title: The effect of repeated exposures to low-dose UV radiation on the apoptosis of peripheral blood mononuclear cells.
abstract: OBJECTIVE
  To investigate whether repeated exposures to low-dose UV or solar-simulated radiation induce apoptosis of peripheral blood mononuclear cells.
  
  
  METHODS
  Cohort study in a healthy population.
  
  
  METHODS
  Departments of Dermatology and Hematology, Medical University of Lodz, Lodz, Poland.
  
  
  METHODS
  Ninety-eight healthy volunteers were divided into the following 4 groups: group A, whole-body irradiated with a 0.7-minimal erythema dose (MED) of UV-B daily on 10 consecutive days followed by a single dose of 3 MEDs on a small body area 24 hours later; group B, whole body irradiated with 120 J/m(2) solar-simulated radiation (10 consecutive days, then single-dose UV-B exposure of 3 MEDs on a small body area after 24 hours); group C, irradiated with a single UV-B dose of 3 MEDs on a small body area; and group D, irradiated with a single UV-B dose of 4 MEDs on a small body area.
  
  
  METHODS
  Apoptosis of peripheral blood mononuclear cells as well as expression of several apoptosis-regulating proteins in response to irradiation.
  
  
  RESULTS
  Ten daily whole-body suberythemal exposures to UV-B or solar-simulated radiation enhanced the apoptosis of peripheral blood mononuclear cells, while the single erythemal doses on the small body area, either on their own or following the repeated exposures, did not increase the level significantly. Increase in Bax and p73 protein expression and down-regulation of Mcl-1 and Bcl-2 correlated with enhanced apoptosis.
  
  
  CONCLUSIONS
  Repeated suberythemal UV exposures enhance the apoptosis of peripheral blood mononuclear cells in healthy subjects.
authors.affiliation: Department of Dermatology, Medical University of Lodz, Lodz, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Narbutt
authors.forename: Barbara
authors.initials: B
authors.lastname: Cebula
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Lesiak
authors.forename: Anna
authors.initials: A
authors.lastname: Sysa-Jedrzejowska
authors.forename: Mary
authors.initials: M
authors.lastname: Norval
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Robak
authors.forename: Piotr
authors.initials: P
authors.lastname: Smolewski
mesh_terms: D000328:Adult; D017209:Apoptosis / Q000528:radiation effects*; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D007111:Immunity, Cellular / Q000528:radiation effects; D020287:In Situ Nick-End Labeling; D007963:Leukocytes, Mononuclear / Q000502:physiology / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D011829:Radiation Dosage; D012867:Skin / Q000276:immunology / Q000473:pathology / Q000528:radiation effects*; D014466:Ultraviolet Rays; D014916:Whole-Body Irradiation; D055815:Young Adult
chemical_list: D051017:Apoptosis Regulatory Proteins