Trans-activator of transcription-mediated delivery of NEP1-40 protein into brain has a neuroprotective effect against focal cerebral ischemic injury via inhibition of neuronal apoptosis.
BACKGROUND
The Nogo-66 antagonistic peptide (NEP1-40) is a potential candidate for therapeutic intervention of neuronal injury. However, delivery of the proteins across the blood-brain barrier is severely limited by its size and biochemical properties. The current study was designed to evaluate the transducible effects of the trans-activator of transcription (TAT) transduction system for NEP1-40 to cross the blood-brain barrier and to clarify whether intraperitoneal administration of TAT-NEP1-40 could protect cerebral neurons from ischemic injury.


METHODS
Adult male Sprague-Dawley rats were submitted to a 120-min focal ischemia and received an intraperitoneal injection of No-TAT-NEP1-40, TAT-NEP1-40, TAT-beta-galactosidase, or vehicle. The existence of the proteins in the brain was analyzed with immunofluorescence and Western blot techniques at 6 h after injection. Brain ischemic injury was evaluated by neurologic deficit scores, infarction volumes, terminal deoxynucleotidyl transferase-mediated dUDP-biotin nick end labeling staining, and assay of caspase-3 activity.


RESULTS
Western blot analysis and immunofluorescence staining confirmed the presence of TAT-NEP1-40 protein in the brains 6 h after injection. Intraperitoneal injection of TAT-NEP1-40 could attenuate the numbers of terminal deoxynucleotidyl transferase-mediated dUDP-biotin nick end labeling-positive cells and activated caspase-3 positive cells, and increase the viability of the cells in the ischemic bounder zone, compared with that treated with No-TAT-NEP1-40, TAT-beta-Gal, or vehicle. Furthermore, treatment with TAT-NEP1-40 significantly improved the neurologic outcomes and reduced the size of the infarction in rats.


CONCLUSIONS
The results demonstrate that the TAT-NEP1-40 could be efficiently delivered into the rat brains and improve ischemia-induced neurologic outcomes through attenuating cell apoptosis in ischemic brains.
Wang
Qiang
Q
Department of Anesthesiology, Xijing Hospital, Fourth Military Medical University, Xi'an, China.
Gou
Xingchun
X
Xiong
Lize
L
Jin
Weilin
W
Chen
Shaoyang
S
Hou
Lichao
L
Xu
Lixian
L
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D001812:Blood-Brain Barrier; D015153:Blotting, Western; D001921:Brain / Q000187:drug effects*; D002545:Brain Ischemia / Q000517:prevention & control*; D004195:Disease Models, Animal; D005455:Fluorescent Antibody Technique / Q000379:methods; D015696:Gene Products, tat / Q000008:administration & dosage / Q000235:genetics; D008297:Male; D009185:Myelin Proteins / Q000235:genetics / Q000627:therapeutic use*; D009474:Neurons / Q000187:drug effects; D018696:Neuroprotective Agents / Q000008:administration & dosage / Q000302:isolation & purification / Q000627:therapeutic use; D010446:Peptide Fragments / Q000235:genetics / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage / Q000302:isolation & purification / Q000627:therapeutic use*
D015696:Gene Products, tat; D009185:Myelin Proteins; C509624:NEP1-40 protein, human; D018696:Neuroprotective Agents; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins