The neuroendocrine hormone norepinephrine increases Pseudomonas aeruginosa PA14 virulence through the las quorum-sensing pathway

Manjunath Hegde, Thomas K. Wood, Arul Jayaraman

Research output: Contribution to journalArticle

38 Scopus citations

Abstract

It has been proposed that the gastrointestinal tract environment containing high levels of neuroendocrine hormones is important for gut-derived Pseudomonas aeruginosa infections. In this study, we report that the hormone norepinephrine increases P. aeruginosa PA14 growth, virulence factor production, invasion of HCT-8 epithelial cells, and swimming motility in a concentration-dependent manner. Transcriptome analysis of P. aeruginosa exposed to 500 μM, but not 50 μM, norepinephrine for 7 h showed that genes involved in the regulation of the virulence determinants pyocyanin, elastase, and the Pseudomonas quinolone signal (PQS, 2-heptyl-3-hydroxy-4-quinolone) were upregulated. The production of rhamnolipids, which are also important in P. aeruginosa infections, was not significantly altered in suspension cultures upon exposure to 500 μM norepinephrine but decreased on semisolid surfaces. Swarming motility, a phenotype that is directly influenced by rhamnolipids, was also decreased upon 500 μM norepinephrine exposure. The increase in the transcriptional activation of lasR but not that of rhlR and the increase in the levels of PQS suggest that the effects of norepinephrine are mediated primarily through the las quorum-sensing pathway. Together, our data strongly suggest that norepinephrine can play an important role in gut-derived infections by increasing the pathogenicity of P. aeruginosa PA14.

Original languageEnglish (US)
Pages (from-to)763-776
Number of pages14
JournalApplied Microbiology and Biotechnology
Volume84
Issue number4
DOIs
StatePublished - Sep 1 2009

All Science Journal Classification (ASJC) codes

  • Biotechnology
  • Applied Microbiology and Biotechnology

Fingerprint Dive into the research topics of 'The neuroendocrine hormone norepinephrine increases Pseudomonas aeruginosa PA14 virulence through the las quorum-sensing pathway'. Together they form a unique fingerprint.

  • Cite this