Project description:MicroRNA profile comparison of the corneal endothelium of young and old mice: implications for senescence of the corneal endothelium We collected the corneal endothelia from 30 mice aged 10-13 weeks and the corneal endothelia from 30 mice aged 2 years. The samples were pooled into six groups (y1, y2, y3 and s1, s2, s3). Each group comprised corneal endothelia from ten mice, and these six groups were used for a genome-wide microRNA microarray study.
Project description:Genome wide DNA methylation profiling of normal human corneal endothelium and human corneal endothelium from FECD cases. The Illumina Infinium MethylationEPIC 850K BeadChip was used to obtain DNA methylation profiles across approximately 850,000 CpGs in genomic DNA from human corneal endothelium samples. Samples included 11 non-FECD donors, 17 FECD cases.
Project description:This SuperSeries is composed of the following subset Series: GSE24979: MicroRNA-145 Regulates Human Corneal Epithelial Differentiation [Agilent-016436 array data] GSE24980: MicroRNA-145 Regulates Human Corneal Epithelial Differentiation [Agilent-014850 array data] Refer to individual Series
Project description:The corneal endothelium plays a primary role in maintaining corneal homeostasis and clarity, and must be surgically replaced with allogenic donor corneal endothelium in the event of visually significant dysfunction. However, a worldwide shortage of donor corneal tissue has led to a search for alternative sources of transplantable tissue. Cultured human corneal endothelial cells (HCEnC) have been shown to restore corneal clarity in experimental models of corneal endothelial dysfunction in animal models, but characterization of cultured HCEnC remains incomplete. To this end, we utilized next-generation RNA sequencing technology to compare the transcriptomic profile of ex vivo human corneal endothelium (evHCEnC) with that of primary HCEnC and HCEnC lines, and to determine the utility of cultured and immortalized corneal endothelial cells as models of in vivo corneal endothelium. Multidimensional analyses of the transcriptome datasets demonstrated that primary HCEnC have a closer relationship to evHCEnC than do immortalized HCEnC. Subsequent analyses showed that the majority of the genes specifically expressed in HCEnC (not expressed in ex vivo corneal epithelium or fibroblasts) demonstrated a marked variability of expression in cultured cells compared with evHCEnC. In addition, genes associated with either corneal endothelial cell function or corneal endothelial dystrophies were investigated. Significant differences in gene expression and protein levels were observed in the cultured cells compared with evHCEnC for each of the genes tested except for AGBL1 and LOXHD1, which were not detected by RNA-seq or qPCR. Our transcriptomic analysis suggests that at a molecular level primary HCEnC most closely resemble evHCEC and thus represent a viable therapeutic option for managing corneal endothelial dysfunction. Our findings also suggest that investigators should perform an assessment of the entire transcriptome of cultured HCEnC prior to determination of the potential clinical utility of the cultured HCEnC for the management of corneal endothelial cell failure. Transcriptomes from ex vivo corneal endothelium, primary cultures and three cell lines were compared. Three samples of each endothelial cell group were submitted for RNA sequencing for a total of 15 samples. The transcriptome for the ex vivo corneal endothelium was used as the reference (i.e., proxy for in vivo corneal endothelium). Transcript abundances for a subset of genes associated with corneal endothelial cell function or disease were validated with qPCR and western blot. Samples of ex vivo endothelium used for validation were independent replicates not used for RNA-sequencing.
Project description:Fuchs’ endothelial corneal dystrophy (FECD) is a progressive vision impairing disease caused by thickening of Descemet’s membrane and gradual degeneration and loss of corneal endothelial cells. The aim of this study was to identify differentially expressed genes between FECD-affected and unaffected corneal endothelium to gain insight into the pathophysiological mechanisms underlying this disease. Microarray gene expression analysis was performed on total RNA from FECD-affected and unaffected corneal endothelium-Descemet’s membrane (CE-DM) specimens using the Illumina HumanHT-12 v3.0 expression array. RNA from pools of FECD-affected (n=3 per pool) and individual unaffected (n=3) specimens was used for comparison. Altered expression of a sub-set of differentially expressed genes was validated by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) in independent specimens. Bioinformatics analysis was performed using InnateDB to reveal functional relationships among the differentially expressed genes and molecular pathways involved in the disease. A total of 16,513 genes were found expressed in the corneal endothelium of which 142 genes were differentially expressed between FECD-affected and unaffected endothelium (log2 fold-change ≥1.5, corrected p-value ≤0.05). Most of the genes were up-regulated (126) and a small proportion down-regulated (16) in affected corneal endothelium. Of the twelve genes prioritised for validation, differential expression of 10 genes, including those ranked 57th and 81st by significance validated by qRT-PCR (8 up-regulated and 2 downregulated, corrected p ≤0.05), one gene showed a trend for up-regulation in affected endothelium, consistent with the microarray analysis and another was up-regulated in an independent study indicating robustness of the differential expression dataset. Bioinformatic analysis revealed significant over-representation of differentially expressed genes in extracellular matrix reorganisation, cellular remodelling, immune response, and inflammation. Network analysis showed functional inter-relatedness of the majority of the dysregulated genes and revealed known direct functional relationships between 20 of the genes; many of these genes have roles in macrophage differentiation, phagocytosis and inflammation. This is the second report of microarray gene expression analysis in FECD. This study revealed a set of highly dysregulated genes in the corneal endothelium in FECD. More than a third of the dysregulated genes in the disease have been discovered for the first time and thus are novel. The dysregulated genes strongly suggest the presence of phagocytic cells, most likely immune cells, and inflammation in corneal endothelium in the disease. This study provides a molecular framework for delineating the mechanisms underlying these cellular processes in FECD.
Project description:The advent of cell culture-based methods for the establishment and expansion of human corneal endothelial cells (CEnC) has provided an available source of transplantable corneal endothelium, with a significant potential to challenge the one donor-one recipient paradigm. However, concerns over cell state identity remain, and a comprehensive characterization of the cultured CEnC has not been performed. To this end, we compared two established CEnC culture methods by assessing cell function and characterizing the transcriptomic changes that occur during in vitro expansion. In confluent monolayers, low mitogenic culture conditions preserved corneal endothelial cell state identity better than culture in high mitogenic conditions. Expansion by continuous passaging induced replicative cell senescence. Transcriptomic analysis of the senescent phenotype identified a cell senescence signature distinct for CEnC. We identified activation of both classic and new cell signaling pathways that may be targeted to prevent senescence, a significant barrier to realizing the potential clinical utility of in vitro expansion.
Project description:To investigate the microRNA expression in human limbal-peripheral corneal (LPC) epithelia containing corneal epithelial progenitor cells (CEPCs) and early transit amplifying cells, we have employed Human microRNA Microarray V2 (Agilent) as a screening platform to identify specific microRNAs. We discovered a differential expression of 18 microRNAs against central corneal (CC) epithelia, which contains late transit amplifying cells and terminally differentiated cells. Among them, cluster miR-143/145 was expressed strongly in LPC but at low levels in CC epithelia and this was validated by real-time PCR and locked nucleic acid-based in situ hybridization. LPC and CC epithelia, separated by 1-mm in width, were dissected from human cornea for small RNA extraction. Total RNA was extracted by Trizol/chloroform and purified with RNeasy mini spin column. RNA samples with 28S/18S ratios in the range of 1.4 to 1.8 were used for microRNA profiling using an Agilent Human microRNA Microarray V2 platform.
Project description:To investigate the microRNA expression in human limbal-peripheral corneal (LPC) epithelia containing corneal epithelial progenitor cells (CEPCs) and early transit amplifying cells, we have employed Human microRNA Microarray V2 (Agilent) as a screening platform to identify specific microRNAs. We discovered a differential expression of 18 microRNAs against central corneal (CC) epithelia, which contains late transit amplifying cells and terminally differentiated cells. Among them, cluster miR-143/145 was expressed strongly in LPC but at low levels in CC epithelia and this was validated by real-time PCR and locked nucleic acid-based in situ hybridization.
Project description:Considerable interest has been generated for the development through cell-tissue engineering of suitable corneal endothelial graft alternatives, which can potentially alleviate the shortage of corneal transplant material. The advent of less invasive suture-less key-hole surgery options such as DescemetM-bM-^@M-^Ys Stripping Endothelial Keratoplasty (DSEK) and DescemetM-bM-^@M-^Ys Membrane Endothelial Keratoplasty (DMEK), which involve transplantation of solely the endothelial layer instead of full thickness cornea, provide further impetus for the development of alternative endothelial grafts for clinical applications. A major challenge for this endeavor is the lack of specific markers for this cell type. To identify genes that reliably mark corneal endothelial cells (CECs) in vivo and in vitro, we performed RNA-sequencing on freshly isolated human CECs (from both young and old donors), CEC cultures, and corneal stroma. Gene expression of these corneal cell types were also compared to that of other human tissue types. Based on high throughput comparative gene expression analysis, we identified a panel of markers that are: i) highly expressed in CECs from both young donors and old donors; ii) expressed in CECs in vivo and in vitro; and iii) not expressed in corneal stroma keratocytes and the activated corneal stroma fibroblasts. These were SLC4A11, COL8A2 and CYYR1. The use of this panel of genes in combination reliably ascertains the identity of the CEC cell type. A total of 20 donor corneas consisting of 10 single donor corneas and 5 paired donor corneas were used in this study. Donor age ranged from 19 - 76. This RNA-seq study included 15 pooled corneas (5 each) used form CEC old, CEC young and stroma samples.