Fig. 4

Alterations of mitochondrial respiration in CRT-G561R fibroblasts. (A) Oxygen consumption rate (OCR) profiles of CRT-WT and CRT-G561R fibroblasts. Arrows indicate sequential addition of oligomycin (1 µM), carbonyl cyanide-p-trifluoromethoxyphenylhydrazone (FCCP, 4 µM), rotenone (0.5 µM), and antimycin A (0.5 µM). (B) Estimation of mitochondrial respiratory parameters, including basal respiration, ATP production-linked respiration, proton leakage, maximal respiration, spare respiratory capacity, and non-mitochondrial oxygen consumption, of CRT-WT and CRT-G561R fibroblasts. (C) Relative mitochondrial DNA (mtDNA) copy numbers in CRT-WT and CRT-G561R fibroblasts. (D) Ratio of OCR in mitochondrial respiratory parameters to mtDNA copy number. (E) Extracellular acidification rate (ECAR) profiles of CRT-WT and CRT-G561R fibroblasts. Arrows indicate sequential addition of oligomycin (1 µM), FCCP (4 µM), rotenone (0.5 µM), and antimycin A (0.5 µM). (F) Estimation of basal ECAR, maximal (oligomycin-stimulated) ECAR, and glycolytic reserve (maximal – basal) of CRT-WT and CRT-G561R fibroblasts. (G) Amount of lactate released into 24-h conditioned medium of CRT-WT and CRT-G561R fibroblasts. Culture supernatants containing 10% FBS were assayed by the lactate assay kit-WST. Data are presented as mean ± SD (CRT-WT, n = 6–9; CRT-G561R, n = 4–6 independent biological samples). *p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001, significantly different from CRT-WT fibroblasts.