1
|
Tangeman JA, Rebull SM, Grajales-Esquivel E, Weaver JM, Bendezu-Sayas S, Robinson ML, Lachke SA, Del Rio-Tsonis K. Integrated single-cell multiomics uncovers foundational regulatory mechanisms of lens development and pathology. Development 2024; 151:dev202249. [PMID: 38180241 PMCID: PMC10906490 DOI: 10.1242/dev.202249] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 11/28/2023] [Indexed: 01/06/2024]
Abstract
Ocular lens development entails epithelial to fiber cell differentiation, defects in which cause congenital cataracts. We report the first single-cell multiomic atlas of lens development, leveraging snRNA-seq, snATAC-seq and CUT&RUN-seq to discover previously unreported mechanisms of cell fate determination and cataract-linked regulatory networks. A comprehensive profile of cis- and trans-regulatory interactions, including for the cataract-linked transcription factor MAF, is established across a temporal trajectory of fiber cell differentiation. Furthermore, we identify an epigenetic paradigm of cellular differentiation, defined by progressive loss of the H3K27 methylation writer Polycomb repressive complex 2 (PRC2). PRC2 localizes to heterochromatin domains across master-regulator transcription factor gene bodies, suggesting it safeguards epithelial cell fate. Moreover, we demonstrate that FGF hyper-stimulation in vivo leads to MAF network activation and the emergence of novel lens cell states. Collectively, these data depict a comprehensive portrait of lens fiber cell differentiation, while defining regulatory effectors of cell identity and cataract formation.
Collapse
Affiliation(s)
- Jared A. Tangeman
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, USA
| | - Sofia M. Rebull
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Erika Grajales-Esquivel
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
| | - Jacob M. Weaver
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, USA
| | - Stacy Bendezu-Sayas
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, USA
| | - Michael L. Robinson
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, USA
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
- Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE 19713, USA
| | - Katia Del Rio-Tsonis
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056, USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056, USA
| |
Collapse
|
2
|
Tangeman JA, Rebull SM, Grajales-Esquivel E, Weaver JM, Bendezu-Sayas S, Robinson ML, Lachke SA, Rio-Tsonis KD. Integrated single-cell multiomics uncovers foundational regulatory mechanisms of lens development and pathology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.10.548451. [PMID: 37502967 PMCID: PMC10369908 DOI: 10.1101/2023.07.10.548451] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Ocular lens development entails epithelial to fiber cell differentiation, defects in which cause congenital cataract. We report the first single-cell multiomic atlas of lens development, leveraging snRNA-seq, snATAC-seq, and CUT&RUN-seq to discover novel mechanisms of cell fate determination and cataract-linked regulatory networks. A comprehensive profile of cis- and trans-regulatory interactions, including for the cataract-linked transcription factor MAF, is established across a temporal trajectory of fiber cell differentiation. Further, we divulge a conserved epigenetic paradigm of cellular differentiation, defined by progressive loss of H3K27 methylation writer Polycomb repressive complex 2 (PRC2). PRC2 localizes to heterochromatin domains across master-regulator transcription factor gene bodies, suggesting it safeguards epithelial cell fate. Moreover, we demonstrate that FGF hyper-stimulation in vivo leads to MAF network activation and the emergence of novel lens cell states. Collectively, these data depict a comprehensive portrait of lens fiber cell differentiation, while defining regulatory effectors of cell identity and cataract formation.
Collapse
Affiliation(s)
- Jared A Tangeman
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056 USA
| | - Sofia M Rebull
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
| | - Erika Grajales-Esquivel
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
| | - Jacob M Weaver
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056 USA
| | - Stacy Bendezu-Sayas
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056 USA
| | - Michael L Robinson
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056 USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
- Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE 19713 USA
| | - Katia Del Rio-Tsonis
- Department of Biology and Center for Visual Sciences, Miami University, Oxford, OH 45056 USA
- Cell, Molecular, and Structural Biology Program, Miami University, Oxford, OH 45056 USA
| |
Collapse
|
3
|
Koç Ş. A possible follow-up method for diabetic heart failure patients. Int J Clin Pract 2021; 75:e14794. [PMID: 34482595 DOI: 10.1111/ijcp.14794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2021] [Accepted: 09/02/2021] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION Plasma osmolarity is maintained through various mechanisms. The osmolarity of the aqueous humor around the crystalline lens is correlated with plasma osmolarity. A vacuole can be formed in the lens upon changes in osmolarity. The sodium-glucose cotransporter 2 inhibitors (SGLT2i) are new in the treatment of heart failure. They can cause osmotic diuresis but do not affect plasma osmolarity. OBJECTIVE It is unclear if the presence or absence of lens vacuole changes can monitor diabetic heart failure and SGLT2i treatment efficacy. METHODS Web of Science, PubMed and Scopus databases were searched for relevant articles about osmolarity, diabetes, transient receptor potential vanilloid channel, diabetic heart failure, lens vacuoles up to May 2021. MAIN MESSAGE The effect of SGLT2i on osmosis underlies its benefit to heart failure, but this in turn affects many other mechanisms. Failure to experience osmolarity changes will reduce the negative changes in terms of heart failure affected by osmolarity. A practical observable method is needed. CONCLUSIONS There is a possibility of using lens vacuoles in the follow-up of diabetic heart failure patients.
Collapse
Affiliation(s)
- Şahbender Koç
- University of Health Sciences, Keçiören Education and Training Hospital, Ankara, Turkey
| |
Collapse
|
4
|
Choquet H, Melles RB, Anand D, Yin J, Cuellar-Partida G, Wang W, Hoffmann TJ, Nair KS, Hysi PG, Lachke SA, Jorgenson E. A large multiethnic GWAS meta-analysis of cataract identifies new risk loci and sex-specific effects. Nat Commun 2021; 12:3595. [PMID: 34127677 PMCID: PMC8203611 DOI: 10.1038/s41467-021-23873-8] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 05/17/2021] [Indexed: 01/16/2023] Open
Abstract
Cataract is the leading cause of blindness among the elderly worldwide and cataract surgery is one of the most common operations performed in the United States. As the genetic etiology of cataract formation remains unclear, we conducted a multiethnic genome-wide association meta-analysis, combining results from the GERA and UK Biobank cohorts, and tested for replication in the 23andMe research cohort. We report 54 genome-wide significant loci, 37 of which were novel. Sex-stratified analyses identified CASP7 as an additional novel locus specific to women. We show that genes within or near 80% of the cataract-associated loci are significantly expressed and/or enriched-expressed in the mouse lens across various spatiotemporal stages as per iSyTE analysis. Furthermore, iSyTE shows 32 candidate genes in the associated loci have altered gene expression in 9 different gene perturbation mouse models of lens defects/cataract, suggesting their relevance to lens biology. Our work provides further insight into the complex genetic architecture of cataract susceptibility.
Collapse
Affiliation(s)
- Hélène Choquet
- Kaiser Permanente Northern California (KPNC), Division of Research, Oakland, CA, USA.
| | | | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Jie Yin
- Kaiser Permanente Northern California (KPNC), Division of Research, Oakland, CA, USA
| | | | | | | | - Thomas J Hoffmann
- Institute for Human Genetics, UCSF, San Francisco, CA, USA.,Department of Epidemiology and Biostatistics, UCSF, San Francisco, CA, USA
| | - K Saidas Nair
- Departments of Ophthalmology and Anatomy, School of Medicine, UCSF, San Francisco, CA, USA
| | - Pirro G Hysi
- King's College London, Section of Ophthalmology, School of Life Course Sciences, London, UK.,King's College London, Department of Twin Research and Genetic Epidemiology, London, UK.,University College London, Great Ormond Street Hospital Institute of Child Health, London, UK
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, USA.,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, USA
| | - Eric Jorgenson
- Kaiser Permanente Northern California (KPNC), Division of Research, Oakland, CA, USA
| |
Collapse
|
5
|
A transcriptomic analysis of diploid and triploid Atlantic salmon lenses with and without cataracts. Exp Eye Res 2020; 199:108150. [PMID: 32735797 DOI: 10.1016/j.exer.2020.108150] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 07/08/2020] [Accepted: 07/09/2020] [Indexed: 11/23/2022]
Abstract
To avoid negative environmental impacts of escapees and potential inter-breeding with wild populations, the Atlantic salmon farming industry has and continues to extensively test triploid fish that are sterile. However, they often show differences in performance, physiology, behavior and morphology compared to diploid fish, with increased prevalence of vertebral deformities and ocular cataracts as two of the most severe disorders. Here, we investigated the mechanisms behind the higher prevalence of cataracts in triploid salmon, by comparing the transcriptional patterns in lenses of diploid and triploid Atlantic salmon, with and without cataracts. We assembled and characterized the Atlantic salmon lens transcriptome and used RNA-seq to search for the molecular basis for cataract development in triploid fish. Transcriptional screening showed only modest differences in lens mRNA levels in diploid and triploid fish, with few uniquely expressed genes. In total, there were 165 differentially expressed genes (DEGs) between the cataractous diploid and triploid lens. Of these, most were expressed at lower levels in triploid fish. Differential expression was observed for genes encoding proteins with known function in the retina (phototransduction) and proteins associated with repair and compensation mechanisms. The results suggest a higher susceptibility to oxidative stress in triploid lenses, and that mechanisms connected to the ability to handle damaged proteins are differentially affected in cataractous lenses from diploid and triploid salmon.
Collapse
|
6
|
Kakrana A, Yang A, Anand D, Djordjevic D, Ramachandruni D, Singh A, Huang H, Ho JWK, Lachke SA. iSyTE 2.0: a database for expression-based gene discovery in the eye. Nucleic Acids Res 2019; 46:D875-D885. [PMID: 29036527 PMCID: PMC5753381 DOI: 10.1093/nar/gkx837] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Accepted: 09/11/2017] [Indexed: 12/20/2022] Open
Abstract
Although successful in identifying new cataract-linked genes, the previous version of the database iSyTE (integrated Systems Tool for Eye gene discovery) was based on expression information on just three mouse lens stages and was functionally limited to visualization by only UCSC-Genome Browser tracks. To increase its efficacy, here we provide an enhanced iSyTE version 2.0 (URL: http://research.bioinformatics.udel.edu/iSyTE) based on well-curated, comprehensive genome-level lens expression data as a one-stop portal for the effective visualization and analysis of candidate genes in lens development and disease. iSyTE 2.0 includes all publicly available lens Affymetrix and Illumina microarray datasets representing a broad range of embryonic and postnatal stages from wild-type and specific gene-perturbation mouse mutants with eye defects. Further, we developed a new user-friendly web interface for direct access and cogent visualization of the curated expression data, which supports convenient searches and a range of downstream analyses. The utility of these new iSyTE 2.0 features is illustrated through examples of established genes associated with lens development and pathobiology, which serve as tutorials for its application by the end-user. iSyTE 2.0 will facilitate the prioritization of eye development and disease-linked candidate genes in studies involving transcriptomics or next-generation sequencing data, linkage analysis and GWAS approaches.
Collapse
Affiliation(s)
- Atul Kakrana
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA
| | - Andrian Yang
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.,St. Vincent's Clinical School, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Djordje Djordjevic
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.,St. Vincent's Clinical School, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Deepti Ramachandruni
- Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| | - Abhyudai Singh
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA.,Department of Electrical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Hongzhan Huang
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA
| | - Joshua W K Ho
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia.,St. Vincent's Clinical School, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Salil A Lachke
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE 19711, USA.,Department of Biological Sciences, University of Delaware, Newark, DE 19716, USA
| |
Collapse
|
7
|
Anand D, Kakrana A, Siddam AD, Huang H, Saadi I, Lachke SA. RNA sequencing-based transcriptomic profiles of embryonic lens development for cataract gene discovery. Hum Genet 2018; 137:941-954. [PMID: 30417254 DOI: 10.1007/s00439-018-1958-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/07/2018] [Indexed: 12/21/2022]
Abstract
Isolated or syndromic congenital cataracts are heterogeneous developmental defects, making the identification of the associated genes challenging. In the past, mouse lens expression microarrays have been successfully applied in bioinformatics tools (e.g., iSyTE) to facilitate human cataract-associated gene discovery. To develop a new resource for geneticists, we report high-throughput RNA sequencing (RNA-seq) profiles of mouse lens at key embryonic stages (E)10.5 (lens pit), E12.5 (primary fiber cell differentiation), E14.5 and E16.5 (secondary fiber cell differentiation). These stages capture important events as the lens develops from an invaginating placode into a transparent tissue. Previously, in silico whole-embryo body (WB)-subtraction-based "lens-enriched" expression has been effective in prioritizing cataract-linked genes. To apply an analogous approach, we generated new mouse WB RNA-seq datasets and show that in silico WB subtraction of lens RNA-seq datasets successfully identifies key genes based on lens-enriched expression. At ≥2 counts-per-million expression, ≥1.5 log2 fold-enrichment (p < 0.05) cutoff, E10.5 lens exhibits 1401 enriched genes (17% lens-expressed genes), E12.5 lens exhibits 1937 enriched genes (22% lens-expressed genes), E14.5 lens exhibits 2514 enriched genes (31% lens-expressed genes), and E16.5 lens exhibits 2745 enriched genes (34% lens-expressed genes). Biological pathway analysis identified genes associated with lens development, transcription regulation and signaling pathways, among other functional groups. Furthermore, these new RNA-seq data confirmed high expression of established cataract-linked genes and identified new potential regulators in the lens. Finally, we developed new lens stage-specific UCSC Genome Brower annotation tracks and made these publicly accessible through iSyTE ( https://research.bioinformatics.udel.edu/iSyTE/ ) for user-friendly visualization of lens gene expression/enrichment to prioritize genes from high-throughput data from cataract cases.
Collapse
Affiliation(s)
- Deepti Anand
- Department of Biological Sciences, University of Delaware, 105 The Green, Delaware Avenue, 236 Wolf Hall, Newark, DE, 19716, USA
| | - Atul Kakrana
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19716, USA
| | - Archana D Siddam
- Department of Biological Sciences, University of Delaware, 105 The Green, Delaware Avenue, 236 Wolf Hall, Newark, DE, 19716, USA
| | - Hongzhan Huang
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19716, USA
| | - Irfan Saadi
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS, 66160, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, 105 The Green, Delaware Avenue, 236 Wolf Hall, Newark, DE, 19716, USA. .,Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19716, USA.
| |
Collapse
|
8
|
Swarup A, Bell BA, Du J, Han JYS, Soto J, Abel ED, Bravo-Nuevo A, FitzGerald PG, Peachey NS, Philp NJ. Deletion of GLUT1 in mouse lens epithelium leads to cataract formation. Exp Eye Res 2018; 172:45-53. [PMID: 29604281 PMCID: PMC6716165 DOI: 10.1016/j.exer.2018.03.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 10/17/2022]
Abstract
The primary energy substrate of the lens is glucose and uptake of glucose from the aqueous humor is dependent on glucose transporters. GLUT1, the facilitated glucose transporter encoded by Slc2a1 is expressed in the epithelium of bovine, human and rat lenses. In the current study, we examined the expression of GLUT1 in the mouse lens and determined its role in maintaining lens transparency by studying effects of postnatal deletion of Slc2a1. In situ hybridization and immunofluorescence labeling were used to determine the expression and subcellular distribution of GLUT1 in the lens. Slc2a1 was knocked out of the lens epithelium by crossing transgenic mice expressing Cre recombinase under control of the GFAP promoter with Slc2a1loxP/loxP mice to generate Slc2a1loxP/loxP;GFAP-Cre+/0 (LensΔGlut1) mice. LensΔGlut1 mice developed visible lens opacities by around 3 months of age, which corresponded temporally with the total loss of detectable GLUT1 expression in the lens. Spectral domain optical coherence tomography (SD-OCT) imaging was used to monitor the formation of cataracts over time. SD-OCT imaging revealed that small nuclear cataracts were first apparent in the lenses of LensΔGlut1 mice beginning at about 2.7 months of age. Longitudinal SD-OCT imaging of LensΔGlut1 mice revealed disruption of mature secondary fiber cells after 3 months of age. Histological sections of eyes from LensΔGlut1 mice confirmed the disruption of the secondary fiber cells. The structural changes were most pronounced in fiber cells that had lost their organelles. In contrast, the histology of the lens epithelium in these mice appeared normal. Lactate and ATP were measured in lenses from LensΔGlut1 and control mice at 2 and 3 months of age. At 2 months of age, when GLUT1 was still detectable in the lens epithelium, albeit at low levels, the amount of lactate and ATP were not significantly different from controls. However, in lenses isolated from 3-month-old LensΔGlut1 mice, when GLUT1 was no longer detectable, levels of lactate and ATP were 50% lower than controls. Our findings demonstrate that in vivo, the transparency of mature lens fiber cells was dependent on glycolysis for ATP and the loss of GLUT1 transporters led to cataract formation. In contrast, lens epithelium and cortical fiber cells have mitochondria and could utilize other substrates to support their anabolic and catabolic needs.
Collapse
Affiliation(s)
- Aditi Swarup
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Brent A Bell
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Jianhai Du
- West Virginia University Eye Institute, Morgantown, WV, USA
| | - John Y S Han
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Jamie Soto
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA; Division of Endocrinology & Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - E Dale Abel
- Fraternal Order of Eagles Diabetes Research Center, University of Iowa, Iowa City, IA, USA; Division of Endocrinology & Metabolism, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Arturo Bravo-Nuevo
- Department of Bio-Medical Sciences, Philadelphia College of Osteopathic Medicine, Philadelphia, PA, USA
| | - Paul G FitzGerald
- Department of Cell Biology & Human Anatomy, University of California at Davis, Davis, CA, USA
| | - Neal S Peachey
- Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; Louis Stokes Cleveland VA Medical Center, Cleveland, OH, USA; Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH, USA
| | - Nancy J Philp
- Department of Pathology, Anatomy & Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
9
|
Anand D, Lachke SA. Systems biology of lens development: A paradigm for disease gene discovery in the eye. Exp Eye Res 2016; 156:22-33. [PMID: 26992779 DOI: 10.1016/j.exer.2016.03.010] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 03/08/2016] [Accepted: 03/11/2016] [Indexed: 12/19/2022]
Abstract
Over the past several decades, the biology of the developing lens has been investigated using molecular genetics-based approaches in various vertebrate model systems. These efforts, involving target gene knockouts or knockdowns, have led to major advances in our understanding of lens morphogenesis and the pathological basis of cataracts, as well as of other lens related eye defects. In particular, we now have a functional understanding of regulators such as Pax6, Six3, Sox2, Oct1 (Pou2f1), Meis1, Pnox1, Zeb2 (Sip1), Mab21l1, Foxe3, Tfap2a (Ap2-alpha), Pitx3, Sox11, Prox1, Sox1, c-Maf, Mafg, Mafk, Hsf4, Fgfrs, Bmp7, and Tdrd7 in this tissue. However, whether these individual regulators interact or their targets overlap, and the significance of such interactions during lens morphogenesis, is not well defined. The arrival of high-throughput approaches for gene expression profiling (microarrays, RNA-sequencing (RNA-seq), etc.), which can be coupled with chromatin immunoprecipitation (ChIP) or RNA immunoprecipitation (RIP) assays, along with improved computational resources and publically available datasets (e.g. those containing comprehensive protein-protein, protein-DNA information), presents new opportunities to advance our understanding of the lens tissue on a global systems level. Such systems-level knowledge will lead to the derivation of the underlying lens gene regulatory network (GRN), defined as a circuit map of the regulator-target interactions functional in lens development, which can be applied to expedite cataract gene discovery. In this review, we cover the various systems-level approaches such as microarrays, RNA-seq, and ChIP that are already being applied to lens studies and discuss strategies for assembling and interpreting these vast amounts of high-throughput information for effective dispersion to the scientific community. In particular, we discuss strategies for effective interpretation of this new information in the context of the rich knowledge obtained through the application of traditional single-gene focused experiments on the lens. Finally, we discuss our vision for integrating these diverse high-throughput datasets in a single web-based user-friendly tool iSyTE (integrated Systems Tool for Eye gene discovery) - a resource that is already proving effective in the identification and characterization of genes linked to lens development and cataract. We anticipate that application of a similar approach to other ocular tissues such as the retina and the cornea, and even other organ systems, will significantly impact disease gene discovery.
Collapse
Affiliation(s)
- Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, USA; Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, USA.
| |
Collapse
|
10
|
Huynh MH, Zhu SJ, Kollara A, Brown T, Winklbauer R, Ringuette M. Knockdown of SPARC leads to decreased cell-cell adhesion and lens cataracts during post-gastrula development in Xenopus laevis. Dev Genes Evol 2011; 220:315-27. [PMID: 21384171 DOI: 10.1007/s00427-010-0349-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Accepted: 12/16/2010] [Indexed: 12/01/2022]
Abstract
SPARC is a multifunctional matricellular glycoprotein with complex, transient tissue distribution during embryonic development. In Xenopus laevis embryos, zygotic activation of SPARC is first detected during late gastrulation, undergoing rapid changes in its spatiotemporal distribution throughout organogenesis. Injections of anti-sense Xenopus SPARC morpholinos (XSMOs) into 2- and 4-cell embryos led to a dose-dependent dissociation of embryos during neurula and tailbud stages of development. Animal cap explants derived from XSMO-injected embryos also dissociated, resulting in the formation of amorphous ciliated microspheres. At low doses of XSMOs, lens cataracts were formed, phenocopying that observed in Sparc-null mice. At XSMOs concentrations that did not result in a loss of axial tissue integrity, adhesion between myotomes at intersomitic borders was compromised with a reduction in SPARC concentration. The combined data suggest a critical requirement for SPARC during post-gastrula development in Xenopus embryos and that SPARC, directly or indirectly, promotes cell-cell adhesion in vivo.
Collapse
Affiliation(s)
- My-Hang Huynh
- Department of Microbiology & Immunology, University of Michigan Medical School, Ann Arbor, 48109-5620, USA
| | | | | | | | | | | |
Collapse
|
11
|
Koehler A, Desser S, Chang B, MacDonald J, Tepass U, Ringuette M. Molecular evolution of SPARC: absence of the acidic module and expression in the endoderm of the starlet sea anemone, Nematostella vectensis. Dev Genes Evol 2009; 219:509-21. [DOI: 10.1007/s00427-009-0313-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2009] [Accepted: 12/02/2009] [Indexed: 11/29/2022]
|
12
|
The role of SPARC in extracellular matrix assembly. J Cell Commun Signal 2009; 3:239-46. [PMID: 19798598 PMCID: PMC2778582 DOI: 10.1007/s12079-009-0062-6] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Accepted: 08/20/2009] [Indexed: 11/27/2022] Open
Abstract
SPARC is a collagen-binding matricellular protein. Expression of SPARC in adult tissues is frequently associated with excessive deposition of collagen and SPARC-null mice fail to generate a robust fibrotic response to a variety of stimuli. This review summarizes recent advancements in the characterization of the binding of SPARC to collagens and describes the results of studies that implicate a function for SPARC in the regulation of the assembly of basal lamina and fibrillar collagen in the ECM. Potential cellular mechanisms that underlie SPARC activity in ECM deposition are also explored.
Collapse
|