Adipose Tissue-Derived Exosome Maintains Metabolic Balance of Extracellular Matrix in Rat Nucleus Pulposus Cells

This study aimed to investigate the protective effect of adipose tissue-derived exosomes (AT-Exo) on rat nucleus pulposus cells (NPCs).

Ultracentrifugation was used to extract exosomes from rat adipose tissue. Transmission electron microscopy (TEM), Western blot, and nanoparticle tracking analysis (NTA) were used to characterize the exosomes. Tert-butyl hydrogen peroxide (TBHP) was used to induce apoptosis of rat NPCs. Cell viability was determined by CCK-8 assay. AT-Exo was administered to investigate its effect on rat NPCs using Western blot and immunofluorescence staining.

AT-Exo was successfully extracted and characterized by NTA, TEM, and Western blots. Uptake assay showed that AT-Exo can be taken up by the NPCs. TBHP (60 μM) resulted in decreased cell viability and increased apoptosis of NPCs. Interestingly, AT-Exo protected NPCs against TBHP, indicated by increased cell viability, decreased apoptosis, upregulated Aggrecan and type II collagen deposition, and downregulated matrix metalloproteinase 3/13.

In summary, rat adipose tissue-derived exosomes can increase the levels of Aggrecan, type II collagen, and Bcl2, and decrease the levels of matrix metalloproteinase 3/13, cleaved caspase3, and Bax. Therefore, rat adipose tissue-derived exosomes can maintain metabolic balance of extracellular matrix and protect against apoptosis in rat nucleus pulposus cells.