Effect of UVA fluence rate on indicators of oxidative stress in human dermal fibroblasts.
During the course of a day human skin is exposed to solar UV radiation that fluctuates in fluence rate within the UVA (290-315 nm) and UVB (315-400 nm) spectrum. Variables affecting the fluence rate reaching skin cells include differences in UVA and UVB penetrating ability, presence or absence of sunscreens, atmospheric conditions, and season and geographical location where the exposure occurs. Our study determined the effect of UVA fluence rate in solar-simulated (SSR) and tanning-bed radiation (TBR) on four indicators of oxidative stress---protein oxidation, glutathione, heme oxygenase-1, and reactive oxygen species--in human dermal fibroblasts after receiving equivalent UVA and UVB doses. Our results show that the higher UVA fluence rate in TBR increases the level of all four indicators of oxidative stress. In sequential exposures when cells are exposed first to SSR, the lower UVA fluence rate in SSR induces a protective response that protects against oxidative stress following a second exposure to a higher UVA fluence rate. Our studies underscore the important role of UVA fluence rate in determining how human skin cells respond to a given dose of radiation containing both UVA and UVB radiation.
Hoerter
James D
JD
Ferris State University, Department of Biological Sciences, Big Rapids, MI 49307 USA. hoerterj@ferris.edu
Ward
Christopher S
CS
Bale
Kyle D
KD
Gizachew
Admasu N
AN
Graham
Rachelle
R
Reynolds
Jaclyn
J
Ward
Melanie E
ME
Choi
Chesca
C
Kagabo
Jean-Leonard
JL
Sauer
Michael
M
Kuipers
Tara
T
Hotchkiss
Timothy
T
Banner
Nate
N
Chellson
Renee A
RA
Ohaeri
Theresa
T
Gant
Langston
L
Vanderhill
Leah
L
D002478:Cells, Cultured; D005347:Fibroblasts / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects; D005978:Glutathione / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D006801:Humans; D008856:Microscopy, Fluorescence; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D012867:Skin / Q000166:cytology / Q000201:enzymology / Q000378:metabolism / Q000528:radiation effects*; D014466:Ultraviolet Rays
D017382:Reactive Oxygen Species; D006419:Heme Oxygenase (Decyclizing); D005978:Glutathione