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The tetraspanin protein, CD9, is expressed by progenitor cells committed to oligodendrogenesis and is linked to β1 integrin, CD81, and Tspan‐2
Author(s) -
Terada Nobuo,
Baracskay Karen,
Kinter Mike,
Melrose Shona,
Brophy Peter J.,
Boucheix Claude,
Bjartmar Carl,
Kidd Grahame,
Trapp Bruce D.
Publication year - 2002
Publication title -
glia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.954
H-Index - 164
eISSN - 1098-1136
pISSN - 0894-1491
DOI - 10.1002/glia.10134
Subject(s) - tetraspanin , biology , oligodendrocyte , microbiology and biotechnology , immunoprecipitation , biotinylation , progenitor cell , nestin , cd81 , myelin , myelin basic protein , integrin , neural stem cell , immunology , stem cell , neuroscience , cell , antibody , genetics , central nervous system , hepatitis c virus , virus
Previous studies identified the tetraspanin protein CD9 in myelinating oligodendrocytes. The present report extends these observations by identifying CD9 in a subpopulation of oligodendrocyte progenitor cells (OPCs) and in premyelinating oligodendrocytes in rodents. NG2‐positive cells expressed CD9 in a temporal and spatial pattern during development that was consistent with CD9 expression in OPCs just prior to their differentiation into premyelinating oligodendrocytes. NG2‐positive cells in mature brains were CD9‐negative. CD9 expression during oligodendrocyte development in vitro supported this hypothesis, as all CD9‐positive cells became O4‐positive when switched to oligodendrocyte differentiating media. CD9 immunoreactivity was enriched in myelinating oligodendrocytes and their processes, and the outer aspects of myelin internodes. Immunoprecipitation of CD9 from postnatal rat cerebrum coprecipitated β1 integrin, CD81, and Tspan‐2, another tetraspanin protein recently identified in oligodendrocytes. Following surface biotinylation of oligodendrocytes in vitro, biotinylated β1 integrin was identified in a CD9 immunoprecipitate. These data support a molecular link between surface integrins and a CD9, Tspan‐2 molecular web during the differentiation of oligodendrocytes. Oligodendrocyte production and myelination appears to be normal in CD9‐deficient mice. These data support the hypothesis that CD9 helps form the tetraspanin web beneath the plasma membranes of progenitor cells committed to oligodendrogenesis, but that CD9 is not essential for oligodendrogenesis and myelination. GLIA 40:350–359, 2002. © 2002 Wiley‐Liss, Inc.