Limbal Niche
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REPOSITORIES: ENA
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Project description:Comprehensive transcriptome analysis of four distinct human limbal compartments, including basal limbal crypts (BLCs), superficial limbal crypts (SLCs), cornea, and the supporting stroma, with the aid of laser capture microdissection and deep RNA sequencing.
2013-07-01 | E-MTAB-1498 | biostudies-arrayexpress
Project description:Compared to stem cells in other tissues, relatively little is known about the limbal niche, which is believed to play a pivotal role in regulating self-renewal and fate decision of limbal epithelial stem cells. Here we comprehensively investigated the human limbal niche with single-cell RNA sequencing. On analysis, all 47,627 cells located at human Limbus was classified into 14 clusters, and 8 types of cells were annotated. Specifically, we depicted the heterogeneity and hierarchy of limbal epithelial cells, and revealed a consecutive differentiation trajectory from limbal stem/progenitor cells by RNA velocity and pseudotime analyses. Besides, representative signaling pathway components and cell-cell communications engaged in limbal niche regulation were deciphered, suggesting a tightly regulation of the microenvironment around limbal stem/progenitor cells. Finally, comparative analysis revealed conservational and divergent transcriptional signals across species. Overall, this study provides an unbiased and systematic view of transcriptional organization of human Limbus, and dissected cell-contact-dependent regulations of limbal niche, providing foundations for investigating the cellular and molecular mechanisms, pathogenesis of related disease and potential interventions.
2021-06-14 | GSE157474 | GEO
Project description:Limbal epithelial stem cell (LESC) deficiency represents a significant clinical problem especially in bilateral cases. Induced pluripotent stem cells (iPSC) may be a promising source of LESC, allowing standardized and continual propagation and banking. The objective of this study was to generate iPSC from human limbal epithelial cultures and differentiate them back into limbal epithelial cells using substrata mimicking the natural LESC niche. Using Yamanaka’s episomal vectors limbal-derived iPSC were reprogrammed from LESC cultured from donor corneoscleral rims and from human skin fibroblasts. A clone from limbal-derived iPSC expressed stemness markers, had a diploid karyotype, and produced teratomas in nude mice representing three germ layers. Compared to parental LESC, this clone had fewer specific gene methylation changes revealed using the Illumina Infinium Methylation 450k Beadchips than compared to skin fibroblasts. The expression of putative LESC markers was examined by quantitative RT-PCR and immunostaining in limbal-derived and fibroblast-derived iPSC cultured on denuded human amniotic membrane or denuded cornea. Limbal-derived iPSC had markedly stronger expression of PAX6, ABCG2, Np63, keratins 14, 15, 17, and N-cadherin than fibroblast-derived iPSC. On denuded corneas, limbal-derived iPSC showed the expression of differentiated corneal keratins 3 and 12. The data suggest that iPSC differentiation to a desired lineage may be facilitated by their generation from the same tissue. This may be related to preservation of parental tissue epigenetic methylation signatures in iPSC and use of biological substrata similar to the natural niche of parental cells. The data pave the way for generating transplantable LESC from limbal-derived iPSC. Bisulphite converted DNA from the 12 samples were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
2014-06-30 | E-GEOD-53918 | biostudies-arrayexpress
Project description:Limbal epithelial stem cell (LESC) deficiency represents a significant clinical problem especially in bilateral cases. Induced pluripotent stem cells (iPSC) may be a promising source of LESC, allowing standardized and continual propagation and banking. The objective of this study was to generate iPSC from human limbal epithelial cultures and differentiate them back into limbal epithelial cells using substrata mimicking the natural LESC niche. Using Yamanaka’s episomal vectors limbal-derived iPSC were reprogrammed from LESC cultured from donor corneoscleral rims and from human skin fibroblasts. A clone from limbal-derived iPSC expressed stemness markers, had a diploid karyotype, and produced teratomas in nude mice representing three germ layers. Compared to parental LESC, this clone had fewer specific gene methylation changes revealed using the Illumina Infinium Methylation 450k Beadchips than compared to skin fibroblasts. The expression of putative LESC markers was examined by quantitative RT-PCR and immunostaining in limbal-derived and fibroblast-derived iPSC cultured on denuded human amniotic membrane or denuded cornea. Limbal-derived iPSC had markedly stronger expression of PAX6, ABCG2, Np63, keratins 14, 15, 17, and N-cadherin than fibroblast-derived iPSC. On denuded corneas, limbal-derived iPSC showed the expression of differentiated corneal keratins 3 and 12. The data suggest that iPSC differentiation to a desired lineage may be facilitated by their generation from the same tissue. This may be related to preservation of parental tissue epigenetic methylation signatures in iPSC and use of biological substrata similar to the natural niche of parental cells. The data pave the way for generating transplantable LESC from limbal-derived iPSC.
2014-06-30 | GSE53918 | GEO
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
Project description:Limbal stem cells including epithelial and stromal/Mesenchymal stem cells that contribute to sustained corneal homeostasis, maintain their ability to act as self-renewal progenitor cells by virtue of their limbal niche and intercellular communication. Extracellular vehicles (EVs), including exosomes (Exos), are important paracrine mediators through their cargo transfer for intercellular communication in various stem cell niches. Previously we have shown the differential cargos and regulatory roles of limbal stromal cell (LSC)-derived Exos, in limbal epithelial cells (LEC) in normal (N) and diabetic (DM) limbal niche. In the present study, to have a comprehensive knowledge of reciprocal LEC-LSC crosstalk, we investigated the proteomics and miRNA profile of exosomes derived from LEC and their regulatory roles in LSC in N and DM limbus. Our study showed wound healing and proliferation rates in primary N-LSC were significantly enhanced upon treatment by normal LEC-derived Exos (N-Exos), but not by diabetic Exos (DM-Exos). Further, N-Exos treated LSC showed downregulation of keratocyte markers, ALDH3A1 and lumican, but not keratocan, and upregulation of MSC markers, CD105, CD90, and CD73 compared to the DM-Exos treated LSC. Using next generation sequencing (NGS) and proteomics analysis, we revealed some miRNAs and proteins in the Exos that affect the cellular crosstalk and the function of the cornea. We also documented differences in DM vs. normal LEC-derived Exo’s cargos. Overall, DM-Exos have less effect on LSC proliferation, wound healing, and stem cell maintenance than N-Exos, likely by transferring their cargo proteins and/or regulatory miRNAs targeting cell cycle, ERK/MAPK, TGF-β, EMT, PI3K-Akt-mTOR signaling molecules. This suggests that the small RNA and protein cargo differences in DM vs. N LEC-derived Exos could contribute to the disease state. Our study revealed a complex contribution of Exos to health and diabetic state of corneal homeostasis and suggests the potential of EV therapeutics for diabetic cornea regenerative medicine
2023-10-23 | PXD040918 | Pride
Project description:Limbal and central regoins of the rat cornea epithelium were used to constract 2 SAGE libraries, in order to identify candidate genes to distinguish stem cell from differentiated central cornea epithelium cells. Keywords: gene expression SAGE-based, count cornea epithelium was scraped from central cornea and limbal Epithelium regions of 6 week male Wister rat 16 and 48 eye (respectively).
2006-05-15 | E-GEOD-4121 | biostudies-arrayexpress
Project description:ABCB5 is marker for Limbal epithilal stem cells. A comparison between ABCB5+ versus ABCB5- cultured human limbal epithelial cells was carried out to evaluate the properties of the limbal stem cell ABCB5+ with a special focus on their role in inflammation and angiogenesis.
2023-10-24 | PXD041004 | Pride
Project description:Single-cell analysis of limbal niche heterogeneity and crosstalk with corneal epithelial stem/progenitor cells
| PRJNA661449 | ENA
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