1
|
Karmoker JR, Bounds SE, Cai J. Aryl hydrocarbon receptor (AhR)-mediated immune responses to degeneration of the retinal pigment epithelium. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167351. [PMID: 39004382 PMCID: PMC11330344 DOI: 10.1016/j.bbadis.2024.167351] [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: 03/07/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/16/2024]
Abstract
Injuries to the retinal pigment epithelium (RPE) trigger immune responses, orchestrating interactions within the innate and adaptive immune systems in the outer retina and choroid. We previously reported that interleukin 17 (IL-17) is a pivotal signaling molecule originating from choroidal γδ T cells, exerting protective effects by mediating functional connections between the RPE and subretinal microglia. In this current study, we generated mice with aryl hydrocarbon receptor (AhR) knockout specifically in IL-17-producing cells. These animals had deficiency in IL-17 production from γδ T cells, and exhibited increased sensitivity to both acute and chronic insults targeting the RPE. These findings imply that IL-17 plays a crucial role as a signaling cytokine in preserving the homeostasis of the outer retina and choroid.
Collapse
Affiliation(s)
- James Regun Karmoker
- Department of Biochemistry & Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Sarah E Bounds
- Department of Biochemistry & Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| | - Jiyang Cai
- Department of Biochemistry & Physiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA; Dean McGee Eye Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
| |
Collapse
|
2
|
Becker S, L'Ecuyer Z, Jones BW, Zouache MA, McDonnell FS, Vinberg F. Modeling complex age-related eye disease. Prog Retin Eye Res 2024; 100:101247. [PMID: 38365085 PMCID: PMC11268458 DOI: 10.1016/j.preteyeres.2024.101247] [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: 08/15/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/18/2024]
Abstract
Modeling complex eye diseases like age-related macular degeneration (AMD) and glaucoma poses significant challenges, since these conditions depend highly on age-related changes that occur over several decades, with many contributing factors remaining unknown. Although both diseases exhibit a relatively high heritability of >50%, a large proportion of individuals carrying AMD- or glaucoma-associated genetic risk variants will never develop these diseases. Furthermore, several environmental and lifestyle factors contribute to and modulate the pathogenesis and progression of AMD and glaucoma. Several strategies replicate the impact of genetic risk variants, pathobiological pathways and environmental and lifestyle factors in AMD and glaucoma in mice and other species. In this review we will primarily discuss the most commonly available mouse models, which have and will likely continue to improve our understanding of the pathobiology of age-related eye diseases. Uncertainties persist whether small animal models can truly recapitulate disease progression and vision loss in patients, raising doubts regarding their usefulness when testing novel gene or drug therapies. We will elaborate on concerns that relate to shorter lifespan, body size and allometries, lack of macula and a true lamina cribrosa, as well as absence and sequence disparities of certain genes and differences in their chromosomal location in mice. Since biological, rather than chronological, age likely predisposes an organism for both glaucoma and AMD, more rapidly aging organisms like small rodents may open up possibilities that will make research of these diseases more timely and financially feasible. On the other hand, due to the above-mentioned anatomical and physiological features, as well as pharmacokinetic and -dynamic differences small animal models are not ideal to study the natural progression of vision loss or the efficacy and safety of novel therapies. In this context, we will also discuss the advantages and pitfalls of alternative models that include larger species, such as non-human primates and rabbits, patient-derived retinal organoids, and human organ donor eyes.
Collapse
Affiliation(s)
- Silke Becker
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Zia L'Ecuyer
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Bryan W Jones
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Moussa A Zouache
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA
| | - Fiona S McDonnell
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA
| | - Frans Vinberg
- John A. Moran Eye Center, University of Utah, Salt Lake City, UT, USA; Biomedical Engineering, University of Utah, Salt Lake City, UT, USA.
| |
Collapse
|
3
|
Kim HJ, Zhao J, Walewski JL, Sparrow JR. A High Fat Diet Fosters Elevated Bisretinoids. J Biol Chem 2023; 299:104784. [PMID: 37146972 DOI: 10.1016/j.jbc.2023.104784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 04/28/2023] [Accepted: 04/29/2023] [Indexed: 05/07/2023] Open
Abstract
High dietary fat intake is associated with metabolic dysregulation, but little is known regarding the effects of a high fat diet (HFD) on photoreceptor cell functioning. We explored the intersection of a high fat diet (HFD) and the visual cycle adducts that form in photoreceptor cells by non-enzymatic reactions. In black C57BL/6J mice and albino C57BL/6Jc2j mice raised on a high fat diet until age 3, 6 or 12 months, chromatographically quantified bisretinoids were increased relative to mice on a standard diet. In vivo measurement of fundus autofluorescence, the source of which is bisretinoid, also revealed a significant increase in the HFD-mice. Additionally, mice provided with a diet high in fat presented with elevated retinol-binding protein 4 (RBP4) the protein responsible for transporting retinol in plasma. Vitamin A was elevated in plasma although not in ocular tissue. Bisretinoids form in photoreceptor cell outer segments by random reactions of retinaldehyde with phosphatidylethanolamine. We found that the latter phospholipid was significantly increased in mice fed a HFD versus mice on a control diet. In leptin-deficient ob/ob mice, a genetic model of obesity, plasma levels of Rbp4 protein were higher but bisretinoids in retina were not elevated. Photoreceptor cell viability measured as outer nuclear layer thickness was reduced in the ob/ob mice relative to wild-type. The accelerated formation of bisretinoid we observed in diet induced obese mice is related to the high fat intake and to increased delivery of vitamin A to the visual cycle.
Collapse
Affiliation(s)
- Hye Jin Kim
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Jin Zhao
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Jose L Walewski
- Departments of Medicine, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032
| | - Janet R Sparrow
- Departments of Ophthalmology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032; Departments of Pathology and Cell Biology, Columbia University Medical Center, 635 W. 165(th) Street, New York NY, 10032.
| |
Collapse
|
4
|
Lin Y, Peng T, Li Y, Liu Y. The frequency of early age-related macular degeneration and its relationship with dietary pattern in Hunan, China: a cross-sectional study. BMC Ophthalmol 2022; 22:324. [PMID: 35896997 PMCID: PMC9327240 DOI: 10.1186/s12886-022-02549-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Accepted: 07/22/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE To estimate the frequency of age-related macular degeneration (AMD) among people who underwent health examination in Hunan, China and to determine the relationship between dietary pattern and the risk of AMD. METHODS The Questionnaire was used to collect dietary data from 56,775 study participants of ≥ 50 years old who underwent health examination at the Department of Health Management, the Third Xiangya Hospital of Central South University between January 2017 and December 2019. The diagnosis of AMD was based on the results of color fundus photography (CFP), spectral-domain optical coherence tomography (OCT) and multispectral imaging (MSI). After excluding participants with incomplete records or other ocular disease that may affect the results of fundus examination, a total of 43,672 study participants were included. The univariate and multivariate logistic regression analyses were used to determine the relationship between dietary pattern and the frequency of AMD. RESULTS Among the 43,672 study participants, 1080 (2.5%) had early AMD: the frequencies were 2.6% (n = 674) in men and 2.3% (n = 406) in women; the frequencies were 1.0% (n = 289), 3.6% (n = 401), 9.1% (n = 390) in 50-59, 60-69, ≥ 70 years old, respectively. And the age-standard frequency was 6.6% over the 60 years old in Hunan China. The high-salt intake increased the risk of early AMD [odds ratio (OR) = 1.61, 95% confidence interval (CI) = 1.54-1.68], whereas the intake of meat decreased the risk (OR = 0.90, 95% CI = 0.81-0.99). CONCLUSION In Hunan China, there was a high frequency of early AMD detected through health examination over the 60 years old. And high-salt intake increases the risk of early AMD, whereas intake of meat decreases the risk. Modulating the dietary pattern and reducing the salt intake as an AMD prevention strategy warrant further study.
Collapse
Affiliation(s)
- Yanhui Lin
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ting Peng
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Ying Li
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yu Liu
- Department of Ophthalmology, The Third Xiangya Hospital, Central South University, Street address: No.138,Tongzipo Road,Yuelu District, Hunan, 410013, Changsha, China.
| |
Collapse
|
5
|
High-Fat Diet Alters the Retinal Pigment Epithelium and Choroidal Transcriptome in the Absence of Gut Microbiota. Cells 2022; 11:cells11132076. [PMID: 35805160 PMCID: PMC9266037 DOI: 10.3390/cells11132076] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/22/2022] [Accepted: 06/22/2022] [Indexed: 02/04/2023] Open
Abstract
Relationships between retinal disease, diet, and the gut microbiome have started to emerge. In particular, high-fat diets (HFDs) are associated with the prevalence and progression of several retinal diseases, including age-related macular degeneration (AMD) and diabetic retinopathy (DR). These effects are thought to be partly mediated by the gut microbiome, which modulates interactions between diet and host homeostasis. Nevertheless, the effects of HFDs on the retina and adjacent retinal pigment epithelium (RPE) and choroid at the transcriptional level, independent of gut microbiota, are not well-understood. In this study, we performed the high-throughput RNA-sequencing of germ-free (GF) mice to explore the transcriptional changes induced by HFD in the RPE/choroid. After filtering and cleaning the data, 649 differentially expressed genes (DEGs) were identified, with 616 genes transcriptionally upregulated and 33 genes downregulated by HFD compared to a normal diet (ND). Enrichment analysis for gene ontology (GO) using the DEGs was performed to analyze over-represented biological processes in the RPE/choroid of GF-HFD mice relative to GF-ND mice. GO analysis revealed the upregulation of processes related to angiogenesis, immune response, and the inflammatory response. Additionally, molecular functions that were altered involved extracellular matrix (ECM) binding, ECM structural constituents, and heparin binding. This study demonstrates novel data showing that HFDs can alter RPE/choroid tissue transcription in the absence of the gut microbiome.
Collapse
|
6
|
Allingham MJ, Mettu PS, Cousins SW. Phase 1 Clinical Trial of Elamipretide in Intermediate Age-Related Macular Degeneration and High-Risk Drusen. OPHTHALMOLOGY SCIENCE 2022; 2:100095. [PMID: 36246187 PMCID: PMC9560633 DOI: 10.1016/j.xops.2021.100095] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 10/29/2021] [Accepted: 12/06/2021] [Indexed: 11/25/2022]
Abstract
Purpose To assess safety, tolerability, and feasibility of subcutaneous administration of the mitochondrial-targeted drug elamipretide in patients with intermediate age-related macular degeneration (AMD) and high-risk drusen (HRD) and to perform exploratory analyses of change in visual function. Design Phase 1, single-center, open-label, 24-week clinical trial with preplanned HRD cohort. Participants Adult patients ≥55 years of age with intermediate AMD and HRD. Methods Participants received subcutaneous elamipretide 40 mg daily, with safety and tolerability assessed throughout the study. Ocular assessments included normal-luminance best-corrected visual acuity (BCVA), low-luminance best-corrected visual acuity (LLVA), normal-luminance binocular reading acuity (NLRA), low-luminance binocular reading acuity (LLRA), spectral-domain OCT, fundus autofluorescence (FAF), mesopic microperimetry, dark adaptation, and low-luminance questionnaire (LLQ). Main Outcome Measures The primary end point was safety and tolerability. Prespecified exploratory end points included changes from baseline in BCVA, LLVA, NLRA, LLRA, retinal pigment epithelium (RPE)-drusen complex (DC) volume by OCT, FAF, mesopic microperimetry, dark adaptation, and LLQ results. Results Subcutaneous administration of elamipretide was highly feasible. All participants with HRD (n = 21) experienced 1 or more adverse events (AEs), but all were mild (57%) or moderate (43%), with the most common events related to injection site reactions. No serious systemic AEs occurred. One participant discontinued because of injection site reaction, 1 participant withdrew because they did not wish to continue study visits, and 1 participant withdrew after experiencing transient visual impairment. Among the 18 participants who completed the study, mean change in BCVA from baseline to 24 weeks was +3.6 letters (P = 0.014) and LLVA was +5.6 letters (P = 0.004). Compared with baseline, mean NLRA improved by –0.11 logarithm of the minimum angle of resolution (logMAR) units (P = 0.001), and LLRA by −0.28 logMAR units (P < 0.0001). Significant improvements were found in 6 of 7 subscales of the LLQ (P<0.0015). No significant changes were observed for RPE-DC volume, FAF, mesopic microperimetry, or dark adaptation. Conclusions Elamipretide appeared to be generally safe and well tolerated in treating intermediate AMD and HRD. Exploratory analyses demonstrate a positive effect on visual function, particularly under low-luminance conditions. Further study of elamipretide for treatment of intermediate AMD with HRD is warranted.
Collapse
|
7
|
Kim YK, Hong HK, Yoo HS, Park SP, Park KH. AICAR upregulates ABCA1/ABCG1 expression in the retinal pigment epithelium and reduces Bruch's membrane lipid deposit in ApoE deficient mice. Exp Eye Res 2021; 213:108854. [PMID: 34808137 DOI: 10.1016/j.exer.2021.108854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 11/26/2022]
Abstract
The etiology of age-related macular degeneration (AMD) is diverse; however, recent evidence suggests that the lipid metabolism-cholesterol pathway might be associated with the pathophysiology of AMD. The ATP-binding cassette (ABC) transporters, ABCA1 and ABCG1, are essential for the formation of high-density lipoprotein (HDL) and the regulation of macrophage cholesterol efflux. The failure of retinal or retinal pigment epithelium (RPE) cholesterol efflux to remove excess intracellular lipids causes morphological and functional damage to the retina. In this study, we investigated whether treatment with 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), an AMP-activated protein kinase (AMPK) activator, improves RPE cholesterol efflux and Bruch's membrane (BM) lipid deposits. The protein and mRNA levels of ABCA1 and ABCG1 in ARPE-19 cells and retinal and RPE/choroid tissue from apolipoprotein E-deficient (ApoE-/-) mice were evaluated after 24 weeks of AICAR treatment. The cholesterol efflux capacity of ARPE-19 cells and the cholesterol-accepting capacity of apoB-depleted serum from mice were measured. The thickness of the BM and the degree of lipid deposition were evaluated using electron microscopy. AICAR treatment increased the phosphorylation of AMPK and the protein and mRNA expression of ABCA1 and ABCG1 in vitro. It promoted cholesterol efflux from ARPE-19 cells and upregulated the protein and mRNA levels of ABCA1 and ABCG1 in the retina and RPE in vivo. ApoB-depleted serum from the AICAR-treated group showed enhanced cholesterol-accepting capacity. Long-term treatment with AICAR reduced BM thickening and lipid deposition in ApoE-/- mice. In conclusion, AICAR treatment increased the expression of lipid transporters in the retina and RPE in vivo, facilitated intracellular cholesterol efflux from the RPE in vitro, and improved the functionality of HDL to accept cholesterol effluxed from the cell, possibly via AMPK activation. Collectively, these effects might contribute to the improvement of early age-related pathologic changes in the BM. Pharmacological improvement of RPE cholesterol efflux via AMPK activation may be a potential treatment strategy for AMD.
Collapse
Affiliation(s)
- Yong-Kyu Kim
- Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea
| | - Hye Kyoung Hong
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, South Korea
| | - Hyo Soon Yoo
- Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Bundang Hospital, Seongnam, South Korea; Department of Otorhinolaryngology-Head and Neck Surgery, Seoul National University Hospital, Seoul, South Korea
| | - Sung Pyo Park
- Department of Ophthalmology, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, South Korea.
| | - Kyu Hyung Park
- Department of Ophthalmology, Seoul National University Bundang Hospital, Seongnam, South Korea; Department of Ophthalmology, Seoul National University College of Medicine, Seoul, South Korea.
| |
Collapse
|
8
|
Blasiak J, Szczepanska J, Fila M, Pawlowska E, Kaarniranta K. Potential of Telomerase in Age-Related Macular Degeneration-Involvement of Senescence, DNA Damage Response and Autophagy and a Key Role of PGC-1α. Int J Mol Sci 2021; 22:ijms22137194. [PMID: 34281248 PMCID: PMC8268995 DOI: 10.3390/ijms22137194] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Revised: 06/29/2021] [Accepted: 07/01/2021] [Indexed: 02/07/2023] Open
Abstract
Age-related macular degeneration (AMD), the main cause of vision loss in the elderly, is associated with oxidation in the retina cells promoting telomere attrition. Activation of telomerase was reported to improve macular functions in AMD patients. The catalytic subunit of human telomerase (hTERT) may directly interact with proteins important for senescence, DNA damage response, and autophagy, which are impaired in AMD. hTERT interaction with mTORC1 (mTOR (mechanistic target of rapamycin) complex 1) and PINK1 (PTEN-induced kinase 1) activates macroautophagy and mitophagy, respectively, and removes cellular debris accumulated over AMD progression. Ectopic expression of telomerase in retinal pigment epithelium (RPE) cells lengthened telomeres, reduced senescence, and extended their lifespan. These effects provide evidence for the potential of telomerase in AMD therapy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) may be involved in AMD pathogenesis through decreasing oxidative stress and senescence, regulation of vascular endothelial growth factor (VEGF), and improving autophagy. PGC-1α and TERT form an inhibitory positive feedback loop. In conclusion, telomerase activation and its ectopic expression in RPE cells, as well as controlled clinical trials on the effects of telomerase activation in AMD patients, are justified and should be assisted by PGC-1α modulators to increase the therapeutic potential of telomerase in AMD.
Collapse
Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, Faculty of Biology and Environmental Protection, University of Lodz, Pomorska 141/143, 90-236 Lodz, Poland
- Correspondence: (J.B.); (K.K.)
| | - Joanna Szczepanska
- Department of Pediatric Dentistry, Medical University of Lodz, 92-216 Lodz, Poland;
| | - Michal Fila
- Department of Developmental Neurology and Epileptology, Polish Mother’s Memorial Hospital Research Institute, 93-338 Lodz, Poland;
| | - Elzbieta Pawlowska
- Department of Orthodontics, Medical University of Lodz, 92-217 Lodz, Poland;
| | - Kai Kaarniranta
- Department of Ophthalmology, University of Eastern Finland, 70210 Kuopio, Finland
- Department of Ophthalmology, Kuopio University Hospital, 70210 Kuopio, Finland
- Correspondence: (J.B.); (K.K.)
| |
Collapse
|
9
|
Clarkson-Townsend DA, Douglass AJ, Singh A, Allen RS, Uwaifo IN, Pardue MT. Impacts of high fat diet on ocular outcomes in rodent models of visual disease. Exp Eye Res 2021; 204:108440. [PMID: 33444582 PMCID: PMC7946735 DOI: 10.1016/j.exer.2021.108440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 12/23/2020] [Accepted: 01/05/2021] [Indexed: 02/08/2023]
Abstract
High fat diets (HFD) have been utilized in rodent models of visual disease for over 50 years to model the effects of lipids, metabolic dysfunction, and diet-induced obesity on vision and ocular health. HFD treatment can recapitulate the pathologies of some of the leading causes of blindness, such as age-related macular degeneration (AMD) and diabetic retinopathy (DR) in rodent models of visual disease. However, there are many important factors to consider when using and interpreting these models. To synthesize our current understanding of the importance of lipid signaling, metabolism, and inflammation in HFD-driven visual disease processes, we systematically review the use of HFD in mouse and rat models of visual disease. The resulting literature is grouped into three clusters: models that solely focus on HFD treatment, models of diabetes that utilize both HFD and streptozotocin (STZ), and models of AMD that utilize both HFD and genetic models and/or other exposures. Our findings show that HFD profoundly affects vision, retinal function, many different ocular tissues, and multiple cell types through a variety of mechanisms. We delineate how HFD affects the cornea, lens, uvea, vitreous humor, retina, retinal pigmented epithelium (RPE), and Bruch's membrane (BM). Furthermore, we highlight how HFD impairs several retinal cell types, including glia (microglia), retinal ganglion cells, bipolar cells, photoreceptors, and vascular support cells (endothelial cells and pericytes). However, there are a number of gaps, limitations, and biases in the current literature. We highlight these gaps and discuss experimental design to help guide future studies. Very little is known about how HFD impacts the lens, ciliary bodies, and specific neuronal populations, such as rods, cones, bipolar cells, amacrine cells, and retinal ganglion cells. Additionally, sex bias is an important limitation in the current literature, with few HFD studies utilizing female rodents. Future studies should use ingredient-matched control diets (IMCD), include both sexes in experiments to evaluate sex-specific outcomes, conduct longitudinal metabolic and visual measurements, and capture acute outcomes. In conclusion, HFD is a systemic exposure with profound systemic effects, and rodent models are invaluable in understanding the impacts on visual and ocular disease.
Collapse
Affiliation(s)
- Danielle A Clarkson-Townsend
- Gangarosa Department of Environmental Health, Emory University, Atlanta, GA, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Amber J Douglass
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA
| | - Anayesha Singh
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Emory Center for Ethics, Emory University, Atlanta, GA, USA
| | - Rachael S Allen
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA
| | - Ivie N Uwaifo
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Neuroscience, Emory University, Atlanta, GA, USA
| | - Machelle T Pardue
- Center for Visual and Neurocognitive Rehabilitation, Atlanta VA Healthcare System, Decatur, GA, USA; Department of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, GA, USA.
| |
Collapse
|
10
|
CXCR5/NRF2 double knockout mice develop retinal degeneration phenotype at early adult age. Exp Eye Res 2020; 196:108061. [PMID: 32387618 DOI: 10.1016/j.exer.2020.108061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/14/2020] [Accepted: 05/02/2020] [Indexed: 12/24/2022]
Abstract
The objective of this study is to characterize the retinal degeneration (RD) phenotype of CXCR5/NRF2 double knockout (DKO) mice at the early adult age. CXCR5 KO mice and NRF2 KO mice were bred to create CXCR5/NRF2 DKO mice. The assessment of RD features included fundus and optical coherence tomography (OCT) imaging, periodic acid-Schiff (PAS), and immunofluorescence staining of retinal pigment epithelium (RPE)-choroid flatmounts. Stained samples were imaged with fluorescent microscopy, and Western blots were used to monitor protein expression changes. The staining of cleaved caspase-3 and PNA-lectin was performed to assess the presence of photoreceptor cell apoptosis. Quantification and statistical analyses were performed with Image J and Graphpad software. The young adult (2-6 months) DKO mice exhibited increased hypopigmented spots on fundus and sub-RPE abnormalities on OCT as compared to the CXCR5-KO mice, and C57BL6 WT controls. PAS-stained sections demonstrated aberrant RPE/sub-RPE depositions. The DKO mice had increased sub-RPE depositions of IgG and AMD-associated proteins (β-amyloid, Apolipoprotein-E, C5b-9, and αB-crystallin). The protein expression of AMD-associated proteins and microglia marker (TMEM119) were upregulated at the RPE/BM/choroid complex of DKO mice. The adult DKO mice underwent photoreceptor cell apoptosis compared to the single CXCR5 and NRF2 KO and the WT mice at an early adult age. Mechanistically increased expression of CXCL13 and N-cadherin was observed as a sign of epithelial-mesenchymal transition. The data suggest that the CXCR5/NRF2-DKO mice develop RD characteristics at an early age and may serve as a valuable animal model of RD.
Collapse
|
11
|
Zhu Y, Aredo B, Chen B, Zhao CX, He YG, Ufret-Vincenty RL. Mice With a Combined Deficiency of Superoxide Dismutase 1 (Sod1), DJ-1 (Park7), and Parkin (Prkn) Develop Spontaneous Retinal Degeneration With Aging. Invest Ophthalmol Vis Sci 2020; 60:3740-3751. [PMID: 31487745 PMCID: PMC6733419 DOI: 10.1167/iovs.19-27212] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Chronic oxidative stress is an important mechanism of disease in aging disorders. We do not have a good model to recapitulate AMD and other retinal disorders in which chronic oxidative stress plays an important role. We hypothesized that mice with a combined deficiency in superoxide dismutase 1 (Sod1), DJ-1 (Park-7), and Parkin (Prkn) (triple knock out, TKO) would have an increased level of chronic oxidative stress in the retina, with anatomic and functional consequences just with aging. Methods Eyes of TKO and B6J control mice were (1) monitored with optical coherence tomography (OCT) and electroretinography (ERG) over time, and (2) collected for oxidative marker protein analysis by ELISA or immunohistochemistry and for transmission electron microscopy studies. Results TKO mice developed qualitative disruptions in outer retinal layers in OCT by 3 months, increased accumulation of fundus spots and subretinal microglia by 6 months of age, significant retinal thinning by 9 months, and decreased ERG signal by 12 months. Furthermore, we found increased accumulation of the oxidative marker malondialdehyde (MDA) in the retina and increased basal laminal deposits (BLD) and mitochondria number and size in the retinal pigment epithelium of aging TKO mice. Conclusions TKO mice can serve as a platform to study retinal diseases that involve chronic oxidative stress, including macular degeneration, retinal detachment, and ischemic retinopathies. In order to model each of these diseases, additional disease-specific catalysts or triggers could be superimposed onto the TKO mice. Such studies could provide better insight into disease mechanisms and perhaps lead to new therapeutic approaches.
Collapse
Affiliation(s)
- Yuanfei Zhu
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Bogale Aredo
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Bo Chen
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Cynthia X Zhao
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | - Yu-Guang He
- Department of Ophthalmology, UT Southwestern Medical Center, Dallas, Texas, United States
| | | |
Collapse
|
12
|
Yang C, Xie L, Gu Q, Qiu Q, Wu X, Yin L. 7-Ketocholesterol disturbs RPE cells phagocytosis of the outer segment of photoreceptor and induces inflammation through ERK signaling pathway. Exp Eye Res 2019; 189:107849. [DOI: 10.1016/j.exer.2019.107849] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 10/13/2019] [Accepted: 10/18/2019] [Indexed: 10/25/2022]
|
13
|
Panagiotou M, Deboer T. Chronic high-caloric diet accentuates age-induced sleep alterations in mice. Behav Brain Res 2019; 362:131-139. [PMID: 30639608 DOI: 10.1016/j.bbr.2019.01.017] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 01/09/2019] [Accepted: 01/10/2019] [Indexed: 11/15/2022]
Abstract
Obesity and sleep disturbances comprise major health problems which are likely interrelated. Diet-induced obesity in young mice has been demonstrated to lead towards an altered sleep homeostasis. In the current study, we investigated the effect of chronic (12 weeks) high-caloric diet (HCD, 45% fat) consumption on sleep and the sleep electroencephalogram (EEG) in young and older mice (6-month-old, n = 9; 18-month-old, n = 8 and 24-month-old, n = 4) and compared with age-matched controls on normal chow (n = 11, n = 9 and n = 9 respectively). Half of the 24-month-old mice did not cope well with HCD, therefore this group has a lower n and limited statistical power. We recorded EEG and the electromyogram for continuous 48-h and performed a 6-h sleep deprivation during the second day. In aged HCD fed mice (18 months old) compared to young, an aging effect was still evident, characterized by decreased waking and increased NREM sleep in the dark period, decreased REM sleep during the light period, as well as increased slow-wave-activity (SWA, EEG power in NREM sleep in 0.5-4.0 Hz). Additionally, aged HCD treated mice showed increased NREM sleep and decreased waking, compared to age-matched controls, denoting an enhanced aging phenotype in the sleep architecture. Notably, an overall increase was found in the slow component of SWA (0.5-2.5 Hz) in aged HCD fed mice compared to age-matched controls. Our data suggest that the effect of aging is the dominant variable irrespective of diet. However, a synergistic effect of aging and diet is noted indicating that chronic HCD consumption exacerbates age-associated sleep alterations.
Collapse
Affiliation(s)
- M Panagiotou
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Centre, Leiden, the Netherlands
| | - T Deboer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Centre, Leiden, the Netherlands.
| |
Collapse
|
14
|
Baksheeva VE, Tiulina VV, Tikhomirova NK, Gancharova OS, Komarov SV, Philippov PP, Zamyatnin AA, Senin II, Zernii EY. Suppression of Light-Induced Oxidative Stress in the Retina by Mitochondria-Targeted Antioxidant. Antioxidants (Basel) 2018; 8:E3. [PMID: 30577635 PMCID: PMC6356525 DOI: 10.3390/antiox8010003] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/03/2018] [Accepted: 12/13/2018] [Indexed: 01/06/2023] Open
Abstract
Light-induced oxidation of lipids and proteins provokes retinal injuries and results in progression of degenerative retinal diseases, such as, for instance, iatrogenic photic maculopathies. Having accumulated over years retinal injuries contribute to development of age-related macular degeneration (AMD). Antioxidant treatment is regarded as a promising approach to protecting the retina from light damage and AMD. Here, we examine oxidative processes induced in rabbit retina by excessive light illumination with or without premedication using mitochondria-targeted antioxidant SkQ1 (10-(6'-plastoquinonyl)decyltriphenyl-phosphonium). The retinal extracts obtained from animals euthanized within 1⁻7 days post exposure were analyzed for H₂O₂, malondialdehyde (MDA), total antioxidant activity (AOA), and activities of glutathione peroxidase (GPx) and superoxide dismutase (SOD) using colorimetric and luminescence assays. Oxidation of visual arrestin was monitored by immunoblotting. The light exposure induced lipid peroxidation and H₂O₂ accumulation in the retinal cells. Unexpectedly, it prominently upregulated AOA in retinal extracts although SOD and GPx activities were compromised. These alterations were accompanied by accumulation of disulfide dimers of arrestin revealing oxidative stress in the photoreceptors. Premedication of the eyes with SkQ1 accelerated normalization of H₂O₂ levels and redox-status of lipids and proteins, contemporarily enhancing AOA and, likely, sustaining normal activity of GPx. Thus, SkQ1 protects the retina from light-induced oxidative stress and could be employed to suppress oxidative damage of proteins and lipids contributing to AMD.
Collapse
Affiliation(s)
- Viktoriia E Baksheeva
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Veronika V Tiulina
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Natalia K Tikhomirova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Olga S Gancharova
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
- Institute for Regenerative Medicine, Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| | - Sergey V Komarov
- Department of Biology and Pathology of Domestic, Laboratory and Exotic Animals, Skryabin Moscow State Academy of Veterinary Medicine and Biotechnology, Moscow 109472, Russia.
| | - Pavel P Philippov
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Andrey A Zamyatnin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| | - Ivan I Senin
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
| | - Evgeni Yu Zernii
- Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow 119992, Russia.
- Institute of Molecular Medicine, Sechenov First Moscow State Medical University, Moscow 119991, Russia.
| |
Collapse
|
15
|
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
|
16
|
Zhang M, Chu Y, Mowery J, Konkel B, Galli S, Theos AC, Golestaneh N. Pgc-1α repression and high-fat diet induce age-related macular degeneration-like phenotypes in mice. Dis Model Mech 2018; 11:dmm.032698. [PMID: 29925537 PMCID: PMC6176989 DOI: 10.1242/dmm.032698] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2017] [Accepted: 06/13/2018] [Indexed: 12/28/2022] Open
Abstract
Age-related macular degeneration (AMD) is the major cause of blindness in the elderly in developed countries and its prevalence is increasing with the aging population. AMD initially affects the retinal pigment epithelium (RPE) and gradually leads to secondary photoreceptor degeneration. Recent studies have associated mitochondrial damage with AMD, and we have observed mitochondrial and autophagic dysfunction and repressed peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α; also known as Ppargc1a) in native RPE from AMD donor eyes and their respective induced pluripotent stem cell-derived RPE. To further investigate the effect of PGC-1α repression, we have established a mouse model by feeding Pgc-1α+/− mice with a high-fat diet (HFD) and investigated RPE and retinal health. We show that when mice expressing lower levels of Pgc-1α are exposed to HFD, they present AMD-like abnormalities in RPE and retinal morphology and function. These abnormalities include basal laminar deposits, thickening of Bruch's membrane with drusen marker-containing deposits, RPE and photoreceptor degeneration, decreased mitochondrial activity, increased levels of reactive oxygen species, decreased autophagy dynamics/flux, and increased inflammatory response in the RPE and retina. Our study shows that Pgc-1α is important in outer retina biology and that Pgc-1α+/− mice fed with HFD provide a promising model to study AMD, opening doors for novel treatment strategies. Summary: A new mouse model has been established that exhibits characteristics of human age-related macular degeneration; the model will facilitate further studies of AMD disease mechanisms.
Collapse
Affiliation(s)
- Meng Zhang
- Department of Ophthalmology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Yi Chu
- Department of Ophthalmology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Joseph Mowery
- Electron and Confocal Microscopy Unit, USDA Agricultural Research Service, Beltsville, MD 20705, USA
| | - Brandon Konkel
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Susana Galli
- Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, USA
| | - Alexander C Theos
- Department of Human Science, Georgetown University, Washington, DC 20057, USA
| | - Nady Golestaneh
- Department of Ophthalmology, Georgetown University Medical Center, Washington, DC 20057, USA .,Department of Biochemistry and Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, USA.,Department of Neurology, Georgetown University Medical Center, Washington, DC 20057, USA
| |
Collapse
|
17
|
Kivinen N. The role of autophagy in age-related macular degeneration. Acta Ophthalmol 2018; 96 Suppl A110:1-50. [PMID: 29633521 DOI: 10.1111/aos.13753] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Niko Kivinen
- Department of Ophthalmology; University of Eastern Finland; Kuopio Finland
| |
Collapse
|
18
|
Malek G, Busik J, Grant MB, Choudhary M. Models of retinal diseases and their applicability in drug discovery. Expert Opin Drug Discov 2018; 13:359-377. [PMID: 29382242 DOI: 10.1080/17460441.2018.1430136] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
INTRODUCTION The impact of vision debilitating diseases is a global public health concern, which will continue until effective preventative and management protocols are developed. Two retinal diseases responsible for the majority of vision loss in the working age adults and elderly populations are diabetic retinopathy (DR) and age-related macular degeneration (AMD), respectively. Model systems, which recapitulate aspects of human pathology, are valid experimental modalities that have contributed to the identification of signaling pathways involved in disease development and consequently potential therapies. Areas covered: The pathology of DR and AMD, which serve as the basis for designing appropriate models of disease, is discussed. The authors also review in vitro and in vivo models of DR and AMD and evaluate the utility of these models in exploratory and pre-clinical studies. Expert opinion: The complex nature of non-Mendelian diseases such as DR and AMD has made identification of effective therapeutic treatments challenging. However, the authors believe that while in vivo models are often criticized for not being a 'perfect' recapitulation of disease, they have been valuable experimentally when used with consideration of the strengths and limitations of the experimental model selected and have a place in the drug discovery process.
Collapse
Affiliation(s)
- Goldis Malek
- a Department of Ophthalmology , Duke University School of Medicine , Durham , NC , USA.,b Department of Pathology , Duke University School of Medicine , Durham , NC , USA
| | - Julia Busik
- c Department of Physiology , Michigan State University , East Lansing , MI , USA
| | - Maria B Grant
- d Department of Ophthalmology , University of Alabama at Birmingham , Birmingham , Al , USA
| | - Mayur Choudhary
- a Department of Ophthalmology , Duke University School of Medicine , Durham , NC , USA
| |
Collapse
|
19
|
Choriocapillaris Loss in Advanced Age-Related Macular Degeneration. J Ophthalmol 2018; 2018:8125267. [PMID: 29651346 PMCID: PMC5831971 DOI: 10.1155/2018/8125267] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Revised: 11/29/2017] [Accepted: 12/11/2017] [Indexed: 12/15/2022] Open
Abstract
The purpose of this review is to summarize the current knowledge on choriocapillaris loss in advanced age macular degeneration (AMD). Several histopathological studies in animal models and human eyes had showed that the choriocapillaris density decreases with age. However, the role of choriocapillaris loss is still unclear in AMD and its advanced forms, either choroidal neovascularization (CNV) or geographic atrophy (GA). Some authors have hypothesized that choriocapillaris loss might precede overt retinal pigment epithelium atrophy. Others have hypothesized that deposition of complement complexes on and around the choriocapillaris could be related to the tissue loss observed in early AMD. The development of imaging modalities, such as optical coherence tomography angiography (OCTA), have led to a better understanding of underlying physiopathological mechanisms in AMD. OCTA showed atrophy of choriocapillaris underneath and beyond the region of photoreceptors and RPE loss, in agreement with previous histopathologic studies. The evolution of OCTA technology suggests that CNV seems to originate from regions of severe choriocapillaris alteration. Significant progress has been made in the understanding of development and progression of GA and CNV. In vivo investigation of the choriocapillaris using OCTA may lead to new insights related to underlying disease mechanisms in AMD.
Collapse
|
20
|
Rudolf M, Mir Mohi Sefat A, Miura Y, Tura A, Raasch W, Ranjbar M, Grisanti S, Aherrahrou Z, Wagner A, Messinger JD, Garber DW, Anantharamaiah GM, Curcio CA. ApoA-I Mimetic Peptide 4F Reduces Age-Related Lipid Deposition in Murine Bruch's Membrane and Causes Its Structural Remodeling. Curr Eye Res 2017; 43:135-146. [PMID: 28972410 DOI: 10.1080/02713683.2017.1370118] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
PURPOSE Accumulation of lipoprotein-derived lipids including esterified and unesterified cholesterol in Bruch's membrane of human eyes is a major age-related change involved in initiating and sustaining soft drusen in age-related macular degeneration (AMD). The apolipoprotein (apo) A-I mimetic peptide 4F is a small anti-inflammatory and anti-atherogenic agent, and potent modifier of plasma membranes. We evaluated the effect of intravitreally-injected 4F on murine Bruch's membrane. METHODS We tested single intravitreal injections of 4F doses (0.6 µg, 1.2 µg, 2.4 µg, and placebo scrambled peptide) in ApoEnull mice ≥10 months of age. After 30 days, mice were euthanized. Eyes were processed for either direct immunofluorescence detection of esterified cholesterol (EC) in Bruch's membrane whole mounts via a perfringolysin O-based marker linked to green fluorescent protein or by transmission electron microscopic visualization of Bruch's membrane integrity. Fluorescein isothiocyanate-conjugated 4F was traced after injection. RESULTS All injected eyes showed a dose-dependent reduction of Bruch's membrane EC with a concomitant ultrastructural improvement compared to placebo treated eyes. At a 2.4 µg dose of 4F, EC was reduced on average by ~60% and Bruch's membrane returned to a regular pentalaminar structure and thickness. Tracer studies confirmed that injected 4F reached intraocular targets. CONCLUSION We demonstrated a highly effective pharmacological reduction of EC and restoration of Bruch's membrane ultrastructure. The apoA-I mimetic peptide 4F is a novel way to treat a critical AMD disease process and thus represents a new candidate for treating the underlying cause of AMD.
Collapse
Affiliation(s)
- Martin Rudolf
- a Department of Ophthalmology , University of Lübeck , Lübeck , Germany
| | | | - Yoko Miura
- a Department of Ophthalmology , University of Lübeck , Lübeck , Germany
| | - Aysegül Tura
- a Department of Ophthalmology , University of Lübeck , Lübeck , Germany
| | - Walter Raasch
- b Department of Experimental and Clinical Pharmacology and Toxicology , University of Lübeck , Lübeck , Germany
| | - Mahdy Ranjbar
- a Department of Ophthalmology , University of Lübeck , Lübeck , Germany.,c Laboratory for Angiogenesis & Ocular Cell Transplantation , University of Lübeck , Lübeck , Germany
| | | | - Zouhair Aherrahrou
- d Institute of Integrative and Experimental Genomics , University of Lübeck , Lübeck , Germany
| | - Anna Wagner
- a Department of Ophthalmology , University of Lübeck , Lübeck , Germany
| | - Jeffrey D Messinger
- e Department of Ophthalmology , University of Alabama at Birmingham , Birmingham , AL , USA
| | - David W Garber
- f Atherosclerosis Research Unit , University of Alabama at Birmingham , Birmingham , AL , USA
| | - G M Anantharamaiah
- f Atherosclerosis Research Unit , University of Alabama at Birmingham , Birmingham , AL , USA.,g Department of Medicine, Biochemistry and Molecular Genetics , University of Alabama at Birmingham , Birmingham , AL , USA
| | - Christine A Curcio
- e Department of Ophthalmology , University of Alabama at Birmingham , Birmingham , AL , USA
| |
Collapse
|
21
|
Cammalleri M, Dal Monte M, Locri F, Lardner E, Kvanta A, Rusciano D, André H, Bagnoli P. Efficacy of a Fatty Acids Dietary Supplement in a Polyethylene Glycol-Induced Mouse Model of Retinal Degeneration. Nutrients 2017; 9:nu9101079. [PMID: 28961167 PMCID: PMC5691696 DOI: 10.3390/nu9101079] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/18/2017] [Accepted: 09/27/2017] [Indexed: 01/07/2023] Open
Abstract
Current knowledge of the benefits of nutrition supplements for eye pathologies is based largely on the use of appropriate animal models, together with defined dietary supplementation. Here, C57BL6 mice were subretinally injected with polyethylene glycol (PEG)-400, an established model of retinal degeneration with a dry age-related macular degeneration (AMD)-like phenotype, an eye pathology that lacks treatment. In response to PEG-400, markers of the complement system, angiogenesis, inflammation, gliosis, and macrophage infiltration were upregulated in both retinas and retinal pigment epithelium (RPE)/choroids, whereas dietary supplementation with a mixture based on fatty acids counteracted their upregulation. Major effects include a reduction of inflammation, in both retinas and RPE/choroids, and an inhibition of macrophage infiltration in the choroid, yet not in the retina, suggesting a targeted action through the choroidal vasculature. Histological analysis revealed a thinning of the outer nuclear layer (ONL), together with dysregulation of the epithelium layer in response to PEG-400. In addition, immunohistofluorescence demonstrated Müller cell gliosis and macrophage infiltration into subretinal tissues supporting the molecular findings. Reduced ONL thickness, gliosis, and macrophage infiltration were counteracted by the diet supplement. The present data suggest that fatty acids may represent a useful form of diet supplementation to prevent or limit the progression of dry AMD.
Collapse
Affiliation(s)
- Maurizio Cammalleri
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Massimo Dal Monte
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Interdepartmental Research Center Nutrafood "Nutraceuticals and Food for Health", University of Pisa, via del Borghetto 80, 56124 Pisa, Italy.
| | - Filippo Locri
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Emma Lardner
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Anders Kvanta
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Dario Rusciano
- Sooft Fidia Pharma, Contrada Molino 17, 63833 Montegiorgio (FM), Italy.
| | - Helder André
- Section of Eye and Vision, Department of Clinical Neurosciences, St Erik Hospital, Karolinska Institutet, Polhemsgatan 50, SE-112 82 Stockholm, Sweden.
| | - Paola Bagnoli
- Department of Biology, University of Pisa, via San Zeno 31, 56127 Pisa, Italy.
| |
Collapse
|
22
|
Hashem HE, Abd El-Haleem MR, Amer MG, Bor’i A. Pomegranate protective effect on experimental ischemia/reperfusion retinal injury in rats (histological and biochemical study). Ultrastruct Pathol 2017; 41:346-357. [DOI: 10.1080/01913123.2017.1346737] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Hala E. Hashem
- Histology and Cell Biology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Manal R. Abd El-Haleem
- Histology and Cell Biology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Mona G. Amer
- Histology and Cell Biology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| | - Ashraf Bor’i
- Ophthalmology Department, Faculty of Medicine, Zagazig University, Zagazig, Egypt
| |
Collapse
|
23
|
Stanton JB, Marmorstein AD, Zhang Y, Marmorstein LY. Deletion of Efemp1 Is Protective Against the Development of Sub-RPE Deposits in Mouse Eyes. Invest Ophthalmol Vis Sci 2017; 58:1455-1461. [PMID: 28264101 PMCID: PMC5361459 DOI: 10.1167/iovs.16-20955] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Purpose EFEMP1 (fibulin-3) is mutated in Malattia Leventinese/Doyne's honeycomb retinal dystrophy (ML/DHRD), an inherited macular dystrophy similar to AMD. Both ML/DHRD and AMD are characterized by the presence of sub-RPE deposits. Efemp1 knockout mice do not develop sub-RPE deposits. This study was to test whether sub-RPE deposits can be induced in Efemp1 knockout mice by experimentally applied stress conditions that cause wild-type mice to develop sub-RPE deposits. Methods Efemp1 knockout and control mice at 6, 18, or 24 months old were fed with a synthetic high-fat diet (HFD). Beginning 1 month after starting the HFD, one group of mice was exposed to cigarette smoke daily for 1 month, and another group of mice was subjected to photochemical injury every other day for 2 weeks from a 488-nm argon laser. After the treatments, histologic analysis was performed to assess whether sub-RPE deposits were induced. Results Basal laminar deposits (BLamDs), a form of sub-RPE deposits, were observed in the 18- and 24-month-old wild-type mice but not in Efemp1 knockout mice in any age groups after exposure to HFD and cigarette smoke or laser injury. Conclusions Mice lacking fibulin-3 do not develop sub-RPE deposits. Environmental oxidative stressors (HFD/cigarette smoke or HFD/laser) known to cause BLamD formation in wild-type mice failed to induce BLamD formation in Efemp1 knockout mice. These results suggest that fibulin-3 is a central player in the development of BLamD, and deletion of fibulin-3 is protective against the development of BLamD.
Collapse
Affiliation(s)
- James B Stanton
- Department of Ophthalmology & Vision Science, University of Arizona, Tucson, Arizona, United States
| | - Alan D Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Youwen Zhang
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| | - Lihua Y Marmorstein
- Department of Ophthalmology, Mayo Clinic, Rochester, Minnesota, United States
| |
Collapse
|
24
|
Jones MK, Lu B, Girman S, Wang S. Cell-based therapeutic strategies for replacement and preservation in retinal degenerative diseases. Prog Retin Eye Res 2017; 58:1-27. [PMID: 28111323 PMCID: PMC5441967 DOI: 10.1016/j.preteyeres.2017.01.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2016] [Revised: 01/08/2017] [Accepted: 01/17/2017] [Indexed: 12/13/2022]
Abstract
Cell-based therapeutics offer diverse options for treating retinal degenerative diseases, such as age-related macular degeneration (AMD) and retinitis pigmentosa (RP). AMD is characterized by both genetic and environmental risks factors, whereas RP is mainly a monogenic disorder. Though treatments exist for some patients with neovascular AMD, a majority of retinal degenerative patients have no effective therapeutics, thus indicating a need for universal therapies to target diverse patient populations. Two main cell-based mechanistic approaches are being tested in clinical trials. Replacement therapies utilize cell-derived retinal pigment epithelial (RPE) cells to supplant lost or defective host RPE cells. These cells are similar in morphology and function to native RPE cells and can potentially supplant the responsibilities of RPE in vivo. Preservation therapies utilize supportive cells to aid in visual function and photoreceptor preservation partially by neurotrophic mechanisms. The goal of preservation strategies is to halt or slow the progression of disease and maintain remaining visual function. A number of clinical trials are testing the safety of replacement and preservation cell therapies in patients; however, measures of efficacy will need to be further evaluated. In addition, a number of prevailing concerns with regards to the immune-related response, longevity, and functionality of the grafted cells will need to be addressed in future trials. This review will summarize the current status of cell-based preclinical and clinical studies with a focus on replacement and preservation strategies and the obstacles that remain regarding these types of treatments.
Collapse
Affiliation(s)
- Melissa K Jones
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Bin Lu
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Sergey Girman
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA
| | - Shaomei Wang
- Board of Governors Regenerative Medicine Institute, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Blvd., Los Angeles, CA 90048, USA; David Geffen School of Medicine, University of California Los Angeles, 10833 Le Conte Ave., Los Angeles, CA 90095, USA.
| |
Collapse
|
25
|
Marazita MC, Dugour A, Marquioni-Ramella MD, Figueroa JM, Suburo AM. Oxidative stress-induced premature senescence dysregulates VEGF and CFH expression in retinal pigment epithelial cells: Implications for Age-related Macular Degeneration. Redox Biol 2016; 7:78-87. [PMID: 26654980 PMCID: PMC4683426 DOI: 10.1016/j.redox.2015.11.011] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 11/24/2015] [Accepted: 11/25/2015] [Indexed: 12/14/2022] Open
Abstract
Oxidative stress has a critical role in the pathogenesis of Age-related Macular Degeneration (AMD), a multifactorial disease that includes age, gene variants of complement regulatory proteins and smoking as the main risk factors. Stress-induced premature cellular senescence (SIPS) is postulated to contribute to this condition. In this study, we hypothesized that oxidative damage, promoted by endogenous or exogenous sources, could elicit a senescence response in RPE cells, which would in turn dysregulate the expression of major players in AMD pathogenic mechanisms. We showed that exposure of a human RPE cell line (ARPE-19) to a cigarette smoke concentrate (CSC), not only enhanced Reactive Oxygen Species (ROS) levels, but also induced 8-Hydroxydeoxyguanosine-immunoreactive (8-OHdG) DNA lesions and phosphorylated-Histone 2AX-immunoreactive (p-H2AX) nuclear foci. CSC-nuclear damage was followed by premature senescence as shown by positive senescence associated-β-galactosidase (SA-β-Gal) staining, and p16(INK4a) and p21(Waf-Cip1) protein upregulation. N-acetylcysteine (NAC) treatment, a ROS scavenger, decreased senescence markers, thus supporting the role of oxidative damage in CSC-induced senescence activation. ARPE-19 senescent cultures were also established by exposure to hydrogen peroxide (H2O2), which is an endogenous stress source produced in the retina under photo-oxidation conditions. Senescent cells upregulated the proinflammatory cytokines IL-6 and IL-8, the main markers of the senescence-associated secretory phenotype (SASP). Most important, we show for the first time that senescent ARPE-19 cells upregulated vascular endothelial growth factor (VEGF) and simultaneously downregulated complement factor H (CFH) expression. Since both phenomena are involved in AMD pathogenesis, our results support the hypothesis that SIPS could be a principal player in the induction and progression of AMD. Moreover, they would also explain the striking association of this disease with cigarette smoking.
Collapse
Affiliation(s)
- Mariela C Marazita
- Cell and Molecular Medicine, Facultad de Ciencias Biomédicas, Universidad Austral, Pilar B1629AHJ, Argentina
| | - Andrea Dugour
- Fundación Pablo Cassará, Buenos Aires C1440 FFX, Argentina
| | - Melisa D Marquioni-Ramella
- Cell and Molecular Medicine, Facultad de Ciencias Biomédicas, Universidad Austral, Pilar B1629AHJ, Argentina
| | | | - Angela M Suburo
- Cell and Molecular Medicine, Facultad de Ciencias Biomédicas, Universidad Austral, Pilar B1629AHJ, Argentina.
| |
Collapse
|
26
|
Ferrara D, Waheed NK, Duker JS. Investigating the choriocapillaris and choroidal vasculature with new optical coherence tomography technologies. Prog Retin Eye Res 2015; 52:130-55. [PMID: 26478514 DOI: 10.1016/j.preteyeres.2015.10.002] [Citation(s) in RCA: 192] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 10/09/2015] [Accepted: 10/12/2015] [Indexed: 02/06/2023]
Abstract
The body of knowledge of in vivo investigation of the choroid has been markedly enhanced by recent technological advances in optical coherence tomography (OCT). New insights elucidating the morphological features of the choriocapillaris and choroidal vasculature, in both physiological and pathological conditions, indicate that the choroid plays a pivotal role in many posterior segment diseases. In this article, a review of the histological characteristics of the choroid, which must be considered for the proper interpretation of in vivo imaging, is followed by a comprehensive discussion of fundamental principles of the current state-of-the-art in OCT, including cross-sectional OCT, en face OCT, and OCT angiography using both spectral domain OCT and swept source OCT technologies. A detailed review of the tomographic features of the choroid in the normal eye is followed by relevant findings in prevalent chorioretinal diseases, focusing on major causes of vision loss such as typical early and advanced age-related macular degeneration, polypoidal choroidal vasculopathy, central serous chorioretinopathy, pachychoroid spectrum disorders, diabetic choroidopathy, and myopia.
Collapse
Affiliation(s)
- Daniela Ferrara
- New England Eye Center, Tufts University School of Medicine, 260 Tremont Street, 10th Floor, Boston, MA, USA.
| | - Nadia K Waheed
- New England Eye Center, Tufts University School of Medicine, 260 Tremont Street, 10th Floor, Boston, MA, USA
| | - Jay S Duker
- New England Eye Center, Tufts University School of Medicine, 260 Tremont Street, 10th Floor, Boston, MA, USA
| |
Collapse
|
27
|
Aredo B, Li T, Chen X, Zhang K, Wang CXZ, Gou D, Zhao B, He Y, Ufret-Vincenty RL. A chimeric Cfh transgene leads to increased retinal oxidative stress, inflammation, and accumulation of activated subretinal microglia in mice. Invest Ophthalmol Vis Sci 2015; 56:3427-40. [PMID: 26030099 DOI: 10.1167/iovs.14-16089] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
PURPOSE Variants of complement factor H (Cfh) affecting short consensus repeats (SCRs) 6 to 8 increase the risk of age-related macular degeneration. Our aim was to explore the effect of expressing a Cfh variant on the in vivo susceptibility of the retina and RPE to oxidative stress and inflammation, using chimeric Cfh transgenic mice (chCfhTg). METHODS The chCfhTg and age-matched C57BL/6J (B6) mice were subjected to oxidative stress by either normal aging, or by exposure to a combination of oral hydroquinone (0.8% HQ) and increased light. Eyes were collected for immunohistochemistry of RPE-choroid flat mounts and of retinal sections, ELISA, electron microscopy, and RPE/microglia gene expression analysis. RESULTS Aging mice to 2 years led to an increased accumulation of basal laminar deposits, subretinal microglia/macrophages (MG/MΦ) staining for CD16 and for malondialdehyde (MDA), and MDA-modified proteins in the retina in chCfhTg compared to B6 mice. The chCfhTg mice maintained on HQ diet and increased light showed greater deposition of basal laminar deposits, more accumulation of fundus spots suggestive of MG/MΦ, and increased deposition of C3d in the sub-RPE space, compared to controls. In addition, chCfhTg mice demonstrated upregulation of NLRP3, IP-10, CD68, and TREM-2 in the RNA isolates from RPE/MG/MΦ. CONCLUSIONS Expression of a Cfh transgene introducing a variant in SCRs 6 to 8 was sufficient to lead to increased retinal/RPE susceptibility to oxidative stress, a proinflammatory MG/MΦ phenotype, and a proinflammatory RPE/MG/MΦ gene expression profile in a transgenic mouse model. Our data suggest that altered interactions of Cfh with MDA-modified proteins may be relevant in explaining the effects of the Cfh variant.
Collapse
Affiliation(s)
- Bogale Aredo
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Tao Li
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States 2Department of Ophthalmology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, People's Republic of China
| | - Xiao Chen
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Kaiyan Zhang
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Cynthia Xin-Zhao Wang
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Darlene Gou
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Biren Zhao
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | - Yuguang He
- Department of Ophthalmology UT Southwestern Medical Center, Dallas, Texas, United States
| | | |
Collapse
|
28
|
Novais EA, Badaró E, Regatieri CVS, Duker J, de Oliveira Bonomo PP. Regression of Drusen After Combined Treatment Using Photodynamic Therapy With Verteporfin and Ranibizumab. Ophthalmic Surg Lasers Imaging Retina 2015; 46:275-8. [DOI: 10.3928/23258160-20150213-16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2014] [Accepted: 09/29/2014] [Indexed: 02/04/2023]
|
29
|
Aredo B, Zhang K, Chen X, Wang CXZ, Li T, Ufret-Vincenty RL. Differences in the distribution, phenotype and gene expression of subretinal microglia/macrophages in C57BL/6N (Crb1 rd8/rd8) versus C57BL6/J (Crb1 wt/wt) mice. J Neuroinflammation 2015; 12:6. [PMID: 25588310 PMCID: PMC4305240 DOI: 10.1186/s12974-014-0221-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 12/11/2014] [Indexed: 01/02/2023] Open
Abstract
Background Microglia/macrophages (MG/MΦ) are found in the subretinal space in both mice and humans. Our goal was to study the spatial and temporal distribution, the phenotype, and gene expression of subretinal MG/MΦ in mice with normal retinas and compare them to mice with known retinal pathology. Methods We studied C57BL/6 mice with (C57BL/6N), or without (C57BL/6J) the rd8 mutation in the Crb1 gene (which, in the presence of yet unidentified permissive/modifying genes, leads to a retinal degeneration), and documented their fundus appearance and the change with aging. Immunostaining of retinal pigment epithelium (RPE) flat mounts was done for 1) Ionized calcium binding adaptor (Iba)-1, 2) FcγIII/II Receptor (CD16/CD32, abbreviated as CD16), and 3) Macrophage mannose receptor (MMR). Reverse-transcription quantitative PCR (RT-qPCR) was done for genes involved in oxidative stress, complement activation and inflammation. Results The number of yellow fundus spots correlated highly with subretinal Iba-1+ cells. The total number of subretinal MG/MΦ increased with age in the rd8 mutant mice, but not in the wild-type (WT) mice. There was a centripetal shift in the distribution of the subretinal MG/MΦ with age. Old rd8 mutant mice had a greater number of CD16+ MG/MΦ. CD16+ cells had morphological signs of activation, and this was most prominent in old rd8 mutant mice (P <1×10−8 versus old WT mice). Subretinal MG/MΦ in rd8 mutant mice also expressed iNOS and MHC-II, and had ultrastructural signs of activation. Finally, rd8 mutant mouse RPE/ MG/MΦ RNA isolates showed an upregulation of Ccl2, CFB, C3, NF-kβ, CD200R and TNF-alpha. The retinas of rd8 mutant mice showed upregulation of HO-1, C1q, C4, and Nrf-2. Conclusions When compared to C57BL/6J mice, C57BL/6N mice demonstrate increased accumulation of subretinal MG/MΦ, displaying phenotypical, morphological, and gene-expression characteristics consistent with a pro-inflammatory shift. These changes become more prominent with aging and are likely due to the combination of the rd8 mutation and yet unidentified permissive/modulatory genes in the C57BL/6N mice. In contrast, aging leads to a scavenging phenotype in the C57BL/6J subretinal microglia/macrophages. Electronic supplementary material The online version of this article (doi:10.1186/s12974-014-0221-4) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Bogale Aredo
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9057, USA.
| | - Kaiyan Zhang
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9057, USA. .,Current address: Department of Ophthalmology, Hainan Provincial People's Hospital, Haikou, Hainan, 570203, PR China.
| | - Xiao Chen
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9057, USA. .,Current address: Department of Ophthalmology, Wuhan General Hospital of Guangzhou Military Command, Wuhan, 430070, PR China.
| | - Cynthia Xin-Zhao Wang
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9057, USA.
| | - Tao Li
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9057, USA.
| | - Rafael L Ufret-Vincenty
- Department of Ophthalmology, UT Southwestern Medical Center, 5323 Harry Hines Blvd, Dallas, TX, 75390-9057, USA.
| |
Collapse
|
30
|
Zhao Z, Xu P, Jie Z, Zuo Y, Yu B, Soong L, Sun J, Chen Y, Cai J. γδ T cells as a major source of IL-17 production during age-dependent RPE degeneration. Invest Ophthalmol Vis Sci 2014; 55:6580-9. [PMID: 25212781 PMCID: PMC4203278 DOI: 10.1167/iovs.14-15166] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
PURPOSE Chronic inflammation is a key factor contributing to the progression of age-related macular degeneration (AMD). The goals of the current study were to develop an improved mouse model with retinal pathologic features similar to those of AMD and to characterize the immunoreactive cells in the outer retina and choroid during degeneration of the retinal pigment epithelium (RPE). METHODS Mice deficient in nuclear erythroid 2-related factor 2 (Nrf2) at 12 months of age were fed a high-fat, cholesterol-rich diet for up to 16 weeks. Ocular phenotype was monitored by optical coherence tomography (OCT) and scanning laser ophthalmoscopy (SLO) in live animals, and was further validated by retinal histopathology. Immunofluorescence staining of either cryosections or RPE flat mounts was used to define immunoreactive cells. Flow cytometry analyses were further performed to define the subsets of intraocular T lymphocytes. RESULTS After 16 weeks on a high-fat (HF) diet, 58% of the eyes from Nrf2-/- mice had progression of retinal lesions. Major histocompatibility complex class II (MHC II)-positive microglia, FoxP3+ regulatory T cells (Tregs), and CD3+ IL-17-producing T cells were detected in either the retina or sub-RPE space. Flow cytometry analyses further revealed that most of the IL-17-producing cells were CD3+ CD4- TCRγδ+ cells. CONCLUSIONS The results suggest that the T cell-mediated immune responses played important roles in controlling the progression of AMD-like phenotype in Nrf2-deficient mice.
Collapse
Affiliation(s)
- Zhenyang Zhao
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Pei Xu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Zuliang Jie
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Yiqin Zuo
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Bo Yu
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Lynn Soong
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jiaren Sun
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, Texas, United States
| | - Yan Chen
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States
| | - Jiyang Cai
- Department of Ophthalmology and Visual Sciences, University of Texas Medical Branch, Galveston, Texas, United States Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, Texas, United States
| |
Collapse
|
31
|
Rowan S, Weikel K, Chang ML, Nagel BA, Thinschmidt JS, Carey A, Grant MB, Fliesler SJ, Smith D, Taylor A. Cfh genotype interacts with dietary glycemic index to modulate age-related macular degeneration-like features in mice. Invest Ophthalmol Vis Sci 2014; 55:492-501. [PMID: 24370827 DOI: 10.1167/iovs.13-12413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
PURPOSE Age-related macular degeneration (AMD) is a leading cause of visual impairment worldwide. Genetics and diet contribute to the relative risk for developing AMD, but their interactions are poorly understood. Genetic variations in Complement Factor H (CFH), and dietary glycemic index (GI) are major risk factors for AMD. We explored the effects of GI on development of early AMD-like features and changes to central nervous system (CNS) inflammation in Cfh-null mice. METHODS Aged 11-week-old wild type (WT) C57Bl/6J or Cfh-null mice were group pair-fed high or low GI diets for 33 weeks. At 10 months of age, mice were evaluated for early AMD-like features in the neural retina and RPE by light and electron microscopy. Brains were analyzed for Iba1 macrophage/microglia immunostaining, an indicator of inflammation. RESULTS The 10-month-old WT mice showed no retinal abnormalities on either diet. The Cfh-null mice, however, showed distinct early AMD-like features in the RPE when fed a low GI diet, including vacuolation, disruption of basal infoldings, and increased basal laminar deposits. The Cfh-null mice also showed thinning of the RPE, hypopigmentation, and increased numbers of Iba1-expressing macrophages in the brain, irrespective of diet. CONCLUSIONS The presence of early AMD-like features by 10 months of age in Cfh-null mice fed a low GI diet is surprising, given the apparent protection from the development of such features in aged WT mice or humans consuming lower GI diets. Our findings highlight the need to consider gene-diet interactions when developing animal models and therapeutic approaches to treat AMD.
Collapse
Affiliation(s)
- Sheldon Rowan
- JM-USDA Human Nutrition Research Center on Aging (HNRCA), Tufts University, Boston, Massachusetts
| | | | | | | | | | | | | | | | | | | |
Collapse
|
32
|
Chowdhury HR, Patel N, Sivaprasad S. Ocular neovascularization: potential for the angiopoietin/Tie-2 pathway. EXPERT REVIEW OF OPHTHALMOLOGY 2014. [DOI: 10.1586/17469899.4.1.65] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
33
|
Effect of lutein and antioxidant supplementation on VEGF expression, MMP-2 activity, and ultrastructural alterations in apolipoprotein E-deficient mouse. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:213505. [PMID: 23738034 PMCID: PMC3657460 DOI: 10.1155/2013/213505] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/07/2013] [Revised: 04/05/2013] [Accepted: 04/08/2013] [Indexed: 11/22/2022]
Abstract
Oxidative stress is involved in the pathogenesis of several diseases such as atherosclerosis and age-related macular degeneration (AMD). ApoE-deficient mice (apoE−/−) are a well-established model of genetic hypercholesterolemia and develop retinal alterations similar to those found in humans with AMD. Thus supplementation with lutein or multivitamin plus lutein and glutathione complex (MV) could prevent the onset of these alterations. ApoE−/− mice (n = 40, 3 months old) were treated daily for 3 months with lutein (AE-LUT) or MV (two doses): AE-MV15 (15 mg/kg/day) and AE-MV50 (50 mg/kg/day) and were compared to controls with vehicle (AE-C). Wild-type mice (n = 10) were also used as control (WT-C). ApoE−/− mice showed higher retinal lipid peroxidation and increased VEGF expression and MMP-2 activity, associated with ultrastructural alterations such as basal laminar deposits, vacuoles, and an increase in Bruch's membrane thickness. While lutein alone partially prevented the alterations observed in apoE−/− mice, MV treatment substantially reduced VEGF levels and MMP-2 activity and ameliorated the retinal morphological alterations. These results suggest that oxidative stress in addition to an increased expression and activity of proangiogenic factors could participate in the onset or development of retinal alterations of apoE−/− mice. Moreover, these changes could be prevented by efficient antioxidant treatments.
Collapse
|
34
|
Chu XK, Wang Y, Ardeljan D, Tuo J, Chan CC. Controversial view of a genetically altered mouse model of focal retinal degeneration. Bioengineered 2012. [PMID: 23196746 PMCID: PMC3669152 DOI: 10.4161/bioe.22949] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Tuo et al. (2012) demonstrated tumor necrosis factor-inducible gene 6 recombinant protein (TSG-6) arrest of focal retinal lesions on a Ccl2 and Cx3cr1 double deficient mouse (DKO) on rd8 background (hereon referred to as DKO rd8). DKO rd8, a model of focal retinal degeneration with earlier onset and higher penetrance than Ccl2 and Cx3cr1 single knockout strains, demonstrates characteristic features of AMD such as focal photoreceptor atrophy, retinal pigmented epithelium (RPE) degeneration, elevated ocular A2E levels and complement deposition in addition to retinal dystrophy. The discovery of the accidently introduced Crb1 mutation (rd8) in the C57BL/6N strain has led to the recent opinion that DKO rd8 is not a model of AMD but solely a model of Crb1‑associated retinal degeneration. Differences between DKO rd8 and Crb1rd8 photoreceptor and RPE pathology, as well as increased A2E and immune dysfunction, show that DKO rd8 recapitulates some AMD‑like features in addition to rd8 retinal dystrophy. The appearance of rd8 lesions and Ccl2/Cx3cr1 lesions and the amelioration of most Ccl2/Cx3cr1 lesions in intervention studies show DKO rd8 to be a useful and appropriate model for therapeutic compound screening, such as the case with anti-inflammatory TSG‑6.
Collapse
Affiliation(s)
- Xi K Chu
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | | | | | | | | |
Collapse
|
35
|
Pennesi ME, Neuringer M, Courtney RJ. Animal models of age related macular degeneration. Mol Aspects Med 2012; 33:487-509. [PMID: 22705444 DOI: 10.1016/j.mam.2012.06.003] [Citation(s) in RCA: 275] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Age related macular degeneration (AMD) is the leading cause of vision loss of those over the age of 65 in the industrialized world. The prevalence and need to develop effective treatments for AMD has lead to the development of multiple animal models. AMD is a complex and heterogeneous disease that involves the interaction of both genetic and environmental factors with the unique anatomy of the human macula. Models in mice, rats, rabbits, pigs and non-human primates have recreated many of the histological features of AMD and provided much insight into the underlying pathological mechanisms of this disease. In spite of the large number of models developed, no one model yet recapitulates all of the features of human AMD. However, these models have helped reveal the roles of chronic oxidative damage, inflammation and immune dysregulation, and lipid metabolism in the development of AMD. Models for induced choroidal neovascularization have served as the backbone for testing new therapies. This article will review the diversity of animal models that exist for AMD as well as their strengths and limitations.
Collapse
Affiliation(s)
- Mark E Pennesi
- Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, OR 97239, USA.
| | | | | |
Collapse
|
36
|
Mettu PS, Wielgus AR, Ong SS, Cousins SW. Retinal pigment epithelium response to oxidant injury in the pathogenesis of early age-related macular degeneration. Mol Aspects Med 2012; 33:376-98. [PMID: 22575354 DOI: 10.1016/j.mam.2012.04.006] [Citation(s) in RCA: 77] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 04/14/2012] [Indexed: 01/06/2023]
Abstract
Age-related macular degeneration (AMD) represents the leading cause of vision loss in the elderly. Accumulation of lipid- and protein-rich deposits under the retinal pigment epithelium (RPE) heralds the onset of early AMD, but the pathogenesis of subretinal deposit formation is poorly understood. Numerous hypothetical models of deposit formation have been proposed, including hypotheses for a genetic basis, choroidal hypoperfusion, abnormal barrier formation, and lysosomal failure. This review explore the RPE injury hypothesis, characterized by three distinct stages (1) Initial RPE oxidant injury, caused by any number of endogenous or exogenous oxidants, results in extrusion of cell membrane "blebs," together with decreased activity of matrix metalloproteinases (MMPs), promoting bleb accumulation under the RPE as basal laminar deposits (BLD). (2) RPE cells are subsequently stimulated to increase synthesis of MMPs and other molecules responsible for extracellular matrix turnover (i.e., producing decreased collagen), affecting both RPE basement membrane and Bruchs membrane (BrM). This process leads to progression of BLD into basal linear deposits (BLinD) and drusen by admixture of blebs into BrM, followed by the formation of new basement membrane under the RPE to trap these deposits within BrM. We postulate that various hormones and other plasma-derived molecules related to systemic health cofactors are implicated in this second stage. (3) Finally, macrophages are recruited to sites of RPE injury and deposit formation. The recruitment of nonactivated or scavenging macrophages may remove deposits without further injury, while the recruitment of activated or reparative macrophages, through the release of inflammatory mediators, growth factors, or other substances, may promote complications and progression to the late forms of the disease.
Collapse
Affiliation(s)
- Priyatham S Mettu
- Duke Center for Macular Diseases, Duke Eye Center, Durham, NC 27710, USA
| | | | | | | |
Collapse
|
37
|
Shirinifard A, Glazier JA, Swat M, Gens JS, Family F, Jiang Y, Grossniklaus HE. Adhesion failures determine the pattern of choroidal neovascularization in the eye: a computer simulation study. PLoS Comput Biol 2012; 8:e1002440. [PMID: 22570603 PMCID: PMC3342931 DOI: 10.1371/journal.pcbi.1002440] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2011] [Accepted: 02/07/2012] [Indexed: 11/25/2022] Open
Abstract
Choroidal neovascularization (CNV) of the macular area of the retina is the major cause of severe vision loss in adults. In CNV, after choriocapillaries initially penetrate Bruch's membrane (BrM), invading vessels may regress or expand (CNV initiation). Next, during Early and Late CNV, the expanding vasculature usually spreads in one of three distinct patterns: in a layer between BrM and the retinal pigment epithelium (sub-RPE or Type 1 CNV), in a layer between the RPE and the photoreceptors (sub-retinal or Type 2 CNV) or in both loci simultaneously (combined pattern or Type 3 CNV). While most studies hypothesize that CNV primarily results from growth-factor effects or holes in BrM, our three-dimensional simulations of multi-cell model of the normal and pathological maculae recapitulate the three growth patterns, under the hypothesis that CNV results from combinations of impairment of: 1) RPE-RPE epithelial junctional adhesion, 2) Adhesion of the RPE basement membrane complex to BrM (RPE-BrM adhesion), and 3) Adhesion of the RPE to the photoreceptor outer segments (RPE-POS adhesion). Our key findings are that when an endothelial tip cell penetrates BrM: 1) RPE with normal epithelial junctions, basal attachment to BrM and apical attachment to POS resists CNV. 2) Small holes in BrM do not, by themselves, initiate CNV. 3) RPE with normal epithelial junctions and normal apical RPE-POS adhesion, but weak adhesion to BrM (e.g. due to lipid accumulation in BrM) results in Early sub-RPE CNV. 4) Normal adhesion of RBaM to BrM, but reduced apical RPE-POS or epithelial RPE-RPE adhesion (e.g. due to inflammation) results in Early sub-retinal CNV. 5) Simultaneous reduction in RPE-RPE epithelial binding and RPE-BrM adhesion results in either sub-RPE or sub-retinal CNV which often progresses to combined pattern CNV. These findings suggest that defects in adhesion dominate CNV initiation and progression.
Collapse
Affiliation(s)
- Abbas Shirinifard
- The Biocomplexity Institute and Department of Physics, Indiana University Bloomington, Bloomington, Indiana, United States of America.
| | | | | | | | | | | | | |
Collapse
|
38
|
Dong Z, Li J, Leng Y, Sun X, Hu H, He Y, Tan Z, Ge J. Cyclic intensive light exposure induces retinal lesions similar to age-related macular degeneration in APPswe/PS1 bigenic mice. BMC Neurosci 2012; 13:34. [PMID: 22443196 PMCID: PMC3338397 DOI: 10.1186/1471-2202-13-34] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 03/24/2012] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Intensive light exposure and beta-amyloid (Aβ) aggregates have been known as a risk factor for macular degeneration and an important component in the pathologic drusen structure involved in this disorder, respectively. However, it is unknown whether Aβ deposition mediates or exacerbates light exposure-induced pathogenesis of macular degeneration. Several studies including the one from us already showed accumulation of Aβ deposits in the retina in Alzheimer's transgenic mice. Using histopathological analysis combined with electroretinographic functional assessment, we investigated the effects of cyclic intensive light exposure (CILE) on the architecture of retina and related function in the APPswe/PS1bigenic mouse. RESULTS Histopathological analysis has found significant loss of outer nuclear layer/photoreceptor outer segment and outer plexiform layer along with abnormal hypo- and hyper-pigmentation in the retinal pigment epithelium (RPE), remarkable choroidal neovascularization (CNV), and exaggerated neuroinflammatory responses in the outer retina of APPswe/PS1 bigenic mice following cyclic intensive light exposure (CILE), whereas controls remained little change contrasted with age-matched non-transgenic littermates. CILE-induced degenerative changes in RPE are further confirmed by transmission electron microcopy and manifest as formation of basal laminar deposits, irregular thickening of Bruch's membrane (BrM), deposition of outer collagenous layer (OCL) in the subretinal space, and vacuolation in the RPE. Immunofluorescence microscopy reveals drusenoid Aβ deposits in RPE as well as neovessels attached which are associated with disruption of RPE integrity and provoked neuroinflammatory response as indicated by markedly increased retinal infiltration of microglia. Moreover, both immunohistochemistry and Western blots detect an induction of vascular endothelial growth factor (VEGF) in RPE, which corroborates increased CNV in the outer retina in the bigenic mice challenged by CILE. CONCLUSIONS Our findings demonstrate that degenerative changes in the outer retina in the APPswe/PS1 bigenic mouse induced by CILE are consistent with these in AMD. These results suggest that an Alzheimer's transgenic animal model with accumulation of Aβ deposits might be an alternative animal model for AMD, if combined with other confounding factors such as intensive light exposure for AMD.
Collapse
Affiliation(s)
- Zhizhang Dong
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Salomon RG, Hong L, Hollyfield JG. Discovery of carboxyethylpyrroles (CEPs): critical insights into AMD, autism, cancer, and wound healing from basic research on the chemistry of oxidized phospholipids. Chem Res Toxicol 2011; 24:1803-16. [PMID: 21875030 DOI: 10.1021/tx200206v] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Basic research, exploring the hypothesis that 2-(ω-carboxyethyl)pyrrole (CEP) modifications of proteins are generated nonenzymatically in vivo is delivering a bonanza of molecular mechanistic insights into age-related macular degeneration, autism, cancer, and wound healing. CEPs are produced through covalent modification of protein lysyl ε-amino groups by γ-hydroxyalkenal phospholipids that are formed by oxidative cleavage of docosahexaenate-containing phospholipids. Chemical synthesis of CEP-modified proteins and the production of highly specific antibodies that recognize them preceded and facilitated their detection in vivo and enabled exploration of their biological occurrence and activities. This investigational approach, from the chemistry of biomolecules to disease phenotype, is proving to be remarkably productive.
Collapse
Affiliation(s)
- Robert G Salomon
- Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106-7078, USA.
| | | | | |
Collapse
|
40
|
Kishan AU, Modjtahedi BS, Martins EN, Modjtahedi SP, Morse LS. Lipids and age-related macular degeneration. Surv Ophthalmol 2011; 56:195-213. [PMID: 21439604 DOI: 10.1016/j.survophthal.2010.08.008] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Revised: 08/29/2010] [Accepted: 08/31/2010] [Indexed: 01/17/2023]
Abstract
Given the considerable public health burden imposed by age-related macular degeneration (AMD), much effort has been directed towards elucidating principles of pathogenesis in order to identify risk factors and develop preventive measures and treatments. Together with epidemiological evidence linking cardiovascular risk factors with AMD risk and basic science work examining the role of lipid metabolism in AMD, numerous human studies have assayed a potential relationship between dietary lipids and the development of AMD. We examine the evidence for a role for lipid metabolism in AMD, highlighting key basic biochemical principles, work in animal models, and relevant human studies. The topics of lipoprotein modulation and omega-3 fatty acid intake receive special attention from both a basic science and clinical study standpoint. The evidence suggests that consumption of omega-3 fatty acids, perhaps in concert with antioxidants, may constitute a rational preventative strategy against AMD development, though, absent an appropriately developed double-blind, randomized control trial, insufficient data exist to recommend implementation in the clinical setting at this time.
Collapse
|
41
|
Chavali VRM, Khan NW, Cukras CA, Bartsch DU, Jablonski MM, Ayyagari R. A CTRP5 gene S163R mutation knock-in mouse model for late-onset retinal degeneration. Hum Mol Genet 2011; 20:2000-14. [PMID: 21349921 DOI: 10.1093/hmg/ddr080] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Late-onset retinal macular degeneration (L-ORD) is an autosomal dominant inherited disorder caused by a single missense mutation (S163R) in the CTRP5/C1QTNF5 protein. Early phenotypic features of L-ORD include: dark adaptation abnormalities, nyctalopia, and drusen deposits in the peripheral macular region. Apart from posterior segment abnormalities, these patients also develop abnormally long anterior lens zonules. In the sixth decade of life the rod and cone function declines, accompanied by electroretinogram (ERG) abnormalities. Some patients also develop choroidal neovascularization and glaucoma. In order to understand the disease pathology and mechanisms involved in retinal dystrophy, we generated a knock-in (Ctrp5(+/-)) mouse model carrying the disease-associated mutation in the mouse Ctrp5/C1QTNF5 gene. These mice develop slower rod-b wave recovery consistent with early dark adaptation abnormalities, accumulation of hyperautofluorescence spots, retinal pigment epithelium abnormalities, drusen, Bruch's membrane abnormalities, loss of photoreceptors, and retinal vascular leakage. The Ctrp5(+/-) mice, which have most of the pathological features of age-related macular degeneration, are unique and may serve as a valuable model both to understand the molecular pathology of late-onset retinal degeneration and to evaluate therapies.
Collapse
|
42
|
Nutrition et dégénérescence maculaire liée à l’âge. J Fr Ophtalmol 2010; 33:749-57. [DOI: 10.1016/j.jfo.2010.09.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2009] [Accepted: 09/28/2010] [Indexed: 11/24/2022]
|
43
|
Yang L, Gong H, Wang Y, Wang Y, Yin H, Chen P, Zhang H, Wang Y. Nicotine alters morphology and function of retinal pigment epithelial cells in mice. Toxicol Pathol 2010; 38:560-7. [PMID: 20448088 DOI: 10.1177/0192623310368983] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To study the effects of nicotine on retinal pigment epithelium (RPE) cells in vivo and in vitro, (Balb/c x C57Bl/6) F1 mice were given water containing 100 microg/mL nicotine for six months. Cultured fetal RPE cells were treated with nicotine or lipopolysaccharide for seventy-two hours. Expression of matrix metalloproteinase protein (MMP)2, MMP9, and VEGF was measured using Western blot. Expression of IL6 and IL8 was measured using real-time polymerase chain reaction or enzyme-linked immunosorbent assay. Electron microscopy was performed to observe the effects of nicotine on morphological changes of mice retina or cultured RPE cells, and filamentous actin in RPE cells was stained with phalloidin. Electron microscopy revealed that nicotine-treated mice showed thinner outer nuclear layers, fewer pigment granules in RPE cells, and a damaged photoreceptor-RPE interface when compared with age-control mice. When added to cultured RPE cells, nicotine induced accumulation of osmiophilic lamellated intracellular inclusions in cytoplasm, mitochondrion hypertrophy and vacuolar degeneration, and redistribution of actin in cells without affecting cell proliferation. Expression of MMP2 and MMP9 in nicotine-treated RPE cells was decreased. Nicotine-induced changes in RPE morphology and function provide insight into pathogenesis of smoking-related retinal diseases.
Collapse
Affiliation(s)
- Lingling Yang
- State Key Lab Cultivation Base, Shandong Provincial Key Lab of Ophthalmology, Shandong Eye Institute, Qingdao, China
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Hollyfield JG, Perez VL, Salomon RG. A hapten generated from an oxidation fragment of docosahexaenoic acid is sufficient to initiate age-related macular degeneration. Mol Neurobiol 2010; 41:290-8. [PMID: 20221855 DOI: 10.1007/s12035-010-8110-z] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2009] [Accepted: 02/15/2010] [Indexed: 01/16/2023]
Abstract
The protein adduct carboxyethylpyrrole (CEP) is present in age-related macular degeneration (AMD) eye tissue and in the blood of AMD patients at higher levels than found in age-matched non-AMD tissues. Autoantibodies to CEP are also higher in AMD blood samples than in controls. To test the hypothesis that this hapten is causally involved in initiating an inflammatory response in AMD, we immunized C57BL/6J mice with mouse serum albumin (MSA) adducted with CEP. Immunized mice develop antibodies to CEP, fix complement component-3 in Bruch's membrane, accumulate drusen below the retinal pigment epithelium during aging, show decreased a- and b-wave amplitudes in response to light, and develop lesions in the retinal pigment epithelium mimicking geographic atrophy, the blinding end-stage condition characteristic of the dry form of AMD. Inflammatory cells are present in the region of lesions and may be actively involved in the pathology observed. We conclude that early immunization of mice with CEP-adducted MSA sensitizes these animals to the ongoing production of CEP adducts in the outer retina where DHA is abundant and the conditions for oxidative damage are permissive. In response to this early sensitization, the immune system mounts a complement-mediated attack on the cells of the outer retina where CEP adducts are formed. This animal model for AMD is the first that was developed from an inflammatory signal discovered in eye tissue and blood from AMD patients. It provides a novel opportunity for dissecting the early pathology of AMD and the immune response contributing to this disorder. The availability of a mouse with a mechanistically based AMD-like disease that progresses rapidly is highly desirable. Such a model will allow for the efficient preclinical testing of the much-needed therapeutics quickly and inexpensively.
Collapse
Affiliation(s)
- Joe G Hollyfield
- Cole Eye Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA.
| | | | | |
Collapse
|
45
|
Ramkumar HL, Zhang J, Chan CC. Retinal ultrastructure of murine models of dry age-related macular degeneration (AMD). Prog Retin Eye Res 2010; 29:169-90. [PMID: 20206286 DOI: 10.1016/j.preteyeres.2010.02.002] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Age-related macular degeneration (AMD) is the most prevalent form of irreversible blindness worldwide in the elderly population. The pathology of dry AMD consists of macular degeneration of photoreceptors and the RPE, lipofuscin (A2E) accumulation, and drusen formation. Mice have been widely used for generating models that simulate human AMD features for investigating the pathogenesis, treatment and prevention of the disease. Although the mouse has no macula, focal atrophy of photoreceptors and RPE, lipofuscin accumulation, and increased A2E can develop in aged mouse eyes. However, drusen are rarely seen in mice because of their simpler Bruch's membrane and different process of lipofuscin extrusion compared with humans. Thus, analyzing basal deposits at the ultrastructural level and understanding the ultrastructural pathologic differences between various mouse AMD models are critical to comprehending the significance of research findings and response to possible therapeutic options for dry AMD. Based on the multifactorial pathogenesis of AMD, murine dry AMD models can be classified into three groups. First, genetically engineered mice that target genes related to juvenile macular dystrophies are the most common models, and they include abcr(-/-) (Stargardt disease), transgenic ELOVL4 (Stargardt-3 dominant inheritary disease), Efemp1(R345W/R345W) (Doyne honeycomb retinal dystrophy), and Timp3(S156C/S156C) (Sorsby fundus dystrophy) mice. Other murine models target genes relevant to AMD, including inflammatory genes such as Cfh(-/-), Ccl2(-/-), Ccr2(-/-), Cx3cr1(-/-), and Ccl2(-/-)/cx3cr1(-/-), oxidative stress associated genes such as Sod1(-/-) and Sod2 knockdown, metabolic pathway genes such as neprilysin(-/-) (amyloid beta), transgenic mcd/mcd (cathepsin D), Cp(-/-)/Heph(-/Y) (ferroxidase ceruloplasmin/hepaestin, iron metabolism), and transgenic ApoE4 on high fat and high cholesterol diet (lipid metabolism). Second, mice have also been immunologically manipulated by immunization with carboxyethylpyrrole (CEP), an oxidative fragment of DHA found in drusen, and found to present with dry AMD features. Third, natural mouse strains such as arrd2/arrd2 (Mdm gene mutation) and the senescence accelerated mice (SAM) spontaneously develop features of dry AMD like photoreceptor atrophy and thickening of Bruch's membrane. All the aforementioned models develop retinal lesions with various features that simulate dry AMD lesions: focal photoreceptor degeneration, abnormal RPE with increased lipofuscin, basal infolding, decreased melanosomes and degeneration. However, Bruch's membrane changes are less common. Most mice develop retinal lesions at an older age (6-24 months, depending on the models), while the Ccl2(-/-)/cx3cr1(-/-) mice develop lesions by 4-6 weeks. Although murine models present various degrees of retinal and/or RPE degeneration, classical drusen is extremely rare. Using electron microscopy, small drusenoid deposits are found between RPE and Bruch's membrane in a few models including Efemp1(R345W/R345W), Ccl2(-/-)/cx3cr1(-/-), neprilysin(-/-), transgenic mcd/mcd, and ApoE4 transgenic mice on a high fat diet. High A2E levels are measured in the retinas of abcr(-/-), transgenic ELOVL4, and Ccl2(-/-)/cx3cr1(-/-) mice. In summary, murine models provide useful tools for studying AMD pathogenesis and evaluating novel therapies for this disease. This review compares the major dry AMD murine models and discusses retinal pathology at the ultrastructural level.
Collapse
Affiliation(s)
- Hema L Ramkumar
- Immunopathology Section, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, MD 20892-1857, USA
| | | | | |
Collapse
|
46
|
Albert DM, Neekhra A, Wang S, Darjatmoko SR, Sorenson CM, Dubielzig RR, Sheibani N. Development of choroidal neovascularization in rats with advanced intense cyclic light-induced retinal degeneration. ACTA ACUST UNITED AC 2010; 128:212-22. [PMID: 20142545 DOI: 10.1001/archophthalmol.2009.395] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES To study the progressive changes of intense cyclic light-induced retinal degeneration and to determine whether it results in choroidal neovascularization (CNV). METHODS Albino rats were exposed to 12 hours of 3000-lux cyclic light for 1, 3, or 6 months. Fundus examination, fundus photography, fluorescein and indocyanine green angiography, and optical coherence tomography were performed prior to euthanization. Light-exposed animals were euthanized after 1, 3, or 6 months for histopathological evaluation. Retinas were examined for the presence of 4-hydroxy-2-nonenal- and nitrotyrosine-modified proteins by immunofluorescence staining. RESULTS Long-term intense cyclic light exposure resulted in retinal degeneration with loss of the outer segments of photoreceptors and approximately two-thirds of the outer nuclear layer as well as development of subretinal pigment epithelium neovascularization after 1 month. Almost the entire outer nuclear layer was absent with the presence of CNV, which penetrated the Bruch membrane and extended into the outer retina after 3 months. Absence of the outer nuclear layer, multiple foci of CNV, retinal pigment epithelial fibrous metaplasia, and connective tissue bands containing blood vessels extending into the retina were observed after 6 months. All intense light-exposed animals showed an increased presence of 4-hydroxy-2-nonenal and nitrotyrosine staining. Optical coherence tomographic and angiographic studies confirmed retinal thinning and leakiness of the newly formed blood vessels. CONCLUSIONS Our results suggest that albino rats develop progressive stages of retinal degeneration and CNV after long-term intense cyclic light exposure, allowing the detailed study of the pathogenesis and treatment of age-related macular degeneration. CLINICAL RELEVANCE The ability to study the progressive pathogenesis of age-related macular degeneration and CNV will provide detailed knowledge about the disease and aid in the development of target-specific therapy.
Collapse
Affiliation(s)
- Daniel M Albert
- Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, 600 Highland Ave, K6/458 CSC, Madison, WI 53792-4673, USA
| | | | | | | | | | | | | |
Collapse
|
47
|
Curcio CA, Johnson M, Huang JD, Rudolf M. Aging, age-related macular degeneration, and the response-to-retention of apolipoprotein B-containing lipoproteins. Prog Retin Eye Res 2009; 28:393-422. [PMID: 19698799 PMCID: PMC4319375 DOI: 10.1016/j.preteyeres.2009.08.001] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The largest risk factor for age-related macular degeneration (ARMD) is advanced age. A prominent age-related change in the human retina is the accumulation of histochemically detectable neutral lipid in normal Bruch's membrane (BrM) throughout adulthood. This change has the potential to have a major impact on physiology of the retinal pigment epithelium (RPE). It occurs in the same compartment as drusen and basal linear deposit, the pathognomonic extracellular, lipid-containing lesions of ARMD. Here we present evidence from light microscopic histochemistry, ultrastructure, lipid profiling of tissues and isolated lipoproteins, and gene expression analysis that this deposition can be accounted for by esterified cholesterol-rich, apolipoprotein B-containing lipoprotein particles constitutively produced by the RPE. This work collectively allows ARMD lesion formation and its aftermath to be conceptualized as a response to the retention of a sub-endothelial apolipoprotein B lipoprotein, similar to a widely accepted model of atherosclerotic coronary artery disease (CAD) (Tabas et al., 2007). This approach provides a wide knowledge base and sophisticated clinical armamentarium that can be readily exploited for the development of new model systems and the future benefit of ARMD patients.
Collapse
Affiliation(s)
- Christine A Curcio
- Department of Ophthalmology, University of Alabama School of Medicine, Birmingham, AL 35294-0009, USA.
| | | | | | | |
Collapse
|
48
|
Estrogen receptor beta protects against in vivo injury in RPE cells. Exp Eye Res 2009; 90:10-6. [PMID: 19799898 DOI: 10.1016/j.exer.2009.09.001] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2009] [Revised: 08/28/2009] [Accepted: 09/03/2009] [Indexed: 11/21/2022]
Abstract
Epidemiological data suggest that estrogen deficiency in postmenopausal women may contribute to the severity of AMD. We discovered that 17beta-estradiol (E2) was a crucial regulator of the severity of extracellular matrix turnover (ECM) dysregulation both in vivo and in vitro. We also found in vitro that the presence of estrogen receptor (ER)beta regulates MMP-2 activity. Therefore in an attempt to delineate the role of the ER subtypes, female estrogen receptor knockout (ERKO) mice were fed a high-fat diet, and the eyes were exposed to seven 5-second doses of nonphototoxic levels of blue-green light over 2 weeks. Three months after cessation of blue light treatment, transmission electron microscopy was performed to assess severity of deposits, Bruchs membrane changes, and choriocapillaris endothelial morphology. We found that changes in the trimolecular complex of pro-MMP-2, MMP-14 and TIMP-2 correlated with increased Bruch's membrane thickening or sub-retinal deposit formation (basal laminar deposits) in ERKObeta mice. In addition RPE isolated from ERKObeta mice had an increase in expression of total collagen and a decrease in MMP-2 activity. Finally we found that ERK an intermediate signaling molecule in the MMP pathway was activated in RPE isolated from ERKObeta mice. These data suggest that mice which lack ERbeta are more susceptible to in vivo injury associated with environmental light and high fat diet.
Collapse
|
49
|
Sallo FB, Bereczki E, Csont T, Luthert PJ, Munro P, Ferdinandy P, Sántha M, Lengyel I. Bruch's membrane changes in transgenic mice overexpressing the human biglycan and apolipoprotein b-100 genes. Exp Eye Res 2009; 89:178-86. [PMID: 19324038 DOI: 10.1016/j.exer.2009.03.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2009] [Revised: 03/11/2009] [Accepted: 03/11/2009] [Indexed: 11/18/2022]
Abstract
Age-Related Macular Degeneration (AMD) is characterized by the accumulation of lipid- and protein-rich deposits in Bruch's Membrane (BrM). A consequent decrease in hydraulic conductivity and impairment of transport through BrM may play a central role in the pathogenesis of AMD. The mechanism of deposit formation in AMD had been suggested to show similarities to the formation of atherosclerotic plaques in which the interactions of extracellular matrix proteoglycans with apolipoprotein-B 100 (apoB-100) play an important role. A prime candidate for this interaction is the small leucin-rich proteoglycan biglycan. The aim of our study was to test the effect of the simultaneous overexpression of human apoB-100 and biglycan genes in combination with a high-cholesterol diet on BrM morphology in transgenic mice. Six-weeks-old homozygous apoB-100 or biglycan, hemizygous apoB-100/biglycan transgenic and wild-type C57Bl/6 mice were fed either a standard chow or a diet supplemented with 2% cholesterol for 17 weeks. Animals were sacrificed, serum lipid levels were measured and eyes were processed for transmission electron microscopy (TEM) according to standard protocol. Morphometric analysis of digitally acquired TEM images of BrM showed that in apoB-100 and double transgenic animals fed a high-cholesterol diet, the BrM thickness was significantly increased compared to wild-type animals. Both groups had electron-lucent profiles in clusters, scattered throughout the collagenous layers of BrM, and focal nodules of an amorphous material of intermediate electron-density between the plasma and basement membranes of the retinal pigment epithelium (RPE). BrM thickness in these two groups correlated well with elevated cholesterol levels. Unexpectedly, animals overexpressing biglycan alone showed a marked, diet-independent increase in BrM thickness associated with a layer of a basement membrane-like material in outer BrM. The effects of biglycan overexpression are intriguing and further investigations are needed to elucidate the underlying mechanisms.
Collapse
Affiliation(s)
- Ferenc B Sallo
- Department of Ocular Biology and Therapeutics, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Fujihara M, Bartels E, Nielsen LB, Handa JT. A human apoB100 transgenic mouse expresses human apoB100 in the RPE and develops features of early AMD. Exp Eye Res 2009; 88:1115-23. [PMID: 19450445 DOI: 10.1016/j.exer.2009.01.017] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2008] [Revised: 01/28/2009] [Accepted: 01/28/2009] [Indexed: 11/25/2022]
Abstract
apoB100 lipoprotein particles have been found to accumulate in Bruch membrane prior to the development of age-related macular degeneration (AMD). This work was performed to determine whether mice that overexpress apoB100 in the RPE/choroid and liver develop landmarks of early AMD over time. Mice transgenic for a human genomic fragment encoding the full length human apoB ("apoB100" mice) and litter-mate control mice were given a normal chow or high-fat diet for 12 months. Mice were evaluated for human apoB mRNA expression in the RPE/choroid and liver by RT-qPCR. Phenotypic changes associated with early AMD were evaluated by ultrastructural analysis using transmission electron microscopy. Changes were semi-quantified using linear regression analysis. Both the RPE/choroid and liver of apoB100 mice expressed both human and mouse apoB mRNA. Transmission electron microscopy showed ultrastructural changes consistent with early human AMD including loss of basal infoldings and accumulation of cytoplasmic vacuoles in the RPE, and basal laminar deposits containing long-spacing collagen and heterogeneous debris in Bruch membrane of apoB100 mice. In apoB100 mice given a high-fat diet, basal linear-like deposits were identified in 12-month-old mice. Linear regression analysis showed that the genotype (human apoB transgene) was a stronger influencing factor than high-fat diet in producing AMD-like lesions used in this study. Human apoB100 transgenic mice overexpress apoB in RPE and, with time, develop validated phenotypic changes that are seen in early human AMD. The phenotypic changes were aggravated by feeding a high-fat diet. The apoB100 mouse model could be valuable in determining the role of apoB-containing lipoproteins in triggering the onset of early AMD.
Collapse
Affiliation(s)
- Masashi Fujihara
- Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, MD 21287, USA
| | | | | | | |
Collapse
|