Alcohol use/abuse is a leading cause of neurological damage in humans, especially in the context of alcohol damage to the developing nervous system in fetuses. However, the underlying mechanisms of this neurotoxicity are poorly understood. With this in mind, my goal is to understand alcohol-induced alterations in mitochondrial movements in neurons. The strategic positioning of mitochondria along neuronal processes plays a critical/central role in energy production and Ca2+ homeostasis. Moreover, the maintenance of structurally and functionally distinct axonal and dendritic processes is important for normal neuronal function. This proposal will address a new mechanism by which ethanol may compromise neuron function at the mitochondrial level. Alcohol may alter mitochondrial redistribution in neuronal processes via a rapid onset of oxidative stress (OS), and disrupting the cytoskeletal proteins. One or both of these factors may affect mitochondrial motility. Hence, I hypothesize that alcohol-induced oxidative stress results in the disruption of the temporal movement and spatial distribution of mitochondria in the neuronal processes, and this may contribute to neuronal dysfunction or death. To test this, we will capitalize on a novel live cell imaging approach in conjunction with low density seeded of primary cortical neuron cultures. Our preliminary results provide a strong rationale for our hypothesis and we propose two specific aims. First, determine the effects of alcohol on mitochondrial motility (dose and time-dependent) i.e. changes in direction and its velocity in the axons and dendrites, This approach will utilize live cell imaging confocal, multiphoton and fluorescence microscopic techniques to visually and quantitatively assess mitochondria undergoing anterograde, retrograde and saltatory movements, and, net and instantaneous velocity; Second, determine using similar approaches, whether potential mediators of alcohol-induced oxidative stress (HNE) influences mitochondrial redistribution. The work on 4-hydroxynonenal (HNE) and its relationship to mitochondrial movements, cytoskeletal disruption, its localization in neurons and glutathione status will provide novel insights into the mechanism of action of ethanol. These studies are significant as mitochondrial diseases are mainly reported in organs that have high energy consumption, such as liver, skeletal tissue and brain. Hence, the information gathered will have implications to our future understanding of the role of mitochondrial motility in homeostasis and ? disease states. ? ?
| Maffi, Shivani Kaushal; Rathinam, Mary Latha; Cherian, Priscilla P et al. (2008) Glutathione content as a potential mediator of the vulnerability of cultured fetal cortical neurons to ethanol-induced apoptosis. J Neurosci Res 86:1064-76 |
