1
|
Owsley C, McGwin G, Swain TA, Clark ME, Thomas TN, Goerdt L, Sloan KR, Trittschuh EH, Jiang Y, Owen JP, Lee CS, Curcio CA. Outer Retinal Thickness Is Associated With Cognitive Function in Normal Aging to Intermediate Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2024; 65:16. [PMID: 38717425 PMCID: PMC11090140 DOI: 10.1167/iovs.65.5.16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/25/2024] [Indexed: 05/15/2024] Open
Abstract
Purpose Research on Alzheimer's disease (AD) and precursor states demonstrates a thinner retinal nerve fiber layer (NFL) compared to age-similar controls. Because AD and age-related macular degeneration (AMD) both impact older adults and share risk factors, we asked if retinal layer thicknesses, including NFL, are associated with cognition in AMD. Methods Adults ≥ 70 years with normal retinal aging, early AMD, or intermediate AMD per Age-Related Eye Disease Study (AREDS) nine-step grading of color fundus photography were enrolled in a cross-sectional study. Optical coherence tomography (OCT) volumes underwent 11-line segmentation and adjustments by a trained operator. Evaluated thicknesses reflect the vertical organization of retinal neurons and two vascular watersheds: NFL, ganglion cell layer-inner plexiform layer complex (GCL-IPL), inner retina, outer retina (including retinal pigment epithelium-Bruch's membrane), and total retina. Thicknesses were area weighted to achieve mean thickness across the 6-mm-diameter Early Treatment of Diabetic Retinopathy Study (ETDRS) grid. Cognitive status was assessed by the National Institutes of Health Toolbox cognitive battery for fluid and crystallized cognition. Correlations estimated associations between cognition and thicknesses, adjusting for age. Results Based on 63 subjects (21 per group), thinning of the outer retina was significantly correlated with lower cognition scores (P < 0.05). No other retinal thickness variables were associated with cognition. Conclusions Only the outer retina (photoreceptors, supporting glia, retinal pigment epithelium, Bruch's membrane) is associated with cognition in aging to intermediate AMD; NFL was not associated with cognition, contrary to AD-associated condition reports. Early and intermediate AMD constitute a retinal disease whose earliest, primary impact is in the outer retina. Our findings hint at a unique impact on the brain from the outer retina in persons with AMD.
Collapse
Affiliation(s)
- Cynthia Owsley
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Gerald McGwin
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Thomas A. Swain
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Mark E. Clark
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Tracy N. Thomas
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Lukas Goerdt
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Kenneth R. Sloan
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Emily H. Trittschuh
- VA Puget Sound Geriatric Research Education and Clinical Center, Seattle, Washington, United States
- Department of Psychiatry and Behavioral Sciences, School of Medicine, University of Washington, Seattle, Washington, United States
| | - Yu Jiang
- Department of Ophthalmology, School of Medicine, University of Washington, Seattle, Washington, United States
- The Roger and Angie Karalis Johnson Retina Center, Seattle, Washington, United States
| | - Julia P. Owen
- Department of Ophthalmology, School of Medicine, University of Washington, Seattle, Washington, United States
- The Roger and Angie Karalis Johnson Retina Center, Seattle, Washington, United States
| | - Cecilia S. Lee
- Department of Ophthalmology, School of Medicine, University of Washington, Seattle, Washington, United States
- The Roger and Angie Karalis Johnson Retina Center, Seattle, Washington, United States
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| |
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Chu L, Bi C, Wang C, Zhou H. The Relationship between Complements and Age-Related Macular Degeneration and Its Pathogenesis. J Ophthalmol 2024; 2024:6416773. [PMID: 38205100 PMCID: PMC10776198 DOI: 10.1155/2024/6416773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 06/08/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024] Open
Abstract
Age-related macular degeneration is a retinal disease that causes permanent loss of central vision in people over the age of 65. Its pathogenesis may be related to mitochondrial dysfunction, inflammation, apoptosis, autophagy, complement, intestinal flora, and lipid disorders. In addition, the patient's genes, age, gender, cardiovascular disease, unhealthy diet, and living habits may also be risk factors for this disease. Complement proteins are widely distributed in serum and tissue fluid. In the early 21st century, a connection was found between the complement cascade and age-related macular degeneration. However, little is known about the effect of complement factors on the pathogenesis of age-related macular degeneration. This article reviews the factors associated with age-related macular degeneration, the relationship between each factor and complement, the related functions, and variants and provides new ideas for the treatment of this disease.
Collapse
Affiliation(s)
- Liyuan Chu
- Department of Ophthalmology, China–Japan Union Hospital of Jilin University, Changchun, China
| | - Chaoran Bi
- College of Traditional Chinese Medicine, Hainan Medical University, Haikou, Hainan, China
| | - Caiming Wang
- Department of Ophthalmology, China–Japan Union Hospital of Jilin University, Changchun, China
| | - Hongyan Zhou
- Department of Ophthalmology, China–Japan Union Hospital of Jilin University, Changchun, China
| |
Collapse
|
4
|
Hammer SS, Dorweiler TF, McFarland D, Adu-Agyeiwaah Y, Mast N, El-Darzi N, Fortmann SD, Nooti S, Agrawal DK, Pikuleva IA, Abela GS, Grant MB, Busik JV. Cholesterol crystal formation is a unifying pathogenic mechanism in the development of diabetic retinopathy. Diabetologia 2023; 66:1705-1718. [PMID: 37311879 PMCID: PMC10390399 DOI: 10.1007/s00125-023-05949-w] [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: 12/01/2022] [Accepted: 04/18/2023] [Indexed: 06/15/2023]
Abstract
AIMS/HYPOTHESIS Hyper-reflective crystalline deposits found in retinal lesions have been suggested to predict the progression of diabetic retinopathy, but the nature of these structures remains unknown. METHODS Scanning electron microscopy and immunohistochemistry were used to identify cholesterol crystals (CCs) in human donor, pig and mouse tissue. The effects of CCs were analysed in bovine retinal endothelial cells in vitro and in db/db mice in vivo using quantitative RT-PCR, bulk RNA sequencing, and cell death and permeability assays. Cholesterol homeostasis was determined using 2H2O and 2H7-cholesterol. RESULTS We identified hyper-reflective crystalline deposits in human diabetic retina as CCs. Similarly, CCs were found in the retina of a diabetic mouse model and a high-cholesterol diet-fed pig model. Cell culture studies demonstrated that treatment of retinal cells with CCs can recapitulate all major pathogenic mechanisms leading to diabetic retinopathy, including inflammation, cell death and breakdown of the blood-retinal barrier. Fibrates, statins and α-cyclodextrin effectively dissolved CCs present in in vitro models of diabetic retinopathy, and prevented CC-induced endothelial pathology. Treatment of a diabetic mouse model with α-cyclodextrin reduced cholesterol levels and CC formation in the retina, and prevented diabetic retinopathy. CONCLUSIONS/INTERPRETATION We established that cholesterol accumulation and CC formation are a unifying pathogenic mechanism in the development of diabetic retinopathy.
Collapse
Affiliation(s)
- Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Tim F Dorweiler
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Delaney McFarland
- Department of Physiology, Michigan State University, East Lansing, MI, USA
| | - Yvonne Adu-Agyeiwaah
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Nicole El-Darzi
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Seth D Fortmann
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Sunil Nooti
- Department of Translational Research, Western University of Health Sciences, Pomona, CA, USA
| | - Devendra K Agrawal
- Department of Translational Research, Western University of Health Sciences, Pomona, CA, USA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - George S Abela
- Department of Medicine, Michigan State University, East Lansing, MI, USA
| | - Maria B Grant
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
5
|
Li FF, Wang Y, Chen L, Chen C, Chen Q, Xiang L, Rao FQ, Shen LJ, Zheng QX, Yi Q, Huang XF. Causal effects of serum lipid biomarkers on early age-related macular degeneration using Mendelian randomization. GENES & NUTRITION 2023; 18:11. [PMID: 37479984 PMCID: PMC10362672 DOI: 10.1186/s12263-023-00730-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 06/18/2023] [Indexed: 07/23/2023]
Abstract
BACKGROUND Age-related macular degeneration (AMD) is one of the major causes of vision loss. Early AMD needs to be taken seriously, but the causal effects of lipid biomarkers on early AMD remain unclear. METHODS In this study, two-sample Mendelian randomization (MR) analysis was performed to systematically assess the causal relationships between seven serum lipid biomarkers (apolipoprotein A (ApoA), apolipoprotein B (ApoB), total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL-C), direct low-density lipoprotein cholesterol (LDL-C), lipoprotein A [Lp(a)], and triglycerides (TG)) and risk of early AMD. In total, 14,034 cases and 91,214 controls of European ancestry were included in the analysis (number of SNPs = 11,304,110). RESULTS MR estimates revealed that a higher HDL-C level is strongly associated with increased risk of early AMD (OR = 1.25, 95% CI: 1.15-1.35, P = 2.61 × 10-8). In addition, level of ApoA is also positively associated with risk of early AMD (OR = 2.04, 95% CI: 1.50-2.77, P = 6.27 × 10-6). Conversely, higher levels of TG significantly decrease the risk of early AMD (OR = 0.77, 95% CI: 0.71-0.84, P = 5.02 × 10-10). Sensitivity analyses further supported these associations. Moreover, multivariable MR analyses, adjusted for the effects of correlated lipid biomarkers, yielded similar results. CONCLUSION This study identifies causal relationships between elevated circulating HDL-C/ApoA levels and increased risk of early AMD, in addition to finding that TG specifically reduces the risk of early AMD. These findings contribute to a better understanding of the role of lipid metabolism in drusen formation, particularly in early AMD development.
Collapse
Affiliation(s)
- Fen-Fen Li
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Yuqin Wang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Lishuang Chen
- The Ningbo Eye Hospital, Wenzhou Medical University, Ningbo, China
| | - Chong Chen
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Qi Chen
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Lue Xiang
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Feng-Qin Rao
- School of Pharmaceutical Sciences of Wenzhou Medical University, Wenzhou, China
| | - Li-Jun Shen
- Center for Rehabilitation Medicine, Department of Ophthalmology, Zhejiang Provincial People's Hospital,Affiliated People's Hospital, Hangzhou Medical College, Hangzhou, China
| | - Qin-Xiang Zheng
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
- The Ningbo Eye Hospital, Wenzhou Medical University, Ningbo, China.
| | - Quanyong Yi
- The Ningbo Eye Hospital, Wenzhou Medical University, Ningbo, China.
| | - Xiu-Feng Huang
- Zhejiang Provincial Clinical Research Center for Pediatric Disease, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou, China.
| |
Collapse
|
6
|
El-Darzi N, Mast N, Li Y, Dailey B, Kang M, Rhee DJ, Pikuleva IA. The normalizing effects of the CYP46A1 activator efavirenz on retinal sterol levels and risk factors for glaucoma in Apoj -/- mice. Cell Mol Life Sci 2023; 80:194. [PMID: 37392222 PMCID: PMC10314885 DOI: 10.1007/s00018-023-04848-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 06/16/2023] [Accepted: 06/23/2023] [Indexed: 07/03/2023]
Abstract
Apolipoprotein J (APOJ) is a multifunctional protein with genetic evidence suggesting an association between APOJ polymorphisms and Alzheimer's disease as well as exfoliation glaucoma. Herein we conducted ocular characterizations of Apoj-/- mice and found that their retinal cholesterol levels were decreased and that this genotype had several risk factors for glaucoma: increased intraocular pressure and cup-to-disk ratio and impaired retinal ganglion cell (RGC) function. The latter was not due to RGC degeneration or activation of retinal Muller cells and microglia/macrophages. There was also a decrease in retinal levels of 24-hydroxycholesterol, a suggested neuroprotectant under glaucomatous conditions and a positive allosteric modulator of N-methyl-D-aspartate receptors mediating the light-evoked response of the RGC. Therefore, Apoj-/- mice were treated with low-dose efavirenz, an allosteric activator of CYP46A1 which converts cholesterol into 24-hydroxycholesterol. Efavirenz treatment increased retinal cholesterol and 24-hydroxycholesterol levels, normalized intraocular pressure and cup-to-disk ratio, and rescued in part RGC function. Retinal expression of Abcg1 (a cholesterol efflux transporter), Apoa1 (a constituent of lipoprotein particles), and Scarb1 (a lipoprotein particle receptor) was increased in EVF-treated Apoj-/- mice, indicating increased retinal cholesterol transport on lipoprotein particles. Ocular characterizations of Cyp46a1-/- mice supported the beneficial efavirenz treatment effects via CYP46A1 activation. The data obtained demonstrate an important APOJ role in retinal cholesterol homeostasis and link this apolipoprotein to the glaucoma risk factors and retinal 24-hydroxycholesterol production by CYP46A1. As the CYP46A1 activator efavirenz is an FDA-approved anti-HIV drug, our studies suggest a new therapeutic approach for treatment of glaucomatous conditions.
Collapse
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
| | - Brian Dailey
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Min Kang
- Department of Ophthalmology and Visual Science, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Douglas J Rhee
- 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.
| |
Collapse
|
7
|
Mai S, Zhu X, Wan EYC, Wu S, Yonathan JN, Wang J, Li Y, Ma JYW, Zuo B, Tse DYY, Lo PC, Wang X, Chan KM, Wu DM, Xiong W. Postnatal eye size in mice is controlled by SREBP2-mediated transcriptional repression of Lrp2 and Bmp2. Development 2022; 149:276005. [PMID: 35833708 PMCID: PMC9382895 DOI: 10.1242/dev.200633] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 06/20/2022] [Indexed: 11/20/2022]
Abstract
Eye size is a key parameter of visual function, but the precise mechanisms of eye size control remain poorly understood. Here, we discovered that the lipogenic transcription factor sterol regulatory element-binding protein 2 (SREBP2) has an unanticipated function in the retinal pigment epithelium (RPE) to promote eye size in postnatal mice. SREBP2 transcriptionally represses low density lipoprotein receptor-related protein 2 (Lrp2), which has been shown to restrict eye overgrowth. Bone morphogenetic protein 2 (BMP2) is the downstream effector of Srebp2 and Lrp2, and Bmp2 is suppressed by SREBP2 transcriptionally but activated by Lrp2. During postnatal development, SREBP2 protein expression in the RPE decreases whereas that of Lrp2 and Bmp2 increases as the eye growth rate reduces. Bmp2 is the key determinant of eye size such that its level in mouse RPE inversely correlates with eye size. Notably, RPE-specific Bmp2 overexpression by adeno-associated virus effectively prevents the phenotypes caused by Lrp2 knock out. Together, our study shows that rapid postnatal eye size increase is governed by an RPE-derived signaling pathway, which consists of both positive and negative regulators of eye growth.
Collapse
Affiliation(s)
- Shuyi Mai
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China.,Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Hong Kong, China
| | - Xiaoxuan Zhu
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Esther Yi Ching Wan
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Shengyu Wu
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | | | - Jun Wang
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China
| | - Ying Li
- College of Information and Computer, Taiyuan University of Technology, 030024 Taiyuan, China
| | - Jessica Yuen Wuen Ma
- Centre for Myopia Research, School of Optometry, Hong Kong Polytechnic University, Hong Kong, China
| | - Bing Zuo
- Centre for Myopia Research, School of Optometry, Hong Kong Polytechnic University, Hong Kong, China
| | - Dennis Yan-Yin Tse
- Centre for Myopia Research, School of Optometry, Hong Kong Polytechnic University, Hong Kong, China.,Research Centre for SHARP Vision, Hong Kong Polytechnic University, Hong Kong, China
| | - Pui-Chi Lo
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| | - Xin Wang
- Department of Surgery, The Chinese University of Hong Kong, Shatin, Hong Kong, China
| | - Kui Ming Chan
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| | - David M Wu
- Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA
| | - Wenjun Xiong
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China.,Key Laboratory of Biochip Technology, Biotech and Health Centre, Shenzhen Research Institute of City University of Hong Kong, Shenzhen, China
| |
Collapse
|
8
|
El-Darzi N, Mast N, Buchner DA, Saadane A, Dailey B, Trichonas G, Pikuleva IA. Low-Dose Anti-HIV Drug Efavirenz Mitigates Retinal Vascular Lesions in a Mouse Model of Alzheimer's Disease. Front Pharmacol 2022; 13:902254. [PMID: 35721135 PMCID: PMC9198296 DOI: 10.3389/fphar.2022.902254] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 05/02/2022] [Indexed: 12/02/2022] Open
Abstract
A small dose of the anti-HIV drug efavirenz (EFV) was previously discovered to activate CYP46A1, a cholesterol-eliminating enzyme in the brain, and mitigate some of the manifestation of Alzheimer's disease in 5XFAD mice. Herein, we investigated the retina of these animals, which were found to have genetically determined retinal vascular lesions associated with deposits within the retinal pigment epithelium and subretinal space. We established that EFV treatment activated CYP46A1 in the retina, enhanced retinal cholesterol turnover, and diminished the lesion frequency >5-fold. In addition, the treatment mitigated fluorescein leakage from the aberrant blood vessels, deposit size, activation of retinal macrophages/microglia, and focal accumulations of amyloid β plaques, unesterified cholesterol, and Oil Red O-positive lipids. Studies of retinal transcriptomics and proteomics identified biological processes enriched with differentially expressed genes and proteins. We discuss the mechanisms of the beneficial EFV effects on the retinal phenotype of 5XFAD mice. As EFV is an FDA-approved drug, and we already tested the safety of small-dose EFV in patients with Alzheimer's disease, our data support further clinical investigation of this drug in subjects with retinal vascular lesions or neovascular age-related macular degeneration.
Collapse
Affiliation(s)
- Nicole El-Darzi
- Departments of Ophthalmology and Visual Sciences, Cleveland, OH, United States
| | - Natalia Mast
- Departments of Ophthalmology and Visual Sciences, Cleveland, OH, United States
| | - David A. Buchner
- Departments of Genetics and Genome Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Aicha Saadane
- Departments of Ophthalmology and Visual Sciences, Cleveland, OH, United States
| | - Brian Dailey
- Departments of Ophthalmology and Visual Sciences, Cleveland, OH, United States
| | - Georgios Trichonas
- Departments of Ophthalmology and Visual Sciences, Cleveland, OH, United States
| | - Irina A. Pikuleva
- Departments of Ophthalmology and Visual Sciences, Cleveland, OH, United States,*Correspondence: Irina A. Pikuleva,
| |
Collapse
|
9
|
Bryl A, Mrugacz M, Falkowski M, Zorena K. The Effect of Hyperlipidemia on the Course of Diabetic Retinopathy—Literature Review. J Clin Med 2022; 11:jcm11102761. [PMID: 35628887 PMCID: PMC9146710 DOI: 10.3390/jcm11102761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Revised: 04/29/2022] [Accepted: 05/11/2022] [Indexed: 12/16/2022] Open
Abstract
Diabetes mellitus is a very important social issue, and its retinal complications continue to be one of the major causes of blindness worldwide. The effect of glucose level on the development of retinal retinopathy has been the subject of numerous studies and is well understood. Hypertension and hyperlipidemia have been known to be important risk factors in the development of diabetes complications. However, the mechanisms of this effect have not been fully explained and raise a good deal of controversy. The latest research results suggest that some lipoproteins are closely correlated with the incidence of diabetic retinopathy and that by exerting an impact on their level the disease course can be modulated. Moreover, pharmacotherapy which reduces the level of lipids, particularly by means of statins and fibrate, has been shown to alleviate diabetic retinopathy. Therefore, we have decided to review the latest literature on diabetic retinopathy with respect to the impact of hyperlipidemia and possible preventive measures
Collapse
Affiliation(s)
- Anna Bryl
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, Waszyngtona 17, 15-274 Bialystok, Poland;
- Correspondence:
| | - Małgorzata Mrugacz
- Department of Ophthalmology and Eye Rehabilitation, Medical University of Bialystok, Waszyngtona 17, 15-274 Bialystok, Poland;
| | - Mariusz Falkowski
- PhD Studies, Medical University of Bialystok, 15-089 Bialystok, Poland;
| | - Katarzyna Zorena
- Department of Immunobiology and Environmental Microbiology, Medical University of Gdansk, 80-211 Gdansk, Poland;
| |
Collapse
|
10
|
Jenkins AJ, Grant MB, Busik JV. Lipids, hyperreflective crystalline deposits and diabetic retinopathy: potential systemic and retinal-specific effect of lipid-lowering therapies. Diabetologia 2022; 65:587-603. [PMID: 35149880 PMCID: PMC9377536 DOI: 10.1007/s00125-022-05655-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 12/14/2021] [Indexed: 12/19/2022]
Abstract
The metabolically active retina obtains essential lipids by endogenous biosynthesis and from the systemic circulation. Clinical studies provide limited and sometimes conflicting evidence as to the relationships between circulating lipid levels and the development and progression of diabetic retinopathy in people with diabetes. Cardiovascular-system-focused clinical trials that also evaluated some retinal outcomes demonstrate the potential protective power of lipid-lowering therapies in diabetic retinopathy and some trials with ocular primary endpoints are in progress. Although triacylglycerol-lowering therapies with fibrates afforded some protection against diabetic retinopathy, the effect was independent of changes in traditional blood lipid classes. While systemic LDL-cholesterol lowering with statins did not afford protection against diabetic retinopathy in most clinical trials, and none of the trials focused on retinopathy as the main outcome, data from very large database studies suggest the possible effectiveness of statins. Potential challenges in these studies are discussed, including lipid-independent effects of fibrates and statins, modified lipoproteins and retinal-specific effects of lipid-lowering drugs. Dysregulation of retinal-specific cholesterol metabolism leading to retinal cholesterol accumulation and potential formation of cholesterol crystals are also addressed.
Collapse
Affiliation(s)
- Alicia J Jenkins
- NHMRC Clinical Trials Centre, The University of Sydney, Sydney, NSW, Australia
| | - Maria B Grant
- Department of Ophthalmology and Vision Science, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
11
|
Léger-Charnay E, Gambert S, Martine L, Dubus E, Maire MA, Buteau B, Morala T, Gigot V, Bron AM, Bretillon L, Masson EAY. Retinal cholesterol metabolism is perturbated in response to experimental glaucoma in the rat. PLoS One 2022; 17:e0264787. [PMID: 35275950 PMCID: PMC8916636 DOI: 10.1371/journal.pone.0264787] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Accepted: 02/16/2022] [Indexed: 01/26/2023] Open
Abstract
Alterations of cholesterol metabolism have been described for many neurodegenerative pathologies, such as Alzheimer's disease in the brain and age-related macular degeneration in the retina. Recent evidence suggests that glaucoma, which is characterized by the progressive death of retinal ganglion cells, could also be associated with disruption of cholesterol homeostasis. In the present study we characterized cholesterol metabolism in a rat model of laser-induced intraocular hypertension, the main risk factor for glaucoma. Sterol levels were measured using gas-chromatography and cholesterol-related gene expression using quantitative RT-PCR at various time-points. As early as 18 hours after the laser procedure, genes implicated in cholesterol biosynthesis and uptake were upregulated (+49% and +100% for HMG-CoA reductase and LDLR genes respectively, vs. naive eyes) while genes involved in efflux were downregulated (-26% and -37% for ApoE and CYP27A1 genes, respectively). Cholesterol and precursor levels were consecutively elevated 3 days post-laser (+14%, +40% and +194% for cholesterol, desmosterol and lathosterol, respectively). Interestingly, counter-regulatory mechanisms were transcriptionally activated following these initial dysregulations, which were associated with the restoration of retinal cholesterol homeostasis, favorable to ganglion cell viability, one month after the laser-induced ocular hypertension. In conclusion, we report here for the first time that ocular hypertension is associated with transient major dynamic changes in retinal cholesterol metabolism.
Collapse
Affiliation(s)
- Elise Léger-Charnay
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Ségolène Gambert
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
- Laboratoire de Biochimie Médicale, Plateforme de Biologie Hospitalo-Universitaire, Dijon, France
| | - Lucy Martine
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Elisabeth Dubus
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Marie-Annick Maire
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Bénédicte Buteau
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Tristan Morala
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Vincent Gigot
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Alain M. Bron
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
- Département d’Ophtalmologie, Centre Hospitalo-Universitaire de Dijon, Dijon, France
| | - Lionel Bretillon
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
| | - Elodie A. Y. Masson
- Centre des Sciences du Goût et de l’Alimentation, AgroSup Dijon, CNRS, INRAE, Université Bourgogne Franche-Comté, Dijon, France
- * E-mail:
| |
Collapse
|
12
|
Landowski M, Bhute VJ, Takimoto T, Grindel S, Shahi PK, Pattnaik BR, Ikeda S, Ikeda A. A mutation in transmembrane protein 135 impairs lipid metabolism in mouse eyecups. Sci Rep 2022; 12:756. [PMID: 35031662 PMCID: PMC8760256 DOI: 10.1038/s41598-021-04644-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Accepted: 12/28/2021] [Indexed: 12/13/2022] Open
Abstract
Aging is a significant factor in the development of age-related diseases but how aging disrupts cellular homeostasis to cause age-related retinal disease is unknown. Here, we further our studies on transmembrane protein 135 (Tmem135), a gene involved in retinal aging, by examining the transcriptomic profiles of wild-type, heterozygous and homozygous Tmem135 mutant posterior eyecup samples through RNA sequencing (RNA-Seq). We found significant gene expression changes in both heterozygous and homozygous Tmem135 mutant mouse eyecups that correlate with visual function deficits. Further analysis revealed that expression of many genes involved in lipid metabolism are changed due to the Tmem135 mutation. Consistent with these changes, we found increased lipid accumulation in mutant Tmem135 eyecup samples. Since mutant Tmem135 mice have similar ocular pathologies as human age-related macular degeneration (AMD) eyes, we compared our homozygous Tmem135 mutant eyecup RNA-Seq dataset with transcriptomic datasets of human AMD donor eyes. We found similar changes in genes involved in lipid metabolism between the homozygous Tmem135 mutant eyecups and AMD donor eyes. Our study suggests that the Tmem135 mutation affects lipid metabolism as similarly observed in human AMD eyes, thus Tmem135 mutant mice can serve as a good model for the role of dysregulated lipid metabolism in AMD.
Collapse
Affiliation(s)
- Michael Landowski
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Vijesh J Bhute
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- Department of Chemical Engineering, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Tetsuya Takimoto
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Samuel Grindel
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
| | - Pawan K Shahi
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Bikash R Pattnaik
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison, WI, USA
| | - Sakae Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA
| | - Akihiro Ikeda
- Department of Medical Genetics, University of Wisconsin-Madison, Madison, WI, USA.
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, USA.
| |
Collapse
|
13
|
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: 11] [Impact Index Per Article: 3.7] [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.
Collapse
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
| |
Collapse
|
14
|
Sanchez D, Ganfornina MD. The Lipocalin Apolipoprotein D Functional Portrait: A Systematic Review. Front Physiol 2021; 12:738991. [PMID: 34690812 PMCID: PMC8530192 DOI: 10.3389/fphys.2021.738991] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 08/30/2021] [Indexed: 12/18/2022] Open
Abstract
Apolipoprotein D is a chordate gene early originated in the Lipocalin protein family. Among other features, regulation of its expression in a wide variety of disease conditions in humans, as apparently unrelated as neurodegeneration or breast cancer, have called for attention on this gene. Also, its presence in different tissues, from blood to brain, and different subcellular locations, from HDL lipoparticles to the interior of lysosomes or the surface of extracellular vesicles, poses an interesting challenge in deciphering its physiological function: Is ApoD a moonlighting protein, serving different roles in different cellular compartments, tissues, or organisms? Or does it have a unique biochemical mechanism of action that accounts for such apparently diverse roles in different physiological situations? To answer these questions, we have performed a systematic review of all primary publications where ApoD properties have been investigated in chordates. We conclude that ApoD ligand binding in the Lipocalin pocket, combined with an antioxidant activity performed at the rim of the pocket are properties sufficient to explain ApoD association with different lipid-based structures, where its physiological function is better described as lipid-management than by long-range lipid-transport. Controlling the redox state of these lipid structures in particular subcellular locations or extracellular structures, ApoD is able to modulate an enormous array of apparently diverse processes in the organism, both in health and disease. The new picture emerging from these data should help to put the physiological role of ApoD in new contexts and to inspire well-focused future research.
Collapse
Affiliation(s)
- Diego Sanchez
- Instituto de Biologia y Genetica Molecular, Unidad de Excelencia, Universidad de Valladolid-Consejo Superior de Investigaciones Cientificas, Valladolid, Spain
| | - Maria D Ganfornina
- Instituto de Biologia y Genetica Molecular, Unidad de Excelencia, Universidad de Valladolid-Consejo Superior de Investigaciones Cientificas, Valladolid, Spain
| |
Collapse
|
15
|
Zhou J, Flores-Bellver M, Pan J, Benito-Martin A, Shi C, Onwumere O, Mighty J, Qian J, Zhong X, Hogue T, Amponsah-Antwi B, Einbond L, Gharbaran R, Wu H, Chen BJ, Zheng Z, Tchaikovskaya T, Zhang X, Peinado H, Canto-Soler MV, Redenti S. Human retinal organoids release extracellular vesicles that regulate gene expression in target human retinal progenitor cells. Sci Rep 2021; 11:21128. [PMID: 34702879 PMCID: PMC8548301 DOI: 10.1038/s41598-021-00542-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Accepted: 10/07/2021] [Indexed: 01/23/2023] Open
Abstract
The mechanisms underlying retinal development have not been completely elucidated. Extracellular vesicles (EVs) are novel essential mediators of cell-to-cell communication with emerging roles in developmental processes. Nevertheless, the identification of EVs in human retinal tissue, characterization of their cargo, and analysis of their potential role in retina development has not been accomplished. Three-dimensional retinal tissue derived from human induced pluripotent stem cells (hiPSC) provide an ideal developmental system to achieve this goal. Here we report that hiPSC-derived retinal organoids release exosomes and microvesicles with small noncoding RNA cargo. EV miRNA cargo-predicted targetome correlates with Gene Ontology (GO) pathways involved in mechanisms of retinogenesis relevant to specific developmental stages corresponding to hallmarks of native human retina development. Furthermore, uptake of EVs by human retinal progenitor cells leads to changes in gene expression correlated with EV miRNA cargo predicted gene targets, and mechanisms involved in retinal development, ganglion cell and photoreceptor differentiation and function.
Collapse
Affiliation(s)
- Jing Zhou
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
- Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Miguel Flores-Bellver
- CellSight Ocular Stem Cell and Regeneration Program, Department of Ophthalmology, Sue Anschutz- Rodgers Eye Center, University of Colorado, 12800 East 19th Avenue, Aurora, CO, 80045, USA
| | - Jianbo Pan
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Alberto Benito-Martin
- Departments of Pediatrics, Hematology/Oncology Division, Weill Medical College of Cornell University, 413 E. 69th St., New York, NY, 10021, USA
| | - Cui Shi
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | | | - Jason Mighty
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
- Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Jiang Qian
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Xiufeng Zhong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangzhou, Guangdong, China
| | - Tasmim Hogue
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | | | - Linda Einbond
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | | | - Hao Wu
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
- Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA
| | - Bo-Juen Chen
- New York Genome Center, New York, NY, 10013, USA
| | - Zhiliang Zheng
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA
| | - Tatyana Tchaikovskaya
- Department of Medicine, Liver Research Center, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Xusheng Zhang
- Department of Medicine, Computational Genomics Core in Department of Genetics, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Hector Peinado
- Microenvironment and Metastasis Laboratory, Department of Molecular Oncology, Spanish National Cancer Research Centre (CNIO), 28029, Madrid, Spain
| | - Maria Valeria Canto-Soler
- CellSight Ocular Stem Cell and Regeneration Program, Department of Ophthalmology, Sue Anschutz- Rodgers Eye Center, University of Colorado, 12800 East 19th Avenue, Aurora, CO, 80045, USA.
| | - Stephen Redenti
- Lehman College, 250 Bedford Park Boulevard West, Bronx, NY, 10468, USA.
- Biology Doctoral Program, The Graduate School and University Center, City University of New York, 365 5th Avenue, New York, NY, 10016, USA.
- Biochemistry Doctoral Program, The Graduate School, City University of New York, 365 Fifth Avenue, New York, NY, 10016, USA.
| |
Collapse
|
16
|
Rauscher FG, Wang M, Francke M, Wirkner K, Tönjes A, Engel C, Thiery J, Stenvinkel P, Stumvoll M, Loeffler M, Elze T, Ebert T. Renal function and lipid metabolism are major predictors of circumpapillary retinal nerve fiber layer thickness-the LIFE-Adult Study. BMC Med 2021; 19:202. [PMID: 34488766 PMCID: PMC8422631 DOI: 10.1186/s12916-021-02064-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2021] [Accepted: 07/15/2021] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Circumpapillary retinal nerve fiber layer thickness (cpRNFLT) as assessed by spectral domain optical coherence tomography (SD-OCT) is a new technique used for the detection and evaluation of glaucoma and other optic neuropathies. Before translating cpRNFLT into clinics, it is crucially important to investigate anthropometric, biochemical, and clinical parameters potentially affecting cpRNFLT in a large population-based dataset. METHODS The population-based LIFE-Adult Study randomly selected 10,000 participants from the population registry of Leipzig, Germany. All participants underwent standardized systemic assessment of various cardiometabolic risk markers and ocular imaging, including cpRNFLT measurement using SD-OCT (Spectralis, Heidelberg Engineering). After employing strict SD-OCT quality criteria, 8952 individuals were analyzed. Multivariable linear regression analyses were used to evaluate the independent associations of various cardiometabolic risk markers with sector-specific cpRNFLT. For significant markers, the relative strength of the observed associations was compared to each other to identify the most relevant factors influencing cpRNFLT. In all analyses, the false discovery rate method for multiple comparisons was applied. RESULTS In the entire cohort, female subjects had significantly thicker global and also sectoral cpRNFLT compared to male subjects (p < 0.05). Multivariable linear regression analyses revealed a significant and independent association between global and sectoral cpRNFLT with biomarkers of renal function and lipid profile. Thus, thinner cpRNFLT was associated with worse renal function as assessed by cystatin C and estimated glomerular filtration rate. Furthermore, an adverse lipid profile (i.e., low high-density lipoprotein (HDL) cholesterol, as well as high total, high non-HDL, high low-density lipoprotein cholesterol, and high apolipoprotein B) was independently and statistically significantly related to thicker cpRNFLT. In contrast, we do not observe a significant association between cpRNFLT and markers of inflammation, glucose homeostasis, liver function, blood pressure, or obesity in our sector-specific analysis and globally. CONCLUSIONS Markers of renal function and lipid metabolism are predictors of sectoral cpRNFLT in a large and deeply phenotyped population-based study independently of previously established covariates. Future studies on cpRNFLT should include these biomarkers and need to investigate whether incorporation will improve the diagnosis of early eye diseases based on cpRNFLT.
Collapse
Affiliation(s)
- Franziska G Rauscher
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), Leipzig University, Leipzig, Germany
| | - Mengyu Wang
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA
| | - Mike Francke
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), Leipzig University, Leipzig, Germany
| | - Kerstin Wirkner
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), Leipzig University, Leipzig, Germany
| | - Anke Tönjes
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Christoph Engel
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), Leipzig University, Leipzig, Germany
| | - Joachim Thiery
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Institute of Laboratory Medicine, Clinical Chemistry and Molecular Diagnostics, Leipzig University, Leipzig, Germany
| | - Peter Stenvinkel
- Department of Clinical Science, Intervention and Technology, Division of Renal Medicine, Karolinska Institutet, Stockholm, Sweden
| | - Michael Stumvoll
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany
| | - Markus Loeffler
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Institute for Medical Informatics, Statistics, and Epidemiology (IMISE), Leipzig University, Leipzig, Germany
| | - Tobias Elze
- Leipzig Research Centre for Civilization Diseases (LIFE), Leipzig University, Leipzig, Germany
- Schepens Eye Research Institute, Harvard Medical School, Boston, MA, USA
| | - Thomas Ebert
- Medical Department III - Endocrinology, Nephrology, Rheumatology, University of Leipzig Medical Center, Leipzig, Germany.
- Department of Clinical Science, Intervention and Technology, Division of Renal Medicine, Karolinska Institutet, Stockholm, Sweden.
| |
Collapse
|
17
|
Rajagopal R, Sylvester B, Zhang S, Adak S, Wei X, Bowers M, Jessberger S, Hsu FF, Semenkovich CF. Glucose-mediated de novo lipogenesis in photoreceptors drives early diabetic retinopathy. J Biol Chem 2021; 297:101104. [PMID: 34425110 PMCID: PMC8445899 DOI: 10.1016/j.jbc.2021.101104] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/10/2021] [Accepted: 08/18/2021] [Indexed: 11/23/2022] Open
Abstract
Diabetic retinopathy (DR) is an increasingly frequent cause of blindness across populations; however, the events that initiate pathophysiology of DR remain elusive. Strong preclinical and clinical evidence suggests that abnormalities in retinal lipid metabolism caused by diabetes may account for the origin of this disease. A major arm of lipid metabolism, de novo biosynthesis, is driven by elevation in available glucose, a common thread binding all forms of vision loss in diabetes. Therefore, we hypothesized that aberrant retinal lipid biogenesis is an important promoter of early DR. In murine models, we observed elevations of diabetes-associated retinal de novo lipogenesis ∼70% over control levels. This shift was primarily because of activation of fatty acid synthase (FAS), a rate-limiting enzyme in the biogenic pathway. Activation of FAS was driven by canonical glucose-mediated disinhibition of acetyl-CoA carboxylase, a major upstream regulatory enzyme. Mutant mice expressing gain-of-function FAS demonstrated increased vulnerability to DR, whereas those with FAS deletion in rod photoreceptors maintained preserved visual responses upon induction of diabetes. Excess retinal de novo lipogenesis—either because of diabetes or because of FAS gain of function—was associated with modestly increased levels of palmitate-containing phosphatidylcholine species in synaptic membranes, a finding with as yet uncertain significance. These findings implicate glucose-dependent increases in photoreceptor de novo lipogenesis in the early pathogenesis of DR, although the mechanism of deleterious action of this pathway remains unclear.
Collapse
Affiliation(s)
- Rithwick Rajagopal
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri, USA.
| | - Beau Sylvester
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Sheng Zhang
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Sangeeta Adak
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Xiaochao Wei
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Megan Bowers
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Sebastian Jessberger
- Laboratory of Neural Plasticity, Faculties of Medicine and Science, Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Fong-Fu Hsu
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA
| | - Clay F Semenkovich
- Division of Endocrinology, Metabolism, and Lipid Research, Washington University School of Medicine, Saint Louis, Missouri, USA; Department of Cell Biology and Physiology, Washington University School of Medicine, Saint Louis, Missouri, USA.
| |
Collapse
|
18
|
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.
Collapse
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.
| |
Collapse
|
19
|
Busik JV. Lipid metabolism dysregulation in diabetic retinopathy. J Lipid Res 2021; 62:100017. [PMID: 33581416 PMCID: PMC7892987 DOI: 10.1194/jlr.tr120000981] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 12/15/2020] [Accepted: 12/23/2020] [Indexed: 12/12/2022] Open
Abstract
Lipid metabolic abnormalities have emerged as potential risk factors for the development and progression of diabetic complications, including diabetic retinopathy (DR). This review article provides an overview of the results of clinical trials evaluating the potential benefits of lipid-lowering drugs, such as fibrates, omega-3 fatty acids, and statins, for the prevention and treatment of DR. Although several clinical trials demonstrated that treatment with fibrates leads to improvement of DR, there is a dissociation between the protective effects of fibrates in the retina, and the intended blood lipid classes, including plasma triglycerides, total cholesterol, or HDL:LDL cholesterol ratio. Guided by these findings, plasma lipid and lipoprotein-independent mechanisms are addressed based on clinical, cell culture, and animal model studies. Potential retinal-specific effects of fatty acid oxidation products, cholesterol, and ceramide, as well as lipid-independent effects of PPAR alpha activation, are summarized based on the current literature. Overall, this review highlights promising potential of lipid-based treatment strategies further enhanced by the new knowledge of intraretinal lipids and lipoproteins in DR.
Collapse
Affiliation(s)
- Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, USA.
| |
Collapse
|
20
|
Chen L, Messinger JD, Kar D, Duncan JL, Curcio CA. Biometrics, Impact, and Significance of Basal Linear Deposit and Subretinal Drusenoid Deposit in Age-Related Macular Degeneration. Invest Ophthalmol Vis Sci 2021; 62:33. [PMID: 33512402 PMCID: PMC7846955 DOI: 10.1167/iovs.62.1.33] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 01/04/2021] [Indexed: 02/07/2023] Open
Abstract
Purpose Basal linear deposit (BLinD) is a thin layer of soft drusen material. To elucidate the biology of extracellular deposits conferring age-related macular degeneration (AMD) progression risk and inform multimodal clinical imaging based on optical coherence tomography (OCT), we examined lipid content and regional prevalence of BLinD, soft drusen, pre-BLinD, and subretinal drusenoid deposit (SDD) in AMD and non-AMD aged eyes. We estimated BLinD volume and illustrated its relation to type 1 macular neovascularization (MNV). Methods Donor eyes were classified as early to intermediate AMD (n = 25) and age-matched controls (n = 54). In high-resolution histology, we assessed BLinD/soft drusen thickness at 836 and 1716 locations in AMD and control eyes, respectively. BLinD volume was estimated using solid geometry in donor eyes, one clinically characterized. Results BLinD, drusen, type 1 MNV, and fluid occupy the sub-RPE-basal laminar space. BLinD volume in a 3-mm diameter circle may be as much as 0.0315 mm3. Osmophilic lipid was more concentrated in BLinD/drusen than SDD. In the fovea, BLinD/drusen was prevalent in AMD eyes; pre-BLinD was prevalent in control eyes. SDD was low in the fovea and high in perifovea, especially in AMD eyes. Conclusions Although invisible, BLinD may presage type 1 MNV. BLinD volume approaches the criterion OCT drusen volume of 0.03 mm3 for AMD progression risk. BLinD culminates years of subfoveal lipid accumulation. SDD is detected relatively late in life, with currently unknown precursors. Deposit topography suggests one outer retinal lipid recycling system serving specialized cone and rod physiology, and its dysregulation in AMD is due to impaired transfer to the circulation.
Collapse
Affiliation(s)
- Ling Chen
- The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Ophthalmology, and Chongqing Eye Institute, Chongqing, China
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Jeffrey D. Messinger
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Deepayan Kar
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| | - Jacque L. Duncan
- Department of Ophthalmology, University of California San Francisco, San Francisco, California, United States
| | - Christine A. Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| |
Collapse
|
21
|
Vieira CP, Fortmann SD, Hossain M, Longhini AL, Hammer SS, Asare-Bediako B, Crossman DK, Sielski MS, Adu-Agyeiwaah Y, Dupont M, Floyd JL, Li Calzi S, Lydic T, Welner RS, Blanchard GJ, Busik JV, Grant MB. Selective LXR agonist DMHCA corrects retinal and bone marrow dysfunction in type 2 diabetes. JCI Insight 2020; 5:137230. [PMID: 32641586 DOI: 10.1172/jci.insight.137230] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 05/27/2020] [Indexed: 12/12/2022] Open
Abstract
In diabetic dyslipidemia, cholesterol accumulates in the plasma membrane, decreasing fluidity and thereby suppressing the ability of cells to transduce ligand-activated signaling pathways. Liver X receptors (LXRs) make up the main cellular mechanism by which intracellular cholesterol is regulated and play important roles in inflammation and disease pathogenesis. N, N-dimethyl-3β-hydroxy-cholenamide (DMHCA), a selective LXR agonist, specifically activates the cholesterol efflux arm of the LXR pathway without stimulating triglyceride synthesis. In this study, we use a multisystem approach to understand the effects and molecular mechanisms of DMHCA treatment in type 2 diabetic (db/db) mice and human circulating angiogenic cells (CACs), which are hematopoietic progenitor cells with vascular reparative capacity. We found that DMHCA is sufficient to correct retinal and BM dysfunction in diabetes, thereby restoring retinal structure, function, and cholesterol homeostasis; rejuvenating membrane fluidity in CACs; hampering systemic inflammation; and correcting BM pathology. Using single-cell RNA sequencing on lineage-sca1+c-Kit+ (LSK) hematopoietic stem cells (HSCs) from untreated and DMHCA-treated diabetic mice, we provide potentially novel insights into hematopoiesis and reveal DMHCA's mechanism of action in correcting diabetic HSCs by reducing myeloidosis and increasing CACs and erythrocyte progenitors. Taken together, these findings demonstrate the beneficial effects of DMHCA treatment on diabetes-induced retinal and BM pathology.
Collapse
Affiliation(s)
| | - Seth D Fortmann
- Department of Ophthalmology and Visual Sciences and.,Medical Scientist Training Program (MSTP), School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | | | - Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, Michigan, USA
| | | | - David K Crossman
- Department of Genetics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | | | | | | | | | - Todd Lydic
- Collaborative Mass Spectrometry Core, Michigan State University, East Lansing, Michigan, USA
| | - Robert S Welner
- Department of Hematology and Oncology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Gary J Blanchard
- Medical Scientist Training Program (MSTP), School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | | | | |
Collapse
|
22
|
Studies of ApoD -/- and ApoD -/-ApoE -/- mice uncover the APOD significance for retinal metabolism, function, and status of chorioretinal blood vessels. Cell Mol Life Sci 2020; 78:963-983. [PMID: 32440710 DOI: 10.1007/s00018-020-03546-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/15/2020] [Accepted: 05/07/2020] [Indexed: 12/26/2022]
Abstract
Apolipoprotein D (APOD) is an atypical apolipoprotein with unknown significance for retinal structure and function. Conversely, apolipoprotein E (APOE) is a typical apolipoprotein with established roles in retinal cholesterol transport. Herein, we immunolocalized APOD to the photoreceptor inner segments and conducted ophthalmic characterizations of ApoD-/- and ApoD-/-ApoE-/- mice. ApoD-/- mice had normal levels of retinal sterols but changes in the chorioretinal blood vessels and impaired retinal function. The whole-body glucose disposal was impaired in this genotype but the retinal glucose metabolism was unchanged. ApoD-/-ApoE-/- mice had altered sterol profile in the retina but apparently normal chorioretinal vasculature and function. The whole-body glucose disposal and retinal glucose utilization were enhanced in this genotype. OB-Rb, both leptin and APOD receptor, was found to be expressed in the photoreceptor inner segments and was at increased abundance in the ApoD-/- and ApoD-/-ApoE-/- retinas. Retinal levels of Glut4 and Cd36, the glucose transporter and scavenger receptor, respectively, were increased as well, thus linking APOD to retinal glucose and fatty acid metabolism and suggesting the APOD-OB-Rb-GLUT4/CD36 axis. In vivo isotopic labeling, transmission electron microscopy, and retinal proteomics provided additional insights into the mechanism underlying the retinal phenotypes of ApoD-/- and ApoD-/-ApoE-/- mice. Collectively, our data suggest that the APOD roles in the retina are context specific and could determine retinal glucose fluxes into different pathways. APOD and APOE do not play redundant, complementary or opposing roles in the retina, rather their interplay is more complex and reflects retinal responses elicited by lack of these apolipoproteins.
Collapse
|
23
|
Paraoan L, Sharif U, Carlsson E, Supharattanasitthi W, Mahmud NM, Kamalden TA, Hiscott P, Jackson M, Grierson I. Secretory proteostasis of the retinal pigmented epithelium: Impairment links to age-related macular degeneration. Prog Retin Eye Res 2020; 79:100859. [PMID: 32278708 DOI: 10.1016/j.preteyeres.2020.100859] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/24/2020] [Accepted: 03/26/2020] [Indexed: 12/19/2022]
Abstract
Secretory proteostasis integrates protein synthesis, processing, folding and trafficking pathways that are essential for efficient cellular secretion. For the retinal pigment epithelium (RPE), secretory proteostasis is of vital importance for the maintenance of the structural and functional integrity of apical (photoreceptors) and basal (Bruch's membrane/choroidal blood supply) sides of the environment it resides in. This integrity is achieved through functions governed by RPE secreted proteins, which include extracellular matrix modelling/remodelling, angiogenesis and immune response modulation. Impaired RPE secretory proteostasis affects not only the extracellular environment, but leads to intracellular protein aggregation and ER-stress with subsequent cell death. Ample recent evidence implicates dysregulated proteostasis as a key factor in the development of age-related macular degeneration (AMD), the leading cause of blindness in the developed world, and research aiming to characterise the roles of various proteins implicated in AMD-associated dysregulated proteostasis unveiled unexpected facets of the mechanisms involved in degenerative pathogenesis. This review analyses cellular processes unveiled by the study of the top 200 transcripts most abundantly expressed by the RPE/choroid in the light of the specialised secretory nature of the RPE. Functional roles of these proteins and the mechanisms of their impaired secretion, due to age and genetic-related causes, are analysed in relation to AMD development. Understanding the importance of RPE secretory proteostasis in relation to maintaining retinal health and how it becomes impaired in disease is of paramount importance for the development and assessment of future therapeutic advancements involving gene and cell therapies.
Collapse
Affiliation(s)
- Luminita Paraoan
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom.
| | - Umar Sharif
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Emil Carlsson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Wasu Supharattanasitthi
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom; Department of Physiology, Faculty of Pharmacy, Mahidol University, Bangkok, Thailand
| | - Nur Musfirah Mahmud
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Tengku Ain Kamalden
- Eye Research Centre, Department of Ophthalmology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia
| | - Paul Hiscott
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Malcolm Jackson
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| | - Ian Grierson
- Department of Eye and Vision Science, Institute of Ageing and Chronic Disease, University of Liverpool, Liverpool, United Kingdom
| |
Collapse
|
24
|
Fukuda R, Murakami T. Potential of Lipoprotein-Based Nanoparticulate Formulations for the Treatment of Eye Diseases. Biol Pharm Bull 2020; 43:596-607. [PMID: 32238702 DOI: 10.1248/bpb.b19-00858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lipoproteins are naturally occurring nanoparticles and their main physiological function is the promotion of lipid metabolism. They can be prepared in vitro for use as drug carriers, and these reconstituted lipoproteins show similar biological activity to their natural counterparts. Some lipoproteins can cross the blood-retinal barrier and are involved in intraocular lipid metabolism. Drug-loaded lipoproteins can be delivered to the retina for the treatment of posterior eye diseases. In this review, we have discussed the therapeutic applications of lipoproteins for eye diseases and introduced the emerging animal models used for the evaluation of their therapeutic effects.
Collapse
Affiliation(s)
- Ryosuke Fukuda
- Department of Biotechnology, Graduate School of Engineering, Toyama Prefectural University.,Research Fellow of Japan Society for the Promotion of Science (JSPS)
| | - Tatsuya Murakami
- Department of Pharmaceutical Engineering, Faculty of Engineering, Toyama Prefectural University.,Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University Institute for Advanced Study (KUIAS)
| |
Collapse
|
25
|
Asare-Bediako B, Noothi SK, Li Calzi S, Athmanathan B, Vieira CP, Adu-Agyeiwaah Y, Dupont M, Jones BA, Wang XX, Chakraborty D, Levi M, Nagareddy PR, Grant MB. Characterizing the Retinal Phenotype in the High-Fat Diet and Western Diet Mouse Models of Prediabetes. Cells 2020; 9:cells9020464. [PMID: 32085589 PMCID: PMC7072836 DOI: 10.3390/cells9020464] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 02/07/2020] [Accepted: 02/13/2020] [Indexed: 02/08/2023] Open
Abstract
We sought to delineate the retinal features associated with the high-fat diet (HFD) mouse, a widely used model of obesity. C57BL/6 mice were fed either a high-fat (60% fat; HFD) or low-fat (10% fat; LFD) diet for up to 12 months. The effect of HFD on body weight and insulin resistance were measured. The retina was assessed by electroretinogram (ERG), fundus photography, permeability studies, and trypsin digests for enumeration of acellular capillaries. The HFD cohort experienced hypercholesterolemia when compared to the LFD cohort, but not hyperglycemia. HFD mice developed a higher body weight (60.33 g vs. 30.17g, p < 0.0001) as well as a reduced insulin sensitivity index (9.418 vs. 62.01, p = 0.0002) compared to LFD controls. At 6 months, retinal functional testing demonstrated a reduction in a-wave and b-wave amplitudes. At 12 months, mice on HFD showed evidence of increased retinal nerve infarcts and vascular leakage, reduced vascular density, but no increase in number of acellular capillaries compared to LFD mice. In conclusion, the HFD mouse is a useful model for examining the effect of prediabetes and hypercholesterolemia on the retina. The HFD-induced changes appear to occur slower than those observed in type 2 diabetes (T2D) models but are consistent with other retinopathy models, showing neural damage prior to vascular changes.
Collapse
Affiliation(s)
- Bright Asare-Bediako
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (B.A.-B.); (Y.A.-A.); (M.D.)
| | - Sunil K. Noothi
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Sergio Li Calzi
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Baskaran Athmanathan
- Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.A.); (P.R.N.)
| | - Cristiano P. Vieira
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Yvonne Adu-Agyeiwaah
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (B.A.-B.); (Y.A.-A.); (M.D.)
| | - Mariana Dupont
- Vision Science Graduate Program, School of Optometry, University of Alabama at Birmingham, Birmingham, AL 35233, USA; (B.A.-B.); (Y.A.-A.); (M.D.)
| | - Bryce A. Jones
- Department of Pharmacology and Physiology, Georgetown University, Washington, DC 20057, USA;
| | - Xiaoxin X. Wang
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC 20057, USA; (X.X.W.); (M.L.)
| | - Dibyendu Chakraborty
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
| | - Moshe Levi
- Department of Biochemistry and Molecular & Cellular Biology, Georgetown University, Washington, DC 20057, USA; (X.X.W.); (M.L.)
| | - Prabhakara R. Nagareddy
- Division of Cardiac Surgery, Department of Surgery, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA; (B.A.); (P.R.N.)
| | - Maria B. Grant
- Department of Ophthalmology and Visual Sciences, School of Medicine, The University of Alabama at Birmingham, Birmingham, AL 35294, USA; (S.K.N.); (S.L.C.); (C.P.V.); (D.C.)
- Correspondence:
| |
Collapse
|
26
|
Petrov AM, Astafev AA, Mast N, Saadane A, El-Darzi N, Pikuleva IA. The Interplay between Retinal Pathways of Cholesterol Output and Its Effects on Mouse Retina. Biomolecules 2019; 9:biom9120867. [PMID: 31842366 PMCID: PMC6995521 DOI: 10.3390/biom9120867] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/03/2019] [Accepted: 12/10/2019] [Indexed: 12/14/2022] Open
Abstract
In mammalian retina, cholesterol excess is mainly metabolized to oxysterols by cytochromes P450 27A1 (CYP27A1) and 46A1 (CYP46A1) or removed on lipoprotein particles containing apolipoprotein E (APOE). In contrast, esterification by sterol-O-acyltransferase 1 (SOAT) plays only a minor role in this process. Accordingly, retinal cholesterol levels are unchanged in Soat1-/- mice but are increased in Cyp27a1-/-Cyp46a1-/- and Apoe-/- mice. Herein, we characterized Cyp27a1-/-Cyp46a1-/-Soat1-/- and Cyp27a1-/-Cyp46a1-/-Apoe-/- mice. In the former, retinal cholesterol levels, anatomical gross structure, and vasculature were normal, yet the electroretinographic responses were impaired. Conversely, in Cyp27a1-/-Cyp46a1-/-Apoe-/- mice, retinal cholesterol levels were increased while anatomical structure and vasculature were unaffected with only male mice showing a decrease in electroretinographic responses. Sterol profiling, qRT-PCR, proteomics, and transmission electron microscopy mapped potential compensatory mechanisms in the Cyp27a1-/-Cyp46a1-/-Soat1-/- and Cyp27a1-/-Cyp46a1-/-Apoe-/- retina. These included decreased cholesterol biosynthesis along with enhanced formation of intra- and extracellular vesicles, possibly a reserve mechanism for lowering retinal cholesterol. In addition, there was altered abundance of proteins in Cyp27a1-/-Cyp46a1-/-Soat1-/- mice that can affect photoreceptor function, survival, and retinal energy homeostasis (glucose and fatty acid metabolism). Therefore, the levels of retinal cholesterol do not seem to predict retinal abnormalities, and it is rather the network of compensatory mechanisms that appears to determine retinal phenotype.
Collapse
|
27
|
Léger-Charnay E, Masson EAY, Morala T, Martine L, Buteau B, Leclere L, Bretillon L, Gambert S. Is 24(S)-hydroxycholesterol a potent modulator of cholesterol metabolism in Müller cells? An in vitro study about neuron to glia communication in the retina. Exp Eye Res 2019; 189:107857. [PMID: 31654618 DOI: 10.1016/j.exer.2019.107857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 10/12/2019] [Accepted: 10/21/2019] [Indexed: 11/19/2022]
Abstract
Communication between neurons and glia plays a major role in nervous tissue homeostasis. It is thought to participate in tuning cholesterol metabolism to cellular demand, which is a critical issue for neuronal health. Cholesterol is a membrane lipid crucial for nervous tissue functioning, and perturbed regulation of its metabolism has been linked to several neurodegenerative disorders. In the brain, 24(S)-hydroxycholesterol (24S-OHC) is an oxysterol synthesized by neurons to eliminate cholesterol, and 24S-OHC has been shown to regulate cholesterol metabolism in astrocytes, glial cells which provide cholesterol to neurons. In the retina, 24S-OHC is also an elimination product of cholesterol produced by neurons, especially the retinal ganglion cells. However, it is not known whether Müller cells, the major macroglial cells of the retina, play the role of cholesterol provider for retinal neurons and whether they respond to 24S-OHC signaling, similarly to brain glial cells. In the present study, primary cultures of rat Müller cells were treated with 0, 0.5 or 1.5 μM 24S-OHC for 48 hours. The levels of cholesterol, precursors and oxysterols were quantified using gas chromatography coupled to flame-ionization detection or mass spectrometry. In addition, the expression of key genes related to cholesterol metabolism was analyzed using RTq-PCR. Müller cells were shown to express many genes linked to cholesterol metabolism, including genes coding for proteins implicated in cholesterol biosynthesis (HMGCR), cholesterol uptake and export via lipoproteins (LDL-R, SR-BI, ApoE and ABACA1) and regulation of cholesterol metabolism (SREBP2 and LXRβ). Cholesterol and several of its precursors and oxidative products were present. CYP27A1, the main retinal enzyme implicated in cholesterol elimination via oxysterol production, was quantified at low transcript levels but neither of its two typical products were detected in Müller cells. Furthermore, our results demonstrate that 24S-OHC has a strong hypocholesterolemic effect in Müller cells, leading to cholesterol depletion (-37 % at 1.5 μM). This was mediated by a decrease in cholesterol synthesis, as illustrated by reduced levels of cholesterol precursors: desmosterol (-38 % at 1.5 μM) and lathosterol (-84 % at 1.5 μM), and strong downregulation of HMGCR gene expression (2.4 fold decrease at 1.5μM). In addition, LDL-R and SR-BI gene expression were reduced in response to 24S-OHC treatment (2 fold and 1.6 fold at 1.5 μM, respectively), suggesting diminished lipoprotein uptake by the cells. On the contrary, there was a dramatic overexpression of ABCA1 transporter (10 fold increase at 1.5 μM), probably mediating an increase in cholesterol efflux. Finally, 24S-OHC induced a small but significant upregulation of the CYP27A1 gene. These data indicate that Müller cells possess the necessary cholesterol metabolism machinery and that they are able to sharply adjust their cholesterol metabolism in response to 24S-OHC, a signal molecule of neuronal cholesterol status. This suggests that Müller cells could be major players of cholesterol homeostasis in the retina via neuron-glia crosstalk.
Collapse
Affiliation(s)
- Elise Léger-Charnay
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Elodie A Y Masson
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Tristan Morala
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Lucy Martine
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Bénédicte Buteau
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Laurent Leclere
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Lionel Bretillon
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Ségolène Gambert
- Centre des Sciences du Goût et de l'Alimentation, AgroSup Dijon, CNRS, INRA, Université Bourgogne Franche-Comté, F-21000, Dijon, France; Laboratoire de Biochimie Médicale, Plateforme de Biologie Hospitalo-Universitaire, F-21000, Dijon, France.
| |
Collapse
|
28
|
Pariente A, Peláez R, Pérez-Sala Á, Larráyoz IM. Inflammatory and cell death mechanisms induced by 7-ketocholesterol in the retina. Implications for age-related macular degeneration. Exp Eye Res 2019; 187:107746. [DOI: 10.1016/j.exer.2019.107746] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Revised: 07/25/2019] [Accepted: 07/25/2019] [Indexed: 12/16/2022]
|
29
|
Storti F, Klee K, Todorova V, Steiner R, Othman A, van der Velde-Visser S, Samardzija M, Meneau I, Barben M, Karademir D, Pauzuolyte V, Boye SL, Blaser F, Ullmer C, Dunaief JL, Hornemann T, Rohrer L, den Hollander A, von Eckardstein A, Fingerle J, Maugeais C, Grimm C. Impaired ABCA1/ABCG1-mediated lipid efflux in the mouse retinal pigment epithelium (RPE) leads to retinal degeneration. eLife 2019; 8:45100. [PMID: 30864945 PMCID: PMC6435327 DOI: 10.7554/elife.45100] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 03/12/2019] [Indexed: 01/04/2023] Open
Abstract
Age-related macular degeneration (AMD) is a progressive disease of the retinal pigment epithelium (RPE) and the retina leading to loss of central vision. Polymorphisms in genes involved in lipid metabolism, including the ATP-binding cassette transporter A1 (ABCA1), have been associated with AMD risk. However, the significance of retinal lipid handling for AMD pathogenesis remains elusive. Here, we study the contribution of lipid efflux in the RPE by generating a mouse model lacking ABCA1 and its partner ABCG1 specifically in this layer. Mutant mice show lipid accumulation in the RPE, reduced RPE and retinal function, retinal inflammation and RPE/photoreceptor degeneration. Data from human cell lines indicate that the ABCA1 AMD risk-conferring allele decreases ABCA1 expression, identifying the potential molecular cause that underlies the genetic risk for AMD. Our results highlight the essential homeostatic role for lipid efflux in the RPE and suggest a pathogenic contribution of reduced ABCA1 function to AMD.
Collapse
Affiliation(s)
- Federica Storti
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland
| | - Katrin Klee
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Vyara Todorova
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| | - Regula Steiner
- Institute of Clinical Chemistry, University of Zurich, Schlieren, Switzerland
| | - Alaa Othman
- Institute of Clinical Chemistry, University of Zurich, Schlieren, Switzerland
| | | | - Marijana Samardzija
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland
| | - Isabelle Meneau
- Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland
| | - Maya Barben
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland
| | - Duygu Karademir
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland
| | - Valda Pauzuolyte
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida, Gainesville, United States
| | - Frank Blaser
- Department of Ophthalmology, University Hospital Zurich, Zurich, Switzerland
| | - Christoph Ullmer
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Joshua L Dunaief
- Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, United States
| | - Thorsten Hornemann
- Institute of Clinical Chemistry, University of Zurich, Schlieren, Switzerland
| | - Lucia Rohrer
- Institute of Clinical Chemistry, University of Zurich, Schlieren, Switzerland
| | - Anneke den Hollander
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands.,Department of Ophthalmology, Radboud University Medical Center, Nijmegen, Netherlands
| | | | - Jürgen Fingerle
- Natural and Medical Sciences Institute, University of Tübingen, Tübingen, Germany
| | - Cyrille Maugeais
- Roche Pharma Research and Early Development, Roche Innovation Center Basel, F Hoffmann-La Roche Ltd., Basel, Switzerland
| | - Christian Grimm
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland.,Center for Integrative Human Physiology, University of Zurich, Zurich, Switzerland.,Neuroscience Center Zurich, University of Zurich, Zurich, Switzerland
| |
Collapse
|
30
|
Human complement factor H Y402H polymorphism causes an age-related macular degeneration phenotype and lipoprotein dysregulation in mice. Proc Natl Acad Sci U S A 2019; 116:3703-3711. [PMID: 30808757 PMCID: PMC6397537 DOI: 10.1073/pnas.1814014116] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The complement factor H (CFH) Y402H polymorphism (rs1061170) imparts the strongest risk for age-related macular degeneration (AMD), the leading cause of blindness in the elderly. Popular thinking holds that the CFH H402 variant increases complement activation in the eye, predisposing susceptibility to disease. However, clinical trials of complement inhibitors in AMD patients have failed. Here we provide an explanation, showing CFH variant-specific differences in the presentation of AMD-like pathologies. We show that aged mice expressing the human H402, but not Y402 variant, (i) develop AMD-like symptoms and (ii) display differences in their systemic and ocular lipoprotein levels, but not in their complement activation, after diet. These findings support targeting lipoproteins for the treatment of AMD. One of the strongest susceptibility genes for age-related macular degeneration (AMD) is complement factor H (CFH); however, its impact on AMD pathobiology remains unresolved. Here, the effect of the principal AMD-risk–associated CFH variant (Y402H) on the development and progression of age-dependent AMD-like pathologies was determined in vivo. Transgenic mice expressing equal amounts of the full-length normal human CFH Y402 (CFH-Y/0) or the AMD-risk associated CFH H402 (CFH-H/H) variant on a Cfh−/− background were aged to 90 weeks and switched from normal diet (ND) to a high fat, cholesterol-enriched (HFC) diet for 8 weeks. The resulting phenotype was compared with age-matched controls maintained on ND. Remarkably, an AMD-like phenotype consisting of vision loss, increased retinal pigmented epithelium (RPE) stress, and increased basal laminar deposits was detected only in aged CFH-H/H mice following the HFC diet. These changes were not observed in aged CFH-Y/0 mice or in younger (36- to 40-week-old) CFH mice of both genotypes fed either diet. Biochemical analyses of aged CFH mice after HFC diet revealed genotype-dependent changes in plasma and eyecup lipoproteins, but not complement activation, which correlated with the AMD-like phenotype in old CFH-H/H mice. Specifically, apolipoproteins B48 and A1 are elevated in the RPE/choroid of the aged CFH-H/H mice compared with age-matched control CFH-Y/0 fed a HFC diet. Hence, we demonstrate a functional consequence of the Y402H polymorphism in vivo, which promotes AMD-like pathology development and affects lipoprotein levels in aged mice. These findings support targeting lipoproteins as a viable therapeutic strategy for treating AMD.
Collapse
|
31
|
Collin J, Zerti D, Queen R, Santos-Ferreira T, Bauer R, Coxhead J, Hussain R, Steel D, Mellough C, Ader M, Sernagor E, Armstrong L, Lako M. CRX Expression in Pluripotent Stem Cell-Derived Photoreceptors Marks a Transplantable Subpopulation of Early Cones. Stem Cells 2019; 37:609-622. [PMID: 30681766 PMCID: PMC6519156 DOI: 10.1002/stem.2974] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 11/05/2018] [Accepted: 12/03/2018] [Indexed: 12/27/2022]
Abstract
Death of photoreceptors is a common cause of age-related and inherited retinal dystrophies, and thus their replenishment from renewable stem cell sources is a highly desirable therapeutic goal. Human pluripotent stem cells provide a useful cell source in view of their limitless self-renewal capacity and potential to not only differentiate into cells of the retina but also self-organize into tissue with structure akin to the human retina as part of three-dimensional retinal organoids. Photoreceptor precursors have been isolated from differentiating human pluripotent stem cells through application of cell surface markers or fluorescent reporter approaches and shown to have a similar transcriptome to fetal photoreceptors. In this study, we investigated the transcriptional profile of CRX-expressing photoreceptor precursors derived from human pluripotent stem cells and their engraftment capacity in an animal model of retinitis pigmentosa (Pde6brd1), which is characterized by rapid photoreceptor degeneration. Single cell RNA-Seq analysis revealed the presence of a dominant cell cluster comprising 72% of the cells, which displayed the hallmarks of early cone photoreceptor expression. When transplanted subretinally into the Pde6brd1 mice, the CRX+ cells settled next to the inner nuclear layer and made connections with the inner neurons of the host retina, and approximately one-third of them expressed the pan cone marker, Arrestin 3, indicating further maturation upon integration into the host retina. Together, our data provide valuable molecular insights into the transcriptional profile of human pluripotent stem cells-derived CRX+ photoreceptor precursors and indicate their usefulness as a source of transplantable cone photoreceptors. Stem Cells 2019;37:609-622.
Collapse
Affiliation(s)
- Joseph Collin
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Darin Zerti
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Rachel Queen
- Genomics Core Facility, Newcastle University, Newcastle, United Kingdom
| | - Tiago Santos-Ferreira
- CRTD/Center for Regenerative Therapies Dresden, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Roman Bauer
- Institute of Neuroscience, Newcastle University, Newcastle, United Kingdom
| | - Jonathan Coxhead
- Genomics Core Facility, Newcastle University, Newcastle, United Kingdom
| | - Rafiqul Hussain
- Genomics Core Facility, Newcastle University, Newcastle, United Kingdom
| | - David Steel
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Carla Mellough
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Marius Ader
- CRTD/Center for Regenerative Therapies Dresden, Center for Molecular and Cellular Bioengineering, Technische Universität Dresden, Dresden, Germany
| | - Evelyne Sernagor
- Institute of Neuroscience, Newcastle University, Newcastle, United Kingdom
| | - Lyle Armstrong
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| | - Majlinda Lako
- Institute of Genetic Medicine, Newcastle University, Newcastle, United Kingdom
| |
Collapse
|
32
|
König S, Hadrian K, Schlatt S, Wistuba J, Thanos S, Böhm M. Topographic protein profiling of the age-related proteome in the retinal pigment epithelium of Callithrix jacchus with respect to macular degeneration. J Proteomics 2019; 191:1-15. [DOI: 10.1016/j.jprot.2018.05.016] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 05/12/2018] [Accepted: 05/28/2018] [Indexed: 12/27/2022]
|
33
|
Active Cholesterol Efflux in the Retina and Retinal Pigment Epithelium. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1185:51-55. [PMID: 31884588 DOI: 10.1007/978-3-030-27378-1_9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The importance of cholesterol as a structural component of photoreceptors and the association between impaired cholesterol homeostasis and age-related macular degeneration (AMD) prompted in the last years a deep investigation of its metabolism in the retina. Here, we focus on the export of cholesterol from intracellular membranes to extracellular acceptors, an active mechanism mediated by the ATP-binding cassette transporters A1 and G1 (ABCA1 and G1) also known as "active cholesterol efflux." Expression of genes involved in this pathway was shown for most retinal cells, while functional in vitro assays focused on the retinal pigment epithelium (RPE) due to availability of cell models. Cell-specific knockout (KO) mice were generated in the past years, and their characterization unveils an important role of the ABCA1/G1 pathway in RPE, rods, and retinal inflammatory cells. The actual involvement of cholesterol efflux in the pathogenesis of AMD still needs to be demonstrated and will help in establishing the scientific rationale for targeting the ABCA1/G1 pathway in retinal diseases.
Collapse
|
34
|
On the origin of proteins in human drusen: The meet, greet and stick hypothesis. Prog Retin Eye Res 2018; 70:55-84. [PMID: 30572124 DOI: 10.1016/j.preteyeres.2018.12.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 12/11/2018] [Accepted: 12/12/2018] [Indexed: 12/12/2022]
Abstract
Retinal drusen formation is not only a clinical hallmark for the development of age-related macular degeneration (AMD) but also for other disorders, such as Alzheimer's disease and renal diseases. The initiation and growth of drusen is poorly understood. Attention has focused on lipids and minerals, but relatively little is known about the origin of drusen-associated proteins and how they are retained in the space between the basal lamina of the retinal pigment epithelium and the inner collagenous layer space (sub-RPE-BL space). While some authors suggested that drusen proteins are mainly derived from cellular debris from processed photoreceptor outer segments and the RPE, others suggest a choroidal cell or blood origin. Here, we reviewed and supplemented the existing literature on the molecular composition of the retina/choroid complex, to gain a more complete understanding of the sources of proteins in drusen. These "drusenomics" studies showed that a considerable proportion of currently identified drusen proteins is uniquely originating from the blood. A smaller, but still large fraction of drusen proteins comes from both blood and/or RPE. Only a small proportion of drusen proteins is uniquely derived from the photoreceptors or choroid. We next evaluated how drusen components may "meet, greet and stick" to each other and/or to structures like hydroxyapatite spherules to form macroscopic deposits in the sub-RPE-BL space. Finally, we discuss implications of our findings with respect to the previously proposed homology between drusenogenesis in AMD and plaque formation in atherosclerosis.
Collapse
|
35
|
Roizenblatt M, Naranjit N, Maia M, Gehlbach PL. The Question of a Role for Statins in Age-Related Macular Degeneration. Int J Mol Sci 2018; 19:ijms19113688. [PMID: 30469381 PMCID: PMC6274767 DOI: 10.3390/ijms19113688] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 11/18/2018] [Accepted: 11/19/2018] [Indexed: 01/22/2023] Open
Abstract
Age-related macular degeneration (AMD) is the leading cause of irreversible central vision loss in patients over the age of 65 years in industrialized countries. Epidemiologic studies suggest that high dietary fat intake is a risk factor for the development and progression of both vascular and retinal disease. These, and other associations, suggest a hypothesis linking elevated cholesterol and AMD progression. It follows, therefore, that cholesterol-lowering medications, such as statins, may influence the onset and progression of AMD. However, the findings have been inconclusive as to whether statins play a role in AMD. Due to the significant public health implications of a potential inhibitory effect of statins on the onset and progression of AMD, it is important to continually evaluate emerging findings germane to this question.
Collapse
Affiliation(s)
- Marina Roizenblatt
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
- Department of Ophthalmology, Federal University of São Paulo, São Paulo 04023-062, Brazil.
- Vision Institute, IPEPO, Department of Ophthalmology, Paulista Medical School, Federal University of São Paulo, São Paulo 04038-032, Brazil.
| | - Nara Naranjit
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| | - Mauricio Maia
- Department of Ophthalmology, Federal University of São Paulo, São Paulo 04023-062, Brazil.
- Vision Institute, IPEPO, Department of Ophthalmology, Paulista Medical School, Federal University of São Paulo, São Paulo 04038-032, Brazil.
| | - Peter L Gehlbach
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
| |
Collapse
|
36
|
Curcio CA. Soft Drusen in Age-Related Macular Degeneration: Biology and Targeting Via the Oil Spill Strategies. Invest Ophthalmol Vis Sci 2018; 59:AMD160-AMD181. [PMID: 30357336 PMCID: PMC6733535 DOI: 10.1167/iovs.18-24882] [Citation(s) in RCA: 173] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
AMD is a major cause of legal blindness in older adults approachable through multidisciplinary research involving human tissues and patients. AMD is a vascular-metabolic-inflammatory disease, in which two sets of extracellular deposits, soft drusen/basal linear deposit (BLinD) and subretinal drusenoid deposit (SDD), confer risk for end-stages of atrophy and neovascularization. Understanding how deposits form can lead to insights for new preventions and therapy. The topographic correspondence of BLinD and SDD with cones and rods, respectively, suggest newly realized exchange pathways among outer retinal cells and across Bruch's membrane and the subretinal space, in service of highly evolved, eye-specific physiology. This review focuses on soft drusen/BLinD, summarizing evidence that a major ultrastructural component is large apolipoprotein B,E-containing, cholesterol-rich lipoproteins secreted by the retinal pigment epithelium (RPE) that offload unneeded lipids of dietary and outer segment origin to create an atherosclerosis-like progression in the subRPE-basal lamina space. Clinical observations and an RPE cell culture system combine to suggest that soft drusen/BLinD form when secretions of functional RPE back up in the subRPE-basal lamina space by impaired egress across aged Bruch's membrane-choriocapillary endothelium. The soft drusen lifecycle includes growth, anterior migration of RPE atop drusen, then collapse, and atrophy. Proof-of-concept studies in humans and animal models suggest that targeting the “Oil Spill in Bruch's membrane” offers promise of treating a process in early AMD that underlies progression to both end-stages. A companion article addresses the antecedents of soft drusen within the biology of the macula.
Collapse
Affiliation(s)
- Christine A Curcio
- Department of Ophthalmology and Visual Sciences, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States
| |
Collapse
|
37
|
Saadane A, Petrov A, Mast N, El-Darzi N, Dao T, Alnemri A, Song Y, Dunaief JL, Pikuleva IA. Mechanisms that minimize retinal impact of apolipoprotein E absence. J Lipid Res 2018; 59:2368-2382. [PMID: 30333155 DOI: 10.1194/jlr.m090043] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Revised: 10/17/2018] [Indexed: 01/28/2023] Open
Abstract
Apolipoprotein E (APOE) is a component of lipid-transporting particles and a recognition ligand for receptors, which bind these particles. The APOE isoform ε2 is a risk factor for age-related macular degeneration; nevertheless, APOE absence in humans and mice does not significantly affect the retina. We found that retinal cholesterol biosynthesis and the levels of retinal cholesterol were increased in Apoe-/- mice, whereas cholesterol elimination by metabolism was decreased. No focal cholesterol deposits were observed in the Apoe-/- retina. Retinal proteomics identified the most abundant cholesterol-related proteins in WT mice and revealed that, of these cholesterol-related proteins, only APOA4 had increased expression in the Apoe-/- retina. In addition, there were changes in retinal abundance of proteins involved in proinflammatory and antiinflammatory responses, cellular cytoskeleton maintenance, vesicular traffic, and retinal iron homeostasis. The data obtained indicate that when APOE is absent, particles containing APOA1, APOA4, and APOJ still transport cholesterol in the intraretinal space, but these particles are not taken up by retinal cells. Therefore, cholesterol biosynthesis inside retinal cells increase, whereas metabolism to oxysterols decreases to prevent cells from cholesterol depletion. These and other compensatory changes underlie only a minor retinal phenotype in Apoe-/- mice.
Collapse
Affiliation(s)
- Aicha Saadane
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Alexey Petrov
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Nicole El-Darzi
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Tung Dao
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| | - Ahab Alnemri
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ying Song
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Joshua L Dunaief
- F. M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH
| |
Collapse
|
38
|
Mast N, Bederman IR, Pikuleva IA. Retinal Cholesterol Content Is Reduced in Simvastatin-Treated Mice Due to Inhibited Local Biosynthesis Albeit Increased Uptake of Serum Cholesterol. Drug Metab Dispos 2018; 46:1528-1537. [PMID: 30115644 DOI: 10.1124/dmd.118.083345] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 08/14/2018] [Indexed: 12/18/2022] Open
Abstract
Statins, a class of cholesterol-lowering drugs, are currently being investigated for treatment of age-related macular degeneration, a retinal disease. Herein, retinal and serum concentrations of four statins (atorvastatin, simvastatin, pravastatin, and rosuvastatin) were evaluated after mice were given a single drug dose of 60 mg/kg body weight. All statins, except rosuvastatin, were detected in the retina: atorvastatin and pravastatin at 1.6 pmol and simvastatin at 4.1 pmol. Serum statin concentrations (pmol/ml) were 223 (simvastatin), 1401 (atorvastatin), 2792 (pravastatin), and 9050 (rosuvastatin). Simvastatin was then administered to mice daily for 6 weeks at 60 mg/kg body weight. Simvastatin treatment reduced serum cholesterol levels by 18% and retinal content of cholesterol and lathosterol (but not desmosterol) by 24% and 21%, respectively. The relative contributions of retinal cholesterol biosynthesis and retinal uptake of serum cholesterol to total retinal cholesterol input were changed as well. These contributions were 79% and 21%, respectively, in vehicle-treated mice and 69% and 31%, respectively, in simvastatin-treated mice. Thus, simvastatin treatment lowered retinal cholesterol because a compensatory upregulation of retinal uptake of serum cholesterol was not sufficient to overcome the effect of inhibited retinal biosynthesis. Simultaneously, simvastatin-treated mice had a 2.9-fold increase in retinal expression of Cd36, the major receptor clearing oxidized low-density lipoproteins from Bruch's membrane. Notably, simvastatin treatment essentially did not affect brain cholesterol homeostasis. Our results reveal the statin effect on the retinal and brain cholesterol input and are of value for future clinical investigations of statins as potential therapeutics for age-related macular degeneration.
Collapse
Affiliation(s)
- Natalia Mast
- Departments of Ophthalmology and Visual Sciences (N.M., I.A.P.) and Pediatrics (I.R.B.), Case Western Reserve University, Cleveland, Ohio
| | - Ilya R Bederman
- Departments of Ophthalmology and Visual Sciences (N.M., I.A.P.) and Pediatrics (I.R.B.), Case Western Reserve University, Cleveland, Ohio
| | - Irina A Pikuleva
- Departments of Ophthalmology and Visual Sciences (N.M., I.A.P.) and Pediatrics (I.R.B.), Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
39
|
Fan Q, Maranville JC, Fritsche L, Sim X, Cheung CMG, Chen LJ, Gorski M, Yamashiro K, Ahn J, Laude A, Dorajoo R, Lim TH, Teo YY, Blaustein RO, Yoshimura N, Park KH, Pang CP, Tai ES, Khor CC, Wong TY, Runz H, Cheng CY. HDL-cholesterol levels and risk of age-related macular degeneration: a multiethnic genetic study using Mendelian randomization. Int J Epidemiol 2018; 46:1891-1902. [PMID: 29025108 PMCID: PMC5837540 DOI: 10.1093/ije/dyx189] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/17/2017] [Indexed: 02/07/2023] Open
Abstract
Background Dyslipidemia, particularly high-density lipoprotein cholesterol (HDL-C), has recently been implicated in the pathogenesis of age-related macular degeneration (AMD), the leading cause of vision loss. However, epidemiological studies have yielded conflicting results. Methods We investigated the causal role of plasma lipid levels in AMD in multiethnic populations comprising 16 144 advanced AMD cases and 17 832 controls of European descent, together with 2219 cases and 5275 controls of Asian descent, using Mendelian randomization in three models. Model 1 is a conventional meta-analysis which does not account for pleiotropy of instrumental variable (IV) effects. Model 2 is a univariate, inverse variance weighted regression analysis that accounts for potential unbalanced pleiotropy using MR-Egger method. Finally, Model 3 is a multivariate regression analysis that addresses pleiotropy by MR-Egger method and by adjusting for effects on other lipid traits. Results A 1 standard deviation (SD) higher HDL-cholesterol level was associated with an odds ratio (OR) for AMD of 1.17 (95% confidence interval: 1.07–1.29) in Europeans (P = 6.88 × 10–4) and of 1.58 (1.24–2.00) in Asians (P = 2.92 × 10–4) in Model 3. The corresponding OR estimates were 1.30 (1.09–1.55) in Europeans (P = 3.18 × 10–3) and 1.42 (1.11—1.80) in Asians (P = 4.42 × 10–3) in Model 1, and 1.21 (1.11–1.31) in Europeans (P = 3.12 × 10–5) and 1.51 (1.20–1.91) in Asians (P = 7.61 × 10–4) in Model 2. Conversely, neither LDL-C (Europeans: OR = 0.96, P = 0.272; Asians: OR = 1.02, P = 0.874; Model 3) nor triglyceride levels (Europeans: OR = 0.91, P = 0.102; Asians: OR = 1.06, P = 0.613) were associated with AMD. We also assessed the association between lipid levels and polypoidal choroidal vasculopathy (PCV) in Asians, a subtype of AMD, and found a similar trend for association of PCV with HDL-C levels. Conclusions Our study shows that high levels of plasma HDL-C are causally associated with an increased risk for advanced AMD in European and Asian populations, implying that strategies reducing HDL-C levels may be useful to prevent and treat AMD.
Collapse
Affiliation(s)
- Qiao Fan
- Center for Quantitative Medicine, Duke-NUS Medical School, Singapore
| | | | - Lars Fritsche
- Center for Statistical Genetics, Department of Biostatistics, University of Michigan, Ann Arbor, USA
| | - Xueling Sim
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore
| | | | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - Mathias Gorski
- Department of Genetic Epidemiology, University of Regensburg, Regensburg, Germany
| | - Kenji Yamashiro
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Jeeyun Ahn
- Department of Ophthalmology, Seoul National University Bundang Hospital, Gyeonggi, Korea
| | - Augustinus Laude
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | - Rajkumar Dorajoo
- Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Tock Han Lim
- National Healthcare Group Eye Institute, Tan Tock Seng Hospital, Singapore
| | - Yik-Ying Teo
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.,Department of Statistics and Applied Probability, National University of Singapore, Singapore
| | | | - Nagahisa Yoshimura
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Kyu-Hyung Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Gyeonggi, Korea
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, Chinese University of Hong Kong, Hong Kong, China
| | - E Shyong Tai
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.,Department of Medicine, National University Health System and National University of Singapore, Singapore
| | - Chiea Chuen Khor
- Singapore Eye Research Institute, Singapore National Eye Center, Singapore.,Genome Institute of Singapore, Agency for Science, Technology and Research, Singapore
| | - Tien Yin Wong
- Saw Swee Hock School of Public Health, National University of Singapore and National University Health System, Singapore.,Singapore Eye Research Institute, Singapore National Eye Center, Singapore.,Clinical Sciences, Duke-NUS Medical School, Singapore
| | - Heiko Runz
- Merck Research Laboratories, Kenilworth, NJ, USA
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Center, Singapore.,Clinical Sciences, Duke-NUS Medical School, Singapore
| |
Collapse
|
40
|
El-Darzi N, Astafev A, Mast N, Saadane A, Lam M, Pikuleva IA. N, N-Dimethyl-3β-hydroxycholenamide Reduces Retinal Cholesterol via Partial Inhibition of Retinal Cholesterol Biosynthesis Rather Than its Liver X Receptor Transcriptional Activity. Front Pharmacol 2018; 9:827. [PMID: 30090064 PMCID: PMC6069453 DOI: 10.3389/fphar.2018.00827] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2018] [Accepted: 07/09/2018] [Indexed: 12/19/2022] Open
Abstract
N,N-dimethyl-3β-hydroxycholenamide (DMHCA) is an experimental pharmaceutical and a steroidal liver X receptor (LXR) agonist, which does not induce undesired hepatic lipogenesis. Herein, DMHCA was evaluated for its retinal effects on normal C57BL/6J and Cyp27a1−/−Cyp46a1−/− mice; the latter having higher retinal total and esterified cholesterol in addition to retinal vascular abnormalities. Different doses and two formulations were used for DMHCA delivery either via drinking water (C57BL/6J mice) or by oral gavage (Cyp27a1−/−Cyp46a1−/− mice). The duration of treatment was 1 week for C57BL/6J mice and 2 or 4 weeks for Cyp27a1−/−Cyp46a1−/− mice. In both genotypes, the higher DMHCA doses (37–80 mg/kg of body weight/day) neither increased serum triglycerides nor serum cholesterol but altered the levels of retinal sterols. Total retinal cholesterol was decreased in the DMHCA-treated mice, mainly due to a decrease in retinal unesterified cholesterol. In addition, retinal levels of cholesterol precursors lanosterol, zymosterol, desmosterol, and lathosterol were changed in Cyp27a1−/−Cyp46a1−/− mice. In both genotypes, DMHCA effect on retinal expression of the LXR target genes was only moderate and gender-specific. Collectively, the data obtained provide evidence for a decrease in retinal cholesterol as a result of DMHCA acting in the retina as an enzyme inhibitor of cholesterol biosynthesis rather than a LXR transcriptional activator. Specifically, DMHCA appears to partially inhibit the cholesterol biosynthetic enzyme Δ24-dehydrocholesterol reductase rather than upregulate the expression of LXR target genes involved in reverse cholesterol transport. The identified DMHCA dosages, formulations, and routes of delivery as well as the observed effects on the retina should be considered in future studies using DMHCA as a potential therapeutic for age-related macular degeneration and diabetic retinopathy.
Collapse
Affiliation(s)
- Nicole El-Darzi
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Artem Astafev
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Aicha Saadane
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Morrie Lam
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH, United States
| |
Collapse
|
41
|
van Leeuwen EM, Emri E, Merle BMJ, Colijn JM, Kersten E, Cougnard-Gregoire A, Dammeier S, Meester-Smoor M, Pool FM, de Jong EK, Delcourt C, Rodrigez-Bocanegra E, Biarnés M, Luthert PJ, Ueffing M, Klaver CCW, Nogoceke E, den Hollander AI, Lengyel I. A new perspective on lipid research in age-related macular degeneration. Prog Retin Eye Res 2018; 67:56-86. [PMID: 29729972 DOI: 10.1016/j.preteyeres.2018.04.006] [Citation(s) in RCA: 140] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Revised: 04/25/2018] [Accepted: 04/30/2018] [Indexed: 12/15/2022]
Abstract
There is an urgency to find new treatment strategies that could prevent or delay the onset or progression of AMD. Different classes of lipids and lipoproteins metabolism genes have been associated with AMD in a multiple ways, but despite the ever-increasing knowledge base, we still do not understand fully how circulating lipids or local lipid metabolism contribute to AMD. It is essential to clarify whether dietary lipids, systemic or local lipoprotein metabolismtrafficking of lipids in the retina should be targeted in the disease. In this article, we critically evaluate what has been reported in the literature and identify new directions needed to bring about a significant advance in our understanding of the role for lipids in AMD. This may help to develop potential new treatment strategies through targeting the lipid homeostasis.
Collapse
Affiliation(s)
- Elisabeth M van Leeuwen
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Eszter Emri
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom
| | - Benedicte M J Merle
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000, Bordeaux, France
| | - Johanna M Colijn
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - Eveline Kersten
- Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Audrey Cougnard-Gregoire
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000, Bordeaux, France
| | - Sascha Dammeier
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Germany
| | - Magda Meester-Smoor
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands
| | | | - Eiko K de Jong
- Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Cécile Delcourt
- Univ. Bordeaux, Inserm, Bordeaux Population Health Research Center, Team LEHA, UMR 1219, F-33000, Bordeaux, France
| | | | | | | | - Marius Ueffing
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Germany
| | - Caroline C W Klaver
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Erasmus Medical Center, Rotterdam, The Netherlands; Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands
| | - Everson Nogoceke
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Anneke I den Hollander
- Department of Ophthalmology, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behavior, Nijmegen, The Netherlands; Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Imre Lengyel
- Centre for Experimental Medicine, Queen's University Belfast, Belfast, United Kingdom.
| |
Collapse
|
42
|
Lam M, Mast N, Pikuleva IA. Drugs and Scaffold That Inhibit Cytochrome P450 27A1 In Vitro and In Vivo. Mol Pharmacol 2017; 93:101-108. [PMID: 29192124 DOI: 10.1124/mol.117.110742] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Accepted: 11/27/2017] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 27A1 (CYP27A1) is a ubiquitous enzyme that hydroxylates cholesterol and other sterols. Complete CYP27A1 deficiency owing to genetic mutations is detrimental to human health, whereas 50% of activity retention is not and does not affect the whole body cholesterol levels. CYP27A1 is considered a potential therapeutic target in breast cancer and age-related neurodegenerative diseases; however, CYP27A1 inhibition should be ≤50%. Herein, 131 pharmaceuticals were tested for their effect on CYP27A1-mediated cholesterol 27-hydroxylation by in vitro enzyme assay. Of them, 14 drugs inhibited CYP27A1 by ≥75% and were evaluated for in vitro binding to the enzyme active site and for inhibition constants. All drugs except one (dasatinib) elicited a spectral response in CYP27A1 and had Ki values for cholesterol 27-hydroxylation either in the submicromolar (clevidipine, delavirdine, etravirine, felodipine, nicardipine, nilotinib, and sorafenib) or low micromolar range (abiratone, candesartan, celecoxib, dasatinib, nilvadipine, nimodipine, and regorafenib). Clevidipine, felodipine, nicardipine, nilvadipine, and nimodipine have the same 1,4-dihydropyridine scaffold and are indicated for hypertension. We used two of these antihypertensives (felodipine and nilvadipine) for administration to mice at a 1-mg/kg of body weight dose, daily, for 7 days. Mouse 27-hydroxycholesterol levels in the plasma, brain, and liver were reduced, whereas tissue levels of total cholesterol were unchanged. Structure-activity relationships within the 1,4-dihydropyridine scaffold were investigated, and features important for CY27A1 inhibition were identified. We confirmed our previous finding that CYP27A1 is a druggable enzyme and found additional drugs as well as the scaffold with potential for partial CYP27A1 inhibition in humans.
Collapse
Affiliation(s)
- Morrie Lam
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio
| | - Natalia Mast
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio
| | - Irina A Pikuleva
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio
| |
Collapse
|
43
|
Kim SJ, Kim JE, Kim YW, Kim JY, Park SY. Nutritional regulation of renal lipogenic factor expression in mice: comparison to regulation in the liver and skeletal muscle. Am J Physiol Renal Physiol 2017; 313:F887-F898. [DOI: 10.1152/ajprenal.00594.2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 05/08/2017] [Accepted: 05/18/2017] [Indexed: 12/16/2022] Open
Abstract
Regulation of lipogenesis by pathophysiological factors in the liver and skeletal muscle is well understood; however, regulation in the kidney is still unclear. To elucidate nutritional regulation of lipogenic factors in the kidney, we measured the renal expression of lipogenic transcriptional factors and enzymes during fasting and refeeding in chow-fed and high-fat-fed mice. We also examined the regulatory effect of the liver X receptor (LXR) on the expression of lipogenic factors. The renal gene expression of sterol regulatory element-binding protein (SREBP)-1c and fatty acid synthase (FAS) was reduced by fasting for 48 h and restored by refeeding, whereas the mRNA levels of forkhead box O (FOXO)1/3 were increased by fasting and restored by refeeding. Accordingly, protein levels of SREBP-1, FAS, and phosphorylated FOXO1/3 were reduced by fasting and restored by refeeding. The patterns of lipogenic factors expression in the kidney were similar to those in the liver and skeletal muscle. However, this phasic regulation of renal lipogenic gene expression was blunted in diet-induced obese mice. LXR agonist TO901317 increased the lipogenic gene expression and the protein levels of SREBP-1 precursor and FAS but not nuclear SREBP-1. Moreover, increases in insulin-induced gene mRNA and nuclear carbohydrate-responsive element binding protein (ChREBP) levels were observed in the TO901317-treated mice. These results suggest that the kidney shows flexible suppression and restoration of lipogenic factors following fasting and refeeding in lean mice, but this is blunted in obese mice. LXR is involved in the renal expression of lipogenic enzymes, and ChREBP may mediate the response.
Collapse
Affiliation(s)
- Suk-Jeong Kim
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea; and
- Smart-Aging Convergence Research Center, College of Medicine, Yeungnam University, Daegu, Republic of Korea
| | - Ji-Eun Kim
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea; and
- Smart-Aging Convergence Research Center, College of Medicine, Yeungnam University, Daegu, Republic of Korea
| | - Yong-Woon Kim
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea; and
| | - Jong-Yeon Kim
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea; and
| | - So-Young Park
- Department of Physiology, College of Medicine, Yeungnam University, Daegu, Republic of Korea; and
- Smart-Aging Convergence Research Center, College of Medicine, Yeungnam University, Daegu, Republic of Korea
| |
Collapse
|
44
|
Storti F, Raphael G, Griesser V, Klee K, Drawnel F, Willburger C, Scholz R, Langmann T, von Eckardstein A, Fingerle J, Grimm C, Maugeais C. Regulated efflux of photoreceptor outer segment-derived cholesterol by human RPE cells. Exp Eye Res 2017; 165:65-77. [PMID: 28943268 DOI: 10.1016/j.exer.2017.09.008] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 09/18/2017] [Indexed: 12/19/2022]
Abstract
Genetic studies have linked age-related macular degeneration (AMD) to genes involved in high-density lipoprotein (HDL) metabolism, including ATP-binding cassette transporter A1 (ABCA1). The retinal pigment epithelium (RPE) handles large amounts of lipids, among others cholesterol, partially derived from internalized photoreceptor outer segments (OS) and lipids physiologically accumulate in the aging eye. To analyze the potential function of ABCA1 in the eye, we measured cholesterol efflux, the first step of HDL generation, in RPE cells. We show the expression of selected genes related to HDL metabolism in mouse and human eyecups as well as in ARPE-19 and human primary RPE cells. Immunofluorescence staining revealed localization of ABCA1 on both sides of polarized RPE cells. This was functionally confirmed by directional efflux to apolipoprotein AI (ApoA-I) of 3H-labeled cholesterol given to the cells via serum or via OS. ABCA1 expression and activity was modulated using a liver-X-receptor (LXR) agonist and an ABCA1 neutralizing antibody, demonstrating that the efflux was ABCA1-dependent. We concluded that the ABCA1-mediated lipid efflux pathway, and hence HDL biosynthesis, is functional in RPE cells towards both the basal (choroidal) and apical (subretinal) space. Impaired activity of the pathway might cause age-related perturbations of lipid homeostasis in the outer retina and thus may contribute to disease development and/or progression.
Collapse
Affiliation(s)
- Federica Storti
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland
| | - Gabriele Raphael
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Vera Griesser
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Katrin Klee
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland
| | - Faye Drawnel
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Carolin Willburger
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Rebecca Scholz
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | | | - Jürgen Fingerle
- Natural and Medical Sciences Institute, University of Tübingen, Tübingen, Germany
| | - Christian Grimm
- Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Schlieren, Switzerland; Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland; Neuroscience Center Zurich (ZNZ), University of Zurich, Zurich, Switzerland.
| | - Cyrille Maugeais
- Roche Innovation Center Basel, F. Hoffmann-La Roche Ltd, Basel, Switzerland
| |
Collapse
|
45
|
Cheung CMG, Gan A, Fan Q, Chee ML, Apte RS, Khor CC, Yeo I, Mathur R, Cheng CY, Wong TY, Tai ES. Plasma lipoprotein subfraction concentrations are associated with lipid metabolism and age-related macular degeneration. J Lipid Res 2017; 58:1785-1796. [PMID: 28698208 PMCID: PMC5580892 DOI: 10.1194/jlr.m073684] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 07/06/2017] [Indexed: 01/09/2023] Open
Abstract
Disturbance in lipid metabolism has been suggested as a major pathogenic factor for age-related macular degeneration (AMD). Conventional lipid measures have been inconsistently associated with AMD. Other factors that can alter lipid metabolism include lipoprotein phenotype and genetic mutations. We performed a case-control study to examine the association between lipoprotein profile and neovascular AMD (nAMD) and whether the cholesterylester transfer protein (CETP) D442G mutation modulates these associations. Patients with nAMD had significantly higher concentrations of HDL and IDL compared with controls. The increase in HDL particles in nAMD patients was driven by an excess of medium-sized particles. Concurrently, patients with nAMD also had lower Apo A-1, lower VLDL and chylomicron lipoprotein. Many of these associations showed a dose-dependent association between controls, early AMD cases, and nAMD cases. Adjustment for the presence of the D442G mutation at the CETP locus did not significantly alter the increased AMD risk associated with HDL particle concentration. AMD is associated with variation in many lipoprotein subclasses, including increased HDL and IDL particles and decreased Apo A-1, VLDL, and chylomicron particles. These data suggest widespread systemic disturbance in lipid metabolism in the pathogenesis of AMD, including possible alterations in lipoprotein carrier capacity.
Collapse
Affiliation(s)
- Chui Ming Gemmy Cheung
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Ophthalmology and Visual Sciences Program, Duke-NUS Medical School, National University of Singapore, Singapore.
| | - Alfred Gan
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Qiao Fan
- Centre for Quantitative Medicine, Duke-NUS Medical School, National University of Singapore, Singapore
| | - Miao Ling Chee
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore
| | - Rajendra S Apte
- Ophthalmology and Visual Sciences, Developmental Biology and Medicine, Washington University School of Medicine, St. Louis, MO
| | | | - Ian Yeo
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmology and Visual Sciences Program, Duke-NUS Medical School, National University of Singapore, Singapore
| | - Ranjana Mathur
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmology and Visual Sciences Program, Duke-NUS Medical School, National University of Singapore, Singapore
| | - Ching-Yu Cheng
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Ophthalmology and Visual Sciences Program, Duke-NUS Medical School, National University of Singapore, Singapore
| | - Tien Yin Wong
- Singapore Eye Research Institute, Singapore National Eye Centre, Singapore; Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore; Ophthalmology and Visual Sciences Program, Duke-NUS Medical School, National University of Singapore, Singapore
| | - E Shyong Tai
- Department of Medicine, Cardiovascular and Metabolic Disorders Programme, National University of Singapore, Singapore
| |
Collapse
|
46
|
Genetic background influences susceptibility to chemotherapy-induced hematotoxicity. THE PHARMACOGENOMICS JOURNAL 2017; 18:319-330. [PMID: 28607509 PMCID: PMC5729066 DOI: 10.1038/tpj.2017.23] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Revised: 04/26/2017] [Accepted: 05/01/2017] [Indexed: 12/23/2022]
Abstract
Hematotoxicity is a life-threatening side effect of many chemotherapy regimens. While clinical factors influence patient responses, genetic factors may also play an important role. We sought to identify genomic loci that influence chemotherapy-induced hematotoxicity by dosing Diversity Outbred mice with one of three chemotherapy drugs; doxorubicin, cyclophosphamide or docetaxel. We observed that each drug had a distinct effect on both the changes in blood cell sub-populations and the underlying genetic architecture of hematotoxicity. For doxorubicin, we mapped the change in cell counts before and after dosing and found that alleles of ATP-binding cassette B1B (Abcb1b) on chromosome 5 influence all cell populations. For cyclophosphamide and docetaxel, we found that each cell population was influenced by distinct loci, none of which overlapped between drugs. These results suggest that susceptibility to chemotherapy-induced hematotoxicity is influenced by different genes for different chemotherapy drugs.
Collapse
|
47
|
Hammer SS, Busik JV. The role of dyslipidemia in diabetic retinopathy. Vision Res 2017; 139:228-236. [PMID: 28545981 DOI: 10.1016/j.visres.2017.04.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/06/2017] [Accepted: 04/13/2017] [Indexed: 02/08/2023]
Abstract
Diabetic retinopathy (DR) affects over 93million people worldwide and is the number one cause of blindness among working age adults. These indicators coupled with the projected rise of patients diagnosed with diabetes, makes DR a serious and prevalent vision threating disease. Data from recent clinical trials demonstrate that in addition to the well accepted role of hyperglycemia, dyslipidemia is an important, but often overlooked factor in the development of DR. The central aim of this review article is to showcase the critical role of dyslipidemia in DR progression as well as highlight novel therapeutic solutions that take advantage of the vital roles lipid metabolism plays in DR progression.
Collapse
Affiliation(s)
- Sandra S Hammer
- Department of Physiology, Michigan State University, East Lansing, MI, United States
| | - Julia V Busik
- Department of Physiology, Michigan State University, East Lansing, MI, United States.
| |
Collapse
|
48
|
Potential protective function of the sterol regulatory element binding factor 1-fatty acid desaturase 1/2 axis in early-stage age-related macular degeneration. Heliyon 2017; 3:e00266. [PMID: 28367511 PMCID: PMC5362043 DOI: 10.1016/j.heliyon.2017.e00266] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 03/06/2017] [Accepted: 03/09/2017] [Indexed: 12/12/2022] Open
Abstract
Age-related macular degeneration (AMD) is the most common cause of vision loss in elderly individuals throughout the developed world. Inhibitors of vascular endothelial growth factor have been successfully used to treat choroidal neovascularization in late-stage AMD. The pathogenesis of early-stage AMD, however, remains largely unknown, impairing efforts to develop effective therapies that prevent progression to late-stage AMD. To address this, we performed comparative transcriptomics of macular and extramacular retinal pigmented epithelium-choroid (RPE-choroid) tissue from early-stage AMD patients. We found that expression of fatty acid desaturase 1 (FADS1), FADS2, and acetyl-CoA acetyltransferase 2 (ACAT2) is increased in macular but not extramacular tissue, possibly through activation of sterol regulatory element binding factor 1 (SREBF1). Consistent with this, we also found that expression of Fads1 is increased in RPE-choroid in a mouse model of early-stage AMD. In zebrafish, deletion of fads2, which encodes a protein that functions as both Fads1 and Fads2 in other species, enhanced apoptosis in the retina upon exposure to intense light. Similarly, pharmacological inhibition of Srebf1 enhanced apoptosis and reduced fads2 expression in zebrafish exposed to intense light. These results suggest that the SREBF1-FADS1/2 axis may be activated in macular RPE-choroid as a protective response during early-stage AMD and could thus be a therapeutic target for early-stage AMD.
Collapse
|
49
|
Mast N, Anderson KW, Lin JB, Li Y, Turko IV, Tatsuoka C, Bjorkhem I, Pikuleva IA. Cytochrome P450 27A1 Deficiency and Regional Differences in Brain Sterol Metabolism Cause Preferential Cholestanol Accumulation in the Cerebellum. J Biol Chem 2017; 292:4913-4924. [PMID: 28190002 DOI: 10.1074/jbc.m116.774760] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2016] [Revised: 02/10/2017] [Indexed: 01/04/2023] Open
Abstract
Cytochrome P450 27A1 (CYP27A1 or sterol 27-hydroxylase) is a ubiquitous, multifunctional enzyme catalyzing regio- and stereospecific hydroxylation of different sterols. In humans, complete CYP27A1 deficiency leads to cerebrotendinous xanthomatosis or nodule formation in tendons and brain (preferentially in the cerebellum) rich in cholesterol and cholestanol, the 5α-saturated analog of cholesterol. In Cyp27a1-/- mice, xanthomas are not formed, despite a significant cholestanol increase in the brain and cerebellum. The mechanism behind cholestanol production has been clarified, yet little is known about its metabolism, except that CYP27A1 might metabolize cholestanol. It also is unclear why CYP27A1 deficiency results in preferential cholestanol accumulation in the cerebellum. We hypothesized that cholestanol might be metabolized by CYP46A1, the principal cholesterol 24-hydroxylase in the brain. We quantified sterols along with CYP27A1 and CYP46A1 in mouse models (Cyp27a1-/-, Cyp46a1-/-, Cyp27a1-/-Cyp46a1-/-, and two wild type strains) and human brain specimens. In vitro experiments with purified P450s were conducted as well. We demonstrate that CYP46A1 is involved in cholestanol removal from the brain and that several factors contribute to the preferential increase in cholestanol in the cerebellum arising from CYP27A1 deficiency. These factors include (i) low cerebellar abundance of CYP46A1 and high cerebellar abundance of CYP27A1, the lack of which probably selectively increases the cerebellar cholestanol production; (ii) spatial separation in the cerebellum of cholesterol/cholestanol-metabolizing P450s from a pool of metabolically available cholestanol; and (iii) weak cerebellar regulation of cholesterol biosynthesis. We identified a new physiological role of CYP46A1, an important brain enzyme and cytochrome P450 that could be activated pharmacologically.
Collapse
Affiliation(s)
- Natalia Mast
- From the Departments of Ophthalmology and Visual Sciences and
| | - Kyle W Anderson
- the Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.,the Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, and
| | - Joseph B Lin
- From the Departments of Ophthalmology and Visual Sciences and
| | - Yong Li
- From the Departments of Ophthalmology and Visual Sciences and
| | - Illarion V Turko
- the Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.,the Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, and
| | - Curtis Tatsuoka
- Neurology, Case Western Reserve University, Cleveland, Ohio 44106
| | - Ingemar Bjorkhem
- the Division of Clinical Chemistry, Department of Laboratory Medicine, Karolinska Institute, 141 86 Huddinge, Sweden
| | | |
Collapse
|
50
|
Zarubina AV, Neely DC, Clark ME, Huisingh CE, Samuels BC, Zhang Y, McGwin G, Owsley C, Curcio CA. Reply. Ophthalmology 2017; 124:e20-e21. [PMID: 28126088 PMCID: PMC6052762 DOI: 10.1016/j.ophtha.2016.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 05/13/2016] [Indexed: 11/17/2022] Open
Affiliation(s)
- Anna V Zarubina
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - David C Neely
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Mark E Clark
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Carrie E Huisingh
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama
| | - Brian C Samuels
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Yuhua Zhang
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Gerald McGwin
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama; Department of Epidemiology, School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama
| | - Cynthia Owsley
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Christine A Curcio
- Department of Ophthalmology, School of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.
| |
Collapse
|