Extracellular signal-regulated kinases 1/2 and Akt contribute to triclosan-stimulated proliferation of JB6 Cl 41-5a cells
- 451 Downloads
Triclosan is a broad spectrum anti-bacterial agent widely used in many personal care products, household items, medical devices, and clinical settings. Human exposure to triclosan is mainly through oral and dermal routes. In previous studies, we found that sub-chronic dermal exposure of B6C3F1 mice to triclosan induced epidermal hyperplasia and focal necrosis; however, the mechanisms for these responses remain elusive. In this study, using mouse epidermis-derived JB6 Cl 41-5a cells, we found that triclosan stimulated cell growth in a concentration- and time-dependent manner. Enhanced cell proliferation was demonstrated by a substantial increase in the percentage of BrdU-positive cells, an elevation in the protein levels of cyclin D1 and cyclin A, and a reduction in the protein level of p27Kip1. Western blotting analysis revealed that triclosan induced the activation of extracellular signal-regulated kinases 1/2 (ERK1/2), c-Jun N-terminal kinases (JNK), p38, and Akt. Pre-treatment of the cells with PD184352, an inhibitor of the upstream kinase MEK1/2, or with wortmannin, an inhibitor of phosphoinositide 3-kinase, blocked triclosan-mediated phosphorylation of ERK1/2 and Akt, respectively, and substantially suppressed triclosan-stimulated cell proliferation, whereas the JNK inhibitor SP600125 or the p38 inhibitor SB203580 had little to no effect on triclosan-stimulated cell proliferation. The phosphorylation activation of ERK1/2 and Akt was further confirmed on the skin of mice dermally administered triclosan. These data suggest that the activation of ERK1/2 and Akt is involved in triclosan-stimulated proliferation of JB6 Cl 41-5a cells.
KeywordsTriclosan JB6 cells Cell proliferation Extracellular signal-regulated kinases 1/2 Akt
Yuanfeng Wu and Si Chen were supported by an appointment to the Postgraduate Research in the Division of Biochemical Toxicology at the National Center for Toxicological Research administered by Oak Ridge Institute for Science Education through an interagency agreement between the U.S. Department of Energy and the U.S. FDA. This research was supported through an interagency agreement between the National Center for Toxicological Research, U.S. Food and Drug Administration (FDA) and the National Toxicology Program, National Institute of Environmental Health Sciences. (FDA IAG: 224-07-0007; NIH Y1ES1027).
Conflict of interest
The authors declare that there are no conflict of interests.
- Canesi L, Ciacci C, Lorusso LC et al (2007) Effects of Triclosan on Mytilus galloprovincialis hemocyte function and digestive gland enzyme activities: possible modes of action on non target organisms. Comp Biochem Physiol C: Toxicol Pharmacol 145(3):464–472. doi: 10.1016/j.cbpc.2007.02.002 Google Scholar
- DeSalva SJ, Kong BM, Lin YJ (1989) Triclosan: a safety profile. Am J Dent 2 Spec no 185–196Google Scholar
- Gotz C, Pfeiffer R, Tigges J et al (2012a) Xenobiotic metabolism capacities of human skin in comparison with a 3D epidermis model and keratinocyte-based cell culture as in vitro alternatives for chemical testing: activating enzymes (phase I). Exp Dermatol 21(5):358–363. doi: 10.1111/j.1600-0625.2012.01486.x PubMedCrossRefGoogle Scholar
- Gotz C, Pfeiffer R, Tigges J et al (2012b) Xenobiotic metabolism capacities of human skin in comparison with a 3D-epidermis model and keratinocyte-based cell culture as in vitro alternatives for chemical testing: phase II enzymes. Exp Dermatol 21(5):364–369. doi: 10.1111/j.1600-0625.2012.01478.x PubMedCrossRefGoogle Scholar
- Kumar R, Alam S, Chaudhari BP, et al. (2013) Ochratoxin A-induced cell proliferation and tumor promotion in mouse skin by activating the expression of cyclin-D1 and cyclooxygenase-2 through nuclear factor-kappa B and activator protein-1. Carcinogenesis 34(3):647–657. doi: 10.1093/carcin/bgs368 PubMedCrossRefGoogle Scholar
- Morrison DK (2012) MAP kinase pathways. Cold Spring Harb Perspect Biol 4(11) doi: 10.1101/cshperspect.a011254
- Netzlaff F, Lehr CM, Wertz PW, Schaefer UF (2005) The human epidermis models EpiSkin, SkinEthic and EpiDerm: an evaluation of morphology and their suitability for testing phototoxicity, irritancy, corrosivity, and substance transport. Eur J Pharm Biopharm Off J Arbeitsgemeinschaft fur Pharmazeutische Verfahrenstechnik eV 60(2):167–178. doi: 10.1016/j.ejpb.2005.03.004 Google Scholar
- Nguyen TT, Scimeca JC, Filloux C, Peraldi P, Carpentier JL, Van Obberghen E (1993) Co-regulation of the mitogen-activated protein kinase, extracellular signal-regulated kinase 1, and the 90-kDa ribosomal S6 kinase in PC12 cells. Distinct effects of the neurotrophic factor, nerve growth factor, and the mitogenic factor, epidermal growth factor. J Biol Chem 268(13):9803–9810PubMedGoogle Scholar
- Sun H, Lesche R, Li DM et al (1999) PTEN modulates cell cycle progression and cell survival by regulating phosphatidylinositol 3,4,5,-trisphosphate and Akt/protein kinase B signaling pathway. Proc Natl Acad Sci USA 96(11):6199–6204. doi: 10.1073/pnas.96.11.6199 PubMedCentralPubMedCrossRefGoogle Scholar
- Trimmer GW, Hostetler KA, Phillips RD, et al (1994) 90-Day subchronic dermal toxicity study in the rat with satellite group with Irgasan DP300 (MRD-92-399). FDA Docket 1975N-0183H, OTC volume number 116Google Scholar
- Vanlandingham MM, Fang JL, Beland FA, et al (2013) 13-week dermal toxicity of triclosan in B6C3F1 mice. The toxicologist, SOT 2013 annual meeting, p 223Google Scholar