In the retina of adult teleosts, stem cells are sustained in two specialized niches: the ciliary marginal zone (CMZ) and the microenvironment surrounding adult Mller glia. Recently, Mller glia were identified as the regenerative stem cells in the teleost retina. Secreted signaling molecules that regulate neuronal regeneration in the retina are largely unknown. In a microarray screen to discover such factors, we identified midkine-b (mdkb). Midkine is a highly conserved heparin-binding growth factor with numerous biological functions. The zebrafish genome encodes two distinct midkine genes: mdka and mdkb. Here, we describe the cellular expression of mdka and mdkb during retinal development and the initial, proliferative phase of photoreceptor regeneration. The results show that in the embryonic and larval retina mdka and mdkb are expressed in stem cells, retinal progenitors and neurons in distinct patterns that suggest different functions for the two molecules. Following the selective death of photoreceptors in the adult, mdka and mdkb are co-expressed in horizontal cells and proliferating Mller glia and their neurogenic progeny. These data reveal that Mdka and Mdkb are signaling factors present in the retinal stem cell niches in both embryonic and mature retinas, and that their cellular expression is actively modulated during retinal development and regeneration.
Cellular expression of midkine-a and midkine-b during retinal development and photoreceptor regeneration in zebrafish.
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View SamplesIt is known that CBFB-MYH11, the fusion gene generated by inversion of chromosome 16 in human acute myeloid leukemia, is causative for oncogenic transformation. However, the mechanism by which CBFB-MYH11 initiates leukemogenesis is not clear. Previously published reports showed that CBFB-MYH11 dominantly inhibits RUNX1 and CBFB, and such inhibition has been suggested as the mechanism for leukemogenesis. However, knockin mice expressing Cbfb-MYH11 (Cbfb+/MYH11) showed defects in primitive hematopoiesis not seen in Cbfb null (Cbfb-/-) embryos indicating that Cbfb-MYH11 has repression independent activities as well.
Cbfb/Runx1 repression-independent blockage of differentiation and accumulation of Csf2rb-expressing cells by Cbfb-MYH11.
Specimen part
View SamplesThe C-terminus of CBF-SMMHC, the fusion protein produced by a chromosome 16 inversion in acute myeloid leukemia subtype M4Eo, contains domains for self-mulimerization and transcriptional repression, both of which have been proposed to be important for leukemogenesis by CBF-SMMHC. To test the role of the fusion protein's C-terminus in vivo, we generated knock-in mice expressing a C-terminally truncated CBF-SMMHC (CBF-SMMHCC95). Embryos with a single copy of CBF-SMMHCDC95 were viable and showed no defects in hematopoiesis, while embryos homozygous for the CBF-SMMHCC95 allele had hematopoietic defects and died in mid-gestation, similar to embryos with a single-copy of the full-length CBF-SMMHCC95.
The C-terminus of CBFβ-SMMHC is required to induce embryonic hematopoietic defects and leukemogenesis.
Specimen part
View SamplesResults showed that Chd7 deficiency delay Cbfb-MYH11 induced leukemia, to explore the mechanism, We also performed microarray analysis on c-Kit+ leukemic cells to determine gene expression differences between Mx1-Cre, Cbfb+/56M and Chd7f/f, Mx1-Cre, Cbfb+/56M leukemic cells.
<i>Chd7</i> deficiency delays leukemogenesis in mice induced by <i>Cbfb-MYH11</i>.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
An epigenetic mechanism mediates developmental nicotine effects on neuronal structure and behavior.
Age, Specimen part
View SamplesOur group recently described a population of antigen presenting cells that appear to be critical in psoriasis pathogenesis, termed inflammatory myeloid dendritic cells (CD11c+ BDCA1-). Triggering receptor expressed on myeloid cells type-1 (TREM-1) signaling was a major canonical pathway in the published transcriptome of these cells. TREM-1 is a member of the immunoglobulin superfamily, active through the DAP12 signaling pathway, with an unknown ligand. Activation through TREM-1 induces inflammatory cytokines including IL-8, MCP/CCL2 and TNF. We now show that TREM-1 was expressed in the skin of healthy and psoriatic patients, and there was increased soluble TREM-1 in the circulation of psoriasis patients. In psoriasis lesions, TREM-1 was co-localized with dendritic cells as well as CD31+ endothelial cells. TREM-1 expression was reduced with successful NB-UVB, etanercept and anti-IL-17 treatments. An in vitro model of PGN-activated monocytes as inflammatory myeloid DCs was developed to study TREM-1 blockade, and treatment with a TREM-1 blocking chimera decreased allogeneic Th17 activation, as well as IL-17 production. Furthermore, TREM-1 blockade of ex vivo psoriatic dendritic cells in an alloMLR also showed a decrease in IL-17. Together, these data suggest that the TREM-1 signaling pathway offers a novel therapeutic target to prevent the effects of inflammatory myeloid DCs in psoriasis.
TREM-1 as a potential therapeutic target in psoriasis.
Specimen part
View SamplesDevelopmental nicotine exposure causes persistent changes in cortical neuron morphology and in behavior.
An epigenetic mechanism mediates developmental nicotine effects on neuronal structure and behavior.
Age, Specimen part
View SamplesThe Ts1Cje mouse model of Down syndrome (DS) has partial triplication of mouse chromosome 16 (MMU16), which is partially homologous to human chromosome 21. The mouse model develops various neuropathological features identified in DS individuals. We analysed the effect of partial triplication of the MMU16 segment on global gene expression in the cerebral cortex, cerebellum and hippocampus of Ts1Cje mice at 4 time-points; postnatal day (P)1, P15, P30 and P84.
Functional transcriptome analysis of the postnatal brain of the Ts1Cje mouse model for Down syndrome reveals global disruption of interferon-related molecular networks.
Sex, Specimen part
View SamplesTo understand the development of new psoriasis lesions, we studied a group of moderate-to-severe psoriasis patients who experienced a relapse after ceasing efalizumab (anti-CD11a, Raptiva, Genentech). There were increased CD3+ T cells, neutrophils, CD11c+ and CD83+ myeloid DCs, but no increase in CD1c+ resident myeloid DCs. In relapsed lesions, there were many CD11c+CD1c-, inflammatory myeloid DCs identified by TNFSF10/TRAIL, TNF, and iNOS. CD11c+ cells in relapsed lesions co-expressed CD14 and CD16 in situ. Efalizumab induced an improvement in many psoriasis genes, and during relapse, the majority of these genes reversed back to a lesional state. Gene Set Enrichment Analysis (GSEA) of the transcriptome of relapsed tissue showed that many of the gene sets known to be present in psoriasis were also highly enriched in relapse. Hence, on ceasing efalizumab, T cells and myeloid cells rapidly enter the skin to cause classic psoriasis.
Post-therapeutic relapse of psoriasis after CD11a blockade is associated with T cells and inflammatory myeloid DCs.
Specimen part, Disease, Disease stage, Treatment, Subject, Time
View SamplesDominant RUNX1 inhibition has been proposed as a common pathway for CBF-leukemia. CBFb-SMMHC, a fusion protein in human acute myeloid leukemia (AML), dominantly inhibits RUNX1 largely through its RUNX1 high-affinity binding domain (HABD). We generated knock-in mice expressing CBFb-SMMHC with a HABD deletion, CBFb-SMMHCd179-221. These mice developed leukemia highly efficiently, even though hematopoietic defects associated with Runx1-inhibition were partially rescued.
Accelerated leukemogenesis by truncated CBF beta-SMMHC defective in high-affinity binding with RUNX1.
Specimen part
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