NHE3 Controls Proliferation and Migration of Colonic Epithelial Cells

Area of Science:

• Gastroenterology and Hepatology
• Cell Biology
• Molecular Biology

Background:

• Na+/H+ exchanger 3 (NHE3; SLC9A3) is crucial for gut pH regulation and nutrient absorption.
• NHE3 deficiency in mice leads to IBD-like symptoms, and SLC9A3 mutations are linked to early-onset IBD.
• The role of NHE3 in epithelial cell functions, particularly during injury and repair, is not well understood.

Purpose of the Study:

• To investigate the role of NHE3 in colonic epithelial cell proliferation and migration during wound healing.
• To elucidate the molecular mechanisms underlying NHE3's function in epithelial repair.

Main Methods:

• Utilized colonic organoids from NHE3+/+ and NHE3-/- mice.
• Employed SK-CO-15 cells with shRNA-mediated NHE3 knockdown (NHE3KD).
• Assessed cell proliferation, migration, wound healing, ECM adhesion, focal adhesion kinase (FAK) activation, and gene transcription.

Main Results:

• NHE3-deficient colonoids exhibited increased cell proliferation and reduced ECM adhesion.
• NHE3 deficiency enhanced spontaneous motility and migration in wound healing models.
• Increased migration was linked to FAK and Src activation, with FAK inhibition reversing the effect.

Conclusions:

• NHE3 inhibition, independent of inflammation or microbial factors, may promote epithelial wound healing by modulating cellular plasticity.
• These findings reveal novel, pleiotropic roles for NHE3 in maintaining mucosal homeostasis.
• Targeting NHE3 could offer a permissible therapeutic strategy for enhancing gut repair.