Net sulfatide synthesis, galactosylceramide sulfotransferase and arylsulfatase A activity in the developing cerebrum and cerebellum of normal mice and myelin-deficient jimpy mice.
Net sulfatide synthesis, galactosylceramide sulfotransferase (EC 2.8.2.11) and arylsulfatase A (EC 3.1.6.1) activities were measured in two brain regions, cerebrum and cerebellum, of normal and jimpy mice during postnatal development. In normally myelinating mice, two phases of increasing rates of net sulfatide synthesis were observed, the first coinciding with oligodendrocyte proliferation and the second with myelination. Net sulfatide synthesis was quantitatively higher in the cerebellum than in the cerebrum. In both brain regions, the developmental patterns of net sulfatide synthesis were related to the activity patterns of both galactosylceramide sulfotransferase and arylsulfatase A. In jimpy mice, a neurological mutant showing hypomyelination in brain, the first phase of net sulfatide synthesis was preserved in both brain regions and galactosylceramide sulfotransferase and arylsulfatase A activities were normal up to 12 days. However, during the phase in which myelination occurred in controls, the net sulfatide synthesis in both brain regions of jimpy mice was zero or even negative. The sulfatide deficit was larger in the cerebellum than in the cerebrum. In both mutant brain parts, galactosylceramide sulfotransferase activity increased up to 12 days showing about 50% of the maximal activities observed in normal brain regions. Thereafter up to 15 days, enzyme activity decreased to about 25% of that of controls and remained low in both brain regions. The developmental patterns and the activities of arylsulfatase A were, however, normal in the cerebrum and cerebellum of jimpy mice. These results suggest that the enzyme activities and the developmental patterns of galactosylceramide sulfotransferase and arylsulfatase A as measured in vitro reflect to a high degree their functional activity in vivo. Furthermore, sulfatide degradation by arylsulfatase A seems to be important in regulating net sulfatide synthesis during normal and impaired myelination.
D000818:Animals; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D002531:Cerebellum / Q000254:growth & development / Q000378:metabolism*; D002553:Cerebroside-Sulfatase / Q000378:metabolism*; D002554:Cerebrosides / Q000378:metabolism; D008297:Male; D051379:Mice; D008816:Mice, Jimpy; D009186:Myelin Sheath / Q000378:metabolism; D013429:Sulfatases / Q000378:metabolism*; D013433:Sulfoglycosphingolipids / Q000096:biosynthesis*; D015238:Sulfotransferases; D013466:Sulfurtransferases / Q000378:metabolism*
D002554:Cerebrosides; D013433:Sulfoglycosphingolipids; D013466:Sulfurtransferases; D015238:Sulfotransferases; C020556:galactosylceramide sulfotransferase; D013429:Sulfatases; D002553:Cerebroside-Sulfatase