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Vöcking O, Famulski JK. A temporal single cell transcriptome atlas of zebrafish anterior segment development. Sci Rep 2023; 13:5656. [PMID: 37024546 PMCID: PMC10079958 DOI: 10.1038/s41598-023-32212-4] [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: 11/02/2022] [Accepted: 03/24/2023] [Indexed: 04/08/2023] Open
Abstract
Anterior segment dysgenesis (ASD), resulting in vision impairment, stems from maldevelopment of anterior segment (AS) tissues. Incidence of ASD has been linked to malfunction of periocular mesenchyme cells (POM). POM cells specify into anterior segment mesenchyme (ASM) cells which colonize and produce AS tissues. In this study we uncover ASM developmental trajectories associated with formation of the AS. Using a transgenic line of zebrafish that fluorescently labels the ASM throughout development, Tg[foxc1b:GFP], we isolated GFP+ ASM cells at several developmental timepoints (48-144 hpf) and performed single cell RNA sequencing. Clustering analysis indicates subdifferentiation of ASM as early as 48 hpf and subsequent diversification into corneal epithelium/endothelium/stroma, or annular ligament (AL) lineages. Tracking individual clusters reveals common developmental pathways, up to 72 hpf, for the AL and corneal endothelium/stroma and distinct pathways for corneal epithelium starting at 48 hpf. Spatiotemporal validation of over 80 genes found associated with AS development demonstrates a high degree of conservation with mammalian trabecular meshwork and corneal tissues. In addition, we characterize thirteen novel genes associated with annular ligament and seven with corneal development. Overall, the data provide a molecular verification of the long-standing hypothesis that POM derived ASM give rise to AS tissues and highlight the high degree of conservation between zebrafish and mammals.
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Affiliation(s)
- Oliver Vöcking
- Department of Biology, University of Kentucky, Lexington, USA
| | - J K Famulski
- Department of Biology, University of Kentucky, Lexington, USA.
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Schwend T. Wiring the ocular surface: A focus on the comparative anatomy and molecular regulation of sensory innervation of the cornea. Differentiation 2023:S0301-4681(23)00010-5. [PMID: 36997455 DOI: 10.1016/j.diff.2023.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 01/23/2023] [Indexed: 01/29/2023]
Abstract
The cornea is richly innervated with sensory nerves that function to detect and clear harmful debris from the surface of the eye, promote growth and survival of the corneal epithelium and hasten wound healing following ocular disease or trauma. Given their importance to eye health, the neuroanatomy of the cornea has for many years been a source of intense investigation. Resultantly, complete nerve architecture maps exist for adult human and many animal models and these maps reveal few major differences across species. Interestingly, recent work has revealed considerable variation across species in how sensory nerves are acquired during developmental innervation of the cornea. Highlighting such species-distinct key differences, but also similarities, this review provides a full, comparative anatomy analysis of sensory innervation of the cornea for all species studied to date. Further, this article comprehensively describes the molecules that have been shown to guide and direct nerves toward, into and through developing corneal tissue as the final architectural pattern of the cornea's neuroanatomy is established. Such knowledge is useful for researchers and clinicians seeking to better understand the anatomical and molecular basis of corneal nerve pathologies and to hasten neuro-regeneration following infection, trauma or surgery that damage the ocular surface and its corneal nerves.
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BMP3 inhibits TGFβ2-mediated myofibroblast differentiation during wound healing of the embryonic cornea. NPJ Regen Med 2022; 7:36. [PMID: 35879352 PMCID: PMC9314337 DOI: 10.1038/s41536-022-00232-9] [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: 12/02/2021] [Accepted: 07/06/2022] [Indexed: 11/29/2022] Open
Abstract
Often acute damage to the cornea initiates drastic tissue remodeling, resulting in fibrotic scarring that disrupts light transmission and precedes vision impairment. Very little is known about the factors that can mitigate fibrosis and promote scar-free cornea wound healing. We previously described transient myofibroblast differentiation during non-fibrotic repair in an embryonic cornea injury model. Here, we sought to elucidate the mechanistic regulation of myofibroblast differentiation during embryonic cornea wound healing. We found that alpha-smooth muscle actin (αSMA)-positive myofibroblasts are superficial and their presence inversely correlates with wound closure. Expression of TGFβ2 and nuclear localization of pSMAD2 were elevated during myofibroblast induction. BMP3 and BMP7 were localized in the corneal epithelium and corresponded with pSMAD1/5/8 activation and absence of myofibroblasts in the healing stroma. In vitro analyses with corneal fibroblasts revealed that BMP3 inhibits the persistence of TGFβ2-induced myofibroblasts by promoting disassembly of focal adhesions and αSMA fibers. This was confirmed by the expression of vinculin and pFAK. Together, these data highlight a mechanism to inhibit myofibroblast persistence during cornea wound repair.
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McClellan S, Pitchaikannu A, Wright R, Bessert D, Iulianelli M, Hazlett LD, Xu S. Prophylactic Knockdown of the miR-183/96/182 Cluster Ameliorates Pseudomonas aeruginosa-Induced Keratitis. Invest Ophthalmol Vis Sci 2021; 62:14. [PMID: 34919120 PMCID: PMC8684302 DOI: 10.1167/iovs.62.15.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Previously, we demonstrated that miR-183/96/182 cluster (miR-183C) knockout mice exhibit decreased severity of Pseudomonas aeruginosa (PA)-induced keratitis. This study tests the hypothesis that prophylactic knockdown of miR-183C ameliorates PA keratitis indicative of a therapeutic potential. Methods Eight-week-old miR-183C wild-type and C57BL/6J inbred mice were used. Locked nucleic acid-modified anti-miR-183C or negative control oligoribonucleotides with scrambled sequences (NC ORNs) were injected subconjunctivally 1 day before and then topically applied once daily for 5 days post-infection (dpi) (strain 19660). Corneal disease was graded at 1, 3, and 5 dpi. Corneas were harvested for RT-PCR, ELISA, immunofluorescence (IF), myeloperoxidase and plate count assays, and flow cytometry. Corneal nerve density was evaluated in flatmounted corneas by IF staining with anti-β-III tubulin antibody. Results Anti-miR-183C downregulated miR-183C in the cornea. It resulted in an increase in IL-1β at 1 dpi, which was decreased at 5 dpi; fewer polymorphonuclear leukocytes (PMNs) at 5 dpi; lower viable bacterial plate count at both 1 and 5 dpi; increased percentages of MHCII+ macrophages (Mϕ) and dendritic cells (DCs), consistent with enhanced activation/maturation; and decreased severity of PA keratitis. Anti-miR-183C treatment in the cornea of naïve mice resulted in a transient reduction of corneal nerve density, which was fully recovered one week after the last anti-miR application. miR-183C targets repulsive axon-guidance receptor molecule Neuropilin 1, which may mediate the effect of anti-miR-183C on corneal nerve regression. Conclusions Prophylactic miR-183C knockdown is protective against PA keratitis through its regulation of innate immunity, corneal innervation, and neuroimmune interactions.
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Affiliation(s)
- Sharon McClellan
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Ahalya Pitchaikannu
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Robert Wright
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Denise Bessert
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Mason Iulianelli
- Departments of Biological Sciences and Public Health, College of Liberal Arts and Sciences, Wayne State University, Detroit, Michigan, United States
| | - Linda D Hazlett
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
| | - Shunbin Xu
- Department of Ophthalmology, Visual and Anatomical Sciences, School of Medicine, Wayne State University, Detroit, Michigan, United States
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Babushkina A, Lwigale P. Periocular neural crest cell differentiation into corneal endothelium is influenced by signals in the nascent corneal environment. Dev Biol 2020; 465:119-129. [PMID: 32697973 DOI: 10.1016/j.ydbio.2020.06.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 06/25/2020] [Accepted: 06/26/2020] [Indexed: 12/13/2022]
Abstract
During ocular development, periocular neural crest cells (pNC) migrate into the region between the lens and presumptive corneal epithelium to form the corneal endothelium and stromal keratocytes. Although defects in neural crest cell development are associated with ocular dysgenesis, very little is known about the molecular mechanisms involved in this process. This study focuses on the corneal endothelium, a monolayer of specialized cells that are essential for maintaining normal hydration and transparency of the cornea. In avians, corneal endothelial cells are first to be specified from the pNC during their migration into the presumptive corneal region. To investigate the signals required for formation of the corneal endothelium, we utilized orthotopic and heterotopic injections of dissociated quail pNC into chick ocular regions. We find that pNC are multipotent and that the nascent cornea is competent to induce differentiation of ectopically injected pNC into corneal endothelium. Injected pNC downregulate expression of multipotency transcription factors and upregulate genes that are consistent with ontogenesis of the chick corneal endothelium. Importantly, we showed that TGFβ2 is expressed by the nascent lens and the corneal endothelium, and that TGFβ signaling plays a critical role in changing the molecular signature of pNC in vitro. Collectively, our results demonstrate the significance of the ocular environmental cues towards pNC differentiation, and have potential implications for clinical application of stem cells in the anterior segment.
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Affiliation(s)
- Anna Babushkina
- BioSciences, Rice University, 6100 Main Street, Houston, TX, USA
| | - Peter Lwigale
- BioSciences, Rice University, 6100 Main Street, Houston, TX, USA.
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Patel M, Pham NTK, Ziegenhorn E, Pisano A, Deaton RJ, Kim S, Rajarathnam V, Schwend T. Unique and overlapping effects of triiodothyronine (T3) and thyroxine (T4) on sensory innervation of the chick cornea. Exp Eye Res 2020; 194:108007. [PMID: 32194064 DOI: 10.1016/j.exer.2020.108007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 02/01/2020] [Accepted: 03/15/2020] [Indexed: 12/28/2022]
Abstract
Multiple aspects of cornea development, including the innervation of the cornea by trigeminal axons, are sensitive to embryonic levels of thyroid hormone (TH). Although previous work showed that increased TH levels could enhance the rate of axonal extension within the cornea in a thyroxine (T4)-dependent manner, details underlying the stimulatory effect of TH on cornea innervation are unclear. Here, by examining the effects throughout all stages of cornea innervation of the two main THs, triiodothyronine (T3) and T4, we provide a more complete characterization of the stimulatory effects of TH on corneal nerves and begin to unravel the underlying molecular mechanisms. During development, trigeminal axons are initially repelled at the corneal periphery and encircle the cornea in a pericorneal nerve ring prior to advancing into the corneal stroma radially from all along the nerve ring. Overall, exogenous T3 led to pleiotropic effects throughout all stages of cornea innervation, whereas the effects of exogenous T4 was confined to timepoints following completion of the nerve ring. Specifically, exogenous T3 accelerated the formation of the pericorneal nerve ring. By utilizing in vitro neuronal explants studies we demonstrated that T3 acts as a trophic factor to directly stimulate trigeminal nerve growth. Further, exogenous T3 caused disorganized and precocious innervation of the cornea, accompanied by the downregulation of inhibitory Robo receptors that normally act to regulate the timing of nerve advancement into the Slit-expressing corneal tissues. Following nerve ring completion, the growth rate and branching behavior of nerves as they advanced into and through the cornea were found to be stimulated equally by T3 or T4. These stimulatory influences of T3/T4 over nerves likely arose as secondary consequences brought on by TH-mediated modulations to the corneal extracellular matrix. Specifically, we found that the levels of nerve-inhibitory keratan- and chondroitin-sulfate containing proteoglycans and associated sulfation enzymes were dramatically altered in the presence of exogenous T3 or T4. Altogether, these findings uncover new roles for TH on corneal development and shed insight into the mechanistic basis of both T3 and T4 on cornea innervation.
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Affiliation(s)
- Mansi Patel
- Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Ngan T K Pham
- Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Elise Ziegenhorn
- Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Alyssa Pisano
- Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA
| | - Ryan J Deaton
- Department of Pathology, University of Illinois at Chicago, Chicago, IL, USA
| | - Shinho Kim
- Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA
| | | | - Tyler Schwend
- Department of Biology, Illinois Wesleyan University, Bloomington, IL, USA.
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Cell-independent matrix configuration in early corneal development. Exp Eye Res 2019; 187:107772. [PMID: 31445001 PMCID: PMC6892249 DOI: 10.1016/j.exer.2019.107772] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 08/01/2019] [Accepted: 08/20/2019] [Indexed: 01/01/2023]
Abstract
Mechanisms controlling the spatial configuration of the remarkably ordered collagen-rich extracellular matrix of the transparent cornea remain incompletely understood. We previously described the assembly of the emerging corneal matrix in the mid and late stages of embryogenesis and concluded that collagen fibril organisation was driven by cell-directed mechanisms. Here, the early stages of corneal morphogenesis were examined by serial block face scanning electron microscopy of embryonic chick corneas starting at embryonic day three (E3), followed by a Fourier transform analysis of three-dimensional datasets and theoretical considerations of factors that influence matrix formation. Eyes developing normally and eyes that had the lens surgically removed at E3 were studied. Uniformly thin collagen fibrils are deposited by surface ectoderm-derived corneal epithelium in the primary stroma of the developing chick cornea and form an acellular matrix with a striking micro-lamellar orthogonal arrangement. Fourier transform analysis supported this observation and indicated that adjacent micro-lamellae display a clockwise rotation of fibril orientation, depth-wise below the epithelium. We present a model which attempts to explain how, in the absence of cells in the primary stroma, collagen organisation might be influenced by cell-independent, intrinsic mechanisms, such as fibril axial charge derived from associated proteoglycans. On a supra-lamellar scale, fine cords of non-collagenous filamentous matrix were detected over large tissue volumes. These extend into the developing cornea from the epithelial basal lamina and appear to associate with the neural crest cells that migrate inwardly to form, first the corneal endothelium and then keratocytes which synthesise the mature, secondary corneal stroma. In a small number of experimental specimens, matrix cords were present even when periocular neural crest cell migration and corneal morphogenesis had been perturbed following removal of the lens at E3. Highly-ordered connective tissue appears early in development of the avian cornea. Cell-independent mechanisms may contribute to the organisation of collagen fibrils into an orthogonal array. Matrix cords from epithelium into stroma contact invading neural crest cells.
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McKay TB, Seyed-Razavi Y, Ghezzi CE, Dieckmann G, Nieland TJF, Cairns DM, Pollard RE, Hamrah P, Kaplan DL. Corneal pain and experimental model development. Prog Retin Eye Res 2019; 71:88-113. [PMID: 30453079 PMCID: PMC6690397 DOI: 10.1016/j.preteyeres.2018.11.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/03/2018] [Accepted: 11/13/2018] [Indexed: 12/13/2022]
Abstract
The cornea is a valuable tissue for studying peripheral sensory nerve structure and regeneration due to its avascularity, transparency, and dense innervation. Somatosensory innervation of the cornea serves to identify changes in environmental stimuli at the ocular surface, thereby promoting barrier function to protect the eye against injury or infection. Due to regulatory demands to screen ocular safety of potential chemical exposure, a need remains to develop functional human tissue models to predict ocular damage and pain using in vitro-based systems to increase throughput and minimize animal use. In this review, we summarize the anatomical and functional roles of corneal innervation in propagation of sensory input, corneal neuropathies associated with pain, and the status of current in vivo and in vitro models. Emphasis is placed on tissue engineering approaches to study the human corneal pain response in vitro with integration of proper cell types, controlled microenvironment, and high-throughput readouts to predict pain induction. Further developments in this field will aid in defining molecular signatures to distinguish acute and chronic pain triggers based on the immune response and epithelial, stromal, and neuronal interactions that occur at the ocular surface that lead to functional outcomes in the brain depending on severity and persistence of the stimulus.
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Affiliation(s)
- Tina B McKay
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Yashar Seyed-Razavi
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Chiara E Ghezzi
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Gabriela Dieckmann
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - Thomas J F Nieland
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Dana M Cairns
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Rachel E Pollard
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA
| | - Pedram Hamrah
- Center for Translational Ocular Immunology and Cornea Service, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA, USA
| | - David L Kaplan
- Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA, 02155, USA.
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Wang G, Jiang LM, Tan BY, Li PZ, Zhang PL, Zhang Y, Cheng X, Ma ZL, Li ZJ, Brand-Saberi B, Yang X. Cell survival controlled by lens-derived Sema3A-Nrp1 is vital on caffeine-suppressed corneal innervation during chick organogenesis. J Cell Physiol 2019; 234:9826-9838. [PMID: 30362583 DOI: 10.1002/jcp.27671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 10/04/2018] [Indexed: 12/29/2022]
Abstract
In this study, we investigated the effect of caffeine overexposure on corneal innervation in the early chicken embryo. Caffeine administration restricted corneal innervation by affecting trigeminal nerve development. Immunohistochemistry for phospho-Histone3 (pHIS3) and C-caspase3 revealed that cell survival was repressed by caffeine administration. Whole-mount in situ hybridization against semaphorin 3A (Sema3A) and neuropilin-1 (Nrp1) showed that both caffeine and 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH, a free radical generator) administration upregulates the expression of both Sema3A and Nrp1. Next, we demonstrated that lens ablation in the developing chicken embryos significantly affected NF-labeled periocular nerve fascicles and innervation to the central eye region. Subsequently, we used a neuroblastoma cell line to investigate in vitro whether or not Sema3A-Nrp1 signaling exerts a key role on the caffeine-suppressed neuron survival. Knocking-down Sema3A through transfection with Sema3A-siRNA dramatically decreased the responsiveness of cells to caffeine administration, as well as cell apoptosis. We suggest that Sema3A-Nrp1 signaling regulates Trp53 and Cdkn1a through Slit2-Robo1 and Ephb2. Taken together, we speculate here that caffeine-enhanced reactive oxygen species upregulates Sema3A-Nrp1 expression in the lens and periocular tissues, resulting in corneal cell apoptosis, accompanied by its chemorepellent role on the invasion of the developing cornea by trigeminal sensory fibers.
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Affiliation(s)
- Guang Wang
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education, Jinan University, Guangzhou, China
| | - Ling-Min Jiang
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
| | - Bao-Yi Tan
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
| | - Pei-Zhi Li
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
| | - Pei-Ling Zhang
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
| | - Yu Zhang
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
| | - Xin Cheng
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education, Jinan University, Guangzhou, China
| | - Zheng-Lai Ma
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
| | - Zhi-Jie Li
- Institute of Ophthalmology, School of Medicine, Jinan University, Guangzhou, China
| | - Beate Brand-Saberi
- Department of Anatomy and Molecular Embryology, Ruhr-University Bochum, Bochum, Germany
| | - Xuesong Yang
- Department of Histology and Embryology, International Joint Laboratory for Embryonic Development & Prenatal Medicine, Medical College, Jinan University, Guangzhou, China
- Key Laboratory for Regenerative Medicine of the Ministry of Education, Jinan University, Guangzhou, China
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Cui R, Lwigale P. Expression of the heparin-binding growth factors Midkine and pleiotrophin during ocular development. Gene Expr Patterns 2019; 32:28-37. [PMID: 30825522 DOI: 10.1016/j.gep.2019.02.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/18/2019] [Accepted: 02/21/2019] [Indexed: 12/17/2022]
Abstract
Midkine (MDK) and Pleiotrophin (PTN) belong to a group of heparin-binding growth factors that has been shown to have pleiotropic functions in various biological processes during development and disease. Development of the vertebrate eye is a multistep process that involves coordinated interactions between neuronal and non-neuronal cells, but very little is known about the potential function of MDK and PTN in these processes. In this study, we demonstrate by section in situ hybridization, the spatiotemporal expression of MDK and PTN during ocular development in chick and mouse. We show that MDK and PTN are expressed in dynamic patterns that overlap in a few non-neuronal tissues in the anterior eye and in neuronal cell layers of the posterior eye. We show that the expression patterns of MDK and PTN are only conserved in a few tissues in chick and mouse but they overlap with the expression of some of their receptors LRP1, RPTPZ, ALK, NOTCH2, ITGβ1, SDC1, and SDC3. The dynamic expression patterns of MDK, PTN and their receptors suggest that they function together during the multistep process of ocular development and they may play important roles in cell proliferation, adhesion, and migration of neuronal and non-neuronal cells.
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Affiliation(s)
- Ruda Cui
- Department of BioSciences, Rice University, Houston, TX, USA
| | - Peter Lwigale
- Department of BioSciences, Rice University, Houston, TX, USA.
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11
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Melrose J. Keratan sulfate (KS)-proteoglycans and neuronal regulation in health and disease: the importance of KS-glycodynamics and interactive capability with neuroregulatory ligands. J Neurochem 2019; 149:170-194. [PMID: 30578672 DOI: 10.1111/jnc.14652] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Revised: 11/26/2018] [Accepted: 12/13/2018] [Indexed: 12/18/2022]
Abstract
Compared to the other classes of glycosaminoglycans (GAGs), that is, chondroitin/dermatan sulfate, heparin/heparan sulfate and hyaluronan, keratan sulfate (KS), have the least known of its interactive properties. In the human body, the cornea and the brain are the two most abundant tissue sources of KS. Embryonic KS is synthesized as a linear poly-N-acetyllactosamine chain of d-galactose-GlcNAc repeat disaccharides which become progressively sulfated with development, sulfation of GlcNAc is more predominant than galactose. KS contains multi-sulfated high-charge density, monosulfated and non-sulfated poly-N-acetyllactosamine regions and thus is a heterogeneous molecule in terms of chain length and charge distribution. A recent proteomics study on corneal KS demonstrated its interactivity with members of the Slit-Robbo and Ephrin-Ephrin receptor families and proteins which regulate Rho GTPase signaling and actin polymerization/depolymerization in neural development and differentiation. KS decorates a number of peripheral nervous system/CNS proteoglycan (PG) core proteins. The astrocyte KS-PG abakan defines functional margins of the brain and is up-regulated following trauma. The chondroitin sulfate/KS PG aggrecan forms perineuronal nets which are dynamic neuroprotective structures with anti-oxidant properties and roles in neural differentiation, development and synaptic plasticity. Brain phosphacan a chondroitin sulfate, KS, HNK-1 PG have roles in neural development and repair. The intracellular microtubule and synaptic vesicle KS-PGs MAP1B and SV2 have roles in metabolite transport, storage, and export of neurotransmitters and cytoskeletal assembly. MAP1B has binding sites for tubulin and actin through which it promotes cytoskeletal development in growth cones and is highly expressed during neurite extension. The interactive capability of KS with neuroregulatory ligands indicate varied roles for KS-PGs in development and regenerative neural processes.
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Affiliation(s)
- James Melrose
- Raymond Purves Bone and Joint Research Laboratory, Kolling Institute, St. Leonards, New South Wales, Australia.,Graduate School of Biomedical Engineering, University of New South Wales, Sydney, New South Wales, Australia.,Sydney Medical School, Northern Campus, Royal North Shore Hospital, The University of Sydney, New South Wales, Australia.,Faculty of Medicine and Health, Royal North Shore Hospital, The University of Sydney, St. Leonards, New South Wales, Australia
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Genetic Analysis of the Organization, Development, and Plasticity of Corneal Innervation in Mice. J Neurosci 2018; 39:1150-1168. [PMID: 30587537 DOI: 10.1523/jneurosci.1401-18.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Revised: 10/05/2018] [Accepted: 11/24/2018] [Indexed: 11/21/2022] Open
Abstract
The cornea has the densest sensory innervation of the body, originating primarily from neurons in the trigeminal ganglion. The basic principles of cornea nerve patterning have been established many years ago using classic neuroanatomical methods, such as immunocytochemistry and electrophysiology. Our understanding of the morphology and distribution of the sensory nerves in the skin has considerably progressed over the past few years through the generation and analysis of a variety of genetically modified mouse lines. Surprisingly, these lines were not used to study corneal axons. Here, we have screened a collection of transgenic and knockin mice (of both sexes) to select lines allowing the visualization and genetic manipulation of corneal nerves. We identified multiple lines, including some in which different types of corneal axons can be simultaneously observed with fluorescent proteins expressed in a combinatorial manner. We also provide the first description of the morphology and arborization of single corneal axons and identify three main types of branching pattern. We applied this genetic strategy to the analysis of corneal nerve development and plasticity. We provide direct evidence for a progressive reduction of the density of corneal innervation during aging. We also show that the semaphorin receptor neuropilin-1 acts cell-autonomously to control the development of corneal axons and that early axon guidance defects have long-term consequences on corneal innervation.SIGNIFICANCE STATEMENT We have screened a collection of transgenic and knockin mice and identify lines allowing the visualization and genetic manipulation of corneal nerves. We provide the first description of the arborization pattern of single corneal axons. We also present applications of this genetic strategy to the analysis of corneal nerve development and remodeling during aging.
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Talbot CJ, Kubilus JK. Developmental analysis of SV2 in the embryonic chicken corneal epithelium. Exp Eye Res 2018; 172:137-143. [PMID: 29654771 DOI: 10.1016/j.exer.2018.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 03/21/2018] [Accepted: 04/06/2018] [Indexed: 11/20/2022]
Abstract
Intraepithelial corneal nerves (ICNs) help protect the cornea as part of the blink reflex and by modulating tear production. ICNs are also thought to regulate the health and homeostasis of the cornea through the release of trophic factors. Disruption to these nerves can lead to vision loss. Despite their importance little is known about how corneal nerves function and even less is known about how the cornea is initially innervated during its embryonic development. Here, we investigated the innervation of the embryonic chicken cornea. Western blot and immunohistochemistry were used to characterize the localization of the synaptic vesicle marker SV2, a molecule thought to be involved in the release of trophic factors from sensory nerves. The data show that both SV2 and synaptotagmin co-localize to ICNs. Nerves in the conjunctiva also contained SV2 and synaptotagmin, but these were localized to below the basal layers of the conjunctiva epithelium. SV2 isolated from corneal epithelium migrates in western blot at a heavier weight than SV2 isolated from brain, which suggests a role in vesicle targeting, as the deglycosylating enzyme PnGase does not affect corneal SV2.
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Affiliation(s)
- Christopher J Talbot
- Department of Immunology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA
| | - James K Kubilus
- Department of Immunology, Tufts University School of Medicine, 136 Harrison Avenue, Boston, MA 02111, USA.
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Zhang M, Zhou Q, Luo Y, Nguyen T, Rosenblatt MI, Guaiquil VH. Semaphorin3A induces nerve regeneration in the adult cornea-a switch from its repulsive role in development. PLoS One 2018; 13:e0191962. [PMID: 29370308 PMCID: PMC5785010 DOI: 10.1371/journal.pone.0191962] [Citation(s) in RCA: 82] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Accepted: 01/15/2018] [Indexed: 12/25/2022] Open
Abstract
The peripheral sensory nerves that innervate the cornea can be easily damaged by trauma, surgery, infection or diabetes. Several growth factors and axon guidance molecules, such as Semaphorin3A (Sema3A) are upregulated upon cornea injury. Nerves can regenerate after injury but do not recover their original density and patterning. Sema3A is a well known axon guidance and growth cone repellent protein during development, however its role in adult cornea nerve regeneration remains undetermined. Here we investigated the neuro-regenerative potential of Sema3A on adult peripheral nervous system neurons such as those that innervate the cornea. First, we examined the gene expression profile of the Semaphorin class 3 family members and found that all are expressed in the cornea. However, upon cornea injury there is a fast increase in Sema3A expression. We then corroborated that Sema3A totally abolished the growth promoting effect of nerve growth factor (NGF) on embryonic neurons and observed signs of growth cone collapse and axonal retraction after 30 min of Sema3A addition. However, in adult isolated trigeminal ganglia or dorsal root ganglia neurons, Sema3A did not inhibited the NGF-induced neuronal growth. Furthermore, adult neurons treated with Sema3A alone produced similar neuronal growth to cells treated with NGF and the length of the neurites and branching was comparable between both treatments. These effects were replicated in vivo, where thy1-YFP neurofluorescent mice subjected to cornea epithelium debridement and receiving intrastromal pellet implantation containing Sema3A showed increased corneal nerve regeneration than those receiving pellets with vehicle. In adult PNS neurons, Sema3A is a potent inducer of neuronal growth in vitro and cornea nerve regeneration in vivo. Our data indicates a functional switch for the role of Sema3A in PNS neurons where the well-described repulsive role during development changes to a growth promoting effect during adulthood. The high expression of Sema3A in the normal and injured adult corneas could be related to its role as a growth factor.
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Affiliation(s)
- Min Zhang
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Qiang Zhou
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Yuncin Luo
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Tara Nguyen
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Mark I. Rosenblatt
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
| | - Victor H. Guaiquil
- Department of Ophthalmology and Visual Sciences, University of Illinois-Chicago, Chicago, Illinois, United States of America
- * E-mail:
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15
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Gordon E, Stang BV, Heidel J, Poulsen KP, Cebra CK, Schlipf JW. Pharmacokinetic evaluation and safety of topical 1% morphine sulfate application on the healthy equine eye. Vet Ophthalmol 2018; 21:516-523. [PMID: 29350477 DOI: 10.1111/vop.12541] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To determine if corneal epithelial cell integrity is detrimentally affected by short-term administration of 1.0% morphine sulfate. Additionally, we sought to determine if topical 1.0% morphine applied to the equine cornea would result in ocular or systemic absorption. ANIMAL STUDIED Six healthy horses. PROCEDURE Morphine sulfate (1.0%) was applied topically to one eye every four hours for 72 h before horses were euthanized. Serum samples were collected at varying time points during the study and aqueous and vitreous humor were collected immediately after euthanasia. Morphine quantification in serum, aqueous, and vitreous humor was performed by ELISA. Treated and control corneas were submitted for histopathology. Horses were monitored for adverse ocular and systemic effects throughout the study period. RESULTS All horses developed mild mucoid ocular discharge in the treated eye. One horse developed a fever during treatment. Morphine was detected in the aqueous humor of the treated eye for all horses with mean ± standard deviation of 165.18 ng/mL ± 87.69 ng/mL. Morphine was detected in vitreous humor of the treated eye of 5 of 6 horses with mean ± standard deviation of 4.87 ± 4.46 ng/mL. Morphine was detected in the serum of 5 of 6 horses at varying time points. Maximum systemic concentration reached in a single horse was 6.98 ng/mL. Corneal histopathology revealed no difference in microscopic appearance between morphine-treated and control corneas. CONCLUSIONS Topical administration of 1.0% morphine sulfate did not appear to cause any significant ocular or systemic adverse effects. Topical ophthalmic morphine application resulted in both ocular and systemic absorption.
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Affiliation(s)
- Emma Gordon
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Bernadette V Stang
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Jerry Heidel
- Department of Biomedical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - Keith P Poulsen
- Department of Medical Sciences, School of Veterinary Medicine and Wisconsin Veterinary Diagnostic Laboratory, University of Wisconsin-Madison, Madison, WI, USA
| | - Christopher K Cebra
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
| | - John W Schlipf
- Department of Clinical Sciences, College of Veterinary Medicine, Oregon State University, Corvallis, OR, USA
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16
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Kubilus JK, Zapater I Morales C, Linsenmayer TF. The Corneal Epithelial Barrier and Its Developmental Role in Isolating Corneal Epithelial and Conjunctival Cells From One Another. Invest Ophthalmol Vis Sci 2017; 58:1665-1672. [PMID: 28319640 PMCID: PMC5361589 DOI: 10.1167/iovs.16-20737] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Purpose During development, the corneal epithelium (CE) and the conjunctiva are derived from the surface ectoderm. Here we have examined how, during development, the cells of these two issues become isolated from each other. Methods Epithelia from the anterior eyes of chicken embryos were labeled with the fluorescent, lipophilic dye, 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate (DiI). DiI was placed on the epithelial surface of the developing anterior eye and its diffusion was monitored by fluorescence microscopy. Concomitant morphologic changes in the surface cells of these epithelial were examined by scanning electron microscopy. Immunofluorescence was used to analyze the expression of cytokeratin K3, ZO-1, N-cadherin and Connexin-43 and the function of gap junctions was analyzed using a cut-loading with the fluorescent dye rhodamine-dextran. Results Prior to embryonic day 8 (E8), DiI placed on the surface of the CE spreads throughout all the epithelial cells of the anterior eye. When older eyes were similarly labeled, dye diffusion was restricted to the CE. Similarly, diffusion of DiI placed on the conjunctival surface after E8 was restricted to the conjunctiva. Scanning electron microscopy showed that developmentally (1) physical separations progressively form between the cells of the CE and those of the conjunctiva, and (2) by E8 these separations form a ring that completely encompasses the cornea. The functional restriction of gap junctions between these tissues did not occur until E14. Conclusions During ocular development, a barrier to the diffusion of DiI forms between the contiguous CE and conjunctiva prior to the differential expression of gap junctions within these tissues.
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Affiliation(s)
- James K Kubilus
- Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - Carolina Zapater I Morales
- Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - Thomas F Linsenmayer
- Department of Integrative Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States
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17
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Wang X, Gregory-Evans K, Wasan KM, Sivak O, Shan X, Gregory-Evans CY. Efficacy of Postnatal In Vivo Nonsense Suppression Therapy in a Pax6 Mouse Model of Aniridia. MOLECULAR THERAPY. NUCLEIC ACIDS 2017. [PMID: 28624217 PMCID: PMC5440746 DOI: 10.1016/j.omtn.2017.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Nonsense mutations leading to premature stop codons are common occurring in approximately 12% of all human genetic diseases. Thus, pharmacological nonsense mutation suppression strategies would be beneficial to a large number of patients if the drugs could be targeted to the affected tissues at the appropriate time. Here, we used nonsense suppression to manipulate Pax6 dosage at different developmental times in the eye of the small eye (Pax6Sey/+; G194X) mouse model of aniridia. Efficacy was assessed by functional assays for visual capacity, including electroretinography and optokinetic tracking (OKT), in addition to histological and biochemical studies. Malformation defects in the Pax6Sey/+ postnatal eye responded to topically delivered nonsense suppression in a dose- and time-dependent manner. Elevated levels of Mmp9, a direct downstream target of Pax6 in the cornea, were observed with the different treatment regimens. The lens capsule was particularly sensitive to Pax6 dosage, revealing a potential new role for Pax6 in lens capsule maintenance and development. The remarkable capacity of malformed ocular tissue to respond postnatally to Pax6 dosage in vivo demonstrates that the use of nonsense suppression could be a valuable therapeutic approach for blinding diseases caused by nonsense mutations.
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Affiliation(s)
- Xia Wang
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC V5Z 3N9, Canada
| | - Kevin Gregory-Evans
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC V5Z 3N9, Canada
| | - Kishor M Wasan
- College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, SK S7N 5A2, Canada
| | - Olena Sivak
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC V5Z 3N9, Canada
| | - Xianghong Shan
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC V5Z 3N9, Canada
| | - Cheryl Y Gregory-Evans
- Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, BC V5Z 3N9, Canada.
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18
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Ojeda AF, Munjaal RP, Lwigale PY. Knockdown of CXCL14 disrupts neurovascular patterning during ocular development. Dev Biol 2017; 423:77-91. [PMID: 28095300 DOI: 10.1016/j.ydbio.2017.01.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/12/2016] [Accepted: 01/13/2017] [Indexed: 02/06/2023]
Abstract
The C-X-C motif ligand 14 (CXCL14) is a recently discovered chemokine that is highly conserved in vertebrates and expressed in various embryonic and adult tissues. CXCL14 signaling has been implicated to function as an antiangiogenic and anticancer agent in adults. However, its function during development is unknown. We previously identified novel expression of CXCL14 mRNA in various ocular tissues during development. Here, we show that CXCL14 protein is expressed in the anterior eye at a critical time during neurovascular development and in the retina during neurogenesis. We report that RCAS-mediated knockdown of CXCL14 causes severe neural defects in the eye including precocious and excessive innervation of the cornea and iris. Absence of CXCL14 results in the malformation of the neural retina and misprojection of the retinal ganglion neurons. The ocular neural defects may be due to loss of CXCL12 modulation since recombinant CXCL14 diminishes CXCL12-induced axon growth in vitro. Furthermore, we show that knockdown of CXCL14 causes neovascularization of the cornea. Altogether, our results show for the first time that CXCL14 plays a critical role in modulating neurogenesis and inhibiting ectopic vascularization of the cornea during ocular development.
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Affiliation(s)
- Ana F Ojeda
- BioSciences, Rice University, 6100 Main Street, Houston, TX, United States; Universidad Santo Tomas, sede Puerto Montt, Buenavecindad #91, Décima región de los Lagos, Chile
| | - Ravi P Munjaal
- BioSciences, Rice University, 6100 Main Street, Houston, TX, United States
| | - Peter Y Lwigale
- BioSciences, Rice University, 6100 Main Street, Houston, TX, United States.
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19
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Cruzat A, Qazi Y, Hamrah P. In Vivo Confocal Microscopy of Corneal Nerves in Health and Disease. Ocul Surf 2017; 15:15-47. [PMID: 27771327 PMCID: PMC5512932 DOI: 10.1016/j.jtos.2016.09.004] [Citation(s) in RCA: 218] [Impact Index Per Article: 31.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2016] [Revised: 09/19/2016] [Accepted: 09/25/2016] [Indexed: 12/20/2022]
Abstract
In vivo confocal microscopy (IVCM) is becoming an indispensable tool for studying corneal physiology and disease. Enabling the dissection of corneal architecture at a cellular level, this technique offers fast and noninvasive in vivo imaging of the cornea with images comparable to those of ex vivo histochemical techniques. Corneal nerves bear substantial relevance to clinicians and scientists alike, given their pivotal roles in regulation of corneal sensation, maintenance of epithelial integrity, as well as proliferation and promotion of wound healing. Thus, IVCM offers a unique method to study corneal nerve alterations in a myriad of conditions, such as ocular and systemic diseases and following corneal surgery, without altering the tissue microenvironment. Of particular interest has been the correlation of corneal subbasal nerves to their function, which has been studied in normal eyes, contact lens wearers, and patients with keratoconus, infectious keratitis, corneal dystrophies, and neurotrophic keratopathy. Longitudinal studies have applied IVCM to investigate the effects of corneal surgery on nerves, demonstrating their regenerative capacity. IVCM is increasingly important in the diagnosis and management of systemic conditions such as peripheral diabetic neuropathy and, more recently, in ocular diseases. In this review, we outline the principles and applications of IVCM in the study of corneal nerves in various ocular and systemic diseases.
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Affiliation(s)
- Andrea Cruzat
- Cornea & Refractive Surgery Service, Department of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Boston, MA, USA; Department of Ophthalmology, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Yureeda Qazi
- Cornea & Refractive Surgery Service, Department of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Pedram Hamrah
- Cornea & Refractive Surgery Service, Department of Ophthalmology, Massachusetts Eye & Ear Infirmary, Harvard Medical School, Boston, MA, USA; Boston Image Reading Center, Tufts Medical Center, Tufts University School of Medicine, Boston, MA; Cornea Service, New England Eye Center, Department of Ophthalmology, Tufts Medical Center, Tufts University School of Medicine, Boston, MA.
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20
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Masuda T, Taniguchi M. Contribution of semaphorins to the formation of the peripheral nervous system in higher vertebrates. Cell Adh Migr 2016; 10:593-603. [PMID: 27715392 PMCID: PMC5160040 DOI: 10.1080/19336918.2016.1243644] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Semaphorins are a large family of proteins characterized by sema domains and play a key role not only in the formation of neural circuits, but in the immune system, angiogenesis, tumor progression, and bone metabolism. To date, 15 semaphorins have been reported to be involved in the formation of the peripheral nervous system (PNS) in higher vertebrates. A number of experiments have revealed their functions in the PNS, where they act mainly as axonal guidance cues (as repellents or attractants). Semaphorins also play an important role in the migration of neurons and formation of sensory-motor connections in the PNS. This review summarizes recent knowledge regarding the functions of higher vertebrate semaphorins in the formation of the PNS.
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Affiliation(s)
- Tomoyuki Masuda
- a Department of Neurobiology , Faculty of Medicine, University of Tsukuba , Ibaraki , Japan.,b Doctoral and Master's Programs in Kansei , Behavioral and Brain Sciences, Graduate School of Comprehensive Human Sciences, University of Tsukuba , Ibaraki , Japan
| | - Masahiko Taniguchi
- c Department of Cell Science , Research Institute for Frontier Medicine, Sapporo Medical University School of Medicine , Hokkaido , Japan
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Corneal Development: Different Cells from a Common Progenitor. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:43-59. [PMID: 26310148 DOI: 10.1016/bs.pmbts.2015.04.003] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Development of the vertebrate cornea is a multistep process that involves cellular interactions between various ectodermal-derived tissues. Bilateral interactions between the neural ectoderm-derived optic vesicles and the cranial ectoderm give rise to the presumptive corneal epithelium and other epithelia of the ocular surface. Interactions between the neural tube and the adjacent ectoderm give rise to the neural crest cells, a highly migratory and multipotent cell population. Neural crest cells migrate between the lens and presumptive corneal epithelium to form the corneal endothelium and the stromal keratocytes. The sensory nerves that abundantly innervate the corneal stroma and epithelium originate from the neural crest- and ectodermal placode-derived trigeminal ganglion. Concomitant with corneal innervation is the formation of the limbal vascular plexus and the establishment of corneal avascularity. This review summarizes historical and current research to provide an overview of the genesis of the cellular layers of the cornea, corneal innervation, and avascularity.
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22
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Lens Development and Crystallin Gene Expression. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:129-67. [DOI: 10.1016/bs.pmbts.2015.05.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Canner JP, Linsenmayer TF, Kubilus JK. Developmental regulation of trigeminal TRPA1 by the cornea. Invest Ophthalmol Vis Sci 2014; 56:29-36. [PMID: 25503452 DOI: 10.1167/iovs.14-15035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The cornea is densely innervated with nociceptive nerves that detect deleterious stimuli at the ocular surface and transduce these stimuli as sensations of pain. Thus, nociception is a major factor involved in preventing damage to corneal tissues. One class of molecules that is thought to be involved in detecting such stimuli is the transient receptor potential (TRP) family of ion channels. However, little is known about the acquisition of these channels during corneal development. Therefore, the present study examined the developmental acquisition of these receptors and elucidated certain parameters involved in this acquisition. METHODS Quantitative RT-PCR was used to measure the expression of genes including TRPA and Ret in vivo. In vitro cocultures between cornea and the ophthalmic lobe of the trigeminal ganglion were used to test interactions between nerves and corneas along with recombinant proteins. RESULTS TRPA1 mRNA showed a progressive temporal increase in the ophthalmic lobe of the trigeminal ganglion in vivo during embryonic development. In vitro, TRPA1 expression was significantly increased in the ganglion when cocultured with cornea, compared to ganglia cultured alone. Similarly, the addition of exogenous neurotrophin-3 (NT3) protein to cultured ganglia increased the expression of TRPA1 more than 100-fold. Addition of NT3 and neurturin synergistically increased TRPA1 expression in embryonic day (E)8 ganglia, but this effect was lost at E12. At E8, Ret+ nonpeptidergic neurons are specified in the trigeminal ganglion. CONCLUSIONS Corneal-derived factors increase TRPA1 expression in trigeminal nonpeptidergic neurons during their embryonic specification.
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Affiliation(s)
- James P Canner
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Department of Integrated Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States Department of Pharmacology, Emory University School of Medicine, Atlanta, Georgia, United States
| | - Thomas F Linsenmayer
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Department of Integrated Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States
| | - James K Kubilus
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Department of Integrated Physiology and Pathobiology, Tufts University School of Medicine, Boston, Massachusetts, United States
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Effects of polysialic acid on sensory innervation of the cornea. Dev Biol 2014; 398:193-205. [PMID: 25478909 DOI: 10.1016/j.ydbio.2014.11.020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 11/07/2014] [Accepted: 11/19/2014] [Indexed: 01/08/2023]
Abstract
Sensory trigeminal growth cones innervate the cornea in a coordinated fashion during embryonic development. Polysialic acid (polySia) is known for its important roles during nerve development and regeneration. The purpose of this work is to determine whether polySia, present in developing eyefronts and on the surface of sensory nerves, may provide guidance cues to nerves during corneal innervation. Expression and localization of polySia in embryonic day (E)5-14 chick eyefronts and E9 trigeminal ganglia were identified using Western blotting and immunostaining. Effects of polySia removal on trigeminal nerve growth behavior were determined in vivo, using exogenous endoneuraminidase (endoN) treatments to remove polySia substrates during chick cornea development, and in vitro, using neuronal explant cultures. PolySia substrates, made by the physical adsorption of colominic acid to a surface coated with poly-d-lysine (PDL), were used as a model to investigate functions of the polySia expressed in axonal environments. PolySia was localized within developing eyefronts and on trigeminal sensory nerves. Distributions of PolySia in corneas and pericorneal regions are developmentally regulated. PolySia removal caused defasciculation of the limbal nerve trunk in vivo from E7 to E10. Removal of polySia on trigeminal neurites inhibited neurite outgrowth and caused axon defasciculation, but did not affect Neural Cell Adhesion Molecule (NCAM) expression or Schwann cell migration in vitro. PolySia substrates in vitro inhibited outgrowth of trigeminal neurites and promoted their fasciculation. In conclusion, polySia is localized on corneal nerves and in their targeting environment during early developing stages of chick embryos. PolySias promote fasciculation of trigeminal axons in vivo and in vitro, whereas, in contrast, their removal promotes defasciculation.
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Sema3A maintains corneal avascularity during development by inhibiting Vegf induced angioblast migration. Dev Biol 2014; 391:241-50. [PMID: 24809797 DOI: 10.1016/j.ydbio.2014.04.017] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Revised: 04/14/2014] [Accepted: 04/23/2014] [Indexed: 12/25/2022]
Abstract
Corneal avascularity is important for optical clarity and normal vision. However, the molecular mechanisms that prevent angioblast migration and vascularization of the developing cornea are not clear. Previously we showed that periocular angioblasts and forming ocular blood vessels avoid the presumptive cornea despite dynamic ingression of neural crest cells. In the current study, we investigate the role of Semaphorin3A (Sema3A), a cell guidance chemorepellent, on angioblast migration and corneal avascularity during development. We show that Sema3A, Vegf, and Nrp1 are expressed in the anterior eye during cornea development. Sema3A mRNA transcripts are expressed at significantly higher levels than Vegf in the lens that is positioned adjacent to the presumptive cornea. Blockade of Sema3A signaling via lens removal or injection of a synthetic Sema3A inhibitor causes ectopic migration of angioblasts into the cornea and results in its subsequent vascularization. In addition, using bead implantation, we demonstrate that exogenous Sema3A protein inhibits Vegf-induced vascularization of the cornea. In agreement with these findings, loss of Sema/Nrp1 signaling in Nrp1(Sema-) mutant mice results in ectopic angioblasts and vascularization of the embryonic mouse corneas. Altogether, our results reveal Sema3A signaling as an important cue during the establishment of corneal avascularity in both chick and mouse embryos. Our study introduces cornea development as a new model for studying the mechanisms involved in vascular patterning during embryogenesis and it also provides new insights into therapeutic potential for Sema3A in neovascular diseases.
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Shaheen BS, Bakir M, Jain S. Corneal nerves in health and disease. Surv Ophthalmol 2014; 59:263-85. [PMID: 24461367 PMCID: PMC4004679 DOI: 10.1016/j.survophthal.2013.09.002] [Citation(s) in RCA: 305] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 08/23/2013] [Accepted: 09/03/2013] [Indexed: 12/14/2022]
Abstract
Corneal nerves are responsible for the sensations of touch, pain, and temperature and play an important role in the blink reflex, wound healing, and tear production and secretion. Corneal nerve dysfunction is a frequent feature of diseases that cause opacities and result in corneal blindness. Corneal opacities rank as the second most frequent cause of blindness. Technological advances in in vivo corneal nerve imaging, such as optical coherence tomography and confocal scanning, have generated new knowledge regarding the phenomenological events that occur during reinnervation of the cornea following disease, injury, or surgery. The recent availability of transgenic neurofluorescent murine models has stimulated the search for molecular modulators of corneal nerve regeneration. New evidence suggests that neuroregenerative and inflammatory pathways in the cornea are intertwined. Evidence-based treatment of neurotrophic corneal diseases includes using neuroregenerative (blood component-based and neurotrophic factors), neuroprotective, and ensconcing (bandage contact lens and amniotic membrane) strategies and avoiding anti-inflammatory therapies, such as cyclosporine and corticosteroids.
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Affiliation(s)
- Brittany Simmons Shaheen
- Corneal Neurobiology Laboratory, Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - May Bakir
- Corneal Neurobiology Laboratory, Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois
| | - Sandeep Jain
- Corneal Neurobiology Laboratory, Department of Ophthalmology and Visual Sciences, College of Medicine, University of Illinois at Chicago, Chicago, Illinois.
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27
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Spurlin JW, Lwigale PY. Wounded embryonic corneas exhibit nonfibrotic regeneration and complete innervation. Invest Ophthalmol Vis Sci 2013; 54:6334-44. [PMID: 24003085 PMCID: PMC3783042 DOI: 10.1167/iovs.13-12504] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 08/16/2013] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Wound healing in adult corneas is characterized by activation of keratocytes and extracellular matrix (ECM) synthesis that results in fibrotic scar formation and loss of transparency. Since most fetal wounds heal without scaring, we investigated the regenerative potential of wounded embryonic corneas. METHODS On embryonic day (E) 7 chick corneas were wounded by making a linear incision traversing the epithelium and anterior stroma. Wounded corneas were collected between E7 and E18, and analyzed for apoptosis, cell proliferation, staining of ECM components, and corneal innervation. RESULTS Substantial wound retraction was observed within 16-hours postwounding (hpw) and partial re-epithelialized by 5-days postwounding (dpw). Corneal wounds were fully re-epithelialized by 11 dpw with no visible scars. There was no difference in the number of cells undergoing apoptosis between wounded and control corneas. Cell proliferation was reduced in the wounded corneas, albeit mitotic cells in the regenerating epithelium. Staining for alpha-smooth muscle actin (α-SMA), tenascin, and fibronectin was vivid but transient at the wound site. Staining for procollagen I, perlecan, and keratan sulfate proteoglycan was reduced at the wound site. Wounded corneas were fully regenerated by 11 dpw and showed similar patterns of staining for ECM components, albeit an increase in perlecan staining. Corneal innervation was inhibited during wound healing, but regenerated corneas were innervated similar to controls. CONCLUSIONS These data show that minimal keratocyte activation, rapid ECM reconstruction, and proper innervation occur during nonfibrotic regeneration of the embryonic cornea.
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Affiliation(s)
- James W Spurlin
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas
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Sarkar J, Chaudhary S, Jassim SH, Ozturk O, Chamon W, Ganesh B, Tibrewal S, Gandhi S, Byun YS, Hallak J, Mahmud DL, Mahmud N, Rondelli D, Jain S. CD11b+GR1+ myeloid cells secrete NGF and promote trigeminal ganglion neurite growth: implications for corneal nerve regeneration. Invest Ophthalmol Vis Sci 2013; 54:5920-36. [PMID: 23942970 DOI: 10.1167/iovs.13-12237] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE We characterized fluorescent bone marrow cells (YFP(+) BMCs) in the thy1-YFP mouse and determine if they promote trigeminal ganglion (TG) cell neurite growth. METHODS Excimer laser annular keratectomy was performed in thy1-YFP mice, and corneas were imaged. BMCs were harvested from femur and tibia, and the expression of surface markers on YFP(+) BMCs was analyzed by flow cytometry. The immunosuppressive action of BMCs (YFP(+) and YFP(-)) was evaluated in an allogenic mixed lymphocyte reaction (MLR). Neurotrophic action of BMCs (YFP(+) and YFP(-)) was determined in compartmental and transwell cultures of dissociated TG cells. RESULTS Following annular keratectomy, YFP(+) BMCs infiltrated the cornea. YFP(+) BMCs shared surface markers (CD11b+Gr1+Ly6C+Ly6G-F4/80(low)) with monocytic myeloid-derived suppressor cells (MDSCs), had similar morphology, and suppressed T-cell proliferation in allogenic MLR in a dose-dependent manner. YFP(+) BMCs, but not YFP(-) BMCs, significantly increased growth of TG neurites in vitro. When cultured in a transwell with TG neurites, YFP(+) BMCs expressed neurotrophins and secreted nerve growth factor (NGF) in conditioned medium. YFP(+) BMCs that infiltrated the cornea maintained their phenotype and actions (neuronal and immune). CONCLUSIONS YFP(+) BMCs in thy1-YFP mice have immunophenotypic features of MDSCs. They secrete NGF and promote neuroregeneration. Their immunosuppressive and neurotrophic actions are preserved after corneal infiltration. These findings increase our understanding of the beneficial roles played by leukocyte trafficking in the cornea and may lead to therapeutic strategies that use NGF-secreting myeloid cells to repair diseased or injured neurons.
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Affiliation(s)
- Joy Sarkar
- Corneal Neurobiology Laboratory, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago, Illinois, USA
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Schwend T, Deaton RJ, Zhang Y, Caterson B, Conrad GW. Corneal sulfated glycosaminoglycans and their effects on trigeminal nerve growth cone behavior in vitro: roles for ECM in cornea innervation. Invest Ophthalmol Vis Sci 2012; 53:8118-37. [PMID: 23132805 PMCID: PMC3522437 DOI: 10.1167/iovs.12-10832] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 10/16/2012] [Accepted: 10/27/2012] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Sensory trigeminal nerve growth cones innervate the cornea in a highly coordinated fashion. The purpose of this study was to determine if extracellular matrix glycosaminoglycans (ECM-GAGs), including keratan sulfate (KS), dermatan sulfate (DS), and chondroitin sulfate A (CSA) and C (CSC), polymerized in developing eyefronts, may provide guidance cues to nerves during cornea innervation. METHODS Immunostaining using antineuron-specific-β-tubulin and monoclonal antibodies for KS, DS, and CSA/C was performed on eyefronts from embryonic day (E) 9 to E14 and staining visualized by confocal microscopy. Effects of purified GAGs on trigeminal nerve growth cone behavior were tested using in vitro neuronal explant cultures. RESULTS At E9 to E10, nerves exiting the pericorneal nerve ring grew as tight fascicles, advancing straight toward the corneal stroma. In contrast, upon entering the stroma, nerves bifurcated repeatedly as they extended anteriorly toward the epithelium. KS was localized in the path of trigeminal nerves, whereas DS and CSA/C-rich areas were avoided by growth cones. When E10 trigeminal neurons were cultured on different substrates comprised of purified GAG molecules, their neurite growth cone behavior varied depending on GAG type, concentration, and mode of presentation (immobilized versus soluble). High concentrations of immobilized KS, DS, and CSA/C inhibited neurite growth to varying degrees. Neurites traversing lower, permissive concentrations of immobilized DS and CSA/C displayed increased fasciculation and decreased branching, whereas KS caused decreased fasciculation and increased branching. Enzymatic digestion of sulfated GAGs canceled their effects on trigeminal neurons. CONCLUSIONS Data herein suggest that GAGs may direct the movement of trigeminal nerve growth cones innervating the cornea.
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Affiliation(s)
- Tyler Schwend
- From the Division of Biology, Kansas State University, Manhattan, Kansas
| | - Ryan J. Deaton
- Department of Pathology, University of Illinois at Chicago, Chicago, Illinois; and
| | - Yuntao Zhang
- From the Division of Biology, Kansas State University, Manhattan, Kansas
| | - Bruce Caterson
- Connective Tissue Biology Laboratories, School of Biosciences, Cardiff University, Cardiff, Wales, United Kingdom
| | - Gary W. Conrad
- From the Division of Biology, Kansas State University, Manhattan, Kansas
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Omoto M, Yoshida S, Miyashita H, Kawakita T, Yoshida K, Kishino A, Kimura T, Shibata S, Tsubota K, Okano H, Shimmura S. The semaphorin 3A inhibitor SM-345431 accelerates peripheral nerve regeneration and sensitivity in a murine corneal transplantation model. PLoS One 2012; 7:e47716. [PMID: 23152758 PMCID: PMC3494696 DOI: 10.1371/journal.pone.0047716] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2012] [Accepted: 09/14/2012] [Indexed: 11/19/2022] Open
Abstract
Background Peripheral nerve damage of the cornea is a complication following surgery or infection which may lead to decreased visual function. We examined the efficacy of the semaphorin 3A inhibitor, SM-345431, in promoting regeneration of peripheral nerves in a mouse corneal transplantation model. Methodology/Principal Findings P0-Cre/Floxed-EGFP mice which express EGFP in peripheral nerves cells were used as recipients of corneal transplantation with syngeneic wild-type mouse cornea donors. SM-345431 was administered subconjunctivally every 2 days while control mice received vehicle only. Mice were followed for 3 weeks and the length of regenerating nerves was measured by EGFP fluorescence and immunohistochemistry against βIII tubulin. Cornea sensitivity was also measured by the Cochet-Bonnet esthesiometer. CD31 staining was used to determine corneal neovascularization as a possible side effect of SM-345431. Regeneration of βIII tubulin positive peripheral nerves was significantly higher in SM-345431 treated mice compared to control. Furthermore, corneal sensitivity significantly improved in the SM-345431 group by 3 weeks after transplantation. Neovascularization was limited to the peripheral cornea with no difference between SM-345431 group and control. Conclusions/Significance Subconjunctival injections of SM-345431 promoted a robust network of regenerating nerves as well as functional recovery of corneal sensation in a mouse keratoplasty model, suggesting a novel therapeutic strategy for treating neurotrophic corneal disease.
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Affiliation(s)
- Masahiro Omoto
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Satoru Yoshida
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Miyashita
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Tetsuya Kawakita
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Kenji Yoshida
- Genomic Science Laboratories, Dainippon Sumitomo Pharma Co., Ltd., Tokyo, Japan
| | - Akiyoshi Kishino
- Genomic Science Laboratories, Dainippon Sumitomo Pharma Co., Ltd., Tokyo, Japan
| | - Toru Kimura
- Genomic Science Laboratories, Dainippon Sumitomo Pharma Co., Ltd., Tokyo, Japan
| | - Shinsuke Shibata
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
| | - Kazuo Tsubota
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
| | - Hideyuki Okano
- Department of Physiology, Keio University School of Medicine, Tokyo, Japan
- * E-mail: (HO); (SS)
| | - Shigeto Shimmura
- Department of Ophthalmology, Keio University School of Medicine, Tokyo, Japan
- * E-mail: (HO); (SS)
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McKenna CC, Munjaal RP, Lwigale PY. Distinct roles for neuropilin1 and neuropilin2 during mouse corneal innervation. PLoS One 2012; 7:e37175. [PMID: 22615927 PMCID: PMC3352890 DOI: 10.1371/journal.pone.0037175] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 04/16/2012] [Indexed: 11/19/2022] Open
Abstract
Trigeminal sensory innervation of the cornea is critical for protection and synthesis of neuropeptides required for normal vision. Little is known about axon guidance during mammalian corneal innervation. In contrast to the chick where a pericorneal nerve ring forms via Npn/Sema signaling, mouse corneal axons project directly into the presumptive cornea without initial formation of an analogous nerve ring. Here we show that during development of the mouse cornea, Npn1 is strongly expressed by the trigeminal ganglion whereas Npn2 is expressed at low levels. At the same time Sema3A and Sema3F are expressed in distinct patterns in the ocular tissues. Npn1(sema-/-) mutant corneas become precociously and aberrantly innervated by nerve bundles that project further into the corneal stroma. In contrast, stromal innervation was not affected in Npn2(-/-) mutants. The corneal epithelium was prematurely innervated in both Npn1(sema-/-) and Npn2(-/-) mutants. These defects were exacerbated in Npn1(sema-/-);Npn2(-/-) double mutants, which in addition showed ectopic innervation of the region between the optic cup and lens vesicle. Collectively, our data show that Sema3A/Npn1 and Sema3F/Npn2 signaling play distinct roles and both are required for proper innervation of the mouse cornea.
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Affiliation(s)
- Chelsey C. McKenna
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
| | - Ravi P. Munjaal
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
| | - Peter Y. Lwigale
- Department of Biochemistry and Cell Biology, Rice University, Houston, Texas, United States of America
- * E-mail:
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Mao X, Schwend T, Conrad GW. Expression and localization of neural cell adhesion molecule and polysialic acid during chick corneal development. Invest Ophthalmol Vis Sci 2012; 53:1234-43. [PMID: 22281821 DOI: 10.1167/iovs.11-8834] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE To assay for expression and localization of neural cell adhesion molecule (NCAM) and polysialic acid (polySia) in the chick cornea during embryonic and postnatal development. METHODS Real time quantitative PCR and Western blot analyses were used to determine NCAM expression and polysiaylation in embryonic, hatchling, and adult chick corneas. Immunofluorescence staining for NCAM and polySia was conducted on cryosections of embryonic and adult corneas, whole embryonic corneas, and trigeminal neurons. RESULTS NCAM and ST8SiaII mRNA transcripts peaked by embryonic day (E)9, remained steady between E10 and E14 and slowly decreased thereafter during embryonic development. Both gene transcripts showed > 190-fold decline in the adult chick cornea compared with E9. In contrast, ST8SiaIV expression gradually decreased 26.5-fold from E6 to E19, increased thereafter, and rose to the early embryonic level in the adult cornea. Western blot analysis revealed NCAM was polysialylated and its expression developmentally changed. Other polysiaylated proteins aside from NCAM were also detected by Western blot analysis. Five NCAM isoforms including NCAM-120, NCAM-180 and three soluble NCAM isoforms with low molecular weights (87-96 kDa) were present in chick corneas, with NCAM-120 being the predominate isoform. NCAM was localized to the epithelium, stroma, and stromal extracellular matrix (ECM) of the embryonic cornea. In stroma, NCAM expression shifted from anterior to posterior stroma during embryonic development and eventually became undetectable in 20-week-old adult cornea. Additionally, both NCAM and polySia were detected on embryonic corneal and pericorneal nerves. CONCLUSIONS NCAM and polySia are expressed and developmentally regulated in chick corneas. Both membrane-associated and soluble NCAM isoforms are expressed in chick corneas. The distributions of NCAM and polySia in cornea and on corneal nerves suggest their potential functions in corneal innervation.
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Affiliation(s)
- Xiuli Mao
- Division of Biology, Kansas State University, Manhattan, Kansas 66506-4901, USA.
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Schwend T, Lwigale PY, Conrad GW. Nerve repulsion by the lens and cornea during cornea innervation is dependent on Robo-Slit signaling and diminishes with neuron age. Dev Biol 2012; 363:115-27. [PMID: 22236962 PMCID: PMC3288411 DOI: 10.1016/j.ydbio.2011.12.039] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Revised: 12/15/2011] [Accepted: 12/16/2011] [Indexed: 11/29/2022]
Abstract
The cornea, the most densely innervated tissue on the surface of the body, becomes innervated in a series of highly coordinated developmental events. During cornea development, chick trigeminal nerve growth cones reach the cornea margin at embryonic day (E)5, where they are initially repelled for days from E5 to E8, instead encircling the corneal periphery in a nerve ring prior to entering on E9. The molecular events coordinating growth cone guidance during cornea development are poorly understood. Here we evaluated a potential role for the Robo-Slit nerve guidance family. We found that Slits 1, 2 and 3 expression in the cornea and lens persisted during all stages of cornea innervation examined. Robo1 expression was developmentally regulated in trigeminal cell bodies, expressed robustly during nerve ring formation (E5-8), then later declining concurrent with projection of growth cones into the cornea. In this study we provide in vivo and in vitro evidence that Robo-Slit signaling guides trigeminal nerves during cornea innervation. Transient, localized inhibition of Robo-Slit signaling, by means of beads loaded with inhibitory Robo-Fc protein implanted into the developing eyefield in vivo, led to disorganized nerve ring formation and premature cornea innervation. Additionally, when trigeminal explants (source of neurons) were oriented adjacent to lens vesicles or corneas (source of repellant molecules) in organotypic tissue culture both lens and cornea tissues strongly repelled E7 trigeminal neurites, except in the presence of inhibitory Robo-Fc protein. In contrast, E10 trigeminal neurites were not as strongly repelled by cornea, and presence of Robo-Slit inhibitory protein had no effect. In full, these findings suggest that nerve repulsion from the lens and cornea during nerve ring formation is mediated by Robo-Slit signaling. Later, a shift in nerve guidance behavior occurs, in part due to molecular changes in trigeminal neurons, including Robo1 downregulation, thus allowing nerves to find the Slit-expressing cornea permissive for growth cones.
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Affiliation(s)
- Tyler Schwend
- Division of Biology, Ackert Hall, Kansas State University, Manhattan, KS 66506, USA.
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Griswold SL, Lwigale PY. Analysis of neural crest migration and differentiation by cross-species transplantation. J Vis Exp 2012:3622. [PMID: 22349214 DOI: 10.3791/3622] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Avian embryos provide a unique platform for studying many vertebrate developmental processes, due to the easy access of the embryos within the egg. Chimeric avian embryos, in which quail donor tissue is transplanted into a chick embryo in ovo, combine the power of indelible genetic labeling of cell populations with the ease of manipulation presented by the avian embryo. Quail-chick chimeras are a classical tool for tracing migratory neural crest cells (NCCs). NCCs are a transient migratory population of cells in the embryo, which originate in the dorsal region of the developing neural tube. They undergo an epithelial to mesenchymal transition and subsequently migrate to other regions of the embryo, where they differentiate into various cell types including cartilage, melanocytes, neurons and glia. NCCs are multipotent, and their ultimate fate is influenced by 1) the region of the neural tube in which they originate along the rostro-caudal axis of the embryo, 2) signals from neighboring cells as they migrate, and 3) the microenvironment of their ultimate destination within the embryo. Tracing these cells from their point of origin at the neural tube, to their final position and fate within the embryo, provides important insight into the developmental processes that regulate patterning and organogenesis. Transplantation of complementary regions of donor neural tube (homotopic grafting) or different regions of donor neural tube (heterotopic grafting) can reveal differences in pre-specification of NCCs along the rostro-caudal axis. This technique can be further adapted to transplant a unilateral compartment of the neural tube, such that one side is derived from donor tissue, and the contralateral side remains unperturbed in the host embryo, yielding an internal control within the same sample. It can also be adapted for transplantation of brain segments in later embryos, after HH10, when the anterior neural tube has closed. Here we report techniques for generating quail-chick chimeras via neural tube transplantation, which allow for tracing of migratory NCCs derived from a discrete segment of the neural tube. Species-specific labeling of the donor-derived cells with the quail-specific QCPN antibody allows the researcher to distinguish donor and host cells at the experimental end point. This technique is straightforward, inexpensive, and has many applications, including fate-mapping, cell lineage tracing, and identifying pre-patterning events along the rostro-caudal axis. Because of the ease of access to the avian embryo, the quail-chick graft technique may be combined with other manipulations, including but not limited to lens ablation, injection of inhibitory molecules, or genetic manipulation via electroporation of expression plasmids, to identify the response of particular migratory streams of NCCs to perturbations in the embryo's developmental program. Furthermore, this grafting technique may also be used to generate other interspecific chimeric embryos such as quail-duck chimeras to study NCC contribution to craniofacial morphogenesis, or mouse-chick chimeras to combine the power of mouse genetics with the ease of manipulation of the avian embryo.
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McKenna CC, Lwigale PY. Innervation of the mouse cornea during development. Invest Ophthalmol Vis Sci 2011; 52:30-5. [PMID: 20811061 DOI: 10.1167/iovs.10-5902] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Dense innervation of the cornea is important for maintaining its homeostasis and transparency. Although corneal nerves have been well studied in adults, little is known about mammalian corneal innervation during development. This study provides a detailed profile of nerves at various stages of mouse cornea development. METHODS Mouse heads and corneas were collected at various stages of development including embryonic days (E)12.5 to E16.5, postnatal days (P)0, P10, three weeks after birth, and the adult. Corneas were immunostained with an anti-neuron-specific β-tubulin antibody (TUJ1). Fluorescently labeled nerves in whole-mount tissues and sections were imaged and analyzed for their axonal projections during eye development. RESULTS The first nerve bundles appear at the periphery of the anterior portion of the eye by E12.5. Initial projection into the stroma occurs at E13.5 without formation of a pericorneal nerve ring. Between E13.5 and E16.5, nerve bundles project directly into the periphery of the presumptive cornea stroma. They branch repeatedly as they extend toward the cornea center and epithelium. Concomitantly, nerve bundles originating from four quadrants of the eye bifurcate into smaller branches that innervate the entire stroma. The first epithelial innervation occurs at E16.5. Epithelial nerves arrange into patterns that project toward the center subsequently forming a swirl at three weeks after birth, which becomes more pronounced in adults. CONCLUSIONS Nerve bundles that arise from four quadrants of the eye innervate the mouse cornea. The nerve bundles directly innervate the stroma without forming a pericorneal nerve ring. Radial arrangement of epithelial nerves gradually becomes centrally oriented, subsequently forming a swirl pattern.
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Affiliation(s)
- Chelsey C McKenna
- Department of Biochemistry and Cell Biology, Rice University, Houston, TX, USA
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Taniguchi M, Masuda T, Mikami Y, Kimura M, Yoshida T, Mishina M, Shimizu T. Identification and characterization of a novel zebrafish semaphorin. Neurosci Lett 2010; 488:215-20. [PMID: 21094219 DOI: 10.1016/j.neulet.2010.11.032] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2010] [Revised: 11/12/2010] [Accepted: 11/12/2010] [Indexed: 10/18/2022]
Abstract
The semaphorin gene family contains numerous secreted and transmembrane proteins. Some of them function as the repulsive and attractive axon guidance molecules during development. Herein, we report the cloning and characterization of a novel member of zebrafish semaphorin gene, semaphorin 6E (sema6E). Sema6E is expressed predominantly in the nervous system during embryogenesis. Results also show that Sema6E binds Plexin-A1, but not other Plexins. Sema6E chemorepels not only dorsal root ganglion axons but also sympathetic axons. Therefore, Sema6E might utilize Plexin-A1 as a receptor to repel axons of the specific types during development.
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Affiliation(s)
- Masahiko Taniguchi
- Department of Biochemistry, Cancer Research Institute, Sapporo Medical University School of Medicine, S-1 W-17, Chuo-ku, Sapporo, Hokkaido 060-8556, Japan.
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Developmental guidance of embryonic corneal innervation: roles of Semaphorin3A and Slit2. Dev Biol 2010; 344:172-84. [PMID: 20471970 DOI: 10.1016/j.ydbio.2010.04.032] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2010] [Revised: 04/26/2010] [Accepted: 04/27/2010] [Indexed: 11/23/2022]
Abstract
The cornea is one of the most densely innervated structures of the body. In the developing chicken embryo, nerves from the ophthalmic trigeminal ganglion (OTG) innervate the cornea in a series of spatially and temporally regulated events. However, little is known concerning the signals that regulate these events. Here we have examined the involvement of the axon guidance molecules Semaphorin3A and Slit2, and their respective receptors, Neuropilin-1 and Robo2. Expression analyses of early corneas suggest an involvement of both Semaphorin3A and Slit2 in preventing nerves from entering the corneal stroma until the proper time (i.e., they serve as negative regulators), and analyses of their receptors support this conclusion. At later stages of development the expression of Semaphorin3A is again consistent with its serving as a negative regulator-this time for nerves entering the corneal epithelium. However, expression analyses of Robo2 at this stage raised the possibility that Slit2 had switched from a negative regulator to a positive regulator. In support of such a switch, functional analyses-by addition of recombinant Slit2 protein or immunoneutralization with a Slit2 antibody-showed that at an early stage Slit2 negatively regulates the outgrowth of nerves from the OTG, whereas at the later stage it positively regulated the growth of nerves by increasing nerve branching within the corneal epithelium.
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Ko JA, Akamatsu Y, Yanai R, Nishida T. Effects of semaphorin 3A overexpression in corneal fibroblasts on the expression of adherens-junction proteins in corneal epithelial cells. Biochem Biophys Res Commun 2010; 396:781-6. [PMID: 20382125 DOI: 10.1016/j.bbrc.2010.04.029] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Accepted: 04/03/2010] [Indexed: 11/30/2022]
Abstract
Interactions between epithelial cells and fibroblasts play important roles in tissue homeostasis. Semaphorins are a family of glycoproteins that contribute to axon guidance during development. With the use of a coculture system in which human corneal fibroblasts and epithelial cells are cultured on opposite sides of a collagen membrane, we have examined the effects of overexpression of semaphorin 3A in corneal fibroblasts on the expression of junctional proteins in corneal epithelial cells. Reverse transcription-polymerase chain reaction as well as immunoblot and immunofluorescence analyses revealed that the overexpression of semaphorin 3A in corneal fibroblasts increased the expression of E-cadherin and N-cadherin in corneal epithelial cells at both the mRNA and protein levels. These effects of semaphorin 3A were dependent on the presence of extracellular Ca(2+). Our findings indicate that semaphorin 3A released from corneal fibroblasts may play an important role in the regulation of intercellular communication between corneal epithelial cells as well as in the maintenance of corneal structure and function.
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Affiliation(s)
- Ji-Ae Ko
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube City, Yamaguchi 755-8505, Japan.
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Conrad AH, Zhang Y, Tasheva ES, Conrad GW. Proteomic analysis of potential keratan sulfate, chondroitin sulfate A, and hyaluronic acid molecular interactions. Invest Ophthalmol Vis Sci 2010; 51:4500-15. [PMID: 20375348 DOI: 10.1167/iovs.09-4914] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Corneal stroma extracellular matrix (ECM) glycosaminoglycans (GAGs) include keratan sulfate (KS), chondroitin sulfate A (CSA), and hyaluronic acid (HA). Embryonic corneal keratocytes and sensory nerve fibers grow and differentiate according to chemical cues they receive from the ECM. This study asked which of the proteins that may regulate keratocytes or corneal nerve growth cone immigration interact with corneal GAGs. METHODS Biotinylated KS (bKS), CSA (bCSA), and HA (bHA) were prepared and used in microarray protocols to assess their interactions with 8268 proteins and a custom microarray of 85 extracellular epitopes of nerve growth-related proteins. Surface plasmon resonance (SPR) was performed with bKS and SLIT2, and their ka, kd, and KD were determined. RESULTS Highly sulfated KS interacted with 217 microarray proteins, including 75 kinases, several membrane or secreted proteins, many cytoskeletal proteins, and many nerve function proteins. CSA interacted with 24 proteins, including 10 kinases and 2 cell surface proteins. HA interacted with 6 proteins, including several ECM-related structural proteins. Of 85 ECM nerve-related epitopes, KS bound 40 proteins, including SLIT, 2 ROBOs, 9 EPHs, 8 Ephrins (EFNs), 8 semaphorins (SEMAs), and 2 nerve growth factor receptors. CSA bound nine proteins, including ROBO2, 2 EPHs, 1 EFN, two SEMAs, and netrin 4. HA bound no ECM nerve-related epitopes. SPR confirmed that KS binds SLIT2 strongly. The KS core protein mimecan/osteoglycin bound 15 proteins. CONCLUSIONS Corneal stromal GAGs bind, and thus could alter the availability or conformation of, many proteins that may influence keratocyte and nerve growth cone behavior in the cornea.
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Affiliation(s)
- Abigail H Conrad
- Division of Biology, Kansas State University, Manhattan, Kansas 66506-4901, USA.
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Morishige N, Ko JA, Morita Y, Nishida T. Expression of semaphorin 3A in the rat corneal epithelium during wound healing. Biochem Biophys Res Commun 2010; 395:451-7. [PMID: 20331965 DOI: 10.1016/j.bbrc.2010.03.124] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 03/19/2010] [Indexed: 01/02/2023]
Abstract
The neural guidance protein semaphorin 3A (Sema3A) is expressed in corneal epithelial cells of the adult rat. We have now further investigated the localization of Sema3A in the normal rat corneal epithelium as well as changes in its expression pattern during wound healing after central corneal epithelial debridement. The expression pattern of Sema3A was compared with that of the tight-junction protein zonula occludens-1 (ZO-1), the gap-junction protein connexin43 (Cx43), or the cell proliferation marker Ki67. Immunofluorescence analysis revealed that Sema3A was present predominantly in the membrane of basal and wing cells of the intact corneal epithelium. The expression of Sema3A at the basal side of basal cells was increased in the peripheral epithelium compared with that in the central region. Sema3A was detected in all layers at the leading edge of the migrating corneal epithelium at 6h after central epithelial debridement. The expression of Sema3A was markedly up-regulated in the basal and lateral membranes of columnar basal cells apparent in the thickened, newly healed epithelium at 1 day after debridement, but it had largely returned to the normal pattern at 3 days after debridement. The expression of ZO-1 was restricted to superficial epithelial cells and remained mostly unchanged during the wound healing process. The expression of Cx43 in basal cells was down-regulated at the leading edge of the migrating epithelium but was stable in the remaining portion of the epithelium. Ki67 was not detected in basal cells of the central epithelium at 1 day after epithelial debridement, when Sema3A was prominently expressed. Immunoblot analysis showed that the abundance of Sema3A in the central cornea was increased 1 day after epithelial debridement, whereas that of ZO-1 or Cx43 remained largely unchanged. This increase in Sema3A expression was accompanied by up-regulation of the Sema3A coreceptor neuropilin-1. Our observations have thus shown that the expression of Sema3A is increased markedly in basal cells of the newly healed corneal epithelium, and that this up-regulation of Sema3A is not associated with cell proliferation. They further suggest that Sema3A might play a role in the regulation of corneal epithelial wound healing.
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Affiliation(s)
- Naoyuki Morishige
- Department of Ophthalmology, Yamaguchi University Graduate School of Medicine, 1-1-1 Minami-Kogushi, Ube, Yamaguchi 755-8505, Japan
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Dynamic expression of axon guidance cues required for optic tract development is controlled by fibroblast growth factor signaling. J Neurosci 2010; 30:685-93. [PMID: 20071533 DOI: 10.1523/jneurosci.4165-09.2010] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Axons are guided to their targets by molecular cues expressed in their environment. How is the presence of these cues regulated? Although some evidence indicates that morphogens establish guidance cue expression as part of their role in patterning tissues, an important question is whether morphogens are then required to maintain guidance signals. We found that fibroblast growth factor (FGF) signaling sustains the expression of two guidance cues, semaphorin3A (xsema3A) and slit1 (xslit1), throughout the period of Xenopus optic tract development. With FGF receptor inhibition, xsema3A and xslit1 levels were rapidly diminished, and retinal ganglion cell axons arrested in the mid-diencephalon, before reaching their target. Importantly, direct downregulation of XSema3A and XSlit1 mostly phenocopied this axon guidance defect. Thus, FGFs promote continued presence of specific guidance cues critical for normal optic tract development, suggesting a second later role for morphogens, independent of tissue patterning, in maintaining select cues by acting to regulate their transcription.
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Abstract
The vertebrate eye comprises tissues from different embryonic origins: the lens and the cornea are derived from the surface ectoderm, but the retina and the epithelial layers of the iris and ciliary body are from the anterior neural plate. The timely action of transcription factors and inductive signals ensure the correct development of the different eye components. Establishing the genetic basis of eye defects in zebrafishes, mouse, and human has been an important tool for the detailed analysis of this complex process. A single eye field forms centrally within the anterior neural plate during gastrulation; it is characterized on the molecular level by the expression of "eye-field transcription factors." The single eye field is separated into two, forming the optic vesicle and later (under influence of the lens placode) the optic cup. The lens develops from the lens placode (surface ectoderm) under influence of the underlying optic vesicle. Pax6 acts in this phase as master control gene, and genes encoding cytoskeletal proteins, structural proteins, or membrane proteins become activated. The cornea forms from the surface ectoderm, and cells from the periocular mesenchyme migrate into the cornea giving rise for the future cornea stroma. Similarly, the iris and ciliary body form from the optic cup. The outer layer of the optic cup becomes the retinal pigmented epithelium, and the main part of the inner layer of the optic cup forms later the neural retina with six different types of cells including the photoreceptors. The retinal ganglion cells grow toward the optic stalk forming the optic nerve. This review describes the major molecular players and cellular processes during eye development as they are known from frogs, zebrafish, chick, and mice-showing also differences among species and missing links for future research. The relevance to human disorders is one of the major aspects covered throughout the review.
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Affiliation(s)
- Jochen Graw
- Helmholtz Center Munich-German Research Center for Environmental Health, Institute of Developmental Genetics, Neuherberg, Germany
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Lwigale PY, Bronner-Fraser M. Semaphorin3A/neuropilin-1 signaling acts as a molecular switch regulating neural crest migration during cornea development. Dev Biol 2009; 336:257-65. [PMID: 19833121 PMCID: PMC2800376 DOI: 10.1016/j.ydbio.2009.10.008] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 09/11/2009] [Accepted: 10/06/2009] [Indexed: 10/20/2022]
Abstract
Cranial neural crest cells migrate into the periocular region and later contribute to various ocular tissues including the cornea, ciliary body and iris. After reaching the eye, they initially pause before migrating over the lens to form the cornea. Interestingly, removal of the lens leads to premature invasion and abnormal differentiation of the cornea. In exploring the molecular mechanisms underlying this effect, we find that semaphorin3A (Sema3A) is expressed in the lens placode and epithelium continuously throughout eye development. Interestingly, neuropilin-1 (Npn-1) is expressed by periocular neural crest but down-regulated, in a manner independent of the lens, by the subpopulation that migrates into the eye and gives rise to the cornea endothelium and stroma. In contrast, Npn-1 expressing neural crest cells remain in the periocular region and contribute to the anterior uvea and ocular blood vessels. Introduction of a peptide that inhibits Sema3A/Npn-1 signaling results in premature entry of neural crest cells over the lens that phenocopies lens ablation. Furthermore, Sema3A inhibits periocular neural crest migration in vitro. Taken together, our data reveal a novel and essential role of Sema3A/Npn-1 signaling in coordinating periocular neural crest migration that is vital for proper ocular development.
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Affiliation(s)
- Peter Y Lwigale
- Department of Biochemistry and Cell Biology, MS 140, Rice University, P.O. Box 1892, Houston, TX 77251, USA.
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Kubilus JK, Linsenmayer TF. Developmental corneal innervation: interactions between nerves and specialized apical corneal epithelial cells. Invest Ophthalmol Vis Sci 2009; 51:782-9. [PMID: 19741242 DOI: 10.1167/iovs.09-3942] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
PURPOSE The corneal epithelium is one of the most highly innervated structures in the body, and proper innervation is necessary for corneal maintenance and sensation. However, little is known about how these nerves function and how innervation occurs developmentally. The authors have examined certain aspects of corneal innervation in the developing chicken embryo. METHODS DiI was used to determine the source of the neurons responsible for innervating the cornea. Immunohistochemistry, electron microscopy, and immunoelectron microscopy were used to examine corneal innervation and the relationships that develop between nerves and corneal epithelial cells. RESULTS Corneal nerves in the embryonic chicken originate entirely from the ophthalmic lobe of the trigeminal ganglion. Within the cornea the nerves interact with apical corneal epithelial (ACE) cells to form specialized structures that are synapse-like because they contain accumulations of vesicles and have the SV2 synaptic vesicle protein. These ACE cells themselves have unique characteristics, including transient expression of the neuronal isoform of class III beta-tubulin and formation of extensive intercellular channels and clefts that contain these specialized synapse-like structures and nerves; in addition, they are mitotically active. Given that these ACE cells react with a monoclonal antibody against this neuronal isoform of beta-tubulin (the TuJ-1 antibody), we have termed them TuJ-1(+)ACE cells. CONCLUSIONS During avian corneal development the nerves make close associations with a specialized type of ACE cell. There they form synapse-like structures, suggesting that not all nerves within the CE terminate as free nerve endings.
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Affiliation(s)
- James K Kubilus
- Program in Cell, Molecular and Developmental Biology, Sackler School of Graduate Biomedical Sciences, Department of Anatomy and Cellular Biology, Tufts University School of Medicine, Boston, Massachusetts, USA
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Conrad AH, Albrecht M, Pettit-Scott M, Conrad GW. Embryonic corneal Schwann cells express some Schwann cell marker mRNAs, but no mature Schwann cell marker proteins. Invest Ophthalmol Vis Sci 2009; 50:4173-84. [PMID: 19387082 DOI: 10.1167/iovs.08-3136] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
PURPOSE Embryonic chick nerves encircle the cornea in pericorneal tissue until embryonic day (E)9, then penetrate the anterior corneal stroma, invade the epithelium, and branch over the corneal surface through E20. Adult corneal nerves, cut during transplantation or LASIK, never fully regenerate. Schwann cells (SCs) protect nerve fibers and augment nerve repair. This study evaluates SC differentiation in embryonic chick corneas. METHODS Fertile chicken eggs were incubated from E0 at 38 degrees C, 45% humidity. Dissected permeabilized corneas plus pericorneal tissue were immunostained for SC marker proteins. Other corneas were paraffin embedded, sectioned, and processed by in situ hybridization for corneal-, nerve-related, and SC marker gene expression. E9 to E20 corneas, dissected from pericorneal tissue, were assessed by real-time PCR (QPCR) for mRNA expression. RESULTS QPCR revealed unchanging low to moderate SLIT2/ROBO and NTN/UNC5 family, BACE1, and CADM3/CADM4 expressions, but high NEO1 expression. EGR2 and POU3F1 expressions never surpassed PAX3 expression. ITGNA6/ITGNB4 expressions increased 20-fold; ITGNB1 expression was high. SC marker S100 and MBP expressions increased; MAG, GFAP, and SCMP expressions were very low. Antibodies against the MPZ, MAG, S100, and SCMP proteins immunostained along pericorneal nerves, but not along corneal nerves. In the cornea, SLIT2 and SOX10 mRNAs were expressed in anterior stroma and epithelium, whereas PAX3, S100, MBP, and MPZL1 mRNAs were expressed only in corneal epithelium. CONCLUSIONS Embryonic chick corneas contain SCs, as defined by SOX10 and PAX3 transcription, which remain immature, at least in part because of stromal transcriptional and epithelial translational regulation of some SC marker gene expression.
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Affiliation(s)
- Abigail H Conrad
- Division of Biology, Kansas State University, Manhattan, Kansas 66506-4901, USA.
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Ko JA, Morishige N, Yanai R, Nishida T. Up-regulation of semaphorin 3A in human corneal fibroblasts by epidermal growth factor released from cocultured human corneal epithelial cells. Biochem Biophys Res Commun 2008; 377:104-8. [DOI: 10.1016/j.bbrc.2008.09.085] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 09/19/2008] [Indexed: 01/22/2023]
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Bannerman P, Ara J, Hahn A, Hong L, McCauley E, Friesen K, Pleasure D. Peripheral nerve regeneration is delayed in neuropilin 2-deficient mice. J Neurosci Res 2008; 86:3163-9. [PMID: 18615644 PMCID: PMC2574585 DOI: 10.1002/jnr.21766] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peripheral nerve transection or crush induces expression of class 3 semaphorins by epineurial and perineurial cells at the injury site and of the neuropilins neuropilin-1 and neuropilin-2 by Schwann and perineurial cells in the nerve segment distal to the injury. Neuropilin-dependent class 3 semaphorin signaling guides axons during neural development, but the significance of this signaling system for regeneration of adult peripheral nerves is not known. To test the hypothesis that neuropilin-2 facilitates peripheral-nerve axonal regeneration, we crushed sciatic nerves of adult neuropilin-2-deficient and littermate control mice. Axonal regeneration through the crush site and into the distal nerve segment, repression by the regenerating axons of Schwann cell p75 neurotrophin receptor expression, remyelination of the regenerating axons, and recovery of normal gait were all significantly slower in the neuropilin-2-deficient mice than in the control mice. Thus, neuropilin-2 facilitates peripheral-nerve axonal regeneration.
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Affiliation(s)
- Peter Bannerman
- Institute for Pediatric Regenerative Medicine, UC Davis School of Medicine, Sacramento CA
| | - Jahan Ara
- Dep’t of Pediatrics, Drexel University College of Medicine, Philadelphia PA
| | | | - Lindy Hong
- Institute for Pediatric Regenerative Medicine, UC Davis School of Medicine, Sacramento CA
| | - Erica McCauley
- Institute for Pediatric Regenerative Medicine, UC Davis School of Medicine, Sacramento CA
| | - Katie Friesen
- Institute for Pediatric Regenerative Medicine, UC Davis School of Medicine, Sacramento CA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, UC Davis School of Medicine, Sacramento CA
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Sakimoto T, Kim TI, Ellenberg D, Fukai N, Jain S, Azar DT, Chang JH. Collagen XVIII and corneal reinnervation following keratectomy. FEBS Lett 2008; 582:3674-80. [PMID: 18840438 DOI: 10.1016/j.febslet.2008.09.052] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2008] [Revised: 09/14/2008] [Accepted: 09/25/2008] [Indexed: 10/21/2022]
Abstract
The significance of collagen XVIII in the regulation of corneal reinnervation remains largely unknown. We used whole-mount immunoconfocal microscopy to localize collagen XVIII to the nerve basement membrane of wild-type (WT) mouse corneas. Transmission electron microscopy showed corneal nerve disorganization in collagen XVIII knockout mice (col18a1(-/-)). Antibody 2H3-specific neurofilament colocalized with collagens XVIII and IV and laminin-2 in WT mouse corneas, but did not colocalize with collagen IV and laminin-2 in col18a1(-/-) mouse corneas. Following keratectomy, col18a1(-/-) mice displayed decreased corneal neurite extension compared to WT mice. Our data indicate that collagen XVIII may play an important role in corneal reinnervation after wounding.
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Affiliation(s)
- Tohru Sakimoto
- Schepens Eye Research Institute, Harvard University, Boston, MA, USA
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Zhang Y, Burgess D, Overbeek PA, Govindarajan V. Dominant inhibition of lens placode formation in mice. Dev Biol 2008; 323:53-63. [PMID: 18778700 DOI: 10.1016/j.ydbio.2008.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 07/25/2008] [Accepted: 08/14/2008] [Indexed: 11/29/2022]
Abstract
The lens in the vertebrate eye has been shown to be critical for proper differentiation of the surrounding ocular tissues including the cornea, iris and ciliary body. In mice, previous investigators have assayed the consequences of molecular ablation of the lens. However, in these studies, lens ablation was initiated (and completed) after the cornea, retina, iris and ciliary body had initiated their differentiation programs thereby precluding analysis of the early role of the lens in fate determination of these tissues. In the present study, we have ablated the lens precursor cells of the surface ectoderm by generation of transgenic mice that express an attenuated version of diphtheria toxin (Tox176) linked to a modified Pax6 promoter that is active in the lens ectodermal precursors. In these mice, lens precursor cells fail to express Sox2, Prox1 and alphaA-crystallin and die before the formation of a lens placode. The Tox176 mice also showed profound alterations in the corneal differentiation program. The corneal epithelium displayed histological features of the skin, and expressed markers of skin differentiation such as Keratin 1 and 10 instead of Keratin 12, a marker of corneal epithelial differentiation. In the Tox176 mice, in the absence of the lens, extensive folding of the retina was seen. However, differentiation of the major cell types in the retina including the ganglion, amacrine, bipolar and horizontal cells was not affected. Unexpectedly, ectopic placement of the retinal pigmented epithelium was seen between the folds of the retina. Initial specification of the presumptive ciliary body and iris at the anterior margins of the retina was not altered in the Tox176 mice but their subsequent differentiation was blocked. Lacrimal and Harderian glands, which are derived from the Pax6-expressing surface ectodermal precursors, also failed to differentiate. These results suggest that, in mice, specification of the retina, ciliary body and iris occurs at the very outset of eye development and independent of the lens. In addition, our results also suggest that the lens cells of the surface ectoderm may be critical for the proper differentiation of the corneal epithelium.
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Affiliation(s)
- Yan Zhang
- Department of Surgery, 254 Criss III, 2500 California Plaza, Creighton University, Omaha, NE 68178, USA
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