Sustained elevation of sympathetic activity is an important contributor to pathological cardiac hypertrophy, ventricular arrhythmias, and left ventricular contractile dysfunction in chronic heart failure. The orphan nuclear receptor NR4A2 is an immediate early response gene activated in the heart under beta-adrenergic stimulation. The goal of this study was to identify the transcriptional remodeling events induced by NR4A2 expression in cardiomyocytes, and their impact on the physiological response of those cells to sustained beta-adrenergic stimulation. Treatment of adult rat ventricular myocytes (ARVMs) with isoproterenol induced a rapid (< 4 hours) but transient (< 24 hours) increase in NR4A2 expression levels that was accompanied by increased nuclear localization of the transcription factor. Adenovirus-mediated overexpression of NR4A2 modulated the expression of genes linked to adrenoceptor signaling, calcium signaling, cell growth and proliferation, and counteracted the increase in protein synthesis rate and cell surface area mediated by chronic isoproterenol stimulation. In consistence with those findings, NR4A2 overexpression also blocked the phosphorylative activation of ERK1/2, Akt, and of their downstream effector in protein synthesis p70S6K. Prominent among the transcriptional changes induced by NR4A2 was the > 7-fold up-regulation of the dual-specificity phosphatases DUSP2 and DUSP14, two known inhibitors of ERK1/2. Pre-treatment of NR4A2-overexpressing cardiomyocytes with the DUSPs inhibitor BCI prevented the inhibition of ERK1/2 and p70S6K following isoproterenol stimulation. In conclusion, our results suggest that NR4A2 acts as a novel negative feedback regulator of the beta-adrenergic receptor-mediated growth response in cardiomyocytes, and this at least partly through DUSP-mediated inhibition of ERK1/2 signaling. Overall design: Isolated adult rat ventricular myocytes (ARVMs) were transduced at 50 m.o.i. with a recombinant adenovirus containing the full-length cDNA of human NR4A2 under the transcriptional control of the CMV promoter (Vector Biolabs Ad-h-NR4A2; Cat. No: ADV-217057). ARVMs transduced with a recombinant eGFP adenovirus (Vector Biolabs Ad-GFP; Cat. No. 1060) were used as the cell transduction control. At 48 hours post transduction, total RNA was etracted. A total of six independent experiments were performed using ARVMs isolated from different Sprague Dawley rats.
Nuclear receptor subfamily 4 group A member 2 inhibits activation of ERK signaling and cell growth in response to β-adrenergic stimulation in adult rat cardiomyocytes.
Specimen part, Cell line, Subject
View SamplesPolyamines (putrescine, spermidine, and spermine) are major organic polycations essential for a wide spectrum of cellular processes. The cells require mechanisms to maintain homeostasis of intracellular polyamines to prevent otherwise severe adverse effects. We performed a detailed transcriptome profile analysis of P. aeruginosa in response to agmatine and putrescine with an emphasis in polyamine catabolism. Agmatine serves as precursor compound for putrescine (and hence spermidine and spermine), which was proposed to convert into GABA and succinate before entering the TCA cycle in support of cell growth as the sole source of carbon and nitrogen. Two acetylpolyamine amidohydrolases, AphA and AphB, were identified to be involved in the conversion of agmatine into putrescine. Enzymatic products of AphA were confirmed by mass spectrometry analysis. Interestingly, the alanine-pyruvate cycle was shown indispensable for polyamine utilization. The newly identified dadRAX locus, encoding the regulator, alanine transaminase and racemase respectively, coupled with SpuC, the major putrescine-pyruvate transaminase, were key components to maintain alanine homeostasis. Corresponding mutant strains were severely hampered in polyamine utilization. On the other hand, the alternative gamma-glutamylation pathway for the conversion of putrescine into GABA was also discussed. Subsequently, GabD, GabT and PA5313 were identified for GABA utilization. Growth defect of PA5313 gabT double mutant in GABA suggested the importance of these two transaminases. The succinic-semialdehyde dehydrogenase activity of GabD and its induction by GABA was also demonstrated in vitro. Polyamine utilization in general was proven independent of the PhoPQ two-component system even the expression of which was induced by polyamines. Multiple potent catabolic pathways as depicted in this study could serve pivotal roles in control of intracellular polyamine levels.
Transcriptome analysis of agmatine and putrescine catabolism in Pseudomonas aeruginosa PAO1.
No sample metadata fields
View SamplesCD4+ T lymphocytes are key to immunological memory, but little is known about the lifestyle of memory CD4+ T lymphocytes. We showed that in the memory phase of specific immune responses to antigens, most of the memory CD4+ T lymphocytes relocated into the bone marrow (BM) within 3-8 weeks after their generation, a process involving integrin a2. Antigen-specific memory CD4+ T lymphocytes expressed Ly-6C to a high degree, unlike most splenic CD44hiCD62L- CD4+ T lymphocytes. In adult mice, more than 80% of Ly-6Chi CD44hiCD62L- memory CD4+ T lymphocytes were in the BM. In the BM, they are located next to IL-7-expressing VCAM-1+ stroma cells, and were in a resting state. Upon challenge with antigen, they rapidly expressed cytokines and CD154 and induced the production of high-affinity antibodies, indicating their functional activity in vivo and marking them as professional memory T helper cells
Professional memory CD4+ T lymphocytes preferentially reside and rest in the bone marrow.
Specimen part
View SamplesPathogen-associated molecular patterns decisively influence antiviral immune responses, whereas the contribution of endogenous signals of tissue damage, also known as damage-associated molecular patterns or alarmins, remains ill-defined. We show that interleukin-33 (IL-33), an alarmin released from necrotic cells, is necessary for potent CD8+ T cell (CTL) responses to replicating, prototypic RNA and DNA viruses in mice. IL-33 signaled through its receptor on activated CTLs, enhanced clonal expansion in a MyD88-dependent, CTL-intrinsic fashion, determined polyfunctional effector cell differentiation and was necessary for virus control. Moreover, recombinant IL-33 augmented vaccine-induced CTL responses. Radio-resistant cells of the splenic T cell zone produced IL-33, and efficient CTL responses required IL-33 from radio-resistant cells but not from hematopoietic cells. Thus, alarmin release by radio-resistant cells orchestrates protective antiviral CTL responses.
The alarmin interleukin-33 drives protective antiviral CD8⁺ T cell responses.
Specimen part
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The alarmin IL-33 promotes regulatory T-cell function in the intestine.
Specimen part
View SamplesIL-23 negatively regulates St2 and Gata3 expression in intestinal CD4+ T cells
The alarmin IL-33 promotes regulatory T-cell function in the intestine.
Specimen part
View SamplesResident stem/progenitor cells in the lung are important for tissue homeostasis and repair. However, a progenitor population for alveolar type II (ATII) cells in adult human lungs have not been identified. Here we isolated alveolar epithelial progenitor cells (AEPCs) from adult human lungs. AEPCs showed mesenchymal stem cell (MSC)-like characteristics combined with ATII cell-phenotypes. AEPCs had the capability for self-renewal and the potential to generate ATII cells in vitro. Furthermore, cells expressing similar markers were present within alveolar walls in normal lungs and these cells were significantly increased in ATII cell hyperplasias. These results suggest that adult human lungs contain a progenitor population for ATII cells.
Isolation of alveolar epithelial type II progenitor cells from adult human lungs.
Sex, Age, Specimen part
View SamplesResident stem/progenitor cells in lungs are important for tissue homeostasis and repair. We isolated human lung progenitor cells and named alveolar epithelial progenitor cells (AEPCs)(Fujino N, et al. 2011. Lab Invest. 91:363). AEPCs have phenotypes of both alveolar epithelial type II (ATII) cells and mesenchymal stem cells. AEPCs had the potential to generate ATII-like cells in vitro. ATII-like cells derived from AEPCs expressed protein and mRNA of pulmonary surfactant, and displayed lamellar bodies containing the surfactants. However, it has not been evaluated whether global gene expression of the ATII-like cells from AEPCs was similar to that of mature ATII cells isolated from human lung tissues. This study demonstrated gene expression profiles of ATII-like cells from AEPCs. In addition, transcriptomes in AEPCs and mature ATII cells were deposited in the GEO website (GSE21095 and GSE29133, respectively).
Analysis of gene expression profiles in alveolar epithelial type II-like cells differentiated from human alveolar epithelial progenitor cells.
Sex, Age, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Autoregulation of Th1-mediated inflammation by twist1.
No sample metadata fields
View SamplesGene expression profiling of repeatedly activated compared to recently activated Th1 cells to identify genes that play a role in chronic inflammatory disorders and may qualify as diagnostic or therapeutic targets;
Autoregulation of Th1-mediated inflammation by twist1.
No sample metadata fields
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