A Novel Small-Molecule Inhibitor Targeting the IL-6 Receptor β Subunit, Glycoprotein 130

J Immunol. 2015 Jul 1;195(1):237-45. doi: 10.4049/jimmunol.1402908. Epub 2015 May 29.

Abstract

IL-6 is a major causative factor of inflammatory disease. Although IL-6 and its signaling pathways are promising targets, orally available small-molecule drugs specific for IL-6 have not been developed. To discover IL-6 antagonists, we screened our in-house chemical library and identified LMT-28, a novel synthetic compound, as a candidate IL-6 blocker. The activity, mechanism of action, and direct molecular target of LMT-28 were investigated. A reporter gene assay showed that LMT-28 suppressed activation of STAT3 induced by IL-6, but not activation induced by leukemia inhibitory factor. In addition, LMT-28 downregulated IL-6-stimulated phosphorylation of STAT3, gp130, and JAK2 protein and substantially inhibited IL-6-dependent TF-1 cell proliferation. LMT-28 antagonized IL-6-induced TNF-α production in vivo. In pathologic models, oral administration of LMT-28 alleviated collagen-induced arthritis and acute pancreatitis in mice. Based on the observation of upstream IL-6 signal inhibition by LMT-28, we hypothesized IL-6, IL-6Rα, or gp130 to be putative molecular targets. We subsequently demonstrated direct interaction of LMT-28 with gp130 and specific reduction of IL-6/IL-6Rα complex binding to gp130 in the presence of LMT-28, which was measured by surface plasmon resonance analysis. Taken together, our data suggest that LMT-28 is a novel synthetic IL-6 inhibitor that functions through direct binding to gp130.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Administration, Oral
  • Animals
  • Anti-Inflammatory Agents, Non-Steroidal / pharmacology*
  • Arthritis, Experimental / drug therapy*
  • Arthritis, Experimental / genetics
  • Arthritis, Experimental / immunology
  • Arthritis, Experimental / pathology
  • Cell Line, Tumor
  • Cytokine Receptor gp130 / antagonists & inhibitors*
  • Cytokine Receptor gp130 / genetics
  • Cytokine Receptor gp130 / immunology
  • Gene Expression Regulation
  • Hep G2 Cells
  • Humans
  • Interleukin-6 / antagonists & inhibitors*
  • Interleukin-6 / genetics
  • Interleukin-6 / immunology
  • Janus Kinase 2 / antagonists & inhibitors
  • Janus Kinase 2 / genetics
  • Janus Kinase 2 / immunology
  • Leukocytes / drug effects
  • Leukocytes / immunology
  • Leukocytes / pathology
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred DBA
  • Oxazolidinones / pharmacology*
  • Pancreatitis / drug therapy*
  • Pancreatitis / genetics
  • Pancreatitis / immunology
  • Pancreatitis / pathology
  • Phosphorylation
  • STAT3 Transcription Factor / antagonists & inhibitors
  • STAT3 Transcription Factor / genetics
  • STAT3 Transcription Factor / immunology
  • Signal Transduction
  • Small Molecule Libraries / pharmacology*
  • Tumor Necrosis Factor-alpha / antagonists & inhibitors
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / immunology

Substances

  • Anti-Inflammatory Agents, Non-Steroidal
  • Il6st protein, mouse
  • Interleukin-6
  • LMT-28
  • Oxazolidinones
  • STAT3 Transcription Factor
  • Small Molecule Libraries
  • Stat3 protein, mouse
  • Tumor Necrosis Factor-alpha
  • Cytokine Receptor gp130
  • Jak2 protein, mouse
  • Janus Kinase 2