大肠杆菌对体外培养的奶牛乳腺上皮细胞bFGF及其受体FGFR2表达的影响

摘要

Objective] To explore the effects of heat-inactivated Escherichia coli on the expression of bFGF and FGFR2 mRNA and protein in vitro bovine mammary epithelial cells.[Method] The mammary epithelial cells cultured in vitro were exposed to the heat-inactivated E.coli at 105 , 106 and 108 cfu/mL, respectively.The total RNA and protein were extracted from the cells after 6, 12, 24 and 48 h, respectively, for examinations by real-time RT-PCR and western blot.[ Result] The bFGF mRNA expressions in all cells treated with different concentration of bacteria were significantly higher than that in control cells at every time point (P <0.01).bFGF expression quantity was the maximum at 24 h, and then reduced.BMEC bFGF protein expression enhanced as the E.coli concentration increased, and reached the maximum value at 24 h.Except the 6 h group, FGFR2 mRNA relative expression quantity showed a trend of decrease-increase-decrease as the E.coli concentration enhanced, and reached the maximum at 48 h.Compared with control group, FGFR2 protein expression in treatment groups increased as the bacteria concentration enhanced.[ Conclusion] Heat-inactivated E.coli up-regulates the expression of bFGF and FGFR2 mRNA and protein in bovine mammary epithelial cells, showing concentration and time dependence.%[目的]探讨大肠杆菌（Escherichia coli）对体外培养的奶牛乳腺上皮细胞（BMEC）bFGF及其受体FGFR2表达的影响。[方法]取热灭活的0、105、106和108 CFU／mL浓度的大肠杆菌作用于体外培养的奶牛乳腺上皮细胞，分别在作用后6、12、24和48 h，采用荧光定量PCR和Western blot方法检测bFGF和FGFR2的mRNA和蛋白的表达情况。[结果] bFGF mRNA表达与对照组相比随着大肠杆菌浓度的升高而显著上调（P＜0．01），24 h bFGF表达量最高。 BMEC bFGF蛋白表达随着大肠杆菌浓度的增加而上调，24 h表达量达到最高；FGFR2 mRNA相对表达量除6 h组外随大肠杆菌浓度的增加而呈现降低、升高、降低的变化趋势，48 h表达量达到最高。各处理组与对照组相比FGFR2蛋白表达随时间的延长、菌液浓度的增加而上调。[结论]大肠杆菌刺激奶牛乳腺上皮细胞可以明显促进bFGF和FGFR2的表达，具有浓度和时间依赖性。