Autophagy after experimental intracerebral hemorrhage.
Autophagy contributes to ischemic brain injury, but it is not clear if autophagy occurs after intracerebral hemorrhage (ICH). This study examined whether ICH-induced cell death is partly autophagic. It then examined the role of iron in inducing this form of cell death after ICH. Male, adult Sprague-Dawley rats received an infusion of autologous whole blood or ferrous iron into the right basal ganglia. Control rats (sham) had a needle insertion. The rats were killed at 1, 3, 7, or 28 days later. Some rats were treated with either deferoxamine or vehicle after ICH. Microtubule-associated protein light chain-3 (LC3), a biomarker of autophagosome, and cathepsin D, a lysosomal biomarker, were measured by Western blot analysis and immunohistochemistry. Immunofluorescent double-labeling was used to identify the cell types expressing cathepsin D. Electron microscopy was performed to examine the cellular ultrastructure changes after ICH. We found that conversion of LC3-I to LC3-II, cathepsin D expression, and vacuole formation are increased in the ipsilateral basal ganglia after ICH. Intracerebral infusion of iron also resulted in enhanced conversion of LC3-I to LC3-II and increased cathepsin D levels. Deferoxamine (an iron chelator) treatment significantly reduced the conversion of LC3-I to LC3-II and cathepsin D levels after ICH. Our results demonstrated that autophagy occurs after ICH, and iron has a key role in ICH-induced autophagy. This also suggests that iron-induced autophagy may play a role in brain injury in other diseases associated with iron overload.
He
Yangdong
Y
Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan 48109-2200, USA.
Wan
Shu
S
Hua
Ya
Y
Keep
Richard F
RF
Xi
Guohua
G
D000818:Animals; D001343:Autophagy / Q000187:drug effects / Q000502:physiology*; D001479:Basal Ganglia / Q000378:metabolism* / Q000473:pathology*; D015153:Blotting, Western; D002402:Cathepsin D / Q000378:metabolism; D002543:Cerebral Hemorrhage / Q000378:metabolism* / Q000473:pathology*; D003676:Deferoxamine / Q000633:toxicity; D005296:Ferrous Compounds / Q000633:toxicity; D007501:Iron / Q000633:toxicity; D008297:Male; D008854:Microscopy, Electron; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017262:Siderophores / Q000633:toxicity; D014463:Ultrasonography; D014617:Vacuoles / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology
D002402:Cathepsin D; D003676:Deferoxamine; D005296:Ferrous Compounds; D007501:Iron; D008869:Microtubule-Associated Proteins; D017262:Siderophores; C526109:Anxa3 protein, rat