microRNAs, important regulators of cell proliferation and apoptosis, have been shown to be involved in the pathogenesis of acute myeloid leukemia in adulthood AML. However, comprehensive studies in AML of children and adolescents are missing so far. We investigated the miRNA expression profiles of different AML subtypes from 102 pediatric patients in comparison to CD34+ cells from healthy donors and adult AML patients, in order to identify differentially expressed miRNAs. Pediatric samples with core factor binding acute myeloid leukemia and promyelocytic leukemia could be distinguished from each other and MLL rearranged AML subtypes by 9 and 18 miRNAs, respectively. miR-126, -146a, -181a/b, -100, and miR-125b were identified as highest differentially expressed with marked difference of expression between pediatric and adulthood samples of the same cytogenetic subgroup. We next isolated the miRNA targeting complex from t(8;21) and t(15;17) cell line models and comprehensively identified bound miRNAs and targeted mRNAs by a newly devised immunoprecipitation assay followed by rapid microarray detection. Our findings indicate separate binding preferences for the four human Argonaute proteins. Subsequent bioinformatic analysis revealed a concerted action of different Ago proteins in the regulation of AML-relevant pathways, providing an experimental based database of miRNA-mRNA target interaction in Argonaute proteins.
MicroRNAs distinguish cytogenetic subgroups in pediatric AML and contribute to complex regulatory networks in AML-relevant pathways.
Specimen part
View SamplesIn contrast to the migration of leukocytes from blood vessels into tissues, and the involvement of adhesion molecules and chemokines in this process, the migration of leukocytes from the tissue into lymphatic vessels is much less well understood. This can, in part be explained by the fact that murine lymphatic endothelial cells (LECs) have proven particularly hard to isolate and propagate in culture. Hence, it has been difficult to establish suitable models to study this process in vitro. Combining magnetic bead-based purification and fluorescence-activated cell sorting (FACS), we have isolated LECs (immorto-LECs) from the skin of mice which express a temperature-sensitive SV40 large T antigen (H-2Kb-tsA58 mice; ImmortoMice) in all cell types under the control of the MHC-class-I-promotor, H-2Kb. The isolated cells are viable for more than 30 passages when cultured at 33 C, the temperature at which the large T antigen is stably expressed. Furthermore, immorto-LECs tolerate several days of culture at 37 C, but become senescent if continuously cultured at this temperature. All cells stably express endothelial and lymphatic markers like CD31, podoplanin, Prox-1 and VEGFR-3 up to passage 30. When cultured in presence of tumor necrosis factor-alpha (TNF-a), immorto-LECs upregulate adhesion molecules, such as ICAM-1, VCAM-1 and E-selectin, similarly to what has been reported to occur under inflammatory conditions in vivo. Overall, our findings establish immorto-LECs as a useful and handy tool for the in vitro investigation of immune cell transmigration across lymphatic endothelium.
Tissue inflammation modulates gene expression of lymphatic endothelial cells and dendritic cell migration in a stimulus-dependent manner.
Specimen part
View SamplesAnalysis of T-cells isolated from CD3+ T-cells of patients with B-cell chronic lymphocytic leukemia (B-CLL). In contrast to other types of cancers, the non-malignant T-cell compartment of B CLL patients is expanded. Results provide insights into the role of T-cells in B-CLL.
Expanded CD8+ T cells of murine and human CLL are driven into a senescent KLRG1+ effector memory phenotype.
Specimen part
View SamplesDeficiency of the human short stature homeobox-containing gene (SHOX) has been identified in several disorders characterized by reduced height and skeletal anomalies such as Turner, Leri-Weill and Langer syndrome as well as idiopathic short stature. Although highly conserved in vertebrates, rodents lack a SHOX orthologue.
Identification of novel SHOX target genes in the developing limb using a transgenic mouse model.
Specimen part
View SamplesBasophil functional state was determined using the Flow2CAST Basophil Activation Test (BAT). Human basophils were isolated from whole blood of three house dust mite (HDM) responsive donors with reactive basophils and two donors with anergic basophils. Basophil isolation was performed using the EasySep Human Basophil Enrichment kit (Stemcell). Purity of the basophils was determined by flow cytometry and ranged from 96 - 99%. For stimulation, 75,000 basophils were incubated for 4 hr with or without 50 ul of anti-FCERI antibody (Bhlmann Laboratories) in a total volume of 200 ul of Stimulation Buffer provided by the Flow2CAST kit. After incubation, the basophils were collected and re-suspended in TRIzol Reagent (Life Technologies). Total RNA was extracted using double extraction protocol using the guanidinium thiocyanate-phenol-chloroform extraction (Trizol Invitrogen), followed by a Qiagen RNeasy Micro clean-up procedure. cDNA and ST-ssDNA were prepared, fragmented and labeled according to Nugen WT Ovation Pico RNA Amplification and WT Ovation Exon kit and Encore Biotin protocols. The labeled ssDNA was hybridized on the Affymetrix Human GeneChip 1.0 ST Arrays, which subsequently were processed and stained using GeneChip Fluidics Station 450. The stained GeneChip Arrays were scanned in the Microarray Facility at the Biopolis Shared Facility using a GeneChip Scanner 3000. Quality control for the Arrays was performed using the Affymetrix Expression Console Software.
Systematic characterization of basophil anergy.
Specimen part, Subject
View SamplesHCN4 channels are the major HCN channel isoform expressed in the sinoatrial node (SAN) and play a key role in cardiac pacemaking. We have characterized the gene expression profile in the SAN of adult mice expressing cAMP-insensitive HCN4 channels (HCN4FEA mice) in comparison to WT mice.
cAMP-dependent regulation of HCN4 controls the tonic entrainment process in sinoatrial node pacemaker cells.
Sex, Specimen part
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