Effect of aluminium on lipid peroxidation of human high density lipoproteins.
We investigated the effect of aluminium (Al3+) on lipid peroxidation and physico-chemical properties of high density lipoproteins (HDL) isolated from human plasma. Our results demonstrated that Al3+ enhances lipid peroxidation of human HDL as shown by the significant increase in lipid hydroperoxides in Al-treated HDL with respect to control HDL. The oxidative effect was higher at acid pH (pH 5.5) with respect to pH 7.4. Moreover, a stimulating effect of Al3+ on iron-induced lipid peroxidation of HDL was demonstrated. The study of the effect of Al3+ on the physico-chemical properties of HDL, using the fluorescence polarization (Pf) of the probes TMA-DPH (1-(4-trimethylammoniumphenyl)-6-phenyl-1,3,5-hexatriene iodide) and DPH (1,6-diphenyl-1,3,5-hexatriene), showed a significant decrease of Pf in Al-treated HDL with respect to control. These results suggest that Al3+ induces a decrease of molecular order at the lipoprotein surface. Moreover, the study of tryptophan (Trp) fluorescence demonstrated that aluminium induces structural modifications of HDL apoproteins and on HDL physico-chemical properties. The effect of Al3+ on lipid peroxidation of HDL was observed at aluminium concentrations similar to those observed in the brain of patients affected by neurological diseases. Aluminium-induced oxidative damage of HDL could be involved in the development of neurological diseases.
Ferretti
G
G
Institute of Biochemistry, Faculty of Medicine, University of Ancona, Via Ranieri, 1-60131, Ancona, Italy. g.ferretti@popcsi.unian.it
Marchionni
C
C
Bacchetti
T
T
Galeazzi
T
T
Dousset
N
N
D000535:Aluminum / Q000494:pharmacology*; D004161:Diphenylhexatriene / Q000031:analogs & derivatives* / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D005296:Ferrous Compounds / Q000494:pharmacology; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015227:Lipid Peroxidation / Q000187:drug effects*; D008054:Lipid Peroxides / Q000378:metabolism; D008075:Lipoproteins, HDL / Q000097:blood / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D013050:Spectrometry, Fluorescence; D017392:Thiobarbituric Acid Reactive Substances / Q000737:chemistry / Q000378:metabolism; D014364:Tryptophan / Q000737:chemistry
D005296:Ferrous Compounds; D005456:Fluorescent Dyes; D008054:Lipid Peroxides; D008075:Lipoproteins, HDL; D017392:Thiobarbituric Acid Reactive Substances; D004161:Diphenylhexatriene; C033628:1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene; D014364:Tryptophan; D000535:Aluminum