Fig. 4: Sirt6 inhibits chondrocyte senescence by regulating the IL-15/JAK3/STAT5 signaling pathway.

a, b Heat map (a) and Volcano plot (b) demonstrating differentially expressed genes (fold change >2 or <0.5, Benjamini–Hochberg-corrected p) in Sirt6 KO chondrocytes vs controls. Notably, STAT5, JAK3, and IL-15 were observed to be significantly upregulated. c GO analysis of upregulated genes from Sirt6 KO chondrocytes for biological processes (BP), cellular component (CC), and molecular function (MF). d KEGG and GSEA analysis demonstrating JAK/STAT signaling pathway enriched in OA. e The rescue experiments were performed in human OA chondrocytes to validate the relationship between Sirt6 and IL-15/JAK3/STAT5 signaling pathway. pcDNA3.1-Sirt6, Sirt6 siRNA, or pcDNA3.1-Sirt6 + pcDNA3.1-STAT5 was transfected into human OA chondrocytes. After 48 h, the related genes were analyzed. n = 3 independent biological replicates per group. f–h Human chondrocytes were infected with Ad-control or Ad-Sirt6, then treated with or without IL-15 (2 ng/mL) for the indicated time. n = 3 independent biological replicates per group (f). Immunofluorescent staining of cellular Stat5 and nuclear and cytoplasm fraction of Stat5 (g). n = 3 independent biological replicates per group. Western blot analysis of p-Stat5 and Stat5 expression level. n = 3 independent biological replicates per group (h). i Human chondrocytes were transfected with Stat5, then treated with or without IL-15 (2 ng/mL). Whole-cell lysates were immunoprecipitated with anti-Sirt6 or anti-Stat5 antibodies, and precipitated proteins were detected by anti-Stat5 or anti-Sirt6 antibodies, respectively. Western blot detection of nuclear acetylation level of Stat5 in human chondrocytes with or without IL-15 treatment. n = 3 independent biological replicates per group. j Human chondrocytes were transfected with the Stat5 reporter and Stat5 with or without Sirt6, then treated with or without IL-15 for 12 h. Luciferase activity was normalized to β-gal. n = 6 independent biological replicates per group. k ChIP assay analysis of human chondrocytes infected with Ad-control or Ad-Sirt6, then treated with or without IL-15. n = 6 independent biological replicates per group. Scar bar: g 20 μm. Data were presented as the mean ± s.e.m. P values are from two-tailed Mann–Whitney U-test (a–d), one-way ANOVA test followed by Tukey’s post hoc test (e, g) or Brown–Forsythe and Welch ANOVA test followed by Tamhane’s T2 post hoc analysis (j, k). Source data are provided as a Source Data file.