Human Retinal Pigment Epithelial Cells Express Scavenger Receptors BI and BII

Duncan, Keith G.; Bailey, Kathy; Kane, John P.; Schwartz, Daniel M.

doi:10.1006/bbrc.2002.6756

Cited by 78 publications

(54 citation statements)

References 41 publications

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“…Second, in Drosophila, mutation in the gene ninaD encoding a protein receptor that has high homology to the two mammalian receptors, SR-BI and CD36, was associated with a loss of carotenoid accumulation in the eye (29). Finally, both SR-BI and CD36 receptors are expressed in human RPE cells (41,42). The participation of SR-BI in carotenoid uptake by RPE cells was demonstrated using two distinct approaches.…”

Section: Discussionmentioning

confidence: 99%

“…Human RPE cells express both scavenger receptors SR-BI and CD36 (41,42). The purpose of this experiment was to test the possibility that these two protein transporters could participate in the carotenoid transport into RPE using specific antibodies targeting each of the proteins (anti-CD36 and anti-SR-BI, respectively).…”

Section: The Blocking Antibody Against Sr-bi Diminished Carotenoid Upmentioning

confidence: 99%

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Xanthophylls are preferentially taken up compared with β-carotene by retinal cells via a SRBI-dependent mechanism*

During

Doraiswamy

Harrison

2008

Journal of Lipid Research

150

122

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The purpose of this study was to investigate the mechanisms by which carotenoids [xanthophylls vs. bcarotene (b-C)] are taken up by retinal pigment epithelial (RPE) cells. The human RPE cell line, ARPE-19, was used. When ARPE-19 cells were fully differentiated (7-9 weeks), the xanthophylls lutein (LUT) and zeaxanthin (ZEA) were taken up by cells to an extent 2-fold higher than b-C (P , 0.05). At 9 weeks, cellular uptakes were 1.6, 2.5, and 3.2%, respectively, for b-C, LUT, and ZEA. Similar extents were observed when carotenoids were delivered in either Tween 40 or "chylomicrons" produced by Caco-2 cells. Differentiated ARPE-19 cells did not exhibit any detectable b-C 15,15′-oxygenase activity or convert exogenous b-C into vitamin A. When using specific antibodies against the lipid transporters cluster determinant 36 (CD36) and scavenger receptor class B type I (SR-BI), cellular uptake of b-C and ZEA were significantly decreased (40-60%) with anti-SR-BI but not with anti-CD36. Small interfering RNA transfection for SR-BI led to marked knockdown of SR-BI protein expression (?90%), which resulted in decreased b-C and ZEA uptakes by 51% and 87%, respectively. Thus, the present data show that RPE cells preferentially take up xanthophylls versus the carotene by a process that appears to be entirely SR-BI-dependent for ZEA and partly so for b-C. This mechanism may explain, in part, the preferential accumulation of xanthophylls in the macula of the retina.-During, A., S. Doraiswamy, and E. H. Harrison. Xanthophylls are preferentially taken up compared with b-carotene by retinal cells via a SRBI-dependent mechanism.

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Section: Discussionmentioning

confidence: 99%

Section: The Blocking Antibody Against Sr-bi Diminished Carotenoid Upmentioning

confidence: 99%

Xanthophylls are preferentially taken up compared with β-carotene by retinal cells via a SRBI-dependent mechanism*

During

Doraiswamy

Harrison

2008

Journal of Lipid Research

150

122

View full text Add to dashboard Cite

show abstract

“…RPE expresses functional receptors for both LDL (LDL-R) and HDL (scavenger receptor B-I, SRB-I) and takes up these plasma lipoproteins ( 109,(135)(136)(137)(138), likely for resupply of essential lipophilic nutrients and cellular constituents. LDL-derived cholesterol taken up by RPE partitions remarkably fast (within hours) into membranes of the neurosensory retina ( 109,139 ).…”

Section: The Barrier Hypothesis: Lipid Accumulation and Transport Thrmentioning

confidence: 99%

Apolipoprotein B-containing lipoproteins in retinal aging and age-related macular degeneration

Curcio

Johnson

Huang

et al. 2010

Journal of Lipid Research

169

145

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“…This close anatomical association between the RPE and photoreceptors is one of the factors that promotes the ability of the RPE to, on the one hand, provide nutrients and oxygen to the photoreceptor cells and, on the other hand, eliminate metabolic wastes generated by the neural retina, including those resulting from the shedding of outer segments tips and their subsequent phagocytosis and degradation by the RPE. The RPE cells express a variety of lipoprotein-specifi c and scavenger receptors: VLDL receptor ( 47 ), LDL receptor (LDL-R) ( 12,48,49 ), and the so-called scavenger receptors CD36 ( 48,(50)(51)(52)(53)(54), SR-BI, and BII ( 50,52,55,56 ). Interestingly, LDL-R was also localized to the endothelial cells of the choriocapillaris, the photoreceptor inner segments, retinal ganglion cells, and Müller cells ( 12 ).…”

Section: Uptake and Intraretinal Exchange Of Cholesterol By The Retinamentioning

confidence: 99%

The ins and outs of cholesterol in the vertebrate retina

Fliesler

Brétillon

2010

Journal of Lipid Research

133

138

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Journal of Lipid Research Volume 51, 2010 3399 plus glial cells (Müller cells, astrocytes, and microglia).[For an excellent overview of retinal structure and cytoarchitecture, see ( 1 ) and http://webvision.med.utah. edu/]. The neuronal cells are distributed into discrete histological layers in the fully differentiated retina ( Fig. 1 ), with the ganglion cell layer arranged proximal to the vitreous and the photoreceptor cells (rods and cones) residing at the opposite side of the neural retina, just underneath the retinal pigment epithelium (RPE) layer. The RPE is a monolayer of polarized epithelial cells that serves as the interface between the neural retina and the choroid, the blood supply to the outer cell layers of the retina. The apical tips of the photoreceptor outer segments (OS) are adjacent to and invaginate into the apical face of the RPE (one of the few examples of apical-apical cellular contact in the body) ( Fig. 1C ). Bruch's membrane (BrM; Fig. 1B, C ) is not a membrane, per se, but rather a pentalaminar structure that consists of the basement membranes of the RPE cells and the endothelial cells of the choriocapillaris ( Fig. 1C ), plus the extracellular matrix that fi lls the space between these two membranes [reviewed in ( 2, 3 )].The relatively modest compendium of cell types mentioned above, however, belies the amazing, higher order complexity of this sensory tissue. It has been estimated that there are actually about 55 anatomically distinct neuronal cell types in the adult mammalian retina, of which about 22 have been thoroughly characterized with regard to their fi ne structure and functional repertoire [reviewed in ( 4 )]. For example, photoreceptors consist of both rods and cones, with cones being subdivided into two (three in Abstract The vertebrate retina has multiple demands for utilization of cholesterol and must meet those demands either by synthesizing its own supply of cholesterol or by importing cholesterol from extraretinal sources, or both. Unlike the blood-brain barrier, the blood-retina barrier allows uptake of cholesterol from the circulation via a lipoprotein-based/receptor-mediated mechanism. Under normal conditions, cholesterol homeostasis is tightly regulated; also, cholesterol exists in the neural retina overwhelmingly in unesterifi ed form, and sterol intermediates are present in minimal to negligible quantities. However, under certain pathological conditions, either due to an inborn error in cholesterol biosynthesis or as a consequence of exposure to selective inhibitors of enzymes in the cholesterol pathway, the ratio of sterol intermediates to cholesterol in the retina can rise dramatically and persist, in some cases resulting in progressive degeneration that signifi cantly compromises the structure and function of the retina. The mature vertebrate retina is a highly stratifi ed, multicellular tissue classically described as consisting of six fundamental neuronal cell types (photoreceptor, bipolar, ganglion, horizontal, amacrine, and interplexiform cells) the normal...

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Human Retinal Pigment Epithelial Cells Express Scavenger Receptors BI and BII

Cited by 78 publications

References 41 publications

Xanthophylls are preferentially taken up compared with β-carotene by retinal cells via a SRBI-dependent mechanism*

Xanthophylls are preferentially taken up compared with β-carotene by retinal cells via a SRBI-dependent mechanism*

Apolipoprotein B-containing lipoproteins in retinal aging and age-related macular degeneration

The ins and outs of cholesterol in the vertebrate retina

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