title: Increased IL-17 expression in degenerated human discs and increased production in cultured annulus cells exposed to IL-1ß and TNF-α.
abstract: IL-17 is expressed in a number of tissues including the intervertebral disc, where it exerts strong inflammatory properties. We evaluated IL-17 using immunolocalization in herniated and non-herniated human discs, IL-17 gene expression, and the production of IL-17 by annulus cells cultured in three dimensions in the presence of IL-1ß or TNF-α. There was no difference in the percentage of IL-17 positive cells in annulus or nucleus in herniated vs. non-herniated disc specimens. Molecular studies confirmed expression of IL-17 in disc tissue, with significantly increased expression in more degenerated discs; there was no difference in expression between herniated vs. non-herniated discs. Exposure to IL-1ß or TNF-α resulted in significantly greater production of IL-17. Our findings expand understanding of IL-17 production by disc cells and reveal the importance of non-canonical IL-17 production in the disc. Significantly greater expression of IL-17 in more degenerated discs adds to our understanding of the changes in disc cell function with advancing stages of disc degeneration.
authors.affiliation: Department of Orthopaedic Surgery, Carolinas Medical Center, P.O. Box 32861, Charlotte, NC 28232, USA. helen.gruber@carolinashealthcare.org
authors.forename: H E
authors.initials: HE
authors.lastname: Gruber
authors.forename: G L
authors.initials: GL
authors.lastname: Hoelscher
authors.forename: J A
authors.initials: JA
authors.lastname: Ingram
authors.forename: H J
authors.initials: HJ
authors.lastname: Norton
authors.forename: E N
authors.initials: EN
authors.lastname: Hanley
mesh_terms: D000328:Adult; D000368:Aged; D002478:Cells, Cultured; D005786:Gene Expression Regulation / Q000187:drug effects*; D006801:Humans; D007150:Immunohistochemistry; D007231:Infant, Newborn; D020381:Interleukin-17 / Q000235:genetics* / Q000378:metabolism*; D053583:Interleukin-1beta / Q000494:pharmacology*; D007403:Intervertebral Disc / Q000473:pathology; D055959:Intervertebral Disc Degeneration / Q000503:physiopathology*; D046228:Microarray Analysis; D008875:Middle Aged; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D020381:Interleukin-17; D053583:Interleukin-1beta; D014409:Tumor Necrosis Factor-alpha