Targeted retrograde gene delivery of brain-derived neurotrophic factor suppresses apoptosis of neurons and oligodendroglia after spinal cord injury in rats.
METHODS
Histologic and immunohistochemical studies after targeted retrograde adenovirus (AdV)-mediated brain-derived neurotrophic factor (BDNF) gene delivery via intramuscular injection in rats with injured spinal cord.


OBJECTIVE
To investigate the neuroprotective effect of targeted retrograde AdV-BDNF gene transfection in the traumatically injured spinal cord in terms of prevention of apoptosis of neurons and oligodendrocytes.


BACKGROUND
Several studies investigated the neuroprotective effects of neurotrophins including BDNF on spinal cord injury, with respect to prevention of neural cell apoptosis in injured spinal cord. However, no report has described the potential effect of targeted retrograde neurotrophic factor gene delivery in injured spinal cord on prevention of neural cell apoptosis.


METHODS
AdV-BDNF or AdV-LacZ was used for retrograde delivery via bilateral sternomastoid muscles to the spinal accessory motoneurons immediately after spinal cord injury in rats. Localization of beta-galactosidase expression produced by LacZ gene or AdV-BDNF gene transfection was examined by immunofluorescence staining and double staining of cell markers (NeuN, RIP, GFAP, OX-42, and NG2) in the injured spinal cord. TUNEL-positive cells were counted and immunoreactivity to active caspase-3 and NG2 was examined after gene injection.


RESULTS
Retrograde delivery of LacZ marker gene was identified in cervical spinal neurons and glial cells including oligodendrocytes in the white matter.AdV-BDNF transfection resulted in a significant decrease in the number of TUNEL-positive apoptotic cells by downregulating the caspase apoptotic pathway, with significant promotion of NG2 expression in injured spinal cord, compared with AdV-LacZ injection.


CONCLUSIONS
Our results suggest that targeted retrograde BDNF gene delivery suppresses apoptosis of neurons and oligodendrocytes in the injured rat spinal cord.
Nakajima
Hideaki
H
Department of Orthopaedics and Rehabilitation Medicine, The University of Fukui, Fukui, Japan.
Uchida
Kenzo
K
Yayama
Takafumi
T
Kobayashi
Shigeru
S
Guerrero
Alexander Rodriguez
AR
Furukawa
Shoei
S
Baba
Hisatoshi
H
D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D015153:Blotting, Western; D019208:Brain-Derived Neurotrophic Factor / Q000235:genetics* / Q000378:metabolism; D002574:Cervical Vertebrae; D015316:Genetic Therapy; D005822:Genetic Vectors / Q000235:genetics; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D009474:Neurons / Q000378:metabolism* / Q000473:pathology; D009836:Oligodendroglia / Q000378:metabolism* / Q000473:pathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013119:Spinal Cord Injuries / Q000235:genetics* / Q000473:pathology / Q000628:therapy*; D018709:Statistics, Nonparametric
D019208:Brain-Derived Neurotrophic Factor