Fig. 3: Upregulation and ablation of ROMO1 bidirectionally regulate mitochondrial respiration and mPTP opening.
From: ROMO1 overexpression protects the mitochondrial cysteinome from oxidations in aging
a Altered oxygen consumption rate (OCR) of heart mitochondria from TG and cKO mice. Glutamate and malate were used as substrates. 250 µM ADP, 4 µM oligomycin (Oligo), 4 µM FCCP, and 2 µM antimycin A (AA) were added sequentially as indicated by the arrows. Data are mean ± s.e.m. n = 11 measurements from 3 WT mice, n = 17 measurements from 3 TG mice, n = 9 measurements from 3 Control mice, n = 5 measurements from 3 cKO mice. 3-month-old male mice were used. min, minute. b OCR changes of hepatocytes from TG and hKO mice. Glucose and pyruvate were used as substrates. 1 µM Oligo, 1 µM FCCP, and 1 µM rotenone (Rot)/AA were added sequentially as indicated by the arrows. Data are mean ± s.e.m. n = 4 measurements from 3 WT mice, n = 4 measurements from 3 TG mice, n = 9 measurements from 3 Control mice, n = 9 measurements from 3 hKO mice. 3-month-old male mice were used. c–f Opposite effects of ROMO1 upregulation and ablation on Ca2+ retention capacity (CRC) of heart and liver mitochondria. Left panels: Representative traces of the CRC assay as indicated by Fluo-5N fluorescence changes. Right panels: Quantifications of mitochondrial CRC. Data are mean ± s.e.m. In (c), n = 5 WT mice, n = 4 TG mice; in (d), n = 6 Control mice, n = 6 cKO mice; in (e), n = 4 WT mice, n = 4 TG mice; in (f), n = 4 Control mice, n = 6 hKO mice. 3-month-old male mice were used. AU, arbitrary units. s, second. g Representative confocal images of TMRM fluorescence in isolated mouse cardiomyocytes after 100 μM H2O2 treatment. mPTP opening was indicated by an irreversible loss of TMRM-reported ΔΨm. Scale bars, 50 μm. h Quantifications of latency of mPTP opening indicated by ΔΨm loss in response to H2O2 treatment in TG and cKO cardiomyocytes. Data are mean ± s.e.m. n = 25 dishes from 4 WT mice, n = 28 dishes from 4 TG mice, n = 29 dishes from 3 Control mice, n = 27 dishes from 5 cKO mice. 3-month-old male mice were used. In a–f, h, two-tailed unpaired Student’s t-test with Welch’s correction was used. *p < 0.05, **p < 0.01, ***p < 0.001. Source data are provided as a Source Data file.
