title: Heat shock protein 70 expression induced by diode laser irradiation on choroid-retinal endothelial cells in vitro.
abstract: OBJECTIVE
  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.
authors.affiliation: Department of Ophthalmology, Ruijin Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Du
authors.forename: Qiong
authors.initials: Q
authors.lastname: Zhang
authors.forename: Shisheng
authors.initials: S
authors.lastname: Zhang
authors.forename: Ling
authors.initials: L
authors.lastname: Wang
authors.forename: Jingcai
authors.initials: J
authors.lastname: Lian
mesh_terms: D000818:Animals; D017304:Annexin A5; D002460:Cell Line; D002467:Cell Nucleus / Q000528:radiation effects / Q000648:ultrastructure; D002470:Cell Survival / Q000528:radiation effects; D002829:Choroid / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D003593:Cytoplasm / Q000528:radiation effects / Q000648:ultrastructure; D004307:Dose-Response Relationship, Radiation; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D005455:Fluorescent Antibody Technique; D015870:Gene Expression / Q000528:radiation effects; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism*; D054023:Lasers, Semiconductor; D008251:Macaca; D012160:Retina / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*
chemical_list: D017304:Annexin A5; D018840:HSP70 Heat-Shock Proteins