Non-classical monocytes as mediators of tissue destruction in arthritis. Academic Article uri icon

Overview

abstract

  • OBJECTIVES: Bone destruction in rheumatoid arthritis is mediated by osteoclasts (OC), which are derived from precursor cells of the myeloid lineage. The role of the two monocyte subsets, classical monocytes (expressing CD115, Ly6C and CCR2) and non-classical monocytes (which are CD115 positive, but low in Ly6C and CCR2), in serving as precursors for OC in arthritis is still elusive. METHODS: We investigated CCR2-/- mice, which lack circulating classical monocytes, crossed into hTNFtg mice for the extent of joint damage. We analysed monocyte subsets in hTNFtg and K/BxN serum transfer arthritis by flow cytometry. We sorted monocyte subsets and analysed their potential to differentiate into OC and their transcriptional response in response to RANKL by RNA sequencing. With these data, we performed a gene ontology enrichment analysis and gene set enrichment analysis. RESULTS: We show that in hTNFtg arthritis local bone erosion and OC generation are even enhanced in the absence of CCR2. We further show the numbers of non-classical monocytes in blood are elevated and are significantly correlated with histological signs of joint destruction. Sorted non-classical monocytes display an increased capacity to differentiate into OCs. This is associated with an increased expression of signal transduction components of RANK, most importantly TRAF6, leading to an increased responsiveness to RANKL. CONCLUSION: Therefore, non-classical monocytes are pivotal cells in arthritis tissue damage and a possible target for therapeutically intervention for the prevention of inflammatory joint damage.

publication date

  • June 29, 2018

Research

keywords

  • Arthritis, Experimental
  • Arthritis, Rheumatoid
  • Bone Resorption
  • Monocytes
  • Osteoclasts

Identity

PubMed Central ID

  • PMC6161666

Scopus Document Identifier

  • 85049311233

Digital Object Identifier (DOI)

  • 10.2217/imt.13.94

PubMed ID

  • 29959183

Additional Document Info

volume

  • 77

issue

  • 10