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Suppression of NFAT5-mediated Inflammation and Chronic Arthritis by Novel κB-binding Inhibitors
Eun-Jin Han1, Hyun Young Kim2, Naeun Lee1
1Center for Integrative Rheumatoid Transcriptomics and Dynamics, The Catholic University of Korea, Seoul, Republic of Korea.
Abstract:
Nuclear factor of activated T cells 5 (NFAT5) has been implicated in the pathogenesis of various human diseases, including cancer and arthritis. However, therapeutic agents inhibiting NFAT5 activity are currently unavailable. To discover NFAT5 inhibitors, a library of >40,000 chemicals was screened for the suppression of nitric oxide, a direct target regulated by NFAT5 activity, through high-throughput screening. We validated the anti-NFAT5 activity of 198 primary hit compounds using an NFAT5-dependent reporter assay and identified the novel NFAT5 suppressor KRN2, 13-(2-fluoro)-benzylberberine, and its derivative KRN5. KRN2 inhibited NFAT5 upregulation in macrophages stimulated with lipopolysaccharide and repressed the formation of NF-κB p65-DNA complexes in the NFAT5 promoter region. Interestingly, KRN2 selectively suppressed the expression of pro-inflammatory genes, including Nos2 and Il6, without hampering high-salt-induced NFAT5 and its target gene expressions. Moreover, KRN2 and KRN5, the latter of which exhibits high oral bioavailability and metabolic stability, ameliorated experimentally induced arthritis in mice without serious adverse effects, decreasing pro-inflammatory cytokine production. Particularly, orally administered KRN5 was stronger in suppressing arthritis than methotrexate, a commonly used anti-rheumatic drug, displaying better potency and safety than its original compound, berberine. Therefore, KRN2 and KRN5 can be potential therapeutic agents in the treatment of chronic arthritis.
Insights
Researchers discovered KRN2 and KRN5, novel inhibitors of Nuclear Factor of activated T cells 5 (NFAT5). These compounds effectively treat arthritis in mice by reducing inflammation, showing promise as new therapeutic agents.
Area of Science:
- Molecular Biology
- Immunology
- Pharmacology
Background:
- Nuclear factor of activated T cells 5 (NFAT5) is implicated in diseases like cancer and arthritis.
- Currently, no therapeutic agents effectively inhibit NFAT5 activity.
Purpose of the Study:
- To discover novel small-molecule inhibitors of NFAT5.
- To evaluate the therapeutic potential of identified inhibitors in preclinical models of arthritis.
Main Methods:
- High-throughput screening of over 40,000 chemicals to identify suppressors of nitric oxide, a target regulated by NFAT5.
- Validation of hit compounds using an NFAT5-dependent reporter assay.
- In vitro assays to assess NFAT5 inhibition and gene expression modulation.
- In vivo studies using a mouse model of experimentally induced arthritis.
Main Results:
- Identified KRN2 (13-(2-fluoro)-benzylberberine) and its derivative KRN5 as novel NFAT5 suppressors.
- KRN2 inhibited NFAT5 upregulation and repressed NF-κB p65-DNA complex formation.
- KRN2 selectively suppressed pro-inflammatory genes (Nos2, Il6) without affecting high-salt-induced NFAT5 activity.
- KRN5 demonstrated high oral bioavailability and metabolic stability.
- Both KRN2 and KRN5 ameliorated arthritis in mice, reducing pro-inflammatory cytokines with no serious adverse effects.
- Orally administered KRN5 showed superior potency and safety compared to methotrexate and berberine in treating arthritis.
Conclusions:
- KRN2 and KRN5 are potent NFAT5 inhibitors with therapeutic potential for chronic inflammatory diseases like arthritis.
- KRN5 exhibits favorable pharmacokinetic properties and superior efficacy and safety compared to existing treatments.
- These compounds represent promising candidates for the development of novel anti-arthritic therapies.