MMP13 and intervertebral disk degenerative disorder: In addition, injection of adenoviral circ-GBR10 alleviated the degenerative alterations of the NP, including enhanced Erk1/2 phosphorylation, collagen-II and aggrecan upregulation and inhibited the expression of MMP-13, ADAMT-5 in the rat model of IDD (Fig. 6g).