Oxidative Stress and Lymphocyte Alterations in Chronic Relapsing Experimental Allergic Encephalomyelitis in the Rat Hippocampus and Protective Effects of an Ethanolamine Phosphate Salt.

Chronic relapsing experimental allergic encephalomyelitis (CR-EAE) exhibits neuropathological and immunological dysfunctions similar to those found in multiple sclerosis (MS) and has been used as an animal model of MS. Inflammatory infiltrates and oxidative stress have been linked to the development of both diseases. Ethanolamine plasmalogen derivates have been shown to be powerful antioxidants and immunomodulators. Therefore, the objective of this study was to analyse inflammatory infiltrates, the state of the oxidative defences and the possible protective effects of calcium, magnesium and phosphate ethanolamine (EAP) in the CR-EAE rat hippocampus. To this aim, we evaluated, by immunohistochemistry, T cell infiltrates, Iba-1+ (a marker of activated microglia) immunoreactivity and TUNEL (+) cells. We also measured the protein levels and activity of the antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GP) and glutathione reductase (GR). In addition, reduced (GSH) and oxidized (GSSG) glutathione levels, lipid peroxidation and cholesterol as well as desmosterol content were determined. We found an increase in T cell infiltrates and Iba1+ immunoreactivity, lipid peroxidation, SOD, GP and GR activities as well as enhanced cholesterol levels and a decrease in CAT activity, GSH and desmosterol levels in the first and second attack in the CR-EAE rat hippocampus. Pretreatment of CR-EAE rats with EAP led to a delay in the onset of the clinical signs of the disease as well as a decrease in inflammatory infiltrates and alterations of the antioxidant defences in the hippocampus. Altogether, the present results suggest a protective role of EAP in the CR-EAE rat hippocampus.

Implicacion del colesterol de membrana en la proliferacion, ciclo y diferenciacion de las celulas leucemicas humanas HL-60 / Membrane cholesterol involvement in HL-60 human leukaemia cell proliferation, cycle and differentiation

Introduccion El metabolismo del colesterol esta alterado en celulas leucemicas, existiendo controversia acerca del uso combinado de estatinas y agentes quimioterapeuticos en el tratamiento contra el cancer. En nuestro laboratorio habiamos demostrado con anterioridad como la deficiencia de colesterol mediante el uso de inhibidores distales de su biosontesis inducoa la diferenciacion de las celulas humanas HL-60 hacia granulocitos. Se desconoce hasta la fecha si la extraccion del colesterol de la membrana de estas celulas es capaz de producir un proceso de diferenciacion similar, lo que podria abrir una via mas hacia nuevas lineas terapeuticas. Material y metodos Las celulas HL-60 se mantuvieron en un medio libre de colesterol y se extrajo el colesterol de membrana mediante el uso (..) (AU)

Introduction Cholesterol metabolism is increased in leukaemia cells and, accordingly, the use of chemotherapeutic agents in combination with statins for cancer treatment is being evaluated. In our laboratory, we demonstrated that cholesterol deficiency, as produced by distal inhibitors of the cholesterol biosynthesis pathway, induces the differentiation of HL-60 human leukaemia cells through the granulocytic pathway. The aim of the present work was to determine whether the selective extraction of cholesterol from the cell membrane induces cell differentiation, which may open new possibilities in cancer therapy and other proliferative processes. Material and methods Promyelocytic HL-60 cells were maintained in a cholesterol-free medium. Cholesterol was extracted by incubating the cells in the presence of methyl-¦Â-cyclodextrin. Cholesterol cell content was measured by HPLC; cell proliferation was assessed by cell counting; cell cycle distribution was analysed by flow cytometry. Cell differentiation was assessed by measuring CD11c expression by flow cytometry and NADPH oxidase components by Western blot.ResultsTreatment with methyl-¦Â-cyclodextrin reduced the cholesterol content in cells, and resulted in cell proliferation inhibition, the induction of CD11c expression and the synthesis of p47phox and p67phox.Conclusions Selective extraction of membrane cholesterol in HL-60 cells triggers cell differentiation, as indicated by the expression of both CD11c and NADPH oxidase components.ResultsTreatment with methyl-¦Â-cyclodextrin reduced the cell cholesterol content and inhibited cell proliferation in a dose-dependent manner. As this treatment is prolonged, part of the cells die but a substantial proportion of cells survives and acquire differentiation markers, such as CD11c, p47phox and p67phox.(..) (AU)