Lentivirus production

293FT cells were transfected with USP53-overexpressing lentivirus or USP53 shRNA along with packaging plasmid (delta 8.9) and envelop plasmid (VSV-G) using Lipofectamine LTX & Plus Reagent (Invitrogen, Carlsbad, CA, USA) according to the manufacturer’s instructions. DMEM-LG supplemented with 10% FBS was changed 6 h after transfection. The supernatants containing virus were collected 24 and 48 h after initial transfection, filtered with a 0.45-μm syringe filter (Millipore), separated into aliquots, and stored at -80 °C until use. hBMSCs were seeded onto 6-well plates at a density of 1 × 10⁵ cells/well and transfected with purified lentiviruses for 24 h. Puromycin (10 μg/mL; Sigma, St. Louis, MO, USA) was used for selection, and stable lentivirus-infected hBMSCs were used in experiments. Information on the lentiviral vectors is provided in Supplementary Table S7.