title: Ciprofloxacin reduces the stimulation of prostaglandin E(2) output by interleukin-1beta in human tendon-derived cells.
abstract: OBJECTIVE
  Fluoroquinolone antibiotics such as ciprofloxacin can induce tendon pathology and have various effects on tendon-derived cells in culture. We are investigating whether ciprofloxacin modifies signalling responses in tendon cells.
  
  
  METHODS
  Human Achilles tendon-derived cells were preincubated with or without ciprofloxacin (50 mug/ml) and were then challenged with interleukin-1beta (IL-1beta, 1 ng/ml) for up to 48 h. Prostaglandin E2 (PGE2) output was assayed by ELISA. The expression of cyclooxygenase-2 (COX-2) was examined by Western blotting.
  
  
  RESULTS
  IL-1beta stimulated a substantial and prolonged increase in the output of PGE2. Preincubation with ciprofloxacin reduced IL-1beta-induced PGE2 output at all times tested; the reduction at 48 h was 69% (99% confidence interval 59-79%; 15 experiments). Norfloxacin and ofloxacin also reduced PGE2 output. However, ciprofloxacin did not affect the induction of COX-2 by IL-1beta, measured at 4 or 48 h.
  
  
  CONCLUSIONS
  Ciprofloxacin reduces IL-1beta-induced PGE2 output in tendon-derived cells. The reduction in PGE2 output could modulate various cellular activities of IL-1beta, and may be implicated in fluoroquinolone-induced tendinopathy.
authors.affiliation: Addenbrooke's Hospital, Cambridge, UK.
authors.forename: A N
authors.initials: AN
authors.lastname: Corps
authors.forename: V A
authors.initials: VA
authors.lastname: Curry
authors.forename: R L
authors.initials: RL
authors.lastname: Harrall
authors.forename: D
authors.initials: D
authors.lastname: Dutt
authors.forename: B L
authors.initials: BL
authors.lastname: Hazleman
authors.forename: G P
authors.initials: GP
authors.lastname: Riley
mesh_terms: D000125:Achilles Tendon / Q000378:metabolism*; D000890:Anti-Infective Agents / Q000494:pharmacology*; D015153:Blotting, Western; D002478:Cells, Cultured; D002939:Ciprofloxacin / Q000494:pharmacology*; D051546:Cyclooxygenase 2; D015232:Dinoprostone / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D007527:Isoenzymes / Q000378:metabolism; D008565:Membrane Proteins; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism
chemical_list: D000890:Anti-Infective Agents; D007375:Interleukin-1; D007527:Isoenzymes; D008565:Membrane Proteins; D002939:Ciprofloxacin; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases; D015232:Dinoprostone