Objective To explore the molecular mechanism of miR-515-5p in inhibiting chondrocyte apoptosis and alleviating inflammatory response in osteoarthritis (OA). Methods Human cartilage cell line C28/I2 was cultured in vitro and treated with 10 ng/mL interleukin 1β (IL-1β) for 24 hours to construct an in vitro OA model. C28/I2 cells were transfected with miR mimics, mimics negative control (NC), over expression (oe)-NC, and oe-Toll-like receptor 4 (TLR4), respectively, and then treated with 10 ng/mL IL-1β for 24 hours to establish OA model. Cell proliferation capacity was detected by cell counting kit 8 and 5-Ethynyl-2’-deoxyuridine, cell apoptosis and cell cycle were detected by flow cytometry, and B-cell lymphoma 2 protion (Bcl-2), Bcl-2-associated X protein (Bax), cleaved-Caspase-3, TLR4, myeloid differentiation primary response gene 88 (MyD88), p65 and phosphorylated p65 (p-p65) protein expression levels were detected by Western blot. Real-time fluorescence quantitative PCR was used to detect mRNA expression levels of miR-515-5p and TLR4, and ELISA was used to detect pro-inflammatory factor prostaglandin E2 (PGE2), tumor necrosis factor α (TNF -α), and IL-6 levels in cell supernatant. The potential binding sites between miR-515-5p and TLR4 were predicted by BiBiServ2 database, and the targeting relationship between miR-515-5p and TLR4 was verified by dual luciferase reporting assay. Results After the treatment of C28/I2 cells with IL-1β, the expressions of miR-515-5p and Bcl-2 protein and the proliferation ability of C28/I2 cells significantly reduced. The expression levels of Bax and cleaved-Caspase-3 protein, the levels of pro-inflammatory factors (PGE2, TNF-α, IL-6) in the supernatant of C28/I2 cells, and the apoptosis of C28/I2 cells significantly increased. In addition, the proportion of the cells at S phase and G2 phase decreased significantly, and the proportion of cells at G1 phase increased significantly, suggesting that the cell cycle was blocked after IL-1β treatment. After transfection with miR mimics, the expression level of miR-515-5p in the cells significantly up-regulated, partially reversing the apoptosis of OA chondrocytes induced by IL-1β, and alleviating the cycle arrest and inflammatory response of OA chondrocytes. After treating C28/I2 cells with IL-1β, the mRNA and protein levels of TLR4 significantly increased. Overexpression of miR-515-5p targeted inhibition of TLR4 expression and blocked activation of MyD88/nuclear factor κB (NF-κB) pathway. Overexpression of TLR4 could partially reverse the effect of miR mimics on IL-1β-induced apoptosis and inflammation of OA chondrocytes. ConclusionmiR-515-5p negatively regulates the expression of TLR4, inhibits the activation of MyD88/NF-κB pathway and apoptosis of OA chondrocytes, and effectively alleviates the inflammatory response of the cells.
Objective To investigate the surgical method and short-term effectiveness of arthroscopy edge-to-edge #-shaped suture in the treatment of the complete radial tear of the lateral meniscus body. Methods The clinical data of 13 patients with complete radial tear of lateral meniscus body between May 2020 and August 2023 were retrospectively analyzed. There were 10 males and 3 females, aged 15-38 years (mean, 24.2 years). There were 11 cases of acute injury and 2 cases of chronic injury, with time from injury to admission ranging from 2 days to 5 months. All patients had tenderness in the lateral joint space, and 2 patients with chronic injury had positive McMurray’s sign. All patients were treated with arthroscopic edge-to-edge #-shaped suture technique. The knee joint activity and tenderness in the lateral joint space were detected, and the healing of the incision and the occurrence of complications were observed. X-ray films and MRI of the knee joint were performed to evaluate joint degeneration and meniscus healing. Lysholm score, International Knee Documentation Committee (IKDC) subjective score, Tegner score, and visual analogue scale (VAS) score were used to evaluate the functional recovery before and after operation. Results The operation time ranged from 46 to 100 minutes (mean, 80.08 minutes). All the incisions healed by first intention, and no complications such as intraoperative vascular and nerve injury or postoperative infection occurred. All 13 patients were followed up 20-59 months (mean, 29.3 months). All patients had no limitation of knee extension and flexion. One patient with chronic injury continued to have tenderness in the lateral space of the knee joint, while the remaining patients had no tenderness, swelling, and locking in the lateral space. Immediate postoperative MRI of knee joint showed continuous recovery of the lateral meniscus. At last follow-up, no degenerative changes were observed in X-ray films of knee joint. Except for 1 patient with chronic injury, the MRI of the other patients showed the healing performance after lateral meniscus suture. Lysholm score, IKDC subjective score, Tegner score, and VAS score all significantly improved when compared with those before operation (P<0.05). Conclusion The edge-to-edge #-shaped suture technique can effectively repair the complete radial tear of the lateral meniscus body, and the short-term effectiveness is satisfactory.