The attenuation of insulin-like growth factor signaling may be responsible for relative reduction in matrix synthesis in degenerated areas of osteoarthritic cartilage.
Chondrocyte
IGF
IGF1R
IRS1
Laser capture microdissection
Matrix synthesis
Osteoarthritis
Sp1
Journal
BMC musculoskeletal disorders
ISSN: 1471-2474
Titre abrégé: BMC Musculoskelet Disord
Pays: England
ID NLM: 100968565
Informations de publication
Date de publication:
27 Feb 2021
27 Feb 2021
Historique:
received:
08
08
2020
accepted:
17
02
2021
entrez:
28
2
2021
pubmed:
1
3
2021
medline:
15
5
2021
Statut:
epublish
Résumé
In osteoarthritis (OA), cartilage matrix is lost gradually despite enhanced matrix synthesis by chondrocytes. This paradox may be explained, at least partly, by reduced chondrocyte anabolism in degenerated area of OA cartilage. However, to date, it is not known why chondrocyte anabolism is suppressed in those areas. Cartilage was obtained from control knees and end-stage OA knees in macroscopically preserved areas and degenerated areas, and gene expression was analyzed in respective regions of cartilage using laser capture microdissection and qPCR. For the cartilage protein analysis, cartilage was obtained from preserved areas and degenerated areas of OA knees in pairs, and proteins were extracted using urea buffer. Protein concentrations were determined by Luminex and compared between the areas. Cartilage explants prepared from preserved areas and degenerated areas of OA knees were cultured in the presence or absence of an AKT inhibitor, and the gene expression was evaluated by qPCR. Finally, the expression of SP1 was evaluated in OA and control cartilage, and the significance of Sp1 on the expression of IGF1R and IRS1 was investigated in experiments using primary cultured chondrocytes. Within OA cartilage, the expression of IGF-1, IGF-2, IGF1R and IRS1 was reduced in degenerated areas compared to preserved areas, while the expression of all six IGF-binding protein genes examined was enhanced in the former areas. Consistent results were obtained by a protein analysis. In explant culture, the inhibition of AKT signaling abrogated the abundant matrix gene expression in the preserved areas over the degenerated areas, indicating that suppressed matrix synthesis in degenerated areas may be ascribed, at least partly, to attenuated IGF signaling. Within OA cartilage, the expression of Sp1 was considerably reduced in severely degenerated areas compared to preserved areas, which correlated well with the expression of IGF1R and IRS1. In experiments using primary cultured chondrocytes, the expression of IGF1R and IRS1 was enhanced by the induction of Sp1 expression and reduced by the suppression of Sp1 expression. The results of this study suggest that attenuated IGF signaling may be responsible, at least partly, for the reduced matrix synthesis in degenerated areas of OA cartilage.
Sections du résumé
BACKGROUND
BACKGROUND
In osteoarthritis (OA), cartilage matrix is lost gradually despite enhanced matrix synthesis by chondrocytes. This paradox may be explained, at least partly, by reduced chondrocyte anabolism in degenerated area of OA cartilage. However, to date, it is not known why chondrocyte anabolism is suppressed in those areas.
METHODS
METHODS
Cartilage was obtained from control knees and end-stage OA knees in macroscopically preserved areas and degenerated areas, and gene expression was analyzed in respective regions of cartilage using laser capture microdissection and qPCR. For the cartilage protein analysis, cartilage was obtained from preserved areas and degenerated areas of OA knees in pairs, and proteins were extracted using urea buffer. Protein concentrations were determined by Luminex and compared between the areas. Cartilage explants prepared from preserved areas and degenerated areas of OA knees were cultured in the presence or absence of an AKT inhibitor, and the gene expression was evaluated by qPCR. Finally, the expression of SP1 was evaluated in OA and control cartilage, and the significance of Sp1 on the expression of IGF1R and IRS1 was investigated in experiments using primary cultured chondrocytes.
RESULTS
RESULTS
Within OA cartilage, the expression of IGF-1, IGF-2, IGF1R and IRS1 was reduced in degenerated areas compared to preserved areas, while the expression of all six IGF-binding protein genes examined was enhanced in the former areas. Consistent results were obtained by a protein analysis. In explant culture, the inhibition of AKT signaling abrogated the abundant matrix gene expression in the preserved areas over the degenerated areas, indicating that suppressed matrix synthesis in degenerated areas may be ascribed, at least partly, to attenuated IGF signaling. Within OA cartilage, the expression of Sp1 was considerably reduced in severely degenerated areas compared to preserved areas, which correlated well with the expression of IGF1R and IRS1. In experiments using primary cultured chondrocytes, the expression of IGF1R and IRS1 was enhanced by the induction of Sp1 expression and reduced by the suppression of Sp1 expression.
CONCLUSIONS
CONCLUSIONS
The results of this study suggest that attenuated IGF signaling may be responsible, at least partly, for the reduced matrix synthesis in degenerated areas of OA cartilage.
Identifiants
pubmed: 33639898
doi: 10.1186/s12891-021-04096-w
pii: 10.1186/s12891-021-04096-w
pmc: PMC7916266
doi:
Substances chimiques
Insulin-Like Growth Factor I
67763-96-6
Types de publication
Journal Article
Langues
eng
Sous-ensembles de citation
IM
Pagination
231Subventions
Organisme : The Japan Society for the Promotion of the Science
ID : 18K16638
Organisme : The Japan Society for the Promotion of the Science
ID : 18K16638
Organisme : The Japan Society for the Promotion of the Science
ID : 20K09447
Références
Arch Biochem Biophys. 1988 Dec;267(2):416-25
pubmed: 3214163
Arthritis Rheum. 1996 Jun;39(6):968-78
pubmed: 8651991
Growth Horm IGF Res. 2014 Aug;24(4):112-8
pubmed: 24863809
Int J Biochem Cell Biol. 1995 Oct;27(10):987-94
pubmed: 7497000
Iowa Orthop J. 2000;20:1-10
pubmed: 10934618
Arthritis Rheum. 2001 Dec;44(12):2777-89
pubmed: 11762938
Arthritis Rheum. 2011 Jul;63(7):1938-49
pubmed: 21425129
Arthritis Rheum. 2002 Sep;46(9):2358-67
pubmed: 12355483
Arthritis Rheum. 2008 Dec;58(12):3843-53
pubmed: 19035477
Science. 1996 Nov 8;274(5289):998-1001
pubmed: 8875945
Ann Rheum Dis. 1992 Apr;51(4):440-7
pubmed: 1586240
J Cell Biochem. 2015 Dec;116(12):2858-69
pubmed: 26015264
Arthritis Rheum. 1994 Feb;37(2):253-63
pubmed: 7510486
J Orthop Res. 2008 Apr;26(4):465-74
pubmed: 18050312
Arthritis Rheum. 2008 Jan;58(1):154-63
pubmed: 18163492
J Histochem Cytochem. 1996 Feb;44(2):133-41
pubmed: 8609369
Arthritis Rheum. 1997 Mar;40(3):562-9
pubmed: 9082945
J Orthop Res. 2020 Mar;38(3):653-662
pubmed: 31608492
J Biol Chem. 2006 Sep 15;281(37):27229-41
pubmed: 16835229
Osteoarthritis Cartilage. 2005 May;13(5):439-48
pubmed: 15882567
Methods Mol Biol. 2011;755:449-59
pubmed: 21761327
Biochem J. 1986 Dec 1;240(2):423-30
pubmed: 3545187
Biochim Biophys Acta. 2012 Jan;1824(1):133-45
pubmed: 21777704
Arthritis Rheum. 1986 Aug;29(8):1039-49
pubmed: 3741515
J Rheumatol. 1999 Apr;26(4):870-9
pubmed: 10229409
Br J Rheumatol. 1996 Nov;35(11):1044-55
pubmed: 8948288
Mol Endocrinol. 1995 Oct;9(10):1367-79
pubmed: 8544845
Rheumatology (Oxford). 2006 Feb;45(2):129-38
pubmed: 16278282
J Biol Chem. 2009 Nov 13;284(46):31972-81
pubmed: 19762915
Mol Endocrinol. 1992 Oct;6(10):1545-58
pubmed: 1448110
Arthritis Rheum. 2012 Jun;64(6):1697-707
pubmed: 22392533
Arch Biochem Biophys. 1997 Jul 15;343(2):164-72
pubmed: 9224726
Biochem J. 2005 Aug 1;389(Pt 3):723-9
pubmed: 15801908
J Orthop Res. 2012 Jul;30(7):1026-31
pubmed: 22180348