Low fucosylation defines the glycocalyx of progenitor cells and melanocytes in the limbal epithelial stem cell niche
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ABSTRACT:
PROVIDER: PRJNA1053313 | ENA |
REPOSITORIES: ENA
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Project description:It is widely recognized that the glycocalyx has significant implications in regulating the self-renewal and differentiation of adult stem cells. Yet, its composition remains poorly understood. Here, we show that the fucose-binding Aleuria aurantia lectin (AAL) binds differentially to basal cells in the stratified epithelium of the human limbus, hair follicle and meibomian gland duct. Using fluorescence-activated cell sorting in combination with single-cell transcriptomics, we find that most epithelial progenitor cells and melanocytes in the limbus display low AAL staining (AALlow) on their cell surface, an attribute that is gradually lost in epithelial cells as they differentiate into mature corneal cells. AALlow epithelial cells were enriched in putative limbal stem cell markers and displayed high proliferative potential. Further analyses revealed that AALlow epithelial cells had reduced expression of GDP-mannose-4,6-dehydratase, an enzyme catalyzing the first and regulatory steps in the de novo biosynthesis of GDP-fucose, and that inhibition of fucosylation using a small-molecule fucose analogue stimulated the proliferative potential of limbal epithelial cells ex vivo. These results provide critical insights into the composition of the glycocalyx in adult stem cells and could thereby have implications to the regeneration of the human limbal stem cell niche.
2024-12-19 | GSE250294 | GEO
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: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:We profiled over 400 spots within each sample and spatially located major cell types through the integration with reference the single-cell RNA sequencing data. Based on Robust Cell Type Decomposition (RCTD) technology, limbal epithelial stem cells (LESCs) were mainly localized in the basement membrane, and limbal niche cells were predominantly situated within the stromal area. Following, the limbus was divided into 4 regions based on histological structure, and the differential expressed genes among the four regions were analyzed. Notably, our investigation revealed significantly higher levels of GPHB5 and PERP within the epithelium of the middle region, precisely where LESCs predominantly reside. Concurrently, the activation of critical pathways such as "Protein Binding" and "ECM-receptor interaction" were discovered in this same region, underscoring its pivotal role in maintaining the limbal niche. Subsequently, cell-cell communication analysis was conducted on essential cells inside the niche microenvironment. Remarkably, we observed that limbal mesenchymal stem cells exhibit the largest amounts of ligands associated with LESCs, with melanocytes closely trailing behind. The widespread activity of COL6A2/CD44 signaling among limbal mesenchymal stem cells, melanocytes, immune cells, and LESCs, indicate its essential role in mediating bidirectional communication via the Collagen pathway. Additionally, a myriad of ligand-receptor interactions and pathways regulatory crosstalk among diverse cell types were exhibited.
2025-01-30 | GSE262250 | GEO
Project description:Cancer secretome is a reservoir for aberrant glycosylation. How therapies alter this post59 translational cancer hallmark and the consequences thereof remain elusive. Here we show that an elevated secretome fucosylation is a pan-cancer signature of both response and resistance to multiple targeted therapies. Large-scale pharmacogenomics revealed that fucosylation genes display widespread association with resistance to these therapies. In both cancer cell cultures and patients, targeted kinase inhibitors distinctively induced core fucosylation of secreted proteins less than 60 kDa. Label-free proteomics of N-glycomes revealed that fucosylation of the antioxidant PON1 is a critical component of the therapy66 induced secretome. Core fucosylation in the Golgi impacts PON1 stability and folding prior to secretion, promoting a more degradation-resistant PON1. Non-specific and PON1-specific secretome deglycosylation both limited the expansion of resistant clones in a tumor regression model. Our findings demonstrate that core fucosylation is a common modification indirectly induced by targeted therapies that paradoxically promotes resistance.
2023-04-05 | GSE160205 | 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.
2014-06-30 | GSE53918 | GEO
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: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