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GSE24886
Mus musculus
16 Downloadable Samples
Description
Exosomes are small extracellular nano-vesicles of endocytic origin that mediate different signals between cells, by surface interactions and by shuttling of functional RNA from one cell to another. In this study, we show that exosomes, produced by mouse mast cells exposed to oxidative stress, change their mRNA content and also that these exosomes can influence the response of other cells to oxidative stress by providing recipient cells with a resistance against oxidative stress. Finally, we also show that UV-light affect the biological functions associated with exosomes released under oxidative stress. These results argue that exosomal shuttle of RNA is involved in cell-to-cell communication, by influencing the response of recipient cells to an external stimulus.
Publication Title
Exosomes communicate protective messages during oxidative stress; possible role of exosomal shuttle RNA.
Sample Metadata Fields
Specimen part, Cell line
View Samples- Mus musculus
- 5 Downloadable Samples
Description
The aim of our study is to determine the functions of histone deacetylases (HDACs) 1 and 2 in Schwann cells during postnatal development of the peripheral nervous system (PNS). Schwann cells are the myelinating glial cells of the PNS. At birth, mouse sciatic nerves mature in 2 subsequent phases: 1/ big caliber axons get sorted into a 1 to 1 relationship with Schwann cells, 2/ Schwann cells build a myelin sheath around sorted axons. In mice where both HDAC1 & HDAC2 have been specifically knocked out in Schwann cells, both phases are impaired. HDACs are chromatin remodeling enzymes, they can thus alter gene expression directly. We want to identify which genes controlled by HDAC1 and HDAC2 in Schwann cells are necessary for the maturation of sciatic nerves. Because HDAC1 and HDAC2 can compensate for each other loss to some extend, we will first analyze changes of gene expression in HDAC1/HDAC2 double KO animals. We expect to gain critical insights into the molecular mechanisms controlling Schwann cell differentiation and myelination. This knowledge is of key importance for the success of regenerative medicine in peripheral neuropathies, nerve tumors, and transplantation paradigms in non-regenerative CNS lesions and in large PNS injuries.
Publication Title
HDAC1 and HDAC2 control the transcriptional program of myelination and the survival of Schwann cells.
Sample Metadata Fields
Disease, Disease stage
View Samples- Mus musculus
- 21 Downloadable Samples
Description
Mouse aorta smooth muscle cells (SMCs) express TNF receptor superfamily member 1A (TNFR1) and lymphotoxin receptor (LTR). Circumstantial evidence has linked the SMC LTR to tertiary lymphoid organogenesis in diseased aortae of hyperlipidemic mice. Here, we explored potential roles of TNFR1 and LTR activation in cultured SMCs. TNFR1 signaling by TNF activated the classical RelA NF-B pathway, whereas LTR signaling by agonistic anti LTR antibody activated both the classical RelA and alternative RelB NF-B pathways. Addition of both agonists synergized to enhance p100 inhibitor processing to the p52 subunit of NF-B and promoted its nuclear translocation suggesting RelA-RelB cross-talk in transcription regulation. Correspondingly, microarrays showed that simultaneous TNFR1 and LTR activation when compared to activation of single receptors was followed by markedly elevated levels of mRNAs encoding leukocyte homeostatic chemokines CCL2, CCL5, CXCL1, and CX3CL1. Furthermore, SMCs acquired prototypical features of mesenchymal cells known as lymphoid tissue organizers (LTOs), which control tertiary lymphoid organogenesis in autoimmune diseases, through hyperinduction of CCL7, CCL9, CXCL13, CCL19, CXCL16, VCAM-1, and ICAM-1. Experiments with ltbr-/- SMCs suggested that the LTR-RelB activation component of NF-B signaling was obligatory to generate the LTO phenotype. TNFR1-LTR crosstalk also resulted in augmented synthesis and prolonged secretion of lymphorganogenic chemokine proteins into the culture medium. Thus, combined TNFR1-LTR signaling triggers SMC transdifferentiation into a phenotype that strikingly resembles LTOs. LTO-like SMCs may adopt a thus far unrecognized role in diseased arteries, i.e. to coordinate tertiary lymphoid organogenesis in atherosclerosis, aortic aneurysm, and transplant vasculopathy.
Publication Title
Mouse aorta smooth muscle cells differentiate into lymphoid tissue organizer-like cells on combined tumor necrosis factor receptor-1/lymphotoxin beta-receptor NF-kappaB signaling.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 5 Downloadable Samples
Description
Cultured mouse aorta endothelial cells (from 8-12 weeks old C57BL/6J mice, passage 2-3) were exposed to phosphate buffered saline (control) or a combination of TNFalpha plus agonistic alpha-LTR antibody for 24 hours as described in Ltzer et al. 2009. Arterioscler. Thromb. Vasc. Biol., in press. Total RNA was extracted and microarrays were prepared.
Publication Title
Mouse aorta smooth muscle cells differentiate into lymphoid tissue organizer-like cells on combined tumor necrosis factor receptor-1/lymphotoxin beta-receptor NF-kappaB signaling.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 35 Downloadable Samples
Description
We previously observed that formation of aorta and innominate artery atherosclerotic lesions in the intima of hyperlipidemic apoE-deficient mice but not wild-type mice was accompanied by a marked age-dependent adventitial T cell infiltration. As the mice aged, adventitial T cells formed T/T cell-, T/B cell-, and T/B/dendritic cell aggregates adjacent to atherosclerotic lesions. Some of the adventitial infiltrates formed large clusters of various immune cells including T cells, B cells (centrocytes, follicular mantle cells), dendritic cells, follicular dendritic cells, and plasma cells with preferential formation in the suprarenal portion of the abdominal aorta. These data demonstrated that the immune lineage cell composition of atherosclerotic lesions and adventitia were distinct: The macrophage-foam cell-, T cell-, and SMC-dominated cell composition of atherosclerosis lesions versus the presence of immune cells capable of carrying out antigen-dependent T cell-driven humoral immune responses in the adventitia also indicated that immune reactions carried out in lesions or the adventitia are fundamentaly different. To distinguish between immunity-regulating genes in atherosclerosis lesions versus the adventitia, a combination of microarray profiling and laser capture microdissection was used. Stringent filters revealed 1163 differentially up-regulated probesets in apoE-/- mouse aortae at 78 weeks (w) versus 6 w. A fuzzy c-means cluster algorythm identified 2 clusters that significantly differed in their slope angles between time points: An apparent atherosclerosis cluster consisted of 771 probesets and an apparent adventitia cluster consisted of 392 probesets. Up-regulated genes at 32 w mirrored the influx of monocyte/macrophages into intima lesions whereas genes up-regulated between 32-78 w mirrored adventitial inflammation. To segregate both clusters into separate gene ontology (GO) molecular function groups, we determined statistically significant up-regulation (unpaired Student t-test; p < 0.05) between 6-32 w for the atherosclerosis cluster and between 32-78 w for the adventitia cluster. Among others, GO molecular function terms cytokine activity, cytokine binding, and immunoglobulin binding in the atherosclerosis cluster and cytokine activity, chemokine receptor activity, and antigen binding in the ATLO cluster suggested candidate genes in relation to inflammation triggered by macrophages or adventitia infiltration, respectively. Among other prototype atherosclerosis genes such as Itgax (complement receptor 4), Cd68, Lysz (lysozyme), Vcam1, and Icam1, the atherosclerosis cluster showed markedly overrepresented prototype macrophage/foam cell genes regulating inflammation in cytokine activity (GO: 0005125): Spp1 (osteopontin) and Il6; in cytokine binding (GO: 0019955) Cd74, Il10rb, Ccr2, and Ccr5; and in immunoglobulin binding (GO: 00119865) the proinflammatory galactose-binding lectin Lgals3, as well as genes in scavenger receptor activity and lipid transporter activity. By contrast, the adventitia cluster showed overrepresented genes regulating B cell recruitment, B cell maturation, germinal center formation, and autoimmunity in cytokine activity including Cxcl13, Ccl21, and Ltb, in CXC chemokine receptor activity the secondary lymphoid organ counterreceptor of CXCL13 Blr1 (also known as Cxcr5), Cxcr3, and Cxcr6; and in antigen binding several histocompatibility-2 loci and various markedly expressed immunoglobulin genes. As embryonic lymph node development and tertiary lymphoid organ neogenesis share common features signal intensities of genes specifying the GO molecular function term lymph node development (GO: 0048535) were examined in arrays prepared from wild-type and apoE-/- aortae. These results showed that Id2, Nfkb1, and Ltbr were constitutively expressed at significant levels in aortae of both mouse genotypes whereas other genes including Lta, Ltb, Glycam1, and the two lymphorganogenic genes Cxcl13 and Ccl21 were induced at 78 w in apoE-deficient aortae only. Thus, genes expressed by macrophage-foam cells and genes regulating ATLO neogenesis, embryonic lymph node development, or B cell maturation were constitutively expressed in the arterial wall in both genotypes or emerged in a stepwise fashion at 32 w and 78 w. To verify microarray signal intensity data, separate aortae extracts were examined by quantitative RT-PCR (QRT-PCR) analyses of wild-type and apoE-deficient mice at 32 and 78 w. These data showed that array signal values accurately reflected gene transcripts. Cell lineage analyses of the adventitial infiltrate and kinetic aorta microarray- and QRT-PCR analyses thus provided circumstantial evidence that immune responses in atherosclerosis intima lesions and the adventitia were distinct. To examine this possibility further, we selected areas of the abdominal aorta burdened with advanced lesions and separated lesions and corresponding adventitial infiltrates of 78 w old apoE-deficient mice by laser dissection microscopy. In addition, adventitiae of aorta segments that were not associated with adjacent lesions and adventitiae of wild-type mice were prepared. Consistent with the lack of a major adventitial leukocyte infiltration, wild-type adventitiae showed gene expression levels that were similar to lesion-free adventitiae of apoE-deficient mice indicating that atherosclerotic lesions directly affected adventitial inflammation in a segmental fashion. Stringent filter criteria identified genes that were differentially expressed in adventitiae and atherosclerotic lesions. Statistical analyses of overrepresented genes in GO molecular function or biological process groups were particularly instructive in cytokine activity, cytokine binding, antigen processing and presentation as well as in lymph node development. Thus, adventitiae in aorta segments with associated atherosclerotic lesions in cytokine activity showed overrepresentation of genes known to be associated with tertiary lymphoid organ formation including Cxcl13, Ccl21, and Ltb, whereas atherosclerotic lesions showed overrepresentation of prototype atherosclerosis-associated genes Ssp1 (osteopontin), Bmp4 (bone morphogenic protein 4), and Cxc3cl1 (fractalkine); in cytokine binding adventitiae showed overrepresentation of receptors implicated in B cell immunity and autoimmunity including Brl1 (counterreceptor for CXCL13), Ccr7, Tnfrsf4, and Cxcr3 whereas lesions showed overrepresentation of inflammatory mediator receptors including Tnfrs1b, Tgfbr1, and Il7r; moreover, in antigen processing and presentation, adventitiae showed overrepresentation of several histocompatibility loci; additional adventitial gene expression overrepresentations were observed in lymph node development (Fas, SpiB, Ltb, Flt3) whereas lesions showed expression of prototype macrophage genes including Tlr4, Tgfb1, and Tgfb2. These data provide comprehensive topographical transcriptome information in adventitial tissue adjacent to atherosclerotic lesions versus lesions and are expected to form the basis for future cell lineage expression analyses using single cell detection methodology including ISH.
Publication Title
Lymphotoxin beta receptor signaling promotes tertiary lymphoid organogenesis in the aorta adventitia of aged ApoE-/- mice.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples