Characterization of oligodendrocyte CD200 in rats

• Main Authors: TIEN-NI LO, 羅典妮
• Other Authors: CHING-HSIANG WU
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/06275307102882226410

碩士 === 國防醫學院 === 生物及解剖學研究所 === 95 === Abstract Glial cells in the central nervous system include astrocytes, oligodendrocytes, microglia and ependymal cells. Oligodendrocytes which we focus on in the present study show few long and thin processes investing the axons and forming the myelin sheath through kinds of adhesion molecules, in particular the immunoglobulin superfamily. Also being a member of immunoglobulin superfamily, CD200 contains two immunoglobulin domains and mediates cell-cell interaction by binding with CD200 receptor. The previous researches pointed out that CD200 was distributed at some neurons, including neuronal cell bodies and axon processes in the cerebellum, and related to the axonogenesis and myelination. These evidences lead us to assume that CD200 may exist on oligodendrocytes and play the importance role in events relating to axonal growth and myelination. In this connection, the purposes of the present study are to examine CD200 expression on oligodendrocytes. Our results showed that CD200 immunoreactivity was distributed along the nerve fibers in a patchy pattern and at oligodendrocyte-like cells in the optic nerves and primary glial culture. The labeled cells were confirmed as an oligodendrocyte using the double labeling of CD200 and RIP (oligodendrocyte marker) and laser confocal microscope. Examinations with the electron microscope and enriched oligodendrocyte culture also verified the existence of oligodendrocyte CD200. To know the role of oligodendrocyte CD200, co-cultures of oligodendrocytes and microglia that possessing CD200 receptors (CD200R) and the treatment of anti-CD200 or anti-CD200R antibody in these mixed glial cultures were applied. We found that oligodendrocytes were died after treatment of anti-CD200 antibody in dose-dependent manner, while microglia spread out more widely when anti-CD200R antibody was added. In the culture model of the neurosphere that oligodendrocytes constituted most of the neural precursor cells progeny, we found that the spreading and adhesion of the neurospheres were inhibited with the treatment of anti-CD200 antibody that also interfered the migration of differentiating oligodendrocytes from neurospheres. Our results showed that CD200 immunoreactivity was distributed at cytoplasmic membrane of oligodendrocytes and the loops at paranodular region. Unexpectedly, oligodendrocytes were degenerated when incubated with anti-CD200 antibody in dose-dependent manner, but microglia spread out more widely as anti-CD200R antibody was added. Furthermore, in the culture model of the neurosphere that oligodendrocytes constituted most of the neural precursor cells progeny, we found that the spreading and adhesion of the neurospheres were inhibited with the treatment of anti-CD200 antibody that also interfered the migration of differentiating oligodendrocytes from neurospheres.