In germ cells, Piwi proteins interact with a specific class of small non-coding RNAs, piwi-interacting RNAs (piRNAs). Together, these form a pathway that represses transposable elements, thus safeguarding germ cell genomes. While basic models describe the operation of piRNA pathways, neither the protein compositions of Piwi complexes, the critical protein-protein interactions that drive small RNA production and target recognition, or the precise molecular consequences of conserved localization to germline structures, call nuage, is well understood. We purified the three murine Piwi family proteins, Mili, Miwi, and Miwi2, from mouse germ cells and characterized their interacting protein partners. Piwi proteins were found in complex with Prmt5/Wdr77, an enzyme that di-methylates arginine residues. By immunoprecipitation with specific antibodies and by mass spectrometry, we found that Piwi proteins are arginine methylated at conserved positions in their amino termini. These modifications are essential to direct complex formation with specific Tudor-domain proteins, whose interactions with Piwis can be required for localization of RNP complexes in cytoplasmic nuage, proper piRNA expression, and transposon silencing. Considered together, our findings indicate that arginine methylation drives the assembly of multi-protein machines whose integrity and specific sub-cellular localization is necessary for efficient function of the piRNA pathway. Keywords: gene regulation study Overall design: Total small RNA in embryonic and post-birth mouse testes of tdrd1 and tdrd6 mutants
RNF17 blocks promiscuous activity of PIWI proteins in mouse testes.
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View SamplesMammalian spermatogonial stem cells (SSCs) spontaneously convert to multipotent adult spermatogonial-derived stem cells (MASCs) during in vitro expansion. Here, we examine the epigenetic signature of SSCs and MASCs, identifying bivalent histone H3-lysine4 and -lysine27 trimethylation at somatic gene promoters in SSCs and an ESC-like promoter chromatin state in MASCs. Overall design: Examination of gene expression in different cell types.
Epigenetic profiles signify cell fate plasticity in unipotent spermatogonial stem and progenitor cells.
Specimen part, Cell line, Subject
View SamplesModern functional genomic approaches may help to better understand the molecular events involved in tissue morphogenesis and to identify molecular signatures and pathways. We have recently applied transcriptomic profiling to evidence molecular signatures in the development of the normal chicken chorioallantoic membrane and in tumor engrafted on the CAM. We have now extended our studies by performing a transcriptome analysis in the wound model of the chicken CAM which is another relevant model of tissue morphogenesis. To induce granulation tissue formation, we performed wounding of the chicken CAM and compared gene expression to normal CAM at the same stage of development. Matched control samples from the same individual were used. We observed a total of 282 genes up-regulated and 44 genes downregulated assuming a false-discovery rate at 5 % and a fold change > 2. Furthermore, bioinformatics analysis lead to the identification of several categories that are associated to organismal injury, tissue morphology, cellular movement, inflammatory disease, development and immune system. Endothelial cell data filtering leads to the identification of several new genes with an endothelial cell signature. In summary, the chick chorioallantoic wound model allows the identification of gene signatures involved in granulation tissue formation and neoangiogenesis. This may constitute a fertile ground for further studies.
Gene signatures in wound tissue as evidenced by molecular profiling in the chick embryo model.
Specimen part
View SamplesSynovial fibroblasts in persistent inflammatory arthritis have been suggested to have parallels with cancer growth and wound healing, both of which involve a stereotypical serum response program. We tested the hypothesis that a serum response program can be used to classify diseased tissues, and investigated the serum response program in fibroblasts from multiple anatomical sites and two diseases. To test our hypothesis we utilized a bioinformatics approach to explore a publicly available microarray dataset including RA, OA and normal synovial tissue, then extended those findings in a new microarray dataset representing matched synovial, bone marrow and skin fibroblasts cultured from RA and OA patients undergoing arthroplasty. The classical fibroblast serum response program discretely classified RA, OA and normal synovial tissues. Analysis of low and high serum treated fibroblast microarray data revealed a hierarchy of control, with anatomical site the most powerful classifier followed by response to serum and then disease. In contrast to skin and bone marrow fibroblasts, exposure of synovial fibroblasts to serum led to convergence of RA and OA expression profiles. Pathway analysis revealed three inter-linked gene networks characterising OA synovial fibroblasts: Cell remodelling through insulin-like growth factors, differentiation and angiogenesis through 3 integrin, and regulation of apoptosis through CD44. We have demonstrated that Fibroblast serum response signatures define disease at the tissue level, and that an OA specific, serum dependent repression of genes involved in cell adhesion, extracellular matrix remodelling and apoptosis is a critical discriminator between cultured OA and RA synovial fibroblasts.
Stromal transcriptional profiles reveal hierarchies of anatomical site, serum response and disease and identify disease specific pathways.
Specimen part, Disease
View SamplesHexose-6-phosphate dehydrogenase (H6PD)is the initial component of a pentose phosphate pathway inside the endoplasmic reticulum (ER) that generates NADPH for ER enzymes. In liver, H6PD is required for the 11-oxoreductase activity of 11ss-hydroxysteroid dehydrogenase type 1 (11ss-HSD1), which converts inactive 11-oxo glucocorticoids to their active 11-hydroxyl counterparts; consequently, H6PD null mice are relatively insensitive to glucocorticoids, exhibiting fasting hypoglycemia, increased insulin sensitivity despite elevated circulating levels of corticosterone, and increased basal and insulin-stimulated glucose uptake in muscles normally enriched in Type II (fast) fibers which have increased glycogen content. They also display a progressive vacuolar myopathy evident after 4 weeks of age.
Deletion of hexose-6-phosphate dehydrogenase activates the unfolded protein response pathway and induces skeletal myopathy.
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View SamplesStudy the training exercise effects in chronic obstructive pulmonary disease (COPD) patients and aged-matched healthy individuals. Skeletal muscle biopsies from 9 stable COPD patients with normal fat free mass index (FFMI, 21Kg/m2) (COPDN), 6 COPD patients with low FFMI (16Kg/m2) (COPL), and 12 healthy sedentary subjects (FFMI 21Kg/m2) before and after 8 weeks of a supervised endurance exercise program were analyzed.
A systems biology approach identifies molecular networks defining skeletal muscle abnormalities in chronic obstructive pulmonary disease.
Specimen part, Disease, Disease stage, Subject
View SamplesDefects in neutrophil number and survival are common to both hematologic disorders and chronic inflammatory diseases. At sites of inflammation, neutrophils respond to multiple signals that activate protein kinase A (PKA) signalling, which positively regulates neutrophil survival. We aimed to study the transcriptional responses to several stimuli in human neutrophils.
NR4A orphan nuclear receptor family members, NR4A2 and NR4A3, regulate neutrophil number and survival.
Specimen part
View SamplesWe addressed the clinical significance and mechanisms behind in vitro cellular responses to ionising radiation (IR)-induced DNA double strand breaks in 74 paediatric ALL patients. We found an apoptosis-resistant response in 36% of patients and an apoptosis-sensitive response in the remaining 64% of leukaemias. Global gene expression profiling of 11 apoptosis-resistant and 11 apoptosis-sensitive ALLs revealed abnormal up-regulation of multiple pro-survival pathways in response to IR in apoptosis-resistant leukaemias and differential post-transcriptional activation of the PI3-Akt pathway was observed in representative resistant cases. It is possible that abnormal pro-survival responses to DNA damage provide one of the mechanisms of primary resistance in ALL .
Stratification of pediatric ALL by in vitro cellular responses to DNA double-strand breaks provides insight into the molecular mechanisms underlying clinical response.
No sample metadata fields
View SamplesP1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using pericarps at two different stages, 14 and 25 days after pollination (DAP). High-throughput sequencing using the Illumina platform resulted in the generation of ~20 million high quality reads, from which ~90% aligned to the recently completed maize genome sequence corresponding to ~5 million reads for each one of the four samples. Overall design: Examination of two different RNA samples from two different stages of maize pericarp tissues.
A genome-wide regulatory framework identifies maize pericarp color1 controlled genes.
Specimen part, Subject
View SamplesP1 encodes an R2R3-MYB transcription factor responsible for the accumulation of insecticidal flavones in maize silks and red phlobaphene pigments in pericarps and other floral tissues, which contributed to making P1 an important visual marker since the dawn of modern genetics. We conducted RNA-Seq using from maize silks obtained at 2-3 days after emergence. High-throughput sequencing using the Illumina platform resulted in the generation of ~14 million high quality reads, corresponding to ~7 million reads for each sample, from which 76% aligned to the maize genome. Overall design: Examination of two different RNA samples from maize silks obtained at 2-3 days after emergence
A genome-wide regulatory framework identifies maize pericarp color1 controlled genes.
Specimen part, Subject
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