目的:研究G蛋白耦联受体激酶相互作用分子1(G-protein-coupled receptor kinase interacting protein 1,GIT1),细胞外信号调节激酶1/2(Extracellular signal-regulated kinases1 and 2,ERK1/2)在脊髓缺血再灌注损伤过程中的作用。方法:...目的:研究G蛋白耦联受体激酶相互作用分子1(G-protein-coupled receptor kinase interacting protein 1,GIT1),细胞外信号调节激酶1/2(Extracellular signal-regulated kinases1 and 2,ERK1/2)在脊髓缺血再灌注损伤过程中的作用。方法:电镜观察缺血30min再灌注不同时间段[A组(对照组)再灌注0min、B组再灌注30min、C组再灌注2h、D组再灌注8h]脊髓组织标本的形态学改变,Westernblot检测各组脊髓标本中ERK1/2和GIT1的表达及其磷酸化,免疫共沉淀分析GIT1同活化的ERK1/2(phospho-ERK1/2,pERK1/2)相互作用的变化,免疫组织化学分析pERK1/2在神经细胞内的定位表达。结果:电镜结果显示D组脊髓神经细胞出现早期凋亡的征象;Western blot结果显示pERK1/2的表达、GIT1的磷酸化在C、D二组较对照组明显增加且均随再灌注时间延长呈明显增加的趋势;免疫共沉淀结果显示GIT1-pERK1/2结合力在C、D两组较对照组明显增加;免疫组织化学结果显示pERK1/2明显滞留于C、D两组的脊髓神经细胞胞浆区内。结论:缺血再灌注损伤过程中ERK1/2的活化以及在胞核外区域的滞留可能导致了脊髓神经细胞的凋亡,而GIT1作为细胞浆内局部黏附蛋白同pERK1/2的结合可能导致了其在胞浆区的滞留。展开更多
目的:设计构建G蛋白偶联受体激酶结合蛋白1(G protein coupled receptor kinase interacting protein 1,GIT1)野生型(WT)及点突变型(Y293F)慢病毒载体,探讨293位点对GIT1功能的影响。方法:用PCR从小鼠cDNA文库中扩增GIT1-WT,将其连接到...目的:设计构建G蛋白偶联受体激酶结合蛋白1(G protein coupled receptor kinase interacting protein 1,GIT1)野生型(WT)及点突变型(Y293F)慢病毒载体,探讨293位点对GIT1功能的影响。方法:用PCR从小鼠cDNA文库中扩增GIT1-WT,将其连接到慢病毒载体PLJM-GFP中,构建质粒PLJM-GFP-GIT1-WT,测序鉴定。利用TaKaRa MutanBEST Kit试剂盒,对PLJM-GFP-GIT1-WT进行定点突变,构建质粒PLJM-GFP-GIT1-Y293F,测序鉴定。重组慢病毒载体转染包装细胞293T,获取病毒上清感染培养至第4代的小鼠成骨细胞。划痕愈合试验检测成骨细胞迁移能力的变化。结果:通过PCR鉴定、双酶切鉴定及测序鉴定,成功构建了PLJM-GFP-GIT1-WT与PLJM-GFP-GIT1-Y293F。划痕愈合试验观察,与PLJM-GFP-GIT1-WT相比,PLJM-GFP-GIT1-Y293F明显抑制成骨细胞迁移。结论:GIT1功能的正常发挥有赖于293位点适时的磷酸化。展开更多
GIT1,a G-protein-coupled receptor kinase interacting protein,has been reported to be involved in neurite outgrowth.However,the neurobiological functions of the protein remain unclear.In this study,we found that GIT1 w...GIT1,a G-protein-coupled receptor kinase interacting protein,has been reported to be involved in neurite outgrowth.However,the neurobiological functions of the protein remain unclear.In this study,we found that GIT1 was highly expressed in the nervous system,and its expression was maintained throughout all stages of neuritogenesis in the brain.In primary cultured mouse hippocampal neurons from GIT1 knockout mice,there was a significant reduction in total neurite length per neuron,as well as in the average length of axon-like structures,which could not be prevented by nerve growth factor treatment.Overexpression of GIT1 significantly promoted axon growth and fully rescued the axon outgrowth defect in the primary hippocampal neuron cultures from GIT1 knockout mice.The GIT1 N terminal region,including the ADP ribosylation factor-GTPase activating protein domain,the ankyrin domains and the Spa2 homology domain,were sufficient to enhance axonal extension.Importantly,GIT1 bound to many tubulin proteins and microtubule-associated proteins,and it accelerated microtubule assembly in vitro.Collectively,our findings suggest that GIT1 promotes neurite outgrowth,at least partially by stimulating microtubule assembly.This study provides new insight into the cellular and molecular pathogenesis of GIT1-associated neurological diseases.展开更多
文摘目的:设计构建G蛋白偶联受体激酶结合蛋白1(G protein coupled receptor kinase interacting protein 1,GIT1)野生型(WT)及点突变型(Y293F)慢病毒载体,探讨293位点对GIT1功能的影响。方法:用PCR从小鼠cDNA文库中扩增GIT1-WT,将其连接到慢病毒载体PLJM-GFP中,构建质粒PLJM-GFP-GIT1-WT,测序鉴定。利用TaKaRa MutanBEST Kit试剂盒,对PLJM-GFP-GIT1-WT进行定点突变,构建质粒PLJM-GFP-GIT1-Y293F,测序鉴定。重组慢病毒载体转染包装细胞293T,获取病毒上清感染培养至第4代的小鼠成骨细胞。划痕愈合试验检测成骨细胞迁移能力的变化。结果:通过PCR鉴定、双酶切鉴定及测序鉴定,成功构建了PLJM-GFP-GIT1-WT与PLJM-GFP-GIT1-Y293F。划痕愈合试验观察,与PLJM-GFP-GIT1-WT相比,PLJM-GFP-GIT1-Y293F明显抑制成骨细胞迁移。结论:GIT1功能的正常发挥有赖于293位点适时的磷酸化。
基金supported by the grants to HLS from the National Natural Science Foundation of China(81371507)Medicine and Engineering Cross-talking Funds of Shanghai Jiao Tong University(YG2013MS40)+8 种基金Science and Technology Projects of Shanghai Jiao Tong University Medical School(13XJ10016)the National Basic Research Program of China(973 Program2013CB945600)by the grants to WQG from the Chinese Ministry of Science and Technology(2012CB966800 and 2013CB945600)the National Natural Science Foundation of China(81130038 and 81372189)the Science and Technology Commission of Shanghai Municipality(Pujiang Program)the Shanghai Health Bureau Key Disciplines and Specialties Foundationthe Shanghai Education Committee Key Discipline and Specialties Foundation(J50208)KC Wong Foundation
文摘GIT1,a G-protein-coupled receptor kinase interacting protein,has been reported to be involved in neurite outgrowth.However,the neurobiological functions of the protein remain unclear.In this study,we found that GIT1 was highly expressed in the nervous system,and its expression was maintained throughout all stages of neuritogenesis in the brain.In primary cultured mouse hippocampal neurons from GIT1 knockout mice,there was a significant reduction in total neurite length per neuron,as well as in the average length of axon-like structures,which could not be prevented by nerve growth factor treatment.Overexpression of GIT1 significantly promoted axon growth and fully rescued the axon outgrowth defect in the primary hippocampal neuron cultures from GIT1 knockout mice.The GIT1 N terminal region,including the ADP ribosylation factor-GTPase activating protein domain,the ankyrin domains and the Spa2 homology domain,were sufficient to enhance axonal extension.Importantly,GIT1 bound to many tubulin proteins and microtubule-associated proteins,and it accelerated microtubule assembly in vitro.Collectively,our findings suggest that GIT1 promotes neurite outgrowth,at least partially by stimulating microtubule assembly.This study provides new insight into the cellular and molecular pathogenesis of GIT1-associated neurological diseases.
