IADR Abstract Archives

Continuous Tensile Strain Inhibits IGF Expression in TMJ Disc Cells

One of the most promising approaches to successfully inhibit inflammation, cartilage degradation, and pain in arthritis is mechanical loading of inflamed joints. We have recently shown that tensile forces can inhibit the expression of several proinflammatory and catabolic genes in fibrochondrocytes from temporomandibular joint (TMJ) discs. Whether tensile forces can also promote repair of fibrocartilage in arthritic TMJs by stimulating the synthesis of components of the insulin-like growth factor (IGF) system has yet to be determined.

Objectives: This in vitro study was performed to determine if continuous tensile strain regulates the gene expression of IGF1, IGF2, IGF1 receptor (IGF1R), insulin receptor substrate (IRS1), and IGF-binding proteins (IGFBP) 3 and 5 in TMJ disc cells.

Methods: TMJ disc cells from six 3-week-old male Wistar rats were seeded on collagen type I-coated BioFlex® plates and subjected to continuous tensile strain at low (3%) and high magnitudes (20%) by using a simple strain device for 4 and 24 h. RNA was extracted and real-time PCR was performed using an iCycler iQ detection system to analyze the gene expression of the components of the IGF system. For statistical analysis, One-Way ANOVA and the post-hoc multiple comparison Tukey test were applied. Differences were regarded as statistically significant at values of p<0.05.

Results: The gene expression of IGF1, IGF2, IGF1R, IRS1, IGFBP3, and IGFBP5 was significantly (p<0.05) inhibited when cells were subjected to continuous tensile strain, as compared to control at both time points. Tensile strain of high magnitude induced a stronger inhibition of all molecules as compared to strain of low magnitude.

Conclusion: Continuous tensile strain seems to downregulate the IGF system and may, therefore, reduce the potential of fibrocartilage for growth and repair in TMJs.


Continental European and Israeli Divisions Meeting
2007 Continental European and Israeli Divisions Meeting (Thessaloniki, Greece)
Thessaloniki, Greece
2007
46
Scientific Groups
  • Rath-deschner, Birgit  ( University of Bonn, Bonn, N/A, Germany )
  • Deschner, James  ( University of Bonn, Bonn, N/A, Germany )
  • Reimann, Susanne  ( University of Bonn, Bonn, N/A, Germany )
  • Bourauel, Christoph  ( University of Bonn, Bonn, N/A, Germany )
  • Götz, Werner  ( University of Bonn, Bonn, N/A, Germany )
  • Jepsen, Soren  ( University of Bonn, Bonn, N/A, Germany )
  • Jager, Andreas  ( University of Bonn, Bonn, N/A, Germany )
    • Oral Session
    Craniofacial Biology/TMJ
    09/27/2007