Transplanted neural stem/progenitor cells generate myelinating oligodendrocytes and Schwann cells in spinal cord demyelination and dysmyelination
Introduction
There is considerable interest in stem cell therapy for the treatment of the injured or diseased nervous system. The presence of neural stem/progenitor cells in the adult mammalian brain and spinal cord (Reynolds and Weiss, 1992, Weiss et al., 1996) has suggested their potential therapeutic application. Adult neural stem/progenitor cells (NSPCs) are self-renewing and multipotent, capable of generating both neurons and glia in vitro (Reynolds and Weiss, 1992, Weiss et al., 1996). When cultured in the presence of growth factors they form neurospheres which are free-floating colonies of cells primarily composed of progenitor cells and< 1% stem cells (Morshead et al., 1994). Transplantation of NSPCs derived from the adult rodent spinal cord or subventricular zone of the forebrain produced limited functional recovery after spinal cord injury (Vacanti et al., 2001, Hofstetter et al., 2005, Karimi-Abdolrezaee et al., 2006, Pfeifer et al., 2006). In the spinal cord, NSPCs reside close to the ependymal/periventricular region since multipotential self-renewing neurospheres were generated only when the cultured tissue included parts of the central canal (Martens et al., 2002). In lower vertebrates, ependymal cells rapidly proliferate and differentiate into neurons and glia to regenerate the transected cord (Nordlander and Singer, 1978, Dervan and Roberts, 2003). In adult mammals, ependymal cells proliferate in response to several types of spinal cord trauma (Vaquero et al., 1981, Bruni and Anderson, 1987, Wallace et al., 1987, Beattie et al., 1997, Johansson et al., 1999, Namiki and Tator, 1999, Takahashi et al., 2003, Mothe and Tator, 2005, Horky et al., 2006). However, endogenous NSPCs appear to have only limited regenerative capacity for repair. Increasing cell numbers through transplantation may enhance this regenerative potential.
Stem cell therapy may be particularly effective for remyelination in diseases or injuries associated with demyelination. Recently, we reported that NSPCs derived from the periventricular region of the adult spinal cord showed an intrinsic capacity for predominant oligodendrocytic differentiation without targeted manipulation by neurotrophic factors or other agents (Kulbatski et al., 2007). The current study examines the differentiation potential and myelinogenic capacity of adult spinal cord NSPCs transplanted into the spinal cord of two complementary models of demyelination, focal demyelination induced by X-irradiation/ethidium bromide (X-EB) which leaves a population of demyelinated axons in a glial-free environment (Blakemore, 1982, Crang et al., 1992), and adult shiverer mutant mice which carry a spontaneous mutation of myelin basic protein (MBP) resulting in a lack of central myelin, a model of congenital dysmyelination with a long-term irreversible myelin deficiency (Privat et al., 1979, Chernoff, 1981). Although the myelination potential of many cell types has been examined in experimental studies (Radtke et al., 2007), to our knowledge, this is the first study to examine the differentiation and myelinogenic capacity of adult spinal cord stem/progenitors in focal demyelination and dysmyelination of the adult rodent spinal cord. Our findings demonstrate that spinal cord NSPCs differentiate into oligodendrocytes or Schwann-like cells depending on the host environment, and that these cells are capable of myelinating axons in the demyelinated and dysmyelinated adult rodent spinal cord.
Section snippets
Isolation and culture of adult periventricular spinal cord NSPCs
NSPCs were isolated from the spinal cords of transgenic adult Wistar rats expressing enhanced green fluorescent protein (GFP) (Wistar-TgN(CAG-GFP)184ys) (YS Institute Inc., Utsunomiya, Tochigi, Japan). The GFP transgene is driven by chicken β-actin promoter and cytomegalovirus enhancer (Hakamata et al., 2001). NSPCs isolated from these rats stably express the transgene long term both in vitro and in vivo (Mothe et al., 2005). The isolation and generation of periventricular neurospheres were
Adult spinal cord periventricular neurospheres are multipotent
NSPCs were isolated from the periventricular region of the spinal cord from adult GFP transgenic rats and grown as free-floating neurospheres in uncoated tissue culture flasks. The neurospheres were cultured in the presence of the growth factors EGF and FGF2 and passaged weekly for expansion. Neurospheres from passages 3 or 4 were used in both the in vitro and in vivo experiments.
Figs. 1A–C shows GFP expression of a single sphere with high levels of nestin, a marker for neural/stem progenitor
Discussion
In the present study, we show that transplanted adult spinal cord NSPCs preferentially differentiate along an oligodendroglial lineage in both the focal demyelination lesion and the dysmyelinated shiverer spinal cord. However, in both EB and X-EB lesions, some of the oligodendrocytic progeny remyelinate axons, yet a significant proportion of the transplanted cells express a Schwann cell phenotype and generate peripheral myelin. In culture, we show that spinal cord NSPCs do not express a Schwann
Acknowledgments
This work was supported by operating grants to C.H.T from the Christopher Reeve Paralysis Foundation, MS Society of Canada, International Foundation of Research in Paraplegia, and in part by CIHR NET team grant. A. J. M. was supported by fellowships from the Ontario Neurotrauma Foundation and CIHR. We thank Linda Lee and Rita van Bendegem for the technical assistance and Iris Kulbatski for culturing some of the cells used for the focal demyelination transplantation experiments. We thank Dr.
References (68)
- et al.
Transplantation of clonal neural precursor cells derived from adult human brain establishes functional peripheral myelin in the rat spinal cord
Exp Neurol
(2001) - et al.
Endogenous repair after spinal cord contusion injuries in the rat
Exp Neurol
(1997) - et al.
The presence of astrocytes in areas of demyelination influences remyelination following transplantation of oligodendrocyte progenitors
Exp Neurol
(2003) - et al.
Pluripotent stem cells engrafted into the normal or lesioned adult rat spinal cord are restricted to a glial lineage
Exp Neurol
(2001) - et al.
The differentiation of glial cell progenitor populations following transplantation into non-repairing central nervous system glial lesions in adult animals
J Neuroimmunol
(1992) - et al.
Transplanted CG4 cells (an oligodendrocyte progenitor cell line) survive, migrate, and contribute to repair of areas of demyelination in X-irradiated and damaged spinal cord but not in normal spinal cord
Exp Neurol
(1996) - et al.
BMP signaling initiates a neural crest differentiation program in embryonic rat CNS stem cells
Exp Neurol
(2004) - et al.
Green fluorescent protein-transgenic rat: a tool for organ transplantation research
Biochem Biophys Res Commun
(2001) - et al.
Identification of a neural stem cell in the adult mammalian central nervous system
Cell
(1999) - et al.
Transplantation of bulk-separated oligodendrocytes into the brains of shiverer mutant mice: immunohistochemical and electron microscopic studies on the myelination
Brain Res
(1986)
Sonic hedgehog-regulated oligodendrocyte lineage genes encoding bHLH proteins in the mammalian central nervous system
Neuron
Myelination by oligodendrocytes isolated from 4–6-week-old rat central nervous system and transplanted into newborn shiverer brain
J Neurol Sci
Neural stem cells in the adult mammalian forebrain: a relatively quiescent subpopulation of subependymal cells
Neuron
Proliferation, migration, and differentiation of ependymal region stem/progenitor cells following minimal injury in the adult rat spinal cord
Neuroscience
A common neural progenitor for the CNS and PNS
Dev Biol
Absence of the major dense line in myelin of the mutant mouse “shiverer”
Neurosci Lett
Demyelinating diseases and potential repair strategies
Int J Dev Neurosci
Endogenous Nkx2.2+/Olig2+ oligodendrocyte precursor cells fail to remyelinate the demyelinated adult rat spinal cord in the absence of astrocytes
Exp Neurol
Distinct neural stem cells proliferate in response to EGF and FGF in the developing mouse telencephalon
Dev Biol
Tissue-engineered spinal cord
Transplant Proc
Chronic regenerative changes in the spinal cord after cord compression injury in rats
Surg Neurol
Identification of a novel family of oligodendrocyte lineage-specific basic helix-loop-helix transcription factors
Neuron
Remyelination of the spinal cord following intravenous delivery of bone marrow cells
Glia
Expression of the APC tumor suppressor protein in oligodendroglia
Glia
Observations on remyelination in the rabbit spinal cord following demyelination induced by lysolecithin
Neuropathol Appl Neurobiol
Ethidium bromide induced demyelination in the spinal cord of the cat
Neuropathol Appl Neurobiol
The case for a central nervous system (CNS) origin for the Schwann cells that remyelinate CNS axons following concurrent loss of oligodendrocytes and astrocytes
Neuropathol Appl Neurobiol
The relationship between type-1 astrocytes, Schwann cells and oligodendrocytes following transplantation of glial cell cultures into demyelinating lesions in the adult rat spinal cord
J Neurocytol
Ependyma of the rat fourth ventricle and central canal: response to injury
Acta Anat (Basel)
Negative regulation of central nervous system myelination by polysialylated-neural cell adhesion molecule
Proc Natl Acad Sci U S A
Re-expression of PSA-NCAM by demyelinated axons: an inhibitor of remyelination in multiple sclerosis?
Brain
Shiverer: an autosomal recessive mutant mouse with myelin deficiency
J Hered
Human neural stem cells differentiate and promote locomotor recovery in spinal cord-injured mice
Proc Natl Acad Sci U S A
Reaction of spinal cord central canal cells to cord transection and their contribution to cord regeneration
J Comp Neurol
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