Systemic administration of PEP-1-SOD1 fusion protein improves functional recovery by inhibition of neuronal cell death after spinal cord injury.
Spinal cord injury (SCI) produces excessive levels of reactive oxygen species (ROS) that induce apoptosis of neurons. Cu,Zn-superoxide dismutase (SOD1) is a key antioxidant enzyme that detoxifies intracellular ROS, thereby protecting cells from oxidative damage. PEP-1 is a peptide carrier capable of delivering full-length native peptides or proteins into cells. In the study described here, we fused a human SOD1 gene with PEP-1 in a bacterial expression vector to produce a genetic in-frame PEP-1-SOD1 fusion protein; we then investigated the neuroprotective effect of the fusion protein after SCI. The expressed and purified PEP-1-SOD1 was efficiently delivered into cultured cells and spinal cords in vivo, and the delivered fusion protein was biologically active. Systemic administration of PEP-1-SOD1 significantly decreased levels of ROS and protein carbonylation and nitration in spinal motor neurons after injury. PEP-1-SOD1 treatment also significantly inhibited mitochondrial cytochrome c release and activation of caspase-9 and caspase-3 in spinal cords after injury. Furthermore, PEP-1-SOD1 treatment significantly reduced ROS-induced apoptosis of motor neurons and improved functional recovery after SCI. These results suggest that PEP-1-SOD1 may provide a novel strategy for the therapeutic delivery of antioxidant enzymes that protect neurons from ROS after SCI.
Yune
Tae Young
TY
Age-Related and Brain Diseases Research Center, Kyung Hee University, Seoul 130-701, Korea. tyune@khu.ac.kr
Lee
Jee Youn
JY
Jiang
Mei Hua
MH
Kim
Dae Won
DW
Choi
Soo Young
SY
Oh
Tae Hwan
TH
D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D017209:Apoptosis / Q000502:physiology; D015153:Blotting, Western; D003543:Cysteamine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D006801:Humans; D007150:Immunohistochemistry; D020287:In Situ Nick-End Labeling; D008297:Male; D009474:Neurons / Q000378:metabolism / Q000473:pathology; D010455:Peptides / Q000008:administration & dosage*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000008:administration & dosage*; D020127:Recovery of Function / Q000502:physiology*; D013119:Spinal Cord Injuries / Q000378:metabolism / Q000473:pathology / Q000628:therapy*; D013482:Superoxide Dismutase / Q000008:administration & dosage*; D000072105:Superoxide Dismutase-1
D000975:Antioxidants; C503924:Pep-1 peptide; D010455:Peptides; D017382:Reactive Oxygen Species; D011993:Recombinant Fusion Proteins; C000606290:SOD1 protein, human; D003543:Cysteamine; C000606292:Sod1 protein, rat; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1