Project description:Global gene expression analysis was performed comparing human skeletal muscle samples from patients with various forms of muscular dystrophy and mitochondrial myopathies in order to identify specific gene expression changes associated with collagen VI deficiency (leading to UllrichM-BM-4s Congenital Muscular Dystrophy) and depletion of mitochondrial DNA relative to other mitochondrial myopathies We analysed the gene expression profile of skeletal muscle from children suffering from mitochondrial myopathies and various forms of muscular dystrophy relative to skeletal muscle from healthy children using commercially available arrays that represents the complete human genome (Agilent Human SurePrintGE, 8x60K )
Project description:To study whether increase in mitochondrial oxidative stress (SOD2 removal) and decrease in mitochondrial DNA repair (Ogg1 dMTS) results into increase in mitochondrial DNA mutation load. Oxidative stress has been suggested to induce mutations in mtDNA. To verify this, we extracted and sequenced (Illumina) mitochondrial DNA from heart Sod2 knockout animals that were also deficient for mitochondrial base-excision repair. The repair deficiency was induced by removing the genomic region encoding for the predicted mitochondrial targeting sequence from endogenous OGG1 (L2 to W23) called Ogg1 dMTS mice, thus excluding the protein from mitochondria. OGG1 is a DNA glycosylase that recognizes and repairs 8-oxo-dG damage from DNA. Oxidative stress can induce 8-oxo-dG lesions, thus we removed the mitochondrial matrix localized superoxide dismutase (SOD2) from these mice to increase the level of oxidative stress. 8-oxo-dG lesion can be mutagenic because some DNA repair polymerases are known to erroneously incorporate adenosine opposite to 8-oxo-dG during replication leading to GC>TA transversion mutations.