NG2 Cell Response in the CNP-EGFP Mouse After Contusive Spinal Cord Injury

作者：Lytle Judith M; Chittajallu Ramesh; Wrathall Jean R; Gallo Vittorio^*

来源：GLIA, 2009, 57(3): 270-285.

DOI：10.1002/glia.20755

• oligodendrocyte progenitor cells
• olig2
• CNP gene
• endogenous repair
• cell proliferation
• glial growth factor
• fibroblast growth factor

NG2( ) cells in the adult CNS are a heterogeneous population. The extent to which the subpopulation of NG2( ) cells that function as oligodendrocyte progenitor cells (OPCs) respond to spinal cord injury (SCI) and recapitulate their normal developmental progression remains unclear. We used the CNP-EGFP mouse, in which oligodendrocyte lineage cells express EGFP, to study NG2 cells in the normal and injured spinal cord. In white matter of uninjured mice, bipolar EGFP( )NG2( ) cells and multipolar EGFP(neg)NG2( ) cells were identified. After SCI, EGFP( )NG2( ) cell proliferation in residual white matter peaked at 3 days post injury (DPI) rostral to the epicenter, while EGFP"'gNG2' cell proliferation peaked at 7 DPI at the epicenter. The expression of transcription factors, Olig2, Sox10, and Sox17, and the basic electrophysiological membrane parameters and potassium current phenotype of the EGFP( )NG2( ) population after injury were consistent with those of proliferative OPCs during development. EGFP(neg)NG2( ) cells did not express transcription factors involved in oligodendrogenesis. EGFP( )CC1( ) oligodendrocytes at 6 weeks included cells that incorporated BrdU during the peak of EGFP( )NG2( ) cell proliferation. EGFP(neg)9CC1( ) oligodendrocytes were never observed. Treatment with glial growth factor 2 and fibroblast growth factor 2 enhanced oligodendrogenesis and increased the number of EGFP(neg)NG2( ) cells. Therefore, based on EGFP and transcription factor expression, spatio-temporal proliferation patterns, and response to growth factors, two populations of NG2( ) cells can be identified that react to SCI. The EGFP( )NG2( ) cells undergo cellular and physiological changes in response to SCI that are similar to those that occur in early postnatal NG2( ) cells during developmental oligodendrogenesis.

• 出版日期2009-2