Localized mobilization of intracellular calcium promotes epithelial repair in vivo

Abstract

We report that localized intracellular Ca2+ mobilization occurs at the site of gastric surface epithelial damage in vivo, and investigate the role of intracellular and extracellular Ca2+ in stimulating the epithelial cell migration that mediates tissue repair. Experiments used anesthetized yellow cameleon 3.0 (intracellular Ca2+ sensor) transgenic mice, with the surgically exposed gastric mucosa imaged with confocal/two‐photon microscopy. CFP was excited at 840 nm and Ca2+ dynamics measured as FRET/CFP ratio. Photodamage (high intensity 840 nm light) was imposed on 3–5 gastric epithelial surface cells, leading to a microscopic lesion that healed within 15 min. During repair, intracellular Ca2+ selectively increased in restituting epithelial cells directly adjacent to the damaged area. Pretreatment with either chelerythrine (PKC inhibitor), U‐73122 (phospholipase C [PLC] inhibitor), or verapamil (voltage‐activated Ca2+ channel blocker) inhibited repair of damage, and these agents also inhibited the intracellular Ca2+increase. Addition of 10 mM luminal Ca2+ rescued the slowed repair of damage caused by verapamil or indomethacin (COX inhibitor), and partially rescued the increase of intracellular Ca2. Intracellular Ca2+ mobilization in restituting epithelial cells plays an important role in gastric repair in vivo, and is regulated by eicosanoids, PKC, PLC and voltage operated Ca2+ channels. NIDDK RO1‐DK‐54940 and University of Cincinnati Research Council Funding.