First published online September 13, 2007
Stem Cells
Vol. 25 No.
12
December 2007, pp.
3204
-3214
doi:10.1634/stemcells.2007-0284; www.StemCells.com
© 2007 AlphaMed Press
TISSUE-SPECIFIC STEM CELLS |
Bone Morphogenetic Protein Signaling and Olig1/2 Interact to Regulate the Differentiation and Maturation of Adult Oligodendrocyte Precursor Cells
Xiaoxin Chenga,b,
Yaping Wanga,b,d,
Qian Hea,b,
Mengsheng Qiua,c,
Scott R. Whittemorea,b,c,
Qilin Caoa,b
aKentucky Spinal Cord Injury Research Center and
Departments of bNeurological Surgery and
cAnatomical Sciences and Neurobiology, University of Louisville School of Medicine, Louisville, Kentucky, USA;
dDepartment of Anesthesiology, Second Xian-Ya Hospital of South Central University, Changsha, Hunan, People's Republic of China
Key Words. Adult oligodendrocyte precursor cell • Spinal cord • Bone morphogenetic protein • Transcription factor • Differentiation • Remyelination
Correspondence: Qilin Cao, M.D., Kentucky Spinal Cord Injury Research Center, Department of Neurological Surgery, MDR 616, 511 South Floyd Street, University of Louisville School of Medicine, Louisville, Kentucky 40202, USA. Telephone: 502-852-0284; Fax: 502-852-5148; e-mail: q0cao001{at}gwise.louisville.edu
Received April 18, 2007;
accepted for publication August 31, 2007.
First published online in STEM CELLS EXPRESS September 13, 2007.
Promotion of remyelination is an important therapeutic strategy for the treatment of the demyelinating neurological disorders. Adult oligodendrocyte precursor cells (OPCs), which normally reside quiescently in the adult central nervous system (CNS), become activated and proliferative after demyelinating lesions. However, the extent of endogenous remyelination is limited because of the failure of adult OPCs to mature into myelinating oligodendrocytes (OLs) in the demyelinated CNS. Understanding the molecular mechanisms that regulate the differentiation of adult OPCs could lead to new therapeutic strategies to treat these disorders. In this study, we established a stable culture of adult spinal cord OPCs and developed a reliable in vitro protocol to induce their sequential differentiation. Adult OPCs expressed bone morphogenetic protein (BMP) type Ia, Ib, and II receptor subunits, which are required for BMP signal transduction. BMP2 and 4 promoted dose-dependent astrocyte differentiation of adult OPCs with concurrent suppression of OL differentiation. Treatment of OPCs with BMP2 and 4 increased ID4 expression and decreased the expression of olig1 and olig2. Overexpression of olig1 or olig2 blocked the astrocyte differentiation of adult OPCs induced by BMP2 and 4. Furthermore, overexpression of both olig1 and olig2, but not olig1 or olig2 alone, rescued OL differentiation from inhibition by BMP2 and 4. Our results demonstrated that downregulation of olig1 and olig2 is an important mechanism by which BMP2 and 4 inhibit OL differentiation of adult OPCs. These data suggest that blocking BMP signaling combined with olig1/2 overexpression could be a useful therapeutic strategy to enhance endogenous remyelination and facilitate functional recovery in CNS demyelinated disorders.
Disclosure of potential conflicts of interest is found at the end of this article.

Copyright © 2007 by AlphaMed Press.