Eye lens organoids going simple: characterization of a new model
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ABSTRACT: To characterized a new model for lens development, a 3’ end RNA-seq was perform on the cell in 2D culture, on the all organoids (3D) and on the external and internal part of the organoids obtain with laser microdissection follow by RNA-extraction
Project description:Signals from the lens regulate multiple aspects of eye development, including establishment of eye size, patterning of the presumptive iris and ciliary body in the anterior optic cup and migration and differentiation of neural crest cells. To advance understanding of the molecular regulation of eye development by the lens, we performed transcriptome analysis of lens-removed and contralateral unoperated embryonic chicken eyes. Lens-regulated genes implicated in periocular mesenchyme, cornea and anterior optic cup development were identified. Identified candidates included genes known to be regulated by lens-derived signals and important for anterior eye development, including WNT pathway genes. Factors not previously implicated in eye development also were identified, paving the way for additional research in this area. Genes associated with nervous system development were upregulated in lens-removed eyes, but the presumptive ciliary body and iris region did not adopt a neural retina identity following lens removal. Intriguingly, transcriptomic differences were identified in retinas from male versus female chicken embryos, suggesting sexual dimorphism from early stages. These analyses have identified candidate genes and biological pathways involved in eye development, providing avenues for new research in this area.
Project description:This study is to characterize the molecular components that could contribute to the formation of lens extracellular diffusion barrier. Three regions were isolated from lens cortex using laser capture microdissection and the proteome changes in these three regions were studied.
Project description:E12.5 mouse lens epithelium and fiber cells were collected using Leica LMD 6000 Laser microdissection system. Total RNA was isolated from epithelium and fiber cells using Qiagen RNeasy kit
Project description:Purpose: While the bioinformatics gene-discovery tool iSyTE (integrated Systems Tool for Eye gene discovery) has proved effective in identifying new cataract-linked genes, it primarily depended on lens-enriched expression of just three wild-type mouse embryonic stages. To increase iSyTE’s efficacy, a broad range of embryonic (E) and postnatal (P) lens microarray datasets from wild-type and specific gene-perturbation mutant mice were analyzed and a new web-interface was developed for their effective access and downstream-analysis. Methods: Five new mouse lens microarrays were generated and analyzed with all publicly available Affymetrix and Illumina lens datasets representing the stages E9.5, E10.25, E10.5, E11.5, E12.5, E15.5, E16.5, E17.5, E19.5, P0, P2, P4, P8, P12, P20, P28, P30, P42, P52, P56, P60 and mouse mutants for the genes: Brg1, CBP:p300, E2f1:E2f2:E2f3, Foxe3, Hsf4, Klf4, Mafg:Mafk, Notch2, Pax6, Sparc, Tdrd7. Results: The integrated lens microarray analysis accurately reflects established gene expression patterns and defines a new lens-signature gene-set for embryonic and postnatal stages that includes several novel candidates namely, Grifin, Ogn, Fabp5, Mboat1, Tmem40, Dhx32, Aldoc, Pgam2, Hmgn3, Mocs2, Gprc5b, Gstm1, Npl, and Zbtb8b. Combined analyses of 32 developmental/genetic data-conditions identifies several new transcription and signaling factors that potentially function in lens development and/or homeostasis. Conclusions: The updated iSyTE web-interface: (1) comprehensively informs on normal lens developmental and cataract-associated transcriptome dynamics and identifies new high-priority candidates for these processes, and (2) offers user-friendly visualization.
Project description:The eye lens is composed of fiber cells, which differentiate from epithelial cells on its anterior surface. In concert with this differentiation, a set of proteins essential for lens function is synthesized, and the cellular organelles are degraded. To understand the molecular mechanism of the lens cell differentiation, we compared the gene expression profiles between epithelial and cortical fiber cells of young mouse lens using a microarray analysis. Keywords: cell-type comparison
Project description:Background: During eye lens development the fetal 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 in the regulation of genes required for mature lens structure and function. Since HIF1α is a master regulator of the hypoxic response, these lens properties also implicate HIF1α as a potential requirement for lens formation and homeostasis. Here, we employed a multiomics approach combining CUT&RUN, RNAseq 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 8,375 HIF1α-DNA binding complexes in the chick lens genome. 1,190 HIF1α-DNA binding complexes were significantly clustered within chromatin accessible regions (χ2 test p < 1x10-55) 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 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 development, 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.
Project description:Background: During eye lens development the fetal 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 in the regulation of genes required for mature lens structure and function. Since HIF1α is a master regulator of the hypoxic response, these lens properties also implicate HIF1α as a potential requirement for lens formation and homeostasis. Here, we employed a multiomics approach combining CUT&RUN, RNAseq 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 8,375 HIF1α-DNA binding complexes in the chick lens genome. 1,190 HIF1α-DNA binding complexes were significantly clustered within chromatin accessible regions (χ2 test p < 1x10-55) 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 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 development, 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.
Project description: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. 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 < 1x10-42). mCG levels were inversely correlated with chromatin accessibility determined by Assay for transposase-accessible sequencing (ATAC-seq) (Pearson correlation r = -0.86, p < 1x10-300). 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. 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.
Project description: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. 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 < 1x10-42). mCG levels were inversely correlated with chromatin accessibility determined by Assay for transposase-accessible sequencing (ATAC-seq) (Pearson correlation r = -0.86, p < 1x10-300). 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. 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.