Intracellular ROS level is increased in fibroblasts of triple A syndrome patients.
Triple A syndrome is named after the main symptoms of alacrima, achalasia, and adrenal insufficiency but also presents with a variety of neurological impairments. To investigate the causes of progressive neurodegeneration, we examined the oxidative status of fibroblast cultures derived from triple A syndrome patients in comparison to control cells. Patient cells showed a 2.1-fold increased basal level of reactive oxygen species (ROS) and a massive boost after induction of artificial oxidative stress by paraquat. We examined the expression of the ROS-detoxifying enzymes superoxide dismutase 1 and 2 (SOD1, SOD2), catalase, and glutathione reductase. The basal expression of SOD1 was significantly (1.3-fold) increased, and the expression of catalase was 0.7-fold decreased in patient cells after induction of artificial oxidative stress. We show that the mitochondrial network is 1.8-fold more extensive in patient cells compared to control fibroblasts although the maximal ATP synthesis was unchanged. Despite having the same energy potential as the controls, the patient cells showed a 1.4-fold increase in doubling time. We conclude that fibroblasts of triple A patients have a higher basal ROS level and an increased response to artificially induced oxidative stress and undergo "stress-induced premature senescence". The increased sensitivity to oxidative stress may be a major mechanism for the neurodegeneration in triple A syndrome.
Kind
Barbara
B
Children's Hospital, Technical University Dresden, Fetscherstr. 74, 01307, Dresden, Germany. barbara.kind@uniklinikum-dresden.de
Koehler
Katrin
K
Krumbholz
Manuela
M
Landgraf
Dana
D
Huebner
Angela
A
D000309:Adrenal Insufficiency / Q000201:enzymology / Q000378:metabolism; D002374:Catalase / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D002648:Child; D002675:Child, Preschool; D004931:Esophageal Achalasia / Q000201:enzymology / Q000378:metabolism; D005260:Female; D005347:Fibroblasts / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D005979:Glutathione Peroxidase / Q000235:genetics / Q000378:metabolism; D006801:Humans; D007223:Infant; D042541:Intracellular Space / Q000378:metabolism*; D008297:Male; D053078:Membrane Potential, Mitochondrial; D008954:Models, Biological; D010617:Phenanthridines / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012235:Rhodamines / Q000378:metabolism; D013482:Superoxide Dismutase / Q000235:genetics / Q000378:metabolism; D000072105:Superoxide Dismutase-1
C521281:5-(6'-triphenylphosphoniumhexyl)-5,6-dihydro-6-phenyl-3,8-phenanthridinediammine; D010617:Phenanthridines; D017382:Reactive Oxygen Species; D012235:Rhodamines; C000606290:SOD1 protein, human; C058319:dihydrorhodamine 123; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1