小鼠神经系统中蛋白质降解通路调控分子的表达和分布  

Expression and Distribution of Molecules Regulating Protein Degradation Pathway in Nervous System of Mice

作　　者：宋彬彬 董文洲 贾炳泉 甄然 彭宇 杨璇 于佳 SONG Binbin;DONG Wenzhou;JIA Bingquan;ZHEN Ran;PENG Yu;YANG Xuan;YU Jia(Beijing Geriatric Hospital,Beijing University of Chinese Medicine,Beijing 100095,China)

机构地区：[1]北京中医药大学附属北京老年医院,北京100095

出　　处：《实验动物与比较医学》2020年第6期463-469,共7页Laboratory Animal and Comparative Medicine

基　　金：北京市自然科学基金资助项目(7202077);北京市科技新星计划资助项目(Z181100006218045);北京老年医院科研专项(2019bjlnyy-青-4)。

摘　　要：目的探讨细胞蛋白质降解通路调控分子在小鼠神经系统中的表达和分布情况。方法以6周龄野生型C57BL/6J小鼠眼、脑、脊髓、坐骨神经和肌肉组织为材料,采用蛋白质印迹法检测不同组织、解剖部位和亚细胞结构中蛋白质降解通路相关蛋白的分布和表达差异。结果蛋白质降解通路相关蛋白组织蛋白酶D(Cathepsin D)、溶酶体关联膜蛋白2(lysosomalassociated membrane protein 2,LAMP2)、自噬微管相关蛋白轻链3A/B(microtubule-associated protein 1A/1B-light chain 3,LC3A/B)、自噬相关蛋白3(autophagy-related protein 3,Atg3)、Ras相关GTP结合蛋白7(Ras-related GTP-binding protein 7,Rab7)、钙蛋白酶(Calpain)大小亚基以及钙蛋白酶抑制蛋白(Calpastatin)在小鼠眼、脑、脊髓和肌肉中均有分布,但表达水平有一定差异。与小鼠脊髓相比,坐骨神经中Calpastatin含量没有明显差异(P>0.05),但泛素、Cathepsin D、LAMP2、LC3A/B、Atg3、Rab7、Calpain1大亚基含量明显减少(P <0.05),Calpain小亚基含量明显增加(P<0.05)。结论生理条件下泛素-蛋白酶体系统和自噬系统在细胞中广泛存在,且在神经元中其主要发生于胞体;而Calpain系统中剪切型Calpain小亚基的含量在轴突束中相对较高,这提示在神经元轴突中Calpain降解通路可能发挥主要功能。Objective To investigate the expression and distribution of the molecules regulating protein degradation pathway in the nervous system of mice. Methods The eye, olfactory bulb,cortex, hippocampus, striatum, midbrain, cerebellum, brainstem, spinal cord, sciatic nerve and muscle of 6 weeks wild-type C57 BL/6 J mice were collected. Then the distribution and expression of key proteins in protein degradation pathway in different tissues, anatomical sites and subcellular structures were determined by Western blotting. Results Cathepsin D, lysosomal-associated membrane protein 2(LAMP2), microtubule-associated protein 1 A/1 B-light chain 3(LC3 A/B),autophagy-related protein(Atg3), Ras-related GTP-binding protein7(Rab7), Calpain and Calpastatin had different expression levels in the eye, brain, spinal cord, sciatic nerve and muscle. Compared to the spinal cord, the sciatic nerve showed decreased levels of ubiquitin, Cathepsin D, LAMP2, total LC3 A/B, Atg3, Rab7 and full length of Calpain1 large subunit(P<0.05), and increased level of Calpain small subunit(P<0.05). Conclusion The ubiquitin-proteasome system and autophagy mainly are widespread in the cell under physiological conditions, which mainly occurs in the cell body of neurons;but the level of spliced Calpain small in axon is relatively high, which suggests that Calpain degradation pathway may play a major role in axon.

关 键 词：泛素-蛋白酶体系统 自噬 钙蛋白酶 脊髓 坐骨神经 小鼠 

分 类 号：R744.8[医药卫生—神经病学与精神病学] Q95-33[医药卫生—临床医学]