國內(nèi)外研究發(fā)現(xiàn)

1、原文摘要 目的 國內(nèi)外研究發(fā)現(xiàn)，N-Shc的表達(dá)僅局限于發(fā)育中的和成年動(dòng)物的中樞神經(jīng)系統(tǒng)中，可能可以保護(hù)神經(jīng)細(xì)胞免受氧化應(yīng)激引起的細(xì)胞凋亡；Shc蛋白參與了哺乳動(dòng)物的多種細(xì)胞的重要、基本的信號(hào)轉(zhuǎn)導(dǎo)途徑，調(diào)節(jié)哺乳動(dòng)物的壽命、衰老；Shc A (Shc)、 Shc B (Sck)、Shc C (N-Shc)是Shc蛋白家族的三個(gè)成員；而N-Shc的表達(dá)、活化與年齡的關(guān)系尚不清楚。本實(shí)驗(yàn)研究大鼠海馬N-Shc 蛋白的表達(dá)，以及經(jīng)H2O2刺激后磷酸化N-Shc 的水平改變隨年齡的增加而變化的規(guī)律，探討增齡對N-Shc 表達(dá)和活性改變的影響。方法 根據(jù)不同的年齡，把大鼠分為幼年組（3月齡）、成年組（6月

2、齡）和老年組（18月齡）。采用蛋白免疫印跡的方法，以鼠單克隆N-Shc 抗體為第一抗體、辣根過氧化物酶結(jié)合的抗-鼠IgG為第二抗體，對各組大鼠海馬N-Shc 蛋白的表達(dá)進(jìn)行分析； H2O2分別刺激0、5、15、30分鐘后，用羊多克隆N-Shc 抗體將所有N-Shc 蛋白沉降下來，先后以抗-磷酸酪氨酸(pTyr)單克隆抗體4G10、鼠單克隆N-Shc 抗體為第一抗體，以辣根過氧化物酶結(jié)合的抗-鼠IgG為第二抗體，分別測出磷酸化N-Shc 蛋白和總N-Shc 蛋白的含量，以兩者的比值作為N-Shc 蛋白的磷酸化N-Shc水平，并對其隨年齡的改變情況進(jìn)行分析。結(jié)果N-Shc 蛋白在神經(jīng)系統(tǒng)中各個(gè)區(qū)域

3、富集，在外周組織心臟、肝臟、肌肉組織中幾乎不能被檢測到；幼年組、成年組、老年組海馬N-Shc 蛋白的含量依次減少，幼年組與成年組、老年組之間有顯著性差異（p分別為0.0091、0.0021），但成年組和老年組之間沒有顯著性差異（p為0.4483）；H2O2處理后，幼年組、成年組、老年組海馬N-Shc 蛋白磷酸化水平也依次減少，幼年組與成年組、老年組之間有顯著性差異（p均<0.0001），但成年組和老年組之間沒有顯著性差異（p為0.1828 ）；隨著刺激時(shí)間的增加，幼年組和成年組大鼠海馬N-Shc 蛋白的活化有明顯的變化，而老年組大鼠海馬N-Shc 蛋白的活化幾乎沒有變化。 結(jié)論 本實(shí)驗(yàn)借

4、助免疫印跡技術(shù)，進(jìn)行了年齡對SD大鼠海馬N-Shc 蛋白表達(dá)和磷酸化水平改變的影響的初步研究。實(shí)驗(yàn)結(jié)果表明，隨著年齡的增加，大鼠海馬N-Shc 蛋白的表達(dá)水平下降，所表達(dá)的N-Shc 蛋白在氧化應(yīng)激后磷酸化水平也下降，即海馬中N-Shc 的表達(dá)和活性隨著年齡的增加而出現(xiàn)減少的趨勢。關(guān)鍵字 增齡；N-Shc；海馬；氧化應(yīng)激The effect of age on the activation of neuronal Shc in response to oxidative stressDepartment of Preventive MedicineZhejiang University Sch

5、ool of Public HealthUndergraduate: Ye LumengTutor: Zhu Waner譯文Abstract Objective：Researches have reported, that the expression of N-Shc are limited in central nervous system of both majority and in growth mammalians, and it may do importance in protecting nerve cell from apoptosis caused by oxidativ

6、e stress; Shc participate in many important signal transduction pathway of mammalians, and regulate their life and aging; Shc A (Shc)、 Shc B (Sck)、Shc C (N-Shc) constitute family of Shc-like adaptor proteins; the relationships between the expression and activation of N-Shc and age are still not clea

7、r.In order to study the change of the expression of N-Shc in the hippocampi of male SD rat and the change of its phosphotyrosine in response to H2O2 stimulation during aging, and explore the possible effects of age on the expression and activation of N-Shc . Methods：Animals were divided into four gr

8、oups according to their age, 3 month for young group, 6 months for adult group, and 18 months for aged group, and through western blot analysis and immunoprecipitation-immunoblotting, using Mouse monoclonal N-Shc antibody as first antibody and horseradish peroxidase (HRP)-conjugated anti-mouse IgG a

9、s second antibody, analysed the change of the expression of N-Shc in the hippocampi; and using mouse anti-phosphotyrosine (pTyr) antibody 4G10 and Mouse monoclonal N-Shc antibody as first antibody, horseradish peroxidase (HRP)-conjugated anti-mouse IgG as second antibody, ananlysis the change of its

10、 phosphotyrosine in response to H2O2 stimulation, take the ratio of tyrosine-phosphorylated N-Shc and total N-Shc as the level of activation of N-Shc. Results：N-Shc expressed specially in the neural tissue, and we could hardly detect any N-Shc in tissue of heart, liver and muscles; the expression of

11、 N-Shc in the hippocampi decreased during aging, and were statistically significant between young group and adult group (p=0.0091), and between young group and aged group (p=0.0021), but were not statistically significant between adult group and aged group (p=0.4483); after H2O2 stimulation, the pho

12、sphotyrosine of N-Shc decreased during aging, either, and were statistically significant between young group and adult group(p<0.0001), and between young group and aged group (p<0.0001), but were not statistically significant between adult group and aged group (p=0.1828). As the stimulus duration increases, the activation of N-Shc changes visibly in young groupand adult group, while it almost unchanges in