FRI0018 Sp1 Interference Prevents Joint Destruction of Ra through Inhibitory Effects of Gliostatin and Matrix Metalloproteinase-3
Authors: K. Ikuta, Y. Waguri-Nagaya, N. Tatematsu, Y. Kawaguchi, T. Terazawa, M. Kobayashi, M. Aoyama, K. Asai, T. Otsuka
Journal: Annals of the Rheumatic Diseases (2016)

<h3>Background</h3> Gliostatin (GLS) has angiogenic and arthritogenic activities, which plays an important role in joint destruction as well as matrix metalloproteinase (MMP)- 3 in rheumatoid arthritis (RA). We previously reported that the expression of GLS in serum from RA patients was significantly correlated with disease activity, and that the expression of MMP-3 was induced by GLS in RA fibroblast-like synoviocytes (FLSs). The human GLS and MMP-3 gene promoter contains consensus binding sites for the DNA binding protein Sp1. Here we examined whether Sp1 was necessary for GLS and MMP-3 productions in RA. <h3>Objectives</h3> The purpose of this study was to investigate whether the effect of Sp1 interference using the Sp1 inhibitor mithramycin and RNA interference on GLS and MMP-3 productions in FLSs derived from patients with RA. <h3>Methods</h3> FLSs were cultured from synovial specimens obtained from 10 RA patients during total knee arthroplasty, and were stimulated by tumour necrosis factor (TNF)-α with or without treatment of mithramycin. The gene and protein expressions of GLS and MMP-3 were studied using the quantitative reverse-transcription polymerase chain reaction (RT-PCR) and an enzyme immunoassay. Intracellular signalling pathway activation was determined by a small interfering RNA (siRNA) transfection. <h3>Results</h3> GLS and MMP-3 productions were suppressed in FLSs by siRNA against Sp1 transfection. TNF-α (1 ng/ml) significantly increased GLS and MMP-3 expressions in RA FLSs; these effects were reduced by pre-treatment with mithramycin (300 nM). <h3>Conclusions</h3> Our results showed that pretreatment of mithramycin and Sp1 silencing resulted in a significant suppression of GLS and MMP-3 productions in TNF-α-stimulated FLSs compared to controls. The present study indicates that expression of the GLS and MMP-3 gene is mediated, in part, through the transcription factor Sp1.As physiological concentrations of mithramycin can regulate GLS and MMP-3 productions in RA, mithramycin is a promising candidate for anti-rheumatic therapy. <h3>References</h3> Takeuchi, et al.: Aberrant production of gliostatin/platelet-derived endothelial cell growth factor in rheumatoid arthritis. Arthritis Rheum 1994; 37: 662–72. Muro H, et al. Autocrine induction of gliostatin/platelet-derived endothelial cell growth factor (GLS/PD-ECGF) and GLS-induced expression of matrix metalloproteinases in rheumatoid arthritis synoviocytes. Rheumatol 1999; 38: 1195 -1202. Ikuta K, et al. The Sp1 transcription factor is essential for the expression of gliostatin/thymidine phosphorylase in rheumatoid fibroblast-like synoviocytes. Arthritis Res Ther. 2012; 14:R87 <h3>Acknowledgement</h3> This research was supported by a Grant-in-Aid for Scientific Research (C) (26462309) from the Japan Society for the Promotion of Science. <h3>Disclosure of Interest</h3> K. Ikuta: None declared, Y. Waguri-Nagaya Grant/research support from: Biomet Japan, Inc, Chugai Pharmaceutical Co., Ltd., Astellas Pharma Inc., Merck Sharp &amp; Dohme Co., AbbVie Japan Co., Ltd., Ono Pharmaceutical Co., Ltd., N. Tatematsu: None declared, Y. Kawaguchi: None declared, T. Terazawa: None declared, M. Kobayashi: None declared, M. Aoyama: None declared, K. Asai: None declared, T. Otsuka: None declared