Figure 1. Cleaved CASP1, IL-1β and IL-18 was higher expressed in NPCs with higher ROS level. (A) Magnetic resonance images of the discs of patients with intervertebral disc degeneration of different Pfirrmann’s classifications. A, B, C, D and E represented the images of patients with grade I, II, III, IV and V intervertebral disc degeneration. (B) The representative spinal magnetic resonance images and gross pictures of included patients of grade IV and V treated with transforaminal endoscope. (C) The immunohistochemical staining for detection of CASP1 in tissues from patients of grade IV and V (magnification: ×200, scale bar = 100μm). (D) The mRNA expression of CD24 in nucleus pulposus cells isolated from included patients with intervertebral disc degeneration of grade IV and V. (E) The representative images of immunofluorescence staining for detection of COL2A1 and ACAN in the cultured nucleus pulposus cells from patients of grade IV and V (magnification: ×400, scale bar = 50μm). (F) The flow cytometry for detecting the reactive oxygen species level in the cultured nucleus pulposus cells from case1 and case 2. (G) The comparison of the percentage of nucleus pulposus cells with high ROS level of patients with intervertebral disc degeneration of grade IV and V. (H) The representative western blot images showing the expression of p20, cleaved IL-1β, and cleaved IL-18 in the nucleus pulposus cells isolated from patients of grade IV and V. (I) The comparison of pyroptosis related proteins between the patients of grade IV and V based on western blot results. The data were presented as the mean ± SEM. *P < 0.05.