The transcriptional coactivator ANGUSTIFOLIA 3 (AN3) stimulates cell proliferation during Arabidopsis leaf development, but the molecular mechanism is largely unknown. We show here that inducible nuclear localization of AN3 during initial leaf growth results in differential expression of important transcriptional regulators, including GROWTH REGULATING FACTORs (GRFs). Chromatin purification further revealed the presence of AN3 at the loci of GRF5, GRF6, CYTOKININ RESPONSE FACTOR 2 (CRF2), CONSTANS-LIKE 5 (COL5), HECATE 1 (HEC1), and ARABIDOPSIS RESPONSE REGULATOR 4 (ARR4). Tandem affinity purification of protein complexes using AN3 as bait identified plant SWITCH/SUCROSE NONFERMENTING (SWI/SNF) chromatin remodeling complexes formed around the ATPases BRAHMA (BRM) or SPLAYED (SYD). Moreover, SWI/SNF ASSOCIATED PROTEIN 73B (SWP73B) is recruited by AN3 to the promoter of GRF5, GRF3, COL5, and ARR4, and both SWP73B and BRM occupy the HEC1 promoter. Furthermore, we show that AN3 and BRM genetically interact. The data indicate that AN3 associates with chromatin remodelers to regulate transcription. In addition, modification of SWI3C expression levels increases leaf size, underlining the importance of chromatin dynamics for growth regulation. Our results place the SWI/SNF-AN3 module as a major player at the transition from cell proliferation to cell differentiation in a developing leaf.
ANGUSTIFOLIA3 binds to SWI/SNF chromatin remodeling complexes to regulate transcription during Arabidopsis leaf development.
Specimen part, Time
View SamplesThis study compares directed cardiac differentiation time-courses using (i) HuES6 cells with endogenous ISL1 knockout + inducible ISL1 transgene, and (ii) wild-type HuES6 cells.
Revised roles of ISL1 in a hES cell-based model of human heart chamber specification.
Specimen part, Time
View SamplesThe atrioventricular (AV) node is a recurrent source of potentially life-threatening arrhythmias. Nevertheless, limited data are available on its developmental control or molecular phenotype. We used a novel AV node-specific reporter mouse to gain insight into the gene programs determining the formation and phenotype of the AV node. In the transgenic reporter, green fluorescent protein (GFP) expression was driven by 160 kbp of Tbx3 and flanking sequences. GFP was selectively expressed in the AV canal of embryos, and in the AV node of adults, while all other Tbx3+ conduction system components, including the AV bundle, were devoid of GFP expression. Fluorescent AV nodal (Tbx3BAC-Egfp) and complementary working (NppaBAC336-Egfp) myocardial cell populations of E10.5 embryos and E17.5 fetuses were purified using fluorescence-activated cell sorting, and their expression profiles were assessed by microarray analysis. We constructed a comprehensive list of sodium, calcium, and potassium channels specific for the nodal or working myocard. Furthermore, the data revealed that the AV node and the working myocardium phenotypes diverge during development, but that the functional gene classes characteristic for both compartments are maintained. Interestingly, the AV node-specific gene repertoire consisted of multiple neurotrophic factors not yet appreciated to play a role in nodal development. These data present the first genome-wide transcription profiles of the AV node during development, providing valuable information concerning its molecular identity.
Gene expression profiling of the forming atrioventricular node using a novel tbx3-based node-specific transgenic reporter.
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View SamplesWe have analysed a family with an autosomal recessive type of tetraplegic cerebral palsy with mental retardation, reduction of cerebral white matter, and atrophy of the cerebellum in an inbred sibship.
Mutation in the AP4M1 gene provides a model for neuroaxonal injury in cerebral palsy.
Sex, Specimen part
View SamplesHereditary Persistence of Fetal Hemoglobin (HPFH) is characterized by persistent high levels of fetal hemoglobin (HbF) in adults. Several contributory factors, both genetic and environmental, have been identified, but others remain elusive. Ten of twenty-seven members from a Maltese family presented with HPFH. A genome-wide SNP scan followed by linkage analysis revealed a candidate region on chromosome 19p13.12-13. Sequencing identified a nonsense mutation in the KLF1 gene, p.K288X, ablating the DNA binding domain of this key erythroid transcriptional regulator. Only HPFH family members were heterozygote carriers of this mutation. Expression profiling on primary erythroid progenitors revealed down-regulation of KLF1 target genes in HPFH samples. Functional assays demonstrated that, in addition to its established role in adult globin expression, KLF1 is a critical activator of the BCL11A gene, encoding a suppressor of HbF expression. These observations provide a rationale for the effects of KLF1 haploinsufficiency on HbF levels. To identify differentially expressed genes, RNA was isolated from erythroid progenitors (HEPs) cultured from peripheral blood of four HPFH (KLF1 p.K288X/wt) and four non-HPFH family members (wt/wt) and used for genome-wide expression analysis.
Haploinsufficiency for the erythroid transcription factor KLF1 causes hereditary persistence of fetal hemoglobin.
Specimen part
View SamplesAnalysis of glucose and Lipid metabolism in male and female offspring after protein restriction of the mother
Sex-dependent programming of glucose and fatty acid metabolism in mouse offspring by maternal protein restriction.
Sex, Specimen part
View SamplesMaternal diet is associated with the development of metabolism-related and other non-communicable diseases in offspring. Underlying mechanisms, functional profiles, and molecular markers are only starting to be revealed. Here, we explored the physiological and molecular impact of maternal Western-style diet on the liver of male and female offspring. C57BL/6 dams were exposed to either a low fat/low cholesterol diet (LFD) or a Western-style high fat/high cholesterol diet (WSD) for six weeks before mating, as well as during gestation and lactation. Dams and offspring were sacrificed at postnatal day 14, and body, liver, and blood parameters were assessed. The impact of maternal WSD on the pups' liver gene expression was characterised by whole-transcriptome microarray analysis. Exclusively male offspring had significantly higher body weight upon maternal WSD. In offspring of both sexes of WSD dams, liver and blood parameters, as well as hepatic gene expression profiles were changed. In total, 686 and 604 genes were differentially expressed in liver (p0.01) of males and females, respectively. Only 10% of these significantly changed genes overlapped in both sexes. In males, in particular alterations of gene expression with respect to developmental functions and processes were observed, such as Wnt/beta-catenin signalling. In females, mainly genes important for lipid metabolism, including cholesterol synthesis, were changed. We conclude that maternal WSD affects physiological parameters and induces substantial changes in the molecular profile of the liver in two-week-old pups. Remarkably, the observed biological responses of the offspring reveal pronounced sex-specificity.
Maternal Western-style high fat diet induces sex-specific physiological and molecular changes in two-week-old mouse offspring.
Sex, Age, Specimen part
View SamplesThere is increasing appreciation for sexually dimorphic effects, but the molecular mechanisms underlying these effects are only partially understood. In the present study, we explored transcriptomics and epigenetic differences in the small intestine and colon of prepubescent male and female mice. In addition, the microbiota composition of the colonic luminal content has been examined. At postnatal day 14, male and female C57BL/6 mice were sacrificed and the small intestine, colon and content of luminal colon were isolated. Gene expression of both segments of the intestine was analysed by microarray analysis. DNA methylation of the promoter regions of selected sexually dimorphic genes was examined by pyrosequencing. Composition of the microbiota was explored by deep sequencing. Sexually dimorphic genes were observed in both segments of the intestine of 2-week-old mouse pups, with a stronger effect in the small intestine. Amongst the total of 349 genes displaying a sexually dimorphic effect in the small intestine and/or colon, several candidates exhibited a previously established function in the intestine (i.e. Nts, Nucb2, Alox5ap and Retnl). In addition, differential expression of genes linked to intestinal bowel disease (i.e. Ccr3, Ccl11 and Tnfr) and colorectal cancer development (i.e. Wt1 and Mmp25) was observed between males and females. Amongst the genes displaying significant sexually dimorphic expression, nine genes were histone-modifying enzymes, suggesting that epigenetic mechanisms might be a potential underlying regulatory mechanism. However, our results reveal no significant changes in DNA methylation of analysed CpGs within the selected differentially expressed genes. With respect to the bacterial community composition in the colon, a dominant effect of litter origin was found but no significant sex effect was detected. However, a sex effect on the dominance of specific taxa was observed. This study reveals molecular dissimilarities between males and females in the small intestine and colon of prepubescent mice, which might underlie differences in physiological functioning and in disease predisposition in the two sexes.
Sexually dimorphic characteristics of the small intestine and colon of prepubescent C57BL/6 mice.
Sex, Age, Specimen part
View SamplesDuring the last few decades, the long-lasting consequences of nutritional programming during the early phase of life have become increasingly evident, but the effects of maternal nutrition on the developing intestine are currently still relatively underexplored. In this study, we investigated in mice the effects of a maternal Western-style (WS) high fat/cholesterol diet, given during the perinatal period, on gene expression and microbiota composition of two-week-old offspring. Microarray analysis revealed that a perinatal WS diet caused significant changes in gene expression in the small intestine and colon of the suckling offspring. A strong sexually dimorphic effect was observed in the affected genes. However, pathway analysis of the differentially expressed genes displayed that in both sexes metabolic and immune functions were strongly affected. Integration of the microbiota and gene expression data applying a multivariate correlation analyses revealed that Bacteroidaceae, Porphyromonadaceae and Lachnospiraceae were the bacterial families that most strongly correlated with gene expression in the colon and not with the bacterial families displaying the most pronounced change due to perinatal exposure to a WS diet. Amongst the genes demonstrating a strong correlation with one or more bacterial families were genes of key importance for intestinal development or functioning (i.e., Pitx2 and Ace2). In conclusion, our data demonstrate a strong programming effect of a maternal WS diet on the development of the intestine in the offspring.
Maternal exposure to a Western-style diet causes differences in intestinal microbiota composition and gene expression of suckling mouse pups.
Sex, Age, Specimen part
View SamplesInterleukin-6 (IL-6) is an important growth factor for estrogen receptor-alpha (ER) positive breast cancer, and elevated serum IL-6 is associated with poor prognosis. We firstly demonstrated that pSTAT3 is the primary downstream IL-6 signaling pathway in ER-positive breast cancer, using ten different breast cancer cell lines. Three-dimensional cultures of these cell lines were also used to develop a 17-gene IL-6 specific gene signature that could be used to identify IL-6 driven disease. This signature included a variety of genes involved in immune cell function and migration, cell growth and apoptosis, and the tumor microenvironment. To further validate this IL-6 signature, we obtained 36 human ER-positive breast cancer tumor samples with matched serum for gene expression profiling and determination of an IL-6 pathway activation score (PAS). Patients with high IL-6 PAS were also enriched for elevated serum IL-6 (>=10 pg/ml). We then utilized a murine MCF-7 xenograft model to determine the role of IL-6 in ER-positive breast cancer and potential anti-IL-6 therapy in vivo. When IL-6 was administered in vivo, MCF-7 cells engrafted without the need for estrogen supplementation. Subsequently, we prophylactically treated mice at MCF-7 engraftment with an anti-IL-6 antibody (siltuximab), fulvestrant or combination therapy. Siltuximab alone was able to blunt MCF-7 engraftment. Similarly, when tumors were allowed to grow to 125 mm3 before treatment, siltuximab alone demonstrated tumor regressions in 90% (9/10) of tumors. Given the established role for IL-6 in ER+ breast cancer, this data demonstrates the potential for anti-IL-6 therapeutics.
Interleukin-6 is a potential therapeutic target in interleukin-6 dependent, estrogen receptor-α-positive breast cancer.
Specimen part
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