Er:YAG laser irradiation increases prostaglandin E production via the induction of cyclooxygenase-2 mRNA in human gingival fibroblasts

J Periodontal Res. 2005 Apr;40(2):182-6. doi: 10.1111/j.1600-0765.2005.00789.x.


Background and objectives: It has been reported that both prostaglandin E2 (PGE2) and Er:YAG laser irradiation accelerate wound healing. The stimulatory action of laser seems to occur during the proliferative stage of healing by stimulation of prostaglandin E2 and cyclooxygenase-2 (COX-2), which are crucial early mediators in the natural healing process. We have then investigated the effect of Er:YAG laser irradiation on PGE2 production and COX-2 gene expression in human gingival fibroblast in vitro.

Material and methods: Cultured fibroblasts were exposed to low-power Er:YAG laser irradiation with an energy density of 3.37 J/cm2. The amount of PGE2 production was measured by enzyme-linked immunosorbent assay (ELISA). COX-2 mRNA level, which is a critical enzyme for PGE2 production, was analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR).

Results: Er:YAG laser significantly increased PGE2 production by human gingival fibroblasts. COX-2 mRNA, which was hardly detectable in control, increased dramatically after irradiation. COX-2 inhibitor, NS398, completely inhibited the PGE2 synthesis stimulated by Er:YAG laser irradiation.

Conclusion: Our results showed that Er:YAG laser irradiation appears to exert its stimulative action on gingival fibroblasts proliferation through the production of PGE2 via the expression of COX-2. This should be considered as one of the important regulatory pathways to accelerate wound healing after Er:YAG laser irradiation.

MeSH terms

  • Cell Proliferation
  • Cyclooxygenase 2
  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors / pharmacology
  • Dinoprostone / biosynthesis*
  • Enzyme Induction / radiation effects
  • Fibroblasts / cytology
  • Fibroblasts / enzymology
  • Fibroblasts / radiation effects*
  • Gingiva / cytology*
  • Humans
  • Indomethacin / pharmacology
  • Laser Therapy*
  • Membrane Proteins
  • Nitrobenzenes / pharmacology
  • Prostaglandin-Endoperoxide Synthases / biosynthesis*
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction / methods
  • Sulfonamides / pharmacology
  • Wound Healing / radiation effects


  • Cyclooxygenase 2 Inhibitors
  • Cyclooxygenase Inhibitors
  • Membrane Proteins
  • Nitrobenzenes
  • RNA, Messenger
  • Sulfonamides
  • N-(2-cyclohexyloxy-4-nitrophenyl)methanesulfonamide
  • Cyclooxygenase 2
  • PTGS2 protein, human
  • Prostaglandin-Endoperoxide Synthases
  • Dinoprostone
  • Indomethacin