Impact of oxidative stress on the cytoskeleton of pancreatic epithelial cells

Abstract

In the present study the effect of reactive oxygen species on the morphological changes of pancreatic epithelial cells in a three-dimensional culture system was investigated. In addition, the expression of signaling molecules during this process was determined. Matrigel™ was used to construct a three-dimensional culture model of pancreatic epithelial and cancer cells. The cultured cells were stimulated with 1 or 200 µmol/l H2O2 (a typical reactive oxygen species), and the morphological changes were then evaluated after 15 min, 1 h and 4 h. The cytoskeleton of the cells was observed using laser scanning confocal microscopy with immunofluorescence staining. In addition, the nuclear content of nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) was detected using ELISA. The results demonstrated that treatment with 200 µmol/l H2O2 induced cell contraction after 15 min, and cell morphology recovered after 1 h; however, cell size was reduced after 4 h. Consequently, intracellular actin and microtubules were rapidly lost following H2O2 treatment, and the cytoskeleton became indistinct and eventually disintegrated after 4 h. Similar observations were noted for the normal pancreatic epithelial and cancer cells. By contrast, treatment with 1 µmol/l H2O2 did not affect the morphology and cytoskeleton of pancreatic epithelial cells. In addition, 200 µmol/l H2O2 treatment increased the activity of NF-κB gradually, while 1 µmol/l H2O2 treatment was found to have little impact on the activity of NF-κB. Therefore, it was demonstrated that oxidative stress can induce the early onset of reversible cell contraction and cytoskeleton depolarization in pancreatic epithelial cells, and can increase NF-κB expression.