scholarly journals Comprehensive population-based genome sequencing provides insight into hematopoietic regulatory mechanisms

2016 ◽  
Author(s):  
Michael Guo ◽  
Satish K. Nandakumar ◽  
Jacob C. Ulirsch ◽  
Seyedeh Maryam Zekavat ◽  
Jason D. Buenrostro ◽  
...  
Keyword(s):  
Blood Cell ◽  
Genome Sequencing ◽  
Association Studies ◽  
Population Based ◽  
Regulatory Mechanisms ◽  
Data Sets ◽  
Lineage Specification ◽  
High Coverage ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells

ABSTRACTGenetic variants affecting hematopoiesis can influence commonly measured blood cell traits. To identify factors that affect hematopoiesis, we performed association studies for blood cell traits in the population-based Estonian Biobank using high coverage whole genome sequencing (WGS) in 2,284 samples and SNP genotyping in an additional ~17,000 samples. Our analyses identified 17 associations across 14 blood cell traits. Integration of WGS-based fine-mapping and complementary epigenomic data sets provided evidence for causal mechanisms at several loci, including at a novel basophil count-associated locus near the master hematopoietic transcription factor CEBPA. The fine-mapped variant at this basophil count association near CEBPA overlapped an enhancer active in common myeloid progenitors and influenced its activity. In situ perturbation of this enhancer by CRISPR/Cas9 mutagenesis in hematopoietic stem and progenitor cells demonstrated that it is necessary for and specifically regulates CEBPA expression during basophil differentiation. We additionally identified basophil count-associated variation at another more pleiotropic myeloid enhancer near GATA2, highlighting regulatory mechanisms for ordered expression of master hematopoietic regulators during lineage specification. Our study illustrates how population-based genetic studies can provide key insights into poorly understood cell differentiation processes of considerable physiologic relevance.

scholarly journals Comprehensive population-based genome sequencing provides insight into hematopoietic regulatory mechanisms

2016 ◽  
Vol 114 (3) ◽  
pp. E327-E336 ◽  
Author(s):  
Michael H. Guo ◽  
Satish K. Nandakumar ◽  
Jacob C. Ulirsch ◽  
Seyedeh M. Zekavat ◽  
Jason D. Buenrostro ◽  
...  
Keyword(s):  
Blood Cell ◽  
Genome Sequencing ◽  
Association Studies ◽  
Population Based ◽  
Regulatory Mechanisms ◽  
Lineage Specification ◽  
High Coverage ◽  
Hematopoietic Stem ◽  
Phenotype Data ◽  
Stem And Progenitor Cells

Genetic variants affecting hematopoiesis can influence commonly measured blood cell traits. To identify factors that affect hematopoiesis, we performed association studies for blood cell traits in the population-based Estonian Biobank using high-coverage whole-genome sequencing (WGS) in 2,284 samples and SNP genotyping in an additional 14,904 samples. Using up to 7,134 samples with available phenotype data, our analyses identified 17 associations across 14 blood cell traits. Integration of WGS-based fine-mapping and complementary epigenomic datasets provided evidence for causal mechanisms at several loci, including at a previously undiscovered basophil count-associated locus near the master hematopoietic transcription factor CEBPA. The fine-mapped variant at this basophil count association near CEBPA overlapped an enhancer active in common myeloid progenitors and influenced its activity. In situ perturbation of this enhancer by CRISPR/Cas9 mutagenesis in hematopoietic stem and progenitor cells demonstrated that it is necessary for and specifically regulates CEBPA expression during basophil differentiation. We additionally identified basophil count-associated variation at another more pleiotropic myeloid enhancer near GATA2, highlighting regulatory mechanisms for ordered expression of master hematopoietic regulators during lineage specification. Our study illustrates how population-based genetic studies can provide key insights into poorly understood cell differentiation processes of considerable physiologic relevance.

scholarly journals Signaling Pathways That Regulate Normal and Aberrant Red Blood Cell Development

Genes ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1646
Author(s):  
Mark C. Wilkes ◽  
Aya Shibuya ◽  
Kathleen M. Sakamoto
Keyword(s):  
Blood Cell ◽  
Signaling Pathways ◽  
Therapeutic Potential ◽  
Cell Development ◽  
Signaling Cascades ◽  
Hematopoietic Stem ◽  
Multiple Substrates ◽  
Stem And Progenitor Cells ◽  
Multiple Copies ◽  
Phosphoinositide 3 Kinase

Blood cell development is regulated through intrinsic gene regulation and local factors including the microenvironment and cytokines. The differentiation of hematopoietic stem and progenitor cells (HSPCs) into mature erythrocytes is dependent on these cytokines binding to and stimulating their cognate receptors and the signaling cascades they initiate. Many of these pathways include kinases that can diversify signals by phosphorylating multiple substrates and amplify signals by phosphorylating multiple copies of each substrate. Indeed, synthesis of many of these cytokines is regulated by a number of signaling pathways including phosphoinositide 3-kinase (PI3K)-, extracellular signal related kinases (ERK)-, and p38 kinase-dependent pathways. Therefore, kinases act both upstream and downstream of the erythropoiesis-regulating cytokines. While many of the cytokines are well characterized, the nuanced members of the network of kinases responsible for appropriate induction of, and response to, these cytokines remains poorly defined. Here, we will examine the kinase signaling cascades required for erythropoiesis and emphasize the importance, complexity, enormous amount remaining to be characterized, and therapeutic potential that will accompany our comprehensive understanding of the erythroid kinome in both healthy and diseased states.

scholarly journals B-1 lymphoid cells develop independently of Notch signaling during mouse embryonic development

2020 ◽  
Author(s):  
Nathalia Azevedo ◽  
Elisa Bertesago ◽  
Ismail Ismailoglu ◽  
Michael Kyba ◽  
Michihiro Kobayashi ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Development ◽  
Blood Cell ◽  
Notch Signaling ◽  
Embryonic Stem ◽  
Cell Types ◽  
Lymphoid Cells ◽  
Lineage Specification ◽  
Hematopoietic Stem

AbstractThe in vitro generation from pluripotent stem cells (PSCs) of different blood cell types, in particular those that are not replenished by hematopoietic stem cells (HSCs) like fetal-derived tissue-resident macrophages and innate-like lymphocytes, is of a particular interest. In order to succeed in this endeavor, a thorough understanding of the pathway interplay promoting lineage specification for the different blood cell types is needed. Notch signaling is essential for the HSC generation and their derivatives, but its requirement for tissue-resident immune cells is unknown. Using mouse embryonic stem cells (mESCs) to recapitulate murine embryonic development, we have studied the requirement for Notch signaling during the earliest B-lymphopoiesis and found that Rbpj-deficient mESCs are able to generate B-1 cells. Their Notch-independence was confirmed in ex vivo experiments using Rbpj-deficient embryos. In addition, we found that upregulation of Notch signaling was needed for the emergence of B-2 lymphoid cells. Taken together, these findings indicate that control of Notch signaling dosage is critical for the different B-cell lineage specification and provides pivotal information for their in vitro generation from PSCs for therapeutic applications.

scholarly journals Whole genome sequencing identifies common and rare structural variants contributing to hematologic traits in the NHLBI TOPMed program

2021 ◽  
Author(s):  
Marsha M. Wheeler ◽  
Adrienne M Stilp ◽  
Shuquan Rao ◽  
Bjarni V Halldorsson ◽  
Doruk V Beyter ◽  
...  
Keyword(s):  
Blood Cell ◽  
Whole Genome Sequencing ◽  
Genome Sequencing ◽  
Association Studies ◽  
Regulatory Elements ◽  
Chromatin Domain ◽  
Genome Wide Association Studies ◽  
Whole Genome ◽  
Structural Variants ◽  
Genome Wide

Genome-wide association studies (GWAS) have identified thousands of single nucleotide variants and small indels that contribute to the genetic architecture of hematologic traits. While structural variants (SVs) are known to cause rare blood or hematopoietic disorders, the genome-wide contribution of SVs to quantitative blood cell trait variation is unknown. Here we utilized SVs detected from whole genome sequencing (WGS) in ancestrally diverse participants of the NHLBI TOPMed program (N=50,675). Using single variant tests, we assessed the association of common and rare SVs with red cell-, white cell-, and platelet-related quantitative traits. The results show 33 independent SVs (23 common and 10 rare) reaching genome-wide significance. The majority of significant association signals (N=27) replicated in independent datasets from deCODE genetics and the UK BioBank. Moreover, most trait-associated SVs (N=24) are within 1Mb of previously-reported GWAS loci. SV analyses additionally discovered an association between a complex structural variant on 17p11.2 and white blood cell-related phenotypes. Based on functional annotation, the majority of significant SVs are located in non-coding regions (N=26) and predicted to impact regulatory elements and/or local chromatin domain boundaries in blood cells. We predict that several trait-associated SVs represent the causal variant. This is supported by genome-editing experiments which provide evidence that a deletion associated with lower monocyte counts leads to disruption of an S1PR3 monocyte enhancer and decreased S1PR3 expression.

scholarly journals The vascular niche controls Drosophila hematopoiesis via fibroblast growth factor signaling

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Manon Destalminil-Letourneau ◽  
Ismaël Morin-Poulard ◽  
Yushun Tian ◽  
Nathalie Vanzo ◽  
Michele Crozatier
Keyword(s):  
Blood Cell ◽  
Vascular System ◽  
Lymph Gland ◽  
Growth Factor Signaling ◽  
Hematopoietic Progenitors ◽  
Hematopoietic Progenitor ◽  
Fibroblast Growth Factor Signaling ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells ◽  
Signaling Center

In adult mammals, hematopoiesis, the production of blood cells from hematopoietic stem and progenitor cells (HSPCs), is tightly regulated by extrinsic signals from the microenvironment called ‘niche’. Bone marrow HSPCs are heterogeneous and controlled by both endosteal and vascular niches. The Drosophila hematopoietic lymph gland is located along the cardiac tube which corresponds to the vascular system. In the lymph gland, the niche called Posterior Signaling Center controls only a subset of the heterogeneous hematopoietic progenitor population indicating that additional signals are necessary. Here we report that the vascular system acts as a second niche to control lymph gland homeostasis. The FGF ligand Branchless produced by vascular cells activates the FGF pathway in hematopoietic progenitors. By regulating intracellular calcium levels, FGF signaling maintains progenitor pools and prevents blood cell differentiation. This study reveals that two niches contribute to the control ofDrosophila blood cell homeostasis through their differential regulation of progenitors.

Clonal Features of Hematopoietic Stem and Progenitor Cells in Aging

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 243-243
Author(s):  
Jianlong Sun ◽  
Fernando D. Camargo
Keyword(s):  
Blood Cell ◽  
Progenitor Cells ◽  
Peripheral Blood ◽  
Cell Populations ◽  
Multilineage Differentiation ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Cell Production ◽  
Stem And Progenitor Cells

Abstract It is traditionally thought that Hematopoietic Stem Cells (HSCs) maintain blood homeostasis through long-term self-renewal and multilineage differentiation. This concept, however, is challenged by two recent studies in which the fundamental features of unperturbed hematopoiesis are evaluated by different approaches of lineage tracing. Both the kinetic analysis of HSC output by the Rodewald group and our clonal analysis with transposon barcoding suggest a dominant role of non-transplantable short-term HSCs and progenitors, but not the long-term HSCs, in driving native blood cell production. In addition, our longitudinal analysis of peripheral blood demonstrates extensive clonal succession in granulocyte production. These findings collectively suggest a distinct mechanism of native hematopoiesis that differs significantly from what has been learned in transplantation experiments. At the same time, they bring to light new questions regarding the ultimate fate of the progenitor population and the exact contribution of HSCs under normal physiological conditions. To address these questions, we examined clonal features of HSCs and progenitors in aged mice. Our results show a progressive reduction in clonal complexity and a concurrent increase in clonal stability when blood granulocytes are analyzed up to a hundred ten weeks after transposon barcoding. As time elapses, clonal overlapping between granulocytes and B cells become much more extensive, suggesting an increased tendency toward multilineage differentiation during aging. Analysis of stem and progenitor cells in bone marrow of aged mice reveals prevalent lineage output by multipotent progenitors (MPPs), whereas a lower fraction of HSC clones are found to produce mature progeny. While this overall pattern of differentiation is reminiscent of what has been observed in young and middle-aged animals, a two-fold increase in HSC clonal output was observed in these old mice, indicating their increased contribution to blood cell production. A comparison of clonal compositions in blood and marrow cell populations demonstrates an MPP origin of stable peripheral blood clones, and a smaller fraction of these clones can even be traced back to HSCs. These observations hence suggest extensive self-renewal and asymmetric cell division of these two cell populations in aging. Taken together, our results indicate that the aged hematopoietic system is characterized by reduced clonal complexity, increased clonal persistence, and HSC activation. The higher propensity to self-renewal during aging may also explain the elevated risk of malignant transformation in the elderly population. Disclosures Camargo: Cell Signaling Technologies: Consultancy; Vital Therapies: Consultancy.

scholarly journals Vasopressin stimulates the proliferation and differentiation of red blood cell precursors and improves recovery from anemia

2017 ◽  
Vol 9 (418) ◽  
pp. eaao1632 ◽  
Author(s):  
Balázs Mayer ◽  
Krisztián Németh ◽  
Miklós Krepuska ◽  
Vamsee D. Myneni ◽  
Dragan Maric ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Peripheral Blood Cell ◽  
Hematopoietic Stem ◽  
Proliferation And Differentiation ◽  
Stem And Progenitor Cells ◽  
Mouse Cells ◽  
Delayed Recovery ◽  
Human And Mouse ◽  
Sublethal Irradiation

Arginine vasopressin (AVP) made by hypothalamic neurons is released into the circulation to stimulate water resorption by the kidneys and restore water balance after blood loss. Patients who lack this antidiuretic hormone suffer from central diabetes insipidus. We observed that many of these patients were anemic and asked whether AVP might play a role in red blood cell (RBC) production. We found that all three AVP receptors are expressed in human and mouse hematopoietic stem and progenitor cells. The AVPR1B appears to play the most important role in regulating erythropoiesis in both human and mouse cells. AVP increases phosphorylation of signal transducer and activator of transcription 5, as erythropoietin (EPO) does. After sublethal irradiation, AVP-deficient Brattleboro rats showed delayed recovery of RBC numbers compared to control rats. In mouse models of anemia (induced by bleeding, irradiation, or increased destruction of circulating RBCs), AVP increased the number of circulating RBCs independently of EPO. In these models, AVP appears to jump-start peripheral blood cell replenishment until EPO can take over. We suggest that specific AVPR1B agonists might be used to induce fast RBC production after bleeding, drug toxicity, or chemotherapy.

scholarly journals A stemness screen reveals C3orf54/INKA1 as a promoter of human leukemia stem cell latency

Blood ◽  
2019 ◽  
Vol 133 (20) ◽  
pp. 2198-2211 ◽  
Author(s):  
Kerstin B. Kaufmann ◽  
Laura Garcia-Prat ◽  
Qiang Liu ◽  
Stanley W. K. Ng ◽  
Shin-Ichiro Takayanagi ◽  
...  
Keyword(s):  
Stem Cell ◽  
Molecular Mechanisms ◽  
Data Sets ◽  
Human Leukemia ◽  
Human Cord Blood ◽  
Orphan Gene ◽  
Hematopoietic Stem ◽  
Concomitant Reduction ◽  
Stem And Progenitor Cells

Abstract There is a growing body of evidence that the molecular properties of leukemia stem cells (LSCs) are associated with clinical outcomes in acute myeloid leukemia (AML), and LSCs have been linked to therapy failure and relapse. Thus, a better understanding of the molecular mechanisms that contribute to the persistence and regenerative potential of LSCs is expected to result in the development of more effective therapies. We therefore interrogated functionally validated data sets of LSC-specific genes together with their known protein interactors and selected 64 candidates for a competitive in vivo gain-of-function screen to identify genes that enhanced stemness in human cord blood hematopoietic stem and progenitor cells. A consistent effect observed for the top hits was the ability to restrain early repopulation kinetics while preserving regenerative potential. Overexpression (OE) of the most promising candidate, the orphan gene C3orf54/INKA1, in a patient-derived AML model (8227) promoted the retention of LSCs in a primitive state manifested by relative expansion of CD34+ cells, accumulation of cells in G0, and reduced output of differentiated progeny. Despite delayed early repopulation, at later times, INKA1-OE resulted in the expansion of self-renewing LSCs. In contrast, INKA1 silencing in primary AML reduced regenerative potential. Mechanistically, our multidimensional confocal analysis found that INKA1 regulates G0 exit by interfering with nuclear localization of its target PAK4, with concomitant reduction of global H4K16ac levels. These data identify INKA1 as a novel regulator of LSC latency and reveal a link between the regulation of stem cell kinetics and pool size during regeneration.

scholarly journals Jak2V617F and Dnmt3a loss cooperate to induce myelofibrosis through activated enhancer-driven inflammation

Blood ◽  
2018 ◽  
Vol 132 (26) ◽  
pp. 2707-2721 ◽  
Author(s):  
Sebastien Jacquelin ◽  
Jasmin Straube ◽  
Leanne Cooper ◽  
Therese Vu ◽  
Axia Song ◽  
...  
Keyword(s):  
Early Stage ◽  
Myeloproliferative Neoplasms ◽  
Chromatin Accessibility ◽  
Transcriptional Analysis ◽  
Data Sets ◽  
Inflammatory Signaling ◽  
Hematopoietic Stem ◽  
Stem And Progenitor Cells ◽  
Expression Program

Abstract Myeloproliferative neoplasms (MPNs) are a group of blood cancers that arise following the sequential acquisition of genetic lesions in hematopoietic stem and progenitor cells (HSPCs). We identify mutational cooperation between Jak2V617F expression and Dnmt3a loss that drives progression from early-stage polycythemia vera to advanced myelofibrosis. Using in vivo, clustered regularly interspaced short palindromic repeats (CRISPR) with CRISPR-associated protein 9 (Cas9) disruption of Dnmt3a in Jak2V617F knockin HSPC, we show that Dnmt3a loss blocks the accumulation of erythroid elements and causes fibrotic infiltration within the bone marrow and spleen. Transcriptional analysis and integration with human data sets identified a core DNMT3A-driven gene-expression program shared across multiple models and contexts of Dnmt3a loss. Aberrant self-renewal and inflammatory signaling were seen in Dnmt3a−/− Jak2V617F HSPC, driven by increased chromatin accessibility at enhancer elements. These findings identify oncogenic cooperativity between Jak2V617F-driven MPN and Dnmt3a loss, leading to activation of HSPC enhancer–driven inflammatory signaling.

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