Autophagy Mediates Astrocyte Death During Zinc-Potentiated Ischemia--Reperfusion Injury
Abstract
Pathological release of excess zinc ions and the resultant increase in intracellular zinc has been implicated in ischemic brain cell death, although the underlying mechanisms are not fully understood. Since zinc promotes the formation of the autophagic signal, reactive oxygen species (ROS), and increases autophagy, a known mechanism of cell death, we hypothesized that autophagy is involved in zinc-induced hypoxic cell death. To study this hypothesis, we determined the effect of zinc on autophagy and ROS generation in C8-D1A astrocytes subjected to hypoxia and rexoygenation (H/R), simulating ischemic stroke. C8-D1A astrocytes subjected to 3-h hypoxia and 18-h reoxygenation exhibited dramatically increased autophagy and astrocyte cell death in the presence of 100 μM zinc. Pharmacological inhibition of autophagy decreased zinc-potentiated H/R-induced cell death, while scavenging ROS reduced both autophagy and cell death caused by zinc-potentiated H/R. These data indicate that zinc-potentiated increases in ROS lead to over-exuberant autophagy and increased cell death in H/R-treated astrocytes. Furthermore, our elucidation of this novel mechanism indicates that modulation of autophagy, ROS, and zinc levels may be useful targets in d...Continue Reading
References
Citations
Related Concepts
Related Feeds
Brain Ischemia
Brain ischemia is a condition in which there is insufficient blood flow to the brain to meet metabolic demand. Discover the latest research on brain ischemia here.
Astrocytes
Astrocytes are glial cells that support the blood-brain barrier, facilitate neurotransmission, provide nutrients to neurons, and help repair damaged nervous tissues. Here is the latest research.
Autophagy & Model Organisms
Autophagy is a cellular process that allows degradation by the lysosome of cytoplasmic components such as proteins or organelles. Here is the latest research on autophagy & model organisms
Brain Injury & Trauma
brain injury after impact to the head is due to both immediate mechanical effects and delayed responses of neural tissues.