1
|
Gędaj A, Gregorczyk P, Żukowska D, Chorążewska A, Ciura K, Kalka M, Porębska N, Opaliński Ł. Glycosylation of FGF/FGFR: An underrated sweet code regulating cellular signaling programs. Cytokine Growth Factor Rev 2024; 77:39-55. [PMID: 38719671 DOI: 10.1016/j.cytogfr.2024.04.001] [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: 03/21/2024] [Revised: 04/23/2024] [Accepted: 04/23/2024] [Indexed: 06/22/2024]
Abstract
Fibroblast growth factors (FGFs) and their receptors (FGFRs) constitute plasma-membrane localized signaling hubs that transmit signals from the extracellular environment to the cell interior, governing pivotal cellular processes like motility, metabolism, differentiation, division and death. FGF/FGFR signaling is critical for human body development and homeostasis; dysregulation of FGF/FGFR units is observed in numerous developmental diseases and in about 10% of human cancers. Glycosylation is a highly abundant posttranslational modification that is critical for physiological and pathological functions of the cell. Glycosylation is also very common within FGF/FGFR signaling hubs. Vast majority of FGFs (15 out of 22 members) are N-glycosylated and few FGFs are O-glycosylated. Glycosylation is even more abundant within FGFRs; all FGFRs are heavily N-glycosylated in numerous positions within their extracellular domains. A growing number of studies points on the multiple roles of glycosylation in fine-tuning FGF/FGFR signaling. Glycosylation modifies secretion of FGFs, determines their stability and affects interaction with FGFRs and co-receptors. Glycosylation of FGFRs determines their intracellular sorting, constitutes autoinhibitory mechanism within FGFRs and adjusts FGF and co-receptor recognition. Sugar chains attached to FGFs and FGFRs constitute also a form of code that is differentially decrypted by extracellular lectins, galectins, which transform FGF/FGFR signaling at multiple levels. This review focuses on the identified functions of glycosylation within FGFs and FGFRs and discusses their relevance for the cell physiology in health and disease.
Collapse
Affiliation(s)
- Aleksandra Gędaj
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Paulina Gregorczyk
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Dominika Żukowska
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Aleksandra Chorążewska
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Krzysztof Ciura
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Marta Kalka
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Natalia Porębska
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland
| | - Łukasz Opaliński
- Department of Protein Engineering, Faculty of Biotechnology, University of Wroclaw, Joliot-Curie 14a, Wroclaw 50-383, Poland.
| |
Collapse
|
2
|
Wang Z, Gletten RB, Schey KL. Spatially Resolved Proteomics Reveals Lens Suture-Related Cell-Cell Junctional Protein Distributions. Invest Ophthalmol Vis Sci 2023; 64:28. [PMID: 37603353 PMCID: PMC10445239 DOI: 10.1167/iovs.64.11.28] [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: 05/17/2023] [Accepted: 07/31/2023] [Indexed: 08/22/2023] Open
Abstract
Purpose Lens transparency relies on the precise organization of lens fiber cells. The formation of the highly ordered lens architecture results from not only cell-cell adhesion along the lateral interfaces, but also from proper organization of fiber cells tips at lens sutures. Little is known about the cell adhesion between fiber tips at the sutures. The purpose of this study is to map suture-specific protein distributions. Methods Tissue sections were obtained from fresh frozen bovine lenses and washes were performed to remove soluble proteins and to retain membrane and membrane associated proteins. Imaging mass spectrometry (IMS) combined with on-tissue trypsin digestion was used to visualize protein spatial distributions. Sutures and adjacent regions were captured by laser capture microdissection and samples were digested by trypsin. Proteins were analyzed by liquid chromatography tandem MS and quantified by label-free quantification. Protein spatial distributions were confirmed by immunofluorescence. Results IMS results showed enrichment of adherens junction proteins cadherin-2 and armadillo repeat gene deleted in velo-cardio-facial syndrome (ARVCF) in both anterior and posterior sutures of bovine lenses. Liquid chromatography tandem MS confirmed higher expression of cadherin-2 and ARVCF and other adherens junction proteins including catenin α2 (CTNNA2) and catenin β1 (CTNNB1) in sutures. In contrast, IMS indicated low expression of gap junction protein connexin 50 and connexin 46 in the suture regions. The localization of cadherin-2 and connexin 50 was confirmed by immunofluorescence. Conclusions The complementary expression of adherens junction proteins and gap junction proteins in lens suture regions implicates adherens junctions in fiber cell tip adhesion and in maintaining the integrity of the lens.
Collapse
Affiliation(s)
- Zhen Wang
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Romell B. Gletten
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| | - Kevin L. Schey
- Department of Biochemistry and Mass Spectrometry Research Center, Vanderbilt University School of Medicine, Nashville, Tennessee, United States
| |
Collapse
|
3
|
Rodríguez-Solana P, Arruti N, Nieves-Moreno M, Mena R, Rodríguez-Jiménez C, Guerrero-Carretero M, Acal JC, Blasco J, Peralta JM, Del Pozo Á, Montaño VEF, Dios-Blázquez LD, Fernández-Alcalde C, González-Atienza C, Sánchez-Cazorla E, Gómez-Cano MDLÁ, Delgado-Mora L, Noval S, Vallespín E. Whole Exome Sequencing of 20 Spanish Families: Candidate Genes for Non-Syndromic Pediatric Cataracts. Int J Mol Sci 2023; 24:11429. [PMID: 37511188 PMCID: PMC10380485 DOI: 10.3390/ijms241411429] [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: 05/25/2023] [Revised: 06/23/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Non-syndromic pediatric cataracts are defined as opacification of the crystalline lens that occurs during the first years of life without affecting other organs. Given that this disease is one of the most frequent causes of reversible blindness in childhood, the main objective of this study was to propose new responsible gene candidates that would allow a more targeted genetic approach and expand our genetic knowledge about the disease. We present a whole exome sequencing (WES) study of 20 Spanish families with non-syndromic pediatric cataracts and a previous negative result on an ophthalmology next-generation sequencing panel. After ophthalmological evaluation and collection of peripheral blood samples from these families, WES was performed. We were able to reach a genetic diagnosis in 10% of the families analyzed and found genes that could cause pediatric cataracts in 35% of the cohort. Of the variants found, 18.2% were classified as pathogenic, 9% as likely pathogenic, and 72.8% as variants of uncertain significance. However, we did not find conclusive results in 55% of the families studied, which suggests further studies are needed. The results of this WES study allow us to propose LONP1, ACACA, TRPM1, CLIC5, HSPE1, ODF1, PIKFYVE, and CHMP4A as potential candidates to further investigate for their role in pediatric cataracts, and AQP5 and locus 2q37 as causal genes.
Collapse
Affiliation(s)
- Patricia Rodríguez-Solana
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - Natalia Arruti
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
| | - María Nieves-Moreno
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
| | - Rocío Mena
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
| | - Carmen Rodríguez-Jiménez
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - Marta Guerrero-Carretero
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Juan Carlos Acal
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Joana Blasco
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Jesús M. Peralta
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Ángela Del Pozo
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
- Clinical Bioinformatics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain;
| | - Victoria E. F. Montaño
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
| | - Lucía De Dios-Blázquez
- Clinical Bioinformatics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain;
| | - Celia Fernández-Alcalde
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
| | - Carmen González-Atienza
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - Eloísa Sánchez-Cazorla
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
| | - María de Los Ángeles Gómez-Cano
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
- Clinical Genetics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain
| | - Luna Delgado-Mora
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
- Clinical Genetics Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, CIBERER, La Paz University Hospital, 28046 Madrid, Spain
| | - Susana Noval
- Department of Pediatric Ophthalmology, IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (N.A.); (M.N.-M.); (M.G.-C.); (J.C.A.); (J.B.); (J.M.P.); (C.F.-A.); (S.N.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
| | - Elena Vallespín
- Molecular Ophthalmology Section, Institute of Medical and Molecular Genetics (INGEMM), IdiPaz, La Paz University Hospital, 28046 Madrid, Spain; (P.R.-S.); (R.M.); (C.R.-J.); (V.E.F.M.); (C.G.-A.); (E.S.-C.)
- European Reference Network on Eye Diseases (ERN-EYE), La Paz University Hospital, 28046 Madrid, Spain
- Biomedical Research Center in the Rare Diseases Network (CIBERER), Carlos II Health Institute (ISCIII), 28029 Madrid, Spain; (Á.D.P.); (M.d.L.Á.G.-C.); (L.D.-M.)
| |
Collapse
|
4
|
Disatham J, Brennan L, Cvekl A, Kantorow M. Multiomics Analysis Reveals Novel Genetic Determinants for Lens Differentiation, Structure, and Transparency. Biomolecules 2023; 13:693. [PMID: 37189439 PMCID: PMC10136076 DOI: 10.3390/biom13040693] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 04/13/2023] [Accepted: 04/16/2023] [Indexed: 05/17/2023] Open
Abstract
Recent advances in next-generation sequencing and data analysis have provided new gateways for identification of novel genome-wide genetic determinants governing tissue development and disease. These advances have revolutionized our understanding of cellular differentiation, homeostasis, and specialized function in multiple tissues. Bioinformatic and functional analysis of these genetic determinants and the pathways they regulate have provided a novel basis for the design of functional experiments to answer a wide range of long-sought biological questions. A well-characterized model for the application of these emerging technologies is the development and differentiation of the ocular lens and how individual pathways regulate lens morphogenesis, gene expression, transparency, and refraction. Recent applications of next-generation sequencing analysis on well-characterized chicken and mouse lens differentiation models using a variety of omics techniques including RNA-seq, ATAC-seq, whole-genome bisulfite sequencing (WGBS), chip-seq, and CUT&RUN have revealed a wide range of essential biological pathways and chromatin features governing lens structure and function. Multiomics integration of these data has established new gene functions and cellular processes essential for lens formation, homeostasis, and transparency including the identification of novel transcription control pathways, autophagy remodeling pathways, and signal transduction pathways, among others. This review summarizes recent omics technologies applied to the lens, methods for integrating multiomics data, and how these recent technologies have advanced our understanding ocular biology and function. The approach and analysis are relevant to identifying the features and functional requirements of more complex tissues and disease states.
Collapse
Affiliation(s)
- Joshua Disatham
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA; (J.D.); (L.B.)
| | - Lisa Brennan
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA; (J.D.); (L.B.)
| | - Ales Cvekl
- Departments of Ophthalmology and Visual Sciences and Genetics, Albert Einstein College of Medicine, Bronx, NY 10461, USA;
| | - Marc Kantorow
- Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL 33431, USA; (J.D.); (L.B.)
| |
Collapse
|
5
|
Paidi SK, Zhang Q, Yang Y, Xia CH, Ji N, Gong X. Adaptive optical two-photon fluorescence microscopy probes cellular organization of ocular lenses in vivo. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.01.17.524320. [PMID: 36711806 PMCID: PMC9882239 DOI: 10.1101/2023.01.17.524320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The mammalian ocular lens is an avascular multicellular organ that grows continuously throughout life. Traditionally, its cellular organization is investigated using dissected lenses, which eliminates in vivo environmental and structural support. Here, we demonstrated that two-photon fluorescence microscopy (2PFM) can visualize lens cells in vivo. To maintain subcellular resolution at depth, we employed adaptive optics (AO) to correct aberrations due to ocular and lens tissues, which led to substantial signal and resolution improvements. Imaging lens cells up to 980 μm deep, we observed novel cellular organizations including suture-associated voids, enlarged vacuoles, and large cavities, contrary to the conventional view of a highly ordered organization. We tracked these features longitudinally over weeks and observed the incorporation of new cells during growth. Taken together, non-invasive longitudinal in vivo imaging of lens morphology using AO 2PFM will allow us to directly observe the development or alterations of lens cellular organization in living animals.
Collapse
Affiliation(s)
- Santosh Kumar Paidi
- School of Optometry, University of California, Berkeley, California 94720, USA
| | - Qinrong Zhang
- Department of Physics, University of California, Berkeley, California 94720, USA,Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
| | - Yuhan Yang
- Department of Physics, University of California, Berkeley, California 94720, USA
| | - Chun-Hong Xia
- School of Optometry, University of California, Berkeley, California 94720, USA,Vision Science Program, University of California, Berkeley, California 94720, USA
| | - Na Ji
- Department of Physics, University of California, Berkeley, California 94720, USA,Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA,Helen Wills Neuroscience Institute, University of California, Berkeley, CA 94720, USA,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA,Corresponding authors: Xiaohua Gong () and Na Ji ()
| | - Xiaohua Gong
- School of Optometry, University of California, Berkeley, California 94720, USA,Vision Science Program, University of California, Berkeley, California 94720, USA,Corresponding authors: Xiaohua Gong () and Na Ji ()
| |
Collapse
|
6
|
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.
Collapse
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.
| |
Collapse
|
7
|
Mutation of the EPHA2 Tyrosine-Kinase Domain Dysregulates Cell Pattern Formation and Cytoskeletal Gene Expression in the Lens. Cells 2021; 10:cells10102606. [PMID: 34685586 PMCID: PMC8534143 DOI: 10.3390/cells10102606] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 12/13/2022] Open
Abstract
Genetic variations in ephrin type-A receptor 2 (EPHA2) have been associated with inherited and age-related forms of cataract in humans. Here, we have characterized the eye lens phenotype and transcript profile of germline Epha2 knock-in mutant mice homozygous for either a missense variant associated with age-related cataract in humans (Epha2-Q722) or a novel insertion-deletion mutation (Epha2-indel722) that were both located within the tyrosine-kinase domain of EPHA2. Confocal imaging of ex vivo lenses from Epha2-indel722 mice on a fluorescent reporter background revealed misalignment of epithelial-to-fiber cell meridional-rows at the lens equator and severe disturbance of Y-suture formation at the lens poles, whereas Epha2-Q722 lenses displayed mild disturbance of posterior sutures. Immunofluorescent labeling showed that EPHA2 was localized to radial columns of hexagonal fiber cell membranes in Epha2-Q722 lenses, whereas Epha2-indel722 lenses displayed disorganized radial cell columns and cytoplasmic retention of EPHA2. Immunoprecipitation/blotting studies indicated that EPHA2 formed strong complexes with Src kinase and was mostly serine phosphorylated in the lens. RNA sequencing analysis revealed differential expression of several cytoskeleton-associated genes in Epha2-mutant and Epha2-null lenses including shared downregulation of Lgsn and Clic5. Collectively, our data suggest that mutations within the tyrosine-kinase domain of EPHA2 result in lens cell patterning defects and dysregulated expression of several cytoskeleton-associated proteins.
Collapse
|
8
|
Wang Z, Cantrell LS, Schey KL. Spatially Resolved Proteomic Analysis of the Lens Extracellular Diffusion Barrier. Invest Ophthalmol Vis Sci 2021; 62:25. [PMID: 34554179 PMCID: PMC8475287 DOI: 10.1167/iovs.62.12.25] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/05/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose The presence of a physical barrier to molecular diffusion through lenticular extracellular space has been repeatedly detected. This extracellular diffusion barrier has been proposed to restrict the movement of solutes into the lens and to direct nutrients into the lens core via the sutures at both poles. The purpose of this study is to characterize the molecular components that could contribute to the formation of this barrier. Methods Three distinct regions in the bovine lens cortex were captured by laser capture microdissection guided by dye penetration. Proteins were digested by Lys C and trypsin. Mass spectrometry-based proteomic analysis followed by gene ontology and protein interaction network analysis was performed. Results Dye penetration showed that fiber cells first shrink the extracellular spaces of the broad sides followed by closure of the extracellular space between narrow sides at a normalized lens distance (r/a) of 0.9. Accompanying the closure of extracellular space of the broad sides, dramatic proteomic changes were detected, including upregulation of several cell junctional proteins. AQP0 and its interacting partners, Ezrin and Radixin, were among a few proteins that were upregulated, accompanying the closure of extracellular space of the narrow sides, suggesting a particularly important role for AQP0 in controlling the narrowing of the extracellular spaces between fiber cells. The results also provided important information related to biological processes that occur during fiber cell differentiation such as organelle degradation, cytoskeletal remodeling, and glutathione synthesis. Conclusions The formation of a lens extracellular diffusion barrier is accompanied by significant membrane and cytoskeletal protein remodeling.
Collapse
Affiliation(s)
- Zhen Wang
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Lee S. Cantrell
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States
| | - Kevin L. Schey
- Department of Biochemistry, Vanderbilt University, Nashville, Tennessee, United States
| |
Collapse
|
9
|
Faranda AP, Shihan MH, Wang Y, Duncan MK. The aging mouse lens transcriptome. Exp Eye Res 2021; 209:108663. [PMID: 34119483 DOI: 10.1016/j.exer.2021.108663] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 05/04/2021] [Accepted: 06/01/2021] [Indexed: 02/06/2023]
Abstract
Age is a major risk factor for cataract (ARC). However, the influence of aging on the lens transcriptome is under studied. Lens epithelial (LEC) and fiber cells (LFC) were isolated from young (3 month old) and aged (24 month old) C57BL/6J mice, and the transcriptome elucidated via RNAseq. EdgeR estimated differential gene expression in pairwise contrasts, and Advaita's Ipathway guide and custom R scripts were used to evaluate the potential biological significance of differentially expressed genes (DEGs). This analysis revealed age-dependent decreases in lens differentiation marker expression in both LECs and LFCs, with gamma crystallin transcripts downregulating nearly 50 fold in aged LFCs. The expression of the transcription factors Hsf4 and Maf, which are known to activate lens fiber cell preferred genes, are downregulated, while FoxE3, which represses gamma crystallin expression, is upregulated in aged fibers. Aged LECs upregulate genes controlling the immune response, complement pathways, and cellular stress responses, including glutathione peroxidase 3 (Gpx3). Aged LFCs exhibit broad changes in the expression of genes regulating cell communication, and upregulate genes involved in antigen processing/presentation and cholesterol metabolism, while changes in the expression of mitochondrial respiratory chain genes are consistent with mitochondrial stress, including upregulation of NDufa4l2, which encodes an alternate electron transport chain protein. However, age did not profoundly affect the response of LECs to injury as both young and aged LECs upregulate inflammatory gene signatures at 24 h post injury to similar extents. These RNAseq profiles provide a rich data set that can be mined to understand the genetic regulation of lens aging and how this impinges on the pathophysiology of age related cataract.
Collapse
Affiliation(s)
- Adam P Faranda
- Department of Biological Sciences University of Delaware Newark, DE, 19716, USA
| | - Mahbubul H Shihan
- Department of Biological Sciences University of Delaware Newark, DE, 19716, USA
| | - Yan Wang
- Department of Biological Sciences University of Delaware Newark, DE, 19716, USA
| | - Melinda K Duncan
- Department of Biological Sciences University of Delaware Newark, DE, 19716, USA.
| |
Collapse
|
10
|
Ruan X, Liu Z, Luo L, Liu Y. The Structure of the Lens and Its Associations with the Visual Quality. BMJ Open Ophthalmol 2020; 5:e000459. [PMID: 33024825 PMCID: PMC7511618 DOI: 10.1136/bmjophth-2020-000459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/30/2022] Open
Abstract
In humans, the lens is the organ with the ability to change morphology and refractive power, designated as accommodation, to focus light from various distances and obtain clear retinal image. The accommodative ability of the lens depends on its structure and biological parameters. The lens grows throughout the life, forming specific lens sutures and a unique gradient refractive index, and possesses regenerative ability under certain circumstances. Minimally invasive lens surgery that preserves endogenous lens epithelial stem/progenitor cells (LECs) can achieve functional lens regeneration in humans. The lens is the main source of intraocular aberration, especially intraocular higher-order aberrations (IHOAs) which is found to be binocularly symmetrical in phakic eyes. There is a compensation mechanism between corneal aberrations and lens aberrations. Therefore, the structure and the biological parameters of the lens, the binocular relationship of the lens and the correlation between the lens and cornea affect visual quality. This paper summarises the above findings and their current and potential applications in refractive surgeries, providing a comprehensive understanding of the lens as a strong determinant of visual quality in the optical system.
Collapse
Affiliation(s)
- Xiaoting Ruan
- State Key Laboratory of Ophthalmology, Sun Yat-Sen University Zhongshan Ophthalmic Center, Guangzhou, China
| | - Zhenzhen Liu
- State Key Laboratory of Ophthalmology, Sun Yat-Sen University Zhongshan Ophthalmic Center, Guangzhou, China
| | - Lixia Luo
- State Key Laboratory of Ophthalmology, Sun Yat-Sen University Zhongshan Ophthalmic Center, Guangzhou, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Sun Yat-Sen University Zhongshan Ophthalmic Center, Guangzhou, China
| |
Collapse
|
11
|
Ma Z, Li J, Jiang H, Chu Y. Expression of α-Klotho Is Downregulated and Associated with Oxidative Stress in the Lens in Streptozotocin-induced Diabetic Rats. Curr Eye Res 2020; 46:482-489. [PMID: 32744464 DOI: 10.1080/02713683.2020.1805768] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Purpose: Oxidative stress, an imbalance between the production of reactive oxygen species and antioxidant defenses, plays an important role in the pathogenesis of diabetic cataract. The lens in diabetes mellitus (DM) has been shown to exhibit impaired antioxidant defenses, but the underlying mechanisms remain poorly understood. Accumulating evidence reveals that Klotho family genes can regulate antioxidant defenses and prevent oxidative stress in multiple tissues. Here, we examined whether DM alters Klotho expression in the lens and if so, whether altered Klotho expression is associated with oxidative stress in the lens in DM. Methods: Male Wistar rats were divided into DM and control groups. DM was induced by injection of streptozotocin (STZ, 60 mg/kg ip) and control rats were injected with vehicle. Twelve weeks after DM induction, levels of α-Klotho in plasma, expression of α- and γ-Klotho, and nuclear factor erythroid 2-related factor 2 (Nrf2), and levels of antioxidants superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione (GSH) and oxidative stress marker malondialdehyde (MDA) in the lens were measured. Results: Diabetic rats had markedly higher blood glucose concentrations and lower plasma α-Klotho levels than control rats. Both α- and γ-Klotho were expressed in the lens in diabetic and control rats. The expression of α-Klotho but not γ-Klotho in the lens was downregulated in diabetic rats, which was accompanied by reduced expression of nuclear Nrf2 and levels of all antioxidants and increased levels of MDA. Moreover, expression of α-Klotho in the lens was positively correlated with expression of nuclear Nrf2 and levels of all antioxidants, but negatively correlated with levels of MDA. Conclusions: These findings suggest that DM selectively reduces α-Klotho levels in the circulation and lens, which may attenuate transcriptional activity of Nrf2 and impair antioxidant defenses in response to oxidative insults, contributing to oxidative stress and cataract formation in DM.
Collapse
Affiliation(s)
- Zhongxu Ma
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Jing Li
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Hao Jiang
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yanhua Chu
- Tianjin Eye Hospital, Tianjin Key Laboratory of Ophthalmology and Vision Science, Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| |
Collapse
|
12
|
Moos WH, Faller DV, Glavas IP, Harpp DN, Kanara I, Mavrakis AN, Pernokas J, Pernokas M, Pinkert CA, Powers WR, Sampani K, Steliou K, Vavvas DG, Zamboni RJ, Kodukula K, Chen X. Klotho Pathways, Myelination Disorders, Neurodegenerative Diseases, and Epigenetic Drugs. Biores Open Access 2020; 9:94-105. [PMID: 32257625 PMCID: PMC7133426 DOI: 10.1089/biores.2020.0004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
In this review we outline a rationale for identifying neuroprotectants aimed at inducing endogenous Klotho activity and expression, which is epigenetic action, by definition. Such an approach should promote remyelination and/or stimulate myelin repair by acting on mitochondrial function, thereby heralding a life-saving path forward for patients suffering from neuroinflammatory diseases. Disorders of myelin in the nervous system damage the transmission of signals, resulting in loss of vision, motion, sensation, and other functions depending on the affected nerves, currently with no effective treatment. Klotho genes and their single-pass transmembrane Klotho proteins are powerful governors of the threads of life and death, true to the origin of their name, Fates, in Greek mythology. Among its many important functions, Klotho is an obligatory co-receptor that binds, activates, and/or potentiates critical fibroblast growth factor activity. Since the discovery of Klotho a little over two decades ago, it has become ever more apparent that when Klotho pathways go awry, oxidative stress and mitochondrial dysfunction take over, and age-related chronic disorders are likely to follow. The physiological consequences can be wide ranging, potentially wreaking havoc on the brain, eye, kidney, muscle, and more. Central nervous system disorders, neurodegenerative in nature, and especially those affecting the myelin sheath, represent worthy targets for advancing therapies that act upon Klotho pathways. Current drugs for these diseases, even therapeutics that are disease modifying rather than treating only the symptoms, leave much room for improvement. It is thus no wonder that this topic has caught the attention of biomedical researchers around the world.
Collapse
Affiliation(s)
- Walter H. Moos
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of California San Francisco, San Francisco, San Francisco, California
- ShangPharma Innovation, Inc., South San Francisco, California
| | - Douglas V. Faller
- Department of Medicine, Boston University School of Medicine, Boston, Massachusetts
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts
| | - Ioannis P. Glavas
- Department of Ophthalmology, New York University School of Medicine, New York, New York
| | - David N. Harpp
- Department of Chemistry, McGill University, Montreal, Canada
| | | | - Anastasios N. Mavrakis
- Department of Medicine, Tufts University School of Medicine, St. Elizabeth's Medical Center, Boston, Massachusetts
| | - Julie Pernokas
- Advanced Dental Associates of New England, Woburn, Massachusetts
| | - Mark Pernokas
- Advanced Dental Associates of New England, Woburn, Massachusetts
| | - Carl A. Pinkert
- Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, Alabama
| | - Whitney R. Powers
- Department of Health Sciences, Boston University, Boston, Massachusetts
- Department of Anatomy, Boston University School of Medicine, Boston, Massachusetts
| | - Konstantina Sampani
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Beetham Eye Institute, Joslin Diabetes Center, Boston, Massachusetts
| | - Kosta Steliou
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts
- PhenoMatriX, Inc., Natick, Massachusetts
| | - Demetrios G. Vavvas
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| | | | | | - Xiaohong Chen
- Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts
- Retina Service, Angiogenesis Laboratory, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts
| |
Collapse
|