Synergistic Inhibition of Tumor Necrosis Factor-Alpha-Stimulated Pro-Inflammatory Cytokine Expression in HaCaT Cells by a Combination of Rapamycin and Mycophenolic Acid

• Published in: Annals of dermatology Vol. 27; no. 1; pp. 32 - 39
• Main Authors: Min Young Kim, Yun Young Lim, Hyeong Mi Kim, Young Min Park, Hoon Kang, Beom Joon Kim
• Format: Journal Article
• Language: Korean
• Published: 대한피부과학회 28.02.2015
• Subjects: Anti-inflammation; Mycophenolic acid; Sirolimus; Tumor necrosis factor-alpha
• ISSN: 1013-9087; 2005-3894

Background: Keratinocytes release various pro-inflammatorycytokines, chemokines, and adhesion molecules such asintercellular adhesion molecule 1 (ICAM-1) in response tocytokines such as tumor necrosis factor (TNF)-α and interferon(IFN)-γ. Rapamycin and mycophenolic acid (MPA)have potent immunosuppressive activity because theyinhibit lymphocyte proliferation. Objective: We investigated the effects of rapamycin andMPA on the expression of inflammation-related factors suchas ICAM-1 and inducible nitric oxide synthase (iNOS),pro-inflammatory cytokines and chemokines, and relatedsignaling pathways in TNF-α-stimulated HaCaT cells. Methods: The viability of HaCaT cells treated with rapamycinand MPA was confirmed using MTT assay. The expressionof various cytokines such as interleukin (IL)-1β, IL-6,and IL-8; inflammation-related factors such as ICAM-1 andiNOS; and the activation of mitogen activated protein kinase(MAPK) signaling pathways mediated by extracellular signal-related kinases (ERK), p38, and c-Jun N-terminal kinases(JNK) in TNF-α-stimulated HaCaT cells were confirmedusing reverse transcription-polymerase chain reaction andwestern blotting. Results: Combined treatment of TNF-α-induced HaCaTcells with rapamycin and MPA decreased ICAM-1 and iNOSexpression and ERK and p38 activation more than treatmentwith either drug alone. The most significant decrease wasobserved with a combination of rapamycin (80 nM) and MPA(20 nM). These results show that co-treatment with theseagents has a synergistic anti-inflammatory effect by blockingthe activation of the ERK/p38 MAPK signaling pathway andthus suppressing the TNF-α-induced expression of ICAM-1and iNOS. Conclusion: The combination of rapamycin and MPA couldpotentially be used as a therapeutic approach in inflammatoryskin diseases. (Ann Dermatol 27(1) 32∼39, 2015)