Fig. 6

Notch1-ADAM8 positive feedback loop promoted OA phenotype in vitro. a: Q-PCR and Western blotting results indicated that overexpression of ADAM8 in chondrocytes stimulated the expression of Notch1 and Hes1. b: the level of the secreted form of TNF-α, IL-6, ADAM8 and EGF were stimulated by IL-1β, however, were blocked by the knockdown of Hes1. c: Western blotting and d: immunofluorescence results indicated that, the protein level of Aggrecan and Collagen II by the knockdown of Hes1, however, were blocked by ADAM8 overexpression. e: the protein level of ki67 was stimulated by the knockdown of Hes1, however, was blocked by the overexpression of ADAM8. f: cell apoptosis of chondrocytes was suppressed by the knockdown of Hes1, however, was promoted again by the overexpression of ADAM8. g: the protein level of Notch1, Hes1, ADAM8, EGFR, p-ERK/ERK, p-NF-kB p65/NF-kB p65 and MMP-9 were suppressed by the knockdown of Hes1, however, were rescued by ADAM8 overexpression