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Zhang C, Jiao Q, Wang M, Zhu Z, Zhao J, Zheng Y. High correlated color temperature artificial lighting impairs retinal pigment epithelium integrity and chloride ion transport: A potential mechanism for choroidal thinning. Biochem Biophys Res Commun 2024; 718:150078. [PMID: 38735140 DOI: 10.1016/j.bbrc.2024.150078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 04/04/2024] [Accepted: 05/07/2024] [Indexed: 05/14/2024]
Abstract
Among the environmental factors contributing to myopia, the role of correlated color temperature (CCT) of ambient light emerges as a key element warranting in-depth investigation. The choroid, a highly vascularized and dynamic structure, often undergoes thinning during the progression of myopia, though the precise mechanism remains elusive. The retinal pigment epithelium (RPE), the outermost layer of the retina, plays a pivotal role in regulating the transport of ion and fluid between the subretinal space and the choroid. A hypothesis suggests that variations in choroidal thickness (ChT) may be modulated by transepithelial fluid movement across the RPE. Our experimental results demonstrate that high CCT illumination significantly compromised the integrity of tight junctions in the RPE and disrupted chloride ion transport. This functional impairment of the RPE may lead to a reduction in fluid transfer across the RPE, consequently resulting in choroidal thinning and potentially accelerating axial elongation. Our findings provide support for the crucial role of the RPE in regulating ChT. Furthermore, we emphasize the potential hazards posed by high CCT artificial illumination on the RPE, the choroid, and refractive development, underscoring the importance of developing eye-friendly artificial light sources to aid in the prevention and control of myopia.
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Affiliation(s)
- Chenchen Zhang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130041, PR China
| | - Qing Jiao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130041, PR China
| | - Mingxuan Wang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130041, PR China
| | - Zhe Zhu
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Eye Institute of Shandong First Medical University, Qingdao, 266000, PR China
| | - Jing Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130041, PR China
| | - Yajuan Zheng
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130041, PR China.
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Chen R, Swale DR. Functional interactions between potassium-chloride cotransporter (KCC) and inward rectifier potassium (Kir) channels in the insect central nervous system. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2023; 192:105389. [PMID: 37105628 DOI: 10.1016/j.pestbp.2023.105389] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/07/2023] [Accepted: 03/07/2023] [Indexed: 06/19/2023]
Abstract
The K+/Cl- cotransporter (KCC) is the primary mechanism by which mature neurons maintain low intracellular chloride (Cl-) concentration and has been shown to be functionally coupled to the GABA-gated chloride channels (GGCC) in Drosophila central neurons. Further, pharmacological inhibition of KCC has been shown to lead to acute toxicity of mosquitoes that highlights the toxicological relevance of insect KCC. Yet, gaps in knowledge remain regarding physiological drivers of KCC function and interactions of ion flux mechanisms upstream of GGCC in insects. Considering this, we employed electrophysiological and fluorescent microscopy techniques to further characterize KCC in the insect nervous system. Fluorescent microscopy indicated insect KCC2 is expressed in rdl neurons, which is the neuron type responsible for GABA-mediated neurotransmission, and are coexpressed with inward rectifier potassium (Kir) 2 channels. Coexpression of Kir2 and KCC2 suggested the possibility of functional coupling between these two K+ flux pathways. Indeed, extracellular recordings of Drosophila CNS showed pre-block of Kir channels prior to block of KCC led to a significant (P < 0.001) increase in CNS firing rates over baseline that when taken together, supports functional coupling of Kir to KCC function. Additionally, we documented a synergistic increase to toxicity of VU0463271, an established KCC inhibitor, above the expected additive toxicity after co-treatment with the Kir inhibitor, VU041. These data expand current knowledge regarding the physiological roles of KCC and Kir channels in the insect nervous system by defining additional pathways that facilitate inhibitory neurotransmission through GGCC.
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Affiliation(s)
- Rui Chen
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, United States of America
| | - Daniel R Swale
- Department of Entomology, Louisiana State University AgCenter, Baton Rouge, LA, United States of America; Emerging Pathogens Institute, Department of Entomology and Nematology, University of Florida, Gainesville, FL 32610, United States of America.
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Liu H, Schaeffel F, Yang Z, Feldkaemper MP. GABAB Receptor Activation Affects Eye Growth in Chickens with Visually Induced Refractive Errors. Biomolecules 2023; 13:biom13030434. [PMID: 36979369 PMCID: PMC10046083 DOI: 10.3390/biom13030434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Revised: 02/08/2023] [Accepted: 02/13/2023] [Indexed: 03/02/2023] Open
Abstract
This study aims to explore the role of GABAB receptors in the development of deprivation myopia (DM), lens-induced myopia (LIM) and lens-induced hyperopia (LIH). Chicks were intravitreally injected with 25 µg baclofen (GABABR agonist) in one eye and saline into the fellow eye. Choroidal thickness (ChT) was measured via OCT before and 2, 4, 6, 8, 24 h after injection. ChT decreased strongly at 6 and 8 h after baclofen injection and returned back to baseline level after 24 h. Moreover, chicks were monocularly treated with translucent diffusers, −7D or +7D lenses and randomly assigned to baclofen or saline treatment. DM chicks were injected daily into both eyes, while LIM and LIH chicks were monocularly injected into the lens-wearing eyes, for 4 days. Refractive error, axial length and ChT were measured before and after treatment. Dopamine and its metabolites were analyzed via HPLC. Baclofen significantly reduced the myopic shift and eye growth in DM and LIM eyes. However, it did not change ChT compared to respective saline-injected eyes. On the other hand, baclofen inhibited the hyperopic shift and choroidal thickening in LIH eyes. All the baclofen-injected eyes showed significantly lower vitreal DOPAC content. Since GABA is an inhibitory ubiquitous neurotransmitter, interfering with its signaling affects spatial retinal processing and therefore refractive error development with both diffusers and lenses.
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Affiliation(s)
- Hong Liu
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, 72076 Tuebingen, Germany
- Aier Institute of Optometry and Vision Science, Aier Eye Hospital Group, Changsha 410000, China
| | - Frank Schaeffel
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, 72076 Tuebingen, Germany
- Myopia Research Group, Institute of Molecular and Clinical Ophthalmology Basel (IOB), 4031 Basel, Switzerland
| | - Zhikuan Yang
- Aier Institute of Optometry and Vision Science, Aier Eye Hospital Group, Changsha 410000, China
- Hunan Province Optometry Engineering and Technology Research Center, Changsha 410000, China
- Hunan Province International Cooperation Base for Optometry Science and Technology, Changsha 410000, China
- Correspondence: (Z.Y.); (M.P.F.)
| | - Marita Pauline Feldkaemper
- Section of Neurobiology of the Eye, Ophthalmic Research Institute, University of Tuebingen, 72076 Tuebingen, Germany
- Correspondence: (Z.Y.); (M.P.F.)
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Huang Y, Chen X, Zhuang J, Yu K. The Role of Retinal Dysfunction in Myopia Development. Cell Mol Neurobiol 2022:10.1007/s10571-022-01309-1. [DOI: 10.1007/s10571-022-01309-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 11/16/2022] [Indexed: 11/27/2022]
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Brown DM, Mazade R, Clarkson-Townsend D, Hogan K, Datta Roy PM, Pardue MT. Candidate pathways for retina to scleral signaling in refractive eye growth. Exp Eye Res 2022; 219:109071. [PMID: 35447101 PMCID: PMC9701099 DOI: 10.1016/j.exer.2022.109071] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 03/25/2022] [Accepted: 04/05/2022] [Indexed: 12/22/2022]
Abstract
The global prevalence of myopia, or nearsightedness, has increased at an alarming rate over the last few decades. An eye is myopic if incoming light focuses prior to reaching the retinal photoreceptors, which indicates a mismatch in its shape and optical power. This mismatch commonly results from excessive axial elongation. Important drivers of the myopia epidemic include environmental factors, genetic factors, and their interactions, e.g., genetic factors influencing the effects of environmental factors. One factor often hypothesized to be a driver of the myopia epidemic is environmental light, which has changed drastically and rapidly on a global scale. In support of this, it is well established that eye size is regulated by a homeostatic process that incorporates visual cues (emmetropization). This process allows the eye to detect and minimize refractive errors quite accurately and locally over time by modulating the rate of elongation of the eye via remodeling its outermost coat, the sclera. Critically, emmetropization is not dependent on post-retinal processing. Thus, visual cues appear to influence axial elongation through a retina-to-sclera, or retinoscleral, signaling cascade, capable of transmitting information from the innermost layer of the eye to the outermost layer. Despite significant global research interest, the specifics of retinoscleral signaling pathways remain elusive. While a few pharmacological treatments have proven to be effective in slowing axial elongation (most notably topical atropine), the mechanisms behind these treatments are still not fully understood. Additionally, several retinal neuromodulators, neurotransmitters, and other small molecules have been found to influence axial length and/or refractive error or be influenced by myopigenic cues, yet little progress has been made explaining how the signal that originates in the retina crosses the highly vascular choroid to affect the sclera. Here, we compile and synthesize the evidence surrounding three of the major candidate pathways receiving significant research attention - dopamine, retinoic acid, and adenosine. All three candidates have both correlational and causal evidence backing their involvement in axial elongation and have been implicated by multiple independent research groups across diverse species. Two hypothesized mechanisms are presented for how a retina-originating signal crosses the choroid - via 1) all-trans retinoic acid or 2) choroidal blood flow influencing scleral oxygenation. Evidence of crosstalk between the pathways is discussed in the context of these two mechanisms.
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Affiliation(s)
- Dillon M Brown
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Reece Mazade
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Danielle Clarkson-Townsend
- Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA; Division of Sleep and Circadian Disorders, Brigham and Women's Hospital, Harvard Medical School, 221 Longwood Avenue, Boston, MA, 02115, USA; Division of Sleep Medicine, Harvard Medical School, Boston, MA, 02115, USA; Gangarosa Department of Environmental Health, Emory University, 1518 Clifton Rd, Atlanta, GA, 30322, USA
| | - Kelleigh Hogan
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Pooja M Datta Roy
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA
| | - Machelle T Pardue
- Department of Biomedical Engineering, Georgia Institute of Technology/Emory University, 313 Ferst Drive, Atlanta, GA, 30332, USA; Center for Visual and Neurocognitive Rehabilitation, Atlanta Veterans Affairs Healthcare System, 1670 Clairmont Rd, Atlanta, GA, 30033, USA.
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Zhang H, Wong CL, Shan SW, Li KK, Cheng AK, Lee KL, Ge J, To CH, Do CW. Characterisation of Cl‐ transporter and channels in experimentally induced myopic chick eyes. Clin Exp Optom 2021; 94:528-35. [DOI: 10.1111/j.1444-0938.2011.00611.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Hengli Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‐Sen University, China
- The Centre for Myopia Research, School of Optometry and the
| | - Chun Lung Wong
- The Centre for Myopia Research, School of Optometry and the
| | - Sze Wan Shan
- The Centre for Myopia Research, School of Optometry and the
| | - King Kit Li
- The Centre for Myopia Research, School of Optometry and the
| | - Angela K Cheng
- The Centre for Myopia Research, School of Optometry and the
| | - Kam Len Lee
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong SAR, China, E‐mail:
| | - Jian Ge
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat‐Sen University, China
| | - Chi Ho To
- The Centre for Myopia Research, School of Optometry and the
| | - Chi Wai Do
- The Centre for Myopia Research, School of Optometry and the
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RNA-seq and GSEA identifies suppression of ligand-gated chloride efflux channels as the major gene pathway contributing to form deprivation myopia. Sci Rep 2021; 11:5280. [PMID: 33674625 PMCID: PMC7935918 DOI: 10.1038/s41598-021-84338-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 01/15/2021] [Indexed: 12/13/2022] Open
Abstract
Currently there is no consensus regarding the aetiology of the excessive ocular volume that characterizes high myopia. Thus, we aimed to test whether the gene pathways identified by gene set enrichment analysis of RNA-seq transcriptomics refutes the predictions of the Retinal Ion Driven Efflux (RIDE) hypothesis when applied to the induction of form-deprivation myopia (FDM) and subsequent recovery (post-occluder removal). We found that the induction of profound FDM led to significant suppression in the ligand-gated chloride ion channel transport pathway via suppression of glycine, GABAA and GABAC ionotropic receptors. Post-occluder removal for short term recovery from FDM of 6 h and 24 h, induced significant upregulation of the gene families linked to cone receptor phototransduction, mitochondrial energy, and complement pathways. These findings support a model of form deprivation myopia as a Cl− ion driven adaptive fluid response to the modulation of the visual signal cascade by form deprivation that in turn affects the resultant ionic environment of the outer and inner retinal tissues, axial and vitreal elongation as predicted by the RIDE model. Occluder removal and return to normal light conditions led to return to more normal upregulation of phototransduction, slowed growth rate, refractive recovery and apparent return towards physiological homeostasis.
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Stone RA, Wei W, Sarfare S, McGeehan B, Engelhart KC, Khurana TS, Maguire MG, Iuvone PM, Nickla DL. Visual Image Quality Impacts Circadian Rhythm-Related Gene Expression in Retina and in Choroid: A Potential Mechanism for Ametropias. Invest Ophthalmol Vis Sci 2020; 61:13. [PMID: 32396635 PMCID: PMC7405616 DOI: 10.1167/iovs.61.5.13] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/21/2020] [Indexed: 12/11/2022] Open
Abstract
Purpose Stimulated by evidence implicating diurnal/circadian rhythms and light in refractive development, we studied the expression over 24 hours of selected clock and circadian rhythm-related genes in retina/retinal pigment epithelium (RPE) and choroid of experimental ametropias in chicks. Methods Newly hatched chicks, entrained to a 12-hour light/dark cycle for 12 to 14 days, either experienced nonrestricted vision OU (i.e., in both eyes) or received an image-blurring diffuser or a minus 10-diopter (D) or a plus 10-D defocusing lens over one eye. Starting 1 day later and at 4-hour intervals for 24 hours, the retina/RPE and choroid were separately dissected. Without pooling, total RNA was extracted, converted to cDNA, and assayed by quantitative PCR for the expression of the following genes: Opn4m, Clock, Npas2, Per3, Cry1, Arntl, and Mtnr1a. Results The expression of each gene in retina/RPE and in choroid of eyes with nonrestricted vision OU varied over 24 hours, with equal levels OU for most genes and times. Altered visual input influenced gene expression in complex patterns that varied by gene, visual input, time, and eye, affecting experimental eyes with altered vision and also contralateral eyes with nonrestricted vision. Discussion Altering visual input in ways known to induce ametropias alters the retinal/RPE and choroidal expression of circadian rhythm-related genes, further linking circadian biology with eye growth regulation. While further investigations are needed, studying circadian processes may help understand refractive mechanisms and the increasing myopia prevalence in contemporary societies where lighting patterns can desynchronize endogenous rhythms from the natural environmental light/dark cycle.
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Affiliation(s)
- Richard A. Stone
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Wenjie Wei
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Shanta Sarfare
- Department of Bioscience, New England College of Optometry, Boston, Massachusetts, United States
| | - Brendan McGeehan
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - K. Cameron Engelhart
- Department of Bioscience, New England College of Optometry, Boston, Massachusetts, United States
| | - Tejvir S. Khurana
- Department of Physiology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - Maureen G. Maguire
- Department of Ophthalmology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States
| | - P. Michael Iuvone
- Departments of Ophthalmology and Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Debora L. Nickla
- Department of Bioscience, New England College of Optometry, Boston, Massachusetts, United States
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Troilo D, Smith EL, Nickla DL, Ashby R, Tkatchenko AV, Ostrin LA, Gawne TJ, Pardue MT, Summers JA, Kee CS, Schroedl F, Wahl S, Jones L. IMI - Report on Experimental Models of Emmetropization and Myopia. Invest Ophthalmol Vis Sci 2019; 60:M31-M88. [PMID: 30817827 PMCID: PMC6738517 DOI: 10.1167/iovs.18-25967] [Citation(s) in RCA: 215] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 10/20/2018] [Indexed: 11/24/2022] Open
Abstract
The results of many studies in a variety of species have significantly advanced our understanding of the role of visual experience and the mechanisms of postnatal eye growth, and the development of myopia. This paper surveys and reviews the major contributions that experimental studies using animal models have made to our thinking about emmetropization and development of myopia. These studies established important concepts informing our knowledge of the visual regulation of eye growth and refractive development and have transformed treatment strategies for myopia. Several major findings have come from studies of experimental animal models. These include the eye's ability to detect the sign of retinal defocus and undergo compensatory growth, the local retinal control of eye growth, regulatory changes in choroidal thickness, and the identification of components in the biochemistry of eye growth leading to the characterization of signal cascades regulating eye growth and refractive state. Several of these findings provided the proofs of concepts that form the scientific basis of new and effective clinical treatments for controlling myopia progression in humans. Experimental animal models continue to provide new insights into the cellular and molecular mechanisms of eye growth control, including the identification of potential new targets for drug development and future treatments needed to stem the increasing prevalence of myopia and the vision-threatening conditions associated with this disease.
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Affiliation(s)
- David Troilo
- SUNY College of Optometry, State University of New York, New York, New York, United States
| | - Earl L. Smith
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Debora L. Nickla
- Biomedical Sciences and Disease, New England College of Optometry, Boston, Massachusetts, United States
| | - Regan Ashby
- Health Research Institute, University of Canberra, Canberra, Australia
| | - Andrei V. Tkatchenko
- Department of Ophthalmology, Department of Pathology and Cell Biology, Columbia University, New York, New York, United States
| | - Lisa A. Ostrin
- College of Optometry, University of Houston, Houston, Texas, United States
| | - Timothy J. Gawne
- School of Optometry, University of Alabama Birmingham, Birmingham, Alabama, United States
| | - Machelle T. Pardue
- Biomedical Engineering, Georgia Tech College of Engineering, Atlanta, Georgia, United States31
| | - Jody A. Summers
- College of Medicine, University of Oklahoma, Oklahoma City, Oklahoma, United States
| | - Chea-su Kee
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, SAR, China
| | - Falk Schroedl
- Departments of Ophthalmology and Anatomy, Paracelsus Medical University, Salzburg, Austria
| | - Siegfried Wahl
- Institute for Ophthalmic Research, University of Tuebingen, Zeiss Vision Science Laboratory, Tuebingen, Germany
| | - Lyndon Jones
- CORE, School of Optometry and Vision Science, University of Waterloo, Ontario, Canada
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Genetic Association Study of KCNQ5 Polymorphisms with High Myopia. BIOMED RESEARCH INTERNATIONAL 2017; 2017:3024156. [PMID: 28884119 PMCID: PMC5572591 DOI: 10.1155/2017/3024156] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 06/10/2017] [Accepted: 07/17/2017] [Indexed: 02/05/2023]
Abstract
Identification of genetic variations related to high myopia may advance our knowledge of the etiopathogenesis of refractive error. This study investigated the role of potassium channel gene (KCNQ5) polymorphisms in high myopia. We performed a case-control study of 1563 unrelated Han Chinese subjects (809 cases of high myopia and 754 emmetropic controls). Five tag single-nucleotide polymorphisms (SNPs) of KCNQ5 were genotyped, and association testing with high myopia was conducted using logistic regression analysis adjusted for sex and age to give Pasym values, and multiple comparisons were corrected by permutation test to give Pemp values. All five noncoding SNPs were associated with high myopia. The SNP rs7744813, previously shown to be associated with refractive error and myopia in two GWAS, showed an odds ratio of 0.75 (95% CI 0.63-0.90; Pemp = 0.0058) for the minor allele. The top SNP rs9342979 showed an odds ratio of 0.75 (95% CI 0.64-0.89; Pemp = 0.0045) for the minor allele. Both SNPs are located within enhancer histone marks and DNase-hypersensitive sites. Our data support the involvement of KCNQ5 gene polymorphisms in the genetic susceptibility to high myopia and further exploration of KCNQ5 as a risk factor for high myopia.
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Goldberg LA, Rucker FJ. Opposing effects of atropine and timolol on the color and luminance emmetropization mechanisms in chicks. Vision Res 2016; 122:1-11. [PMID: 26971621 PMCID: PMC4861675 DOI: 10.1016/j.visres.2016.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Revised: 03/04/2016] [Accepted: 03/08/2016] [Indexed: 11/29/2022]
Abstract
This study analyzed the luminance and color emmetropization response in chicks treated with the nonselective parasympathetic antagonist atropine and the sympathetic β-receptor blocker timolol. Chicks were binocularly exposed (8h/day) for 4days to one of three illumination conditions: 2Hz sinusoidal luminance flicker, 2Hz sinusoidal blue/yellow color flicker, or steady light (mean 680lux). Atropine experiments involved monocular daily injections of either 20μl of atropine (18nmol) or 20μl of phosphate-buffered saline. Timolol experiments involved monocular daily applications of 2 drops of 0.5% timolol or 2 drops of distilled H2O. Changes in the experimental eye were compared with those in the fellow eye after correction for the effects of saline/water treatments. Atropine caused a reduction in axial length with both luminance flicker (-0.078±0.021mm) and color flicker (-0.054±0.017mm), and a reduction in vitreous chamber depth with luminance flicker (-0.095±0.023mm), evoking a hyperopic shift in refraction (3.40±1.77D). Timolol produced an increase in axial length with luminance flicker (0.045±0.030mm) and a myopic shift in refraction (-4.07±0.92D), while color flicker caused a significant decrease in axial length (-0.046±0.017mm) that was associated with choroidal thinning (-0.046±0.015mm). The opposing effects on growth and refraction seen with atropine and timolol suggest a balancing mechanism between the parasympathetic and β-receptor mediated sympathetic system through stimulation of the retina with luminance and color contrast.
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Affiliation(s)
- Laura A Goldberg
- New England College of Optometry, 424 Beacon Street, Boston, MA 02115, United States.
| | - Frances J Rucker
- New England College of Optometry, 424 Beacon Street, Boston, MA 02115, United States
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Zhang Y, Wildsoet CF. RPE and Choroid Mechanisms Underlying Ocular Growth and Myopia. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:221-40. [PMID: 26310157 DOI: 10.1016/bs.pmbts.2015.06.014] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Myopia is the most common type of refractive errors and one of the world's leading causes of blindness. Visual manipulations in animal models have provided convincing evidence for the role of environmental factors in myopia development. These models along with in vitro studies have provided important insights into underlying mechanisms. The key locations of the retinal pigment epithelium (RPE) and choroid make them plausible conduits for relaying growth regulatory signals originating in the retina to the sclera, which ultimately determines eye size and shape. Identifying the key signal molecules and their targets may lead to the development of new myopia control treatments. This section summarizes findings implicating the RPE and choroid in myopia development. For RPE and/or choroid, changes in morphology, activity of ion channels/transporters, as well as in gene and protein expression, have been linked to altered eye growth. Both tissues thus represent potential targets for novel therapies for myopia.
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Affiliation(s)
- Yan Zhang
- School of Optometry, University of California, Berkeley, California, USA.
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13
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Ion channels and transporters of the retinal pigment epithelium. Exp Eye Res 2014; 126:27-37. [DOI: 10.1016/j.exer.2014.05.005] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 12/19/2022]
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Rouhier MF, Hine RM, Park ST, Raphemot R, Denton J, Piermarini PM, Beyenbach KW. Excretion of NaCl and KCl loads in mosquitoes. 2. Effects of the small molecule Kir channel modulator VU573 and its inactive analog VU342. Am J Physiol Regul Integr Comp Physiol 2014; 307:R850-61. [PMID: 25056106 DOI: 10.1152/ajpregu.00106.2014] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The effect of two small molecules VU342 and VU573 on renal functions in the yellow fever mosquito Aedes aegypti was investigated in vitro and in vivo. In isolated Malpighian tubules, VU342 (10 μM) had no effect on the transepithelial secretion of Na(+), K(+), Cl(-), and water. In contrast, 10 μM VU573 first stimulated and then inhibited the transepithelial secretion of fluid when the tubules were bathed in Na(+)-rich or K(+)-rich Ringer solution. The early stimulation was blocked by bumetanide, suggesting the transient stimulation of Na-K-2Cl cotransport, and the late inhibition of fluid secretion was consistent with the known block of AeKir1, an Aedes inward rectifier K(+) channel, by VU573. VU342 and VU573 at a hemolymph concentration of about 11 μM had no effect on the diuresis triggered by hemolymph Na(+) or K(+) loads. VU342 at a hemolymph concentration of 420 μM had no effect on the diuresis elicited by hemolymph Na(+) or K(+) loads. In contrast, the same concentration of VU573 significantly diminished the Na(+) diuresis by inhibiting the urinary excretion of Na(+), Cl(-), and water. In K(+)-loaded mosquitoes, 420 μM VU573 significantly diminished the K(+) diuresis by inhibiting the urinary excretion of K(+), Na(+), Cl(-), and water. We conclude that 1) the effects of VU573 observed in isolated Malpighian tubules are overwhelmed in vivo by the diuresis triggered with the coinjection of Na(+) and K(+) loads, and 2) at a hemolymph concentration of 420 μM VU573 affects Kir channels systemically, including those that might be involved in the release of diuretic hormones.
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Affiliation(s)
- Matthew F Rouhier
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio
| | - Rebecca M Hine
- Department of Biomedical Sciences, Cornell University, Ithaca, New York; and
| | - Seokhwan Terry Park
- Department of Biomedical Sciences, Cornell University, Ithaca, New York; and
| | - Rene Raphemot
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Jerod Denton
- Department of Anesthesiology, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Peter M Piermarini
- Department of Entomology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, Ohio
| | - Klaus W Beyenbach
- Department of Biomedical Sciences, Cornell University, Ithaca, New York; and
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15
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Christian PG, Harkin DG, Schmid KL. GABAergic agents modify the response of chick scleral fibroblasts to myopic and hyperopic eye cup tissues. Curr Eye Res 2013; 39:172-87. [PMID: 24073754 DOI: 10.3109/02713683.2013.834941] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE GABA antagonists inhibit experimental myopia in chick and GABA receptors have been localized to chick sclera and the retinal pigment epithelium (RPE). The RPE and the choroid alter scleral DNA and glycosaminoglycan (GAG) content in vitro; opposite effects have been observed for tissues from myopic and hyperopic eyes. The aim was to determine the effect of GABAergic agents on the DNA and GAG content of chick scleral fibroblasts directly and in co-culture with ocular tissues from myopic and hyperopic chick eyes. MATERIALS AND METHODS Primary cultures of fibroblastic cells expressing vimentin and α-smooth muscle actin were established. GABAergic agents were added separately (i) to the culture medium of the scleral cells and (ii) to the culture medium of the scleral cells with the addition of posterior eye cup tissue (retina, RPE, retina + RPE, choroid + RPE) to cell culture inserts. Ocular tissues were obtained from chick eyes wearing + 15D (lens-induced hyperopia, LIH) or -15D lenses (lens-induced myopia, LIM) for three days (post-hatch day 5-8) (n = 12). GAG and DNA content of scleral fibroblasts were measured. RESULTS GABA agents had a small direct effect on scleral cell GAG and DNA content but a larger effect was measured when GABA agents were added to the culture medium with myopic and hyperopic RPE and choroid + RPE tissues. GABA agonists increased (p = 0.002) whereas antagonists decreased (p = 0.0004) DNA content of scleral cells; effects were opposite for scleral GAG content. GABA agents significantly altered the effect of both LIM and LIH tissues (p = 0.0005) compared to control; the effects were greater for LIM tissue versus LIH tissue co-culture (p = 0.0004). CONCLUSION GABAergic agents affect the DNA and GAG content of scleral fibroblasts both directly and when co-cultured with ocular tissues. GABA antagonists that prevent myopia development in chick model could act via a scleral mechanism utilizing the RPE/choroid.
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Affiliation(s)
- Parul G Christian
- Faculty of Health and Vision Improvement Domain, Institute of Health and Biomedical Innovation, QUT and School of Medicine, University of Queensland , Brisbane , Australia
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16
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Pattnaik BR, Tokarz S, Asuma MP, Schroeder T, Sharma A, Mitchell JC, Edwards AO, Pillers DAM. Snowflake vitreoretinal degeneration (SVD) mutation R162W provides new insights into Kir7.1 ion channel structure and function. PLoS One 2013; 8:e71744. [PMID: 23977131 PMCID: PMC3747230 DOI: 10.1371/journal.pone.0071744] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2013] [Accepted: 07/02/2013] [Indexed: 01/08/2023] Open
Abstract
Snowflake Vitreoretinal Degeneration (SVD) is associated with the R162W mutation of the Kir7.1 inwardly-rectifying potassium channel. Kir7.1 is found at the apical membrane of Retinal Pigment Epithelial (RPE) cells, adjacent to the photoreceptor neurons. The SVD phenotype ranges from RPE degeneration to an abnormal b-wave to a liquid vitreous. We sought to determine how this mutation alters the structure and function of the human Kir7.1 channel. In this study, we expressed a Kir7.1 construct with the R162W mutation in CHO cells to evaluate function of the ion channel. Compared to the wild-type protein, the mutant protein exhibited a non-functional Kir channel that resulted in depolarization of the resting membrane potential. Upon co-expression with wild-type Kir7.1, R162W mutant showed a reduction of IKir7.1 and positive shift in ‘0’ current potential. Homology modeling based on the structure of a bacterial Kir channel protein suggested that the effect of R162W mutation is a result of loss of hydrogen bonding by the regulatory lipid binding domain of the cytoplasmic structure.
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Affiliation(s)
- Bikash R. Pattnaik
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
- Department of Ophthalmology and Visual Sciences, University of Wisconsin, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin, United States of America
- * E-mail:
| | - Sara Tokarz
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Matti P. Asuma
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Tyler Schroeder
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Anil Sharma
- Department of Experimental Pathology, Mayo Clinic, Rochester, Minnesota, United States of America
| | - Julie C. Mitchell
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, United States of America
| | - Albert O. Edwards
- Institute for Molecular Biology, University of Oregon, and Oregon Retina, Eugene, Oregon, United States of America
| | - De-Ann M. Pillers
- Department of Pediatrics, University of Wisconsin, Madison, Wisconsin, United States of America
- McPherson Eye Research Institute, University of Wisconsin, Madison, Wisconsin, United States of America
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17
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Cheng ZY, Wang XP, Schmid KL, Liu L. Identification of GABA receptors in chick retinal pigment epithelium. Neurosci Lett 2013; 539:43-7. [DOI: 10.1016/j.neulet.2013.01.038] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Accepted: 01/18/2013] [Indexed: 01/09/2023]
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18
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Murphy MJ, Crewther SG. Ouabain inhibition of Na/K-ATPase across the retina prevents signed refractive compensation to lens-induced defocus, but not default ocular growth in young chicks. F1000Res 2013; 2:97. [PMID: 25506418 PMCID: PMC4257142 DOI: 10.12688/f1000research.2-97.v1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 03/23/2013] [Indexed: 01/21/2023] Open
Abstract
Purpose: The relevance of retinal integrity and energy pathways to ocular growth and induction of refractive errors has seldom been investigated. Thus, we used ouabain to target the channels that are essential for the maintenance of membrane potentials in cells, sodium potassium ATPase (Na/K-ATPase), to examine refractive compensation and ocular growth in response to lens-induced defocus in the chick. Methods: A single intravitreal injection of 1 mM ouabain in dimethyl sulfoxide (DMSO) carrier or DMSO alone was followed by monocular defocus with positive or negative 10 D lens (or no lens) from post-hatching days 5-9 under 12/12 hr light/dark conditions. Biometry and dark-adapted flash and electroretinography (ERG) were conducted on day 9, followed by immunohistological analyses. Results: Ouabain inhibited differential ocular growth and refractive compensation to signed defocus compared to DMSO. By 4-days post-ouabain injection all components of the typical ERG responses to light had been eliminated, and widespread histological damage was apparent, though some ‘default state’ ocular growth was measurable. Immunohistochemistry demonstrated reduction in the specialized water channel Aquaporin 4 (AQP4) expression and increased evidence of caspase 3 expression (a cell death associated protein) in ouabain-treated eyes compared with DMSO alone. Conclusion: The current study demonstrates that blockade of photoreceptor and inner retinal responses to light onset and offset by ouabain inhibits differential refractive compensation to optical blur, but does not prevent ocular growth.
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Affiliation(s)
- Melanie J Murphy
- School of Psychological Science, La Trobe University, Melbourne, 3086, Australia
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19
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Shen W, Purpura LA, Li B, Nan C, Chang IJ, Ripps H. Regulation of synaptic transmission at the photoreceptor terminal: a novel role for the cation-chloride co-transporter NKCC1. J Physiol 2012; 591:133-47. [PMID: 23090945 DOI: 10.1113/jphysiol.2012.241042] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The Na(+)-K(+)-2Cl(-) co-transporter type 1 (NKCC1) is localized primarily throughout the outer plexiform layer (OPL) of the distal retina, a synaptic lamina that is comprised of the axon terminals of photoreceptors and the dendrites of horizontal and bipolar cells. Although known to play a key role in development, signal transmission and the gating of sensory signals in other regions of the retina and in the CNS, the contribution of NKCC1 to synaptic transmission within the OPL is largely unknown. In the present study, we investigated the function of NKCC1 at the photoreceptor-horizontal cell synapse by recording the electrical responses of photoreceptors and horizontal cells before and after blocking the activity of the transporter with bumetanide (BMN). Because NKCC1 co-transports 1 Na(+), 1 K(+) and 2 Cl(-), it is electroneutral and its activation had little effect on membrane conductance. However, recordings from postsynaptic horizontal cells revealed that inhibiting NKCC1 with BMN greatly increased glutamate release from both rod and cone terminals. In addition, we found that NKCC1 directly regulates Ca(2+)-dependent exocytosis at the photoreceptor synapse, raising the possibility that NKCC1 serves to suppress bulk release of glutamate vesicles from photoreceptor terminals in the dark and at light offset. Interestingly, NKCC1 gene and protein expressions were upregulated by light, which we attribute to the light-induced release of dopamine acting on D1-like receptors. In sum, our study reveals a new role for NKCC1 in the regulation of synaptic transmission in photoreceptors.
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Affiliation(s)
- Wen Shen
- Department of Biomedical Science, Charles E Schmidt College of Medicine, Florida Atlantic University, 777 Glades Road, Boca Raton, FL 33431, USA.
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20
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Kyrieleis HA, Löwik MM, Pronk I, Cruysberg HR, Kremer JA, Oyen WJ, van den Heuvel BL, Wetzels JF, Levtchenko EN. Long-term outcome of biopsy-proven, frequently relapsing minimal-change nephrotic syndrome in children. Clin J Am Soc Nephrol 2009; 4:1593-600. [PMID: 19808243 PMCID: PMC2758253 DOI: 10.2215/cjn.05691108] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Accepted: 07/30/2009] [Indexed: 12/19/2022]
Abstract
BACKGROUND AND OBJECTIVES Frequently relapsing and steroid-dependent minimal-change nephrotic syndrome (MCNS) that originates in childhood can persist after puberty in >20% of patients. These patients require immunosuppressive treatment during several decades of their life. We examined long-term adverse effects of persistent nephrotic syndrome and immunosuppressive medications, focusing on renal function, growth, obesity, osteoporosis, hypertension, ocular complications, and fertility in adult patients with biopsy-proven childhood-onset MCNS. Molecular analysis was performed to evaluate a possible association of a complicated course of MCNS with podocyte gene mutations. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We performed a prospective clinical examination of 15 adult patients that included serum and urine analysis; dual-energy x-ray absorptiometry; ophthalmologic examination; semen examination; and molecular analysis of NPHS1, NPHS2, CD2AP, and ACTN4 genes. RESULTS All patients had normal GFR. Most frequent long-term complications were hypertension (in seven of 15 patients) and osteoporosis in one third of patients. Oligozoospermia was found in one patient, reduced sperm motility in four of eight patients, and teratozoospermia in six of eight patients. Ophthalmologic examination revealed myopia in 10 of 15 patients and cataract in three of 15 patients. CONCLUSIONS Children with MCNS that persists after puberty are at risk for complications such as osteoporosis, hypertension, cataract, and sperm abnormalities. Our study underscores a need for more effective and less toxic therapies for relapsing MCNS.
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Affiliation(s)
| | | | | | | | | | | | - Bert L.P. van den Heuvel
- Department of Pediatric Nephrology
- Laboratory of Pediatrics and Neurology
- Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
| | - Jack F.M. Wetzels
- Department of Nephrology, Radboud University Nijmegen Medical Centre, Nijmegen, Netherlands; and
| | - Elena N. Levtchenko
- Department of Pediatric Nephrology
- Department of Pediatric Nephrology, University Hospitals Leuven, Leuven, Belgium
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