Project description:Consistent with clinical observations that posterior uveitis frequently involves the retinal vasculature and recent recognition of vascular heterogeneity, we hypothesized that retinal vascular endothelium was a cell population of unique molecular phenotype. Donor-matched cultures of primary retinal and choroidal endothelial cells from 6 human cadavers were incubated with either Toxoplasma gondii tachyzoites (10:1, parasite:cell) or Escherichia coli lipopolysaccharide (100 ng/mL); control cultures were simultaneously incubated with medium. Gene expression profiling of endothelial cells was performed using oligonucleotide arrays containing probes designed to detect 8747 human transcripts. After normalization, differential gene expression was assessed by the significance analysis of microarrays, with the false discovery rate set at 5 %. For selected genes, differences in level of expression between retinal and choroidal cells were evaluated by real-time RT-PCR. Graphical descriptive analysis demonstrated strong correlation between gene expression of unstimulated retinal and choroidal endothelial cells, but also highlighted distinctly different patterns of expression that were greater than differences noted between donors or between unstimulated and stimulated cells. Overall, 779 of 8,747 transcripts (8.9 %) were differentially represented. Notably, the 330 transcripts that were present at higher levels in retinal cells included a larger percentage of transcripts encoding molecules involved in the immune response. Differential gene expression was confirmed for 12 transcripts by RT-PCR. Retinal and choroidal vascular endothelial cells display distinctive gene expression profiles. Our findings suggest the possibility of treating posterior uveitis by targeting specific interactions between the retinal endothelial cell and an infiltrating leukocyte. Experiment Overall Design: Retinal and choroidal vascular endothelial cells were isolated from both eyes of 6 human cadaver donors. Endothelial cells of each subtype from each donor were separately pooled and cultured. In a first series of experiments (Experiment 1), donor-matched cultures of retinal and choroidal endothelial cells derived from 3 donors were incubated with either T. gondii tachyzoites or medium alone. In a second set of experiments (Experiment 2), cultured retinal and choroidal endothelial cells derived from the other 3 donors were stimulated with LPS or medium alone. Whenever possible, 2 replicate dishes of endothelial cells were subjected to each set of conditions. Subsequent to incubations, mRNA was extracted from a cell lysate prepared from each dish of cells, and cRNA derived from each mRNA preparation was separately hybridized to one oligonucleotide expression array.
Project description:Consistent with clinical observations that posterior uveitis frequently involves the retinal vasculature and recent recognition of vascular heterogeneity, we hypothesized that retinal vascular endothelium was a cell population of unique molecular phenotype. Donor-matched cultures of primary retinal and choroidal endothelial cells from 6 human cadavers were incubated with either Toxoplasma gondii tachyzoites (10:1, parasite:cell) or Escherichia coli lipopolysaccharide (100 ng/mL); control cultures were simultaneously incubated with medium. Gene expression profiling of endothelial cells was performed using oligonucleotide arrays containing probes designed to detect 8747 human transcripts. After normalization, differential gene expression was assessed by the significance analysis of microarrays, with the false discovery rate set at 5 %. For selected genes, differences in level of expression between retinal and choroidal cells were evaluated by real-time RT-PCR. Graphical descriptive analysis demonstrated strong correlation between gene expression of unstimulated retinal and choroidal endothelial cells, but also highlighted distinctly different patterns of expression that were greater than differences noted between donors or between unstimulated and stimulated cells. Overall, 779 of 8,747 transcripts (8.9 %) were differentially represented. Notably, the 330 transcripts that were present at higher levels in retinal cells included a larger percentage of transcripts encoding molecules involved in the immune response. Differential gene expression was confirmed for 12 transcripts by RT-PCR. Retinal and choroidal vascular endothelial cells display distinctive gene expression profiles. Our findings suggest the possibility of treating posterior uveitis by targeting specific interactions between the retinal endothelial cell and an infiltrating leukocyte. Keywords: Cell type comparison, stress response
Project description:PURPOSE Diseases that involve choroidal or retinal endothelial vascular cells are leading causes of vision loss: age-related macular degeneration, retinal ischemic vasculopathies and non-infectious posterior uveitis. Proteins differentially expressed by these endothelial cell populations are potential drug targets. We used deep proteomics to define the molecular phenotype of human choroidal and retinal endothelial cells at the protein level. METHODS Choroidal and retinal endothelial cells were separately isolated from 5 human eye pairs by selection on CD31. Total protein was extracted and digested, and peptide fractions were analysed by reverse-phase liquid chromatography tandem mass spectrometry. Peptide sequences were assigned to fragment ion spectra and proteins were inferred using public protein databases. Protein abundance was determined by spectral counting. Protein expression in choroidal versus retinal endothelial cells was compared using edgeR package in R, and annotation enrichment analysis was performed. RESULTS Human choroidal or retinal endothelial cells expressed 5042 non-redundant proteins. Setting the false discovery rate at 5%, 498 proteins (14.4%) of 3454 quantifiable proteins with minimum mean spectral counts of 2.5 were differentially expressed between cell populations. Choroidal and retinal endothelial cells were enriched in angiogenic proteins, and retinal endothelial cells were also enriched in immunologic proteins. CONCLUSIONS This work demonstrates the protein heterogeneity of human choroidal and retinal vascular endothelial cells and provides multiple candidates for further study as novel treatments or drug targets for posterior eye diseases.
Project description:To compare the gene expression profiles of unpassaged, proliferating HUVEC and human iris, retinal and choroidal microvascular endothelial cells. Gene expression profiling revealed significant differences between HUVEC and ocular microvascular endothelial cells suggesting that HUVE cells may not be a suitable surrogate when studying pathophysiological mechanisms of ocular disorders. There were significant differences in the gene expression of important cell signalling pathways in human retinal and choroidal ECs. These differences may be important in the mechanisms and treatment of choroidal and retinal neovascularisation. 12 arrays are included. Endothelial cells were derived from 4 tissues: iris, retina, choroid and human umbilical vein. RNA extracts from cells were hybridised to Affymetrix HGU133plus2 arrays in triplicate.
Project description:To compare the gene expression profiles of unpassaged, proliferating HUVEC and human iris, retinal and choroidal microvascular endothelial cells. Gene expression profiling revealed significant differences between HUVEC and ocular microvascular endothelial cells suggesting that HUVE cells may not be a suitable surrogate when studying pathophysiological mechanisms of ocular disorders. There were significant differences in the gene expression of important cell signalling pathways in human retinal and choroidal ECs. These differences may be important in the mechanisms and treatment of choroidal and retinal neovascularisation.
Project description:Retinal pigment epithelial (RPE) cells and choroidal stromal fibroblast (CSF) were isolated from healthy human donor eyes. Cells were cultured and RNA extracted.
Project description:To investigate the differences in gene expression between matched human macular and peripheral choroidal endothelial cells (CEC) and matched human macular inner and outer CEC. The gene expression profiles of the unpassaged cell types were compared using Affymetrix GeneChip arrays.
Project description:The activity and survival of retinal photoreceptors depend on support functions performed by the retinal pigment epithelium (RPE) and on oxygen and nutrients delivered by blood vessels in the underlying choroid. By combining single cell and bulk RNA sequencing, we categorized mouse RPE/choroid cell types and characterized the tissue-specific transcriptomic features of choroidal endothelial cells. We found that choroidal endothelium adjacent to the RPE expresses high levels of Indian Hedgehog, and identified its downstream target as stromal GLI1+ mesenchymal stem cell-like cells. Genetic impairment of Hedgehog signaling in vivo induced significant loss of choroidal mast cells, as well as an altered inflammatory response and exacerbated visual function defects after retinal damage. Our studies reveal the cellular and molecular landscape of adult RPE/choroid and uncover a Hedgehog-regulated choroidal immunomodulatory signaling circuit. These results open new avenues for the study and treatment of retinal vascular diseases and choroid-related inflammatory blinding disorders.
Project description:Purpose: The goals of this study were to identify cell specific expression patterns of the retinal pigment epithelium (RPE) and a variety of choroidal cell types originating from the macula and the periphery of human donor eyes, with a particular emphasis on identifying expression signatures of choroidal endothelial cells. Methods: Independent libraries were prepared for macular and peripheral samples of combined RPE/choroid from seven donors in two single cell sequencing experiments. In the first experiment, 8-mm macular and peripheral punches of RPE/choroid from Donors 1-3 were digested in papain prior to cryopreservation and subsequent GEM barcoding/library construction. Donors 1-2 had no noted ophthalmologic disease documented, while Donor 3 was diagnosed with age-related macular degeneration. In the second experiment, 12-mm macular and peripheral punches of RPE/choroid from Donors 4-7 were digested in collagenase II prior to cryopreservation, CD31-magentic bead enrichment and subsequent GEM barcoding/library construction. Donors 5-7 had no noted ophthalmologic disease documented, while Donor 4 was diagnosed with age-related macular degeneration. In both experiments, libraries were sequenced on a HiSeq4000. Sequenced reads were mapped to the human genome build hg19 will CellRanger(v3.0.1) and filters removed cells likely to be doublets or cells with a high proportion of mitochondrial reads. Clustering of cells with similar expression profiles was performed with Seurat (v3.0.2). Results: In the first experiment with unenriched RPE/choroid from donors 1-3, we recovered 4,355 cells post filtering with 40,177,477 corresponding reads. A total of 2,167 cells originated from the macula and 2,168 cells originated from the periphery. A total of 11 clusters were identified, and highly enriched genes in each cluster were used to classify clusters into their presumed dominant cell type. Differential expression analysis was performed between cells of macular and peripheral origin in each cluster and between donors with and without a history of age-related macular degeneration. Results: In the second experiment with CD31-enriched RPE/choroid from donors 4-7, we recovered 14,234 cells post filtering with 135,742,297 corresponding reads. A total of 7,647 cells originated from the macula and 6,587 cells originated from the periphery. A total of 8,521 of these cells were presumed endothelial cells. A total of 13 clusters were identified, and highly enriched genes in each cluster were used to classify clusters into their presumed dominant cell type(s). Differential expression analysis was performed between cells of macular and peripheral origin in each cluster and between donors with and without a history of age-related macular degeneration. Within each of the endothelial clusters (Clusters 5-8), differential expression analysis was performed between each cluster and the remaining endothelial cells. Conclusions: This study provides a large atlas of single-cell level gene expression patterns of the human retinal pigment epithelium and choroidal cell types. We identify expression patterns of most expected choroidal cell populations and describe macular versus peripheral regional differences. We additionally identify enriched transcripts in specific cell populations in age-related macular degeneration. We characterize gene expression patterns along the choroidal vascular tree, and identify populations of arterial, capillary, and venous endothelial cells. Our results show that single-cell sequencing can be performed on human RPE/choroid after cryopreservation, and that CD31 magnetic bead enrichment can be employed to enrich for endothelial cells for single-cell sequencing.
Project description:Age-related macular degeneration (AMD) is a common, blinding disease of the elderly in which macular photoreceptor cells, retinal pigment epithelium, and choriocapillaris endothelial cells ultimately degenerate. Recent studies have found that degeneration of the choriocapillaris occurs early in this disease and that this endothelial cell dropout is concomitant with increased deposition of the complement membrane attack complex (MAC) at the choroidal endothelium. However, the impact of MAC injury to choroidal endothelial cells is poorly understood. To model this event in vitro, and to study the downstream consequences of MAC injury, endothelial cells were exposed to complement from human serum, compared to heat inactivated serum which lacks complement components. Cells exposed to complement components in human serum showed increased labeling with antibodies directed against the MAC, time and dose dependent cell death as assessed by lactate dehydrogenase assay, and increased permeability. RNA-Seq analysis following complement injury revealed increased expression of genes associated with angiogenesis including matrix metalloproteases (MMPs) 3 and 9, and VEGF-A. The MAC-induced increase in MMP9 RNA expression was validated using C5 depleted serum compared to C5 reconstitited serum. Increased levels of MMP9 were also determined using Western blot and zymography. These data suggest that, in addition to cell lysis, complement attack on choroidal endothelial cells promotes an angiogenic phenotype in surviving cells. RNA-Seq of RF/6A (cultured choroidal endothelial cells from Rhesus macaque) treated with either 50% heat-inactivated human serum ([CONTROL], n=3) or 50% normal human serum (active complement membrane attack complex [MAC], n=3)