Two-photon imaging of remyelination of spinal cord axons by engrafted neural precursor cells in a viral model of multiple sclerosis.
Neural precursor cells (NPCs) offer a promising approach for treating demyelinating diseases. However, the cellular dynamics that underlie transplanted NPC-mediated remyelination have not been described. Using two-photon imaging of a newly developed ventral spinal cord preparation and a viral model of demyelination, we describe the motility and intercellular interactions of transplanted mouse NPCs expressing green fluorescent protein (GFP) with damaged axons expressing yellow fluorescent protein (YFP). Our findings reveal focal axonal degeneration that occurs in the ventral side of the spinal cord within 1 wk following intracranial instillation with the neurotropic JHM strain of mouse hepatitis virus (JHMV). Axonal damage precedes extensive demyelination and is characterized by swelling along the length of the axon, loss of YFP signal, and transected appearance. NPCs engrafted into spinal cords of JHMV-infected mice exhibited diminished migration velocities and increased proliferation compared with transplanted cells in noninfected mice. NPCs preferentially accumulated within areas of axonal damage, initiated direct contact with axons, and subsequently expressed the myelin proteolipid protein gene, initiating remyelination. These findings indicate that NPCs transplanted into an inflammatory demyelinating microenvironment participate directly in therapeutic outcome through the wrapping of myelin around damaged neurons.
Department of Physiology and Biophysics,Institute for Immunology.
Milton L
ML
Greenberg
Department of Molecular Biology and Biochemistry,Sue and Bill Gross Stem Cell Center.
Jason G
JG
Weinger
Department of Physiology and Biophysics,Institute for Immunology.
Melanie P
MP
Matheu
Department of Molecular Biology and Biochemistry,Sue and Bill Gross Stem Cell Center.
Kevin S
KS
Carbajal
Department of Physiology and Biophysics,Department of Neurobiology and Behavior, and.
Ian
I
Parker
Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045.
Wendy B
WB
Macklin
Institute for Immunology,Department of Molecular Biology and Biochemistry,Sue and Bill Gross Stem Cell Center,Multiple Sclerosis Research Center, University of California, Irvine, CA 92697; and mcahalan@uci.edu tom.lane@path.utah.edu.
Thomas E
TE
Lane
Department of Physiology and Biophysics,Institute for Immunology,Multiple Sclerosis Research Center, University of California, Irvine, CA 92697; and mcahalan@uci.edu tom.lane@path.utah.edu.
Michael D
MD
Cahalan
D000818:Animals; D001369:Axons / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism; D002454:Cell Differentiation / Q000502:physiology; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D003711:Demyelinating Diseases / Q000473:pathology / Q000503:physiopathology / Q000628:therapy; D004195:Disease Models, Animal; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006524:Hepatitis, Viral, Animal / Q000150:complications; D008164:Luminescent Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009103:Multiple Sclerosis / Q000473:pathology / Q000628:therapy* / Q000821:virology; D006517:Murine hepatitis virus; D009186:Myelin Sheath / Q000502:physiology*; D009416:Nerve Regeneration / Q000502:physiology*; D058953:Neural Stem Cells / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology; D033581:Stem Cell Transplantation / Q000379:methods*
D001426:Bacterial Proteins; D008164:Luminescent Proteins; C054562:yellow fluorescent protein, Bacteria; D049452:Green Fluorescent Proteins
central nervous system; differentiation; microscopy; myelination; stem