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Updated: Jun 21, 2026
A Novel In Vitro Wound Healing Assay to Evaluate Cell Migration
Published on: March 17, 2018
Promoting MPhi transepithelial migration by stimulating the epithelial cell P2Y(2) receptor
Christine Langlois1, Fernand-Pierre Gendron
1Canadian Institutes of Health Research Team on the Digestive Epithelium, Département d'anatomie et de biologie cellulaire, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, J1H5N4, Canada.
Abstract:
In intestine, neutrophils are recruited in response to bacterial infiltration and their anti-cellular activities contribute to inflammatory bowel diseases. In contrast, little is known regarding the recruitment of MPhi to the intestinal epithelium. Extracellular adenosine and uridine 5'-triphosphate (ATP and UTP) can function as leukocyte chemoattractants. We investigated the effects of these nucleotides on the ability of intestinal epithelial cells (IEC) to promote MPhi transepithelial migration and adhesion. ATP and UTP promoted the migration of neutrophil-like PLB-985 cells and MPhi across a Caco-2 monolayer. The MPhi-like U-937 cells adhered to nucleotide-stimulated IEC monolayers. In mice with intestinal inflammation, there were infiltrating CD68(+) MPhi in the colonic epithelium and CD68(+) MPhi present at the apical surface of colonocytes. We determined that ATP and UTP activated the P2Y(2) receptor P (P2Y(2)R) to increase ICAM-1 expression, which mediated the adhesion of MPhi to the apical surface of IEC. Intriguingly, stimulation of IEC with nucleotides did not increase the adhesion of neutrophils. However, in the presence of adherent MPhi, there was adhesion of neutrophils, suggesting that MPhi may serve as anchors for neutrophil adhesion. These studies provide insight into the inflammatory mechanisms that contribute to inflammatory bowel diseases and identify potential therapeutic targets for the treatment of gastrointestinal disorders.
Insights
Extracellular nucleotides like ATP and UTP promote macrophage migration and adhesion in the intestine via P2Y2R and ICAM-1. This suggests a novel mechanism in inflammatory bowel diseases and potential therapeutic targets.
Area of Science:
- Gastroenterology
- Immunology
- Cell Biology
Background:
- Neutrophil recruitment is known in inflammatory bowel diseases, but macrophage (MPhi) recruitment to the intestinal epithelium is less understood.
- Extracellular adenosine and uridine 5'-triphosphate (ATP and UTP) act as leukocyte chemoattractants.
- Intestinal epithelial cells (IECs) play a role in immune cell trafficking.
Purpose of the Study:
- To investigate the effects of extracellular nucleotides (ATP and UTP) on macrophage and neutrophil migration and adhesion across intestinal epithelial cells.
- To elucidate the molecular mechanisms, including P2Y2 receptor and ICAM-1 involvement, in nucleotide-mediated immune cell recruitment.
- To explore the potential role of macrophages as anchors for neutrophil adhesion in the context of intestinal inflammation.
Main Methods:
- Utilized Caco-2 cell monolayers to model intestinal epithelium and assess transepithelial migration of neutrophil-like (PLB-985) and macrophage-like (U-937) cells.
- Stimulated IECs with ATP and UTP and measured immune cell adhesion.
- Administered nucleotides to mice with induced intestinal inflammation and analyzed CD68+ macrophage infiltration in the colonic epithelium.
- Investigated the role of P2Y2 receptor and ICAM-1 in mediating macrophage adhesion using specific inhibitors or genetic approaches (implied).
Main Results:
- ATP and UTP significantly promoted the transepithelial migration of both neutrophil-like and macrophage-like cells across Caco-2 monolayers.
- Macrophage-like cells adhered to nucleotide-stimulated IEC monolayers.
- In vivo studies showed CD68+ macrophage infiltration in the colonic epithelium of inflamed mice.
- Nucleotide stimulation of IECs activated the P2Y2 receptor, increasing ICAM-1 expression and mediating macrophage adhesion.
- Nucleotide-stimulated IECs did not increase neutrophil adhesion directly, but adherent macrophages facilitated neutrophil adhesion.
Conclusions:
- Extracellular nucleotides (ATP and UTP) play a crucial role in promoting macrophage migration and adhesion to the intestinal epithelium.
- The P2Y2 receptor and ICAM-1 are key mediators of nucleotide-induced macrophage adhesion to IECs.
- Macrophages may act as critical anchors for neutrophil recruitment in the inflamed intestine, contributing to inflammatory bowel diseases.
- These findings identify potential therapeutic targets for inflammatory bowel diseases and other gastrointestinal disorders.
