Characterization of three human oligodendroglial cell lines as a model to study oligodendrocyte injury: morphology and oligodendrocyte-specific gene expression.

Oligodendrocytes, the myelin-forming cells of the central nervous system, are the target of pathogenic immune responses in multiple sclerosis. Primary cultures of human oligodendrocytes have been used to unravel the cellular and molecular mechanisms of immune-mediated injury of oligodendrocytes. However, these studies are hampered by the limited availability of viable human brain tissue. The present study was aimed at comparing the morphological and biochemical characteristics of the human oligodendroglial cell lines HOG, MO3.13 and KG-1C. We have determined oligodendrocyte-associated features of these lines and analyzed the degree to which they can be used as a model of human oligodendrocytes arrested at specific developmental stages. The oligodendroglial cell lines all exhibited markers of immature oligodendrocytes, such as CNPase and GalC, but not the astrocytic marker GFAP. Differentiation could be induced in HOG and MO3.13 cells, as was seen through a decrease in proliferation, an increase in process extension without formation of myelin sheets and up-regulation of genes associated with mature oligodendrocytes such as MBP and MOG. Microarray analysis revealed the expression of MAG, MOBP and OMG genes in HOG cells. The KG-1C cells displayed poor growth characteristics in the recommended conditions. In conclusion, our data show that the oligodendroglial cell lines HOG and MO3.13 can be used as a model of human oligodendrocytes "arrested" in an immature developmental stage. Culturing in appropriate medium can induce further differentiation of these cells. These cell lines can therefore be applied as a model to study immune-mediated injury of oligodendrocytes in relation to disease.