CAPSAICIN-ENHANCED RIBOSOMAL PROTEIN P2 EXPRESSION AND RECOVERY OF TIGHT JUNCTION PERMEABILITY IN HUMAN INTESTINAL Caco-2 CELLS

摘要

On the basis of transepithelial electrical resistance measurements, we found that capsaicin (100 mu M)treated-human intestinal Caco-2 cells show a momentary decrease in tight-junction (TJ) permeability followed by a complete recovery. We used proteomeanalysis to search for proteins that are associated with the recovery of TJ permeability in capsaicin-treated Caco-2 cells. A protein of relative molecular mass of 14 kDa was found to be expressed higher in capsaicin-treated cells than in nontreated cells. Mass spectrometry and sequence analyse revealed that the protein expressed significantly by capsaicin treatment was the ribosomal protein P2 was and its cDNA sequence was identical to that found in the human genome database. An increase in amount ofcellular filamentous actin (F-actin) was shown after 8 h of incubation with capsaicin. It is reported that ribosomal protein P2 can activate elongation factor 2, which stabilizes F-actin filaments, and that the deploymerization of F-actin was associatedwith the decrement in TJ permeability. Consequently, these results suggest that ribosomal protein P2 plays an important role in the recovery of the TJ permeability in capsaicin-treated human intestinal Caco-2 cells.