Oxidative stress is linked to dopaminergic (DA) neurodegeneration in Parkinson’s disease. Our laboratory reported slowly progressive DA neurodegeneration in the zitter (zi) rat, which is Attractin (Atrn) deficient. However, little is known about the function of Atrn in the central nervous system (CNS). Thus, we investigated whether DA neurodegeneration in the zi rat was induced by oxidative stress, and how Atrn affects oxidative stress. First, we summarize our previous in vivo data, which revealed suppression of DA neurodegeneration using antioxidants (vitamin E and melatonin) in zi rats. Second, our current ex vivo and in vitro studies are introduced. Using primary neuronal cultures of zi mesencephalon as a model of Atrn-deficient neurons or Atrn-GFP-overexpressing HEK293 cells, accumulation of reactive oxygen species (ROS) in mitochondria and cell viability was examined under oxidative stress. Atrn-deficient neurons accumulated excess ROS in mitochondria, resulting in neurodegeneration, whereas Atrn-overexpressing cells showed suppression of ROS accumulation under oxidative stress. These results showed that Atrn plays a suppressive role against ROS and that the loss of Atrn function induced excess ROS accumulation and led to DA neurodegeneration. This is the first report to show that Atrn directly modulates mitochondrial ROS accumulation in the CNS.
Part of the book: Free Radicals and Diseases