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Upreti A, Padula SL, Weaver JM, Wagner BD, Kneller AM, Petulla AL, Lachke SA, Robinson ML. A Transcriptomics Analysis of the Regulation of Lens Fiber Cell Differentiation in the Absence of FGFRs and PTEN. Cells 2024; 13:1222. [PMID: 39056803 PMCID: PMC11274593 DOI: 10.3390/cells13141222] [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: 04/24/2024] [Revised: 06/28/2024] [Accepted: 07/17/2024] [Indexed: 07/28/2024] Open
Abstract
Adding 50% vitreous humor to the media surrounding lens explants induces fiber cell differentiation and a significant immune/inflammatory response. While Fgfr loss blocks differentiation in lens epithelial explants, this blockage is partially reversed by deleting Pten. To investigate the functions of the Fgfrs and Pten during lens fiber cell differentiation, we utilized a lens epithelial explant system and conducted RNA sequencing on vitreous humor-exposed explants lacking Fgfrs, or Pten or both Fgfrs and Pten. We found that Fgfr loss impairs both vitreous-induced differentiation and inflammation while the additional loss of Pten restores these responses. Furthermore, transcriptomic analysis suggested that PDGFR-signaling in FGFR-deficient explants is required to mediate the rescue of vitreous-induced fiber differentiation in explants lacking both Fgfrs and Pten. The blockage of β-crystallin induction in explants lacking both Fgfrs and Pten in the presence of a PDGFR inhibitor supports this hypothesis. Our findings demonstrate that a wide array of genes associated with fiber cell differentiation are downstream of FGFR-signaling and that the vitreous-induced immune responses also depend on FGFR-signaling. Our data also demonstrate that many of the vitreous-induced gene-expression changes in Fgfr-deficient explants are rescued in explants lacking both Fgfrs and Pten.
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Affiliation(s)
- Anil Upreti
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA; (A.U.); (S.L.P.); (J.M.W.)
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
| | - Stephanie L. Padula
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA; (A.U.); (S.L.P.); (J.M.W.)
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
| | - Jacob M. Weaver
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA; (A.U.); (S.L.P.); (J.M.W.)
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
| | - Brad D. Wagner
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
| | - Allison M. Kneller
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
| | - Anthony L. Petulla
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA;
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19716, USA
| | - Michael L. Robinson
- Cell, Molecular and Structural Biology Program, Miami University, Oxford, OH 45056, USA; (A.U.); (S.L.P.); (J.M.W.)
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA; (B.D.W.); (A.M.K.); (A.L.P.)
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Zhang L, Liu X, Li W, Liu K, Zhang J, Liu X, Wang J. Integrative transcriptomic profiling of ncRNAs and mRNAs in developing mouse lens. Front Genet 2024; 15:1405715. [PMID: 38933921 PMCID: PMC11199715 DOI: 10.3389/fgene.2024.1405715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024] Open
Abstract
In recent years, burgeoning research has underscored the pivotal role of non-coding RNA in orchestrating the growth, development, and pathogenesis of various diseases across organisms. However, despite these advances, our understanding of the specific contributions of long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs) to lens development remains notably limited. Clarifying the intricate gene regulatory networks is imperative for unraveling the molecular underpinnings of lens-related disorders. In this study, we aimed to address this gap by conducting a comprehensive analysis of the expression profiles of messenger RNAs (mRNAs), lncRNAs, and circRNAs at critical developmental time points of the mouse lens, encompassing both embryonic (E10.5, E12.5, and E16.5) and postnatal stages (P0.5, P10.5, and P60). Leveraging RNA-sequencing technology, we identified key transcripts pivotal to lens development. Our analysis revealed differentially expressed (DE) mRNAs, lncRNAs, and circRNAs across various developmental stages. Particularly noteworthy, there were 1831 co-differentially expressed (CO-DE) mRNAs, 150 CO-DE lncRNAs, and 13 CO-DE circRNAs identified during embryonic stages. Gene Ontology (GO) enrichment analysis unveiled associations primarily related to lens development, DNA conformational changes, and angiogenesis among DE mRNAs and lncRNAs. Furthermore, employing protein-protein interaction networks, mRNA-lncRNA co-expression networks, and circRNA-microRNA-mRNA networks, we predicted candidate key molecules implicated in lens development. Our findings underscore the pivotal roles of lncRNAs and circRNAs in this process, offering fresh insights into the pathogenesis of lens-related disorders and paving the way for future exploration in this field.
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Affiliation(s)
- Liyun Zhang
- Department of Ophthalmology, General Hospital of Central Theater Command, Wuhan, China
| | - Xin Liu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, China
| | - Wei Li
- Department of Pediatric Respiratory Medicine, Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Kaiqing Liu
- The Department of Urology, The Third Affiliated Hospital of Shenzhen University, Shenzhen, Guangdong, China
| | - Jing Zhang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, China
| | - Xinhua Liu
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, China
| | - Jiantao Wang
- Shenzhen Eye Hospital, Jinan University, Shenzhen Eye Institute, Shenzhen, Guangdong, China
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Zhang L, Zhang ZF, Hui YN, He F, Guan XR, Zhou J. Oxidative Stress Participates in Age-Related Cataract Formation by Disrupting Connection between Lens Epithelial Cells through c-Src/VEGF Pathway. Curr Eye Res 2024; 49:380-390. [PMID: 38108278 DOI: 10.1080/02713683.2023.2293456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Accepted: 12/05/2023] [Indexed: 12/19/2023]
Abstract
PURPOSE To observe the effects of oxidative stress on vascular endothelial growth factor (VEGF) and connections of lens epithelial cells. METHODS Human lens epithelium of patients with age-related cataract (ARC), both SRA01/04 cells and whole mice lens stimulated by H2O2 were employed. VEGF in human aqueous humor of ARC-patients and the supernatant of SRA01/04 cells was determined by ELISA. The expressions of VEFG in human lens epithelium were detected by immunofluorescence staining. Multiple linear regression analysis and spearman rank-order correlation were used to determine the associations between VEGF and parameters of ARC individuals. In H2O2-induced SRA01/04 cells, Catalase (CAT), PP1 (inhibitor of c-Src kinase) and Avastin (VEGF antibody) were used to inhibit the effects of H2O2, activation of c-Src kinase and VEGF, which were detected by Western blot. The alterations of ZO-1 and N-cadherin were tested by immunofluorescence staining and Western blot. In H2O2-induced whole lens, the changes of opacification area in different treatment of inhibitors were observed. RESULTS The secretion of VEGF in aqueous humor and expression of VEGF in the lens epithelium of ARC patients increased significantly with age. In H2O2-induced SRA01/04 cells, the VEGF in the supernatant was increased with the culture duration and the dose of H2O2. The expressions of p-Src418 and VEGF were also up-regulated, whereas the expressions of ZO-1 and N-cadherin were down-regulated. CAT effectively prevented these changes induced by H2O2, while PP1 inhibited not only p-Src418 but also up-regulation of VEGF, Avastin partially inhibited VEGF up-regulation. Both PP1 and Avastin prevented down-regulation of ZO-1 and N-cadherin, respectively, but Avastin combined with PP1 had no significant synergistic effects. In H2O2-induced cataract, CAT prevented development of opacification area effectively, and PP1 and Avastin did partially. CONCLUSIONS Oxidative stress disrupts connections of lens epithelial cells by activating c-Src/VEGF, inhibiting which may prevent cataract.
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Affiliation(s)
- Le Zhang
- Department of Ophthalmology, Eye Institute of PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
- Department of Ophthalmology, Northwest Woman's and Children's Hospital, Xi'an, Shaanxi, China
| | - Zi-Feng Zhang
- Department of Ophthalmology, Eye Institute of PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Yan-Nian Hui
- Department of Ophthalmology, Eye Institute of PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Fang He
- Department of Ophthalmology, Eye Institute of PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Xiao-Rong Guan
- Department of Ophthalmology, Eye Institute of PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Jian Zhou
- Department of Ophthalmology, Eye Institute of PLA, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
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Zhu Y, Li D, Reyes-Ortega F, Chinnery HR, Schneider-Futschik EK. Ocular development after highly effective modulator treatment early in life. Front Pharmacol 2023; 14:1265138. [PMID: 37795027 PMCID: PMC10547496 DOI: 10.3389/fphar.2023.1265138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2023] [Accepted: 09/06/2023] [Indexed: 10/06/2023] Open
Abstract
Highly effective cystic fibrosis (CF) transmembrane conductance regulator (CFTR) modulator therapies (HEMT), including elexacaftor-tezacaftor-ivacaftor, correct the underlying molecular defect causing CF. HEMT decreases general symptom burden by improving clinical metrics and quality of life for most people with CF (PwCF) with eligible CFTR variants. This has resulted in more pregnancies in women living with CF. All HEMT are known to be able pass through the placenta and into breast milk in mothers who continue on this therapy while pregnant and breast feeding. Toxicity studies of HEMT in young rats demonstrated infant cataracts, and case reports have reported the presence of congenital cataracts in early life exposure to HEMT. This article reviews the evidence for how HEMT influences the dynamic and interdependent processes of healthy and abnormal lens development in the context of HEMT exposure during pregnancy and breastfeeding, and raises questions that remain unanswered.
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Affiliation(s)
- Yimin Zhu
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Danni Li
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Felisa Reyes-Ortega
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia
- Department of Ophthalmology, Maimonides Biomedical Research Institute of Cordoba (IMIBIC), Reina Sofia University Hospital and University of Cordoba, Cordoba, Spain
| | - Holly R. Chinnery
- Department of Optometry and Vision Sciences, The University of Melbourne, Parkville, VIC, Australia
| | - Elena K. Schneider-Futschik
- Department of Biochemistry and Pharmacology, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, VIC, Australia
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Cvekl A, Camerino MJ. Generation of Lens Progenitor Cells and Lentoid Bodies from Pluripotent Stem Cells: Novel Tools for Human Lens Development and Ocular Disease Etiology. Cells 2022; 11:cells11213516. [PMID: 36359912 PMCID: PMC9658148 DOI: 10.3390/cells11213516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/31/2022] [Accepted: 11/02/2022] [Indexed: 11/09/2022] Open
Abstract
In vitro differentiation of human pluripotent stem cells (hPSCs) into specialized tissues and organs represents a powerful approach to gain insight into those cellular and molecular mechanisms regulating human development. Although normal embryonic eye development is a complex process, generation of ocular organoids and specific ocular tissues from pluripotent stem cells has provided invaluable insights into the formation of lineage-committed progenitor cell populations, signal transduction pathways, and self-organization principles. This review provides a comprehensive summary of recent advances in generation of adenohypophyseal, olfactory, and lens placodes, lens progenitor cells and three-dimensional (3D) primitive lenses, "lentoid bodies", and "micro-lenses". These cells are produced alone or "community-grown" with other ocular tissues. Lentoid bodies/micro-lenses generated from human patients carrying mutations in crystallin genes demonstrate proof-of-principle that these cells are suitable for mechanistic studies of cataractogenesis. Taken together, current and emerging advanced in vitro differentiation methods pave the road to understand molecular mechanisms of cataract formation caused by the entire spectrum of mutations in DNA-binding regulatory genes, such as PAX6, SOX2, FOXE3, MAF, PITX3, and HSF4, individual crystallins, and other genes such as BFSP1, BFSP2, EPHA2, GJA3, GJA8, LIM2, MIP, and TDRD7 represented in human cataract patients.
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Affiliation(s)
- Aleš Cvekl
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Correspondence: ; Tel.: +1-718-430-3217; Fax: +1-718-430-8778
| | - Michael John Camerino
- Departments Ophthalmology and Visual Sciences, Albert Einstein College of Medicine, Bronx, NY 10461, USA
- Department of Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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Boneva SK, Wolf J, Wieghofer P, Sebag J, Lange CAK. Hyalocyte functions and immunology. EXPERT REVIEW OF OPHTHALMOLOGY 2022. [DOI: 10.1080/17469899.2022.2100763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- Stefaniya K Boneva
- Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Julian Wolf
- Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter Wieghofer
- Cellular Neuroanatomy, Institute of Theoretical Medicine, Medical Faculty, University of Augsburg, Augsburg, Germany
| | - J Sebag
- Doheny Eye Institute, UCLA, Pasadena, CA, USA
- UCLA Geffen School of Medicine, Los Angeles, CA, USA
- VMR Institute for Vitreous Macula Retina, Huntington Beach, California, USA
| | - Clemens AK Lange
- Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Ophtha-Lab, Department of Ophthalmology at St. Franziskus Hospital, Muenster, Germany
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Disatham J, Brennan L, Jiao X, Ma Z, Hejtmancik JF, Kantorow M. Changes in DNA methylation hallmark alterations in chromatin accessibility and gene expression for eye lens differentiation. Epigenetics Chromatin 2022; 15:8. [PMID: 35246225 PMCID: PMC8897925 DOI: 10.1186/s13072-022-00440-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Accepted: 02/16/2022] [Indexed: 12/13/2022] Open
Abstract
Background Methylation at cytosines (mCG) is a well-known regulator of gene expression, but its requirements for cellular differentiation have yet to be fully elucidated. A well-studied cellular differentiation model system is the eye lens, consisting of a single anterior layer of epithelial cells that migrate laterally and differentiate into a core of fiber cells. Here, we explore the genome-wide relationships between mCG methylation, chromatin accessibility and gene expression during differentiation of eye lens epithelial cells into fiber cells. Results Whole genome bisulfite sequencing identified 7621 genomic loci exhibiting significant differences in mCG levels between lens epithelial and fiber cells. Changes in mCG levels were inversely correlated with the differentiation state-specific expression of 1285 genes preferentially expressed in either lens fiber or lens epithelial cells (Pearson correlation r = − 0.37, p < 1 × 10–42). mCG levels were inversely correlated with chromatin accessibility determined by assay for transposase-accessible sequencing (ATAC-seq) (Pearson correlation r = − 0.86, p < 1 × 10–300). Many of the genes exhibiting altered regions of DNA methylation, chromatin accessibility and gene expression levels in fiber cells relative to epithelial cells are associated with lens fiber cell structure, homeostasis and transparency. These include lens crystallins (CRYBA4, CRYBB1, CRYGN, CRYBB2), lens beaded filament proteins (BFSP1, BFSP2), transcription factors (HSF4, SOX2, HIF1A), and Notch signaling pathway members (NOTCH1, NOTCH2, HEY1, HES5). Analysis of regions exhibiting cell-type specific alterations in DNA methylation revealed an overrepresentation of consensus sequences of multiple transcription factors known to play key roles in lens cell differentiation including HIF1A, SOX2, and the MAF family of transcription factors. Conclusions Collectively, these results link DNA methylation with control of chromatin accessibility and gene expression changes required for eye lens differentiation. The results also point to a role for DNA methylation in the regulation of transcription factors previously identified to be important for lens cell differentiation. Supplementary Information The online version contains supplementary material available at 10.1186/s13072-022-00440-z.
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Affiliation(s)
- Joshua Disatham
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Lisa Brennan
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA
| | - Xiaodong Jiao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Zhiwei Ma
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - J Fielding Hejtmancik
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Marc Kantorow
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, USA.
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Khokhar S, Surve A, Verma S, Azad S, Chandra P, Dhull C, Vohra R. Cataract in retinopathy of prematurity - A review. Indian J Ophthalmol 2022; 70:369-377. [PMID: 35086199 PMCID: PMC9023920 DOI: 10.4103/ijo.ijo_125_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Preterm babies with retinopathy of prematurity (ROP) can become blind if they do not receive appropriate timely intervention. The presence of cataract in these individuals in addition to visual deprivation amblyopia, also delays proper screening, adequate treatment, and makes follow-up assessment difficult. Anatomical differences in these infants and amblyopia management, especially in unilateral cataract, are other important concerns, and hence, management of these cases with cataract and ROP is challenging. In this review, studies where ROP cases were associated with cataract, were evaluated with a focus on preterm individuals less than 6 months age. Preterm babies are at increased risk of developing cataract because of systemic factors. In addition, those with ROP may have cataract associated with retinal detachment or treatment received. The type of cataract, risk factors, and pathophysiology associated with each cause varies. This review highlights these different aspects of cataract in ROP including causes, pathophysiology, types of cataracts, and management. The management of these cases is critical in terms of the timing of cataract surgery and the challenges associated with surgery and posterior segment management for ROP. Anatomical differences, preoperative retina status, pupillary dilatation, neovascularization of iris in aggressive posterior ROP, fundus examination, amblyopia, and follow-up are various important aspects in the management of the same. The preoperative workup, intraoperative challenges, postoperative care, and rehabilitation in these individuals are discussed.
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Affiliation(s)
- Sudarshan Khokhar
- Cataract and Refractive Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Abhidnya Surve
- Cataract and Refractive Service; Vitreoretinal, Uvea and ROP Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Saurabh Verma
- Cataract and Refractive Service; Vitreoretinal, Uvea and ROP Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Shorya Azad
- Vitreoretinal, Uvea and ROP Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Parijat Chandra
- Vitreoretinal, Uvea and ROP Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Chirakshi Dhull
- Cataract and Refractive Service; Vitreoretinal, Uvea and ROP Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
| | - Rajpal Vohra
- Vitreoretinal, Uvea and ROP Service; Dr. Rajendra Prasad Center for Ophthalmic Sciences, All India Institute of Medical Sciences, Ansari Nagar, New Delhi, India
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Disatham J, Brennan L, Chauss D, Kantorow J, Afzali B, Kantorow M. A functional map of genomic HIF1α-DNA complexes in the eye lens revealed through multiomics analysis. BMC Genomics 2021; 22:497. [PMID: 34215186 PMCID: PMC8254356 DOI: 10.1186/s12864-021-07795-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 06/09/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND During eye lens development the embryonic vasculature regresses leaving the lens without a direct oxygen source. Both embryonically and throughout adult life, the lens contains a decreasing oxygen gradient from the surface to the core that parallels the natural differentiation of immature surface epithelial cells into mature core transparent fiber cells. These properties of the lens suggest a potential role for hypoxia and the master regulator of the hypoxic response, hypoxia-inducible transcription factor 1 (HIF1), in the regulation of genes required for lens fiber cell differentiation, structure and transparency. Here, we employed a multiomics approach combining CUT&RUN, RNA-seq and ATACseq analysis to establish the genomic complement of lens HIF1α binding sites, genes activated or repressed by HIF1α and the chromatin states of HIF1α-regulated genes. RESULTS CUT&RUN analysis revealed 8375 HIF1α-DNA binding complexes in the chick lens genome. One thousand one hundred ninety HIF1α-DNA binding complexes were significantly clustered within chromatin accessible regions (χ2 test p < 1 × 10- 55) identified by ATACseq. Formation of the identified HIF1α-DNA complexes paralleled the activation or repression of 526 genes, 116 of which contained HIF1α binding sites within 10kB of the transcription start sites. Some of the identified HIF1α genes have previously established lens functions while others have novel functions never before examined in the lens. GO and pathway analysis of these genes implicate HIF1α in the control of a wide-variety of cellular pathways potentially critical for lens fiber cell formation, structure and function including glycolysis, cell cycle regulation, chromatin remodeling, Notch and Wnt signaling, differentiation, development, and transparency. CONCLUSIONS These data establish the first functional map of genomic HIF1α-DNA complexes in the eye lens. They identify HIF1α as an important regulator of a wide-variety of genes previously shown to be critical for lens formation and function and they reveal a requirement for HIF1α in the regulation of a wide-variety of genes not yet examined for lens function. They support a requirement for HIF1α in lens fiber cell formation, structure and function and they provide a basis for understanding the potential roles and requirements for HIF1α in the development, structure and function of more complex tissues.
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Affiliation(s)
- Joshua Disatham
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd., Boca Raton, FL 33431 USA
| | - Lisa Brennan
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd., Boca Raton, FL 33431 USA
| | - Daniel Chauss
- Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD 20892 USA
| | | | - Behdad Afzali
- Immunoregulation Section, Kidney Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH, Bethesda, MD 20892 USA
| | - Marc Kantorow
- Charles E. Schmidt College of Medicine, Florida Atlantic University, 777 Glades Rd., Boca Raton, FL 33431 USA
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Wang L, Liu WX, Huang XG. MicroRNA-199a-3p inhibits angiogenesis by targeting the VEGF/PI3K/AKT signalling pathway in an in vitro model of diabetic retinopathy. Exp Mol Pathol 2020; 116:104488. [PMID: 32622012 DOI: 10.1016/j.yexmp.2020.104488] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 06/19/2020] [Accepted: 06/26/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Diabetic retinopathy (DR) is a major inducer of blindness and visual impairment. As a critical cause for DR, hyperglycaemia is able to trigger multiple biochemical alterations. MiRNAs, which contain various functions, can effectively regulate blood glucose levels. This research aims to confirm the roles of miRNA-199a-3p in the progression of angiogenesis in an in vitro model of DR. METHODS Quantitative real-time polymerase chain reaction (qRT-PCR) was carried to determine the expression levels of miR-199a-3p and VEGF in both hRMECs and APRE-19 cells. The luciferase reporter assay was used to study the interaction between miR-199a-3p and VEGF. Western blot assay was conducted to examine the expression levels of VEGF and the PI3K/AKT signalling pathway. The cell proliferation capacity was detected via the CCK-8 test. The impact of miR-199a-3p on migration was determined using Transwell and wound healing assays. A Matrigel tube formation assay was employed to determine the vascular formation of hRMECs. Flow cytometry was used to determine cell apoptosis in the presence of LY294002 as a PI3K inhibitor. RESULTS Our results showed that high glucose (HG) decreased the relative expression level of miR-199a-3p but increased VEGF expression in hRMECs and APRE-19 cells. MiR-199a-3p inhibitor augmented cell growth, migration and angiogenesis of hRMECs. Moreover, upregulation of miR-199a-3p evidently alleviated the increases in cell proliferation, migration and angiogenesis caused by HG. In addition, the luciferase reporter assay indicated that miR-199a-3p directly targeted VEGF. The overexpression of miR-199a-3p obviously restrained the HG-stimulated PI3K/AKT signalling pathway and angiogenesis, which could be further inhibited by LY294002. Moreover, LY294002 could slightly ameliorate the miR-199a-3p inhibitor-stimulated PI3K/AKT signalling pathway and angiogenesis. CONCLUSION MiR-199a-3p upregulation ameliorated HG-stimulated angiogenesis of hRMECs by modulating the PI3K/AKT pathway through inhibiting VEGF. Although retinal neovascularization in vivo has not been studied, these in vitro findings provide more evidence for the role of miR-199a-3p upregulation against HG-induced angiogenesis.
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Affiliation(s)
- Ling Wang
- Department of Ophthalmology, the First Affiliated Hospital of Hainan Medical University, Haikou 570102, PR China
| | - Wei-Xian Liu
- Department of Ophthalmology, the First Affiliated Hospital of Hainan Medical University, Haikou 570102, PR China
| | - Xiong-Gao Huang
- Department of Ophthalmology, the First Affiliated Hospital of Hainan Medical University, Haikou 570102, PR China.
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Wang Z, Liu CH, Huang S, Chen J. Assessment and Characterization of Hyaloid Vessels in Mice. J Vis Exp 2019. [PMID: 31157789 DOI: 10.3791/59222] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
In the eye, the embryonic hyaloid vessels nourish the developing lens and retina and regress when the retinal vessels develop. Persistent or failed regression of hyaloid vessels can be seen in diseases such as persistent hyperplastic primary vitreous (PHPV), leading to an obstructed light path and impaired visual function. Understanding the mechanisms underlying the hyaloid vessel regression may lead to new molecular insights into the vascular regression process and potential new ways to manage diseases with persistent hyaloid vessels. Here we describe the procedures for imaging hyaloid in live mice with optical coherence tomography (OCT) and fundus fluorescein angiography (FFA) and a detailed technical protocol of isolating and flat-mounting hyaloid ex vivo for quantitative analysis. Low-density lipoprotein receptor-related protein 5 (LRP5) knockout mice were used as an experimental model of persistent hyaloid vessels, to illustrate the techniques. Together, these techniques may facilitate a thorough assessment of hyaloid vessels as an experimental model of vascular regression and studies on the mechanism of persistent hyaloid vessels.
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Affiliation(s)
- Zhongxiao Wang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School
| | - Chi-Hsiu Liu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School
| | - Shuo Huang
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School
| | - Jing Chen
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School; The Manton Center for Orphan Disease Research, Boston Children's Hospital, Harvard Medical School;
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Functional non-coding polymorphism in an EPHA2 promoter PAX2 binding site modifies expression and alters the MAPK and AKT pathways. Sci Rep 2017; 7:9992. [PMID: 28855599 PMCID: PMC5577203 DOI: 10.1038/s41598-017-10117-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Accepted: 08/04/2017] [Indexed: 01/11/2023] Open
Abstract
To identify possible genetic variants influencing expression of EPHA2 (Ephrin-receptor Type-A2), a tyrosine kinase receptor that has been shown to be important for lens development and to contribute to both congenital and age related cataract when mutated, the extended promoter region of EPHA2 was screened for variants. SNP rs6603883 lies in a PAX2 binding site in the EPHA2 promoter region. The C (minor) allele decreased EPHA2 transcriptional activity relative to the T allele by reducing the binding affinity of PAX2. Knockdown of PAX2 in human lens epithelial (HLE) cells decreased endogenous expression of EPHA2. Whole RNA sequencing showed that extracellular matrix (ECM), MAPK-AKT signaling pathways and cytoskeleton related genes were dysregulated in EPHA2 knockdown HLE cells. Taken together, these results indicate a functional non-coding SNP in EPHA2 promoter affects PAX2 binding and reduces EPHA2 expression. They further suggest that decreasing EPHA2 levels alters MAPK, AKT signaling pathways and ECM and cytoskeletal genes in lens cells that could contribute to cataract. These results demonstrate a direct role for PAX2 in EPHA2 expression and help delineate the role of EPHA2 in development and homeostasis required for lens transparency.
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HIF-1α SUMOylation affects the stability and transcriptional activity of HIF-1α in human lens epithelial cells. Graefes Arch Clin Exp Ophthalmol 2015; 253:1279-90. [PMID: 25877955 DOI: 10.1007/s00417-015-2999-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/02/2015] [Accepted: 03/25/2015] [Indexed: 01/11/2023] Open
Abstract
PURPOSE High blood glucose can induce oxidative damage and result in diabetic cataract. Oxidative stress induces various signal pathways including HIF-1α transcriptional signal to attenuate the damage of lenses. Whether HIF-1α SUMOylation can increase the activation of HIF-1α or if high glucose can affect the SUMOylation of HIF-1α in cultured human lens epithelial cells (HLECs) is still unknown, as well as the function of HIF-1α SUMOylation in oxidative damage induced by high glucose in HLECs. In the present study, we examined SUMO and SUMO E3 (Cbx4 and PIASy) expression induced by high glucose, and investigated SUMO or SUMO E3 overexpression that enhanced HIF-1α SUMOylation in HLECs. METHODS SRA01/04 cells, one kind of human lens epithelial cell line, were addressed in media with 5.5 mmol/l (normal control group), 25 mmol/l (high glucose1 group) and 50 mmol/l (high glucose2 group) final glucose respectively. Expression of SUMO1 ~ 4, Cbx4, PIASy, HIF-1α, GLUT1, and VEGFA were detected in the mRNA and protein levels by RT-PCR and Western blot analysis. Protein expression localization and co-localization were examined by immunofluorescence and co-immunofluorescence. The effects of SUMO overexpression, SUMO E3 overexpression, and Proteasome inhibitor MG132 respectively on the stability and transcriptional activity of HIF-1α were analyzed by immunoblot. RESULTS High glucose treatment induced SUMO1-4 expression and enhanced the expression of Cbx4 and PIASy. It also increased the expression of HIF-1α, GLUT1, and VEGFA. The co-localization of HIF-1α and SUMO was mainly in the nucleus induced by high glucose. Further studies showed that SUMO overexpression or SUMO E3 overexpression could enhance HIF-1α stability and transcriptional activity in HLECs. Proteasome inhibitor MG132 protected the stability and transcriptional activity of HIF-1α in the SRA01/04 cells. CONCLUSIONS HIF-1α SUMOylation affected the stability and transcriptional activity of HIF-1α in cultured human lens epithelial cells; SUMO overexpression or SUMO E3 overexpression enhanced the expression of HIF-1α, which is involved in inhibiting cell apoptosis and protecting lens opacification, and presumably plays a key role in protecting lenses from diabetic cataract.
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14
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Dorà NJ, Collinson JM, Hill RE, West JD. Hemizygous Le-Cre transgenic mice have severe eye abnormalities on some genetic backgrounds in the absence of LoxP sites. PLoS One 2014; 9:e109193. [PMID: 25272013 PMCID: PMC4182886 DOI: 10.1371/journal.pone.0109193] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2014] [Accepted: 08/29/2014] [Indexed: 11/18/2022] Open
Abstract
Eye phenotypes were investigated in Le-CreTg/−; Pax6fl/+ mice, which were expected to show tissue-specific reduction of Pax6 in surface ectoderm derivatives. To provide a better comparison with our previous studies of Pax6+/− eye phenotypes, hemizygous Le-CreTg/− and heterozygous Pax6fl/+mice were crossed onto the CBA/Ca genetic background. After the Le-Cre transgene had been backcrossed to CBA/Ca for seven generations, significant eye abnormalities occurred in some hemizygous Le-CreTg/−; Pax6+/+ controls (without a floxed Pax6fl allele) as well as experimental Le-CreTg/−; Pax6fl/+ mice. However, no abnormalities were seen in Le-Cre−/−; Pax6fl/+ or Le-Cre−/−; Pax6+/+ controls (without the Le-Cre transgene). The severity and frequency of the eye abnormalities in Le-CreTg/−; Pax6+/+ control mice diminished after backcrossing Le-CreTg/− mice to the original FVB/N strain for two generations, showing that the effect was reversible. This genetic background effect suggests that the eye abnormalities are a consequence of an interaction between the Le-Cre transgene and alleles of unknown modifier genes present in certain genetic backgrounds. The abnormalities were also ameliorated by introducing additional Pax6 gene copies on a CBA/Ca background, suggesting involvement of Pax6 depletion in Le-CreTg/−; Pax6+/+ mice rather than direct action of Cre recombinase on cryptic pseudo-loxP sites. One possibility is that expression of Cre recombinase from the Pax6-Le regulatory sequences in the Le-Cre transgene depletes cofactors required for endogenous Pax6 gene expression. Our observation that eye abnormalities can occur in hemizygous Le-CreTg/−; Pax6+/+ mice, in the absence of a floxed allele, demonstrates the importance of including all the relevant genetic controls in Cre-loxP experiments.
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Affiliation(s)
- Natalie J. Dorà
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
| | - J. Martin Collinson
- Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Robert E. Hill
- Medical Research Council Human Genetics Unit, Medical Research Council Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - John D. West
- Centre for Integrative Physiology, University of Edinburgh, Edinburgh, United Kingdom
- * E-mail:
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15
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Hartsock A, Lee C, Arnold V, Gross JM. In vivo analysis of hyaloid vasculature morphogenesis in zebrafish: A role for the lens in maturation and maintenance of the hyaloid. Dev Biol 2014; 394:327-39. [PMID: 25127995 DOI: 10.1016/j.ydbio.2014.07.024] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/28/2014] [Accepted: 07/30/2014] [Indexed: 01/11/2023]
Abstract
Two vascular networks nourish the embryonic eye as it develops - the hyaloid vasculature, located at the anterior of the eye between the retina and lens, and the choroidal vasculature, located at the posterior of the eye, surrounding the optic cup. Little is known about hyaloid development and morphogenesis, however. To begin to identify the morphogenetic underpinnings of hyaloid formation, we utilized in vivo time-lapse confocal imaging to characterize morphogenesis of the zebrafish hyaloid through 5 days post fertilization (dpf). Our data segregate hyaloid formation into three distinct morphogenetic stages: Stage I: arrival of hyaloid cells at the lens and formation of the hyaloid loop; Stage II: formation of a branched hyaloid network; Stage III: refinement of the hyaloid network. Utilizing fixed and dissected tissues, distinct Stage II and Stage III aspects of hyaloid formation were quantified over time. Combining in vivo imaging with microangiography, we demonstrate that the hyaloid system becomes fully enclosed by 5dpf. To begin to identify the molecular and cellular mechanisms underlying hyaloid morphogenesis, we identified a recessive mutation in the mab21l2 gene, and in a subset of mab21l2 mutants the lens does not form. Utilizing these "lens-less" mutants, we determined whether the lens was required for hyaloid morphogenesis. Our data demonstrate that the lens is not required for Stage I of hyaloid formation; however, Stages II and III of hyaloid formation are disrupted in the absence of a lens, supporting a role for the lens in hyaloid maturation and maintenance. Taken together, this study provides a foundation on which the cellular, molecular and embryologic mechanisms underlying hyaloid morphogenesis can be elucidated.
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Affiliation(s)
- Andrea Hartsock
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, United States
| | - Chanjae Lee
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, United States
| | - Victoria Arnold
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, United States
| | - Jeffrey M Gross
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, TX 78712, United States.
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16
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Chen Y, Wu Q, Miao A, Jiang Y, Wu X, Wang Z, Wu F, Lu Y. Effect of HSF4b on age related cataract may through its novel downstream target Hif1α. Biochem Biophys Res Commun 2014; 453:674-8. [PMID: 25088997 DOI: 10.1016/j.bbrc.2014.07.118] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 07/24/2014] [Indexed: 01/15/2023]
Abstract
Our previous study identified five new heat shock factor 4 (HSF4) mutations in 150 age-related cataract (ARC) patients which indicated that HSF4 mutations may be associated with this disease. Hypoxia-inducible factor (Hif1α) is an important downstream target of HSF4b. It has been found that Hif1α play also important roles in cataract development. To identify if HSF4b play it role in cataract development through HIF1α, we transfected SRA01/04 lens epithelial cells with small hairpin RNA of HSF4b and measured expressions Hif1α after transfection. Then, we perform chromatin immunoprecipitation quantitative PCR to see the relationship between HSF4b and HIF1α. We found that HSF4 downregulation led to decrease of HIF1α mRNA expression. Furthermore, we demonstrated by ChIP followed by quantitative PCR (ChIP-qPCR) that these HIF-1α is bound by HSF4b near promoters, not gene bodies.
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Affiliation(s)
- Yan Chen
- Department of Ophthalmology, Sixth People's Hospital Affiliated of Shanghai Jiaotong University, China; Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China
| | - Qiang Wu
- Department of Ophthalmology, Sixth People's Hospital Affiliated of Shanghai Jiaotong University, China
| | - Aizhu Miao
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China
| | - Yongxiang Jiang
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China
| | - XinHua Wu
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China
| | - Zhentian Wang
- State Key Lab of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Feizhen Wu
- State Key Lab of Genetic Engineering, Institute of Genetics, School of Life Science, Fudan University, Shanghai, China
| | - Yi Lu
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, China.
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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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Son AI, Sheleg M, Cooper MA, Sun Y, Kleiman NJ, Zhou R. Formation of persistent hyperplastic primary vitreous in ephrin-A5-/- mice. Invest Ophthalmol Vis Sci 2014; 55:1594-606. [PMID: 24550361 DOI: 10.1167/iovs.13-12706] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE Primary vitreous regression is a critical event in mammalian eye development required for proper ocular maturity and unhindered vision. Failure of this event results in the eye disease persistent hyperplastic primary vitreous (PHPV), also identified as persistent fetal vasculature (PFV), a condition characterized by the presence of a fibrovascular mass adjacent to the lens and retina, and associated with visual disability and blindness. Here, we identify ephrin-A5 to be a critical regulator for primary vitreous regression. METHODS Wild-type and ephrin-A5(-/-) eyes were examined at various developmental stages to determine the progression of PHPV. Eye tissue was sectioned and examined by H&E staining. Protein expression and localization was determined through immunohistochemistry. Relative levels of Eph receptors were determined by RT-PCR. RESULTS Ephrin-A5(-/-) animals develop ocular phenotypes representative of PHPV, most notably the presence of a large hyperplastic mass posterior to the lens that remains throughout the lifetime of the animal. The aberrant tissue in these mutant mice consists of residual hyaloid vessels surrounded by pigmented cells of neural crest origin. Labeling with bromodeoxyuridine (BrdU) and detection of proliferating cell nuclear antigen (PCNA) expression shows that the mass in ephrin-A5(-/-) animals is mitotically active in embryonic and postnatal stages. CONCLUSIONS Ephrin-A5 is a critical factor that regulates primary vitreous regression.
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Affiliation(s)
- Alexander I Son
- Department of Chemical Biology, Susan Lehman-Cullman Laboratory for Cancer Research, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, New Jersey
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19
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Neelam S, Brooks MM, Cammarata PR. Lenticular cytoprotection. Part 1: the role of hypoxia inducible factors-1α and -2α and vascular endothelial growth factor in lens epithelial cell survival in hypoxia. Mol Vis 2013; 19:1-15. [PMID: 23335846 PMCID: PMC3541047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Accepted: 12/14/2012] [Indexed: 11/20/2022] Open
Abstract
PURPOSE The prosurvival signaling cascades that mediate the unique ability of human lens epithelial cells to survive in their naturally hypoxic environment are not well defined. Hypoxia induces the synthesis of the hypoxia inducible factor HIF-1α that in turn, plays a crucial role in modulating a downstream survival scheme, where vascular endothelial growth factor (VEGF) also plays a major role. To date, no published reports in the lens literature attest to the expression and functionality of HIF-2α and the role it might play in regulating VEGF expression. The aim of this study was to identify the functional expression of the hypoxia inducible factors HIF-1α and HIF-2α and establish their role in regulating VEGF expression. Furthermore, we demonstrate a link between sustained VEGF expression and the ability of the hypoxic human lens epithelial cell to thrive in low oxygen conditions and resist mitochondrial membrane permeability transition (also referred to as lenticular cytoprotection). METHODS Hypoxia inducible factor translation inhibitors were used to demonstrate the role of HIF-1α and HIF-2α and the simultaneous expression of both hypoxic inducible factors to determine their role in regulating VEGF expression. Axitinib, which inhibits lenticular cell autophosphorylation of its VEGF receptor, was employed to demonstrate a role for the VEGF-VEGFR2 receptor complex in regulating Bcl-2 expression. Specific antisera and western blot analysis were used to detect the protein levels of HIF-1α and HIF-2α, as well as the proapoptotic protein, BAX and the prosurvival protein, Bcl-2. VEGF levels were analyzed with enzyme-linked immunosorbent assay (ELISA). The potentiometric dye, 5,5',6,6'-tetrachloro1,1',3,3'-tetraethyl-benzimidazolylcarbocyanine iodide, was used to determine the effect of the inhibitors on mitochondrial membrane permeability transition. RESULTS Cultured human lens epithelial cells (HLE-B3) maintained under hypoxic condition (1% oxygen) displayed consistent accumulation of VEGF throughout the 72 h incubation period. Using hypoxia inducible factor translation inhibitors targeting HIF-1α or HIF-2α, the specific inhibition of each protein did not diminish VEGF synthesis. The combined inhibition of HIF-1α and HIF-2α expression, using a double hypoxia inducible factor translation inhibitor, markedly decreased the level of VEGF. The inhibition of VEGF synthesis was associated with a profound deficiency in the level of the prosurvival protein, Bcl-2. Axitinib also prevented the VEGF-mediated expression of Bcl-2. The loss of VEGF coupled with the decrease in intracellular Bcl-2 correlated with marked mitochondrial depolarization, an early predictor of cellular apoptosis. CONCLUSIONS Our data support a model in which the sustained synthesis of VEGF in human lens epithelial cells, maintained under hypoxic condition, is regulated by a compensatory inter-relationship between HIF-1α and HIF-2α. VEGF acts as a prosurvival factor in hypoxic lens epithelial cells by maintaining consistent expression of the prosurvival protein Bcl-2, which likely prevents the translocation of cytosolic BAX to the outer mitochondrial membrane, thus preventing the initiation of mitochondrial depolarization.
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Ford KM, Saint-Geniez M, Walshe TE, D'Amore PA. Expression and role of VEGF--a in the ciliary body. Invest Ophthalmol Vis Sci 2012; 53:7520-7. [PMID: 23081980 DOI: 10.1167/iovs.12-10098] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
PURPOSE The role of VEGF-A in the normal ciliary body is largely unexplored. The ciliary body is similar in many respects to the choroid plexus of the brain, and we demonstrated previously the importance of VEGF-A in maintenance of choroid plexus vasculature and ependymal cells. Therefore, the role of VEGF-A in ciliary body homeostasis was explored. METHODS Swiss-Webster mice (VEGF-LacZ) were used to determine VEGF-A expression during ciliary body development and in the adult. VEGFR2 expression was determined in adult wild type C56BL/6J mice. Systemic VEGF-A neutralization in vivo was achieved with adenovirus-mediated overexpression of soluble VEGFR1 (sFlt1). Following VEGF-A neutralization, the ciliary epithelium was analyzed by light microscopy and transmission electron microscopy (TEM). The effect of VEGF-A blockade on ciliary body function also was assessed by measuring intraocular pressure. RESULTS VEGF-A expression was detected at embryonic day 18.5 (E18.5), the onset of ciliary process formation. In the adult ciliary body, VEGF-A was expressed by the pigmented epithelium, whereas VEGFR2 was localized primarily to the capillary endothelium and nonpigmented epithelium. Systemic VEGF-A neutralization led to a thinning of the nonpigmented epithelium, vacuolization of the pigmented epithelium, loss of capillary fenestrations, and thrombosis. These changes were associated with impaired ciliary body function, as evidenced by decreased intraocular pressure in sFlt1-overexpressing animals (15.31 ± 2.06 mm Hg) relative to controls (18.69 ± 1.49 mm Hg). CONCLUSIONS VEGF-A has an important role in ciliary body homeostasis. Potential for undesired off-target effects should be considered with the chronic use of anti-VEGF-A therapies.
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Affiliation(s)
- Knatokie M Ford
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, Massachusetts 02114, USA
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Huang TQ, Wang Y, Ebrahem Q, Chen Y, Cheng C, Doughman YQ, Watanabe M, Dunwoodie SL, Yang YC. Deletion of HIF-1α partially rescues the abnormal hyaloid vascular system in Cited2 conditional knockout mouse eyes. Mol Vis 2012; 18:1260-70. [PMID: 22665973 PMCID: PMC3365139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Accepted: 05/09/2012] [Indexed: 12/04/2022] Open
Abstract
PURPOSE Cited2 (CBP/p300-interacting transactivators with glutamic acid (E) and aspartic acid (D)-rich tail 2) is a member of a new family of transcriptional modulators. Cited2 null embryos exhibit hyaloid hypercellularity consisting of aberrant vasculature in the eye. The purpose of the study is to address whether abnormal lenticular development is a primary defect of Cited2 deletion and whether deletion of hypoxia inducible factor (HIF)-1α or an HIF-1α target gene, vascular endothelial growth factor (VEGF), could rescue abnormal hyaloid vascular system (HVS) in Cited2 deficient adult eyes. METHODS Le-Cre specific Cited2 knockout (Cited2(CKO)) mice with or without deletion of HIF-1α or VEGF were generated by standard Cre-Lox methods. Eyes collected from six-eight weeks old mice were characterized by Real Time PCR and immunohistological staining. RESULTS Cited2(CKO) mice had smaller lenses, abnormal lens stalk formation, and failed regression of the HVS in the adult eye. The eye phenotype had features similar to persistent hyperplastic primary vitreous (PHPV), a human congenital eye disorder leading to abnormal lenticular development. Deletion of HIF-1α or VEGF in Cited2 knockout eyes partially rescued the abnormal HVS but had no effect on the smaller lens and abnormal lens stalk differentiation. Intravitreal injection of Topotecan (TPT), a compound that inhibits HIF-1α expression, partially eliminated HVS defects in Cited2(CKO) lenses. CONCLUSIONS Abnormal HVS is a primary defect in Cited2 knockout mice, resulting in part from dysregulated functions of HIF-1 and VEGF. The Cited2(CKO) mouse line could be used as a novel disease model for PHPV and as an in vivo model for testing potential HIF-1 inhibitors.
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Affiliation(s)
- Tai-Qin Huang
- Department of Biochemistry and Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Yiwei Wang
- Department of Biochemistry and Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Quteba Ebrahem
- Department of Ophthalmology, Cole Eye Institute, Cleveland Clinic Lerner College of Medicine, Cleveland, OH
| | - Yu Chen
- Department of Pharmacology, Rainbow Babies' and Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Cindy Cheng
- Department of Biochemistry and Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Yong Qiu Doughman
- Department of Pediatrics, Rainbow Babies' and Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Michiko Watanabe
- Department of Pediatrics, Rainbow Babies' and Children's Hospital, Case Western Reserve University School of Medicine, Cleveland, OH
| | - Sally L. Dunwoodie
- Developmental and Stem Cell Biology Division, The Victor Chang Cardiac Research Institute, Darlinghurst, NSW. St Vincent’s Clinical School University of New South Wales, Kensington, NSW, Australia
| | - Yu-Chung Yang
- Department of Biochemistry and Cancer Center, Case Western Reserve University School of Medicine, Cleveland, OH
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