Figure 3: Vitamin E reverses a high glucose-induced repair defect and enhances survival of mechanically injured cells.
(a) BS-C-1 cells were cultured in 30 mM glucose (red squares) for 14 weeks, a treatment previously shown to produce deficient membrane repair. Mannitol (30 mM) serves as an iso-osmolar control (black dots). Glucose-treated cells were loaded with 200 μM α-tocopherol (green triangles) or 200 μM Trolox (blue diamonds) for 24 h. Laser assay demonstrates a significant decrease (P<0.001; n=14) in dye uptake in the α-tocopherol (green triangles) and Trolox- (blue diamonds) treated cells compared with the untreated controls (red squares). (b) C2C12 myoblasts in a 96-well plate were loaded with 200 μM α-tocopherol (α-T; green bars) or left untreated (UNT; black bars) for 24 h. A live/dead assay was performed after mechanically scraping the cells off the plate in the presence of PBS containing Ca2+. Survival was calculated by reference to a non-wounded (not scraped) population of cells. Scraping of cells that were first osmotically shocked by immersion in distilled water provides a positive reference for cell death (H2O). A significant (P<0.0001; n=4) increase in survival was observed in the α-tocopherol-treated cells relative to untreated controls. (c) The same procedure, as in b, was followed for HeLa cells, and, in addition, a population of cells was treated with 200 μM water-soluble vitamin E (TX; blue bars). A significant (P<0.001; n=4) increase in survival was observed in the α-tocopherol and Trolox-treated cells relative to untreated controls. Data are presented as the mean±s.e.m.
