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Toledano S, Lu H, Palacio A, Ziv K, Kessler O, Schaal S, Neufeld G, Barak Y. A Sema3C Mutant Resistant to Cleavage by Furin (FR-Sema3C) Inhibits Choroidal Neovascularization. PLoS One 2016; 11:e0168122. [PMID: 28036336 PMCID: PMC5201251 DOI: 10.1371/journal.pone.0168122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2016] [Accepted: 11/23/2016] [Indexed: 01/13/2023] Open
Abstract
In age-related macular degeneration (AMD), abnormal sub retinal choroidal neovascularization (CNV) is a major cause of blindness. FR-sema3C is a point mutated form of semaphorin-3C that is resistant to cleavage by furin like pro-protein convertases (FPPC). We have found in previous work that FR-sema3C functions as an anti-angiogenic factor. In this study we investigated the possible use of FR-sema3C as an inhibitor of CNV. FR-sema3C inhibits VEGF as well as PDGF-BB signal transduction in endothelial cells and to less extent bFGF induced signal transduction using a mechanism that does not depend upon the binding of VEGF like the drugs that are currently the mainstay treatment for AMD. CNV was induced in eyes of C57 black mice by laser photocoagulation. Intravitreal injection of FR-Sema3C or aflibercept (VEGF-trap) was then used to inhibit CNV formation. Invading choroidal vessels were visualized a week later by injection of FITC-dextran into the circulation, followed by the measurement of the area of the invading blood vessels. Injection of 0.1 μg FR-Sema3C inhibited CNV by 55% (P<0.01) and was as effective as 5 μg aflibercept. FR-sema3C did not display any adverse effects on retinal function following its injection into eyes of healthy mice as assessed by optokinetic reflex (OKR) and Electro-retinogram (ERG) criteria. Furthermore, FR-sema3C did not induce apoptosis in the retina as determined by TUNEL nor was there any discernable structural damage to the retina as assessed by several immuno-histochemical criteria. Our results suggest that FR-sema3C could perhaps be used for the treatment of AMD, and that it may perhaps be of benefit to patients that do not respond well to current treatments relying on VEGF sequestering agents.
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Affiliation(s)
- Shira Toledano
- Cancer Research and Vascular Biology Center, The Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Huayi Lu
- Second Hospital of Jilin University, Changchun, Jilin Province, P.R. China
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
| | - Agustina Palacio
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
| | - Keren Ziv
- Cancer Research and Vascular Biology Center, The Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Ofra Kessler
- Cancer Research and Vascular Biology Center, The Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
| | - Shlomit Schaal
- Department of Ophthalmology and Visual Sciences, University of Louisville, Louisville, Kentucky, United States of America
- Department of Ophthalmology and Visual Sciences, University of Massachusetts School of Medicine, Massachusetts, United States of America
- * E-mail: (SS); (GN); (YB)
| | - Gera Neufeld
- Cancer Research and Vascular Biology Center, The Bruce Rappaport Faculty of Medicine, Technion, Israel Institute of Technology, Haifa, Israel
- * E-mail: (SS); (GN); (YB)
| | - Yoreh Barak
- Department of Ophthalmology, RAMBAM Medical Center, Haifa, Israel
- * E-mail: (SS); (GN); (YB)
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2
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Lagali PS, Medina CF, Zhao BYH, Yan K, Baker AN, Coupland SG, Tsilfidis C, Wallace VA, Picketts DJ. Retinal interneuron survival requires non-cell-autonomous Atrx activity. Hum Mol Genet 2016; 25:4787-4803. [PMID: 28173139 DOI: 10.1093/hmg/ddw306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/25/2016] [Accepted: 08/30/2016] [Indexed: 01/13/2023] Open
Abstract
ATRX is a chromatin remodeling protein that is mutated in several intellectual disability disorders including alpha-thalassemia/mental retardation, X-linked (ATR-X) syndrome. We previously reported the prevalence of ophthalmological defects in ATR-X syndrome patients, and accordingly we find morphological and functional visual abnormalities in a mouse model harboring a mutation occurring in ATR-X patients. The visual system abnormalities observed in these mice parallels the Atrx-null retinal phenotype characterized by interneuron defects and selective loss of amacrine and horizontal cells. The mechanisms that underlie selective neuronal vulnerability and neurodegeneration in the central nervous system upon Atrx mutation or deletion are unknown. To interrogate the cellular specificity of Atrx for its retinal neuroprotective functions, we employed a combination of temporal and lineage-restricted conditional ablation strategies to generate five different conditional knockout mouse models, and subsequently identified a non-cell-autonomous requirement for Atrx in bipolar cells for inhibitory interneuron survival in the retina. Atrx-deficient retinal bipolar cells exhibit functional, structural and molecular alterations consistent with impairments in neuronal activity and connectivity. Gene expression changes in the Atrx-null retina indicate defective synaptic structure and neuronal circuitry, suggest excitotoxic mechanisms of neurodegeneration, and demonstrate that common targets of ATRX in the forebrain and retina may contribute to similar neuropathological processes underlying cognitive impairment and visual dysfunction in ATR-X syndrome.
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Affiliation(s)
- Pamela S Lagali
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Chantal F Medina
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Brandon Y H Zhao
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Adam N Baker
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Stuart G Coupland
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Ophthalmology, University of Ottawa, Ottawa, ON K1H 8M5, Canada,,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Catherine Tsilfidis
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Ophthalmology, University of Ottawa, Ottawa, ON K1H 8M5, Canada,,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Valerie A Wallace
- Vision Research Division, Krembil Research Institute, Toronto, Ontario, Canada M5T 2S8,,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada,,Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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3
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Tu HY, Chiao CC. Cx36 expression in the AII-mediated rod pathway is activity dependent in the developing rabbit retina. Dev Neurobiol 2016; 76:473-86. [PMID: 26084632 DOI: 10.1002/dneu.22320] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 12/20/2022]
Abstract
Gap junctions are composed of connexin 36 (Cx36) and play a critical role in the rod photoreceptor signaling pathways of the vertebrate retina. Despite the fact that their connection and modulation in various rod pathways have been extensively studied in adult animals, little is known about the contribution and regulation of gap junctions to the development of the AII amacrine cell (AC)-mediated rod pathway. Using immunohistochemistry and microinjection, this study demonstrates a steady increase in relative Cx36 protein expression in both plexiform layers of the rabbit retina at around the time of eye opening. However, immediately after eye opening, most Cx36 immunoreactive AII ACs show no gap junction coupling pattern to neighboring cells and it is not until the third postnatal week that AII cells begin to exhibit an adult-like tracer-coupling pattern. Moreover, studies using dark-rearing and AMPA receptor blockade during postnatal development both revealed that relative levels of Cx36 immunoreactivity in AII ACs were increased when neural activity was inhibited. Our findings suggest that Cx36 expression in the AII-mediated rod pathway is activity dependent in the developing rabbit retina.
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Affiliation(s)
- Hung-Ya Tu
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, 30013, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu, 30013, Taiwan
| | - Chuan-Chin Chiao
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, 30013, Taiwan
- Department of Life Science, National Tsing Hua University, Hsinchu, 30013, Taiwan
- Institute of Systems Neuroscience, National Tsing Hua University, Hsinchu, 30013, Taiwan
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4
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Huh YJ, Choi JS, Jeon CJ. Localization of Rod Bipolar Cells in the Mammalian Retina Using an Antibody Against the α1c L-type Ca(2+) Channel. Acta Histochem Cytochem 2015; 48:47-52. [PMID: 26019373 PMCID: PMC4427564 DOI: 10.1267/ahc.14049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 03/16/2015] [Indexed: 11/22/2022] Open
Abstract
Bipolar cells transmit stimuli via graded changes in membrane potential and neurotransmitter release is modulated by Ca2+ influx through L-type Ca2+ channels. The purpose of this study was to determine whether the α1c subunit of L-type voltage-gated Ca2+ channel (α1c L-type Ca2+ channel) colocalizes with protein kinase C alpha (PKC-α), which labels rod bipolar cells. Retinal whole mounts and vertical sections from mouse, hamster, rabbit, and dog were immunolabeled with antibodies against PKC-α and α1c L-type Ca2+ channel, using fluorescein isothiocyanate (FITC) and Cy5 as visualizing agents. PKC-α-immunoreactive cells were morphologically identical to rod bipolar cells as previously reported. Their cell bodies were located within the inner nuclear layer, dendritic processes branched into the outer plexiform layer, and axons extended into the inner plexiform layer. Immunostaining showed that α1c L-type Ca2+ channel colocalized with PKC-α in rod bipolar cells. The identical expression of PKC-α and α1c L-type Ca2+ channel indicates that the α1c L-type Ca2+ channel has a specific role in rod bipolar cells, and the antibody against the α1c L-type Ca2+ channel may be a useful marker for studying the distribution of rod bipolar cells in mouse, hamster, rabbit, and dog retinas.
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Affiliation(s)
- Yu-Jin Huh
- Department of Biology, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University
| | - Jae-Sik Choi
- Department of Biology, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University
| | - Chang-Jin Jeon
- Department of Biology, School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, College of Natural Sciences, and Brain Science and Engineering Institute, Kyungpook National University
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5
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Soudry S, Zemel E, Loewenstein A, Perlman I. The developing mammalian retina is partially protected from gentamicin toxicity. Exp Eye Res 2009; 88:1152-60. [DOI: 10.1016/j.exer.2009.02.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 01/24/2009] [Accepted: 02/03/2009] [Indexed: 10/21/2022]
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6
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Wu ML, Chiao CC. Light deprivation delays morphological differentiation of bipolar cells in the rabbit retina. Brain Res 2007; 1170:13-9. [PMID: 17716634 DOI: 10.1016/j.brainres.2007.06.091] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 06/15/2007] [Accepted: 06/20/2007] [Indexed: 01/22/2023]
Abstract
Bipolar cells are responsible for transmitting light signals from the photoreceptors to the ganglion cells in the vertebrate retina. Their maturation process is not only important for establishing normal visual function, but may also underlie the dendritic remodeling of ganglion cells during development. It is known that light deprivation affects the synaptic connections of ganglion cells in the mammalian retina, but little is known about impact of visual experience on bipolar cell development. We used dye injection and gene gun labeling to identify bipolar cells, and characterized their morphological differentiation in normal-reared and dark-reared rabbits. Our results show that immature bipolar cells can be found as early as P1-3, and most characteristic bipolar cells can be identified during P4-6. More importantly, we found that light deprivation causes a delay rather than a permanent arrest of bipolar cell maturation in the rabbit retina. By eye opening at P10-11, both normal-reared and dark-reared rabbits possessed adult-like bipolar cells. This suggests that visual experience has a facilitating effect on the morphological differentiation of bipolar cells.
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Affiliation(s)
- Mu-Ling Wu
- Institute of Molecular Medicine, National Tsing Hua University, Hsinchu, 30013, Taiwan
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7
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Baker GE, Dovey M, Davda P, Guibal C, Jeffery G. Protein kinase C immunoreactivity in the pigmented and albino rat retina. Eur J Neurosci 2006; 22:2481-8. [PMID: 16307591 DOI: 10.1111/j.1460-9568.2005.04453.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The albino retina is abnormal. The central region is under-developed and some cell populations are reduced or increased in number. Not least of these anomalies is the deficit in the rod population in hypopigmented rodents and carnivores. Given this abnormality we have examined the distribution of rod bipolar cells in albino rats to determine whether this subsequent stage in the rod pathway is similarly disrupted. A monoclonal antibody to protein kinase C was used to determine the distribution of rod bipolar cells in juvenile and adult pigmented and albino rats. Immunoreactive rod bipolar cells and their processes were counted in transverse sections passing through both the central and peripheral retina. The mean densities of immunoreactive cells were significantly reduced in albino retinas at both juvenile (postnatal day 15) and adult stages, in the former by 14% and the latter by 9%. This was evident across the entire central-to-peripheral extent of the retina. The reduced rod photoreceptor population found in albinos appears therefore to be consequential for the magnitude of their major target population, rod bipolar cells. The decrease in the rod bipolar population indicates a change in retinal cytoarchitecture and implies a disruption of functional organization of the albino retina, especially that underlying the scotopic channel. This, coupled with observations that some other retinal interneuronal populations may be disrupted, implies disordered retinal processing in albinos and emphasizes the likelihood that abnormal visual function in albinos may be as much a result of anomalous retinal circuitry as of the known photoreceptor deficit or chiasmatic misrouting.
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Affiliation(s)
- Gary E Baker
- Department of Optometry & Visual Science, City University, Northampton Square, London EC1V 0HB, UK.
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8
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Catalani E, Gangitano C, Bosco L, Casini G. Expression of the neurokinin 1 receptor in the mouse retina. Neuroscience 2005; 128:519-30. [PMID: 15381281 DOI: 10.1016/j.neuroscience.2004.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/02/2004] [Indexed: 10/26/2022]
Abstract
Previous studies have revealed that the expression pattern of the neurokinin 1 receptor (the preferred receptor for substance P, SP) varies in different mammalian retinas. We investigated NK1 receptor expression in the mouse retina to provide background information for future studies in transgenic mice on SP functional roles in the retina. Mouse retinal sections were treated for single and double-label immunofluorescence. NK1 receptor immunoreactivity was in bipolar cells and in numerous amacrine cells. Double-label studies showed that NK1 receptor-expressing bipolar cells constituted a population of ON-type cone bipolar cells, since they were distinct from rod bipolar cells and contained glycine. They were nonrandomly distributed with highest density in central retina. These cells were similar and may correspond to the population of NK1 receptor-expressing bipolar cells of the rabbit retina. Different subsets of NK1 receptor-expressing amacrine cells were identified on the basis of the expression of selected neurotransmitter substances: i) about 23% of NK1 receptor-expressing amacrine cells also contained glycine; ii) the remaining 77% were likely to be GABAergic, although some inconsistency was observed in the GABA immunostaining obtained with two different GABA antibodies; iii) all dopaminergic amacrine cells also expressed NK1 receptors; iv) about one third of SP-containing amacrine cells also expressed NK1 receptors. These findings confirm and expand previous observations in rat and rabbit retinas. In particular, common to all three species is the expression of NK1 receptors in dopaminergic amacrine cells, indicating that SP neurotransmission may be a universal feature of the circuitry of the dopaminergic amacrine cell. Peculiar to the mouse retina is the presence of putative NK1 autoreceptors expressed by SP-containing amacrine cells.
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Affiliation(s)
- E Catalani
- Dipartimento di Scienze Ambientali, Università della Tuscia, Largo dell'Università, Blocco D snc, 01100 Viterbo, Italy
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Lee EJ, Kim HJ, Lim EJ, Kim IB, Kang WS, Oh SJ, Rickman DW, Chung JW, Chun MH. AII amacrine cells in the mammalian retina show disabled-1 immunoreactivity. J Comp Neurol 2004; 470:372-81. [PMID: 14961563 DOI: 10.1002/cne.20010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Disabled 1 (Dab1) is an adapter molecule in a signaling pathway, stimulated by Reelin, which controls cell positioning in the developing brain. It has been localized to AII amacrine cells in the mouse and guinea pig retinas. This study was conducted to identify whether Dab1 is commonly localized to AII amacrine cells in the retinas of other mammals. We investigated Dab1-labeled cells in human, rat, rabbit, and cat retinas in detail by immunocytochemistry with antisera against Dab1. Dab1 immunoreactivity was found in certain populations of amacrine cells, with lobular appendages in the outer half of the inner plexiform layer (IPL) and a bushy, smooth dendritic tree in the inner half of the IPL. Double-labeling experiments demonstrated that all Dab1-immunoreactive amacrine cells were immunoreactive to antisera against calretinin or parvalbumin (i.e., other markers for AII amacrine cells in the mammalian retina) and that they made contacts with the axon terminals of the rod bipolar cells in the IPL close to the ganglion cell layer. Furthermore, all Dab1-labeled amacrine cells showed glycine transporter-1 immunoreactivity, indicating that they are glycinergic. The peak density was relatively high in the human and rat retinas, moderate in the cat retina, and low in the rabbit retina. Together, these morphological and histochemical observations clearly indicate that Dab1 is commonly localized to AII amacrine cells and that antiserum against Dab1 is a reliable and specific marker for AII amacrine cells of diverse mammals.
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Affiliation(s)
- Eun-Jin Lee
- Department of Anatomy, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
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10
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Casini G, Dal Monte M, Petrucci C, Gambellini G, Grouselle D, Allen JP, Kreienkamp HJ, Richter D, Epelbaum J, Bagnoli P. Altered morphology of rod bipolar cell axonal terminals in the retinas of mice carrying genetic deletion of somatostatin subtype receptor 1 or 2. Eur J Neurosci 2004; 19:43-54. [PMID: 14750962 DOI: 10.1111/j.1460-9568.2004.03081.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Somatostatin (SRIF), similar to other neuropeptides, is likely to influence the morpho-functional characteristics of neurons. We studied possible morphological alterations of mouse retinal neurons following genetic deletion of SRIF subtype receptor 1 [sst1 knockout (KO)] or 2 (sst2 KO). In sst1 KO retinas, axonal terminals of rod bipolar cells (RBCs), identified with protein kinase C immunoreactivity, were 25% larger than in controls. In contrast, in sst2 KO retinas, RBC axonal terminals were significantly smaller (-14%). No major ultrastructural differences were observed between control and KO RBCs. In sst2 KO retinas, SRIF levels decreased by about 35%, while both sst1 receptor mRNA and protein increased by about 170% and 100%, respectively. This compares to previous results reporting an increase of both retinal SRIF and sst2 receptors following sst1 receptor deletion. Together, these findings suggest that, on the one hand, sst1 receptor deletion induces over-expression of sst2 receptors, and vice versa; on the other hand, that an imbalance in sst1 and sst2 receptor expression and/or changes in the levels of retinal SRIF induced by sst1 or sst2 receptor deletion are responsible for the morphological changes in RBC axonal terminals. Similar alterations of RBC terminals were observed in KO retinas at 2 weeks of age (eye opening). In addition, reverse transcription-polymerase chain reaction analysis of the expression of sst2 and sst1 receptors in developing sst1 and sst2 KO retinas, respectively, demonstrated that these receptors are up-regulated at or near eye opening. These findings suggest that the integrity of the somatostatinergic system during development is necessary for proper RBC maturation.
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Affiliation(s)
- Giovanni Casini
- Dipartimento di Scienze Ambientali, Università della Tuscia, 01100 Viterbo, Italy.
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11
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Casini G, Sabatini A, Catalani E, Willems D, Bosco L, Brecha NC. Expression of the neurokinin 1 receptor in the rabbit retina. Neuroscience 2003; 115:1309-21. [PMID: 12453499 DOI: 10.1016/s0306-4522(02)00408-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Substance P is the preferred ligand for the neurokinin 1 (NK1) receptor. In vertebrate retinas, substance P is expressed by amacrine, interplexiform and ganglion cells. Substance P influences the activity of amacrine and ganglion cells and it is reported to evoke dopamine release. We investigated NK1 receptor expression in the rabbit retina using affinity-purified NK1 receptor antibodies. NK1 receptors were expressed by two distinct populations of retinal neurons. One is a population of ON-type bipolar cells characterized by axonal arborizations that ramified in the inner plexiform layer near the ganglion cell layer. Double-label studies showed that NK1 receptor-expressing bipolar cells were distinct from rod bipolar cells and from other immunocytochemically identified types of cone bipolar cells. Their density was about 2250 cells/mm2 in the visual streak and 1115 cells/mm2 in ventral mid-periphery. They were distributed in a non-random pattern. In the outer plexiform layer, the dendrites of these bipolar cells converged into heavily immunostained clusters having a punctate appearance. The density of these clusters in mid-peripheral ventral regions (about 13000 clusters/mm2) was similar to the reported cone density [Famiglietti and Sharpe (1995) Vis. Neurosci. 12, 1151-1175], suggesting these dendrites contact all cone photoreceptors. The second NK1 receptor expressing cell population corresponds to the tyrosine hydroxylase-containing amacrine cell population. NK1 receptor immunostaining was localized to the cell body and processes, but not to the processes that form the 'rings' that are known to encircle somata of AII amacrine cells. These findings show that NK1 receptor immunoreactivity is localized to a population of ON-type cone bipolar cells and to dopaminergic amacrine cells, suggesting that substance P acting on NK1 receptors influences multiple retinal circuits in the rabbit retina.
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Affiliation(s)
- G Casini
- Dipartimento di Scienze Ambientali, Università della Tuscia, 01100, Viterbo, Italy.
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12
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Carvalho AL, Correia S, Faro CJ, Duarte CB, Carvalho AP, Pires EMV. Phosphorylation of GluR4 AMPA-type glutamate receptor subunit by protein kinase C in cultured retina amacrine neurons. Eur J Neurosci 2002; 15:465-74. [PMID: 11876774 DOI: 10.1046/j.0953-816x.2001.01881.x] [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: 11/20/2022]
Abstract
We have previously reported that the activity of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors is potentiated by protein kinase C (PKC) in cultured chick retina amacrine neurons, and that constitutive PKC activity is necessary for basal AMPA receptor activity (Carvalho et al., 1998). In this study, we evaluated the phosphorylation of the GluR4 subunit, which is very abundant in cultured amacrine neurons, to correlate it with the effects of PKC on AMPA receptor activity in these cells. 32P-labelling of GluR4 increased upon AMPA receptor stimulation or cell treatment with phorbol 12-myristate 13-acetate (PMA) before stimulating with kainate. By contrast, phosphorylation of GluR4 was not changed when PKC was inhibited by treating the cells with the selective PKC inhibitor GF 109203X before stimulation with kainate. We conclude that GluR4 is phosphorylated upon PKC activation and/or stimulation of AMPA receptors in cultured amacrine cells. Additionally, AMPA receptor activation with kainate in cultured chick amacrine cells leads to translocation of conventional and novel PKC isoforms to the cell membrane, suggesting that PKC could be activated upon AMPA receptor stimulation in these cells.
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Affiliation(s)
- Ana Luísa Carvalho
- Centre for Neuroscience and Cell Biology, University of Coimbra, Portugal.
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13
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Fontanesi G, Gargini C, Bagnoli P. Postnatal development of somatostatin 2A (sst2A) receptors expression in the rabbit retina. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2000; 123:67-80. [PMID: 11020551 DOI: 10.1016/s0165-3806(00)00073-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the retina, somatostatin (SRIF) acts as a neuromodulator by interacting with specific SRIF subtype (sst) receptors. Aim of this investigation was to determine the cellular localization of the sst2A receptor isoform in the postnatal rabbit retina. Receptor immunoreactivity was localized using the antiserum K-230, directed to the C-terminus of the human sst2A receptor. In the postnatal rabbit retina, sst2A receptors were abundantly expressed without significant regional differences. They were localized predominantly to rod bipolar cells, identified with a protein kinase C (PKC) antibody, to amacrine cells, some of which also containing tyrosine hydroxylase (TH), and to presumed rare horizontal cells. Quantitative analysis showed that sst2A-immunoreactive (-IR) bipolar and amacrine cells reached their maximum density and absolute number at the time of eye opening, when the expression pattern of sst2A receptors was similar to that in adult retinas. In the adult retina, 68% of the PKC-IR rod bipolars and 34% of the TH-IR amacrine cells were observed to also express sst2A receptors. The appearance of sst2A receptor immunolabeling prior to eye opening and the developmental profile of sst2A receptor expression are compatible with a role of SRIF in the maturation of retinal circuitries. The partial expression of sst2A receptors in PKC-IR rod bipolar cells and in TH-IR amacrine cells may suggest some type of heterogeneity within these cell populations.
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Affiliation(s)
- G Fontanesi
- Dipartimento di Fisiologia e Biochimica 'G. Moruzzi', Universita' di Pisa, Via S. Zeno 31, 56127, Pisa, Italy
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14
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Caminos E, Velasco A, Jarrín M, Aijón J, Lara JM. Protein kinase C-like immunoreactive cells in embryo and adult chicken retinas. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1999; 118:227-30. [PMID: 10611524 DOI: 10.1016/s0165-3806(99)00156-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Morphological evidence of a temporal parallelism between the appearance of the alpha isoform of protein kinase C (PKC) and some processes such as synaptogenesis in the plexiform layers of the chicken retina is offered. Immunostaining experiments were performed throughout embryonic, young and adult chicken life. The results help to understand the development of rod bipolar cells.
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Affiliation(s)
- E Caminos
- Departamento de Biología Celular y Patología, Facultad de Medicina, Instituto de Neurociencias de Castilla y León, Universidad de Salamanca, Campus Unamuno, 37007, Salamanca, Spain
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15
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Casini G, Rickman DW, Trasarti L, Brecha NC. Postnatal development of parvalbumin immunoreactive amacrine cells in the rabbit retina. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1998; 111:107-17. [PMID: 9804913 DOI: 10.1016/s0165-3806(98)00127-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
In the adult rabbit, rat and cat retina, parvalbumin (PV) immunoreactivity is primarily localized to a population of narrow-field, bistratified amacrine cells, the AII amacrine cells-major interneurons of the rod pathway. This investigation examines the postnatal development of PV immunoreactivity in order to better understand the ontogeny of the AII amacrine cell population and the formation of the rod pathway. Rabbit retinas at various postnatal ages were processed for immunohistochemistry using a monoclonal antibody directed to PV and analyzed morphometrically. On the day of birth, PV immunoreactive cell bodies are numerous in the proximal inner nuclear layer (INL) in all retinal regions. These cells have a primary process directed towards the inner plexiform layer (IPL). At postnatal day (PND) 2, a few faint immunoreactive processes are observed in the IPL. At PND 4, well-stained processes are observed to ramify mainly in the proximal IPL. At PND 6, strongly immunoreactive processes are present in both the distal and proximal IPL, and at PND 10 they form a continuous, dense plexus in both levels of the IPL. By PND 10, the morphology of PV immunoreactive cells is similar to PV immunoreactive cells in adult retinas. The density of PV immunoreactive cells in the proximal INL increases from PND 2 to PND 5, then it gradually decreases to adult values, while the total number of PV immunoreactive cell bodies increases until PND 10. PV immunoreactive amacrine cells at PND 2, as in the adult, are nonrandomly distributed across the retinal surface. These studies show that PV immunoreactive amacrine cells have a developmental profile that is similar to several other amacrine cell types. This includes the elaboration of processes in the IPL during the first postnatal week and a mature appearance towards the end of the second week of life, about the time of eye opening. These observations indicate that the AII amacrine cell may participate in the processing of visual information at eye opening.
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Affiliation(s)
- G Casini
- Department of Environmental Sciences, Tuscia University, 01100, Viterbo, Italy
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16
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Lima L, Cubillos S. Taurine-stimulated outgrowth from the retina is impaired by protein kinase C activators and phosphatase inhibitors. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1998; 442:423-30. [PMID: 9635059 DOI: 10.1007/978-1-4899-0117-0_52] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Taurine increases neurite elongation of post-crush goldfish retinal explants, as well as the number of outgrowing isolated cells from goldfish and rat retina in culture. The trophic effect of taurine is related to an elevation in calcium flux rather than increased cell proliferation. Since taurine regulates phosphorylation in rat retina, we investigated if this process could be involved in the mechanism of taurine action on outgrowth. Control and taurine-supplemented post-crush goldfish retinal explants were cultured in the presence of protein kinase C activators or phosphatase inhibitors, and the length of neurites was measured after five days in culture. In some cases, there was an inhibition of the stimulatory effect of taurine without a modification in basal outgrowth. In others, outgrowth of control explants was also reduced. A certain level of protein phosphorylation seems to be critical for the trophic effect of taurine in the retina.
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Affiliation(s)
- L Lima
- Laboratorio de Neuroquímica, Instituto Venezolano de Investigaciones Científicas, Caracas, Venezuela
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17
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Casini G, Trasarti L, Andolfi L, Bagnoli P. Morphologic maturation of tachykinin peptide-expressing cells in the postnatal rabbit retina. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1997; 99:131-41. [PMID: 9125466 DOI: 10.1016/s0165-3806(96)00206-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Tachykinin (TK) peptides, which include substance P, neurokinin A, two neurokinin A-related peptides and neurokinin B, are widely present in the nervous system, including the retina, where they act as neurotransmitters/modulators as well as growth factors. In the present study, we investigated the maturation of TK-immunoreactive (IR) cells in the rabbit retina with the aim of further contributing to the knowledge of the development of transmitter-identified retinal cell populations. In the adult retina, the pattern of TK immunostaining is consistent with the presence of TK peptides in amacrine, displaced amacrine, interplexiform and ganglion cells. In the newborn retina, intensely immunostained TK-IR somata are located in the ganglion cell layer (GCL) and in the inner nuclear layer (INL) adjacent to the inner plexiform layer (IPL). They are characterized by an oval-shaped cell body originating a single process without ramifications. TK-IR processes are occasionally observed in the IPL and in the outer plexiform layer (OPL). Long TK-IR fiber bundles are observed in the ganglion cell axon layer. TK-IR profiles resembling small somata are rarely observed in the INL adjacent to the OPL. At postnatal day (PND) 2, some TK-IR cells display more complex morphologic features, including processes with secondary ramifications. Long TK-IR processes in the IPL are often seen to terminate with growth cones. Between PND 6 and PND 11 (eye opening), there is a dramatic increase in the number of immunolabeled processes with growth cones both in the IPL and in the OPL and the mature lamination of TK-IR fibers in laminae 1, 3 and 5 of the IPL is established. TK-IR cells attain mature morphological characteristics and the rare, putative TK-IR somata in the distal INL are no longer observed. After eye opening, growth cones are not present and the pattern typical of the adult is reached. These observations indicate that the development of TK-IR cells can be divided into an early phase (from birth to PND 6) in which these cells establish their morphological characteristics, and a later phase (from PND 6 to eye opening) in which they are involved in active growth of their processes and likely in synapse formation. Since TK peptides are thought to play neurotrophic actions in the developing nervous system and they are consistently present in the retina throughout postnatal development, they may also act as growth factors during retinal maturation.
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Affiliation(s)
- G Casini
- Department of Environmental Sciences, Tuscia University, Viterbo, Italy
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