Protein antibodies

The medium was removed from the wells, and the cells were washed with phosphate-buffered saline (PBS). Human or mouse NPCs were lysed using radioimmunoprecipitation assay buffer (Beyotime, China). The protein extract was separated using 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, transferred to a polyvinylidene difluoride (PVDF) membrane (Bio-Rad, Hercules, CA, USA), and blocked with skim milk powder for 1 h. The PVDF membrane was incubated with protein antibodies (1:1000, Abcam) at 4 °C overnight (collagen II, aggrecan, SOX9, MMP3, MMP13, ADAMTS4, and ADAMTS5). After washing with Tris-buffered saline with 0.1% Tween® 20, the cells were further incubated with the secondary antibody at room temperature (25 °C) for 2 h. Protein bands were observed using the LAS-4000 Science Imaging System (Fujifilm, Tokyo, Japan) and analyzed with ImageJ software (National Institutes of Health, Bethesda, MD, USA).

The alphalipoic acid injection (Yabao Pharmaceutical Group Co. Ltd.), nab-paclitaxel injection (Fresenius Kabi USA, LLC), and normal saline injection (Tianrui Pharmaceutical, Zhejiang, China) were obtained from Zhongshan Hospital of Fudan University (Shanghai, China). The mRNA extraction kit, cDNA extraction kit, RNA amplification kit, primer design, and synthesis were provided by Takara (Takara Bio Inc., Shiga, Japan). Protein antibodies were purchased from Abcam Inc. (Cambridge, MA, USA).