Fig. 1

Human intervertebral disc undergone fibrosis with degeneration. a–c Intervertebral disc samples were gathered, and their paraffin section was made to undergo Safranin O-Fast Green stain. Asterisks indicate the nucleus pulposus region of the disc, arrows indicate the approach to dissect the discs, boxes indicate the area of samples to be stained. d IOD levels of the green region were analyzed by IPP.6.0 and subsequently calculated with Graphpad8.0 by ordinary one-way ANOVA test. e Immunofluorescence assay of TGFβ, TGFβR1, FSP1, Col2a1, and Col1a1 in the NP region and fibrosis NP region described in a– c. f IOD levels of the red region were analyzed by IPP.6.0 and subsequently calculated with Graphpad8.0 by Student t test. All data are presented as mean ± sd. from three experiments. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001