Hypoxia may cause pulmonary and brain edema, pulmonary hypertension, aberrant metabolism and early mortality. To better understand pathological processes associated with hypoxia, we examined gene expression in Chuvash polycythemia (CP) blood mononuclear cells. CP is a congenital disorder of up-regulated hypoxic response at normoxia wherein VHLR200W homozygosity leads to elevated hypoxia inducible factor (HIF)-1 and HIF-2 levels, thromboses, pulmonary hypertension, lower systemic blood pressure (SBP) and increased mortality. VHLR200W homozygotes are often treated by phlebotomy resulting in iron deficiency, allowing us to evaluate an interaction of augmented hypoxia sensing with iron deficiency.
Iron deficiency modifies gene expression variation induced by augmented hypoxia sensing.
Sex, Specimen part
View SamplesThese studies utilized two TCR transgenic mouse lines, LLO118 and LLO56, that our laboratory has developed and characterized, which recognize the same Listeria monocytogenes LLO/IO-Ab epitope with equal affinities. When 104 naive CD4+ LLO T cells are transferred into a B6 mouse and one day later infected with wild type Listeria monocytogenes, the LLO118 T cells have a more robust primary expansion than LLO56. In contrast, after a secondary challenge, LLO56 T cells have a much greater expansion than LLO118 T cells. One striking phenotypic difference between the LLO118 and LLO56 T cells lies in their CD5 expression. CD5 expression has been shown to correlate directly with TCR affinity for self-pMHC and tonic signaling. LLO56 cells have a higher basal phosphorylation of the TCR chain, and they have significantly increased expression of Nur77 mRNA. These transcriptional profiling experiments examined if there were transcriptional differences between LLO118 and LLO56 T cells, either naive or after D7 of infection, that would account for their disparate in vivo behaviors.
Tonic TCR Signaling Inversely Regulates the Basal Metabolism of CD4<sup>+</sup> T Cells.
Specimen part
View SamplesmRNA expression in Eµ-Myc lymphoma cells expressing or lacking miR-17~92 Overall design: Eµ-Myc B-cell lymphomas harboring conditional alleles of miR-17~92 were cultured with or without 4-OHT to generate isogenic tumour cells with homozygous deletion of miR-17~92. Wild type (fl) and miR-17~92-deleted (del) Eµ-Myc cells were cultured for 48 hours under regular growth conditions, and RNA isolated for sequencing analysis.
The miR-17∼92 microRNA Cluster Is a Global Regulator of Tumor Metabolism.
Specimen part, Subject
View SamplesMost cancer deaths are caused by metastases, which are the end-results of circulating tumor cells (CTC) that detach from the cancer primary and succeed to survive in distant organs. The aim of the present study was to develop a gene signature of CTC and to assess its prognostic relevance after surgery for pancreatic ductaladenocarcinoma (PDAC).
Pancreatic cancer circulating tumour cells express a cell motility gene signature that predicts survival after surgery.
Sex, Age, Disease stage
View SamplesChoroideremia (CHM) is a progressive X-linked retinopathy caused by mutations in the CHM gene, which encodes Rab escort protein-1 (REP-1), an escort protein involved in the prenylation of Rabs. Under-prenylation of certain Rabs, as a result of loss of function mutations in REP-1, could affect vesicular trafficking, exocytosis and secretion. To evaluate this hypothesis, intracellular vesicle transport, lysosomal acidification and rates of proteolytic degradation were studied in monocytes (CD14+ fraction) and primary skin fibroblasts from the nine age-matched controls and thirteen CHM patients carrying 10 different loss-of-function mutations.
Loss-of-function mutations in Rab escort protein 1 (REP-1) affect intracellular transport in fibroblasts and monocytes of choroideremia patients.
Specimen part, Disease
View SamplesThe type III RNase Dicer is responsible for the maturation and function of microRNA (miRNA) molecules in the cell. It is now well documented that Dicer and the fine-tuning of the miRNA gene network are important for neuronal integrity. However, the underlying mechanisms involved in neuronal death, particularly in the adult brain, remain poorly defined. Here, we show that absence of Dicer in the adult forebrain is accompanied by a mixed neurodegenerative phenotype. While neuronal loss is observed in the hippocampus, cellular shrinkage is predominant in the cortex. Interestingly, neuronal degeneration coincides with the hyperphosphorylation of endogenous tau at several epitopes previously associated with neurofibrillary pathology. Transcriptome analysis of enzymes involved in tau phosphorylation identified ERK1 as one of the candidate kinases responsible for this event in vivo. We further demonstrate that miRNAs belonging to the miR-15 family are potent regulators of ERK1 expression in mouse neuronal cells and co-expressed with ERK1/2 in vivo. Last, we show that miR-15a is specifically downregulated in Alzheimers disease brain. In sum, these results support the hypothesis that changes in the miRNA network may contribute to a neurodegenerative phenotype by affecting tau phosphorylation.
Genetic ablation of Dicer in adult forebrain neurons results in abnormal tau hyperphosphorylation and neurodegeneration.
Specimen part
View SamplesThe most common form of senile dementia, Alzheimer’s disease (AD), is characterized by Aß plaques and neurofibrillary tangles in the CNS. AD genetic studies have identified high-risk hypomorphic variants in TREM2, a myeloid cell surface receptor that enables concerted microglial responses to Aß plaques and neuronal cell death, including proliferation, survival, clustering and phagocytosis. How TREM2 promotes these responses is not known. Here, we demonstrate that TREM2 drives mTOR signaling, which maintains high ATP levels, supports biosynthetic pathways and suppresses AMPK phosphorylation and autophagy. In vitro, TREM2-deficient macrophages undergo dramatically increased autophagy and die in response to growth factor limitation or ER stress. Excessive autophagy is also evident in microglia from Trem2-/- 5XFAD mice and in post-mortem specimens from AD patients carrying TREM2 risk variants. Metabolic derailment, autophagy and cell death can be circumvented by engaging alternative energy production pathways. Thus, restoring microglial energetic and anabolic levels may be a future therapeutic avenue for TREM2-associated neurological disease. Overall design: Bone marrow-derived macrophages (BMDMs) from WT and Trem2–/– mice were cultured in either 0.5% or 10% LCCM overnight in complete RPMI. Some samples cells were stimulated with 10 ng/ml LPS for 4 hours.
TREM2 Maintains Microglial Metabolic Fitness in Alzheimer's Disease.
Specimen part, Cell line, Treatment, Subject
View SamplesThe emergence of multidrug resistant (MDR) Mycobacterium tuberculosis (Mtb) strains, resistant to the frontline anti-tubercular drugs rifampicin and isoniazid, forces treatment with less effective and toxic second-line drugs and stands to derail TB control efforts. However, the immune response to MDR Mtb infection remains poorly understood. Here, we determined the RNA transcriptional profile of in vitro generated macrophages to infection with either drug susceptible Mtb HN878 or MDR Mtb W_7642 infection. Overall design: Bone marrow-derived macrophages (BMDMs) from WT and Il1r1–/– mice were derived in 7 days in GM-CSF supplemented complete DMEM. Cells were infected with either Mtb HN878 or Mtb W_7642 (multiplicity of infection = 1) and RNA samples collected after 6 days.
Mycobacterium tuberculosis carrying a rifampicin drug resistance mutation reprograms macrophage metabolism through cell wall lipid changes.
Cell line, Subject
View SamplesThe retinal pigment epithelium (RPE) is a polarized cell layer that is critical for photoreceptor function and survival. Its unique relationship to the photoreceptors and its specific physiology makes the RPE a critical determinant of human vision. Therefore we performed global expression profiling of native and cultured human fetal and adult RPE and determined a unique set of highly-expressed genes (called the signature set) by comparing the observed RPE gene profiles to the Novartis expression database (SymAtlas: http://wombat.gnf.org/index.html) of 78 tissues.
Transcriptome analysis and molecular signature of human retinal pigment epithelium.
Specimen part, Cell line
View SamplesIn mammals, expansion of adipose tissue mass induces accumulation of adipose tissue macrophages (ATMs). We isolated CD11c- (FB) and CD11c+ (FBC) perigonadal ATMs from SVCs of lean (C57BL/6J Lep +/+) and obese leptin-deficient (C57BL/6J Lep ob/ob) mice.
Obesity activates a program of lysosomal-dependent lipid metabolism in adipose tissue macrophages independently of classic activation.
Specimen part
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