Acute molecular perturbation of inducible nitric oxide synthase with an antisense approach enhances neuronal preservation and functional recovery after contusive spinal cord injury.
Inducible nitric oxide synthase (iNOS) is a key mediator of inflammation and oxidative stress produced during pathological conditions, including neurodegenerative diseases and central nervous system (CNS) injury. iNOS is responsible for the formation of high levels of nitric oxide (NO). The production of highly reactive and cytotoxic NO species, such as peroxynitrite, plays an important role in secondary tissue damage. We have previously demonstrated that acute administration of iNOS antisense oligonucleotides (ASOs) 3 h after moderate contusive spinal cord injury (SCI) potently inhibits iNOS-mediated increases in NO levels, leading to reduced blood-spinal cord barrier permeability, decreased neutrophil accumulation, and less neuronal cell death. In the current study we investigated if iNOS ASOs could also provide long-term (10-week) histological and behavioral improvements after moderate thoracic T8 contusive SCI. Adult rats were randomly assigned to three groups (n=10/group): SCI alone, SCI and mixed base control oligonucleotides (MBOs), or SCI and iNOS ASOs (200 nM). Oligonucleotides were administered by spinal superfusion 3 h after injury. Behavioral analysis (Basso-Beattie-Bresnahan [BBB] score and subscore) was employed weekly for 10 weeks post-SCI. Although animals treated with iNOS ASOs demonstrated no significant differences in BBB scores compared to controls, subscore analysis revealed a significant improvement in foot positioning, trunk stability, and tail clearance. Histologically, while no gross improvement in preserved white and gray matter was observed, greater numbers of surviving neurons were present adjacent to the lesion site in iNOS ASO-treated animals than controls. These results support the effectiveness of targeting iNOS acutely as a therapeutic approach after SCI.
The Miami Project to Cure Paralysis, The Neuroscience Program, The Interdisciplinary Stem Cell Institute, University of Miami, Miller School of Medicine, Miami, Florida, USA.
Dominic M
DM
Maggio
Katina
K
Chatzipanteli
Neil
N
Masters
Samik P
SP
Patel
W Dalton
WD
Dietrich
Damien D
DD
Pearse
D000578:Amidines / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology / Q000627:therapeutic use; D001812:Blood-Brain Barrier; D003288:Contusions / Q000201:enzymology / Q000628:therapy; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D006146:Guanidines / Q000494:pharmacology / Q000627:therapeutic use; D008124:Locomotion / Q000502:physiology; D009474:Neurons / Q000201:enzymology*; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors* / Q000235:genetics*; D016376:Oligonucleotides, Antisense / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D020127:Recovery of Function / Q000235:genetics*; D013119:Spinal Cord Injuries / Q000201:enzymology* / Q000628:therapy*
D000578:Amidines; D001596:Benzylamines; D004791:Enzyme Inhibitors; D006146:Guanidines; C104820:N-(3-(aminomethyl)benzyl)acetamidine; D016376:Oligonucleotides, Antisense; D052247:Nitric Oxide Synthase Type II; C004479:pimagedine