Background: toxins TcdA and TcdB are responsible for diarrhea and colitis. Lack of functional studies in organoid models of the gut prompted us to elucidate the toxin's effects on epithelial barrier function and the molecular mechanisms for diarrhea and inflammation.
Methods: Human adult colon organoids were cultured on membrane inserts. Tight junction (TJ) proteins and actin cytoskeleton were analyzed for expression via Western blotting and via confocal laser-scanning microscopy for subcellular localization.
Results: Polarized intestinal organoid monolayers were established from stem cell-containing colon organoids to apply toxins from the apical side and to perform functional measurements in the organoid model. The toxins caused a reduction in transepithelial electrical resistance in human colonic organoid monolayers with sublethal concentrations. Concomitantly, we detected increased paracellular permeability fluorescein and FITC-dextran-4000. Human colonic organoid monolayers exposed to the toxins exhibited redistribution of barrier-forming TJ proteins claudin-1, -4 and tricellulin, whereas channel-forming claudin-2 expression was increased. Perijunctional F-actin cytoskeleton organization was affected.
Conclusions: Adult stem cell-derived human colonic organoid monolayers were applicable as a colon infection model for electrophysiological measurements. The TJ changes noted can explain the epithelial barrier dysfunction and diarrhea in patients, as well as increased entry of luminal antigens triggering inflammation.
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http://dx.doi.org/10.3390/toxins15110643 | DOI Listing |
Front Vet Sci
December 2024
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Washington State University, Pullman, WA, United States.
Dogs are increasingly recognized as valuable large animal models for understanding human intestinal diseases, as they naturally develop conditions similar to those in humans, such as Enterohemorrhagic , , inflammatory bowel disease, and ulcerative colitis. Given the similarity in gut flora between dogs and humans, canine intestinal models are ideal for translational research. However, conventional extracellular matrix-embedded organoids present challenges in accessing the lumen, which is critical for gut function.
View Article and Find Full Text PDFJ Adv Res
December 2024
Hubei Key Laboratory of Animal Nutrition and Feed Science, Wuhan Polytechnic University, Wuhan 430023, China. Electronic address:
Introduction: Inflammatory bowel disease (IBD) is often associated with impaired proliferation and differentiation of intestinal stem cells (ISCs). Eicosapentaenoic acid (EPA), which is predominantly found in fish oil, has been recognized for its intestinal health benefits, although the potential mechanisms are not well understood.
Objectives: This study aimed to investigate the regulatory role and mechanism of EPA in colonic epithelial regeneration, specifically from the perspective of ISCs.
FEBS Lett
December 2024
Nutri-Life Science Laboratory, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
The colonic epithelium plays a crucial role in gastrointestinal homeostasis, and colon organoids enable investigation into the molecular mechanisms underlying colonic physiology. However, the method for differentiating induced pluripotent stem cells (iPSCs) into human colon organoids (HCOs) is not necessarily standardized, and studies using HCOs are limited. This study refines the differentiation of HCOs by comparing two protocols reported in Cell Stem Cell and Nature Medicine journals.
View Article and Find Full Text PDFbioRxiv
December 2024
Division of Molecular Medicine, Department of Medicine, University of Minnesota, Minneapolis, MN USA.
Metabolic reprogramming is a hallmark of cancer, enabling tumor cells to adapt to and exploit their microenvironment for sustained growth. The liver is a common site of metastasis, but the interactions between tumor cells and hepatocytes remain poorly understood. In the context of liver metastasis, these interactions play a crucial role in promoting tumor survival and progression.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Banner Alzheimer's Institute, Phoenix, Arizona, USA.
Introduction: While there may be microbial contributions to Alzheimer's disease (AD), findings have been inconclusive. We recently reported an AD-associated CD83(+) microglia subtype associated with increased immunoglobulin G4 (IgG4) in the transverse colon (TC).
Methods: We used immunohistochemistry (IHC), IgG4 repertoire profiling, and brain organoid experiments to explore this association.
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