d Overview of iPSC lines used in this study. Orange stars: mutation site blue stars: correction site black underlines: artificially introduced silent mutations gRNA: guide RNA HDR: homology direct repair. c Genome editing approach to correct mutation c.769G > A in patient line S2, and to introduce the same mutation in control line C1.
b Electropherograms showing 5′ > 3′ sequences of SURF1 in iPSCs from patients S1 and S2 carrying the mutations c.530T > G p.(V177G) and c.769G > A p.(G257R), respectively. MM mitochondrial membrane, IMM inner mitochondrial membrane, IMS intermembrane space. Accordingly, SURF1 mutations lead to defective COX assembly 15, 16, the absence of SURF1 or its yeast homolog Shy1 cause severe COX deficiency 8, 17, and fibroblasts and muscle fibers carrying SURF1 mutations display decreased COX activity 7, 8, 16.Ī Mitochondrial respiratory chain and putative SURF1 function in CIV assembly.
When the stability of this active COX site is impaired, the whole COX assembly can be compromised 13, 14. SURF1 appears particularly important for the assembly of mtDNA-encoded proteins MT-CO1, MT-CO2, and MT-CO3, which constitute the catalytic core of COX 11, 12. SURF1 protein is located in the mitochondrial inner membrane and is involved in the assembly of CIV, i.e., the cytochrome c oxidase (COX) (Fig. SURF1 gene contains 9 exons, is located on chromosome 9q34, and encodes a protein that is highly conserved among eukaryotes and prokaryotes 10. One of the most frequently mutated nuclear genes in LS is the SURF1 gene (Surfeit locus protein 1, NM_003172.2) 7, 8, 9. The most commonly affected mitochondrial complexes in LS are complex I (CI) and complex IV (CIV) 6. Mutations in more than 75 genes of nuclear or mitochondrial DNA (mtDNA) can cause LS 5. Leigh syndrome (LS) affects 1 in 36,000 newborns 3 and causes lactic acidosis and symmetric lesions in the central nervous system (CNS), predominantly of basal ganglia and brainstem, leading to intellectual disability and muscle weakness with a peak of mortality before three years of age 4. The most severe pediatric manifestation of mitochondrial disease is Leigh syndrome (OMIM #256000) 2. Mitochondrial disease represents the largest class of inborn errors of metabolism mainly comprising monogenic disorders that disrupt oxidative phosphorylation (OXPHOS) 1. Our findings provide mechanistic insights and suggest potential interventional strategies for a rare mitochondrial disease. SURF1 gene augmentation and PGC1A induction via bezafibrate treatment supported the metabolic programming of LS NPCs, leading to restored neuronal morphogenesis. LS NPCs carrying mutations in the complex I gene NDUFS4 recapitulated morphogenesis defects. The defects emerged at the level of neural progenitor cells (NPCs), which retained a glycolytic proliferative state that failed to instruct neuronal morphogenesis. Single-cell RNA-sequencing and multi-omics analysis revealed compromised neuronal morphogenesis in mutant neural cultures and brain organoids. Using patient-derived induced pluripotent stem cells and CRISPR/Cas9 engineering, we developed a human model of LS caused by mutations in the complex IV assembly gene SURF1. The lack of effective models hampers our understanding of the mechanisms underlying the neuronal pathology of LS. Leigh syndrome (LS) is a severe manifestation of mitochondrial disease in children and is currently incurable. Nature Communications volume 12, Article number: 1929 ( 2021) Defective metabolic programming impairs early neuronal morphogenesis in neural cultures and an organoid model of Leigh syndrome
0 kommentar(er)
