Dataset Information

Lipoprotein particles of intraocular origin in human Bruch membrane: an unusual lipid profile.

ABSTRACT:

Purpose

Throughout adulthood, Bruch membrane (BrM) accumulates esterified cholesterol (EC) associated with abundant 60- to 80-nm-diameter lipoprotein-like particles (LLP), putative apolipoprotein B (apoB) lipoproteins secreted by the retinal pigment epithelium (RPE). In the present study, neutral lipid, phospholipids, and retinoid components of human BrM-LLP were assayed.

Methods

Particles isolated from paired choroids of human donors were subjected to comprehensive lipid profiling (preparative liquid chromatography [LC] gas chromatography [GC]), thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), Western blot analysis, and negative stain electron microscopy. Results were compared to plasma lipoproteins isolated from normolipemic volunteers and to conditioned medium from RPE-J cells supplemented with palmitate to induce particle synthesis and secretion.

Results

EC was the largest component (32.4+/-7.9 mol%) of BrM-LLP lipids. EC was 11.3-fold more abundant than triglyceride (TG), unlike large apoB lipoproteins in plasma. Of the fatty acids (FA) esterified to cholesterol, linoleate (18:2n6) was the most abundant (41.7+/-4.7 mol%). Retinyl ester (RE) was detectable at picomolar levels in BrM-LLP. Notably scarce in any BrM-LLP lipid class was the photoreceptor-abundant FA docosahexaenoate (DHA, 22:6n3). RPE-J cells synthesized apoB and numerous EC-rich spherical particles.

Conclusions

BrM-LLP composition resembles plasma LDL more than it does photoreceptors. An EC-rich core is possible for newly synthesized lipoproteins as well as those processed in plasma. Abundant EC could contribute to a transport barrier in aging and lesion formation in age-related maculopathy (ARM). Analysis of BrM-LLP composition has revealed new aspects of retinal cholesterol and retinoid homeostasis.

SUBMITTER: Wang L

PROVIDER: S-EPMC2692837 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature

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Publications

Lipoprotein particles of intraocular origin in human Bruch membrane: an unusual lipid profile.

Wang Lan L Li Chuan-Ming CM Rudolf Martin M Belyaeva Olga V OV Chung Byung Hong BH Messinger Jeffrey D JD Kedishvili Natalia Y NY Curcio Christine A CA

Investigative ophthalmology & visual science 20080920 2

<h4>Purpose</h4>Throughout adulthood, Bruch membrane (BrM) accumulates esterified cholesterol (EC) associated with abundant 60- to 80-nm-diameter lipoprotein-like particles (LLP), putative apolipoprotein B (apoB) lipoproteins secreted by the retinal pigment epithelium (RPE). In the present study, neutral lipid, phospholipids, and retinoid components of human BrM-LLP were assayed.<h4>Methods</h4>Particles isolated from paired choroids of human donors were subjected to comprehensive lipid profilin ...[more]

PMID: 18806290

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Dataset Information

Lipoprotein particles of intraocular origin in human Bruch membrane: an unusual lipid profile.

Purpose

Methods

Results

Conclusions

Publications

Lipoprotein particles of intraocular origin in human Bruch membrane: an unusual lipid profile.

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