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Venturini G, Kokona D, Steiner BL, Bulla EG, Jovanovic J, Zinkernagel MS, Escher P. In vivo analysis of onset and progression of retinal degeneration in the Nr2e3 rd7/rd7 mouse model of enhanced S-cone sensitivity syndrome. Sci Rep 2021; 11:19032. [PMID: 34561487 PMCID: PMC8463594 DOI: 10.1038/s41598-021-98271-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 09/06/2021] [Indexed: 12/02/2022] Open
Abstract
The photoreceptor-specific nuclear receptor Nr2e3 is not expressed in Nr2e3rd7/rd7 mice, a mouse model of the recessively inherited retinal degeneration enhanced S-cone sensitivity syndrome (ESCS). We characterized in detail C57BL/6J Nr2e3rd7/rd7 mice in vivo by fundus photography, optical coherence tomography and fluorescein angiography and, post mortem, by histology and immunohistochemistry. White retinal spots and so-called 'rosettes' first appear at postnatal day (P) 12 in the dorsal retina and reach maximal expansion at P21. The highest density in 'rosettes' is observed within a region located between 100 and 350 µM from the optic nerve head. 'Rosettes' disappear between 9 to 12 months. Non-apoptotic cell death markers are detected during the slow photoreceptor degeneration, at a rate of an approximately 3% reduction of outer nuclear layer thickness per month, as observed from 7 to 31 months of age. In vivo analysis of Nr2e3rd7/rd7 Cx3cr1gfp/+ retinas identified microglial cells within 'rosettes' from P21 on. Subretinal macrophages were observed in vivo and by confocal microscopy earliest in 12-months-old Nr2e3rd7/rd7 retinas. At P21, S-opsin expression and the number of S-opsin expressing dorsal cones was increased. The dorso-ventral M-cone gradient was present in Nr2e3rd7/rd7 retinas, but M-opsin expression and M-opsin expressing cones were decreased. Retinal vasculature was normal.
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Affiliation(s)
- Giulia Venturini
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Despina Kokona
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Beatrice L Steiner
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Emanuele G Bulla
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Joel Jovanovic
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Martin S Zinkernagel
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland
- Department of BioMedical Research, University of Bern, Bern, Switzerland
| | - Pascal Escher
- Department of Ophthalmology, Inselspital, Bern University Hospital, Bern, Switzerland.
- Department of BioMedical Research, University of Bern, Bern, Switzerland.
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Dixon MA, Greferath U, Fletcher EL, Jobling AI. The Contribution of Microglia to the Development and Maturation of the Visual System. Front Cell Neurosci 2021; 15:659843. [PMID: 33967697 PMCID: PMC8102829 DOI: 10.3389/fncel.2021.659843] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/29/2021] [Indexed: 12/20/2022] Open
Abstract
Microglia, the resident immune cells of the central nervous system (CNS), were once considered quiescent cells that sat in readiness for reacting to disease and injury. Over the last decade, however, it has become clear that microglia play essential roles in maintaining the normal nervous system. The retina is an easily accessible part of the central nervous system and therefore much has been learned about the function of microglia from studies in the retina and visual system. Anatomically, microglia have processes that contact all synapses within the retina, as well as blood vessels in the major vascular plexuses. Microglia contribute to development of the visual system by contributing to neurogenesis, maturation of cone photoreceptors, as well as refining synaptic contacts. They can respond to neural signals and in turn release a range of cytokines and neurotrophic factors that have downstream consequences on neural function. Moreover, in light of their extensive contact with blood vessels, they are also essential for regulation of vascular development and integrity. This review article summarizes what we have learned about the role of microglia in maintaining the normal visual system and how this has helped in understanding their role in the central nervous system more broadly.
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Affiliation(s)
- Michael A Dixon
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Ursula Greferath
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Erica L Fletcher
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
| | - Andrew I Jobling
- Department of Anatomy and Physiology, The University of Melbourne, Melbourne, VIC, Australia
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Short Interruptions of Imposed Hyperopic Defocus Earlier in Treatment are More Effective at Preventing Myopia Development. Sci Rep 2019; 9:11459. [PMID: 31391523 PMCID: PMC6685965 DOI: 10.1038/s41598-019-48009-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022] Open
Abstract
The purpose of this study was to evaluate the effect of interrupting negative lens wear for short periods early or late during the development of lens-induced myopia in marmosets. Sixteen marmosets were reared with a −5D contact lens on their right eye (plano on contralateral eye) for 8 weeks. Eight marmosets had lenses removed for 30 mins twice/day during the first four weeks (early interruption) and eight during the last four weeks (late interruption). Data were compared to treated controls that wore lenses continuously (N = 12) and untreated controls (N = 10). Interocular differences (IOD) in vitreous chamber (VC) depth and central and peripheral mean spherical refractive error (MSE) were measured at baseline and after four (T4) and eight (T8) weeks of treatment. Visual experience during the interruptions was monitored by measuring refraction while marmosets were seated at the center of a 1 m radius viewing cylinder. At T4 the eyes that were interrupted early were not different from untreated controls (p = 0.10) and at T8 had grown less and were less myopic than those interrupted later (IOD change from baseline, VC: +0.07 ± 0.04 mm vs +0.20 ± 0.03 mm, p < 0.05; MSE: −1.59 ± 0.26D vs −2.63 ± 0.60D, p = 0.13). Eyes interrupted later were not different from treated controls (MSE, p = 0.99; VC, p = 0.60) and grew at the same rate as during the first four weeks of uninterrupted lens wear (T4 − T0: 3.67 ± 1.1 µm/day, T8 − T4: 3.56 ± 1.3 µm/day p = 0.96). Peripheral refraction was a predictive factor for the amount of myopia developed only when the interruption was not effective. In summary, interrupting hyperopic defocus with short periods of myopic defocus before compensation occurs prevents axial myopia from developing. After myopia develops, interruption is less effective.
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Bowl W, Lorenz B, Stieger K, Schweinfurth S, Holve K, Andrassi-Darida M. Fundus-Controlled Dark Adaptometry in Young Children Without and With Spontaneously Regressed Retinopathy of Prematurity. Transl Vis Sci Technol 2019; 8:62. [PMID: 31293816 PMCID: PMC6602151 DOI: 10.1167/tvst.8.3.62] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 03/20/2019] [Indexed: 02/01/2023] Open
Abstract
PURPOSE We correlate dark adaptation course with foveal morphologic alterations in preterm and term-born children using a modified fundus-controlled perimeter and spectral domain-optical coherence tomography (SD-OCT) imaging. METHODS We performed fundus-controlled chromatic dark adaptometry in premature children aged 6 to 13 years without retinopathy of prematurity (no-ROP; n = 61) and with spontaneously regressed ROP (sr-ROP, n = 29), and in 11 age-matched term-born children. The degree of macular developmental arrest (MDA), defined as a disproportion of the outer nuclear layer to inner retinal layers in the fovea (ONL+/IRL-ratio), was analyzed with the DiOCTA tool in SD-OCT scans. RESULTS Children with MDA showed a flatter dark adaptation course progression with a significant rod-mediated sensitivity recovery delay (0.0113 vs. 0.0253 dB/s; P < 0.001). Preterm-born children with regular foveal morphology reached the final rod-mediated dark-adapted threshold at 12 minutes after bleach at 18.8 dB, compared to after 18.7 minutes at 17.6 dB in children with MDA (no significant difference in final threshold; P = 0.773). The cone-mediated dark adaptation progression showed a significant lower final threshold in children with MDA (6.0 vs. 8.1 dB; P = 0.004). CONCLUSIONS Changes in dark adaptation were seen in the presence of MDA observed in premature children in the no-ROP and sr-ROP groups. MDA in former premature children is associated with functional deficits of cone and rod photoreceptor visual pathways. TRANSLATIONAL RELEVANCE Morphologic alterations in the central retina of premature children, evident in SD-OCT, are associated with long-term functional deficits in the rod and cone pathways, particularly evident in the rod dark adaptation course measured at 12° eccentricity. This indicates a more widespread retinal functional pathology not limited to the fovea, but occurring together with foveal alterations best defined as MDA.
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Affiliation(s)
- Wadim Bowl
- Department of Ophthalmology, Justus-Liebig-University, Giessen, Germany
| | - Birgit Lorenz
- Department of Ophthalmology, Justus-Liebig-University, Giessen, Germany
| | - Knut Stieger
- Department of Ophthalmology, Justus-Liebig-University, Giessen, Germany
| | | | - Kerstin Holve
- Department of Ophthalmology, Justus-Liebig-University, Giessen, Germany
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The Role of the Microglial Cx3cr1 Pathway in the Postnatal Maturation of Retinal Photoreceptors. J Neurosci 2018; 38:4708-4723. [PMID: 29669747 DOI: 10.1523/jneurosci.2368-17.2018] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 03/22/2018] [Accepted: 04/10/2018] [Indexed: 11/21/2022] Open
Abstract
Microglia are the resident immune cells of the CNS, and their response to infection, injury and disease is well documented. More recently, microglia have been shown to play a role in normal CNS development, with the fractalkine-Cx3cr1 signaling pathway of particular importance. This work describes the interaction between the light-sensitive photoreceptors and microglia during eye opening, a time of postnatal photoreceptor maturation. Genetic removal of Cx3cr1 (Cx3cr1GFP/GFP ) led to an early retinal dysfunction soon after eye opening [postnatal day 17 (P17)] and cone photoreceptor loss (P30 onward) in mice of either sex. This dysfunction occurred at a time when fractalkine expression was predominantly outer retinal, when there was an increased microglial presence near the photoreceptor layer and increased microglial-cone photoreceptor contacts. Photoreceptor maturation and outer segment elongation was coincident with increased opsin photopigment expression in wild-type retina, while this was aberrant in the Cx3cr1GFP/GFP retina and outer segment length was reduced. A beadchip array highlighted Cx3cr1 regulation of genes involved in the photoreceptor cilium, a key structure that is important for outer segment elongation. This was confirmed with quantitative PCR with specific cilium-related genes, Rpgr and Rpgrip1, downregulated at eye opening (P14). While the overall cilium structure was unaffected, expression of Rpgr, Rpgrip1, and centrin were restricted to more proximal regions of the transitional zone. This study highlighted a novel role for microglia in postnatal neuronal development within the retina, with loss of fractalkine-Cx3cr1 signaling leading to an altered distribution of cilium proteins, failure of outer segment elongation and ultimately cone photoreceptor loss.SIGNIFICANCE STATEMENT Microglia are involved in CNS development and disease. This work highlights the role of microglia in postnatal development of the light-detecting photoreceptor neurons within the mouse retina. Loss of the microglial Cx3cr1 signaling pathway resulted in specific alterations in the cilium, a key structure in photoreceptor outer segment elongation. The distribution of key components of the cilium transitional zone, Rpgr, Rpgrip1, and centrin, were altered in retinae lacking Cx3cr1 with reduced outer segment length and cone photoreceptor death observed at later postnatal ages. This work identifies a novel role for microglia in the postnatal maturation of retinal photoreceptors.
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Abstract
The continuing worldwide epidemic of retinopathy of prematurity (ROP), a leading cause of childhood visual impairment, strongly motivates further research into mechanisms of the disease. Although the hallmark of ROP is abnormal retinal vasculature, a growing body of evidence supports a critical role for the neural retina in the ROP disease process. The age of onset of ROP coincides with the rapid developmental increase in rod photoreceptor outer segment length and rhodopsin content of the retina with escalation of energy demands. Using a combination of non-invasive electroretinographic (ERG), psychophysical, and image analysis procedures, the neural retina and its vasculature have been studied in prematurely born human subjects, both with and without ROP, and in rats that model the key vascular and neural parameters found in human ROP subjects. These data are compared to comprehensive numeric summaries of the neural and vascular features in normally developing human and rat retina. In rats, biochemical, anatomical, and molecular biological investigations are paired with the non-invasive assessments. ROP, even if mild, primarily and persistently alters the structure and function of photoreceptors. Post-receptor neurons and retinal vasculature, which are intimately related, are also affected by ROP; conspicuous neurovascular abnormalities disappear, but subtle structural anomalies and functional deficits may persist years after clinical ROP resolves. The data from human subjects and rat models identify photoreceptor and post-receptor targets for interventions that promise improved outcomes for children at risk for ROP.
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Affiliation(s)
- Anne B Fulton
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Ave., Boston, MA 02115-5737, USA.
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Barnaby AM, Hansen RM, Moskowitz A, Fulton AB. Development of scotopic visual thresholds in retinopathy of prematurity. Invest Ophthalmol Vis Sci 2007; 48:4854-60. [PMID: 17898313 PMCID: PMC2225992 DOI: 10.1167/iovs.07-0406] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE To test the hypothesis that the late-maturing parafoveal rod photoreceptors are more vulnerable than peripheral rods to the effects of retinopathy of prematurity (ROP). METHODS Twenty-four infants with a history of preterm birth (gestational age at birth </=31 weeks) participated in a longitudinal study: 12 had mild ROP that resolved without treatment, and 12 had never had ROP. Thresholds for detecting stimuli (2 degrees diameter, 50 ms duration) presented 10 degrees (parafoveal) and 30 degrees (peripheral) from a central fixation target were estimated by using a preferential-looking METHOD At each visit, thresholds at both sites were obtained in random order. Thresholds of the preterm subjects were compared with those of previously reported term infants. RESULTS The course of threshold maturation in subjects with ROP was significantly prolonged (P </= 0.01) compared with those who had never had ROP and with term-born control subjects. On average, parafoveal thresholds in subjects with ROP reached the adult level at a median age of 12 (range, 6-18) months, and peripheral thresholds reached the adult level at 9 (range, 5-12) months. Median thresholds in subjects who had never had ROP reached adult levels at both sites by approximately 7 months. CONCLUSIONS The slower development of parafoveal compared with peripheral thresholds in subjects with a history of ROP is evidence that the late-maturing parafoveal rods are more affected by the ROP disease process.
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Affiliation(s)
- Amber M Barnaby
- Department of Ophthalmology, Children's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA
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Abstract
We tested the hypothesis that the kinetics of recovery of the rod photoresponse differ between mature and immature rods. A paired flash paradigm was used. The effect of a test flash on the ERG a-wave response to a probe flash presented 60 to 2 s after the test flash was studied. The functions summarizing the interaction between the test and probe flash did not differ significantly between infants and adults if the stimuli were equated for estimated proportion of rhodopsin isomerized/rod/flash. The kinetics of rod cell recovery are likely the same in infants and adults.
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Affiliation(s)
- Anne B Fulton
- Department of Ophthalmology, Children's Hospital and Harvard Medical School, 300 Longwood Avenue, Boston, MA 02115, USA.
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