title: Catecholamines promote the expression of virulence and oxidative stress genes in Porphyromonas gingivalis.
abstract: OBJECTIVE
  Stress has been identified as an important risk factor in the development of many infectious diseases, including periodontitis. Porphyromonas gingivalis, a gram-negative oral anaerobic bacterium, is considered an important pathogen in chronic periodontitis. Microorganisms, including P. gingivalis, that participate in infectious diseases have been shown to respond to catecholamines released during stress processes by modifying their growth and virulence. Therefore, the purpose of this study was to evaluate the effects of adrenaline and noradrenaline on the growth, antimicrobial susceptibility and gene expression in P. gingivalis.
  
  
  METHODS
  P. gingivalis was incubated in the presence of adrenaline and noradrenaline (100 μm) for different time-periods in rich (Tryptic soy broth supplemented with 0.2% yeast extract, 5 μg/mL of hemin and 1 μg/mL of menadione) and poor (serum-SAPI minimal medium and serum-SAPI minimal medium supplemented with 5 μg/mL of hemin and 1 μg/mL of menadione) media, and growth was evaluated based on absorbance at 660 nm. Bacterial susceptibility to metronidazole was examined after exposure to adrenaline and noradrenaline. The expression of genes involved in iron acquisition, stress oxidative protection and virulence were also evaluated using RT-quantitative PCR.
  
  
  RESULTS
  Catecholamines did not interfere with the growth of P. gingivalis, regardless of nutritional or hemin conditions. In addition, bacterial susceptibility to metronidazole was not modified by exposure to adrenaline or noradrenaline. However, the expression of genes related to iron acquisition (hmuR), oxidative stress (tpx, oxyR, dps, sodB and aphC) and pathogenesis (hem, hagA and ragA) were stimulated upon exposure to adrenaline and/or noradrenaline.
  
  
  CONCLUSIONS
  Adrenaline and noradrenaline can induce changes in gene expression related to oxidative stress and virulence factors in P. gingivalis. The present study is, in part, a step toward understanding the stress-pathogen interactions that may occur in periodontal disease.
authors.affiliation: Department of Physiological Sciences, Area of Pharmacology, Anesthesiology and Therapeutics, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil.
authors.forename: T S
authors.initials: TS
authors.lastname: Graziano
authors.forename: P
authors.initials: P
authors.lastname: Closs
authors.forename: T
authors.initials: T
authors.lastname: Poppi
authors.forename: G C
authors.initials: GC
authors.lastname: Franco
authors.forename: J R
authors.initials: JR
authors.lastname: Cortelli
authors.forename: F C
authors.initials: FC
authors.lastname: Groppo
authors.forename: K
authors.initials: K
authors.lastname: Cogo
mesh_terms: D000322:Adrenergic Agonists / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D001431:Bacteriological Techniques; D004268:DNA-Binding Proteins / Q000235:genetics; D004837:Epinephrine / Q000494:pharmacology*; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects; D006388:Hemagglutinins / Q000235:genetics; D006427:Hemin / Q000494:pharmacology; D006460:Hemolysin Proteins / Q000235:genetics; D006801:Humans; D037102:Lectins / Q000235:genetics; D008795:Metronidazole / Q000494:pharmacology; D009638:Norepinephrine / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects* / Q000235:genetics; D010518:Periodontitis / Q000382:microbiology; D010544:Peroxidases / Q000235:genetics; D054464:Peroxiredoxins / Q000235:genetics; D016966:Porphyromonas gingivalis / Q000187:drug effects* / Q000235:genetics / Q000472:pathogenicity; D013482:Superoxide Dismutase / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000322:Adrenergic Agonists; D000890:Anti-Infective Agents; D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; C083911:DPS protein, Bacteria; D006388:Hemagglutinins; D006460:Hemolysin Proteins; D037102:Lectins; C530740:OxyR protein, P gingivalis; C484343:RagA protein, Porphyromonas gingivalis; D014157:Transcription Factors; D037521:Virulence Factors; C114923:hemagglutinin A, Porphyromonas gingivalis; D008795:Metronidazole; D006427:Hemin; D010544:Peroxidases; D054464:Peroxiredoxins; C087504:SodB protein, Bacteria; D013482:Superoxide Dismutase; D009638:Norepinephrine; D004837:Epinephrine
keywords: Porphyromonas gingivalis; catecholamines; epinephrine; norepinephrine; periodontitis