The Dahl salt-sensitive (S) rat model develops chronic hypertensive disease when fed a high salt diet that ultimately results in renal and heart failure, as well as prevalent cerebrovascular pathologies. Phenotypic changes in the cerebral vasculature are preceded by changes in gene expression, and evidence supports a role for extracellular signal-regulated kinase 1/2 (ERK1/2) in vascular cell proliferation, yet little is known regarding ERK1/2 regulated gene transcription in cerebrovascular smooth muscle during hypertension. Findings presented here support the hypothesis that salt-induced hypertensive disease results in upregulation of ERK1/2 activity and ERK1/2-regulated genes that promote remodeling in cerebral resistance arteries. Dahl S rats were fed either a 0.4% NaCl (low salt, LS) or 8% NaCl (high salt, HS) diet until evidence of left ventricular dysfunction. Gene expression profiling using oligonucleotide array analysis detected a significant fold-change of 1.5 or greater in 133 out of 15,923 genes examined. Mitogen-activated protein kinase (MAPK)-regulated genes were overrepresented and provided a link to genes involved in proliferation and extracellular matrix signaling including plasminogen activator inhibitor I (PAI-1), osteopontin (OPN) and junB. These data suggests that salt induced hypertensive disease promotes hyperplasia and changes in matricellular genes that are likely important in vascular remodeling.
Genes overexpressed in cerebral arteries following salt-induced hypertensive disease are regulated by angiotensin II, JunB, and CREB.
Specimen part
View SamplesCell migration contributes to normal development and homeostasis as well as to pathological processes such as inflammation and tumor metastasis. Previous genetic screens have revealed a few major signaling pathways that govern follicle cell migrations in the Drosophila ovary, several of which elicit transcriptional responses. However few downstream targets of the critical transcriptional regulators, such as the C/EBP homolog SLBO, have been identified. To characterize the gene expression profile of two migratory cell populations and identify SLBO targets, we employed a magnetic bead based cell separation approach to purify border cells and centripetal cells expressing the mouse CD8 antigen, and carried out whole genome microarray analysis.
Analysis of cell migration using whole-genome expression profiling of migratory cells in the Drosophila ovary.
Sex, Specimen part
View SamplesMetabolism in cancer serves to provide energy and key biomolecules that sustain cell growth, a process that is frequently accompanied by decreased mitochondrial use of glucose. Importantly, metabolic intermediates including mitochondrial metabolites are central substrates for post-translational modifications at the core of cellular signalling and epigenetics. However, the molecular means that coordinate the use of mitochondrial metabolites for anabolism and nuclear protein modification are poorly understood. Here, we unexpectedly found that genetic and pharmacological inactivation of Pyruvate Dehydrogenase A1 (PDHA1), a subunit of pyruvate dehydrogenase complex (PDC) that regulates mitochondrial metabolism16 inhibits prostate cancer development in different mouse and human xenograft tumour models. Intriguingly, we found that lipid biosynthesis was strongly affected in prostate tumours upon PDC inactivation. Mechanistically, we found that nuclear PDC controls the expression of Sterol regulatory element-binding transcription factor (SREBF) target genes by mediating histone acetylation whereas mitochondrial PDC provides cytosolic citrate for lipid synthesis in a coordinated effort to sustain anabolism. In line with the oncogenic function of PDC in prostate cancer, we find that PDHA1 and the PDC activator, Pyruvate dehydrogenase phospatase 1 (PDP1), are frequently amplified and overexpressed at both gene and protein level in these tumours. Taken together, our findings demonstrate that both mitochondrial and nuclear PDC sustains prostate tumourigenesis by controlling lipid biosynthesis thereby pointing at this complex as a novel target for cancer therapy.
Compartmentalized activities of the pyruvate dehydrogenase complex sustain lipogenesis in prostate cancer.
No sample metadata fields
View SamplesMutations in Hedgehog (Hh) pathway genes, leading to constitutive activation of Smoothened (Smo), occur in sporadic medulloblastoma, the most common brain cancer in children. Antagonists of Smo induce tumor regression in mouse models of medulloblastoma and hold great promise for targeted therapy for this tumor. However, acquired resistance has emerged as one of the major challenges of targeted cancer therapy. Here, we describe novel mechanisms of acquired resistance to Smo antagonists in medulloblastoma. NVP-LDE225, a potent and selective Smo antagonist, inhibits Hh signaling and induces tumor regressions in allograft models of medulloblastoma that are driven by mutations of Patched (Ptch), a tumor suppressor in the Hh pathway. However, after long-term treatment, evidence of acquired resistance was observed. Genome-wide profiling of resistant tumors revealed distinct mechanisms to evade the inhibitory effects of Smo antagonists. Chromosomal amplification of Gli2, a downstream effector of Hh signaling, reactivated Hh signaling and restored tumor growth. Analysis of pathway gene-expression signatures selectively deregulated in resistant tumors identified increased phosphoinosite-3-kinase (PI3K) signaling as another potential resistance mechanism. Probing the functional relevance of increased PI3K signaling, we showed that the combination of NVP-LDE225 with the dual PI3K/mTOR inhibitor NVP-BEZ235 markedly delayed the development of resistance. Our findings have important clinical implications for future treatment strategies in medulloblastoma.
Interfering with resistance to smoothened antagonists by inhibition of the PI3K pathway in medulloblastoma.
Treatment
View SamplesAs RIG-I activation induces potent IFN-I responses,we analyzed the role of IFN-I in intestinal tissue protection and prevention of GVHD. We performed RNA sequencing with tissue samples from SI of WT mice that received TBI -/+ previous 3pRNA treatment and -/+ antibody-mediated blockade of IFNAR. Application of 3pRNA before TBI resulted in a significant increase of IFN-inducible genes in the SI as compared to solely irradiated mice. Blockade of IFNAR signaling abrogated 3pRNA-mediated up-regulation of IFN-induced genes, demonstrating that RIG-I-induced gene-regulation depends on IFN-I. Overall design: Balb/c mice were solely irradiated (9Gy) (n=3), pretreated with Rig-I agonist 3pRNA prior (d-1) to irradiation (n=3) or pre-treated with 3pRNA (d-1) + anti-IFNaR1 blocking antibody (d-2) prior to irradiation (n=3). RNA from small intestines was isolated 12h after irradiation and used for RNA sequencing.
RIG-I/MAVS and STING signaling promote gut integrity during irradiation- and immune-mediated tissue injury.
Cell line, Subject
View SamplesSome infectious agents are associated with non-Hodgkin lymphoma development. Here we have used p53-deficient mice chronically injected with Streptococcus pneumoniae (Spn) with the aim to develop an animal model of infection-associated lymphomagenesis. We show that repeated stimulations with heat-killed Spn significantly enhanced the incidence of peripheral T-cell lymphoma (PTCL) in these mice. Phenotypic studies and gene expression profile analyses indicate that these PTCL arose from chronically stimulated natural killer T (NKT) cells, a T cell lineage that exhibits unique properties. Furthermore, lymphoma development was blocked when these PTCL were transferred to recipients lacking CD1d expression or treated with blocking CD1d mAbs, thus demonstrating that in vivo TCR/CD1d interactions are required for these PTCL survival. In conclusion, we have identified a new entity of peripheral T-cell lymphoma that originates from CD1d-restricted natural killer T (NKT) cells. Our results could refine the classification of PTCL and pave the way for the development of new immunotherapeutic approaches.
CD1d-restricted peripheral T cell lymphoma in mice and humans.
Age, Specimen part
View SamplesIn order to establish a list of candidate direct COUP-TFI gene targets in the inner ear, we analyzed the differential gene expression profiles of the wild-type and the COUP-TFI/ P0 inner ears.
Genome-wide analysis of binding sites and direct target genes of the orphan nuclear receptor NR2F1/COUP-TFI.
Specimen part
View SamplesBy utilizing mast cells lacking Dnmt3a, we found that this enzyme is involved in restraining mast cell responses to stimuli, both in vitro and in vivo.
<i>Dnmt3a</i> restrains mast cell inflammatory responses.
Sex, Specimen part, Treatment
View SamplesSeveral studies demonstrated IgVH mutation status and ZAP-70 expression as the most relevant prognostic markers in CLL, suggesting the separation of two patient subgroups: with good (MTZAP-70-) and poor prognosis (UMZAP-70+). We determined gene expression of B cells in 112 CLL patients divided into three classes: the first with IgVHMT and ZAP-70-, the second with IgVHUM and ZAP-70+, and the third included both IgVHUM ZAP-70- and IgVHMT ZAP-70+. We found LPL, AGPAT2, MBOAT1, CHPT1, AGPAT4, PLD1 genes encoding enzymes involved in lipid (glycerolipid/glycerophospholipid) metabolism overexpressed in UMZAP-70+. In addition, this study demonstrates the role of ARSD, a gene belonging to the sphingolipid metabolism, as a new gene significantly overexpressed in UMZAP-70+ in respect to MTZAP-70-. ARSD protein was found at significantly higher concentrations in UMZAP-70+ compared to MTZAP-70- CLL B cells and B cells from healthy individuals by Western blotting. Statistical analysis identified a strong correlation between ARSD and IgVH mutation status; ARSD protein level was associated with the requirement of therapy for CLL patients and for this purpose it is as good as IgVH mutational status. Our study highlights ARSD as a promising new prognostic factor in CLL and sphingolipid metabolism as a putative new biological mechanism in CLL.
Gene expression profiling identifies ARSD as a new marker of disease progression and the sphingolipid metabolism as a potential novel metabolism in chronic lymphocytic leukemia.
Sex, Age, Disease, Disease stage
View SamplesMale patients (n=6, mean age 62 years) with NYHA III-IV and an left ventricular ejection fraction of <35% despite pharmacological therapy received 35 hours of enhanced external counterpulsation (EECP) over a period of 7 weeks.
Effects of enhanced external counterpulsation on skeletal muscle gene expression in patients with severe heart failure.
Sex, Specimen part, Treatment, Subject
View Samples