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Aggrecanase cleavage in juvenile idiopathic arthritis patients is minimally detected in the aggrecan interglobular domain but robust at the aggrecan C-terminus.

Struglics, André LU ; Lohmander, Stefan LU ; Last, Karena; Akikusa, Jonathan; Allen, Roger and Fosang, Amanda J (2012) In Arthritis and Rheumatism
Abstract
OBJECTIVE:

To understand aggrecan degradation in juvenile idiopathic arthritis (JIA), the pattern and abundance of aggrecan fragments in synovial fluid aspirates from JIA patients were analysed and compared with aggrecan fragments in synovial fluids from patients with other arthritides, juvenile knee injury and a knee-healthy reference group.



METHODS:

The concentration of sulphated glycosaminoglycans in synovial fluid was measured by the Alcian blue precipitation assay. Aggrecan fragments were purified by dissociative CsCl density gradient centrifugation, deglycosylated and analysed by Western blot using antibodies specific for either aggrecanase-derived ARGS, SELE and KEEE neoepitopes, or the... (More)
OBJECTIVE:

To understand aggrecan degradation in juvenile idiopathic arthritis (JIA), the pattern and abundance of aggrecan fragments in synovial fluid aspirates from JIA patients were analysed and compared with aggrecan fragments in synovial fluids from patients with other arthritides, juvenile knee injury and a knee-healthy reference group.



METHODS:

The concentration of sulphated glycosaminoglycans in synovial fluid was measured by the Alcian blue precipitation assay. Aggrecan fragments were purified by dissociative CsCl density gradient centrifugation, deglycosylated and analysed by Western blot using antibodies specific for either aggrecanase-derived ARGS, SELE and KEEE neoepitopes, or the aggrecan G3-domain.



RESULTS:

The concentration of sulphated glycosaminoglycans in JIA synovial fluids was significantly lower compared with the levels in fluids from OA (P<0.001), juvenile knee injury (P=0.006) and knee-healthy reference (P=0.022) groups. Western blot analysis detected KEEE, SELE, and G3 fragments generated by aggrecanase cleavage in the chondroitin sulphate-rich region of JIA aggrecan. The pattern of JIA aggrecan fragments was not identical to that in synovial fluids pooled from OA patients, although there were notable similarities. Surprisingly, aggrecanase-derived ARGS fragments were barely detectable in the JIA synovial fluids, in marked contrast to the levels of ARGS fragments in OA synovial fluids.



CONCLUSIONS:

Aggrecanases appear to cleave minimally in the interglobular domain of aggrecan in JIA patients despite robust levels of cleavage in aggrecan's chondroitin-sulphate rich region. The results suggest that unlike other arthritides, aggrecanase cleavage in the aggrecan interglobular domain might not be a major pathogenic event in JIA. © 2012 American College of Rheumatology. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Arthritis and Rheumatism
publisher
John Wiley & Sons
external identifiers
  • wos:000311706300040
  • pmid:22886575
  • scopus:84870326196
ISSN
1529-0131
DOI
10.1002/art.34665
language
English
LU publication?
yes
id
62dec222-c09b-45c6-bca0-b155d2dc5c5f (old id 3047574)
alternative location
http://www.ncbi.nlm.nih.gov/pubmed/22886575?dopt=Abstract
date added to LUP
2012-09-05 19:26:40
date last changed
2017-09-24 04:40:18
@article{62dec222-c09b-45c6-bca0-b155d2dc5c5f,
  abstract     = {OBJECTIVE: <br/><br>
To understand aggrecan degradation in juvenile idiopathic arthritis (JIA), the pattern and abundance of aggrecan fragments in synovial fluid aspirates from JIA patients were analysed and compared with aggrecan fragments in synovial fluids from patients with other arthritides, juvenile knee injury and a knee-healthy reference group. <br/><br>
<br/><br>
METHODS: <br/><br>
The concentration of sulphated glycosaminoglycans in synovial fluid was measured by the Alcian blue precipitation assay. Aggrecan fragments were purified by dissociative CsCl density gradient centrifugation, deglycosylated and analysed by Western blot using antibodies specific for either aggrecanase-derived ARGS, SELE and KEEE neoepitopes, or the aggrecan G3-domain. <br/><br>
<br/><br>
RESULTS: <br/><br>
The concentration of sulphated glycosaminoglycans in JIA synovial fluids was significantly lower compared with the levels in fluids from OA (P&lt;0.001), juvenile knee injury (P=0.006) and knee-healthy reference (P=0.022) groups. Western blot analysis detected KEEE, SELE, and G3 fragments generated by aggrecanase cleavage in the chondroitin sulphate-rich region of JIA aggrecan. The pattern of JIA aggrecan fragments was not identical to that in synovial fluids pooled from OA patients, although there were notable similarities. Surprisingly, aggrecanase-derived ARGS fragments were barely detectable in the JIA synovial fluids, in marked contrast to the levels of ARGS fragments in OA synovial fluids. <br/><br>
<br/><br>
CONCLUSIONS: <br/><br>
Aggrecanases appear to cleave minimally in the interglobular domain of aggrecan in JIA patients despite robust levels of cleavage in aggrecan's chondroitin-sulphate rich region. The results suggest that unlike other arthritides, aggrecanase cleavage in the aggrecan interglobular domain might not be a major pathogenic event in JIA. © 2012 American College of Rheumatology.},
  author       = {Struglics, André and Lohmander, Stefan and Last, Karena and Akikusa, Jonathan and Allen, Roger and Fosang, Amanda J},
  issn         = {1529-0131},
  language     = {eng},
  month        = {08},
  publisher    = {John Wiley & Sons},
  series       = {Arthritis and Rheumatism},
  title        = {Aggrecanase cleavage in juvenile idiopathic arthritis patients is minimally detected in the aggrecan interglobular domain but robust at the aggrecan C-terminus.},
  url          = {http://dx.doi.org/10.1002/art.34665},
  year         = {2012},
}