Article

The arthritis severity locus Cia5d is a novel genetic regulator of the invasive properties of synovial fibroblasts.

Feinstein Institute for Medical Research, Manhasset, NY 11030, USA.
Arthritis & Rheumatology (Impact Factor: 7.87). 09/2008; 58(8):2296-306. DOI: 10.1002/art.23610
Source: PubMed

ABSTRACT The synovial fibroblast, or fibroblast-like synoviocyte (FLS), has a central role in pannus invasion and destruction of cartilage and bone in rheumatoid arthritis (RA). However, regulation of the FLS remains incompletely understood. The aim of this study was to determine whether the invasive properties of FLS are genetically regulated by arthritis severity loci.
DA rats (arthritis susceptible) and rat strains congenic for arthritis-protective intervals were studied. Primary FLS cell lines were generated from each strain and used in a well-established FLS invasion model through a collagen-rich barrier. Cells or culture supernatants were analyzed for gene expression, activity of different matrix metalloproteinases (MMPs), cytoskeleton integrity, and cell proliferation.
The median number of FLS from DA.F344(Cia5d) rats that invaded through the collagen-rich barrier was reduced 86.5% compared with the median number of invading FLS from DA rats. Histologic examination showed that DA.F344(Cia5d) rats preserved a normal joint without pannus, hyperplasia, or erosions. FLS from DA.F344(Cia5d) rats produced significantly lower levels of active MMP-2 compared with FLS from DA rats, but the levels of proMMP-2 and MMP-2 messenger RNA in DA.F344(Cia5d) rats were similar to those in DA rats. Treatment of FLS from DA rats with an MMP-2 inhibitor reduced cell invasion to a level similar to that in DA.F344(Cia5d) rats, demonstrating that MMP-2 activity accounted for the difference between FLS from these 2 strains. Analysis of MMP-2-activating pathways revealed increased levels of soluble membrane type 1 (MT1)-MMP in DA rats compared with DA.F344(Cia5d) rats.
These data represent the first evidence for a genetic component in the regulation of FLS invasion. A gene located within the Cia5d interval accounts for this effect and operates via the regulation of soluble MT1-MMP production and MMP-2 activation. These observations suggest novel potential pathways for prognostication and therapy.

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    Genetics 05/2014; · 4.87 Impact Factor
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    ABSTRACT: Little is known about the genes regulating disease severity and joint damage in rheumatoid arthritis (RA). In the present study we analyzed the gene expression characteristics of synovial tissues from four different strains congenic for non-MHC loci that develop mild and non-erosive arthritis, compared with severe and erosive DA rats. DA.F344(Cia3d),DA.F344(Cia5a), DA.ACI(Cia10) and DA.ACI(Cia25) rats developed mild arthritis compared with DA. 685 genes had significantly different expression between congenics and DA, independently of the specific congenic interval, suggesting that these genes represent a new non-genetic core group of mediators of arthritis severity. This core group included genes not previously implicated on, or with unclear role in arthritis severity such as Tnn, Clec4m and Spond1 among others increased in DA. The core genes also included Scd1, Selenbp1 and Slc7a10 increased in congenics. Genes implicated in nuclear receptor activity, xenobiotic and lipid metabolism were also increased in the congenics, correlating with protection. Several disease mediators were among the core genes reduced in congenics, including IL-6, IL-17 and Ccl2. Analyses of upstream regulators (genes, pathways or chemicals) suggested reduced activation of Stat3 and TLR-related genes and chemicals in congenics. Additionally, cigarette smoking was among the upstream regulators activated in DA, while p53 was an upstream regulator activated in congenics. Congenic-specific differential expression and detection was observed in each individual strain. In conclusion, this new non-genetically regulated core genes of disease severity or protection in arthritis should provide new insight into critical pathways and potential new environmental risk factor for arthritis.
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    ABSTRACT: Objective The fibroblast-like synoviocytes (FLS) in the synovial intimal lining of the joint are key mediators of inflammation and joint destruction in rheumatoid arthritis (RA). In RA, these cells aggressively invade the extracellular matrix, producing cartilage-degrading proteases and inflammatory cytokines. The behavior of FLS is controlled by multiple interconnected signal transduction pathways involving reversible phosphorylation of proteins on tyrosine residues. However, little is known about the role of the protein tyrosine phosphatases (PTPs) in FLS function. This study was undertaken to explore the expression of all of the PTP genes (the PTPome) in FLS. MethodsA comparative screening of the expression of the PTPome in FLS from patients with RA and patients with osteoarthritis (OA) was conducted. The functional effect on RA FLS of SH2 domain–containing phosphatase 2 (SHP-2), a PTP that was up-regulated in RA, was then analyzed by knockdown using cell-permeable antisense oligonucleotides. ResultsPTPN11 was overexpressed in RA FLS compared to OA FLS. Knockdown of PTPN11, which encodes SHP-2, reduced the invasion, migration, adhesion, spreading, and survival of RA FLS. Additionally, signaling in response to growth factors and inflammatory cytokines was impaired by SHP-2 knockdown. RA FLS that were deficient in SHP-2 exhibited decreased activation of focal adhesion kinase and mitogen-activated protein kinases. Conclusion These findings indicate that SHP-2 has a novel role in mediating human FLS function and suggest that it promotes the invasiveness and survival of RA FLS. Further investigation may reveal SHP-2 to be a candidate therapeutic target for RA.
    Arthritis & Rheumatology 05/2013; 65(5). · 7.48 Impact Factor

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