Cell-Matrix Interactions Contribute to Barrier Function in Human Colon Organoids

Abstract

The importance of cell-matrix adhesion to barrier control in the colon is unclear. The goals of the present study were to: (i) determine if disruption of colon epithelial cell interactions with the extracellular matrix alters permeability control measurement and (ii) determine if increasing the elaboration of protein components of cell-matrix adhesion complexes can mitigate the effects of cell-matrix disruption. Human colon organoids were interrogated for transepithelial electrical resistance (TEER) under control conditions and in the presence of Aquamin®, a multi-mineral product. A function-blocking antibody directed at the C-terminal region of the laminin α chain was used in parallel. The effects of Aquamin® on cell-matrix adhesion protein expression were determined in a proteomic screen and by Western blotting. Aquamin® increased the expression of multiple basement membrane, hemidesmosomal and focal adhesion proteins as well as keratin 8 and 18. TEER values were higher in the presence of Aquamin® than they were under control conditions. The blocking antibody reduced TEER values under both conditions but was most effective in the absence of Aquamin®, where expression of cell-matrix adhesion proteins was lower to begin with. These findings provide evidence that cell-matrix interactions contribute to barrier control in the colon.

Ginkgetin improved experimental colitis by inhibiting intestinal epithelial cell apoptosis through EGFR/PI3K/AKT signaling

“…6,7 Our data showed that Ginkgetin was found had a protective effect on intestinal barrier function in DSS-induced enteritis mice and TNFαinduced organoid models, further confirming that the regulation of intestinal barrier function is one of the targets for protecting against colitis. Where TEER is used as an indicator of barrier integrity, our data show that colon tissue and monolayers of colonic organoids have robust TEER development, which is consistent with the report by Jelinsky et al and Varani et al [28][29][30] However, there was severe loss of TEER after stimulation with DSS and TNF-α, which was restored by GK treatment. monolayer of columnar intestinal epithelial cells structural basis for maintaining the integrity of the intestinal barrier.…”

“…Briefly, colon organoids were dissociated into single cells and seeded into the Matrigel‐coated Transwell upper chamber at a density of 2 million cells/mL. The cells were incubate at 37°C and 5% CO 2 for 1 day, and after TNF‐α and GK intervention, the TEER value of monolayer cells was measured using a resistive system 29,30 …”

Human intestinal organoids: Modeling gastrointestinal physiology and immunopathology — current applications and limitations

“…Using human colonoids/colonoid monolayers and cell line cultures, its capacity to promote mucosal healing and intestinal barrier restoration was evaluated by analyzing the gene expression of key barrier proteins and TEER [58]. In a series of related studies, the multimineral extract, Aquamin, derived from red marine algae, was shown to improve barrier function in both control and UC colonoids compared with untreated controls [54][55][56]. When human UC colonoids were treated with Aquamin morphometric analysis showed modestly increased lumen diameter and wall thickness, and proteomic analysis showed increased barrier function markers, ion transporters, and mucin, compared with controls, suggesting a potential benefit for increased mineral consumption in UC [55].…”

“…The implications of a compromised barrier in vivo include increased paracellular diffusion, and potential exposure of immune cells to luminal content, including microbiota, initiating a perpetuating inflammatory response [14]. Our understanding of factors affecting barrier function has advanced considerably with the use of organoids [13,54].…”

“… f Techniques — targeted gene and protein expression techniques such as RT‐qPCR, western blotting, immunofluorescent (IF) microscopy, immunohistochemistry (IHC), electrochemiluminescence immunoassay and ELISA [54, 61, 65]. Global gene or protein expression techniques on single cell or whole organoids [13, 16, 44].…”