title: In Vivo Delivery of a Bcl-xL Fusion Protein Containing the TAT Protein Transduction Domain Protects against Ischemic Brain Injury and Neuronal Apoptosis.
abstract: Bcl-xL is a well characterized death-suppressing molecule of the Bcl-2 family. Bcl-xL is expressed in embryonic and adult neurons of the CNS and may play a critical role in preventing neuronal apoptosis that occurs during brain development or results from diverse pathologic stimuli, including cerebral ischemia. In this study, we used a novel approach to study the potential neuroprotective effect of Bcl-xL as a therapeutic agent in the murine model of focal ischemia/reperfusion. We created a Bcl-xL fusion protein, designated as PTD-HA-Bcl-xL, which contains the protein transduction domain (PTD) derived from the human immunodeficiency TAT protein. We demonstrated that this fusion protein is highly efficient in transducing into primary neurons in cultures and potently inhibited staurosporin-induced neuronal apoptosis. Furthermore, intraperitoneal injection of PTD-HA-Bcl-xL into mice resulted in robust protein transduction in neurons in various brain regions within 1-2 hr, and decreased cerebral infarction (up to approximately 40%) in a dose-dependent manner, as determined at 3 d after 90 min of focal ischemia. PTD-HA-Bcl-xL was effective even when it was administered after the completion of ischemia (up to 45 min), and the protective effect was independent of the changes in cerebral blood flow or other physiological parameters. Finally, as shown by immunohistochemistry, Western blotting, and substrate-cleavage assays, PTD-HA-Bcl-xL attenuated ischemia-induced caspase-3 activation in ischemic neurons. These results thus confirm the neuroprotective effect of Bcl-xL against ischemic brain injury and provide the first evidence that the PTD can be used to efficiently transduce a biologically active neuroprotectant in experimental cerebral ischemia.
authors.affiliation: Department of Neurology and Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Guodong
authors.initials: G
authors.lastname: Cao
authors.forename: Wei
authors.initials: W
authors.lastname: Pei
authors.forename: Hailiang
authors.initials: H
authors.lastname: Ge
authors.forename: Qinhua
authors.initials: Q
authors.lastname: Liang
authors.forename: Yumin
authors.initials: Y
authors.lastname: Luo
authors.forename: Frank R
authors.initials: FR
authors.lastname: Sharp
authors.forename: Aigang
authors.initials: A
authors.lastname: Lu
authors.forename: Ruiqiong
authors.initials: R
authors.lastname: Ran
authors.forename: Steven H
authors.initials: SH
authors.lastname: Graham
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
mesh_terms: D000818:Animals; D017209:Apoptosis; D001921:Brain / Q000473:pathology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D015696:Gene Products, tat / Q000737:chemistry*; D007267:Injections; D002546:Ischemic Attack, Transient / Q000473:pathology / Q000517:prevention & control*; D007700:Kinetics; D051379:Mice; D009474:Neurons / Q000473:pathology*; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000627:therapeutic use; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000008:administration & dosage / Q000235:genetics / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D051020:bcl-X Protein
chemical_list: C494812:Bcl2l1 protein, mouse; C494813:Bcl2l1 protein, rat; D015696:Gene Products, tat; D018696:Neuroprotective Agents; D019253:Proto-Oncogene Proteins c-bcl-2; D011993:Recombinant Fusion Proteins; D051020:bcl-X Protein