The study aims to explore the effect of mesenchymal stem cells-derived exosomes (MSCs-Exo) on staurosporine (STS)-induced chondrocyte apoptosis before and after exposure to pulsed electromagnetic field (PEMF) at different frequencies. The AMSCs were extracted from the epididymal fat of healthy rats before and after exposure to the PEMF at 1 mT amplitude and a frequency of 15, 45, and 75 Hz, respectively, in an incubator. MSCs-Exo was extracted and identified. Exosomes were labeled with DiO fluorescent dye, and then co-cultured with STS-induced chondrocytes for 24 h. Cellular uptake of MSC-Exo, apoptosis, and the protein and mRNA expression of aggrecan, caspase-3 and collagenⅡA in chondrocytes were observed. The study demonstrated that the exposure of 75 Hz PEMF was superior to 15 and 45 Hz PEMF in enhancing the effect of exosomes in alleviating chondrocyte apoptosis and promoting cell matrix synthesis. This study lays a foundation for the regulatory mechanism of PEMF stimulation on MSCs-Exo in inhibiting chondrocyte apoptosis, and opens up a new direction for the prevention and treatment of osteoarthritis.
本研究旨在探索脉冲电磁场（PEMF）调控间充质干细胞外泌体（MSCs-Exo）对软骨细胞凋亡的作用。采用强度1 mT，频率15、45、75 Hz的PEMF在体外干预MSCs 30 min后提取外泌体并鉴定。荧光标记PEMF干预前后的MSCs-Exo，并分别与星形孢菌素（STS）诱导的软骨细胞共培养24 h，观察软骨细胞对MSCs-Exo的摄取、细胞的凋亡及细胞内aggrecan、caspase-3和collagenⅡA的基因和蛋白表达变化。与15 Hz组和45 Hz组相比，75 Hz的PEMF显著增强了MSCs-Exo抑制软骨细胞凋亡、促进细胞外基质合成的作用。本研究为应用PEMF调控MSCs-Exo的生物学功能提供了研究基础，为优化利用MSCs-Exo抑制软骨细胞凋亡提供了新的研究方向。.
Keywords: Apoptosis; Chondrocyte; Exosomes; Mesenchymal stem cells; Pulsed electromagnetic fields.