Nerve Damage May Be Triggered By Cell-Surface Sugar Defects In Multiple Sclerosis Patients

Main Category: Multiple Sclerosis
Also Included In: Neurology / Neuroscience;  Biology / Biochemistry;  Genetics
Article Date: 23 Sep 2007 - 8:00 PDT

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Defects on cell-surface sugars may promote the short-term inflammation and long-term neurodegeneration that occurs in the central nervous system of multiple sclerosis patients, according to University of California, Irvine researchers.

The findings also suggest that a dietary supplement similar to glucosamine may be useful as an oral therapy to correct these defects and to treat both the short-term and the long-term symptoms of the disease. Study results appear on the online version of the Journal of Biological Chemistry.

"The findings raise the possibility that these may both be treated by metabolic therapy," said Dr. Michael Demetriou, an assistant professor of neurology, and microbiology and molecular genetics. "This is particularly important, as therapies are not currently available to treat neurodegeneration in MS."

In tests on mice, Demetriou found that genetic deficiencies in a process called protein glycosylation led to a spontaneous disease very similar to MS, including paralysis associated with inflammatory damage to the protective myelin coating on nerve cells and degeneration of axons and neurons. Protein glycosylation refers to the addition of specific sugars to proteins; virtually all cell-surface and secreted proteins have complex sugars attached to them.

MS is a two-stage disease, with initial attacks of inflammatory demyelination, which damages myelin, followed approximately 10 years later by a slow, progressive neurdegenerative phase marked by loss of axons and nerve cells.

The irreversible damage to the central nervous system induced by neurodegeneration in MS leads to long term disability, including paralysis, incoordination, dementia and pain, and is not targeted by currently available therapies.

Demetriou's findings provide the first genetic model of MS in which both inflammatory demyelination and neurodegeneration arise from defects in a single biological pathway.

In previous studies, Demetriou found that the dietary supplement N-acetylglucosamine (GlcNAc), which is similar but more effective than the widely available glucosamine, corrected defects in protein glycosylation in cells and inhibited inflammatory demyelination in mice. The new study opens the possibility that metabolic therapy with GlcNAc may also prevent neurodegeneration. Studies in humans are required to assess the potential of this therapy in MS.

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Article adapted by Medical News Today from original press release.
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Sung-Uk Lee, Ani Grigorian, I-Ju Chen, Guoyan Gao and Dr. Tahseen Mozaffar of UC Irvine and Judy Pawling and Colin McKerlie of the Samuel Lunenfeld Research Institute in Toronto participated in the study, which was supported by the National Multiple Sclerosis Society, the Juvenile Diabetes Research Foundation, the Wadsworth Foundation and the National Institutes of Health.

About the University of California, Irvine: The University of California, Irvine is a top-ranked university dedicated to research, scholarship and community service. Founded in 1965, UCI is among the fastest-growing University of California campuses, with more than 25,000 undergraduate and graduate students and about 1,800 faculty members. The second-largest employer in dynamic Orange County, UCI contributes an annual economic impact of $3.7 billion.

Source: Tom Vasich
University of California - Irvine