The hypothalamus is a central regulator of many behaviors essential for survival such as temperature regulation, food intake and circadian rhythms. However, the molecular pathways that mediate hypothalamic development are largely unknown. To identify genes expressed in developing mouse hypothalamus, microarray analysis at 12 different developmental time points was performed. Developmental in situ hybridization was conducted for 1,045 genes dynamically expressed by microarray analysis. In this way, we identified markers that stably labeled each major hypothalamic nucleus over the entire course of neurogenesis, and thus constructed a detailed molecular atlas of the developing hypothalamus. As proof of concept for the utility of this data, we used these markers to analyze the phenotype of mice where Sonic Hedgehog (Shh) was selectively deleted from hypothalamic neuroepithelium, demonstrating an essential role for Shh in anterior hypothalamic patterning. Our results serve as a resource for functional investigations of hypothalamic development, connectivity, physiology, and dysfunction.
A genomic atlas of mouse hypothalamic development.
Sex, Specimen part
View SamplesThe mechanism of CD4(+) T cell depletion during chronic human immunodeficiency virus type 1 (HIV-1) infection remains unknown. Many studies suggest a significant role for chronic CD4(+) T cell activation. We assumed that the pathogenic process of excessive CD4(+) T cell activation would be reflected in the transcriptional profiles of activated CD4(+) T cells. Here we demonstrate that the transcriptional programs of in vivo activated CD4(+) T cells from untreated HIV(+) individuals are clearly different from those activated CD4(+) T cells from HIV(-) individuals. We observed a dramatic up-regulation of cell cycle-associated and interferon-stimulated transcripts in activated CD4(+) T cells of untreated HIV(+) individuals. Furthermore, we find an enrichment of proliferative and Type I interferon-responsive transcription factor binding sites in the promoters of genes that are differentially expressed in activated CD4(+) T cells of untreated HIV(+) individuals compared to HIV(-) individuals. We confirm these findings by examination of in vivo activated CD4(+) T cells. Taken together, these results suggest that activated CD4(+) T cells from untreated HIV(+) individuals are in a hyper-proliferative state that is modulated by Type I interferons. From these results, we propose a new model for CD4(+) T cell depletion during chronic HIV-1 infection.
Chronic CD4+ T-cell activation and depletion in human immunodeficiency virus type 1 infection: type I interferon-mediated disruption of T-cell dynamics.
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View SamplesSilencing of tumor suppressor genes plays a vital role in head and neck carcinogenesis. Aberrant hypermethylation in the promoter region of some known or putative tumor suppressor genes (TSGs) occurs frequently during the development of various cancers including head and neck squamous cell carcinoma (HNSCC). In this study we used an expanded mRNA expression profiling approach followed by microarray expression analysis to identify epigenetically inactivated genes in HNSCC. Two HNSCC cell lines were treated with 5-aza-2-deoxycytidine followed by microarray analysis to identify epigenetically silenced genes in HNSCC. 1960, 614, and 427 genes were upregulated in HNSCC cell lines JHU-012, JHU-011 and the combination of both cell lines, respectively. HNSCC tumor and normal mucosal samples were used for gene profiling by a 47K mRNA gene expression array and we found, 7140 genes were downregulated in HNSCC tumors compared to normal mucosa as determined by microarray analysis and were integrated with cell line data. Integrative analysis defined 126 candidate genes, of which only seven genes showed differentially methylation in tumors and no methylation in normal mucosa after bisulfite sequencing. After validation by QMSP, one gene, GNG7, was confirmed as being highly methylated in tumors and unmethylated in normal mucosal and salivary rinse samples demonstrating cancer-specific methylation in HNSCC tissues. TXNIP and TUSC2 were partially methylated in tumors and normal salivary rinses but unmethylated in normal mucosa. We concluded GNG7 as a highly specific promoter methylated gene associated with HNSCC. In addition, TXNIP and TUSC2 are also potential biomarkers for HNSCC.
Identification of guanine nucleotide-binding protein γ-7 as an epigenetically silenced gene in head and neck cancer by gene expression profiling.
Sex
View SamplesThis SuperSeries is composed of the SubSeries listed below.
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Cell line
View SamplesThe objective of this experiment was to determine changes in gene expression upon loss of alfa-1 in C.elegans under well-fed and starvation conditions. The human C9orf72 has an orthologue in C. elegans based on sequence homology, which is the F18A1.6 gene and also recently named as alfa-1 (ALS/FTD-associated gene homolog 1). We analyzed the domain structure of ALFA-1 and found that it shares the same DENN domains as human C9orf72, including the uDENN, cDENN, and dDENN domains. We obtained a mutant strain of the alfa-1 gene, which has a mutant allele (ok3062) of 486 bp deletion and 24 bp insertion in the region of exon 3 and exon 4. To understand the changes in gene expression in the alfa-1 mutant C. elegans, we performed the microarray gene expression profiling experiments under the defined conditions.
C9orf72/ALFA-1 controls TFEB/HLH-30-dependent metabolism through dynamic regulation of Rag GTPases.
Treatment
View SamplesNrf2 null mice administered CDDO-IM
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Sex, Specimen part, Compound
View SamplesLDL or Ox-LDL 200ug/ml, which showed no loss of viability after a 48 hour exposure, induced a physiological and pathological transcriptional response, respectively. LDL induced a downregulation of genes associated with cholesterol biosynthesis while ox-LDL induced transcriptional alterations in genes related to inflammation, matrix expansion, lipid metabolism and processing, and apoptosis. Pentraxin-3 was secreted into the culture medium after RPE cells were stimulated with ox-LDL, and immunohistochemically evident in Bruchs membrane of human macular samples with age-related macular degeneration. ARPE-19 cells exposed to 200?g/ml ox-LDL had a 38% apoptosis rate compared to less than 1% when exposed to LDL or untreated controls (p<0.0001).
Oxidized low density lipoproteins induce a pathologic response by retinal pigmented epithelial cells.
No sample metadata fields
View SamplesMutation of rod photoreceptor-enriched transcription factors is a major cause of inherited blindness. We identified the orphan nuclear hormone receptor ERR as selectively expressed in rod photoreceptors. Overexpression of ERR induces expression of rod-specific genes in retinas of both wildtype and in Nrl-/- mice, which lack rod photoreceptors. Mutation of ERR results in dysfunction and degeneration of rods, while inverse agonists of ERR trigger rapid rod degeneration, which is rescued by constitutively active mutants of ERR. ERR coordinates expression of multiple genes that are rate-limiting regulators of ATP generation and consumption in photoreceptors. Furthermore, enhancing ERR activity rescues photoreceptor defects that result from loss of the photoreceptor-specific transcription factor Crx. Our findings demonstrate that ERR is a critical regulator of rod photoreceptor function and survival, and suggest that ERR agonists may be useful in the treatment of certain retinal dystrophies.
No associated publication
Sex
View SamplesStudying chemical disturbances during neural differentiation of mES cells has been established as an alternative in vitro testing approach for the identification of developmental toxicants. miRNAs represent a class of small regulatory RNA molecules, which bind to target mRNAs thereby repressing their translation. Many studies have shown an essential role of miRNAs in regulation of gene expression during development and ESC differentiation. Thus, neural differentiation of ESC in vitro allows investigating the role of miRNAs in chemical-mediated developmental toxicity. We analyzed the expression of miRNAs and transcriptomics changes during neural differentiation of mESC exposed to the developmental neurotoxicant sodium valproate (VPA). A total of 110 miRNAs and 377 mRNAs were identified differently expressed in neural differentiating mES cells under VPA treatment (300M) compared to solvent control on day 16 of differentiation. Analysis of miRNA expression revealed that valproate switches the lineage specification from neural to myogenic differentiation (upregulation of muscle-enriched miRNAs mir-206, mir-133a and mir-10a and downregulation of neuro-specific miRNAs mir-124a, mir-128 and mir-137). The findings on the miRNA level could be confirmed on mRNA level (induction of expression of myogenic regulatory factors (MRFs) as well as muscle specific genes (Actc1, calponin, myosin light chain, asporin, decorin) and repression of genes involved in neurogenesis (Otx1 and 2, Zic3, 4, 5)) as well as morphologically by immunocytochemistry. The observed results were VPA specific and most probably due to inhibition of histone deacetylase (HDAC) activity of VPA for two reasons: (i) we did not observe any induction of muscle specific miRNAs in neural differentiating ES cells exposed to the unrelated developmental neurotoxicant sodium arsenite; (ii) expression of muscle specific mir-206 and muscle enriched mir-10a was similarly increased in cells exposed to a structurally different HDAC inhibitor, trichostatin A (TSA). Furthermore, using our in vitro cell system we could confirm an aberrant expression of known VPA target genes and genes involved in neural tube closure. We conclude that miRNA expression profiling is a suitable molecular endpoint for developmental neurotoxicity. Observed lineage shift into myogenesis, where miRNAs play a significant role, could be a major developmental neurotoxical mechanism of VPA.
No associated publication
Cell line
View SamplesComparison of gene experission profiles of Ecoli WT3110 and phoU mutant
PhoU is a persistence switch involved in persister formation and tolerance to multiple antibiotics and stresses in Escherichia coli.
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