Jin Yichao, Lin Yingying, Feng Jun-feng, Jia Feng, Gao Guoyi, Jiang Ji-yao
Department of Neurosurgery, Ren-Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
Department of Neurosurgery, Ren-Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, People's Republic of China.
World Neurosurg. 2015 Aug;84(2):420-30. doi: 10.1016/j.wneu.2015.03.039. Epub 2015 Mar 31.
Multiple mechanisms participated in the cell death after fluid percussion traumatic brain injury (TBI). In the present study, we evaluated the effect on cell death in the injured cortex after fluid percussion TBI and investigated a possible role of autophagy.
TBI model was induced by a fluid percussion TBI device. Moderate hypothermia (32°C) was achieved by partial immersion in a water bath (0°C) under general anesthesia for 4 hours. All rats were killed at 6 or 24 hours after TBI.
Cleaved caspase 3 evaluated with Western blotting and terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate-biotin nick end labeling-positive cells in injured cortex were significantly increased 6 hours after fluid percussion TBI and were further up-regulated 24 hours after TBI, dramatic up-regulation of Beclin-1 and protein light chain-3 expression levels was also observed. Further up-regulation of biomarkers of autophagy, attenuation of caspase 3 up-regulation and reduction of cell death was observed after 4 hours of hypothermia. Immunofluorescence analysis for cell localization demonstrated that protein light chain-3- and Beclin-1-positive cells included neurons and glial cells in the injured cortex after TBI and hypothermic treatment. By ultrastructural observation, autolysosomes in injured cortex were significantly increased at 6 and 24 hours after TBI and were further up-regulated after TBI hypothermic treatment.
These data suggest that hypothermic treatment could attenuate TBI-induced cell death in this fluid percussion TBI model, possibly through activation of autophagy pathway.
多种机制参与了液体冲击性脑损伤（TBI）后的细胞死亡。在本研究中，我们评估了液体冲击性TBI后对损伤皮质中细胞死亡的影响，并研究了自噬的可能作用。
采用液体冲击性TBI装置诱导TBI模型。在全身麻醉下将大鼠部分浸入0°C水浴中4小时以实现中度低温（32°C）。所有大鼠在TBI后6或24小时处死。
通过蛋白质印迹法评估的裂解型半胱天冬酶3以及损伤皮质中末端脱氧核苷酸转移酶介导的2'-脱氧尿苷5'-三磷酸生物素缺口末端标记阳性细胞在液体冲击性TBI后6小时显著增加，并在TBI后24小时进一步上调，同时还观察到Beclin-1和轻链3蛋白表达水平的显著上调。低温处理4小时后，观察到自噬生物标志物进一步上调、半胱天冬酶3上调减弱以及细胞死亡减少。细胞定位的免疫荧光分析表明，TBI和低温处理后损伤皮质中轻链3和Beclin-1阳性细胞包括神经元和胶质细胞。通过超微结构观察，TBI后6和24小时损伤皮质中的自噬溶酶体显著增加，并在TBI低温处理后进一步上调。
这些数据表明，在该液体冲击性TBI模型中，低温治疗可能通过激活自噬途径减轻TBI诱导的细胞死亡。
