Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is an aggressive hematological. We used transcriptomic analysis to investigate LXR pathway, and cholesterol metabolism in leukemic cells. Malignancy with a poor prognosis that derives from plasmacytoid dendritic cells (PDC). No consensus for optimal treatment modalities is available today and the full characterization of this leukemia is still emerging. We identified here a BPDCN-specific transcriptomic profile when compared to those of acute myeloid leukemia (AML) and T-acute lymphoblastic leukemia (T-ALL), as well as the transcriptomic signature of primary PDC. This BPDCN gene signature identified a dysregulation of genes involved in cholesterol homeostasis, some of them being liver X receptor (LXR) target genes. LXR agonist treatment of primary BPDCN cells and BPDCN cell lines restored LXR target gene expression and increased cholesterol efflux via the upregulation of ATP Binding Cassette (ABC) transporters, ABCA1 and ABCG1. LXR agonist treatment was responsible for limiting BPDCN cell proliferation and inducing intrinsic apoptotic cell death. LXR activation in BPDCN cells was shown to interfere with three signaling pathways associated with leukemic cell survival, namely: NF-B activation, as well as Akt and STAT5 phosphorylation in response to the BPDCN growth/survival factor IL-3. These effects were increased by the stimulation of cholesterol efflux through a lipid acceptor, the apolipoprotein A1. In vivo experiments using a mouse model of BPDCN cell xenograft revealed a decrease of leukemic cell infiltration and BPDCN-induced cytopenia associated with an increased survival after LXR agonist treatment. This demonstrates that cholesterol homeostasis is modified in BPDCN and can be normalized by treatment with LXR agonists which can be proposed as a new therapeutic approach.
LXR agonist treatment of blastic plasmacytoid dendritic cell neoplasm restores cholesterol efflux and triggers apoptosis.
Specimen part, Disease, Disease stage
View SamplesVaccine adjuvants enhance adaptive immunity to co-administered antigens. Whereas the modes of action are multiple, the activation of antigen-presenting cells (APC) like dendritic cells by adjuvants is a prerequisite. Detection of microbial signals by innate sensors like Toll-like receptors (TLR) is a major mechanism of APC activation. Most candidate or licensed vaccines assume that adjuvant activity of TLR agonists depends on direct effect on APCs. This study addressed whether TLR stimulation of non-hematopoietic cells could contribute to the adjuvant effect. Nasal administration of flagellin enhanced Tcell- and antibody-mediated immunity to co-administered antigens in a TLR5-dependent but inflammasome-independent manner. We found that lung radioresistant cells were sufficient to promote immunity, thereby suggesting that direct TLR5-mediated APC stimulation is dispensable to adjuvant activity. Consistent with this, radioresistant compartment is essential to stimulate the swift TLR5-dependent transcription. The transcriptional response was restricted to the epithelial compartment and was associated to the production of a narrow set of mediators including the chemokine CCL20, known to promote APC recruitment in mucosal tissues. Besides, flagellin was rapidly degraded in lower airways and was not transported into lung parenchyma or peripheral tissues. This study therefore suggests an unexpected mechanism for how TLR agonists act as adjuvant and how epithelium is instrumental to sense and integrate microbial signals to promote adaptive immunity. In conclusion, the immune-enhancing effect of adjuvants on epithelial cells can be harnessed for improving vaccines.
No associated publication
Specimen part, Treatment
View SamplesMurine embryonic fibroblasts were isolated from WT and DGAT1,DGAT2-KO (D1D2KO) animals. mRNA was isolated from cells untreated (UNDIFF) or treated (DIFF) according to standard differentiation protocol for adipocytes (Harris, C, et al. JLR 2011).
DGAT enzymes are required for triacylglycerol synthesis and lipid droplets in adipocytes.
Specimen part
View SamplesBased on the developmental origin of health of disease hypothesis, we previously showed that prenatal 70% maternal food restriction (FR30) predisposes the offspring to development of pathologies in adulthood. In the present study, we focused on the liver gene expression profile of standard and high fat (HF)-fed FR30 adult offspring.
No associated publication
Sex, Age, Specimen part
View SamplesTranscription profiling by array of pancreas from KrasG12D, Ela-Tgfa and KrasG12D Ela-Tgfa mice
Concomitant pancreatic activation of Kras(G12D) and Tgfa results in cystic papillary neoplasms reminiscent of human IPMN.
Age, Specimen part
View SamplesThe NfkB-pathway is activated early during acute pancreatitis. We investigated the influence on gene expression of two pancreas-specific deletions interfering with NfkB-activation. Pancreata from 8 week old mice were prepared, RNA was isolated and Affymetrix microarray expression analysis was performed.
Deletion of IkBa induces RelA to alleviate acute pancreatitis in mice through upregulation of Spi2a
Age, Specimen part, Disease, Disease stage, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Protein Syndesmos is a novel RNA-binding protein that regulates primary cilia formation.
Specimen part, Cell line
View SamplesWe show here that SDOS interacts with another important cancer-linked protein, the chaperone TRAP1, associates with actively translating polyribosomes and represses translation. Moreover, we demonstrate that SDOS binds directly RNA in living cells. Combining individual gene expression profiling, nucleotide cross-linking and immunoprecipitation (iCLIP), and ribosome profiling, we discover several crucial pathways regulated post-transcriptionally by SDOS.
No associated publication
Cell line
View SamplesWe have studied the genes activated in human liver transplantation to identify potential target genes for the prevention or treatment of related injuries.
Wide gene expression profiling of ischemia-reperfusion injury in human liver transplantation.
Sex, Age, Specimen part, Subject
View SamplesIn order to define the transcriptional network functionally regulated by Pax8 as well as infer its direct targets, we performed RNAi to knock-down Pax8 gene in FRTL-5 thyroid cells. Expression data from three independent silencing experiments were analyzed by microarray technology unraveling 2815 genes differentially expressed between silenced cells and controls. Of these, 1421 genes were down-regulated and 1394 genes were up-regulated 72hrs after Pax8 silencing.
Identification of novel Pax8 targets in FRTL-5 thyroid cells by gene silencing and expression microarray analysis.
Cell line
View Samples