Mitochondrial dysfunctions in leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL)

• Published in: PloS one Vol. 14; no. 10; p. e0224173
• Main Authors: Lin, Tsu-Kung, Chang, Yung-Yee, Lin, Hung-Yu, Liou, Chia-Wei, Wang, Pei-Wen, Chuang, Jiin-Haur, Chen, Shang-Der, Chuang, Yao-Chung, Huang, Sheng-Teng, Hsu, Te-Yao, Peng, Cheng-Huei, Lan, Min-Yu
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 31.10.2019; Public Library of Science (PLoS)
• Subjects: Aminoacyl-tRNA synthetases; Aspartate-tRNA ligase; Aspartate-tRNA Ligase - deficiency; Aspartate-tRNA Ligase - genetics; Base Sequence; Bioenergetics; Biology and Life Sciences; Biosynthesis; Brain stem; Chains; Deoxyribonucleic acid; Disease; DNA; EDTA; Electron transport; Elongation; Fibroblasts; Fibroblasts - pathology; Gene mutation; Genes; Genetic aspects; Hospitals; Humans; Lactates; Lactic acid; Leukodystrophy; Leukoencephalopathies - genetics; Leukoencephalopathies - pathology; Leukoencephalopathy; Ligases; Maintenance; Medical schools; Medicine; Medicine and Health Sciences; Mitochondria; Mitochondria - pathology; Mitochondrial diseases; Mitochondrial Diseases - genetics; Mitochondrial Diseases - pathology; Mitochondrial DNA; Morphology; Mutation; Neurology; Oxidative stress; Oxygen; Oxygen consumption; Pediatrics; Physiology; Proteins; RNA; Spinal cord; Transfer RNA; Translations; tRNA; United States > US; Taiwan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0224173

Several inherited human diseases have been linked to mitochondrial aminoacyl-tRNA synthetases (mtARSs). Leukoencephalopathy with brainstem and spinal cord involvement and lactate elevation (LBSL) is a leukodystrophy caused by mutations in the DARS2 gene which encodes mitochondrial aspartyl-tRNA synthetase. As mitochondrial ARSs are key components of the mitochondrial translation apparatus, we investigated the effects of DARS2 mutations on mitochondrial functions and mitochondrial morphology in an LBSL patient. In fibroblasts from the patient with LBSL, biosynthesis of respiratory chain complex proteins encoded by mitochondrial DNA was decreased, while those encoded by nuclear DNA were not. Cellular oxygen consumption rates and respiratory control ratio were decreased in the LBSL patient; in addition, fragmentation of mitochondria was increased, while their tubular elongation and interconnectivity were decreased. Taken together, these findings suggest that DARS2 mutations impair translations of mitochondrial DNA-encoded respiratory chain complex proteins, consequently causing dysfunction of cellular respiration and impediment of mitochondrial dynamics, which highlights the role of mtARSs in the maintenance of normal mitochondrial bioenergetics and dynamics.