i(3)so3-galactosylceramide and Central-Nervous-System-Diseases

CNS myelin is strongly inhibitory to growing axons and is thought to be a major contributor to CNS axon regenerative failure. Although a number of proteins present in myelin, including Nogo, MAG, and oligodendrocyte-myelin glycoprotein (OMgp), have been identified as myelin-associated inhibitors, studies of mice lacking these genes suggest that additional inhibitors present in CNS myelin remain to be identified. Here we have investigated the hypothesis that myelin lipids contribute to CNS regenerative failure. We identified sulfatide, a major constituent of CNS myelin, as a novel myelin-associated inhibitor of neurite outgrowth. Sulfatide, but not galactocerebroside or ceramide, strongly inhibited the neurite outgrowth of retinal ganglion cells (RGCs) when used as a purified lipid substrate. The mechanism involved in sulfatide-mediated inhibition may share features with other known inhibitors, because the Rho inhibitor C3 transferase lessened these effects. Myelin in which sulfatide was lacking or blocked using specific antibodies was significantly less inhibitory to RGC neurite outgrowth in vitro than was wild-type myelin, indicating that sulfatide is a major component of the inhibitory activity of CNS myelin. Mice unable to make sulfatide did not regenerate RGC axons more robustly after optic nerve crush than wild-type littermates under normal conditions but did exhibit a small but significant enhancement in the extent of zymosan-induced regeneration. These results demonstrate that specific lipids can powerfully inhibit axon growth, identify sulfatide as a novel myelin-associated axon growth inhibitor, and provide evidence that sulfatide inhibition contributes to axon regenerative failure in vivo.

Topics: Animals; Animals, Newborn; Antibodies; Axons; Cell Survival; Cells, Cultured; Central Nervous System Diseases; Disease Models, Animal; Humans; Mice; Mice, Inbred C57BL; Mice, Knockout; Models, Biological; Myelin Proteins; Nerve Regeneration; Neural Inhibition; Optic Nerve Injuries; Rats; Rats, Sprague-Dawley; Retinal Ganglion Cells; rhoA GTP-Binding Protein; Sulfoglycosphingolipids; Sulfotransferases; Sulfurtransferases; Transfection; Zymosan

The identity of target antigen(s) in multiple sclerosis (MS) remains elusive despite much effort to identify it. We analyzed cerebrospinal fluid (CSF) from patients with MS, other neurological diseases (OND), other diseases (OD) and healthy controls for antibodies against purified sulfatide, a major glycosphingolipid of human myelin, by an enzyme-linked immunosorbent assay (ELISA) and a thin-layer chromatogram (TLC)-immunostaining technique. Elevated anti-sulfatide antibodies were significantly higher in MS patients as compared with the OND group (p<0.05) and all controls combined (P<0.025). Binding of high titer antibodies to sulfatide was confirmed with TLC-immunostaining. Anti-sulfatide antibodies were detected in all subtypes of MS although the frequency was higher in patients with secondary progressive MS (SPMS) than in patients with primary progressive (PPMS) and relapsing-remitting MS (RRMS). The data demonstrate a humoral response to sulfatide in the CSF of patients with MS.

Topics: Adult; Aged; Aged, 80 and over; Autoantibodies; Central Nervous System Diseases; Chromatography, Thin Layer; Diabetes Mellitus; Enzyme-Linked Immunosorbent Assay; Female; Humans; Lupus Vulgaris; Male; Middle Aged; Multiple Sclerosis; Myelin Sheath; Myocardial Infarction; Neoplasms; Protein Binding; Recurrence; Sulfoglycosphingolipids

A woman aged 21 with a variant form of metachromatic leucodystrophy (MLD) combined with another form of leucodystrophy is described. The clinical symptoms were retinitis pigmentosa and progressive neurological deficits such as mental retardation, dystonia, pyramidal tract involvement and peripheral neuropathy. The biochemical findings were marked deficiency of arylsulfatase-A and cerebroside-sulfatase in cultured fibroblasts and excretion of sulfatides in the urine. Sulfatide-loading of cultured fibroblasts showed almost normal uptake and degradation of sulfatides. The patient's sister suffers from a clinically similar neurological disease, but normal activity of arylsulfatase-A was found in her leucocytes. A severe oral-facial dystonia in the patient was successfully controlled by l-dopa.

Topics: Adult; Central Nervous System Diseases; Cerebroside-Sulfatase; Female; Fibroblasts; Humans; Intellectual Disability; Leukocytes; Leukodystrophy, Metachromatic; Nerve Degeneration; Neuromuscular Diseases; Retinitis Pigmentosa; Sulfoglycosphingolipids

Topics: Animals; Brain; Cell Differentiation; Central Nervous System Diseases; Cholesterol; Chromatography, Thin Layer; Demyelinating Diseases; Diffuse Cerebral Sclerosis of Schilder; Disease Models, Animal; DNA; Electrophoresis, Polyacrylamide Gel; Male; Mice; Mice, Inbred Strains; Myelin Basic Protein; Myelin Sheath; Nerve Fibers, Myelinated; Nerve Tissue Proteins; Neuroglia; Phospholipids; RNA; Sulfoglycosphingolipids

Myelin was isolated from the brains of "quaking" and littermate control animals and its composition was determined. The brains of quaking animals contained approximately one-fourth as much myelin as the control animals. There were qualitative as well as quantitative differences between the myelin from the two groups. By continuous cesium chloride gradient flotation it was shown that the myelin from the quaking animals consisted solely of a band corresponding to the heavier and smaller of the two bands found in normal controls. Cholesterol and glycolipids were lower and phospholipids (mainly phosphatidylcholine) and protein were higher in quaking animals than in controls. Also, phosphatidal-ethanolamine was decreased, and several consistent differences in the fatty acids (both unsubstituted and hydroxy) and aldehydes of the component lipids were found. In general there were smaller amounts of monounsaturated fatty acids in quaking animals. We suggest from these findings that myelin in the quaking mouse has certain compositional similarities with juvenile myelin, but it may be an abnormal type of myelin.

Topics: Animals; Body Weight; Brain; Central Nervous System Diseases; Centrifugation, Density Gradient; Cerebrosides; Cholesterol; Chromatography, Gas; Chromatography, Thin Layer; Fatty Acids; Female; Mice; Mice, Inbred Strains; Mutation; Myelin Sheath; Organ Size; Phosphatidylcholines; Phosphatidylethanolamines; Phospholipids; Seizures; Sphingomyelins; Sulfoglycosphingolipids