A drug-induced accelerated senescence (DIAS) is a possibility to study aging in time lapse.
Currently, the oxidative stress (or free radical) theory of aging is the most popular explanation of how aging occurs at the molecular level. Accordingly, a stress-induced senescence-like phenotype of human dermal fibroblasts can be induced in vitro by the exposure of human diploid fibroblasts to subcytotoxic concentrations of hydrogen peroxide. However, several biomarkers of replicative senescence e.g. cell cycle arrest and enlarged morphology are abrogated 14 days after treatment, indicating that reactive oxygen species (ROS) rather acts as a trigger for short-term senescence (1-3 days) than being responsible for the maintenance of the senescence-like phenotype. Further, DNA-damaging factors are discussed resulting in a permanent senescent cell type. To induce long-term premature senescence and to understand the molecular alterations occurring during the aging process, we analyzed mitomycin C (MMC) as an alkylating DNA-damaging agent and ROS producer. Human dermal fibroblasts (HDF), used as model for skin aging, were exposed to non-cytotoxic concentrations of MMC and analyzed for potential markers of cellular aging, for example enlarged morphology, activity of senescence-associated-ß-galactosidase, cell cycle arrest, increased ROS production and MMP1-activity, which are well-documented for HDF in replicative senescence. Our data show that mitomycin C treatment results in a drug-induced accelerated senescence (DIAS) with long-term expression of senescence markers, demonstrating that a combination of different susceptibility factors, here ROS and DNA alkylation, are necessary to induce a permanent senescent cell type.
Institute of Biochemistry & Molecular Biology I, Medical Faculty, Heinrich-Heine-University, Düsseldorf, Germany, lirija.alili@web.de.
Lirija
L
Alili
Johanna
J
Diekmann
Melanie
M
Giesen
Olaf
O
Holtkötter
Peter
P
Brenneisen
D015153:Blotting, Western; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000187:drug effects* / Q000235:genetics; D002675:Child, Preschool; D004249:DNA Damage / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D016685:Mitomycin / Q000009:adverse effects / Q000494:pharmacology*; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D013997:Time Factors
D017382:Reactive Oxygen Species; D016685:Mitomycin