Effects of SP600125 on autophagy and neurocyte loss in the hippocampus of rats with subarachnoid hemorrhage / 医学研究生学报

ABSTRACT

Objective Moderate autophagy helps improve the viability of neurocytes.This study aims to investigate the effect of SP600125 on the autophagy and loss of nerve cells in the hippocampus in rats with subarachnoid hemorrhage (SHA).Methods Forty healthy male SD rats were equally randomized into a sham operation, an DMSO group, an SAH model, and an SP600125 group.The SAH model was established by vascular puncture and the rats of the SP600125 group were injected with 10 μL of SP600125 (3 μg/μL) into the lateral cerebral ventricle at 30 minutes before modeling.Sham group and SAH group were injected with equal volume of normal saline, DMSO group was injected with the same amount of DMSO.The animals were sacrificed at 24 hours after modeling for observation of the changes in the morphology and the number of neurons in the hippocampus by HE staining and qualitative and quantitative determination of the expressions of the p-JNK protein and the autophagy markers beclin-1 and LC3-II by immunohistochemistry and Western blot.Results Compared with the sham operation group, the neurons exhibited a disordered arrangement and the cells were polygonal and decreased in number in the hippocampus of the SAH models, while milder neuronal injury and more cells were observed in the rats of the SP600125 group than in the SAH models.The mean optical density values of Beclin-1, LC3-II and p-JNK in the hippocampus were significantly higher in the SAH models (14.66±4.40, 12.62±3.46, and 12.82±3.68) and DMSO (13.85±3.85、11.59±4.52、13.03±3.53), and the SP600125 group (9.86±3.14, 6.78±2.56, and 5.60±2.42) than in the sham operation group (1.56±0.28, 1.60±0.30, and 1.58±0.32) (P<0.05), but markedly lower in the SP600125 than in the SAH model group (P<0.05).The expressions of Beclin-1, LC3-II and p-JNK were remarkably increased in the SAH models (0.474±0.122, 0.668±0.130, and 0.496±0.124) and DMSO (0.432±0.102、0.628±0.113、0.416±0.094) and the SP600125 group (0.264±0.106, 0.332±0.113, and 0.219±0.104) than in the sham operation group (1.56±0.28, 1.60±0.30, and 1.58±0.32) (P<0.05), but significantly decreased in the SP600125 group as compared with the SAH models (P<0.05).Conclusion SP600125 has a protective effect on the neurocytes in the hippocampus of SAH rats, which may be associated with SP600125 moderately activating neuronal autophagy by inhibiting the activity of the JNK signaling pathway.