Autophagic Degradation of Gasdermin D Protects against Nucleus Pulposus Cell Pyroptosis and Retards Intervertebral Disc Degeneration In Vivo

Figure 4

Impaired autophagy activity aggravated LPS-induced NP cell pyroptosis in vitro. (a) Western blot analysis and quantification of NLRP3, cleaved caspase-1, and GSDMD-N protein levels. GAPDH was used as an internal control. (b) Measurement of extracellular LDH activity in NP cells. (c) ELISA analysis assessed the levels of secreted TNF-α, IL-1β, and IL-6. (d) Flow cytometry analyzed the pyroptotic cells, which were double positive of activated caspase-1 and PI. (e) The rate of double-positive cells was calculated. (g) Double immunofluorescence analysis showed the expression level of LC3 (red) and GSDMD-N (green). Scale bar, 50 μm. (f) The relative mean fluorescence in each group was calculated. Data were presented as the , . , , and vs. the corresponding LPS group; ns, , no significant difference.

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