Premium
Compartmentalization of eicosanoid substrates, signaling lipids, and enzymes into nanoparticles in human cerebrospinal fluid
Author(s) -
Fonteh Alfred Nji,
Oborina Elena,
Harrington Michael
Publication year - 2010
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.24.1_supplement.845.2
Subject(s) - chemistry , biochemistry , enzyme , sphingomyelin , chromatography , eicosanoid , membrane , arachidonic acid
Objective To find out whether lipid substrates and metabolizing enzymes are compartmentalized into discrete particles in human cerebrospinal fluid (CSF). Methods Lumbar CSF was fractionated by ultracentrifugation to obtain a 17,000 g pellet (P2), a 200,000 g pellet (P3), and supernatant fluid (S3). We used transmission electron microscopy (TEM) to examine the morphology of particles, and liquid chromatography tandem mass spectrometry (LCMS) to obtain lipid composition of all fractions. Colorimetric or fluorometric assays, and shotgun sequencing were used to measure enzyme activities and identify proteins, respectively. Results TEM revealed particles of different sizes (30–200 nM) and structures in P3 fractions. Organic extraction showed P3 fractions contained lipids. LCMS identified the major phospholipid classes in P3. Positive or negative parent ion scanning revealed enrichment of polyunsaturated fatty acids, phosphatidylinositol and sphingomyelin in P3 compared with S3 fractions. Shotgun sequencing and enzyme activity assay identified proteins and enzymes of the prostaglandin biosynthetic pathway in P3. Conclusions There are discrete membrane particles within CSF that are compositionally distinct from bulk CSF. Compartmentalization of enzymes on these particles can play important roles in brain function by controlling the metabolism of eicosanoid and other lipid signaling pathways.