SCIP/Oct-6, Krox-20, and desert hedgehog mRNA expression during CNS remyelination by transplanted olfactory ensheathing cells.
Olfactory ensheathing cells (OECs), although having a separate developmental origin to Schwann cells, are able to generate myelin sheaths following transplantation into areas of CNS demyelination that are remarkably similar to those made by Schwann cells. The transcriptional control of Schwann cell myelination has been well documented, in particular the role of SCIP/Oct-6 and Krox-20. It is not known, however, whether these transcription factors are also expressed when OECs assume a myelinating phenotype. In this study, we addressed this question by using a transplantation approach to generate myelinating OECs and then examined the expression of SCIP/Oct-6 and Krox-20 mRNA by in situ hybridization using oligonucleotide probes. We also examined the expression of desert hedgehog (Dhh), a Schwann cell-derived signaling molecule that is responsible for regulating the development of the connective tissue elements in peripheral nerve, which bear similarities to the morphologies adopted by nonmyelinating transplanted cells. Our results indicate that both Krox-20 and Dhh mRNA are strongly expressed by transplanted OECs, with SCIP mRNA present at much lower levels. The expression of Krox-20 relative to the expression of P0 mRNA by the transplanted OECs is consistent with its playing a similar role in OEC myelination to that in Schwann cell myelination, while the expression of Dhh suggests a possible mechanism for the diverse morphologies that cells adopt following OEC transplantation into the damaged CNS. Taken together, our results provide further evidence for the close similarity of OECs and Schwann cells and suggest that, despite their separate origins, the manner in which they generate a peripheral-type myelin sheath involves similar regulatory mechanisms.
Smith
P M
PM
Department of Clinical Veterinary Medicine, University of Cambridge, Cambridge, UK.
Sim
F J
FJ
Barnett
S C
SC
Franklin
R J
RJ
D000818:Animals; D000831:Animals, Newborn; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D016380:Brain Tissue Transplantation; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics*; D051767:Early Growth Response Protein 2; D005786:Gene Expression Regulation / Q000502:physiology; D053823:Hedgehog Proteins; D017403:In Situ Hybridization; D018993:Myelin P0 Protein / Q000235:genetics; D009186:Myelin Sheath / Q000378:metabolism* / Q000648:ultrastructure; D009416:Nerve Regeneration / Q000502:physiology*; D009457:Neuroglia / Q000378:metabolism* / Q000637:transplantation / Q000648:ultrastructure; D050816:Octamer Transcription Factor-6; D009830:Olfactory Bulb / Q000378:metabolism* / Q000637:transplantation / Q000648:ultrastructure; D015345:Oligonucleotide Probes; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D013116:Spinal Cord / Q000166:cytology / Q000378:metabolism / Q000601:surgery; D013119:Spinal Cord Injuries / Q000378:metabolism* / Q000503:physiopathology / Q000601:surgery; D015534:Trans-Activators / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
D004268:DNA-Binding Proteins; D051767:Early Growth Response Protein 2; C497328:Egr2 protein, rat; D053823:Hedgehog Proteins; D018993:Myelin P0 Protein; D015345:Oligonucleotide Probes; C494179:Pou3f1 protein, rat; D012333:RNA, Messenger; D015534:Trans-Activators; D014157:Transcription Factors; D050816:Octamer Transcription Factor-6