RESUMEN
A major next step in hematopoietic stem cell (HSC) biology is to enhance our quantitative understanding of cellular and evolutionary dynamics involved in undisturbed hematopoiesis. Mathematical models have been and continue to be key in this respect, and are most powerful when parameterized experimentally and containing sufficient biological complexity. In this paper, we use data from label propagation experiments in mice to parameterize a mathematical model of hematopoiesis that includes homeostatic control mechanisms as well as clonal evolution. We find that nonlinear feedback control can drastically change the interpretation of kinetic estimates at homeostasis. This suggests that short-term HSC and multipotent progenitors can dynamically adjust to sustain themselves temporarily in the absence of long-term HSCs, even if they differentiate more often than they self-renew in undisturbed homeostasis. Additionally, the presence of feedback control in the model renders the system resilient against mutant invasion. Invasion barriers, however, can be overcome by a combination of age-related changes in stem cell differentiation and evolutionary niche construction dynamics based on a mutant-associated inflammatory environment. This helps us understand the evolution of e.g., TET2 or DNMT3A mutants, and how to potentially reduce mutant burden.
Asunto(s)
Diferenciación Celular , Hematopoyesis , Células Madre Hematopoyéticas , Mutación , Animales , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Ratones , Hematopoyesis/genética , Hematopoyesis/fisiología , ADN Metiltransferasa 3A/metabolismo , Homeostasis , ADN (Citosina-5-)-Metiltransferasas/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , Modelos Biológicos , Linaje de la Célula , Dioxigenasas , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Evolución Clonal , Modelos TeóricosRESUMEN
Hematopoietic stem cells (HSCs) react to various stress conditions. However, it is unclear whether and how HSCs respond to severe anemia. Here, we demonstrate that upon induction of acute anemia, HSCs rapidly proliferate and enhance their erythroid differentiation potential. In severe anemia, lipoprotein profiles largely change and the concentration of ApoE increases. In HSCs, transcription levels of lipid metabolism-related genes, such as very low-density lipoprotein receptor (Vldlr), are upregulated. Stimulation of HSCs with ApoE enhances their erythroid potential, whereas HSCs in Apoe knockout mice do not respond to anemia induction. VldlrhighHSCs show higher erythroid potential, which is enhanced after acute anemia induction. VldlrhighHSCs are epigenetically distinct because of their low chromatin accessibility, and more chromatin regions are closed upon acute anemia induction. Chromatin regions closed upon acute anemia induction are mainly binding sites of Erg. Inhibition of Erg enhanced the erythroid differentiation potential of HSCs. Our findings indicate that lipoprotein metabolism plays an important role in HSC regulation under severe anemic conditions.
Asunto(s)
Anemia , Apolipoproteínas E , Diferenciación Celular , Células Madre Hematopoyéticas , Lipoproteínas , Animales , Anemia/metabolismo , Anemia/genética , Células Madre Hematopoyéticas/metabolismo , Ratones , Apolipoproteínas E/metabolismo , Apolipoproteínas E/genética , Lipoproteínas/metabolismo , Ratones Endogámicos C57BL , Ratones Noqueados , Receptores de LDL/metabolismo , Receptores de LDL/genética , Masculino , Cromatina/metabolismo , Eritropoyesis/genética , Células Eritroides/metabolismoRESUMEN
Age is a risk factor for hematologic malignancies. Attributes of the aging hematopoietic system include increased myelopoiesis, impaired adaptive immunity, and a functional decline of the hematopoietic stem cells (HSCs) that maintain hematopoiesis. Changes in the composition of diverse HSC subsets have been suggested to be responsible for age-related alterations, however, the underlying regulatory mechanisms are incompletely understood in the context of HSC heterogeneity. In this study, we investigated how distinct HSC subsets, separated by CD49b, functionally and molecularly change their behavior with age. We demonstrate that the lineage differentiation of both lymphoid-biased and myeloid-biased HSC subsets progressively shifts to a higher myeloid cellular output during aging. In parallel, we show that HSCs selectively undergo age-dependent gene expression and gene regulatory changes in a progressive manner, which is initiated already in the juvenile stage. Overall, our studies suggest that aging intrinsically alters both cellular and molecular properties of HSCs.
Asunto(s)
Envejecimiento , Células Madre Hematopoyéticas , Ratones Endogámicos C57BL , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/citología , Animales , Envejecimiento/genética , Envejecimiento/fisiología , Ratones , Diferenciación Celular , Linaje de la Célula/genética , Hematopoyesis/genética , Células Mieloides/metabolismo , Células Mieloides/citología , Masculino , Regulación de la Expresión Génica , FemeninoRESUMEN
BACKGROUND: Hematopoietic stem progenitor cells (HSPCs) undergo phenotypical and functional changes during their emergence and development. Although the molecular programs governing the development of human hematopoietic stem cells (HSCs) have been investigated broadly, the relationships between dynamic metabolic alterations and their functions remain poorly characterized. METHODS: In this study, we comprehensively described the proteomics of HSPCs in the human fetal liver (FL), umbilical cord blood (UCB), and adult bone marrow (aBM). The metabolic state of human HSPCs was assessed via a Seahorse assay, RTâPCR, and flow cytometry-based metabolic-related analysis. To investigate whether perturbing glutathione metabolism affects reactive oxygen species (ROS) production, the metabolic state, and the expansion of human HSPCs, HSPCs were treated with buthionine sulfoximine (BSO), an inhibitor of glutathione synthetase, and N-acetyl-L-cysteine (NAC). RESULTS: We investigated the metabolomic landscape of human HSPCs from the fetal, perinatal, and adult developmental stages by in-depth quantitative proteomics and predicted a metabolic switch from the oxidative state to the glycolytic state during human HSPC development. Seahorse assays, mitochondrial activity, ROS level, glucose uptake, and protein synthesis rate analysis supported our findings. In addition, immune-related pathways and antigen presentation were upregulated in UCB or aBM HSPCs, indicating their functional maturation upon development. Glutathione-related metabolic perturbations resulted in distinct responses in human HSPCs and progenitors. Furthermore, the molecular and immunophenotypic differences between human HSPCs at different developmental stages were revealed at the protein level for the first time. CONCLUSION: The metabolic landscape of human HSPCs at three developmental stages (FL, UCB, and aBM), combined with proteomics and functional validations, substantially extends our understanding of HSC metabolic regulation. These findings provide valuable resources for understanding human HSC function and development during fetal and adult life.
Asunto(s)
Células Madre Hematopoyéticas , Proteómica , Especies Reactivas de Oxígeno , Humanos , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/citología , Proteómica/métodos , Especies Reactivas de Oxígeno/metabolismo , Feto/metabolismo , Feto/citología , Adulto , Sangre Fetal/citología , Sangre Fetal/metabolismo , Butionina Sulfoximina/farmacología , Glutatión/metabolismoRESUMEN
Lifelong hematopoiesis is sustained by crosstalk between hematopoietic stem and progenitor cells (HSPCs) and specialized bone marrow niches. Acute myeloid leukemia (AML) upends that balance, as leukemic blasts secrete factors that remodel the bone marrow into a self-reinforcing leukemic niche. The inflammatory secretome behind this compartmental adaptation accounts for a progressive decline in hematopoietic function that leads to diagnosis and persists through early treatment. Not surprisingly, the mediators of an acute inflammatory injury and HSPC suppression have attracted much attention in an effort to alleviate morbidity and improve outcomes. HSPCs typically recover during disease remission and re-expand in the bone marrow (BM), but little is known about potentially lasting consequences for stem cells and progenitors. We recently showed that AML-experienced HSPCs actively participate in the inflammatory process during leukemic progression. HSPCs are constituent components of the innate immune system, and elegant studies of infection and experimental inflammation over the past decade have described the generation of an adoptively transferable, innate immune memory. Building on this paradigm, we discuss the potential translational relevance of a durable legacy in AML-experienced HSPC.
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Células Madre Hematopoyéticas , Inflamación , Leucemia Mieloide Aguda , Nicho de Células Madre , Humanos , Leucemia Mieloide Aguda/inmunología , Leucemia Mieloide Aguda/patología , Leucemia Mieloide Aguda/metabolismo , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/inmunología , Animales , Inflamación/inmunología , Inflamación/patología , Inflamación/metabolismo , Memoria Inmunológica , Inmunidad Innata , Microambiente Tumoral/inmunología , HematopoyesisRESUMEN
Arterial endothelial cells (AECs) are the founder cells for intraembryonic haematopoiesis. Here, we report a method for the efficient generation of human haemogenic DLL4+ AECs from pluripotent stem cells (PSC). Time-series single-cell RNA-sequencing reveals the dynamic evolution of haematopoiesis and lymphopoiesis, generating cell types with counterparts present in early human embryos, including stages marked by the pre-haematopoietic stem cell genes MECOM/EVI1, MLLT3 and SPINK2. DLL4+ AECs robustly support lymphoid differentiation, without the requirement for exogenous NOTCH ligands. Using this system, we find IL7 acts as a morphogenic factor determining the fate choice between the T and innate lymphoid lineages and also plays a role in regulating the relative expression level of RAG1. Moreover, we document a developmental pathway by which human RAG1+ lymphoid precursors give rise to the natural killer cell lineage. Our study describes an efficient method for producing lymphoid progenitors, providing insights into their endothelial and haematopoietic ontogeny, and establishing a platform to investigate the development of the human blood system.
Asunto(s)
Hematopoyesis , Linfopoyesis , Humanos , Hematopoyesis/genética , Linfopoyesis/genética , Células Endoteliales/metabolismo , Células Endoteliales/citología , Diferenciación Celular , Linaje de la Célula/genética , Interleucina-7/metabolismo , Interleucina-7/genética , Células Madre Pluripotentes/metabolismo , Células Madre Pluripotentes/citología , Proteínas de Unión al Calcio/metabolismo , Proteínas de Unión al Calcio/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/genética , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/citología , Hemangioblastos/metabolismo , Hemangioblastos/citología , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Proteínas de Homeodominio/metabolismo , Proteínas de Homeodominio/genética , Análisis de la Célula Individual/métodos , Receptores Notch/metabolismo , Receptores Notch/genéticaRESUMEN
Recent advances in imaging suggested that spatial organization of hematopoietic cells in their bone marrow microenvironment (niche) regulates cell expansion, governing progression, and leukemic transformation of hematological clonal disorders. However, our ability to interrogate the niche in pre-malignant conditions has been limited, as standard murine models of these diseases rely largely on transplantation of the mutant clones into conditioned mice where the marrow microenvironment is compromised. Here, we leveraged live-animal microscopy and ultralow dose whole body or focal irradiation to capture single cells and early expansion of benign/pre-malignant clones in the functionally preserved microenvironment. 0.5 Gy whole body irradiation (WBI) allowed steady engraftment of cells beyond 30 weeks compared to non-conditioned controls. In-vivo tracking and functional analyses of the microenvironment showed no change in vessel integrity, cell viability, and HSC-supportive functions of the stromal cells, suggesting minimal inflammation after the radiation insult. The approach enabled in vivo imaging of Tet2+/- and its healthy counterpart, showing preferential localization within a shared microenvironment while forming discrete micro-niches. Notably, stationary association with the niche only occurred in a subset of cells and would not be identified without live imaging. This strategy may be broadly applied to study clonal disorders in a spatial context.
Asunto(s)
Hematopoyesis Clonal , Nicho de Células Madre , Animales , Ratones , Nicho de Células Madre/efectos de la radiación , Células Madre Hematopoyéticas/efectos de la radiación , Células Madre Hematopoyéticas/metabolismo , Irradiación Corporal Total , Ratones Endogámicos C57BL , Rastreo Celular/métodos , Microscopía Intravital/métodosRESUMEN
Most gene functions have been discovered through phenotypic observations under loss of function experiments that lack temporal control. However, cell signaling relies on limited transcriptional effectors, having to be re-used temporally and spatially within the organism. Despite that, the dynamic nature of signaling pathways have been overlooked due to the difficulty on their assessment, resulting in important bottlenecks. Here, we have utilized the rapid and synchronized developmental transitions occurring within the zebrafish embryo, in conjunction with custom NF-kB reporter embryos driving destabilized fluorophores that report signaling dynamics in real time. We reveal that NF-kB signaling works as a clock that controls the developmental progression of hematopoietic stem and progenitor cells (HSPCs) by two p65 activity waves that inhibit cell cycle. Temporal disruption of each wave results in contrasting phenotypic outcomes: loss of HSPCs due to impaired specification versus proliferative expansion and failure to delaminate from their niche. We also show functional conservation during human hematopoietic development using iPSC models. Our work identifies p65 as a previously unrecognized contributor to cell cycle regulation, revealing why and when pro-inflammatory signaling is required during HSPC development. It highlights the importance of considering and leveraging cell signaling as a temporally dynamic entity.
Asunto(s)
Ciclo Celular , Células Madre Hematopoyéticas , Transducción de Señal , Pez Cebra , Animales , Humanos , Diferenciación Celular , Proliferación Celular , Embrión no Mamífero/metabolismo , Regulación del Desarrollo de la Expresión Génica , Hematopoyesis , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/citología , Factor de Transcripción ReIA/metabolismo , Pez Cebra/embriología , Proteínas de Pez Cebra/metabolismo , Proteínas de Pez Cebra/genéticaRESUMEN
Oncostatin M (OSM) is a member of the interleukin-6 (IL-6) family of cytokines and has been found to have anti-inflammatory and pro-inflammatory properties in various cellular and disease contexts. OSM signals through two receptor complexes, one of which includes OSMRß. Here, we investigated OSM-OSMRß signaling in adult mouse hematopoietic stem cells (HSCs) using the conditional Osmrfl/fl mouse model B6;129-Osmrtm1.1Nat/J. We crossed Osmrfl/fl mice to interferon-inducible Mx1-Cre, which is robustly induced in adult HSCs. From these mice, we isolated HSCs by flow cytometry, stimulated with recombinant OSM or vehicle for 1 hour, and assessed gene expression changes in control versus Osmr knockout HSCs by RNA-seq. This data may be utilized to investigate OSMRß -dependent and -independent OSM signaling as well as the transcriptional effects of an IL-6 family cytokine on mouse HSCs to further define its anti-inflammatory versus pro-inflammatory properties.
Asunto(s)
Células Madre Hematopoyéticas , Oncostatina M , Transducción de Señal , Animales , Ratones , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/efectos de los fármacos , Oncostatina M/farmacología , Subunidad beta del Receptor de Oncostatina M/genética , Análisis de Secuencia de ARN , Receptores de Oncostatina M/genética , RNA-SeqRESUMEN
The conditions supporting the generation of microglia-like cells in the central nervous system (CNS) after transplantation of hematopoietic stem/progenitor cells (HSPC) have been studied to advance the treatment of neurodegenerative disorders. Here, we explored the transplantation efficacy of different cell subsets and delivery routes with the goal of favoring the establishment of a stable and exclusive engraftment of HSPCs and their progeny in the CNS of female mice. In this setting, we show that the CNS environment drives the expansion, distribution and myeloid differentiation of the locally transplanted cells towards a microglia-like phenotype. Intra-CNS transplantation of HSPCs engineered to overexpress TREM2 decreased neuroinflammation, Aß aggregation and improved memory in 5xFAD female mice. Our proof of concept study demonstrates the therapeutic potential of HSPC gene therapy for Alzheimer's disease.
Asunto(s)
Enfermedad de Alzheimer , Modelos Animales de Enfermedad , Terapia Genética , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas , Ratones Transgénicos , Microglía , Animales , Enfermedad de Alzheimer/terapia , Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Terapia Genética/métodos , Femenino , Trasplante de Células Madre Hematopoyéticas/métodos , Ratones , Microglía/metabolismo , Células Madre Hematopoyéticas/metabolismo , Receptores Inmunológicos/genética , Receptores Inmunológicos/metabolismo , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Péptidos beta-Amiloides/metabolismo , Diferenciación Celular , Humanos , Ratones Endogámicos C57BLRESUMEN
Ionizing radiation exposure can cause damage to diverse tissues and organs, with the hematopoietic system being the most sensitive. However, limited information is available regarding the radiosensitivity of various hematopoietic cell populations in the bone marrow due to the high heterogeneity of the hematopoietic system. In this study, we observed that granulocyte-macrophage progenitors, hematopoietic stem/progenitor cells, and B cells within the bone marrow showed the highest sensitivity, exhibiting a rapid decrease in cell numbers following irradiation. Nonetheless, neutrophils, natural killer (NK) cells, T cells, and dendritic cells demonstrated a certain degree of radioresistance, with neutrophils exhibiting the most pronounced resistance. By employing single-cell transcriptome sequencing, we investigated the early responsive genes in various cell types following irradiation, revealing that distinct gene expression profiles emerged between radiosensitive and radioresistant cells. In B cells, radiation exposure led to a specific upregulation of genes associated with mitochondrial respiratory chain complexes, suggesting a connection between these complexes and cell radiosensitivity. In neutrophils, radiation exposure resulted in fewer gene alterations, indicating their potential for distinct mechanisms in radiation resistance. Collectively, this study provides insights into the molecular mechanism for the heterogeneity of radiosensitivity among the various bone marrow hematopoietic cell populations.
Asunto(s)
Radiación Ionizante , Análisis de la Célula Individual , Transcriptoma , Animales , Ratones , Análisis de la Célula Individual/métodos , Transcriptoma/efectos de la radiación , Células de la Médula Ósea/efectos de la radiación , Células de la Médula Ósea/metabolismo , Ratones Endogámicos C57BL , Tolerancia a Radiación/genética , Perfilación de la Expresión Génica , Células Madre Hematopoyéticas/efectos de la radiación , Células Madre Hematopoyéticas/metabolismo , Neutrófilos/efectos de la radiación , Neutrófilos/metabolismoRESUMEN
Clonal hematopoiesis of indeterminate potential (CHIP) is linked to diverse aging-related diseases, including hematologic malignancy and atherosclerotic cardiovascular disease (ASCVD). While CHIP is common among older adults, the underlying factors driving its development are largely unknown. To address this, we performed whole-exome sequencing on 8,374 blood DNA samples collected from 4,187 Atherosclerosis Risk in Communities Study (ARIC) participants over a median follow-up of 21 years. During this period, 735 participants developed incident CHIP. Splicing factor genes (SF3B1, SRSF2, U2AF1, and ZRSR2) and TET2 CHIP grow significantly faster than DNMT3A non-R882 clones. We find that age at baseline and sex significantly influence the incidence of CHIP, while ASCVD and other traditional ASCVD risk factors do not exhibit such associations. Additionally, baseline synonymous passenger mutations are strongly associated with CHIP status and are predictive of new CHIP clone acquisition and clonal growth over extended follow-up, providing valuable insights into clonal dynamics of aging hematopoietic stem and progenitor cells. This study also reveals associations between germline genetic variants and incident CHIP. Our comprehensive longitudinal assessment yields insights into cell-intrinsic and -extrinsic factors contributing to the development and progression of CHIP clones in older adults.
Asunto(s)
Hematopoyesis Clonal , Dioxigenasas , Humanos , Hematopoyesis Clonal/genética , Masculino , Femenino , Anciano , Estudios Longitudinales , Persona de Mediana Edad , Dioxigenasas/genética , ADN Metiltransferasa 3A , Factores de Empalme de ARN/genética , Factores de Empalme de ARN/metabolismo , Aterosclerosis/genética , Factores de Riesgo , Secuenciación del Exoma , Proteínas de Unión al ADN/genética , Proteínas Proto-Oncogénicas/genética , Proteínas Proto-Oncogénicas/metabolismo , ADN (Citosina-5-)-Metiltransferasas/genética , ADN (Citosina-5-)-Metiltransferasas/metabolismo , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/citología , Envejecimiento/genética , Incidencia , MutaciónRESUMEN
Macrophages maintain hematopoietic stem cell (HSC) quality by assessing cell surface Calreticulin (Calr), an "eat-me" signal induced by reactive oxygen species (ROS). Using zebrafish genetics, we identified Beta-2-microglobulin (B2m) as a crucial "don't eat-me" signal on blood stem cells. A chemical screen revealed inducers of surface Calr that promoted HSC proliferation without triggering ROS or macrophage clearance. Whole-genome CRISPR-Cas9 screening showed that Toll-like receptor 3 (Tlr3) signaling regulated b2m expression. Targeting b2m or tlr3 reduced the HSC clonality. Elevated B2m levels correlated with high expression of repetitive element (RE) transcripts. Overall, our data suggest that RE-associated double-stranded RNA could interact with TLR3 to stimulate surface expression of B2m on hematopoietic stem and progenitor cells. These findings suggest that the balance of Calr and B2m regulates macrophage-HSC interactions and defines hematopoietic clonality.
Asunto(s)
Calreticulina , Células Madre Hematopoyéticas , Macrófagos , Fagocitosis , Receptor Toll-Like 3 , Microglobulina beta-2 , Animales , Microglobulina beta-2/genética , Microglobulina beta-2/metabolismo , Calreticulina/metabolismo , Calreticulina/genética , Proliferación Celular , Sistemas CRISPR-Cas , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/citología , Macrófagos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Secuencias Repetitivas de Ácidos Nucleicos , Transducción de Señal , Receptor Toll-Like 3/metabolismo , Receptor Toll-Like 3/genética , Pez Cebra , Proteínas de Pez Cebra/metabolismo , Proteínas de Pez Cebra/genéticaRESUMEN
The contribution of endocardial cells (EdCs) to the hematopoietic lineages has been strongly debated. Here, we provide evidence that in zebrafish, the endocardium gives rise to and maintains a stable population of hematopoietic cells. Using single-cell sequencing, we identify an endocardial subpopulation expressing enriched levels of hematopoietic-promoting genes. High-resolution microscopy and photoconversion tracing experiments uncover hematopoietic cells, mainly hematopoietic stem and progenitor cells (HSPCs)/megakaryocyte-erythroid precursors (MEPs), derived from EdCs as well as the dorsal aorta stably attached to the endocardium. Emergence of HSPCs/MEPs in hearts cultured ex vivo without external hematopoietic sources, as well as longitudinal imaging of the beating heart using light sheet microscopy, support endocardial contribution to hematopoiesis. Maintenance of these hematopoietic cells depends on the adhesion factors Integrin α4 and Vcam1 but is at least partly independent of cardiac trabeculation or shear stress. Finally, blocking primitive erythropoiesis increases cardiac-residing hematopoietic cells, suggesting that the endocardium is a hematopoietic reservoir. Altogether, these studies uncover the endocardium as a resident tissue for HSPCs/MEPs and a de novo source of hematopoietic cells.
Asunto(s)
Endocardio , Células Madre Hematopoyéticas , Pez Cebra , Animales , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Endocardio/citología , Endocardio/metabolismo , Hematopoyesis/fisiología , Corazón/fisiología , Molécula 1 de Adhesión Celular Vascular/metabolismo , Molécula 1 de Adhesión Celular Vascular/genética , Proteínas de Pez Cebra/metabolismo , Proteínas de Pez Cebra/genética , Análisis de la Célula Individual , Linaje de la Célula , Eritropoyesis/fisiología , Animales Modificados GenéticamenteRESUMEN
Hematopoietic stem and progenitor cells (HSPCs) give rise to all cell types of the hematopoietic system through various processes, including asymmetric divisions. However, the contribution of stromal cells of the hematopoietic niches in the control of HSPC asymmetric divisions remains unknown. Using polyacrylamide microwells as minimalist niches, we show that specific heterotypic interactions with osteoblast and endothelial cells promote asymmetric divisions of human HSPCs. Upon interaction, HSPCs polarize in interphase with the centrosome, the Golgi apparatus, and lysosomes positioned close to the site of contact. Subsequently, during mitosis, HSPCs orient their spindle perpendicular to the plane of contact. This division mode gives rise to siblings with unequal amounts of lysosomes and of the differentiation marker CD34. Such asymmetric inheritance generates heterogeneity in the progeny, which is likely to contribute to the plasticity of the early steps of hematopoiesis.
Asunto(s)
Células Madre Hematopoyéticas , Humanos , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/metabolismo , Hematopoyesis/fisiología , Diferenciación Celular , Mitosis , Osteoblastos/citología , Osteoblastos/metabolismo , Células Endoteliales/citología , Células Endoteliales/metabolismo , División Celular Asimétrica , Lisosomas/metabolismo , Centrosoma/metabolismo , Antígenos CD34/metabolismo , Aparato de Golgi/metabolismo , División CelularRESUMEN
The treatment of patients diagnosed with hematologic malignancies typically includes hematopoietic stem cell transplantation (HSCT) as part of a therapeutic standard of care. The primary graft source of hematopoietic stem and progenitor cells (HSPCs) for HSCT is mobilized from the bone marrow into the peripheral blood of allogeneic donors or patients. More recently, these mobilized HSPCs have also been the source for gene editing strategies to treat diseases such as sickle-cell anemia. For a HSCT to be successful, it requires the infusion of a sufficient number of HSPCs that are capable of adequate homing to the bone marrow niche and the subsequent regeneration of stable trilineage hematopoiesis in a timely manner. Granulocyte-colony-stimulating factor (G-CSF) is currently the most frequently used agent for HSPC mobilization. However, it requires five or more daily infusions to produce an adequate number of HSPCs and the use of G-CSF alone often results in suboptimal stem cell yields in a significant number of patients. Furthermore, there are several undesirable side effects associated with G-CSF, and it is contraindicated for use in sickle-cell anemia patients, where it has been linked to serious vaso-occlusive and thrombotic events. The chemokine receptor CXCR4 and the cell surface integrin α4ß1 (very late antigen 4 (VLA4)) are both involved in the homing and retention of HSPCs within the bone marrow microenvironment. Preclinical and/or clinical studies have shown that targeted disruption of the interaction of the CXCR4 or VLA4 receptors with their endogenous ligands within the bone marrow niche results in the rapid and reversible mobilization of HSPCs into the peripheral circulation and is synergistic when combined with G-CSF. In this review, we discuss the roles CXCR4 and VLA4 play in bone marrow homing and retention and will summarize more recent development of small-molecule CXCR4 and VLA4 inhibitors that, when combined, can synergistically improve the magnitude, quality and convenience of HSPC mobilization for stem cell transplantation and ex vivo gene therapy after the administration of just a single dose. This optimized regimen has the potential to afford a superior alternative to G-CSF for HSPC mobilization.
Asunto(s)
Movilización de Célula Madre Hematopoyética , Células Madre Hematopoyéticas , Integrina alfa4beta1 , Receptores CXCR4 , Humanos , Receptores CXCR4/metabolismo , Receptores CXCR4/antagonistas & inhibidores , Movilización de Célula Madre Hematopoyética/métodos , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/efectos de los fármacos , Células Madre Hematopoyéticas/citología , Integrina alfa4beta1/metabolismo , Integrina alfa4beta1/antagonistas & inhibidores , Animales , Factor Estimulante de Colonias de Granulocitos/farmacología , Factor Estimulante de Colonias de Granulocitos/metabolismo , Trasplante de Células Madre HematopoyéticasRESUMEN
The HLA genes are associated with various autoimmune pathologies, with the control of the immune response also being significant in organs and cells transplantation. The aim of the study is to identify the HLA-A, HLA-B, and HLA-C alleles frequencies in the analyzed Romanian cohort. We performed HLA typing using next-generation sequencing (NGS) in a Romanian cohort to estimate class I HLA allele frequencies up to a six-digit resolution. A total of 420 voluntary donors from the National Registry of Voluntary Hematopoietic Stem Cell Donors (RNDVCSH) were included in the study for HLA genotyping. Peripheral blood samples were taken and brought to the Fundeni Clinical Institute during 2020-2021. HLA genotyping was performed using the Immucor Mia Fora NGS MFlex kit. A total of 109 different alleles were detected in 420 analyzed samples, out of which 31 were for HLA-A, 49 for HLA-B, and 29 for HLA-C. The most frequent HLA-A alleles were HLA-A*02:01:01 (26.11%), HLA-A*01:01:01 (12.5%), HLA-A*24:02:01 (11.67%), HLA-A*03:01:01 (9.72%), HLA-A*11:01:01, and HLA-A*32:01:01 (each with 8.6%). For the HLA-B locus, the most frequent allele was HLA-B*18:01:01 (11.25%), followed by HLA-B*51:01:01 (10.83%) and HLA-B*08:01:01 (7.78%). The most common HLA-C alleles were HLA-C*07:01:01 (17.36%), HLA-C*04:01:01 (13.47%), and HLA-C*12:03:01 (10.69%). Follow-up studies are ongoing for confirming the detected results.
Asunto(s)
Frecuencia de los Genes , Antígenos HLA-A , Antígenos HLA-B , Antígenos HLA-C , Donantes de Tejidos , Humanos , Antígenos HLA-C/genética , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Masculino , Femenino , Alelos , Rumanía , Células Madre Hematopoyéticas/metabolismo , Trasplante de Células Madre Hematopoyéticas , Adulto , Secuenciación de Nucleótidos de Alto Rendimiento , Prueba de Histocompatibilidad/métodos , Genotipo , Persona de Mediana EdadRESUMEN
Philadelphia-Negative Myeloproliferative neoplasms (MPNs) are a diverse group of blood cancers leading to excessive production of mature blood cells. These chronic diseases, including polycythemia vera (PV), essential thrombocythemia (ET), and primary myelofibrosis (PMF), can significantly impact patient quality of life and are still incurable in the vast majority of the cases. This review examines the mechanobiology within a bone marrow niche, emphasizing the role of mechanical cues and the primary cilium in the pathophysiology of MPNs. It discusses the influence of extracellular matrix components, cell-cell and cell-matrix interactions, and mechanosensitive structures on hematopoietic stem cell (HSC) behavior and disease progression. Additionally, the potential implications of the primary cilium as a chemo- and mechanosensory organelle in bone marrow cells are explored, highlighting its involvement in signaling pathways crucial for hematopoietic regulation. This review proposes future research directions to better understand the dysregulated bone marrow niche in MPNs and to identify novel therapeutic targets.
Asunto(s)
Cilios , Trastornos Mieloproliferativos , Humanos , Trastornos Mieloproliferativos/metabolismo , Trastornos Mieloproliferativos/patología , Trastornos Mieloproliferativos/fisiopatología , Cilios/metabolismo , Cilios/patología , Animales , Médula Ósea/patología , Médula Ósea/metabolismo , Células Madre Hematopoyéticas/metabolismo , Mecanotransducción Celular , Matriz Extracelular/metabolismo , Transducción de Señal , Células de la Médula Ósea/metabolismo , Células de la Médula Ósea/patologíaRESUMEN
Background and aim: Bone marrow stem cells (BM-SCs) and their progeny play a central role in tissue repair and regeneration. In patients with chronic liver failure, bone marrow (BM) reserve is severally compromised and they showed marked defects in the resolution of injury and infection, leading to liver failure and the onset of decompensation. Whether BM failure is the cause or consequence of liver failure during cirrhosis is not known. In this study, we aimed to determine the underlying relationship between BM failure and regeneration failure in cirrhosis. Methodology: C57Bl/6(J) mice were used to develop chronic liver injury through intra-peritoneal administration of carbon tetrachloride (CCl4) for 15 weeks (0.1-0.5 ml/kg). Animals were sacrificed to study the transition of cirrhosis and BM defects. To restore the BM-SC reserve; healthy BM cells were infused via intra-BM infusion and assessed for changes in liver injury, regeneration, and BM-SC reserve. Results: Using a CCl4-induced animal - model of cirrhosis, we showed the loss of BM-SCs reserve occurred before regeneration failure and the onset of non-acute decompensation. Intra-BM infusion of healthy BM cells induced the repopulation of native hematopoietic stem cells (HSCs) in cirrhotic BM. Restoring BM-HSCs reserve augments liver macrophage-mediated clearance of infection and inflammation dampens neutrophil-mediated inflammation, accelerates fibrosis regression, enhances hepatocyte proliferation, and delays the onset of non-acute decompensation. Conclusion: These findings suggest that loss of BM-HSCs reserve underlies the compromised innate immune function of the liver, drives regeneration failure, and the onset of non-acute decompensation. We further provide the proof-of-concept that rejuvenating BM-HSC reserve can serve as a potential therapeutic approach for preventing regeneration failure and transition to decompensated cirrhosis.