β-榄香烯体外诱导大鼠神经胶质瘤细胞热休克蛋白70的表达及肿瘤细胞的凋亡

目的探讨β-榄香烯体外对胶质瘤细胞的抑制作用及其机制。方法用MTT法观察β-榄香烯作用下大鼠神经胶质瘤细胞(C6细胞)生存情况；用FCM法检测C6细胞膜热休克蛋白70(HSP70)的表达及细胞周期；电镜观察瘤细胞的超微结构变化。结果(1)榄香烯组、丝裂霉素组、榄香烯+丝裂霉素组C6细胞的生存率均下降,生存的抑制作用呈剂量依赖性。(2)榄香烯组、榄香烯+热休克组C6细胞株胞膜上HSP70蛋白的表达率(63．88%、97．84%)均较对照组(平均4．72%)显著增高(P＜0．05)。(3)FCM检测经β-榄香烯(0．2mg/ml)处理的C6细胞S期细胞比例上升(53．80%),G_2-M期的细胞数目下降(4．67%),有亚二倍体峰(23．37%),电镜发现凋亡小体。结论β-榄香烯能抑制C6细胞的增殖,可诱导C6细胞膜HSP70蛋白的表达。使肿瘤细胞凋亡可能是其抗瘤效应的一个重要机制。

人骨保护素-分枝杆菌热休克蛋白70融合蛋白的克隆与表达及其活性鉴定

目的:为解决类风湿性关节炎中骨破坏及炎症损伤两大难题,拟克隆人骨保护素功能区与分枝杆菌热休克蛋白70肽段融合基因,进一步观察其在大肠杆菌中的表达并鉴定活性。方法:实验于2006-05/2007-09在首都医科大学免疫学系实验室完成。采用反转录-聚合酶链反应技术从人骨肉瘤细胞系MG63总RNA中扩增骨保护素成熟肽段编码区基因,构建pGEM-TEasy-骨保护素重组质粒。以此为模板,聚合酶链反应扩增骨保护素-热休克蛋白70功能区DNA,构建重组表达载体pET-28a-骨保护素-热休克蛋白70,将其转化E.coli.BL21(DE3),经异丙基硫代半乳糖苷诱导后收集菌体蛋白,以十二烷基硫酸钠-聚丙烯酰胺凝胶电泳及蛋白免疫印迹鉴定该融合蛋白的表达,以破骨细胞生长抑制实验及抑炎实验检测该融合蛋白的生物学活性。结果:①实验最终获得人骨保护素全长基因片段,人骨保护素-热休克蛋白70功能区DNA片段已被正确插入到pET-28a载体中,转化菌株可表达人骨保护素-热休克蛋白70融合蛋白。②十二烷基硫酸钠-聚丙烯酰胺凝胶电泳分析显示约在Mr22000处有蛋白的超表达,而未诱导菌株未发现有此条带。③蛋白免疫印迹检测表明,融合蛋白能与抗人骨保护素单克隆抗体特异性结合。④破骨细胞生长抑制实验表明,该融合蛋白能够减少破骨细胞的生成数量,具有体外抑制骨破坏的生物活性。⑤抑炎实验表明,融合蛋白具有显著减轻迟发型超敏反应小鼠模型炎症反应程度的作用,说明融合蛋白中热休克蛋白70具有抑制炎症的生物学活性。结论:在E.coli.BL21(DE3)中表达了骨保护素-热休克蛋白70融合蛋白,体外功能实验证实该融合蛋白具有一定的生物学活性。

Increased heat shock protein 70 expression in the pancreas of rats with endotoxic shock

AIM： To investigate the ultra-structural changes and heat shock protein 70 （HSP70） expression in the pancreas of rats with endotoxic shock and to detect their possible relationship. METHODS： A total of 33 Wistar rats were randomly divided into three groups： control group （given normal saline）, small dose lipopolysaccharide （LPS） group （given LPS 5 mg/kg） and large dose LPS group （given LPS 10 mg/kg）. Pancreas was explanted to detect the ultrastructural changes by TEM and the HSP70 expression by immunohistochemistry and Western blot. RESULTS： Rats given small doses of LPS showed swelling and loss of mitochondrial cristae of acinar cells and increased number of autophagic vacuoles in the cytoplasm of acinar cells. Rats given large doses of LPS showed swelling, vacuolization, and obvious myeloid changes of mitochondrial cristae of acinar cells, increased number of autophagic vacuoles in the cytoplasm of acinar cells. HSPT0 expression was increased compared to the control group （P〈0.05）. CONCLUSION： Small doses of LPS may induce stronger expression of HSP70, promote autophagocytosis and ameliorate ultra-structural injuries.

Expression and significance of heat shock protein 70 and glucose-regulated protein 94 in human esophageal carcinoma

AIM: To investigate the expression and significance of heat shock protein 70 (HSP70) and glucose-regulated protein 94 (grp94) in human esophageai carcinoma and adjacent normal tissues. METHODS: The expression of HSP70 and grp94 in 78 human esophageai cancer and adjacent normal tissues was studied by immunohistochemistry and pathology photograph analysis. RESULTS: Both esophageai cancer and adjacent normal tissues could express HSP70 and grp94. Of the 78 cases of esophageai carcinoma, 95.0%(72/78) showed positive HSP70, mainly stained in nuclei, while grp94 was mainly stained in cell plasma, and the positive rate was 71.8% (56/78).There was a significant difference in the expression of HSP70 and grp94 between esophageai cancer and adjacent normal tissues (P<0.01). Compared with adjacent normal tissues, there was a significant difference between differential types and HSP70 expression (P<0.01). CONCLUSION: HSP70 and grp94 express differently in cell plasma and nuclei. The expression intensity of HSP70 is related to the differentiation of esophageai carcinoma.

Effect of Temperature on Gene Expression in the Pearl Oyster Pinctada fucata

In this study, we examined the effect of elevated temperature on the expression patterns of genes, i.e., nacrein, irr, n16, n19, and hsp70 in the pearl oyster Pinctada fucata. The experiment was carried out at 4 temperatures, i.e., 20℃(ambient, control), 24, 28℃, and 32℃. The expression levels of target genes in P. fucata were assayed at 0, 6, 24, 48, and 96 h via real-time polymerase chain reaction. Results showed that the expression levels of nacrein and irr had no significant variations among different time points below 28℃, but significantly increased over time at 32℃. The expression levels of n16 and n19 did not change markedly at 20℃. The former increased significantly at 6 h and 24 h while the latter substantially decreased during 6–96 h at 24, 28 and 32℃. Among different temperatures, the level of n16 was significantly lower at 20℃ than at other temperatures during 6–96 h, and the level of n19 significantly varied among different temperatures at 48 h and 96 h. The expression level of hsp70 was significantly higher at 32℃ than at 20, 24 and 28℃ at 24 h. These results demonstrated that elevated temperature impacted the physiological processes of P. fucata and potentially influenced its adaptability to thermal stress.

Increased expression of Hsp70 and co-localization with nuclear protein in cells infected with the Hantaan virus

Objective To investigate the effect of Hantaan virus infection on the expression of stress genes. Methods Techniques of virus infection, Western blot, immunohistochemistry, dual-immunofluorecsence staining, laser scanning confocal microscopy, RNA dot blot and in situ hybridization were used.Results Expression of heat shock protein 70 (Hsp70) was observed in cells infected with HTV as well as the translocation of Hsp70 from cytoplasm to nucleoli following virus infection. The variable distribution of Hsp70 was related to the various time after infection. Double-label indirect immunofluorescence of nuclear protein (NP) and Hsp70 in infected cells demonstrated co-localization of these proteins in the cytoplasm. Conclusion Overexpression of Hsp70 can be induced directly by Hantaan virus, which may be associated with virus protein assembly. The Hantaan virus proteins co-localize with, and possibly form a physical complex with cellular Hsp70 in infected cells.