Fig. 5.

HDAC3 Overexpression delays chondrocyte aging and OA progression. a, b Western Blotting analysis of HDAC3, p16^INK4a, p21, and p53 expression in the primary chondrocytes of mice which transfected adenovirus containing HDAC3 (Ad-HDAC3) or Ad-NC cultivated on 10:1 PDMS substrates (n = 5). c Representative images of safranin O/fast green and immunofluorescence staining of HDAC3 in cartilage of mice intra-articularly injected with AAV-NC or AAV-HDAC3 after DMM surgery. Scale bars: 50 µm. d Quantification of HDAC3-positive chondrocytes based on staining results in (c) (n = 5). e Quantification of the OARSI scale based on staining results in (c) (n = 5). f Representative images of immunofluorescence staining of p16^INK4a, p21, and p53 in cartilage of mice intra-articularly injected with AAV-NC or AAV-HDAC3 after DMM surgery. Scale bars: 50 µm. g Quantification of p16^INK4a, p21, and p53-positive chondrocytes based on staining results in (f) (n = 5). h Representative images of immunofluorescence staining of PINK1, Parkin, and Lc3 in cartilage of mice intra-articularly injected with AAV-NC or AAV-HDAC3 after DMM surgery. Scale bars: 50 µm. i Quantification of PINK1, Parkin and Lc3-positive chondrocytes based on staining results in (h) (n = 5). *P < 0.05, **P < 0.01, ***P < 0.001. OA osteoarthritis, DAPI 4’,6-diamidino-2-phenylindole, OARSI Osteoarthritis Research Society International, AAV-HDAC3 adenovirus expressing small hairpin HDAC3, AAV-NC negative control