Axin2-expressing calvarial suture stem cells can contribute to calvarial development, homeostatic maintenance, repair, and regeneration.
Stem cells of the suture mesenchyme in craniofacial bone development, repair and regeneration.
Specimen part
View SamplesTranscription factors drive organogenesis, from the initiation of cell fate decisions to the maintenance and implementation of these decisions. The Drosophila embryonic salivary gland provides an excellent platform for unraveling the underlying transcriptional networks of organ development because Drosophila is relatively unencumbered by significant genetic redundancy. The highly conserved FoxA family transcription factors are essential for various aspects of organogenesis in all animals that have been studied. Here, we explore the role of the single Drosophila FoxA protein Fork head (Fkh) in salivary gland organogenesis using two genome-wide strategies. A large-scale in situ hybridization analysis reveals a major role for Fkh in maintaining the salivary gland fate decision and controlling salivary gland physiological activity, in addition to its previously known roles in morphogenesis and survival. The majority of salivary gland genes (59%) are affected by fkh loss, mainly at later stages of salivary gland development. We show that global expression of Fkh cannot drive ectopic salivary gland formation. Thus, unlike the worm FoxA protein PHA-4, Fkh does not function to specify cell fate. In addition, Fkh only indirectly regulates many salivary gland genes, which is also distinct from the role of PHA-4 in organogenesis. Our microarray analyses reveal unexpected roles for Fkh in blocking terminal differentiation and in endoreduplication in the salivary gland and in other Fkh-expressing embryonic tissues. Overall, this study demonstrates an important role for Fkh in determining how an organ preserves its identity throughout development and provides an alternative paradigm for how FoxA proteins function in organogenesis.
Genome-wide analysis reveals a major role in cell fate maintenance and an unexpected role in endoreduplication for the Drosophila FoxA gene Fork head.
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View SamplesFoxA transcription factors play major roles in organ-specific gene expression. How FoxA proteins achieve specificity is unclear, given their broad expression patterns and requirements in multiple cell types. Here, we characterize Sage, a basic helix-loop-helix (bHLH) transcription factor expressed exclusively in the Drosophila salivary gland (SG). We identify Sage targets and show that not only are both Sage and the single Drosophila FoxA protein, Fork head (Fkh), required for expression of these genes, but coexpression of Sage and Fkh is sufficient to drive target gene expression in multiple other cell types. Sage and Fkh drive expression of the bZip transcription factor Senseless (Sens), which boosts expression of Sage/Fkh targets. Importantly, Sage, Fkh and Sens colocalize on salivary gland polytene chromosomes. Thus, Fkh drives cell-type specific gene expression as part of a tissue-specific transcription module that includes Sage and Sens, providing a new paradigm for how mammalian FoxA proteins acheive specificity.
Organ-specific gene expression: the bHLH protein Sage provides tissue specificity to Drosophila FoxA.
Specimen part
View SamplesTo recruit phagocytes, apoptotic cells characteristically release ATP, which functions as a danger signal. Here, we found that the culture supernatant of apoptotic cells activated the macrophages to express anti-inflammatory genes such as NR4A and Thbs1. A high level of AMP accumulated in the apoptotic cell supernatant in a Pannexin1-dependent manner. A nucleotidase inhibitor and A2a adenosine receptor antagonist inhibited the apoptotic supernatant-induced gene expression, suggesting AMP was metabolized to adenosine by an ecto-5-nucleotidase expressed on macrophages, to activate the macrophage A2a adenosine receptor. Intraperitoneal injection of zymosan into AdoR A2a- or Panx1-deficient mice produced high, sustained levels of inflammatory mediators in the peritoneal lavage. These results indicated that AMP from apoptotic cells suppresses inflammation as a calm down signal.
Immunosuppression via adenosine receptor activation by adenosine monophosphate released from apoptotic cells.
Sex, Age, Specimen part
View SamplesBasal-like and luminal breast tumors have distinct clinical behavior and molecular profiles, yet the underlying mechanisms are poorly defined. To interrogate processes that determine these distinct phenotypes and their inheritance pattern, we generated somatic cell fusions and performed integrated genetic and epigenetic (DNA methylation and chromatin) profiling. We found that the basal-like trait is generally dominant and it is largely defined by epigenetic repression of luminal transcription factors. Definition of super-enhancers highlighted a core program common in luminal cells but high degree of heterogeneity in basal-like breast cancers that correlates with clinical outcome. We also found that protein extracts of basal-like cells is sufficient to induce luminal-to-basal phenotypic switch implying a trigger of basal-like autoregulatory circuits. We determined that KDM6A might be required for luminal-basal fusions, and identified EN1, TBX18, and TCF4 as candidate transcriptional regulators of luminal-to-basal switch. Our findings highlight the remarkable epigenetic plasticity of breast cancer cells. Overall design: RNA-Seq in breast cancer cell-lines
Somatic Cell Fusions Reveal Extensive Heterogeneity in Basal-like Breast Cancer.
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View SamplesBackground: The insulin/IGF/relaxin family represents a group of structurally related but functionally diverse proteins. The family member Relaxin-2 has been evaluated in clinical trials for its efficacy in the treatment of acute heart failure. In this study, we assessed the role of Insulin-like peptide 6 (Insl6), another member of this protein family, in murine heart failure models using genetic loss-of-function and protein delivery methods. Methods and Results: Insl6-deficient (Insl6-KO) and wild-type (C57BL/6N) mice were administered angiotensin II or isoproterenol via continuous infusion with an osmotic pump or via intraperitoneal injection once a day, respectively for 2 weeks. In both models, Insl6-KO mice exhibited greater cardiac systolic dysfunction and left ventricular dilatation hypertrophy. Cardiac dysfunction in the Insl6-KO mice was associated with more extensive cardiac fibrosis and greater expression of fibrosis-associated genes. The continuous infusion of chemically synthesized INSL6 significantly attenuated left ventricular systolic dysfunction and cardiac fibrosis induced by isoproterenol infusion. Gene expression profiling suggests Lxr/ Rxr signaling is activated in the isoproterenol-challenged hearts treated with INSL6 protein. Conclusions: Endogenous Insl6 protein inhibits cardiac systolic dysfunction and cardiac fibrosis in angiotensin II- and isoproterenol-induced cardiac stress models. The administration of recombinant Insl6 protein could have utility for the treatment of heart failure and cardiac fibrosis.
Relaxin Family Member Insulin-Like Peptide 6 Ameliorates Cardiac Fibrosis and Prevents Cardiac Remodeling in Murine Heart Failure Models.
Sex, Specimen part, Treatment
View SamplesGerminal centers (GCs) are clusters of activated B cells built on stromal cells known as follicular dendritic cells (FDCs). In the Peyers patches (PPs), GCs are chronically induced by bacteria and are the major sites for generation of gut IgA immune responses. Whether FDCs directly contribute to the IgA production in PP GCs is unknown.
The sensing of environmental stimuli by follicular dendritic cells promotes immunoglobulin A generation in the gut.
Specimen part
View SamplesAnalysis of class switch recombination, maturation or differenciation of B cells at gene expression levels. The hypothesis tested in the present study was that TLR signaling in B cells plays an pivotal role for class switch, maturation and differenciation. Overall design: Total RNA obtained from cultured splenic B cells. Gene expression compared between control and cKO B cells.
Control of Toll-like receptor-mediated T cell-independent type 1 antibody responses by the inducible nuclear protein IκB-ζ.
No sample metadata fields
View SamplesAscorbic acid (AA) is a powerful antioxidant and play as a cofactor for various enzymes in vivo. In this study, we investigated the effect of AA depletion on gene expression in the liver and lipid metabolism by using SMP30/GNL knockout (KO) mice which are unable to biosynthesis AA. First, we performed microarray analysis. Briefly, SMP30/GNL KO mice were weaned and divided into two groups; AA-depleted and supplemented groups, which mice were free access to water containing 1.5 g/L AA. After 4 weeks, mRNA was isolated and purified from the liver. In this study, Affymetrix GeneChip was used for microarray analysis. Actually, AA-depletion altered many gene expressions related to lipid metabolism. Especially, Cytochrome P450 7a1 (Cyp7a1), a late-limiting enzyme of bile acid biosynthesis, gene expression was significantly up-regulated. We also confirmed Cyp7a1 protein levels by Western blotting. Next, we investigated the influence of AA depletion on lipid metabolism. We examined the lipid and bile acid levels in the liver, plasma, and gallbladder from SMP30/GNL KO mice. Amount of total bile acid (TBA), free fatty acid (FA), total cholesterol (TC), triglyceride (TG), and phospholipids (PL) were measured by colorimetric method. AA depletion reduced TBA levels in the liver and gallbladder. However, FA, TC, TG, and PL in the plasma and liver were not changed by AA depletion. Although Cyp7a1 gene expression and protein levels were increased by AA depletion, amount of bile acid were reduced. Conclusively, we have shown that AA depletion reduced bile acid biosynthesis and elevated Cyp7a1 gene expression and protein levels. Thus, AA is an essential for bile acid biosynthesis pathway.
Ascorbic acid deficiency affects genes for oxidation-reduction and lipid metabolism in livers from SMP30/GNL knockout mice.
Sex, Specimen part
View SamplesWe examined gene expression induced by Rhipicephalus microplus bites on host skin of tick-resistant and tick-susceptible breeds of bovines, Nelore and Holstein respectively, when they underwent a primary infestation.
Immune and biochemical responses in skin differ between bovine hosts genetically susceptible and resistant to the cattle tick Rhipicephalus microplus.
Sex, Specimen part, Subject, Time
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