58,859 results on '"Haematopoiesis"'
Search Results
2. Sialic acid in the regulation of blood cell production, differentiation and turnover.
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Irons, Eric Edward, Gc, Sajina, and Lau, Joseph T. Y.
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SIALIC acids , *GLYCOLIPIDS , *MEMBRANE glycoproteins , *CELLULAR control mechanisms , *BLOOD cells , *POST-translational modification - Abstract
Sialic acid is a unique sugar moiety that resides in the distal and most accessible position of the glycans on mammalian cell surface and extracellular glycoproteins and glycolipids. The potential for sialic acid to obscure underlying structures has long been postulated, but the means by which such structural changes directly affect biological processes continues to be elucidated. Here, we appraise the growing body of literature detailing the importance of sialic acid for the generation, differentiation, function and death of haematopoietic cells. We conclude that sialylation is a critical post‐translational modification utilized in haematopoiesis to meet the dynamic needs of the organism by enforcing rapid changes in availability of lineage‐specific cell types. Though long thought to be generated only cell‐autonomously within the intracellular ER‐Golgi secretory apparatus, emerging data also demonstrate previously unexpected diversity in the mechanisms of sialylation. Emphasis is afforded to the mechanism of extrinsic sialylation, whereby extracellular enzymes remodel cell surface and extracellular glycans, supported by charged sugar donor molecules from activated platelets. [ABSTRACT FROM AUTHOR]
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- 2024
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3. Recent Developments in the Role of Protein Tyrosine Phosphatase 1B (PTP1B) as a Regulator of Immune Cell Signalling in Health and Disease.
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Read, Neve E. and Wilson, Heather M.
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PHOSPHOPROTEIN phosphatases , *CELL communication , *INSULIN receptors , *PROTEIN-tyrosine phosphatase , *CELLULAR signal transduction , *CELL physiology , *HEMATOLOGIC malignancies - Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a non-receptor tyrosine phosphatase best known for its role in regulating insulin and leptin signalling. Recently, knowledge on the role of PTP1B as a major regulator of multiple signalling pathways involved in cell growth, proliferation, viability and metabolism has expanded, and PTP1B is recognised as a therapeutic target in several human disorders, including diabetes, obesity, cardiovascular diseases and hematopoietic malignancies. The function of PTP1B in the immune system was largely overlooked until it was discovered that PTP1B negatively regulates the Janus kinase—a signal transducer and activator of the transcription (JAK/STAT) signalling pathway, which plays a significant role in modulating immune responses. PTP1B is now known to determine the magnitude of many signalling pathways that drive immune cell activation and function. As such, PTP1B inhibitors are being developed and tested in the context of inflammation and autoimmune diseases. Here, we provide an up-to-date summary of the molecular role of PTP1B in regulating immune cell function and how targeting its expression and/or activity has the potential to change the outcomes of immune-mediated and inflammatory disorders. [ABSTRACT FROM AUTHOR]
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- 2024
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4. UBXN3B is crucial for B lymphopoiesisResearch in context
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Tingting Geng, Duomeng Yang, Tao Lin, Andrew G. Harrison, Binsheng Wang, Ziming Cao, Blake Torrance, Zhichao Fan, Kepeng Wang, Yanlin Wang, Long Yang, Laura Haynes, Gong Cheng, Anthony T. Vella, Richard A. Flavell, Joao P. Pereira, Erol Fikrig, and Penghua Wang
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UBXN ,Haematopoiesis ,Lymphopoiesis ,B cell ,COVID-19 ,Medicine ,Medicine (General) ,R5-920 - Abstract
Summary: Background: The ubiquitin regulatory X (UBX) domain-containing proteins (UBXNs) are putative adaptors for ubiquitin ligases and valosin-containing protein; however, their in vivo physiological functions remain poorly characterised. We recently showed that UBXN3B is essential for activating innate immunity to DNA viruses and controlling DNA/RNA virus infection. Herein, we investigate its role in adaptive immunity. Methods: We evaluated the antibody responses to multiple viruses and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza in tamoxifen-inducible global and constitutive B cell-specific Ubxn3b knockout mice; quantified various immune populations, B lineage progenitors/precursors, B cell receptor (BCR) signalling and apoptosis by flow cytometry, immunoblotting and immunofluorescence microscopy. We also performed bone marrow transfer, single-cell and bulk RNA sequencing. Findings: Both global and B cell-specific Ubxn3b knockout mice present a marked reduction in small precursor B-II (>60%), immature (>70%) and mature B (>95%) cell numbers. Transfer of wildtype bone marrow to irradiated global Ubxn3b knockouts restores normal B lymphopoiesis, while reverse transplantation does not. The mature B population shrinks rapidly with apoptosis and higher pro and activated caspase-3 protein levels were observed following induction of Ubxn3b knockout. Mechanistically, Ubxn3b deficiency leads to impaired pre-BCR signalling and cell cycle arrest. Ubxn3b knockout mice are highly vulnerable to respiratory viruses, with increased viral loads and prolonged immunopathology in the lung, and reduced production of virus-specific IgM/IgG. Interpretation: UBXN3B is essential for B lymphopoiesis by maintaining constitutive pre-BCR signalling and cell survival in a cell-intrinsic manner. Funding: United States National Institutes of Health grants, R01AI132526 and R21AI155820.
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- 2024
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5. Baicalein attenuates oxidative damage in mice haematopoietic cells through regulation of PDGFRβ
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Huanying Ren, Jingyi Feng, Minglin Hong, Zhuang Liu, Daniel Muteb Muyey, Yaofang Zhang, Zhifang Xu, Yanhong Tan, Fanggang Ren, Jianmei Chang, Xiuhua Chen, and Hongwei Wang
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Baicalein ,Oxidative stress ,PDGFRβ ,Haematopoiesis ,Biology (General) ,QH301-705.5 ,Medicine - Abstract
Platelet-derived growth factor receptor β (PDGFRβ) plays a crucial role in murine haematopoiesis. Baicalein (BAI), a naturally occurring flavonoid, can alleviate disease damage through anti-oxidative, anti-apoptotic, and anti-inflammatory mechanisms. However, whether BAI attenuates oxidative damage in murine haematopoietic cells by PDGFRβ remains unexplored. In this study, we utilized a tert-butyl hydroperoxide (TBHP)-induced BaF3 cell injury model and an ionising radiation (IR)-induced mice injury model to investigate the impact of the presence or absence of PDGFRβ on the pharmacological effects of BAI. In addition, the BAI-PDGFRβ interaction was characterized by molecular docking and dynamics simulations. The results show that a specific concentration of BAI led to increased cell viability, reduced reactive oxygen species (ROS) content, upregulated nuclear factor erythroid 2-related factor 2 (NRF2) expression, and its downstream target genes heme oxygenase 1 (HO-1) and NAD(P)H Quinone Dehydrogenase 1 (NQO1), and activated protein kinase B (AKT) pathway in cells expressing PDGFRβ plasmid and experiencing damage. Similarly, BAI elevated lineage−Sca1+cKIT+ (LSK) cell proportion, promoted haematopoietic restoration, enhanced NRF2-mediated antioxidant response in PDGFRβ+/+ mice. However, despite BAI usage, PDGFRβ knockout mice (PDGFRβ−/−) showed lower LSK proportion and less antioxidant capacity than the total body irradiation (TBI) group. Furthermore, we demonstrated an interaction between BAI and PDGFRβ at the molecular level. Collectively, our results indicate that BAI attenuates oxidative stress injury and helps promote haematopoietic cell recovery through regulation of PDGFRβ.
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- 2024
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6. Genetic relations between type 1 diabetes, coronary artery disease and leukocyte counts
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Adebekun, Jolade, Nadig, Ajay, Saarah, Priscilla, Asgari, Samira, Kachuri, Linda, and Alagpulinsa, David A.
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- 2024
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7. Tracking early mammalian organogenesis - prediction and validation of differentiation trajectories at whole organism scale.
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Imaz-Rosshandler, Ivan, Rode, Christina, Guibentif, Carolina, Harland, Luke T. G., Ton, Mai-Linh N., Dhapola, Parashar, Keitley, Daniel, Argelaguet, Ricard, Calero-Nieto, Fernando J., Nichols, Jennifer, Marioni, John C., de Bruijn, Marella F. T. R., and Göttgens, Berthold
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ANIMAL development , *MORPHOGENESIS , *GASTRULATION , *DEVELOPMENTAL biology , *MICROSCOPY , *IDENTIFICATION of animals - Abstract
Early organogenesis represents a key step in animal development, during which pluripotent cells diversify to initiate organ formation. Here, we sampled 300,000 single-cell transcriptomes from mouse embryos between E8.5 and E9.5 in 6-h intervals and combined this new dataset with our previous atlas (E6.5-E8.5) to produce a densely sampled timecourse of >400,000 cells from early gastrulation to organogenesis. Computational lineage reconstruction identified complex waves of blood and endothelial development, including a new programme for somite-derived endothelium. We also dissected the E7.5 primitive streak into four adjacent regions, performed scRNA-seq and predicted cell fates computationally. Finally, we defined developmental state/fate relationships by combining orthotopic grafting, microscopic analysis and scRNA-seq to transcriptionally determine cell fates of grafted primitive streak regions after 24 h of in vitro embryo culture. Experimentally determined fate outcomes were in good agreement with computationally predicted fates, demonstrating how classical grafting experiments can be revisited to establish high-resolution cell state/fate relationships. Such interdisciplinary approaches will benefit future studies in developmental biology and guide the in vitro production of cells for organ regeneration and repair. [ABSTRACT FROM AUTHOR]
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- 2024
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8. Interplay of Zeb2a, Id2a and Batf3 regulates microglia and dendritic cell development in the zebrafish brain.
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Linh Thi My Nguyen, Hassan, Shaoli, Hongru Pan, Shuting Wu, and Zilong Wen
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DENDRITIC cells , *NEURAL development , *MICROGLIA , *MYELOID cells , *HOMEOSTASIS , *LEUCINE zippers - Abstract
In vertebrates, the central nervous system (CNS) harbours various immune cells, including parenchymal microglia, perivascular macrophages and dendritic cells, which act in coordination to establish an immune network to regulate neurogenesis and neural function, and to maintain the homeostasis of the CNS. Recent single cell transcriptomic profiling has revealed that the adult zebrafish CNS contains microglia, plasmacytoid dendritic cells (pDCs) and two conventional dendritic cells (cDCs), ccl35+ cDCs and cnn3a+cDCs. However, how these distinct myeloid cells are established in the adult zebrafish CNS remains incompletely defined. Here, we show that the Inhibitor of DNA binding 2a (Id2a) is essential for the development of pDCs and cDCs but is dispensable for the formation of microglia, whereas the Basic leucine zipper transcription factor ATF-like 3 (Batf3) acts downstream of id2a and is required exclusively for the formation of the cnn3a+ cDC subset. In contrast, the Zinc finger E-box-binding homeobox 2a (Zeb2a) promotes the expansion of microglia and inhibits the DC specification, possibly through repressing id2a expression. Our study unravels the genetic networks that govern the development of microglia and brainassociated DCs in the zebrafish CNS. [ABSTRACT FROM AUTHOR]
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- 2024
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9. Micro‐environment alterations through time leading to myeloid malignancies.
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Nyamondo, Kudzai and Wheadon, Helen
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HOMEOSTASIS , *HEMATOPOIETIC system , *HEMATOPOIETIC stem cells , *LEAD time (Supply chain management) , *BONE marrow , *HEMATOPOIESIS - Abstract
The micro‐environment plays a critical role in haematopoietic stem cell (HSC) development, self‐renewal, differentiation and maintenance by providing a supportive cellular framework and essential molecular cues to sustain homeostasis. In ageing and development of age‐related clonal haematopoiesis, the combined contribution of intrinsic alterations in haematopoietic stem cells and their surrounding micro‐environment can promote myeloid skewing and release of pro‐inflammatory cytokines. A pro‐inflammatory micro‐environment is a common feature in the initiation and sustenance of several myeloid malignancies. Furthermore, remodelling of the micro‐environment is recognized to potentiate the survival of malignant over normal cells. This review explores micro‐environmental interactions in the haematopoietic system of adults, especially how the bone marrow micro‐environment is impacted by ageing, the onset of age‐related clonal haematopoiesis and the development of myeloid malignancies. In addition, we also discuss the possible role age‐related clonal haematopoiesis and chronic inflammatory conditions play in altering the bone marrow micro‐environment dynamics. Finally, we explore the importance of in vitro models that accurately mimic different aspects of the bone marrow micro‐environment in order to study normal and malignant haematopoiesis. LINKED ARTICLES: This article is part of a themed issue on Cancer Microenvironment and Pharmacological Interventions. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v181.2/issuetoc [ABSTRACT FROM AUTHOR]
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- 2024
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10. Mechanisms of disease transformation in myeloproliferative neoplasms
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O'Sullivan, Jennifer, Mead, Adam, Harrison, Claire, and Psaila, Bethan
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Haematopoiesis ,Haematology - Abstract
Myeloproliferative neoplasms are heterogeneous clonal haematological malignancies where disease initiation occurs by acquisition of a somatic mutation in a haematopoietic stem cell. This mutation most often occurs in a janus kinase-signal transducer and activator of transcription signalling gene which drives constitutive janus kinase-signal transducer and activator of transcription signalling, with ensuing clonal expansion of downstream progenitor cells. Importantly, intra-tumoural cellular and molecular heterogeneity underscores the phenotypic heterogeneity of myeloproliferative neoplasms. Various factors drive disease progression but additional somatic mutations contribute significantly. Current myeloproliferative neoplasm therapies show limited effects on modifying disease biology and treatment resistance is common, associated with disease progression. Understanding whether distinct mutational profiles are associated with treatment resistance and examining the molecular signatures of mutant disease- driving haematopoietic stem and progenitor cells may reveal novel therapeutic targets and most importantly, lead to development of new treatments for these patients. Single-cell genomics approaches are ideally placed to achieve this through multi-omic technologies that can isolate mutant and non-mutant disease-driving stem and progenitor cells. My overarching aims were to firstly to understand whether distinct mutational profiles were associated with treatment-resistant/intolerant myeloproliferative neoplasms and increased risk of disease progression and secondly to gain insights into the mechanisms driving transformation within a molecularly-defined myeloproliferative neoplasm subgroup through studying the disease- driving haematopoietic stem and progenitor cells. Study of two treatment-intolerant/resistant myeloproliferative neoplasm cohorts uncovered distinct molecular profiles. In hydroxycarbamide- resistant/intolerant essential thrombocythaemia, I observed increased TP53 and SF3B1 mutations in patients with myelofibrotic progression which importantly was not alleviated with ruxolitinib treatment. Analysis of a second, more advanced myeloproliferative neoplasm cohort of ruxolitinib-resistant/intolerant myelofibrosis patients showed a novel finding of enhanced RAS- pathway mutations. To understand how SF3B1 mutations collaborated with JAK2V617F mutations to accelerate myelofibrotic progression, I applied two single-cell multi-omic approaches. The first, 10X genomics, characterised the haematopoietic cellular landscape in JAK2V617F-SF3B1-mutated myeloproliferative neoplasms and the second, TARGET-seq, paired mutation and gene expression information in the same cell to enable gene and splicing signature analysis of the mutated disease-driving and also non-mutant haematopoietic stem and progenitor cells. Through 10X genomics analysis, I identified an abnormal expansion in earlier erythroid, megakaryocyte and most prominently eosinophil-basophil-mast cell progenitors in JAK2V617F- SF3B1-mutated haematopoietic stem and progenitor cells. I resolved the clonal architecture of JAK2V617F-SF3B1-mutated myeloproliferative neoplasms, observing that in the majority of cases, double mutant cells were present and that SF3B1 was the founding event. Uniquely, full-length transcriptome TARGET-seq made analysis of SF3B1-mutated aberrant splicing events possible. This uncovered novel biologically relevant aberrant splicing events in the STAT1 gene. These events were a reduction in intron retention which would have an expected consequence of increased STAT1 activation. This analysis couples abnormal splicing with enhanced janus kinase-signal transducer and activator of transcription signalling to support a mechanism for an accelerated myeloproliferative neoplasm phenotype in JAK2V617F-SF3B1- mutated myeloproliferative neoplasms. In conclusion, this analysis established SF3B1 mutations in myeloproliferative neoplasms promote myelofibrotic disease progression and resolved the clonal architecture of JAK2V617F- SF3B1-mutated myeloproliferative neoplasms identifying abnormally expanded haematopoietic stem and progenitor cells populations. SF3B1-mutant specific splicing signatures were discovered that would be expected to augment janus kinase-signal transducer and activator of transcription signalling supporting mechanism by which SF3B1 cooperates with JAK2V617F to promote an accelerated myeloproliferative neoplasm phenotype. The overarching aim is translating this new knowledge into patient benefit. Incorporation of spliceosome mutation information into clinical tools may improve risk stratification and specifically for JAK2V617F- SF3B1-mutated myeloproliferative neoplasms, a move towards precision medicine may be achievable through development of therapies targeting STAT1.
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- 2022
11. Clonal dynamics of haematopoiesis across the human lifespan
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Mitchell, Emily, Laurenti, Elisa, and Campbell, Peter
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haematopoiesis ,ageing ,clonal dynamics ,haematopoietic stem cells ,chemotherapy - Abstract
The haematopoietic system manifests several age-associated phenotypes including anaemia; loss of regenerative capacity, especially in the face of insults such as infection, chemotherapy or blood loss; and increased risk of clonal haematopoiesis and blood cancers. The cellular alterations that underpin these age-related phenotypes, which typically manifest in individuals aged over 70, remain elusive. In my thesis I have aimed to investigate whether changes in HSC population structure with age might underlie any aspects of haematopoietic system ageing. In addition, I have investigated the impact of chemotherapeutic perturbations on haematopoietic stem cell mutation burden and clonal dynamics. To answer the ageing question, I have sequenced 3579 genomes from single-cell-derived colonies of haematopoietic stem cell/multipotent progenitors (HSC/MPPs) from 10 haematologically normal subjects aged 0-81 years. HSC/MPPs accumulated 17 somatic mutations/year after birth with no increased rate of mutation accumulation in the elderly. HSC/MPP telomere length declined by 30 bp/yr. To interrogate changes in HSC population structure with age, I used the pattern of unique and shared mutations between the sampled cells from each individual to reconstruct their phylogenetic relationships. I found that haematopoiesis in adults aged < 65 was polyclonal, with high indices of clonal diversity. In contrast, haematopoiesis in individuals aged >75 showed profoundly decreased clonal diversity. In each elderly subject, 30-60% of haematopoiesis was accounted for by 12-18 independent clones, each contributing 1-34% of blood production. Most clones had begun their expansion before age 40, but only 22% had known driver mutations. I used the ratio of non-synonymous to synonymous mutations (dN/dS) to identify any excess of non-synonymous (driver) mutations in the dataset. This genome-wide selection analysis estimated that the set of 300 - 400 HSC/MPPs sampled from each adult individual harboured around 100 driver mutations, over 10-fold higher than the number of known drivers we could identify. Novel drivers affected a wider pool of genes than identified in blood cancers. Simulations from a simple model of haematopoiesis, with constant HSC population size and constant acquisition of driver mutations conferring moderate fitness benefits, entirely explained the abrupt change in clonal structure observed over the age of 70. By old age the majority of HSCs harbour at least one driver mutation. Our data supports the view that dramatically decreased clonal diversity is a universal feature of haematopoiesis in elderly humans, underpinned by pervasive positive selection acting on many more genes than currently known. Finally, I also sequenced haematopoietic progenitor cells from individuals exposed to a wide range of chemotherapeutic agents. I was able to identify an increased mutation burden associated with a number of chemotherapeutic agents, including platinum and alkylating agents, some of which conferred thousands of excess mutations. There was a wide variation in mutation burden conferred from agents within the same class, meaning that there are potential patient benefits from switching drugs in commonly used regimens. I show that chemotherapy given in childhood can profoundly impact clonal dynamics in later life.
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- 2022
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12. Single cell analysis provides insight into haematopoietic differentiation of human embryonic stem cells
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Nnadi, Nneka Concilia, Medvinsky, Alexander, and Kaji, Keisuke
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hESC ,haematopoiesis ,scRNA-seq ,mitochondria activity - Abstract
One of the challenges in regenerative medicine remains generating functional haematopoietic stem cells (HSCs) of clinical quantity. Utilizing data from single cell RNA sequencing (scRNA-seq) of human embryonic stem cells (hESC) derived cells, I explored the differences that exist between in vitro and in vivo haematopoiesis, with the aim that understanding these differences could help improve future chances of generating HSCs in vitro. In the first part of this project, functional analysis into in vitro differentiation using an established haematopoietic differentiation protocol, confirmed that the protocol is myeloid and NK lineage biased compared to umbilical cord blood, with the population lineage dynamics changing over time. Using scRNA-seq, I investigated dynamic gene expression of cell populations emerging during hESC differentiation. I show that the haematogenic endothelium capable of generating the haematopoietic progenitors emerges as early as day 6 of differentiation. I also show that priming of the arterial endothelial cells to the haematogenic endothelium, and subsequent emergence of haematopoietic progenitors is associated with an increase in ribosomal and mitochondrial activity. Finally, a comparative analysis of the hESCs generated dataset with publicly available dataset of embryonic haematopoietic tissues revealed that hESC derived haematopoiesis, associated with increased mitochondrial gene activity, is likely mimicking events of the yolk sac haematopoiesis, rather than the haematopoiesis occurring in the AGM region. Based on the findings presented here, I hypothesize that increased mitochondrial activity, likely due to the normoxic culture conditions, may be contributing to the challenge in generating HSCs from hESCs in the dish.
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- 2022
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13. The impact of clinically relevant culture on human haematopoietic stem cells : a kinetic analysis at single cell resolution
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Johnson, Carys and Laurenti, Elisa
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haematopoietic stem cell ,gene therapy ,haematopoiesis ,HSC ,cell cycle - Abstract
Haematopoietic stem cell (HSC) ex vivo gene therapy is now successfully used to treat an in-creasing number of monogenic disorders affecting the blood system. The ultimate efficacy of this therapy depends upon successful targeting of long-term haematopoietic stem cells (LT-HSCs), which are characterised by a predominantly quiescent status and sustained self-renewal capacity. Clinical ex vivo gene therapy protocols target the heterogenous mix of stem and pro-genitor cells encompassed in the CD34+ fraction with a limited understanding of how ex vivo manipulation impacts a purified LT-HSC subset. Importantly, long-term repopulation capacity is lost over culture, although the kinetics and molecular drivers of this process remain unclear. To address these questions, I perform single cell RNA-Seq, in vitro functional assays and in vivo transplantation in a time resolved manner following cord blood (CB) culture in differentiation facilitating conditions and mobilized peripheral blood (mPB) culture during a lentiviral ex vivo gene therapy protocol. First, I characterise the molecular impact of a 62 hr lentiviral ex vivo gene therapy protocol on mPB LT-HSC, short-term HSC (ST-HSC) and CD34+ cells. I reveal that the ex vivo protocol dramatically rewires the quiescent LT-HSC transcriptome and demonstrate that the majority of transcriptional changes are attributed to the culture conditions rather than lentiviral transduction. Secondly, I refine the kinetics associated with HSC functional attrition over the first complete cell cycle ex vivo. Long-term repopulation capacity is maintained for the first 6 hr irrespective of HSC source or tested culture conditions. I identify the 6 hr time-point as encompassing an adaptation period where LT-HSCs are rapidly responding to the instructive signals of culture and is molecularly underpinned by transient upregulation of cell stress response signalling. Follow-ing the 6 hr time-point, long-term repopulation capacity drops dramatically by 24 hr in CB culture and 62 hr in mPB culture. Loss of HSC function is correlated with reduced survival, cell cycle progression (late G1-M), sharp upregulation of MYC and a reduced ability to resolve proteostatic stress. Taken together, my results demonstrate that the 6 to 24 hr transition point is instrumental for the determination of LT-HSC cell fate ex vivo. Finally, using an ex vivo culture system of reversible early G1 arrest, I formally test whether cell cycle progression drives loss of self-renewal capacity in culture. Long-term in vivo transplantation approaches conclusively establish that cell cycle progression is not responsible for the loss of long-term repopulation capacity associated with clinically relevant HSC culture.
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- 2022
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14. Capturing the first haematopoietic stem cell : the needle in the haystack
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Vink, Chris, Dzierzak, Elaine, and Ottersbach, Katrin
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haematopoietic stem cell ,HSC ,AGM ,single cell ,Transcriptome ,mouse ,embryo ,developmental haematopoiesis ,Haematopoiesis ,haematopoietic regeneration - Abstract
The most powerful cell in the blood differentiation hierarchy is the haematopoietic stem cell (HSC). It is the only cell capable of building an entire haematopoietic system from scratch, i.e. long-term (LT) repopulating a multilineage blood system within a lethally irradiated recipient. Though primitive blood is generated at early embryonic stages, it is only from embryonic day (E)10.5 of mouse development (4-5 weeks in human gestation) onwards that the definitive adult haematopoietic system is established with the formation of LT-HSCs. These first HSCs emerge in small ventral intra-aortic haematopoietic clusters (IAHCs) in the aorta-gonad-mesonephros (AGM) region. Like with many systems, a tight regulation of gene expression by master transcription factors (TF) is what ultimately drives cell fate change. Gata2 is one such TF known to play a crucial role in mouse definitive haematopoiesis. Through the work of de Pater et al. (2013) (Chapter 1) it became clear that Gata2 is both required for the generation of the very first HSCs and also, unlike other key TFs like Runx1, the survival of HSCs. The earliest HSCs are generated through an endothelial-to-haematopoietic transition (EHT), a process where flat arterial haemogenic endothelial cells (HECs) round up into IAHCs, containing HSCs. Solaimani Kartalaei et al. (2015) (Chapter 4) discovered that Gpr56 is one of the most highly upregulated genes during EHT (in mouse) and that it is essential for HSC generation (in zebrafish). Gpr56 is also a target of the key haematopoietic 'heptad' TFs in both mouse and human blood progenitors. To examine another signalling pathway required in the embryo for HSC generation, we used a BMP responsive element (BRE)-GFP transgenic mouse to show that all AGM HSCs are BMP-activated (Crisan et al., 2015) (Chapter 6). At slightly later stages, in the foetal liver and bone marrow, HSC heterogeneity starts to appear with the presence of genetically distinct BMP- and non-BMP activated HSCs. Given the importance of the 'heptad' TFs in establishing HSC identity, we next developed a novel Gata2-Venus (G2V) reporter mouse to isolate and examine the dynamics and function of live Gata2-expressing and non-expressing cells (Kaimakis et al., 2016) (Chapter 2). Gata2 is expressed in all HSCs, however haematopoietic progenitors can be generated either Gata2-dependently or -independently, the latter being less potent and genetically distinct from the first. With Eich et al. (2018) (Chapter 3) we went further and deciphered the role of Gata2 in haematopoietic fate establishment. By using time-lapse imaging of E10.5 live aortic sections of G2V embryos, we discovered rapid pulsatile level changes in Gata2 expression, specifically in those single cells undergoing EHT. This finding indicated the highly unstable genetic state of individual cells undergoing fate change. Furthermore, aortic cells haploinsufficient for Gata2 show many fewer pulsatile and EHT events, emphasizing the importance of Gata2 levels in this process. Having defined the specific (medium) levels of Gata2(Venus) protein in the population containing the first HSCs, we used our G2V model to isolate a pure population of HSCs as they are generated for the first time in development (Vink et al., 2020) (Chapter 5). Through iterations of index-sorting, single-cell transcriptomics and functional analyses we were able to greatly enrich for HSCs (~70x compared to Eich et al. (2018)). Based on refined CD31, cKit and CD27 expression and specific physical parameters we isolated the first cells with an HSC identity and identified their precise gene expression profile. Immunohistochemistry localized these HSCs to only the smallest IAHCs. The combined effort of my research and novel tools generated to facilitate the creation of this body of work/portfolio have now led us for the first time to study the one or two cells per embryo that harbour HSC identity at the developmental time when they are beginning to be made. Now that we have cracked the genetic code of the true HSC, the field is one step closer to translating these findings and applying them to producing human clinically relevant HSCs, which will ultimately improve transplantation therapies and benefit the fight against leukaemia.
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- 2022
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15. An interactive resource of molecular signalling in the developing human haematopoietic stem cell niche.
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Crosse, Edie I., Binagui-Casas, Anahi, Gordon-Keylock, Sabrina, Rybtsov, Stanislav, Tamagno, Sara, Olofsson, Didrik, Anderson, Richard A., and Medvinsky, Alexander
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STEM cell niches , *HUMAN stem cells , *PLURIPOTENT stem cells , *MOLECULAR interactions , *HEMATOPOIETIC stem cells , *RESEARCH personnel - Abstract
The emergence of definitive human haematopoietic stem cells (HSCs) from Carnegie Stage (CS) 14 to CS17 in the aorta-gonad-mesonephros (AGM) region is a tightly regulated process. Previously, we conducted spatial transcriptomic analysis of the human AGM region at the end of this period (CS16/CS17) and identified secreted factors involved in HSC development. Here, we extend ouranalysis to investigate the progression of dorso-ventral polarised signalling around the dorsal aorta over the entire period of HSC emergence. Our results reveal a dramatic increase in ventral signalling complexity from the CS13-CS14 transition, coinciding with the first appearance of definitive HSCs. We further observe stage-specific changes in signalling up to CS17, which may underpin the step-wise maturation of HSCs described in the mouse model. The data-rich resource is also presented in an online interface enabling in silico analysis of molecular interactions between spatially defined domains of the AGM region. This resource will be of particular interest for researchers studying mechanisms underlying human HSC development as well as those developing in vitro methods for the generation of clinically relevant HSCs from pluripotent stem cells. [ABSTRACT FROM AUTHOR]
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- 2023
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16. Modulation of haematopoiesis by protozoal and helminth parasites.
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Cunningham, Kyle T. and Mills, Kingston H. G.
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HEMATOPOIESIS , *PARASITES , *HEMATOPOIETIC stem cells , *PROTOZOAN diseases , *MYELOID cells , *BONE marrow - Abstract
During inflammation, haematopoietic stem cells (HSCs) in the bone marrow (BM) and periphery rapidly expand and preferentially differentiate into myeloid cells that mediate innate immune responses. HSCs can be directed into quiescence or differentiation by sensing alterations to the haematopoietic niche, including cytokines, chemokines, and pathogen‐derived products. Most studies attempting to identify the mechanisms of haematopoiesis have focused on bacterial and viral infections. From intracellular protozoan infections to large multicellular worms, parasites are a global health burden and represent major immunological challenges that remain poorly defined in the context of haematopoiesis. Immune responses to parasites vary drastically, and parasites have developed sophisticated immunomodulatory mechanisms that allow development of chronic infections. Recent advances in imaging, genomic sequencing, and mouse models have shed new light on how parasites induce unique forms of emergency haematopoiesis. In addition, parasites can modify the haematopoiesis in the BM and periphery to improve their survival in the host. Parasites can also induce long‐lasting modifications to HSCs, altering future immune responses to infection, inflammation or transplantation, a term sometimes referred to as central trained immunity. In this review, we highlight the current understanding of parasite‐induced haematopoiesis and how parasites target this process to promote chronic infections. [ABSTRACT FROM AUTHOR]
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- 2023
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17. Mini review of metabolism in leukaemia: from complexity to the clinic
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Kevin M. Rattigan
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metabolism ,leukaemia ,haematopoiesis ,immunity ,stem cell (SC) ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
The importance of metabolism to cancer has increasingly been recognised and this is particularly the case for leukaemia. This has opened the possibility of targeting dysregulated metabolism with the aim of increasing the effectiveness of current therapies, some of which are anti-metabolites. One key challenge to be addressed is avoiding negative side effects due to shared metabolic dependencies between leukaemic and normal cells. This Mini Review will discuss how our understanding of wide-ranging effects of metabolism is continuing to evolve thanks to recent discoveries, as well as how metabolism can both directly and indirectly affect leukaemia cell functions. This includes introducing how metabolism is compartmentalised at levels ranging from organelle to whole body as well as how the metabolome can modify other ‘Omes.’ This Mini Review also places a focus on the overlay in metabolic demands of normal haematopoietic and immune cells. Finally, how therapies targeting metabolic processes have already delivered success, as well as the promise of new therapies targeting metabolism that are currently being investigated in clinical trials, will also be discussed.
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- 2024
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18. The parasitic worm product ES-62 protects against collagen-induced arthritis by resetting the gut-bone marrow axis in a microbiome-dependent manner
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Margaret M. Harnett, James Doonan, Anuradha Tarafdar, Miguel A. Pineda, Josephine Duncombe-Moore, Geraldine Buitrago, Piaopiao Pan, Paul A. Hoskisson, Colin Selman, and William Harnett
- Subjects
arthritis ,ES-62 ,gut ,haematopoiesis ,helminth ,inflammation ,Arctic medicine. Tropical medicine ,RC955-962 - Abstract
The parasitic worm-derived immunomodulator, ES-62 rescues defective levels of IL-10-producing regulatory B cells (Bregs) and suppresses chronic Th1/Th17-driven inflammation to protect against joint destruction in the mouse collagen-induced arthritis (CIA) model of rheumatoid arthritis. Such autoimmune arthritis is also associated with dysbiosis of the gut microbiota and disruption of intestinal barrier integrity. We recently further exploited the CIA model to show that ES-62’s prevention of joint destruction is associated with protection of intestinal barrier integrity and normalization of the gut microbiota, thereby suppressing the gut pathology that precedes the onset of autoimmunity and joint damage in CIA-mice. As the status of the gut microbiota impacts on immune responses by influencing haematopoiesis, we have therefore investigated whether ES-62 harnesses the homeostatic mechanisms regulating this gut-bone marrow (BM) axis to resolve the chronic inflammation promoting autoimmunity and joint destruction in CIA. Reflecting this, ES-62 was found to counteract the BM myeloid/lymphoid bias typically associated with chronic inflammation and infection. This was achieved primarily by ES-62 acting to maintain the levels of lymphoid lineages (B220+ and CD3+ cells) observed in naïve, healthy mice but lost from the BM of CIA-mice. Moreover, ES-62’s ability to prevent bone-destroying osteoclastogenesis was found to be associated with its suppression of CIA-induced upregulation of osteoclast progenitors (OCPs) in the BM. Critically, and supporting ES-62’s targeting of the gut-BM axis, this rewiring of inflammatory haematopoiesis was lost in mice with a depleted microbiome. Underlining the importance of ES-62’s actions in restoring steady-state haematopoiesis, the BM levels of B and T lymphoid cells were shown to be inversely correlated, whilst the levels of OCPs positively correlated, with the severity of joint damage in CIA-mice.
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- 2024
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19. Recent Developments in the Role of Protein Tyrosine Phosphatase 1B (PTP1B) as a Regulator of Immune Cell Signalling in Health and Disease
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Neve E. Read and Heather M. Wilson
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protein tyrosine phosphatase 1B (PTP1B) ,signalling ,immune cells ,inflammation ,haematopoiesis ,disease ,Biology (General) ,QH301-705.5 ,Chemistry ,QD1-999 - Abstract
Protein tyrosine phosphatase 1B (PTP1B) is a non-receptor tyrosine phosphatase best known for its role in regulating insulin and leptin signalling. Recently, knowledge on the role of PTP1B as a major regulator of multiple signalling pathways involved in cell growth, proliferation, viability and metabolism has expanded, and PTP1B is recognised as a therapeutic target in several human disorders, including diabetes, obesity, cardiovascular diseases and hematopoietic malignancies. The function of PTP1B in the immune system was largely overlooked until it was discovered that PTP1B negatively regulates the Janus kinase—a signal transducer and activator of the transcription (JAK/STAT) signalling pathway, which plays a significant role in modulating immune responses. PTP1B is now known to determine the magnitude of many signalling pathways that drive immune cell activation and function. As such, PTP1B inhibitors are being developed and tested in the context of inflammation and autoimmune diseases. Here, we provide an up-to-date summary of the molecular role of PTP1B in regulating immune cell function and how targeting its expression and/or activity has the potential to change the outcomes of immune-mediated and inflammatory disorders.
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- 2024
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20. Identification of novel drivers of haematopoietic stem cell fate using low cell number proteomics and single cell profiling
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Bode, Daniel, Gottgens, Berthold, and Kent, David
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Proteomics ,Stem cells ,haematopoiesis ,Multiomics ,Self-renewal ,Molecular profiling - Abstract
The abrogation and de-regulation of cellular decisions in adult haematopoietic stem cells (HSCs) have been widely recognised as key contributing factors in ageing and disease. In particular, acquired mutations altering HSC self-renewal contribute to the formation of pre-leukaemic disorders, such as myeloproliferative neoplasms (MPNs), and ultimately to their transformation to acute myeloid leukaemia. Therefore, we urgently require a complete characterisation of the underlying molecular pathways of HSC self-renewal in order to provide crucial insights into disease progression and to help inform novel strategies for ex vivo expansion for gene therapy applications. To date, advances in functional and molecular single cell technologies have provided unprecedented resolution of heterogeneous HSC populations and their transcriptional landscapes. In contrast, the scarcity of functional HSCs and technical limitations of unbiased proteomic screening technology have prevented comprehensive characterisation of protein networks governing HSC fate. To overcome these technical limitations, we developed an optimised mass spectrometry workflow to interrogate as few as 10,000 HSCs and multiplex up to 16 cell fractions. Using this approach, we were able to quantify in excess of 4,000 proteins, while reducing the required cell input 30-fold. To identify key molecular drivers of in vivo HSC self-renewal, we probed HSC populations with increasing self-renewal potency, including TET2-deficient HSCs exhibiting a self-renewal advantage in MPN mouse models. Here, we observed reshaping of extracellular matrix protein networks, indicating a potential physical role of the neighbouring bone marrow niche cells for regulating HSC fate. Next, we integrated proteomic and transcriptomic to characterise the molecular pathways underlying HSC self-renewal across numerous -omics technologies. Here, we identified a wide range of intrinsic regulatory pathways and described molecular mechanisms regulating intracellular calcium levels in HSCs. In the final results chapter, we explored the ex vivo expansion of HSCs, since this is of paramount importance for the delivery of gene and cellular therapies against a plethora of monogenic haematological diseases. Recently pioneered HSC expansion protocols greatly enhanced the yield of phenotypic HSCs, but such cultures exhibit significant clone-to-clone variability in long-term self-renewal potency and differentiation. By linking the transplantation outcomes with transcriptional profiles of individual single cell-derived clones, we derived a novel gene signature for ex vivo expanded HSCs with long-term self-renewal potency and characterised key molecular pathways governing HSC fate throughout expansion. Furthermore, we identified a reporter strategy for prospectively isolating expanded HSCs. Together, these findings provided an insight into the molecular machinery underlying HSC self-renewal within the native bone marrow niche and during ex vivo expansion. Comprehensive multi-omic profiling also revealed the intricate relationship of gene expression profiles with the proteomic phenotype within the HSC compartment. Finally, we propose an optimised workflow for performing comprehensive proteomics on any rare cell populations which will be of use to researchers investigating a wide-range of cellular biology questions.
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- 2021
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21. Novel roles of KAT2A chromatin complexes ATAC and SAGA in normal and malignant haematopoiesis
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De Jesus Arede, Liliana and Pina, Cristina
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KAT2A ,ATAC complex ,SAGA complex ,epigenetics ,haematopoiesis ,acute myeloid leukaemia - Abstract
Haematopoiesis is a dynamic process by which the full array of blood cell types originates from multipotent haematopoietic stem cells (HSCs). The blood system has long been an attractive model to explore how cell fate decisions are conducted at the molecular level, to generate the vast diversity of blood cell types. Blood cell fate choice is for the most part regulated by transcription factors and epigenetic modifiers. The enzymatic activities of epigenetic regulators are of particular importance in malignant haematopoiesis such as leukaemia, given their reversible nature and potential for therapeutic targeting. Epigenetic histone modifiers are often found within large multi-subunit complexes, whereby their catalytic activity is exercised. However, very little is known about how epigenetic enzymes take advantage of their participating chromatin complexes in order to accomplish their functions. In the blood system, no studies have formally examined how different epigenetic complexes with the same enzymatic component coordinate cell fate choices. Here, I focus on KAT2A, a lysine acetyltransferase responsible for Histone 3 Lysine 9 acetylation (H3K9ac), and a vulnerability in Acute Myeloid Leukaemia (AML), as well as its 2 containing complexes: Ada-Two-A-Containing (ATAC) and Spt-Ada-Gcn5-Acetyltransferase (SAGA). I combine cell functional and molecular assays of human cord blood (CB) haematopoietic cells and AML cells to dissect KAT2A roles depending on its participation in ATAC or SAGA complexes. Firstly, I demonstrate that KAT2A regulates CB erythroid progenitor specification and survival. I uncover unique contributions of the ATAC complex to erythroid lineage specification, whereas SAGA acts late in differentiation. This suggests that KAT2A plays stage-specific roles, which are unique to the complexes it integrates. While KAT2A regulates specification and survival of erythroid progenitors via ATAC through control of biosynthetic activity, it fine-tunes progression of erythroid differentiation through participation in SAGA. Secondly, I explored the roles of ATAC and SAGA in leukaemic haematopoiesis. I found that ATAC regulates proliferation through control of biosynthetic activity. Instead, SAGA participates in maintenance of the characteristic block in AML cell differentiation, compatible with a generic control of cell identity through preservation of cell-type specific transcriptional programmes. My data is consistent with a model in which the ATAC complex has pervasive roles in maintenance of self-renewing cells, while SAGA acts to stabilise cell-type specific programmes, preserving cell identity. Understanding ATAC and SAGA unique chromatin regulatory mechanisms has important implications for the tailored design of new drugs for clinical application.
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- 2021
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22. Clinical uses of recombinant haematopoietic growth factors in paediatrics.
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Mullen, Christopher Gerard and Halsey, Christina
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CHRONIC kidney failure ,GRANULOCYTE-colony stimulating factor ,HEMATOPOIETIC growth factors ,PEDIATRICS ,ERYTHROPOIETIN - Abstract
The formation of blood cells, haematopoiesis, is regulated by a family of extracellular glycosylated proteins called haematopoietic growth factors. Over the past four decades their identification, purification and cloning has led to the development of recombinant haematopoietic growth factors for medicinal use. These growth factors play a valuable role in treatment of a variety of childhood conditions, ranging from anaemia of chronic kidney disease through to rare congenital bone marrow failure syndromes. Erythropoietin and granulocyte-colony stimulating factor are the two recombinant haematopoietic growth factors in most widespread use in paediatrics and paediatricians should be aware of their indications and their side effects when managing patients. This review articles gives an overview of the major recombinant haematopoietic growth factors used in children, their indications, and their toxicities. [ABSTRACT FROM AUTHOR]
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- 2023
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23. Clonal haematopoiesis of indeterminate potential in patients with venous thromboembolism.
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Guillotin, Florence, Mercier, Éric, Fortier, Mathieu, Bouvier, Sylvie, Jacquet, Quentin, Dallo, Marine, Chéa, Mathias, Bourguignon, Chloé, Cochery-Nouvellon, Éva, Perez-Martin, Antonia, and Gris, Jean-Christophe
- Abstract
Over the last decade, the concept of Clonal haematopoiesis of undetermined potential (CHIP) has emerged. Low frequency somatic mutations in hematopoietic cells can occur with age and might allow formation of clones in individuals with no characterized haematological pathology. These CHIP mutations are associated with an increased risk of cancer or atherothrombosis, and their prevalence are more and more studied in pathologies with an inflammatory component. In our study, we analysed, by next generation sequencing, the prevalence of CHIP mutation in 94 patients with deep venous thrombosis (DVT), distinguishing two clinical phenotypes: provoked distal and non-provoked proximal DVTs. We show that there is no difference in CHIP prevalence between these two groups, nor with a matched-aged control group. The number of mutation per patients and the affected genes remain also the same between the three groups. Consequently and despite the relative small number of patients in each cohort, it seems that CHIP is not a strong concern in venous thromboembolism. [ABSTRACT FROM AUTHOR]
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- 2023
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24. Consequences of HIV infection in the bone marrow niche.
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Herd, Candice Lee, Mellet, Juanita, Mashingaidze, Tsungai, Durandt, Chrisna, and Pepper, Michael Sean
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HIV infections ,BONE marrow ,BONE marrow cells ,BLOOD cells ,CELL communication - Abstract
Dysregulation of the bone marrow niche resulting from the direct and indirect effects of HIV infection contributes to haematological abnormalities observed in HIV patients. The bone marrow niche is a complex, multicellular environment which functions primarily in the maintenance of haematopoietic stem/progenitor cells (HSPCs). These adult stem cells are responsible for replacing blood and immune cells over the course of a lifetime. Cells of the bone marrow niche support HSPCs and help to orchestrate the quiescence, self-renewal and differentiation of HSPCs through chemical and molecular signals and cell-cell interactions. This narrative review discusses the HIV-associated dysregulation of the bone marrow niche, as well as the susceptibility of HSPCs to infection by HIV. [ABSTRACT FROM AUTHOR]
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- 2023
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25. Optimal experimental design for mathematical models of haematopoiesis.
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Lomeli, Luis Martinez, Iniguez, Abdon, Tata, Prasanthi, Jena, Nilamani, Liu, Zhong-Ying, Van Etten, Richard, Lander, Arthur D, Shahbaba, Babak, Lowengrub, John S, and Minin, Vladimir N
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Animals ,Bayes Theorem ,Cell Division ,Hematopoiesis ,Models ,Biological ,Research Design ,Bayesian analysis ,differential equations ,feedback and feedforward regulation ,haematopoiesis ,stem cells ,1.1 Normal biological development and functioning ,Generic health relevance ,stat.ME ,q-bio.QM ,stat.AP ,General Science & Technology - Abstract
The haematopoietic system has a highly regulated and complex structure in which cells are organized to successfully create and maintain new blood cells. It is known that feedback regulation is crucial to tightly control this system, but the specific mechanisms by which control is exerted are not completely understood. In this work, we aim to uncover the underlying mechanisms in haematopoiesis by conducting perturbation experiments, where animal subjects are exposed to an external agent in order to observe the system response and evolution. We have developed a novel Bayesian hierarchical framework for optimal design of perturbation experiments and proper analysis of the data collected. We use a deterministic model that accounts for feedback and feedforward regulation on cell division rates and self-renewal probabilities. A significant obstacle is that the experimental data are not longitudinal, rather each data point corresponds to a different animal. We overcome this difficulty by modelling the unobserved cellular levels as latent variables. We then use principles of Bayesian experimental design to optimally distribute time points at which the haematopoietic cells are quantified. We evaluate our approach using synthetic and real experimental data and show that an optimal design can lead to better estimates of model parameters.
- Published
- 2021
26. Irradiation Haematopoiesis Recovery Orchestrated by IL-12/IL-12Rβ1/TYK2/STAT3-Initiated Osteogenic Differentiation of Mouse Bone Marrow-Derived Mesenchymal Stem Cells
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Li, Fengjie, Zhang, Rong, Hu, Changpeng, Ran, Qian, Xiang, Yang, Xiang, Lixin, Chen, Li, Yang, Yang, Li, Shengwen Calvin, Zhang, Gang, and Li, Zhongjun
- Subjects
Medical Biotechnology ,Biomedical and Clinical Sciences ,Regenerative Medicine ,Transplantation ,Stem Cell Research ,Stem Cell Research - Nonembryonic - Human ,Stem Cell Research - Nonembryonic - Non-Human ,irradiation ,haematopoiesis ,recovery ,osteogenesis ,IL-12 ,Biological sciences ,Biomedical and clinical sciences - Abstract
PurposeRepairing the irradiation-induced osteogenic differentiation injury of bone marrow mesenchymal stem cells (BM-MSCs) is beneficial to recovering haematopoiesis injury in radiotherapy; however, its mechanism is elusive. Our study aimed to help meet the needs of understanding the effects of radiotherapy on BM-MSC osteogenic potential.Methods and materialsBalb/c mice and the BM-MSCs were used to evaluate the irradiation-induced osteogenic differentiation injury in vivo. The cellular and molecular characterization were applied to determine the mechanism for recovery of irradiation-derived haematopoiesis injuries.ResultsWe report a functional role of IL-12 in acute irradiation hematopoietic injury recovery and intend to dissect the possible mechanisms through BM-MSC, other than the direct effect of IL-12 on hematopoietic stem and progenitor cells (HSPCs). Specifically, we show that early use of IL-12 enhanced the osteogenic differentiation of BM-MSCs through IL-12Rβ1/TYK2/STAT3 signaling; furthermore, IL-12 induced osteogenesis facilitated bone formation and irradiation hematopoiesis recovery when transplanted BM-MSCs in the femur of Balb/c mice. For the mechanism of action, we found that IL-12 receptor beta 1 (IL-12Rβ1) expression of irradiated BM-MSCs was upregulated rapidly, coincidentally consistent with early use of IL-12 induced osteogenic differentiation enhancement. IL-12Rβ1 and tyrosine kinase 2 gene (Tyk2) silencing experiments and phosphotyrosine of signal transducer and activator of transcription 3 (p-STAT3) suppression experiments indicated the IL-12Rβ1/TYK2/STAT3 signaling was essential in IL-12-induced osteogenic differentiation enhancement of BM-MSCs.ConclusionThese findings suggested that IL-12 may exert BM-MSCs-based hematopoietic recovery by repairing osteogenic differentiation abilities damages through IL-12Rβ1/TYK2/STAT3 signaling pathway post-irradiation.
- Published
- 2021
27. Single-cell multi-omics and lineage tracing to dissect cell fate decision-making
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Laleh Haghverdi and Leif S. Ludwig
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cell fate decision ,mathematical and computational models ,multi-omics ,clonal tracking ,haematopoiesis ,embryogenesis ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Summary: The concept of cell fate relates to the future identity of a cell, and its daughters, which is obtained via cell differentiation and division. Understanding, predicting, and manipulating cell fate has been a long-sought goal of developmental and regenerative biology. Recent insights obtained from single-cell genomic and integrative lineage-tracing approaches have further aided to identify molecular features predictive of cell fate. In this perspective, we discuss these approaches with a focus on theoretical concepts and future directions of the field to dissect molecular mechanisms underlying cell fate.
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- 2023
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28. Investigating the role of interferon-γ signalling for malaria dyserythropoiesis
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Nwoke, Eze Chukwunyere, Potocnik, Alexandre, and Rowe, Alex
- Subjects
Dyserythropoiesis ,malaria ,interferon gamma ,haematopoiesis - Abstract
In innate and adaptive immunity, the proinflammatory type 1 cytokine interferon gamma (IFN-γ), is well known for its protective role particularly against intracellular pathogens. However, this type 2 interferon has been implicated in the pathology of several diseases. In malaria, it has been demonstrated that IFN-γ exerts both protective and pathological roles. In humans and in mouse models, the acute infection results in aberrant erythroid differentiation termed dyserythropoiesis which contributes to the development of severe malarial anaemia. The mechanism that drives this process is poorly understood. However, recent data from our lab suggests a role for IFN-γ as the one candidate to mediate the manifestation of early dyserythropoiesis. This study aimed to determine the stages of erythropoiesis in the bone marrow (BM) and spleen that are perturbed by malaria, and investigate if IFN-γ signalling in the haematopoietic compartment alone, is sufficient to promote suppression of erythropoiesis during malaria. To address the first aim, I used three murine models of experimental malaria which differ in virulence, parasite burden, proinflammatory cytokine induction and elicited immune response. In all malaria models, I observed an expansion of the erythroid progenitors in the bone marrow and spleen, nevertheless, this expansion failed to reflect in the number of downstream precursors. Early in infection, there was no change in the absolute number of erythroid precursors in infected mice, in comparison to naive gender and age matched controls, but at peak parasitaemia at the time points sampled, there was a significant contraction in the number of all erythroid precursor stages, from the proerythroblast to the orthochromatic erythroblast. Furthermore, I observed that this aberration of erythropoiesis in the BM and spleen manifests independently of the degree of peripheral parasite burden, suggesting a role for proinflammatory cytokines, in particular, IFN-γ in mediating this process. To further decipher the role of IFN-γ for malaria dyserythropoiesis, I made use of the Vav1::iCre/Ifngr2fl/fl mice, which are deficient in IFN-γ signalling specifically in haematopoietic cells. I observed that the absolute number of BM lineage negative (LIN-) cells, erythroid progenitors and erythroid precursors was significantly higher in Vav1::iCre/Ifngr2fl/fl mice, in comparison to control mice. Interestingly, the absolute number of basophilic and polychromatic erythroblasts in infected Vav1::iCre/Ifngr2fl/fl mice was significantly higher than in naive mice which was not the case for infected control mice. Based on these observations, my results suggest that IFN-γ plays a key role in malaria dyserythropoiesis by inhibiting the expansion and differentiation of erythroid progenitors and precursors, through a direct signalling in haematopoietic cells. In this study, I have demonstrated a novel and unpublished method for the identification and isolation of erythroid progenitor subsets at high purity and showed for the first time in an in vivo setting, that IFN-γ signalling in the haematopoietic compartment alone is crucial for malaria dyserythropoiesis.
- Published
- 2020
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29. Characterisation of human Haematopoietic Stem Cell differentiation and exit from quiescence at single cell resolution
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Belluschi, Serena and Laurenti, Elisa
- Subjects
616.02 ,haematopoiesis ,haematopoietic stem cells ,stem cells ,blood ,single cell ,quiescence - Abstract
Blood formation is coordinated by a set of functionally heterogeneous haematopoietic stem cell (HSC) compartments both in mouse and in human. However, how this diversity is regulated at the cellular and molecular level and when HSC multipotency is lost is still not known, in particular in humans. Quiescence is an important property of HSCs and fine regulation of the balance between quiescence and cell cycle entry is of vital importance for maintaining a healthy HSC pool and avoid haematological malignancies. Very little is known about how molecular networks change during exit from quiescence and no studies have formally examined if cell fate decisions occur during this process or later on during the cell cycle. Here, I combine index sorting, in-vitro single cell functional assays and single cell RNA-sequencing with xenotransplantation assays to profile single human HSC properties in the purest HSC compartment reported to date (CD49+ HSCs) and to understand when the first steps of lineage restriction occur during HSC differentiation. Moreover, I use an in-vitro model system to comprehensively study HSC activation and to investigate whether HSC self-renewal is lost during quiescence exit or during cell cycle progression. First, I unveil an unexpected degree of intrinsic functional and molecular heterogeneity within the human CD49f+ HSC pool. I demonstrate that the first restriction step towards the lymphoid lineage occurs already within the CD49f+ HSC compartment and generates erythroid-deficient myeloid-lymphoid committed cells. Within this compartment, transcriptional programmes and lineage potential progressively change along a gradient of opposing cell surface expression of CLEC9A and CD34. Two functionally distinct populations can be identified and purified. CLEC9Ahi CD34lo cells contain long-term repopulating multipotent HSCs with slow quiescence exit kinetics, whereas CLEC9Alo CD34hi cells are restricted to myelo-lymphoid differentiation and display infrequent but durable repopulation capacity. Second, I demonstrate that a drastic transcriptional remodelling reflective of the fast metabolic activation seen in ex-vivo cultured HSCs occurs during quiescence exit, and independently of cell cycle progression. In-vivo data show that the reduction in repopulation capacity that accompanies HSC culture also occurs independently of cell cycle progression. Recent work highlighted the active role of mitochondria and metabolism in HSC fate decision and self-renewal. My data is consistent with a model in which the metabolic remodelling seen during exit from quiescence represents the first step towards loss of self-renewal and differentiation. This has important implications for improving ex-vivo protocols for HSC culture and HSC transplants.
- Published
- 2020
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30. TLR7 activation at epithelial barriers promotes emergency myelopoiesis and lung antiviral immunity
- Author
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William D Jackson, Chiara Giacomassi, Sophie Ward, Amber Owen, Tiago C Luis, Sarah Spear, Kevin J Woollard, Cecilia Johansson, Jessica Strid, and Marina Botto
- Subjects
monocytes ,TLR ,virus ,skin ,haematopoiesis ,macrophages ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
Monocytes are heterogeneous innate effector leukocytes generated in the bone marrow and released into circulation in a CCR2-dependent manner. During infection or inflammation, myelopoiesis is modulated to rapidly meet the demand for more effector cells. Danger signals from peripheral tissues can influence this process. Herein we demonstrate that repetitive TLR7 stimulation via the epithelial barriers drove a potent emergency bone marrow monocyte response in mice. This process was unique to TLR7 activation and occurred independently of the canonical CCR2 and CX3CR1 axes or prototypical cytokines. The monocytes egressing the bone marrow had an immature Ly6C-high profile and differentiated into vascular Ly6C-low monocytes and tissue macrophages in multiple organs. They displayed a blunted cytokine response to further TLR7 stimulation and reduced lung viral load after RSV and influenza virus infection. These data provide insights into the emergency myelopoiesis likely to occur in response to the encounter of single-stranded RNA viruses at barrier sites.
- Published
- 2023
- Full Text
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31. Consequences of HIV infection in the bone marrow niche
- Author
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Candice Lee Herd, Juanita Mellet, Tsungai Mashingaidze, Chrisna Durandt, and Michael Sean Pepper
- Subjects
bone marrow niche ,HIV ,haematopoiesis ,haematopoietic stem/progenitor cell ,dysregulation ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Dysregulation of the bone marrow niche resulting from the direct and indirect effects of HIV infection contributes to haematological abnormalities observed in HIV patients. The bone marrow niche is a complex, multicellular environment which functions primarily in the maintenance of haematopoietic stem/progenitor cells (HSPCs). These adult stem cells are responsible for replacing blood and immune cells over the course of a lifetime. Cells of the bone marrow niche support HSPCs and help to orchestrate the quiescence, self-renewal and differentiation of HSPCs through chemical and molecular signals and cell-cell interactions. This narrative review discusses the HIV-associated dysregulation of the bone marrow niche, as well as the susceptibility of HSPCs to infection by HIV.
- Published
- 2023
- Full Text
- View/download PDF
32. Individual modelling of haematotoxicity with NARX neural networks: A knowledge transfer approach
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Marie Steinacker, Yuri Kheifetz, and Markus Scholz
- Subjects
Recurrent neural networks ,System identification ,Haematopoiesis ,Precision medicine ,Transfer learning ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
Cytotoxic cancer therapy often results in dose-limiting haematotoxic side effects. Predicting an individual's risk is a major objective in precision medicine of cancer treatment. In this regard, patient heterogeneity presents a significant challenge. In this paper, we explore the use of hypothesis-free machine learning models based on recurrent nonlinear auto-regressive networks with exogenous inputs (NARX) as an approach to achieve this goal. Also, we propose a knowledge transfer approach to ameliorate the issue of sparse individual data, which typically hampers learning of individual networks. We demonstrate the feasibility of our approach based on a virtual patient population generated using a semi-mechanistic model of haematopoiesis and imposing different cytotoxic therapy scenarios on it. Employing different techniques of model optimisation, we derive robust and parsimonious individual networks with good generalisation performances. Moreover, we analyse in detail possible factors influencing the generalisation performance. Results suggest that our transfer learning approach using NARX networks can provide robust predictions of individual patient's response to treatment. As a practical perspective, we apply our approach to individual time series data of two patients with non-Hodgkin's lymphoma.
- Published
- 2023
- Full Text
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33. The Haematopoietically-expressed homeobox transcription factor: roles in development, physiology and disease.
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Jackson, Jacob T., Nutt, Stephen L., and McCormack, Matthew P.
- Subjects
TRANSCRIPTION factors ,HEMATOPOIETIC stem cells ,PHYSIOLOGY ,EMBRYOLOGY ,ISLANDS of Langerhans ,PANCREATIC fistula - Abstract
The Haematopoietically expressed homeobox transcription factor (Hhex) is a transcriptional repressor that is of fundamental importance across species, as evident by its evolutionary conservation spanning fish, amphibians, birds, mice and humans. Indeed, Hhex maintains its vital functions throughout the lifespan of the organism, beginning in the oocyte, through fundamental stages of embryogenesis in the foregut endoderm. The endodermal development driven by Hhex gives rise to endocrine organs such as the pancreas in a process which is likely linked to its role as a risk factor in diabetes and pancreatic disorders. Hhex is also required for the normal development of the bile duct and liver, the latter also importantly being the initial site of haematopoiesis. These haematopoietic origins are governed by Hhex, leading to its crucial later roles in definitive haematopoietic stem cell (HSC) self-renewal, lymphopoiesis and haematological malignancy. Hhex is also necessary for the developing forebrain and thyroid gland, with this reliance on Hhex evident in its role in endocrine disorders later in life including a potential role in Alzheimer's disease. Thus, the roles of Hhex in embryological development throughout evolution appear to be linked to its later roles in a variety of disease processes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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34. Post-injury Bone Marrow Failure
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Briggs, Gabrielle D., Coccolini, Federico, Series Editor, Coimbra, Raul, Series Editor, Kirkpatrick, Andrew W., Series Editor, Di Saverio, Salomone, Series Editor, Ansaloni, Luca, Editorial Board Member, Balogh, Zsolt, Editorial Board Member, Biffl, Walt, Editorial Board Member, Catena, Fausto, Editorial Board Member, Davis, Kimberly, Editorial Board Member, Ferrada, Paula, Editorial Board Member, Fraga, Gustavo, Editorial Board Member, Ivatury, Rao, Editorial Board Member, Kluger, Yoram, Editorial Board Member, Leppaniemi, Ari, Editorial Board Member, Maier, Ron, Editorial Board Member, Moore, Ernest E., Editorial Board Member, Napolitano, Lena, Editorial Board Member, Peitzman, Andrew, Editorial Board Member, Reilly, Patrick, Editorial Board Member, Rizoli, Sandro, Editorial Board Member, Sakakushev, Boris E., Editorial Board Member, Sartelli, Massimo, Editorial Board Member, Scalea, Thomas, Editorial Board Member, Spain, David, Editorial Board Member, Stahel, Philip, Editorial Board Member, Sugrue, Michael, Editorial Board Member, Velmahos, George, Editorial Board Member, Weber, Dieter, Editorial Board Member, and Balogh, Zsolt J., editor
- Published
- 2022
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35. The pre-clinical evolution of haematological malignancies
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Collord, Grace and Vassiliou, George
- Subjects
haematopoiesis ,acute myeloid leukaemia ,lymphoid malignacies ,clonal haematopoiesis ,cancer evolution - Abstract
Cancer-associated somatic mutations frequently drive clonal expansions in normal ageing tissues. However, the factors governing whether pre-cancerous cells transform into cancer are poorly understood, hindering identification of clones that are clinically significant rather than benign sequelae of ageing. The main aim of this dissertation has been to explore this process in the haematopoietic system, where leukaemia-associated mutations are detectable in >10% of individuals over the age of 50. This phenomenon, termed clonal haematopoiesis (CH), is associated with an increased risk of blood cancers, though only a small minority of individuals progress. Acute myeloid leukaemia (AML) is the commonest acute leukaemia in adults, and usually presents abruptly with complications of bone marrow failure. Using deep targeted sequencing of stored blood DNA samples from individuals who went on to develop AML and controls, we identified features of CH that predict leukaemic progression. The number, type and burden of genetic changes, as well as certain clinical variables, were predictive of AML-free survival. Examining the pre-clinical evolution of lymphoid malignancies using a similar study design and broader sequencing approach also revealed genetic and clinical features predictive of malignant transformation. The final part of this study investigates the prevalence of clonal haematopoiesis in childhood cancer survivors treated with intensive chemo- or radiotherapy. In contrast to adult cancer patients, the prevalence of CH in children is not dramatically increased by cytotoxic treatment. Collectively, these findings provide proof of principle that benign and pre-malignant clonal expansions in normal blood (and perhaps other tissues) may be distinguishable years prior to overt malignant transformation. This could in future enable earlier detection of those at high risk of blood cancers, and stimulate research into possible interventions to reduce the risk of progression.
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- 2019
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36. The physiology of smoltification and seawater adaptation in rainbow trout
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Morro-Cortès, Bernat, Albalat, Amaya, and MacKenzie, Simon
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639.3 ,Aquaculture ,Steelhead trout ,mass spectrometry ,ATPase ,MALDI-TOF ,LC-MS/MS ,Photoperiod ,Temperature ,Desmoltification ,Biological clock ,Haematopoiesis ,Proteomics ,Growth-stunted fish ,Runt ,IGF ,IGFbp ,Somatotropic axis ,Production ,Rainbow trout ,Fishes--Genetics ,Fishes--Physiology ,Fishes--Effect of temperature on - Abstract
Seawater-transferred rainbow trout (Oncorhynchus mykiss) has become an attractive aquaculture product in recent years. Industrial interest is mainly due to its resistance to infectious pancreatic necrosis and its adaptability to brackish water, which allows farming in otherwise unexploited locations. However, most practices for the aquaculture of this species have been imported from Atlantic salmon (Salmo salar) without evidence data supporting their suitability for the species. These include protocols to induce their preadaptation to seawater (smoltification). As a result, following seawater transfer, large numbers of fish die (around 10%) or become growth-stunted (GS; 10-60%). Therefore, species-specific rearing protocols and seawater-readiness biomarkers are needed. In the present PhD thesis, the effects of different photoperiod and temperature protocols for rearing in freshwater were assessed on the development of smoltification traits and subsequent seawater performance. This was achieved by using an array of molecular tools to measure osmoregulation-, growth- and haematopoiesis-related genes, proteins and hormones. Moreover, the discovery of potential seawater-readiness biomarkers and the study of smoltification, seawater adaptation and GS fish development were performed using several mass spectrometry proteomic and lipidomic approaches. Results suggest that winter light signals are inadvisable for the species, while all tested summer signals produced similar good results. Moreover, increased temperature protocols not only failed to improve smoltification and growth but potentially compromised the immune system of the fish. Overall, continuous light seems an advisable light regime, irrespective of temperature. Moreover, new promising potential biomarkers for seawater-readiness were identified using proteomics, while also suggesting a previously unknown role of these proteins in smoltification and seawater adaptation. Finally, GS development was shown to be related to low insulin-like growth factor 1 levels following seawater transfer. Moreover, other related factors to the phenotype were higher stress levels, possibly caused by bullying by bigger fish, and hepatic anomalies related to oxidative stress.
- Published
- 2019
37. Charting the single-cell transcriptional landscape of haematopoiesis
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Hamey, Fiona Kathryn and Göttgens, Berthold
- Subjects
572.8 ,Haematopoiesis ,Computational biology ,Bioinformatics ,Stem cell ,Single-cell - Abstract
High turnover in the haematopoietic system is sustained by stem and progenitor cells, which divide and mature to produce the range of cell types present in the blood. This complex system has long served as a model of differentiation in adult stem cell systems and its study has important clinical relevance. Maintaining a healthy blood system requires regulation of haematopoietic cell fate decisions, with severe dysregulation of these fate choices observed in diseases such as leukaemia. As transcriptional regulation is known to play a role in this regulation, the gene expression of many haematopoietic progenitors has been measured. However, many of the classic populations are actually extremely heterogeneous in both expression and function, highlighting the need for characterising the haematopoietic progenitor compartment at the level of individual cells. The first aim of this work was to chart the single-cell transcriptional landscape of the haematopoietic stem and progenitor cell (HSPC) compartment. To build a comprehensive map of this landscape, 1,654 HSPCs from mouse bone marrow were profiled using single-cell RNA-sequencing. Analysis of these data generated a useful resource, and reconstructed changes in gene expression, cell cycle and RNA content along differentiation trajectories to three blood lineages. To investigate how single-cell gene expression can be used to learn about regulatory relationships, data measuring the expression of 41 genes (including 31 transcription factors) in 2,167 stem and progenitor cells were used to construct Boolean gene regulatory network models describing the regulation of differentiation from stem cells to two different progenitor populations. The inferred relationships revealed positive regulation of Nfe2 and Cbfa2t3h by Gata2 that was unique to differentiation towards megakaryocyte-erythroid progenitors, which was subsequently experimentally validated. The next study focused on investigating the link between transcriptional and functional heterogeneity within blood progenitor populations. Single-cell profiles of human cord blood progenitors revealed a continuum of lympho-myeloid gene expression. Culture assays performed to assess the functional output of single cells found both unilineage and bilineage output and, by investigating the link between surface marker expression and function, a new sorting strategy was devised that was able to enrich for function within conventional lympho-myeloid progenitor sorting gates. The final project aimed to study changes to the HSPC compartment in a perturbed state. A droplet-based single-cell RNA-sequencing dataset of 44,802 cells was analysed to identify entry points to eight blood lineages and to characterise gene expression changes in this transcriptional landscape. Mapping single-cell data from W41/W41 Kit mutant mice highlighted quantitative shifts in progenitor populations such as a reduction in mast cell progenitors and an increase towards more mature progenitors along the erythroid trajectory. Differential gene expression identified upregulation of stress response and a reduction of apoptosis during erythropoiesis as potential compensatory mechanisms in the Kit mutant progenitors. Together this body of work characterises the HSPC compartment at single-cell level and provides methods for how single-cell data can be used to discover regulatory relationships, link expression heterogeneity to function, and investigate changes in the transcriptional landscape in a perturbed environment.
- Published
- 2019
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38. Resolving cell fate : experimental, computational and mathematical methods in single cell transcriptomic analysis
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Jawaid, Wajid, Gottgens, Berthold, and Nichols, Jennifer
- Subjects
616.02 ,Single cell ,Transcriptomics ,10X Genomics ,sequencing ,high-throughput ,neural network ,tSNE ,diffusion maps ,gaussian process ,developmental biology ,embryology ,haematopoiesis ,stem cell ,cell fate ,fate ,differentiation ,waddington ,landscape ,PCA ,leukotriene ,LTC4 ,Flk1 ,blood ,endothelium ,heart ,cardiac ,transcription termination variants ,3 prime ,3' ,sequence capture ,drop out - Abstract
Deeper understanding of the embryological origins of tissues and organs is likely to provide insights into novel clinically relevant preventative and therapeutic strategies. To do so effectively and at a large scale so as to have clinical significance requires an exhaustive and meticulously accurate knowledge of normal morphological development and the underlying molecular pathways. A variety of lineage tracing and classical molecular biology techniques have led to key insights but emerging technologies now offer the possibility of more fine grained and precise measurements at the level of the single cell rather than ensembles of heterogeneous cells. In this study the rapidly developing technology of single cell RNA sequencing was combined with the development of state of the art computational methods to study murine gastrulation and early organogenesis at a hitherto unprecedented granularity. A comprehensive analysis of FLK1+ cells harvested from gastrulating murine embryos was performed. In-silico reconstruction of pseudo-temporal and pseudo-spacial relations were demonstrated. Using prior knowledge of known driver genes deeper substructure was revealed in clusters that were initially defined by unsupervised algorithms, illustrating that careful implementation of supervised approaches can outperform naïve unsupervised methods. In this way multiple members of the leukotriene branch of the arachidonic acid pathway were found to be enriched within a subset of the endothelial cluster that has a molecular signature consistent with yolk sac derived definitive wave haematopoiesis. This was subsequently validated in an in-vitro embryonic stem cell differentiation colony assay. By developing a novel adaptation to tSNE dimensionality reduction that now allows new data points to be mapped backed to previously calculated embeddings, the FLK1+ data set became a reference to which cells from other experiments were mapped. The Tal1-/- knockout mutant was characterised, reaffirming the known phenotype with complete failure of embryonic haematopoiesis. Analysing the Tal1-/- endothelial cluster shows definitively in the in-vivo organism no activation of an alternative cardiac fate programme as was previously postulated from an in-vitro model system. Additionally tSNE mapped Brachyury cells into the void in the FLK1+ dataset and identified a node like population. Loss of spacial context remains an Achilles' heel of single cell protocols. Generation of the single cell suspensions leads to disruption of cellular contacts and loss of any spacial information. A novel method is described which uses tSNE of bulk spacial data to pre- condition a tSNE map upon which single cells can then be computationally positioned reconstructing spacial context. To model gene interactions and perturbations from single-cell data, a hybrid feed-forward deep neural network was trained on branching pseudo-temporally arranged single cell qPCR data of in-vivo wild-type murine developmental haematopoiesis. Strikingly despite the model never having 'seen' a mutant, in-silico gene perturbations in the deep neural network are able to faithfully reproduce the Tal1-/- phenotype. In summary the use of single cell transcriptomics to probe early murine embryology com- bined with development of new methods has uncovered a novel pathway in embryonic haematopoietic development and allowed in-silico reconstruction of a short period of early embryonic haematopoiesis. Critically these methods have broad application within the fields of developmental and stem cell biology.
- Published
- 2019
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39. Modelling of arterial and haemogenic endothelium development from mouse and human pluripotent stem cells
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Ruiz Villalobos, Juan Pablo, Porcher, Catherine, and Patient, Roger
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616.02 ,Stem Cell Biology ,Developmental Biology ,Haematopoiesis - Abstract
One of the most promising objectives of clinical haematology is to derive transplantable autologous haematopoietic stem and progenitor cells (HSPCs) from human pluripotent stem cell (PSC) sources in vitro, but efficient and clinically relevant methodologies remain unavailable. Observations in the developing vertebrate embryo indicate that the haematopoietic stem cells (HSCs) capable of long-term engraftment are produced by the third and last wave of haematopoietic development. This occurs in the developing dorsal aorta (DA) from haemogenic endothelium (HE) in close association with an arterial vascular endothelial niche. Notch and Vascular endothelial growth factor A (VEGFA) signalling pathways are critical regulators of arterial identity and HSPC development. To better understand the lack of engrafting HSCs in in vitro PSC differentiation protocols, we further characterised a previously published, serum-free murine embryonic stem cell (mESC) embryoid body (EB) differentiation system. Results showed lack of a robust arterial niche and Notch signalling, and production of HSPCs resembling the erythro-myeloid progenitors (EMP) normally detected during one of the earlier, extra-embryonic waves of haematopoietic development. We then showed that transiently culturing cells with high concentrations of VEGFA led to activation of an arterial programme in cultured cells, though this was insufficient to drive HSC differentiation. Importantly, we showed the haematopoietic potential of arterial delta-like 4 (DLL4) expressing cells depends on VEGFA concentrations in the culture, demonstrating the potential of arterial cells to become HE. To adapt these findings to a more clinically-translatable setting, we also characterised a serum-free, monolayer-based system for the differentiation of human HSPCs previously developed in the lab, commercially available as STEMdiff™ Hematopoietic Kit. Similar to results in the murine system, the supporting niche showed limited arterial vascular endothelium differentiation and was instead primarily composed of mesenchymal stromal-like cells. Culturing cells in high concentrations of VEGFA markedly enhanced arterial endothelium formation throughout culture, and concurrently decreased mesenchymal stroma. Likewise, we observed the presence of immunophenotypic DLL4
+ HE at early stages in cultures treated with high VEGFA concentrations, confirming data obtained from the mESC system. Despite lack of engraftment capacity of HSPCs, our studies contribute potential insights to the question of the haematopoietic potential of arterial endothelium. This will guide further improvement of currently available protocols to support in vitro HSPC differentiation.- Published
- 2019
40. In Vitro Human Haematopoietic Stem Cell Expansion and Differentiation.
- Author
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Bozhilov, Yavor K., Hsu, Ian, Brown, Elizabeth J., and Wilkinson, Adam C.
- Subjects
- *
HEMATOPOIETIC stem cells , *HUMAN stem cells , *MULTIPOTENT stem cells , *HEMATOPOIETIC system , *CELL differentiation , *CELL culture , *CORD blood , *ERYTHROCYTES - Abstract
The haematopoietic system plays an essential role in our health and survival. It is comprised of a range of mature blood and immune cell types, including oxygen-carrying erythrocytes, platelet-producing megakaryocytes and infection-fighting myeloid and lymphoid cells. Self-renewing multipotent haematopoietic stem cells (HSCs) and a range of intermediate haematopoietic progenitor cell types differentiate into these mature cell types to continuously support haematopoietic system homeostasis throughout life. This process of haematopoiesis is tightly regulated in vivo and primarily takes place in the bone marrow. Over the years, a range of in vitro culture systems have been developed, either to expand haematopoietic stem and progenitor cells or to differentiate them into the various haematopoietic lineages, based on the use of recombinant cytokines, co-culture systems and/or small molecules. These approaches provide important tractable models to study human haematopoiesis in vitro. Additionally, haematopoietic cell culture systems are being developed and clinical tested as a source of cell products for transplantation and transfusion medicine. This review discusses the in vitro culture protocols for human HSC expansion and differentiation, and summarises the key factors involved in these biological processes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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41. The Haematopoietically-expressed homeobox transcription factor: roles in development, physiology and disease
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Jacob T. Jackson, Stephen L. Nutt, and Matthew P. McCormack
- Subjects
transcription factor ,Hhex ,diabetes ,haematopoiesis ,leakamia ,AML ,Immunologic diseases. Allergy ,RC581-607 - Abstract
The Haematopoietically expressed homeobox transcription factor (Hhex) is a transcriptional repressor that is of fundamental importance across species, as evident by its evolutionary conservation spanning fish, amphibians, birds, mice and humans. Indeed, Hhex maintains its vital functions throughout the lifespan of the organism, beginning in the oocyte, through fundamental stages of embryogenesis in the foregut endoderm. The endodermal development driven by Hhex gives rise to endocrine organs such as the pancreas in a process which is likely linked to its role as a risk factor in diabetes and pancreatic disorders. Hhex is also required for the normal development of the bile duct and liver, the latter also importantly being the initial site of haematopoiesis. These haematopoietic origins are governed by Hhex, leading to its crucial later roles in definitive haematopoietic stem cell (HSC) self-renewal, lymphopoiesis and haematological malignancy. Hhex is also necessary for the developing forebrain and thyroid gland, with this reliance on Hhex evident in its role in endocrine disorders later in life including a potential role in Alzheimer’s disease. Thus, the roles of Hhex in embryological development throughout evolution appear to be linked to its later roles in a variety of disease processes.
- Published
- 2023
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42. Retinoic acid receptor regulation of decision-making for cell differentiation
- Author
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Geoffrey Brown
- Subjects
retinoic acid receptors ,vitamin A ,stem cells ,differentiation ,haematopoiesis ,Biology (General) ,QH301-705.5 - Abstract
All-trans retinoic acid (ATRA) activation of retinoic acid receptors (RARs) is crucial to an organism’s proper development as established by findings for mouse foetuses from dams fed a vitamin A-deficient diet. ATRA influences decision-making by embryonic stem (ES) cells for differentiation including lineage fate. From studies of knockout mice, RARα and RARγ regulate haematopoiesis whereby active RARα modulates the frequency of decision-making for myeloid differentiation, but is not essential for myelopoiesis, and active RARγ supports stem cell self-renewal and maintenance. From studies of zebrafish embryo development, active RARγ plays a negative role in stem cell decision-making for differentiation whereby, in the absence of exogenous ATRA, selective agonism of RARγ disrupted stem cell decision-making for differentiation patterning for development. From transactivation studies, 0.24 nM ATRA transactivated RARγ and 19.3 nM (80-fold more) was needed to transactivate RARα. Therefore, the dose of ATRA that cells are exposed to in vivo, from gradients created by cells that synthesize and metabolize, is important to RARγ versus RARα and RARγ activation and balancing of the involvements in modulating stem cell maintenance versus decision-making for differentiation. RARγ activation favours stemness whereas concomitant or temporal activation of RARγ and RARα favours differentiation. Crosstalk with signalling events that are provoked by membrane receptors is also important.
- Published
- 2023
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43. Hematopoietic Stem Cells and Regeneration
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Mitch Biermann and Tannishtha Reya
- Subjects
Regeneration (biology) ,Hematopoietic stem cell ,hemic and immune systems ,Biology ,Hematopoietic Stem Cells ,Regenerative medicine ,General Biochemistry, Genetics and Molecular Biology ,Transplantation ,Haematopoiesis ,medicine.anatomical_structure ,Cancer research ,medicine ,Bone marrow ,Stem cell ,Adult stem cell - Abstract
Hematopoietic stem cell (HSC) regeneration is the remarkable process by which extremely rare, normally inactive cells of the bone marrow can replace an entire organ if called to do so by injury or harnessed by transplantation. HSC research is arguably the first quantitative single-cell science and the foundation of adult stem cell biology. Bone marrow transplant is the oldest and most refined technique of regenerative medicine. Here we review the intertwined history of the discovery of HSCs and bone marrow transplant, the molecular and cellular mechanisms of HSC self-renewal, and the use of HSCs and their derivatives for cell therapy.
- Published
- 2024
44. Behind the developing brains and beating hearts of stem cell-derived embryo models
- Author
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Gianluca Amadei and David M. Glover
- Subjects
stem cells ,embryo models ,haematopoiesis ,Biology (General) ,QH301-705.5 - Abstract
Studies over the past decade have shown how stem cells representing embryonic and extra-embryonic tissues of the mouse can self-assemble in the culture dish to recapitulate an astonishing part of early embryonic development. A systematic analysis has demonstrated how pluripotent embryonic stem cells can be induced to behave like the implanting epiblast; how they can interact with trophectoderm stem cells to form a patterned structure resembling the implanting embryo prior to gastrulation; and how the third stem cell type—extra-embryonic endoderm cells—can be incorporated to generate structures that undergo the cell movements and gene expression patterns of gastrulation. Moreover, such stem cell-derived embryo models can proceed to neurulation and establish progenitors for all parts of the brain and neural tube, somites, beating heart structures and gut tube. They develop within extra-embryonic yolk sacs that initiate haematopoiesis. Here we trace this journey of discovery.
- Published
- 2023
- Full Text
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45. Clinical and mechanistic insights into the roles of DDX41 in haematological malignancies.
- Author
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Weinreb, Joshua T. and Bowman, Teresa V.
- Subjects
- *
MYELODYSPLASTIC syndromes , *CELL physiology , *ACUTE myeloid leukemia , *GERM cells - Abstract
DEAD‐box Helicase 41 (DDX41) is a member of the DExD/H‐box helicase family that has a variety of cellular functions. Of note, germline and somatic mutations in the DDX41 gene are prevalently found in myeloid malignancies. Here, we present a comprehensive and analytic review covering relevant clinical, translational and basic science findings on DDX41. We first describe the initial characterisation of DDX41 mutations in patients affected by myelodysplastic syndromes, their associated clinical characteristics, and current treatment modalities. We then cover the known cellular functions of DDX41, spanning from its discovery in Drosophila as a neuroregulator through its more recently described roles in inflammatory signalling, R‐loop metabolism and snoRNA processing. We end with a summary of the identified basic functions of DDX41 that when perturbed may contribute to the underlying pathology of haematologic neoplasms. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
46. Lessons from early life: understanding development to expand stem cells and treat cancers.
- Author
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Bain, Fiona M., Che, James L. C., Jassinskaja, Maria, and Kent, David G.
- Subjects
- *
CANCER stem cells , *EMBRYOLOGY , *SINGLE parents , *BONE marrow , *GENE therapy - Abstract
Haematopoietic stem cell (HSC) self-renewal is a process that is essential for the development and homeostasis of the blood system. Self-renewal expansion divisions, which create two daughter HSCs from a single parent HSC, can be harnessed to create large numbers of HSCs for a wide range of cell and gene therapies, but the same process is also a driver of the abnormal expansion of HSCs in diseases such as cancer. Although HSCs are first produced during early embryonic development, the key stage and location where they undergo maximal expansion is in the foetal liver, making this tissue a rich source of data for deciphering the molecules driving HSC self-renewal. Another equally interesting stage occurs post-birth, several weeks after HSCs have migrated to the bone marrow, when HSCs undergo a developmental switch and adopt a more dormant state. Characterising these transition points during development is key, both for understanding the evolution of haematological malignancies and for developing methods to promote HSC expansion. In this Spotlight article, we provide an overview of some of the key insights that studying HSC development have brought to the fields of HSC expansion and translational medicine, many of which set the stage for the next big breakthroughs in the field. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
47. Mask Protection Against Lead Exposure and Its Correlation with Erythropoiesis in Automotive Body Painters at Ligu District, Semarang, Indonesia
- Author
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Santosa B, Rosidi A, Anggraini H, Latrobdiba ZM, Damayanti FN, and Nugroho HSW
- Subjects
mask ,lead ,haematopoiesis ,automotive painters ,Diseases of the blood and blood-forming organs ,RC633-647.5 - Abstract
Budi Santosa,1 Ali Rosidi,2 Herlisa Anggraini,3 Zahra Maharani Latrobdiba,2 Fitriani Nur Damayanti,4 Heru Santoso Wahito Nugroho5 1Department of Medical Laboratory Science, Universitas Muhammadiyah Semarang, Semarang, Indonesia; 2Department of Nutrition, Faculty of Nursing and Health Science, Universitas Muhammadiyah Semarang, Semarang, Indonesia; 3Department of Medical Laboratory Technology, Faculty of Nursing and Health Science, Universitas Muhammadiyah Semarang, Semarang, Indonesia; 4Department of Midwifery, Faculty of Nursing and Health Science, Universitas Muhammadiyah Semarang, Semarang, Indonesia; 5Department of Health, Poltekkes Kemenkes Surabaya, Surabaya, IndonesiaCorrespondence: Budi Santosa, Department of Medical Laboratory Science, Universitas Muhammadiyah Semarang, Jl. Kedungmundu Raya 18, Semarang, 50273, Central Java, Indonesia Email budisantosa@unimus.ac.idIntroduction: Automotive body painters are at risk of excessive lead exposure that may compromise their health. This study examined the protective effects of masks against lead exposure and its correlation with blood profile of automotive body painters at Ligu district, Semarang, Indonesia.Material and Methods: This cross-sectional study included 61 painters at Ligu district, Semarang, Indonesia (mean age 45 years, 100% male). Mask use was categorized into “frequent” and “infrequent”. Blood samples were taken to measure lead exposure and haematological parameters (haemoglobin/HGB, erythrocytes/RBC, haematocrit/HCT, mean corpuscular haemoglobin/MCH, mean corpuscular volume/MCV, mean corpuscular haemoglobin concentration/MCHC). Effectivity of mask use against lead exposure was analysed with Fisher’s exact test, while lead exposure and haematopoietic parameters were evaluated with Pearson’s correlation tests.Results: There were 26 automotive painters (42.6%) classified as unfrequent mask users, and all of them had high blood lead levels. Most haematopoiesis parameters were in normal range. Workers with infrequent mask use were 1.269 more likely to be exposed to lead compared to those with frequent mask use (CI 95%, 1.082– 1.552). Significant associations were found between lead exposure and RBC (p=0.0, r=− 0.53), HGB (p=0, r=− 0.61), and HCT (p=0.00, r=− 0.61). No significant correlations were observed between lead exposure and MCV, MCH, MCHC.Conclusion: Lead exposure was significantly associated with haematological parameters RBC, HGB, and HCT, confirming the effects of prolonged exposure on blood profile. However, mask use provided significant protection against lead exposure in automotive body painters and should be an obligatory gear for workers.Keywords: mask, lead, haematopoiesis, automotive painters
- Published
- 2022
48. Dysfunctional bone marrow endothelial progenitor cells are involved in patients with myelodysplastic syndromes
- Author
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Tong Xing, Zhong-Shi Lyu, Cai-Wen Duan, Hong-Yan Zhao, Shu-Qian Tang, Qi Wen, Yuan-Yuan Zhang, Meng Lv, Yu Wang, Lan-Ping Xu, Xiao-Hui Zhang, Xiao-Jun Huang, and Yuan Kong
- Subjects
Myelodysplastic syndromes ,Endothelial progenitor cells ,Haematopoiesis ,Immune regulation ,Medicine - Abstract
Abstract Background Myelodysplastic syndromes (MDS) are a group of heterogeneous myeloid clonal disorders characterized by ineffective haematopoiesis and immune deregulation. Emerging evidence has shown the effect of bone marrow (BM) endothelial progenitor cells (EPCs) in regulating haematopoiesis and immune balance. However, the number and functions of BM EPCs in patients with different stages of MDS remain largely unknown. Methods Patients with MDS (N = 30), de novo acute myeloid leukaemia (AML) (N = 15), and healthy donors (HDs) (N = 15) were enrolled. MDS patients were divided into lower-risk MDS (N = 15) and higher-risk MDS (N = 15) groups according to the dichotomization of the Revised International Prognostic Scoring System. Flow cytometry was performed to analyse the number of BM EPCs. Tube formation and migration assays were performed to evaluate the functions of BM EPCs. In order to assess the gene expression profiles of BM EPCs, RNA sequencing (RNA-seq) were performed. BM EPC supporting abilities of haematopoietic stem cells (HSCs), leukaemia cells and T cells were assessed by in vitro coculture experiments. Results Increased but dysfunctional BM EPCs were found in MDS patients compared with HDs, especially in patients with higher-risk MDS. RNA-seq indicated the progressive change and differences of haematopoiesis- and immune-related pathways and genes in MDS BM EPCs. In vitro coculture experiments verified that BM EPCs from HDs, lower-risk MDS, and higher-risk MDS to AML exhibited a progressively decreased ability to support HSCs, manifested as elevated apoptosis rates and intracellular reactive oxygen species (ROS) levels and decreased colony-forming unit plating efficiencies of HSCs. Moreover, BM EPCs from higher-risk MDS patients demonstrated an increased ability to support leukaemia cells, characterized by increased proliferation, leukaemia colony-forming unit plating efficiencies, decreased apoptosis rates and apoptosis-related genes. Furthermore, BM EPCs induced T cell differentiation towards more immune-tolerant cells in higher-risk MDS patients in vitro. In addition, the levels of intracellular ROS and the apoptosis ratios were increased in BM EPCs from MDS patients, especially in higher-risk MDS patients, which may be therapeutic candidates for MDS patients. Conclusion Our results suggest that dysfunctional BM EPCs are involved in MDS patients, which indicates that improving haematopoiesis supporting ability and immuneregulation ability of BM EPCs may represent a promising therapeutic approach for MDS patients.
- Published
- 2022
- Full Text
- View/download PDF
49. Baicalein attenuates oxidative damage in mice haematopoietic cells through regulation of PDGFRβ.
- Author
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Ren, Huanying, Feng, Jingyi, Hong, Minglin, Liu, Zhuang, Muyey, Daniel Muteb, Zhang, Yaofang, Xu, Zhifang, Tan, Yanhong, Ren, Fanggang, Chang, Jianmei, Chen, Xiuhua, and Wang, Hongwei
- Subjects
- *
NUCLEAR factor E2 related factor , *ERYTHROCYTE membranes , *PLATELET-derived growth factor receptors , *NAD (Coenzyme) , *CELLULAR control mechanisms , *PROTEIN kinase B , *FETAL hemoglobin , *TOTAL body irradiation - Abstract
Platelet-derived growth factor receptor β (PDGFRβ) plays a crucial role in murine haematopoiesis. Baicalein (BAI), a naturally occurring flavonoid, can alleviate disease damage through anti-oxidative, anti-apoptotic, and anti-inflammatory mechanisms. However, whether BAI attenuates oxidative damage in murine haematopoietic cells by PDGFRβ remains unexplored. In this study, we utilized a tert -butyl hydroperoxide (TBHP)-induced BaF3 cell injury model and an ionising radiation (IR)-induced mice injury model to investigate the impact of the presence or absence of PDGFRβ on the pharmacological effects of BAI. In addition, the BAI-PDGFRβ interaction was characterized by molecular docking and dynamics simulations. The results show that a specific concentration of BAI led to increased cell viability, reduced reactive oxygen species (ROS) content, upregulated nuclear factor erythroid 2-related factor 2 (NRF2) expression, and its downstream target genes heme oxygenase 1 (HO-1) and NAD(P)H Quinone Dehydrogenase 1 (NQO1), and activated protein kinase B (AKT) pathway in cells expressing PDGFRβ plasmid and experiencing damage. Similarly, BAI elevated lineage−Sca1+cKIT+ (LSK) cell proportion, promoted haematopoietic restoration, enhanced NRF2-mediated antioxidant response in PDGFRβ+/+ mice. However, despite BAI usage, PDGFRβ knockout mice (PDGFRβ−/−) showed lower LSK proportion and less antioxidant capacity than the total body irradiation (TBI) group. Furthermore, we demonstrated an interaction between BAI and PDGFRβ at the molecular level. Collectively, our results indicate that BAI attenuates oxidative stress injury and helps promote haematopoietic cell recovery through regulation of PDGFRβ. • Baicalein attenuates haematopoietic harm caused by oxidative stress. • Baicalein enhances the NRF2 antioxidant pathway through PDGFRβ. • Baicalein interacts with PDGFRβ. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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50. Mitochondria and the Tumour Microenvironment in Blood Cancer
- Author
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Moore, Jamie A., Mistry, Jayna J., Rushworth, Stuart A., Crusio, Wim E., Series Editor, Dong, Haidong, Series Editor, Radeke, Heinfried H., Series Editor, Rezaei, Nima, Series Editor, Steinlein, Ortrud, Series Editor, Xiao, Junjie, Series Editor, and Birbrair, Alexander, editor
- Published
- 2021
- Full Text
- View/download PDF
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