ATP modulates load-inducible IL-1beta, COX 2, and MMP-3 gene expression in human tendon cells.

Journal Article (Journal Article)

Tendon cells receive mechanical signals from the load bearing matrices. The response to mechanical stimulation is crucial for tendon function. However, overloading tendon cells may deteriorate extracellular matrix integrity by activating intrinsic factors such as matrix metalloproteinases (MMPs) that trigger matrix destruction. We hypothesized that mechanical loading might induce interleukin-1beta (IL-1beta) in tendon cells, which can induce MMPs, and that extracellular ATP might inhibit the load-inducible gene expression. Human tendon cells isolated from flexor digitorum profundus tendons (FDPs) of four patients were made quiescent and treated with ATP (10 or 100 microM) for 5 min, then stretched equibiaxially (1 Hz, 3.5% elongation) for 2 h followed by an 18-h-rest period. Stretching induced IL-1beta, cyclooxygenase 2 (COX 2), and MMP-3 genes but not MMP-1. ATP reduced the load-inducible gene expression but had no effect alone. A medium change caused tendon cells to secrete ATP into the medium, as did exogenous UTP. The data demonstrate that mechanical loading induces ATP release in tendon cells and stimulates expression of IL-1beta, COX 2, and MMP-3. Load-induced endogenous IL-1beta may trigger matrix remodeling or a more destructive pathway(s) involving IL-1beta, COX 2, and MMP-3. Concomitant autocrine and paracrine release of ATP may serve as a negative feedback mechanism to limit activation of such an injurious pathway. Attenuation or failure of this negative feedback mechanism may result in the progression to tendinosis.

Full Text

Duke Authors

Cited Authors

  • Tsuzaki, M; Bynum, D; Almekinders, L; Yang, X; Faber, J; Banes, AJ

Published Date

  • June 1, 2003

Published In

Volume / Issue

  • 89 / 3

Start / End Page

  • 556 - 562

PubMed ID

  • 12761889

International Standard Serial Number (ISSN)

  • 0730-2312

Digital Object Identifier (DOI)

  • 10.1002/jcb.10534


  • eng

Conference Location

  • United States