Molecular Mechanisms of MMP9 Expression in Astrocytes Induced by Heme and Iron

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Title: Molecular Mechanisms of MMP9 Expression in Astrocytes Induced by Heme and Iron
Authors: Hasim, Mohamed Shaad
Date: 2012
Abstract: The disruption of the blood-brain barrier (BBB) occurs after ischemic and hemorrhagic stroke and contributes to secondary brain damage. Matrix metalloproteinase-9 (MMP9) has been identified to be the main mediator of post-stroke BBB disruption. It is unknown whether deposition of heme/iron in the brain following stroke would affect MMP9 expression. In this study, I have demonstrated that heme/iron up-regulated MMP9 expression in rat astrocytes and that this upregulation was most likely due to reactive oxygen species (ROS) generated by heme/iron deposition on cells. ROS can activate AP-1 and NFκB signaling pathways which were responsible for increased MMP9 expression. Inhibiting AP-1 and NFκB decreased MMP9 expression. Heme/iron deposition also activated Nrf-2 and increased the expression of neuroprotective heme oxygenase-1. My study suggests that heme and iron deposition generates ROS and increases MMP9 expression through AP-1 and NFκB signaling pathways and that targeting these pathways or clearance of heme and iron may modulate MMP9 expression for reduced damage.
URL: http://hdl.handle.net/10393/23575
http://dx.doi.org/10.20381/ruor-6252
CollectionThèses, 2011 - // Theses, 2011 -
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