摘要
Background The most significant biological change in intervertebral disc degeneration is the decrease of chondrocyte specific gene and protein expression of Sox9 and collagen type Ⅱ. Interleukin-1 （IL-1） is not expressed in the normal intervertebral disc tissue but increases in the degenerated intervertebral disc tissue. This suggests that IL-1 may play a role in regulation of the expression of Sox9 and collagen type Ⅱ. Methods Human intervertebral disc cells were isolated and cultured. Sox9 and collagen type Ⅱ expression during treatment with IL-1, with or without the nuclear factor-κB （NF-κB） activity inhibitor curcumin, were detected by using reverse transcription-polymerase chain reaction （RT-PCR） and Western blotting, and the activity of the NF-κB signaling pathway was detected by the electrophoretic mobility shift assay （EMSA）. Results IL-1 lowered the mRNA level and protein expression of Sox9 and collagen type Ⅱ in the cultured intervertebral disc cells in a dose dependent manner （P 〈0.05）, and this effect was attenuated by curcumin. Curcumin alone had no effect on Sox9 and collagen type Ⅱ expression （P 〉0.05）. IL-1 at concentrations of 0.1 ng/ml, 1 ng/ml and 10 ng/ml could stimulate the activity of NF-κB in the intervertebral disc cells in a dose dependent manner （P 〈0.05） that was inhibited by curcumin. Conclusions We demonstrated the previously unknown function of IL-1 in inhibiting Sox9 and collagen type Ⅱ via NF-κB in the intervertebral disc cells. This inhibition can be attenuated by curcumin, which is an effective NF-κB activity inhibitor.
Background The most significant biological change in intervertebral disc degeneration is the decrease of chondrocyte specific gene and protein expression of Sox9 and collagen type Ⅱ. Interleukin-1 （IL-1） is not expressed in the normal intervertebral disc tissue but increases in the degenerated intervertebral disc tissue. This suggests that IL-1 may play a role in regulation of the expression of Sox9 and collagen type Ⅱ. Methods Human intervertebral disc cells were isolated and cultured. Sox9 and collagen type Ⅱ expression during treatment with IL-1, with or without the nuclear factor-κB （NF-κB） activity inhibitor curcumin, were detected by using reverse transcription-polymerase chain reaction （RT-PCR） and Western blotting, and the activity of the NF-κB signaling pathway was detected by the electrophoretic mobility shift assay （EMSA）. Results IL-1 lowered the mRNA level and protein expression of Sox9 and collagen type Ⅱ in the cultured intervertebral disc cells in a dose dependent manner （P 〈0.05）, and this effect was attenuated by curcumin. Curcumin alone had no effect on Sox9 and collagen type Ⅱ expression （P 〉0.05）. IL-1 at concentrations of 0.1 ng/ml, 1 ng/ml and 10 ng/ml could stimulate the activity of NF-κB in the intervertebral disc cells in a dose dependent manner （P 〈0.05） that was inhibited by curcumin. Conclusions We demonstrated the previously unknown function of IL-1 in inhibiting Sox9 and collagen type Ⅱ via NF-κB in the intervertebral disc cells. This inhibition can be attenuated by curcumin, which is an effective NF-κB activity inhibitor.
基金
The study was supported by a grant from the National Natural Science Foundation of China （No. 2004NSFC30471741）.
