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Motipally SI, Kolson DR, Guan T, Kolandaivelu S. Aberrant lipid accumulation and retinal pigment epithelium dysfunction in PRCD-deficient mice. Exp Eye Res 2024; 246:110016. [PMID: 39098587 DOI: 10.1016/j.exer.2024.110016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Revised: 07/24/2024] [Accepted: 07/30/2024] [Indexed: 08/06/2024]
Abstract
Progressive Rod-Cone Degeneration (PRCD) is an integral membrane protein found in photoreceptor outer segment (OS) disc membranes and its function remains unknown. Mutations in Prcd are implicated in Retinitis pigmentosa (RP) in humans and multiple dog breeds. PRCD-deficient models exhibit decreased levels of cholesterol in the plasma. However, potential changes in the retinal cholesterol remain unexplored. In addition, impaired phagocytosis observed in these animal models points to potential deficits in the retinal pigment epithelium (RPE). Here, using a Prcd-/- murine model we investigated the alterations in the retinal cholesterol levels and impairments in the structural and functional integrity of the RPE. Lipidomic and immunohistochemical analyses show a 5-fold increase in the levels of cholesteryl esters (C.Es) and lipid deposits in the PRCD-deficient retina, respectively, indicating alterations in total retinal cholesterol. Furthermore, the RPE of Prcd-/- mice exhibit a 1.7-fold increase in the expression of lipid transporter gene ATP-binding cassette transporter A1 (Abca1). Longitudinal fundus and spectral domain optical coherence tomography (SD-OCT) examinations showed focal lesions and RPE hyperreflectivity. Strikingly, the RPE of Prcd-/- mice exhibited age-related pathological features such as lipofuscin accumulation, Bruch's membrane (BrM) deposits and drusenoid focal deposits, mirroring an Age-related Macular Degeneration (AMD)-like phenotype. We propose that the extensive lipofuscin accumulation likely impairs lysosomal function, leading to the defective phagocytosis observed in Prcd-/- mice. Our findings support the dysregulation of retinal cholesterol homeostasis in the absence of PRCD. Further, we demonstrate that progressive photoreceptor degeneration in Prcd-/- mice is accompanied by progressive structural and functional deficits in the RPE, which likely exacerbates vision loss over time.
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Affiliation(s)
- Sree I Motipally
- Department of Neuroscience, Rockefeller Neuroscience Institute, 33 Medical Centre Drive, West Virginia University, Morgantown, WV, 26506, USA; Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA
| | - Douglas R Kolson
- Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA
| | - Tongju Guan
- Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA; Department of Biochemistry and Molecular Medicine, 64 Medical Center Drive, West Virginia University, Morgantown, WV, 26505-9193, USA
| | - Saravanan Kolandaivelu
- Department of Ophthalmology and Visual Sciences, One Medical Center Drive, ERMA 2nd Floor, West Virginia University, Morgantown, WV, 26505-9193, USA; Department of Biochemistry and Molecular Medicine, 64 Medical Center Drive, West Virginia University, Morgantown, WV, 26505-9193, USA.
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2
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Xu B, Hu Y, Di J, Liu Z, Yu Z, Han L, Ning Y. The negative association between the docosapentaenoic acid intake and the incidence of AMD based on NHANES 2005-2008. Front Nutr 2024; 11:1435775. [PMID: 39119460 PMCID: PMC11306050 DOI: 10.3389/fnut.2024.1435775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2024] [Accepted: 07/12/2024] [Indexed: 08/10/2024] Open
Abstract
Introduction Age-related macular degeneration (AMD) is an ophthalmic disease that causes visual impairment and is one of the leading causes of blindness in the elderly. Fatty acids are essential nutrients required by the body and play a cornerstone role in the life activities of the body. Many studies have reported that fatty acids are involved in the development of AMD. To confirm this association, we conducted the present study. Methods We analyzed the association between all fatty acid intake and AMD using National Health and Nutrition Examination Survey (NHANES) data from 2005-2008. Quantile regression was performed to assess the effect of fatty acids on AMD at different intake levels. Results After adjusting for covariates, only saturated fatty acids showed no significant difference between AMD patients and non-AMD patients (23.64 g vs. 26.03 g, p = 0.052). Total fat (70.88 g vs. 78.86 g, p = 0.024), monounsaturated fatty acids (25.87 g vs. 28.95 g, p = 0.019), polyunsaturated fatty acids (15.10 g vs. 17.07 g, p = 0.017) showed significant differences between the two groups. When AMD was considered as an outcome, the association between AMD and docosaentaenoic acid (DPA) was negative in the multivariate logic model (model 1: OR = <0.001, 95% CI = <0.001 ~ 0.734; model 2: OR = <0.001, 95% CI = <0.001 ~ 0.002; model 3: OR = <0.001, 95% CI = <0.001 ~ 0.002). In the quantile regression, DPA was shown to be negatively associated with the presence of AMD only in the fourth quartile in model 2 and model 3 (model 2: OR = <0.001, 95% CI = <0.001 ~ 0.927; model 3: OR = <0.001, 95% CI = <0.001 ~ 0.775). Discussion Therefore, based on above results, we concluded that DPA intake could prevent the development of AMD.
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Affiliation(s)
- Baiwei Xu
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
- Eye Hospital of China Medical University, Shenyang, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang, China
| | - Yi Hu
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
- Eye Hospital of China Medical University, Shenyang, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang, China
| | - Jie Di
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
- Eye Hospital of China Medical University, Shenyang, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang, China
| | - Zhongwei Liu
- Department of Anesthesiology, Shengjing Hospital of China Medical University, Shenyang, China
| | - Ziyan Yu
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
- Eye Hospital of China Medical University, Shenyang, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang, China
| | - Lin Han
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
- Eye Hospital of China Medical University, Shenyang, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang, China
| | - Yuan Ning
- Department of Ophthalmology, The Fourth Affiliated Hospital of China Medical University, Shenyang, China
- Eye Hospital of China Medical University, Shenyang, China
- Key Lens Research Laboratory of Liaoning Province, Shenyang, China
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Voisin A, Pénaguin A, Gaillard A, Leveziel N. RNASeq profiling of retinal pigment epithelial cells derived from induced pluripotent stem cells revealed 3 genes involved in lipid homeostasis in age-related macular degeneration. Exp Eye Res 2024; 246:109999. [PMID: 38996902 DOI: 10.1016/j.exer.2024.109999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 06/13/2024] [Accepted: 07/08/2024] [Indexed: 07/14/2024]
Abstract
Age-related macular degeneration (AMD) is characterized by visual impairment observed in elderly population. Two forms of the disease are generally described, the atrophic (AMDa) and exudative forms (AMDe). Up until now, no curative treatment is available for this disease. The retinal pigment epithelium (RPE) plays a central role in the pathogenesis of age-related macular degeneration. Here, involvement of RPE dysfunction in AMD onset and progression was analyzed by a comparison of transcriptome profiles of hiPSC-RPE derived from healthy individuals or individuals affected by AMDa or AMDe. The analysis highlighted almost 1000 genes differentially expressed between the three comparison groups. Among these genes, 33 genes were already known to be involved in AMD pathogenesis. To establish an AMD genetic signature, we focused on genes differentially expressed in both AMDa/e cell lines compared to control cells and focused on the three genes (ABCA1, RPN2, RB1CC1) that were related to lipidic homeostasis. Differences in level expression of these three genes are found not only in control and AMDa/e cell lines, but also between AMDa and AMDe populations.
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Affiliation(s)
- Audrey Voisin
- University of Poitiers, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86073, France; INSERM, U1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86022, France; CHU Poitiers, Poitiers, F-86021, France.
| | - Amaury Pénaguin
- University of Poitiers, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86073, France; INSERM, U1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86022, France; Laboratoires THEA, Clermont-Ferrand, France
| | - Afsaneh Gaillard
- University of Poitiers, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86073, France; INSERM, U1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86022, France
| | - Nicolas Leveziel
- University of Poitiers, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86073, France; INSERM, U1084, Laboratoire de Neurosciences Expérimentales et Cliniques, Equipe Thérapie cellulaire dans les pathologies cérébrales, Poitiers, F-86022, France; CHU Poitiers, Poitiers, F-86021, France
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Hullugundi SK, Dolkas J, Chernov AV, Yaksh TL, Eddinger KA, Angert M, Catroli GF, Strongin AY, Dougherty PM, Li Y, Quehenberger O, Armando A, Shubayev VI. Cholesterol-dependent LXR transcription factor activity represses pronociceptive effects of estrogen in sensory neurons and pain induced by myelin basic protein fragments. Brain Behav Immun Health 2024; 38:100757. [PMID: 38590761 PMCID: PMC10999831 DOI: 10.1016/j.bbih.2024.100757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Accepted: 03/17/2024] [Indexed: 04/10/2024] Open
Abstract
Background A bioactive myelin basic protein (MBP) fragment, comprising MBP84-104, is released in sciatic nerve after chronic constriction injury (CCI). Intraneural injection (IN) of MBP84-104 in an intact sciatic nerve is sufficient to induce persistent neuropathic pain-like behavior via robust transcriptional remodeling at the injection site and ipsilateral dorsal root ganglia (DRG) and spinal cord. The sex (female)-specific pronociceptive activity of MBP84-104 associates with sex-specific changes in cholesterol metabolism and activation of estrogen receptor (ESR)1 signaling. Methods In male and female normal and post-CCI rat sciatic nerves, we assessed: (i) cholesterol precursor and metabolite levels by lipidomics; (ii) MBP84-104 interactors by mass spectrometry of MBP84-104 pull-down; and (iii) liver X receptor (LXR)α protein expression by immunoblotting. To test the effect of LXRα stimulation on IN MBP84-104-induced mechanical hypersensitivity, the LXRα expression was confirmed along the segmental neuraxis, in DRG and spinal cord, followed by von Frey testing of the effect of intrathecally administered synthetic LXR agonist, GW3965. In cultured male and female rat DRGs exposed to MBP84-104 and/or estrogen treatments, transcriptional effect of LXR stimulation by GW3965 was assessed on downstream cholesterol transporter Abc, interleukin (IL)-6, and pronociceptive Cacna2d1 gene expression. Results CCI regulated LXRα ligand and receptor levels in nerves of both sexes, with cholesterol precursors, desmosterol and 7-DHC, and oxysterol elevated in females relative to males. MBP84-104 interacted with nuclear receptor coactivator (Ncoa)1, known to activate LXRα, injury-specific in nerves of both sexes. LXR stimulation suppressed ESR1-induced IL-6 and Cacna2d1 expression in cultured DRGs of both sexes and attenuated MBP84-104-induced pain in females. Conclusion The injury-released bioactive MBP fragments induce pronociceptive changes by selective inactivation of nuclear transcription factors, including LXRα. By Ncoa1 sequestration, bioactive MBP fragments render LXRα function to counteract pronociceptive activity of estrogen/ESR1 in sensory neurons. This effect of MBP fragments is prevalent in females due to high circulating estrogen levels in females relative to males. Restoring LXR activity presents a promising therapeutic strategy in management of neuropathic pain induced by bioactive MBP.
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Affiliation(s)
- Swathi K. Hullugundi
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, La Jolla, CA, USA
| | - Jennifer Dolkas
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, La Jolla, CA, USA
| | - Andrei V. Chernov
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, La Jolla, CA, USA
| | - Tony L. Yaksh
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
| | - Kelly A. Eddinger
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
| | - Mila Angert
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, La Jolla, CA, USA
| | - Glaucilene Ferreira Catroli
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, La Jolla, CA, USA
| | - Alex Y. Strongin
- Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, USA
| | - Patrick M. Dougherty
- Department of Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Yan Li
- Department of Pain Medicine, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Aaron Armando
- Lipidomics Core, University of California, San Diego, La Jolla, CA, USA
| | - Veronica I. Shubayev
- Department of Anesthesiology, University of California, San Diego, La Jolla, CA, USA
- VA San Diego Healthcare System, La Jolla, CA, USA
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5
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Andreazzoli M, Longoni B, Angeloni D, Demontis GC. Retinoid Synthesis Regulation by Retinal Cells in Health and Disease. Cells 2024; 13:871. [PMID: 38786093 PMCID: PMC11120330 DOI: 10.3390/cells13100871] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 05/13/2024] [Accepted: 05/13/2024] [Indexed: 05/25/2024] Open
Abstract
Vision starts in retinal photoreceptors when specialized proteins (opsins) sense photons via their covalently bonded vitamin A derivative 11cis retinaldehyde (11cis-RAL). The reaction of non-enzymatic aldehydes with amino groups lacks specificity, and the reaction products may trigger cell damage. However, the reduced synthesis of 11cis-RAL results in photoreceptor demise and suggests the need for careful control over 11cis-RAL handling by retinal cells. This perspective focuses on retinoid(s) synthesis, their control in the adult retina, and their role during retina development. It also explores the potential importance of 9cis vitamin A derivatives in regulating retinoid synthesis and their impact on photoreceptor development and survival. Additionally, recent advancements suggesting the pivotal nature of retinoid synthesis regulation for cone cell viability are discussed.
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Affiliation(s)
| | - Biancamaria Longoni
- Department of Translational Medicine and New Technologies in Medicine, University of Pisa, 56126 Pisa, Italy
| | - Debora Angeloni
- The Institute of Biorobotics, Scuola Superiore Sant’Anna, 56127 Pisa, Italy
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Vasović DD, Ivković S, Živanović A, Major T, Milašin JM, Nikolić NS, Simonović JM, Šutulović N, Hrnčić D, Stanojlović O, Vesković M, Rašić DM, Mladenović D. Reduced light exposure mitigates streptozotocin-induced vascular changes and gliosis in diabetic retina by an anti-inflammatory effect and increased retinal cholesterol turnover. Chem Biol Interact 2024; 394:110996. [PMID: 38593908 DOI: 10.1016/j.cbi.2024.110996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 04/02/2024] [Accepted: 04/04/2024] [Indexed: 04/11/2024]
Abstract
Diabetic retinopathy is not cured efficiently and changes of lifestyle measures may delay early retinal injury in diabetes. The aim of our study was to investigate the effects of reduced daily light exposure on retinal vascular changes in streptozotocin (STZ)-induced model of DM with emphasis on inflammation, Aqp4 expression, visual cycle and cholesterol metabolism-related gene expression in rat retina and RPE. Male Wistar rats were divided into the following groups: 1. control; 2. diabetic group (DM) treated with streptozotocin (100 mg/kg); 3. group exposed to light/dark cycle 6/18 h (6/18); 4. diabetic group exposed to light/dark cycle 6/18 h (DM+6/18). Retinal vascular abnormalities were estimated based on lectin staining, while the expression of genes involved in the visual cycle, cholesterol metabolism, and inflammation was determined by qRT-PCR. Reduced light exposure alleviated vasculopathy, gliosis and the expression of IL-1 and TNF-α in the retina with increased perivascular Aqp4 expression. The expression of genes involved in visual cycle and cholesterol metabolism was significantly up-regulated in RPE in DM+6/18 vs. DM group. In the retina only the expression of APOE was significantly higher in DM+6/18 vs. DM group. Reduced light exposure mitigates vascular changes and gliosis in DM via its anti-inflammatory effect, increased retinal cholesterol turnover and perivascular Aqp4 expression.
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Affiliation(s)
- Dolika D Vasović
- Eye Hospital, University Clinical Centre of Serbia, 11000, Belgrade, Serbia
| | - Sanja Ivković
- Department of Molecular Biology and Endocrinology, Vinca - Institute for Nuclear Sciences, National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Ana Živanović
- Department of Molecular Biology and Endocrinology, Vinca - Institute for Nuclear Sciences, National Institute of Republic of Serbia, University of Belgrade, 11000, Belgrade, Serbia
| | - Tamara Major
- Department of Pharmacology, Faculty of Pharmacy, University of Belgrade, 11000, Belgrade, Serbia
| | - Jelena M Milašin
- Department of Human Genetics, School of Dental Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Nađa S Nikolić
- Department of Human Genetics, School of Dental Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Jelena M Simonović
- Department of Human Genetics, School of Dental Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Nikola Šutulović
- Laboratory for Neurophysiology, Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Dragan Hrnčić
- Laboratory for Neurophysiology, Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Olivera Stanojlović
- Laboratory for Neurophysiology, Institute of Medical Physiology "Richard Burian", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Milena Vesković
- Institute of Pathophysiology "Ljubodrag Buba Mihailovic", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Dejan M Rašić
- Eye Hospital, University Clinical Centre of Serbia, 11000, Belgrade, Serbia; School of Medicine, University of Belgrade, 11000, Belgrade, Serbia
| | - Dušan Mladenović
- Institute of Pathophysiology "Ljubodrag Buba Mihailovic", Faculty of Medicine, University of Belgrade, 11000, Belgrade, Serbia.
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7
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Anderson G, Borooah S, Megaw R, Bagnaninchi P, Weller R, McLeod A, Dhillon B. UVR and RPE - The Good, the Bad and the degenerate Macula. Prog Retin Eye Res 2024; 100:101233. [PMID: 38135244 DOI: 10.1016/j.preteyeres.2023.101233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Revised: 12/15/2023] [Accepted: 12/15/2023] [Indexed: 12/24/2023]
Abstract
Ultraviolet Radiation (UVR) has a well-established causative influence within the aetiology of conditions of the skin and the anterior segment of the eye. However, a grounded assessment of the role of UVR within conditions of the retina has been hampered by a historical lack of quantitative, and spectrally resolved, assessment of how UVR impacts upon the retina in terms congruent with contemporary theories of ageing. In this review, we sought to summarise the key findings of research investigating the connection between UVR exposure in retinal cytopathology while identifying necessary avenues for future research which can deliver a deeper understanding of UVR's place within the retinal risk landscape.
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Affiliation(s)
- Graham Anderson
- Centre for Regenerative Medicine, University of Edinburgh, Edinburgh BioQuarter, EH16 4UU, UK
| | - Shyamanga Borooah
- Viterbi Family Department of Ophthalmology, Shiley Eye Institute, UC San Diego, CA, 92093-0946, USA
| | - Roly Megaw
- Institute of Genetics and Cancer, University of Edinburgh, Western General Hospital, EH4 2XU, UK; Department of Clinical Ophthalmology, National Health Service Scotland, Edinburgh, EH3 9HA, UK
| | - Pierre Bagnaninchi
- Centre for Regenerative Medicine, University of Edinburgh, Edinburgh BioQuarter, EH16 4UU, UK; Robert O Curle Eyelab, Instute for Regeneration and Repair, Edinburgh BioQuarter, 4-5 Little France Drive, Edinburgh, EH16 4UU, UK
| | - Richard Weller
- Centre for Inflammation Research, University of Edinburgh, Edinburgh BioQuarter, EH16 4TJ, UK
| | - Andrew McLeod
- School of GeoSciences, University of Edinburgh, Crew Building, King's Buildings, EH9 3FF, UK
| | - Baljean Dhillon
- Department of Clinical Ophthalmology, National Health Service Scotland, Edinburgh, EH3 9HA, UK; Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh BioQuarter, EH16 4SB, UK; Robert O Curle Eyelab, Instute for Regeneration and Repair, Edinburgh BioQuarter, 4-5 Little France Drive, Edinburgh, EH16 4UU, UK.
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8
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Ban N, Shinojima A, Negishi K, Kurihara T. Drusen in AMD from the Perspective of Cholesterol Metabolism and Hypoxic Response. J Clin Med 2024; 13:2608. [PMID: 38731137 PMCID: PMC11084323 DOI: 10.3390/jcm13092608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Revised: 04/15/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Drusen are one of the most characteristic pathologies of precursor lesion of age-related macular degeneration (AMD). Drusen comprise a yellowish white substance that accumulates typically under the retinal pigment epithelium (RPE), and their constituents are lipids, complement, amyloid, crystallin, and others. In the past, many researchers have focused on drusen and tried to elucidate the pathophysiology of AMD because they believed that disease progression from early AMD to advanced AMD might be based on drusen or drusen might cause AMD. In fact, it is well established that drusen are the hallmark of precursor lesion of AMD and a major risk factor for AMD progression mainly based on their size and number. However, the existence of advanced AMD without drusen has long been recognized. For example, polypoidal choroidal vasculopathy (PCV), which comprises the majority of AMD cases in Asians, often lacks drusen. Thus, there is the possibility that drusen might be no more than a biomarker of AMD and not a cause of AMD. Now is the time to reconsider the relationship between AMD and drusen. In this review, we focus on early AMD pathogenesis based on basic research from the perspective of cholesterol metabolism and hypoxic response in the retina, and we discuss the role of drusen.
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Affiliation(s)
- Norimitsu Ban
- Laboratory of Aging and Retinal Biology, Keio University School of Medicine, Tokyo 160-8582, Japan;
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
| | - Ari Shinojima
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan
| | - Kazuno Negishi
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
| | - Toshihide Kurihara
- Department of Ophthalmology, Keio University School of Medicine, Tokyo 160-8582, Japan; (A.S.); (K.N.)
- Laboratory of Photobiology, Keio University School of Medicine, Tokyo 160-8582, Japan
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9
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Grubaugh CR, Dhingra A, Prakash B, Montenegro D, Sparrow JR, Daniele LL, Curcio CA, Bell BA, Hussain MM, Boesze-Battaglia K. Microsomal triglyceride transfer protein is necessary to maintain lipid homeostasis and retinal function. FASEB J 2024; 38:e23522. [PMID: 38445789 PMCID: PMC10949407 DOI: 10.1096/fj.202302491r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 02/07/2024] [Accepted: 02/16/2024] [Indexed: 03/07/2024]
Abstract
Lipid processing by the retinal pigment epithelium (RPE) is necessary to maintain retinal health and function. Dysregulation of retinal lipid homeostasis due to normal aging or age-related disease triggers lipid accumulation within the RPE, on Bruch's membrane (BrM), and in the subretinal space. In its role as a hub for lipid trafficking into and out of the neural retina, the RPE packages a significant amount of lipid into lipid droplets for storage and into apolipoprotein B (APOB)-containing lipoproteins (Blps) for export. Microsomal triglyceride transfer protein (MTP), encoded by the MTTP gene, is essential for Blp assembly. Herein we test the hypothesis that MTP expression in the RPE is essential to maintain lipid balance and retinal function using the newly generated RPEΔMttp mouse model. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic depletion of Mttp from the RPE results in intracellular lipid accumulation, increased photoreceptor-associated cholesterol deposits, and photoreceptor cell death, and loss of rod but not cone function. RPE-specific reduction in Mttp had no significant effect on plasma lipids and lipoproteins. While APOB was decreased in the RPE, most ocular retinoids remained unchanged, with the exception of the storage form of retinoid, retinyl ester. Thus suggesting that RPE MTP is critical for Blp synthesis and assembly but is not directly involved in plasma lipoprotein metabolism. These studies demonstrate that RPE-specific MTP expression is necessary to establish and maintain retinal lipid homeostasis and visual function.
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Affiliation(s)
- Catharina R. Grubaugh
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Binu Prakash
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Diego Montenegro
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY, 10027 USA
| | - Janet R. Sparrow
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY, 10027 USA
| | - Lauren L. Daniele
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brent A. Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104 USA
| | - M. Mahmood Hussain
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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10
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Zheng F, Su J, Wang J, Zhan Q, Su M, Ding S, Li W, Zhu YT, Guo P. Expression of ATP-Binding Cassette Transporter A1 (ABCA1) in Eyelid Tissues and Meibomian Gland Epithelial Cells. Invest Ophthalmol Vis Sci 2024; 65:24. [PMID: 38502139 PMCID: PMC10959198 DOI: 10.1167/iovs.65.3.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 02/27/2024] [Indexed: 03/20/2024] Open
Abstract
Purpose To validate the adenosine triphosphate (ATP)-binding cassette transporter A1 (ABCA1) expression and distribution in human eyelid tissues and meibomian gland epithelial cells. Methods Meibomian gland tissues from human eyelids were isolated by collagenase A digestion and cultured in defined keratinocyte serum-free medium (DKSFM). Infrared imaging was used to analyze the general morphology of meibomian glands. Hematoxylin and eosin (H&E) staining and Oil Red O staining were used to observe the morphological structure and lipid secretion in the human meibomian gland tissues. Quantitative real-time polymerase chain reaction, western blotting, and immunostaining were used to detect the mRNA and protein expression and cytolocalization of ABCA1 in the meibomian gland tissues and cultured cells. Results The degree of loss of human meibomian gland tissue was related to age. Meibomian gland lipid metabolism was also associated with age. Additionally, human meibomian gland tissues express ABCA1 mRNA and protein; glandular epithelial cells express more ABCA1 mRNA and protein than acinar cells, and their expression in acinar cells decreases with differentiation. Furthermore, the expression of ABCA1 was downregulated in abnormal meibomian gland tissues. ABCA1 was mainly localized on the cell membrane in primary human meibomian gland epithelial cells (pHMGECs), whereas it was localized in the cytoplasm of immortalized human meibomian gland epithelial cells (iHMGECs). The mRNA and protein levels of ABCA1 in pHMGECs were higher than those in iHMGECs. Conclusions Meibomian gland tissues of the human eyelid degenerate with age. ABCA1 expression in acinar cells decreases after differentiation and plays an important role in meibomian gland metabolism.
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Affiliation(s)
- Fang Zheng
- Department of Ophthalmology, Jinzhou Medical University, Jinzhou, China
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Jingjing Su
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Jiaoman Wang
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Qing Zhan
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Mei Su
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Sicheng Ding
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
| | - Wei Li
- Eye Institute of Xiamen University, School of Medicine, Xiamen University, Xiamen, China
| | | | - Ping Guo
- Shenzhen Eye Institute, Shenzhen Eye Hospital, Jinan University, Shenzhen, China
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11
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Matulevičiūtė I, Tatarūnas V, Skipskis V, Čiapienė I, Veikutienė A, Lesauskaitė V, Dobilienė O, Žaliūnienė D. Coronary artery disease, its associations with ocular, genetic and blood lipid parameters. Eye (Lond) 2024; 38:372-379. [PMID: 37587376 PMCID: PMC10810895 DOI: 10.1038/s41433-023-02703-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/31/2023] [Accepted: 08/07/2023] [Indexed: 08/18/2023] Open
Abstract
BACKGROUND/OBJECTIVES To investigate the associations between ophthalmic parameters, CYP4F2 (rs2108622) and ABCA1 (rs1883025) polymorphisms and coronary artery disease, considering the accessibility, non-invasive origin of retinal examination and its possible resemblance to coronary arteries. SUBJECTS/METHODS Overall 165 participants divided into groups based on the coronary angiography results and clinical status: control group (N = 73), MI group (N = 63), 3VD (three vessel disease) (N = 24). All the participants underwent total ophthalmic examination - optical coherence tomography (OCT) and OCT angiography of the macula region were performed and evaluated. Total cholesterol, high-density lipoprotein, low-density lipoprotein and triglyceride cholesterol (Tg-C) were tested. A standard manufacturer's protocol for CYP4F2 (rs2108622) and ABCA1 (rs1883025) was used for genotyping with TaqMan probes. RESULTS GCL+ layer was thicker in control group vs. 3VD group (74.00; 62.67-94.67 (median; min.-max.) vs. 71.06; 51.33-78.44, p = 0.037). T allele carriers under ABCA1 rs1883025 dominant model were shown to have ticker retina and smaller foveal avascular zone in superficial capillary plexus and smaller Tg-C concentration. ABCA1 rs1883025 was associated with retinal thickness (OR = 0.575, 95% CI 0.348-0.948, p = 0.030). Univariate logistic regression showed that ABCA1 rs1883025 CT genotype is associated with decreased risk for coronary artery disease development under overdominant genetic model (OR = 0.498, 95% CI 0.254-0.976; p = 0.042) and codominant genetic model (OR = 0.468, 95% CI 0.232-0.945, p = 0.034). CONCLUSIONS Results of this study confirmed that non-invasive methods such as OCT of eye might be used for identification of patients at risk of CAD.
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Affiliation(s)
- Indrė Matulevičiūtė
- Department of Ophthalmology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
| | - Vacis Tatarūnas
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Vilius Skipskis
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Ieva Čiapienė
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Audronė Veikutienė
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Vaiva Lesauskaitė
- Institute of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Olivija Dobilienė
- Department of Cardiology, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Dalia Žaliūnienė
- Department of Ophthalmology, Lithuanian University of Health Sciences, Kaunas, Lithuania
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12
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Yu M, Zhao S. Functional role of translocator protein and its ligands in ocular diseases (Review). Mol Med Rep 2024; 29:33. [PMID: 38186312 PMCID: PMC10804439 DOI: 10.3892/mmr.2024.13157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 12/08/2023] [Indexed: 01/09/2024] Open
Abstract
The 18 kDa translocator protein (TSPO) is an essential outer mitochondrial membrane protein that is responsible for mitochondrial transport, maintenance of mitochondrial homeostasis and normal physiological cell function. The role of TSPO in the pathogenesis of ocular diseases is a growing area of interest. More notably, TSPO exerts positive effects in regulating various pathophysiological processes, such as the inflammatory response, oxidative stress, steroid synthesis and modulation of microglial function, in combination with a variety of specific ligands such as 1‑(2‑chlorophenyl‑N‑methylpropyl)‑3‑isoquinolinecarboxamide, 4'‑chlorodiazepam and XBD173. In the present review, the expression of TSPO in ocular tissues and the functional role of TSPO and its ligands in diverse ocular diseases was discussed.
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Affiliation(s)
- Mingyi Yu
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 30384, P.R. China
| | - Shaozhen Zhao
- Tianjin Key Laboratory of Retinal Functions and Diseases, Tianjin Branch of National Clinical Research Center for Ocular Disease, Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Tianjin 30384, P.R. China
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13
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El-Darzi N, Mast N, Li Y, Pikuleva IA. APOB100 transgenic mice exemplify how the systemic circulation content may affect the retina without altering retinal cholesterol input. Cell Mol Life Sci 2024; 81:52. [PMID: 38253888 PMCID: PMC10803575 DOI: 10.1007/s00018-023-05056-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 10/24/2023] [Accepted: 11/17/2023] [Indexed: 01/24/2024]
Abstract
Apolipoprotein B (APOB) is a constituent of unique lipoprotein particles (LPPs) produced in the retinal pigment epithelium (RPE), which separates the neural retina from Bruch's membrane (BrM) and choroidal circulation. These LPPs accumulate with age in BrM and contribute to the development of age-related macular degeneration, a major blinding disease. The APOB100 transgenic expression in mice, which unlike humans lack the full-length APOB100, leads to lipid deposits in BrM. Herein, we further characterized APOB100 transgenic mice. We imaged mouse retina in vivo and assessed chorioretinal lipid distribution, retinal sterol levels, retinal cholesterol input, and serum content as well as tracked indocyanine green-bound LPPs in mouse plasma and retina after an intraperitoneal injection. Retinal function and differentially expressed proteins were also investigated. APOB100 transgenic mice had increased serum LDL content and an additional higher density HDL subpopulation; their retinal cholesterol levels (initially decreased) became normal with age. The LPP cycling between the RPE and choroidal circulation was increased. Yet, LPP trafficking from the RPE to the neural retina was limited, and total retinal cholesterol input did not change. There were lipid deposits in the RPE and BrM, and retinal function was impaired. Retinal proteomics provided mechanistic insights. Collectively, our data suggested that the serum LDL/HDL ratio may not affect retinal pathways of cholesterol input as serum LPP load is mainly handled by the RPE, which offloads LPP excess to the choroidal circulation rather than neural retina. Different HDL subpopulations should be considered in studies linking serum LPPs and age-related macular degeneration.
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Affiliation(s)
- Nicole El-Darzi
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Natalia Mast
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Yong Li
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA.
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Zeng GG, Lei Q, Jiang WL, Zhang XX, Nie L, Gong X, Zheng K. A new perspective on the current and future development potential of ABCG1. Curr Probl Cardiol 2024; 49:102161. [PMID: 37875209 DOI: 10.1016/j.cpcardiol.2023.102161] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 10/20/2023] [Indexed: 10/26/2023]
Abstract
ABCG1 is an essential protein involved in the efflux of intracellular cholesterol to the extracellular space, thus playing a critical role in reducing cholesterol accumulation in neighboring tissues. Bibliometric analysis pertains to the interdisciplinary field of quantitative examination of diverse documents using mathematical and statistical techniques. It integrates the investigation of structural and temporal patterns in academic publications with an exploration of subject focus and forms of uncertainty. This research paper examines the historical evolution, current areas of interest, and future development trends of ABCG1 through bibliometric analysis. This study aims to offer readers insights into the research status and emerging trends of ABCG1, thereby assisting researchers in the exciting field to explore novel research avenues. Following rigorous selection, research on ABCG1 has remained highly active over the past two decades. ABCG1 has even started to emerge in previously unrelated fields, such as the field of cancer research. According to the analysis conducted by Citespace, a lot of keywords and influential citations were identified. ABCG1 has been found to establish a connection between cancer and cardiovascular disease, highlighting their interrelationship. This review aims to assist readers who have limited familiarity with ABCG1 research in gaining a rapid understanding of its developmental trajectory. Additionally, it aims to offer researchers potential areas of focus for future studies related to ABCG1.
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Affiliation(s)
- Guang-Gui Zeng
- Affiliated Hengyang Hospital of Hunan Normal University & Hengyang Central Hospital, Hengyang, Hunan 421001, China; Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China; 2020 Grade Excellent Doctor Class of Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Qiong Lei
- Hunan Polytechnic of Environment and Biology, Hengyang, Hunan 421001, China
| | - Wan-Li Jiang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China; Departments of Clinical Medicine, Hengyang Medical College, University of South China, Hengyang, Hunan 421001, China
| | - Xing-Xing Zhang
- Institute of Cardiovascular Disease, Key Laboratory for Arteriosclerology of Hunan Province, Hunan International Scientific and Technological Cooperation Base of Arteriosclerotic Disease, Hengyang Medical School, University of South China, Hengyang, Hunan 421001, China
| | - Liluo Nie
- Affiliated Hengyang Hospital of Hunan Normal University & Hengyang Central Hospital, Hengyang, Hunan 421001, China
| | - Xianghao Gong
- Affiliated Hengyang Hospital of Hunan Normal University & Hengyang Central Hospital, Hengyang, Hunan 421001, China.
| | - Kang Zheng
- Affiliated Hengyang Hospital of Hunan Normal University & Hengyang Central Hospital, Hengyang, Hunan 421001, China.
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15
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Grubaugh CR, Dhingra A, Prakash B, Montenegro D, Sparrow JR, Daniele LL, Curcio CA, Bell BA, Hussain MM, Boesze-Battaglia K. Microsomal triglyceride transfer protein is necessary to maintain lipid homeostasis and retinal function. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.06.570418. [PMID: 38105975 PMCID: PMC10723417 DOI: 10.1101/2023.12.06.570418] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Lipid processing by the retinal pigment epithelium (RPE) is necessary to maintain retinal health and function. Dysregulation of retinal lipid homeostasis due to normal aging or to age-related disease triggers lipid accumulation within the RPE, on Bruch's membrane (BrM), and in the subretinal space. In its role as a hub for lipid trafficking into and out of the neural retina, the RPE packages a significant amount of lipid into lipid droplets for storage and into apolipoprotein B (apoB)-containing lipoproteins (Blps) for export. Microsomal triglyceride transfer protein (MTP), encoded by the MTTP gene, is essential for Blp assembly. Herein we test the hypothesis that MTP expression in the RPE is essential to maintain lipid balance and retinal function using the newly generated RPEΔMttp mouse model. Using non-invasive ocular imaging, electroretinography, and histochemical and biochemical analyses we show that genetic deletion of Mttp from the RPE results in intracellular lipid accumulation, increased photoreceptor -associated cholesterol deposits and photoreceptor cell death, and loss of rod but not cone function. RPE-specific ablation of Mttp had no significant effect on plasma lipids and lipoproteins. While, apoB was decreased in the RPE, ocular retinoid concentrations remained unchanged. Thus suggesting that RPE MTP is critical for Blp synthesis and assembly but not directly involved in ocular retinoid and plasma lipoprotein metabolism. These studies demonstrate that RPE-specific MTP expression is necessary to establish and maintain retinal lipid homeostasis and visual function.
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Affiliation(s)
- Catharina R. Grubaugh
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anuradha Dhingra
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Binu Prakash
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Diego Montenegro
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY,10027 USA
| | - Janet R. Sparrow
- Department of Ophthalmology and Department of Pathology and Cell Biology, Columbia University, New York, NY,10027 USA
| | - Lauren L. Daniele
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Brent A. Bell
- Department of Ophthalmology, University of Pennsylvania, Philadelphia, PA, 19104 USA
| | - M. Mahmood Hussain
- Department of Foundations of Medicine, New York University Grossman Long Island School of Medicine, Mineola, NY, 11501 USA
| | - Kathleen Boesze-Battaglia
- Department of Basic and Translational Sciences, University of Pennsylvania, Philadelphia, PA 19104, USA
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16
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Fuentevilla-Álvarez G, Huesca-Gómez C, Paz-Torres YE, González-Moyotl N, Soto ME, García-Valdivia JA, Sámano R, Martínez-Rosas M, Meza-Toledo SE, Gamboa R. Evaluation of the participation of ABCA1 transporter in epicardial and mediastinal adipose tissue from patients with coronary artery disease. ARCHIVES OF ENDOCRINOLOGY AND METABOLISM 2023; 68:e230188. [PMID: 37988669 PMCID: PMC10916836 DOI: 10.20945/2359-4292-2023-0188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 06/01/2023] [Indexed: 11/23/2023]
Abstract
Objective Recent studies have shown a relationship between adipose tissue and coronary artery disease (CAD). The ABCA1 transporter regulates cellular cholesterol content and reverses cholesterol transport. The aim of this study was to determine the relationship between single nucleotide polymorphisms (SNPs) R230C, C-17G, and C-69T and their expression in epicardial and mediastinal adipose tissue in Mexican patients with CAD. Subjects and methods The study included 71 patients with CAD and a control group consisting of 64 patients who underwent heart valve replacement. SNPs were determined using TaqMan probes. mRNA was extracted using TriPure Isolation from epicardial and mediastinal adipose tissue. Quantification and expression analyses were done using RT-qPCR. Results R230C showed a higher frequency of the GG genotype in the CAD group (70.4%) than the control group (57.8%) [OR 0.34, 95% CI (0.14-0.82) p = 0.014]. Similarly, C-17G (rs2740483) showed a statistically significant difference in the CC genotype in the CAD group (63.3%) in comparison to the controls (28.1%) [OR 4.42, 95% CI (2.13-9.16), p = 0.001]. mRNA expression in SNP R230C showed statistically significant overexpression in the AA genotype compared to the GG genotype in CAD patients [11.01 (4.31-15.24) vs. 3.86 (2.47-12.50), p = 0.015]. Conclusion The results suggest that the GG genotype of R230C and CC genotype of C-17G are strongly associated with the development of CAD in Mexican patients. In addition, under-expression of mRNA in the GG genotype in R230C is associated with patients undergoing revascularization.
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Affiliation(s)
- Giovanny Fuentevilla-Álvarez
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México
- Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional (IPN), Ciudad de México, México
| | - Claudia Huesca-Gómez
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México
| | - Yazmín Estela Paz-Torres
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México
| | - Nadia González-Moyotl
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México
| | - María Elena Soto
- Departamento de Inmunología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México
- Cardiovascular Line in American British Cowdray (ABC) Medical Center, I.A.P. A.B.C.,Mexico City, Mexico
| | | | - Reyna Sámano
- Coordinación de Nutrición y Bioprogramación, Instituto Nacional de Perinatología,Ciudad de México, México
| | - Martín Martínez-Rosas
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México
| | - Sergio Enrique Meza-Toledo
- Departamento de Bioquímica, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional (IPN), Ciudad de México, México
| | - Ricardo Gamboa
- Departamento de Fisiología, Instituto Nacional de Cardiología "Ignacio Chávez", Ciudad de México, México,
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17
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Leung AM, Rao MB, Raju N, Chung M, Klinger A, Rowe DJ, Li X, Levine EM. A framework to identify functional interactors that contribute to disrupted early retinal development in Vsx2 ocular retardation J mice. Dev Dyn 2023; 252:1338-1362. [PMID: 37259952 PMCID: PMC10689574 DOI: 10.1002/dvdy.629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 04/29/2023] [Accepted: 05/08/2023] [Indexed: 06/02/2023] Open
Abstract
BACKGROUND A goal of developmental genetics is to identify functional interactions that underlie phenotypes caused by mutations. We sought to identify functional interactors of Vsx2, which when mutated, disrupts early retinal development. We utilized the Vsx2 loss-of-function mouse, ocular retardation J (orJ), to assess interactions based on principles of positive and negative epistasis as applied to bulk transcriptome data. This was first tested in vivo with Mitf, a target of Vsx2 repression, and then to cultures of orJ retina treated with inhibitors of Retinoid-X Receptors (RXR) to target Rxrg, an up-regulated gene in the orJ retina, and gamma-Secretase, an enzyme required for Notch signaling, a key mediator of retinal proliferation and neurogenesis. RESULTS Whereas Mitf exhibited robust positive epistasis with Vsx2, it only partially accounts for the orJ phenotype, suggesting other functional interactors. RXR inhibition yielded minimal evidence for epistasis between Vsx2 and Rxrg. In contrast, gamma-Secretase inhibition caused hundreds of Vsx2-dependent genes associated with proliferation to deviate further from wild-type, providing evidence for convergent negative epistasis with Vsx2 in regulating tissue growth. CONCLUSIONS Combining in vivo and ex vivo testing with transcriptome analysis revealed quantitative and qualitative characteristics of functional interaction between Vsx2, Mitf, RXR, and gamma-Secretase activities.
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Affiliation(s)
- Amanda M. Leung
- Department of Cell and Developmental Biology, Vanderbilt
University, Nashville TN 37232
| | - Mahesh B. Rao
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
| | - Nathan Raju
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
| | - Minh Chung
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
| | - Allison Klinger
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
| | - DiAnna J. Rowe
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
| | - Xiaodong Li
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
| | - Edward M. Levine
- Department of Cell and Developmental Biology, Vanderbilt
University, Nashville TN 37232
- Department of Ophthalmology and Visual Sciences, Vanderbilt
University Medical Center, Nashville TN 37232
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Cao Y, Ibrahim KS, Li X, Wong A, Wu Y, Yu XD, Zhou X, Tan Z, He Z, Craft JA, Shu X. Chinese medicine, Qijudihuang pill, mediates cholesterol metabolism and regulates gut microbiota in high-fat diet-fed mice, implications for age-related macular degeneration. Front Immunol 2023; 14:1274401. [PMID: 37901244 PMCID: PMC10602650 DOI: 10.3389/fimmu.2023.1274401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Accepted: 09/21/2023] [Indexed: 10/31/2023] Open
Abstract
Background Traditional Chinese Medicines have been used for thousands of years but without any sound empirical basis. One such preparation is the Qijudihuang pill (QP), a mixture of eight herbs, that has been used in China for the treatment of various conditions including age-related macular degeneration (AMD), the most common cause of blindness in the aged population. In order to explain the mechanism behind the effect of QP, we used an AMD model of high-fat diet (HFD) fed mice to investigate cholesterol homeostasis, oxidative stress, inflammation and gut microbiota. Methods Mice were randomly divided into three groups, one group was fed with control diet (CD), the other two groups were fed with high-fat-diet (HFD). One HFD group was treated with QP, both CD and the other HFD groups were treated with vehicles. Tissue samples were collected after the treatment. Cholesterol levels in retina, retinal pigment epithelium (RPE), liver and serum were determined using a commercial kit. The expression of enzymes involved in cholesterol metabolism, inflammation and oxidative stress was measured with qRT-PCR. Gut microbiota was analyzed using 16S rRNA sequencing. Results In the majority of the lipid determinations, analytes were elevated by HFD but this was reversed by QP. Cholesterol metabolism including the enzymes of bile acid (BA) formation was suppressed by HFD but again this was reversed by QP. BAs play a major role in signaling between host and microbiome and this is disrupted by HFD resulting in major changes in the composition of colonic bacterial communities. Associated with these changes are predictions of the metabolic pathway complexity and abundance of individual pathways. These concerned substrate breakdowns, energy production and the biosynthesis of pro-inflammatory factors but were changed back to control characteristics by QP. Conclusion We propose that the ability of QP to reverse these HFD-induced effects is related to mechanisms acting to lower cholesterol level, oxidative stress and inflammation, and to modulate gut microbiota.
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Affiliation(s)
- Yanqun Cao
- Pu Ai Medical School, Shaoyang University, Shaoyang, Hunan, China
| | - Khalid S. Ibrahim
- Department of Biological and Biomedical Sciences , Glasgow Caledonian University, Glasgow, United Kingdom
- Department of Biology, Faculty of Science, University of Zakho, Zakho, Iraq
| | - Xing Li
- Pu Ai Medical School, Shaoyang University, Shaoyang, Hunan, China
| | - Aileen Wong
- Department of Biological and Biomedical Sciences , Glasgow Caledonian University, Glasgow, United Kingdom
| | - Yi Wu
- School of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Xu-Dong Yu
- Pu Ai Medical School, Shaoyang University, Shaoyang, Hunan, China
| | - Xinzhi Zhou
- Department of Biological and Biomedical Sciences , Glasgow Caledonian University, Glasgow, United Kingdom
| | - Zhoujin Tan
- School of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha, Hunan, China
| | - Zhiming He
- Pu Ai Medical School, Shaoyang University, Shaoyang, Hunan, China
| | - John A. Craft
- Department of Biological and Biomedical Sciences , Glasgow Caledonian University, Glasgow, United Kingdom
| | - Xinhua Shu
- Pu Ai Medical School, Shaoyang University, Shaoyang, Hunan, China
- Department of Biological and Biomedical Sciences , Glasgow Caledonian University, Glasgow, United Kingdom
- Department of Vision Science , Glasgow Caledonian University, Glasgow, United Kingdom
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Sun RX, Zhu HJ, Zhang YR, Wang JN, Wang Y, Cao QC, Ji JD, Jiang C, Yuan ST, Chen X, Liu QH. ALKBH5 causes retinal pigment epithelium anomalies and choroidal neovascularization in age-related macular degeneration via the AKT/mTOR pathway. Cell Rep 2023; 42:112779. [PMID: 37436898 DOI: 10.1016/j.celrep.2023.112779] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Revised: 05/24/2023] [Accepted: 06/25/2023] [Indexed: 07/14/2023] Open
Abstract
Retinal pigment epithelium (RPE) dysfunction and choroidal neovascularization (CNV) are predominant features of age-related macular degeneration (AMD), with an unclear mechanism. Herein, we show that RNA demethylase α-ketoglutarate-dependent dioxygenase alkB homolog 5 (ALKBH5) is up-regulated in AMD. In RPE cells, ALKBH5 overexpression associates with depolarization, oxidative stress, disturbed autophagy, irregular lipid homeostasis, and elevated VEGF-A secretion, which subsequently promotes proliferation, migration, and tube formation of vascular endothelial cells. Consistently, ALKBH5 overexpression in mice RPE correlates with various pathological phenotypes, including visual impairments, RPE anomalies, choroidal neovascularization (CNV), and interrupted retinal homeostasis. Mechanistically, ALKBH5 regulates retinal features through its demethylation activity. It targets PIK3C2B and regulates the AKT/mTOR signaling pathway with YTHDF2 as the N6-methyladenosine reader. IOX1, an ALKBH5 inhibitor, suppresses hypoxia-induced RPE dysfunction and CNV progression. Collectively, we demonstrate that ALKBH5 induces RPE dysfunction and CNV progression in AMD via PIK3C2B-mediated activation of the AKT/mTOR pathway. Pharmacological inhibitors of ALKBH5, like IOX1, are promising therapeutic options for AMD.
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Affiliation(s)
- Ru-Xu Sun
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Hong-Jing Zhu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Ye-Ran Zhang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Jia-Nan Wang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Ying Wang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Qiu-Chen Cao
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Jiang-Dong Ji
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Chao Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China
| | - Song-Tao Yuan
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China.
| | - Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China.
| | - Qing-Huai Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical University, Nanjing 210029, China.
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20
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Li Z, Li Y, Hou Y, Fan Y, Jiang H, Li B, Zhu H, Liu Y, Zhang L, Zhang J, Wu M, Ma T, Zhao T, Ma L. Association of Plasma Vitamins and Carotenoids, DNA Methylation of LCAT, and Risk of Age-Related Macular Degeneration. Nutrients 2023; 15:2985. [PMID: 37447314 DOI: 10.3390/nu15132985] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 06/07/2023] [Accepted: 06/08/2023] [Indexed: 07/15/2023] Open
Abstract
Dysregulation of lipid metabolism has been implicated in age-related macular degeneration (AMD), the leading cause of blindness among the elderly. Lecithin cholesterol acyltransferase (LCAT) is an important enzyme responsible for lipid metabolism, which could be regulated by DNA methylation during the development of various age-related diseases. This study aimed to assess the association between LCAT DNA methylation and the risk of AMD, and to examine whether plasma vitamin and carotenoid concentrations modified this association. A total of 126 cases of AMD and 174 controls were included in the present analysis. LCAT DNA methylation was detected by quantitative real-time methylation-1specific PCR (qMSP). Circulating vitamins and carotenoids were measured using reversed-phase high-performance liquid chromatography (RP-HPLC). DNA methylation of LCAT was significantly higher in patients with AMD than those in the control subjects. After multivariable adjustment, participants in the highest tertile of LCAT DNA methylation had a 5.37-fold higher risk (95% CI: 2.56, 11.28) of AMD compared with those in the lowest tertile. Each standard deviation (SD) increment of LCAT DNA methylation was associated with a 2.23-fold (95% CI: 1.58, 3.13) increased risk of AMD. There was a J-shaped association between LCAT DNA methylation and AMD risk (Pnon-linearity = 0.03). Higher concentrations of plasma retinol and β-cryptoxanthin were significantly associated with decreased levels of LCAT DNA methylation, with the multivariate-adjusted β coefficient being -0.05 (95% CI: -0.08, -0.01) and -0.25 (95% CI: -0.42, -0.08), respectively. In joint analyses of LCAT DNA methylation and plasma vitamin and carotenoid concentrations, the inverse association between increased LCAT DNA methylation and AMD risk was more pronounced among participants who had a lower concentration of plasma retinol and β-cryptoxanthin. These findings highlight the importance of comprehensively assessing LCAT DNA methylation and increasing vitamin and carotenoid status for the prevention of AMD.
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Affiliation(s)
- Zhaofang Li
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Yajing Li
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Yijing Hou
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Yahui Fan
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Hong Jiang
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Baoyu Li
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Hailu Zhu
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Yaning Liu
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Lei Zhang
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Jie Zhang
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Min Wu
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
| | - Tianyou Ma
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an 710061, China
| | - Tong Zhao
- College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi'an 710119, China
| | - Le Ma
- School of Public Health, Xi'an Jiaotong University Health Science Center, Xi'an 710061, China
- Key Laboratory of Environment and Genes Related to Diseases, Xi'an Jiaotong University, Ministry of Education of China, Xi'an 710061, China
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21
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Distéfano-Gagné F, Bitarafan S, Lacroix S, Gosselin D. Roles and regulation of microglia activity in multiple sclerosis: insights from animal models. Nat Rev Neurosci 2023:10.1038/s41583-023-00709-6. [PMID: 37268822 DOI: 10.1038/s41583-023-00709-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/28/2023] [Indexed: 06/04/2023]
Abstract
As resident macrophages of the CNS, microglia are critical immune effectors of inflammatory lesions and associated neural dysfunctions. In multiple sclerosis (MS) and its animal models, chronic microglial inflammatory activity damages myelin and disrupts axonal and synaptic activity. In contrast to these detrimental effects, the potent phagocytic and tissue-remodelling capabilities of microglia support critical endogenous repair mechanisms. Although these opposing capabilities have long been appreciated, a precise understanding of their underlying molecular effectors is only beginning to emerge. Here, we review recent advances in our understanding of the roles of microglia in animal models of MS and demyelinating lesions and the mechanisms that underlie their damaging and repairing activities. We also discuss how the structured organization and regulation of the genome enables complex transcriptional heterogeneity within the microglial cell population at demyelinating lesions.
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Affiliation(s)
- Félix Distéfano-Gagné
- Axe Neuroscience, Centre de Recherche du CHU de Québec - Université Laval, Québec, Québec, Canada
- Département de Médecine Moléculaire de la Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - Sara Bitarafan
- Axe Neuroscience, Centre de Recherche du CHU de Québec - Université Laval, Québec, Québec, Canada
- Département de Médecine Moléculaire de la Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - Steve Lacroix
- Axe Neuroscience, Centre de Recherche du CHU de Québec - Université Laval, Québec, Québec, Canada
- Département de Médecine Moléculaire de la Faculté de Médecine, Université Laval, Québec, Québec, Canada
| | - David Gosselin
- Axe Neuroscience, Centre de Recherche du CHU de Québec - Université Laval, Québec, Québec, Canada.
- Département de Médecine Moléculaire de la Faculté de Médecine, Université Laval, Québec, Québec, Canada.
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22
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Choudhary M, Malek G. Potential therapeutic targets for age-related macular degeneration: The nuclear option. Prog Retin Eye Res 2023; 94:101130. [PMID: 36220751 PMCID: PMC10082136 DOI: 10.1016/j.preteyeres.2022.101130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 09/18/2022] [Accepted: 09/18/2022] [Indexed: 02/07/2023]
Abstract
The functions and activities of nuclear receptors, the largest family of transcription factors in the human genome, have classically focused on their ability to act as steroid and hormone sensors in endocrine organs. However, they are responsible for a diverse array of physiological functions, including cellular homeostasis and metabolism, during development and aging. Though the eye is not a traditional endocrine organ, recent studies have revealed high expression levels of nuclear receptors in cells throughout the posterior pole. These findings have precipitated an interest in investigating the role of these transcription factors in the eye as a function of age and ocular disease, in particular age-related macular degeneration (AMD). As the leading cause of vision impairment in the elderly, identifying signaling pathways that may be targeted for AMD therapy is of great importance, given the lack of therapeutic options for over 85% of patients with this disease. Herein we review this relatively new field and recent findings supporting the hypothesis that the eye is a secondary endocrine organ, in which nuclear receptors serve as the bedrock for biological processes in cells vulnerable in AMD, including retinal pigment epithelial and choroidal endothelial cells, and discuss the therapeutic potential of targeting these receptors for AMD.
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Affiliation(s)
- Mayur Choudhary
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA
| | - Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
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23
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von Eckardstein A, März W, Laufs U. [HDL - Quo vadis]. Dtsch Med Wochenschr 2023; 148:627-635. [PMID: 37080216 PMCID: PMC10139774 DOI: 10.1055/a-1516-2731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/22/2023]
Abstract
Many epidemiological studies found low plasma levels of high-density lipoprotein (HDL) cholesterol (HDL-C) associated with an increased risk of atherosclerotic cardiovascular disease (ASCVD). In cell culture and animal models, HDL particles show many anti-atherogenic actions. However, until now, clinical trials did not find any prevention of ASCVD events by drugs elevating HDL-C levels, at least not beyond statins. Also, genetic studies show no associations of HDL-C levels altering variants with cardiovascular risk. Therefore, the causal role and clinical benefit of HDL-C elevation in ASCVD are questioned. However, the interpretation of previous data has important limitations: First, the inverse relationship of HDL-C with the risk of ASCVD is limited to concentrations < 60 mg/dl (< 1.5 mmol/l). Higher concentrations do not reduce the risk of ASCVD events and are even associated with increased mortality. Therefore, neither the higher-the-better strategies of earlier drug developments nor the assumption of linear cause-and-effect relationships in Mendelian randomization trials are justified. Second, most of the drugs tested so far do not act specifically on HDL metabolism. Therefore, the futile endpoint studies question the clinical benefit of the investigated drugs, but not the importance of HDL in ASCVD. Third, the vascular functions of HDL are not exerted by its cholesterol content (i.e. HDL-C), but by a variety of other molecules. Comprehensive knowledge of the structure-function-disease relationships of HDL particles and their molecules is a prerequisite for testing their physiological and pathogenic relevance and possibly for optimizing the diagnosis and treatment of persons with HDL-associated risk of ASCVD, but also for other diseases, such as diabetes, chronic kidney disease, infections, autoimmune and neurodegenerative diseases.
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24
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Peters F, Grimm C. Regulation of ABCA1 by miR-33 and miR-34a in the Aging Eye. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:55-59. [PMID: 37440014 DOI: 10.1007/978-3-031-27681-1_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Many age-related diseases, including age-related macular degeneration (AMD), go along with local lipid accumulation and dysregulated lipid metabolism. Several genes involved in lipid metabolism, including ATP-binding cassette transporter A1 (ABCA1), were associated with AMD through genome-wide association studies. Recent studies have shown that loss of ABCA1 in the retinal pigment epithelium (RPE) leads to lipid accumulation and RPE atrophy, a hallmark of AMD, and that antagonizing ABCA1-targeting microRNAs (miRNAs) attenuated pathological changes to the RPE or to macrophages. Here, we focus on two lipid metabolism-modulating miRNAs, miR-33 and miR-34a, which show increased expression in aging RPE cells, and on their potential to regulate ABCA1 levels, cholesterol efflux, and lipid accumulation in AMD pathogenesis.
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Affiliation(s)
- Florian Peters
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Schlieren, Switzerland.
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, Schlieren, Switzerland
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25
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Malek G, Campisi J, Kitazawa K, Webster C, Lakkaraju A, Skowronska-Krawczyk D. Does senescence play a role in age-related macular degeneration? Exp Eye Res 2022; 225:109254. [PMID: 36150544 PMCID: PMC10032649 DOI: 10.1016/j.exer.2022.109254] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2021] [Revised: 09/07/2022] [Accepted: 09/14/2022] [Indexed: 12/29/2022]
Abstract
Advanced age is the most established risk factor for developing age-related macular degeneration (AMD), one of the leading causes of visual impairment in the elderly, in Western and developed countries. Similarly, after middle age, there is an exponential increase in pathologic molecular and cellular events that can induce senescence, traditionally defined as an irreversible loss of the cells' ability to divide and most recently reported to also occur in select post-mitotic and terminally differentiated cells, such as neurons. Together these facts raise the question as to whether or not cellular senescence, may play a role in the development of AMD. A number of studies have reported the effect of ocular-relevant inducers of senescence using primarily in vitro models of poorly polarized, actively dividing retinal pigment epithelial (RPE) cell lines. However, in interpretating the data, the fidelity of these culture models to the RPE in vivo, must be considered. Fewer studies have explored the presence and/or impact of senescent cells in in vivo models that present with phenotypic features of AMD, leaving this an open field for further investigation. The goal of this review is to discuss current thoughts on the potential role of senescence in AMD development and progression, with consideration of the model systems used and their relevance to human disease.
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Affiliation(s)
- Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Judith Campisi
- Buck Institute for Research on Aging, Novato, CA, USA; Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Koji Kitazawa
- Buck Institute for Research on Aging, Novato, CA, USA; Department of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Corey Webster
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Aparna Lakkaraju
- Departments of Ophthalmology and Anatomy, School of Medicine, University of California, San Francisco, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, University of California, Irvine, CA, USA
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26
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Farnoodian M, Bose D, Khristov V, Susaimanickam PJ, Maddileti S, Mariappan I, Abu-Asab M, Campos M, Villasmil R, Wan Q, Maminishkis A, McGaughey D, Barone F, Gundry RL, Riordon DR, Boheler KR, Sharma R, Bharti K. Cell-autonomous lipid-handling defects in Stargardt iPSC-derived retinal pigment epithelium cells. Stem Cell Reports 2022; 17:2438-2450. [DOI: 10.1016/j.stemcr.2022.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 09/30/2022] [Accepted: 10/03/2022] [Indexed: 11/06/2022] Open
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27
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Bharti K, den Hollander AI, Lakkaraju A, Sinha D, Williams DS, Finnemann SC, Bowes-Rickman C, Malek G, D'Amore PA. Cell culture models to study retinal pigment epithelium-related pathogenesis in age-related macular degeneration. Exp Eye Res 2022; 222:109170. [PMID: 35835183 PMCID: PMC9444976 DOI: 10.1016/j.exer.2022.109170] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 06/23/2022] [Accepted: 06/29/2022] [Indexed: 11/04/2022]
Abstract
Age-related macular degeneration (AMD) is a disease that affects the macula - the central part of the retina. It is a leading cause of irreversible vision loss in the elderly. AMD onset is marked by the presence of lipid- and protein-rich extracellular deposits beneath the retinal pigment epithelium (RPE), a monolayer of polarized, pigmented epithelial cells located between the photoreceptors and the choroidal blood supply. Progression of AMD to the late nonexudative "dry" stage of AMD, also called geographic atrophy, is linked to progressive loss of areas of the RPE, photoreceptors, and underlying choriocapillaris leading to a severe decline in patients' vision. Differential susceptibility of macular RPE in AMD and the lack of an anatomical macula in most lab animal models has promoted the use of in vitro models of the RPE. In addition, the need for high throughput platforms to test potential therapies has driven the creation and characterization of in vitro model systems that recapitulate morphologic and functional abnormalities associated with human AMD. These models range from spontaneously formed cell line ARPE19, immortalized cell lines such as hTERT-RPE1, RPE-J, and D407, to primary human (fetal or adult) or animal (mouse and pig) RPE cells, and embryonic and induced pluripotent stem cell (iPSC) derived RPE. Hallmark RPE phenotypes, such as cobblestone morphology, pigmentation, and polarization, vary significantly betweendifferent models and culture conditions used in different labs, which would directly impact their usability for investigating different aspects of AMD biology. Here the AMD Disease Models task group of the Ryan Initiative for Macular Research (RIMR) provides a summary of several currently used in vitro RPE models, historical aspects of their development, RPE phenotypes that are attainable in these models, their ability to model different aspects of AMD pathophysiology, and pros/cons for their use in the RPE and AMD fields. In addition, due to the burgeoning use of iPSC derived RPE cells, the critical need for developing standards for differentiating and rigorously characterizing RPE cell appearance, morphology, and function are discussed.
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Affiliation(s)
- Kapil Bharti
- Ocular and Stem Cell Translational Research Section, National Eye Institute, NIH, Bethesda, MD, USA.
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Nijmegen, the Netherlands; AbbVie, Genomics Research Center, Cambridge, MA, USA.
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, University of California, San Francisco, USA.
| | - Debasish Sinha
- Department of Ophthalmology, Cell Biology and Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA; Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - David S Williams
- Stein Eye Institute, Departments of Ophthalmology and Neurobiology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA.
| | - Silvia C Finnemann
- Center of Cancer, Genetic Diseases, and Gene Regulation, Department of Biological Sciences, Fordham University, Bronx, NY, USA.
| | - Catherine Bowes-Rickman
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Cell Biology, Duke University School of Medicine, Durham, NC, USA.
| | - Goldis Malek
- Duke Eye Center, Department of Ophthalmology, Duke University School of Medicine, Durham, NC, USA; Department of Pathology, Duke University School of Medicine, Durham, NC, USA.
| | - Patricia A D'Amore
- Mass Eye and Ear, Departments of Ophthalmology and Pathology, Harvard Medical School, Boston, MA, USA.
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28
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HDL, cholesterol efflux, and ABCA1: Free from good and evil dualism. J Pharmacol Sci 2022; 150:81-89. [DOI: 10.1016/j.jphs.2022.07.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 07/15/2022] [Accepted: 07/25/2022] [Indexed: 11/19/2022] Open
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29
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Shughoury A, Sevgi DD, Ciulla TA. Molecular Genetic Mechanisms in Age-Related Macular Degeneration. Genes (Basel) 2022; 13:genes13071233. [PMID: 35886016 PMCID: PMC9316037 DOI: 10.3390/genes13071233] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/30/2022] [Accepted: 07/05/2022] [Indexed: 11/29/2022] Open
Abstract
Age-related macular degeneration (AMD) is among the leading causes of irreversible blindness worldwide. In addition to environmental risk factors, such as tobacco use and diet, genetic background has long been established as a major risk factor for the development of AMD. However, our ability to predict disease risk and personalize treatment remains limited by our nascent understanding of the molecular mechanisms underlying AMD pathogenesis. Research into the molecular genetics of AMD over the past two decades has uncovered 52 independent gene variants and 34 independent loci that are implicated in the development of AMD, accounting for over half of the genetic risk. This research has helped delineate at least five major pathways that may be disrupted in the pathogenesis of AMD: the complement system, extracellular matrix remodeling, lipid metabolism, angiogenesis, and oxidative stress response. This review surveys our current understanding of each of these disease mechanisms, in turn, along with their associated pathogenic gene variants. Continued research into the molecular genetics of AMD holds great promise for the development of precision-targeted, personalized therapies that bring us closer to a cure for this debilitating disease.
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Affiliation(s)
- Aumer Shughoury
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Duriye Damla Sevgi
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Thomas A Ciulla
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN 46202, USA
- Clearside Biomedical, Inc., Alpharetta, GA 30005, USA
- Midwest Eye Institute, Indianapolis, IN 46290, USA
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30
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Neuroprotection for Age-Related Macular Degeneration. OPHTHALMOLOGY SCIENCE 2022; 2:100192. [PMID: 36570623 PMCID: PMC9767822 DOI: 10.1016/j.xops.2022.100192] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 06/24/2022] [Accepted: 06/28/2022] [Indexed: 12/27/2022]
Abstract
Age-related macular degeneration (AMD) is a leading cause of blindness worldwide. Early to intermediate AMD is characterized by the accumulation of lipid- and protein-rich drusen. Late stages of the disease are characterized by the development of choroidal neovascularization, termed "exudative" or "neovascular AMD," or retinal pigment epithelium (RPE) cell and photoreceptor death, termed "geographic atrophy" (GA) in advanced nonexudative AMD. Although we have effective treatments for exudative AMD in the form of anti-VEGF agents, they have no role for patients with GA. Neuroprotection strategies have emerged as a possible way to slow photoreceptor degeneration and vision loss in patients with GA. These approaches include reduction of oxidative stress, modulation of the visual cycle, reduction of toxic molecules, inhibition of pathologic protein activity, prevention of cellular apoptosis or programmed necrosis (necroptosis), inhibition of inflammation, direct activation of neurotrophic factors, delivery of umbilical tissue-derived cells, and RPE replacement. Despite active investigation in this area and significant promise based on preclinical studies, many clinical studies have not yielded successful results. We discuss selected past and current neuroprotection trials for AMD, highlight the lessons learned from these past studies, and discuss our perspective regarding remaining questions that must be answered before neuroprotection can be successfully applied in the field of AMD research.
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Key Words
- AD, Alzheimer disease
- ALA, alpha lipoic acid
- AMD, age-related macular degeneration
- AREDS, Age-Related Eye Disease Study
- AREDS2, Age-Related Eye Disease Study 2
- Age-related macular degeneration
- CFH, complement factor H
- CNTF, ciliary neurotrophic factor
- GA, geographic atrophy
- HTRA1, high-temperature requirement A1
- IOP, intraocular pressure
- Neuroprotection
- RBP, retinol-binding protein
- RGC, retinal ganglion cell
- RIPK3, receptor-interacting serine/threonine-protein kinase 3
- ROS, reactive oxygen species
- RPE, retinal pigment epithelium
- Retinal degeneration
- VA, visual acuity
- iPSC, induced pluripotent stem cell
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31
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Liu B, Cong C, Li Z, Hao L, Yuan X, Wang W, Shi Y, Liu T. Analysis of the aqueous humor lipid profile in patients with polypoidal choroidal vasculopathy. Exp Eye Res 2022; 222:109160. [PMID: 35753432 DOI: 10.1016/j.exer.2022.109160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/07/2022] [Accepted: 06/20/2022] [Indexed: 11/04/2022]
Abstract
This study aimed to investigate the lipid profiles of aqueous humor from polypoidal choroidal vasculopathy (PCV) patients and identify potential biomarkers to increase the understanding of PCV pathomechanism. An ultra-high performance liquid chromatography-tandem mass spectrometry based untargeted lipidomic analysis was performed to acquire lipid profiles of aqueous humor of PCV patients and control subjects. Differentially expressed lipids were identified by univariate and multivariate analyses. A receiver operator characteristic curve (ROC) analysis was conducted to confirm the potential of identified lipids as biomarkers. Sixteen PCV patients and twenty-eight control subjects were enrolled in this study. In total, we identified 33 lipid classes and 639 lipid species in aqueous humor using the LipidSearch software. Of them, 50 differential lipids were obtained by combining univariate and multivariate statistical analyses (VIP>1 and P < 0.05), and 19 potential lipid biomarkers were identified by ROC analysis. In addition, significant alterations were found in several metabolic pathways, including glycerophospholipid, glycerolipid, and glycosylphosphatidylinositol-anchor biosynthesis. This study is the first to systematically characterize the alterations in lipid profiles in aqueous humor of PCV patients and screen for the potential lipid biomarkers for PCV diagnosis and treatment intervention. The results of this study are likely to broaden our understanding of the pathogenesis of PCV and contribute to improvements in the diagnosis and treatment of the disease.
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Affiliation(s)
- Bing Liu
- Department of Ophthalmology, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250033, China
| | - Chenyang Cong
- Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250002, China
| | - Zhongen Li
- Affiliated Eye Hospital of Shandong University of Traditional Chinese Medicine, Jinan, 250002, China; Shandong University of Traditional Chinese Medicine, Jinan, 250002, China
| | - Linlin Hao
- Department of Ophthalmology, The Second Hospital, Cheeloo College of Medicine, Shandong University, Jinan, 250033, China
| | - Xiaomeng Yuan
- Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Jinan, 250021, China
| | - Wenqi Wang
- Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Jinan, 250021, China
| | - Yanmei Shi
- Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Jinan, 250021, China
| | - Tingting Liu
- Eye Institute of Shandong First Medical University, Eye Hospital of Shandong First Medical University (Shandong Eye Hospital), State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, School of Ophthalmology, Shandong First Medical University, Jinan, 250021, China.
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Gao P, Jia D, Li P, Huang Y, Hu H, Sun K, Lv Y, Chen X, Han Y, Zhang Z, Ren X, Wang Q, Liu F, Tang Z, Liu M. Accumulation of Lipid Droplets in a Novel Bietti Crystalline Dystrophy Zebrafish Model With Impaired PPARα Pathway. Invest Ophthalmol Vis Sci 2022; 63:32. [PMID: 35616930 PMCID: PMC9150832 DOI: 10.1167/iovs.63.5.32] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Bietti crystalline dystrophy (BCD) is a progressive retinal degenerative disease primarily characterized by numerous crystal-like deposits and degeneration of retinal pigment epithelium (RPE) and photoreceptor cells. CYP4V2 (cytochrome P450 family 4 subfamily V member 2) is currently the only disease-causing gene for BCD. We aimed to generate a zebrafish model to explore the functional role of CYP4V2 in the development of BCD and identify potential therapeutic targets for future studies. Methods The cyp4v7 and cyp4v8 (homologous genes of CYP4V2) knockout zebrafish lines were generated by CRISPR/Cas9 technology. The morphology of photoreceptor and RPE cells and the accumulation of lipid droplets in RPE cells were investigated at a series of different developmental stages through histological analysis, immunofluorescence, and lipid staining. Transcriptome analysis was performed to investigate the changes in gene expression of RPE cells during the progression of BCD. Results Progressive retinal degeneration including RPE atrophy and photoreceptor loss was observed in the mutant zebrafish as early as seven months after fertilization. We also observed the excessive accumulation of lipid droplets in RPE cells from three months after fertilization, which preceded the retinal degeneration by several months. Transcriptome analysis suggested that multiple metabolism pathways, especially the lipid metabolism pathways, were significantly changed in RPE cells. The down-regulation of the peroxisome proliferator-activated receptor α (PPARα) pathway was further confirmed in the mutant zebrafish and CYP4V2-knockdown human RPE-1 cells. Conclusions Our work established an animal model that recapitulates the symptoms of BCD patients and revealed that abnormal lipid metabolism in RPE cells, probably caused by dysregulation of the PPARα pathway, might be the main and direct consequence of CYP4V2 deficiency. These findings will deepen our understanding of the pathogenesis of BCD and provide potential therapeutic approaches.
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Affiliation(s)
- Pan Gao
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Danna Jia
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Pei Li
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yuwen Huang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Hualei Hu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Kui Sun
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yuexia Lv
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Xiang Chen
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Yunqiao Han
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Zuxiao Zhang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Xiang Ren
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Qing Wang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Fei Liu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, The Innovative Academy of Seed Design, Hubei Hongshan Laboratory, Chinese Academy of Sciences, Wuhan, China.,University of Chinese Academy of Sciences, Beijing, China
| | - Zhaohui Tang
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
| | - Mugen Liu
- Key Laboratory of Molecular Biophysics of Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, Hubei, PR China
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Peters F, Ebner LJA, Atac D, Maggi J, Berger W, den Hollander AI, Grimm C. Regulation of ABCA1 by AMD-Associated Genetic Variants and Hypoxia in iPSC-RPE. Int J Mol Sci 2022; 23:ijms23063194. [PMID: 35328615 PMCID: PMC8953808 DOI: 10.3390/ijms23063194] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 02/04/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive disease of the macula characterized by atrophy of the retinal pigment epithelium (RPE) and photoreceptor degeneration, leading to severe vision loss at advanced stages in the elderly population. Impaired reverse cholesterol transport (RCT) as well as intracellular lipid accumulation in the RPE are implicated in AMD pathogenesis. Here, we focus on ATP-binding cassette transporter A1 (ABCA1), a major cholesterol transport protein in the RPE, and analyze conditions that lead to ABCA1 dysregulation in induced pluripotent stem cell (iPSC)-derived RPE cells (iRPEs). Our results indicate that the risk-conferring alleles rs1883025 (C) and rs2740488 (A) in ABCA1 are associated with increased ABCA1 mRNA and protein levels and reduced efficiency of cholesterol efflux from the RPE. Hypoxia, an environmental risk factor for AMD, reduced expression of ABCA1 and increased intracellular lipid accumulation. Treatment with a liver X receptor (LXR) agonist led to an increase in ABCA1 expression and reduced lipid accumulation. Our data strengthen the homeostatic role of cholesterol efflux in the RPE and suggest that increasing cellular cholesterol export by stimulating ABCA1 expression might lessen lipid load, improving RPE survival and reducing the risk of developing AMD.
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Affiliation(s)
- Florian Peters
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
| | - Lynn J. A. Ebner
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
| | - David Atac
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Jordi Maggi
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Wolfgang Berger
- Institute of Medical Molecular Genetics, University of Zurich, 8952 Zurich, Switzerland; (D.A.); (J.M.); (W.B.)
| | - Anneke I. den Hollander
- Department of Ophthalmology, Radboud University Medical Center, 6525 Nijmegen, The Netherlands;
- AbbVie, Genomic Research Center, 200 Sidney Street, Cambridge, MA 02139, USA
| | - Christian Grimm
- Laboratory for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8952 Zurich, Switzerland;
- Correspondence: (F.P.); (C.G.)
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Pressly JD, Gurumani MZ, Varona Santos JT, Fornoni A, Merscher S, Al-Ali H. Adaptive and maladaptive roles of lipid droplets in health and disease. Am J Physiol Cell Physiol 2022; 322:C468-C481. [PMID: 35108119 PMCID: PMC8917915 DOI: 10.1152/ajpcell.00239.2021] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Advances in the understanding of lipid droplet biology have revealed essential roles for these organelles in mediating proper cellular homeostasis and stress response. Lipid droplets were initially thought to play a passive role in energy storage. However, recent studies demonstrate that they have substantially broader functions, including protection from reactive oxygen species, endoplasmic reticulum stress, and lipotoxicity. Dysregulation of lipid droplet homeostasis is associated with various pathologies spanning neurological, metabolic, cardiovascular, oncological, and renal diseases. This review provides an overview of the current understanding of lipid droplet biology in both health and disease.
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Affiliation(s)
- Jeffrey D. Pressly
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Margaret Z. Gurumani
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Javier T. Varona Santos
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Alessia Fornoni
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Sandra Merscher
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida
| | - Hassan Al-Ali
- 1Katz Division of Nephrology and Hypertension and Katz Family Drug Discovery Center, University of Miami, Miller School of Medicine, Miami, Florida,2Department of Medicine, University of Miami, Miller School of Medicine, Miami, Florida,3Department of Neurological Surgery, University of Miami, Miller School of Medicine, Miami, Florida,4The Miami Project to Cure Paralysis, University of Miami, Miller School of Medicine, Miami, Florida,5Sylvester Comprehensive Cancer Center, University of Miami, Miller School of Medicine, Miami, Florida
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35
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Chuang JZ, Yang N, Nakajima N, Otsu W, Fu C, Yang HH, Lee MP, Akbar AF, Badea TC, Guo Z, Nuruzzaman A, Hsu KS, Dunaief JL, Sung CH. Retinal pigment epithelium-specific CLIC4 mutant is a mouse model of dry age-related macular degeneration. Nat Commun 2022; 13:374. [PMID: 35042858 PMCID: PMC8766482 DOI: 10.1038/s41467-021-27935-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/21/2021] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of blindness among the elderly. Dry AMD has unclear etiology and no treatment. Lipid-rich drusen are the hallmark of dry AMD. An AMD mouse model and insights into drusenogenesis are keys to better understanding of this disease. Chloride intracellular channel 4 (CLIC4) is a pleomorphic protein regulating diverse biological functions. Here we show that retinal pigment epithelium (RPE)-specific Clic4 knockout mice exhibit a full spectrum of functional and pathological hallmarks of dry AMD. Multidisciplinary longitudinal studies of disease progression in these mice support a mechanistic model that links RPE cell-autonomous aberrant lipid metabolism and transport to drusen formation.
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Affiliation(s)
- Jen-Zen Chuang
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
| | - Nan Yang
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Nobuyuki Nakajima
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
- Department of Urology, Tokai University, Kanagawa, Japan
| | - Wataru Otsu
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
- Department of Biomedical Research Laboratory, Gifu Pharmaceutical University, Gifu, Japan
| | - Cheng Fu
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Howard Hua Yang
- The Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Maxwell Ping Lee
- The Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | | | - Tudor Constantin Badea
- National Eye Institute, National institute of Health, Bethesda, MD, USA
- Research and Development Institute, Transilvania University of Brasov, School of Medicine, Brasov, Romania
| | - Ziqi Guo
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Afnan Nuruzzaman
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
| | - Kuo-Shun Hsu
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA
- Sloan Kettering Cancer Institute, New York, NY, USA
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ching-Hwa Sung
- Department of Ophthalmology, Margaret M. Dyson Vision Research Institute, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
- Department of Cell and Developmental Biology, Weill Cornell Medicine, 1300 York Avenue, New York, NY, 10065, USA.
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Gnanaguru G, Mackey A, Choi EY, Arta A, Rossato FA, Gero TW, Urquhart AJ, Scott DA, D'Amore PA, Ng YSE. Discovery of sterically-hindered phenol compounds with potent cytoprotective activities against ox-LDL-induced retinal pigment epithelial cell death as a potential pharmacotherapy. Free Radic Biol Med 2022; 178:360-368. [PMID: 34843917 PMCID: PMC8758799 DOI: 10.1016/j.freeradbiomed.2021.11.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 10/22/2021] [Accepted: 11/19/2021] [Indexed: 01/03/2023]
Abstract
Late-stage dry age-related macular degeneration (AMD) or geographic atrophy (GA) is an irreversible blinding condition characterized by degeneration of retinal pigment epithelium (RPE) and the associated photoreceptors. Clinical and genetic evidence supports a role for dysfunctional lipid processing and accumulation of harmful oxidized lipids in the pathogenesis of GA. Using an oxidized low-density lipoprotein (ox-LDL)-induced RPE death assay, we screened and identified sterically-hindered phenol compounds with potent protective activities for RPE. The phenol-containing PPARγ agonist, troglitazone, protected against ox-LDL-induced RPE cell death, whereas other more potent PPARγ agonists did not protect RPE cells. Knockdown of PPARγ did not affect the protective activity of troglitazone in RPE, confirming the protective function is not due to the thiazolidine (TZD) group of troglitazone. Prototypical hindered phenol trolox and its analogs potently protected against ox-LDL-induced RPE cell death whereas potent antioxidants without the phenol group failed to protect RPE. Hindered phenols preserved lysosomal integrity against ox-LDL-induced damage and FITC-labeled trolox was localized to the lysosomes in RPE cells. Analogs of trolox inhibited reactive oxygen species (ROS) formation induced by ox-LDL uptake in a dose-dependent fashion and were effective at sub-micromolar concentrations. Treatment with trolox analog 2,2,5,7,8-pentamethyl-6-chromanol (PMC) significantly induced the expression of the lysosomal protein NPC-1 and reduced intracellular cholesterol level upon ox-LDL uptake. Our data indicate that the lysosomal-localized hindered phenols are uniquely potent in protecting the RPE against the toxic effects of ox-LDL, and may represent a novel pharmacotherapy to preserve the vision in patients with GA.
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Affiliation(s)
- Gopalan Gnanaguru
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Ashley Mackey
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Eun Young Choi
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Anthoula Arta
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA; Department of Health Technology, Institut for Sundhedsteknologi, Lyngby, Denmark
| | - Franco Aparecido Rossato
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Thomas W Gero
- Department of Cancer Biology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
| | - Andrew J Urquhart
- Department of Health Technology, Institut for Sundhedsteknologi, Lyngby, Denmark
| | - David A Scott
- Department of Cancer Biology, Dana-Farber Cancer Institute, 450 Brookline Ave, Boston, MA, 02215, USA
| | - Patricia A D'Amore
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA
| | - Yin Shan E Ng
- Harvard Ophthalmology, Schepens Eye Research Institute of Massachusetts Eye and Ear, Boston, MA, USA.
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Zheng A, Dubuis G, Georgieva M, Ferreira CSM, Serulla M, Del Carmen Conde Rubio M, Trofimenko E, Mercier T, Decosterd L, Widmann C. HDLs extract lipophilic drugs from cells. J Cell Sci 2021; 135:273878. [PMID: 34981808 PMCID: PMC8919334 DOI: 10.1242/jcs.258644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2021] [Accepted: 12/14/2021] [Indexed: 11/20/2022] Open
Abstract
High-density lipoproteins (HDLs) prevent cell death induced by a variety of cytotoxic drugs. The underlying mechanisms are however still poorly understood. Here, we present evidence that HDLs efficiently protect cells against thapsigargin (TG), a sarco/endoplasmic reticulum (ER) Ca2+-ATPase (SERCA) inhibitor, by extracting the drug from cells. Drug efflux could also be triggered to some extent by low-density lipoproteins and serum. HDLs did not reverse the non-lethal mild ER stress response induced by low TG concentrations or by SERCA knockdown, but HDLs inhibited the toxic SERCA-independent effects mediated by high TG concentrations. HDLs could extract other lipophilic compounds, but not hydrophilic substances. This work shows that HDLs utilize their capacity of loading themselves with lipophilic compounds, akin to their ability to extract cellular cholesterol, to reduce the cell content of hydrophobic drugs. This can be beneficial if lipophilic xenobiotics are toxic but may be detrimental to the therapeutic benefit of lipophilic drugs such as glibenclamide. Summary: HDLs, akin to their capacity for extracting cholesterol, can remove lipophilic compounds from cells, thus protecting the cells when these compounds are toxic.
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Affiliation(s)
- Adi Zheng
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
| | - Gilles Dubuis
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
| | - Maria Georgieva
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
| | | | - Marc Serulla
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
| | | | - Evgeniya Trofimenko
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
| | - Thomas Mercier
- Laboratory of Clinical Pharmacology, Lausanne University Hospital (CHUV) and University of Lausanne, Switzerland
| | - Laurent Decosterd
- Laboratory of Clinical Pharmacology, Lausanne University Hospital (CHUV) and University of Lausanne, Switzerland
| | - Christian Widmann
- Department of Biomedical Sciences, University of Lausanne, Bugnon 7, 1005 Lausanne, Switzerland
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Lewandowski D, Sander CL, Tworak A, Gao F, Xu Q, Skowronska-Krawczyk D. Dynamic lipid turnover in photoreceptors and retinal pigment epithelium throughout life. Prog Retin Eye Res 2021; 89:101037. [PMID: 34971765 PMCID: PMC10361839 DOI: 10.1016/j.preteyeres.2021.101037] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 12/13/2022]
Abstract
The retinal pigment epithelium-photoreceptor interphase is renewed each day in a stunning display of cellular interdependence. While photoreceptors use photosensitive pigments to convert light into electrical signals, the RPE supports photoreceptors in their function by phagocytizing shed photoreceptor tips, regulating the blood retina barrier, and modulating inflammatory responses, as well as regenerating the 11-cis-retinal chromophore via the classical visual cycle. These processes involve multiple protein complexes, tightly regulated ligand-receptors interactions, and a plethora of lipids and protein-lipids interactions. The role of lipids in maintaining a healthy interplay between the RPE and photoreceptors has not been fully delineated. In recent years, novel technologies have resulted in major advancements in understanding several facets of this interplay, including the involvement of lipids in phagocytosis and phagolysosome function, nutrient recycling, and the metabolic dependence between the two cell types. In this review, we aim to integrate the complex role of lipids in photoreceptor and RPE function, emphasizing the dynamic exchange between the cells as well as discuss how these processes are affected in aging and retinal diseases.
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Affiliation(s)
- Dominik Lewandowski
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Christopher L Sander
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Pharmacology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Aleksander Tworak
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Fangyuan Gao
- Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Qianlan Xu
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA
| | - Dorota Skowronska-Krawczyk
- Department of Physiology and Biophysics, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA; Department of Ophthalmology, Center for Translational Vision Research, School of Medicine, UC Irvine, Irvine, CA, USA.
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Kim YK, Hong HK, Yoo HS, Park SP, Park KH. AICAR upregulates ABCA1/ABCG1 expression in the retinal pigment epithelium and reduces Bruch's membrane lipid deposit in ApoE deficient mice. Exp Eye Res 2021; 213:108854. [PMID: 34808137 DOI: 10.1016/j.exer.2021.108854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 11/26/2022]
Abstract
The etiology of age-related macular degeneration (AMD) is diverse; however, recent evidence suggests that the lipid metabolism-cholesterol pathway might be associated with the pathophysiology of AMD. The ATP-binding cassette (ABC) transporters, ABCA1 and ABCG1, are essential for the formation of high-density lipoprotein (HDL) and the regulation of macrophage cholesterol efflux. The failure of retinal or retinal pigment epithelium (RPE) cholesterol efflux to remove excess intracellular lipids causes morphological and functional damage to the retina. In this study, we investigated whether treatment with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an AMP-activated protein kinase (AMPK) activator, improves RPE cholesterol efflux and Bruch's membrane (BM) lipid deposits. The protein and mRNA levels of ABCA1 and ABCG1 in ARPE-19 cells and retinal and RPE/choroid tissue from apolipoprotein E-deficient (ApoE-/-) mice were evaluated after 24 weeks of AICAR treatment. The cholesterol efflux capacity of ARPE-19 cells and the cholesterol-accepting capacity of apoB-depleted serum from mice were measured. The thickness of the BM and the degree of lipid deposition were evaluated using electron microscopy. AICAR treatment increased the phosphorylation of AMPK and the protein and mRNA expression of ABCA1 and ABCG1 in vitro. It promoted cholesterol efflux from ARPE-19 cells and upregulated the protein and mRNA levels of ABCA1 and ABCG1 in the retina and RPE in vivo. ApoB-depleted serum from the AICAR-treated group showed enhanced cholesterol-accepting capacity. Long-term treatment with AICAR reduced BM thickening and lipid deposition in ApoE-/- mice. In conclusion, AICAR treatment increased the expression of lipid transporters in the retina and RPE in vivo, facilitated intracellular cholesterol efflux from the RPE in vitro, and improved the functionality of HDL to accept cholesterol effluxed from the cell, possibly via AMPK activation. Collectively, these effects might contribute to the improvement of early age-related pathologic changes in the BM. Pharmacological improvement of RPE cholesterol efflux via AMPK activation may be a potential treatment strategy for AMD.
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Affiliation(s)
- Yong-Kyu Kim
- Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea
| | - Hye Kyoung Hong
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Hyo Soon Yoo
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, South Korea
| | - Sung Pyo Park
- Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea.
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, South Korea; Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea.
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40
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Landowski M, Bowes Rickman C. Targeting Lipid Metabolism for the Treatment of Age-Related Macular Degeneration: Insights from Preclinical Mouse Models. J Ocul Pharmacol Ther 2021; 38:3-32. [PMID: 34788573 PMCID: PMC8817708 DOI: 10.1089/jop.2021.0067] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Age-related macular degeneration (AMD) is a major leading cause of irreversible visual impairment in the world with limited therapeutic interventions. Histological, biochemical, genetic, and epidemiological studies strongly implicate dysregulated lipid metabolism in the retinal pigmented epithelium (RPE) in AMD pathobiology. However, effective therapies targeting lipid metabolism still need to be identified and developed for this blinding disease. To test lipid metabolism-targeting therapies, preclinical AMD mouse models are needed to establish therapeutic efficacy and the role of lipid metabolism in the development of AMD-like pathology. In this review, we provide a comprehensive overview of current AMD mouse models available to researchers that could be used to provide preclinical evidence supporting therapies targeting lipid metabolism for AMD. Based on previous studies of AMD mouse models, we discuss strategies to modulate lipid metabolism as well as examples of studies evaluating lipid-targeting therapeutics to restore lipid processing in the RPE. The use of AMD mouse models may lead to worthy lipid-targeting candidate therapies for clinical trials to prevent the blindness caused by AMD.
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Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, Wisconsin, USA.,McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Catherine Bowes Rickman
- Department of Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA.,Department of Cell Biology, Duke University Medical Center, Durham, North Carolina, USA
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41
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Wu Z, Fletcher EL, Kumar H, Greferath U, Guymer RH. Reticular pseudodrusen: A critical phenotype in age-related macular degeneration. Prog Retin Eye Res 2021; 88:101017. [PMID: 34752916 DOI: 10.1016/j.preteyeres.2021.101017] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 10/07/2021] [Accepted: 10/29/2021] [Indexed: 12/18/2022]
Abstract
Reticular pseudodrusen (RPD), or subretinal drusenoid deposits (SDD), refer to distinct lesions that occur in the subretinal space. Over the past three decades, their presence in association with age-related macular degeneration (AMD) has become increasingly recognized, especially as RPD have become more easily distinguished with newer clinical imaging modalities. There is also an increasing appreciation that RPD appear to be a critical AMD phenotype, where understanding their pathogenesis will provide further insights into the processes driving vision loss in AMD. However, key barriers to understanding the current evidence related to the independent impact of RPD include the heterogeneity in defining their presence, and failure to account for the confounding impact of the concurrent presence and severity of AMD pathology. This review thus critically discusses the current evidence on the prevalence and clinical significance of RPD and proposes a clinical imaging definition of RPD that will help move the field forward in gathering further key knowledge about this critical phenotype. It also proposes a putative mechanism for RPD formation and how they may drive progression to vision loss in AMD, through examining current evidence and presenting novel findings from preclinical and clinical studies.
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Affiliation(s)
- Zhichao Wu
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Erica L Fletcher
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Himeesh Kumar
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia
| | - Ursula Greferath
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Robyn H Guymer
- Centre for Eye Research Australia, Royal Victorian Eye and Ear Hospital, East Melbourne, Australia; Ophthalmology, Department of Surgery, The University of Melbourne, Melbourne, Australia.
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Zang J, Gesemann M, Keim J, Samardzija M, Grimm C, Neuhauss SCF. Circadian regulation of vertebrate cone photoreceptor function. eLife 2021; 10:e68903. [PMID: 34550876 PMCID: PMC8494479 DOI: 10.7554/elife.68903] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 09/20/2021] [Indexed: 12/16/2022] Open
Abstract
Eukaryotes generally display a circadian rhythm as an adaption to the reoccurring day/night cycle. This is particularly true for visual physiology that is directly affected by changing light conditions. Here we investigate the influence of the circadian rhythm on the expression and function of visual transduction cascade regulators in diurnal zebrafish and nocturnal mice. We focused on regulators of shut-off kinetics such as Recoverins, Arrestins, Opsin kinases, and Regulator of G-protein signaling that have direct effects on temporal vision. Transcript as well as protein levels of most analyzed genes show a robust circadian rhythm-dependent regulation, which correlates with changes in photoresponse kinetics. Electroretinography demonstrates that photoresponse recovery in zebrafish is delayed in the evening and accelerated in the morning. Functional rhythmicity persists in continuous darkness, and it is reversed by an inverted light cycle and disrupted by constant light. This is in line with our finding that orthologous gene transcripts from diurnal zebrafish and nocturnal mice are often expressed in an anti-phasic daily rhythm.
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Affiliation(s)
- Jingjing Zang
- University of Zurich, Department of Molecular Life SciencesZurichSwitzerland
| | - Matthias Gesemann
- University of Zurich, Department of Molecular Life SciencesZurichSwitzerland
| | - Jennifer Keim
- University of Zurich, Department of Molecular Life SciencesZurichSwitzerland
| | - Marijana Samardzija
- Lab for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of ZurichZurichSwitzerland
| | - Christian Grimm
- Lab for Retinal Cell Biology, Department of Ophthalmology, University Hospital Zurich, University of ZurichZurichSwitzerland
| | - Stephan CF Neuhauss
- University of Zurich, Department of Molecular Life SciencesZurichSwitzerland
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ABCA1 rs1883025 and CYP4F2 rs2108622 Gene Polymorphism Association with Age-Related Macular Degeneration and Anti-VEGF Treatment. MEDICINA-LITHUANIA 2021; 57:medicina57090974. [PMID: 34577897 PMCID: PMC8470098 DOI: 10.3390/medicina57090974] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 12/22/2022]
Abstract
Background and Objectives: The age-related macular degeneration (AMD) pathophysiology is multifactorial, as it consists of interactions between aging, genetic, and environmental factors. We aimed to determine a relationship between AMD and the genes controlling lipid metabolism, and to assess its association with treatment results. The purpose was to find the ABCA1 rs1883025 and CYP4F2 rs2108622 gene polymorphisms in patients with exudative AMD (eAMD) treated with anti-VEGF. Materials and Methods: The study enroled 104 patients with eAMD and 201 healthy persons in a control group. The genotyping of rs1883025 and rs2108622 was performed using the RT-PCR method. The best-corrected visual acuity (BCVA) and central retinal thickness (CRT) were measured before anti-VEGF therapy, then at three and six months during the therapy, using optical coherence tomography (OCT). The patients were grouped to responders and non-responders according to the changes in BCVA and CRT. Results: The T allele at rs1883025 was more frequent in non-responder eAMD patients compared to responder eAMD patients (41.7% vs. 21.1%; p = 0.009). The analysis of rs2108622 gene polymorphism did not reveal any differences in the distribution of C/C, C/T, and T/T genotypes between the eAMD group and the control group (56.35%, 39.78%, and 3.87% in the eAMD group and 53.33%, 39.05% and 7.62% in the control group, respectively, p = 0.286). The comparison of CRT and BCVA between the rs2108622 genotypes revealed statistically significant differences: CRT was thicker for the CC carriers than for those with CT and TT genotypes (p = 0.030). Conclusion: The rs1883025 T allele was found to play a more significant role in non-responder eAMD patients compared to responder eAMD patients. The rs2108622 genotypes revealed statistically significant differences: CRT was thicker for the CC carriers than for those with CT and TT genotypes.
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44
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Taylor AW, Hsu S, Ng TF. The Role of Retinal Pigment Epithelial Cells in Regulation of Macrophages/Microglial Cells in Retinal Immunobiology. Front Immunol 2021; 12:724601. [PMID: 34484232 PMCID: PMC8414138 DOI: 10.3389/fimmu.2021.724601] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 07/28/2021] [Indexed: 12/28/2022] Open
Abstract
The ocular tissue microenvironment is immune privileged and uses several mechanisms of immunosuppression to prevent the induction of inflammation. Besides being a blood-barrier and source of photoreceptor nutrients, the retinal pigment epithelial cells (RPE) regulate the activity of immune cells within the retina. These mechanisms involve the expression of immunomodulating molecules that make macrophages and microglial cells suppress inflammation and promote immune tolerance. The RPE have an important role in ocular immune privilege to regulate the behavior of immune cells within the retina. Reviewed is the current understanding of how RPE mediate this regulation and the changes seen under pathological conditions.
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Affiliation(s)
- Andrew W Taylor
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
| | - Samuel Hsu
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
| | - Tat Fong Ng
- Department of Ophthalmology, Boston University School of Medicine, Boston, MA, United States
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45
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von Eckardstein A. High Density Lipoproteins: Is There a Comeback as a Therapeutic Target? Handb Exp Pharmacol 2021; 270:157-200. [PMID: 34463854 DOI: 10.1007/164_2021_536] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Low plasma levels of High Density Lipoprotein (HDL) cholesterol (HDL-C) are associated with increased risks of atherosclerotic cardiovascular disease (ASCVD). In cell culture and animal models, HDL particles exert multiple potentially anti-atherogenic effects. However, drugs increasing HDL-C have failed to prevent cardiovascular endpoints. Mendelian Randomization studies neither found any genetic causality for the associations of HDL-C levels with differences in cardiovascular risk. Therefore, the causal role and, hence, utility as a therapeutic target of HDL has been questioned. However, the biomarker "HDL-C" as well as the interpretation of previous data has several important limitations: First, the inverse relationship of HDL-C with risk of ASCVD is neither linear nor continuous. Hence, neither the-higher-the-better strategies of previous drug developments nor previous linear cause-effect relationships assuming Mendelian randomization approaches appear appropriate. Second, most of the drugs previously tested do not target HDL metabolism specifically so that the futile trials question the clinical utility of the investigated drugs rather than the causal role of HDL in ASCVD. Third, the cholesterol of HDL measured as HDL-C neither exerts nor reports any HDL function. Comprehensive knowledge of structure-function-disease relationships of HDL particles and associated molecules will be a pre-requisite, to test them for their physiological and pathogenic relevance and exploit them for the diagnostic and therapeutic management of individuals at HDL-associated risk of ASCVD but also other diseases, for example diabetes, chronic kidney disease, infections, autoimmune and neurodegenerative diseases.
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Affiliation(s)
- Arnold von Eckardstein
- Institute of Clinical Chemistry, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
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46
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Almarhoun M, Biswas L, Alhasani RH, Wong A, Tchivelekete GM, Zhou X, Patterson S, Bartholomew C, Shu X. Overexpression of STARD3 attenuates oxidized LDL-induced oxidative stress and inflammation in retinal pigment epithelial cells. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158927. [PMID: 33771709 DOI: 10.1016/j.bbalip.2021.158927] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 02/26/2021] [Accepted: 03/20/2021] [Indexed: 01/23/2023]
Abstract
Age-related macular degeneration (AMD) is the most common cause of visual disorder in aged people and may lead to complete blindness with ageing. The major clinical feature of AMD is the presence of cholesterol enriched deposits underneath the retinal pigment epithelium (RPE) cells. The deposits can induce oxidative stress and inflammation. It has been suggested that abnormal cholesterol homeostasis contributes to the pathogenesis of AMD. However, the functional role of defective cholesterol homeostasis in AMD remains elusive. STARD proteins are a family of proteins that contain a steroidogenic acute regulatory protein-related lipid transfer domain. There are fifteen STARD proteins in mammals and some, such as STARD3, are responsible for cholesterol trafficking. Previously there was no study of STARD proteins in retinal cholesterol metabolism and trafficking. Here we examined expression of the Stard3 gene in mouse retinal and RPE cells at ages of 2 and 20 months. We found that expression of Stard 3 gene transcripts in both mouse RPE and retina was significantly decreased at age of 20 months when compared to that of age 2 months old. We created a stable ARPE-19 cell line overexpressing STARD3 and found this resulted in increased cholesterol efflux, reduced accumulation of intracellular oxidized LDL, increased antioxidant capacity and lower levels of inflammatory cytokines. The data suggested that STARD3 is a potential target for AMD through promoting the removal of intracellular cholesterol and slowing the disease progression.
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Affiliation(s)
- Mohammad Almarhoun
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Lincoln Biswas
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Reem Hasaballah Alhasani
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom; Department of Biology, Faculty of Applied Science, Umm Al-Qura University, Makkah, Saudi Arabia
| | - Aileen Wong
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Gabriel Mbuta Tchivelekete
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Xinzhi Zhou
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Steven Patterson
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Chris Bartholomew
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom
| | - Xinhua Shu
- Department of Biological and Biomedical Sciences, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom; Department of Vision Science, Glasgow Caledonian University, Glasgow G4 0BA, United Kingdom; School of Basic Medical Sciences, Shaoyang University, Shaoyang, Hunan 422000, PR China.
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47
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La Cunza N, Tan LX, Thamban T, Germer CJ, Rathnasamy G, Toops KA, Lakkaraju A. Mitochondria-dependent phase separation of disease-relevant proteins drives pathological features of age-related macular degeneration. JCI Insight 2021; 6:142254. [PMID: 33822768 PMCID: PMC8262309 DOI: 10.1172/jci.insight.142254] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/31/2021] [Indexed: 01/21/2023] Open
Abstract
Age-related macular degeneration (AMD) damages the retinal pigment epithelium (RPE), the tissue that safeguards photoreceptor health, leading to irreversible vision loss. Polymorphisms in cholesterol and complement genes are implicated in AMD, yet mechanisms linking risk variants to RPE injury remain unclear. We sought to determine how allelic variants in the apolipoprotein E cholesterol transporter modulate RPE homeostasis and function. Using live-cell imaging, we show that inefficient cholesterol transport by the AMD risk-associated ApoE2 increases RPE ceramide, leading to autophagic defects and complement-mediated mitochondrial damage. Mitochondrial injury drives redox state–sensitive cysteine-mediated phase separation of ApoE2, forming biomolecular condensates that could nucleate drusen. The protective ApoE4 isoform lacks these cysteines and is resistant to phase separation and condensate formation. In Abca–/– Stargardt macular degeneration mice, mitochondrial dysfunction induces liquid-liquid phase separation of p62/SQSTM1, a multifunctional protein that regulates autophagy. Drugs that decrease RPE cholesterol or ceramide prevent mitochondrial injury and phase separation in vitro and in vivo. In AMD donor RPE, mitochondrial fragmentation correlates with ApoE and p62 condensates. Our studies demonstrate that major AMD genetic and biological risk pathways converge upon RPE mitochondria, and identify mitochondrial stress-mediated protein phase separation as an important pathogenic mechanism and promising therapeutic target in AMD.
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Affiliation(s)
- Nilsa La Cunza
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA
| | - Li Xuan Tan
- Department of Ophthalmology, School of Medicine, and
| | | | - Colin J Germer
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA
| | | | - Kimberly A Toops
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Aparna Lakkaraju
- Department of Ophthalmology, School of Medicine, and.,Pharmaceutical Sciences and Pharmacogenomics Graduate Program, Graduate Division, University of California, San Francisco, California, USA.,Department of Anatomy, School of Medicine, University of California, San Francisco, California, USA
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48
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Lewandowski CT, Khan MW, BenAissa M, Dubrovskyi O, Ackerman-Berrier M, LaDu MJ, Layden BT, Thatcher GRJ. Metabolomic analysis of a selective ABCA1 inducer in obesogenic challenge provides a rationale for therapeutic development. EBioMedicine 2021; 66:103287. [PMID: 33752129 PMCID: PMC8010624 DOI: 10.1016/j.ebiom.2021.103287] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 03/02/2021] [Accepted: 03/02/2021] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND Therapeutic agents with novel mechanisms of action are needed to combat the growing epidemic of type 2 diabetes (T2D) and related metabolic syndromes. Liver X receptor (LXR) agonists possess preclinical efficacy yet produce side effects due to excessive lipogenesis. Anticipating that many beneficial and detrimental effects of LXR agonists are mediated by ABCA1 and SREPB1c expression, respectively, we hypothesized that a phenotypic optimization strategy prioritizing selective ABCA1 induction would identify an efficacious lead compound with an improved side effect profile over existing LXRβ agonists. METHODS We synthesized and characterized a novel small molecule for selective induction of ABCA1 vs. SREBP1c in vitro. This compound was evaluated in both wild-type mice and a high-fat diet (HFD) mouse model of obesity-driven diabetes through functional, biochemical, and metabolomic analysis. FINDINGS Six weeks of oral administration of our lead compound attenuated weight gain, glucose intolerance, insulin signaling deficits, and adiposity. Global metabolomics revealed suppression of gluconeogenesis, free fatty acids, and pro-inflammatory metabolites. Target identification linked these beneficial effects to selective LXRβ agonism and PPAR/RXR antagonism. INTERPRETATION Our observations in the HFD model, combined with the absence of lipogenesis and neutropenia in WT mice, support this novel approach to therapeutic development for T2D and related conditions.
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Affiliation(s)
- Cutler T Lewandowski
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Md Wasim Khan
- Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott St., Chicago, IL 60612, USA
| | - Manel BenAissa
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Oleksii Dubrovskyi
- Department of Pharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL, USA
| | - Martha Ackerman-Berrier
- Department of Pharmacology and Toxicology, University of Arizona, 1295N. Martin, Tucson, AZ 85721, USA
| | - Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, Chicago, IL, USA
| | - Brian T Layden
- Department of Medicine, University of Illinois at Chicago, 835 S. Wolcott St., Chicago, IL 60612, USA.
| | - Gregory R J Thatcher
- Department of Pharmacology and Toxicology, University of Arizona, 1295N. Martin, Tucson, AZ 85721, USA.
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49
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Targeting of miR-33 ameliorates phenotypes linked to age-related macular degeneration. Mol Ther 2021; 29:2281-2293. [PMID: 33744470 DOI: 10.1016/j.ymthe.2021.03.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 12/03/2020] [Accepted: 03/15/2021] [Indexed: 12/20/2022] Open
Abstract
Abnormal cholesterol/lipid homeostasis is linked to neurodegenerative conditions such as age-related macular degeneration (AMD), which is a leading cause of blindness in the elderly. The most prevalent form, termed "dry" AMD, is characterized by pathological cholesterol accumulation beneath the retinal pigment epithelial (RPE) cell layer and inflammation-linked degeneration in the retina. We show here that the cholesterol-regulating microRNA miR-33 was elevated in the RPE of aging mice. Expression of the miR-33 target ATP-binding cassette transporter (ABCA1), a cholesterol efflux pump genetically linked to AMD, declined reciprocally in the RPE with age. In accord, miR-33 modulated ABCA1 expression and cholesterol efflux in human RPE cells. Subcutaneous delivery of miR-33 antisense oligonucleotides (ASO) to aging mice and non-human primates fed a Western-type high fat/cholesterol diet resulted in increased ABCA1 expression, decreased cholesterol accumulation, and reduced immune cell infiltration in the RPE cell layer, accompanied by decreased pathological changes to RPE morphology. These findings suggest that miR-33 targeting may decrease cholesterol deposition and ameliorate AMD initiation and progression.
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50
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Abstract
Cholesterol is a quantitatively and biologically significant constituent of all mammalian cell membrane, including those that comprise the retina. Retinal cholesterol homeostasis entails the interplay between de novo synthesis, uptake, intraretinal sterol transport, metabolism, and efflux. Defects in these complex processes are associated with several congenital and age-related disorders of the visual system. Herein, we provide an overview of the following topics: (a) cholesterol synthesis in the neural retina; (b) lipoprotein uptake and intraretinal sterol transport in the neural retina and the retinal pigment epithelium (RPE); (c) cholesterol efflux from the neural retina and the RPE; and (d) biology and pathobiology of defects in sterol synthesis and sterol oxidation in the neural retina and the RPE. We focus, in particular, on studies involving animal models of monogenic disorders pertinent to the above topics, as well as in vitro models using biochemical, metabolic, and omic approaches. We also identify current knowledge gaps and opportunities in the field that beg further research in this topic area.
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Affiliation(s)
- Sriganesh Ramachandra Rao
- Departments of Ophthalmology and Biochemistry and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY, USA
| | - Steven J Fliesler
- Departments of Ophthalmology and Biochemistry and Neuroscience Graduate Program, Jacobs School of Medicine and Biomedical Sciences, State University of New York- University at Buffalo, Buffalo, NY, USA; Research Service, VA Western NY Healthcare System, Buffalo, NY, USA.
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