Tip60 is a key histone acetyltransferase (HAT) enzyme that plays a central role in diverse biological processes critical for general cell function, however the chromatin-mediated cell-type specific developmental pathways that are dependent exclusively upon the HAT activity of Tip60 remain to be explored. Here, we investigate the role of Tip60 HAT activity in transcriptional control during multicellular development, in vivo by examining genome-wide changes in gene expression in a Drosophila model system specifically depleted for endogenous dTip60 HAT function. We show that amino acid residue E431 in the catalytic HAT domain of dTip60 is critical for the acetylation of endogenous histone H4 in our fly model in vivo, and demonstrate that dTip60 HAT activity is essential for multicellular development. Moreover, our results uncover a novel role for Tip60 HAT activity in controlling neuronal specific gene expression profiles essential for nervous system function as well as a central regulatory role for Tip60 HAT function in general metabolism.
Microarray analysis uncovers a role for Tip60 in nervous system function and general metabolism.
Specimen part
View SamplesAim:Transcriptional analysis of NKX2.2 knockdown versus control in human pancreatic islets Methods:Pancreatic islets from 3 human donors were transduced with an adenovirus encoding an shRNA directed against human NKX2.2 or a scrambled shRNA control. Total RNA was extracted.Libraries were prepared from total RNA (RIN>8) with the TruSeq RNA prep kit (Illumina) and sequenced using the HiSeq2000 (Illumina) instrument. More than 20 million reads were mapped to the human genome (Human: NCBI/build37.2)) using Tophat (version 2.0.4) with 4 mismatches and 10 maximum multiple hits. Significantly differentially expressed genes were calculated using DEseq. Results: Among the dysregulated genes with a p-value=0.05 are important genes for the maintenance of beta cell function and idenity. Conclusion: Nkx2.2 is a critical regulator of beta cell function and identity Overall design: mRNA profiles of the pancreatic islets from 3 human donors transduced with Ad.sh-NKX2.2 or scramble sh-RNA control vector were generated by deep sequencing , using Illumina HiSeq2000.
Genetic evidence that Nkx2.2 acts primarily downstream of Neurog3 in pancreatic endocrine lineage development.
Specimen part, Subject
View SamplesAim:Transcriptional analysis of the pancreatic islets of adult Nkx2.2 flox/flox; RipCre mice versus control Methods:Pancreatic islets from 4week old Nkx2.2 mutant mice and controls were isolated and total RNA was extracted.Libraries were prepared from total RNA (RIN>8) with the TruSeq RNA prep kit (Illumina) and sequenced using the HiSeq2000 (Illumina) instrument. More than 20 million reads were mapped to the mouse genome (UCSC/mm9) using Tophat (version 2.0.4) with 4 mismatches and 10 maximum multiple hits. Significantly differentially expressed genes were calculated using DEseq. Results: Among the downregulated genes with a p-value=0.05 are important genes for beta cell function and idenity.Among the upregulated genes with a p-value=0.05 are non beta endocrine hormones. Conclusion: Nkx2.2 activates important beta cell genes and actively represses non beta cell genes Overall design: mRNA profiles of the pancreatic islets of 4 week old control and Nkx2.2 mutant mice were generated by deep sequencing , in triplicate, using Illumina HiSeq2000.
Genetic evidence that Nkx2.2 acts primarily downstream of Neurog3 in pancreatic endocrine lineage development.
Specimen part, Subject
View SamplesCholesterol is one of the key molecules in mammals and the most striking examples of its deficiency are the inborn errors of cholesterol biosynthesis that manifest in severe whole body phenotypes. Liver, the principal site of cholesterol homeostasis, has rarely been investigated in these defects. We thus focused on the hepatocyte-specific deletion of lanosterol 14-demethylase (CYP51) catalyzing the rate-limiting step in the post-squalene part of cholesterol synthesis.
Lessons from hepatocyte-specific Cyp51 knockout mice: impaired cholesterol synthesis leads to oval cell-driven liver injury.
Sex, Specimen part, Treatment
View SamplesUnperturbed cholesterol homeostasis is important for normal development and sexual maturation in mice. Cyp51 is the rate limiting step in the post-lanosteorl part of cholesterol biosynthesis. Unlike the full body knockout, hepatocyte specific Cyp51 knockout mice survive throughout adulthood, however their livers are severly affected. Several of the hepatocyte specific Cyp51 knockout mice develop severe liver injury or die prior to reaching adulthood (from 4-10 weeks of age; designated as runts). We aim to uncover the timing and the mechanistic background governing the liver damage and sex differences.
Disrupting Hepatocyte Cyp51 from Cholesterol Synthesis Leads to Progressive Liver Injury in the Developing Mouse and Decreases RORC Signalling.
Sex, Specimen part
View SamplesDEAD-box RNA helicases eIF4A and Ded1 are believed to promote translation initiation by resolving mRNA secondary structures that impede ribosome attachment at the mRNA 5' end or subsequent scanning of the 5'UTR, but whether they perform distinct functions or act redundantly in vivo is poorly understood. We compared the effects of mutations in Ded1 or eIF4A on global translational efficiencies (TEs) in yeast by ribosome footprint profiling. Despite similar reductions in bulk translation, inactivation of a cold-sensitive Ded1 mutant substantially reduced the TEs of >600 mRNAs, whereas inactivation of a temperature-sensitive eIF4A mutant yielded <40 similarly impaired mRNAs. The broader requirement for Ded1 did not reflect more pervasive secondary structures at low temperature, as inactivation of temperature-sensitive and cold-sensitive ded1 mutants gave highly correlated results. Interestingly, Ded1-dependent mRNAs exhibit greater than average 5'UTR length and propensity for secondary structure, implicating Ded1 in scanning though structured 5' UTRs. Reporter assays confirmed that cap- distal stem-loop insertions increase dependence on Ded1 but not eIF4A for efficient translation. While only a small fraction of mRNAs is strongly dependent on eIF4A, this dependence is significantly correlated with requirements for Ded1 and 5'UTR features characteristic of Ded1- dependent mRNAs. Our findings suggest that Ded1 is critically required to promote scanning through secondary structures within 5'UTRs; and while eIF4A cooperates with Ded1 in this function, it also promotes a step of initiation common to virtually all yeast mRNAs. Overall design: We compared the effects of mutations in Ded1 or eIF4A on global translational efficiencies (TEs) in yeast by ribosome footprint profiling.The study includes 32 samples, comprised of 16 mRNA-Seq samples and 16 ribosome footprint profiling samples, derived from biological replicates of 3 mutant strains, ded1-cs, ded1-ts and tif1-ts, and the corresponding wild-type strains. The tif1-ts mutant and its wild-type counterpart were analyzed at 30°C and 37°C.
Functional interplay between DEAD-box RNA helicases Ded1 and Dbp1 in preinitiation complex attachment and scanning on structured mRNAs in vivo.
Subject
View SamplesSpinal muscular atrophy (SMA) is one of the most common inherited forms of neurological disease leading to infant mortality. Patients exhibit selective loss of lower motor neurons resulting in muscle weakness, paralysis, and often death. Although patient fibroblasts have been used extensively to study SMA, motor neurons have a unique anatomy and physiology which may underlie their vulnerability to the disease process. Here we report the generation of induced pluripotent stem (iPS) cells from skin fibroblast samples taken from a child with SMA. These cells expanded robustly in culture, maintained the disease genotype, and generated motor neurons that showed selective deficits compared to those derived from the childs unaffected mother. This is the first study to show human iPS cells can be used to model the specific pathology seen in a genetically inherited disease. As such, it represents a promising resource to study disease mechanisms, screen novel drug compounds, and develop new therapies.
Induced pluripotent stem cells from a spinal muscular atrophy patient.
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View SamplesAlthough many genes have been proposed to be involved in prostate carcinogenesis, no single gene or gene profile has shown to have prognostic value. The main challenge for clinical management is to distinguish slowly growing tumors from those that will relapse. In this study, we compared expression profiles of 18 prostate samples (7 with Gleason 6, 8 with Gleason 7 and 3 with Gleason score equal or higher than 8) and 5 non-neoplastic prostate samples, using the GeneChip Human Exon Array 1.0 ST of Affymetrix. Microarray analysis revealed 99 genes showing statistically significant differences among tumors with Gleason score 6, 7 and 8. In addition, mRNA expression of 29 selected genes was analyzed by qRT-PCR with microfluidic cards in an extended series of 30 prostate tumors. From these, 29 were selected to be validated and the differential expression of 18 of them (62%) was independently confirmed by quantitative real-time RT-PCR (14 upregulated and 4 downregulated in higher Gleason scores) in the extended series. This list was further narrowed down to 12 genes that were differentially expressed in tumors with Gleason score of 6-7 vs 8. Finally, the protein levels of two genes from the 12-gene signature (SEC14L1 and TCEB1) were additionally validated by immunohistochemistry. Strong protein levels of both genes were correlated with Gleason score, stage, and PSA progression.
A 12-gene expression signature is associated with aggressive histological in prostate cancer: SEC14L1 and TCEB1 genes are potential markers of progression.
Specimen part
View SamplesComparative microarray-based transcriptome analysis of A. thaliana mlo2 mlo6 mlo12 mutants and wild type plants upon Golovinomyces orontii inoculation revealed an increased and accelerated accumulation of many defense-related transcripts. Despite the biotrophic nature of the interaction, this included the non-canonical activation of a jasmonic acid/ethylene-dependent transcriptional program.
Key Components of Different Plant Defense Pathways Are Dispensable for Powdery Mildew Resistance of the Arabidopsis <i>mlo2 mlo6 mlo12</i> Triple Mutant.
Specimen part, Treatment
View SamplesEpidermal stem cells ensure proper faring of skin homeostatic processes under both physiological and challenging conditions. Currently, the molecular events underpinning ageing within the epidermal stem cell niche are poorly understood.
In Silico Analysis of the Age-Dependent Evolution of the Transcriptome of Mouse Skin Stem Cells.
Age, Specimen part
View Samples