Repeated exposure of mouse dermal fibroblasts at a sub-cytotoxic dose of UVB leads to premature senescence: a robust model of cellular photoaging.
BACKGROUND
Photoaging skin is due to accumulative effect of UV irradiation that mainly imposes its damage on dermal fibroblasts. To mimic the specific cellular responses invoked by long term effect of UVB, it is preferable to develop a photo-damaged model in vitro based on repeated UVB exposure instead of a single exposure.


OBJECTIVE
To develop a photo-damaged model of fibroblasts by repeated UVB exposure allowing for investigation of molecular mechanism underlying premature senescence and testing of potential anti-photoaging compounds.


METHODS
Mouse dermal fibroblasts (MDFs) at early passages (passages 1-3) were exposed to a series of 4 sub-cytotoxic dose of UVB. The senescent phenotypes were detected at 24 or 48h after the last irradiation including cell viability, ROS generation, mitochondrial membrane potential, cell cycle, production and degradation of extracellular matrix.


RESULTS
Repeated exposure of UVB resulted in remarkable features of senescence. It effectively avoided the disadvantages of single dose such as induction of cell death rather than senescence, inadequate stress resulting in cellular self-rehabilitation.


CONCLUSIONS
Our work confirms the possibility of detecting cellular machinery that mediates UVB damage to fibroblasts in vitro by repeated exposure, while the potential molecular mechanisms including cell surface receptors, protein kinase signal transduction pathways, and transcription factors remain to be further evaluated.
Department of Plastic and Reconstructive Surgery, Hua Dong Hospital, Fu Dan University, Shanghai, China.
Ji-ping
JP
Zeng
Department of Laboratory Medicine, Hua Dong Hospital, Fu Dan University, Shanghai, China.
Bo
B
Bi
Department of Plastic and Reconstructive Surgery, Hua Dong Hospital, Fu Dan University, Shanghai, China.
Liang
L
Chen
Department of Plastic and Reconstructive Surgery, Hua Dong Hospital, Fu Dan University, Shanghai, China.
Ping
P
Yang
Department of Plastic and Reconstructive Surgery, Hua Dong Hospital, Fu Dan University, Shanghai, China.
Yu
Y
Guo
Department of Plastic and Reconstructive Surgery, Hua Dong Hospital, Fu Dan University, Shanghai, China.
Yi-qun
YQ
Zhou
Department of Plastic and Reconstructive Surgery, Hua Dong Hospital, Fu Dan University, Shanghai, China. Electronic address: tianyiliucn@126.com.
Tian-yi
TY
Liu
D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D059447:Cell Cycle Checkpoints / Q000528:radiation effects; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D016922:Cellular Senescence / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D005109:Extracellular Matrix / Q000378:metabolism; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051379:Mice; D010641:Phenotype; D017382:Reactive Oxygen Species / Q000378:metabolism; D012867:Skin / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D015595:Skin Aging / Q000528:radiation effects*; D013997:Time Factors; D014466:Ultraviolet Rays
D017382:Reactive Oxygen Species
Dermal fibroblast; Photoaging; Stress-induced premature senescence (SIPS); UVB