Silk sericin protein of tropical tasar silkworm inhibits UVB-induced apoptosis in human skin keratinocytes
- 993 Downloads
The silk protein sericin has been identified as a potent antioxidant and photoprotective agent against ultraviolet B (UVB) irradiation in mouse skin model. In this study, we have investigated the anti-apoptotic effect of sericin in UVB (30 mJ/cm2)-irradiated human keratinocytes. Flow cytometry analysis has shown that pre-treatment with sericin inhibits UVB-induced apoptosis. The pre-treatment with sericin suppresses bax expression, up-regulates the expression of bcl-2, prevents both the activation of caspase-3 and cleavage of Poly (ADP-ribose) polymerase. Generation of intracellular hydrogen peroxide in UVB-treated keratinocytes is inhibited through pre-treatment with sericin suggesting that sericin probably prevents mitochondrial damage.
KeywordsSericin Keratinocytes UVB H2O2
Reactive oxygen species
Thiazolyl tetrazolium compound
- DHR 123
Poly (ADP-ribose) polymerase
The authors express gratitude to Dr. Gautam Banerjee, Hindustan Lever Limited, India, for his constant support for preparation of the manuscript. This work was financially supported by the Department of Science and Technology, Department of Biotechnology, Council for Scientific and Industrial Research, New Delhi. We are thankful to Directorate of Sericulture, Midnapore District, West Bengal State, and Central Silk Board, Bangiriposi, Orissa State, for providing the silk cocoons. R.D. also wishes to thank CSIR for fellowship.
- 3.De Gruijl FR, Sterenborg HJ, Forbes PD, Davies RE, Cole C, Kelfkens G, van Weelden H, Slaper H, van der Leun JC (1995) Wavelength dependence of skin cancer induction by ultraviolet irradiation of albino hairless mice. Cancer Res 53:53–60Google Scholar
- 9.Jolly MS, Sen S, Ahsen MM (1974) Tasar culture. Ambika Publishers, Bombay, p 25Google Scholar
- 11.Kaplan D, Adams WW, Farmer B, Viney C (1994) Silk polymers: materials science and biotechnology. Wiley Publishers, New YorkGoogle Scholar
- 23.Mandal M, Younes M, Swan E, Samar A, Jasser A, Doan D, Yigitbasi O, McMurphey A, Ludwick J, El-Naggar AK, Bucana C, Mills GB, Myers JN (2006) The Akt inhibitor KP372-1 inhibits proliferation and induces apoptosis and anoikis in squamous cell carcinoma of the head and neck. Oral Oncol 42:430–439PubMedCrossRefGoogle Scholar
- 30.Van Laethem A, Van Kelst S, Lippens S, Declercq W, Vandenabeele P, Janssens S, Vandenheede JR, Garmyn M, Agostinis P (2004) Activation of p38 MAPK is required for Bax translocation to mitochondria, cytochrome c release and apoptosis induced by UVB irradiation in human keratinocytes. FASEB J 18:1946–1948PubMedGoogle Scholar