金黄色葡萄球菌对体外培养的奶牛乳腺上皮细胞PDGF-BB mRNA及蛋白表达的影响

The effect of Staphylococcus aureus on PDGF-BB mRNA expression and protein secretion in bovine mammary epithelial cells cultured in vitro

为研究金黄色葡萄球菌(S.aureus)对奶牛乳腺上皮细胞(BMEC)中PDGF-BB m RNA及蛋白表达的影响,本研究采用热灭活的不同浓度的S.aureus菌液(0、105、106、108cfu/m L)作用于BMEC,分别在不同时间点(6 h、12 h、24 h、48 h)利用荧光定量PCR和western blot方法检测PDGF-BB m RNA及其蛋白的相对表达量。结果显示,不同浓度菌液处理组的PDGF-BB m RNA相对表达量随着作用时间延长表达量升高(p<0.05)。6 h处理组随着菌液浓度的升高,PDGF-BB m RNA的相对表达量呈升高趋势;12 h处理组随着菌液浓度的升高,PDGF-BB m RNA的相对表达量呈降低趋势;24 h和48 h处理组105cfu/m L菌液处理组PDGF-BB m RNA相对表达量最高(p<0.05)。同时,各时间点不同浓度菌液处理组PDGF-BB蛋白的相对表达量和m RNA表达基本一致。本研究表明,热灭活的S.aureus能够促进BMEC PDGF-BB m RNA和蛋白的表达。

The aim of this study was to explore the effect of heat-inactivated Staphylococcus aureus on the expression of PDGF-BB mRNA and protein in bovine mammary epithelial cells. In this study, the mammary epithelial cells cultured in vitro were exposed to the heat-inactivated S.aureus at 105 efu/mL, 106 cfu/mL and 108 cfu/mL, respectively, and the total RNA and protein were extracted from the cells at 6, 12, 24 and 48 hours respectively for examinations by real-time RT-PCR and western blot. The results showed that the PDGF-BB mRNA expressions in all cells treated with different concentration of bacteria were significantly higher than that in control ceils at every time point （p〈0.05）. Furthermore, the protein secretion of PDGF-BB in treated cells was also significantly higher than that in control cells. In conclusion, the results indicated that heat-inactivated S.aureus up-regulated the expression ofPDGF-BB mRNA and protein in bovine mammary epithelial cells.