Potential of olfactory ensheathing cells for cell-based therapy in spinal cord injury

Abstract

Abstract-Contusive spinal cord injury (SCI) results in a complex lesion that includes cellular and axonal loss, microglia and macrophage activation, and demyelination. These changes result in permanent neurological deficits in people with SCI and in high financial costs to society. Unlike the peripheral nervous system (PNS), in which axonal regeneration can occur, axonal regeneration in the central nervous system (CNS) is extremely limited. This limited regeneration is thought to result from a lack of a permissive environment and from active inhibitory molecules that are present in the CNS but minimal in the PNS. Currently, cell transplantation approaches are among several experimental strategies being investigated for the treatment of SCI. In the olfactory system, a specialized glial cell called the olfactory ensheathing cell (OEC) has been shown to improve functional outcome when transplanted into rodents with SCI, and clinical studies transplanting OECs into patients with SCI are ongoing in China, Portugal, and other sites. Yet, a number of controversial issues related to OEC biology and transplantation must be addressed to understand the rationale and expectations for OEC cell therapy approaches in SCI. This review provides information on these issues for spinal cord medicine clinicians.

The Development of a ɛ-Polycaprolactone Scaffold for Central Nervous System Repair

“…Polymers can also be blended with each other, to combine properties of their constituent materials including PCL/PGLA 13 and PCL/ chitosan. 14,15 They can be combined with other treatment strategies, such as cell transplants including glia that is, Schwann cells or olfactory ensheathing cells (OECs), neural progenitor cells, or stem cells [16][17][18][19] ; or impregnated with compounds noted for their neurotrophic properties or ability to disrupt the inhibitory scar environment. This combinatorial approach has demonstrated some success in the encouragement of neurite outgrowth or functional recovery, such as the combination of a PCL scaffold with neural progenitor cell implantation and perfusion with chondroitinase ABC, 18 or PCL nanofibers impregnated with the brainderived neurotrophic factor.…”

The Immunohistochemical Characterization of Human Fetal Olfactory Bulb and Olfactory Ensheathing Cells in Culture as a Source for Clinical CNS Restoration

“…More and more literature reviews give us more and more hope that OEC transplantation to be one of the most promising therapeutic strategies (Barnett and Riddell, 2007;Sasaki et al, 2007;Bauchet et al, 2008;Bunge, 2008;Radtke et al, 2008;Richter and Roskams, 2008;Kawaja et al, 2009); OECs have been successfully transplanted in acute (Resnick et al, 2003;Polentes et al, 2004;Collazos-Castro et al, 2005;Lopez-Vales et al, 2006;Andrews and Stelzner, 2007;Sasaki et al, 2007) and chronic (Andrews and Stelzner, 2004;Lopez-Vales et al, 2007) models of rodent spinal cord injury. Data obtained using various injury models support the view that OEC transplants can reduce cavitation, increase axonal sprouting and regeneration, and a moderate degree of functional motoric recovery (Li et al, 1997;Ramon-Cueto et al, 2000;Collazos-Castro et al, 2005;Lopez-Vales et al, 2007;Sasaki et al, 2007).…”

Stem Cells: New Hope For Spinal Cord Injury

“…OECs have the dual nature of astroglial cells and Schwann cells (33). Several preclinical SCI studies have reported the occurrence of axonal extension, remyelination and neuroprotection after OEC transplantation (34,35,36,37,38). OECs migrate to injured sites and secrete a large number of factors that are necessary for the growth, development, differentiation, and maturation of different types of neurons and reduce astrocyte activity and glial scar formation (39,40).…”