A means for targeting therapeutics to peripheral nervous system neurons with axonal damage.
OBJECTIVE
Delivery of biological therapeutics to motor and dorsal root ganglion neurons remains a major hurdle in the development of treatments for a variety of neurological processes, including peripheral nerve injury, pain, and motor neuron diseases. Because nerve cell bodies are important in initiating and controlling axonal regeneration, targeted delivery is an appealing strategy to deliver therapeutic proteins after peripheral nerve injury.


METHODS
Tet1 is a 12-aa peptide, isolated through phage display that is selected for tetanus toxin C fragment-like binding properties. In this study, we surveyed its uptake and retrograde transport using compartmented cultures and sciatic nerve injections. We then characterized the time course of this delivery. Finally, to confirm the retrograde transport involvement, a colchicine pretreatment was performed. We also performed competitive binding studies between Tet1 and a recombinant tetanus toxin C fragment using recombinant tetanus toxin C fragment enzyme-linked immunosorbent assay.


RESULTS
We were able to demonstrate efficient uptake and retrograde axonal transport of the Tet1 peptide in vitro and in vivo. Intraneural colchicine pretreatment partially blocked fluorescence detection in the spinal cord, revealing a retrograde axonal transport mechanism. Finally, a competitive enzyme-linked immunosorbent assay experiment revealed Tet1-specific binding to the recombinant tetanus toxin C fragment axon terminal trisialogangliosides receptor.


CONCLUSIONS
These properties of Tet1 can be applied to the development of therapeutic viral vectors and fusion proteins for neuronal targeting and enhanced spinal cord delivery in the treatment of nerve regeneration, neuroprotection, analgesia, and spasticity. Small peptides can be easily fused to larger proteins without significantly modifying their function and can be used to alter the binding and uptake properties of these proteins.
Federici
Thais
T
Liu
James K
JK
Teng
Qingshan
Q
Yang
Jun
J
Boulis
Nicholas M
NM
D000818:Animals; D001370:Axonal Transport / Q000187:drug effects / Q000502:physiology; D001369:Axons / Q000187:drug effects / Q000378:metabolism*; D016503:Drug Delivery Systems / Q000379:methods*; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D010446:Peptide Fragments / Q000008:administration & dosage / Q000378:metabolism; D017933:Peripheral Nervous System / Q000187:drug effects / Q000293:injuries* / Q000378:metabolism*; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013744:Tetanus Toxin / Q000008:administration & dosage / Q000378:metabolism
D010446:Peptide Fragments; D004364:Pharmaceutical Preparations; D013744:Tetanus Toxin; C040635:tetanus toxin fragment C