In the developing brain, heightened plasticity during the critical period enables the proper formation of neural circuits. Here we identify the “navigator” neurons, a group of perinatally born olfactory sensory neurons, as playing an essential role in establishing the olfactory map during the critical period. The navigator axons project circuitously in the olfactory bulb and traverse multiple glomeruli before terminating in perspective glomeruli. These neurons undergo a phase of exuberant axon growth and exhibit a shortened lifespan. Single cell transcriptome analyses reveal distinct molecular signatures for the navigators. Extending their lifespan prolongs the period of exuberant growth and perturbs axon convergence. Conversely, genetic ablation experiment indicates that, despite postnatal neurogenesis, only the navigators are endowed with the ability to establish a convergent map. The presence and the proper removal of the navigator neurons are both required to establish tight axon convergence into the glomeruli. Overall design: 10X scRNA-seq was preformed on 4 samples of 4 ages of the olfactory epethelium of CD-1 mice. These ages were postanatal days 0, 3, 7, 21.
A Population of Navigator Neurons Is Essential for Olfactory Map Formation during the Critical Period.
Specimen part, Cell line, Subject
View SamplesThe Philadelphia chromosome (Ph) encoding the oncogenic BCR-ABL1 kinase defines a subset of ALL with a particularly unfavorable prognosis. Acute lymphoblastic leukemia (ALL) cells are derived from B cell precursors in most cases and typically carry rearranged immunglobulin heavy chain (IGH) variable (V) region genes devoid of somatic mutations. Somatic hypermutation is restricted to mature germinal center B cells and depends on activation-induced cytidine deaminase (AID). Studying AID expression in 108 cases of ALL, we detected AID mRNA in 24 of 28 Ph-positive ALLs as compared to 6 of 80 Ph-negative ALLs. Forced expression of BCR-ABL1 in Ph-negative ALL cells and inhibition of the BCR-ABL1-kinase showed that aberrant expression of AID depends on BCR-ABL1 kinase activity. Consistent with aberrant AID expression in Ph-positive ALL, IGH V region genes and BCL6 were mutated in many Ph-positive but unmutated in most Ph-negative cases. In addition, AID introduced DNA-single-strand breaks within the tumor suppressor gene CDKN2B in Ph-positive ALL cells, which was sensitive to BCR-ABL1 kinase inhibition and silencing of AID expression by RNA interference. These findings identify AID as a BCR-ABL1-induced mutator in Ph-positive ALL cells, which may be relevant with respect to the particularly unfavorable prognosis of this leukemia subset.
Activation-induced cytidine deaminase acts as a mutator in BCR-ABL1-transformed acute lymphoblastic leukemia cells.
No sample metadata fields
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 SamplesAffymetrix gene expression AID-GFP-positive vs AID-GFP-negative
The B cell mutator AID promotes B lymphoid blast crisis and drug resistance in chronic myeloid leukemia.
No sample metadata fields
View SamplesUsing RNA-seq we identified the gene expression changes in GC B cells from LSD1 wild-type or LSD1-deficient mice immunized with T cell dependent antigens (Sheep Red Blood cells) Overall design: RNA seq of sorted GC B cell populations from 3 littermate mice per genotype (3 wild-type, 3 knockout)
Histone demethylase LSD1 is required for germinal center formation and BCL6-driven lymphomagenesis.
Specimen part, Subject
View SamplesThis analysis focused on identifying factors that protect pre-B cells against DNA double strand break (DSB)-mediated DNA damage stress during pre-B cell differentiation. Differentiation of pre-B cells including immunoglobulin light chain gene recombination were performed by withdrawal of interleukin-7 (IL-7) from IL-7-dependent murine pre-B cells or by inhibition of the BCR-ABL1 kinase activity in BCR-ABL1-transformed pre-B cells.
BCL6 is critical for the development of a diverse primary B cell repertoire.
Specimen part
View SamplesPrecursor B-lineage acute lymphoblastic leukemia (pre-B ALL) can be subdivided into different categories based on genetic abnormalities.
Pre-B cell receptor-mediated cell cycle arrest in Philadelphia chromosome-positive acute lymphoblastic leukemia requires IKAROS function.
Specimen part
View SamplesThe Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which defines a subset of acute lymphoblastic leukemia (ALL) with a particularly unfavorable prognosis. In this study, the tyrosine kinase inhibitor imatinib was used for pharmacological inhibition of BCR-ABL1. Gene expression profiles of Ph+ ALL cell lines were analyzed in response to imatinib treatment.
BCL6 enables Ph+ acute lymphoblastic leukaemia cells to survive BCR-ABL1 kinase inhibition.
Specimen part, Cell line
View SamplesThe Philadelphia chromosome (Ph) encodes the oncogenic BCR-ABL1 tyrosine kinase, which is present in almost every patient with chronic myeloid leukemia. In this study, the tyrosine kinase inhibitor Imatinib was used for pharmacological inhibition of BCR-ABL1. Gene expression profiles of CML cell lines were analyzed in response to Imatinib treatment.
BCL6 enables Ph+ acute lymphoblastic leukaemia cells to survive BCR-ABL1 kinase inhibition.
Specimen part, Cell line
View SamplesPatients relapsing with FLT3-ITD mutant acute myeloid leukemia (AML) after allogeneic hematopoietic cell transplantation (allo-HCT) have a one-year-survival below 20%. We observed that sorafenib increased IL-15 production by FLT3-ITD+-leukemia cells, which synergized with the allogeneic CD8+T-cell response, leading to long-term survival in murine and humanized FLT3-ITD+AML models. Using IL-15 deficiency in recipient tissues or leukemia cells, IL-15 production upon sorafenib-treatment could be attributed to leukemia cells. Sorafenib treatment-related IL-15 production caused an increase in CD8+CD107a+IFN-+ T-cells with features of longevity (Bcl-2high/reduced PD-1-levels), which eradicated leukemia in secondary recipients. Mechanistically, sorafenib reduced ATF4 expression, thereby blocking negative regulation of IRF7-activation, which enhances IL-15 transcription. Consistent with the mouse data, IL-15 and pIRF7 levels increased in leukemic blasts of FLT3-ITD+AML patients upon sorafenib treatment. Analysis of 130 patients with FLT3-ITD-mutant AML relapsing after allo-HCT showed the highest complete remission-rate and median overall-survival-rate in the sorafenib/donor lymphocyte infusion (DLI) group compared to all other groups (chemotherapy, chemotherapy/DLI, sorafenib alone). Our findings indicate that the synergism of DLI and sorafenib is mediated via reduced ATF4 expression, causing activation of the pIRF7/IL-15-axis in leukemia cells. The sorafenib/DLI strategy therefore has the potential for an immune-mediated cure of FLT3-ITD-mutant AML- relapse, an otherwise fatal complication after allo-HCT.
Sorafenib promotes graft-versus-leukemia activity in mice and humans through IL-15 production in FLT3-ITD-mutant leukemia cells.
Specimen part, Treatment, Time
View Samples