Inflammation stimulates myelination by transplanted oligodendrocyte precursor cells.
Inflammation associated with CNS demyelination provides an important stimulus for the activation of endogenous oligodendrocyte precursor cells (OPCs) and subsequent remyelination. This view is largely based on "loss-of-function" studies, whereby remyelination is impaired following depletion of inflammatory cells or mediators. However, "gain-of-function" approaches, asking whether inflammation directly enhances remyelination, have received less attention. We have addressed this issue using a model in which OPCs transplanted into the adult rat retina myelinate retinal ganglion cell axons around the point of injection. Inflammation (characterized by increased expression of the macrophage marker ED1 and the astrocyte marker GFAP, and the up-regulation of multiple cytokines) was induced in the retina by the administration of the TLR-2 ligand zymosan. Myelination, revealed by MBP+ myelin sheaths, was substantially increased when OPCs were injected into the inflamed retina compared to that achieved following transplantation into the normal, noninflamed retina. Our results have important implications for the development of immunomodulatory treatments for acute demyelinating disease and for the therapeutic creation of proremyelination environments in chronic demyelinating disease.
Setzu
Anna
A
Cambridge Centre for Brain Repair and MS Society Cambridge Centre for Myelin Repair,University of Cambridge, Cambridge, United Kingdom.
Lathia
Justin D
JD
Zhao
Chao
C
Wells
Karen
K
Rao
Mahendra S
MS
Ffrench-Constant
Charles
C
Franklin
Robin J M
RJ
D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D017690:Cell Transplantation / Q000502:physiology; D002540:Cerebral Cortex / Q000166:cytology; D005904:Glial Fibrillary Acidic Protein / Q000378:metabolism; D007150:Immunohistochemistry; D007908:Lens, Crystalline / Q000293:injuries; D008024:Ligands; D009186:Myelin Sheath / Q000502:physiology*; D009412:Nerve Fibers / Q000502:physiology; D009836:Oligodendroglia / Q000502:physiology* / Q000637:transplantation*; D020411:Oligonucleotide Array Sequence Analysis; D051381:Rats; D011916:Rats, Inbred F344; D012160:Retina / Q000166:cytology; D012173:Retinitis / Q000139:chemically induced / Q000473:pathology* / Q000628:therapy*; D051195:Toll-Like Receptor 2 / Q000187:drug effects; D015054:Zymosan
D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D008024:Ligands; C495343:Tlr2 protein, rat; D051195:Toll-Like Receptor 2; D015054:Zymosan