Chinese Journal of Dermatology ›› 2010, Vol. 43 ›› Issue (10): 726-729.

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Changes of molecular markers in cultured skin stem cells exposed to ultraviolet B (UVB) in vitro

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  • Received:2010-02-05 Revised:2010-03-30 Online:2010-10-15 Published:2010-10-09

Abstract:

Objective To investigate the changes of molecular markers in cultured skin stem cells exposed to UVB in vitro. Methods Skin stem cells were isolated and cultured according to their adherasion ability, and identified by immunohistochemistry using anti-K15 and anti-β-integrin antibodies. Then, a part of the skin stem cells were irradiated with UVB at 10 mJ/cm2 for 2 times. After 24-hour additional culture, the expressions of CD34, beta-catenin and p53 were detected with immunohistochemistry. Results Skin stem cells showed a high density in culture free of irradiation, which were round or polygon with a clear shape, well-distributed cytoplasm, high N/C ratio; mitotic cells could be seen. In unirradiated skin stem cells, beta-catenin was expressed predominantly in cell membrane and cytoplasm, with a positive expression rate of 64.74% and 8.4% in membrane and cytoplasm respectively; p53 was expressed mainly in cell cytoplasm and nuclei, with a positive expression rate of 6.9% in cell nuclei. After exposure to UVB, skin stem cells decreased in cell density and N/C ratios with a deformed and anomalous shape, vacuoles were present in cytoplasm, and some cells experienced karyopyknosis or apoptosis. Additionally, in irradiated cells, beta-catenin was expressed predominantly in cytoplasm with a positive expression rate of 64.74% and 0 in cytoplasm and nuclei, respectively; p53 was expressed mainly in nuclei with a positive expression rate of 100%. CD34 was detected in neither unirradiated nor irradiated skin stem cells. Conclusion UVB can promote beta-catenin to accumulate in cytoplasm as well as beta-catenin and p53 to migrate from cytoplasm to nuclei.

Key words: Skin stem cells,UVB , beta-Catenin , P53