Arthritis & Rheumatism, Volume 60,
October 2009 Abstract Supplement
The 2009 ACR/ARHP Annual Scientific Meeting
Philadelphia October 16-21, 2009.
Anti-Destructive Effects of Trichostatin A (TSA) Are Partly Mediated through Altered Expression of Histone Deacetylase 7 (HDAC7)
Hemmatazad1, Hossein, Rodrigues1, Hanna Maciejewska, Huber1, Lars C., Gay1, Renate E., Kolling2, Christoph, Michel1, Beat A., Gay1, Steffen
Joint destruction in rheumatoid arthritis (RA) is mainly mediated by matrix metalloproteinases (MMPs). There are several reports indicating that histone deacetylase inhibitors (HDACi) modulate the expression of MMPs and therefore block cartilage destruction. In the present study, we investigate the role of specific HDACs with respect to the reported anti-destructive effects of TSA in RA synovial fibroblasts.
Synovial fibroblasts were obtained from RA patients undergoing surgical joint replacement and used at passages 46. The constitutive and TNF-a (10ng/ml)/IL-1b (1ng/ml) stimulated expression of HDACs (111) together with the expression of MMP1 and MMP3 was measured after incubating the cells with TSA (2mM for 24h) by TaqMan Real-time PCR. Specific gene knockdown of HDAC7 was achieved by siRNA. To assess the expression on protein level, antibodies against MMP1 and MMP3 were used for Western blot.
In unstimulated cells (n=3), the expression of HDAC6, 7 and 9 was reduced significantly after treatment with TSA, while the expression of HDAC3 was increased. Furthermore, in TNF-a/IL-1b-stimulated fibroblasts (n=3), TSA down-regulated the expression of HDAC5, 6, 7, 8 and 9 significantly while the expression of HDAC1, 2, and 3 was up-regulated. Of interest, the most considerable change in the expression of HDACs was observed for HDAC7, which was down-regulated by 86 ± 6 and 87 ± 5% (n=3, p<0.05) in both, unstimulated and TNF-a/IL-1b-stimulated cells. In addition, TSA could down-regulate the mRNA expression of MMP1 and MMP3 in TNF-a/IL-1b-stimulated cells (n=6) by 89 ± 9 and 85 ± 7% respectively (p<0.05), while the expression in unstimulated cells was unaffected. These results were confirmed on the protein level using Western blot. Most interestingly, after specific gene knockdown of HDAC7 in stimulated RASF (n=8), the mRNA expression of MMP1 and MMP3 was significantly reduced by 48 ± 25 and 48 ± 27% (p<0.05).
We conclude that the anti-destructive effect of TSA observed in RASF is at least in part, due to the down-regulation of HDAC7. This observation may present HDAC7 as a novel target to prevent joint destruction in RA.
To cite this abstract, please use the following information:
Hemmatazad, Hossein, Rodrigues, Hanna Maciejewska, Huber, Lars C., Gay, Renate E., Kolling, Christoph, Michel, Beat A., et al; Anti-Destructive Effects of Trichostatin A (TSA) Are Partly Mediated through Altered Expression of Histone Deacetylase 7 (HDAC7) [abstract]. Arthritis Rheum 2009;60 Suppl 10 :733