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RING-finger type E3 ubiquitin ligase inhibitors as novel candidates for the treatment of rheumatoid arthritis.

Yagishita N, Aratani S, Leach C, Amano T, Yamano Y, Nakatani K, Nishioka K, Nakajima T - Int. J. Mol. Med. (2012)

Bottom Line: We recently cloned synoviolin, a RING-type E3 ubiquitin ligase implicated in the endoplasmic reticulum-associated degradation (ERAD) pathway.Moreover, these inhibitors suppressed the proliferation of rheumatoid synovial cells, and significantly reduced the severity of disease in a mouse model of RA.Our results suggest that inhibition of synoviolin is a potentially useful approach in the treatment of RA.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.

ABSTRACT
Rheumatoid arthritis (RA) significantly affects quality of life. We recently cloned synoviolin, a RING-type E3 ubiquitin ligase implicated in the endoplasmic reticulum-associated degradation (ERAD) pathway. Synoviolin is highly expressed in rheumatoid synovial cells and may be involved in the pathogenesis of RA. Inhibition of synoviolin activity is a potentially useful therapeutic approach for the treatment of RA. We conducted a high-throughput screen of small molecules to find inhibitors of synoviolin autoubiquitination activity. We identified two classes of small molecules, named LS-101 and LS-102, which inhibited synoviolin activity. LS-102 selectively inhibited synoviolin enzymatic activity, while LS-101 inhibited a broad array of RING-type E3 ligases. Moreover, these inhibitors suppressed the proliferation of rheumatoid synovial cells, and significantly reduced the severity of disease in a mouse model of RA. Our results suggest that inhibition of synoviolin is a potentially useful approach in the treatment of RA.

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Screening for synoviolin inhibitors. (A) Scheme of high-throughput screening ofsynoviolin-induced ubiquitination assay. (B) Inhibition of synoviolin33P-polyubiquitination by LS-101 and chemical structure of LS-101. (C)Inhibition of synoviolin 33P-polyubiquitination by LS-102 and chemicalstructure of LS-102.
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f1-ijmm-30-06-1281: Screening for synoviolin inhibitors. (A) Scheme of high-throughput screening ofsynoviolin-induced ubiquitination assay. (B) Inhibition of synoviolin33P-polyubiquitination by LS-101 and chemical structure of LS-101. (C)Inhibition of synoviolin 33P-polyubiquitination by LS-102 and chemicalstructure of LS-102.

Mentions: To identify small molecule inhibitors of synoviolin autoubiquitination, we screened theLead Discovery Service program of Pharmacopeia, which includes more than four millioncompounds from Pharmacopeia’s Compound Collection (18). Herein we monitored 33P-autoubiquitinatedsynoviolin in cell lysates containing GST-synoviolinΔTM in the presence of ATP,E1, E2, and 33P-labeled ubiquitin (Fig. 1A). The primary screen was conducted with multiple compoundsper well (10–20 compounds per well) at an estimated screening concentration of2–10 μM. Mixtures of compounds showing potential activity in the primaryscreen were then rescreened individually. Compounds demonstrating activity in thisreconfirmation assay were resynthesized and retested. Two unique compounds, termed LS-101and LS-102, inhibited the autoubiquitination of synoviolin with a 50% inhibitoryconcentration value (IC50) of ∼15 μM (Fig. 1B) and 20 μM (Fig. 1C), respectively.


RING-finger type E3 ubiquitin ligase inhibitors as novel candidates for the treatment of rheumatoid arthritis.

Yagishita N, Aratani S, Leach C, Amano T, Yamano Y, Nakatani K, Nishioka K, Nakajima T - Int. J. Mol. Med. (2012)

Screening for synoviolin inhibitors. (A) Scheme of high-throughput screening ofsynoviolin-induced ubiquitination assay. (B) Inhibition of synoviolin33P-polyubiquitination by LS-101 and chemical structure of LS-101. (C)Inhibition of synoviolin 33P-polyubiquitination by LS-102 and chemicalstructure of LS-102.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4042867&req=5

f1-ijmm-30-06-1281: Screening for synoviolin inhibitors. (A) Scheme of high-throughput screening ofsynoviolin-induced ubiquitination assay. (B) Inhibition of synoviolin33P-polyubiquitination by LS-101 and chemical structure of LS-101. (C)Inhibition of synoviolin 33P-polyubiquitination by LS-102 and chemicalstructure of LS-102.
Mentions: To identify small molecule inhibitors of synoviolin autoubiquitination, we screened theLead Discovery Service program of Pharmacopeia, which includes more than four millioncompounds from Pharmacopeia’s Compound Collection (18). Herein we monitored 33P-autoubiquitinatedsynoviolin in cell lysates containing GST-synoviolinΔTM in the presence of ATP,E1, E2, and 33P-labeled ubiquitin (Fig. 1A). The primary screen was conducted with multiple compoundsper well (10–20 compounds per well) at an estimated screening concentration of2–10 μM. Mixtures of compounds showing potential activity in the primaryscreen were then rescreened individually. Compounds demonstrating activity in thisreconfirmation assay were resynthesized and retested. Two unique compounds, termed LS-101and LS-102, inhibited the autoubiquitination of synoviolin with a 50% inhibitoryconcentration value (IC50) of ∼15 μM (Fig. 1B) and 20 μM (Fig. 1C), respectively.

Bottom Line: We recently cloned synoviolin, a RING-type E3 ubiquitin ligase implicated in the endoplasmic reticulum-associated degradation (ERAD) pathway.Moreover, these inhibitors suppressed the proliferation of rheumatoid synovial cells, and significantly reduced the severity of disease in a mouse model of RA.Our results suggest that inhibition of synoviolin is a potentially useful approach in the treatment of RA.

View Article: PubMed Central - PubMed

Affiliation: Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki, Kanagawa, Japan.

ABSTRACT
Rheumatoid arthritis (RA) significantly affects quality of life. We recently cloned synoviolin, a RING-type E3 ubiquitin ligase implicated in the endoplasmic reticulum-associated degradation (ERAD) pathway. Synoviolin is highly expressed in rheumatoid synovial cells and may be involved in the pathogenesis of RA. Inhibition of synoviolin activity is a potentially useful therapeutic approach for the treatment of RA. We conducted a high-throughput screen of small molecules to find inhibitors of synoviolin autoubiquitination activity. We identified two classes of small molecules, named LS-101 and LS-102, which inhibited synoviolin activity. LS-102 selectively inhibited synoviolin enzymatic activity, while LS-101 inhibited a broad array of RING-type E3 ligases. Moreover, these inhibitors suppressed the proliferation of rheumatoid synovial cells, and significantly reduced the severity of disease in a mouse model of RA. Our results suggest that inhibition of synoviolin is a potentially useful approach in the treatment of RA.

Show MeSH
Related in: MedlinePlus