Meprin Metalloproteases Generate Biologically Active Soluble Interleukin-6 Receptor to Induce Trans-Signaling

Sci Rep. 2017 Mar 9:7:44053. doi: 10.1038/srep44053.

Abstract

Soluble Interleukin-6 receptor (sIL-6R) mediated trans-signaling is an important pro-inflammatory stimulus associated with pathological conditions, such as arthritis, neurodegeneration and inflammatory bowel disease. The sIL-6R is generated proteolytically from its membrane bound form and A Disintegrin And Metalloprotease (ADAM) 10 and 17 were shown to perform ectodomain shedding of the receptor in vitro and in vivo. However, under certain conditions not all sIL-6R could be assigned to ADAM10/17 activity. Here, we demonstrate that the IL-6R is a shedding substrate of soluble meprin α and membrane bound meprin β, resulting in bioactive sIL-6R that is capable of inducing IL-6 trans-signaling. We determined cleavage within the N-terminal part of the IL-6R stalk region, distinct from the cleavage site reported for ADAM10/17. Interestingly, meprin β can be shed from the cell surface by ADAM10/17 and the observation that soluble meprin β is not capable of shedding the IL-6R suggests a regulatory mechanism towards trans-signaling. Additionally, we observed a significant negative correlation of meprin β expression and IL-6R levels on human granulocytes, providing evidence for in vivo function of this proteolytic interaction.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ADAM10 Protein / genetics
  • ADAM10 Protein / metabolism
  • ADAM17 Protein / genetics
  • ADAM17 Protein / metabolism
  • Amyloid Precursor Protein Secretases / genetics
  • Amyloid Precursor Protein Secretases / metabolism
  • HEK293 Cells
  • Humans
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Metalloendopeptidases / genetics
  • Metalloendopeptidases / metabolism*
  • Receptors, Interleukin-6 / genetics
  • Receptors, Interleukin-6 / metabolism*
  • Signal Transduction*
  • Solubility

Substances

  • IL6R protein, human
  • Membrane Proteins
  • Receptors, Interleukin-6
  • Amyloid Precursor Protein Secretases
  • Metalloendopeptidases
  • meprin A
  • ADAM10 Protein
  • ADAM10 protein, human
  • ADAM17 Protein
  • ADAM17 protein, human