中文摘要：

灯盏花乙素（scutellarin,Scu）具有清热解毒、扩张心脑血管、改善微循环等作用.通过观察不同浓度Scu对猪肾小管上皮细胞（pig kidney proximal tubular,LLC-PK1）热休克蛋白72（heat shock protein 72,HSP72）、B细胞淋巴瘤/白血病-2（B-cellymphoma/leukemia-2,Bcl-2）及Bcl-2相关X蛋白（Bcl-2associated X protein,Bax）表达的影响,探讨灯盏花乙素提高细胞耐热性的可能机制.将培养的LLC-PK1细胞随机分为37℃空白对照（Ⅰ组）,42℃单纯热应激1 h（Ⅱ组）,以及分别用不同浓度（1×10-5、1×10-6和1×10-7 mol/L）Scu处理并42℃热应激lh组（分别为Ⅲ、Ⅳ和Ⅴ组）,提取各组细胞总RNA和总蛋白,用实时荧光定量PCR和Western blot分别检测HSP72、Bcl-2和Bax基因及蛋白的表达量.结果显示,与Ⅰ组相比,Ⅱ组LLC-PK1细胞HSP72和Bax的mRNA及蛋白表达量显著升高（P＜0.05）,Bcl-2/Bax mRNA和蛋白比值显著降低（P＜0.05）,Bcl-2 mRNA和蛋白表达量并无显著差异（P＞0.05）.与Ⅱ组相比,Ⅳ和Ⅴ组LLC-PK1细胞HSP72 mRNA和蛋白的表达量均显著升高（P＜0.05）,Ⅲ组无显著差异（P＞0.05）;Ⅳ组细胞Bcl-2 mRNA和蛋白表达量均显著升高（P＜0.05）,Ⅲ和Ⅳ组并无显著差异（P＞0.05）;Ⅲ、Ⅳ和Ⅴ组Bax mRNA和蛋白表达量均显著降低（P＜0.05）;Ⅳ和Ⅴ组Bcl-2/Bax蛋白比值显著升高（P＜0.05）.研究结果表明,热应激条件下Scu可诱导LLC-PK1细胞HSP72表达,提高Bcl-2/Bax比值.结果提示,Scu可增强细胞的抗热休克作用.本研究丰富了体外培养细胞热应激反应的理论,为在实践中增加细胞抗热休克能力提供了理论依据.

英文摘要：

Scutellarin （Scu） has many beneficial effects clinically such as heat-clearing,detoxicating,expansion of blood vessels and improving microcirculation.The protective effects of scutellarin on improving the heat resistant of pig kidney proximal tubular （LLC-PK1） cells were studied by measuring expressions of heat shock protein 72 （HSP 72）,B-cellymphoma/leukemia-2 （Bcl-2） and Bcl-2 associated X protein （Bax） of the cells treated with different concentrations of Scu.The LLC-PK1 cells cultured in vitro were randomly divided into five groups including 37 ℃ control group （Ⅰ）,42 ℃ heat stress group （Ⅱ）,1 × 10-5 mol/L Scutreated group （Ⅲ）,1 × 10-6 mol/L Scu-treated group （Ⅳ） and 1 × 10-7 mol/L Scu-treated group （Ⅴ）,respectively.The total RNA and protein in all groups of cells were extracted,then the mRNA and protein content of HSP72,Bax and Bcl-2 in the cells were detected by qPCR and Western blot,respectively.Our results showed that the mRNA and protein expression of HSP72 and Bax all increased significantly （P＜0.05）,Bcl-2/Bax ratio decreased significantly in group Ⅱ compared with group Ⅰ （P＜0.05）,while expression of Bcl-2 had no significant difference （P＞0.05）.Treatments with various concentrations of Scu significantly increased both expressions of Bcl-2 in group Ⅳ and HSP72 in groups Ⅳ andⅤ compared with group Ⅱ （P＜0.05） at mRNA and protein level,while neither HSP72 nor Bcl-2 in group Ⅲ had any significant differences.The mRNA and protein expressions of Bax in Scu-treated groups were obviously decreased compared with group Ⅱ.The protein ratios of Bcl-2/Bax in both group Ⅳ and Ⅴ were significantly increased compared with group Ⅱ （P＜0.01）.All above results indicated that Scu could induce HSP72 expression,increase Bcl-2/Bax ratio and enhance heat resistance of LLC-PK1 cells under heat stress condition.Our result enriches the theory of heat stress response in cells cultured in vitro,which provides theoretical basis