FIG. 5.

Effect of Trolox on cellular oxygen consumption, Δψ, expression of fully assembled oxidative phosphorylation (OXPHOS) complexes and maximal activity of citrate synthase (CS), and OXPHOS complexes in human skin fibroblasts. (A) Analysis of O₂ consumption in vehicle- (CT) and Trolox-treated cells and the effect of the CV inhibitor oligomycin (OLI), the mitochondrial uncoupler FCCP, and the CI inhibitor rotenone (ROT). Capital letters indicate routine (R), leak (L), maximal (E), and minimal (ROX) O₂ consumption. (B) Average Δψ, as reflected by mitochondrial TMRM intensity. (C) Expression of fully assembled CI to CV, as revealed by blue-native (BN) PAGE electrophoresis of mitoplasts isolated from vehicle (CT)- and Trolox-treated cells (CT+Trolox). The bar graphs indicate the Trolox-induced change in expression. (D) Effect of Trolox on CS activity. (E) Effect of Trolox on CI activity. (F) Effect of Trolox on CII activity. (G) Effect of Trolox on CIII activity. (H) Effect of Trolox on CIV activity. (I) Effect of Trolox on CV activity. (J) Relationship between the Trolox-induced increase in expression of the fully assembled complex and maximal activity for CI–CV (data taken from panels C to I). The dotted line represents a proportional increase in expression and activity. In this figure, significant differences between CT- and the Trolox-treated condition are marked by **(p<0.01) and ***(p<0.001). Numerals (N) represent the number of individual assays (A and D–I), cells (B) or independent experiments (C).