Inhibiting a spinal cord signaling pathway protects against ischemia injury in rats.

Abstract

OBJECTIVE:

The aim of the study was to examine whether the cannabinoid agonist WIN55212-2 could attenuate ischemic spinal cord injury (SCI) in rats through inhibition of GAPDH/Siah1 signaling.

METHODS:

Male Sprague-Dawley rats were distributed randomly into 5 groups: (1) sham group that received no aortic occlusion and injected intraperitoneally (i.p.) with vehicle control after reperfusion; (2) control group that received a 12-minute aortic occlusion and injected i.p. with vehicle control after reperfusion; (3) WIN55212-2 group (WIN) that received the aortic occlusion and injected i.p. with 1 mg/kg of WIN55212-2 after reperfusion; and (4) WIN55212-2 plus AM251 group and (5) WIN55212-2 plus AM630 group that received the same surgical operation as the WIN group, except that 1 mg/kg of AM251 or AM630 was injected i.p. 30 min before each dose of WIN55212-2 injection, respectively. Neurologic function was assessed 48 hours after reperfusion. Histopathologic examination was performed to determine the number of normal neurons in anterior spinal cord. Protein expression of active caspase-3, total caspase-3, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), inducible nitric oxide synthase (iNOS), nuclear factor kappa light chain enhancer of activated B cells (NF-κB), Siah1, tumor necrosis factor α, and interleukin 1β were determined with Western blot and enzyme-linked immunosorbent assay; coimmunoprecipitation assays were also used to determine GAPDH/Siah1 complexing. Finally, terminal deoxynucleotidyl transferase dUTP nick end labeling staining was used to determine neuronal apoptosis in the lumbar spinal cord.

RESULTS:

The nuclear translocation of GAPDH and Siah1 in the spinal cord was initiated after ischemic spinal cord injury (SCI) along with the increased formation of GAPDH/Siah1 complexes. However, the activation of GAPDH/Siah1 was blocked by WIN. In addition, the treatment of WIN55212-2 promoted neuronal survival in the spinal cord, reduced apoptosis and inflammation, and improved neurologic scores. Furthermore, these beneficial effects of WIN55212-2 were abolished by the combined treatment of the CB2 antagonist AM630, but not the CB1 antagonist AM251.

CONCLUSIONS:

Our findings reveal GAPDH/Siah1 signaling cascades as a novel therapeutic target for ischemic SCI and identify WIN55212-2 with the potential to treat ischemic SCI by targeting this pathway.

• Authors: Jia Huo, Rui Ma, Xin Chai, Hong-Jin Liang, Peng Jiang, Xiao-Ling Zhu, Xin Chen, Bin-Xiao Su
• Journal: The Journal of thoracic and cardiovascular surgery (J Thorac Cardiovasc Surg) Vol. 157 Issue 2 Pg. 494-503.e1 (02 2019) ISSN: 1097-685X [Electronic] United States
• PMID: 30195603 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2018 The American Association for Thoracic Surgery. Published by Elsevier Inc. All rights reserved.

Chemical References

• Benzoxazines
• Cannabinoid Receptor Agonists
• Morpholines
• Naphthalenes
• Nuclear Proteins
• (3R)-((2,3-dihydro-5-methyl-3-((4-morpholinyl)methyl)pyrrolo-(1,2,3-de)-1,4-benzoxazin-6-yl)(1-naphthalenyl))methanone
• Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating)
• Ubiquitin-Protein Ligases
• seven in absentia proteins

Topics

• Animals
• Apoptosis (drug effects)
• Benzoxazines (pharmacology)
• Cannabinoid Receptor Agonists (pharmacology)
• Glyceraldehyde-3-Phosphate Dehydrogenase (Phosphorylating) (metabolism)
• Inflammation (metabolism)
• Male
• Morpholines (pharmacology)
• Naphthalenes (pharmacology)
• Neurons (cytology, drug effects)
• Nuclear Proteins (metabolism)
• Rats
• Rats, Sprague-Dawley
• Signal Transduction (drug effects)
• Spinal Cord (drug effects, metabolism)
• Spinal Cord Ischemia (drug therapy, prevention & control)
• Ubiquitin-Protein Ligases (metabolism)