Intestinal-epithelial LSD1 controls goblet cell maturation and effector responses required for gut immunity to bacterial and helminth infection

Infectious and inflammatory diseases in the intestine remain a serious threat for patients world-wide. Reprogramming of the intestinal epithelium towards a protective effector state is important to manage inflammation and immunity and can be therapeutically targeted. The role of epigenetic regulatory enzymes within these processes is not yet defined. Here, we use a mouse model that has an intestinal-epithelial specific deletion of the histone demethylase Lsd1 (cKO mice), which maintains the epithelium in a fixed reparative state. Challenge of cKO mice with bacteria-induced colitis or a helminth infection model both resulted in increased pathogenesis. Mechanistically, we discovered that LSD1 is important for goblet cell maturation and goblet-cell effector molecules such as RELMß. We propose that this may be in part mediated by directly controlling genes that facilitate cytoskeletal organization, which is important in goblet cell biology. This study therefore identifies intestinal-epithelial epigenetic regulation by LSD1 as a critical element in host protection from infection

Correction: Relevance of TNBS-Colitis in Rats: A Methodological Study with Endoscopic, Histologic and Transcriptomic Characterization and Correlation to IBD.

Rectal instillation of trinitrobenzene sulphonic acid (TNBS) in ethanol is an established model for inflammatory bowel disease (IBD). We aimed to 1) set up a TNBS-colitis protocol resulting in an endoscopic and histologic picture resembling IBD, 2) study the correlation between endoscopic, histologic and gene expression alterations at different time points after colitis induction, and 3) compare rat and human IBD mucosal transcriptomic data to evaluate whether TNBS-colitis is an appropriate model of IBD.Five female Sprague Daley rats received TNBS diluted in 50% ethanol (18 mg/0.6 ml) rectally. The rats underwent colonoscopy with biopsy at different time points. RNA was extracted from rat biopsies and microarray was performed. PCR and in situ hybridization (ISH) were done for validation of microarray results. Rat microarray profiles were compared to human IBD expression profiles (25 ulcerative colitis Endoscopic score demonstrated mild to moderate colitis after three and seven days, but declined after twelve days. Histologic changes corresponded with the endoscopic appearance. Over-represented Gene Ontology Biological Processes included: Cell Adhesion, Immune Response, Lipid Metabolic Process, and Tissue Regeneration. IL-1α, IL-1β, TLR2, TLR4, PRNP were all significantly up-regulated, while PPARγ was significantly down-regulated. Among genes with highest fold change (FC) were SPINK4, LBP, ADA, RETNLB and IL-1α. The highest concordance in differential expression between TNBS and IBD transcriptomes was three days after colitis induction. ISH and PCR results corresponded with the microarray data. The most concordantly expressed biologically relevant pathways included TNF signaling, Cell junction organization, and Interleukin-1 processing.Endoscopy with biopsies in TNBS-colitis is useful to follow temporal changes of inflammation visually and histologically, and to acquire tissue for gene expression analyses. TNBS-colitis is an appropriate model to study specific biological processes in IBD

Concordance analysis between TNBS-colitis and IBD transcriptomes at the level of biological pathways.

<p><i>T3 vs. T0</i> compared to <i>CD vs. normal</i> (top) <i>and UC vs. normal</i> (bottom). Left, scatter plots of pathway activity scores of KEGG pathways in TNBS and IBD samples. Right, scatter plots of pathway activity scores of Reactome pathways in TNBS and IBD samples. Rho values correspond to Spearman correlation coefficients with <i>p</i>-values representing the level of significance of the correlation. Numbers in the legend correspond to the total number of pathways assigned to each category. A similar figure (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054543#pone.0054543.s002" target="_blank">Figure S2</a>) for concordant analysis of <i>T7 vs. T0</i> and <i>T12 vs. T0</i>, compared to <i>CD vs. normal</i> and <i>UC vs. normal</i> is shown in the supplementary section (KEGG and Reactome score change at the top and bottom, for T7 vs. T0 and T12 vs. T0, respectively).</p

P-values and FCs for the target genes at every time point.

<p>P-values and FCs for the target genes at every time point.</p

Representative endoscopic images of TNBS (30 mg/ml, 0.6 ml) associated changes at different time points and MEICS-score at T0, T3, T7 and T12.

<p>(A) Granulated and edematous mucosa at T3 and T7, and ulcerations at T12 were evident in Rat 1. At T7, small ulcerations/erosions were identified in Rat 4. In Rat 5, an ulceration is visible at T7 and at T12, a stricturing ulcer has developed. (B) The MEICS-score at T3 was significantly different from T12 (<i>p</i> = 0.02).</p

Histologic appearance of an endoscopic biopsy and whole colon specimen.

<p>(A) Endoscopic biopsy collected at T7 showing evidence of a crypt abscess (arrow), and mucosal gland distortion. Objective x40. (B) Histologic image of a whole colon specimen collected at termination of the study (T12) identifying distorted mucosal glands, and an ulceration with completed reepithelialization and underlying submucosal inflammation (arrow). Objective x4. The slides were stained with hematoxylin and eosin.</p