Intracellular trafficking is essential for proper cell signaling. In the pancreas, secretory cells rely on trafficking to regulate blood glucose and digestion. Pancreatic disorders reflect defects in function or development, evoking considerable interest in understanding the molecular genetics governing pancreatic organogenesis. Here, we show the transcription factor NFIA regulates trafficking in both the embryonic and adult pancreas, affecting both developmental cell fate decisions and adult physiology. NFIA deletion from pancreatic progenitors led to the development of more acinar cells and ducts and fewer endocrine cells, whereas ectopic NFIA promoted endocrine formation. We found that NFIA's effects on trafficking influence endocrine/exocrine cell fate decisions through regulation of Notch. Adult NFIA-deficient mice develop diabetic phenotypes due to impaired insulin granule trafficking and defects in acinar zymogen secretion. This study shows how a single transcription factor, NFIA, thus exerts profound effects on both embryonic cell fate and adult physiology by regulating vesicle trafficking. Overall design: 2 control and 2 NFIA fl/fl; Pdx1-cre samples, from pooled embryonic litters at E17.5
Pancreatic Cell Fate Determination Relies on Notch Ligand Trafficking by NFIA.
Specimen part, Cell line, Subject
View SamplesDevelopmental regulation of gliogenesis in the mammalian CNS is incompletely understood, in part due to a limited repertoire of lineage-specific genes. We used Aldh1l1-GFP as a marker for gliogenic radial glia and later-stage precursors of developing astrocytes and performed gene expression profiling of these cells. We then used this dataset to identify candidate transcription factors that may serve as glial markers or regulators of glial fate. Our analysis generated a database of developmental stage-related markers of Aldh1l1+ cells between murine embryonic day 13.5-18.5. Using these data we identify the bZIP transcription factor Nfe2l1 and demonstrate that it promotes glial fate under direct Sox9 regulatory control. Thus, this dataset represents a resource for identifying novel regulators of glial development.
Expression profiling of Aldh1l1-precursors in the developing spinal cord reveals glial lineage-specific genes and direct Sox9-Nfe2l1 interactions.
Specimen part
View SamplesAs a starting point for dissecting the cellular heterogeneity of gliomas, different subpopulations from a CRISPR mouse model of glioma were profiled for gene expression. Because we initially identified these astrocyte subpopulations in the mouse brain, we first sought to determine whether their malignant analogues are present in mouse models of glioma. Towards this, we recently developed a mouse model of malignant glioma, one that utilizes E16.5 IUE approaches in combination with CRISPR mediated gene editing, where we use IUE to introduce gRNA vectors to delete NFI, PTEN, and p53, CAS9, and a GFP reporter, resulting in the generation of malignant glioma at P70. Using the GFP label to distinguish tumor from normal brain tissue, along with FACS-based selection against the glioma stem cell (GSC) and endothelial cells (see methods), we screened our tumor models for the presence of these prospective astroglial populations in the non-GSC fractions of these tumors. Overall design: Gene expression profiles (by RNA-seq) were taken of mouse glioma cells of three different populations.
Identification of diverse astrocyte populations and their malignant analogs.
Specimen part, Subject
View SamplesWe demonstrate for the first time that the extracellular matrix glycoprotein Tenascin-C regulates the expression of key patterning genes during late embryonic spinal cord development, leading to a timely maturation of gliogenic neural precursor cells. We first show that Tenascin-C is expressed by gliogenic neural precursor cells during late embryonic development. The loss of Tenascin-C leads to a sustained generation and delayed migration of Fibroblast growth factor receptor 3 expressing immature astrocytes in vivo. Furthermore, we could demonstrate an upregulation of Nk2 transcription factor related locus 2 (Nkx2.2) and its downstream target Sulfatase 1 in vivo. A dorsal expansion of Nkx2.2-positive cells within the ventral spinal cord indicates a potential progenitor cell domain shift. Moreover, Sulfatase 1 is known to regulate growth factor signalling by cleaving sulphate residues from heparan sulphate proteoglycans. Consistent with this possibility we observed changes in both Fibroblast growth factor 2 and Epidermal growth factor responsiveness of spinal cord neural precursor cells. Taken together our data clearly show that Tenascin-C promotes the astroglial lineage progression during spinal cord development.
The extracellular matrix molecule tenascin C modulates expression levels and territories of key patterning genes during spinal cord astrocyte specification.
Specimen part
View SamplesThe functional status of the tumor repressor protein (TP53 or TRP53) is a defining feature of ovarian cancer. Mutant or null alleles of TP53 are expressed in greater than 90% of all high-grade serous adenocarcinomas. Wild type TP53 is elevated in low-grade serous adenocarcinomas in women and in our Pten/Kras/Amhr2-Cre mutant mouse model. Disruption of the Trp53 gene in this mouse model did not lead to high-grade ovarian cancer but did increase expression of estrogen receptor alpha (ERalpha; ESR1) and markedly enhanced the responsiveness of these cells to estrogen. Specifically, when Trp53 positive and Trp53 null mutant mice were treated with estradiol or vehicle, only the Trp53 null and Esr1 positive tumors respond vigorously to estradiol in vivo and exhibit features characteristic of high-grade type ovarian cancer: invasive growth into the ovarian stroma, rampant metastases to the peritoneal cavity and signs of genomic instability. Estrogen promoted and progesterone suppressed the growth of Trp53 null ovarian tumors and tumor cells injected intraperitoneally (IP), subcutaneously (SC) or when grown in matrigel. Exposure of the Trp53 depleted cells to estrogen also has a profound impact on the tumor microenvironment and immune-related events. These results led to the new paradigm that TRP53 status is related to the susceptibility of transformed ovarian surface epithelial (OSE) cells to estradiol-induced metastases and genomic instability. This novel finding is relevant not only for women during their reproductive years but also for women on hormone (estradiol) replacement therapies.
Tumor repressor protein 53 and steroid hormones provide a new paradigm for ovarian cancer metastases.
Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Hematopoietic stem and progenitor cells acquire distinct DNA-hypermethylation during in vitro culture.
Specimen part, Subject
View SamplesThe 5HT system is organized into rostral and caudal populations with discrete anatomical locations and opposite axonal trajectories in the developing hindbrain. 5HT neuron cell bodies in the rostral subdivision migrate to the midbrain and pons and extend ascending projections throughout the forebrain. 5HT cell bodies in the caudal subdivision migrate to the ventral medulla and caudal half of the pons and provide descending projections to the brainstem and spinal cord.
Distinct transcriptomes define rostral and caudal serotonin neurons.
Specimen part
View SamplesHematopoietic stem and progenitor cells (HPCs) can be maintained in vitro, but the vast majority of their progeny loses stemness during culture. We have analyzed DNA methylation (DNAm) profiles of freshly isolated CD34+ cells and upon expansion on either tissue culture plastic (TCP) or mesenchymal stromal cells (MSCs). Cultured HPCs acquired significant DNA-hypermethylation, particularly in up-stream promoter regions and shore-regions of CpG islands (CGIs). To analyze if these DNAm changes are relevant for differential gene expression we analyzed gene expression profiles of additional samples. As expected highly expressed genes (10% with highest signal intensity in gene expression arrays) were hardly methylated at promoter regions, CGIs and shore-regions.
Hematopoietic stem and progenitor cells acquire distinct DNA-hypermethylation during in vitro culture.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Epigenetic rejuvenation of mesenchymal stromal cells derived from induced pluripotent stem cells.
Specimen part, Subject
View SamplesMacrophage activation by bacterial lipopolysaccharides (LPS) is induced through Toll-like receptor 4 (TLR4). The synthesis and activity of TLR4 downstream signalling molecules modulates the expression of pro- and anti-inflammatory cytokines. To address the impact of post-transcriptional regulation on that process, we performed RIP-Chip analysis. Differential association of mRNAs with heterogeneous ribonucleoprotein K (hnRNP K), an mRNA-specific translational regulator in differentiating haematopoietic cells, was studied in non-induced and LPS-activated macrophages. Analysis of interactions affected by LPS revealed an enrichment of mRNAs encoding TLR4 downstream kinases and their modulators. We focused on transforming growth factor activated kinase-1 (TAK1), a central player in TLR4 signalling. HnRNP K interacts specifically with a sequence in the TAK1 mRNA 3' UTR in vitro. Silencing of hnRNP K does not affect TAK1 mRNA synthesis and stability, but enhances TAK1 mRNA translation, resulting in elevated TNF-alpha, IL-1beta and IL-10 mRNA expression. Our data suggest that the hnRNP K-3' UTR complex inhibits TAK1 mRNA translation in non-induced macrophages. LPS-dependent TLR4 activation abrogates translational repression and newly synthesised TAK1 initiates the inflammatory response of macrophages.
Translation control of TAK1 mRNA by hnRNP K modulates LPS-induced macrophage activation.
Specimen part, Cell line, Treatment
View Samples