Fig. 3

Inhibition of the leptin-Lepr signaling pathway mitigated SSC senescence and OA progression. A GO enrichment of pathways associated with significantly upregulated genes (p.adjust < 0.05) in the normal versus OA 8W groups. B GSEA enrichment of pathways associated with significantly upregulated genes (p.adjust < 0.05) in the normal versus OA 8W groups. C, D mRNA levels of leptin in osteochondral tissues from human (C) and OA mice (D) samples. The N side represents the less severely diseased side of the source joint, whereas the O side represents the more severely diseased side of the joint. E Schematic of the experimental design. The mice were subjected to ACLT surgery and received intra-articular treatment (n = 3). F, G Representative images of safranin O/Fast Green staining and OARSI grades of the mice that received different treatments at 8 weeks after ALCT surgery. Scale bars, 100 μm. H Representative images of COL II IHC in the articular cartilage and subchondral bone of mice that received different treatments at 8 weeks after ALCT surgery. Scale bar, 100 μm. I Quantitative analysis of the COL II area in articular cartilage and subchondral bone. J IF staining of Grem1 and P21 in the subchondral bones of mice that received different treatments at 8 weeks after ALCT surgery. The white arrows indicate P21-positive cells. Scale bar, 100 μm. K Proportion of Grem1⁺P21⁺ cells among Grem1⁺ cells. L Micro-CT scans of knee joints from various treatment groups after ALCT surgery. M, N Microarchitectures of tibial subchondral bones showing BV/TV (M) and SBP.th (N). Quantitative analyses were conducted using the IHC Profiler plug-in for ImageJ. All data are presented as the mean ± S.D. *P < 0.05; **P < 0.01; ***P < 0.001; ns, not significant