Insights into the Effects of the Dental Stem Cell Secretome on Nerve Regeneration: Towards Cell-Free Treatment

Figure 4

Schematic illustrating the role of DSC secretomes modulating the nerve regeneration in PNS. Axon of the neuron is myelinated by the Schwann cells (SCs). Nerve injury has caused the myelin sheaths and axon degenerated. There are series of macrophage activation by several GFs and cytokine involved to remove the debris of degenerating fibers like A2M cytokine that recognized by specific receptor on macrophages. On the other hand, MCP-1 and sSiglec-9 induced the polarization of M2 macrophage. This has caused MCP-1/sSiglec-9-induced M2 macrophages expressed six factors that are known to affect the functional properties of SCs. The six factors are IGF-1, NRG1, BDNF, CNTF, VEGF and GDNF. These factors promote the proliferation, migration, and differentiation of SCs that can enhance axonal regeneration. Neuron image adopted and modified from Mey et al. [75].