Biphasic pro-melanogenic and pro-apoptotic effects of all-trans-retinoic acid (ATRA) on human melanocytes: time-course study
| Autor: | Maria Rodica Cosgarea, Gertrude-Emilia Costin, Elena Diana Olteanu, David A. Norris, Ioana Baldea, Adriana Filip, Stanca A. Birlea, Yiqun G. Shellman, Katerina Kechris |
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| Rok vydání: | 2012 |
| Předmět: |
Adult
Time Factors Cell Survival Tyrosinase Administration Topical Retinoic acid Apoptosis Tretinoin Dermatology Biology Pharmacology Biochemistry Antioxidants Melanin Superoxide dismutase Histones chemistry.chemical_compound Young Adult Annexin Humans Microscopy Phase-Contrast Annexin A5 Cytotoxicity Molecular Biology Cells Cultured Cell Proliferation Melanins Cell growth Monophenol Monooxygenase Superoxide Dismutase Catalase Phenotype chemistry Spectrophotometry biology.protein Melanocytes |
| Zdroj: | Journal of dermatological science. 72(2) |
| ISSN: | 1873-569X |
| Popis: | Background The effects of retinoids on melanogenesis and their mechanism as depigmenting agents in topical therapy have not been fully elucidated. Conflicting data about their impact on melanogenic pathways have been reported. Objective To investigate the effects of all-trans-retinoic acid (ATRA) on normal human melanocytes from Caucasian subjects. Methods We assessed ATRA's cytotoxicity by measuring viability with a cell proliferation assay, and apoptotic effects using Annexin V and γ-H 2 AX markers. ATRA's melanogenic activity was investigated based on spectrophotometric measurement of melanin content and tyrosinase enzymatic activity. Tyrosinase expression was assessed by Western blotting. We tested the antioxidant activity of superoxide dismutase (SOD) and catalase (CAT) in melanocytes using a spectrophotometric assay. Results Of the concentrations tested in this 72h time-course study, the 1.0μM ATRA had a well-defined two-stage pro-melanogenic and pro-apoptotic effect on melanocytes. In the first 6h, treated cells showed significant increase ( p ≤0.01) of melanin content, tyrosinase, SOD, and CAT activities compared to the controls. While overall tyrosinase expression was not affected by ATRA, all other tested parameters decreased progressively beyond the short-term point of 6h. ATRA treatment of over 6h induced melanocyte apoptosis, as shown by the time-dependent decrease in cell viability, coupled with significant increase in Annexin V positive cells and nuclear accumulation of γ-H 2 AX foci. Conclusion The results obtained using this testing platform show a biphasic ATRA action: immediate pro-melanogenic effect and longer-term exposure pro-apoptotic activity. These data qualify ATRA as a potent tool to better understand the mechanisms that regulate the pigmentary system. |
| Databáze: | OpenAIRE |
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