Project description:Limbal vs. corneal epithelial basal cell gene expression patterns were identified and compared. Experiment Overall Design: 8 limbal and 8 corneal epithelial basal cells samples from 8 mice were dissected and mRNAs were isolated and amplified for microarray analysis
Project description:PURPOSE: To provide a detailed gene expression profile of the normal postnatal mouse cornea. METHODS: Serial analysis of gene expression (SAGE) was performed on postnatal day (PN)9 and adult mouse (6 week) total corneas. The expression of selected genes was analyzed by in situ hybridization. RESULTS: A total of 64,272 PN9 and 62,206 adult tags were sequenced. Mouse corneal transcriptomes are composed of at least 19,544 and 18,509 unique mRNAs, respectively. One third of the unique tags were expressed at both stages, whereas a third was identified exclusively in PN9 or adult corneas. Three hundred thirty-four PN9 and 339 adult tags were enriched more than fivefold over other published nonocular libraries. Abundant transcripts were associated with metabolic functions, redox activities, and barrier integrity. Three members of the Ly-6/uPAR family whose functions are unknown in the cornea constitute more than 1% of the total mRNA. Aquaporin 5, epithelial membrane protein and glutathione-S-transferase (GST) omega-1, and GST alpha-4 mRNAs were preferentially expressed in distinct corneal epithelial layers, providing new markers for stratification. More than 200 tags were differentially expressed, of which 25 mediate transcription. CONCLUSIONS: In addition to providing a detailed profile of expressed genes in the PN9 and mature mouse cornea, the present SAGE data demonstrate dynamic changes in gene expression after eye opening and provide new probes for exploring corneal epithelial cell stratification, development, and function and for exploring the intricate relationship between programmed and environmentally induced gene expression in the cornea. Keywords: other
Project description:Limbal stem cells (LSCs), known as corneal epithelial stem cells, are located at the basal epithelial layer of the corneal limbus and serve an important function in maintaining the homeostasis of the corneal epithelium. Several putative molecular markers of LSCs have been previously identified. However, the specificity of these markers remains largely controversial. To address this gap in the current understanding of LSCs, we performed a transcriptome profiling of heterogeneous corneal limbal basal cells using single-cell transcriptomics technology to identify LSCs and their exclusive markers. We isolated limbal basal cells from two young donors, constructed scRNA-seq libraries, generated RNA-sequencing data using the 10x Genomics platform, and then finally obtained the transcriptome of about 18,000 individual single-cells using Cell ranger (https://10xgenomics.com). Next, we performed quality control, filtering and data integration using Seurat package (https://satijalab.org/seurat), about 16,400 cells were retained for further downstream analysis such as dimensional reduction, unsupervised clustering, and Differentially expressed gene selection, trajectory analysis and visualization. We identified 11 unique clusters of cells assigned to a putative cell type based on published known biomarkers for differentiation, proliferation and putative epithelial stem cells. As a results, we found 2 Terminally Differentiated Cell (TDC), 3 Post-Mitotic Cell (PMC), 1 Transient Amplifying Cell (TAC), 2 Limbal Progenitor Cell (LPC), Putative Limbal Stem Cell (LSC) and 2 Melanocyte (MC) sub-cell type clusters. Furthermore, we confirmed the trajectory order of LSC differentiation for 9 clusters using Pseudotemporal and Functional PCA analysis. Lastly, we validated each assigned cell subtypes and determined their location in human corneal limbus tissue with 9 markers using RNAscope We were able to reveal the heterogeneity of corneal limbal basal epithelium by defining novel dynamic trajectories for cell types in a pseudotemporal manner. This approach allowed us to identify the distinct clusters of LSCs and progenitors with exclusively expressed markers, and might apply for translational research on regenerating a normal corneal epithelium and restoring vision.
Project description:Transplantation of ex vivo expanded limbal stem cells (LSC) is the main treatment for limbal stem cell deficiency though the clinical problem of donor tissues shortage. Recently, as the development of tissue engineering, embryonic stem cells (ESC) derived corneal epithelial-like cells (ESC-CEC) has become a new direction to this issue.Our group successfully induced ESC into corneal epithelial-like cells, and in the present study we explored various aspects of physiological properties of ESC-CEC. The experiment included three samples: hES, the human embryonic stem cell line H1, RA_SB, the corneal epithelial-like cells derived from hES by differentiation with RA and SB, epithelial_cell, the primary human limbal stem cells from cadaver eyes. hES, the human embryonic stem cell line H1, RA_SB, the corneal epithelial-like cells derived from hES by differentiation with RA and SB, epithelial_cell, the primary human limbal stem cells from cadaver eyes.
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
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.
Project description:Epithelial and stromal/mesenchymal limbal stem cells contribute to corneal homeostasis and cell renewal. Extracellular vesicles (EVs), including exosomes (Exos), can be paracrine mediators of intercellular communication. Previously, we described cargos and regulatory roles of limbal stromal cell (LSC)-derived Exos in non-diabetic (N) and diabetic (DM) limbal epithelial cells (LEC). Presently, we quantify the miRNA and proteome profiles of human LEC-derived Exos and their regulatory roles in N- and DM-LSC. We revealed some miRNA and protein differences in DM vs. N-LEC-derived Exos' cargos including proteins involved in Exo biogenesis and packaging that may affect Exo production and ultimately cellular crosstalk and corneal function. Treatment by N-Exos, but not by DM-Exos enhanced wound healing in cultured N-LSC and increased proliferation rate in N and DM LSCs vs. corresponding untreated (control) cells. N-Exos treated LSC reduced keratocyte markers ALDH3A1 and lumican, and increased MSC markers CD73, CD90 and CD105 vs. control LSC. These being opposite to the changes quantified in wounded LSCs. Overall, N-LEC Exos have a more pronounced effect on LSC wound healing, proliferation, and stem cell marker expression than DM-LEC Exos. This suggests that regulatory miRNA and protein cargo differences in DM- vs. N-LEC-derived Exos could contribute to the disease state.
Project description:We successfully induced corneal epithelial cells from human iPSCs. Then, we perfomed global expression analysis using microarray to compare the character of hiPSC-derived corneal epithelial cells with that of the other kinds of cells. Total RNA was obtained from human iPSCs (hiPSCs), human iPSC-derived corneal epithelial cells (hiCECs), human corneal limbal epithelial cells (HCECs), human oral keratinocytes (HOKs), human dermal fibroblasts (HDFs) and six weeks-differentiated hiPSCs (hiPSC-derived ocular surface ectoderm, OSE) using the QIAZol reagent. A microarray analysis using Sure Print G3 human 8x60K slides (Agilent technologies) was performed at Takara Bio (Shiga, Japan).
Project description:Transplantation of ex vivo expanded limbal stem cells (LSC) is the main treatment for limbal stem cell deficiency though the clinical problem of donor tissues shortage. Recently, as the development of tissue engineering, embryonic stem cells (ESC) derived corneal epithelial-like cells (ESC-CEC) has become a new direction to this issue.Our group successfully induced ESC into corneal epithelial-like cells, and in the present study we explored various aspects of physiological properties of ESC-CEC.