Effect of Thrombin-Induced MCP-1 and MMP-3 Production Via PAR1 Expression in Murine Intervertebral Discs

Sci Rep. 2018 Jul 27;8(1):11320. doi: 10.1038/s41598-018-29669-z.

Abstract

Structural changes in nucleus pulposus cells induce intervertebral disc (IVD) degeneration as a consequence of cytokine generation, biochemical products, and changes in the local environment. We have previously shown that inflammatory cytokines induce murine IVD (mIVD) angiogenesis and macrophage migration. Although the physiological roles of thrombin, a known proinflammatory factor, are documented, its relationship to IVD degeneration remains largely unexplored. Thrombin mediates cellular responses via the activation of protease-activated receptors such as PAR1 which has been studied in numerous cell types, but not extensively in IVD cells. This study was designed to investigate the endogenous expression of thrombin, tissue factor, and PAR1 in cultured coccygeal mIVDs. Thrombin exclusively induced MCP-1 via the MAPK-ERK and PI3K-AKT pathways. MCP-1 produced by mIVDs induced macrophage migration and thrombin treatment increased MMP-3 production to induce mIVD degeneration. These effects of thrombin on mIVDs were abrogated by a PAR1 inhibitor and suggest that thrombin may be a novel factor capable of stimulating cytokine activity implicated in the regulation several aspects of mIVDs. Mechanisms governing mIVDs, which are regulated by thrombin/PAR1 signaling, require elucidation if our understanding of IVD degenerative mechanisms is to advance.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Movement / drug effects
  • Chemokine CCL2 / genetics*
  • Cytokines / genetics
  • Gene Expression Regulation / drug effects
  • Humans
  • Intervertebral Disc / metabolism
  • Intervertebral Disc / pathology
  • Intervertebral Disc Degeneration / genetics*
  • Intervertebral Disc Degeneration / pathology
  • MAP Kinase Signaling System / genetics
  • Matrix Metalloproteinase 3 / genetics*
  • Mice
  • Nucleus Pulposus / metabolism
  • Nucleus Pulposus / pathology
  • Phosphatidylinositol 3-Kinases / genetics
  • Proto-Oncogene Proteins c-akt / genetics
  • Receptor, PAR-1 / genetics*
  • Signal Transduction / drug effects
  • Thrombin / administration & dosage
  • Thrombin / metabolism

Substances

  • Ccl2 protein, mouse
  • Chemokine CCL2
  • Cytokines
  • Receptor, PAR-1
  • Phosphatidylinositol 3-Kinases
  • Proto-Oncogene Proteins c-akt
  • Thrombin
  • Matrix Metalloproteinase 3