title: A comparative evaluation of the small leucine-rich proteoglycans of pathological human intervertebral discs.
abstract: OBJECTIVE
  Proteoglycans are important to the functioning of the intervertebral disc. In addition to aggrecan there are the small leucine-rich proteoglycans (SLRPs). These are less common but in other locations their functions include collagen organisation, sequestering growth factors and stimulating inflammation. We have performed a comparative analysis of the SLRP core protein species present in intervertebral discs with various pathologies.
  
  
  METHODS
  Eighteen intervertebral discs from patients with scoliosis (n = 7, 19-53 years), degenerative disc disease (n = 6, 35-51 years) and herniations (n = 5, 33-58 years) were used in this study. Proteoglycans were dissociatively extracted from disc tissues and the SLRPs (biglycan, decorin, fibromodulin, keratocan and lumican) assessed by Western blotting following deglycosylation with chondroitinase ABC and keratanase.
  
  
  RESULTS
  Intact SLRP core proteins and a number of core protein fragments were identified in most of the discs examined. Biglycan and fibromodulin were the most extensively fragmented. Keratocan generally occurred as two bands, one representing the intact core protein, the other a smaller fragment. The intact core protein of lumican was detected in all samples with fragmentation evident in only one of the older scoliotic discs. Decorin was less obvious in the disc samples and showed little fragmentation.
  
  
  CONCLUSIONS
  In this cohort of pathological intervertebral discs, fragmentation of certain SLRP core proteins was common, indicating that some SLRPs are extensively processed during the pathological process. Identification of specific SLRP fragments which correlate with disc pathology may not only help understand their aetiopathogeneses, but also provide biomarkers which can be used to monitor disease progression or to identify particular disc disorders.
authors.affiliation: Centre for Spinal Studies, ISTM-Keele University, Robert Jones & Agnes Hunt Orthopaedic Hospital, Oswestry, SY10 7AG, UK. Sharon.Owen@rjah.nhs.uk
authors.forename: Sharon
authors.initials: S
authors.lastname: Brown
authors.forename: James
authors.initials: J
authors.lastname: Melrose
authors.forename: Bruce
authors.initials: B
authors.lastname: Caterson
authors.forename: Peter
authors.initials: P
authors.lastname: Roughley
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Eisenstein
authors.forename: Sally
authors.initials: S
authors.lastname: Roberts
mesh_terms: D000328:Adult; D058578:Biglycan / Q000378:metabolism; D011508:Chondroitin Sulfate Proteoglycans / Q000378:metabolism; D015331:Cohort Studies; D058575:Decorin / Q000378:metabolism; D018450:Disease Progression; D016326:Extracellular Matrix Proteins / Q000378:metabolism; D005260:Female; D000071235:Fibromodulin; D006801:Humans; D007403:Intervertebral Disc / Q000378:metabolism*; D055959:Intervertebral Disc Degeneration / Q000378:metabolism* / Q000473:pathology; D007405:Intervertebral Disc Displacement / Q000378:metabolism* / Q000473:pathology; D007632:Keratan Sulfate / Q000378:metabolism; D007930:Leucine / Q000378:metabolism*; D000071234:Lumican; D008297:Male; D008875:Middle Aged; D011509:Proteoglycans / Q000378:metabolism*; D012600:Scoliosis / Q000378:metabolism* / Q000473:pathology
chemical_list: D058578:Biglycan; D011508:Chondroitin Sulfate Proteoglycans; D058575:Decorin; D016326:Extracellular Matrix Proteins; C000604330:FMOD protein, human; C490948:KERA protein, human; C000604306:LUM protein, human; D000071234:Lumican; D011509:Proteoglycans; D000071235:Fibromodulin; D007632:Keratan Sulfate; D007930:Leucine