Potential role of ferric hemoglobin in MS pathogenesis: Effects of oxidative stress and extracellular methemoglobin or its degradation products on myelin components
| Autor: | Shannon L.J. Sproul, Mary E.L. Henein, Danielle K. Lanthier, George Harauz, Vladimir V. Bamm |
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| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Iron Proteolipids Phosphatidylserines medicine.disease_cause Protein oxidation Phosphatidylinositols Biochemistry Methemoglobin 03 medical and health sciences Myelin chemistry.chemical_compound Hemoglobins Mice 0302 clinical medicine Lipid oxidation Physiology (medical) medicine Animals Humans Unilamellar Liposomes biology Phosphatidylethanolamines Myelin Basic Protein Recombinant Proteins Myelin basic protein Sphingomyelins Solutions Oxidative Stress 030104 developmental biology medicine.anatomical_structure Cholesterol chemistry biology.protein Phosphatidylcholines Hemin Hemoglobin Oxidation-Reduction 030217 neurology & neurosurgery Oxidative stress |
| Zdroj: | Free radical biologymedicine. 112 |
| ISSN: | 1873-4596 |
| Popis: | There is a well-documented relationship between cerebral vasculature and multiple sclerosis (MS) lesions: abnormal accumulations of iron have been found in the walls of the dilated veins in cerebral MS plaques. The source of this iron is unknown, but could be related to the recognized phenomenon of capillary and venous hemorrhages leading to blood extravasation. In turn, hemorrhaging leading to hemolysis results in extracellular release of hemoglobin, a reactive molecule that could induce local oxidative stress, inflammation, and tissue damage. Our previous studies with a reduced form of hemoglobin (oxyHb) have demonstrated its ability to cause extensive lipid and protein oxidation in vitro, which would result in membrane destabilization. Here, we investigated in further detail the mechanism by which the more abundant oxidized form of extracellular hemoglobin (metHb), and dissociated hemin, cause direct oxidative damage to myelin components, specifically membrane-mimetic lipid vesicles and myelin basic protein (MBP), a highly-abundant protein in the CNS. Oxidation of lipids was assessed by the formation of conjugated diene/triene and malondialdehyde, and oxidation of MBP was demonstrated by the bityrosine formation and by the change in protein mass. Our results show that metHb causes oxidative damage to MBP and myelin lipids, partly by transferring its hemin moiety to protein and lipid, but mostly as an intact protein possibly via formation of a ferryl radical. These results elucidating the mechanism of extracellular hemoglobin-induced oxidative damage to myelin components support the need for further research into vascular pathology in MS pathogenesis, to gain insight into the role of iron deposits and/or in stimulation of different comorbidities associated with the disease. |
| Databáze: | OpenAIRE |
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