耐甲氧西林金黄色葡萄球菌诱导牛乳腺上皮细胞炎症反应的分子标志物研究

Molecular Marker Study of Inflammatory Reaction in Bovine Mammary Epithelium Cell Line Induced by Methicillin-Resistant Staphylococcus aureus

旨在获得耐甲氧西林金黄色葡萄球菌(MRSA)诱导牛乳腺上皮细胞炎症反应的关键分子标志物。本研究以牛乳腺上皮细胞系Mac-T为试验材料,利用MRSA进行体外感染,通过与普通金葡菌感染组及未感染组进行比较,检测隐性乳房炎候选基因TRAPPC9、JAK2及炎症指示因子IL-6基因在MRSA感染不同时间点的基因表达量。结果显示,与未感染的对照组相比,MRSA菌株体外感染Mac-T细胞6h时,TRAPPC9基因表达量显著降低(P<0.05);感染8h时,JAK2基因表达量显著降低(P<0.05);金葡菌菌株感染Mac-T细胞6h时,TRAPPC9与JAK2基因表达量均显著降低(P<0.05)。与普通金葡菌相比,经MRSA处理6和10h时,Mac-T细胞的TRAPPC9、JAK2及IL-6基因表达量均较高,且感染6h时,MRSA处理组TRAPPC9基因表达量显著高于金葡菌处理组(P<0.05)。结果表明,MRSA及金葡菌感染Mac-T细胞后,3个基因表达变化规律基本相似,MRSA菌株感染更不易引起宿主细胞JAK2基因表达量的变化,而TRAPPC9基因则可作为MRSA金葡菌及普通金葡菌感染的首选分子标志物。

The aim of this study was to acquire key molecular marker related to inflammatory reaction of bovine mammary epithelium cells induced by Methicillin-resistant Staphylococcus aureus（MRSA）.In this study,bovine mammary epithelium cell line（Mac-T）was infected with MRSA in vitro by compared with the cells treated by S.aureus as well the untreated cells.The expression levels of two candidate genes associated with subclinical mastitis（（trafficking protein particle complex 9（TRAPPC9）,Janus Kinase 2（JAK2））and one pro-inflammatory gene（interleukin 6,IL-6）were detected and compared among infected groups and non-infected group at different timepoints.Comparing with the untreated cells,the results showed that the mRNA expression level of TRAPPC9 significantly decreased（P〈0.05）in the Mac-T cells at 6hpost stimulation by MRSA,while that of JAK2 significantly decreased（P〈0.05）at 8h;And the expression levels of TRAPPC9 and JAK2in the cells significantly decreased（P〈0.05）at 6hpost infection by S.aureus.Compared with S.aureus stimuli,the expression levels of TRAPPC9,JAK2 and IL-6in the Mac-T cells were moderately higher at 6and 10 hpost infection by MRSA.Especially,the expression level of TRAPPC9 was significantly higher in MRSA treated cells（P〈0.05）compared to S.aureustreated cells at 6hpost infection.These results suggest that the genes expression changes in the Mac-T cells were similar after the infection of MRSA and S.aureus,while the gene expression changes of JAK2 in the cells was delayed from MRSA infection compared to S.aureus.TRAPPC9 can be used as the preferred molecular marker for detecting MRSA and S.aureusinfection in bovine mammary epithelium cells.