UVB-induced premature senescence of human diploid skin fibroblasts.
In this work, we show that repeated stresses with UVB (290-320 nm) induce stress-induced premature senescence (SIPS) of skin human diploid fibroblasts (HDFs). HDFs at early cumulative population doublings were exposed three or five times to increasing subcytotoxic doses of UVB with one stress per day. After 2 days of recovery, several biomarkers of replicative senescence were established. First, there was an increase in the proportion of cells positive for senescence-associated beta-galactosidase activity. Second, there was a loss of replicative potential as assessed by a very low level of [3H]-thymidine incorporation. Third, the steady-state level of the mRNA of three senescence-associated genes, i.e. fibronectin, osteonectin and SM22, was increased in HDFs at 72 h after three and five exposures to UVB. In conclusion, these results suggest that it is possible to induce SIPS in HDFs after repeated exposures to subcytotoxic doses of UVB. This model could be used to test whether HDFs in UVB-induced premature senescence are able to promote epithelial cell growth and tumorigenesis in skin, as shown recently with HDFs in H(2)O(2)-induced premature senescence.
Laboratory of Cellular Biochemistry and Biology, Department of Biology, University of Namur (FUNDP), Rue de Bruxelles 61, B-5000, Namur, Belgium.
Florence
F
Chainiaux
Joao-Pedro
JP
Magalhaes
François
F
Eliaers
José
J
Remacle
Olivier
O
Toussaint
D002460:Cell Line; D016922:Cellular Senescence / Q000528:radiation effects*; D004171:Diploidy; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism / Q000528:radiation effects*; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000528:radiation effects; D006801:Humans; D008840:Microfilament Proteins / Q000235:genetics / Q000378:metabolism; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D015676:Osteonectin / Q000235:genetics / Q000378:metabolism; D012867:Skin / Q000166:cytology / Q000528:radiation effects*; D014466:Ultraviolet Rays / Q000009:adverse effects*; D001616:beta-Galactosidase / Q000378:metabolism
D005353:Fibronectins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D015676:Osteonectin; C058992:Tagln protein, mouse; C051615:transgelin; D001616:beta-Galactosidase