TGF-β/Smad/ADAMTS-7 Axis Regulates the Process of Curcumin in Promoting the Cartilage Cells Proliferation

To explore the function of curcumin on the cartilage cells, the cell proliferation and apoptosis by transforming growth factor-beta/suppressor of mothers against decapentaplegic/a disintegrin and metalloproteinase with thrombospondin motifs-7 axis was the objective of the study. The cell viability was detected by cell counting kit-8. The expression of transforming growth factor-beta, suppressor of mothers against decapentaplegic protein, a disintegrin and metalloproteinase with thrombospondin motifs-7, caspase-9, B-cell lymphoma 2, Bcl-2-associated X protein was determined by Western blot. The cartilage cells were treated with 1 mmol/l sodium nitroprusside for 24 h. Then, the cells were treated with different concentration of curcumin for 24 h. We found that 1 μmol/l curcumin could recover the cartilage cells proliferation. The transforming growth factor-beta and suppressor of mothers against decapentaplegic protein show high expression and a disintegrin and metalloproteinase with thrombospondin motifs-7 was low in the curcumin treatment group. Meanwhile, the apoptosis pathway was also detected. The caspase-9 and B-cell lymphoma 2 was higher in the curcumin treatment group than without curcumin group. However, the Bcl-2-associated X protein was lower. The cell viability, a disintegrin and metalloproteinase with thrombospondin motifs-7, caspase-9, B-cell lymphoma 2 and Bcl-2-associated X proteins also show no changes with or without curcumin when the transforming growth factor-beta was inhibited. We found that a disintegrin and metalloproteinase with thrombospondin motifs-7 show over expression, the transforming growth factor-beta and suppressor of mothers against decapentaplegic protein show high expression in the curcumin treatment group, the cell viability, caspase-9, B-cell lymphoma 2 and Bcl-2-associated X proteins show no changes with or without curcumin. Curcumin can promote the cartilage cells proliferation via transforming growth factor-beta/suppressor of mothers against decapentaplegic/a disintegrin and metalloproteinase with thrombospondin motifs-7 axis and inhibit the cell apoptosis.