Modulation of Cell-cell Contacts during Intestinal Restitution <i>In Vitro</i> and Effects of Epidermal Growth Factor (EGF)

Abstract

Mucous epithelia represent a major barrier to the outside world and are capable of undergoing rapid repair after injury by cell migration, a process called “restitution”. Here, a sensitive RT-PCR method was applied allowing systematic gene expression analysis of separated stationary and migratory non-transformed IEC-18 and IEC-6 cells after scratch wounding. The focus was on genes related to cell-cell contacts. Furthermore, the effect of epidermal growth factor (EGF) on gene expression was studied. Most of the genes investigated here were down-regulated in migratory cells. Many of the alterations are expected to affect the permeability of tight junctions. Also the nectin-afadin complex of adherens junctions was modulated as well as the expression of both the chemokine receptor CXCR4 and the EGF receptor. Of note, restitution was not accompanied by the epithelial-mesenchymal transition (EMT). EGF treatment severely affected the expression of genes important for cell-cell contact and cell communication such as selected tight junction components, CXCR4, and TFF3. Many of these genes are known to be involved in EMT and metastasis. Of special note, most of the expression changes induced by EGF are in contrast to the changes observed in migratory cells.

Drug Interaction Studies Reveal That Simotinib Upregulates Intestinal Absorption by Increasing the Paracellular Permeability of Intestinal Epithelial Cells

“…Reducing expression of cell junction genes led to increased paracellular permeability. A previous study reported that several cell junction genes were modulated by EGF, 15) so we tested whether simotinib increased the paracellular permeability by modulating the expression of those cell junction genes. RNA and protein were extracted from Caco-2 cells treated with different concentrations of simotinib (0, 0.005, 0.02, 0.1, 0.5, 2.0 µM).…”

Selective Non-Steroidal Glucocorticoid Receptor Agonists Attenuate Inflammation but Do Not Impair Intestinal Epithelial Cell Restitution In Vitro

“…In addition to TGF-β, the extracellular stimulus EGF is also known as a strong enhancer of epithelial cell restitution [24], [33], [34] and triggers the ERK1/2/MAPK pathway, which is linked to cell migration and proliferation. Thus, the migration properties of IEC-6 cells in the presence or absence of exogenously added EGF and PD98059, a selective inhibitor of MEK1 phosphorylation upstream of ERK1/2, were examined, to see if Dex or the SEGRAs CpdA and ZK216348 modulate intestinal epithelial migration by this pathway.…”

“…With respect to mucosal healing, one of the regulatory peptides, EGF, likewise a strong enhancer of epithelial cell restitution [24], [33], [34], and its signalling via the EGF/ERK1/2/MAPK pathway, are of particular interest, as its downstream targets are involved in cellular events such as cell motility and proliferation [28], [44], and the influence of GCs upon the EGF/ERK1/2/MAPK pathway is also well documented [45], [46]. Indeed, addition of exogenous EGF in combination with Dex led to a complete restoration of the Dex-mediated decrease of restitution in the utilised in vitro wound healing model.…”

Tff3 is Expressed in Neurons and Microglial Cells

“…The cDNA was also checked for contaminating chromosomal DNA by amplification of a promoter sequence from the β-actin gene. The specific primer pairs used in this study are listed in Table 1 or have been published previously [20,21]. …”