Calcified Tissue International

, Volume 80, Issue 3, pp 192–200

Expression and Role of Interleukin-6 in Distraction Osteogenesis

  • T.-J. Cho
  • J. A. Kim
  • C. Y. Chung
  • W. J. Yoo
  • L. C. Gerstenfeld
  • T. A. Einhorn
  • I. H. Choi
Article

DOI: 10.1007/s00223-006-0240-y

Cite this article as:
Cho, TJ., Kim, J.A., Chung, C.Y. et al. Calcif Tissue Int (2007) 80: 192. doi:10.1007/s00223-006-0240-y

Abstract

Distraction osteogenesis is a special form of bone healing in which well-controlled distraction stresses and consequent tensile strains within callus tissue induce very efficient new bone formation. Proinflammatory cytokines are involved during the early phase of fracture healing and callus remodeling. Temporal expression patterns of proinflammatory cytokines were assessed in Sprague-Dawley rat tibial models of distraction osteogenesis and acute lengthening, and only interleukin-6 (IL-6) was found to be specifically induced during the distraction phase. IL-6 immunoreactivity was detected not only in hemopoietic cells and osteoblasts but also in the spindle-shaped cells of the fibrous interzone, where most of the tensile strains are concentrated. In vitro study revealed that IL-6 did not affect the proliferation of C3H10T1/2 cells, mouse bone marrow stromal cells (MSCs), or MC3T3-E1 cells; but its blocking antibody reduced the proliferation of C3H10T1/2 cells and MSCs. The mRNA expression of COL1A1 and osteopontin were not changed by IL-6 or its blocking antibody, but the alkaline phosphatase activities of MC3T3-E1 cells were increased by IL-6 and decreased by its blocking antibody. These findings indicate that IL-6 is a proinflammatory cytokine that responds to tensile strain during distraction osteogenesis. IL-6 negatively affects the proliferation of primitive mesenchymal cells, whereas the differentiation of more mature osteoblastic lineage cells is enhanced by IL-6 in vitro. IL-6 appears to be one of the cytokines involved in the complex network of signal cascades evoked during distraction osteogenesis and may differentially affect immature and mature osteoblastic lineage cells.

Keywords

Interleukin-6 Distraction osteogenesis Proinflammatory cytokine 

Copyright information

© Springer Science+Business Media, Inc. 2007

Authors and Affiliations

  • T.-J. Cho
    • 1
  • J. A. Kim
    • 1
  • C. Y. Chung
    • 1
  • W. J. Yoo
    • 1
  • L. C. Gerstenfeld
    • 2
  • T. A. Einhorn
    • 2
  • I. H. Choi
    • 1
  1. 1.Department of Orthopaedic SurgerySeoul National University College of MedicineSeoulRepublic of Korea
  2. 2.Department of Orthopaedic SurgeryBoston University School of MedicineBostonUSA