甲基苯丙胺中毒大鼠纹状体COX-2、PGE2、EP2 受体及小胶质细胞 表达的研究

目的:通过研究COX-2、PGE2、EP2受体及小胶质细胞在甲基苯丙胺中毒大鼠纹状体内的表达变化探讨甲基苯丙胺中毒大鼠纹状体中COX-2/PGE2系统与小胶质细胞活化之间的关系。方法:将40只健康成年雄性SD大鼠,随机分成对照组10只和实验组30只(实验组分成三个亚组,分为末次给药后1天组、2天组和3天组,n=10)。实验组给予10mg/kg的MA腹腔注射,对照组给予同样剂量的生理盐水,每天注射两次,注射时间为8:00、20:00,连续注射4天。分别于末次给药后的第1天、第2天、第3天处杀。用免疫组化技术对中毒大鼠纹状体(CPU)中COX-2、EP2受体及Iba1(钙离子接头蛋白,小胶质细胞内一种特异性标记物)的表达进行检测,并进行图像分析。另外,取大鼠的纹状体运用酶联免疫法检测PGE2的含量。结果:COX-2、PGE2、EP2受体及小胶质细胞在各组均有表达。与对照组相比,实验组中:COX-2、PGE2、EP2受体的1天组表达均不同程度下降;2天组中COX-2表达水平大幅度上升,PGE2、EP2受体表达仍低于正常水平;3天组COX-2表达水平继续升高,而PGE2、EP2受体表达趋于正常组水平。而小胶质细胞表达水平则是三个实验组均高于正常组,且3天组高于2天组,2天组高于1天组。对照组与实验组有显著性差异(P<0.05)。结论:COX-2/PGE2系统与甲基苯丙胺中毒大鼠纹状体内小胶质细胞活化无明显相关性;COX-2与甲基苯丙胺的神经毒性有关。     

miR-939-5p对糖尿病视性网膜病变和视网膜微血管内皮细胞的调控作用

摘要 目的：探究miR-939-5p对糖尿病性视网膜病变和人视网膜微血管内皮细胞（HRMEC）的调控作用。方法：将miR-939-5p模拟物（miR-939-5p-mimic）或miR-939-5p抑制剂（miR-939-5p-inhibitor）转染到HRMEC中,并将细胞用高糖（HG组,25 mM）或低糖（LG组,5 mM）处理24 h。通过细胞计数试剂盒8（CCK-8）来检测细胞活力,EdU法检测细胞DNA的复制能力,Hoechst 33258染色检测细胞凋亡,使用双荧光素酶试剂盒E2920验证miR-939-5p与NOS2 3''-UTR之间的结合关系。对大鼠腹腔注射65 mg/kg的链脲佐菌素（STZ）诱导DR模型,通过RT-qPCR检测miR-939-5p水平,Western Blot检测诱导型一氧化氮合酶（NOS2）水平,苏木精伊红（HE）染色检查大鼠视网膜形态,免疫组织化学染色检测视网膜Claudin-5和Occludin的表达,伊文思蓝染色检测大鼠血视网膜屏障（BRB）通透性,ELISA法检测大鼠房水中白介素-1β（IL-1β）和肿瘤坏死因子-α（TNF-α）的水平。结果：与LG组的HRMEC相比,HG组的miR-939-5p显著降低,而NOS2蛋白水平显著升高（P<0.05）。荧光素酶活性测定显示,与NC-mimic组相比,miR-939-5p-mimic与pGL3-NOS2-WT共转染组的荧光素酶活性显著降低（P<0.05）。与HG+NC-mimic组相比,HG+miR-939-5p-mimic组的miR-939-5p水平和细胞活力显著升高,而NOS2蛋白水平和细胞凋亡率显著降低（P<0.05）。与DR组相比,miR-939-5p-Agomir组大鼠视网膜组织病变减轻,Claudin-5和Occludin的表达水平明显升高,伊文思蓝浓度显著降低（P<0.05）;与DR组相比,miR-939-5p-Agomir组大鼠房水中IL-1β和TNF-α的水平均显著降低（P<0.05）。结论：在高糖培养的HRMEC中和DR大鼠视网膜中,miR-939-5p为低表达模式,NOS2为高表达模式。上调miR-939-5p通过靶向抑制NOS2对DR大鼠视网膜和HRMEC提供保护作用。     

甲基苯丙胺中毒大鼠纹状体COX-2、PGE2、EP2受体及小胶质细胞表达的研究

目的：通过研究COX-2、PGE2、EP2受体及小胶质细胞在甲基苯丙胺中毒大鼠纹状体内的表达变化探讨甲基苯丙胺中毒大鼠纹状体中COX-2／PGE2系统与小胶质细胞活化之间的关系。方法：将40只健康成年雄性SD大鼠,随机分成对照组10只和实验组30只（实验组分成三个亚组,分为末次给药后1天组、2天组和3天组,n=10）。实验组给予10mg／kg的MA腹腔注射,对照组给予同样剂量的生理盐水,每天注射两次,注射时间为8：00、20：00,连续注射4天。分别于末次给药后的第1天、第2天、第3天处杀。用免疫组化技术对中毒大鼠纹状体（CPU）中COX-2、EP2受体及Iba1（钙离子接头蛋白,小胶质细胞内一种特异性标记物）的表达进行检测,并进行图像分析。另外,取大鼠的纹状体运用酶联免疫法检测PGE2的含量。结果：COX-2、PGE2、EP2受体及小胶质细胞在各组均有表达。与对照组相比,实验组中：COX-2、PGE2、EP2受体的1天组表达均不同程度下降;2天组中COX-2表达水平大幅度上升,PGE2、EP2受体表达仍低于正常水平;3天组COX-2表达水平继续升高,而PGE2、EP2受体表达趋于正常组水平。而小胶质细胞表达水平则是三个实验组均高于正常组,且3天组高于2天组,2天组高于l天组。对照组与实验组有显著性差异（P〈0．05）。结论：COX-2／PGE2系统与甲基苯丙胺中毒大鼠纹状体内小胶质细胞活化无明显相关性;COX-2与甲基苯丙胺的神经毒性有关。     

康柏西普在糖尿病大鼠早期视网膜病变中的作用及对VEGF、ICAM-1及CRP的影响

摘要 目的：探讨康柏西普在糖尿病大鼠早期视网膜病变中的作用及对血管内皮生长因子 (vascular endothelial growth factor,VEGF)和细胞间粘附分子-1(Intercellular adhesion molecule-1,ICAM-1)及C-反应蛋白(C-reactive protein,CRP)的影响。方法：糖尿病大鼠早期视网膜病变模型(n=27)随机平分为三组-模型组、替米沙坦组与康柏西普组,造模成功后当天三组分别给予注射生理盐水、替米沙坦、康柏西普治疗,1次/w,持续4 w,检测VEGF、ICAM-1及CRP表达情况。结果：大鼠造模成功后均出现食欲增多、饮水、尿量、体重减轻的现象。替米沙坦组与康柏西普组治疗第1 w与第4 w的体重高于模型组(P<0.05),康柏西普组高于替米沙坦组(P<0.05)。替米沙坦组与康柏西普组治疗第1 w与第4 w的空腹血糖低于模型组(P<0.05),康柏西普组低于替米沙坦组(P<0.05)。替米沙坦组与康柏西普组治疗第4 w的视网膜VEGF、ICAM-1、CRP蛋白相对表达水平低于模型组(P<0.05),康柏西普组低于替米沙坦组(P<0.05)。康柏西普组视网膜厚度变薄不明显,内、外核层细胞排列整齐,神经纤维层未见明显空泡样变性。结论：康柏西普在糖尿病大鼠早期视网膜病变中的应用能抑制VEGF、ICAM-1及CRP的表达,能促进降低血糖,增加大鼠体重。     

优思悦对多囊卵巢综合征模型大鼠卵巢功能的影响及其机制研究

摘要 目的：探讨优思悦对硫酸脱氢表雄酮（dehydroepiandrosterone,DHEA）诱导的多囊卵巢综合征模型大鼠体内性激素：睾酮( testosterone,T)、雌二醇( estradiol,E2 )、促黄体生成素( luteinizing hormone,LH)及卵泡刺激素( follicle－stimulating hormone,FSH)及PI3K /AKT信号通路的的影响。方法：将60只雌性SD大鼠随机均分为3组,包括空白组、模型组及治疗组。空白组每日颈部皮下注射0.2 mL大豆油,其余各组每日颈部皮下注射DHEA 60 mg/kg+0.2 mL大豆油,持续注射35 d。造模第21 d时,每日上午制备大鼠阴道涂片,将其放置在显微镜下观察,根据细胞形态判定大鼠的动情周期,无动情周期规律视为造模成功。造模第36 d时,连续4 w对大鼠进行灌胃,每天一次。检测大鼠阴道分泌物的细胞形态、大鼠卵巢中卵泡发育的情况。放射免疫法测定大鼠血清中T、E2、LH、FSH的含量;RT-qPCR法检测大鼠卵巢组织中PI3K /AKT信号通路相关因子（IＲS-1、AKT-2、CSK-3β、GLUT-4 mRNA和PTEN mRNA）的表达变化。结果：空白组大鼠的动情周期有规律性,而模型组大鼠的动情周期失去规律性,且模型组大鼠卵巢中的卵泡呈囊状扩张,血清中T、LH水平明显升高（P<0.05）,同时卵巢组织中的IRS-1、AKT-2、CSK-3β、GLUT-4 mRNA表达减少（P<0.05）,PTEN mRNA表达增多（P<0.05）。与模型组比较,优思悦可改善PCOS模型大鼠动情周期,降低血清T、LH水平（P<0.05）,改善卵泡发育,减少囊状扩张卵泡的形成,上调IRS-1、AKT-2、CSK-3β、GLUT-4 mRNA表达量,下调PTEN mRNA 表达量。结论：优思悦可有效治疗DHEA诱导的PCOS模型大鼠,与卵巢中的PI3K /AKT信号通路相关因子的基因表达相关。     

保护素DX对类风湿关节炎大鼠模型中PI3K/AKT/mTOR信号通路的影响

摘要 目的：研究保护素DX（PDX）对类风湿关节炎（RA）大鼠模型的治疗作用及机制,及其对PI3K/AKT/mTOR信号通路的影响。方法：通过皮下注射牛Ⅱ型胶原与弗氏完全佐剂诱导RA大鼠模型,建模后将SD大鼠随机分为4组：对照组（n=12）：正常SD大鼠;RA组（n=12）：RA模型大鼠;低剂量PDX处理组（n=12,L-PDX组）：接受10 μg/kg/d PDX治疗的RA模型大鼠;高剂量PDX处理组（n=12,H-PDX）：接受20 μg/kg/d PDX治疗的RA模型大鼠。各组大鼠治疗4周后,采用ELISA法检测血清中IgA、IgG、IgM、TNF-α、IFN-γ、IL-4和IL-10的水平。通过苏木精伊红（HE）染色评价大鼠踝关节病变。通过免疫组化染色或Western blot检测滑膜组织中PI3K、p-PI3K、AKT、p-AKT、mTOR、p-mTOR、Bcl-2、Bax、LC3-I、LC3-II和Becline-1的表达。结果：与RA组相比,L-PDX组和H-PDX组的关节炎指数（AI）评分均显著降低（P<0.05）,炎性细胞浸润、软骨破坏程度及滑膜上皮细胞增生减轻。与RA组相比,L-PDX组和H-PDX组的血清IgA、IgG和IgM含量均降低（P<0.05）。与RA组相比,L-PDX组和H-PDX组的血清TNF-α和IFN-γ水平均降低,IL-4和IL-10水平均升高（P<0.05）。与RA组相比,L-PDX组和H-PDX组大鼠踝关节滑膜组织中的p-PI3K/PI3K、p-AKT/AKT、p-mTOR/mTOR和Bcl-2的蛋白相对表达量均降低,而Bax、LC3-II/LC3-I和Becline-1的蛋白相对表达量均升高（P<0.05）。结论：本研究表明PDX可有效减轻RA大鼠症状,其机制与调节B淋巴细胞活化和体液免疫、纠正Th1/Th2失衡、抑制PI3K/Akt/mTOR信号通路有关。     

牡荆素对大鼠脑缺血再灌注损伤后的小胶质细胞/巨噬细胞M2极化的影响

摘要 目的：探究牡荆素（Vitexin）对大鼠脑缺血再灌注损伤（CIRI）后的小胶质细胞巨噬细胞M2极化的影响。方法：采用改良的Longa法建立大鼠右侧中动脉阻塞/再灌注（MCAO/R）模型。建模后,将大鼠分为假手术组（Sham,n=10）、MCAO/R组（n=12）、Vitexin组（n=12）和Vitexin+脂多糖（LPS）组（n=12）。Sham组和MCAO/R组腹腔注射2 mL 0.9%生理盐水,Vitexin组腹腔注射2 mL牡荆素溶液（3 mg/kg）,Vitexin+LPS组腹腔注射1 mL牡荆素溶液（3 mg/kg）和1 mL LPS溶液（0.5 mg/kg）。1次/d,连续14 d。给药14 d后,根据Zea Longa 5分法对大鼠进行神经功能评分。通过2,3,5-三苯基四唑氯化物（TTC）法检测脑梗死体积。采用双重免疫荧光染色方法检测大脑缺血半影区CD16/32+/Iba1+、CD206+/Iba1+的共表达。通过qRT-PCR或Western blot检测大脑缺血半影区Toll样受体4（TLR4）、肿瘤坏死因子-α（TNF-α）、白细胞介素-1β（IL-1β）、IL-1β、IL-4、IL-10、核因子-κB（NF-κB）p65的mRNA或蛋白表达。使用商用试剂盒检测大脑缺血半影区丙二醛（MDA）、超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-Px）的含量。结果：与MCAO/R组相比,Vitexin组神经功能评分降低,脑梗死体积降低,MDA水平降低,SOD和GSH-Px水平升高（P<0.05）。与MCAO/R组相比,Vitexin组CD16/32+/Iba1+的阳性细胞数量降低,CD206+/Iba1+的阳性细胞数量升高,TNF-α和IL-1β的mRNA水平降低,而IL-4和IL-10的mRNA水平升高（P<0.05）。与MCAO/R组相比,Vitexin组TLR4 mRNA和蛋白水平降低,细胞核NF-κB p65的蛋白表达水平降低（P<0.05）。然而,LPS给药逆转了牡荆素对上述指标的影响（P<0.05）。结论：牡荆素部分通过TLR4/NF-κB信号通路促进大鼠CIRI后小胶质细胞/巨噬细胞向M2表型极化,从而促进神经功能恢复。     

枸杞多糖对糖尿病大鼠视网膜神经元的保护作用及其机制

目的:观察枸杞多糖(LBP)对糖尿病大鼠视网膜神经细胞的保护作用,并探讨其作用机制。方法:18只SD大鼠随机分为3组(n=6):正常对照组(NC),糖尿病模型组(DM)和LBP治疗组(DM+LBP),通过一次性腹腔注射链脲佐菌素(STZ)的方法制备糖尿病大鼠模型。DM+LBP组按1 mg/(kg·d)剂量的LBP灌胃12周。治疗结束后检测大鼠体重、空腹血糖、视网膜活性氧簇(ROS)的生成、视网膜神经节细胞(RGCs)和无长突细胞的表达、视网膜NF-E2相关因子2(Nrf2)和血红素加氧酶-1(HO-1)的蛋白表达。结果:STZ诱导糖尿病大鼠模型造模成功率100%。与NC组相比,DM组大鼠体重明显降低、空腹血糖值升高、ROS的生成明显增加、RGCs和无长突细胞的数量均明显减少(P<0.01)。与DM组相比,LBP治疗组大鼠体重升高、血糖降低、ROS的生成减少、RGCs和无长突细胞的数量均明显增加(P<0.01或P<0.05);视网膜Nrf2和HO-1的蛋白表达均明显升高(P<0.01)。结论:LBP能改善糖尿病大鼠视网膜的氧化应激状态,对糖尿病大鼠视网膜神经细胞有一定的保护效应,其作用机制可能与其激活Nrf2/HO-1信号通路有关。     

香草醛对新生大鼠缺氧缺血性脑损伤的神经保护作用研究

摘要 目的：探讨香草醛对新生大鼠缺氧缺血性脑损伤(HIBI)的神经保护作用及机制。方法：参考Rice-Vannucci方法建立HIBI大鼠模型。HIBI大鼠建模后立即腹腔注射20 mg/kg（HIBI+20Van组）或40 mg/kg（HIBI+40Van组）的香草醛,每隔12 h给药,连续7 d。然后评估大鼠的神经行为及脑组织中IL-1β、IL-6和TNF-α的水平。对BV2小胶质细胞进行氧糖剥夺/复氧(OGD/R)处理,并用20 μM香草醛培养。通过Western blot及免疫荧光检测HMGB1、NF-κB p65、SIRT1、MyD88和TLR4的表达水平。通过乳酸脱氢酶（LDH）释放测定试剂盒测定用不同BV2细胞培养基处理的原代神经元的LDH释放。结果：与HIBI组比较,HIBI+20Van组和HIBI+50Van组新生大鼠的前肢悬吊时间和旷场得分均升高,脑组织中的IL-1β、IL-6和TNF-α的水平均降低。香草醛均升高了HIBI大鼠和OGD/R处理的BV2细胞质中的SIRT1的表达水平,降低了TLR4、MyD88和HMGB1的表达水平及细胞核中NF-κB p65的表达水平（P<0.05）。香草醛降低了原代神经元的LDH释放量（P<0.05）。结论：香草醛通过调节SIRT1/HMGB1/TLR4/MyD88/NF-κB信号通路抑制HIBI引起的神经炎症,从而提高HIBI大鼠的神经功能。     

蜂毒素通过下调F2RL1表达从而遏制胶质瘤细胞荷瘤小鼠肿瘤增殖的机制

摘要 目的：探讨蜂毒素通过下调F2RL1表达从而遏制胶质瘤细胞荷瘤小鼠肿瘤增殖的机制。方法：40只雄性 NOD/SCID小鼠（5周龄,15-18 g）购自北京维塔河实验动物技术公司。实验前,让小鼠适应环境一周。NOD/SCID 小鼠在右侧海马体中注射了2×10⁵ U87-MG细胞建立异种移植模型。当肿瘤体积增长到100 mm³时,将小鼠随机分为模型组（空腹注射生理盐水）和蜂毒素组（腹腔注射5 mg/kg 蜂毒素）,每组20只小鼠。在第5天(注射的第5天)、第10天、第15天每次处死5只小鼠,通过实时PCR分析小鼠肿瘤组织中F2RL1、Bcl-2、Bax和Capase-3的mRNA表达。使用卡尺测量荷瘤小鼠肿瘤体积,使用电子天平对肿瘤组织进行称重测量。通过蛋白印迹分析肿瘤组织中p-PI3K、p-AKT 和p-mTOR的蛋白表达。通过TUNEL染色检测人脑肿瘤中凋亡细胞的百分比。结果：蜂毒素组F2RL1 mRNA表达较模型组降低（P<0.05）,蜂毒素抑制F2RL1 mRNA表达。第5 d、10 d和15 d测得肿瘤体积发现蜂毒素肿瘤体积较模型组减小（P<0.05）。第5 d、10 d和15 d测得肿瘤体积发现蜂毒素肿瘤重量较模型组减轻（P<0.05）。蜂毒素组p-PI3K、p-AKT 和p-mTOR的蛋白表达较模型组降低（P<0.05）。蜂毒素组Bax和Capase-3的mRNA表达较模型组降低（P<0.05）,蜂毒素组Bcl-2 mRNA表达较模型组升高（P<0.05）。蜂毒素组TUNEL阳性细胞的百分比较较模型组升高（P<0.05）。结论：蜂毒素通过下调肿瘤小鼠体内F2RL1表达抑制PI3K/AKT信号通路激活,促进了体内肿瘤细胞凋亡,从而有效抑制经胶质瘤细胞的生长、增殖。     

Synthesis of novel NBD-GM1 and NBD-GM2 for the transfer activity of GM2-activator protein by a FRET-based assay system

The ganglioside-activator protein is an essential cofactor for the lysosomal degradation of ganglioside GM2 (GM2) by beta-hexosaminidase A. It mediates the interaction between the water-soluble exohydrolase and its membrane-embedded glycolipid substrate at the lipid-water interphase. Mutations in the gene encoding this glycoprotein result in a fatal neurological storage disorder, the AB variant of GM2-gangliosidosis. In order to efficiently and sensitively probe the glycolipid binding and membrane activity of this cofactor, we synthesized two new fluorescent glycosphingolipid (GSL) probes, 2-NBD-GM1 and 2-NBD-GM2. Both compounds were synthesized in a convergent and multistep synthesis starting from the respective gangliosides isolated from natural sources. The added functionality of 2-aminogangliosides allowed us to introduce the chromophore into the region between the polar head group and the hydrophobic anchor of the lipid. Both fluorescent glycolipids exhibited an extremely low off-rate in model membranes and displayed very efficient resonance energy transfer to rhodamine-dioleoyl phosphoglycerol ethanolamine (rhodamine-PE) as acceptor. The binding to GM2-activator protein (GM2AP) and the degrading enzyme was shown to be unaltered compared to their natural analogues. A novel fluorescence-resonance energy transfer (FRET) assay was developed to monitor in real time the protein-mediated intervesicular transfer of these lipids from donor to acceptor liposomes. The data obtained indicate that this rapid and robust system presented here should serve as a valuable tool to probe quantitatively and comprehensively the membrane activity of GM2AP and other sphingolipid activator proteins and facilitate further structure-function studies aimed at delineating independently the lipid- and the enzyme-binding mode of these essential cofactors.     

高转移倾向乳腺癌细胞中p-ERK促进增殖和迁移作用的信号转导途径

在建立乳腺癌细胞MCF-7高转移倾向亚克隆LM-MCF-7细胞株的基础上,为阐明LM-MCF-7细胞具有更强增殖和迁移能力的分子机制,对其相关分子及其信号转导途径进行了探讨.免疫印迹结果显示,与MCF-7细胞相比,LM-MCF-7细胞中p-ERK1/2水平显著升高.流式细胞术和“伤口愈合”实验结果表明,ERK1/2的特异性抑制剂PD98059可明显抑制LM-MCF-7细胞的高增殖和高迁移能力.免疫印迹检测发现,与MCF-7细胞相比,LM-MCF-7细胞中与增殖和迁移相关的因子,如β-catenin、细胞周期蛋白D1、磷酸化肌球蛋白轻链（p-MLC）和肌球蛋白轻链激酶（MLCK）的水平呈明显增高,PD98059对这些因子水平的增高具有抑制作用.免疫荧光染色显示,LM-MCF-7细胞中β-catenin分布在细胞核中,应用PD98059处理后,β-catenin主要分布在胞浆中.上述研究结果表明,在LM-MCF-7细胞中活化的ERK1/2水平升高,是导致该细胞增殖和迁移能力增强的重要原因之一,与ERK1/2-MLCK-p-MLC和ERK1/2-β-catenin 细胞周期蛋白D1等信号转导途径有密切的关系.     

Topoisomerase IIalpha gene (TOP2A) amplification and deletion in cancer--more common than anticipated.

In solid tumours the predominant genetic mechanism for oncogene activation is through amplification of genes. The HER-2 (also known as ErbB2/c-erbB2/HER-2/neu) oncogene is the most frequently amplified oncogene in breast cancer and is also commonly amplified in other forms of cancer. The HER-2 amplicon also contains other biologically relevant genes with altered copy numbers, among these genes is the topoisomerase IIalpha (TOP2A). TOP2A gene is located adjacent to the HER-2 oncogene at the chromosome location 17q12-q21 and is either amplified or deleted, with equal frequency, in almost 90% of HER-2 amplified primary breast tumours. Recent data suggest that amplification and deletion of TOP2A may account for both sensitivity and resistance to topoII-inhibitor-chemotherapy, depending on the specific genetic defect at the TOP2A locus. In this issue of the Cytopathology, Bofin et al. present preliminary evidence for high prevalance of TOP2A amplification and deletion not only in the HER-2 amplified breast tumours, but also in the primary breast tumours without the HER-2 amplification. This finding together with the concept that TOP2A gene amplification and deletion seem to account for both relative chemosensitivity and resistance to topoII-inhibitor therapy further highlights the importance of screening for TOP2A gene copy number aberrations when topoII-inhibitors are considered either alone or in combination of other chemotherapeutic drugs for the treatment of cancer patients.     

Coexpression of oncostatin M and its receptors and evidence for STAT3 activation in human ovarian carcinomas

The expression of oncostatin M and leukemia inhibitory factor (LIF), JAK-STAT activators and members of the interleukin-6 family of cytokines, were examined in a series of primary ovarian carcinomas using immunohistochemistry. The malignant epithelial cells of all 29 ovarian carcinomas examined expressed oncostatin M; none expressed LIF. Oncostatin M can activate two related receptors, one consisting of a low-affinity LIF receptor subunit, LIFR beta, which forms a heterocomplex with the gp130 signal transducing protein and can recognize both oncostatin M and LIF, and a second heterocomplex consisting of a subunit that specifically recognizes oncostatin M, OSMR beta, and the gp130 protein. By immunohistochemistry, 25 of 25 ovarian carcinomas examined expressed the LIFR beta subunit in the malignant epithelial cells (all samples express gp130), and two-thirds the ovarian carcinomas studied expressed OSMR beta mRNA as determined by RT-PCR. Thus oncostatin M and its receptors are commonly coexpressed in malignant ovarian epithelial cells, and represent a potential autocrine loop in this tumor type. STAT3, of one the signaling proteins downstream of the oncostatin M/LIF receptors, was found in its phosphorylated, activated form (phosphotyrosine 705 STAT3) in the malignant epithelial cells of 17 of 23 ovarian carcinomas examined (74%) as determined by immunohistochemistry; this suggests that this protein is constitutively activated in most ovarian carcinomas, as it is in many other human malignancies. Recombinant human Oncostatin M (rhOSM) can induce the transient tyrosine 705 phosphorylation of STAT3 in serum-starved LIFR beta/OSMR beta expressing ovarian carcinoma cell lines, but does not alter cell growth and effects only a modest increase in the apoptotic rate in these cultured cells. Oncostatin M and its receptors may be part of a network of cytokine systems within ovarian carcinomas that may act to maintain STAT3 in its activated form, a phenomenon associated with the malignant phenotype.     

AP2/EREBP转录因子在植物发育和胁迫应答中的作用

AP2／EREBP（APETALA2/ethylene-responsive element binding proteins）是一个起源古老的转录因子超家族,它含有1个或2个由约60—70个氨基酸残基组成的非常保守的DNA结合域（DNA-binding domain）,即AP2／ERF结构域。根据AP2／ERF结构域的数目,AP2／EREBP转录因子可以分为2个亚族：EREBP亚族（具有1个AP2／ERF结构域）和AP2亚族（具有2个AP2／ERF结构域）。AP2亚族转录因子有调控花、胚珠和种子发育的功能,而EREBP亚族转录因子（包括DREB类和ERF类）的主要功能是调节植物对激素（乙烯和ABA等）、病原和胁迫（低温、干旱及高盐）等的应答反应。本文讨论了AP2／EREBP转录因子在植物发育和胁迫应答中的研究进展。     

Distinctions in lymphocyte responses to IL-2 and IL-15 reflect differential ligand binding interactions with the IL-2Rbeta chain and suggest differential roles for the IL-2Ralpha and IL-15Ralpha subunits

More interleukin 15 (IL-15) than IL-2 was needed to generate comparable proliferative responses by phytohaemagglutinin (PHA) blasts and Tf-1beta cells expressing high affinity and intermediate affinity IL-2 receptor (IL-2R) complexes, respectively. The focus of these experiments was to determine the contribution of the shared IL-2 and IL-15 receptor components to these dose-response differences. Some of this difference can be attributed to the role of the IL-2Rbeta chain, in that HuMikbeta1, a monoclonal antibody recognizing the IL-2Rbeta chain, blocks 92.2+/-2.5% (mean+/-SE) of the IL-2 proliferative response by Tf-1beta cells but only inhibits 57.9+/-3.7% of the IL-15 response, indicating that IL-2 and IL-15 may physically utilize the IL-2Rbeta chain differently. Monoclonal antibody 341, which recognizes IL-2Rbeta but does not inhibit IL-2 binding to the IL-2Rbeta chain, blocks 35.4+/-2.3% of IL-15-stimulated proliferation of PHA blasts, while not affecting the IL-2-stimulated proliferation. Finally, although HuMikbeta1 does not inhibit IL-2 responses by PHA blasts bearing high affinity IL-2 receptors, HuMikbeta1 does block IL-15-stimulated proliferation by these same cells bearing high affinity IL-15 receptors (88.5+/-1.6% inhibition). This indicates that the role of IL-15Ralpha in the high affinity IL-15R complex is distinct from that of IL-2Ralpha in the high affinity IL-2R complex. Overall, these studies show that the physical interactions of the IL-2Rbetagammac complex with IL-2 are different than the interactions with IL-15.     

新疆地区酸马奶中酵母菌的鉴定及其生物多样性分析

从新疆少数民族牧民家庭采集的28份传统工艺酿造酸马奶样品中分离出87株酵母菌,并对其进行了生理生化鉴定、分子生物学鉴定和生物多样性分析。生化试验结果表明,新疆地区酸马奶中的酵母菌为Saccharomyces unisporus(占总分离株的48.3%),Kluyveromyces marxianus(27.6%),Pichia membranaefaciens(15.0%)和Saccharomyces cerevisiae(9.2%)。选取其中的6株酵母菌和1株参考菌株,进行大亚基(26S)rDNA D1/D2区域(600bp左右)碱基序列分析,并通过GenBank进行同源序列搜索以确定各菌株的归属,进一步验证生理生化方法的正确性。从得到的结果中可以看出,S.unisporus和K.marxianus为新疆地区酸马奶中的优势菌。     

Regulation of beta2-adrenergic receptors on CD4 and CD8 positive lymphocytes by cytokines in vitro

Increasing evidence points to a close relationship between the autonomic nervous system and the immune system. To further investigate mechanisms regulating beta2-adrenergic receptor (beta2R) expression in lymphocytes, the influence of cytokines on the density of beta2R on purified CD4+ and CD8+ lymphocytes was determined in vitro. beta2R were determined by means of a radioligand binding assay with (125I)iodocyanopindolol. CD4+ and CD8+ lymphocytes were incubated with catecholamines, interleukin 1beta (IL-1beta) and interleukin 2 (IL-2) for 6-72 h. The results demonstrate declining beta2R numbers on CD4+ and CD8+ lymphocytes in vitro augmented by epinephrine. IL-1beta has no effect on beta2R expression compared to medium. However, incubation with IL-2 resulted in an up-regulation of beta2R on CD8+ lymphocytes. Thus, the study demonstrates a differential regulation of beta2R on T-lymphocyte subpopulations with CD8+ lymphocytes being more susceptible to mechanisms of beta2R modulation than CD4+ lymphocytes. The findings further strengthen the concept of a close interplay between the autonomic nervous system and the immune system.     

CUEDC2中CUE结构域的表达纯化及结构初探

目的:建立CUEDC2中CUE结构域的原核表达系统,获得13C、15N同位素标记的CUE结构域蛋白质,以用于结构生物学研究。方法:利用分子生物学方法将CUE结构域编码序列构建到pET-28a原核表达系统,表达和纯化13C、15N标记的重组蛋白;用SDS-PAGE等方法对其进行鉴定。结果:目的蛋白经SDS-PAGE和MALDI-TOF/MS检测,相对分子质量正确,圆二色谱和核磁共振波谱结果显示目的蛋白折叠良好。结论:获得了高浓度、高纯度、折叠良好的CUE结构域标记蛋白质,利于进一步的结构生物学研究。