Cellular transplantation for repair of spinal cord injury is a promising therapeutic strategy that includes the use of a variety of neural and non-neural cells isolated or derived from embryonic and adult tissue as well as embryonic stem cells and induced pluripotent stem cells.
In particular, transplants of neural progenitor cells (NPCs) have been shown to limit secondary injury and scar formation and create a permissive environment in the injured spinal cord through the provision of neurotrophic molecules and growth supporting matrices that promote growth of injured host axons.
Importantly, transplants of NPC are unique in their potential to replace lost neural cells - including neurons, astrocytes, and oligodendrocytes - critical for reconstruction of the normal microenvironment of the spinal cord and restoration of connectivity and function.
The model that Prof. Itzhak Fischer comes from Drexel University in USA has proposed focuses on the formation of a functional relay to reconnect the injured spinal cord and requires the formation of two synaptic connections, one between host axons and graft-derived neurons, and the other between graft axons and target sites within the host (Figure 1).
The design of such a relay requires specific steps that assure:
- graft survival and generation of neurons,
- axon growth into and out of the graft by host axons and graft-derived neurons, respectively and
- formation of physiologically active synaptic connections and restoration of function.
The relevant study has been published in Neural Regeneration Research (Vol. 9, No. 12, 2014).
Article: "Transplanting neural progenitors to build a neuronal relay across the injured spinal cord." by Christopher Haas, Itzhak Fischer (Drexel University College of Medicine, Department of Neurobiology & Anatomy, Philadelphia, PA, USA)
Haas C, Fischer I. Transplanting neural progenitors to build a neuronal relay across the injured spinal cord. Neural Regen Res. 2014;9(12): 1173-1176.
This image depicts forming a synaptic relay to reconnect the injured sensory system.
Image credit: Neural Regeneration Research