Fig. 4
The effect of lopinavir on cartilage aging and degeneration depends on Zmpste24 inhibition. a Representative images of Lamin A immunofluorescence staining in primary chondrocytes from wild-type mice and Zmpste24-/- mice after lopinavir treatment. Scale bar: 10 μm. b Quantitative analysis of nuclear blebbing cells. c, d SA-β-gal staining and quantitative analysis in primary chondrocytes from wild-type mice and Zmpste24-/- mice after lopinavir treatment. Scale bar: 100 μm. e RT-qPCR experiment to detect the mRNA expression levels of Zmpste24, Col2a1, Sox9, and p21 in mouse primary cells after lopinavir treatment. f, g Toluidine Blue and Alcian Blue staining of micromass of different primary chondrocytes after lopinavir treatment, and quantitative analysis. h Western Blot analysis of Col2a1, Sox9, Lamin A, p16INK4a, and p21 protein expression in different primary chondrocytes after lopinavir treatment. i Flowchart of the animal experiment. j Representative images of X-ray, micro-CT, HE staining, and Safranine O staining in wild-type mice and Zmpste24-/- mice after further intraperitoneal injection of lopinavir/ritonavir following DMM surgery. Scale bar: 100 μm. n = 6, 7 or 8 per group. k–m Quantitative analysis of synovial inflammation score, Safranine O-positive cartilage area, and OARSI score. Data are shown as mean ± SD. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.000 1
