OBJECTIVE: To verify whether enhanced substrate-level phosphorylation increases viability and adenosine 5'-triphosphate (ATP) content of cells with neuropathy, ataxia, and retinitis pigmentosa/maternally inherited Leigh syndrome (NARP/MILS) mitochondrial DNA mutations and ATP synthase dysfunction. DESIGN: We used cell lines "poisoned" with oligomycin, the specific inhibitor of ATP synthase, and "natural" models, including transmitochondrial human cell lines (cybrids) harboring 2 different pathogenic mutations associated with the NARP/MILS phenotypes. MAIN OUTCOME MEASURES: Cell survival, morphology, and ATP content. RESULTS: When normal human fibroblasts cultured in glucose-free medium were forced to increase energy consumption by exposure to the ionophore gramicidin or were energy challenged by oligomycin inhibition, their survival at 72 hours was 5%, but this increased to 70% when the medium was supplemented with alpha-ketoglutarate/aspartate to boost mitochondrial substrate-level phosphorylation. Homoplasmic cybrids harboring the 8993T-->G NARP mutation were also protected from death (75% vs 15% survival at 72 hours) by the supplemented medium and their ATP content was similar to controls. CONCLUSIONS: These results show that ATP synthase-deficient cells can be rescued by increasing mitochondrial substrate-level phosphorylation and suggest potential dietary or pharmacological therapeutic approaches based on the supplementation of alpha-ketoglutarate/aspartate to patients with impaired ATP synthase activity.
OBJECTIVE: To verify whether enhanced substrate-level phosphorylation increases viability and adenosine 5'-triphosphate (ATP) content of cells with neuropathy, ataxia, and retinitis pigmentosa/maternally inherited Leigh syndrome (NARP/MILS) mitochondrial DNA mutations and ATP synthase dysfunction. DESIGN: We used cell lines "poisoned" with oligomycin, the specific inhibitor of ATP synthase, and "natural" models, including transmitochondrial human cell lines (cybrids) harboring 2 different pathogenic mutations associated with the NARP/MILS phenotypes. MAIN OUTCOME MEASURES: Cell survival, morphology, and ATP content. RESULTS: When normal human fibroblasts cultured in glucose-free medium were forced to increase energy consumption by exposure to the ionophore gramicidin or were energy challenged by oligomycin inhibition, their survival at 72 hours was 5%, but this increased to 70% when the medium was supplemented with alpha-ketoglutarate/aspartate to boost mitochondrial substrate-level phosphorylation. Homoplasmic cybrids harboring the 8993T-->G NARP mutation were also protected from death (75% vs 15% survival at 72 hours) by the supplemented medium and their ATP content was similar to controls. CONCLUSIONS: These results show that ATP synthase-deficient cells can be rescued by increasing mitochondrial substrate-level phosphorylation and suggest potential dietary or pharmacological therapeutic approaches based on the supplementation of alpha-ketoglutarate/aspartate to patients with impaired ATP synthase activity.
Authors: Adam J Kuszak; Michael Graham Espey; Marni J Falk; Marissa A Holmbeck; Giovanni Manfredi; Gerald S Shadel; Hilary J Vernon; Zarazuela Zolkipli-Cunningham Journal: Annu Rev Pathol Date: 2017-11-03 Impact factor: 23.472
Authors: Huiliang Zhang; Guohua Gong; Pei Wang; Zhen Zhang; Stephen C Kolwicz; Peter S Rabinovitch; Rong Tian; Wang Wang Journal: J Mol Cell Cardiol Date: 2018-08-27 Impact factor: 5.000
Authors: Gerald Pfeffer; Emma L Blakely; Charlotte L Alston; Adam Hassani; Mike Boggild; Rita Horvath; David C Samuels; Robert W Taylor; Patrick F Chinnery Journal: J Neurol Neurosurg Psychiatry Date: 2012-05-10 Impact factor: 10.154