title: Syndecan-4 in intervertebral disc and cartilage: Saint or synner?
abstract: The ECM of the intervertebral disc and articular cartilage contains a highly organised network of collagens and proteoglycans which resist compressive forces applied to these tissues. A pathological hallmark of the intervertebral disc is the imbalance between production of anabolic and catabolic factors by the resident cells. This process is thought to be mediated by pro-inflammatory cytokines, predominantly TNF-α and IL-1β, which upregulate expression of matrix degrading enzymes such as MMPs and ADAMTSs. This imbalance ultimately results in tissue degeneration causing failure of the biomechanical function of the tissues. A similar cascade of events is thought to occur in articular cartilage during development of osteoarthritis. Within these skeletal tissues a small, cell surface heparan sulphate proteoglycan; syndecan-4 (SDC4) has been implicated in maintaining physiological functions. However in the degenerating niche of the intervertebral disc and cartilage, dysregulated activities of this molecule may exacerbate pathological changes. Studies in recent years have elucidated a role for SDC4 in mediating matrix degradation in both intervertebral discs and cartilage by controlling ADAMTS-5 function and MMP3 expression. Discourse presented in this review highlights the potential of SDC4 as a possible therapeutic target in slowing the progression of ECM degradation in both degenerative disc disease and osteoarthritis.
authors.affiliation: Department of Orthopaedic Surgery, Sidney Kimmel Medical College and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, USA. Electronic address: Abbie.Binch@Jefferson.edu.
authors.forename: Abbie L A
authors.initials: ALA
authors.lastname: Binch
authors.affiliation: Department of Orthopaedic Surgery, Sidney Kimmel Medical College and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, USA. Electronic address: Irving.Shapiro@Jefferson.edu.
authors.forename: Irving M
authors.initials: IM
authors.lastname: Shapiro
authors.affiliation: Department of Orthopaedic Surgery, Sidney Kimmel Medical College and Graduate Program in Cell and Developmental Biology, Thomas Jefferson University, Philadelphia, USA. Electronic address: Makarand.Risbud@Jefferson.edu.
authors.forename: Makarand V
authors.initials: MV
authors.lastname: Risbud
mesh_terms: D000071116:ADAMTS5 Protein / Q000378:metabolism; D002356:Cartilage / Q000378:metabolism* / Q000473:pathology; D005109:Extracellular Matrix / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D053583:Interleukin-1beta / Q000378:metabolism*; D007403:Intervertebral Disc / Q000378:metabolism* / Q000473:pathology; D007592:Joint Diseases / Q000378:metabolism; D019278:Matrix Metalloproteinase 3 / Q000378:metabolism; D053671:Syndecan-4 / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: C508585:IL1B protein, human; D053583:Interleukin-1beta; C508304:SDC4 protein, human; D053671:Syndecan-4; C439524:TNF protein, human; D014409:Tumor Necrosis Factor-alpha; D000071116:ADAMTS5 Protein; C121532:ADAMTS5 protein, human; C511768:MMP3 protein, human; D019278:Matrix Metalloproteinase 3
keywords: Cartilage; Cytokines; Disc degeneration; Extracellular matrix; Intervertebral disc; Syndecan-4