小泛素样修饰蛋白-1对α-突触核蛋白基因突变或过表达诱导的细胞包涵体形成及细胞凋亡的影响

目的 探讨α-突触核蛋白(α-synuclein)的小泛素样修饰蛋白(small ubiquitin-like modifier,SUMO)-1对α-synuclein基因过表达或突变诱导的细胞包涵体形成及细胞凋亡的影响.方法 构建野生型(WT)、A53T突变型和缺失SUMO-1互作氨基酸的K96R突变型、K96R-A53T突变型α-synuclein真核表达质粒.应用脂质体介导转染方式将构建好的质粒转入HEK293细胞;48 h后Hoechst 33258染色,采用Axiovert200型倒置荧光显微镜观察对细胞的影响,应用四甲基偶氮唑盐检测细胞活力,Annexin V-PE流式细胞仪检测细胞凋亡.结果 将构建所得真核表达质粒经双酶切鉴定及DNA测序证实;将WT型、A53T型、K96R型、K96R-A53T型α-synuclein真核表达质粒转染HEK293细胞,48 h后伊红染色显示转染野生型α-synuclein- pEGFP组及A53T突变型组某些细胞胞浆内出现圆形的嗜酸性小体(类Lewy小体)形成,分别占细胞总数的9.4％和11.7％,转染K96R及K96R-A53T融合表达载体组细胞内嗜酸性小体形成比率为10.2％和9.8％,两两相比差异无统计学意义(P＞0.05).Hoechst染色结果显示,WT组、A53T组细胞核变大,出现着色不均,染色质聚集成斑点状,未见核浓缩或核碎裂.K96R组及K96R-A53T组胞核着色基本均匀.采用四甲基偶氮唑盐法结果显示转染空质粒组细胞活力为96.2％,转染WT组、A53T组细胞活力下降至53.4％及56.1％,转染K96R组及K96R-A53T组细胞活力为72.3％和69.8％;转染48 h后,WT组、A53T组细胞凋亡率分别为32.2％和34.1％,转染K96R组及K96R-A53T突变组细胞凋亡率下降为19.4％和20.3％,两两相比差异有统计学意义(P＜0.05).结论 SUMO-1对α-synuclein基因过度表达及α-synuclein基因致病突变A53T诱导的细胞包涵体的形成无明显影响;SUMO-1可加强α-synuclein基因过度表达及α-synuclein基因致病突变A53T诱导的细胞毒性及细胞凋亡,提示SUMO-1参与了细胞凋亡过程.     

小泛素样修饰蛋白对α-突触核蛋白线粒体亚细胞定位及α-突触核蛋白经泛素系统降解的影响

目的 探讨α-突触核蛋白(α-synuclein)的小泛素样修饰蛋白1(small ubiquitin-like modifier1,SUMO-1)化修饰对α-synuclein蛋白亚细胞线粒体定位及α-synuelein蛋白经泛素系统降解的影响.方法 构建野生型、A53T突变型和缺失SUMO-1互作氨基酸的K96R突变型α-synuclein真核表达质粒.将野生型、A53T突变型和K96R突变型α-synuclein真核表达质粒分别转染HEK293细胞;在转染后48 h通过应用线粒体染色剂和激光共聚焦技术,观察野生型、A53T突变型及缺失SUMO-1修饰的α-synuclein蛋白的亚细胞线粒体定位和蛋白聚集情况.在转染后48 h应用anti-ubiquitin抗体进行Western印迹分析,明确野生型、A53T突变型及缺失SUMO-1修饰的α-synuclein蛋白泛素化程度有无差别.结果 将构建所得EGFP-α-synuclein-WT、EGFP-α-synuclein-A53T、EGFP-α-synuclein-K96R真核表达质粒经双酶切鉴定及DNA测序证实;激光共聚焦结果显示野生型、A53T突变型、K96R突变型α-synuclein蛋白均广泛分布于细胞质和细胞核中,以细胞质为主,野生型、A53T型细胞可见绿色荧光物质在胞质积聚,形成强荧光斑块,K96R型胞质内绿色荧光物质聚集少;野生型、A53T突变型、K96R突变型α-synuclein均与线粒体存在共定位,A53T突变型、K96R突变型α-synuclein在SUMO-1修饰或缺失的情况下对α-synuclein蛋白的线粒体亚细胞定位无明显影响.Western印迹结果显示转染缺失SUMO-1互作氨基酸的K96R突变型α-synuclein真核表达质粒组的细胞泛素蛋白的含量与转染空质粒组相比无明显变化,转染野生型、A53T突变型α-synuclein真核表达质粒组HEK293细胞中泛素蛋白的含量减少.结论 α-synuclein基因过度表达及致病突变A53T对α-synuclein蛋白的线粒体亚细胞定位无明显影响;SUMO-1修饰对α-synuclein蛋白的线粒体亚细胞定位也无明显影响;SUMO-1对a-αsynuclein基因过度表达及A53T突变型α-synuclein细胞内泛素化蛋白数量产生影响.     

α-突触核蛋白各结构域与MN9D细胞线粒体的关系

目的 探讨α-突触核蛋白(α-synuclein)各结构域与MN9D细胞线粒体的关系.方法 用PCR方法获得α-synuclein/1～65(N),α-synuclein/61～95(A)及α-synuclein/96～140(C)基因片段,克隆入真核表达质粒pLNCX2,经测序正确后以脂质体转染PT-67细胞,挑取单克隆并扩增,收集上清感染MN9D细胞,分别用Real Time PCR检测细胞基因表达水平,免疫组织化学染色检测蛋白表达,激光扫描共焦显微镜检测蛋白与线粒体共定位,流式细胞术检测细胞状态及线粒体膜电位状态.结果 成功构建了pLNCX2/N、pLNCX2/NAC及pLNCX2/C基因片段的重组真核表达质粒,获得了可稳定表达α-synuclein各基因片段的MN9D细胞株.通过激光扫描共焦显微镜观察,可见α-synuclein/N端与线粒体存在共定位关系;α-synuelein/NAC主要在核内聚集表达;α-synuclein/C端在胞质和胞核内均有表达.JC1染色流式细胞术检测显示,过表达α-synuclein/N实验组细胞线粒体膜电位降低.结论 α-synuclein的N端可能定位于线粒体,并参与调节线粒体功能;α-synuclein/NAC虽具有疏水性但却能穿过核膜,聚集在核仁周围;α-synuclein的C端定位于胞质和核内可能参与多种细胞功能.     

人野生型和A53T突变型α-突触核蛋白慢病毒表达载体的构建及在PC12细胞中的转染

为构建长期稳定表达人野生型和A53T突变型α-突触核蛋白的PC12细胞株,我们首先制备了慢病毒表达载体,经测序鉴定正确后转染PC12细胞,然后通过细胞的免疫荧光染色检测α-synuclein-V5融合蛋白,PCR法扩增转基因PC12细胞的SNCA片段后进行测序检测突变基因,以及Western blot法检测PC12细胞α-synuclein的表达,从而鉴定转基因细胞能否稳定表达目的基因。结果显示:经测序,pLenti6/V5-SNCA-WT和pLenti6/V5-SNCA-A53T表达质粒构建成功;免疫荧光染色示基因转染后,超过95%的PC12细胞中有α-synuclein-V5融合蛋白表达;转基因细胞的SNCA片段测序结果显示,慢病毒表达载体成功整合入PC12细胞基因组;Western blot法检测结果示转基因PC12细胞能够过表达α-synuclein蛋白。以上结果表明我们已成功构建了人野生型和A53T突变型α-突触核蛋白慢病毒表达载体,并且成功建立了稳定的过表达人野生型和A53T突变型α-突触核蛋白的PC12细胞株,这为进一步研究α-突触核蛋白的生理功能及其在Parkinson病发病机制中的作用奠定了基础。     

干扰素-α联合高三尖杉酯碱下调K562细胞端粒酶逆转录酶及端粒酶活性诱导细胞凋亡

目的：研究干扰素-α(IFN-α)联合高三尖杉酯碱(HHT)对K562细胞端粒酶逆转录酶及端粒酶的作用，并探讨其与细胞凋亡的关系。方法:IFN-α、HHT以及两药联合作用K562细胞后用MTT法检测细胞增殖，吉姆萨-瑞氏染色观察细胞形态，PI-Annexin VFITC双染色、流式细胞仪检测细胞凋亡,Krupp改良的荧光素标记的端粒重复扩增方法(TRAP)检测K562细胞端粒酶活性，RT-PCR方法检测hTERT mRNA表达变化。结果:5×106U·L-1 IFN-α分别联合5-40 μg·L-1 HHT诱导K562细胞凋亡从而抑制其生长，单用HHT时IC50为27.35 μg·L-1，联用5×106 U·L-1 IFN-α后IC50降为18.72 μg·L-1；IFN-α与HHT联用明显下调hTERT mRNA表达并抑制K562细胞的端粒酶活性。结论：IFN-α联合HHT可以诱导细胞凋亡，这可能与下调细胞hTERT mRNA的表达水平，抑制端粒酶活性有关。两药联合作用强于单独用药，提示临床IFN-α联合HHT治疗慢性髓细胞白血病（CML）可能比单用HHT效果更好。     

利福平抑制α-synuclein的聚集及对MPP＋诱导细胞损伤的拮抗作用

目的： 探讨利福平对帕金森病致病蛋白α-突触共核蛋白（α-synuclein）聚集的影响，以及对1-甲基-4-苯基-吡啶离子(MPP+)诱导的细胞损伤的拮抗作用。 方法： 选用大鼠嗜铬细胞瘤株PC12细胞，利用MPP+诱导建立帕金森病细胞模型，利福平进行干预；采用MTT法检测细胞活性、Western blotting法检测α-synuclein表达及聚集，流式细胞仪检测细胞凋亡。 结果： 1 mmol/L MPP+组细胞活性明显低于对照组，细胞凋亡率和α-synuclein表达及聚集高于对照组；预先经过100、200和300 μmol/L各浓度利福平处理后，MPP++利福平组细胞活性明显高于1 mmol/L MPP+组，而细胞凋亡率和α-synuclein表达及聚集均低于1 mmol/L MPP+组，并具有明显的剂量-效应关系。 结论： 利福平能够抑制α-synuclein的表达及聚集，并对MPP+诱导的PC12细胞损伤具有拮抗作用。     

磷脂酰肌醇3-激酶通路对脂多糖预激动小胶质细胞高迁移率族蛋白1表达的影响

目的 探讨磷酸肌醇-3激酶/蛋白激酶B(phosphoinositide 3-kinase/protein kinaseB,P13K/Akt)通路对脂多糖 (lipopolyssacride,LPS)预处理体外培养大脑皮质小胶质细胞高迁移率族蛋白1(high mobility group box-1protein 1,HMGB-1)表达的影响.方法 体外分离纯化小鼠大脑皮质小胶质细胞,纯度鉴定后按未刺激对照组、0.01μg/mL LPS单次刺激组(18 h)、1μg/mL LPS刺激组(24 h)、预处理组、PI3K/AKT通路抑制组(2 h)分别进行处理.收获各组细胞与培养上清,采用酶联免疫吸附试验(Enzyme linked immunosorbent assay,ELISA)法检测肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)分泌水平,免疫荧光法检测HMGB-1在细胞中的定位情况,Western blot 检测 HMGB-1和磷酸化Akt的表达水平.结果 PI3K/Akt通路抑制后,LPS预刺激小胶质细胞产生的TNF-α水平较1μg/mL单次刺激组、预刺激组水平降低(P=0.043;P=0.046);磷酸化Akt表达降低,小胶质细胞HMGB-1表达以及向胞浆中转位呈现降低趋势.结论 PI3K/Akt通路在LPS预激诱导的HMGB-1活化中起正性调节作用,这些分子及调节通路的变化参与LPS耐受诱导的重新调配过程,从而共同影响小胶质细胞的最终效应.     

氯胺酮对MPTP诱导的帕金森病小鼠α-synuclein及星形胶质细胞的影响

目的:探究亚麻醉剂量氯胺酮(ketamine)对1-甲基-4-苯基-1,2,3,6-四氢吡啶(MPTP)诱导的帕金森病(PD)小鼠α-突触核蛋白(α-synuclein)及星形胶质细胞的影响。方法:将36只SPF级雄性C57BL/6小鼠随机分为3组(每组12只):NaCl组(腹腔注射生理盐水)、MPTP组(腹腔注射MPTP)和ketamine组(腹腔注射MPTP和ketamine)。悬尾实验和步态分析实验检测3组小鼠间的行为学差异;免疫荧光染色以及Western blot检测小鼠黑质(SN)、纹状体尾壳核(CP)及视皮层(CX)内α-synuclein和胶质细胞原纤维酸性蛋白(GFAP)的表达情况。结果:悬尾实验和步态分析实验结果显示,与NaCl组相比,MPTP组小鼠悬尾不动时间延长,步距减小(P0. 05);与MPTP组相比,ketamine组小鼠悬尾不动时间缩短,步距增大(P0. 05)。免疫荧光染色及Western blot结果显示,MPTP组小鼠SN、CP及CX内α-synuclein和GFAP的表达较NaCl组显著增多(P0. 05),ketamine组小鼠SN、CP及CX内α-synuclein和GFAP的表达较MPTP组显著减少(P0. 05)。结论:亚麻醉剂量氯胺酮对MPTP诱导的PD小鼠α-synuclein的表达及星形胶质细胞的增生有抑制作用。     

α-synuclein在体外培养SH-SY5Y细胞中过表达致自体吞噬

目的：观察α-synuclein转基因细胞内α-synuclein过表达对细胞超微结构的影响。方法：Lipofectamine法转染SH—SY5Y细胞,用G418对转基因细胞进行筛选,免疫荧光细胞化学检测α-synuclein表达,电子显微镜观察转基因细胞超微结构的改变。结果：转基因细胞内出现大小不等、边界明显的自体吞噬体并伴有线粒体结构紊乱。结论：α-synuclein过表达可致细胞出现自体吞噬现象。     

α1-抗糜蛋白酶基因Isehara-1、Isehara-2 突变型与儿童哮喘相关性研究

目的 了解α1-抗糜蛋白酶(AACT)基因Isehara-1、Isehara-2突变型与昆明儿童哮喘发生是否具有相关性。方法 应用聚合酶链反应(PCR)技术、基因测序方法，对30例昆明市汉族哮喘儿童厦20例正常儿童α1-抗糜蛋白酶基因外显子(exon)V进行检测。结果所有研究对象均未发现α1-抗糜蛋白酶基因Isehara-1、Isehara-2突变型。结论 α1-抗糜蛋白酶基因Isehara-1、Isehara-2突变型与30例昆明市汉族儿童哮喘发病无相关关系。     

Modes of reinforcement and gender and culture of experimenter and subject: effects of "alien" and external reinforcement for Japanese and American men and women

In this study, we examined external and "alien" reinforcement (ER and AR. respectively) as a factor in social learning, and studied the combined effects of culture and reinforcement mode. A female (Experiment 1) and a male (Experiment 2) experimenters conducted experimental sessions. Both men and women, who grew up in the same culture as the experimenter, participated and performed the experimental task. A three-way interaction effect of experimenter gender, culture, and reinforcement mode was found on task performance. And the effect was more pronounced for a Japanese experimenter. A female and a male experimenters conducted Experiments 3 and 4, respectively; however participants this time were men and women who grew up in different cultures than the experimenter. Results indicated that the pattern of the subject gender and reinforcement mode interaction effect, when the experimenter was Japanese with American subjects, was exactly opposite to that when the experimenter was American. These experiments showed that AR was as effective for social learning as ER, and that the cultural backgrounds of experimenter and subject influenced AR and ER effectiveness.     

Rates of oxygen consumption and of anaerobic glycolysis in renal cortex and medulla of adult and new-born rats and guinea-pigs

1. Rates of oxygen uptake and of anaerobic glycolysis were estimated in slices from the renal cortex and medulla (a) of adult rats and guinea-pigs, (b) of new-born (1-, 5- and 21-day-old) rats and of guinea-pigs of 1, 12, 21, 24 and 120 hr age.2. In the adult rat, Q(O2) values for the cortex were 12.55 +/- 0.20 (22) and for the medulla: 8.56 +/- 0.17 (22) mul./hr.mg dry weight, while in the new-born rat (24 hr old) they were 10.99 +/- 0.46 (12) and 9.33 +/- 0.18 (9) mul./hr.mg dry weight respectively.3. Values for Q(CO2) (N2) (anaerobic glycolysis) in the 14 hr old new-born rat were in the renal cortex 9.65 +/- 0.35 (5) and in the medulla 7.39 +/- 0.43 (5) mul./hr.mg dry weight; while in the adult they were 2.25 +/- 0.08 (16) and 5.76 +/- 0.14 (16) mul./hr.mg dry weight, respectively.4. In the adult guinea-pig values for Q(CO2) (N2) were of the same order as in the adult rat, though the rate of O(2) uptake was for the cortex 8.12 +/- 0.22 (12) and for the medulla 5.02 +/- 0.23 (11) mul./hr.mg dry weight.5. Though the Q(O2) values in the renal cortex and medulla were smaller in the 1 hr old new-born guinea-pig, they were already increasing in the 12 hr old neonate.6. The results are discussed in the light of enzyme changes occurring during the process of maturation of the nephron as indicated by histochemical observations.     

Timing and intensity of early fevers and the development of allergies and asthma

BACKGROUND: Early childhood fevers appear to protect against later allergies and asthma. What is not known is the time in which fevers exert this effect and whether the degree of temperature increase is important. OBJECTIVE: We sought to examine the relationship between the time and degree of early fevers and later allergies and asthma. METHODS: Eight hundred thirty-five children from southeast Michigan were enrolled at birth. Clinic records from their first 2 years were abstracted for episodes of fever. At age 6 to 7 years, children underwent allergy testing. We examined fevers occurring within 6-month intervals in the first 2 years of life and outcomes at age 6 to 7 years. The primary outcome measures were allergic sensitization, asthma, asthma with allergic sensitization, and asthma without allergic sensitization. RESULTS: In the unadjusted analysis each episode of fever between 7 and 12 months of age was associated with a lower odds of allergic sensitization (odds ratio [OR], 0.71; 95% CI, 0.54-0.93) and asthma with allergic sensitization (OR, 0.43; 95% CI, 0.21-0.90) at age 6 to 7 years. Likewise, every 1 degrees C increase in the maximum temperature between 7 and 12 months was associated with a lower odds of allergic sensitization (OR, 0.77; 95% CI, 0.61-0.96) and asthma with allergic sensitization (OR, 0.62; 95% CI, 0.40-0.94). After adjusting for potential confounders, each episode of fever between 7 and 12 months was associated with a lower likelihood of asthma with allergic sensitization (adjusted OR, 0.33; 95% CI, 0.11-0.94) at age 6 to 7 years. CONCLUSIONS: Both the timing and intensity of childhood fevers appear to be important factors in the development of allergies and asthma.     

纳米水平分子成像与诊疗一体化研究进展与挑战

分子成像能以非侵入性的方式重现活体细胞的生理功能和生物学过程,提高疾病的早期和特异性诊断水平。纳米颗粒/材料具有物理性质可控性高、易于表面修饰、血液循环时间长和可功能化等优点,在疾病诊断与治疗中显示出巨大潜力。但如何阐明纳米材料多功能间的内在联系、解决其代谢及安全性等关键机制难题、实现纳米颗粒/材料多功能性到临床多功能...