Creed M Stary1, Lijun Xu1, Xiaoyun Sun1, Yi-Bing Ouyang1, Robin E White1, Jason Leong1, John Li1, Xiaoxing Xiong1, Rona G Giffard2. 1. From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.). 2. From the Department of Anesthesia, Stanford University School of Medicine, CA (C.M.S, L.X., X.S., Y.-B.O., J. Leong, J. Li, X.X., R.G.G.); and Department of Biology, Westfield State University, MA (R.E.W.). rgiffard@stanford.edu.
Abstract
BACKGROUND AND PURPOSE: MicroRNA (miR)-200c increases rapidly in the brain after transient cerebral ischemia but its role in poststroke brain injury is unclear. Reelin, a regulator of neuronal migration and synaptogenesis, is a predicted target of miR-200c. We hypothesized that miR-200c contributes to injury from transient cerebral ischemia by targeting reelin. METHODS: Brain infarct volume, neurological score and levels of miR-200c, reelin mRNA, and reelin protein were assessed in mice subjected to 1 hour of middle cerebral artery occlusion with or without intracerebroventricular infusion of miR-200c antagomir, mimic, or mismatch control. Direct targeting of reelin by miR-200c was assessed in vitro by dual luciferase assay and immunoblot. RESULTS: Pretreatment with miR-200c antagomir decreased post-middle cerebral artery occlusion brain levels of miR-200c, resulting in a significant reduction in infarct volume and neurological deficit. Changes in brain levels of miR-200c inversely correlated with reelin protein expression. Direct targeting of the Reln 3' untranslated region by miR-200c was verified with dual luciferase assay. Inhibition of miR-200c resulted in an increase in cell survival subsequent to in vitro oxidative injury. This effect was blocked by knockdown of reelin mRNA, whereas application of reelin protein afforded protection. CONCLUSIONS: These findings suggest that the poststroke increase in miR-200c contributes to brain cell death by inhibiting reelin expression, and that reducing poststroke miR-200c is a potential target to mitigate stroke-induced brain injury.
BACKGROUND AND PURPOSE:MicroRNA (miR)-200c increases rapidly in the brain after transient cerebral ischemia but its role in poststroke brain injury is unclear. Reelin, a regulator of neuronal migration and synaptogenesis, is a predicted target of miR-200c. We hypothesized that miR-200c contributes to injury from transient cerebral ischemia by targeting reelin. METHODS: Brain infarct volume, neurological score and levels of miR-200c, reelin mRNA, and reelin protein were assessed in mice subjected to 1 hour of middle cerebral artery occlusion with or without intracerebroventricular infusion of miR-200c antagomir, mimic, or mismatch control. Direct targeting of reelin by miR-200c was assessed in vitro by dual luciferase assay and immunoblot. RESULTS: Pretreatment with miR-200c antagomir decreased post-middle cerebral artery occlusion brain levels of miR-200c, resulting in a significant reduction in infarct volume and neurological deficit. Changes in brain levels of miR-200c inversely correlated with reelin protein expression. Direct targeting of the Reln 3' untranslated region by miR-200c was verified with dual luciferase assay. Inhibition of miR-200c resulted in an increase in cell survival subsequent to in vitro oxidative injury. This effect was blocked by knockdown of reelin mRNA, whereas application of reelin protein afforded protection. CONCLUSIONS: These findings suggest that the poststroke increase in miR-200c contributes to brain cell death by inhibiting reelin expression, and that reducing poststroke miR-200c is a potential target to mitigate stroke-induced brain injury.
Authors: L Dulabon; E C Olson; M G Taglienti; S Eisenhuth; B McGrath; C A Walsh; J A Kreidberg; E S Anton Journal: Neuron Date: 2000-07 Impact factor: 17.173