Although a considerable number of reports indicate an involvement of the Hox-A10 gene in the molecular control of hematopoiesis, the conclusions of such studies are quite controversial since they support, in some cases, a role in the stimulation of stem cell self-renewal and myeloid progenitor expansion while, in others, implicate this transcription factor in the induction of monocyte - macrophage differentiation. To clarify this issue we analyzed the biological effects and the transcriptome changes determined in human primary CD34+ hematopoietic progenitors by retroviral transduction of a full length Hox-A10 cDNA. The results obtained clearly indicated that this homeogene is an inducer of monocyte differentiation, at least partly acting through the up-regulation of MafB gene, recently identified as master regulator of such maturation pathway. By using a combined approach based on computational analysis, EMSA experiments and luciferase assays, we were able to demonstrate the presence of a Hox-A10 binding site in the promoter region of the MafB gene, which suggested the likely molecular mechanism underlying the observed effect. Interestingly, stimulation of the same cells with the Vitamin D3 monocyte differentiation inducer resulted in a clear increase of Hox-A10 and MafB transcripts, indicating the existence of a precise transactivation cascade involving VDR, Hox-A10 and MafB transcription factors. Altogether these data allow to conclude that the Vitamin D3 / Hox-A10 pathway supports MafB function during the induction of monocyte differentiation.
The vitamin D3/Hox-A10 pathway supports MafB function during the monocyte differentiation of human CD34+ hemopoietic progenitors.
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View SamplesZinc is both an essential and potentially toxic metal. It is widely believed that oral zinc supplementation can reduce the effects of the common cold; however, there is strong clinical evidence that intranasal (IN) zinc gluconate (ZG) gel treatment for this purpose causes anosmia, or the loss of the sense of smell, in humans. Using the rat olfactory neuron cell line, Odora, we investigated the molecular mechanism by which zinc exposure exerts its toxic effects on olfactory neurons. Following treatment of Odora cells with 100 and 200 µM ZG for 0-24 h, RNA-seq and in silico analyses revealed up-regulation of pathways associated with zinc metal response, oxidative stress, and ATP production. We observed that Odora cells recovered from zinc-induced oxidative stress, but ATP depletion persisted with longer exposure to ZG. ZG exposure increased levels of NLRP3 and IL-1ß protein levels in a time-dependent manner, suggesting that zinc exposure may cause an inflammasome-mediated cell death, pyroptosis, in olfactory neurons. Overall design: 5 treatment groups, 3 replicates/group, 1 control group, 3 groups treated with 100 µM zinc gluconate for increasing time (6, 12, and 24 h), 1 group treated with 200 µM zinc gluconate for 6 h
Mechanistic studies of the toxicity of zinc gluconate in the olfactory neuronal cell line Odora.
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View SamplesMonoallelic expression of autosomal genes (MAE) is a widespread epigenetic phenomenon which is poorly understood, due in part to current limitations of genome-wide approaches for assessing it. Recently, we reported that a specific histone modification signature is strongly associated with MAE, and demonstrated that it can serve as a proxy of MAE in human lymphoblastoid cells (Nag et al. Elife. 2013 Dec 31;2:e01256). Here, we use murine cells to establish that this chromatin signature is conserved between mouse and human, and is associated with MAE in every tested cell type. Our analyses reveal extensive conservation in the identity of MAE genes between the two species. By applying MAE chromatin signature analysis to a large number of cell and tissue types, we show that the MAE state remains consistent during terminal cell differentiation and is predominant among cell-type specific genes, suggesting a link between MAE and specification of cell identity. Overall design: PolyA RNA purification and subsequent high-throughput sequencing were performed on two independent B-lymphoid clonal cell line, derived from 129S1/SvImJ x CAST/EiJ F1 mice and immortalized with Abelson murine leukemia virus, and on two independent fibroblast clonal cell lines, derived from 129S1/Sv x CAST/EiJ F1 and immortalized with SV40.
Chromatin Signature Identifies Monoallelic Gene Expression Across Mammalian Cell Types.
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View SamplesLung transplantation remains the only viable therapy for patients with end-stage lung disease; however, full utilization of this treatment strategy is severely compromised by the lack of donor lung availability. For example, the vast majority of donor lungs available for transplantation are obtained from brain death (BD) individuals. Unfortunately, the autonomic storm which accompanies BD often results in neurogenic pulmonary edema (NPE), thereby either producing irreversible lung injury or leading to primary graft dysfunction following lung transplantation. We previously demonstrated that sphingosine 1-phosphate (S1P), a phospholipid angiogenic factor and major barrier-enhancing agent, as well as S1P analogues serve to reduce vascular permeability and ischemia/reperfusion (I/R) lung injury in rodents via ligation of the S1P1 receptor, S1PR1. As primary lung graft dysfunction is induced by lung vascular endothelial cell barrier dysfunction, we hypothesized that SEW-2871, a S1PR1 agonist, may attenuate NPE when administered to the donor shortly after BD. Significant lung injury was observed 4h after BD in a rat BD model with ~60% increases in BAL total protein, BAL cell counts, and lung tissue W/D weight ratios. In contrast, rats receiving SEW-2871 (0.1 mg/kg) 15 minutes after the induction of BD and assessed 4h later exhibited significant lung protection (~50% reduction, p=0.01) reflected by reduced BAL total protein, BAL cytokines concentrations, BAL albumin, BAL total cell count and lung tissue wet/dry (W/D) weights ratio. Microarray analysis at 4hrs revealed a global impact of both BD and SEW on lung gene expression with differential expression of a subclass of genes enriched in immune/inflammation response pathways across the 4 experimental groups. Overall, SEW served to attenuate the BD-mediated ie gene expression upregulation. Two potentially useful biomarkers, Tnf and Ccrl2, exhibited gene dysregulation by microarray analysis, which was validated by qPCR. We conclude that SEW-2871 significantly attenuates BD-induced lung injury and may serve as a potential candidate to improve human lung donor availability and transplantation outcomes.
A sphingosine 1-phosphate 1 receptor agonist modulates brain death-induced neurogenic pulmonary injury.
Sex, Specimen part, Treatment
View SamplesCTCF (CCCTC-binding factor) is a highly conserved 11-zinc finger DNA binding protein with tens of thousands of binding sites genome-wide. CTCF acts as a multifunctional regulator of transcription, having been previously associated with activator, repressor, and insulator activity. These diverse regulatory functions are crucial for preimplantation development and are implicated in the regulation of numerous lineage-specific genes. Despite playing a critical role in developmental gene regulation, the mechanisms that underlie developmental changes in CTCF recruitment and function are poorly understood. Our previous work suggested that differences in CTCF’s binding site sequence may affect the regulation of CTCF recruitment, as well as CTCF’s regulatory function. To investigate these two possibilities directly during a developmental process, changes in genome-wide CTCF binding and gene expression were characterized during in vitro differentiation of mouse embryonic stem cells. CTCF binding sites were initially separated into three classes (named LowOc, MedOc, and HighOc) based on similarity to the consensus motif. The LowOc class, with lower-similarity to the consensus motif, is more likely to show changes in binding during differentiation. These more dynamically bound sites are enriched for motifs that confer a lower in vitro affinity for CTCF, suggesting a mechanism where sites with low-binding affinity are more amenable to developmental control. Additionally, by comparing changes in CTCF binding with changes in gene expression during differentiation, we show that LowOc and HighOc sites are associated with distinct regulatory functions. In sum, these results suggest that the regulatory control of CTCF’s binding and function is dependent in part upon specific motifs within its DNA binding site. Overall design: Mouse E14 ES cells were differentiated in vitro for 4.5 days using retinoic acid. RNA-Seq was performed from cells collected before and after differentiation.
CTCF binding site sequence differences are associated with unique regulatory and functional trends during embryonic stem cell differentiation.
Specimen part, Cell line, Subject
View SamplesAML with mutated NPM1 usually carries normal karyotype (NK) but it may harbor chromosomal aberrations whose significance remains unclear. We addressed this question in 631 AML patients with mutated/cytoplasmic NPM1. An abnormal karyotype (AK) was present in 93/631 cases (14.7%), the most frequent abnormalities being +8, +4, -Y, del(9q), +21. Chromosome aberrations in NPM1-mutated AML were similar to, but occurred less frequently than additional chromosome changes found in other AML with recurrent cytogenetic abnormalities according to WHO classification. Four of the 31 NPM1-mutated AML patients karyotyped at different time points had NK at diagnosis but AK at relapse: del(9q) (n=2), t(2;11) (n=1), inv(12) (n=1).
AML with mutated NPM1 carrying a normal or aberrant karyotype show overlapping biologic, pathologic, immunophenotypic, and prognostic features.
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View SamplesHuman induced pluripotent stem (iPS) cells derived from somatic cells of patients hold great promise for modelling human diseases. Dermal fibroblasts are frequently used for reprogramming, but require an invasive skin biopsy and a prolonged period of expansion in cell culture prior to use. Here, we report the derivation of iPS cells from multiple human blood sources including peripheral blood mononuclear cells (PBMCs) harvested by routine venipuncture. Peripheral blood-derived human iPS lines are comparable to human embryonic stem (ES) cells with respect to morphology, expression of surface antigens, activation of endogenous pluripotency genes, DNA methylation and differentiation potential. Analysis of Immunoglobulin and T-cell receptor gene rearrangement revealed that some of the PBMC iPS cells were derived from T-cells, documenting derivation of iPS cells from terminally differentiated cell types. Importantly, peripheral blood cells can be isolated with minimal risk to the donor and can be obtained in sufficient numbers to enable reprogramming without the need for prolonged expansion in culture. Reprogramming from blood cells thus represents a fast, safe and efficient way of generating patient-specific iPS cells.
Reprogramming of T cells from human peripheral blood.
Specimen part, Cell line
View SamplesCholecystokinin (CCK) is a satiety hormone produced by discrete enteroendocrine cells scattered among absorptive cells of the small intestine. CCK is released into blood following a meal; however, the mechanisms inducing hormone secretion are largely unknown. Ingested fat is the major stimulant of CCK secretion. We recently identified a novel member of the lipoprotein remnant receptor family known as immunoglobulin-like domain containing receptor 1 (ILDR1) in intestinal CCK cells and postulated that this receptor conveyed the signal for fat-stimulated CCK secretion. In the intestine, ILDR1 is expressed exclusively in CCK cells. Orogastric administration of fatty acids elevated blood levels of CCK in wild type but not ILDR1-deficient mice, although the CCK secretory response to trypsin inhibitor was retained. The uptake of fluorescently labeled lipoproteins in ILDR1-transfected CHO cells and release of CCK from isolated intestinal cells required a unique combination of fatty acid plus HDL. CCK secretion secondary to ILDR1 activation is associated with increased [Ca2+]i consistent with regulated hormone release. These findings demonstrate that ILDR1 regulates CCK release through a mechanism dependent on fatty acids and lipoproteins and that absorbed fatty acids regulate gastrointestinal hormone secretion.
Immunoglobulin-like domain containing receptor 1 mediates fat-stimulated cholecystokinin secretion.
Specimen part
View SamplesB16F1 cells are a good model to study cell motility and cytoskeletal organization. In our lab, a combination of microscopy and gene silencing was used to approach the problem. Having gene expression profiles for B16F1 would facilitate and support subsequent gene silencing by RNAi as well as potentially identify new molecular players.
Role of fascin in filopodial protrusion.
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View SamplesPurpose: Citron kinase (CitK) knockout mice show a severe form of primary microcephaly, associated with ataxia and lethal epilepsy. This phenotype is caused by massive apoptosis occuring during embryonic and post-natal brain development, associated with cytokinesis failure. Cerebellum is the tissue showing highest sensitivity to CitK loss. The clinical phenotype of CitK knockout mice is significantly resued by P53 inactivation. In addition, CitK/P53 double knockout brains have almost normal levels of apoptosis, but display high percentage of binucleated and multinucleated cells. The aim of this study was to analyze the gene expression changes produced in developing neural tissue by CitK loss and to determine which alterations are P53-dependent. expression changes Methods: We analyzed by RNA sequencing total RNA extracted from P4 cerebellum of mice characterized by the following genotypes: 1. CitK +/-, P53 +/- (CTRL); 2. CitK -/-, P53 +/- (CitK-KO); 3. CitK +/-, P53 -/- (P53-KO); 4. CitK -/-, P53 -/- (D-KO). Biological triplicates were analyzed per every genotype. Conclusions: The loss of CitK leads to a strong reduction of the expression of pro-neural genes and induces a P53-related pro-apoptotic gene sets. The analysis of D-KO mice reveals that most of these changes are P53-dependent, but many genes implicated in growth arrest are induced through P53-independent mechanisms. Overall design: Cerebellar mRNA profiles of 4-day old mice of CTRL, CitK-KO, P53-KO and D-KO mice were generated by deep sequencing, in triplicate, using Illumina HiScan SQ
ZIKA virus elicits P53 activation and genotoxic stress in human neural progenitors similar to mutations involved in severe forms of genetic microcephaly.
Specimen part, Cell line, Subject
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