Natalizumab is a recombinant monoclonal antibody raised against integrin alpha-4 (CD49d). It is approved for the treatment of patients with multiple sclerosis (MS), a chronic inflammatory autoimmune disease of the CNS. Natalizumab blocks leukocyte extravasation across the blood-brain barrier by inhibiting the molecular interaction between integrin alpha-4/beta-1 heterodimers expressed on leukocytes and VCAM-1 on inflammatory-activated CNS endothelium. Here we investigated whether binding of this adhesion-blocking antibody to T lymphocytes modulated their phenotype by direct induction of intracellular signaling events. Natalizumab induced a mild upregulation of IL-2, IFN-gamma and IL-17 expression in activated primary human CD4+ T cells propagated ex vivo from healthy donors, consistent with a pro-inflammatory costimulatory effect on lymphokine expression. Overall, the relative effect of natalizumab was more pronounced in less than in fully activated T cells. Along with this, natalizumab binding triggered rapid MAPK/ERK phosphorylation. Furthermore, it decreased CD49d surface expression on effector cells within a few hours. Sustained CD49d downregulation could be attributed to integrin internalization and degradation. Importantly, also CD4+ T cells from some MS patients receiving their very first dose of natalizumab produced more IL-2, IFN-gamma and IL-17 already 24 h after infusion. Together these data indicate that in addition to its adhesion-blocking mode of action, natalizumab possesses mild direct signaling capacities, which may support a pro-inflammatory phenotype of peripheral blood T lymphocytes. This might explain why a rebound of disease activity is observed in some MS patients after natalizumab cessation.
Natalizumab exerts direct signaling capacity and supports a pro-inflammatory phenotype in some patients with multiple sclerosis.
Specimen part, Disease, Disease stage, Treatment
View SamplesThe anaerobic metabolism of the opportunistic pathogen Pseudomonas aeruginosa is important for growth and survival during persistent infections. The two Fnr-type transcription factors Anr and Dnr regulate different parts of the underlying network. Both are proposed to bind to a non-distinguishable DNA sequence named Anr box.
Anaerobic adaptation in Pseudomonas aeruginosa: definition of the Anr and Dnr regulons.
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View SamplesAnalysis of gene expression in the distal forelimbs Overall design: RNA-Seq polyA on transcripts extracted from the dissection of three pairs of embryonnic forelimbs at E12.5
Nanoscale spatial organization of the HoxD gene cluster in distinct transcriptional states.
Cell line, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Distinct signal transduction pathways downstream of the (P)RR revealed by microarray and ChIP-chip analyses.
Cell line
View SamplesWithin the overall project, we performed a set of microarray and chromatin-immunoprecipitation (ChIP)-chip experiments using siRNA against the (pro)renin receptor ((P)RR), stable overexpression of PLZF, the PLZF translocation inhibitor genistein and the specific V-ATPase inhibitor bafilomycin to dissect transcriptional pathways downstream of the (P)RR.
Distinct signal transduction pathways downstream of the (P)RR revealed by microarray and ChIP-chip analyses.
Cell line
View SamplesWithin the overall project, we performed a set of microarray and chromatin-immunoprecipitation (ChIP)-chip experiments using siRNA against the (pro)renin receptor ((P)RR), stable overexpression of PLZF, the PLZF translocation inhibitor genistein and the specific V-ATPase inhibitor bafilomycin to dissect transcriptional pathways downstream of the (P)RR.
Distinct signal transduction pathways downstream of the (P)RR revealed by microarray and ChIP-chip analyses.
Cell line
View SamplesshRNA-mediated ablation of the RING-finger protein TRIM52 from multiple glioblastoma cell lines reduces proliferation and tumorigenesis. To identify gene signatures underlying this phenomenon, transcritional profile of TRIM52 knockdown cells was compared to control cells. Upon TRIM52 ablation, we find 278 differentially regulated genes. Gene ontology analysis reveals that many of the upregulated genes are associated with glycolysis and biosynthetic processes. Overall design: U87MG glioblastoma cells were stably transduced with doxycycline-inducible shRNA constructs targeting TRIM52 (two different shRNAs) or controls (two different non-targeting shRNAs). Knockdown was induced for five days using 2µg/ml doxycycline. shRNA expressing cells were sorted based on shRNA-coupled GFP expression via flow cytometry. mRNA sequening was performed in duplicate per shRNA cell line.
Human tripartite motif protein 52 is required for cell context-dependent proliferation.
Specimen part, Subject
View SamplesAlthough localized to the mineralized matrix of bone, osteocytes are able to respond to systemic factors such as the calciotropic hormones 1,25(OH)2D3 and PTH. In the present studies, we examine the transcriptomic response to PTH in an osteocyte cell model and found that this hormone regulated an extensive panel of genes. Surprisingly, PTH uniquely modulated two cohorts of genes, one that was expressed and associated with the osteoblast to osteocyte transition and the other a cohort that was expressed only in the mature osteocyte. Interestingly, PTH's effects were largely to oppose the expression of differentiation-related genes in the former cohort, while potentiating the expression of osteocyte-specific genes in the latter cohort. A comparison of the transcriptional effects of PTH with those obtained previously with 1,25(OH)2D3 revealed a subset of genes that was strongly overlapping. While 1,25(OH)2D3 potentiated the expression of osteocyte-specific genes similar to that seen with PTH, the overlap between the two hormones was more limited. Additional experiments identified the PKA-activated phospho-CREB (pCREB) cistrome, revealing that while many of the differentiation-related PTH regulated genes were apparent targets of a PKA-mediated signaling pathway, a reduction in pCREB binding at sites associated with osteocyte-specific PTH targets appeared to involve alternative PTH activation pathways. That pCREB binding activities positioned near important hormone-regulated gene cohorts were localized to control regions of genes was reinforced by the presence of epigenetic enhancer signatures exemplified by unique modifications at histones H3 and H4. These studies suggest that both PTH and 1,25(OH)2D3 may play important and perhaps cooperative roles in limiting osteocyte differentiation from its precursors while simultaneously exerting distinct roles in regulating mature osteocyte function. Our results provide new insight into transcription factor-associated mechanisms through which PTH and 1,25(OH)2D3 regulate a plethora of genes important to the osteoblast/osteocyte lineage. Overall design: Fully differentiated IDG-SW3 cells were treated in biological triplicate with 100nM PTH for 24 hours prior to mRNA isolation and sequencing. Vehicle treated samples were previously published in GSE54783: http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSM1323967 http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSM1323968 http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSM1323969
The parathyroid hormone-regulated transcriptome in osteocytes: parallel actions with 1,25-dihydroxyvitamin D3 to oppose gene expression changes during differentiation and to promote mature cell function.
No sample metadata fields
View SamplesOxidative and Cytokinin treatment of Arabidopsis wildtype, crf6 mutant, and CRF6 overexpressing seedlings
Cytokinin Response Factor 6 Represses Cytokinin-Associated Genes during Oxidative Stress.
Age
View SamplesAssessing the impact of HIV-1 infection on trancriptional program of quiescent CD4 T lymphocytes. Such cells were made susceptible to HIV-1 by dowmodulating SAMHD1 restriction factor using VLP-Vpx without any activation signal.
CD32a is a marker of a CD4 T-cell HIV reservoir harbouring replication-competent proviruses.
Sex, Specimen part
View Samples