title: Simvastatin inhibits IL-17 secretion by targeting multiple IL-17-regulatory cytokines and by inhibiting the expression of IL-17 transcription factor RORC in CD4+ lymphocytes.
abstract: Statins, extensively used as cholesterol-lowering agents, have recently been identified as immunomodulatory agents. This study investigated the statins' mechanisms that target the autoimmune response in humans, and evaluated their therapeutic potential in multiple sclerosis. Our results demonstrated statin-mediated increases in suppressor of cytokine secretion (SOCS) 3 and suppressor of cytokine secretion 7, which negatively regulate the STAT/JAK signal transduction pathway and IL-6 and IL-23 gene expression in monocytes. Simvastatin also induced IFN-gamma, IL-4, and IL-27 production in monocytes, which together inhibited IL-17 transcription and secretion in CD4(+) T cells. IL-17-producing CD4(+) cells, referred to as Th17 cells, have recently been found to play a central role in the development of autoimmune diseases. Furthermore, simvastatin directly inhibited the expression of retinoic acid-related orphan nuclear hormone receptor C, a transcription factor that controls IL-17 production in CD4(+) T cells. This effect was reversed by mevalonic acid, a downstream metabolite of 3-hydroxy-3-methylglutaryl CoA reductase, confirming that simvastatin's specific effect is through the inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase. These results provide evidence for the novel immunomodulatory mechanisms of statins, which selectively target the regulation of cytokine transcription involved in the development of the human autoimmune response. Based on the described immunomodulatory mechanisms, good safety profile and oral bioavailability, statins represent a promising therapeutic approach for multiple sclerosis and other chronic inflammatory diseases.
authors.affiliation: Department of Neurology, University of North Carolina, Chapel Hill, NC 27599, USA.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Jianping
authors.initials: J
authors.lastname: Jin
authors.forename: Xueyan
authors.initials: X
authors.lastname: Peng
authors.forename: Vinod S
authors.initials: VS
authors.lastname: Ramgolam
authors.forename: Silva
authors.initials: S
authors.lastname: Markovic-Plese
mesh_terms: D015153:Blotting, Western; D015496:CD4-Positive T-Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D016207:Cytokines / Q000187:drug effects / Q000378:metabolism; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D007155:Immunologic Factors / Q000494:pharmacology*; D020381:Interleukin-17 / Q000378:metabolism*; D008297:Male; D009000:Monocytes / Q000187:drug effects; D009103:Multiple Sclerosis / Q000235:genetics; D009687:Nuclear Proteins / Q000096:biosynthesis / Q000187:drug effects; D020411:Oligonucleotide Array Sequence Analysis; D018160:Receptors, Cytoplasmic and Nuclear / Q000096:biosynthesis / Q000187:drug effects*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019821:Simvastatin / Q000494:pharmacology*; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins / Q000096:biosynthesis / Q000187:drug effects; D016176:T-Lymphocyte Subsets / Q000187:drug effects / Q000276:immunology / Q000378:metabolism
chemical_list: D016207:Cytokines; D007155:Immunologic Factors; D020381:Interleukin-17; D009687:Nuclear Proteins; D018160:Receptors, Cytoplasmic and Nuclear; C106644:SOCS3 protein, human; C108775:SOCS7 protein, human; D000071223:Suppressor of Cytokine Signaling 3 Protein; D050826:Suppressor of Cytokine Signaling Proteins; D019821:Simvastatin