Journal: iScience

Article Title: Accumulated mtDNA mutations are linked to specific impairments in NADH-linked respiration

doi: 10.1016/j.isci.2026.115184

Figure Lengend Snippet: PolG Mut mitochondria possess selective impairments to NAD-linked Respiration (A) Schematic depiction of the substrates and inhibitors added during the OxPhos kinetics assay. Mitochondrial oxygen consumption ( J O 2 ) across OxPhos kinetics assay in mitochondria isolated from (B) BAT, (C) brain, (D) colon, (E) heart, (F) kidney, (G) Liver, (H) and lung tissue. Ratio of maximal complex I (CI) versus CII-supported mitochondrial J O 2 (I). N = 4–6 per group. Data are presented as mean ± SEM and analyzed using multiple unpaired t tests ( B–5H) or unpaired t test ( I), ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001. Substrates utilized are indicated as follows: creatine kinase (CK; 20 U/mL), ATP (5 mM), phospho-creatine (PCr; 1 mM), cytochrome c (Cyt C; 10 μM; pyruvate (Pyr; 5 mM), malate (Mal; 1 mM), octanoyl-carnitine (Oct; 0.2 mM), glutamate (Glut; 5 mM), rotenone (Rot; 0.5 μM), succinate (Succ; 5 mM) oligomycin (Oligo; 0.02 μM), malonate (Malo; 20 mM), calcium chloride (CaCl 2 ; 0.6 mM) glycerol-3-phosphate (G3P; 10 mM), and antimycin A (Ant A; 0.5 μM). Graphics were generated using BioRender.

Article Snippet: Following freeze fracture, 20μg of mitochondria were added to Respiration Buffer in the Oroboros O2k system followed by Cyt C (10μM).

Techniques: Isolation, Generated

Journal: iScience

Article Title: Accumulated mtDNA mutations are linked to specific impairments in NADH-linked respiration

doi: 10.1016/j.isci.2026.115184

Figure Lengend Snippet: Respiratory capacity within the electron transport system remains intact in PolG Mut mice (A–H) Schematic representing the maximal respiratory capacity protocol. Real-time oxygen consumption ( J O 2 ) in mitochondria isolated from (B) BAT, (C) brain, (D) colon, (E) heart, (F) kidney, (G) Liver, (H) and lung following serial titration of the mitochondrial uncoupling agent, carbonyl cyanide- p -trifluoromethoxyphenylhydrazone (FCCP, FC; 0.25 μM). (I) Maximal mitochondrial respiration achieved during FCCP titration. N = 5–6 per group, Data are presented as mean ± SEM. ∗ p < 0.05, ∗∗ p < 0.01, ∗∗∗∗ p < 0.0001 depict significant post hoc LSD by two-way ANOVA; main effect PolG ( B–4H) or unpaired t test ( I). Substrates utilized are indicated as follows: pyruvate (Pyr; 5 mM), malate (Mal; 1 mM), octanoyl-carnitine (Oct; 0.2 mM), succinate (Succ; 5 mM) cytochrome c (Cyt C, 10 μM). Graphics were generated using BioRender.

Article Snippet: Following freeze fracture, 20μg of mitochondria were added to Respiration Buffer in the Oroboros O2k system followed by Cyt C (10μM).

Techniques: Isolation, Titration, Generated

Journal: iScience

Article Title: Accumulated mtDNA mutations are linked to specific impairments in NADH-linked respiration

doi: 10.1016/j.isci.2026.115184

Figure Lengend Snippet: Mitochondrial respiratory phenotypes are maintained in permeabilized tissue (A) Tissue slices were permeabilized in saponin before assessment of oxygen consumption ( J O 2 ). (B) Intact colon, (C) heart, and (D) liver J O 2 under multiple substrate conditions. (E) Ratio of complex I (CI) versus CII-supported respiration. (F) Dose-response to FCCP titration and (G) maximal respiratory capacity in intact bone marrow-derived mononuclear cells (BMMCs). (H) Mitochondrial J O 2 during OxPhos kinetics technique in permeabilized BMMCs. (I) Ratio of CI versus CII-supported respiration in permeabilized BMMCs. N = 5 per group. Data are presented as mean ± SEM, p < 0.05, ∗∗ p < 0.01, ∗∗∗ p < 0.001,∗∗∗∗ p < 0.00001 depict significant multiple unpaired t tests ( A–6C and 6G), and unpaired t test ( D–6F and 6H). Substrates utilized are indicated as follows: creatine kinase (CK; 20 U/mL), ATP (5 mM), phospho-creatine (PCr; 1 mM), cytochrome c (Cyt C; 10 μM), pyruvate (Pyr; 5 mM), malate (Mal; 1 mM), octanoyl-carnitine (Oct; 0.2 mM), glutamate (Glut; 5 mM), rotenone (Rot; 0.5 μM), succinate (Succ; 5 mM) oligomycin (Oligo; 0.02 μM), malonate (Malo; 20 mM), calcium chloride (CaCl 2 ; 0.6 mM) glycerol-3-phosphate (G3P; 10 mM) antimycin A (Ant A; 0.5 μM), and carbonyl cyanide- p -trifluoromethoxyphenylhydrazone (FCCP, FC; 0.25 μM). Graphics were generated using BioRender.

Article Snippet: Following freeze fracture, 20μg of mitochondria were added to Respiration Buffer in the Oroboros O2k system followed by Cyt C (10μM).

Techniques: Titration, Derivative Assay, Generated