Biomedical engineers from Tufts University have discovered a new protocol that can induce mesenchymal stem cells (MSCs) derived from bone marrow to differentiate into neuron-like cells by treating them with exosomes from cultured cells.
PC12 cells are neuron-like progenitor cells derived from rats that can be successfully grown in culture. The Tufts team, led by Qiaobing Xu, found that exosomes extracted from cultured PC12 cells at various stages of differentiation could drive MSCs to differentiate into neuron-like cells.
Exosomes are very small, hollow particles that a wide range of cells types secrete. These tiny vehicles contain proteins, RNA, and other small molecules, and serve as a vehicle for communication between cells. In the nervous system, exosomes guide the direction of nerve growth, and they control nerve connection and direct peripheral nerve regeneration.
Xu and his team showed that these exosomes contain microRNAs (miRNAs), which a small RNA molecules that regulate gene expression and are known to play a role in neuronal differentiation. They hypothesized that these miRNAs activate neuron-specific genes in the MSCs that receive them and this is the reason these cells begin their journey towards differentiating into neurons.
“In combination with synthetic nanoparticles, we may ultimately be able to use these identified miRNAs or proteins to make synthetic exosomes, thereby avoiding the need to use any kind of neural progenitor cell line to induce neuron growth,” said Xu.
This work was published in PLoS ONE 2015; 10(8): e135111 DOI: 10.1371/journal.pone.0135111.