藏药紫金标抗HSV-1的作用机理研究

目的 :探讨紫金标抗单纯疱疹Ⅰ型病毒 (HSV-1)的作用及机理 ,为进一步开发该药提供理论依据。方法 :采用不同剂量的紫金标作用于适量HSV-1感染的Vero细胞 ,以 50%组织细胞感染量 (TCID₅₀ ) ,细胞病变效应(CPE) ,MTT法和核酸分子杂交作为评价指标。结果 :MTT法测得紫金标的 50 %抑制浓度 (IC₅₀ )为 29.46mg·L^-1,50%中毒浓度 (TC₅₀ )为 1 077mg·L^-1,治疗指数 (TI)为 36.56 ,结果表明紫金标有明显抑制HSV-1的作用 ,其作用强度和有效时间与药物浓度成正比。紫金标无直接灭活HSV-1的作用 ,也不能影响病毒的释放 ;但可干扰HSV -1对宿主细胞的吸附。不同浓度的紫金标能明显抑制HSV-1gD基因复制和mRNA表达。结论 :紫金标具有显著的抗HSV-1的作用 ,能抑制HSV-1对宿主细胞的吸附以及抑制HSV-1gD基因复制与转录。     

Impact of combined prenatal ethanol and prenatal stress exposures on markers of activity-dependent synaptic plasticity in rat dentate gyrus

Prenatal ethanol exposure and prenatal stress can each cause long-lasting deficits in hippocampal synaptic plasticity and disrupt learning and memory processes. However, the mechanisms underlying these perturbations following a learning event are still poorly understood. We examined the effects of prenatal ethanol exposure and prenatal stress exposure, either alone or in combination, on the cytosolic expression of activity-regulated cytoskeletal (ARC) protein and the synaptosomal expression of AMPA-glutamate receptor subunits (GluA1 and GluA2) in dentate gyrus of female adult offspring under baseline conditions and after 2-trial trace conditioning (TTTC). Surprisingly, baseline cytoplasmic ARC expression was significantly elevated in both prenatal treatment groups. In contrast, synaptosomal GluA1 receptor subunit expression was decreased in both prenatal treatment groups. GluA2 subunit expression was elevated in the prenatal stress group. TTTC did not alter ARC levels compared to an unpaired behavioral control (UPC) group in any of the 4 prenatal treatment groups. In contrast, TTTC significantly elevated both synaptosomal GluA1 and GluA2 subunit expression relative to the UPC group in control offspring, an effect that was not observed in any of the other 3 prenatal treatment groups. Given ARC's role in regulating synaptosomal AMPA receptors, these results suggest that prenatal ethanol-induced or prenatal stress exposure-induced increases in baseline ARC levels could contribute to reductions in both baseline and activity-dependent changes in AMPA receptors in a manner that diminishes the role of AMPA receptors in dentate gyrus synaptic plasticity and hippocampal-sensitive learning.     

Coordinated age-dependent and pancreatic-specific expression of mouse Reg2Reg3α, and Reg3β genes

Reg family proteins such as Reg1 and islet neogenesis-associated protein (INGAP) have long been implicated in the growth and/or neogenesis of pancreatic islet cells. Recent reports further suggest similar roles to be played by new members such as Reg2, Reg3α, and Reg3β. We have studied their age-, isoform-, and tissue-specific expressions. RNA and protein were isolated from C57BL/6 mice aged 7, 30, and 90 days. Using real-time polymerase chain reaction, the levels of Reg gene expression in the pancreas were 20–600-fold higher than that in other tissues (?duodenum>stomach>liver); gene expression of Reg2, Reg3α, and Reg3β was age dependent as it was hardly detectable at day 7, increased drastically at day 30, and significantly decreased at day 90; the levels of pancreatic proteins displayed similar age-dependent variations. Using dual-labeled immunofluorescence, Reg2, Reg3α, and Reg3β were abundantly expressed in most acinar cells of the pancreas, in contrast to INGAP which exhibited stepwise increases from day 7 to day 90 and colocalized with the α-cells. These new Reg genes were mainly expressed in the pancreas, with clear age-dependent and isoform-specific patterns.     

HSP70-肿瘤肽复合物的纯化及其对肝癌细胞株HepG-2增殖的作用

目的:应用快速蛋白液相色谱(FPLC)系统从肝癌组织中分离和纯4EHSP70-肽复合物,并研究其对肝癌细胞系HepG-2增殖的影响．方法:将组织进行匀浆、高速离心提取总蛋白后依次进行ConA-Sepharose亲和层析和 DEAE-Sephacel子交换层析分离纯化,所得蛋白经SDS-聚丙烯酰胺凝胶电泳和Western blot进行蛋白分子质量及性质鉴定,Bradford 法测定蛋白浓度;利用MTT方法检测HSP70- 肽复合物对HepG-2细胞增长的情况．结果:分离、纯化得到的蛋白经SDS-聚丙烯酰胺凝胶电泳、考马斯量蓝鉴定为单一带, 分子质量为70 kDa;Western blot结果证实为 HSP70,每10 g组织最终获得1．5 mg的HSP70; HSP70刺激组12,48,72 h与对照组的A值之间有显著差异(0．1 mg／L:t=-0．2500,P=0．00; t=-0．1777,P=0．001:t=-0．3094,P=0．001; 0．5 mg／L:t=-0．2878,P=0．00;t=-0．2044,P= 0．00;t=-0．3285,P=0．00;1 mg／L:t=-0．3118, P=0．00;t=-0．2592,P=0．00;t=-0．1994, P=0．025;5 mg／L:t=-0．4007,P=0．00;t= -0．1302,P=0．016;t=-0．2537,P=0．005),细胞存活率明显高于对照组(P<0．01)．结论:使用本分离纯化方法可获得高纯度 HSP70肽复合物;HSP70肽复合物可以促进 HepG-2细胞的生长．     

氧化苦参碱对人结肠癌细胞P21,P27,Cyclin E1及CDK2表达的影响

目的:观察氧化苦参碱(OM)对人结肠癌细胞P21,P27,Cyclin E1及CDK2表达的影响,研究其抑制细胞增殖的其他途径,探讨OM抗肿瘤的作用机制.方法:培养人结肠癌细胞株SW1116,以2,3,4 g/L OM作用24和48 h,以流式细胞仪测定OM对SW1116细胞的周期阻断作用;并采用RT- PCR、Western blot法测定细胞周期相关蛋白P21、P27、Cyclin E1和CDK2的表达水平.结果:与对照组相比,不同浓度(2,3,4 g/L)OM可使细胞阻滞于G_1/G_0期(24 h:67.5%±0.1%,69.5%±1.4%,71.0%±1.0% vs 58.6%±0.4%,P<0.05;48h:68.5%±0.3%,71.9%±0.9%,78.0%±0.4% vs 58.8%±0.1%,P<0.05),下调Cyclin E1的mRNA和蛋白表达水平(P<0.05),上调细胞周期负调控因子P21、P27的mRNA及蛋白表达水平(P<0.05),降低CDK2的mRNA水平而对其蛋白表达无影响.结论:OM可能通过阻滞细胞周期,降低Cyclin E1蛋白,上调P21、P27的基因表达,来发挥其抗肿瘤作用.     

Spontaneous and pronase‐induced HER2 truncation increases the trastuzumab binding capacity of breast cancer tissues and cell lines

A subgroup of HER2‐overexpressing breast tumours co‐expresses p95 $^{{\rm{HER2}}}$ , a truncated HER2 receptor that retains a functional HER2 kinase domain but lacks the extracellular domain, thus impairing trastuzumab binding. We evaluated p95 $^{{\rm{HER2}}}$ expression in 99 frozen breast carcinoma samples by western blot analysis. The HER2‐positive cell line BT474 treated with pervanadate or pronase was used as a positive control for p95 $^{{\rm{HER2}}}$ expression. Immunohistochemistry was performed on parallel formalin‐fixed, paraffin‐embedded sections of the same case series using antibodies directed against either the intra‐ or extra‐cellular binding domain of HER2. In particular, biotinylated trastuzumab (BiotHER) was used to evaluate the binding capacity of the humanized antibody. To avoid a subjective evaluation of the score values and the percentage of immunostained cells, the slides were scanned and automatically analysed. The number of cases with HER2 overexpression (score 3+) and HER2 gene amplification was higher in the p185 $^{{\rm{HER2}}}$ ‐positive/p95 $^{{\rm{HER2}}}$ ‐positive samples than in the p185 $^{{\rm{HER2}}}$ ‐positive/p95 $^{{\rm{HER2}}}$ ‐negative group. Automated analysis confirmed a significantly higher percentage of 3+ scored cells in p95 $^{{\rm{HER2}}}$ ‐positive cases. Conversely, the percentage of 2+ scored cells was higher in p95 $^{{\rm{HER2}}}$ ‐negative cases. The status of the HER2 extracellular domain was then studied using flow cytometry on BT474 cells after pronase enzymatic digestion using trastuzumab and pertuzumab, while the presence of HER2‐HER3 dimers was studied using a proximity‐ligation assay. In vitro experiments showed that short‐term pronase digestion of BT474 cells produced two HER2 fragments (of 95 and 150 kDa, detectable in tissue specimens as well), increased the binding affinity of trastuzumab, reduced the rate of HER2–HER3 dimers, and did not interfere with pertuzumab‐binding capacity. In conclusion, the presence of p95 $^{{\rm{HER2}}}$ as detected by western blot analysis does not compromise the immunohistochemical detection of HER2. Our data suggest that a reduction of the receptor steric hindrance as induced by enzymatic shedding may facilitate the binding capacity of trastuzumab. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

Anti-Soluble Liver Antigen (SLA) Antibodies in Chronic HCV Infection

Hepatitis C infection is associated with autoimmune disorders, such as the production of autoantibodies. Anti-LKM1 and anti-LC1, immunomarkers of type 2 autoimmune hepatitis, have been previously associated with a HCV infection. Anti-Soluble-Liver-Antigen autoantibodies (SLA) are specifically associated with type 1 and type 2 autoimmune hepatitis and more closely related to patients who relapse after steroid therapy. The recent molecular cloning of the soluble liver antigen provides the opportunity to develop more specific tests for the detection of antibodies against it. The aim of this work is to characterize anti-soluble-liver autoantibodies in sera from patients chronically infected by HCV. A recombinant cDNA from activated Jurkat cells coding for the full length tRNP^(Ser)Sec/SLA antigen was obtained. ELISA, Western Blot and immunoprecipitation tests were developed and used to search for linear and conformational epitopes recognized by anti-SLA antibodies in sera from patients chronically infected by HCV. Anti-soluble liver antigen antibodies were found in sera from 10.4% of HCV-infected patients. The prevalence was significantly increased to 27% when anti-LKM1 was also present. Most anti-SLA reactivity was directed against conformational epitopes on the antigen. The means titers by ELISA were lower than those obtained in type 2 AIH. The result of autoantibody isotyping showed a subclass restriction to IgG1 and also IgG4. This study shows the presence of anti-SLA antibodies in approximately 10% of HCV infected patients. The prevalence of SLA autoantibodies in HCV infected patients increases when LKM1 autoantibodies are also present. The relationship between the prevalence of this characteristic autoimmune hepatitis autoantibody and the implication of an autoimmune phenomenon in the liver injury of patients chronically infected by HCV needs further investigation.     

VEGF-C基因靶向RNA干扰重组表达载体的构建和表达

目的:利用质粒pSilencer3.1-H_1构建针对人血管内皮生长因子-C(VEGF-c)基因的表达载体,测序鉴定并观察在胃癌细胞中的表达.方法:根据质粒pSilencer3.1-H_1要求设计两对小干扰RNA靶序列,退火形成互补的双链,通过与线性化的pSilencer3.0-H_1相应位点连接、转化大肠杆菌,扩增、纯化得到所需质粒,酶切电泳及测序鉴定后转染胃癌细胞株SGC-7901,Western blot检测转染前后VEGF-C基因的蛋白表达.结果:经酶切和测序鉴定,针对VEGF-C基因的siRNA表达载体构建成功.转染胃癌细胞株SGC-7901后,Western blot检测显示VEGF-C基因蛋白表达明显降低,pSilencer3.1-VEGF-C1组抑制效果明显,其抑制率为81.2%,与阴性对照组相比差异具有显著性(P<0.05).结论:成功构建了针对人VEGF-C基因的siRNA表达载体和稳定转染的胃癌细胞株SGC-7901.