The Regulatory Role of NF-kappa B in Autophagy-like Cell Death After Focal Cerebral Ischemia in Mice

• Type of Material: Article
• Authors: W.L. Li, Emory University; Shan Ping Yu, Emory University; D. Chen, Emory University; S.S. Yu, Medical University of South Carolina; Y.J. Jiang, Nanjing University of Chinese Medicine; T. Genetta, Emory University; Ling Wei, Emory University
• Language: English
• Date: 2013-08-06
• Publisher: Elsevier: 12 months
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2013 IBRO.
• License: Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1016/j.neuroscience.2013.03.045
• Title of Journal or Parent Work: Neuroscience
• ISSN: 0306-4522
• Volume: 244
• Start Page: 16
• End Page: 30
• Grant/Funding Information: It was also supported by the NIH Grant NS055077 to the ENNCF (Emory Neurology-NINDS Core Facility).; This work was supported by NIH Grants NS045810 (L.W.), NS062097 (L.W.), NS058710 (L.W.), NS057255 (S.P.Y.) and the American Heart Association Established Investigator Award (LW).
• Keywords: Science & Technology; Akt; autophagy; STROKE; neurovascular unit; TRANSCRIPTION FACTOR; DOUBLE-EDGED-SWORD; the mammalian target of rapamycin (mTOR); cerebral ischemia; BARREL CORTEX; BLOOD-BRAIN-BARRIER; Life Sciences & Biomedicine; Neurosciences; INJURY; NF-kappaB; PATHWAYS; NEUROVASCULAR UNIT; Neurosciences & Neurology; ERYTHROPOIETIN; RAT MODEL; blood-brain barrier
• Research Categories: Biology, Neuroscience; Biology, Cell

Abstract

Autophagy may contribute to ischemia-induced cell death in the brain, but the regulation of autophagic cell death is largely unknown. Nuclear factor kappa B (NF-κB) is a regulator of apoptosis in cerebral ischemia. We examined the hypothesis that autophagy-like cell death could contribute to ischemia-induced brain damage and the process was regulated by NF-κB. In adult wild-type (WT) and NF-κB p50 knockout (p50-/-) mice, focal ischemia in the barrel cortex was induced by ligation of distal branches of the middle cerebral artery. Twelve to 24h later, autophagic activity increased as indicated by enhanced expression of Beclin-1 and LC3 in the ischemic core and/or penumbra regions. This increased autophagy contributed to cell injury, evidenced by terminal deoxynucleotidyltransferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) co-staining and a protective effect achieved by the autophagy inhibitor 3-methyladenine. The number of Beclin-1/TUNEL-positive cells was significantly more in p50-/- mice than in WT mice. Neuronal and vascular cell death, as determined by TUNEL-positive cells co-staining with NeuN or Collagen IV, was more abundant in p50-/- mice. Immunostaining of the endothelial cell tight junction marker occludin revealed more damage to the blood-brain barrier in p50-/- mice. Western blotting of the peri-infarct tissue showed a reduction of Akt-the mammalian target of rapamycin (mTOR) signaling in p50-/- mice after ischemia. These findings provide the first evidence that cerebral ischemia induced autophagy-like injury is regulated by the NF-κB pathway, which may suggest potential treatments for ischemic stroke.