Heat shock protein 70 expression induced by diode laser irradiation on choroid-retinal endothelial cells in vitro

Mol Vis. 2012;18:2380-7. Epub 2012 Sep 21.


Purpose: To investigate the biologic effect of an 810 nm diode laser on the induction of heat shock protein 70 (Hsp70) in choroid-retinal endothelial cells in vitro.

Methods: Cultured rhesus macaque choroid-retinal endothelial cells (RF/6A) were irradiated using an 810 nm diode laser (spot size, 10 mm; duration, 60 s; power, 400-1,500 mW). Cell viability was assessed by annexin V- fluorescein isothiocyanate (FITC) and propidium iodide flow cytometric assay. Hsp70 expression was determined by western blot at 6, 12, 18, 24, and 48 h following laser exposure. Intracellular distribution of Hsp70 was examined by immunofluorescence staining.

Results: The laser-induced cell injury threshold was found to be at a power of 1,100 mW power (fluence, 84.08 J/cm(2)), above which there was significant cell death. Under this power, Hsp70 expression elevated obviously and was stronger at 600-1,000 mW power settings (fluences, 45.86-76.43 J/cm(2)). The expression of Hsp70 peaked at 12-18 h postirradiation, and returned to baseline by 48 h. Immunofluorescence staining indicated the induced Hsp70 expression in both the cytoplasm and the nucleus.

Conclusions: Subthreshold 810 nm diode laser exposure can induce Hsp70 hyperexpression from 12 to 18 h postirradiation in cultured choroid-retinal endothelial cells without obvious cell death. The results could be useful for investigating and designing more effective laser therapies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Annexin A5
  • Cell Line
  • Cell Nucleus / radiation effects
  • Cell Nucleus / ultrastructure
  • Cell Survival / radiation effects
  • Choroid / cytology
  • Choroid / metabolism
  • Choroid / radiation effects*
  • Cytoplasm / radiation effects
  • Cytoplasm / ultrastructure
  • Dose-Response Relationship, Radiation
  • Endothelial Cells / cytology
  • Endothelial Cells / metabolism
  • Endothelial Cells / radiation effects*
  • Fluorescent Antibody Technique
  • Gene Expression / radiation effects
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • Lasers, Semiconductor*
  • Macaca
  • Retina / cytology
  • Retina / metabolism
  • Retina / radiation effects*


  • Annexin A5
  • HSP70 Heat-Shock Proteins