Plant defenses against pathogens and insects are regulated differentially by cross-communicating signaling pathways in which salicylic acid (SA), jasmonic acid (JA) and ethylene (ET) play key roles. To understand how plants integrate pathogen- and insect-induced signals into specific defense responses, we monitored the dynamics of SA, JA, and ET signaling in Arabidopsis after attack by a set of microbial pathogens and herbivorous insects with different modes of attack. Arabidopsis plants were exposed to a pathogenic leaf bacterium (Pseudomonas syringae pv. tomato), a pathogenic leaf fungus (Alternaria brassicicola), tissue-chewing caterpillars (Pieris rapae), cell-content-feeding thrips (Frankliniella occidentalis), or phloem-feeding aphids (Myzus persicae). Monitoring the signal signature in each plant-attacker combination showed that the kinetics of SA, JA, and ET production varies greatly in both quantity and timing. Analysis of global gene expression profiles demonstrated that the signal signature characteristic of each Arabidopsis-attacker combination is orchestrated into a surprisingly complex set of transcriptional alterations in which, in all cases, stress-related genes are overrepresented. Comparison of the transcript profiles revealed that consistent changes induced by pathogens and insects with very different modes of attack can show considerable overlap. Of all consistent changes induced by A. brassicicola, P. rapae, and F. occidentalis, more than 50% were also induced consistently by P. syringae. Notably, although these four attackers all stimulated JA biosynthesis, the majority of the changes in JA-responsive gene expression were attacker-specific. All together our study shows that SA, JA, and ET play a primary role in the orchestration of the plant's defense response, but other regulatory mechanisms, such as pathway cross-talk or additional attacker-induced signals, eventually shape the highly complex attacker-specific defense response.
Signal signature and transcriptome changes of Arabidopsis during pathogen and insect attack.
No sample metadata fields
View SamplesThe human bone marrow (BM) gives rise to all distinct blood cell lineages, including CD1c+ and CD141+ myeloid dendritic cells (DC) and monocytes. These cell subsets are also present in peripheral blood (PB) and lymphoid tissues. However, the difference between the BM and PB compartment in terms of differentiation state and immunological role of DC is not yet known. The BM may represent both a site for development as well as a possible effector site and so far, little is known in this light with respect to different DC subsets. Using genome-wide transcriptional profiling we found clear differences between the BM and PB compartment and a location-dependent clustering for CD1c+ and CD141+ was demonstrated. DC subsets from BM clustered together and separate from the corresponding subsets from PB, which similarly formed a cluster. In BM, a common proliferating and immature differentiating state was observed for the two DC subsets, whereas DC from the PB showed a more immune-activated mature profile. In contrast, BM-derived slan+ non-classical monocytes were closely related to their PB counterparts and not to DC subsets, implying a homogenous prolife irrespective of anatomical localization. Additional functional tests confirmed these transcriptional findings. DC-like functions were prominently exhibited by PB DC. They surpassed BM DC in maturation capacity, cytokine production and induction of CD4+ and CD8+ T cell proliferation. This first study on myeloid DC in healthy human BM offers new information on steady-state DC biology and could potentially serve as a starting point for further research on these immune cells in healthy conditions as well as in diseases.
Human Bone Marrow-Derived Myeloid Dendritic Cells Show an Immature Transcriptional and Functional Profile Compared to Their Peripheral Blood Counterparts and Separate from Slan+ Non-Classical Monocytes.
Specimen part
View SamplesAbstract: Human 6-sulfo LacNac (slan)+ cells have been subject to a paradigm debate. They have previously been classified as a distinct dendritic cell (DC) subset. However, evidence has emerged that they may be more related to monocytes than to DC. To gain deeper insight into the functional specialization of slan+ cells, we have compared them with both conventional myeloid DC subsets (CD1c+ and CD141+) in human peripheral blood. Using genome-wide transcriptional profiling as well as extensive functional tests, we clearly show that slan+ cells form a distinct, non-DC-like, population. They cluster away from both DC subsets and their gene expression profile evidently suggests involvement in distinct inflammatory processes. An extensive comparison with existing genomic data sets also strongly confirmed the relationship of slan+ with the monocytic compartment rather than with DC. From a functional perspective, their ability to induce CD4+ and CD8+ T cell proliferation is relatively low. Combined with the finding that antigen presentation by MHC class II is at the top of under-represented pathways in slan+ cells, this points to a minimal role in directing adaptive T cell immunity. Rather, the higher expression of complement receptors on their cell surface, together with their high secretion of IL-1 and IL-6, imply a specific role in innate inflammatory processes, which is consistent with their recent identification as non-classical monocytes. This study extends our knowledge on DC/monocyte subset biology under steady state conditions and contributes to our understanding of their role in immune-mediated diseases and their potential use in immunotherapeutic strategies.
Transcriptional profiling reveals functional dichotomy between human slan<sup>+</sup> non-classical monocytes and myeloid dendritic cells.
Specimen part
View SamplesSkeletal muscle mitochondrial dysfunction is secondary to T2DM and can be improved by long-term regular exercise training
Physical activity is the key determinant of skeletal muscle mitochondrial function in type 2 diabetes.
Age
View SamplesThe skeletal muscle system plays an important role in the independence of older adults. In this study we examine differences in the skeletal muscle transcriptome between healthy young and older subjects and (pre)frail older adults. Additionally, we examine the effect of resistancetype exercise training on the muscle transcriptome in healthy older subjects and (pre)frail older adults. Baseline transcriptome profiles were measured in muscle biopsies collected from 53 young, 73 healthy older subjects, and 61 frail older subjects. Followup samples from these frail older subjects (31 samples) and healthy older subjects (41 samples) were collected after 6 months of progressive resistancetype exercise training. Frail older subjects trained twice per week and the healthy older subjects trained three times per week. At baseline genes related to mitochondrial function and energy metabolism were differentially expressed between older and young subjects, as well as between healthy and frail older subjects. Three hundred seven genes were differentially expressed after training in both groups. Training affected expression levels of genes related to extracellular matrix, glucose metabolism, and vascularization. Expression of genes that were modulated by exercise training was indicative of muscle strength at baseline. Genes that strongly correlated with strength belonged to the protocadherin gamma gene cluster (r=0.73). Our data suggest significant remaining plasticity of ageing skeletal muscle to adapt to resistancetype exercise training. Some agerelated changes in skeletal muscle gene expression appear to be partially reversed by prolonged resistancetype exercise training. The protocadherin gamma gene cluster may be related to muscle denervation and reinnervation in ageing muscle.
Expression of protocadherin gamma in skeletal muscle tissue is associated with age and muscle weakness.
Sex, Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Suboptimal evolutionary novel environments promote singular altered gravity responses of transcriptome during Drosophila metamorphosis.
Sex, Age
View SamplesGenome-wide transcriptional profiling showed that reducing gravity levels in the International Space Station (ISS) causes important alterations in Drosophila gene expression intimately linked to imposed spaceflight-related environmental constrains during Drosophila metamorphosis. However, simulation experiments on ground testing space-related environmental constraints, show differential responses. Curiously, although particular genes are not common in the different experiments, the same GO groups including a large multigene family related with behavior, stress response and organogenesis are over represented in them. A global and integrative analysis using the gene expression dynamics inspector (GEDI) self-organizing maps, reveals different degrees in the responses of the transcriptome when using different environmental conditions or microgravity/hypergravity simulation devices
Suboptimal evolutionary novel environments promote singular altered gravity responses of transcriptome during Drosophila metamorphosis.
No sample metadata fields
View SamplesThe goal of this study was to gain insight into the molecular heterogeneity of capillary endothelial cells derived from different organs by microarray profiling of freshly isolated cells and identify transcription factors that may determine the specific gene expression profile of endothelial cells from different tissues. The study focused on heart endothelial cells and presents a validated signature of 31 genes that are highly enriched in heart endothelial cells. Within this signature 5 transcription factors were identified and the optimal combination of these transcription factors was determined for specification of the heart endothelial fingerprint.
Meox2/Tcf15 heterodimers program the heart capillary endothelium for cardiac fatty acid uptake.
Sex, Specimen part
View SamplesThe intercalated disc of cardiac myocytes is emerging as a crucial structure in the heart. Loss of intercalated disc proteins like N-cadherin causes lethal cardiac abnormalities, mutations in intercalated disc proteins cause human cardiomyopathy. A comprehensive screen for novel mechanisms in failing hearts demonstrated that expression of the lysosomal integral membrane protein-2 (LIMP-2) is increased in cardiac hypertrophy and heart failure in both rat and human myocardium. Complete loss of LIMP-2 in genetically engineered mice did not affect cardiac development; however these LIMP-2 null mice failed to mount a hypertrophic response to increased blood pressure but developed cardiomyopathy. Disturbed cadherin localization in these hearts suggested that LIMP-2 has important functions outside lysosomes. Indeed, we also find LIMP-2 in the intercalated disc, where it associates with cadherin. RNAi-mediated knockdown of LIMP-2 decreases the binding of phosphorylated b-catenin to cadherin, while overexpression of LIMP-2 has the opposite effect. Taken together, our data show that lysosomal integrated membrane protein-2 is crucial to mount the adaptive hypertrophic response to cardiac loading. We demonstrate a novel role for LIMP-2 as an important mediator of the intercalated disc.
Lysosomal integral membrane protein 2 is a novel component of the cardiac intercalated disc and vital for load-induced cardiac myocyte hypertrophy.
No sample metadata fields
View SamplesEnterotoxigenic Escherichia coli (ETEC) strains that produce both heat-stable (ST) and heat-labile (LT) enterotoxins cause severe post-weaning diarrhea in piglets. However, the relative importance of the individual enterotoxins to the pathogenesis of ETEC infection is poorly understood. In this study, we investigated the effect on virulence of an F4+ ETEC strain when removing some or all of its enterotoxins. Several isogenic mutant strains were constructed that lack the expression of LT in combination with one or both types of ST enterotoxins (STa and/or STb). Host early immune responses induced by these mutant strains 4h after infection were compared to the wild type strain GIS26 (O149:F4ac+, LT+ STa+ STb+). At the same time, the immune response of this wild type ETEC strain was compared to the mock-infected control, demonstrating the expression of porcine inflammatory response genes. For these purposes, the small intestinal segment perfusion (SISP) technique and microarray analysis were used and results were validated by qRT-PCR. We also measured net fluid absorption of pig small intestinal mucosa 4h after infection with wild type ETEC, the mutant strains and PBS (mock-infected). These data indicate an important role for STb in inducing small intestinal secretion early after infection. The microarray analysis of the different mutant strains also revealed an important role for STb in ETEC-induced immune response by the significant differential regulation of immune mediators like matrix metalloproteinase 3, interleukin 1 and interleukin 17. We conclude that STb can play a prominent role in ETEC-induced secretion and early immune response.
Role of heat-stable enterotoxins in the induction of early immune responses in piglets after infection with enterotoxigenic Escherichia coli.
Sex, Specimen part, Treatment
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