Comparative gene expression in the human limbus, conjunctiva and cornea
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE38190 | GEO | 2013/01/01
SECONDARY ACCESSION(S): PRJNA167615
REPOSITORIES: GEO
Similar Datasets
Project description:To date, there is no specific marker for limbal epithelial stem cells. The identification of a marker that is expressed in the limbal epithelium but not in the cornea or conjunctiva epithelium has been a growing need. To search for limbal-specific marker(s), we performed preferential gene profiling in the limbus in direct comparison to that in the cornea and conjunctiva using microarray technique. This study consisted of gene expression profiles comparing the limbus to the cornea and conjunctiva.
2013-01-01 | E-GEOD-38190 | biostudies-arrayexpress
Project description:The identification of a marker that is expressed in the conjunctival epithelium but not in the corneal epithelium has been a growing need. A more specific marker of limbal and conjunctival epithelia would be necessary to detect non-corneal epithelial cells on the corneal surface. To search for conjunctival specific marker(s), we first performed preferential gene profiling in the conjunctiva in direct comparison to that in the cornea using microarray technique. The study consisted of gene expression profiles comparing the cornea and conjunctiva.
2011-06-09 | E-GEOD-29402 | biostudies-arrayexpress
Project description:The identification of a marker that is expressed in the conjunctival epithelium but not in the corneal epithelium has been a growing need. A more specific marker of limbal and conjunctival epithelia would be necessary to detect non-corneal epithelial cells on the corneal surface. To search for conjunctival specific marker(s), we first performed preferential gene profiling in the conjunctiva in direct comparison to that in the cornea using microarray technique.
2011-06-09 | GSE29402 | GEO
Project description:The limbus is a unique anatomic structure that is highly innervated and vascularized yet sets the boundary for the avascularized cornea. The corneal epithelial stem cells are believed to reside at the limbus. The intrinsic and external molecular signals that modulate the differentiation and proliferation of the limbal stems cells are still largely unidentified because of a lack of known specific markers. In this study, we used microarray technology to identify the unique gene expression profile in the limbus by comparing directly to that of its immediate adjacent structures, the cornea and conjunctiva, in the vervet monkey (Chlorocebus aethiops sabaeus). Many new genes were found to be preferentially expressed in the limbus, and two new biological pathways, melanin metabolism and apoptosis, were among other previously known processes identified in the limbus. These findings may shed light on the molecular components of limbal stem cells and their niche. Experiment Overall Design: The study consisted of gene expression profile comparisons across three anatomical structures of the eye. The parts of the eye compared included the cornea, the conjunctiva, and the limbus.
2008-04-06 | E-GEOD-10683 | biostudies-arrayexpress
Project description:Corneal epithelial stem cells reside in the limbus that is the transitional zone between the cornea and conjunctiva, and are essential to maintain the homeostasis of corneal epithelium. However, their characterization is poorly understood. Therefore, we constructed gene expression profiles of limbal epithelial SP and non-SP cell using RNA-sequencing. As a result, limbal epithelial SP cells have immature cell phenotypes with endothelial/mesenchymal cell markers, while limbal epithelial non-SP cells have epithelial progenitor cell markers.
2016-04-18 | GSE79620 | GEO
Project description:PURPOSE. To determine global mRNA expression levels in the corneal and conjunctival epithelia and identify transcripts that exhibit preferential tissue expression. METHODS. cDNA samples derived from human conjunctival and corneal epithelia were hybridized in three independent experiments to a commercial oligonucleotide array representing > 22,000 transcripts. The resulting signal intensities and transcript present/absent calls by the primary microarray analyzing software were used in conjunction with a statistical method to identify transcripts that are preferentially or exclusively (transcripts absent in all three replicates in the other tissue) and significantly (expression >1% of the ß-actin level) expressed in one of the two tissues. EASE was used to identify biological systems comparatively over-represented in either epithelium. Immuno-, and cyto-histochemistry was performed to validate or expand on selected the results of interest. RESULTS. Our analysis identified 332 preferential and 93 exclusive significant corneal epithelial transcripts. The corresponding conjunctival epithelium values were 592 and 211. The over-represented biological processes in the cornea were related to cell adhesion and oxi-redox equilibria and cytoprotection activities. In the conjunctiva the biological processes that were most prominent were related to innate immunity and to melanogenesis. Immunohistochemistry for antigen presenting cells and melanocytes were consistent with these gene signatures. The transcript comparison identified a substantial number of genes that have either not previously been identified or not known to be highly expressed in these two epithelia, including, testican-1, ECM1, a forming isoform, CRTAC1 and NQO1 in the cornea and sPLA2-IIA, multiple MCH class II proteins, IGFBP3, and Na-Pi cotransporter type IIb in the conjunctiva. CONCLUSION. Comparative gene expression profiling led to the identification of many biological processes and previously unknown genes potentially important for the function of corneal and conjunctival epithelia. Keywords: Cell type comparison
2007-02-10 | GSE5543 | GEO
Project description:The limbus is a unique anatomic structure that is highly innervated and vascularized yet sets the boundary for the avascularized cornea. The corneal epithelial stem cells are believed to reside at the limbus. The intrinsic and external molecular signals that modulate the differentiation and proliferation of the limbal stems cells are still largely unidentified because of a lack of known specific markers. In this study, we used microarray technology to identify the unique gene expression profile in the limbus by comparing directly to that of its immediate adjacent structures, the cornea and conjunctiva, in the vervet monkey (Chlorocebus aethiops sabaeus). Many new genes were found to be preferentially expressed in the limbus, and two new biological pathways, melanin metabolism and apoptosis, were among other previously known processes identified in the limbus. These findings may shed light on the molecular components of limbal stem cells and their niche. Keywords: transcription profiling, gene expression
2008-03-05 | GSE10683 | GEO
Project description:To study the development and composition of human ocular surface, we performed single cell (sc) RNA-Seq at key embryonic, fetal and adult stages and generated the first atlas of the corneal and conjunctival cell types from development to adulthood. The conjunctival epithelium is the first to be specified in the epithelial layer , followed by the corneal epithelium and the establishment of proliferative epithelial progenitors, which predate the formation of limbal niche by a few weeks. Bioinformatic comparison of adult cell clusters identified GPHA2,a novel cell-surface marker for quiescent limbal stem cells (qLSCs), whose function is to maintain qLSCs self-renewal. Combining scRNA- and ATAC-Seq analysis, we identified multiple upstream regulators for qLSCs and transit amplifying (TA) cells and demonstrated a close interaction between the immune cells and epithelial stem and progenitor cells in the cornea. Single cell RNA-Seq analysis indicated loss of qLSCs and acquisition of proliferative limbal epithelial progenitor markers during limbal epithelial cell expansion: this phenomenon was independent of culture method used. Extending the single cell analyses to Keratoconus, we were able to reveal activation of collagenase in the corneal stroma and a reduced pool of TA cells in the corneal epithelium as two key mechanistic changes underlying the disease phenotype. Our scRNA-Seq data comparisons of developing and adult cornea and conjunctiva provide a unique resource for defining pathways/genes that could lead to improvement in ex vivo expansion methods for cell based replacement therapies and better understanding and treatment of ocular surface disorders.
2021-04-19 | GSE155683 | GEO
Project description:Recently we had discovered a solid cord like structure at the limbus of human eyes, termed as the Limbal Epithelial Crypt (LEC). It arises from the undersurface of the interpalisade rete ridges and extends towards the conjunctiva over the conjunctival stroma. Anatomical and immunohistochemical studies have shown it to be potentially a Stem Cell Niche. To confirm this hypothesis we conducted comparative gene expression profile of LEC with pathway and Geneontology studies in comparison with other ocular surface epithelial regions such as cornea, limbus, LEC stroma and conjunctiva. Frozen tissue blocks of corneoscleral buttons dissected from cadaver eyes were cryosectioned. These tissue sections from different ocular surface regions were laser microdissected. Extracted RNA was amplified & hybridized to 30,000k Human spotted cDNA microarray chips. Raw data obtained with Genepix Pro6 software was filtered, normalized & analysed on BASE & Jexpresspro software. Unpaired T-Test, Significance Analysis of Microarrays were performed on the data. Database for Annotation, Visualisation, and Integrated Discovery (DAVID) (http://www.DAVID.niaid.nih.gov) and Ingenuity Pathway Analysis (IPA) was used to determine the enriched GO terms and pathways in the differentially expressed genes. Quantitative gene expression analysis (qPCR) and immunohistochemistry was performed on the genes of interest. Statistical analysis for real time PCR was performed on SPSS16 to determine the normalised expression of gene of interest on ocular surface regions. Samples were prepared from five human ocular surface epithelial regions such as Cornea, Limbus, LEC, LEC Stroma, Conjunctiva. There were four replicates in each groups except Cornea and Conjunctiva with 3 each. The Standard Probe (SP) was prepared from mixing equal amount of Corneal and conjunctival epithelial RNA followed by ethanol precipitation. Samples were labelled with Cy5 dye and Standard Probe with Cy3 Dye. These were mixed in equal amount to prepare hybrid probes which were then hybridised to microarray slide.
2010-03-23 | E-GEOD-19035 | biostudies-arrayexpress
Project description:Limbal epithelial stem cells (LESCs) reside within the LSC niche (LSCN), located at the annular transition zone between the cornea and conjunctiva. LESCs are important for the long-term maintenance of the corneal epithelium and critical for repopulating the corneal epithelium after injury. We have recently identified that a hyaluronan (HA)-rich extracellular matrix (ECM) exists within the LSCN, and that this HA matrix is necessary for maintaining LESCs in the “stem cell” state. Herein we further characterized the composition of the LSCN, identifying key components of the HA-rich matrix. We identified that the hyaladherins IαI, TSG-6 and versican are highly expressed in the limbus when compared to the cornea. For IαI, Heavy chain 5 (HC5) was found to be the most highly expressed HC in the mouse and human cornea, and associates with HA forming HA/HC5 specific matrices. CD44 is the most likely receptor that mediates the interaction between LESCs and the HA-specific matrix. The LSCN is composed of a rich HA matrix that contains HA/HC5. HA/HC5 complexes could be used as an improved substrate for culturing LESCs during ex vivo expansion for limbal stem cell transplantation.
2023-11-08 | GSE244412 | GEO