TY - JOUR
T1 - Cyclic mechanical stress induces extracellular matrix degradation in cultured chondrocytes via gene expression of matrix metalloproteinases and interleukin-1
AU - Fujisawa, Takuo
AU - Hattori, Takako
AU - Takahashi, Kojiro
AU - Kuboki, Takuo
AU - Yamashita, Atsushi
AU - Takigawa, Masaharu
PY - 1999
Y1 - 1999
N2 - To clarify the mechanism of cartilage degradation induced by mechanical stress, we investigated the influence of cyclic tension force (CTF) on the metabolism of cultured chondrocytes. The chondrocytes were exposed to CTF using a Flexercell strain unit. Five or 15 kPa of high frequency CTF significantly inhibited the syntheses of DNA, proteoglycan, collagen, and protein. Fifteen kPa of high frequency CTF induced the expression of interleukin-1 (IL-1), matrix metalloproteinase (MMP)-2 and -9 mRNA, and increased the production of pro- and active-MMP-9. The degradation of proteoglycan was inhibited by and MMP inhibitor, indicating that MMPs are involved in the degradation of proteoglycans induced by high frequency CTF. Moreover, reducing the frequency of CTF from high to low decreased the inhibition of proteoglycan synthesis. These findings suggest that the CTF frequency is one of the key determinants of chondrocyte metabolism. Low magnitude CTF, whether high or low frequency, did not cause the gene expression of cartilage degradation factors, suggesting that this CTF magnitude causes only minor changes in the cartilage matrix. High magnitude and frequency CTF caused the gene expression of IL-1 and MMP-9, followed by increases in the production of MMP-2 and -9 proteins, suggesting that excessive and continuous cyclic mechanical stress induces the production of IL-1 and MMP-9, resulting in cartilage degradation.
AB - To clarify the mechanism of cartilage degradation induced by mechanical stress, we investigated the influence of cyclic tension force (CTF) on the metabolism of cultured chondrocytes. The chondrocytes were exposed to CTF using a Flexercell strain unit. Five or 15 kPa of high frequency CTF significantly inhibited the syntheses of DNA, proteoglycan, collagen, and protein. Fifteen kPa of high frequency CTF induced the expression of interleukin-1 (IL-1), matrix metalloproteinase (MMP)-2 and -9 mRNA, and increased the production of pro- and active-MMP-9. The degradation of proteoglycan was inhibited by and MMP inhibitor, indicating that MMPs are involved in the degradation of proteoglycans induced by high frequency CTF. Moreover, reducing the frequency of CTF from high to low decreased the inhibition of proteoglycan synthesis. These findings suggest that the CTF frequency is one of the key determinants of chondrocyte metabolism. Low magnitude CTF, whether high or low frequency, did not cause the gene expression of cartilage degradation factors, suggesting that this CTF magnitude causes only minor changes in the cartilage matrix. High magnitude and frequency CTF caused the gene expression of IL-1 and MMP-9, followed by increases in the production of MMP-2 and -9 proteins, suggesting that excessive and continuous cyclic mechanical stress induces the production of IL-1 and MMP-9, resulting in cartilage degradation.
KW - Chondrocyte
KW - Interleukin (IL)-1
KW - Matrix metalloproteinase (MMP)
KW - Mechanical stress
KW - Proteoglycan
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U2 - 10.1093/oxfordjournals.jbchem.a022376
DO - 10.1093/oxfordjournals.jbchem.a022376
M3 - Article
C2 - 10220591
AN - SCOPUS:0032981665
VL - 125
SP - 966
EP - 975
JO - Journal of Biochemistry
JF - Journal of Biochemistry
SN - 0021-924X
IS - 5
ER -