ABSTRACT: During colonization in the host gastrointestinal tract, the enteric bacteria Campylobacter jejuni is exposed to a variety of signaling molecules including the catecholamine hormones epinephrine (Epi) and norepinephrine (NE). NE has been determined to stimulate the growth of C. jejuni as well as increase its pathogenicity. To investigate the mechanisms of NE or Epi on the biology of C. jejuni, the global gene expression profiles of C. jejuni NCTC 11168 cultured in iron-restricted medium were analyzed in response to NE or Epi. Totally, 183 and 156 genes were differentially expressed by NE and Epi respectively, with 102 differentially expressed genes common between the two treatments. These genes are involved in diverse cellular functions including iron uptake systems, motility, virulence, oxidative stress response, nitrosative stress tolerance, enzyme metabolism, DNA repair and metabolism and ribosomal protein biosynthesis. Adherence to and invasion of Caco-2 cells by C. jejuni were enhanced upon exposure to NE or Epi. These results indicated that NE and Epi have similar effects on the gene expression of C. jejuni and that the effects on gene expression may contribute to elucidate the mechanisms on interaction between host and C. jejuni. Transcriptional profiles were analyzed using microarray to compared the epinephrine (Epi) or norepinephrine (NE) treated and untreated Campylobacter jejuni NCTC 11168. NE or Epi treated and untreated cultures of C. jejuni NCTC 11168 were collected at the mid-log phase (?36 h cultures). Three (for NE or Epi treated culture) or four (for untreated control culture) independent biological replicates were performed. Total RNA was extracted using RiboPure™-Bacteria Kit (Ambion, Life Technologies) according to the manufacturer’s instructions. The quality and quantity of total RNA were determined by an Agilent Bioanalyzer 2100. Total RNA was amplified and labeled by Low Input Quick Amp Labeling Kit, One-Color, following the manufacturer’s instructions. Labeled cRNA were purified by RNeasy mini kit (QIAGEN, GmBH, Germany). Each Slide was hybridized with 600ng Cy3-labeled cRNA using Gene Expression Hybridization Kit (Agilent technologies, Santa Clara, CA, US) in Hybridization Oven, according to the manufacturer’s instructions. After 17 hours hybridization, slides were washed in staining dishes with Gene Expression Wash Buffer Kit (Agilent technologies, Santa Clara, CA, US), followed the manufacturer’s instructions. Slides were scanned by Agilent Microarray Scanner with default settings, Dye channel: Green, Scan resolution=5?m, PMT 100%, 10%, 16bit. Data were extracted with Feature Extraction software 10.7. Raw data were normalized by Quantile algorithm, Gene Spring Software 11.0. The genes with fold change ? 1.5 and P < 0.05 were selected as differentially expressed.
