Extremely low-frequency electromagnetic fields accelerates wound healing modulating MMP-9 and inflammatory cytokines

Cell Prolif. 2018 Apr;51(2):e12432. doi: 10.1111/cpr.12432. Epub 2018 Jan 22.

Abstract

Objectives: In our previous reports, we have demonstrated that extremely low-frequency electromagnetic fields (ELF-EMF) exposure enhances the proliferation of keratinocyte. The present study aimed to clarify effects of ELF-EMF on wound healing and molecular mechanisms involved, using a scratch in vitro model.

Materials and methods: The wounded monolayer cultures of human immortalized keratinocytes (HaCaT), at different ELF-EMF and Sham exposure times were monitored under an inverted microscope. The production and expression of IL-1β, TNF-α, IL-18 and IL-18BP were measured by enzyme-linked immunosorbent assay and quantitative real-time PCR. The activity and the expression of matrix metalloproteinases (MMP)-2/9 was evaluated by zymography and Western blot analysis, respectively. Signal transduction proteins expression (Akt and ERK) was measured by Western blot.

Results: The results of wound healing in vitro assay revealed a significant reduction of cell-free area time-dependent in ELF-EMF-exposed cells compared to Sham condition. Gene expression and release of cytokines analysed were significantly increased in ELF-EMF-exposed cells. Our results further showed that ELF-EMF exposure induced the activity and expressions of MMP-9. Molecular data showed that effects of ELF-EMF might be mediated via Akt and ERK signal pathway, as demonstrated using their specific inhibitors.

Conclusions: Our results highlight ability of ELF-EMF to modulate inflammation mediators and keratinocyte proliferation/migration, playing an important role in wound repair. The ELF-EMF accelerates wound healing modulating expression of the MMP-9 via Akt/ERK pathway.

MeSH terms

  • Cell Line, Transformed
  • Cytokines / metabolism*
  • Electromagnetic Fields*
  • Humans
  • Inflammation / metabolism
  • Inflammation / pathology
  • Inflammation / therapy
  • Keratinocytes / metabolism*
  • Keratinocytes / pathology
  • MAP Kinase Signaling System*
  • Matrix Metalloproteinase 9 / metabolism*
  • Wound Healing*

Substances

  • Cytokines
  • MMP9 protein, human
  • Matrix Metalloproteinase 9