Hematopoietic stem cell (HSC) are regulated by their niche, which limits activation of HSCs, to ensure their maintenance and self-renewal.
Stroma-Derived Connective Tissue Growth Factor Maintains Cell Cycle Progression and Repopulation Activity of Hematopoietic Stem Cells In Vitro.
Cell line
View SamplesMesenchymal stromal cells (MSC) are crucial components of the bone marrow (BM) microenvironment essential for regulating self-renewal, survival and differentiation of hematopoietic stem/progenitor cells (HSPC) in the stem cell niche. MSC are functionally and phenotypically altered in myelodysplastic syndromes (MDS), contributing to disease progression. MDS MSC do not harbor recurrent genetic alterations but have been shown to exhibit an altered methylome compared to MSC from healthy controls. We examined growth, differentiation and HSPC-supporting capacity of ex vivo expanded MSC from MDS patients in comparison to age-matched healthy controls after direct treatment in vitro with the hypomethylating agent azacitidine (AZA). We show that AZA exerts a direct effect on MSC by modulating their differentiation potential. Osteogenesis was significantly boosted in healthy MSC while adipogenesis was inhibited in both healthy and MDS MSC. In co-culture experiments, both AZA treated MDS MSC and healthy MSC exhibited enhanced support of non-clonal HSPC which was associated with increased cell cycle induction. Conversely, clonal MDS HSPC were inhibited by contact with AZA treated MSC. RNA-sequencing analyses of stromal cells revealed changes in pathways essential for HSPC support as well as in immune regulatory pathways. In sum, our data demonstrate that AZA treatment of stromal cells leads to upregulation of HSPC-supportive genes and cell cycle induction in co-cultured healthy HSPC, resulting in a proliferative advantage over clonal HSPC. Thus, restoration of functional hematopoiesis by AZA may be driven by activated stromal support factors in MSC providing cell cycle cues to healthy HSPC. Overall design: RNA sequencing was performed on a mesenchymal stromal cell line (EL08-1D2), either untreated or treated with Azacitidine [(-)AZA vs. (+)AZA].
Direct modulation of the bone marrow mesenchymal stromal cell compartment by azacitidine enhances healthy hematopoiesis.
Treatment, Subject
View SamplesThymocyte selection-associated high mobility group box protein family member 2 (TOX2) is a transcription factor belonging to the TOX family that shares a highly conserved high mobility group DNA binding domain with the other TOX members. While TOX1 has been shown to be an essential regulator of T-cell and natural killer (NK) cell differentiation in mice, little is known about the roles of the other TOX family members in lymphocyte development, particularly in humans. In this study, we found that TOX2 was preferentially expressed in mature human NK cells and was upregulated during in vitro differentiation of NK cells from human umbilical cord blood (UCB)derived CD34+ cells. Gene silencing of TOX2 intrinsically hindered the transition between early developmental stages of NK cells, while overexpression of TOX2 enhanced the development of mature NK cells from UCB CD34+ cells. We subsequently found that TOX2 was independent of ETS-1 but could directly upregulate the transcription of TBX21 (encoding T-BET). Overexpression of T-BET rescued the TOX2 knockdown phenotypes. Given the essential function of T-BET in NK cell differentiation, TOX2 therefore plays a crucial role in controlling normal NK cell development by acting upstream of TBX21 transcriptional regulation.
TOX2 regulates human natural killer cell development by controlling T-BET expression.
Specimen part, Subject
View SamplesHematopoietic stem cells (HSCs) are identified by their ability to sustain prolonged blood cell production in vivo, although recent evidence suggests that durable self-renewal (DSR) is shared by HSC subtypes with distinct self-perpetuating differentiation programs. Net expansions of DSR-HSCs occur in vivo, but molecularly defined conditions that support similar responses in vitro are lacking. We hypothesized that this might require a combination of factors that differentially promote HSC viability, proliferation and self-renewal. We now demonstrate that HSC survival and maintenance of DSR potential is variably supported by different Steel factor (SF)-containing cocktails with similar HSC-mitogenic activities. In addition, stromal cells produce other factors, including nerve growth factor and collagen 1, that can antagonize the apoptosis of initially quiescent adult HSCs and, in combination with SF and interleukin-11, produce >15-fold net expansions of DSR-HSCs ex vivo within 7 days. These findings suggest a new molecular basis for HSC control and expansion.
Distinct stromal cell factor combinations can separately control hematopoietic stem cell survival, proliferation, and self-renewal.
Specimen part
View SamplesHematopoiesis occurs in a microenviroenment in which stromal cells are prominent. Stromal cells have been shown to maintain stem cell behaviour of hematopoietic stem cells. We derived several different stromal cell lines from midgestation embryos which will, or will not maintain hemetopoietic stem cells in cultures.
Efficient hematopoietic differentiation of human embryonic stem cells on stromal cells derived from hematopoietic niches.
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JAK/STAT3 signalling is sufficient and dominant over antagonistic cues for the establishment of naive pluripotency.
Sex, Specimen part, Treatment
View SamplesThis microarray was performed to gain insight in the effect of GY118F stimulation in EpiSCs. This array is part of the following paper to be published in Nature Communications: JAK/STAT3 signalling is sufficient and dominant over antagonistic cues for the establishment of nave pluripotency by Anouk L. van Oosten, Yael Costa, Austin Smith & Jos C.R. Silva
JAK/STAT3 signalling is sufficient and dominant over antagonistic cues for the establishment of naive pluripotency.
Specimen part, Treatment
View SamplesThis microarray was performed to gain insight in the downstream targets of GY118F in iPS cells. This array is part of the following paper to be published in Nature Communications: JAK/STAT3 signalling is sufficient and dominant over antagonistic cues for the establishment of nave pluripotency by Anouk L. van Oosten, Yael Costa, Austin Smith & Jos C.R. Silva
JAK/STAT3 signalling is sufficient and dominant over antagonistic cues for the establishment of naive pluripotency.
Sex, Specimen part, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Protein kinase c-β-dependent activation of NF-κB in stromal cells is indispensable for the survival of chronic lymphocytic leukemia B cells in vivo.
Specimen part, Cell line
View SamplesTumor cell survival critically depends on heterotypic communication with benign cells in the microenvironment. Here we describe a novel survival signaling pathway activated in stromal cells by contact to B-cells from chronic lymphocytic leukemia (CLL) patients. The expression of PKC-II and the subsequent activation of NF-B in bone marrow stromal cells is a prerequisite to support the survival of malignant B-cells. PKC- knockout mice are insusceptible to CLL-transplantations, underscoring the in vivo significance of the PKC-II- NF-B signaling pathway in the tumor microenvironment. Upregulated stromal PKC-II in biopsies from CLL, breast- and pancreatic- cancer patients suggest that this pathway may commonly be activated in a variety of malignancies.
Protein kinase c-β-dependent activation of NF-κB in stromal cells is indispensable for the survival of chronic lymphocytic leukemia B cells in vivo.
Specimen part
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