Molecular characterization of rabbit phospholipid transfer protein: choroid plexus and ependyma synthesize high levels of phospholipid transfer protein.

Phospholipid transfer protein (PLTP) plays an important role in plasma lipoprotein metabolism. However, PLTP is expressed in a wide range of tissues suggesting additional local functions. To analyze the tissue distribution of PLTP in an animal with high-level expression of the structurally and functionally related CETP, we have cloned the full-length cDNA of rabbit PLTP (1,796 bp). Rabbit PLTP cDNA shows high homology to human, murine, and porcine PLTP cDNA, averaging 86.1%, 80.4%, and 86.1%, respectively. Interestingly, the C-terminus contains a unique seven amino acid insertion not found in previously characterized mammalian PLTPs. In clear contradistinction to human PLTP, rabbit PLTP mRNA was prominent in brain. In situ hybridization studies revealed specific, high-level synthesis of PLTP mRNA in choroid plexus and ependyma, the organs responsible for production of cerebrospinal fluid. Consistent with these findings, PLTP activity in cerebrospinal fluid amounted to 23% +/- 3% of that in rabbit plasma. In contrast, neither CETP mRNA nor CETP activity were detectable in rabbit brain.A role of PLTP in the central nervous system could involve some of its actions previously established in vitro, like proteolysis of apolipoproteins, and be physiologically relevant for neurodegenerative disorders such as Alzheimer's disease.

Increased levels of lipid peroxides as predictive of symptomatic vasospasm and poor outcome after aneurysmal subarachnoid hemorrhage.

OBJECT: Cerebral vasospasm remains a devastating medical complication of aneurysmal subarachnoid hemorrhage (SAH). Reactive oxygen species and subsequent lipid peroxidation are reported to participate in the causes of cerebral vasospasm. This clinical study was performed to investigate the relationships between levels of lipid peroxides in cerebrospinal fluid (CSF) and both delayed cerebral vasospasm and clinical outcome after SAH. METHODS: Levels of phosphatidylcholine hydroperoxide (PCOOH) and cholesteryl ester hydroperoxide (CEOOH) in the CSF were measured in 20 patients with aneurysmal SAH. The patients' CSF was collected within 48 hours of hemorrhage onset and on Day 6 or 7 post-SAH. On Day 7, angiography was performed to verify the degree and extent of the vasospasm. The relationship between the patients' clinical profiles and the levels of lipid peroxides in the CSF were investigated. Both PCOOH and CEOOH were detectable in CSF, and their levels decreased within 7 days after onset of SAH. The levels of CEOOH within 48 hours after onset of hemorrhage were significantly higher in patients in whom symptomatic vasospasm later developed than in patients in whom symptomatic vasospasm did not develop (p = 0.002). Levels of PCOOH measured within 48 hours after onset of hemorrhage were significantly higher in patients with poor outcomes than in patients with good outcomes (p = 0.043). CONCLUSIONS: Increased levels of lipid peroxides measured in the CSF during the acute stage of SAH were predictive of both symptomatic vasospasm and poor outcome. Measurements of lipid peroxides in the CSF may be useful prognostically for patient outcomes as well as for predicting symptomatic vasospasm.

Central nervous system lipoproteins in Alzheimer's disease.

Alzheimer's disease (AD) is the most common form of dementia in the United States and has been associated with APOE genotype. Apolipoprotein (apo) E along with apoAI serve as the major apolipoproteins in the central nervous system; however, we are unaware of any study addressing lipoprotein metabolism in AD. We tested the hypothesis that lipoprotein metabolism is altered in patients with AD by isolating and characterizing ventricular fluid (VF) lipoproteins obtained during a rapid autopsy protocol from patients with AD and age-matched nondemented control patients. Our results demonstrated abnormalities in the protein and lipid constituents of VF lipoproteins from AD patients. Apolipoprotein concentration was reduced by half in AD patients relative to controls; however, there was no selective reduction in apoE or apoAI. In addition, cholesteryl ester fatty acids, but not phospholipid fatty acids, from AD patients demonstrated a significant reduction in some polyunsaturated fatty acids (18:2 and 22:6) and an enrichment in 18:0. None of these changes were directly related to APOE genotype. Our data indicate that VF lipoprotein composition is altered, at least terminally, in AD patients, and that these changes are not associated with APOE. These findings suggest that altered VF lipoprotein metabolism may be a component of AD pathogenesis.

Essential fatty acids in the serum and cerebrospinal fluid of multiple sclerosis patients.

Statistical evaluation of essential fatty acids (determined by gas chromatography) in the serum and cerebrospinal fluid of patients with definite MS and acute CCT showed marked differences as compared to healthy subjects. It was also evident that the decrease of essential fatty acids in MS patients differed from that of CCT patients. Whereas the fatty acid levels in the serum of MS patients revealed only minor differences as compared to the controls and CCT patients, MS patients did show a clear decrease, especially of linoleic and arachidonic acids, in the CSF. This difference was most pronounced in cholesterol esters in the CSF. One absorption study with safflower oil demonstrated normal enteral absorption of essential fatty acids and the ability to cross the blood-CSF barrier.