Autophagy-mediated stress response in motor neuron after transient ischemia in rabbits

Objective Spinal cord injury is considered to be related to a vulnerability of spinal motor neurons to ischemia. However, the mechanisms underlying this vulnerability are not fully understood. We investigated the role of autophagy, which is an intracellular bulk degradation process, at motor neuron as a potential mechanism of neuronal death by immunohistochemical analysis for microtubule-associated protein light chain3 (LC3) and γ-aminobutyric-acid type-A-receptor-associated protein (GABARAP) which are considered as markers of autophagy. Methods We used a rabbit spinal cord ischemia model with the use of a balloon catheter. The spinal cord was removed at 8 hours, 1, 2, or 7 days after 15 minutes of transient ischemia, and histologic changes were examined with hematoxylin-eosin staining. Western blot analysis for LC3 and GABARAP, temporal profiles of LC3 and GABARAP immunoreactivity, and double-label fluorescence immunocytochemical studies were performed. Results In the ischemia group, about 85% of motor neurons were preserved until 2 days after reperfusion, but were selectively lost at 7 days ( P Conclusion These data suggest that autophagy was induced in motor neurons by transient spinal cord ischemia in rabbits.