Members of the peroxisome proliferator-activated receptor gamma coactivator (PGC) family are potent inducers of mitochondrial biogenesis. We have tested the potential effect of increased mitochondrial biogenesis in cells derived from patients harboring oxidative phosphorylation defects due to either nuclear or mitochondrial DNA mutations. We found that the PGC-1alpha and/or PGC-1beta expression...

Cell and tissue damage in respiratory chain disorders have been related to increased production of reactive oxygen species (ROS). We measured telomere lengths in such disorders since ROS have also been implicated with telomere shortening. We investigated whole blood cell DNA of 14 patients with MELAS-related mitochondriopathy and two patients with the LHON-associated G11778A mutation of the mit...

Mitochondrial disorders are a group of complex and heterogeneous diseases that may be caused by molecular defects in mitochondrial genomes. Pathogenic mitochondrial DNA (mtDNA) mutations are usually present in the heteroplasmic form. The degree of mtDNA mutation heteroplasmy varies among different tissues. Thus, it is important to detect and quantify the degree of mutation heteroplasmy of mtDNA...

itochondrial cardiomyopathy is one of the main features in patients with mitochondrial diseases caused by mitochondrial DNA (mtDNA) mutations, and it determines the prognosis, as well as encephalopathy.1–3 In particular, an A-to-G transition mutation at nucleotide position 3243 (A3243G) in mtDNA, which was originally discovered in patients with mitochondrial myopathy, encephalopathy, lactic aci...

Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly...

Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes (MELAS) is a rare mitochondrial disorder. Diagnostic criteria for MELAS include typical manifestations of the disease: stroke-like episodes, encephalopathy, evidence of mitochondrial dysfunction (laboratorial or histological) and known mitochondrial DNA gene mutations. Clinical features of MELAS are not necessaril...