Low-density lipoprotein receptor-related protein-1 mediates endocytic clearance of tissue inhibitor of metalloproteinases-1 and promotes its cytokine-like activities

PLoS One. 2014 Jul 30;9(7):e103839. doi: 10.1371/journal.pone.0103839. eCollection 2014.

Abstract

Tissue inhibitor of metalloproteinases-1 (TIMP-1) regulates the extracellular matrix turnover by inhibiting the proteolytic activity of matrix metalloproteinases (MMPs). TIMP-1 also displays MMP-independent activities that influence the behavior of various cell types including neuronal plasticity, but the underlying molecular mechanisms remain mostly unknown. The trans-membrane receptor low-density lipoprotein receptor-related protein-1 (LRP-1) consists of a large extracellular chain with distinct ligand-binding domains that interact with numerous ligands including TIMP-2 and TIMP-3 and a short transmembrane chain with intracellular motifs that allow endocytosis and confer signaling properties to LRP-1. We addressed TIMP-1 interaction with recombinant ligand-binding domains of LRP-1 expressed by CHO cells for endocytosis study, or linked onto sensor chips for surface plasmon resonance analysis. Primary cortical neurons bound and internalized endogenous TIMP-1 through a mechanism mediated by LRP-1. This resulted in inhibition of neurite outgrowth and increased growth cone volume. Using a mutated inactive TIMP-1 variant we showed that TIMP-1 effect on neurone morphology was independent of its MMP inhibitory activity. We conclude that TIMP-1 is a new ligand of LRP-1 and we highlight a new example of its MMP-independent, cytokine-like functions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CHO Cells
  • Cricetinae
  • Cricetulus
  • Cytokines / metabolism
  • Endocytosis
  • Growth Cones / metabolism
  • Low Density Lipoprotein Receptor-Related Protein-1
  • Mice
  • Neurites / metabolism
  • Protein Binding
  • Protein Interaction Domains and Motifs
  • Protein Transport
  • Receptors, LDL / physiology*
  • Tissue Inhibitor of Metalloproteinase-1 / metabolism*
  • Tumor Suppressor Proteins / physiology*

Substances

  • Cytokines
  • Low Density Lipoprotein Receptor-Related Protein-1
  • Lrp1 protein, mouse
  • Receptors, LDL
  • Timp1 protein, mouse
  • Tissue Inhibitor of Metalloproteinase-1
  • Tumor Suppressor Proteins