Motor neuron mitochondrial dysfunction in spinal muscular atrophy
| Autor: | Yong Chao Ma, Han Shi, Aaron S. Zelikovich, Nimrod Miller |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Mitochondrion Biology medicine.disease_cause Muscular Atrophy Spinal Pathogenesis Mice 03 medical and health sciences Genetics medicine Animals Humans Muscle Skeletal Molecular Biology Genetics (clinical) Membrane Potential Mitochondrial Motor Neurons Membrane potential Myocardium High-Throughput Nucleotide Sequencing Articles General Medicine Spinal muscular atrophy Motor neuron medicine.disease SMA Mitochondria Cell biology Disease Models Animal Microscopy Electron Oxidative Stress 030104 developmental biology medicine.anatomical_structure Spinal Cord Axoplasmic transport Transcriptome Oxidative stress |
| Zdroj: | Human Molecular Genetics. 25:3395-3406 |
| ISSN: | 1460-2083 0964-6906 |
| DOI: | 10.1093/hmg/ddw262 |
| Popis: | Spinal muscular atrophy (SMA), the leading genetic cause of infant mortality, predominantly affects high metabolic tissues including motor neurons, skeletal muscles and the heart. Although the genetic cause of SMA has been identified, mechanisms underlying tissue-specific vulnerability are not well understood. To study these mechanisms, we carried out a deep sequencing analysis of the transcriptome of spinal motor neurons in an SMA mouse model, in which we unexpectedly found changes in many genes associated with mitochondrial bioenergetics. Importantly, functional measurement of mitochondrial activities showed decreased basal and maximal mitochondrial respiration in motor neurons from SMA mice. Using a reduction-oxidation sensitive GFP and fluorescence sensors specifically targeted to mitochondria, we found increased oxidative stress level and impaired mitochondrial membrane potential in motor neurons affected by SMA. In addition, mitochondrial mobility was impaired in SMA disease conditions, with decreased retrograde transport but no effect on anterograde transport. We also found significantly increased fragmentation of the mitochondrial network in primary motor neurons from SMA mice, with no change in mitochondria density. Electron microscopy study of SMA mouse spinal cord revealed mitochondria fragmentation, edema and concentric lamellar inclusions in motor neurons affected by the disease. Intriguingly, these functional and structural deficiencies in the SMA mouse model occur during the presymptomatic stage of disease, suggesting a role in initiating SMA. Altogether, our findings reveal a critical role for mitochondrial defects in SMA pathogenesis and suggest a novel target for improving tissue health in the disease. |
| Databáze: | OpenAIRE |
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