@article{5677ff645cdd484bb0f6c18004f9a165,
title = "Sphingosine Toxicity in EAE and MS: Evidence for Ceramide Generation via Serine-Palmitoyltransferase Activation",
abstract = "Multiple sclerosis (MS) is a demyelinating disorder characterized by massive neurodegeneration and profound axonal loss. Since myelin is enriched with sphingolipids and some of them display toxicity, biological function of sphingolipids in demyelination has been investigated in MS brain tissues. An elevation of sphingosine with a decrease in monoglycosylceramide and psychosine (myelin markers) was observed in MS white matter and plaque compared to normal brain tissue. This indicated that sphingosine toxicity might mediate oligodendrocyte degeneration. To explain the source of sphingosine accumulation, total sphingolipid profile was investigated in Lewis rats after inducing experimental autoimmune encephalomyelitis (EAE) and also in human oligodendrocytes in culture. An intermittent increase in ceramide followed by sphingosine accumulation in EAE spinal cord along with a stimulation of serine-palmitoyltransferase (SPT) activity was observed. Apoptosis was identified in the lumbar spinal cord, the most prominent demyelinating area, in the EAE rats. TNFα and IFNγ stimulation of oligodendrocytes in culture also led to an accumulation of ceramide with an elevation of sphingosine. Ceramide elevation was drastically blocked by myriocin, an inhibitor of SPT, and also by FTY720. Myriocin treatment also protected oligodendrocytes from cytokine mediated apoptosis or programmed cell death. Hence, we propose that sphingosine toxicity may contribute to demyelination in both EAE and MS, and the intermittent ceramide accumulation in EAE may, at least partly, be mediated via SPT activation, which is a novel observation that has not been previously reported.",
keywords = "Ceramide, Demyelination, EAE, Multiple sclerosis, Normal appearing white matter, Serine-palmitoyltransferase",
author = "Miller, {Lawrence G.} and Young, {Jennifer A.} and Ray, {Swapan K.} and Guanghu Wang and Purohit, {Sharad B} and Banik, {Naren L.} and Somsankar Dasgupta",
note = "Funding Information: Acknowledgements We thank late Ms. Elaine Terry and Ms. Denise Matzelle for excellent laboratory assistance. This work was supported in part by these grants: NINDS-NS-31355 (SD), NIAAA-11865 (SD), SC State Appropriation # CR22 (SD), NINDS-NS-38146 (NLB), NINDS-NS-41088 (NLB), the National Multiple Sclerosis Society RG-2130 (NLB), NCI-CA-91460 (SKR), NINDS-NS-057811 (SKR), and SC SCIRF-2015-I-0 (SKR). We acknowledge the encouragement and support from Dr. E. L. Hogan, Ex-chair, Department of Neurology, Medical University of South Carolina (MUSC), Charleston, SC, USA and also Dr. David Perry, Department of Biochemistry, MUSC, Charleston, SC, USA for his advice on SPT assay. We acknowledge Prof. E. Bieberich, Augusta University, Augusta, GA, USA for supplying essential reagents and critically reviewing the manuscript. Funding Information: We thank late Ms. Elaine Terry and Ms. Denise Matzelle for excellent laboratory assistance. This work was supported in part by these grants: NINDS-NS-31355 (SD), NIAAA-11865 (SD), SC State Appropriation # CR22 (SD), NINDS-NS-38146 (NLB), NINDS-NS-41088 (NLB), the National Multiple Sclerosis Society RG-2130 (NLB), NCI-CA-91460 (SKR), NINDS-NS-057811 (SKR), and SC SCIRF-2015-I-0 (SKR). We acknowledge the encouragement and support from Dr. E. L. Hogan, Ex-chair, Department of Neurology, Medical University of South Carolina (MUSC), Charleston, SC, USA and also Dr. David Perry, Department of Biochemistry, MUSC, Charleston, SC, USA for his advice on SPT assay. We acknowledge Prof. E. Bieberich, Augusta University, Augusta, GA, USA for supplying essential reagents and critically reviewing the manuscript. Lawrence G. Miller Jr. and Jennifer A. Young contributed equally and were recipients of Summer undergraduate fellowships. Publisher Copyright: {\textcopyright} 2017, Springer Science+Business Media New York.",
year = "2017",
month = oct,
day = "1",
doi = "10.1007/s11064-017-2280-2",
language = "English (US)",
volume = "42",
pages = "2755--2768",
journal = "Neurochemical Research",
issn = "0364-3190",
publisher = "Springer New York",
number = "10",
}