Attachment to laminin-111 facilitates transforming growth factor beta-induced expression of matrix metalloproteinase-3 in synovial fibroblasts.

Abstract

BACKGROUND:

In the synovial membrane of patients with rheumatoid arthritis (RA), a strong expression of laminins and matrix degrading proteases was reported.

AIM:

To investigate the regulation of matrix metalloproteinases (MMPs) in synovial fibroblasts (SFs) of patients with osteoarthritis (OA) and RA by attachment to laminin-1 (LM-111) and in the presence or absence of costimulatory signals provided by transforming growth factor beta (TGFbeta).

METHODS:

SFs were seeded in laminin-coated flasks and activated by addition of TGFbeta. The expression of genes was investigated by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), immunocytochemistry and ELISA, and intracellular signalling pathways by immunoblotting, and by poisoning p38MAPK by SB203580, MEK-ERK by PD98059 and SMAD2 by A-83-01.

RESULTS:

Attachment of SF to LM-111 did not activate the expression of MMPs, but addition of TGFbeta induced a fivefold higher expression of MMP-3. Incubation of SF on LM-111 in the presence of TGFbeta induced a significant 12-fold higher expression of MMP-3 mRNA, and secretion of MMP-3 was elevated 20-fold above controls. Functional blocking of LM-111-integrin interaction reduced the laminin-activated MMP-3 expression significantly. Stimulation of SF by LM-111 and TGFbeta activated the p38MAPK, ERK and SMAD2 pathways, and inhibition of these pathways by using SB203580, PD98059 or A-83-01 confirmed the involvement of these pathways in the regulation of MMP-3.

CONCLUSION:

Attachment of SF to LM-111 by itself has only minor effects on the expression of MMP-1 or MMP-3, but it facilitates the TGFbeta-induced expression of MMP-3 significantly. This mode of MMP-3 induction may therefore contribute to inflammatory joint destruction in RA independent of the proinflammatory cytokines interleukin (IL)1beta or tumour necrosis factor (TNF)alpha.

• Authors: Maik Hoberg, Maximilian Rudert, Thomas Pap, Gerd Klein, Steffen Gay, Wilhelm K Aicher
• Journal: Annals of the rheumatic diseases (Ann Rheum Dis) Vol. 66 Issue 4 Pg. 446-51 (Apr 2007) ISSN: 0003-4967 [Print] England
• PMID: 17124250 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Laminin
• Recombinant Proteins
• Transforming Growth Factor beta
• laminin 1
• Extracellular Signal-Regulated MAP Kinases
• Matrix Metalloproteinase 3

Topics

• Aged
• Arthritis, Rheumatoid (enzymology, metabolism, pathology)
• Cells, Cultured
• Extracellular Signal-Regulated MAP Kinases (metabolism)
• Female
• Fibroblasts (enzymology)
• Gene Expression Regulation, Enzymologic (drug effects)
• Humans
• Laminin (metabolism)
• Male
• Matrix Metalloproteinase 3 (genetics, metabolism)
• Middle Aged
• Phosphorylation
• Recombinant Proteins (pharmacology)
• Reverse Transcriptase Polymerase Chain Reaction (methods)
• Signal Transduction
• Synovial Membrane (enzymology, pathology)
• Transforming Growth Factor beta (pharmacology)