Embryonic stem cells (ESCs) may be able to cure or alleviate the symptoms of various degenerative diseases. However, unresolved issues regarding apoptosis, maintaining function and tumor formation mean a prudent approach should be taken towards advancing ESCs into human clinical trials. The rhesus monkey provides the ideal model organism for developing strategies to prevent immune rejection and test the feasibility, safety and efficacy of ESC-based medical treatments. Transcriptional profiling of rhesus ESCs provides a foundation for future pre-clinical ESC research using non-human primates as the model organism. In this research we use microarray, immunocytochemistry, real-time and standard RT-PCR to characterize and transcriptionally profile rhesus monkey embryonic stem cells. We identify 367 rhesus monkey stemness genes, we demonstrate the high level (>85%) of conservation of rhesus monkey stemness gene expression across five different rhesus monkey embryonic stem cell lines, we demonstrate that rhesus monkey ESC lines maintain a pluripotent undifferentiated state over a wide range of Pou5f1 (Oct-4) expression levels and we compare rhesus monkey, human and murine stemness genes to identify the key mammalian stemness genes.
Transcriptional profiling of rhesus monkey embryonic stem cells.
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View SamplesParthenogenetic embryonic stem cells (PESCs) may have future utility in cell replacement therapies. We examined genome-wide mRNA expression profiles of monkey PESCs relative to ESCs derived from fertilized embryos. Several known paternally-imprinted genes were in the highly down-regulated group in PESCs compared to ESCs. Allele specific expression analysis of paternally-imprinted genes, i.e., those genes whose expression is down-regulated in PESCs, led to the identification of one novel candidate that was exclusively expressed from a paternal allele. Our findings suggest that PESCs could be used as a model for studying genomic imprinting and in the discovery of novel imprinted genes.
Discovery of a novel imprinted gene by transcriptional analysis of parthenogenetic embryonic stem cells.
Sex, Specimen part
View SamplesDerivation of embryonic stem cells (ESC) genetically identical to a patient by somatic cell nuclear transfer (SCNT) holds the potential to cure or alleviate the symptoms of many degenerative diseases while circumventing any immunorejection issues. However, no primate nuclear transfer embryonic stem (ntES) cell lines have been derived to date. Here, we used a modified SCNT technique to produce rhesus macaque SCNT blastocysts at a relatively high efficiency from adult donor cells and we successfully derived two primate ntES cell lines from 304 oocytes (an overall efficiency of 0.7%). Nuclear and mitochondrial DNA analysis confirmed the ntES cell lines were derived from rhesus monkey SCNT blastocysts and both rhesus monkey ntES cell lines exhibited a normal ESC morphology, expressed key stemness markers, were transcriptionally indistinguishable from control ESC lines and differentiated into multiple cell types. This is, to our knowledge, the first confirmed derivation of primate ntES cell lines.
Producing primate embryonic stem cells by somatic cell nuclear transfer.
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View SamplesThere are currently no biological tests that differentiate patients with bipolar disorder (BPD) from healthy controls. While there is evidence that peripheral gene expression differences between patients and controls can be utilized as biomarkers for psychiatric illness, it is unclear whether current use or residual effects of antipsychotic and mood stabilizer medication drives much of the differential transcription. We therefore tested whether expression changes in first-episode, never-medicated bipolar patients, can contribute to a biological classifier that is less influenced by medication and could potentially form a practicable biomarker assay for BPD.
Utilization of never-medicated bipolar disorder patients towards development and validation of a peripheral biomarker profile.
Sex, Age, Specimen part
View SamplesIrritant contact dermatitis (ICD) pathogenesis is not completely understood and the genes participating in the epidermal response towards chemical irritants are only partly known. It is commonly accepted that different irritants have different mechanisms of action in the development of ICD. To define the differential molecular events induced in the epidermis by different irritants, we collected sequential biopsies (, 4 and 24 hours after a single exposure and at day 11 after repeated exposure) from human volunteers exposed to sodium lauryl sulphate (SLS) or nonanoic acid (NON). Gene expression analysis using high-density oligonucleotide microarrays revealed essentially different pathway responses h after exposure: NON transiently induced the IL-6 pathway as well as a number of mitogen activated signalling cascades including ERK and growth factor receptor signalling, whereas SLS transiently downregulated cellular energy metabolism pathways. Differential expression of the cyclooxygenase-2 and matrix metalloproteinase 3 transcripts was confirmed immunohistochemically. After cumulative exposure, 883 genes were differentially expressed while 26 suggested common biomarkers were identified . In conclusion, we bring new insights into two hitherto less well elucidated phases of skin irritancy: the very initial as well as the late phase after single and cumulative exposure, respectively.
Genome-wide expression analysis of human in vivo irritated epidermis: differential profiles induced by sodium lauryl sulfate and nonanoic acid.
Specimen part
View SamplesTo obtain a separation of the epidermal and dermal compartments in order to examine compartment specific biological mechanisms in the skin we incubated 4 mm human skin punch biopsies in ammonium thiocyanate (NH4SCN). We wanted to test 1) the histological quality of the dermo-epidermal separation obtained by different incubation times 2) the amount and quality of extractable epidermal RNA, and 3) its impact on sample RNA expression profiles assessed by large-scale gene expression microarray analysis in both normal and inflamed skin. At 30 minutes incubation, the split between dermis and epidermis was not always histologically well-defined (i.e. occurred partly intra-epidermally) but varied between subjects. Consequently, curettage along the dermal surface of the biopsy was added to the procedure. This modified method resulted in an almost perfect separation of the epidermal and dermal compartments and satisfactory amounts of high-quality RNA were obtained. Hybridization to Affymetrix HG_U133A 2.0 GeneChips showed that ammonium thiocyanate incubation had a minute effect on gene expression resulting in only one significantly downregulated gene (cystatin E/M). We conclude that epidermis can be reproducibly and almost completely separated from the dermis of 4 mm skin biopsies by 30 min incubation in 3.8% ammonium thiocyanate combined with curettage of the dermal surface, producing high-quality RNA suitable for transcriptional analysis. Our refined method of dermo-epidermal separation will undoubtedly prove valuable in the many different settings, where the epidermal and dermal compartments need to be evaluated separately.
Extraction of high-quality epidermal RNA after ammonium thiocyanate-induced dermo-epidermal separation of 4 mm human skin biopsies.
Specimen part, Subject
View SamplesMissense mutations in the gene for the ubiquitously expressed superoxide dismutase-1 (SOD1) are one of the causes of familial amyotrophic lateral sclerosis (ALS), the most common adult onset motor neuron disease in humans killing selectively large motor neurons. Mice and rats overexpressing mutant SOD1 develop an adult onset neurodegenerative disease with hindlimb-paralysis and subsequent death similar to the human condition. In order to analyze the effects of mutant SOD1 expression onto the most affected cell-type in ALS, a small subpopulation of spinal cord cells, we propose to use laser microdissection to isolate mouse lumbar motor neurons and to assess the changes onto the mRNA expression profile using Affymetrix GeneChips compared to control animals. While two studies applying a genomic approach on the ALS mouse models used the entire spinal cord, contributions of changes to motor neurons were masked by the inflammatory effects of mutant SOD1 and the much larger population of non-motor neuronal cells. What is therefore needed is a cell-type specific expression profile that could reveal dysregulations in the transcriptome of the affected motor neurons.
Toxicity from different SOD1 mutants dysregulates the complement system and the neuronal regenerative response in ALS motor neurons.
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View SamplesMetal tolerance is often a result of metal storage or distribution. Thus, with the goal of advancing the molecular understanding of such metal homeostatic mechanisms, natural variation of metal tolerance in Arabidopsis thaliana was investigated. Substantial variation exists in tolerance of excess copper (Cu), zinc (Zn) and cadmium (Cd). Two accessions, Col-0 and Bur-0, and a recombinant inbred line (RIL) population derived from these parents were chosen for further analysis of Cd and Zn tolerance variation, which is evident at different plant ages in various experimental systems and appears to be genetically linked. Three QTLs, explaining in total nearly 50 % of the variation in Cd tolerance, were mapped. The one obvious candidate gene in the mapped intervals, HMA3, is unlikely to contribute to the variation. In order to identify additional candidate genes the Cd responses of Col-0 and Bur-0 were compared at the transcriptome level. The sustained common Cd response of the two accessions was dominated by processes implicated in plant pathogen defense. Accession-specific differences suggested a more efficient activation of acclimative responses as underlying the higher Cd tolerance of Bur-0. The second hypothesis derived from the physiological characterization of the accessions is a reduced Cd accumulation in Bur-0.
Natural variation in Arabidopsis thaliana Cd responses and the detection of quantitative trait loci affecting Cd tolerance.
Specimen part, Treatment
View SamplesThe SWR1 complex replaces the canonical histone H2A with the variant H2A.Z (Htz1 in yeast) at specific chromatin regions. This dynamic alteration in nucleosome structure provides a molecular mechanism to regulate transcription. Here we analysed the transcription profiles of single and double mutants and wild-type cells by whole-genome microarray analysis. Our results indicate that genome-wide transcriptional misregulation in htz1 can be partially or totally suppressed if SWR1 is not formed (swr1), if it forms but cannot bind to chromatin (swc2), or if it binds to chromatin but has no histone replacement activity (swc5). These results suggest that in htz1 the nucleosome remodelling activity of SWR1 affects chromatin integrity because of an attempt to replace H2A with Htz1 in the absence of the latter.
The SWR1 histone replacement complex causes genetic instability and genome-wide transcription misregulation in the absence of H2A.Z.
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View SamplesThe cascade of molecular events involved in mammalian sex determination has been shown to involve the SRY gene, but specific downstream events have eluded researchers for decades. The current study identifies one of the first direct downstream targets of the male sex-determining factor SRY as the basic-helix-loop-helix (bHLH) transcription factor TCF21. SRY was found to directly associate with the Tcf21 promoter SRY/SOX9 response element both in vitro and in vivo during male sex determination. TCF21 was found to promote an in vitro sex reversal of embryonic ovarian cells to promote precursor Sertoli cell differentiation. Therefore, SRY acts directly on the Tcf21 promoter to, in part, initiate a cascade of events associated with Sertoli cell differentiation and embryonic testis development.
Basic helix-loop-helix transcription factor TCF21 is a downstream target of the male sex determining gene SRY.
Sex, Specimen part, Treatment
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