1
|
Salzman MM, Takimoto T, Foster ML, Mowat FM. Differential gene expression between central and peripheral retinal regions in dogs and comparison with humans. Exp Eye Res 2024; 245:109980. [PMID: 38914302 PMCID: PMC11250724 DOI: 10.1016/j.exer.2024.109980] [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: 02/12/2024] [Revised: 06/09/2024] [Accepted: 06/20/2024] [Indexed: 06/26/2024]
Abstract
The dog retina contains a central macula-like region, and there are reports of central retinal disorders in dogs with shared genetic etiologies with humans. Defining central/peripheral gene expression profiles may provide insight into the suitability of dogs as models for human disorders. We determined central/peripheral posterior eye gene expression profiles in dogs and interrogated inherited retinal and macular disease-associated genes for differential expression between central and peripheral regions. Bulk tissue RNA sequencing was performed on 8 mm samples of the dog central and superior peripheral regions, sampling retina and retinal pigmented epithelium/choroid separately. Reads were mapped to CanFam3.1, read counts were analyzed to determine significantly differentially expressed genes (DEGs). A similar analytic pipeline was used with a published bulk-tissue RNA sequencing human dataset. Pathways and processes involved in significantly DEGs were identified (Database for Annotation, Visualization and Integrated Discovery). Dogs and humans shared the extent and direction of central retinal differential gene expression, with multiple shared biological pathways implicated in differential expression. Many genes implicated in heritable retinal disorders in dogs and humans were differentially expressed between central and periphery. Approximately half of genes associated with human age-related macular degeneration were differentially expressed in human and dog tissues. We have identified similarities and differences in central/peripheral gene expression profiles between dogs and humans which can be applied to further define the relevance of dogs as models for human retinal disorders.
Collapse
Affiliation(s)
- Michele M Salzman
- Dept. Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, USA
| | - Tetsuya Takimoto
- Medical Genetics, School of Medicine and Public Health, University of Wisconsin-Madison, USA; Division of Gene Regulation, Division of Data Science, Research Promotion Headquarters, Fujita Health University, Toyoake, Japan
| | - Melanie L Foster
- Dept. Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
| | - Freya M Mowat
- Dept. Surgical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, USA; Dept. Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA; Dept. Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA.
| |
Collapse
|
2
|
Li S, Jin M. Ablation of Fatty Acid Transport Protein-4 Enhances Cone Survival, M-cone Vision, and Synthesis of Cone-Tropic 9- cis-Retinal in rd12 Mouse Model of Leber Congenital Amaurosis. J Neurosci 2024; 44:e1994232024. [PMID: 38811164 PMCID: PMC11223470 DOI: 10.1523/jneurosci.1994-23.2024] [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: 10/12/2023] [Revised: 12/03/2023] [Accepted: 05/22/2024] [Indexed: 05/31/2024] Open
Abstract
The canonical visual cycle employing RPE65 as the retinoid isomerase regenerates 11-cis-retinal to support both rod- and cone-mediated vision. Mutations of RPE65 are associated with Leber congenital amaurosis that results in rod and cone photoreceptor degeneration and vision loss of affected patients at an early age. Dark-reared Rpe65-/- mouse has been known to form isorhodopsin that employs 9-cis-retinal as the photosensitive chromophore. The mechanism regulating 9-cis-retinal synthesis and the role of the endogenous 9-cis-retinal in cone survival and function remain largely unknown. In this study, we found that ablation of fatty acid transport protein-4 (FATP4), a negative regulator of 11-cis-retinol synthesis catalyzed by RPE65, increased the formation of 9-cis-retinal, but not 11-cis-retinal, in a light-independent mechanism in both sexes of RPE65-null rd12 mice. Both rd12 and rd12;Fatp4-/- mice contained a massive amount of all-trans-retinyl esters in the eyes, exhibiting comparable scotopic vision and rod degeneration. However, expression levels of M- and S-opsins as well as numbers of M- and S-cones surviving in the superior retinas of rd12;Fatp4-/ - mice were at least twofold greater than those in age-matched rd12 mice. Moreover, FATP4 deficiency significantly shortened photopic b-wave implicit time, improved M-cone visual function, and substantially deaccelerated the progression of cone degeneration in rd12 mice, whereas FATP4 deficiency in mice with wild-type Rpe65 alleles neither induced 9-cis-retinal formation nor influenced cone survival and function. These results identify FATP4 as a new regulator of synthesis of 9-cis-retinal, which is a "cone-tropic" chromophore supporting cone survival and function in the retinas with defective RPE65.
Collapse
Affiliation(s)
- Songhua Li
- Neuroscience Center, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana 70112
| | - Minghao Jin
- Neuroscience Center, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana 70112
- Department of Ophthalmology, Louisiana State University School of Medicine, LSU Health New Orleans, New Orleans, Louisiana 70112
| |
Collapse
|
3
|
Zhu S, Xie T, Lv Z, Leng YB, Zhang YQ, Xu R, Qin J, Zhou Y, Roy VAL, Han ST. Hierarchies in Visual Pathway: Functions and Inspired Artificial Vision. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2301986. [PMID: 37435995 DOI: 10.1002/adma.202301986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/28/2023] [Accepted: 07/10/2023] [Indexed: 07/13/2023]
Abstract
The development of artificial intelligence has posed a challenge to machine vision based on conventional complementary metal-oxide semiconductor (CMOS) circuits owing to its high latency and inefficient power consumption originating from the data shuffling between memory and computation units. Gaining more insights into the function of every part of the visual pathway for visual perception can bring the capabilities of machine vision in terms of robustness and generality. Hardware acceleration of more energy-efficient and biorealistic artificial vision highly necessitates neuromorphic devices and circuits that are able to mimic the function of each part of the visual pathway. In this paper, we review the structure and function of the entire class of visual neurons from the retina to the primate visual cortex within reach (Chapter 2) are reviewed. Based on the extraction of biological principles, the recent hardware-implemented visual neurons located in different parts of the visual pathway are discussed in detail in Chapters 3 and 4. Furthermore, valuable applications of inspired artificial vision in different scenarios (Chapter 5) are provided. The functional description of the visual pathway and its inspired neuromorphic devices/circuits are expected to provide valuable insights for the design of next-generation artificial visual perception systems.
Collapse
Affiliation(s)
- Shirui Zhu
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Tao Xie
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Ziyu Lv
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yan-Bing Leng
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Yu-Qi Zhang
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Runze Xu
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Jingrun Qin
- Institute of Microscale Optoelectronics, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Ye Zhou
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, P. R. China
| | - Vellaisamy A L Roy
- School of Science and Technology, Hong Kong Metropolitan University, Hong Kong, 999077, P. R. China
| | - Su-Ting Han
- College of Electronics and Information Engineering, Shenzhen University, Shenzhen, 518060, P. R. China
| |
Collapse
|
4
|
Zhang X, Wang X, Zhu H, Zhang D, Chen J, Wen Y, Li Y, Jin L, Xie C, Guo D, Luo T, Tong J, Zhou Y, Shen Y. Short-wavelength artificial light affects visual neural pathway development in mice. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115282. [PMID: 37494734 DOI: 10.1016/j.ecoenv.2023.115282] [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: 11/22/2022] [Revised: 03/21/2023] [Accepted: 07/17/2023] [Indexed: 07/28/2023]
Abstract
Nearly all modern life depends on artificial light; however, it does cause health problems. With certain restrictions of artificial light emitting technology, the influence of the light spectrum is inevitable. The most remarkable problem is its overload in the short wavelength component. Short wavelength artificial light has a wide range of influences from ocular development to mental problems. The visual neuronal pathway, as the primary light-sensing structure, may contain the fundamental mechanism of all light-induced abnormalities. However, how the artificial light spectrum shapes the visual neuronal pathway during development in mammals is poorly understood. We placed C57BL/6 mice in three different spectrum environments (full-spectrum white light: 400-750 nm; violet light: 400 ± 20 nm; green light: 510 ± 20 nm) beginning at eye opening, with a fixed light time of 7:00-19:00. During development, we assessed the ocular axial dimension, visual function and retinal neurons. After two weeks under short wavelength conditions, the ocular axial length (AL), anterior chamber depth (ACD) and length of lens thickness, real vitreous chamber depth and retinal thickness (LLVR) were shorter, visual acuity (VA) decreased, and retinal electrical activity was impaired. The density of S-cones in the dorsal and ventral retinas both decreased after one week under short wavelength conditions. In the ventral retina, it increased after three weeks. Retinal ganglion cell (RGC) density and axon thickness were not influenced; however, the axonal terminals in the lateral geniculate nucleus (LGN) were less clustered and sparse. Amacrine cells (ACs) were significantly more activated. Green light has few effects. The KEGG and GO enrichment analyses showed that many genes related to neural circuitry, synaptic formation and neurotransmitter function were differentially expressed in the short wavelength light group. In conclusion, exposure to short wavelength artificial light in the early stage of vision-dependent development in mice delayed the development of the visual pathway. The axon terminus structure and neurotransmitter function may be the major suffering.
Collapse
Affiliation(s)
- Xuhong Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xiaoyu Wang
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China; Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hong Zhu
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Dongyan Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China; Department of Ophthalmology, Shaoxing Central Hospital, Shaoxing, Zhejiang 312030, China
| | - Jinbo Chen
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yingying Wen
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yanqing Li
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Le Jin
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Chen Xie
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Dongyu Guo
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Ting Luo
- Zhejiang Academy of Agricultural Sciences, Institute of Agroproduct Safety and Nutrition, China
| | - Jianping Tong
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China.
| | - Yudong Zhou
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China; Center for Brain Research and Brain-Machine Integration, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China.
| | - Ye Shen
- Department of Ophthalmology, the First Affiliated Hospital of Zhejiang University, Hangzhou, Zhejiang Province, China.
| |
Collapse
|
5
|
Thyroid Hormone Signaling Is Required for Dynamic Variation in Opsins in the Retina during Metamorphosis of the Japanese Flounder (Paralichthys olivaceus). BIOLOGY 2023; 12:biology12030397. [PMID: 36979089 PMCID: PMC10044895 DOI: 10.3390/biology12030397] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 02/20/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023]
Abstract
In the present study, we investigated the function of thyroid hormones (TH) in visual remodeling during Japanese flounder (Paralichthys olivaceus) metamorphosis through cellular molecular biology experiments. Our results showed that the expression of the five opsin genes of the flounder were highest in eye tissue and varied with the metamorphosis process. The expression of rh1, sws2aβ and lws was positively regulated by exogenous TH, but inhibited by thiourea (TU) compared to the control group. In addition, there was a significant increase in sws2aβ and lws in the rescue experiments performed with TU-treated larvae (p < 0.05). Meanwhile, T3 levels in flounder larvae were increased by TH and decreased by TU. Based on the differences in the expression of the three isoforms of the thyroid hormone receptor (TR) (Trαa, Trαb and Trβ), we further hypothesized that T3 may directly or indirectly regulate the expression of sws2aβ through Trαa. This study demonstrates the regulatory role of TH in opsins during flounder metamorphosis and provides a basis for further investigation on the molecular mechanisms underlying the development of the retinal photoreceptor system in flounders.
Collapse
|
6
|
Saito K, Horiguchi K, Yamada S, Buyandalai B, Ishida E, Matsumoto S, Yoshino S, Nakajima Y, Yamada E, Saito T, Ozawa A, Tajika Y, Akiyama H, Yamada M. Maternal hypothyroidism is associated with M-opsin developmental delay. J Mol Endocrinol 2022; 69:391-399. [PMID: 35900831 DOI: 10.1530/jme-22-0114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 07/19/2022] [Indexed: 11/08/2022]
Abstract
Thyroid hormones are critical for the development of opsins involved in color vision. Hypothyroid mice show delayed M-opsin development and expanded distribution of S-opsin on the retina. However, the effects of maternal hypothyroidism on opsin development remain unknown. This study investigates the effects of congenital central hypothyroidism and maternal hypothyroidism on opsin development in thyrotropin-releasing hormone knockout (TRH-/-) mice. We examined the mRNA expression and protein distribution of S/M-opsin on postnatal days (P)12 and 17, as well as mRNA expression of type 2 and 3 iodothyronine deiodinase (DIO2 and DIO3, respectively) in the retina and type 1 iodothyronine deiodinase (DIO1) in the liver at P12 in TRH+/- mice born to TRH+/- or TRH-/- dams, and conducted S/M-opsin analysis in TRH+/+ or TRH-/- mice born to TRH+/- dams at P12, P17, and P30. M-opsin expression was lower in TRH+/- mice born to TRH-/- dams than in those born to TRH+/- dams, whereas S-opsin expression did not significantly differ between them. DIO1, DIO2, and DIO3 mRNA expression levels were not significantly different between the two groups; therefore, thyroid function in peripheral tissues in the pups was similar. S/M-opsin expression did not significantly differ between the TRH+/+ and TRH-/- mice born to TRH+/- dams on any postnatal day. These results demonstrate that maternal hypothyroidism causes M-opsin developmental delay during the early developmental stages of neonatal mice, and TRH-/- mice, a model of congenital central hypothyroidism, born to a euthyroid dam do not have delayed opsin development.
Collapse
Affiliation(s)
- Kazuma Saito
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
- Department of Ophthalmology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Kazuhiko Horiguchi
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Sayaka Yamada
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Battsetseg Buyandalai
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Emi Ishida
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Shunichi Matsumoto
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Satoshi Yoshino
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yasuyo Nakajima
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Eijiro Yamada
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Tsugumichi Saito
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Atsushi Ozawa
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Yuki Tajika
- Department of Anatomy, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Hideo Akiyama
- Department of Ophthalmology, Gunma University Graduate School of Medicine, Maebashi, Japan
| | - Masanobu Yamada
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Gunma University Graduate School of Medicine, Maebashi, Japan
| |
Collapse
|
7
|
McNerney C, Johnston RJ. Thyroid hormone signaling specifies cone photoreceptor subtypes during eye development: Insights from model organisms and human stem cell-derived retinal organoids. VITAMINS AND HORMONES 2021; 116:51-90. [PMID: 33752828 DOI: 10.1016/bs.vh.2021.03.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Cones are the color-detecting photoreceptors of the vertebrate eye. Cones are specialized into subtypes whose functions are determined by the expression of color-sensitive opsin proteins. Organisms differ greatly in the number and patterning of cone subtypes. Despite these differences, thyroid hormone is an important regulator of opsin expression in most vertebrates. In this chapter, we outline how the timing of thyroid hormone signaling controls cone subtype fates during retinal development. We first examine our current understanding of cone subtype specification in model organisms and then describe advances in human stem cell-derived organoid technology that identified mechanisms controlling development of the human retina.
Collapse
Affiliation(s)
- Christina McNerney
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States
| | - Robert J Johnston
- Department of Biology, Johns Hopkins University, Baltimore, MD, United States.
| |
Collapse
|
8
|
Rojo Arias JE, Economopoulou M, Juárez López DA, Kurzbach A, Au Yeung KH, Englmaier V, Merdausl M, Schaarschmidt M, Ader M, Morawietz H, Funk RHW, Jászai J. VEGF-Trap is a potent modulator of vasoregenerative responses and protects dopaminergic amacrine network integrity in degenerative ischemic neovascular retinopathy. J Neurochem 2019; 153:390-412. [PMID: 31550048 DOI: 10.1111/jnc.14875] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 09/06/2019] [Accepted: 09/18/2019] [Indexed: 12/17/2022]
Abstract
Retinal hypoxia triggers abnormal vessel growth and microvascular hyper-permeability in ischemic retinopathies. Whereas vascular endothelial growth factor A (VEGF-A) inhibitors significantly hinder disease progression, their benefits to retinal neurons remain poorly understood. Similar to humans, oxygen-induced retinopathy (OIR) mice exhibit severe retinal microvascular malformations and profound neuronal dysfunction. OIR mice are thus a phenocopy of human retinopathy of prematurity, and a proxy for investigating advanced stages of proliferative diabetic retinopathy. Hence, the OIR model offers an excellent platform for assessing morpho-functional responses of the ischemic retina to anti-angiogenic therapies. Using this model, we investigated the retinal responses to VEGF-Trap (Aflibercept), an anti-angiogenic agent recognizing ligands of VEGF receptors 1 and 2 that possesses regulatory approval for the treatment of neovascular age-related macular degeneration, macular edema secondary to retinal vein occlusion and diabetic macular edema. Our results indicate that Aflibercept not only reduces the severity of retinal microvascular aberrations but also significantly improves neuroretinal function. Aflibercept administration significantly enhanced light-responsiveness, as revealed by electroretinographic examinations, and led to increased numbers of dopaminergic amacrine cells. Additionally, retinal transcriptional profiling revealed the concerted regulation of both angiogenic and neuronal targets, including transcripts encoding subunits of transmitter receptors relevant to amacrine cell function. Thus, Aflibercept represents a promising therapeutic alternative for the treatment of further progressive ischemic retinal neurovasculopathies beyond the set of disease conditions for which it has regulatory approval. Cover Image for this issue: doi: 10.1111/jnc.14743.
Collapse
Affiliation(s)
- Jesús E Rojo Arias
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Matina Economopoulou
- Department of Ophthalmology, University Hospital Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - David A Juárez López
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Anica Kurzbach
- Medizinische Klinik III, Universitätsklinikum Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany.,German Center for Diabetes Research (DZD e.V.), München-Neuherberg, Germany
| | - Kwan H Au Yeung
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Vanessa Englmaier
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Marie Merdausl
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Martin Schaarschmidt
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - Marius Ader
- DFG-Center for Regenerative Therapies Dresden, Cluster of Excellence, Saxony, Germany
| | - Henning Morawietz
- Department of Medicine III, University Hospital Carl Gustav Carus, Division of Vascular Endothelium and Microcirculation, Technische Universität Dresden, Saxony, Germany
| | - Richard H W Funk
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| | - József Jászai
- Department of Anatomy, Medical Faculty Carl Gustav Carus, Technische Universität Dresden, Saxony, Germany
| |
Collapse
|
9
|
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.
Collapse
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
| |
Collapse
|
10
|
Thyroid Hormone Signaling in Retinal Development, Survival, and Disease. VITAMINS AND HORMONES 2018; 106:333-349. [DOI: 10.1016/bs.vh.2017.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
|
11
|
Temporal profiling of photoreceptor lineage gene expression during murine retinal development. Gene Expr Patterns 2017; 23-24:32-44. [PMID: 28288836 DOI: 10.1016/j.gep.2017.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 02/03/2017] [Accepted: 03/07/2017] [Indexed: 02/08/2023]
Abstract
Rod and cone photoreceptors are photosensitive cells in the retina that convert light to electrical signals that are transmitted to visual processing centres in the brain. During development, cones and rods are generated from a common pool of multipotent retinal progenitor cells (RPCs) that also give rise to other retinal cell types. Cones and rods differentiate in two distinct waves, peaking in mid-embryogenesis and the early postnatal period, respectively. As RPCs transition from making cones to generating rods, there are changes in the expression profiles of genes involved in photoreceptor cell fate specification and differentiation. To better understand the temporal transition from cone to rod genesis, we assessed the timing of onset and offset of expression of a panel of 11 transcription factors and 7 non-transcription factors known to function in photoreceptor development, examining their expression between embryonic day (E) 12.5 and postnatal day (P) 60. Transcription factor expression in the photoreceptor layer was observed as early as E12.5, beginning with Crx, Otx2, Rorb, Neurod1 and Prdm1 expression, followed at E15.5 with the expression of Thrb, Neurog1, Sall3 and Rxrg expression, and at P0 by Nrl and Nr2e3 expression. Of the non-transcription factors, peanut agglutinin lectin staining and cone arrestin protein were observed as early as E15.5 in the developing outer nuclear layer, while transcripts for the cone opsins Opn1mw and Opn1sw and Recoverin protein were detected in photoreceptors by P0. In contrast, Opn1mw and Opn1sw protein were not observed in cones until P7, when rod-specific Gnat1 transcripts and rhodopsin protein were also detected. We have thus identified four transitory stages during murine retina photoreceptor differentiation marked by the period of onset of expression of new photoreceptor lineage genes. By characterizing these stages, we have clarified the dynamic nature of gene expression during the period when photoreceptor identities are progressively acquired during development.
Collapse
|
12
|
Abstract
Thyroid hormone is a crucial regulator of gene expression in the developing and adult retina. Here we sought to map sites of thyroid hormone signaling at the cellular level using the transgenic FINDT3 reporter mouse model in which neurons express β-galactosidase (β-gal) under the control of a hybrid Gal4-TRα receptor when triiodothyronine (T3) and cofactors of thyroid receptor signaling are present. In the adult retina, nearly all neurons of the ganglion cell layer (GCL, ganglion cells and displaced amacrine cells) showed strong β-gal labeling. In the inner nuclear layer (INL), a minority of glycineric and GABAergic amacrine cells showed β-gal labeling, whereas the majority of amacrine cells were unlabeled. At the level of amacrine types, β-gal labeling was found in a large proportion of the glycinergic AII amacrines, but only in a small proportion of the cholinergic/GABAergic 'starburst' amacrines. At postnatal day 10, there also was a high density of strongly β-gal-labeled neurons in the GCL, but only few amacrine cells were labeled in the INL. There was no labeling of bipolar cells, horizontal cells and Müller glia cells at both stages. Most surprisingly, the photoreceptor somata in the outer nuclear layer also showed no β-gal label, although thyroid hormone is known to control cone opsin expression. This is the first record of thyroid hormone signaling in the inner retina of an adult mammal. We hypothesize that T3 levels in photoreceptors are below the detection threshold of the reporter system. The topographical distribution of β-gal-positive cells in the GCL follows the overall neuron distribution in that layer, with more T3-signaling cells in the ventral than the dorsal half-retina.
Collapse
|
13
|
Kulkarni M, Trifunović D, Schubert T, Euler T, Paquet-Durand F. Calcium dynamics change in degenerating cone photoreceptors. Hum Mol Genet 2016; 25:3729-3740. [PMID: 27402880 DOI: 10.1093/hmg/ddw219] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 06/24/2016] [Accepted: 06/25/2016] [Indexed: 11/14/2022] Open
Abstract
Cone photoreceptors (cones) are essential for high-resolution daylight vision and colour perception. Loss of cones in hereditary retinal diseases has a dramatic impact on human vision. The mechanisms underlying cone death are poorly understood, and consequently, there are no treatments available. Previous studies suggest a central role for calcium (Ca2+) homeostasis deficits in photoreceptor degeneration; however, direct evidence for this is scarce and physiological measurements of Ca2+ in degenerating mammalian cones are lacking.Here, we took advantage of the transgenic HR2.1:TN-XL mouse line that expresses a genetically encoded Ca2+ biosensor exclusively in cones. We cross-bred this line with mouse models for primary ("cone photoreceptor function loss-1", cpfl1) and secondary ("retinal degeneration-1", rd1) cone degeneration, respectively, and assessed resting Ca2+ levels and light-evoked Ca2+ responses in cones using two-photon imaging. We found that Ca2+ dynamics were altered in cpfl1 cones, showing higher noise and variable Ca2+ levels, with significantly wider distribution than for wild-type and rd1 cones. Unexpectedly, up to 21% of cpfl1 cones still displayed light-evoked Ca2+ responses, which were larger and slower than wild-type responses. In contrast, genetically intact rd1 cones were characterized by lower noise and complete lack of visual function.Our study demonstrates alterations in cone Ca2+ dynamics in both primary and secondary cone degeneration. Our results are consistent with the view that higher (fluctuating) cone Ca2+ levels are involved in photoreceptor cell death in primary (cpfl1) but not in secondary (rd1) cone degeneration. These findings may guide the future development of therapies targeting photoreceptor Ca2+ homeostasis.
Collapse
Affiliation(s)
- Manoj Kulkarni
- Institute for Ophthalmic Research.,Werner Reichardt Centre for Integrative Neuroscience.,Graduate School of Cellular & Molecular Neuroscience
| | | | - Timm Schubert
- Institute for Ophthalmic Research.,Werner Reichardt Centre for Integrative Neuroscience
| | - Thomas Euler
- Institute for Ophthalmic Research (F.P-D.) (T.E.).,Werner Reichardt Centre for Integrative Neuroscience.,Bernstein Centre for Computational Neuroscience, University of Tübingen, Tübingen, Germany
| | | |
Collapse
|
14
|
Bos R, Gainer C, Feller MB. Role for Visual Experience in the Development of Direction-Selective Circuits. Curr Biol 2016; 26:1367-75. [PMID: 27161499 DOI: 10.1016/j.cub.2016.03.073] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2016] [Revised: 03/08/2016] [Accepted: 03/31/2016] [Indexed: 11/24/2022]
Abstract
Visually guided behavior can depend critically on detecting the direction of object movement. This computation is first performed in the retina where direction is encoded by direction-selective ganglion cells (DSGCs) that respond strongly to an object moving in the preferred direction and weakly to an object moving in the opposite, or null, direction (reviewed in [1]). DSGCs come in multiple types that are classified based on their morphologies, response properties, and targets in the brain. This study focuses on two types-ON and ON-OFF DSGCs. Though animals can sense motion in all directions, the preferred directions of DSGCs in adult retina cluster along distinct directions that we refer to as the cardinal axes. ON DSGCs have three cardinal axes-temporal, ventral, and dorsonasal-while ON-OFF DSGCs have four-nasal, temporal, dorsal, and ventral. How these preferred directions emerge during development is still not understood. Several studies have demonstrated that ON [2] and ON-OFF DSGCs are well tuned at eye-opening, and even a few days prior to eye-opening, in rabbits [3], rats [4], and mice [5-8], suggesting that visual experience is not required to produce direction-selective tuning. However, here we show that at eye-opening the preferred directions of both ON and ON-OFF DSGCs are diffusely distributed and that visual deprivation prevents the preferred directions from clustering along the cardinal axes. Our findings indicate a critical role for visual experience in shaping responses in the retina.
Collapse
Affiliation(s)
- Rémi Bos
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Christian Gainer
- School of Optometry, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Marla B Feller
- Department of Molecular and Cell Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA; Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, CA 94720-3200, USA.
| |
Collapse
|
15
|
AAV-mediated Gene Therapy Halts Retinal Degeneration in PDE6β-deficient Dogs. Mol Ther 2016; 24:867-76. [PMID: 26857842 DOI: 10.1038/mt.2016.37] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Accepted: 02/02/2016] [Indexed: 11/08/2022] Open
Abstract
We previously reported that subretinal injection of AAV2/5 RK.cpde6β allowed long-term preservation of photoreceptor function and vision in the rod-cone dysplasia type 1 (rcd1) dog, a large animal model of naturally occurring PDE6β deficiency. The present study builds on these earlier findings to provide a detailed assessment of the long-term effects of gene therapy on the spatiotemporal pattern of retinal degeneration in rcd1 dogs treated at 20 days of age. We analyzed the density distribution of the retinal layers and of particular photoreceptor cells in 3.5-year-old treated and untreated rcd1 dogs. Whereas no rods were observed outside the bleb or in untreated eyes, gene transfer halted rod degeneration in all vector-exposed regions. Moreover, while gene therapy resulted in the preservation of cones, glial cells and both the inner nuclear and ganglion cell layers, no cells remained in vector-unexposed retinas, except in the visual streak. Finally, the retinal structure of treated 3.5-year-old rcd1 dogs was identical to that of unaffected 4-month-old rcd1 dogs, indicating near complete preservation. Our findings indicate that gene therapy arrests the degenerative process even if intervention is initiated after the onset of photoreceptor degeneration, and point to significant potential of this therapeutic approach in future clinical trials.
Collapse
|
16
|
Abstract
The mouse has become an important model for understanding the neural basis of visual perception. Although it has long been known that mouse lens transmits ultraviolet (UV) light and mouse opsins have absorption in the UV band, little is known about how UV visual information is processed in the mouse brain. Using a custom UV stimulation system and in vivo calcium imaging, we characterized the feature selectivity of layer 2/3 neurons in mouse primary visual cortex (V1). In adult mice, a comparable percentage of the neuronal population responds to UV and visible stimuli, with similar pattern selectivity and receptive field properties. In young mice, the orientation selectivity for UV stimuli increased steadily during development, but not direction selectivity. Our results suggest that, by expanding the spectral window through which the mouse can acquire visual information, UV sensitivity provides an important component for mouse vision.
Collapse
|
17
|
Zhang X, An X, Liu H, Peng J, Cai S, Wang W, Lin DT, Yang Y. The topographical arrangement of cutoff spatial frequencies across lower and upper visual fields in mouse V1. Sci Rep 2015; 5:7734. [PMID: 25583266 PMCID: PMC4291572 DOI: 10.1038/srep07734] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Accepted: 12/10/2014] [Indexed: 11/14/2022] Open
Abstract
The visual response to spatial frequency (SF), a characteristic of spatial structure across position in space, is of particular importance for animal survival. A natural challenge for rodents is to detect predators as early as possible while foraging. Whether neurons in mouse primary visual cortex (V1) are functionally organized to meet this challenge remains unclear. Combining intrinsic signal optical imaging and single-unit recording, we found that the cutoff SF was much greater for neurons whose receptive fields were located above the mouse. Specifically, we discovered that the cutoff SF increased in a gradient that was positively correlated with the elevation in the visual field. This organization was present at eye opening and persisted through adulthood. Dark rearing delayed the maturation of the cutoff SF globally, but had little impact on the topographical organization of the cutoff SF, suggesting that this regional distribution is innately determined. This form of cortical organization of different SFs may benefit the mouse for detection of airborne threats in the natural environment.
Collapse
Affiliation(s)
- Xian Zhang
- CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, P.R. China
| | - Xu An
- CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, P.R. China
| | - Hanxiao Liu
- CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, P.R. China
| | - Jing Peng
- CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, P.R. China
| | - Shanshan Cai
- CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, P.R. China
| | - Wei Wang
- Institute of Neuroscience and State Key Laboratory of Neuroscience, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, P. R. China
| | - Da-Ting Lin
- Intramural Research Programme, National Institute on Drug Abuse, National Institutes of Health, Baltimore MD 21224
| | - Yupeng Yang
- CAS Key Laboratory of Brain Function and Diseases, School of Life Sciences, University of Science and Technology of China, Hefei 230027, P.R. China
| |
Collapse
|
18
|
Abstract
Specific variants of human long-wavelength (L) and middle-wavelength (M) cone opsin genes have recently been associated with a variety of vision disorders caused by cone malfunction, including red-green color vision deficiency, blue cone monochromacy, myopia, and cone dystrophy. Strikingly, unlike disease-causing mutations in rhodopsin, most of the cone opsin alleles that are associated with vision disorders do not have deleterious point mutations. Instead, specific combinations of normal polymorphisms that arose by genetic recombination between the genes encoding L and M opsins appear to cause disease. Knockout/knock-in mice promise to make it possible to study how these deleterious cone opsin variants affect the structure, function, and viability of the cone photoreceptors. Ideally, we would like to evaluate different variants that cause vision disorders in humans against a control pigment that is not associated with vision disorders, and each variant should be expressed as the sole photopigment in each mouse cone, as is the case in humans. To evaluate the feasibility of this approach, we created a line of mice to serve as the control in the analysis of disease-causing mutations by replacing exon 2 through 6 of the mouse M-opsin gene with the corresponding cDNA for a human L-opsin variant that is associated with normal vision. Experiments reported here establish that the resulting pigment, which differs from the endogenous mouse M opsin at 35 amino acid positions, functions normally in mouse cones. This pigment was evaluated in mice with and without coexpression of the mouse short wavelength (S) opsin. Here, the creation and validation of two lines of genetically engineered mice that can be used to study disease-causing variants of human L/M-opsins, in vivo, are described.
Collapse
|
19
|
Isayama T, Chen Y, Kono M, Fabre E, Slavsky M, DeGrip WJ, Ma JX, Crouch RK, Makino CL. Coexpression of three opsins in cone photoreceptors of the salamander Ambystoma tigrinum. J Comp Neurol 2014; 522:2249-65. [PMID: 24374736 DOI: 10.1002/cne.23531] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Revised: 10/24/2013] [Accepted: 12/20/2013] [Indexed: 12/12/2022]
Abstract
Although more than one type of visual opsin is present in the retina of most vertebrates, it was thought that each type of photoreceptor expresses only one opsin. However, evidence has accumulated that some photoreceptors contain more than one opsin, in many cases as a result of a developmental transition from the expression of one opsin to another. The salamander UV-sensitive (UV) cone is particularly notable because it contains three opsins (Makino and Dodd [1996] J Gen Physiol 108:27-34). Two opsin types are expressed at levels more than 100 times lower than the level of the primary opsin. Here, immunohistochemical experiments identified the primary component as a UV cone opsin and the two minor components as the short wavelength-sensitive (S) and long wavelength-sensitive (L) cone opsins. Based on single-cell recordings of 156 photoreceptors, the presence of three components in UV cones of hatchlings and terrestrial adults ruled out a developmental transition. There was no evidence for multiple opsin types within rods or S cones, but immunohistochemistry and partial bleaching in conjunction with single-cell recording revealed that both single and double L cones contained low levels of short wavelength-sensitive pigments in addition to the main L visual pigment. These results raise the possibility that coexpression of multiple opsins in other vertebrates was overlooked because a minor component absorbing at short wavelengths was masked by the main visual pigment or because the expression level of a component absorbing at long wavelengths was exceedingly low.
Collapse
Affiliation(s)
- Tomoki Isayama
- Department of Ophthalmology, Massachusetts Eye and Ear Infirmary and Harvard Medical School, Boston, Massachusetts, 02114
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Ortín-Martínez A, Nadal-Nicolás FM, Jiménez-López M, Alburquerque-Béjar JJ, Nieto-López L, García-Ayuso D, Villegas-Pérez MP, Vidal-Sanz M, Agudo-Barriuso M. Number and distribution of mouse retinal cone photoreceptors: differences between an albino (Swiss) and a pigmented (C57/BL6) strain. PLoS One 2014; 9:e102392. [PMID: 25029531 PMCID: PMC4100816 DOI: 10.1371/journal.pone.0102392] [Citation(s) in RCA: 90] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 06/19/2014] [Indexed: 12/12/2022] Open
Abstract
We purpose here to analyze and compare the population and topography of cone photoreceptors in two mouse strains using automated routines, and to design a method of retinal sampling for their accurate manual quantification. In whole-mounted retinas from pigmented C57/BL6 and albino Swiss mice, the longwave-sensitive (L) and the shortwave-sensitive (S) opsins were immunodetected to analyze the population of each cone type. In another group of retinas both opsins were detected with the same fluorophore to quantify all cones. In a third set of retinas, L-opsin and Brn3a were immunodetected to determine whether L-opsin+cones and retinal ganglion cells (RGCs) have a parallel distribution. Cones and RGCs were automatically quantified and their topography illustrated with isodensity maps. Our results show that pigmented mice have a significantly higher number of total cones (all-cones) and of L-opsin+cones than albinos which, in turn, have a higher population of S-opsin+cones. In pigmented animals 40% of cones are dual (cones that express both opsins), 34% genuine-L (cones that only express the L-opsin), and 26% genuine-S (cones that only express the S-opsin). In albinos, 23% of cones are genuine-S and the proportion of dual cones increases to 76% at the expense of genuine-L cones. In both strains, L-opsin+cones are denser in the central than peripheral retina, and all-cones density increases dorso-ventrally. In pigmented animals S-opsin+cones are scarce in the dorsal retina and very numerous in the ventral retina, being densest in its nasal aspect. In albinos, S-opsin+cones are abundant in the dorsal retina, although their highest densities are also ventral. Based on the densities of each cone population, we propose a sampling method to manually quantify and infer their total population. In conclusion, these data provide the basis to study cone degeneration and its prevention in pathologic conditions.
Collapse
Affiliation(s)
- Arturo Ortín-Martínez
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Espinardo, Murcia, Spain
| | | | - Manuel Jiménez-López
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Espinardo, Murcia, Spain
| | | | - Leticia Nieto-López
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Espinardo, Murcia, Spain
| | - Diego García-Ayuso
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Espinardo, Murcia, Spain
| | - Maria P Villegas-Pérez
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Espinardo, Murcia, Spain
| | - Manuel Vidal-Sanz
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain; Departamento de Oftalmología, Facultad de Medicina, Universidad de Murcia, Espinardo, Murcia, Spain
| | - Marta Agudo-Barriuso
- Instituto Murciano de Investigación Biosanitaria-Virgen de la Arrixaca, El Palmar, Murcia, Spain
| |
Collapse
|
21
|
Suppressing thyroid hormone signaling preserves cone photoreceptors in mouse models of retinal degeneration. Proc Natl Acad Sci U S A 2014; 111:3602-7. [PMID: 24550448 DOI: 10.1073/pnas.1317041111] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cone phototransduction and survival of cones in the human macula is essential for color vision and for visual acuity. Progressive cone degeneration in age-related macular degeneration, Stargardt disease, and recessive cone dystrophies is a major cause of blindness. Thyroid hormone (TH) signaling, which regulates cell proliferation, differentiation, and apoptosis, plays a central role in cone opsin expression and patterning in the retina. Here, we investigated whether TH signaling affects cone viability in inherited retinal degeneration mouse models. Retinol isomerase RPE65-deficient mice [a model of Leber congenital amaurosis (LCA) with rapid cone loss] and cone photoreceptor function loss type 1 mice (severe recessive achromatopsia) were used to determine whether suppressing TH signaling with antithyroid treatment reduces cone death. Further, cone cyclic nucleotide-gated channel B subunit-deficient mice (moderate achromatopsia) and guanylate cyclase 2e-deficient mice (LCA with slower cone loss) were used to determine whether triiodothyronine (T3) treatment (stimulating TH signaling) causes deterioration of cones. We found that cone density in retinol isomerase RPE65-deficient and cone photoreceptor function loss type 1 mice increased about sixfold following antithyroid treatment. Cone density in cone cyclic nucleotide-gated channel B subunit-deficient and guanylate cyclase 2e-deficient mice decreased about 40% following T3 treatment. The effect of TH signaling on cone viability appears to be independent of its regulation on cone opsin expression. This work demonstrates that suppressing TH signaling in retina dystrophy mouse models is protective of cones, providing insights into cone preservation and therapeutic interventions.
Collapse
|
22
|
Retinal cone photoreceptors of the deer mouse Peromyscus maniculatus: development, topography, opsin expression and spectral tuning. PLoS One 2013; 8:e80910. [PMID: 24260509 PMCID: PMC3829927 DOI: 10.1371/journal.pone.0080910] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 10/09/2013] [Indexed: 11/19/2022] Open
Abstract
A quantitative analysis of photoreceptor properties was performed in the retina of the nocturnal deer mouse, Peromyscus maniculatus, using pigmented (wildtype) and albino animals. The aim was to establish whether the deer mouse is a more suitable model species than the house mouse for photoreceptor studies, and whether oculocutaneous albinism affects its photoreceptor properties. In retinal flatmounts, cone photoreceptors were identified by opsin immunostaining, and their numbers, spectral types, and distributions across the retina were determined. Rod photoreceptors were counted using differential interference contrast microscopy. Pigmented P. maniculatus have a rod-dominated retina with rod densities of about 450.000/mm2 and cone densities of 3000 - 6500/mm2. Two cone opsins, shortwave sensitive (S) and middle-to-longwave sensitive (M), are present and expressed in distinct cone types. Partial sequencing of the S opsin gene strongly supports UV sensitivity of the S cone visual pigment. The S cones constitute a 5-15% minority of the cones. Different from house mouse, S and M cone distributions do not have dorsoventral gradients, and coexpression of both opsins in single cones is exceptional (<2% of the cones). In albino P. maniculatus, rod densities are reduced by approximately 40% (270.000/mm2). Overall, cone density and the density of cones exclusively expressing S opsin are not significantly different from pigmented P. maniculatus. However, in albino retinas S opsin is coexpressed with M opsin in 60-90% of the cones and therefore the population of cones expressing only M opsin is significantly reduced to 5-25%. In conclusion, deer mouse cone properties largely conform to the general mammalian pattern, hence the deer mouse may be better suited than the house mouse for the study of certain basic cone properties, including the effects of albinism on cone opsin expression.
Collapse
|
23
|
Mowat FM, Breuwer AR, Bartoe JT, Annear MJ, Zhang Z, Smith AJ, Bainbridge JWB, Petersen-Jones SM, Ali RR. RPE65 gene therapy slows cone loss in Rpe65-deficient dogs. Gene Ther 2012; 20:545-55. [PMID: 22951453 DOI: 10.1038/gt.2012.63] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Recent clinical trials of retinal pigment epithelium gene (RPE65) supplementation therapy in Leber congenital amaurosis type 2 patients have demonstrated improvements in rod and cone function, but it may be some years before the effects of therapy on photoreceptor survival become apparent. The Rpe65-deficient dog is a very useful pre-clinical model in which to test efficacy of therapies, because the dog has a retina with a high degree of similarity to that of humans. In this study, we evaluated the effect of RPE65 gene therapy on photoreceptor survival in order to predict the potential benefit and limitations of therapy in patients. We examined the retinas of Rpe65-deficient dogs after RPE65 gene therapy to evaluate the preservation of rods and cone photoreceptor subtypes. We found that gene therapy preserves both rods and cones. While the moderate loss of rods in the Rpe65-deficient dog retina is slowed by gene therapy, S-cones are lost extensively and gene therapy can prevent that loss, although only within the treated area. Although LM-cones are not lost extensively, cone opsin mislocalization indicates that they are stressed, and this can be partially reversed by gene therapy. Our results suggest that gene therapy may be able to slow cone degeneration in patients if intervention is sufficiently early and also that it is probably important to treat the macula in order to preserve central function.
Collapse
Affiliation(s)
- F M Mowat
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Rister J, Desplan C. The retinal mosaics of opsin expression in invertebrates and vertebrates. Dev Neurobiol 2012; 71:1212-26. [PMID: 21557510 DOI: 10.1002/dneu.20905] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Color vision is found in many invertebrate and vertebrate species. It is the ability to discriminate objects based on the wavelength of emitted light independent of intensity. As it requires the comparison of at least two photoreceptor types with different spectral sensitivities, this process is often mediated by a mosaic made of several photoreceptor types. In this review, we summarize the current knowledge about the formation of retinal mosaics and the regulation of photopigment (opsin) expression in the fly, mouse, and human retina. Despite distinct evolutionary origins, as well as major differences in morphology and phototransduction machineries, there are significant similarities in the stepwise cell-fate decisions that lead from progenitor cells to terminally differentiated photoreceptors that express a particular opsin. Common themes include (i) the use of binary transcriptional switches that distinguish classes of photoreceptors, (ii) the use of gradients of signaling molecules for regional specializations, (iii) stochastic choices that pattern the retina, and (iv) the use of permissive factors with multiple roles in different photoreceptor types.
Collapse
Affiliation(s)
- Jens Rister
- Department of Biology, Center for Developmental Genetics, New York University, USA
| | | |
Collapse
|
25
|
Huberman AD, Niell CM. What can mice tell us about how vision works? Trends Neurosci 2011; 34:464-73. [PMID: 21840069 DOI: 10.1016/j.tins.2011.07.002] [Citation(s) in RCA: 199] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2011] [Revised: 06/28/2011] [Accepted: 07/05/2011] [Indexed: 11/15/2022]
Abstract
Understanding the neural basis of visual perception is a long-standing fundamental goal of neuroscience. Historically, most vision studies were carried out on humans, macaques and cats. Over the past 5 years, however, a growing number of researchers have begun using mice to parse the mechanisms underlying visual processing; the rationale is that, despite having relatively poor acuity, mice are unmatched in terms of the variety and sophistication of tools available to label, monitor and manipulate specific cell types and circuits. In this review, we discuss recent advances in understanding the mouse visual system at the anatomical, receptive field and perceptual level, focusing on the opportunities and constraints those features provide toward the goal of understanding how vision works.
Collapse
Affiliation(s)
- Andrew D Huberman
- Department of Neurosciences, University of California San Diego, La Jolla, CA 92093, USA.
| | | |
Collapse
|
26
|
de Melo J, Peng GH, Chen S, Blackshaw S. The Spalt family transcription factor Sall3 regulates the development of cone photoreceptors and retinal horizontal interneurons. Development 2011; 138:2325-36. [PMID: 21558380 PMCID: PMC3091496 DOI: 10.1242/dev.061846] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The mammalian retina is a tractable model system for analyzing transcriptional networks that guide neural development. Spalt family zinc-finger transcription factors play a crucial role in photoreceptor specification in Drosophila, but their role in mammalian retinal development has not been investigated. In this study, we show that that the spalt homolog Sall3 is prominently expressed in developing cone photoreceptors and horizontal interneurons of the mouse retina and in a subset of cone bipolar cells. We find that Sall3 is both necessary and sufficient to activate the expression of multiple cone-specific genes, and that Sall3 protein is selectively bound to the promoter regions of these genes. Notably, Sall3 shows more prominent expression in short wavelength-sensitive cones than in medium wavelength-sensitive cones, and that Sall3 selectively activates expression of the short but not the medium wavelength-sensitive cone opsin gene. We further observe that Sall3 regulates the differentiation of horizontal interneurons, which form direct synaptic contacts with cone photoreceptors. Loss of function of Sall3 eliminates expression of the horizontal cell-specific transcription factor Lhx1, resulting in a radial displacement of horizontal cells that partially phenocopies the loss of function of Lhx1. These findings not only demonstrate that Spalt family transcription factors play a conserved role in regulating photoreceptor development in insects and mammals, but also identify Sall3 as a factor that regulates terminal differentiation of both cone photoreceptors and their postsynaptic partners.
Collapse
Affiliation(s)
- Jimmy de Melo
- Department of Neuroscience, Johns Hopkins University School of Medicine, 733 N. Broadway Avenue, Baltimore, MD 21287, USA
| | | | | | | |
Collapse
|
27
|
Abstract
Mammalian retinas display an astonishing diversity in the spatial arrangement of their spectral cone photoreceptors, probably in adaptation to different visual environments. Opsin expression patterns like the dorsoventral gradients of short-wave-sensitive (S) and middle- to long-wave-sensitive (M) cone opsin found in many species are established early in development and thought to be stable thereafter throughout life. In mouse early development, thyroid hormone (TH), through its receptor TRβ2, is an important regulator of cone spectral identity. However, the role of TH in the maintenance of the mature cone photoreceptor pattern is unclear. We here show that TH also controls adult cone opsin expression. Methimazole-induced suppression of serum TH in adult mice and rats yielded no changes in cone numbers but reversibly altered cone patterns by activating the expression of S-cone opsin and repressing the expression of M-cone opsin. Furthermore, treatment of athyroid Pax8(-/-) mice with TH restored a wild-type pattern of cone opsin expression that reverted back to the mutant S-opsin-dominated pattern after termination of treatment. No evidence for cone death or the generation of new cones from retinal progenitors was found in retinas that shifted opsin expression patterns. Together, this suggests that opsin expression in terminally differentiated mammalian cones remains subject to control by TH, a finding that is in contradiction to previous work and challenges the current view that opsin identity in mature mammalian cones is fixed by permanent gene silencing.
Collapse
|
28
|
Li X, Li W, Dai X, Kong F, Zheng Q, Zhou X, Lü F, Chang B, Rohrer B, Hauswirth WW, Qu J, Pang JJ. Gene therapy rescues cone structure and function in the 3-month-old rd12 mouse: a model for midcourse RPE65 leber congenital amaurosis. Invest Ophthalmol Vis Sci 2011; 52:7-15. [PMID: 21169527 PMCID: PMC3053305 DOI: 10.1167/iovs.10-6138] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2010] [Revised: 07/25/2010] [Accepted: 07/27/2010] [Indexed: 11/24/2022] Open
Abstract
PURPOSE RPE65 function is necessary in the retinal pigment epithelium (RPE) to generate chromophore for all opsins. Its absence results in vision loss and rapid cone degeneration. Recent Leber congenital amaurosis type 2 (LCA with RPE65 mutations) phase I clinical trials demonstrated restoration of vision on RPE65 gene transfer into RPE cells overlying cones. In the rd12 mouse, a naturally occurring model of RPE65-LCA early cone degeneration was observed; however, some peripheral M-cones remained. A prior study showed that AAV-mediated RPE65 expression can prevent early cone degeneration. The present study was conducted to test whether the remaining cones in older rd12 mice can be rescued. METHODS Subretinal treatment with the scAAV5-smCBA-hRPE65 vector was initiated at postnatal day (P)14 and P90. After 2 months, electroretinograms were recorded, and cone morphology was analyzed by using cone-specific peanut agglutinin and cone opsin-specific antibodies. RESULTS Cone degeneration started centrally and spread ventrally, with cells losing cone-opsin staining before that for the PNA-lectin-positive cone sheath. Gene therapy starting at P14 resulted in almost wild-type M- and S-cone function and morphology. Delaying gene-replacement rescued the remaining M-cones, and most important, more M-cone opsin-positive cells were identified than were present at the onset of gene therapy, suggesting that opsin expression could be reinitiated in cells with cone sheaths. CONCLUSIONS The results support and extend those of the previous study that gene therapy can stop early cone degeneration, and, more important, they provide proof that delayed treatment can restore the function and morphology of the remaining cones. These results have important implications for the ongoing LCA2 clinical trials.
Collapse
Affiliation(s)
- Xia Li
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Wensheng Li
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Xufeng Dai
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Fansheng Kong
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Qinxiang Zheng
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Xiangtian Zhou
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Fan Lü
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Bo Chang
- The Jackson Laboratory, Bar Harbor, Maine
| | - Bärbel Rohrer
- the Department of Ophthalmology and
- Neurosciences Division of Research, Medical University of South Carolina, Charleston, South Carolina; and
| | | | - Jia Qu
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
| | - Ji-jing Pang
- From the Eye Hospital, School of Ophthalmology and Optometry, Wenzhou Medical College, Wenzhou, PR China
- the Department of Ophthalmology, University of Florida, Gainesville, Florida
| |
Collapse
|
29
|
Trifunović D, Dengler K, Michalakis S, Zrenner E, Wissinger B, Paquet-Durand F. cGMP-dependent cone photoreceptor degeneration in the cpfl1 mouse retina. J Comp Neurol 2010; 518:3604-17. [PMID: 20593360 DOI: 10.1002/cne.22416] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Inherited retinal degeneration affecting both rod and cone photoreceptors constitutes one of the leading causes of blindness in the developed world. Such degeneration is at present untreatable, and the underlying neurodegenerative mechanisms are unknown, even though certain genetic causes have been established. The rd1 mouse is one of the best characterized animal models for rod photoreceptor degeneration, whereas the cpfl1 mouse is a recently discovered model for cone cell death. Because both animal models are affected by functionally similar mutations in the rod and cone phosphodiesterase 6 genes, respectively, we asked whether the mechanisms of photoreceptor degeneration in these two mouse lines share common pathways. In the present study, we followed the temporal progression of photoreceptor degeneration in the cpfl1 retina, correlated it with specific metabolic markers, and compared it with the wild-type and the rd1 situation. Similar to corresponding rd1 observations, cpfl1 cone photoreceptor cell death was associated with an accumulation of cyclic guanosine monophosphate (cGMP), activity of calpains, and phosphorylation of vasodilator-stimulated protein (VASP). Cone degeneration progressed rapidly, with a peak in cell death around postnatal day 24. Furthermore, cpfl1 cone photoreceptor migration during early postnatal development was delayed significantly compared with the corresponding wild-type retina. The finding that rod and cone photoreceptor degeneration was associated with the same metabolic markers suggests that in both cell types similar degenerative mechanisms are active. This raises the possibility that equivalent neuroprotective strategies may be used to prevent both rod and cone photoreceptor degeneration.
Collapse
Affiliation(s)
- Dragana Trifunović
- Division of Experimental Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, 72076 Germany
| | | | | | | | | | | |
Collapse
|
30
|
Pias3-dependent SUMOylation controls mammalian cone photoreceptor differentiation. Nat Neurosci 2010; 13:1059-65. [PMID: 20729845 PMCID: PMC2932661 DOI: 10.1038/nn.2618] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Accepted: 07/19/2010] [Indexed: 01/17/2023]
Abstract
Selective expression of retinal cone opsin genes is essential for color vision, but the mechanism mediating this process is poorly understood. Both vertebrate rod and medium wavelength-sensitive (M) cone photoreceptors differentiate by repression of a short wavelength-sensitive (S)-cone differentiation program. We show that Pias3 acts in mouse cone photoreceptors to activate expression of M-opsin and repress expression of S-opsin, with the transcription factors Trβ2 and Rxrγ mediating preferential expression of Pias3 in M-cones. Finally, we observe that Pias3 directly regulates M- and S-cone opsin expression by modulating the cone-enriched transcription factors Rxrγ Rorα, and Trβ1. This study reveals that Pias3-dependent SUMOylation of photoreceptor-specific transcription factors is a common mechanism that controls both rod and cone photoreceptor subtype specification, regulating distinct molecular targets in the two cell types.
Collapse
|
31
|
Transcriptional regulation of photoreceptor development and homeostasis in the mammalian retina. Nat Rev Neurosci 2010; 11:563-76. [PMID: 20648062 DOI: 10.1038/nrn2880] [Citation(s) in RCA: 377] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
In the developing vertebrate retina, diverse neuronal subtypes originate from multipotent progenitors in a conserved order and are integrated into an intricate laminated architecture. Recent progress in mammalian photoreceptor development has identified a complex relationship between six key transcription-regulatory factors (RORbeta, OTX2, NRL, CRX, NR2E3 and TRbeta2) that determine rod versus M cone or S cone cell fate. We propose a step-wise 'transcriptional dominance' model of photoreceptor cell fate determination, with the S cone representing the default state of a generic photoreceptor precursor. Elucidation of gene-regulatory networks that dictate photoreceptor genesis and homeostasis will have wider implications for understanding the development of nervous system function and for the treatment of neurodegenerative diseases.
Collapse
|
32
|
Type 3 deiodinase, a thyroid-hormone-inactivating enzyme, controls survival and maturation of cone photoreceptors. J Neurosci 2010; 30:3347-57. [PMID: 20203194 DOI: 10.1523/jneurosci.5267-09.2010] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Maturation of the mammalian nervous system requires adequate provision of thyroid hormone and mechanisms that enhance tissue responses to the hormone. Here, we report that the development of cones, the photoreceptors for daylight and color vision, requires protection from thyroid hormone by type 3 deiodinase, a thyroid hormone-inactivating enzyme. Type 3 deiodinase, encoded by Dio3, is expressed in the immature mouse retina. In Dio3(-/-) mice, approximately 80% of cones are lost through neonatal cell death. Cones that express opsin photopigments for response to both short (S) and medium-long (M) wavelength light are lost. Rod photoreceptors, which mediate dim light vision, remain essentially intact. Excessive thyroid hormone in wild-type pups also eliminates cones. Cone loss is mediated by cone-specific thyroid hormone receptor beta2 (TRbeta2) as deletion of TRbeta2 rescues cones in Dio3(-/-) mice. However, rescued cones respond to short but not longer wavelength light because TRbeta2 under moderate hormonal stimulation normally induces M opsin and controls the patterning of M and S opsins over the retina. The results suggest that type 3 deiodinase limits hormonal exposure of the cone to levels that safeguard both cone survival and the patterning of opsins that is required for cone function.
Collapse
|
33
|
Ferreiro-Galve S, Rodríguez-Moldes I, Anadón R, Candal E. Patterns of cell proliferation and rod photoreceptor differentiation in shark retinas. J Chem Neuroanat 2010; 39:1-14. [PMID: 19822206 DOI: 10.1016/j.jchemneu.2009.10.001] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 10/05/2009] [Accepted: 10/05/2009] [Indexed: 11/27/2022]
Abstract
We studied the pattern of cell proliferation and its relation with photoreceptor differentiation in the embryonic and postembryonic retina of two elasmobranchs, the lesser spotted dogfish (Scyliorhinus canicula) and the brown shyshark (Haploblepharus fuscus). Cell proliferation was studied with antibodies raised against proliferating cell nuclear antigen (PCNA) and phospho-histone-H3, and early photoreceptor differentiation with an antibody raised against rod opsin. As regards the spatiotemporal distribution of PCNA-immunoreactive cells, our results reveal a gradual loss of PCNA that coincides in a spatiotemporal sequence with the gradient of layer maturation. The presence of a peripheral growth zone containing pure-proliferating retinal progenitors (the ciliary marginal zone) in the adult retina matches with the general pattern observed in other groups of gnathostomous fishes. However, in the shark retina the generation of new cells is not restricted to the ciliary marginal zone but also occurs in retinal areas that contain differentiated cells: (1) in a transition zone that lies between the pure-proliferating ciliary marginal zone and the central (layered) retina; (2) in the differentiating central area up to prehatching embryos where large amounts of PCNA-positive cells were observed even in the inner and outer nuclear layers; (3) and in the retinal pigment epithelium of prehatching embryos. Rod opsin immunoreactivity was observed in both species when the outer plexiform layer begins to be recognized in the central retina and, as we previously observed in trout, coincided temporally with the weakening in PCNA labelling.
Collapse
Affiliation(s)
- Susana Ferreiro-Galve
- Department of Cell Biology and Ecology, University of Santiago de Compostela, 15782-Santiago de Compostela, Spain
| | | | | | | |
Collapse
|
34
|
Retinoid-related orphan nuclear receptor RORbeta is an early-acting factor in rod photoreceptor development. Proc Natl Acad Sci U S A 2009; 106:17534-9. [PMID: 19805139 DOI: 10.1073/pnas.0902425106] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Rods and cones are morphologically and developmentally distinct photoreceptor types with different functions in vision. Cones mediate daylight and color vision and in most mammals express M and S opsin photopigments for sensitivity to medium-long and short light wavelengths, respectively. Rods mediate dim light vision and express rhodopsin photopigment. The transcription factor networks that direct differentiation of each photoreceptor type are incompletely defined. Here, we report that Rorb(-/-) mice lacking retinoid-related orphan nuclear receptor beta lose rods but overproduce primitive S cones that lack outer segments. The phenotype reflects pronounced plasticity between rod and cone lineages and resembles that described for Nrl(-/-) mice lacking neural retina leucine zipper factor. Rorb(-/-) mice lack Nrl expression and reexpression of Nrl in Rorb(-/-) mice converts cones to rod-like cells. Thus, Rorb directs rod development and does so at least in part by inducing the Nrl-mediated pathway of rod differentiation.
Collapse
|
35
|
Xu XL, Fang Y, Lee TC, Forrest D, Gregory-Evans C, Almeida D, Liu A, Jhanwar SC, Abramson DH, Cobrinik D. Retinoblastoma has properties of a cone precursor tumor and depends upon cone-specific MDM2 signaling. Cell 2009; 137:1018-31. [PMID: 19524506 DOI: 10.1016/j.cell.2009.03.051] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2008] [Revised: 01/09/2009] [Accepted: 03/13/2009] [Indexed: 01/18/2023]
Abstract
Retinoblastomas result from the inactivation of the RB1 gene and the loss of Rb protein, yet the cell type in which Rb suppresses retinoblastoma and the circuitry that underlies the need for Rb are undefined. Here, we show that retinoblastoma cells express markers of postmitotic cone precursors but not markers of other retinal cell types. We also demonstrate that human cone precursors prominently express MDM2 and N-Myc, that retinoblastoma cells require both of these proteins for proliferation and survival, and that MDM2 is needed to suppress ARF-induced apoptosis in cultured retinoblastoma cells. Interestingly, retinoblastoma cell MDM2 expression was regulated by the cone-specific RXRgamma transcription factor and a human-specific RXRgamma consensus binding site, and proliferation required RXRgamma, as well as the cone-specific thyroid hormone receptor-beta2. These findings provide support for a cone precursor origin of retinoblastoma and suggest that human cone-specific signaling circuitry sensitizes to the oncogenic effects of RB1 mutations.
Collapse
Affiliation(s)
- Xiaoliang L Xu
- Dyson Vision Research Institute, Weill Cornell Medical College, New York, NY 10021, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
36
|
Developmental expression of thyroid hormone receptor beta2 protein in cone photoreceptors in the mouse. Neuroreport 2009; 20:627-31. [PMID: 19282790 DOI: 10.1097/wnr.0b013e32832a2c63] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Thyroid hormone receptor beta2 (TRbeta2) controls the patterning of cone opsin photopigments that mediate colour vision. We raised an antiserum against TRbeta2 to study cone photoreceptor development by western blot and immunostaining analyses. TRbeta2-positive cells first appeared between embryonic day 10 (E10) and E12. Numbers increased until near birth, correlating with generation of the cone population. At birth, signals decreased until postnatal day 10, then declined to very low levels in adulthood. TRbeta2-positive cells were initially dispersed but became aligned at the edge of the outer neuroblastic layer by E15. Postnatally, these cells migrated inwardly until postnatal day 10, then outwardly to the edge of the outer nuclear layer, the location of mature cones. TRbeta2 represents a functionally unique marker for cone development.
Collapse
|
37
|
Lu A, Ng L, Ma M, Kefas B, Davies TF, Hernandez A, Chan CC, Forrest D. Retarded developmental expression and patterning of retinal cone opsins in hypothyroid mice. Endocrinology 2009; 150:1536-44. [PMID: 18974269 PMCID: PMC2654753 DOI: 10.1210/en.2008-1092] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Color vision is mediated by cone photoreceptors that express opsin photopigments with sensitivities to different light wavelengths. Most mammals, including mice, differentially express M and S opsins for response to medium-long and short wavelengths, respectively. Previous studies demonstrated that a thyroid hormone receptor (TRbeta2) is critical for opsin patterning: in TRbeta2-deficient mice, M opsin is lost and all cones instead express S opsin. Here, to investigate the requirement for thyroid hormone in cone development, we studied Tshr(-/-)mice as a model of congenital hypothyroidism. The onset of M opsin expression in Tshr(-/-)mice was severely delayed until after postnatal d 17 (P17), and M opsin expression failed to attain normal levels at older adult ages. S opsin showed a subtler change with an extended distribution pattern over the superior-inferior axis of the retina. Similar opsin abnormalities were detected in wild-type C57BL/6J mice made hypothyroid by methimazole treatment. In Tshr(-/-) mice, T(3) treatment from P8 recovered significant M opsin expression at P17. Tshr(-/-) mice produced normal numbers of cones, indicating that the major requirement for thyroid hormone is in opsin patterning rather than in cone generation. The phenotype is similar to, although milder than, that caused by loss of TRbeta2 and indicates the necessity for thyroid hormone for cone maturation.
Collapse
Affiliation(s)
- Ailing Lu
- National Institute of Diabetes and Digestive and Kidney Diseases, Clinical Endocrinology Branch, National Institutes of Health, Bethesda, Maryland 20892-1772, USA
| | | | | | | | | | | | | | | |
Collapse
|
38
|
Schulte D, Bumsted-O'Brien KM. Molecular mechanisms of vertebrate retina development: Implications for ganglion cell and photoreceptor patterning. Brain Res 2008; 1192:151-64. [PMID: 17553468 DOI: 10.1016/j.brainres.2007.04.079] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 04/05/2007] [Accepted: 04/20/2007] [Indexed: 12/20/2022]
Abstract
Although the neural retina appears as a relatively uniform tissue when viewed from its surface, it is in fact highly patterned along its anterior-posterior and dorso-ventral axes. The question of how and when such patterns arise has been the subject of intensive investigations over several decades. Most studies aimed at understanding retinal pattern formation have used the retinotectal map, the ordered projections of retinal ganglion cells to the brain, as a functional readout of the pattern. However, other cell types are also topographically organized in the retina. The most commonly recognized example of such a topographic cellular organization is the differential distribution of photoreceptor types across the retina. Photoreceptor patterns are highly species-specific and may represent an important adaptation to the visual niche a given species occupies. Nevertheless, few studies have addressed this functional readout of pattern to date and our understanding of its development has remained superficial. Here, we review recent advances in understanding the molecular cascades that control regionalization of the eye anlage, relate these findings to the development of photoreceptor patterns and discuss common and unique strategies involved in both aspects of retinal pattern formation.
Collapse
Affiliation(s)
- Dorothea Schulte
- Max Planck Institute for Brain Research, Department of Neuroanatomy, Deutschordenst. 46, D-60218 Frankfurt, Germany.
| | | |
Collapse
|
39
|
Applebury ML, Farhangfar F, Glösmann M, Hashimoto K, Kage K, Robbins JT, Shibusawa N, Wondisford FE, Zhang H. Transient expression of thyroid hormone nuclear receptor TRβ2 sets S opsin patterning during cone photoreceptor genesis. Dev Dyn 2007; 236:1203-12. [PMID: 17436273 DOI: 10.1002/dvdy.21155] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Cone photoreceptors in the murine retina are patterned by dorsal repression and ventral activation of S opsin. TR beta 2, the nuclear thyroid hormone receptor beta isoform 2, regulates dorsal repression. To determine the molecular mechanism by which TR beta 2 acts, we compared the spatiotemporal expression of TR beta 2 and S opsin from embryonic day (E) 13 through adulthood in C57BL/6 retinae. TR beta 2 and S opsin are expressed in cone photoreceptors only. Both are transcribed by E13, and their levels increase with cone genesis. TR beta 2 is expressed uniformly, but transiently, across the retina. mRNA levels are maximal by E17 at completion of cone genesis and again minimal before P5. S opsin is also transcribed by E13, but only in ventral cones. Repression in dorsal cones is established by E17, consistent with the occurrence of patterning during cone cell genesis. The uniform expression of TR beta 2 suggests that repression of S opsin requires other dorsal-specific factors in addition to TR beta 2. The mechanism by which TR beta 2 functions was probed in transgenic animals with TR beta 2 ablated, TR beta 2 that is DNA binding defective, and TR beta 2 that is ligand binding defective. These studies show that TR beta 2 is necessary for dorsal repression, but not ventral activation of S opsin. TR beta 2 must bind DNA and the ligand T3 (thyroid hormone) to repress S opsin. Once repression is established, T3 no longer regulates dorsal S opsin repression in adult animals. The transient, embryonic action of TR beta 2 is consistent with a role (direct and/or indirect) in chromatin remodeling that leads to permanent gene silencing in terminally differentiated, dorsal cone photoreceptors.
Collapse
Affiliation(s)
- M L Applebury
- The Howe Laboratory, Harvard Medical School and Massachusetts Eye and Ear Infirmary, Boston, Massachusetts 02114, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Oh ECT, Khan N, Novelli E, Khanna H, Strettoi E, Swaroop A. Transformation of cone precursors to functional rod photoreceptors by bZIP transcription factor NRL. Proc Natl Acad Sci U S A 2007; 104:1679-84. [PMID: 17242361 PMCID: PMC1780067 DOI: 10.1073/pnas.0605934104] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Indexed: 01/23/2023] Open
Abstract
Networks of transcriptional regulatory proteins dictate specification of neural lineages from multipotent retinal progenitors. Rod photoreceptor differentiation requires the basic motif-leucine zipper (bZIP) transcription factor NRL, because loss of Nrl in mice (Nrl-/-) results in complete transformation of rods to functional cones. To examine the role of NRL in cell fate determination, we generated transgenic mice that express Nrl under the control of Crx promoter in postmitotic photoreceptor precursors of WT and Nrl-/- retina. We show that NRL expression, in both genetic backgrounds, leads to a functional retina with only rod photoreceptors. The absence of cones does not alter retinal lamination, although cone synaptic circuitry is now recruited by rods. Ectopic expression of NRL in developing cones can also induce rod-like characteristics and partially suppress cone-specific gene expression. We show that NRL is associated with specific promoter sequences in Thrb (encoding TRbeta2 transcription factor required for M-cone differentiation) and S-opsin and may, therefore, directly participate in transcriptional suppression of cone development. Our studies establish that NRL is not only essential but is sufficient for rod differentiation and that postmitotic photoreceptor precursors are competent to make binary decisions during early retinogenesis.
Collapse
Affiliation(s)
- Edwin C. T. Oh
- *Program in Neuroscience and
- Departments of Ophthalmology and Visual Sciences and
| | - Naheed Khan
- Departments of Ophthalmology and Visual Sciences and
| | | | - Hemant Khanna
- Departments of Ophthalmology and Visual Sciences and
| | - Enrica Strettoi
- Italian National Research Council (CNR), Neuroscience Institute, 56100 Pisa, Italy
| | - Anand Swaroop
- *Program in Neuroscience and
- Departments of Ophthalmology and Visual Sciences and
- Human Genetics, University of Michigan, Ann Arbor, MI 48105
| |
Collapse
|
41
|
Srinivas M, Ng L, Liu H, Jia L, Forrest D. Activation of the Blue Opsin Gene in Cone Photoreceptor Development by Retinoid-Related Orphan Receptor β. Mol Endocrinol 2006; 20:1728-41. [PMID: 16574740 DOI: 10.1210/me.2005-0505] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
AbstractColor vision requires the expression of opsin photopigments with different wavelength sensitivities in retinal cone photoreceptors. The basic color visual system of mammals is dichromatic, involving differential expression in the cone population of two opsins with sensitivity to short (S, blue) or medium (M, green) wavelengths. However, little is known of the factors that directly activate these opsin genes and thereby contribute to the S or M opsin identity of the cone. We report that the orphan nuclear receptor RORβ (retinoid-related orphan receptor β) activates the S opsin gene (Opn1sw) through binding sites upstream of the gene. RORβ lacks a known physiological ligand and activates the Opn1sw promoter modestly alone but strongly in synergy with the retinal cone-rod homeobox factor (CRX), suggesting a cooperative means of enhancing RORβ activity. Comparison of wild-type and mutant lacZ reporter transgenes showed that the RORβ-binding sites in Opn1sw are required for expression in mouse retina. RORβ-deficient mice fail to induce S opsin appropriately during postnatal cone development. Photoreceptors in these mice also lack outer segments, indicating additional functions for RORβ in photoreceptor morphological maturation. The results identify Opn1sw as a target gene for RORβ and suggest a key role for RORβ in regulating opsin expression in the color visual system.
Collapse
Affiliation(s)
- Maya Srinivas
- Department of Human Genetics, Mount Sinai School of Medicine, New York, New York 10029, USA
| | | | | | | | | |
Collapse
|
42
|
Cheng CL, Flamarique IN, Hárosi FI, Rickers-Haunerland J, Haunerland NH. Photoreceptor layer of salmonid fishes: Transformation and loss of single cones in juvenile fish. J Comp Neurol 2006; 495:213-35. [PMID: 16435286 DOI: 10.1002/cne.20879] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The retinas of many vertebrates have cone photoreceptors that express multiple visual pigments. In many of these animals, including humans, the original cones to appear in the retina (which express UV or blue opsin) may change opsin types, giving rise to new spectral phenotypes. Here we used microspectrophotometry and in situ hybridization with cDNA probes to study the distribution of UV and blue cones in the retinas of four species of Pacific salmon (coho, chum, chinook, and pink salmon), in the Atlantic salmon, and in the rainbow/steelhead trout. In Pacific salmon and in the trout, all single cones express a UV opsin at hatching (lambda(max) of the visual pigment approximately 365 nm), and these cones later transform into blue cones by opsin changeover (lambda(max) of the blue visual pigment approximately 434 nm). Cones undergoing UV opsin downregulation exhibit either of two spectral absorbance profiles. The first is characterized by UV and blue absorbance peaks, with blue absorbance dominating the base of the outer segment. The second shows UV absorbance diminishing from the outer segment tip to the base, with no sign of blue absorbance. The first absorbance profile indicates a transformation from UV to blue phenotype by opsin changeover, while the second type suggests that the cone is undergoing apoptosis. These two events (transformation and loss of corner cones) are closely associated in time and progress from ventral to dorsal retina. Each double cone member contains green (lambda(max) approximately 510 nm) or red (lambda(max) approximately 565 nm) visual pigment (double cones are green/red pairs), and, like the rods (lambda(max) approximately 508 nm), do not exhibit opsin changeover. Unlike Pacific salmonids, the Atlantic salmon shows a mixture of UV and blue cones and a partial loss of corner cones at hatching. This study establishes the UV-to-blue cone transformation as a general feature of retinal growth in Pacific salmonids (genus Oncorhynchus).
Collapse
Affiliation(s)
- Christiana L Cheng
- Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada
| | | | | | | | | |
Collapse
|
43
|
Ekesten B, Gouras P. Cone and rod inputs to murine retinal ganglion cells: Evidence of
cone opsin specific channels. Vis Neurosci 2006; 22:893-903. [PMID: 16469196 DOI: 10.1017/s0952523805226172] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2005] [Accepted: 08/25/2005] [Indexed: 11/07/2022]
Abstract
To identify ultraviolet (UV) and middle- (M) wavelength-sensitive cone
and rod signals in murine retinal ganglion cells, single ganglion cell
responses were studied in anesthetized, light-adapted C57/BL6 mice
with tungsten microelectrodes driven through the sclera and vitreous to
the neural retina. One hundred fifty-four ganglion cells were examined in
43 retinas of 34 mice. The retina was stimulated with diffuse flashes
and/or pulses of ultraviolet (360 nm) or green (520 nm) light in the
presence and absence of a strong steady orange adapting light. Twelve
ganglion cells were studied in the dark-adapted retina in order to
identify the signals of rods. Three functionally different types of
ganglion cells were found: (1) phasic responding cells (31%) with no
spontaneous activity and large impulse amplitudes; (2) tonic responding
cells (60%) with irregular, low frequency (5–10 Hz) spontaneous
activity and smaller impulse amplitudes; and (3) metronome-like cells (9%)
with regular, relatively high-frequency (20–40 Hz) spontaneous
activity. A few cells (1%) had habituating responses. Every cell
encountered was affected by diffuse stimulation. The more common two types
were excited at either the ON or OFF or at both the ON and OFF phases of
stimulation. Type III cells had weaker responses, sometimes only inhibited
by turning off a light. In the light-adapted state, most cells received
signals of the same polarity from UV- and M-cones but UV-cone inputs were
usually more dominant, especially in ventral retina. A fraction of cells
received signals from only UV- (18%) or only M- (3%) cones. In rare cases
(2%) these cone inputs had an opposite polarity on the same cell. In the
dark-adapted state, all cells were at least four or five logarithmic units
more sensitive and more to green than ultraviolet light. The results
indicate that co-expression of both UV-and M-cone opsins cannot be
ubiquitous in murine retina. Some cones, especially UV cones, exist
without the presence of any functional M-cone opsin. This must be the case
to explain the presence of ganglion cells that receive inputs only from
UV-cones and others that receive inputs of opposite polarity from UV- and
M-cones. The results support the hypothesis that murine retina has the
physiological capacity to relay signals to the brain that allow the
sensing of chromatic contrast and color vision.
Collapse
Affiliation(s)
- Bjorn Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | | |
Collapse
|
44
|
Gouras P, Ekesten B. Why do mice have ultra-violet vision? Exp Eye Res 2004; 79:887-92. [PMID: 15642326 DOI: 10.1016/j.exer.2004.06.031] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2004] [Accepted: 06/14/2004] [Indexed: 11/28/2022]
Abstract
Murine vision has become a fascinating entity due to discoveries about the histology and physiology of its retina over the past decade. It has two varieties of cones, one serving the traditional green-yellow region of the vision spectrum and another serving the ultra-violet region, essentially invisible to man and many other mammal. This puts unusual constraints on the optical transmission of the murine eye, in particular its relatively large lens. Its ultra-violet vision appears to involve its upper much more than its lower visual field, providing a heuristic clue to its purpose. In addition behavioural evidence exists for colour vision in mice. On the other hand there is unequivocal evidence that many murine cones contain both cone photopigments, an unrealistic but not impossible arrangement for colour vision. A better understanding of how ultra-violet vision is interwoven into cone and rod vision and possible colour vision can be clarified by analysing the responses of single retinal neurons. This paper reviews the current information on this topic and provides new insights from single retinal ganglion cell recordings.
Collapse
Affiliation(s)
- Peter Gouras
- Department of Ophthalmology, Columbia University, 630 W 168th street, New York, NY 10032, USA.
| | | |
Collapse
|
45
|
Ghosh KK, Bujan S, Haverkamp S, Feigenspan A, Wässle H. Types of bipolar cells in the mouse retina. J Comp Neurol 2003; 469:70-82. [PMID: 14689473 DOI: 10.1002/cne.10985] [Citation(s) in RCA: 308] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
We studied the morphology of bipolar cells in fixed vertical tissue sections (slices) of the mouse retina by injecting the cells with Lucifer Yellow and Neurobiotin. Nine different cone bipolar cell types and one rod bipolar cell type were distinguished. The major criteria for classifying the cells were the branching pattern and stratification level of their axon terminals in the inner plexiform layer (IPL). To assess this, the IPL was subdivided into five strata of equal width. The slices were immunostained for calretinin, which labels three horizontal bands serving as a standard measure for the precise localization of the axon terminals. Immunostaining the retina with antibodies against the G-protein Ggamma13, a marker for ON-bipolar cells, made it possible to separate OFF- and ON-bipolar cells. At least two OFF-cone bipolar cells (Types 1 and 2) were immunolabeled with antibodies against the neurokinin 3 receptors (NK3R). A further OFF- and an ON-cone bipolar cell (Types 3 and 5) were immunostained with antibodies against the calcium-binding protein CaB5. The bipolar cell types described here were compared with previous schemes of rat and primate bipolar cells. Homologous types between the three species are discussed.
Collapse
Affiliation(s)
- Krishna K Ghosh
- Department of Neuroanatomy, Max-Planck-Institut für Hirnforschung, Deutschordenstrasse 46, D-60528 Frankfurt/Main, Germany
| | | | | | | | | |
Collapse
|
46
|
Abstract
Thyroid hormone appears to play a critical, yet not fully understood, role in the development of the neuroretina. This review focuses on recent experiments in the rodent, chicken, and amphibian, with an emphasis on how the hormone and its receptor isoforms influence retinal cell proliferation and cell fate decisions. The initial results are fueling the next generation of experiments in the retina, which promise to provide insights into the mechanisms of thyroid hormone action in a wide variety of developing neural tissue.
Collapse
Affiliation(s)
- Sanjiv Harpavat
- Department of Genetics and Howard Hughes Medical Institute, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
47
|
Pacione LR, Szego MJ, Ikeda S, Nishina PM, McInnes RR. PROGRESSTOWARDUNDERSTANDING THEGENETIC ANDBIOCHEMICALMECHANISMS OFINHERITEDPHOTORECEPTORDEGENERATIONS. Annu Rev Neurosci 2003; 26:657-700. [PMID: 14527271 DOI: 10.1146/annurev.neuro.26.041002.131416] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
More than 80 genes associated with human photoreceptor degenerations have been identified. Attention must now turn toward defining the mechanisms that lead to photoreceptor death, which occurs years to decades after the birth of the cells. Consequently, this review focuses on topics that offer insights into such mechanisms, including the one-hit or constant risk model of photoreceptor death; topological patterns of photoreceptor degeneration; mutations in ubiquitously expressed splicing factor genes associated only with photoreceptor degeneration; disorders of the retinal pigment epithelium; modifier genes; and global gene expression analysis of the retina, which will greatly increase our understanding of the downstream events that occur in response to a mutation.
Collapse
Affiliation(s)
- Laura R Pacione
- Programs in Genetics and Developmental Biology, The Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada M5G 1X8
| | | | | | | | | |
Collapse
|
48
|
Azadi S, Zhang Y, Caffé AR, Holmqvist B, van Veen T. Thyroid-beta2 and the retinoid RAR-alpha, RXR-gamma and ROR-beta2 receptor mRNAs; expression profiles in mouse retina, retinal explants and neocortex. Neuroreport 2002; 13:745-50. [PMID: 11997680 DOI: 10.1097/00001756-200205070-00003] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In neonatal retinal explants cultured long-term green cones are missing. Recently it was reported that thyroid hormone beta2 receptors (TR-beta2) are essential for these green cones to differentiate. Therefore transcript level of these receptors was investigated in our mouse retinal explants. However, thyroid receptors function as heterodimers with retinoid receptors (RR); so the fate of selected RRs was similarly analyzed using semi-quantitative RT-PCR. Loss of TR-beta2 and RR (RXR-gamma and ROR-beta2) mRNAs was observed after culturing the neonatal retina for 12 days. This indicates that these proteins are involved in determination of green cone identity. In addition, levels of the selected RR transcripts are differentially affected by short- or long-term culture. In the latter case an attached retinal pigment epithelium seems to play a protective role. Furthermore, divergent diurnal peaks of RR mRNAs are present in young as well as aged mouse retina and neocortex. This data might be relevant in the context of human ageing disorders.
Collapse
Affiliation(s)
- S Azadi
- Department of Ophthalmology, Biomedical Center, University of Lund, Klinikgatan 26, S-221 84 Lund, Sweden
| | | | | | | | | |
Collapse
|
49
|
Abstract
Multiple cell types often differentiate from a pluripotent cell. These cells may then further diversify as distinct subtypes. The visual system provides an ideal model for studying subtype specification as various photoreceptors acquire different functions based on the type of opsin they express. Opsin expression is mostly controlled through transcriptional mechanisms that are evolutionary conserved from Drosophila to humans. In addition, it appears that, from a "default" developmental state, distinct "acquired" photoreceptor states develop upon receiving intrinsic or extrinsic signals. This review discusses factors involved in opsin gene regulation and how their integration may explain how subtype specificity is achieved.
Collapse
Affiliation(s)
- T Cook
- Department of Biology, 1009 Main Building, 100 Washington Square East, New York University, New York, NY 10003, USA
| | | |
Collapse
|
50
|
Caffé AR, Ahuja P, Holmqvist B, Azadi S, Forsell J, Holmqvist I, Söderpalm AK, van Veen T. Mouse retina explants after long-term culture in serum free medium. J Chem Neuroanat 2001; 22:263-73. [PMID: 11719023 DOI: 10.1016/s0891-0618(01)00140-5] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The neonatal mouse retina remains viable as an explant in serum-supplemented growth media for more than 4 weeks. Interpretation of drug effects on this tissue is compromised by the enigmatic composition of the serum. We sought to remove this ambiguity by culturing neonatal as well as late postnatal mouse retina in serum-free nutrient medium. In this study three important observations were made, (1) there is histotypic development of neonatal as well as preservation of late postnatal mouse retinal structure during long-term culture in serum-free medium, although the late postnatal tissue tends to show some loss of cells in the outer nuclear layer. (2) Protein expression in explant photoreceptor cells was similar to that in the litter-matched ones, except for green cone opsin and interphotoreceptor retinoid-binding protein, although mRNA of the latter is present at similar amounts as in age-matched in vivo controls. (3) Cells of the inner retina stained by antibodies to calcium-binding proteins display some novel sprouting of processes. The results show that the mouse retina can be cultured as an explant for more than 4 weeks in a serum-free medium. This represents an important step forward because, (1) the possibility of interference of drug effects by unknown serum factors has been eliminated; and (2) the spent culture medium can be analyzed to investigate biomolecules released by the retina in vitro.
Collapse
Affiliation(s)
- A R Caffé
- Department of Ophthalmology, Biomedical Center-Wallenberg Retina Center, University of Lund, Klinikgatan 26, S-221 84 Lund, Sweden
| | | | | | | | | | | | | | | |
Collapse
|