Transplantation of human neural stem cells transduced with Olig2 transcription factor improves locomotor recovery and enhances myelination in the white matter of rat spinal cord following contusive injury.
BACKGROUND
Contusive spinal cord injury is complicated by a delayed loss of oligodendrocytes, resulting in chronic progressive demyelination. Therefore, transplantation strategies to provide oligodendrocyte lineage cells and to enhance the extent of myelination appear to be justified for spinal cord repair. The present study investigated whether transplantation of human neural stem cells (NSCs) genetically modified to express Olig2 transcription factor, an essential regulator of oligodendrocyte development, can improve locomotor recovery and enhance myelination in a rat contusive spinal cord injury model.


RESULTS
HB1.F3 (F3) immortalized human NSC line was transduced with a retroviral vector encoding Olig2, an essential regulator of oligodendrocyte development. Overexpression of Olig2 in human NSCs (F3.Olig2) induced activation of NKX2.2 and directed differentiation of NSCs into oligodendrocyte lineage cells in vitro. Introduction of Olig2 conferred higher proliferative activity, and a much larger number of F3.Olig2 NSCs were detected by 7 weeks after transplantation into contused spinal cord than that of parental F3 NSCs. F3.Olig2 NSCs exhibited frequent migration towards the white matter, whereas F3 NSCs were mostly confined to the gray matter or around the lesion cavities. Most of F3.Olig2 NSCs occupying the spared white matter differentiated into mature oligodendrocytes. Transplantation of F3.Olig2 NSCs increased the volume of spared white matter and reduced the cavity volume. Moreover, F3.Olig2 grafts significantly increased the thickness of myelin sheath around the axons in the spared white matter. Finally, animals with F3.Olig2 grafts showed an improvement in the quality of hindlimbs locomotion.


CONCLUSIONS
Transplantation of NSCs genetically modified to differentiate into an oligodendrocytic lineage may be an effective strategy to improve functional outcomes following spinal cord trauma. The present study suggests that molecular factors governing cell fate decisions can be manipulated to enhance reparative potential of the cell-based therapy.
Hwang
Dong H
DH
Brain Disease Research Center, Institute for Medical Sciences, Ajou University School of Medicine, Suwon, Korea. drhdh@ajou.ac.kr
Kim
Byung G
BG
Kim
Eun J
EJ
Lee
Seung I
SI
Joo
In S
IS
Suh-Kim
Haeyoung
H
Sohn
Seonghyang
S
Kim
Seung U
SU
D000704:Analysis of Variance; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics*; D002452:Cell Count; D002454:Cell Differentiation; D049109:Cell Proliferation; D002478:Cells, Cultured; D005260:Female; D053686:Fetal Stem Cells / Q000637:transplantation*; D005822:Genetic Vectors / Q000235:genetics; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007150:Immunohistochemistry; D008858:Microscopy, Phase-Contrast; D009043:Motor Activity; D009186:Myelin Sheath / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D009419:Nerve Tissue Proteins / Q000235:genetics*; D009474:Neurons / Q000166:cytology / Q000637:transplantation; D009687:Nuclear Proteins; D000076104:Oligodendrocyte Transcription Factor 2; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013116:Spinal Cord / Q000473:pathology*; D013119:Spinal Cord Injuries / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D013687:Telencephalon / Q000166:cytology; D013904:Thoracic Vertebrae; D014157:Transcription Factors; D014162:Transfection
D051792:Basic Helix-Loop-Helix Proteins; D000090322:Homeobox Protein Nkx-2.2; D018398:Homeodomain Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D000076104:Oligodendrocyte Transcription Factor 2; D014157:Transcription Factors; C000715631:NKX2-2 protein, human; C000715628:Nkx2-2 protein, rat; C405708:OLIG2 protein, human