Regulation of Hematopoietic Stem and Progenitor Cell Fate Determination By the Dpy30 Subunit of Set1/Mll Complexes

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 767-767
Author(s):  
Zhenhua Yang ◽  
Jonathan Augustin ◽  
Jing Hu ◽  
Hao Jiang
Keyword(s):  
Cell Fate ◽  
Conditional Knockout ◽  
Hematopoietic Differentiation ◽  
H3k4 Methylation ◽  
Hematopoietic Stem ◽  
Fate Determination ◽  
Hematological Diseases ◽  
Proliferation And Differentiation ◽  
Methylation Activity

Abstract Many hematological diseases result from aberrant chromatin and gene regulation in the maintenance, proliferation and differentiation of hematopoietic stem and progenitor cells (HSPCs). As the major H3K4 methylation enzymes in mammals, the SET1/MLL family complexes occupy a crucial position in developmental biology, and are considered potential drug targets for epigenetic therapeutics due to the intimate connection of H3K4 methylation with gene expression as well as the extensive association of several subunits in these complexes with many diseases including multiple blood cancers. The SET1/MLL complexes comprise either SET1A, SET1B, MLL1, MLL2, MLL3, or MLL4 as the catalytic subunit, and WDR5, RBBP5, ASH2L, and DPY30 as integral core subunits necessary for the full methylation activity. However, it remains unclear how the enzymatic activity (H3K4 methylation) of these complexes regulates normal and abnormal hematopoiesis, potentially through regulating target genes critically involved in HSPC fate determination. Our previous finding of the direct and important activity of Dpy30 in facilitating genome-wide H3K4 methylation (Jiang et al., Cell 144:513-525, 2011) allows an effective interrogation of the functional role of H3K4 methylation through genetic studies of Dpy30. We have previously shown that Dpy30 is crucial for efficient differentiation of embryonic stem cells by facilitating the induction of many bivalently marked developmental genes (Jiang et al., Cell, 2011). We then demonstrated an important role of human DPY30 in ex vivo proliferation and differentiation of mobilized hematopoietic progenitors, as well as in zebrafish hematopoiesis (Yang et al., Blood, accepted). To further determine a role for Dpy30 and its associated H3K4 methylation in regulating HSPC maintenance and differentiation, we have generated a Dpy30 conditional knockout (KO) mouse model. Hematopoietic KO of Dpy30 in mice resulted in marked reduction of cellular H3K4 methylation and severe pancytopenia. Surprisingly, in contrast to the rapid HSC depletion upon hematopoietic loss of Mll, we detected a massive accumulation of phenotypic early HSPCs at the expense of more downstream hematopoietic cells in the Dpy30 KO mouse bone marrow (BM), despite little effects on cell proliferation and apoptosis. Competitive transplantation assays revealed a profound defect of the Dpy30 KO BM in multilineage hematopoietic reconstitution. These results are most consistent with a defect in hematopoietic differentiation. We have also started mixed BM chimera assays to further investigate the role of Dpy30 in HSPC fate determination. Our early time point results strongly support a defect in hematopoietic differentiation following Dpy30 loss, and demonstrate a role of Dpy30 in the efficient induction of many lineage regulatory genes during the transitions of the hematopoietic cell fate. Our data from later time points in the transplantation assays will allow us to discover if Dpy30 loss has a potential effect on HSC self-renewal, and will be presented and discussed. By revealing a previously unrecognized role of the H3K4 methylation activity of the Set1/Mll complexes in regulating HSPC fate determination, our studies may have important implications for developing therapeutic strategies against certain HSPC-based hematological diseases. Disclosures No relevant conflicts of interest to declare.

scholarly journals Dpy30 is critical for maintaining the identity and function of adult hematopoietic stem cells

2016 ◽  
Vol 213 (11) ◽  
pp. 2349-2364 ◽  
Author(s):  
Zhenhua Yang ◽  
Kushani Shah ◽  
Alireza Khodadadi-Jamayran ◽  
Hao Jiang
Keyword(s):  
Significant Loss ◽  
Conditional Knockout ◽  
H3k4 Methylation ◽  
Hematopoietic Stem ◽  
Conditional Knockout Mouse ◽  
Stem And Progenitor Cells ◽  
Severe Pancytopenia ◽  
And Function ◽  
Methylation Activity

As the major histone H3K4 methyltransferases in mammals, the Set1/Mll complexes play important roles in animal development and are associated with many diseases, including hematological malignancies. However, the role of the H3K4 methylation activity of these complexes in fate determination of hematopoietic stem and progenitor cells (HSCs and HPCs) remains elusive. Here, we address this question by generating a conditional knockout mouse for Dpy30, which is a common core subunit of all Set1/Mll complexes and facilitates genome-wide H3K4 methylation in cells. Dpy30 loss in the adult hematopoietic system results in severe pancytopenia but striking accumulation of HSCs and early HPCs that are defective in multilineage reconstitution, suggesting a differentiation block. In mixed bone marrow chimeras, Dpy30-deficient HSCs cannot differentiate or efficiently up-regulate lineage-regulatory genes, and eventually fail to sustain for long term with significant loss of HSC signature gene expression. Our molecular analyses reveal that Dpy30 directly and preferentially controls H3K4 methylation and expression of many hematopoietic development-associated genes including several key transcriptional and chromatin regulators involved in HSC function. Collectively, our results establish a critical and selective role of Dpy30 and the H3K4 methylation activity of the Set1/Mll complexes for maintaining the identity and function of adult HSCs.

Role of Geminin in cell fate determination of hematopoietic stem cells (HSCs)

2016 ◽  
Vol 104 (3) ◽  
pp. 324-329 ◽  
Author(s):  
Shin’ichiro Yasunaga ◽  
Yoshinori Ohno ◽  
Naoto Shirasu ◽  
Bo Zhang ◽  
Kyoko Suzuki-Takedachi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Cell Fate ◽  
Cell Fate Determination ◽  
Hematopoietic Stem ◽  
Fate Determination

Role of the Dpy30 Subunit of Set1/Mll Complexes in Lymphomagenesis through Epigenetic Regulation of Myc Activity

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 310-310
Author(s):  
Zhenhua Yang ◽  
Kushani Shah ◽  
Jonathan Augustin ◽  
Jing Hu ◽  
Hao Jiang
Keyword(s):  
B Cells ◽  
Functional Role ◽  
Lymphoma Cell ◽  
Conditional Knockout ◽  
H3k4 Methylation ◽  
Hematopoietic Stem ◽  
Catalytic Subunits ◽  
The Core ◽  
Genome Wide

Abstract Epigenetic modulators have emerged as promising targets for treating cancers, especially blood cancers. As the major histone H3K4 methylation enzymes in mammals, the SET1/MLL complexes represent potential drug targets in epigenetic therapeutics due to (i) the intimate connection of H3K4 methylation with gene expression, and (ii) their extensive association with multiple cancers including blood cancers. However, the functional role for the SET1/MLL complexes in tumorigenesis remains largely unclear. The SET1/MLL complexes comprise one of six different catalytic subunits and several shared core subunits including DPY30. We have previously shown that DPY30 directly facilitates genome-wide H3K4 methylation, and plays a crucial role in fundamental cellular processes including proliferation and differentiation, especially in the hematopoietic system. Our new analyses have shown that the core, but not the catalytic, subunits of SET1/MLL complexes is significantly up-regulated in primary human Burkitt's lymphomas bearing MYC-Ig translocations compared to other B lymphomas, and Myc binds to genes encoding the core but not the catalytic subunits. These results indicate that the core subunits are directly regulated by MYC, and prompted us to study their functional role in MYC-driven tumorigenesis. Using a Dpy30 conditional knockout mouse model that we recently established, we have shown a critical role of Dpy30 in the fate determination of hematopoietic stem and progenitor cells. Due to the severe pancytopenia of the knockout mice, we tested if genetically reducing Dpy30 dose may affect Myc-driven tumorigenesis in the Eμ-myc mouse. We found that Eμ-myc; Dpy30+/- mice survived significantly longer than their Eμ-myc littermates (see figure), with the median survival extended from 121 to 180 days, and with significantly alleviated spleen enlargement. Importantly, Dpy30+/- mice (no Eμ-myc) appear completely healthy with normal blood profiles. These results demonstrate that reducing Dpy30 level confers a significant resistance to Myc-driven lymphomagenesis without affecting normal physiology. We then found that, in the presence of Eμ -Myc, Dpy30 heterozygosity significantly increased apoptosis of splenic B cells, and reduced expression of some key anti-apoptotic genes. We further showed that Dpy30 directly bound to and controlled the H3K4 methylation at the regulated anti-apoptosis genes in splenic B cells. These results suggest that Myc overexpression increases the dependence of key apoptosis-regulatory genes on Dpy30, and thus sensitizes tumor cells to Dpy30 inhibition, exhibiting "epigenetic vulnerability". To further study DPY30's role in MYC-dependent tumorigenesis at the molecular level, we have shown that DPY30 depletion in a MYC-dependent B lymphoma cell line markedly reduced (i) the lymphoma cell growth, (ii) expression of MYC targets, and most interestingly, (iii) binding of MYC to many of its genomic targets, as revealed by our ChIP-seq results. These results suggest that, in addition to promoting the expression of MYC gene itself that we previously found, DPY30 also reguates MYC's activity through promoting the genomic binding of MYC protein for target transcription. Taken together, our studies have established an important role of Dpy30 in the Myc-driven lymphomagenesis, partially through its regulation of the target binding activity of Myc. Further studies of the genome-wide impact of Dpy30 inhibition on the chromatin configuration and expression of key tumoregenic genes are undergoing and will be discussed. These studies will help us understand how Dpy30-mediated chromatin modification coordinates with key oncogenes in promoting hematological malignancies, and thus may represent a potential epigenetic target in treatment of certain blood cancers. Figure 1. Figure 1. Disclosures No relevant conflicts of interest to declare.

scholarly journals Control of Hematopoietic Stem Cell Function through Epigenetic Regulation of Energy Metabolism and Genome Integrity

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 772-772
Author(s):  
Zhenhua Yang ◽  
Hao Jiang
Keyword(s):  
Dna Damage ◽  
Stem Cell ◽  
Energy Metabolism ◽  
Cell Fate ◽  
Energy Production ◽  
Cell Function ◽  
Genome Integrity ◽  
H3k4 Methylation ◽  
Hematopoietic Stem ◽  
Fate Determination

Fate determination of hematopoietic stem cells (HSCs), including their maintenance and differentiation, is profoundly influenced by their metabolic state. How HSCs control their metabolism to ensure correct decision making of cell fate remains an outstanding question. Metabolism is regulated by expression and activities of many rate-limiting metabolic enzymes. Histone modifications shape many aspects of DNA-based processes including transcription and DNA damage responses (DDR). H3K4 methylation is best known for its intimate association with active transcription, and is also implicated in DDR, but its role in DDR for stem cell function is unclear. The Set1/Mll complexes comprise one of six different catalytic subunits and several shared core subunits including Dpy30. We have previously shown that Dpy30 directly facilitates genome-wide H3K4 methylation (Jiang et al., Cell 2011), and that Dpy30 knockout (KO) in mouse hematopoietic system disables differentiation and long-term maintenance HSCs (Yang et al., J Exp Med, 2016). While we have identified dysregulation of multiple genes known to be important for HSC maintenance and differentiation, it is unclear what pathways functionally mediate Dpy30's role in HSC fate determination. Our analyses revealed dysregulation of many metabolic genes upon Dpy30 loss in HSCs, prompting us to examine if and how metabolism is affected by Dpy30 loss in HSCs. We found that Dpy30 loss resulted in increased AMPK activation, suggesting a low cellular energy state. Dpy30 loss resulted in significantly decreased mitochondrial membrane potential, while mitochondrial mass was insignificantly reduced, suggesting impaired mitochondrial function in energy production upon Dpy30 loss. Moreover, Dpy30 loss resulted in significant decrease in oxygen consumption in lineage-negative hematopoietic cells. In further support of diminished oxidative phosphorylation, we also found that reactive oxygen species (ROS) was significantly reduced in all hematopoietic lineage cells upon Dpy30 loss. Consistent with the reduced energy production, glucose uptake was found to be significantly reduced in Dpy30 deficient HSCs. Interestingly, we found that the Dpy30 KO HSCs were more quiescent than control HSCs. As HSCs are usually kept quiescent and they increase oxidative phosphorylation and energy production upon activation, our results suggest that Dpy30 plays important role in enabling HSC activation by metabolic reprogramming. In addition to dysregulated energy metabolism, we also found significant increase of γ-H2AX in the Dpy30 KO lineage negative bone marrow cells, suggesting increase in DDR. As the major source of DNA damage, ROS, is decreased in Dpy30 KO HSCs, we examined if the DNA damage repair was affected and thus led to sustained DDR upon Dpy30 loss. We found that Dpy30 KO cells resolved irradiation-induced γ-H2AX foci with significantly lower efficiency, suggesting that Dpy30 and its associated H3K4 methylation is important for efficient DNA damage repair. Importantly, inhibition of DDR by ATM inhibitor partially rescued the colony formation capacity of the Dpy30 KO cells, suggesting that sustained DDR functionally mediates stem cell activities. As we also saw dramatic upregulation of CDK inhibitor p21 upon Dpy30 loss, we reasoned that increased DDR may affect stem cell activity via p21. To test this hypothesis, we have been breeding to get p21 and Dpy30 double KO mice, and will soon (within a month or so) be able to test if loss of p21 can partially rescue the functional defect of Dpy30 KO stem cells, which will demonstrate an important role of CDK inhibitors in stem cell function. Taken together, our results demonstrate that a key chromatin modulator exerts a profound control of stem cell fate determination through regulating energy metabolism and genome integrity. The functional relationship between metabolic dysregulation, DDR, and stem cell function warrants further studies. Moreover, as we previously showed a critical role of Dpy30 in leukemogenesis and Myc-driven lymphomagenesis, it will be of great interest to investigate whether and how loss or inhibition of this key epigenetic modulator affects cellular metabolism and genome integrity as part of cancer-inhibitory mechanisms. Disclosures No relevant conflicts of interest to declare.

Endothelial and Circulating Progenitor Cells in Hematological Diseases and Allogeneic Hematopoietic Stem Cell Transplantation

2018 ◽  
Vol 25 (35) ◽  
pp. 4535-4544 ◽  
Author(s):  
Annalisa Ruggeri ◽  
Annalisa Paviglianiti ◽  
Fernanda Volt ◽  
Chantal Kenzey ◽  
Hanadi Rafii ◽  
...  
Keyword(s):  
Stem Cell ◽  
Hematopoietic Stem Cell Transplantation ◽  
Stem Cell Transplantation ◽  
Cell Transplantation ◽  
Hematopoietic Stem Cell ◽  
Peripheral Blood ◽  
Circulating Endothelial Cells ◽  
Hematopoietic Stem ◽  
Hematological Diseases

Background: Circulating endothelial cells (CECs), originated form endothelial progenitors (EPCs) are mature cells not associated with vessel walls and detached from the endothelium. Normally, they are present in insignificant amounts in the peripheral blood of healthy individuals. On the other hand, elevated CECs and EPCs levels have been reported in the peripheral blood of patients with different types of cancers and other diseases. Objective: This review aims to provide an overview on the characterization of CECs and EPCs, to describe isolation methods and to identify the potential role of these cells in hematological diseases and hematopoietic stem cell transplantation. Methods: We performed a detailed search of peer-reviewed literature using keywords related to CECs, EPCs, allogeneic hematopoietic stem cell transplantation, and hematological diseases (hemoglobinopathies, hodgkin and non-hodgkin lymphoma, acute leukemia, myeloproliferative syndromes, chronic lymphocytic leukemia). Results: CECs and EPCs are potential biomarkers for several clinical conditions involving endothelial turnover and remodeling, such as in hematological diseases. These cells may be involved in disease progression and in the neoplastic process. Moreover, CECs and EPCs are probably involved in endothelial damage which is a marker of several complications following allogeneic hematopoietic stem cell transplantation. Conclusion: This review provides information about the role of CECs and EPCs in hematological malignancies and shows their implication in predicting disease activity as well as improving HSCT outcomes.

scholarly journals Inflammasomes and the Maintenance of Hematopoietic Homeostasis: New Perspectives and Opportunities

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 309
Author(s):  
Lijing Yang ◽  
Mengjia Hu ◽  
Yukai Lu ◽  
Songling Han ◽  
Junping Wang
Keyword(s):  
Purinergic Receptors ◽  
Therapeutic Potential ◽  
Inflammasome Activation ◽  
Hematopoietic Stem ◽  
Hematopoietic Transplantation ◽  
Proliferation And Differentiation ◽  
Extracellular Stimuli ◽  
Transplantation Complications ◽  
Underlying Mechanisms

Hematopoietic stem cells (HSCs) regularly produce various blood cells throughout life via their self-renewal, proliferation, and differentiation abilities. Most HSCs remain quiescent in the bone marrow (BM) and respond in a timely manner to either physiological or pathological cues, but the underlying mechanisms remain to be further elucidated. In the past few years, accumulating evidence has highlighted an intermediate role of inflammasome activation in hematopoietic maintenance, post-hematopoietic transplantation complications, and senescence. As a cytosolic protein complex, the inflammasome participates in immune responses by generating a caspase cascade and inducing cytokine secretion. This process is generally triggered by signals from purinergic receptors that integrate extracellular stimuli such as the metabolic factor ATP via P2 receptors. Furthermore, targeted modulation/inhibition of specific inflammasomes may help to maintain/restore adequate hematopoietic homeostasis. In this review, we will first summarize the possible relationships between inflammasome activation and homeostasis based on certain interesting phenomena. The cellular and molecular mechanism by which purinergic receptors integrate extracellular cues to activate inflammasomes inside HSCs will then be described. We will also discuss the therapeutic potential of targeting inflammasomes and their components in some diseases through pharmacological or genetic strategies.

IMMU-50. GLIOBLASTOMA MANIPULATES HEMATOPOIETIC STEM CELL DIFFERENTIATION OUTCOMES AND DRIVES ALTERED IMMUNE RECONSTITUTION

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi104-vi104
Author(s):  
Bayli DiVita Dean ◽  
Tyler Wildes ◽  
Joseph Dean ◽  
David Shin ◽  
Connor Francis ◽  
...  
Keyword(s):  
Bone Marrow ◽  
T Cell ◽  
Progenitor Cells ◽  
Rna Sequencing ◽  
Cell Fate ◽  
Immune Reconstitution ◽  
Stem Cell Differentiation ◽  
Cell Fate Determination ◽  
Hematopoietic Stem ◽  
Fate Determination

Abstract INTRODUCTION Bone marrow-derived hematopoietic stem and progenitor cells (HSPCs) give rise to the cellular components of the immune system. Unfortunately, immune reconstitution from HSPCs are negatively impacted by solid cancers, including high-grade gliomas. For example, an expansion of myeloid progenitor cells has been previously described across several cancers that originate outside the CNS. A similar expansion of MDSCs coupled with diminished T cell function has also been described in the peripheral blood of patients with newly-diagnosed GBM. Alterations in both lymphoid and myeloid compartments due to CNS malignancy led us to determine how intracranial gliomas impact HSPCs in both their capacity to reconstitute the immune compartment and in their cell fate determination. This is important to better understand the impact of gliomas on immunity and how we can leverage these findings to better develop cellular immunotherapeutics. METHODS HSPCs were isolated from bone marrow of C57BL/6 mice with orthotopic KR158B glioma, or age-matched naïve mice. Experiments were conducted to compare relative changes in: gene expression (RNA-sequencing), precursor frequencies, cell fate determination, and cellular function of cells derived from HSPCs of glioma-bearing mice. RESULTS RNA-sequencing revealed 700+ genes whose expression was significantly up- or downregulated in HSPCs from glioma-bearing mice, particularly those involved with stemness and metabolic activity. Importantly, HSPCs from glioma-bearing mice expressed upregulation of genes involved in myelopoiesis relative to naïve mice. This was coupled with an expansion of granulocyte macrophage precursors (GMPs), the progenitors to gMDSCs. Next, differentiation assays revealed that HSPCs from glioma-bearing mice had higher propensity of differentiating into MDSC under homeostatic conditions relative to controls both in vitro and in vivo. Furthermore, mice bearing intracranial gliomas possess an expansion of MDSCs which are more suppressive on T cell proliferation and hinders T cell-mediated tumor cell killing relative to MDSCs derived from naïve control mice.

scholarly journals Jagged–Delta asymmetry in Notch signaling can give rise to a Sender/Receiver hybrid phenotype

2015 ◽  
Vol 112 (5) ◽  
pp. E402-E409 ◽  
Author(s):  
Marcelo Boareto ◽  
Mohit Kumar Jolly ◽  
Mingyang Lu ◽  
José N. Onuchic ◽  
Cecilia Clementi ◽  
...  
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Target Genes ◽  
Tumor Stroma ◽  
Notch Receptor ◽  
Toggle Switch ◽  
Cell Fate Determination ◽  
Asymmetric Effect ◽  
Fate Determination

Notch signaling pathway mediates cell-fate determination during embryonic development, wound healing, and tumorigenesis. This pathway is activated when the ligand Delta or the ligand Jagged of one cell interacts with the Notch receptor of its neighboring cell, releasing the Notch Intracellular Domain (NICD) that activates many downstream target genes. NICD affects ligand production asymmetrically––it represses Delta, but activates Jagged. Although the dynamical role of Notch–Jagged signaling remains elusive, it is widely recognized that Notch–Delta signaling behaves as an intercellular toggle switch, giving rise to two distinct fates that neighboring cells adopt––Sender (high ligand, low receptor) and Receiver (low ligand, high receptor). Here, we devise a specific theoretical framework that incorporates both Delta and Jagged in Notch signaling circuit to explore the functional role of Jagged in cell-fate determination. We find that the asymmetric effect of NICD renders the circuit to behave as a three-way switch, giving rise to an additional state––a hybrid Sender/Receiver (medium ligand, medium receptor). This phenotype allows neighboring cells to both send and receive signals, thereby attaining similar fates. We also show that due to the asymmetric effect of the glycosyltransferase Fringe, different outcomes are generated depending on which ligand is dominant: Delta-mediated signaling drives neighboring cells to have an opposite fate; Jagged-mediated signaling drives the cell to maintain a similar fate to that of its neighbor. We elucidate the role of Jagged in cell-fate determination and discuss its possible implications in understanding tumor–stroma cross-talk, which frequently entails Notch–Jagged communication.

scholarly journals Present status and expectation of aristaless-related homeobox (ARX) in endocrine pancreas

2019 ◽  
Vol 63 (11-12) ◽  
pp. 579-587 ◽  
Author(s):  
Sai Xu ◽  
Ji-Ping Xu
Keyword(s):  
Transcription Factors ◽  
Cell Fate ◽  
Endocrine Pancreas ◽  
Theoretical Foundation ◽  
Alpha Cell ◽  
Alpha Cells ◽  
Proliferation And Differentiation ◽  
Direct Target ◽  
Vertebrate Central Nervous System

The aristaless-related homeobox (ARX) gene has become one of most frequently mutated genes which is closely linked with development of the vertebrate central nervous system; however, the molecular and clinical bases of its function in the proliferation and differentiation of the endocrine pancreas have not, to date, been systematically characterized. ARX is considered as a regulator which determines endocrine cell fate and a bio-marker of the pancreatic α-cell. Disruption and mutation of ARX are found to lead to the deletion and reduction of α-cells both in mice models and in humans. Furthermore, expression of ARX is regulated by multiple transcription factors involved in development of the pancreas, such as Ngn3, Isl1, Nkx2.2 and Nkx6.1. Taken together, given the vital importance of glucagon in diabetes treatment, it is possible that ARX may down-regulate exorbitant glucagon levels by reducing the number of α-cells as a direct target; thus, the role of ARX in the maintenance of α-cell identity and quantity should be investigated and summarized. This article mainly focuses on the role of ARX in the endocrine pancreas, introduces the ARX-related animal model and transcription factors, and highlights the latest advances in our understanding in order to provide a clearer theoretical foundation for future scientific research.

Sign in / Sign up

Export Citation Format

Share Document