Fig 2: Protective effect of circ_7042 on intervertebral discs in LSI mice. A HE staining results of intervertebral disc nucleus pulposus tissue in mice. B Safranin O-bright green staining results; red is cartilage and glycoprotein, and green is collagen fibre. C–H The expression levels of circ_7042, miR-369-3p, Cdh2, Bmp2, Acan, and Col2a1 were detected by qPCR. *P<0.05, **P<0.01, the two groups were compared between the wires

Fig 3: The role of NRF2 in KGN-modulated antioxidant functions in IL-1ß-stimulated NPCs. Prior to exposure to 5 ?ng/mL IL-1ß and 1 ?µM KGN, NPCs were pre-treated with an NRF2-specific inhibitor, ML385. (A) Immunofluorescence staining revealed intracellular ROS in NPCs. (B) The gene expression of Nrf2, Gpx1, and Hmox1 was quantified using RT-PCR, n ?= ?4. (C) The protein levels of NRF2, GPX1, and HO-1 were measured using Western blot, n ?= ?3. (D–E) The gene expression of Col2a1, Acan, Sox9, Mmp13, and Adamts5 was quantified using RT-PCR, n ?= ?4. (C) The protein levels of COL II, ACAN, SOX9, MMP13, and ADAMTS5 were measured using Western blot. Data are presented as the mean ?± ?standard deviation. Statistically significant differences are indicated by # where P ?< ?0.05 or ## where P ?< ?0.01 compared to the control (CTRL) group; * where P ?< ?0.05 or ** where P ?< ?0.01 between the indicated groups.

Fig 4: The effects of KGN on the matrix synthesis of nucleus pulposus cells (NPCs) under normal culture conditions. NPCs were treated with KGN at concentrations of 0.01, 0.1, and 1 ?µM. (A) Cell proliferation was examined at 1, 3, 5 and 7 days using CCK-8 assay, n ?= ?6. (B) The mRNA expression levels of Col2a1, Acan, and Sox9 as determined by RT-PCR, n ?= ?4. (C) Immunofluorescence staining images showed the expression of COL II proteins in KGN-treated cells. (D–E) The effects of KGN on the protein levels of NP matrix components in NPCs were determined using Western blot, n ?= ?3. Data are shown as the mean ?± ?standard deviation. Statistically significant differences are indicated by # where P ?< ?0.05 or ## where P ?< ?0.01 compared to the control (CTRL) group; * where P ?< ?0.05 or ** where P ?< ?0.01 between the indicated groups.

Fig 5: In vivo mobilization of SIRT3-COX4I2 by honokiol prevented OA development. A) Schematic diagram representing the treatment strategy (n = 6). B) Representative images of S.O. (top), T.B. (middle), and H&E staining (bottom) at 8 weeks postoperatively (n = 6). C,D) Quantitative analysis of the OARSI scale or hyaline versus calcified cartilage (HC/CC) ratio (n = 6). E,F) Representative images of subchondral bone using micro-computed tomography (µCT) reconstruction and quantitative analysis of the ratio of BV/TV (n = 6). G,H) Representative images of H&E staining in the synovium and quantitative analysis of the synovial inflammation (n = 6). I) Representative images of double fluorescent immunostaining for SIRT3 and COX4I2 at 8 weeks postoperatively (n = 6). J) Representative images of immunohistochemistry of COLII, ACAN, MMP13, and ADAMTS5 in articular cartilage (n = 6). Data are presented as mean ± SD. Statistically significant differences between groups were determined at a threshold of p <0.05.