Minireview:Cell biological consequences of Leigh syndrome

Abstract

Mitochondria are double membrane-enveloped organelles that produce ATP in eukaryotic cells through the oxidative phosphorylation (OXPHOS) process. Accordingly, mitochondrial dysfunction is implicated in a broad range of human diseases, such as Parkinson's disease, Alzheimer's disease, cancer and diabetes. From a pediatric perspective, isolated malfunction of the first OXPHOS complex (complex I or NADH:ubiquinone oxidoreductase), is the most frequently observed defect. Complex I dysfunction may manifest itself as Leigh syndrome, which is an early-onset neurodegenerative disorder with a very poor prognosis. In addition to ATP generation, complex I dysfunction can also affect various other key cellular processes, like the generation of reactive oxygen species, maintenance of a sufficiently negative mitochondrial membrane potential, mitochondrial dynamics and calcium homeostasis. In the recent past, we performed a comprehensive live-cell analysis with skin fibroblasts from Leigh syndrome patients. These cells harbored nuclear-DNA encoded mutations in complex I subunits and displayed an isolated complex I deficiency. Here, we provide a brief overview of our key findings and directions for future research.