Osteoblast-derived Laminin-332 is a novel negative regulator of osteoclastogenesis in bone microenvironments

Lab Invest. 2017 Oct;97(10):1235-1244. doi: 10.1038/labinvest.2017.55. Epub 2017 Jun 5.

Abstract

Laminin-332 (Lm-332), a major basement membrane protein, has been shown to provide a niche for some stem cells. Here, we found that Lm-332 was expressed in osteoblasts, and is implicated in the regulation of osteoclast differentiation. Immunofluorescence analysis of laminin-β3, a unique component of Lm-332, indicated specific expression of laminin-β3 in osteoblast-like cells localized on bone surface. RT-PCR analysis confirmed that α3, β3, and γ2 chains of Lm-332 were all expressed in primary osteoblasts prepared from mouse calvaria. Lm-332 markedly inhibited osteoclastogenesis induced by receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL) when bone marrow-derived macrophages (BMMs) were cultured on Lm-332-coated plates. Lm-332 also blocked RANKL-induced activation of mitogen-activated protein kinases (MAPKs) (ERK, JNK, and p38) and expression of NFATc1, c-Fos, and c-Jun. Lm-332 suppressed osteoclast differentiation while retaining macrophage phenotypes, including nonspecific esterase activity and gene expression of lysozyme and EGF-like module-containing mucin-like hormone receptor-like 1 (Emr1). Furthermore, the treatment of primary osteoblasts with osteoclastogenic factors dramatically suppressed expression of Lm-332. These findings suggest that Lm-332 produced by osteoblasts in bone tissues has a pivotal role in controlling normal bone remodeling through suppressing osteoclastogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone and Bones / cytology
  • Bone and Bones / metabolism
  • Cell Adhesion Molecules / metabolism*
  • Cellular Microenvironment / physiology*
  • Kalinin
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitogen-Activated Protein Kinase Kinases / metabolism
  • Osteoblasts / cytology
  • Osteoblasts / metabolism*
  • Osteoclasts / cytology
  • Osteoclasts / metabolism
  • Osteogenesis / physiology*
  • RANK Ligand / metabolism
  • RAW 264.7 Cells

Substances

  • Cell Adhesion Molecules
  • RANK Ligand
  • Tnfsf11 protein, mouse
  • Mitogen-Activated Protein Kinase Kinases