Red Blood Cell Membrane Fluidity in the Etiology of Multiple Sclerosis

Abstract

Organisms adjust the order, or fluidity, of their cellular membranes in response to changes in their physiochemical environment by adjusting the lipid composition of their membranes. We investigated membrane fluidity using the phospholipid, fatty acid and cholesterol content of red blood cells (RBCs) from multiple sclerosis (MS) patients and correlated this with C-reactive protein (CRP) as well as with the severity of neurological outcome as measured by the Kurtzke Expanded Disability Status Scale (EDSS) and its Functional System Scores. The study group consisted of 31 patients with MS and 30 healthy control subjects. Phospholipids were determined using a colorimetric assay, fatty acids by gas chromatography, cholesterol by an enzymatic assay and CRP by a Beckman nephelometer. Cell membrane fluidity was calculated according to previously established formulae. RBC membrane fluidity as measured by the saturated to polyunsaturated fatty acid ratio was higher in patients than in controls (P = 0.04). The phosphatidylethanolamine saturated to polyunsaturated fatty acid ratio showed highly significant positive correlations with the EDSS and CRP < 5 microg/ml. CRP showed significant inverse correlations with the saturated nature but positive correlations with the ordered-crystalline-phase to liquid-crystalline-phase lipid ratio. In this study we show that membrane fluidity as measured by the relationship between membrane fatty acids, phospholipids and cholesterol is closely interrelated with inflammation and disease outcome in patients with MS. In conclusion, our findings suggest that the membrane lipid composition of patients with MS and, consequently, membrane fluidity are altered, which seems to be influenced by the inflammatory status.

The enteric bacterial metabolite propionic acid alters brain and plasma phospholipid molecular species: further development of a rodent model of autism spectrum disorders

“…Monolayer molecular species composition also affects physical properties. Organisms can adjust the order or fluidity of their cellular membranes in response to changes in their physiological environment by altering their lipid composition [50]. Alterations in brain and blood phospholipid composition consistent with an adjustment in the order or fluidity of the membrane in these tissues in response to PPA infusions were observed in this study.…”

“…Phospholipids are the major structural components of neuronal and other cellular membranes, and include PC, PE, PS, PI, and SM [50,51]. All of these phospholipid classes were observed to have altered molecular species distribution following PPA infusion.…”

Gas Chromatography Results Interpretation: Absolute Amounts Versus Relative Percentages

“…The properties of the different phospholipid molecules depend on their different head-groups as well as on the type of fatty acids they contain (Williams, 1998;Horrobin, 1999) and their composition in cell membranes determines the degree of fluidity of the membrane structures. Phospholipids from both red blood cell (Hon et al, 2009c) and peripheral blood mononuclear cell (Hon et al, 2011b) membranes have been reported in detail and specifically their function in determining cell membrane fluidity and their role in disease outcome in patients with multiple sclerosis.…”

Higher minor hemoglobin A2 levels in multiple sclerosis patients correlate with lesser disease severity

“…These observations were neglected until the past few years and no one questioned the influence of RBC fragility and free hemoglobin (Hb) in MS. But this has changed in recent years 2–6. In 2009, an impaired fluidity of RBC membranes in MS was reported 2.…”

“…But this has changed in recent years 2–6. In 2009, an impaired fluidity of RBC membranes in MS was reported 2. In 2011, circulating free Hb was shown to disrupt the blood–brain barrier, accompanied by iron deposition, lipid peroxidation, and perivascular inflammation 3.…”