Brain inflammation, a common feature in neurodegenerative diseases, is a complex series of events, which can be detrimental and even lead to neuronal death. Nonetheless, several studies suggest that inflammatory signals are also positively influencing neural cell proliferation, survival, migration and differentiation. Recently, correlative studies suggested that astrocytes are able to dedifferentiate upon injury, and may thereby re-acquire neural stem cells (NSC) potential. However, the mechanism underlying this dedifferentiation process upon injury remains unclear. In this study, we find that during the early response of reactive gliosis, inflammation induces a conversion of mature astrocytes into neural progenitors. A TNF treatment induces the decrease of specific astrocyte markers, such as GFAP or genes related to glycogen metabolism, while a subset of these cells re-express immaturity markers, such as CD44, Musashi-1 and Oct4. Thus, TNF treatment results in the appearance of cells that exhibit a neural progenitor phenotype and are able to proliferate and differentiate into neurons and/or astrocytes.
Inflammation Promotes a Conversion of Astrocytes into Neural Progenitor Cells via NF-κB Activation.
Specimen part
View SamplesWe expressed either only the E7 oncoprotein or the complete early genome region (CER) of the human papillomavirus type 8 in primary human adult skin keratinocytes.
Novel Insights Into Cellular Changes in HPV8-E7 Positive Keratinocytes: A Transcriptomic and Proteomic Analysis.
Specimen part
View SamplesWe have recently shown a remarkable regenerative capacity of the prenatal heart using a genetic model of mosaic mitochondrial dysfunction in mice. This model is based on inactivation of the X-linked gene encoding holocytochrome c synthase (Hccs) specifically in the developing heart. Loss of HCCS activity results in respiratory chain dysfunction, disturbed cardiomyocyte differentiation and reduced cell cycle activity. The Hccs gene is subjected to X chromosome inactivation, such that in females heterozygous for the heart conditional Hccs knockout approximately 50% of cardiac cells keep the defective X chromosome active and develop mitochondrial dysfunction while the other 50% remain healthy. During heart development, however, the contribution of HCCS deficient cells to the cardiac tissue decreases from 50% at midgestation to 10% at birth. This regeneration of the prenatal heart is mediated by increased proliferation of the healthy cardiac cell population, which compensate for the defective cells and allow the formation of a fully functional heart at birth. Here we performed microarray expression ananlyses on 13.5 dpc control and heterozygous Hccs knockout hearts to identify molecular mechanisms that drive embryonic heart regeneration.
Embryonic cardiomyocytes can orchestrate various cell protective mechanisms to survive mitochondrial stress.
Sex, Specimen part
View SamplesWe report that Zic family (Zic1/2/3) and orphan nuclear receptors family (Esrrb and Nr5a2) transcription factors (TFs) synergistically enhance the reprogramming efficiency when transduced with Oct4, Sox2 and Klf4 (OSK) into murine fibroblasts. To identify the molecular mechanisms underlying this synergy, we analyzed global gene expression at 6 days after introduction of reprogramming factors. As a result, we found that primary targets of these TFs are different when either of TFs was introduced with OSK, but a significant portion of genes including pluripotency makers such as Dppa2 was synergistically upregulated. Further analysis revealed that metabolic pathways are the important targets of these TFs for efficient reprogramming.
Hybrid Cellular Metabolism Coordinated by Zic3 and Esrrb Synergistically Enhances Induction of Naive Pluripotency.
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View SamplesHuman pluripotent stem cells (hPSCs) such as embryonic stem cells and induced pluripotent stem cells are promising materials for cell-based regenerative therapies to heart diseases. However, until realization there are many hurdles such as high efficiency of cardiac differentiation of hPSCs and production of clinical-grade cardiac cells derived from hPSCs. Here, we show that a novel small molecule KY02111 robustly enhances differentiation to functional cardiomyocytes from hPSCs.
A small molecule that promotes cardiac differentiation of human pluripotent stem cells under defined, cytokine- and xeno-free conditions.
Specimen part, Cell line
View SamplesMutations in the enzymes IDH1 and IDH2 have been identified in a wide variety of tumors like glioma, chondrosarcoma, thyroid cancer, lymphoma, melanoma, and in acute myeloid leukemia. Mutated IDH1/2 produces the metabolite 2-hydroxyglutarate (2HG), which interferes with epigenetic regulation of gene expression, and thus may promote tumorigenesis.
Enantiomer-specific and paracrine leukemogenicity of mutant IDH metabolite 2-hydroxyglutarate.
Specimen part
View SamplesExtensive molecular profiling of leukemias and preleukemic diseases has revealed that distinct clinical entities, like acute myeloid (AML) and T-lymphoblastic leukemia, share the same pathogenetic mutations. It is not well understood how the cell of origin, accompanying mutations, extracellular signals or structural differences in a mutated gene determine the phenotypic identity of the malignant disease. We studied the relationship of different protein domains of the MN1 oncogene and their effect on the leukemic phenotype, building on the ability of MN1 to induce leukemia without accompanying mutations. We found that the most C-terminal domain of MN1 was required to block myeloid differentiation at an early stage, and deletion of an extended C-terminal domain resulted in loss of myeloid identity and cell differentiation along the T-cell lineage in vivo. Megakaryocytic/erythroid lineage differentiation was blocked by the most N-terminal domain. In addition, the N-terminus was required for proliferation and leukemogenesis in vitro and in vivo through upregulation of HoxA9, HoxA10 and Meis2. Our results provide evidence that a single oncogene can modulate cellular identity of leukemic cells based on its active domains. It is therefore likely that different mutations in the same oncogene may impact cell fate decisions and phenotypic appearance of malignant diseases.
Cell fate decisions in malignant hematopoiesis: leukemia phenotype is determined by distinct functional domains of the MN1 oncogene.
Specimen part
View SamplesWe aimed to characterize the complex cardiovascular effects of NOsGC stimulation using NO-independent stimulator BAY 41-8543 in a double transgenic rat (dTGR) model of HFpEF.
Nitric oxide-sensitive guanylyl cyclase stimulation improves experimental heart failure with preserved ejection fraction.
Sex, Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome.
Specimen part
View SamplesDifferentiation of hematopoietic stem cells (HSCs) is regulated by a concert of different transcription factors (TFs). A disturbed function of TFs can be the basis of (pre)malignancies such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). Growth Factor Independence 1b (Gfi1b) is a repressing TF with a key role in quiescence of HSCs and emergence and maturation of erythrocytes and platelets. Here, we show that low expression of GFI1B in blast cells is associated with inferior prognosis of MDS and AML patients. Using mouse models with either reduced expression or conditional deletion of Gfi1b, crossed with a mouse model reflecting human MDS or AML, we demonstrate that AML development was accelerated with heterozygous loss of Gfi1b, and latency was further decreased when Gfi1b was conditionally deleted. Loss of Gfi1b significantly enhanced stemness of leukemic cells with upregulation of genes fundamentally involved in leukemia development. On a molecular level, we found that loss of Gfi1b not only increased the levels of reactive oxygen species (ROS) but also induced gene expression changes of key AML pathways such as the p38/AKT pathway. These results demonstrate that Gfi1b functions as an oncosuppressor in MDS/AML development.
Gfi1b: a key player in the genesis and maintenance of acute myeloid leukemia and myelodysplastic syndrome.
Specimen part
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