title: ATP-binding cassette transporter ABCA2 (ABC2) expression in the developing spinal cord and PNS during myelination.
abstract: We examined developmental characteristics of the ATP-binding cassette transporter ABCA2 (or ABC2) -expressing cells in rat spinal cord and peripheral nerves. In adult spinal cord, ABCA2 immunoreactivity was detected in lysosome-like organelles of mature oligodendrocyte cell bodies, and a single specific band was detected by Western blot analysis. In postnatal developing spinal cord, ABCA2 immunolabeling was first detected in a small number of cells restricted to the ventral marginal area and the dorsal funiculus at birth (P0). ABCA2-positive cells were co-immunolabeled by O4, a marker for late progenitor and immature oligodendrocytes. At the same time, myelin basic protein was apparent in the same restricted regions. The number of ABCA2 and O4 co-immunolabeled cells increased quickly in both dorsal and ventral regions from P2 and reached a peak at P8. After transient expression from P0 to P8, O4 labeling in white matter tracts decreased and disappeared. In contrast, ABCA2-positive oligodendrocytes persisted in gray and white matter throughout the spinal cord into adulthood. These data suggest a role for the ABCA2 transporter in maturation of oligodendrocyte lineage cells and the onset of myelination in the central nervous system. In addition, ABCA2 immunoreactivity was detected in the ciliated region of the ependyma in the central canal from early postnatal development. ABCA2 immunoreactivity was also detected in the Schwann cell lineage in developing spinal nerves and in adult trigeminal and sciatic nerves. ABCA2 was also expressed in numerous undetermined cells distributed in para-nerve connective tissues and nerve sheaths throughout early postnatal development. These data indicate multiple levels of involvement for ABCA2 in nervous system development especially with strong evidence for a role in myelination.
authors.affiliation: Department of Neurology, Neurodevelopmental Disorders Laboratory, Program in Neuroscience, University of California at San Francisco, California 94143-0435, USA. zhoucj@itsa.ucsf.edu
authors.forename: Cheng-Ji
authors.initials: CJ
authors.lastname: Zhou
authors.forename: Nobuya
authors.initials: N
authors.lastname: Inagaki
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Pleasure
authors.forename: Li-Xia
authors.initials: LX
authors.lastname: Zhao
authors.forename: Sakae
authors.initials: S
authors.lastname: Kikuyama
authors.forename: Seiji
authors.initials: S
authors.lastname: Shioda
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000032:analysis* / Q000096:biosynthesis; D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D015415:Biomarkers; D019070:Cell Lineage; D004805:Ependyma / Q000737:chemistry / Q000166:cytology / Q000254:growth & development; D005904:Glial Fibrillary Acidic Protein / Q000032:analysis; D007150:Immunohistochemistry; D009186:Myelin Sheath / Q000378:metabolism; D009836:Oligodendroglia / Q000737:chemistry / Q000378:metabolism; D017933:Peripheral Nervous System / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development*; D051381:Rats; D017207:Rats, Sprague-Dawley / Q000378:metabolism*; D012583:Schwann Cells / Q000737:chemistry / Q000378:metabolism; D013116:Spinal Cord / Q000737:chemistry* / Q000166:cytology / Q000254:growth & development*
chemical_list: D018528:ATP-Binding Cassette Transporters; C498825:Abca2 protein, rat; D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein