Fig. 7

Notch1-ADAM8 positive feedback loop promoted the progression of OA rat models. a and b: In the OA animal model, the amount of Aggrecan and Collagen II were lower than the control and were rescued by MW167 or knockdown of ADAM8. The lowest content of Aggrecan and Collagen II were found in the ADAM8 overexpression OA animal model. c: in OA cartilage, the mRNA level of Notch1, Hes1, ADAM8, EGFR, p-ERK, p-NF-kB p65 and MMP-9 were up-regulated and were blocked by the treatment of MW167 or knockdown of ADAM8. Additionally, the overexpression of ADAM8 presented highest level of Notch1, Hes1, ADAM8, EGFR, p-ERK, p-NF-kB p65 and MMP-9. d: in OA cartilage, the protein level of Notch1, Hes1, ADAM8, EGFR, p-ERK, p-NF-kB p65 and MMP-9 were up-regulated and were blocked by the treatment of MW167 or knockdown of ADAM8. Additionally, the overexpression of ADAM8 presented highest level of Notch1, Hes1, ADAM8, EGFR, p-ERK, p-NF-kB p65 and MMP-9. e: toluidine blue staining results indicated that the content of glycoprotein in OA cartilage was significantly lower than the control, however, was rescued by MW167 or knockdown of ADAM8. Additionally, the overexpression of ADAM8 presented lowest content of glycoprotein