Purpose: Marked extracellular matrix (ECM) remodeling occurs in the human optic nerve head in primary open angle glaucoma (POAG). The glial fibrillary acid protein (GFAP) negative lamina cribrosa cell may play an important role in this remodeling process. The authors report the first study of global and ECM-focused gene transcription differentials between GFAP-negative negative lamina cribrosa (LC) cells from normal and POAG human donors. Methods: GFAP-negative LC cell lines were generated from the optic nerve tissue of three normal (n=3) and three POAG (n=3) human donors. Using Affymetrix U133A arrays the transcriptional profile between the normal and diseased groups were compared. Bioinformatic analysis was carried out using robust multichip average (RMA Express) and EASE/David. Real time TaqMan PCR and immunohistochemistry analyses were performed to validate the microarray data. Results: 285 genes were up regulated by greater than 1.5 fold and 413 were down regulated by greater than 1.5 fold in the POAG LC cells versus normal controls. Upregulated genes in POAG LC cells included, SPARC, periostin, thrombospondin, CRTL-1, CTGF and collagen types I, III, V and VIII. Downregulated ECM genes in POAG included MMP-1, fibulin, decorin and tenacsin XB. All TaqMan PCR validation assays were significant (*p<0.05) and consistent with the array data. Immunohistochemistry of one target (periostin) confirmed its differential expression at the protein level in POAG optic nerve head tissue compared with non-glaucomatous controls. Functional annotation and over-representation analysis identified ECM genes as a statistically over-represented class of genes in POAG LC cells compared with normal LC cells. Conclusions: This study reports for the first time that POAG LC cells in-vitro demonstrate up regulated ECM and pro-fibrotic gene expression compared with normal LC cells. This may be a pathological characteristic of this cell type in POAG in-vivo. We believe that the LC cell may be a pivotal regulator of optic nerve head ECM remodeling and an attractive target for future therapeutic strategies in POAG.
Differential global and extra-cellular matrix focused gene expression patterns between normal and glaucomatous human lamina cribrosa cells.
No sample metadata fields
View SamplesThe mechanical effect of raised intraocular pressure is a recognised stimulus for optic neuropathy in primary open angle glaucoma (POAG). Characteristic extra-cellular matrix (ECM) remodelling accompanies axonal damage in the lamina cribrosa (LC) of the optic nerve head in POAG. Glial cells in the lamina cribrosa may play a role in this process but the precise cellular responses to mechanical forces in this region are unknown. The authors examined global gene expression profiles in lamina cribrosa cells exposed to cyclical mechanical stretch, with an emphasis on ECM genes.
Influence of cyclical mechanical strain on extracellular matrix gene expression in human lamina cribrosa cells in vitro.
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Optic nerve crush induces spatial and temporal gene expression patterns in retina and optic nerve of BALB/cJ mice.
Specimen part, Time
View SamplesCentral nervous system (CNS) trauma and neurodegenerative disorders trigger a cascade of cellular and molecular events resulting in neuronal apoptosis and regenerative failure. The pathogenic mechanisms and gene expression changes associated with these detrimental events can be effectively studied using a rodent optic nerve crush (ONC) model. The purpose of this study was to use a mouse ONC model to: (a) evaluate changes in optic nerve (ON) gene expression, (b) identify neurodegenerative pathogenic pathways and (c) discover potential new therapeutic targets.
Optic nerve crush induces spatial and temporal gene expression patterns in retina and optic nerve of BALB/cJ mice.
Specimen part, Time
View SamplesCentral nervous system (CNS) trauma and neurodegenerative disorders trigger a cascade of cellular and molecular events resulting in neuronal apoptosis and regenerative failure. The pathogenic mechanisms and gene expression changes associated with these detrimental events can be effectively studied using a rodent optic nerve crush (ONC) model. The purpose of this study was to use a mouse ONC model to: (a) evaluate changes in retina gene expression, (b) identify neurodegenerative pathogenic pathways and (c) discover potential new therapeutic targets.
Optic nerve crush induces spatial and temporal gene expression patterns in retina and optic nerve of BALB/cJ mice.
Specimen part, Time
View SamplesWe investigated the specificity profiles of a variety of RNA guided adenosine deaminases while exploring roles of NLS/NES and hyperactive mutants via analysis of the transcriptome-wide off-target A->G editing effected by these tools. To this end, HEK 293T cells were transfected with each construct and analyzed by RNA-seq. Untransfected cells were included as controls. From each sample, we collected ~40 million uniquely aligned sequencing reads. We then used Fisher's exact test to quantify significant changes in A->G editing yields, relative to untransfected cells, at each reference adenosine site having sufficient read coverage. The number of sites with at least one A->G editing event detected in any of the samples was computed. Overall design: Study of transcriptome wide A->G off-targets arising due to the overexpression of a variety of RNA guided adenosine deaminases.
In vivo RNA editing of point mutations via RNA-guided adenosine deaminases.
No sample metadata fields
View SamplesTo identify transcripts altered upon LIN-41 knockdown, we transfected either a control siRNA or one of two different LIN-41 siRNAs into human embryonic stem cells and collected total RNA 72 hours after transfection. Overall design: We compared transcript levels between control siRNA or LIN-41 siRNA treated cells.
The let-7/LIN-41 pathway regulates reprogramming to human induced pluripotent stem cells by controlling expression of prodifferentiation genes.
No sample metadata fields
View SamplesInflammation has pleiotropic effects on carcinogenesis and tumor progression. Signaling through the adaptor protein MyD88 promotes carcinogenesis in several chemically induced cancer models. Interestingly, we observed a protective role for MyD88 in the development of AOM/DSS colitis-associated cancer. The inability of Myd88-/- mice to heal ulcers generated upon injury creates an inflammatory environment that increases the frequency of mutations and results in a dramatic increase in adenoma formation and cancer progression. Susceptibility to colitis development and enhanced polyp formation were also observed in Il18-/- mice upon AOM/DSS treatment, suggesting that the phenotype of MyD88 knockouts is in part due to their inability to signal through the IL-18 receptor. This study revealed a previously unknown level of complexity surrounding MyD88 activities downstream of different receptors that differentially impact tissue homeostasis and carcinogenesis.
MyD88-mediated signaling prevents development of adenocarcinomas of the colon: role of interleukin 18.
Specimen part, Disease, Disease stage
View SamplesCells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. To identify genes regulated by hypoxia at the transcriptional level, we pulse-labeled HUVEC cells with 4-thiouridine and sequenced nascent transcripts. Then, we searched genome-wide binding profiles from the ENCODE project for factors that correlated with changes in transcription and identified binding of several components of the Sin3A co-repressor complex, including SIN3A, SAP30 and HDAC1/2, proximal to genes repressed by hypoxia. SIN3A interference revealed that it participates in the downregulation of 75% of the hypoxia-repressed genes in endothelial cells. Unexpectedly, it also blunted the induction of 47% of the upregulated genes, suggesting a role for this corepressor in gene induction. In agreement, ChIP-seq experiments showed that SIN3A preferentially localizes to the promoter region of actively transcribed genes and that SIN3A signal was enriched in hypoxia-repressed genes, prior exposure to the stimulus. Importantly, SINA3 occupancy was not altered by hypoxia in spite of changes in H3K27ac signal. In summary, our results reveal a prominent role for SIN3A in the transcriptional response to hypoxia and suggest a model where modulation of the associated histone deacetylase activity, rather than its recruitment, determines the transcriptional output. Overall design: Exponentially growing non-synchronized HUVEC were exposed to normoxia or hypoxia (21% or 1% oxygen respectively) for 8 hours and pulse-labelled with 4-thiouridine during the last two hours of treatment. RNA was extracted from samples in each condition (total RNA) and an aliquot was subjected to affinity chromatography to purify the 4-thiouridine-labelled (newly transcribed RNA, Newly Tr) and non-labelled (Pre-existent) RNA fractions. All three RNA fractions (total, newly transcribed and pre-existent) from each sample were analyzed by high-throughput sequencing. Submission includes 12 samples corresponding to 3 independent biological replicates.
The SIN3A histone deacetylase complex is required for a complete transcriptional response to hypoxia.
Cell line, Treatment, Subject
View SamplesCells adapt to environmental changes, including fluctuations in oxygen levels, through the induction of specific gene expression programs. To identify genes regulated by hypoxia at the transcriptional level, we pulse-labeled HUVEC cells with 4-thiouridine and sequenced nascent transcripts. Then, we searched genome-wide binding profiles from the ENCODE project for factors that correlated with changes in transcription and identified binding of several components of the Sin3A co-repressor complex, including SIN3A, SAP30 and HDAC1/2, proximal to genes repressed by hypoxia. SIN3A interference revealed that it participates in the downregulation of 75% of the hypoxia-repressed genes in endothelial cells. Unexpectedly, it also blunted the induction of 47% of the upregulated genes, suggesting a role for this corepressor in gene induction. In agreement, ChIP-seq experiments showed that SIN3A preferentially localizes to the promoter region of actively transcribed genes and that SIN3A signal was enriched in hypoxia-repressed genes, prior exposure to the stimulus. Importantly, SINA3 occupancy was not altered by hypoxia in spite of changes in H3K27ac signal. In summary, our results reveal a prominent role for SIN3A in the transcriptional response to hypoxia and suggest a model where modulation of the associated histone deacetylase activity, rather than its recruitment, determines the transcriptional output. Overall design: Exponentially growing non-synchronized HUVEC were transduced with lentiviral particles encoding for shRNA targeting EPAS1 or control shRNA. 72h after infection, cells were exposed to normoxia or hypoxia (21% or 1% oxygen respectively) for 8 hours and pulse-labelled with 4-thiouridine during the last two hours of treatment. RNA was extracted from samples in each condition (total RNA) and an aliquot subjected to affinity chromatography to purify the 4-thiouridine-labelled RNA fraction (newly transcribed RNA, Newly Tr). Both RNA fractions from each condition were analyzed by high-throughput sequencing. Data includes 8 samples from a single biological replicate.
The SIN3A histone deacetylase complex is required for a complete transcriptional response to hypoxia.
Cell line, Subject
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