Mesenchymal stromal cells (MSC) are crucial components of the bone marrow (BM) microenvironment essential for regulating self-renewal, survival and differentiation of hematopoietic stem/progenitor cells (HSPC) in the stem cell niche. MSC are functionally and phenotypically altered in myelodysplastic syndromes (MDS), contributing to disease progression. MDS MSC do not harbor recurrent genetic alterations but have been shown to exhibit an altered methylome compared to MSC from healthy controls. We examined growth, differentiation and HSPC-supporting capacity of ex vivo expanded MSC from MDS patients in comparison to age-matched healthy controls after direct treatment in vitro with the hypomethylating agent azacitidine (AZA). We show that AZA exerts a direct effect on MSC by modulating their differentiation potential. Osteogenesis was significantly boosted in healthy MSC while adipogenesis was inhibited in both healthy and MDS MSC. In co-culture experiments, both AZA treated MDS MSC and healthy MSC exhibited enhanced support of non-clonal HSPC which was associated with increased cell cycle induction. Conversely, clonal MDS HSPC were inhibited by contact with AZA treated MSC. RNA-sequencing analyses of stromal cells revealed changes in pathways essential for HSPC support as well as in immune regulatory pathways. In sum, our data demonstrate that AZA treatment of stromal cells leads to upregulation of HSPC-supportive genes and cell cycle induction in co-cultured healthy HSPC, resulting in a proliferative advantage over clonal HSPC. Thus, restoration of functional hematopoiesis by AZA may be driven by activated stromal support factors in MSC providing cell cycle cues to healthy HSPC. Overall design: RNA sequencing was performed on a mesenchymal stromal cell line (EL08-1D2), either untreated or treated with Azacitidine [(-)AZA vs. (+)AZA].
Direct modulation of the bone marrow mesenchymal stromal cell compartment by azacitidine enhances healthy hematopoiesis.
Treatment, Subject
View SamplesAmyotrophic later sclerosis is a motor neuron disease accompanied by metabolic changes. PGC (PPAR gamma coactivator)-1alpha is a master regulator of mitochondrial biogenesis and function and of critical importance for all metabolically active tissues. PGC-1alpha is a genetic modifier of ALS.
ALS-causing mutations differentially affect PGC-1α expression and function in the brain vs. peripheral tissues.
Specimen part
View SamplesAn increasing amount of evidence suggests that the small intestine may play an important role in the development of metabolic diseases, such as obesity and insulin resistance. The small intestine provides the first barrier between diet and the body. As a result, dysregulation of biological processes and secretion of signal molecules from the small intestine may be of importance in the regulation and dysregulation of whole body metabolic homeostasis. Changes in gene expression of genes involved in lipid metabolism, cell cycle and immune response may contribute to the aetiology of diet-induced obesity and insulin resistance. In the current study we present a detailed investigation on the effects a chow diet, low fat diet and high fat diet on gene expression along the proximal-to-distal axis of the murine small intestine. The reported results provide a knowledge base for upcoming studies on the role of the small intestine in the aetiology of diet-induced diseases.
Cross-species comparison of genes related to nutrient sensing mechanisms expressed along the intestine.
Sex, Specimen part
View SamplesGene expression profiles of bipolar disorder (BD) patients were assessed during both a manic and a euthymic phase and compared both intra-individually, and with the gene expression profiles of controls.
Investigation of manic and euthymic episodes identifies state- and trait-specific gene expression and STAB1 as a new candidate gene for bipolar disorder.
Specimen part, Disease, Subject
View SamplesBreast cancer metastasis to bone is a critical determinant of long-term survival after treatment of primary tumors. We used a mouse model of spontaneous bone metastasis to determine new molecular mechanisms. Differential transcriptome comparisons of primary and metastatic tumor cells revealed that a substantial set of genes suppressed in bone metastases were highly enriched for promoter elements for the type I interferon (IFN) regulatory factor, Irf7, itself suppressed in mouse and human metastases. The critical function of the Irf7 pathway was demonstrated by restoration of exogenous Irf7 or systemic interferon administration, which significantly reduced bone metastases and prolonged metastasis-free survival. Using mice deficient in the type I receptor (Ifnar1-/-) or mature B, T and NK cell responses (NOD Scid IL-2r-/- mice), we demonstrated that Irf7-driven suppression of metastasis was reliant on IFN signaling to host immune cells. Metastasis suppression correlated with decreased accumulation of myeloid-derived suppressor cells and increased CD4++, CD8 T cells and NK cells in the peripheral blood and was reversed by depletion of CD8+ cells and NK cells. Clinical importance of our findings was demonstrated as increased primary tumor Irf7 expression predicted prolonged bone and lung metastasis-free survival. Thus we report for the first time, a novel innate immune pathway, intrinsic to breast cancer cells, whose suppression in turn restricts systemic immunosurveillance to enable metastasis. This pathway may constitute a novel therapeutic target for restricting breast cancer metastases.
Silencing of Irf7 pathways in breast cancer cells promotes bone metastasis through immune escape.
Specimen part
View SamplesGene expression (mRNA) profiling of human ependymomas
Delineation of two clinically and molecularly distinct subgroups of posterior fossa ependymoma.
Sex, Age, Specimen part
View SamplesAsymmetric cell division results in two distinctly fated daughter cells to generate cellular diversity. A major molecular hallmark of an asymmetric division is the unequal partitioning of cell-fate determinant proteins. We have previously established that growth factor signaling promotes protein depalmitoylation to foster polarized protein localization, which in turns drives migration and metastasis. Here, we report protein palmitoylation as a key mechanism for the asymmetric partitioning of the cell-fate determinants Numb (Notch antagonist) and ß-catenin (canonical Wnt regulator) through the activity of a depalmitoylating enzyme, APT1. Using point mutants, we show specific palmitoylated residues on proteins, such as Numb, are required for asymmetric localization. Furthermore, by live-cell imaging, we show that reciprocal interactions between APT1 and CDC42 regulate the asymmetric localization of Numb and ß-catenin to the plasma membrane. This in turn restricts Notch and Wnt transcriptional activity to one daughter cell. Moreover, we show altering APT1 expression changes the transcriptional signatures to those resembling that of Notch and ß-catenin in MDA-MB-231 cells. We also show loss of APT1 depletes the population of CD44+/CD24lo/ALDH+ tumorigenic cells in colony formation assays. Together, the findings of this study demonstrate that palmitoylation, via APT1, is a major mechanism of asymmetric cell division regulating Notch and Wnt-associated protein dynamics, gene expression, and cellular functions. Overall design: Gene expression by RNAseq of MDA-MB-231 triple receptor negative breast cancer cells expressing scramble control vector, shAPT1 knockdown, and APT1wt performed in triplicate. Total of 9 samples were analyzed.
The depalmitoylase APT1 directs the asymmetric partitioning of Notch and Wnt signaling during cell division.
Specimen part, Cell line, Treatment, Subject
View SamplesIKK kinase is essential for the B cell maturation and secondary lymphoid organ development. In the current study, we evaluated the role of IKK in the marginal zone and follicular B lymphocyte development by genetically deleting IKK from the B cell lineage using CD19-Cre mice. The loss of IKK did not affect the normal development of early B cell progenitors. However, a significant decline was observed in the percentage of immature B lymphocytes, mature marginal zone and follicular B cells along with a severe disruption of splenic marginal and follicular B cell zones. A gene expression analysis performed on the RNA extracted from the newly formed B cells (B220+IgMhi) revealed that IKK deficiency produces significant changes in the expression of genes involved in MZ and FO B lymphocyte survival, homing and migration. And several among those genes identified belong to G protein family. Specifically, we validated the upregulated expression of regulator of G protein signaling 13 (RGS13), which is a GTPase activating protein (GAP) that negatively regulates G protein signaling and impede B cell migration. Likewise, promigratory B lymphocyte receptor, the sphingosine-1-phosphate receptor 3 (SIPR3) that couple to Gi showed significantly reduced expression. In addition, an in silico analysis of gene product interactions revealed NF-B signaling pathways to be a major gene regulating networks perturbed with IKK deletion. Taken together, this study reveals IKKNF-B and G protein signaling axis to be central for the MZ and FO B cells survival, maintenance, homing and migration.
IKKα deficiency disrupts the development of marginal zone and follicular B cells.
Specimen part
View SamplesWe prepared small RNA libraries from 29 tumor/normal pairs of human cervical tissue samples. Analysis of the resulting sequences (42 million in total) defined 64 new human microRNA (miRNA) genes. Both arms of the hairpin precursor were observed in twenty-three of the newly identified miRNA candidates. We tested several computational approaches for analysis of class differences between high throughput sequencing datasets, and describe a novel application of log linear model that has provided the most datasets, and describe a novel application of log linear model that has provided the most effective analysis for this data. This method resulted in the identification of 67 miRNAs that were differentially-expressed between the tumor and normal samples at a false discovery rate less than 0.001. Overall design: A total of 29 tumor/normal pairs of human cervical tissue samples were analyzed. Two samples (G699N_2 and G761T_2) were performed in duplicates. No Fastq files for GSM532871 to GSM532889, GSM532929, and GSM532930. Sequence files are provided as text files for these 22 Sample records in GSE20592_RAW.tar. 38 samples with quality scores are available from SRA as SRP002/SRP002326 (see Supplementary file below).
Ultra-high throughput sequencing-based small RNA discovery and discrete statistical biomarker analysis in a collection of cervical tumours and matched controls.
No sample metadata fields
View SamplesThe selective impact of pathogen epidemics on host defenses can be strong but remains transient. By contrast, life-history shifts can durably and continuously modify the balance between costs and benefits, which arbitrates the evolution of host defenses. Their impact, however, has seldom been documented. Here, we show with a simple mathematical model that the selective advantage of the defense system is expected to decrease with decreasing life span. We further document that, in natural populations of the model plant system Arabidopsis thaliana, the expression level of defense genes correlate positively with flowering time, a proxy for the length of vegetative life span. Using a genetic strategy to partition life span-dependent and –independent defense genes, we demonstrate that this positive co-variation is not explained by the pleiotropic action of major regulatory genes controlling both defense and life span. In agreement with our model, this study reveals that natural selection has likely assembled alleles promoting lower expression of defense genes with alleles decreasing the duration of vegetative life span in natural populations of A. thaliana. This is the first study demonstrating that life history evolution has a pervasive impact on the evolution of host immunity. Overall design: Seeds of Bur-0, Col-0 and 278 Bur-0xCol-0 Recombinant Inbred Lines (RIL) obtained after 8 generations of selfing were provided by the Arabidopsis Stock Center at INRA Versailles (France). We selected the 40 RIL in the 15% and 85% quantiles of flowering time for RNA sequencing. Each RIL and the two parental lines were planted in 20 replicates in the conditions described above. At days 14 and 28, the oldest leaf was flash-frozen in liquid nitrogen. Three pools, each combining 13 RIL, were produced at each time point for early and late lines, for a total of 3 biological replicates, 2 pool types (early and late RIL) and 2 time points (14 and 28 days). For each of the two parental lines, leaves of 12 replicates were pooled for each time point.
Assortment of Flowering Time and Immunity Alleles in Natural Arabidopsis thaliana Populations Suggests Immunity and Vegetative Lifespan Strategies Coevolve.
Specimen part, Subject, Time
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