Regular Article
Differential Effects of Interleukin-1 on Hyaluronan and Proteoglycan Metabolism in Two Compartments of the Matrix Formed by Articular Chondrocytes Maintained in Alginate

https://doi.org/10.1006/abbi.1999.1626Get rights and content

Abstract

Phenotypically stable young adult bovine articular chondrocytes suspended in beads of alginate gel were first cultured for 5 days, using daily changes of medium containing 10% fetal bovine serum and supplements. The cells in the beads were then maintained in culture for a further 3 days in the presence or absence of interleukin-1α at 1 ng/ml in the daily change of medium. The exposure to interleukin-1α caused the incorporation of 35S-sulfate into the predominant cartilage proteoglycan, aggrecan, to decrease by approximately 60%. In addition, proteoglycans that had accumulated into the cell-associated matrix during the first 5 days of culture in the absence of interleukin-1α moved into the matrix further removed from the cells and from there into the medium. In contrast, the exposure to interleukin-1α was found to markedly promote the rate of synthesis of hyaluronan, especially during the first 24 h. Over the 3 days of culture in the presence of interleukin-1α, a large proportion of the newly synthesized hyaluronan molecules, as well as those that had previously become residents of the cell-associated matrix, moved out of this compartment and appeared to become permanent residents of the further removed matrix. These results demonstrate that exposure of young adult articular chondrocytes to interleukin-1α has profound effects on the metabolism of hyaluronan, a molecule that plays a critical role in the retention of proteoglycan molecules in the matrix. Importantly, the results suggest that exposure of chondrocytes to interleukin-1 in inflamed joints, such as occurs in rheumatoid arthritis, leads to the rapid loss of coordination of the synthesis of aggrecan and hyaluronan, two of the critical constituents of the proteoglycan aggregate. In addition, we present evidence that these interleukin-1-induced effects differentially alter the metabolism of hyaluronan in the metabolically active cell-associated matrix and the metabolically inactive matrix further removed from the chondrocytes.

References (42)

  • N. Itano et al.

    J. Biol. Chem.

    (1996)
  • Y. Nishida et al.

    J. Biol. Chem.

    (1999)
  • A.M. Shyjan et al.

    J. Biol. Chem.

    (1996)
  • A.P. Spicer et al.

    J. Biol. Chem.

    (1997)
  • K. Watanabe et al.

    J. Biol. Chem.

    (1996)
  • J.A. Buckwalter et al.

    J. Biol. Chem.

    (1982)
  • T.I. Morales et al.

    J. Biol. Chem.

    (1988)
  • H.J. Hauselmann et al.

    Matrix

    (1992)
  • S.S. Mok et al.

    J. Biol. Chem.

    (1994)
  • B. Petit et al.

    Exp. Cell Res.

    (1996)
  • A.J. Fosang et al.

    Matrix

    (1991)
  • L.J. Bonassar et al.

    Arch. Biochem. Biophys.

    (1997)
  • H.P. Benton et al.

    Biochem. Biophys. Res. Commun.

    (1988)
  • K. Masuda et al.

    Anal. Biochem.

    (1994)
  • Y.J. Kim et al.

    Anal. Biochem.

    (1988)
  • S. Chandrasekhar et al.

    Anal. Biochem.

    (1987)
  • J-P. Pelletier et al.

    Rheum. Dis. Clin. North Am.

    (1993)
  • C.K. Ng et al.

    Arch. Biochem. Biophys.

    (1992)
  • C.A. McDevitt

    Ann. Rheum. Dis.

    (1973)
  • C.B. Knudson

    J. Cell Biol.

    (1993)
  • Cited by (31)

    • A stable isotope method for the simultaneous measurement of matrix synthesis and cell proliferation in articular cartilage in vivo

      2009, Osteoarthritis and Cartilage
      Citation Excerpt :

      Indeed, van Beuningen and co-authors reported that age-related differences in IL-1 sensitivity dissipated when using defined, rather than serum-supplemented, medium40, a finding that underscores that the counteracting response to anabolic growth factors modulates the effect of IL-1. In our study, IL-1 also suppressed the rates of fractional HA synthesis and cell proliferation in immature bovine cartilage, whereas adult cartilage exhibited a moderate upregulation of HA synthesis in response to IL-1, which has been demonstrated previously for chondrocytes isolated from bovine animals44,45. In immature cartilage especially, the stimulation of DNA and GAG synthesis by BMP-7 was sufficient to offset the inhibitory effects of IL-1, consistent with the chondroprotective role of BMP-7 shown in vitro46 and in animal studies47.

    View all citing articles on Scopus

    This work was supported by NIH grants AG-04736, AR 43384, and 2-P50-AR 39239.

    2

    To whom correspondence and reprint requests should be addressed. Fax: (312) 942-3053. E-mail: [email protected].

    View full text