氦氧饱和高气压暴露对铜绿假单胞菌PAO1基因表达的诱导调节

Systemic regulation of gene expression in Pseudomonas aeruginosa PAO1 under hyperbaric oxyhelium exposure

摘要:

研究氦氧饱和高气压暴露对铜绿假单胞菌基因表达谱的系统影响, 对急性毒力基因表达的调节。用全基因组DNA芯片分析技术比较菌株暴露前后基因表达谱差异; RT-PCR方法验证部分差异表达基因; 用分光光度法在细胞水平验证弹性蛋白酶含量; 小鼠染毒法观察暴露组细菌毒力在整体动物水平的变化。基因表达谱分析结果表明, 铜绿假单胞菌暴露12 h差异表达基因达243个、72 h差异表达基因为1 168个。72 h差异表达基因中与细菌应激响应、蛋白折叠、转录调节、菌毛和鞭毛合成、毒力因子调节与合成、细菌外膜蛋白和抗原合成的基因大量上调; 部分基因的RT-PCR验证结果与芯片结果一致; 细胞水平验证结果显示暴露72 h细菌毒力表型增强。因此, 氦氧饱和高气压暴露对铜绿假单胞菌基因表达谱有明显影响, 对急性侵袭性感染毒力因子基因表达水平有正向诱导调节作用。

Abstract:

To elucidate the systemic gene expression variation and virulence gene regulation of Pseudomonas aeruginosa in hyperbaric oxyhelium exposure environment. The level of differential gene expression was analyzed by PAO1 genomic DNA chip and 5 strikingly up-regulated genes were confirmed by RT-PCR. The level of elastase was detected by spectrophoto-metric method. Microarrays analysis showed that the expression levels of 243 genes were altered after 12 hours exposure and 1 168 genes altered after 72 hours exposure under the hyperbaric oxyhelium condition. These genes are mainly related to stress-sense/response, protein folding, transcriptional regulation, pili and flagellum metabolism, virulence factors adaptation, membrane proteins or antigens metabolism. The results of RT-PCR showed the same expression trends as in the micro-array. The ability of bacterial infection also increased after 72 hours exposure. Based on the results, we concluded that the hyperbaric oxyhelium environments affected PAO1 genes expression and several virulence-related genes were up-regulated.