC6) and DEFA5. 3. Treated human immortalized colonic epithelial cells (NCM460) and colonoids with pure DEFA5 on the secretion of signatures after 24hr. The control colonoids were not treated. 4. Treated colonoids with/without enterotoxins for 14 days and the spent medium were collected and determined by quantitative expression of DEFA5, CCLCs and other biologic signatures. The experiments were repeated twice. Three statistical methods were used: (i) Univariate analysis; (ii) LASSO; and (iii) Elastic net. DEFA5 bioassay discriminated CC and ulcerative colitis (UC) in a cohort of IC patients with accuracy. A fit logistic model with group CC and UC as the outcome and the DEFA5 as independent variable differentiator with a positive predictive value of 96 percent. IHC staining of CC for MUC6 and DEFA5 stained in different locations indicating that DEFA5 is not co-expressed in UACL and is therefore NOT the genesis of CC, rather a secretagogue for specific signature(s) that underlie the distinct crypt pathobiology of CC. Notably, we observed expansion of signatures after DEFA5 treatment on NCM460 and colonoids cells expressed at different times, intervals, and intensity. These factors are key stem cell niche regulators leading to DEFA5 secreting CCLCs differentiation ‘the colonic ectopy ileal metaplasia formation’ conspicuously of pathogenic importance in CC.
Highlights
Colonic inflammatory bowel disease (IBD), which encompasses ulcerative colitis (UC) and colonic Crohn’s colitis (CC), are two highly heterogeneous chronic relapsing and remitting gastrointestinal disorders in the colon [1,2,3,4]
Representative IHC staining of CC colectomy tissue for Mucin 6 (MUC6) and Human alpha defensin 5 (DEFA5) revealed differing locations, meaning that crypt-cell-like cells (CCLCs)-secreted DEFA5 is not co-expressed in ulcer-associated cell lineage (UACL)
This observation demonstrates that DEFA5 and lysozyme are not expressed in UACL but are in the colonic epithelium lining crypt areas of CC patients and their stromal cell-adjacent normal indicating that the high DEFA5 levels in CC patient samples arise from CCLCs (Fig 2A and 2B)
Summary
Colonic inflammatory bowel disease (IBD), which encompasses ulcerative colitis (UC) and colonic Crohn’s colitis (CC), are two highly heterogeneous chronic relapsing and remitting gastrointestinal disorders in the colon [1,2,3,4]. We recently reported that the antimicrobial peptide alpha defensin 5 (DEFA5, abbreviated as HD5) of human Paneth cell-like cells, apparent crypt-cell-like cells (CCLCs), is a useful biomarker accurately differentiating UC from CC. We applied it in a cohort of patients with indeterminate colitis (IC) resulting in highly accurate determinations for authentic UC or CC many times greater than reported experiences at any academic IBD centers [5]. IBD patients are inflammation-prone, the notion that UC and CC are histologically different and that DEFA5 and/or specific proinflammatory signatures (cytokines, chemokines, and growth factors) play a major role in the etiopathogenesis trigger of these disease subtypes is still not well established. We evaluated DEFA5 treatment as a secretagogue, on immortalized colonic epithelial cells and colonoids to determine which subtypes of signatures are secreted that may be responsible for IBD inflammation and differentiation
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
