Role of neural precursor cells in promoting repair following stroke

Abstract

Stem cell-based therapies for the treatment of stroke have received considerable attention. Two broad approaches to stem cell-based therapies have been taken: the transplantation of exogenous stem cells, and the activation of endogenous neural stem and progenitor cells (together termed neural precursors). Studies examining the transplantation of exogenous cells have demonstrated that neural stem and progenitor cells lead to the most clinically promising results. Endogenous activation of neural precursors has also been explored based on the fact that resident precursor cells have the inherent capacity to proliferate, migrate and differentiate into mature neurons in the uninjured adult brain. Studies have revealed that these neural precursor cell behaviours can be activated following stroke, whereby neural precursors will expand in number, migrate to the infarct site and differentiate into neurons. However, this innate response is insufficient to lead to functional recovery, making it necessary to enhance the activation of endogenous precursors to promote tissue repair and functional recovery. Herein we will discuss the current state of the stem cell-based approaches with a focus on endogenous repair to treat the stroke injured brain.

Adult Neural Stem Cells from the Subventricular Zone Give Rise to Reactive Astrocytes in the Cortex after Stroke

“…The ''lack of success'' from transplantation paradigms and endogenous neurogenesis (Dibajnia and Morshead, 2013) could be the result of astrocyte differentiation favored over neuronal differentiation. Indeed, Shimada et al (2012) showed a loss of neurogenic potential of transplanted cortical derived neurospheres following transplantation back into the uninjured brain; only astrocytes and oligodendrocytes were produced.…”

Enhancing endogenous capacity to repair a stroke-damaged brain: An evolving field for stroke research

“…There are 4 key steps for neurogenesis: proliferation, migration, differentiation, and survival/integration. In a healthy adult brain NSCs/NPCs can accomplish these 4 processes of neurogenesis (Christie and Turnley, 2012; Dibajnia and Morshead, 2013; Kaneko et al, 2011). The newborn neurons participate in recognition, learning and memory in physiological conditions (Christie and Turnley, 2012; Dibajnia and Morshead, 2013; Mak et al, 2007; Ruan et al, 2014).…”

Biomaterial applications in neural therapy and repair

“…With limited endogenous neurogenesis and capacity to regenerate following injury, delivery of exogenous cells and bioactive molecules to the site of injury has shown to modulate the inflammatory response, stimulate endogenous stem cells, and promote neuroprotection and plasticity [86]. These transplanted cells can help in the tissue repair process by directly integrating into the host tissue or by secreting factors that promote neurogenesis [87].…”