Fig. 4: Late-stage NPCs with elevated SRGN aggravate the inflammatory responses.

a Pseudotime kinetics of the IL1B, TNF, and CCL3 genes. b Heatmap of significant inflammatory cytokines based on cytokine array results of different treatments of NPCs. c–f IHC staining and quantitative analysis of IL-1β, TNF-α, and CCL3 in MDD and SDD human IVDs (original magnification ×400, scale bar = 50 µm). g–j IF staining with quantitative analysis of IL-1β, TNF-α, and CCL3 in WT, Srgn^−/−, WT plus AF, and Srgn^−/− plus AF mice 8 weeks after operation (original magnification ×100, ×400, scale bar = 400 µm, 100 µm). k–n IF staining of IL-1β, TNF-α, and CCL3 (red) co-stained with SRGN (green) in NPCs treated with SRGN or si-SRGN (original magnification ×400, ×1000, scale bar = 50 µm, 20 µm). o, p IF staining of IL-1β (green), TNF-α (red), and CCL3 (purple) in WT, Srgn^−/−, WT plus AF, and Srgn^−/− plus AF mice (original magnification ×100, ×400, scale bar = 400 µm, 100 µm). CTR control group, IVDD 1% FBS starvation-induced NPC IVDD group, SRGN recombined SRGN-treated NPC group, SRGN siRNA-transfected NPC group, Intden/Area (AU) integrated density/area (arbitrary units). n = 5 each group. Data are represented as the mean ± standard deviation. p values were determined by two-tailed unpaired t tests for two-group comparisons and one-way ANOVA with a post hoc Bonferroni correction for multiple groups. Source data are provided as a Source Data file.