1
|
Brinks J, van Dijk EHC, Klaassen I, Schlingemann RO, Kielbasa SM, Emri E, Quax PHA, Bergen AA, Meijer OC, Boon CJF. Exploring the choroidal vascular labyrinth and its molecular and structural roles in health and disease. Prog Retin Eye Res 2021; 87:100994. [PMID: 34280556 DOI: 10.1016/j.preteyeres.2021.100994] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 07/04/2021] [Accepted: 07/07/2021] [Indexed: 12/14/2022]
Abstract
The choroid is a key player in maintaining ocular homeostasis and plays a role in a variety of chorioretinal diseases, many of which are poorly understood. Recent advances in the field of single-cell RNA sequencing have yielded valuable insights into the properties of choroidal endothelial cells (CECs). Here, we review the role of the choroid in various physiological and pathophysiological mechanisms, focusing on the role of CECs. We also discuss new insights regarding the phenotypic properties of CECs, CEC subpopulations, and the value of measuring transcriptomics in primary CEC cultures derived from post-mortem eyes. In addition, we discuss key phenotypic, structural, and functional differences that distinguish CECs from other endothelial cells such as retinal vascular endothelial cells. Understanding the specific clinical and molecular properties of the choroid will shed new light on the pathogenesis of the broad clinical range of chorioretinal diseases such as age-related macular degeneration, central serous chorioretinopathy and other diseases within the pachychoroid spectrum, uveitis, and diabetic choroidopathy. Although our knowledge is still relatively limited with respect to the clinical features and molecular pathways that underlie these chorioretinal diseases, we summarise new approaches and discuss future directions for gaining new insights into these sight-threatening diseases and highlight new therapeutic strategies such as pluripotent stem cell‒based technologies and gene therapy.
Collapse
Affiliation(s)
- J Brinks
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - E H C van Dijk
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands
| | - I Klaassen
- Ocular Angiogenesis Group, Departments of Ophthalmology and Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands
| | - R O Schlingemann
- Ocular Angiogenesis Group, Departments of Ophthalmology and Medical Biology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands; Department of Ophthalmology, University of Lausanne, Jules Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - S M Kielbasa
- Department of Medical Statistics and Bioinformatics, Leiden University Medical Center, Leiden, the Netherlands
| | - E Emri
- Department of Clinical Genetics, Section of Ophthalmogenetics, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - P H A Quax
- Department of Vascular Surgery, Leiden University Medical Center, Leiden, the Netherlands; Einthoven Laboratory for Experimental Vascular Medicine, Leiden University Medical Center, Leiden, the Netherlands
| | - A A Bergen
- Department of Clinical Genetics, Section of Ophthalmogenetics, Amsterdam University Medical Centers, Amsterdam, the Netherlands
| | - O C Meijer
- Department of Medicine, Division of Endocrinology and Metabolism, Leiden University Medical Center, Leiden, the Netherlands
| | - C J F Boon
- Department of Ophthalmology, Leiden University Medical Center, Leiden, the Netherlands; Department of Ophthalmology, Amsterdam University Medical Centers, University of Amsterdam, Amsterdam, the Netherlands.
| |
Collapse
|
2
|
Whitmore SS, Sohn EH, Chirco KR, Drack AV, Stone EM, Tucker BA, Mullins RF. Complement activation and choriocapillaris loss in early AMD: implications for pathophysiology and therapy. Prog Retin Eye Res 2015; 45:1-29. [PMID: 25486088 PMCID: PMC4339497 DOI: 10.1016/j.preteyeres.2014.11.005] [Citation(s) in RCA: 159] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 11/19/2014] [Accepted: 11/25/2014] [Indexed: 12/24/2022]
Abstract
Age-related macular degeneration (AMD) is a common and devastating disease that can result in severe visual dysfunction. Over the last decade, great progress has been made in identifying genetic variants that contribute to AMD, many of which lie in genes involved in the complement cascade. In this review we discuss the significance of complement activation in AMD, particularly with respect to the formation of the membrane attack complex in the aging choriocapillaris. We review the clinical, histological and biochemical data that indicate that vascular loss in the choroid occurs very early in the pathogenesis of AMD, and discuss the potential impact of vascular dropout on the retinal pigment epithelium, Bruch's membrane and the photoreceptor cells. Finally, we present a hypothesis for the pathogenesis of early AMD and consider the implications of this model on the development of new therapies.
Collapse
Affiliation(s)
- S Scott Whitmore
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| | - Elliott H Sohn
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| | - Kathleen R Chirco
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| | - Arlene V Drack
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| | - Edwin M Stone
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| | - Budd A Tucker
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| | - Robert F Mullins
- The Stephen A. Wynn Institute for Vision Research, The University of Iowa, United States; Department of Ophthalmology and Visual Sciences, The University of Iowa, United States
| |
Collapse
|
3
|
Abstract
Geographic atrophy is a dry form of age-related macular degeneration (AMD) and a leading cause of blindness in the United States. The mechanism of the disease is unknown and there is no treatment for the disease at present. During aging and the development of geographic atrophy, there is a significant decrease in choroidal density. Since mouse is the only mammal that allows precise genomic manipulation, in vivo studies with genetically altered mice are likely to provide more mechanistic insights about the pathogenic mechanisms of the disease. To establish an efficient and quantitative procedure measuring choroidal density in mice for studies related to choroidal biology and geographic atrophy, we developed a computer-assisted semi-quantitative procedure for mouse choroidal density. In this study, mouse choroidal vessels were immunostained with anti-CD31 antibody and were detected by fluorescently labeled secondary antibody. Confocal or fluorescent microscopic images were analyzed with Adobe Photoshop software to determine the relative density of choroidal vessels. This procedure is relatively simple to perform and can be utilized to measure choroidal density efficiently in mouse models, which may be useful for preclinical studies relevant to the pathogenic mechanisms and therapeutics of geographic atrophy.
Collapse
|
4
|
Patterson AD, Bonzo JA, Li F, Krausz KW, Eichler GS, Aslam S, Tigno X, Weinstein JN, Hansen BC, Idle JR, Gonzalez FJ. Metabolomics reveals attenuation of the SLC6A20 kidney transporter in nonhuman primate and mouse models of type 2 diabetes mellitus. J Biol Chem 2011; 286:19511-22. [PMID: 21487016 PMCID: PMC3103330 DOI: 10.1074/jbc.m111.221739] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2011] [Revised: 04/08/2011] [Indexed: 01/15/2023] Open
Abstract
To enhance understanding of the metabolic indicators of type 2 diabetes mellitus (T2DM) disease pathogenesis and progression, the urinary metabolomes of well characterized rhesus macaques (normal or spontaneously and naturally diabetic) were examined. High-resolution ultra-performance liquid chromatography coupled with the accurate mass determination of time-of-flight mass spectrometry was used to analyze spot urine samples from normal (n = 10) and T2DM (n = 11) male monkeys. The machine-learning algorithm random forests classified urine samples as either from normal or T2DM monkeys. The metabolites important for developing the classifier were further examined for their biological significance. Random forests models had a misclassification error of less than 5%. Metabolites were identified based on accurate masses (<10 ppm) and confirmed by tandem mass spectrometry of authentic compounds. Urinary compounds significantly increased (p < 0.05) in the T2DM when compared with the normal group included glycine betaine (9-fold), citric acid (2.8-fold), kynurenic acid (1.8-fold), glucose (68-fold), and pipecolic acid (6.5-fold). When compared with the conventional definition of T2DM, the metabolites were also useful in defining the T2DM condition, and the urinary elevations in glycine betaine and pipecolic acid (as well as proline) indicated defective re-absorption in the kidney proximal tubules by SLC6A20, a Na(+)-dependent transporter. The mRNA levels of SLC6A20 were significantly reduced in the kidneys of monkeys with T2DM. These observations were validated in the db/db mouse model of T2DM. This study provides convincing evidence of the power of metabolomics for identifying functional changes at many levels in the omics pipeline.
Collapse
Affiliation(s)
| | - Jessica A. Bonzo
- From the Laboratory of Metabolism, Center for Cancer Research, and
| | - Fei Li
- From the Laboratory of Metabolism, Center for Cancer Research, and
| | | | - Gabriel S. Eichler
- the Genomics and Bioinformatics Group, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Sadaf Aslam
- the Departments of Internal Medicine and Pediatrics, University of South Florida, Tampa, Florida 33612, and
| | - Xenia Tigno
- the Departments of Internal Medicine and Pediatrics, University of South Florida, Tampa, Florida 33612, and
| | - John N. Weinstein
- the Genomics and Bioinformatics Group, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892
| | - Barbara C. Hansen
- the Departments of Internal Medicine and Pediatrics, University of South Florida, Tampa, Florida 33612, and
| | - Jeffrey R. Idle
- the Department of Clinical Pharmacology, University of Bern, Bern 3010, Switzerland
| | | |
Collapse
|
5
|
Le YZ, Bai Y, Zhu M, Zheng L. Temporal requirement of RPE-derived VEGF in the development of choroidal vasculature. J Neurochem 2010; 112:1584-92. [PMID: 20067573 DOI: 10.1111/j.1471-4159.2010.06573.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Vascular endothelial growth factor (VEGF-A or VEGF) is a potent growth factor for the development of retinal and choroidal vasculatures. To define the temporal requirement of the retinal pigmented epithelium (RPE)-derived VEGF in choroidal vascular development, we generated conditional VEGF knockout mice using an inducible Cre/lox system. The loss of the RPE-derived VEGF was confirmed with immunoblotting and immunohistochemistry. Retinal function and structure were assessed with electroretinography and histology, respectively. Choroidal vascular density was analyzed with computer-assisted semi-quantitative assay using fluorescently labeled choroidal flat-mounts. Induction of RPE-specific VEGF disruption at embryonic day 10 (E10) or E13 for 2 days caused regulatable decreases in choroidal vascular density, photoreceptor function, and photoreceptor outer nuclear layer thickness. The loss of the RPE-produced VEGF after E15 did not cause detectable defects in choroidal vasculatures and photoreceptor function and morphology. These results suggest that the RPE-derived VEGF plays a critical role in choroidal vascular development during organogenesis before E15.
Collapse
Affiliation(s)
- Yun-Zheng Le
- Department of Medicine Endocrinology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104, USA
| | | | | | | |
Collapse
|
6
|
Hasegawa T, McLeod DS, Bhutto IA, Prow T, Merges CA, Grebe R, Lutty GA. The embryonic human choriocapillaris develops by hemo-vasculogenesis. Dev Dyn 2007; 236:2089-100. [PMID: 17654716 PMCID: PMC4943668 DOI: 10.1002/dvdy.21231] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The purpose of this study was to characterize normal human choroidal vascular development from 6-23 weeks gestation (WG). Markers of endothelial cells (EC) (CD34, CD31, vWf), angioblasts and EC (CD39), leukocytes (CD45), erythroblasts (epsilon chain of hemoglobin, Hb-e), proliferating cells (Ki67), and VEGFR-2 were employed. At 6-7 WG, many erythroblasts were observed within islands of precursor cells in the choriocapillaris layer and others were independent from the islands. Many erythroblasts (Hb-epsilon(+)) were also positive for EC markers and/or VEGFR-2. By 8-12 WG, most of the Hb-epsilon cells had disappeared and vascular lumens became apparent. At 14-23 WG, some EC were proliferating on the scleral side of choriocapillaris in association with forming deeper vessels. In conclusion, embryonic choriocapillaris appears to form initially by hemo-vasculogenesis (blood vessels and blood cells form simultaneously from common precursors) while angiogenesis appears to be the mode of intermediate and large choroidal vessel development in the fetus.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Gerard A. Lutty
- Correspondence to: Gerard A. Lutty, Ph.D., 170 Woods Research Building, Johns Hopkins Hospital, 600 North Wolfe St., Baltimore, MD 21287-9115.
| |
Collapse
|
7
|
Chen CP, Chang SC, Vivian Yang WC. High glucose alters proteoglycan expression and the glycosaminoglycan composition in placentas of women with gestational diabetes mellitus and in cultured trophoblasts. Placenta 2006; 28:97-106. [PMID: 16630654 DOI: 10.1016/j.placenta.2006.02.009] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 02/07/2006] [Accepted: 02/14/2006] [Indexed: 10/24/2022]
Abstract
Impaired glucose metabolism with diabetes may alter the expressions of proteoglycans (PGs), which may impair the biological functions of placenta. In this study, we investigated the expression of PGs and their conjugated glycosaminoglycan (GAG) composition in the placentas of mothers with gestational diabetes mellitus (GDM) and trophoblasts cultured in a high-glucose condition. The PGs by guanidine/HCl extraction and DEAE Sepharose fractionation followed by GAG degradation enzyme digestion analyses showed that the expression of chondroitin sulfate and/or dermatan sulfate (CS/DS) PGs was increased whereas the heparan sulfate (HS) PG was decreased in GDM placentas compared to controls. Western blot analyses demonstrated that the increased CS/DS PGs in GDM placentas were predominantly the small leucine-rich proteoglycans (SLRPs), decorin and biglycan. Increased mRNA expression level was consistently shown by quantitative real-time PCR. Immunohistochemistry indicated intensive staining of decorin and biglycan in the diabetic placenta with different localizations. Additionally, the basement membrane HSPG, perlecan was found to contain both CS/DS and HS in GDM placentas and plain HS in controls. Similar findings of PG alterations induced by hyperglycemia were observed in cultured trophoblast in a high-glucose condition. This study demonstrated that hyperglycemia induced not only the gene expressions of PGs but also alterations in the carried GAG type and composition.
Collapse
Affiliation(s)
- C-P Chen
- Division of High Risk Pregnancy, Mackay Memorial Hospital, Taipei, Taiwan; Mackay Medicine, Nursing and Management College, Taipei, Taiwan
| | | | | |
Collapse
|
8
|
Johnson MA, Lutty GA, McLeod DS, Otsuji T, Flower RW, Sandagar G, Alexander T, Steidl SM, Hansen BC. Ocular structure and function in an aged monkey with spontaneous diabetes mellitus. Exp Eye Res 2005; 80:37-42. [PMID: 15652524 DOI: 10.1016/j.exer.2004.08.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2004] [Accepted: 08/05/2004] [Indexed: 11/27/2022]
Abstract
Diabetes mellitus develops spontaneously in middle-aged, obese rhesus monkeys, thus making them a good model for examining the effects of co-morbid factors on the development of end-organ damage. Changes in structure and function in the eyes of one monkey who spontaneously developed type 2 diabetes are reported here. This animal had concomitant hypertension, high levels of triglycerides and serum cholesterol, and a low fraction of high-density lipoprotein. The eyes showed intraretinal hemorrhages and large areas of retinal capillary nonperfusion. Indo-cyanin green (ICG) angiography revealed a large area of non- or poorly perfused choriocapillaris in one eye, and immunohistochemistry showed loss of viable choriocapillaries in this region. Both basal laminar deposits and hard drusen were present on areas of Bruch's membrane adjacent to nonviable choriocapillaris. Blood flow via the nasal posterior ciliary arteries to this section of choroid was not detectable by color duplex Doppler ultrasound, indicating contribution of extraocular vascular disease to ischemia in this eye. There was a severe decline in number of photoreceptor inner and outer segments, and corresponding reductions in the multifocal electroretinogram (ERG), in the areas of choriocapillaris loss. The ganzfeld ERG indicated loss in both inner and outer retinal function. Much of the ganglion cell layer was absent throughout the retina, possibly reflecting the effect of diabetes as well as chronic open angle glaucoma; the latter diagnosis supported by elevated intraocular pressures and excavated optic disks. In summary, high resolution, enzyme histochemical and histopathological analyses of a diabetic hypertensive monkey retina and choroid after serial functional in vivo analyses have demonstrated the relationship between vascular dysfunction and visual function loss. Choroidal vascular dysfunction in both large and small vessels was associated with age-related macular degeneration-like changes in Bruch's membrane and photoreceptor degeneration.
Collapse
Affiliation(s)
- M A Johnson
- Department of Ophthalmology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|