Fig. 2: CircPKNOX1 delayed the process of disc degeneration in vitro.

A RT-qPCR was used to detect the transfection efficiency of circPKNOX1 siRNA #1, 2, and 3; **P<0.01. Data represent mean ±SD, and the P values were determined by a two-tailed unpaired Student’s t test. B After knocking down circPKNOX1, the expression level of PKNOX1 was detected. Data represent mean±SD, and the P values were determined by a two-tailed unpaired Student’s t test. C Adenoviruses containing circPKNOX1 were used to infect nucleus pulposus cells, and the infection efficiency was detected; ***P<0.001. Data represent mean±SD, and the P values were determined by a two-tailed unpaired Student’s t test. D Green fluorescence indicates infected nucleus pulposus cells. E After circPKNOX1 was knocked down or overexpressed, the expression levels of related proteins (collagen II, aggrecan, SOX9, MMP3, MMP13, ADAMTS4, and ADAMTS-5) were detected using western blotting. F The fluorescence intensity of related proteins (collagen II, aggrecan, ADAMTS4, and MMP13) was observed using an immunofluorescence assay (scale bar, 100μm). After circPKNOX1 was knocked down (G) or circPKNOX1 was overexpressed (H), RT-qPCR was used to detect the expression of related genes; *P<0.05, **P<0.01. Data represent mean±SD, and the P values were determined by a two-tailed unpaired Student’s t test. I Top: the extracellular matrix was detected by Alcian staining. Bottom: the Alcian staining was quantitatively analyzed. Data represent mean±SD, and the P values were determined by a two-tailed unpaired Student’s t test.