Intrathecal Injection of 3-Methyladenine Reduces Neuronal Damage and Promotes Functional Recovery via Autophagy Attenuation after Spinal Cord Ischemia/Reperfusion Injury in Rats
机构：[a]Department of Anesthesia, the Second Affiliated Hospital of Soochow University,Suzhou 215006, China:[b]Department of Orthopaedics, the Second Affiliated Hospital of Soochow University, Suzhou 215006, China:[c]Experimental Center, the Second Affiliated Hospital of Soochow University,Suzhou 215006, China.
The present study aimed to determine the occurrence of autophagy following ischemia/reperfusion (I/R) injury in the rat spinal cord and whether autophagy inhibition contributes to neural tissue damage and loco motor impairment. A spinal cord I/R model was induced via descending thoracic aorta occlusion for 10 min using systemic hypotension (40 mmHg) in adult male Sprague-Dawley rats. Then, 600 nmol 3-methyladenine (3-MA) or vehicle was intrathecally administered. Ultrastructural spinal cord changes were observed via transmission electron microscopy (TEM) and immunofluorescent double-labeling. Western blots were used to determine the protein expression of microtubule-associated protein light chain 3 (LC3) and Beclin 1. Autophagy was activated after spinal cord I/R injury as demonstrated by significantly increased LC3 and Beclin 1 expression at 3-48h after injury. Furthermore, TEM images indicated the presence of autophagosomes and autolysosomes in the injured spinal cord. 3-MA significantly decreased LC3 and Beclin 1 expression and the number of LC3-positive cells in spinal cord of I/R versus vehicle groups. Moreover, the 3-MA-treated rats exhibited better neurobehavioral scores compared with control rats. These findings suggest activation of autophagy leading to neuronal cell death in the I/R injured spinal cord. These effects were significantly inhibited by intrathecal 3-MA administration. Thus intrathecal 3-MA administration may represent a novel treatment target following spinal cord I/R injury.
基金：
This work was supported by Grants
from the Qing Lan Project, the Key Talent Project of Jiangsu
Province, the National Natural Science Foundation of China
(NSFC 81171712, 81102431), the Special Program of Clinical
Medical Science of Jiangsu Province (BL2014040), and the
Priority Academic Program of the Second Affiliated Hospital
of Soochow University (XKQ2015001).
