title: Varying ratios of wavelengths in dual wavelength LED photomodulation alters gene expression profiles in human skin fibroblasts.
abstract: OBJECTIVE
  LED photomodulation has been shown to profoundly influence cellular behavior. A variety of parameters with LED photomodulation can alter cellular response in vitro. The effects of one visible and one infrared wavelength were evaluated to determine the optimal ratio to produce a net increase in dermal collagen by altering the ratio of total energy output of each wavelength. The ratio between the two wavelengths (590 and 870 nm) was shifted in 25% increments.
  
  
  METHODS
  Human skin fibroblasts in culture were exposed to a 590/870 nm LED array with total combined energy density fixed at 4.0 mW/cm.. The ratio of 590/870 nm tested parameters were: 100/0%, 75/25%, 50/50%, 25/75%, and 0/100%. These ratios were delivered using pulsed duty cycle of exposure (250 milliseconds "on" time/100 milliseconds "off" time/100 pulses) for a total energy fluence of 0.1 J/cm.. Gene expression was examined using commercially available extra cellular matrix and adhesion molecule RT PCR Arrays (SA Biosciences, Frederick, MD) at 24 hours post-exposure.
  
  
  RESULTS
  Different expression profiles were noticed for each of the ratios studied. Overall, there was an average (in an 80 gene array) of 6% expression difference in up or downregulation between the arrays. The greatest increase in collagen I and decrease in collagenase (MMP-1) was observed with 75/25% ratio of 590/870 nm. The addition of increasing proportions of IR wavelengths causes alteration in gene expression profile. The ratios of the wavelengths caused variation in magnitude of expression.
  
  
  CONCLUSIONS
  Cell metabolism and gene expression can be altered by simultaneous exposure to multiple wavelengths of low energy light. Varying the ratios of specific wavelength intensity in both visible and near infrared light therapy can strongly influence resulting fibroblast gene expression patterns.
authors.affiliation: Laser Skin & Vein Center of Virginia, Institute of Anti-Aging Research; Virginia Beach, Virginia 23462, USA. mail@lsvcv.com
authors.forename: D H
authors.initials: DH
authors.lastname: McDaniel
authors.forename: R A
authors.initials: RA
authors.lastname: Weiss
authors.forename: R G
authors.initials: RG
authors.lastname: Geronemus
authors.forename: C
authors.initials: C
authors.lastname: Mazur
authors.forename: S
authors.initials: S
authors.lastname: Wilson
authors.forename: M A
authors.initials: MA
authors.lastname: Weiss
mesh_terms: D000076246:CCCTC-Binding Factor; D019002:CD56 Antigen / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D024062:Collagen Type V / Q000235:genetics / Q000378:metabolism; D005347:Fibroblasts / Q000528:radiation effects*; D020869:Gene Expression Profiling; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism; D053507:Matrix Metalloproteinase 11 / Q000235:genetics / Q000378:metabolism; D010789:Phototherapy / Q000379:methods*; D016133:Polymerase Chain Reaction; D012313:RNA / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000166:cytology
chemical_list: D000076246:CCCTC-Binding Factor; C497483:CD44 protein, human; D019002:CD56 Antigen; C530725:COL5A1 protein, human; C000619697:CTCF protein, human; D024062:Collagen Type V; D018960:Hyaluronan Receptors; C522918:NCAM1 protein, human; D012097:Repressor Proteins; D012313:RNA; D053507:Matrix Metalloproteinase 11