Mesenchymal stem cell-derived exosomal miR-223 regulates neuronal cell apoptosis.

Hypoxia limits the survival and function of neurons in the development of Alzheimer's diseases. Exosome-dependent intercellular communication is an emerging signaling mechanism involved in tissue repair and regeneration; however, the effect and underlying mechanism of mesenchymal stem cell-derived exosomes in regulating neuronal cell apoptosis have not been determined. Here, we showed that the establishment of an AD cell model was accompanied by increased HIF-1α expression and cell apoptosis, impaired cell migration, and decreased miR-223. MSC-derived exosomes were internalized by the AD cell coculture model in a time-dependent manner, resulting in reduced cell apoptosis, enhanced cell migration and increased miR-223, and these effects were reversed by KC7F2, a hypoxic inhibitor. Furthermore, MSC-derived exosomal miR-223 inhibited the apoptosis of neurons in vitro by targeting PTEN, thus activating the PI3K/Akt pathway. In addition, exosomes isolated from the serum of AD patients promoted cell apoptosis. In short, our study showed that MSC-derived exosomal miR-223 protected neuronal cells from apoptosis through the PTEN-PI3K/Akt pathway and provided a potential therapeutic approach for AD.