Oxidation Alters Ion Channels During Aging

Oxidative metabolism produces highly reactive oxygen species (ROS). More and more of these toxic compounds accumulate as an organism ages and its antioxidant defenses weaken. In turn, ROS are thought to contribute to aging through damage to proteins, DNA, and cell membranes. Now, Federico Sesti and Shi-Qing Cai of the University of Medicine & Dentistry of New Jersey have demonstrated that ROS also target ion channels that are essential to the proper function of neurons (Nat. Neurosci., DOI: 10.1038/nn.2291). Working with the worm Caenorhabditis elegans, they showed that oxidative modification of KVS-1 potassium ion channels leads to progressive neurodegeneration and loss of chemotaxis ability—a sensory function controlled by KVS-1—during aging. The researchers examined the impact of ROS on transgenic worms that possess oxidation-resistant potassium ion channels and on other worms that produce more than the normal amount of antioxidants. In both cases, Sesti and Cai found that the diminished oxidation of the worms' potassium ion channels preserved neuronal function and chemotaxis ability as the worms aged.