Lipoprotein Lipidic Composition, Lipopolysaccharide Binding Protein, and Bacterial Endotoxin Exposure in Parkinson's Disease: A Pilot Study

Bacterial lipopolysaccharides are able to produce neuroinflammation and dopaminergic receptors degeneration. In addition, they may produce an accumulation of α-synuclein in the area of the substantia Nigra. Recent studies have shown that α-synuclein aggregates may be present also in gastrointestinal neurons of patients with PD. This last finding led to the hypothesis that the intestine might be an early site of PD disease in response to an environmental toxin or pathogen. Forsyth et al. have discovered an impaired intestinal permeability in subjects with recently diagnosed PD, and they found positive correlations between this factor, exposure to LPS and alpha-synuclein accumulation in gastrointestinal neurons. Plasma lipoproteins play a key role in the detoxification of bacterial endotoxins. Lipoprotein chemical composition is related to their detoxing properties. To the best of investigator knowledge, the relationships between lipoprotein chemical composition and LPS in PD have not yet been investigated. Therefore, the aims of this study are: I) to evaluate the chemical composition of VLDL, LDL and HDL in subjects with PD compared to a control group; 2) to analyze the activity of plasma lipid transfer proteins and LPS plasma levels in the same groups of subjects; III) finally, to investigate the correlations between the analyzed parameters.

Subjects and method Twenty patients with PD and twenty healthy controls were recruited for the study. Fasting blood samples were taken for routine laboratory analysis and for the separation of EDTA plasma. Plasma samples stored at -80°C until were used for lipoprotein isolation and analysis and for the measurement of lipid transfer protein and LPS levels.