Objectives: To study whether there is mitochondrial dysfunction in autism, mitochondrial free radicals generation and membrane potential were analyzed in the lymphoblasts.
Methods: The lymphoblasts from autistic and control subjects were obtained from Autism Genetic Resources Exchange Program, and the cell lysates and mitochondria were prepared. MMP was monitored using the fluorescent dye rhodamine123, a cell-permeable cationic dye, which preferentially partitions into mitochondria because of the highly negative MMP. ROS generation in the mitochondria was measured by the oxidation of dihydrorhodamine 123 to fluorescent rhodamine 123, while RNS were measured by using nitric oxide fluorometric assay kit.
Results: Elevated ROS and RNS levels were observed in the mitochondria of autistic lymphoblasts as compared with control lymphoblasts suggesting increased free radical generation by mitochondria in autism. The mitochondrial membrane potential was also reduced in lymphoblasts from autism than in controls.
Conclusions: Our results suggest increased mitochondrial oxidative stress and reduced MMP in autism. Such mitochondrial abnormalities may lead to defects in oxidative phosphorylation and energy metabolism in autism.