Enteroids from stem cells of patients with Crohn's disease reflect intestinal epithelial barrier changes when compared to tissue specimens
Authors: Kollmann Catherine , Meir Michael , Schneider Jonas , Flemming Sven , Burkard Natalie , Metzger Marco , Schlegel Nicolas 
Published: June 2021

Loss of intestinal epithelial barrier function is a key factor in the pathogenesis of Crohn's disease (CD). To further understand the underlying mechanisms, valid in vitro models that closely represent patients' characteristics are required. Therefore, we tested whether human enteroids generated from stem cells of patients suffering from CD may serve as an in vitro model for this purpose and compared them systematically with full wall tissue specimens from the same patients.Following ethical approval, terminal ileum from patients suffering from CD and healthy individuals with an indication for surgery were collected and enteroids were generated from crypt stem cells. Enteroids from CD patients were generated from stem cells that derived from the center of the specimens where inflammation was most pronounced and from the resection margins where no or minimal inflammation was observed. Full wall tissue samples were collected from the same areas. Enteroids and full wall tissues were processed for immunohistochemistry and Western blot to analyze changes of junctional proteins in the different samples. Additionally, HE‐staining was used to score the extent of inflammation based on a previously published semiquantitative scoring system for inflammatory bowel diseases (0= no inflammation; 1= mild inflammation; 2= moderate inflammation; 3= severe inflammation).Histopathological analyses of HE‐stained full wall sections confirmed that tissue from the centre of the specimens from CD patients showed severe inflammation (score 2.6 ± 0.2) compared to moderate inflammation (score 1.8 ± 0.2) at the resection margins, whereas control specimens showed no inflammation. In immunostained and Western blot lysates of full wall tissue specimens from CD patients, a significant loss of epithelial tight junction proteins claudin1, 4 and 5 was evident while pore‐forming claudin2 was increased when compared to specimens from healthy controls. Similarly, the desmosomal cadherins desmoglein2 and desmocollin2 were reduced in samples from CD patients. In contrast, E‐cadherin was only reduced in samples with severe inflammation where in some areas the epithelium was already lost. Interestingly, enteroids generated from the crypt stem cells from the same patients showed the same patterns of changes of junctional proteins as seen in the original sites within the full wall tissue specimens. In particular, changes in claudin2, 4, 5 and desmoglein2 were similarly down‐ or upregulated in enteroids when compared to full wall tissues. Importantly, these changes were present in the enteroids without additional stimulation with cytokines indicating that changes of junctional proteins in enteroids from CD patients are already evident at the stem cell level.Taken together, enteroids from CD patients showed a similar distribution pattern of junctional proteins compared to the corresponding full wall tissue. Therefore, enteroids from patients serve as a valid model to further analyse mechanisms of changes of intestinal barrier function in CD.Support or Funding InformationDFG SCHL1962/5‐1This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.