Abstract
Microbial product lipopolysaccharide has been shown to be involved in the pathogenesis of inflammatory skin diseases. Apocynin has demonstrated to have an anti-inflammatory effect. However, the effect of apocynin on the Toll-like receptor-4-dependent activation of Akt, mammalian target of rapamycin (mTOR), and nuclear factor (NF)-κB pathway, which is involved in productions of inflammatory mediators in keratinocytes, has not been studied. Using human keratinocytes, we investigated the effect of apocynin on the inflammatory mediator production in relation to the Toll-like receptor-4-mediated-Akt/mTOR and NF-κB pathways, which regulates the transcription genes involved in immune and inflammatory responses. Apocynin, Akt inhibitor SH-5, Bay 11-7085 and N-acetylcysteine each attenuated the lipopolysaccharide-induced production of cytokines, PGE2, and chemokines, changes in the levels of Toll-like receptor-4, p-Akt, mTOR, and NF-κB, and production of reactive oxygen species in keratinocytes. The results show that apocynin appears to attenuate the lipopolysaccharide-stimulated production of inflammatory mediators in keratinocytes by suppressing the Toll-like receptor-4-mediated activation of the Akt, mTOR, and NF-κB pathways. The effect of apocynin appears to be attributed to its inhibitory effect on the production of reactive oxygen species. Apocynin appears to attenuate the microbial product-mediated inflammatory skin diseases.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Baker BS (2006) The role of microorganisms in atopic dermatitis. Clin Exp Immunol 144:1–9
Bruinenberg PM, van Dijken JP, Scheffers WA (1983) An enzymic analysis of NADPH production and consumption in Candida utilis. J Gen Microbiol 129:965–971
Chi PL, Chen YW, Hsiao LD, Chen YL, Yang CM (2012) Hemeoxygenase 1 attenuates interleukin-1β-induced cytosolic phospholipase A2 expression via a decrease in NADPH oxidase/reactive oxygen species/activator protein 1 activation in rheumatoid arthritis synovial fibroblasts. Arthritis Rheum 64:2114–2125
de Oliveira AC, Yousif NM, Bhatia HS, Hermanek J, Huell M, Fiebich BL (2016) Poly(I:C) increases the expression of mPGES-1 and COX-2 in rat primary microglia. J Neuroinflammation 13:11
Fu W, Luo H, Parthasarathy S, Mattson MP (1998) Catecholamines potentiate amyloid β-peptide neurotoxicity: involvement of oxidative stress, mitochondrial dysfunction, and perturbed calcium homeostasis. Neurobiol Dis 5:229–243
Ge Y, Xu Y, Sun W, Man Z, Zhu L, Xia X, Zhao L, Zhao Y, Wang X (2012) The molecular mechanisms of the effect of dexamethasone and cyclosporin a on TLR4 /NF-κB signaling pathway activation in oral lichen planus. Gene 508:157–164
Ghosh S, Hayden MS (2008) New regulators of NF-κB in inflammation. Nat Rev Immunol 8:837–848
Gloire G, Legrand-Poels S, Piette J (2006) NF-κB activation by reactive oxygen species: fifteen years later. Biochem Pharmacol 72:1493–1505
Islam SA, Luster AD (2012) T cell homing to epithelial barriers in allergic disease. Nat Med 18:705–715
Kilic T, Parlakpinar H, Taslidere E, Yildiz S, Polat A, Vardi N, Colak C, Ermis H (2015) Protective and therapeutic effect of apocynin on bleomycin-induced lung fibrosis in rats. Inflammation 38:1166–1180
Kim JE, Kim BJ, Jeong MS, Seo SJ, Kim MN, Hong CK, Ro BI (2005) Expression and modulation of LL-37 in normal human keratinocytes, HaCaT cells and inflammatory skin diseases. J Korean Med Sci 20:649–654
Lee SA, Park SH, Kim BC (2008) Raloxifene, a selective estrogen receptor modulator, inhibits lipopolysaccharide-induced nitric oxide production by inhibiting the phosphatidylinositol 3-kinase/Akt/NF-κ B pathway in RAW264.7 macrophage cells. Mol Cells 26:48–52
Lee CS, Jang ER, Kim YJ, Lee MS, Seo SJ, Lee MW (2010) Hirsutenone inhibits lipopolysaccharide-activated NF-κB-induced inflammatory mediator production by suppressing toll-like receptor 4 and ERK activation. Int Immunopharmacol 10:520–525
Liu L, Cui J, Yang Q, Jia C, Xiong M, Ning B, Du X, Wang P, Yu X, Li L, Wang W, Chen Y, Zhang T (2014) Apocynin attenuates isoproterenol-induced myocardial injury and fibrogenesis. Biochem Biophys Res Commun 449:55–61
Morris MC, Gilliam EA, Li L (2015) Innate immune programing by endotoxin and its pathological consequences. Front Immunol 5:680
Mosmann T (1983) Rapid colorimetric assay for cellular growth and survival: application to proliferation and cytotoxicity assays. J Immunol Methods 65:55–63
Mouzaoui S, Djerdjouri B, Makhezer N, Kroviarski Y, El-Benna J, Dang PM (2014) Tumor necrosis factor-α-induced colitis increases NADPH oxidase 1 expression, oxidative stress, and neutrophil recruitment in the colon: preventive effect of apocynin. Mediat Inflamm 2014:312484
Napetschnig J, Wu H (2013) Molecular basis of NF-κB signaling. Annu Rev Biophys 42:443–468
Ngkelo A, Meja K, Yeadon M, Adcock I, Kirkham PA (2012) LPS induced inflammatory responses in human peripheral blood mononuclear cells is mediated through NOX4 and Giα dependent PI-3kinase signalling. J Inflamm (Lond) 9:1
Niebuhr M, Baumert K, Werfel T (2010) TLR-2-mediated cytokine and chemokine secretion in human keratinocytes. Exp Dermatol 19:873–877
Pastore S, Mascia F, Girolomoni G (2006) The contribution of keratinocytes to the pathogenesis of atopic dermatitis. Eur J Dermatol 16:125–131
Pi Y, Zhang LL, Li BH, Guo L, Cao XJ, Gao CY, Li JC (2013) Inhibition of reactive oxygen species generation attenuates TLR4-mediated proinflammatory and proliferative phenotype of vascular smooth muscle cells. Lab Investig 93:880–887
Rebholz B, Haase I, Eckelt B, Paxian S, Flaig MJ, Ghoreschi K, Nedospasov SA, Mailhammer R, Debey-Pascher S, Schultze JL, Weindl G, Förster I, Huss R, Stratis A, Ruzicka T, Röcken M, Pfeffer K, Schmid RM, Rupec RA (2007) Crosstalk between keratinocytes and adaptive immune cells in an IκBα protein-mediated inflammatory disease of the skin. Immunity 27:296–307
Sanchez A, Tripathy D, Yin X, Luo J, Martinez JM, Grammas P (2013) Sunitinib enhances neuronal survival in vitro via NF-κB-mediated signaling and expression of cyclooxygenase-2 and inducible nitric oxide synthase. J Neuroinflammation 10:93
Schaerli P, Moser B (2005) Chemokines: control of primary and memory T-cell traffic. Immunol Res 31:57–74
Schreiber E, Matthias P, Müller MM, Schaffner W (1989) Rapid detection of octamer binding proteins with 'mini-extracts', prepared from a small number of cells. Nucleic Acids Res 17:6419
Siomek A (2012) NF-κB signaling pathway and free radical impact. Acta Biochim Pol 59:323–331
Slomiany BL1, Slomiany A (2010) Ghrelin protection against lipopolysaccharide-induced gastric mucosal cell apoptosis involves constitutive nitric oxide synthase-mediated caspase-3 S-nitrosylation. Mediat Inflamm 2010:280464
Song PI, Park YM, Abraham T, Harten B, Zivony A, Neparidze N, Armstrong CA, Ansel JC (2002) Human keratinocytes express functional CD14 and toll-like receptor 4. J Invest Dermatol 119:424–432
Takeda K, Akira S (2005) Toll-like receptors in innate immunity. Int Immunol 17:1–14
Thomson AW, Turnquist HR, Raimondi G (2009) Immunoregulatory functions of mTOR inhibition. Nat Rev Immunol 9:324–337
Tsuruta D (2009) NF-κB links keratinocytes and lymphocytes in the pathogenesis of psoriasis. Recent Patents Inflamm Allergy Drug Discov 3:40–48
Vestergaard C, Johansen C, Otkjaer K, Deleuran M, Iversen L (2005) Tumor necrosis factor-alpha-induced CTACK/CCL27 (cutaneous T cell-attracting chemokine) production in keratinocytes is controlled by nuclear factor κB. Cytokine 29:49–55
Viačková D, Pekarová M, Crhák T, Búcsaiová M, Matiašovic J, Lojek A, Kubala L (2011) Redox-sensitive regulation of macrophage-inducible nitric oxide synthase expression in vitro does not correlate with the failure of apocynin to prevent lung inflammation induced by endotoxin. Immunobiology 216:457–465
Wei M, Li Z, Xiao L, Yang Z (2015) Effects of ROS-relative NF-κB signaling on high glucose-induced TLR4 and MCP-1 expression in podocyte injury. Mol Immunol 68:261–271
Young CN, Koepke JI, Terlecky LJ, Borkin MS, Boyd SL, Terlecky SR (2008) Reactive oxygen species in tumor necrosis factor-α-activated primary human keratinocytes: implications for psoriasis and inflammatory skin disease. J Invest Dermatol 128:2606–2614
Zheng S, Zhong ZM, Qin S, Chen GX, Wu Q, Zeng JH, Ye WB, Li W, Yuan K, Yao L, Chen JT (2013) Advanced oxidation protein products induce inflammatory response in fibroblast-like synoviocytes through NADPH oxidase -dependent activation of NF-κB. Cell Physiol Biochem 32:972–985
Zhong LM, Zong Y, Sun L, Guo JZ, Zhang W, He Y, Song R, Wang WM, Xiao CJ, Lu D (2012) Resveratrol inhibits inflammatory responses via the mammalian target of rapamycin signaling pathway in cultured LPS-stimulated microglial cells. PLoS One 7:e32195
Acknowledgments
This research was supported by the Chung-Ang University Research Scholarship Grants in 2016, Chung-Ang University, Seoul, South Korea.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Nam, Y.J., Kim, A., Sohn, D.S. et al. Apocynin inhibits Toll-like receptor-4-mediated activation of NF-κB by suppressing the Akt and mTOR pathways. Naunyn-Schmiedeberg's Arch Pharmacol 389, 1267–1277 (2016). https://doi.org/10.1007/s00210-016-1288-5
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00210-016-1288-5