Disrupted cholesterol metabolism promotes age-related photoreceptor neurodegeneration

Photoreceptors have high intrinsic metabolic demand and are exquisitely sensitive to metabolic perturbation. In addition, they shed a large portion of their outer segment lipid membranes in a circadian manner, increasing the metabolic burden on the outer retina associated with the resynthesis of cell membranes and disposal of the cellular cargo. Here, we demonstrate that deletion of both ABCA1 and ABCG1 in rod photoreceptors leads to age-related accumulation of cholesterol metabolites in the outer retina, photoreceptor dysfunction, degeneration of rod outer segments, and ultimately blindness. A high-fat diet significantly accelerates rod neurodegeneration and vision loss, further highlighting the role of lipid homeostasis in regulating photoreceptor neurodegeneration and vision. Photoreceptors have high intrinsic metabolic demand and are exquisitely sensitive to metabolic perturbation. In addition, they shed a large portion of their outer segment lipid membranes in a circadian manner, increasing the metabolic burden on the outer retina associated with the resynthesis of cell membranes and disposal of the cellular cargo. Here, we demonstrate that deletion of both ABCA1 and ABCG1 in rod photoreceptors leads to age-related accumulation of cholesterol metabolites in the outer retina, photoreceptor dysfunction, degeneration of rod outer segments, and ultimately blindness. A high-fat diet significantly accelerates rod neurodegeneration and vision loss, further highlighting the role of lipid homeostasis in regulating photoreceptor neurodegeneration and vision. Metabolic neurodegeneration is a central feature of diverse age-related pathologies such as Alzheimer's disease (1.Arenas F. Garcia-Ruiz C. Fernandez-Checa J.C. Intracellular cholesterol trafficking and impact in neurodegeneration.Front. Mol. Neurosci. 2017; 10: 382Crossref PubMed Scopus (80) Google Scholar) and retinal degeneration (2.Fliesler S.J. Bretillon L. The ins and outs of cholesterol in the vertebrate retina.J. Lipid Res. 2010; 51: 3399-3413Abstract Full Text Full Text PDF PubMed Scopus (95) Google Scholar). The neurosensory retina, an extension of the CNS, is a complex neurovascular tissue whose primary function is to process light and color perceived by photoreceptor neurons and transmit this information to the visual cortex for further processing in order to generate a precise visual image. In the neurosensory retina, photoreceptor degeneration causes blindness in diseases such as retinitis pigmentosa (3.Athanasiou D. Aguila M. Bellingham J. Li W. McCulley C. Reeves P.J. Cheetham M.E. The molecular and cellular basis of rhodopsin retinitis pigmentosa reveals potential strategies for therapy.Prog. Retin. Eye Res. 2018; 62: 1-23Crossref PubMed Scopus (177) Google Scholar) and age-related macular degeneration (AMD) (4.Bowes Rickman C. Farsiu S. Toth C.A. Klingeborn M. Dry age-related macular degeneration: mechanisms, therapeutic targets, and imaging.Invest. Ophthalmol. Vis. Sci. 2013; 54: ORSF68-ORSF80Crossref PubMed Scopus (191) Google Scholar). The retina is also the most metabolically active tissue in the body (5.Niven J.E. Laughlin S.B. Energy limitation as a selective pressure on the evolution of sensory systems.J. Exp. Biol. 2008; 211: 1792-1804Crossref PubMed Scopus (674) Google Scholar, 6.Okawa H. Sampath A.P. Laughlin S.B. Fain G.L. ATP consumption by mammalian rod photoreceptors in darkness and in light.Curr. Biol. 2008; 18: 1917-1921Abstract Full Text Full Text PDF PubMed Scopus (242) Google Scholar) and is exquisitely sensitive to metabolic flux (7.Goldberg A.F. Moritz O.L. Williams D.S. Molecular basis for photoreceptor outer segment architecture.Prog. Retin. Eye Res. 2016; 55: 52-81Crossref PubMed Scopus (101) Google Scholar). A significant portion of this metabolic demand is related to the circadian shedding of about ten percent of photoreceptor lipid bilayer membranes (7.Goldberg A.F. Moritz O.L. Williams D.S. Molecular basis for photoreceptor outer segment architecture.Prog. Retin. Eye Res. 2016; 55: 52-81Crossref PubMed Scopus (101) Google Scholar, 8.Albert A. Alexander D. Boesze-Battaglia K. Cholesterol in the rod outer segment: a complex role in a “simple” system.Chem. Phys. Lipids. 2016; 199: 94-105Crossref PubMed Scopus (24) Google Scholar). Photoreceptor outer segments once shed have to be regenerated, placing a very high biochemical burden on these cells. In addition, the lipid-rich shed outer segments have to be processed by the retinal pigment epithelium (RPE) underneath the neurosensory retina (9.Storti F. Raphael G. Griesser V. Klee K. Drawnel F. Willburger C. Scholz R. Langmann T. von Eckardstein A. Fingerle J. et al.Regulated efflux of photoreceptor outer segment-derived cholesterol by human RPE cells.Exp. Eye Res. 2017; 165: 65-77Crossref PubMed Scopus (44) Google Scholar). These cholesterol-containing lipids are then packaged onto carrier lipoproteins for transport from the eye to the bloodstream using a well-characterized process called reverse cholesterol transport or cholesterol efflux (7.Goldberg A.F. Moritz O.L. Williams D.S. Molecular basis for photoreceptor outer segment architecture.Prog. Retin. Eye Res. 2016; 55: 52-81Crossref PubMed Scopus (101) Google Scholar, 10.Sene A. Apte R.S. Eyeballing cholesterol efflux and macrophage function in disease pathogenesis.Trends Endocrinol. Metab. 2014; 25: 107-114Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar). ABCA1 and ABCG1 play a central role in coordinating reverse cholesterol transport by packaging cholesterol and other lipids onto apolipoprotein carriers, such as ApoA1 and HDL, for transport through the blood stream to the liver (10.Sene A. Apte R.S. Eyeballing cholesterol efflux and macrophage function in disease pathogenesis.Trends Endocrinol. Metab. 2014; 25: 107-114Abstract Full Text Full Text PDF PubMed Scopus (33) Google Scholar, 11.Sene A. Khan A.A. Cox D. Nakamura R.E. Santeford A. Kim B.M. Sidhu R. Onken M.D. Harbour J.W. Hagbi-Levi S. et al.Impaired cholesterol efflux in senescent macrophages promotes age-related macular degeneration.Cell Metab. 2013; 17: 549-561Abstract Full Text Full Text PDF PubMed Scopus (173) Google Scholar). For these reasons, we hypothesized that maintaining physiologic cholesterol homeostasis by ABCA1 and ABCG1 would play a key role in photoreceptor function and survival. In the retina, there are two types of photoreceptors: rods responsible for dim vision and cones responsible for color and daytime vision. Although ABCA1 and ABCG1 have been reported to be expressed in the retina, including in photoreceptors (12.Duncan K.G. Hosseini K. Bailey K.R. Yang H. Lowe R.J. Matthes M.T. Kane J.P. LaVail M.M. Schwartz D.M. Duncan J.L. Expression of reverse cholesterol transport proteins ATP-binding cassette A1 (ABCA1) and scavenger receptor BI (SR-BI) in the retina and retinal pigment epithelium.Br. J. Ophthalmol. 2009; 93: 1116-1120Crossref PubMed Scopus (71) Google Scholar, 13.Ananth S. Gnana-Prakasam J.P. Bhutia Y.D. Veeranan-Karmegam R. Martin P.M. Smith S.B. Ganapathy V. Regulation of the cholesterol efflux transporters ABCA1 and ABCG1 in retina in hemochromatosis and by the endogenous siderophore 2,5-dihydroxybenzoic acid.Biochim. Biophys. Acta. 2014; 1842: 603-612Crossref PubMed Scopus (30) Google Scholar), their function in photoreceptor physiology is largely unknown. In order to assess the functions of ABCA1 and ABCG1 in photoreceptors, we generated mice lacking both Abca1 and Abcg1 specifically from either rods (14.Li S. Chen D. Sauve Y. McCandless J. Chen Y.J. Chen C.K. Rhodopsin-iCre transgenic mouse line for Cre-mediated rod-specific gene targeting.Genesis. 2005; 41: 73-80Crossref PubMed Scopus (103) Google Scholar, 15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar) or cones (15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar, 16.Le Y.Z. Ash J.D. Al-Ubaidi M.R. Chen Y. Ma J.X. Anderson R.E. Targeted expression of Cre recombinase to cone photoreceptors in transgenic mice.Mol. Vis. 2004; 10: 1011-1018PubMed Google Scholar). Retinas were structurally evaluated by biomicroscopy, histology, and electron microscopy at 3–18 months of age. In addition, retinal function and vision were evaluated by electrophysiology. All animal experiments were conducted in accordance with Washington University in St. Louis School of Medicine Animal Care and Use guidelines after approval by the Animal Studies Committee. All mice were housed in a temperature-controlled room under a 12 h light/dark cycle, with free access to food and water. All mouse species used in the experiments are summarized in Table 1. Abca1/gF/F mice were previously characterized (17.Westerterp M. Gourion-Arsiquaud S. Murphy A.J. Shih A. Cremers S. Levine R.L. Tall A.R. Yvan-Charvet L. Regulation of hematopoietic stem and progenitor cell mobilization by cholesterol efflux pathways.Cell Stem Cell. 2012; 11: 195-206Abstract Full Text Full Text PDF PubMed Scopus (190) Google Scholar, 18.Westerterp M. Murphy A.J. Wang M. Pagler T.A. Vengrenyuk Y. Kappus M.S. Gorman D.J. Nagareddy P.R. Zhu X. Abramowicz S. et al.Deficiency of ATP-binding cassette transporters A1 and G1 in macrophages increases inflammation and accelerates atherosclerosis in mice.Circ. Res. 2013; 112: 1456-1465Crossref PubMed Scopus (208) Google Scholar) and were purchased commercially (Jackson Laboratory, Bar Harbor, ME). To generate mice lacking both Abca1 and Abcg1 specifically from rod photoreceptors, we crossed Abca1/g1F/F mice with mice carrying one copy of the rhodopsin-iCre75 (Rhod-iCre) transgene, which were provided by Dr. Ching-Kang Jason Chen and have been previously characterized (14.Li S. Chen D. Sauve Y. McCandless J. Chen Y.J. Chen C.K. Rhodopsin-iCre transgenic mouse line for Cre-mediated rod-specific gene targeting.Genesis. 2005; 41: 73-80Crossref PubMed Scopus (103) Google Scholar, 15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar). To generate mice lacking both Abca1 and Abcg1 specifically from cone photoreceptors, we crossed Abca1/g1F/F mice with mice carrying one copy of the human red/green pigment-Cre (HRGP-Cre) transgene, which were provided by Dr. Yun Le and have been previously characterized (15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar, 16.Le Y.Z. Ash J.D. Al-Ubaidi M.R. Chen Y. Ma J.X. Anderson R.E. Targeted expression of Cre recombinase to cone photoreceptors in transgenic mice.Mol. Vis. 2004; 10: 1011-1018PubMed Google Scholar, 19.Zhou Z. Vinberg F. Schottler F. Doggett T.A. Kefalov V.J. Ferguson T.A. Autophagy supports color vision.Autophagy. 2015; 11: 1821-1832Crossref PubMed Scopus (28) Google Scholar). We confirmed that these mice did not carry the Crb1 gene rd8 mutation (20.Mattapallil M.J. Wawrousek E.F. Chan C.C. Zhao H. Roychoudhury J. Ferguson T.A. Caspi R.R. The Rd8 mutation of the Crb1 gene is present in vendor lines of C57BL/6N mice and embryonic stem cells, and confounds ocular induced mutant phenotypes.Invest. Ophthalmol. Vis. Sci. 2012; 53: 2921-2927Crossref PubMed Scopus (482) Google Scholar) (data not shown). For high-fat diet (HFD) feeding experiments, only male Abca1/g1F/F and Abca1/g1−rod/−rod mice were used. We used an adjusted-calorie diet (42% from fat, 43% kcal from carbohydrate, and 15% kcal from protein; TD.88137; ENVIGO, Indianapolis, IN) (21.Rajagopal R. Bligard G.W. Zhang S. Yin L. Lukasiewicz P. Semenkovich C.F. Functional deficits precede structural lesions in mice with high-fat diet-induced diabetic retinopathy.Diabetes. 2016; 65: 1072-1084Crossref PubMed Scopus (53) Google Scholar) as a HFD, starting from 6 weeks old to the target age of analysis. We used Purina 4043 chow (13% kcal from fat, 62% kcal from carbohydrate, 25% kcal from protein) as the normal diet (21.Rajagopal R. Bligard G.W. Zhang S. Yin L. Lukasiewicz P. Semenkovich C.F. Functional deficits precede structural lesions in mice with high-fat diet-induced diabetic retinopathy.Diabetes. 2016; 65: 1072-1084Crossref PubMed Scopus (53) Google Scholar).TABLE 1Mouse abbreviationsAbbreviationsGenotypeAbca1/gF/FAbca1flox/flox and Abcg1flox/flox Cre-negativeAbca1/g1−rod/−rodAbca1flox/flox and Abcg1flox/flox Rhod-iCre positiveAbca1/g1−cone/−coneAbca1flox/flox and Abcg1flox/flox HRGP-Cre positiveAbca1/g1+rod/−rodAbca1−/flox and Abcg1−/flox Rhod-iCre positiveAbca1/g−F/−F Rhod-iCreAbca1−/− and Abcg1−/− Rhod-iCre positive Open table in a new tab To isolate rod or cone photoreceptors from the retina, we used the Papain Dissociation System (Worthington Biochemical Corporation, Lakewood, NJ) following a previously described modified protocol (22.Feodorova Y. Koch M. Bultman S. Michalakis S. Solovei I. Quick and reliable method for retina dissociation and separation of rod photoreceptor perikarya from adult mice.MethodsX. 2015; 2: 39-46Crossref PubMed Scopus (22) Google Scholar), followed by EasySep Mouse PE or FITC positive selection kit (Stem Cell Technologies, Vancouver, Canada), respectively, following the manufacturer's protocol. We used 1 μg/ml of PE-conjugated anti-CD73 antibodies (Miltenyi Biotec, Bergisch Gladbach, Germany) (15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar) for rod photoreceptors and 5 μg/ml of fluorescein peanut agglutinin (Vector Laboratories, Burlingame, CA) (23.Skaper S.D. Isolation and culture of rat cone photoreceptor cells.Methods Mol. Biol. 2012; 846: 147-158Crossref PubMed Scopus (7) Google Scholar) for cone photoreceptors, respectively. Total RNA was extracted using an RNeasy Micro Plus kit (Qiagen, Hilden, Germany) according to the manufacturer's instructions. To synthesize cDNA, total RNA was added to the high-capacity cDNA reverse and according to manufacturer's instructions. was in using the using and the was using the method with or as the was as previously described (21.Rajagopal R. Bligard G.W. Zhang S. Yin L. Lukasiewicz P. Semenkovich C.F. Functional deficits precede structural lesions in mice with high-fat diet-induced diabetic retinopathy.Diabetes. 2016; 65: 1072-1084Crossref PubMed Scopus (53) Google Scholar). A Technologies, was used. were light mice were with an of and were with eye and was at with a were with and The of a light in darkness or in the of dim after were processed using The of the was from the to the most of the and the was from that to the positive We color and as previously described (15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar, A. S. S. Nakamura R. A. Ferguson T.A. J.L. T. et al.Impaired in macrophages promotes eye 2016; PubMed Scopus Google Scholar), using the animal with to and we mice with an of and and eye and to the We electron microscopy as previously described (15.Lin J.B. Kubota S. Ban N. Yoshida M. Santeford A. Sene A. Nakamura R. Zapata N. Kubota M. Tsubota K. et al.NAMPT-mediated NAD(+) biosynthesis is essential for vision in mice.Cell Reports. 2016; 17: 69-85Abstract Full Text Full Text PDF PubMed Scopus (123) Google Scholar). For were in in for h at room and then at were in at room and in for 1 were then in to with CA) for 1 in were in a of and in 12 of were with a with and and on a electron with an and We used cholesterol to total cholesterol in the neurosensory retina following the manufacturer's protocol. neurosensory retina was with Cholesterol were to of the neurosensory retina We blood from after were at for and then were and in were using and St. following the manufacturer's protocol. in was using an ApoA1 kit following the manufacturer's protocol. To we the to the including and neurosensory retina, were with and then at the was the RPE RPE complex was with of using All of the in of the mouse retina were extracted with of to the and were added as the to the All and as as their were with to the were not for the The of and free cholesterol was with a and a to a in The positive was used for of the and free was used for separation of in and in were from to in at a of All were in for processing was conducted with The of two and was with a a to a with positive was used for these The in and in were from to in and for at a of The processing was conducted with The of the of the and was with a and a to a in A 5 was used for the The and were also used with an at for 12 at a of The processing was conducted with The is reported as of to their to of RPE We with using the for We as a are The deletion of both Abca1 and Abcg1 in Abca1/g1−rod/−rod mouse rod photoreceptors was confirmed by Total cholesterol were in the neurosensory of Abca1/g1−rod/−rod mice with Abca1/g1−rod/−rod were and normal at months of age of HDL, and also did not Although Abca1/g1−rod/−rod mice did not demonstrate a at months of at 12 months of both and were significantly in Abca1/g1−rod/−rod mouse with and other rod photoreceptor and vision In a of cone were normal in Abca1/g1−rod/−rod mouse Although at 12 months electron microscopy of normal at the rod and outer segment J.D. of mammalian rod photoreceptors through the Cell Biol. 2015; 211: PubMed Scopus Google Scholar) in Abca1/g1−rod/−rod mouse In addition, photoreceptor degeneration characterized by outer segment was in Abca1/g1−rod/−rod mouse were normal These structural were also associated with accumulation of large lipid the RPE by confirmed an in the of free cholesterol and cholesterol metabolites underneath the neurosensory retina in the RPE complex with in of the We Abca1/g1−rod/−rod mice to months to to further the months of vision was with further of rod on in Abca1/g1−rod/−rod mice with and other A in cone was also These human diseases rods are for cone and cone after significant rod degeneration N. R. G. F. C. F. L. S. et cone promotes cone by 2015; Full Text Full Text PDF PubMed Scopus Google Scholar). photoreceptor neurodegeneration was on biomicroscopy, as by the the retina These to outer retinal at and the of the RPE on microscopy at the of the RPE and the retina, the and histology, of the outer retina was The RPE also structural including accumulation of lipid photoreceptor and In to Abca1/g1−rod/−rod we also generated mice to the function of ABCA1 and ABCG1 in cone photoreceptors and to The deletion of both Abca1 and Abcg1 in mouse cone photoreceptors was confirmed by to the in Abca1/g1−rod/−rod mouse mouse did not at months old of age in to old Abca1/g1−rod/−rod mouse mouse were and normal at months of age. In order to this was related to cholesterol from the blood stream and associated metabolic we Abca1/g1−rod/−rod mice on a Abca1/g1−rod/−rod mice on a significant neurodegeneration and vision at months with on a microscopy rod outer segment degeneration accumulation of lipid and photoreceptor in the RPE in Abca1/g1−rod/−rod mice on a HFD, which is to the at months of age in Abca1/g1−rod/−rod mice on a normal In this we hypothesized that maintaining physiologic cholesterol homeostasis in photoreceptors by ABCA1 and ABCG1 would play a key role in retinal In of this we that deletion of both Abca1 and Abcg1 in rod photoreceptors leads to age-related accumulation of cholesterol metabolites in the outer retina and retinal In addition, metabolic induced by a significantly this We generated Abca1/g1−rod/−rod mice to the function of ABCA1 and ABCG1 in rod total cholesterol were significantly in Abca1/g1−rod/−rod mouse were not Abca1/g1−rod/−rod were and that cholesterol in rod photoreceptors did not have on retinal and We were in the of on the retinal as a of disease such as in with we Abca1/g1−rod/−rod mice and their to months of age and were to demonstrate rod and cone photoreceptor degeneration and vision In addition, we that lipid in the RPE of from Abca1/g1−rod/−rod not in neurosensory retina, a with the that one of the functions of the RPE is of lipid-rich photoreceptor outer segments shed in a circadian In addition, we the RPE complex for free cholesterol and cholesterol metabolites by The confirmed of free cholesterol and cholesterol metabolites in the RPE an in of the These are in to from mice in which an in A. N. T. cholesterol accumulation and in photoreceptor Biol. 2016; Full Text Full Text PDF PubMed Scopus Google Scholar). The of photoreceptors in are with only about The of rod and cone photoreceptors in human is also very the is Although Abca1/g1−rod/−rod mice significant retinal mouse did not at These that either deletion of Abca1 and Abcg1 in a of photoreceptors not impact visual function or that ABCA1 and ABCG1 are not for normal cone we to cholesterol from the blood stream the of Abca1/g1−rod/−rod mouse In cellular and tissue cholesterol is by a complex and biosynthesis of both responsible for cholesterol and and efflux of which are responsible for cholesterol feeding not retinal in mice (21.Rajagopal R. Bligard G.W. Zhang S. Yin L. Lukasiewicz P. Semenkovich C.F. Functional deficits precede structural lesions in mice with high-fat diet-induced diabetic retinopathy.Diabetes. 2016; 65: 1072-1084Crossref PubMed Scopus (53) Google Scholar), feeding to Abca1/g1−rod/−rod mice photoreceptor neurodegeneration and vision loss, the of Abca1/g1−rod/−rod mice on a normal These that ABCA1 and ABCG1 play in maintaining cholesterol homeostasis in rod photoreceptors and retinal function metabolic in human is high cholesterol causes retinal neurodegeneration or disease For the feature of is accumulation of lipid-rich underneath the RPE most to demonstrate the of such as to disease C.A. C. Y. of and the of age-related macular degeneration in the of 2009; Full Text Full Text PDF PubMed Scopus Google Scholar, C. Eye The of with age-related macular degeneration the Eye 2015; Full Text Full Text PDF PubMed Scopus Google Scholar). in the of cholesterol in rod photoreceptors, retinal a new the or cholesterol and retinal diseases such as In this cholesterol homeostasis as a of age-related rod photoreceptor neurodegeneration and a metabolic of vision in diverse retinal of cholesterol and metabolites in the outer retina be a that leads to and These have potential as have in in cholesterol in and in in diseases such as W. D. M. J. N. et and to age-related macular Sci. 2010; PubMed Scopus Google Scholar, B.M. J. R. L. M. S. J.E. et of age-related macular degeneration a role of the gene Sci. 2010; PubMed Scopus Google Scholar) and disease R. A photoreceptor ATP-binding gene is in macular 17: PubMed Scopus Google Scholar, F. R.S. and transport by ATP-binding cassette proteins and and Biol. 2013; Full Text Full Text PDF PubMed Scopus Google Scholar) that are characterized by and retinal In addition, these have potential the as also demonstrate a role for cholesterol in regulating of the L. D. M. M.T. M. P. T. M. G. D. et cholesterol in the central 2018; PubMed Scopus Google Scholar). Targeted metabolic that ABCA1 and ABCG1 in the retina potential therapeutic and vision The L. for electron microscopy with age-related macular degeneration high-fat diet retinal pigment epithelium

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