i(3)so3-galactosylceramide and Nerve-Degeneration

The pathological cascade leading from primary storage to neural cell dysfunction and death in metachromatic leukodystrophy (MLD) has been poorly elucidated in human-derived neural cell systems. In the present study, we have modeled the progression of pathological events during the differentiation of patient-specific iPSCs to neuroepithelial progenitor cells (iPSC-NPCs) and mature neurons, astrocytes, and oligodendrocytes at the morphological, molecular, and biochemical level. We showed significant sulfatide accumulation and altered sulfatide composition during the differentiation of MLD iPSC-NPCs into neuronal and glial cells. Changes in sulfatide levels and composition were accompanied by the expansion of the lysosomal compartment, oxidative stress, and apoptosis. The neuronal and glial differentiation capacity of MLD iPSC-NPCs was significantly impaired. We showed delayed appearance and/or reduced levels of oligodendroglial and astroglial markers as well as reduced number of neurons and disorganized neuronal network. Restoration of a functional Arylsulfatase A (ARSA) enzyme in MLD cells using lentiviral-mediated gene transfer normalized sulfatide levels and composition, globally rescuing the pathological phenotype. Our study points to MLD iPSC-derived neural progeny as a useful in vitro model to assess the impact of ARSA deficiency along NPC differentiation into neurons and glial cells. In addition, iPSC-derived neural cultures allowed testing the impact of ARSA reconstitution/overexpression on disease correction and, importantly, on the biology and functional features of human NPCs, with important therapeutic implications.

Topics: Apoptosis; Cell Differentiation; Glycosphingolipids; Humans; Induced Pluripotent Stem Cells; Leukodystrophy, Metachromatic; Lysosomes; Models, Biological; Nerve Degeneration; Neural Stem Cells; Neuroglia; Neurons; Oxidative Stress; Reactive Oxygen Species; Sulfoglycosphingolipids

Demyelination and axonal degeneration are the hallmarks of established white matter lesions (WML). The neurochemistry of ongoing WML is only partially known. We explored cerebrospinal fluid (CSF) substances as markers of brain tissue damage in relation to progression of WML rated on magnetic resonance imaging.. CSF from elderly individuals with WML was analyzed for amyloid markers, total τ, hyperphosphorylated τ, neurofilament protein light subunit, sulfatide and CSF/serum-albumin ratio. After 3 years, a follow-up magnetic resonance imaging was performed. Progression of WML was rated using the Rotterdam Progression Scale (RPS).. 37 subjects (age 73.6 ± 4.6 years) were included. Subjects with more pronounced progression (RPS > 2; n = 15) had lower mean sulfatide concentration at baseline as compared to subjects with no or minimal progression (RPS 0-2; n = 22) according to univariate analyses (p = 0.009). Sulfatide was the only biomarker that predicted the RPS score according to regression analysis, explaining 18.9% of the total variance (r = 0.38, p = 0.015).. The correlation of CSF sulfatide levels and RPS scores may reflect a remyelination response to the demyelination process associated with WML. Furthermore, the results strengthen the notion that WML pathology is different from that of Alzheimer's disease.

Topics: Aged; Aged, 80 and over; Alzheimer Disease; Amyloid beta-Peptides; Biomarkers; Brain; Dementia, Vascular; Demyelinating Diseases; Disease Progression; Female; Humans; Image Processing, Computer-Assisted; Leukoaraiosis; Linear Models; Magnetic Resonance Imaging; Male; Nerve Degeneration; Netherlands; Neuropsychological Tests; Predictive Value of Tests; Socioeconomic Factors; Sulfoglycosphingolipids; tau Proteins

Metachromatic leukodystrophy is a lysosomal storage disorder caused by deficiency in the sulfolipid degrading enzyme arylsulfatase A (ASA). In the absence of a functional ASA gene, 3-O-sulfogalactosylceramide (sulfatide; SGalCer) and other sulfolipids accumulate. The storage is associated with progressive demyelination and various finally lethal neurological symptoms. Lipid storage, however, is not restricted to myelin-producing cells but also occurs in neurons. It is unclear whether neuronal storage contributes to symptoms of the patients. Therefore, we have generated transgenic ASA-deficient [ASA(-/-)] mice overexpressing the sulfatide synthesizing enzymes UDP-galactose:ceramide galactosyltransferase (CGT) and cerebroside sulfotransferase (CST) in neurons to provoke neuronal lipid storage. CGT-transgenic ASA(-/-) [CGT/ASA(-/-)] mice showed an accumulation of C18:0 fatty acid-containing SGalCer in the brain. Histochemically, an increase in sulfolipid storage could be detected in central and peripheral neurons of both CGT/ASA(-/-) and CST/ASA(-/-) mice compared with ASA(-/-) mice. CGT/ASA(-/-) mice developed severe neuromotor coordination deficits and weakness of hindlimbs and forelimbs. Light and electron microscopic analyses demonstrated nerve fiber degeneration in the spinal cord of CGT/ASA(-/-) mice. CGT/ASA(-/-) and, to a lesser extent, young ASA(-/-) mice exhibited cortical hyperexcitability, with recurrent spontaneous cortical EEG discharges lasting 5-15 s. These observations suggest that SGalCer accumulation in neurons contributes to disease phenotype.

Topics: Analysis of Variance; Animals; Behavior, Animal; Cerebral Cortex; Cerebroside-Sulfatase; Disease Models, Animal; Electroencephalography; In Situ Hybridization; Leukodystrophy, Metachromatic; Lipids; Mice; Mice, Transgenic; Microscopy, Electron, Transmission; Motor Skills; N-Acylsphingosine Galactosyltransferase; Nerve Degeneration; Neurons; Rats; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Spinal Cord; Sulfoglycosphingolipids; Sulfotransferases

BACKGROUND - To evaluate cerebrospinal fluid (CSF) markers for neuronal degeneration and demyelination in idiopathic normal pressure hydrocephalus (INPH), subcortical arteriosclerotic encephalopathy (SAE), and neurologically healthy subjects. METHODS - Lumbar CSF concentrations of sulfatide, neurofilament protein light (NFL), total-tau (T-tau), hyperphosphorylated tau (P-tau), and beta-amyloid(1-42) (Abeta42) were analyzed in 62 INPH patients, 26 SAE patients, and 23 neurologically healthy controls. In INPH patients, samples before and after shunt surgery were analysed. RESULTS - The CSF concentration of NFL was elevated in INPH and SAE compared with the controls, and levels of T-tau, P-tau, and Abeta42 were lower in INPH compared with SAE and controls. No difference was seen for sulfatide. All markers except Abeta42 were significantly elevated after shunt surgery. CONCLUSIONS - The most striking finding was the power of the combined pattern of NFL, P-tau, and Abeta42 in distinguishing between the clinical diagnoses of INPH, SAE, and neurologically healthy elderly.

Topics: Age Factors; Aged; Aged, 80 and over; Amyloid beta-Peptides; Biomarkers; Cerebrospinal Fluid; Cerebrospinal Fluid Pressure; Cerebrospinal Fluid Shunts; Diagnosis, Differential; Female; Humans; Hydrocephalus, Normal Pressure; Intracranial Arteriosclerosis; Intracranial Hypertension; Male; Middle Aged; Nerve Degeneration; Neurofilament Proteins; Peptide Fragments; Predictive Value of Tests; Sensitivity and Specificity; Sulfoglycosphingolipids; tau Proteins; Up-Regulation

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

Sulfatide synthesis from sulfate is much greater in the peripheral nerves of the Trembler mouse. After nerve transection, during Wallerian degeneration, this synthesis rate drops down very rapidly in both normal and Trembler mice. Twenty-four hours after permanent transection, the rate of synthesis is reduced by 80% in the mutant and 50% in the normal mouse. Four days after transection, the synthesis rate in the Trembler is only 9% of that observed in intact nerves, and 21% of that in the intact nerves of normal animals. After 5 d the synthesis remains constant. Thus, enhanced synthesis of sulfatides in the Trembler mouse is probably not caused by Wallerian degeneration. After crush of the sciatic nerve, the synthesis rate decreases very rapidly in the normal mouse as it does after permanent transection. But during regeneration, from the 7th day, it rises dramatically and 14 d after crush, a 2.5-fold increase in the synthesis rate is observed, compared to that in the contralateral control nerve. This synthesis rate returns to normal 1 mo after crush. In the Trembler, the synthesis decreases for 2 d after crush and increases from then on, eventually reaching the value of the contralateral control Trembler nerve within 2 mo. In the mutant there is no prominent peak of sulfatide synthesis during regeneration.

Topics: Animals; Mice; Mice, Neurologic Mutants; Myelin Sheath; Nerve Crush; Nerve Degeneration; Sciatic Nerve; Sulfates; Sulfoglycosphingolipids; Time Factors; Wallerian Degeneration

The structural alterations of monogalactosylceramides in peripheral nerve were investigated during development, nerve fiber degeneration and regeneration. During early development, hydroxy cerebrosides and sulfatides were the main constituents of the monogalactosylceramides of immature rat sciatic endoneurium. The ratio of hydroxy to nonhydroxy cerebrosides decreased rapidly as myelination proceeded but remained fairly constant throughout adulthood. More than 50% of the adult content of endoneurial monogalactosylceramides was achieved before 21 days of age. The long-chain nonhydroxy fatty acids (above C21) had increased from under 20% to over 80% by day 20, while 24h:0 (h, hydroxy) had already reached approximately 50% of hydroxy cerebrosides by day 12. These results suggest that the biosynthesis of endoneurial monogalactosylceramides and fatty acid elongation take place preferentially at the time when peripheral nerve is undergoing active myelination. During Wallerian degeneration, the maximum decrease of monogalactosylceramides was associated temporally with axonal degeneration and demyelination and particularly with myelin conversion to sudanophilic lipids. By the time that nerve fiber regeneration was well established, both the cerebroside and sulfatide contents had returned to near control values. Cerebrosides and long-chain fatty acids (above C21) appear to be the most sensitive to fiber degeneration while fatty acid elongation is selectively increased during nerve regeneration.

Topics: Animals; Cerebrosides; Chemical Phenomena; Chemistry; Chromatography, Thin Layer; Galactosylceramides; Male; Nerve Degeneration; Peripheral Nerves; Rats; Rats, Inbred Strains; Sulfoglycosphingolipids; Wallerian Degeneration

This report described a new method for the microanalysis of sphingolipids and its application for the characterization of cerebrosides and sulfatides in multiple sclerosis brain and rat sciatic nerves undergoing Wallerian degeneration. Tissue was extracted with isopropanol/hexane (20:78), and the total lipids obtained were subjected to benzoylation-desulfation. A portion of this was directly analyzed by silica-column high performance liquid chromatography for the determination of nonhydroxycerebroside, hydroxycerebroside, nonhydroxysulfatide, and hydroxysulfatide. Another portion was fractionated by thin-layer chromatography, and the spots corresponding to the sphingolipid derivatives were eluted. The material from each spot was analyzed by reverse phase high performance liquid chromatography for its homolog composition. With this new procedure the concentrations and homolog compositions of cerebrosides and sulfatides were measured in plaque, periplaque, and normal-appearing white matter from brains of multiple sclerosis patients and Wallerian degenerated rat sciatic nerves distal to the nerve transection. One piece of plaque studied contained only 1.86, 2.76, 0.60, and 0.45 nmol of nonhydroxycerebroside, hydroxycerebroside, nonhydroxysulfatide and hydroxysulfatide/mg of protein, respectively. These concentrations are less than 1% of those found in normal white matter. Periplaques were found to contain concentrations of these sphingolipids between those of plaque and normal white matter. The levels of these sphingolipids in degenerative nerves were 10-20% below normal the third day after the nerve was severed and about 70% below normal after 10 days. The rate of decrease lessened from ten days to 55 days. The homolog compositions of these sphingolipids in both multiple sclerosis brain and degenerating nerves were similar to those in the control. The implications of these findings and the advantages of this new analytical method are discussed.

Topics: Adult; Animals; Brain; Cerebrosides; Chromatography, High Pressure Liquid; Humans; Lipid Metabolism; Male; Multiple Sclerosis; Nerve Degeneration; Rats; Rats, Inbred Strains; Sciatic Nerve; Sulfoglycosphingolipids; Wallerian Degeneration

Topics: Brain; Brain Chemistry; Brain Stem; Cerebellum; Cerebrosides; Child; Cholesterol; Diffuse Cerebral Sclerosis of Schilder; Frontal Lobe; Gangliosides; Histocytochemistry; Humans; Male; Microscopy, Electron; Nerve Degeneration; Occipital Lobe; Phospholipids; Sphingomyelins; Sulfoglycosphingolipids; Temporal Lobe