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Biochemical analysis of respiratory function in cybrid cell lines harbouring mitochondrial DNA mutations.
- Source :
-
The Biochemical journal [Biochem J] 2004 Dec 01; Vol. 384 (Pt 2), pp. 287-93. - Publication Year :
- 2004
-
Abstract
- We analysed key biochemical features that reflect the balance between glycolysis and glucose oxidation in cybrids (cytoplasmic hybrids) harbouring a representative sample of mitochondrial DNA point mutations and deletions. The cybrids analysed had the same 143B cell nuclear background and were isogenic for the mitochondrial background. The 143B cell line and its rho(0) counterpart were used as controls. All cells analysed were in a dynamic state, and cell number, time of plating, culture medium, extracellular volume and time of harvest and assay were strictly controlled. Intra- and extra-cellular lactate and pyruvate levels were measured in homoplasmic wild-type and mutant cells, and correlated with rates of ATP synthesis and O2 consumption. In all mutant cell lines, except those with the T8993C mutation in the ATPase 6 gene, glycolysis was increased even under conditions of low glucose, as demonstrated by increased levels of extracellular lactate and pyruvate. Extracellular lactate levels were strictly and inversely correlated with rates of ATP synthesis and O2 consumption. These results show increased glycolysis and defective oxidative phosphorylation, irrespective of the type or site of the point mutation or deletion in the mitochondrial genome. The different biochemical consequences of the T8993C mutation suggest a uniquely different pathogenic mechanism for this mutation. However, the distinct clinical features associated with some of these mutations still remain to be elucidated.
- Subjects :
- Adenosine Triphosphate biosynthesis
Blood Platelets chemistry
Blood Platelets metabolism
Cell Line
Citric Acid metabolism
Cytoplasm metabolism
Extracellular Matrix chemistry
Fibroblasts chemistry
Fibroblasts metabolism
Humans
Hybrid Cells metabolism
Intracellular Space chemistry
Lactic Acid metabolism
Myoblasts chemistry
Myoblasts metabolism
Oxygen Consumption physiology
Pyruvic Acid metabolism
Cell Respiration physiology
Cytoplasm chemistry
DNA, Mitochondrial genetics
Hybrid Cells chemistry
Mutation genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1470-8728
- Volume :
- 384
- Issue :
- Pt 2
- Database :
- MEDLINE
- Journal :
- The Biochemical journal
- Publication Type :
- Academic Journal
- Accession number :
- 15324306
- Full Text :
- https://doi.org/10.1042/BJ20040561