Functional analysis of ABCB5 in A375 and G3361 melanoma cells, by comparing stably-transfected controls to ABCB5-shRNA-targeted cells.
ABCB5 maintains melanoma-initiating cells through a proinflammatory cytokine signaling circuit.
Specimen part, Cell line
View SamplesMelanoma growth is driven by malignant melanoma initiating cells (MMIC) identified by expression of the ATP-binding cassette (ABC) member, ABCB5. ABCB5+ melanoma subpopulations have been shown to overexpress the vasculogenic differentiation markers CD144 (VE-cadherin) and TIE-1 and are associated with CD31-negative vasculogenic mimicry (VM), an established biomarker associated with increased patient mortality. Here we identify a critical role for VEGFR-1 signaling in ABCB5+ MMIC-dependent VM and tumor growth. Global gene expression analyses, validated by mRNA and protein determinations, revealed preferential expression of VEGFR-1 on ABCB5+ tumor cells purified from clinical melanomas and established melanoma lines. In vitro, VEGF induced in a VEGFR-1-dependent manner expression of CD144 in ABCB5+ subpopulations that constitutively expressed VEGFR-1, but not in ABCB5- bulk populations that were predominantly VEGFR-1-negative. In vivo, melanomaspecific shRNA-mediated knockdown of VEGFR-1 blocked the development of ABCB5+ VM morphology and inhibited ABCB5+ VM-associated production of the secreted melanoma mitogen, laminin. Moreover, melanoma-specific VEGFR-1 knockdown markedly inhibited tumor growth (by >90%). Our results demonstrate that VEGFR-1 function in MMIC regulates VM and associated laminin production, and show that this function represents one mechanism through which MMIC promote tumor growth.
VEGFR-1 expressed by malignant melanoma-initiating cells is required for tumor growth.
Specimen part
View SamplesRenal artery stenosis (RAS) caused by narrowing of arteries is characterized by microvascular damage. Macrophages are implicated in repair and injury, but the specific populations responsible for these divergent roles have not been identified. Here, we characterized murine kidney F4/80+CD64+ macrophages in three transcriptionally unique populations. Using fate-mapping and parabiosis studies, we demonstrate that CD11b/cint are long-lived kidney-resident (KRM) while CD11chiMf, CD11cloMf are monocyte-derived macrophages. In a murine model of RAS, KRM self-renewed, while CD11chiMf and CD11cloMf increased significantly, which was associated with loss of peritubular capillaries. Replacing the native KRM with monocyte-derived KRM using bone marrow transplantation followed by RAS, amplified loss of peritubular capillaries. To further elucidate the nature of interactions between KRM and peritubular endothelial cells, we performed RNA-sequencing on flow-sorted macrophages from Sham and RAS kidneys. KRM showed a prominent activation pattern in RAS with significant enrichment in reparative pathways, like angiogenesis and wound healing. In culture, KRM increased proliferation of renal peritubular endothelial cells implying direct pro-angiogenic properties. Human homologs of KRM identified as CD11bintCD11cintCD68+ increased in post-stenotic kidney biopsies from RAS patients compared to healthy human kidneys, and inversely correlated to kidney function. Thus, KRM may play protective roles in stenotic kidney injury through expansion and upregulation of pro-angiogenic pathways Overall design: CD11chiMf Sham, n=3; CD11chiMf RAS, n=4; CD11cloMf Sham, n=3; CD11cloMf RAS, n=4; KRM Sham, n=4; KRM RAS, n=3;
Kidney-resident macrophages promote a proangiogenic environment in the normal and chronically ischemic mouse kidney.
Sex, Age, Specimen part, Cell line, Subject
View SamplesBlastic 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 SamplesNeuronal cultures were treated with candesartan at neuroprotective concentrations followed by excitotoxic glutamate amounts. Candesartan significantly reduced glutamate-induced inflammation. To provide mechanistic insight into the potential targets and pathways that may underlie these benefits, we performed genome wide expression profile analysis and evaluated the data by Ingenuity Pathway Analysis (IPA) and Gene Set Enrichment Analysis (GSEA). We found that the inflammation signal transduction pathways were major components of the neuronal response to glutamate excitotoxicity, and that candesartan significantly ameliorated glutamate-induced alterations in gene expression. Further analysis showed significant associations of these genes with two independent published networks identified by microarray analysis of hippocampal samples obtained post-mortem from brains of patients diagnosed with AD .
An integrative genome-wide transcriptome reveals that candesartan is neuroprotective and a candidate therapeutic for Alzheimer's disease.
Specimen part, Treatment
View SamplesMultiple sclerosis (MS) is a neurodegenerative disease with a presumed autoimmune component. Expression profiling in immune cells can therefore be used in order to identify genes and pathways involved in MS pathogenesis.
Systematic review of genome-wide expression studies in multiple sclerosis.
Specimen part, Disease, Disease stage
View SamplesHaving found that LexA degradation was significantly higher under apoptotic like death (ALD) than under SOS conditions, we hypothesized that additional genes tightly regulated by LexA would be transcribed under ALD conditions.
Apoptosis-like death, an extreme SOS response in Escherichia coli.
Disease, Treatment
View SamplesNeuronal function critically depends on coordinated subcellular distribution of mRNAs. Disturbed mRNA processing and axonal transport has been found in spinal muscular atrophy and could be causative for dysfunction and degeneration of motoneurons. Despite the advances made in characterizing the transport mechanisms of several axonal mRNAs, an unbiased approach to identify the axonal repertoire of mRNAs in healthy and degenerating motoneurons has been lacking. Here we used compartmentalized microfluidic chambers to investigate the somatodendritic and axonal mRNA content of cultured motoneurons by microarray analysis. In axons, transcripts related to protein synthesis and energy production were enriched relative to the somatodendritic compartment. Knockdown of Smn, the protein deficient in spinal muscular atrophy, produced a large number of transcript alterations in both compartments. Transcripts related to immune functions, including MHC class I genes, and with roles in RNA splicing were upregulated in the somatodendritic compartment. On the axonal side, transcripts associated with axon growth and synaptic activity were downregulated. These alterations provide evidence that subcellular localization of transcripts with axonal functions as well as regulation of specific transcripts with nonautonomous functions is disturbed in Smn-deficient motoneurons, most likely contributing to the pathophysiology of spinal muscular atrophy.
Subcellular transcriptome alterations in a cell culture model of spinal muscular atrophy point to widespread defects in axonal growth and presynaptic differentiation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Telmisartan Protects a Microglia Cell Line from LPS Injury Beyond AT1 Receptor Blockade or PPARγ Activation.
Specimen part, Cell line, Treatment
View SamplesLPS and Telmisartan co-treatment of microglial BV2 cells.
Telmisartan Protects a Microglia Cell Line from LPS Injury Beyond AT1 Receptor Blockade or PPARγ Activation.
Specimen part, Cell line, Treatment
View Samples