Figure 1.

Multifunctional therapeutic action of transplanted neural stem cells. Transplanted NSCs derived from ESCs, iPSCs, or fetal brain have demonstrated multimodal therapeutic function after intravenous, intraparenchymal, or intracerebroventricular administration (Kokaia et al., 2012; Lau et al., 2015). NSCs demonstrate immunomodulatory function through the expression of cytokines and chemokines in response pro‐inflammatory signaling from activated microglia and infiltrating circulatory immune cells (Huang et al., 2014; Watanabe et al., 2016). NSCs also promote angiogenesis and stimulate neural repair mechanisms including synaptic reorganization and neurogenesis (Andres et al., 2011; Zhang et al., 2011). Transplanted NSCs can act as a cell replacement therapy by differentiating to mature neural cell types (neurons, astrocytes, and oligodendrocytes) and integrating into the host brain tissue (Baker et al., 2017; Kelly et al., 2004; Oki et al., 2012; Tornero et al., 2013). The prepotency of one mechanism to promote tissue repair over another is not well known. Regardless of therapeutic mechanism, the final outcome after NSC transplantation is improved tissue and functional recovery (Kokaia et al., 2012)