过氧化物酶体增殖物激活受体γ激动剂对脊髓损伤后大鼠自噬相关蛋白表达的抑制作用  

Inhibition of peroxisome proliferator activated receptor gamma agonist on autophagy-associated proteins in rats after spinal cord injuries

作　　者：杨晓慧 张钦 庾红林 解国辉[2] Yang Xiaohui;Zhang Qin;Yu Honglin;Xie Guohui(Department of Radiology,Yuncheng Central Hospital Affiliated to Shanxi Medical University,Yuncheng 044000,China;Department of Spine Surgery,Yuncheng Central Hospital Affiliated to Shanxi Medical University,Yuncheng 044000,China)

机构地区：[1]山西医科大学附属运城市中心医院影像科,山西运城044000 [2]山西医科大学附属运城市中心医院脊柱外科,山西运城044000

出　　处：《中华危重症医学杂志（电子版）》2019年第4期223-228,共6页Chinese Journal of Critical Care Medicine:Electronic Edition

基　　金：山西省卫生厅科技基金项目(2011123);甘肃省卫生行业科技计划项目(GSWSKY2016-39);运城市科技基金项目(2015098)

摘　　要：目的探讨过氧化物酶体增殖物激活受体γ(PPARγ)激动剂对脊髓损伤后大鼠自噬相关蛋白表达的抑制作用。方法将60只大鼠分为假手术组、模型组、激动剂组及抑制剂组,每组各15只。通过椎板切除术暴露脊髓,用无菌动脉夹在T6-T7节段硬膜外压迫脊髓造成脊髓损伤模型。假手术组大鼠只接受椎板切除术,激动剂组及抑制剂组大鼠分别在脊髓损伤后腹腔注射PPARγ激动剂罗格列酮和PPARγ抑制剂GW9662(2 mg/kg,每2小时1次)。假手术组和模型组大鼠给予腹腔注射等剂量的等渗NaCl溶液。使用Tarlov’s评分法评估各组大鼠脊髓损伤后3、5、7、14、21、28 d后肢运动功能。采用Western-blotting检测脊髓损伤区组织LC3-Ⅱ/LC3-Ⅰ比值、beclin-1及组织蛋白酶D蛋白的表达水平。采用逆转录聚合酶链反应(RT-PCR)检测脊髓损伤区PPARγmRNA的表达水平。结果 4组大鼠在各时间点运动功能评分比较,差异具有统计学意义(F=25.674,P <0.001)。与假手术组相比,其余各组大鼠脊髓损伤后3、5、7、14、21、28 d运动功能评分均显著降低(P均<0.05)。激动剂组大鼠在脊髓损伤后3、5、7、14、21、28 d运动功能评分均高于模型组及抑制剂组大鼠(P均<0.05)。4组大鼠脊髓损伤后3 d自噬相关蛋白LC3-Ⅱ/LC3-Ⅰ比值、beclin-1、组织蛋白酶D的蛋白及PPARγmRNA表达水平比较,差异均有统计学意义(F=238.213、28.268、172.563、32.492,P均<0.001)。与假手术组比较,模型组、激动剂组及抑制剂组大鼠自噬相关蛋白LC3-Ⅱ/LC3-Ⅰ比值、beclin-1、组织蛋白酶D的蛋白及PPARγmRNA表达水平均显著升高(P均<0.05)。且与激动剂组比较,模型组及抑制剂组大鼠LC3-Ⅱ/LC3-Ⅰ比值及PPARγmRNA均显著降低,而beclin-1及组织蛋白酶D的蛋白表达均显著升高(P均<0.05)。结论大鼠脊髓损伤后,PPARγ激动剂可以通过下调自噬相关蛋白的表达,促进神经功能的恢复。Objective To investigate the inhibitory effect of peroxisome proliferator activated receptor gamma(PPARγ)agonist on autophagy-associated proteins in rats after spinal cord injuries.Methods A total of 60 rats were randomly divided into the sham operation group,model group,agonist group and inhibitor group,with 15 rats in each group.The spinal cord was exposed by laminectomy and the model of spinal cord injuries was established by an epidural compression of the spinal cord with a sterile artery clip at the T6-T7 segment.Rats in the sham operation group only performed laminectomy.Rats in the agonist and inhibitor groups were intraperitoneally injected with rosiglitazone and GW9662(2 mg/kg,once every 2 hours)respectively after spinal cord injuries and rats in the sham operation and model groups were given an equal dose of isotonic NaCl solution by intraperitoneal injection.The hindlimb motor function was assessed on 3,5,7,14,21,and 28 d after spinal cord injuries using the Tarlov's scoring method.The expressions of LC3-Ⅱ/LC3-Ⅰ,beclin-1 and cathepsin D were detected by Western-blotting and the PPARγmRNA expression was examined by reverse transcription-polymerase chain reaction(RT-PCR).Results The Tarlov's scores at different time points among 4 groups were significantly different(F=25.674,P<0.001).Compared with the sham operation group,the Tarlov's scores in the other 3 groups decreased obviously on 3,5,7,14,21,and 28 d after spinal cord injuries(all P<0.05);the Tarlov's scores in the agonist group were much higher than those in the model and inhibitor groups(all P<0.05).The expressions of LC3-Ⅱ/LC3-Ⅰ,beclin-1,cathepsin D and PPARγmRNA on 3 d after spinal cord injuries were significantly different among 4 groups as well(F=238.213,28.268,172.563,32.492;all P<0.001).The expressions of LC3-Ⅱ/LC3-Ⅰ,beclin-1,cathepsin D and PPARγmRNA in the sham operation group were much lower than those in the other 3 groups(all P<0.05).Compared with the agonist group,the expressions of LC3-Ⅱ/LC3-Ⅰand PPARγmRNA decrea

关 键 词：PPARΓ 脊髓损伤 自噬 大鼠 

分 类 号：R73[医药卫生—肿瘤]