Human Bone Marrow Mesenchymal Stem Cell-derived Exosomes Attenuate IL-1β-induced Annulus Fibrosus Cell Damage

Intervertebral disc degeneration (IDD) has high morbidity and high disability. Exosomes as a favorable candidate for IDD treatment is a hot spot of current research.

Exosomes were obtained from bone marrow mesenchymal stem cells (BM-MSCs) of patients with non-open femoral fractures. Then, annulus fibrosus (AF) cells were treated with IL-1β, IL-1β combined with exosomes or IL-1β combined with exosomes and rapamycin. Flow cytometry and CCK-8 assay were performed to explore the apoptosis and cell proliferation. Quantitative real-time PCR and western blot were performed to detect the gene and protein expression.

Exosomes were obtained from BM-MSCs successfully. BM-MSC-derived exosomes suppressed IL-1β-induced inflammation and apoptosis and promoted cell proliferation of AF cells. BM-MSC-derived exosomes inhibited autophagy of AF cells by activating PI3K/AKT/mTOR signaling pathway. The effect of BM-MSC-derived exosomes on inflammation and apoptosis of AF cells was rescued by rapamycin.

In conclusion, our study revealed that BM-MSC-derived exosomes inhibited IL-1β-induced inflammation and apoptosis of AF cells by suppressing autophagy.