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Lim SC, Tajika M, Shimura M, Carey KT, Stroud DA, Murayama K, Ohtake A, McKenzie M. Loss of the Mitochondrial Fatty Acid β-Oxidation Protein Medium-Chain Acyl-Coenzyme A Dehydrogenase Disrupts Oxidative Phosphorylation Protein Complex Stability and Function. Sci Rep 2018; 8:153. [PMID: 29317722 PMCID: PMC5760697 DOI: 10.1038/s41598-017-18530-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 12/13/2017] [Indexed: 12/30/2022] Open
Abstract
Medium-chain acyl-Coenzyme A dehydrogenase (MCAD) is involved in the initial step of mitochondrial fatty acid β-oxidation (FAO). Loss of function results in MCAD deficiency, a disorder that usually presents in childhood with hypoketotic hypoglycemia, vomiting and lethargy. While the disruption of mitochondrial fatty acid metabolism is the primary metabolic defect, secondary defects in mitochondrial oxidative phosphorylation (OXPHOS) may also contribute to disease pathogenesis. Therefore, we examined OXPHOS activity and stability in MCAD-deficient patient fibroblasts that have no detectable MCAD protein. We found a deficit in mitochondrial oxygen consumption, with reduced steady-state levels of OXPHOS complexes I, III and IV, as well as the OXPHOS supercomplex. To examine the mechanisms involved, we generated an MCAD knockout (KO) using human 143B osteosarcoma cells. These cells also exhibited defects in OXPHOS complex function and steady-state levels, as well as disrupted biogenesis of newly-translated OXPHOS subunits. Overall, our findings suggest that the loss of MCAD is associated with a reduction in steady-state OXPHOS complex levels, resulting in secondary defects in OXPHOS function which may contribute to the pathology of MCAD deficiency.
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Affiliation(s)
- Sze Chern Lim
- Centre for Genetic Diseases, Hudson Institute of Medical Research, 3168, Melbourne, Australia.,Department of Molecular and Translational Science, Monash University, 3168, Melbourne, Australia
| | - Makiko Tajika
- Department of Metabolism, Chiba Children's Hospital, 266-0007, Chiba, Japan
| | - Masaru Shimura
- Department of Metabolism, Chiba Children's Hospital, 266-0007, Chiba, Japan
| | - Kirstyn T Carey
- Centre for Cancer Research, Hudson Institute of Medical Research, 3168, Melbourne, Australia
| | - David A Stroud
- Department of Biochemistry and Molecular Biology, Monash Biomedicine Discovery Institute, Monash University, 3800, Melbourne, Australia
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital, 266-0007, Chiba, Japan
| | - Akira Ohtake
- Department of Pediatrics, Saitama Medical University, 350-0495, Saitama, Japan
| | - Matthew McKenzie
- Centre for Genetic Diseases, Hudson Institute of Medical Research, 3168, Melbourne, Australia. .,Department of Molecular and Translational Science, Monash University, 3168, Melbourne, Australia.
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