Parathyroid hormone (PTH) and PTH-like protein (PLP) stimulate interleukin-6 production by osteogenic cells: a possible role of interleukin-6 in osteoclastogenesis

Biochem Biophys Res Commun. 1989 Aug 15;162(3):1546-52. doi: 10.1016/0006-291x(89)90851-6.

Abstract

Osteogenic cells mediate PTH-stimulated osteoclastic bone resorption by a yet unidentified mechanism. We show that primairy rat osteoblast-like cells and the clonal osteogenic sarcoma cell line UMR-106 produce interleukin-6 (IL-6) and that bPTH(1-84) and synthetic hPLP(1-34) stimulate this production dose-dependently. With both peptides a close relation between IL-6 and cyclic-AMP production was found, though for PTH concentrations higher than 2.10(-8) M a clear dissociation was observed. Significant IL-6 activity was also detected in media of cultures of 17-day-old fetal mouse radii and metacarpals which was clearly stimulated by PTH. The source of IL-6 in these bone explants seems to be the osteogenic (cartilage) cells. Treatment of bone explants with IL-6 induced osteoclastic resorption which, however, depended on the bone resorption system used. This bone resorbing action of IL-6 is exerted probably through an effect on the formation of osteoclasts (osteoclastogenesis) rather than on the activation of already existing mature osteoclasts. We suggest that IL-6 produced by osteogenic cells may be a mediator in PTH-stimulated osteoclastic bone resorption.

MeSH terms

  • Animals
  • Bone Resorption* / drug effects
  • Bone and Bones / metabolism
  • Cyclic AMP / biosynthesis
  • In Vitro Techniques
  • Interleukin-6
  • Interleukins / biosynthesis*
  • Interleukins / pharmacology
  • Mice
  • Neoplasm Proteins / pharmacology*
  • Osteoblasts / metabolism*
  • Parathyroid Hormone / pharmacology*
  • Parathyroid Hormone-Related Protein
  • Rats
  • Recombinant Proteins

Substances

  • Interleukin-6
  • Interleukins
  • Neoplasm Proteins
  • Parathyroid Hormone
  • Parathyroid Hormone-Related Protein
  • Recombinant Proteins
  • Cyclic AMP