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THE SPREAD OF DAMAGE IN CULTURED GASTRIC AND COLONIC EPITHELIAL CELLS AFTER PHOTO‐DAMAGE
Author(s) -
MadadaNyakauru Chipo,
Montrose Marshall H
Publication year - 2006
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.20.5.lb29-d
Subject(s) - cell damage , fluorescence microscope , ex vivo , epithelium , biophysics , fluorescence , in vivo , chemistry , microbiology and biotechnology , pathology , in vitro , biology , medicine , optics , biochemistry , physics
The gastrointestinal epithelium can be hurt by chemical or toxin damage, bacterial invasion or other insults. After two‐photon absorption to damage specific gastric cells in vivo , we find that damage spreads to adjacent cells prior to repair. The aim of this study was to ask if damage spreads in tissue culture models of gastric (AGS) or intestinal (HT29) epithelial cells. Cell monolayers on glass coverslips were mounted and superfused on a Zeiss LSM510 two‐photon microscope stage. Cells were imaged over time by transmitted light and two‐photon auto‐fluorescence of NADH (730nm EX, 435‐485nm EM). Photo‐damage, to ~ 240μm 2 (3–5 cells) target areas, was caused by repeated scanning at high laser power. Membrane blebbing and the drop in NADH auto‐fluorescence measured cell damage. Graded levels of damage were seen after 0.4, 0.3 or 0.2 W laser powers at time zero. In photodamaged HT29 cells, blebbing was observed at ~ 0.2, 5 ± 1 or 11 ± 2 min, resp. In AGS cells, blebbing occurred at ~ 0.2, 0.2 and 4 ± 2 min, resp. Five min after 0.4 or 0.2 W light exposure, NADH fluorescence in HT29 cells decreased 26 ± 3% or 11 ± 2%. In AGS cells, the decrease was 38 ± 5% or 6 ± 3%, resp. By both measures, AGS cells were more sensitive to high vs. low light exposure than HT29. Laser power also caused graded damage spread to adjacent (non‐photodamaged) cells and to areas >5 cells distant, suggesting that release of toxic products and/or cell‐cell communication spread damage.