RESUMO
Non-hematopoietic cells are essential contributors to hematopoiesis. However, heterogeneity and spatial organization of these cells in human bone marrow remain largely uncharacterized. We used single-cell RNA sequencing (scRNA-seq) to profile 29,325 non-hematopoietic cells and discovered nine transcriptionally distinct subtypes. We simultaneously profiled 53,417 hematopoietic cells and predicted their interactions with non-hematopoietic subsets. We employed co-detection by indexing (CODEX) to spatially profile over 1.2 million cells. We integrated scRNA-seq and CODEX data to link predicted cellular signaling with spatial proximity. Our analysis revealed a hyperoxygenated arterio-endosteal neighborhood for early myelopoiesis, and an adipocytic localization for early hematopoietic stem and progenitor cells (HSPCs). We used our CODEX atlas to annotate new images and uncovered mesenchymal stromal cell (MSC) expansion and spatial neighborhoods co-enriched for leukemic blasts and MSCs in acute myeloid leukemia (AML) patient samples. This spatially resolved, multiomic atlas of human bone marrow provides a reference for investigation of cellular interactions that drive hematopoiesis.
Assuntos
Medula Óssea , Células-Tronco Hematopoéticas , Células-Tronco Mesenquimais , Proteômica , Análise de Célula Única , Transcriptoma , Humanos , Análise de Célula Única/métodos , Medula Óssea/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/citologia , Proteômica/métodos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Hematopoese , Nicho de Células-Tronco , Células da Medula Óssea/metabolismo , Células da Medula Óssea/citologiaRESUMO
FMS-related tyrosine kinase 3 ligand (FLT3L), encoded by FLT3LG, is a hematopoietic factor essential for the development of natural killer (NK) cells, B cells, and dendritic cells (DCs) in mice. We describe three humans homozygous for a loss-of-function FLT3LG variant with a history of various recurrent infections, including severe cutaneous warts. The patients' bone marrow (BM) was hypoplastic, with low levels of hematopoietic progenitors, particularly myeloid and B cell precursors. Counts of B cells, monocytes, and DCs were low in the patients' blood, whereas the other blood subsets, including NK cells, were affected only moderately, if at all. The patients had normal counts of Langerhans cells (LCs) and dermal macrophages in the skin but lacked dermal DCs. Thus, FLT3L is required for B cell and DC development in mice and humans. However, unlike its murine counterpart, human FLT3L is required for the development of monocytes but not NK cells.
Assuntos
Células Matadoras Naturais , Proteínas de Membrana , Animais , Feminino , Humanos , Masculino , Camundongos , Linfócitos B/metabolismo , Linfócitos B/citologia , Medula Óssea/metabolismo , Linhagem da Célula , Células Dendríticas/metabolismo , Hematopoese , Células-Tronco Hematopoéticas/metabolismo , Células-Tronco Hematopoéticas/citologia , Células Matadoras Naturais/metabolismo , Células Matadoras Naturais/imunologia , Células de Langerhans/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Membrana/genética , Monócitos/metabolismo , Pele/metabolismo , Camundongos Endogâmicos C57BLRESUMO
The bone marrow in the skull is important for shaping immune responses in the brain and meninges, but its molecular makeup among bones and relevance in human diseases remain unclear. Here, we show that the mouse skull has the most distinct transcriptomic profile compared with other bones in states of health and injury, characterized by a late-stage neutrophil phenotype. In humans, proteome analysis reveals that the skull marrow is the most distinct, with differentially expressed neutrophil-related pathways and a unique synaptic protein signature. 3D imaging demonstrates the structural and cellular details of human skull-meninges connections (SMCs) compared with veins. Last, using translocator protein positron emission tomography (TSPO-PET) imaging, we show that the skull bone marrow reflects inflammatory brain responses with a disease-specific spatial distribution in patients with various neurological disorders. The unique molecular profile and anatomical and functional connections of the skull show its potential as a site for diagnosing, monitoring, and treating brain diseases.
Assuntos
Medula Óssea , Doenças do Sistema Nervoso , Crânio , Animais , Humanos , Camundongos , Medula Óssea/metabolismo , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Proteínas de Transporte/metabolismo , Doenças do Sistema Nervoso/metabolismo , Doenças do Sistema Nervoso/patologia , Tomografia por Emissão de Pósitrons/métodos , Receptores de GABA/metabolismo , Crânio/citologia , Crânio/diagnóstico por imagemRESUMO
Clonal hematopoiesis, a condition in which individual hematopoietic stem cell clones generate a disproportionate fraction of blood leukocytes, correlates with higher risk for cardiovascular disease. The mechanisms behind this association are incompletely understood. Here, we show that hematopoietic stem cell division rates are increased in mice and humans with atherosclerosis. Mathematical analysis demonstrates that increased stem cell proliferation expedites somatic evolution and expansion of clones with driver mutations. The experimentally determined division rate elevation in atherosclerosis patients is sufficient to produce a 3.5-fold increased risk of clonal hematopoiesis by age 70. We confirm the accuracy of our theoretical framework in mouse models of atherosclerosis and sleep fragmentation by showing that expansion of competitively transplanted Tet2-/- cells is accelerated under conditions of chronically elevated hematopoietic activity. Hence, increased hematopoietic stem cell proliferation is an important factor contributing to the association between cardiovascular disease and clonal hematopoiesis.
Assuntos
Aterosclerose/patologia , Hematopoiese Clonal , Células-Tronco Hematopoéticas/patologia , Envelhecimento/patologia , Animais , Apolipoproteínas E/genética , Aterosclerose/genética , Medula Óssea/metabolismo , Proliferação de Células , Evolução Clonal , Modelos Animais de Doenças , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Modelos Biológicos , Privação do Sono/patologiaRESUMO
Much has been learned about how cells enter lymphoid tissues. But how do they leave? Sphingosine-1-phosphate (S1P) has emerged over the past decade as a central mediator of lymphocyte egress. In this review, we summarize the current understanding of how S1P promotes exit from the secondary lymphoid organs and thymus. We review what is known about additional requirements for emigration and summarize the mostly distinct requirements for exit from the bone marrow. Egress from lymphoid organs is limited during immune responses, and we examine how this regulation works. There is accumulating evidence for roles of S1P in directing immune cell behavior within lymphoid tissues. How such actions can fit together with the egress-promoting role of S1P is discussed. Finally, we examine current understanding of how FTY720, a drug that targets S1P receptors and is approved for the treatment of multiple sclerosis, causes immune suppression.
Assuntos
Linfócitos/imunologia , Linfócitos/metabolismo , Tecido Linfoide/imunologia , Tecido Linfoide/metabolismo , Lisofosfolipídeos/metabolismo , Esfingosina/análogos & derivados , Animais , Medula Óssea/efeitos dos fármacos , Medula Óssea/imunologia , Medula Óssea/metabolismo , Cloridrato de Fingolimode , Humanos , Imunossupressores/farmacologia , Linfonodos/efeitos dos fármacos , Linfonodos/imunologia , Linfonodos/metabolismo , Linfócitos/efeitos dos fármacos , Tecido Linfoide/efeitos dos fármacos , Lisofosfolipídeos/imunologia , Modelos Biológicos , Propilenoglicóis/farmacologia , Esfingosina/imunologia , Esfingosina/metabolismo , Esfingosina/farmacologia , Timo/efeitos dos fármacos , Timo/imunologia , Timo/metabolismoRESUMO
Nutritional status potentially influences immune responses; however, how nutritional signals regulate cellular dynamics and functionality remains obscure. Herein, we report that temporary fasting drastically reduces the number of lymphocytes by â¼50% in Peyer's patches (PPs), the inductive site of the gut immune response. Subsequent refeeding seemingly restored the number of lymphocytes, but whose cellular composition was conspicuously altered. A large portion of germinal center and IgA+ B cells were lost via apoptosis during fasting. Meanwhile, naive B cells migrated from PPs to the bone marrow during fasting and then back to PPs during refeeding when stromal cells sensed nutritional signals and upregulated CXCL13 expression to recruit naive B cells. Furthermore, temporal fasting before oral immunization with ovalbumin abolished the induction of antigen-specific IgA, failed to induce oral tolerance, and eventually exacerbated food antigen-induced diarrhea. Thus, nutritional signals are critical in maintaining gut immune homeostasis.
Assuntos
Linfócitos B/fisiologia , Imunidade nas Mucosas , Animais , Antígenos/imunologia , Linfócitos B/imunologia , Linfócitos B/metabolismo , Medula Óssea/imunologia , Medula Óssea/metabolismo , Quimiocina CXCL13/genética , Quimiocina CXCL13/metabolismo , Jejum , Regulação da Expressão Gênica , Glicólise , Imunoglobulina A/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Estado Nutricional , Ovalbumina/imunologia , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/metabolismo , Nódulos Linfáticos Agregados/patologia , Receptores CXCR5/genética , Receptores CXCR5/metabolismo , Transdução de Sinais , Células Estromais/citologia , Células Estromais/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Mammals evolved in the face of fluctuating food availability. How the immune system adapts to transient nutritional stress remains poorly understood. Here, we show that memory T cells collapsed in secondary lymphoid organs in the context of dietary restriction (DR) but dramatically accumulated within the bone marrow (BM), where they adopted a state associated with energy conservation. This response was coordinated by glucocorticoids and associated with a profound remodeling of the BM compartment, which included an increase in T cell homing factors, erythropoiesis, and adipogenesis. Adipocytes, as well as CXCR4-CXCL12 and S1P-S1P1R interactions, contributed to enhanced T cell accumulation in BM during DR. Memory T cell homing to BM during DR was associated with enhanced protection against infections and tumors. Together, this work uncovers a fundamental host strategy to sustain and optimize immunological memory during nutritional challenges that involved a temporal and spatial reorganization of the memory pool within "safe haven" compartments.
Assuntos
Medula Óssea/metabolismo , Memória Imunológica , Animais , Medula Óssea/imunologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Restrição Calórica/veterinária , Linhagem Celular Tumoral , Quimiocina CXCL12/metabolismo , Dieta Redutora/veterinária , Metabolismo Energético , Regulação da Expressão Gênica , Glucocorticoides , Melanoma Experimental/mortalidade , Melanoma Experimental/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores CXCR4/metabolismo , Taxa de Sobrevida , Linfócitos T/imunologia , Linfócitos T/metabolismo , Serina-Treonina Quinases TOR/metabolismoRESUMO
Mutations of the CBP/p300 histone acetyltransferase (HAT) domain can be linked to leukemic transformation in humans, suggestive of a checkpoint of leukocyte compartment sizes. Here, we examined the impact of reversible inhibition of this domain by the small-molecule A485. We found that A485 triggered acute and transient mobilization of leukocytes from the bone marrow into the blood. Leukocyte mobilization by A485 was equally potent as, but mechanistically distinct from, granulocyte colony-stimulating factor (G-CSF), which allowed for additive neutrophil mobilization when both compounds were combined. These effects were maintained in models of leukopenia and conferred augmented host defenses. Mechanistically, activation of the hypothalamus-pituitary-adrenal gland (HPA) axis by A485 relayed shifts in leukocyte distribution through corticotropin-releasing hormone receptor 1 (CRHR1) and adrenocorticotropic hormone (ACTH), but independently of glucocorticoids. Our findings identify a strategy for rapid expansion of the blood leukocyte compartment via a neuroendocrine loop, with implications for the treatment of human pathologies.
Assuntos
Medula Óssea , Histona Acetiltransferases , Humanos , Histona Acetiltransferases/metabolismo , Medula Óssea/metabolismo , Histonas/metabolismo , Neutrófilos/metabolismo , Sistema Hipotálamo-Hipofisário/metabolismoRESUMO
Fasting is associated with improved outcomes in cancer. Here, we investigated the impact of fasting on natural killer (NK) cell anti-tumor immunity. Cyclic fasting improved immunity against solid and metastatic tumors in an NK cell-dependent manner. During fasting, NK cells underwent redistribution from peripheral tissues to the bone marrow (BM). In humans, fasting also reduced circulating NK cell numbers. NK cells in the spleen of fasted mice were metabolically rewired by elevated concentrations of fatty acids and glucocorticoids, augmenting fatty acid metabolism via increased expression of the enzyme CPT1A, and Cpt1a deletion impaired NK cell survival and function in this setting. In parallel, redistribution of NK cells to the BM during fasting required the trafficking mediators S1PR5 and CXCR4. These cells were primed by an increased pool of interleukin (IL)-12-expressing BM myeloid cells, which improved IFN-γ production. Our findings identify a link between dietary restriction and optimized innate immune responses, with the potential to enhance immunotherapy strategies.
Assuntos
Jejum , Células Matadoras Naturais , Camundongos Endogâmicos C57BL , Animais , Células Matadoras Naturais/imunologia , Células Matadoras Naturais/metabolismo , Camundongos , Humanos , Neoplasias/imunologia , Medula Óssea/imunologia , Medula Óssea/metabolismo , Camundongos Knockout , Interferon gama/metabolismo , Interferon gama/imunologia , Baço/imunologia , Baço/metabolismo , Imunidade Inata/imunologia , Interleucina-12/metabolismo , Interleucina-12/imunologia , Receptores CXCR4/metabolismoRESUMO
The haematopoietic stem cell (HSC) microenvironment in the bone marrow, termed the niche, ensures haematopoietic homeostasis by controlling the proliferation, self-renewal, differentiation and migration of HSCs and progenitor cells at steady state and in response to emergencies and injury. Improved methods for HSC isolation, driven by advances in single-cell and molecular technologies, have led to a better understanding of their behaviour, heterogeneity and lineage fate and of the niche cells and signals that regulate their function. Niche regulatory signals can be in the form of cell-bound or secreted factors and other local physical cues. A combination of technological advances in bone marrow imaging and genetic manipulation of crucial regulatory factors has enabled the identification of several candidate cell types regulating the niche, including both non-haematopoietic (for example, perivascular mesenchymal stem and endothelial cells) and HSC-derived (for example, megakaryocytes, macrophages and regulatory T cells), with better topographical understanding of HSC localization in the bone marrow. Here, we review advances in our understanding of HSC regulation by niches during homeostasis, ageing and cancer, and we discuss their implications for the development of therapies to rejuvenate aged HSCs or niches or to disrupt self-reinforcing malignant niches.
Assuntos
Envelhecimento/metabolismo , Diferenciação Celular , Células-Tronco Hematopoéticas/metabolismo , Homeostase , Neoplasias/metabolismo , Nicho de Células-Tronco , Envelhecimento/patologia , Animais , Medula Óssea/metabolismo , Medula Óssea/patologia , Senescência Celular , Células Endoteliais/metabolismo , Células Endoteliais/patologia , Células-Tronco Hematopoéticas/patologia , Humanos , Neoplasias/patologiaRESUMO
Myeloid cells encounter stromal cells and their matrix determinants on a continual basis during their residence in any given organ. Here, we examined the impact of the collagen receptor LAIR1 on myeloid cell homeostasis and function. LAIR1 was highly expressed in the myeloid lineage and enriched in non-classical monocytes. Proteomic definition of the LAIR1 interactome identified stromal factor Colec12 as a high-affinity LAIR1 ligand. Proteomic profiling of LAIR1 signaling triggered by Collagen1 and Colec12 highlighted pathways associated with survival, proliferation, and differentiation. Lair1-/- mice had reduced frequencies of Ly6C- monocytes, which were associated with altered proliferation and apoptosis of non-classical monocytes from bone marrow and altered heterogeneity of interstitial macrophages in lung. Myeloid-specific LAIR1 deficiency promoted metastatic growth in a melanoma model and LAIR1 expression associated with improved clinical outcomes in human metastatic melanoma. Thus, monocytes and macrophages rely on LAIR1 sensing of stromal determinants for fitness and function, with relevance in homeostasis and disease.
Assuntos
Homeostase/fisiologia , Pulmão/metabolismo , Macrófagos Alveolares/metabolismo , Monócitos/metabolismo , Receptores Imunológicos/metabolismo , Animais , Apoptose/fisiologia , Medula Óssea/metabolismo , Medula Óssea/patologia , Células COS , Diferenciação Celular/fisiologia , Linhagem Celular , Linhagem Celular Tumoral , Linhagem da Célula/fisiologia , Proliferação de Células/fisiologia , Chlorocebus aethiops , Feminino , Humanos , Pulmão/patologia , Macrófagos Alveolares/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Monócitos/patologia , Células Mieloides/metabolismo , Células Mieloides/patologia , Metástase Neoplásica/patologia , Proteômica/métodos , Transdução de Sinais/fisiologiaRESUMO
Myeloid cells are known to suppress antitumour immunity1. However, the molecular drivers of immunosuppressive myeloid cell states are not well defined. Here we used single-cell RNA sequencing of human and mouse non-small cell lung cancer (NSCLC) lesions, and found that in both species the type 2 cytokine interleukin-4 (IL-4) was predicted to be the primary driver of the tumour-infiltrating monocyte-derived macrophage phenotype. Using a panel of conditional knockout mice, we found that only deletion of the IL-4 receptor IL-4Rα in early myeloid progenitors in bone marrow reduced tumour burden, whereas deletion of IL-4Rα in downstream mature myeloid cells had no effect. Mechanistically, IL-4 derived from bone marrow basophils and eosinophils acted on granulocyte-monocyte progenitors to transcriptionally programme the development of immunosuppressive tumour-promoting myeloid cells. Consequentially, depletion of basophils profoundly reduced tumour burden and normalized myelopoiesis. We subsequently initiated a clinical trial of the IL-4Rα blocking antibody dupilumab2-5 given in conjunction with PD-1/PD-L1 checkpoint blockade in patients with relapsed or refractory NSCLC who had progressed on PD-1/PD-L1 blockade alone (ClinicalTrials.gov identifier NCT05013450 ). Dupilumab supplementation reduced circulating monocytes, expanded tumour-infiltrating CD8 T cells, and in one out of six patients, drove a near-complete clinical response two months after treatment. Our study defines a central role for IL-4 in controlling immunosuppressive myelopoiesis in cancer, identifies a novel combination therapy for immune checkpoint blockade in humans, and highlights cancer as a systemic malady that requires therapeutic strategies beyond the primary disease site.
Assuntos
Medula Óssea , Carcinogênese , Interleucina-4 , Mielopoese , Transdução de Sinais , Animais , Humanos , Camundongos , Antígeno B7-H1/antagonistas & inibidores , Antígeno B7-H1/metabolismo , Medula Óssea/efeitos dos fármacos , Medula Óssea/metabolismo , Carcinogênese/efeitos dos fármacos , Carcinogênese/metabolismo , Carcinogênese/patologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Carcinoma Pulmonar de Células não Pequenas/terapia , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Inibidores de Checkpoint Imunológico/imunologia , Inibidores de Checkpoint Imunológico/farmacologia , Inibidores de Checkpoint Imunológico/uso terapêutico , Interleucina-4/metabolismo , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Neoplasias Pulmonares/terapia , Linfócitos do Interstício Tumoral/efeitos dos fármacos , Linfócitos do Interstício Tumoral/imunologia , Monócitos/efeitos dos fármacos , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/metabolismo , Recidiva , Transdução de Sinais/efeitos dos fármacosRESUMO
Neutrophils are the most abundant peripheral immune cells and thus, are continually replenished by bone marrow-derived progenitors. Still, how newly identified neutrophil subsets fit into the bone marrow neutrophil lineage remains unclear. Here, we use mass cytometry to show that two recently defined human neutrophil progenitor populations contain a homogeneous progenitor subset we term "early neutrophil progenitors" (eNePs) (Lin-CD66b+CD117+CD71+). Surface marker- and RNA-expression analyses, together with in vitro colony formation and in vivo adoptive humanized mouse transfers, indicate that eNePs are the earliest human neutrophil progenitors. Furthermore, we identified CD71 as a marker associated with the earliest neutrophil developmental stages. Expression of CD71 marks proliferating neutrophils, which were expanded in the blood of melanoma patients and detectable in blood and tumors from lung cancer patients. In summary, we establish CD117+CD71+ eNeP as the inceptive human neutrophil progenitor and propose a refined model of the neutrophil developmental lineage in bone marrow.
Assuntos
Antígenos CD/metabolismo , Células da Medula Óssea/citologia , Células Progenitoras Mieloides/metabolismo , Neutrófilos/citologia , Proteínas Proto-Oncogênicas c-kit/metabolismo , Receptores da Transferrina/metabolismo , Transferência Adotiva , Animais , Medula Óssea/metabolismo , Linhagem da Célula , Humanos , Masculino , Melanoma/sangue , Camundongos , Camundongos Endogâmicos NOD , Células Progenitoras Mieloides/citologiaRESUMO
How organ-specific metastatic traits arise in primary tumors remains unknown. Here, we show a role of the breast tumor stroma in selecting cancer cells that are primed for metastasis in bone. Cancer-associated fibroblasts (CAFs) in triple-negative (TN) breast tumors skew heterogeneous cancer cell populations toward a predominance of clones that thrive on the CAF-derived factors CXCL12 and IGF1. Limiting concentrations of these factors select for cancer cells with high Src activity, a known clinical predictor of bone relapse and an enhancer of PI3K-Akt pathway activation by CXCL12 and IGF1. Carcinoma clones selected in this manner are primed for metastasis in the CXCL12-rich microenvironment of the bone marrow. The evidence suggests that stromal signals resembling those of a distant organ select for cancer cells that are primed for metastasis in that organ, thus illuminating the evolution of metastatic traits in a primary tumor and its distant metastases.
Assuntos
Neoplasias Ósseas/secundário , Neoplasias da Mama/patologia , Metástase Neoplásica , Transdução de Sinais , Animais , Medula Óssea/metabolismo , Neoplasias Ósseas/metabolismo , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Quimiocina CXCL12/metabolismo , Fibroblastos/metabolismo , Humanos , Fator de Crescimento Insulin-Like I/metabolismo , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/patologia , Camundongos , Transplante de Neoplasias , Transcrição Gênica , Transplante Heterólogo , Quinases da Família src/genética , Quinases da Família src/metabolismoRESUMO
The human bone marrow (BM) niche sustains hematopoiesis throughout life. We present a method for generating complex BM-like organoids (BMOs) from human induced pluripotent stem cells (iPSCs). BMOs consist of key cell types that self-organize into spatially defined three-dimensional structures mimicking cellular, structural and molecular characteristics of the hematopoietic microenvironment. Functional properties of BMOs include the presence of an in vivo-like vascular network, the presence of multipotent mesenchymal stem/progenitor cells, the support of neutrophil differentiation and responsiveness to inflammatory stimuli. Single-cell RNA sequencing revealed a heterocellular composition including the presence of a hematopoietic stem/progenitor (HSPC) cluster expressing genes of fetal HSCs. BMO-derived HSPCs also exhibited lymphoid potential and a subset demonstrated transient engraftment potential upon xenotransplantation in mice. We show that the BMOs could enable the modeling of hematopoietic developmental aspects and inborn errors of hematopoiesis, as shown for human VPS45 deficiency. Thus, iPSC-derived BMOs serve as a physiologically relevant in vitro model of the human BM microenvironment to study hematopoietic development and BM diseases.
Assuntos
Diferenciação Celular , Hematopoese , Células-Tronco Pluripotentes Induzidas , Organoides , Humanos , Organoides/citologia , Organoides/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Animais , Camundongos , Células-Tronco Hematopoéticas/citologia , Medula Óssea/metabolismo , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Técnicas de Cultura de Células/métodos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismoRESUMO
Disrupting the balance between self-renewal and differentiation of hematopoietic stem cells (HSCs) leads to bone marrow failure or hematologic malignancy. However, how HSCs sustain their quiescent state and avoid type I interferon (IFN)-mediated exhaustion remains elusive. Here we defined a circular RNA that we named cia-cGAS that was highly expressed in the nucleus of long-term (LT)-HSCs. Cia-cGAS deficiency in mice caused elevated expression of type I IFNs in bone marrow and led to decreased numbers of dormant LT-HSCs. Under homeostatic conditions, cia-cGAS bound DNA sensor cGAS in the nucleus to block its synthase activity, thereby protecting dormant LT-HSCs from cGAS-mediated exhaustion. Moreover, cia-cGAS harbored a stronger binding affinity to cGAS than self-DNA did and consequently suppressed cGAS-mediated production of type I IFNs in LT-HSCs. Our findings reveal a mechanism by which cia-cGAS inhibits nuclear cGAS by blocking its enzymatic activity and preventing cGAS from recognizing self-DNA to maintain host homeostasis.
Assuntos
Diferenciação Celular/fisiologia , Células-Tronco Hematopoéticas/citologia , Interferon Tipo I/metabolismo , Nucleotidiltransferases/metabolismo , RNA/metabolismo , Animais , Medula Óssea/metabolismo , Comunicação Celular , Linhagem Celular , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Conformação de Ácido Nucleico , Nucleotidiltransferases/antagonistas & inibidores , Nucleotidiltransferases/genética , RNA/genética , Interferência de RNA , RNA Circular , RNA Interferente Pequeno/genéticaRESUMO
Clonal haematopoiesis, which is highly prevalent in older individuals, arises from somatic mutations that endow a proliferative advantage to haematopoietic cells. Clonal haematopoiesis increases the risk of myocardial infarction and stroke independently of traditional risk factors1. Among the common genetic variants that give rise to clonal haematopoiesis, the JAK2V617F (JAK2VF) mutation, which increases JAK-STAT signalling, occurs at a younger age and imparts the strongest risk of premature coronary heart disease1,2. Here we show increased proliferation of macrophages and prominent formation of necrotic cores in atherosclerotic lesions in mice that express Jak2VF selectively in macrophages, and in chimeric mice that model clonal haematopoiesis. Deletion of the essential inflammasome components caspase 1 and 11, or of the pyroptosis executioner gasdermin D, reversed these adverse changes. Jak2VF lesions showed increased expression of AIM2, oxidative DNA damage and DNA replication stress, and Aim2 deficiency reduced atherosclerosis. Single-cell RNA sequencing analysis of Jak2VF lesions revealed a landscape that was enriched for inflammatory myeloid cells, which were suppressed by deletion of Gsdmd. Inhibition of the inflammasome product interleukin-1ß reduced macrophage proliferation and necrotic formation while increasing the thickness of fibrous caps, indicating that it stabilized plaques. Our findings suggest that increased proliferation and glycolytic metabolism in Jak2VF macrophages lead to DNA replication stress and activation of the AIM2 inflammasome, thereby aggravating atherosclerosis. Precise application of therapies that target interleukin-1ß or specific inflammasomes according to clonal haematopoiesis status could substantially reduce cardiovascular risk.
Assuntos
Aterosclerose/patologia , Hematopoiese Clonal , Proteínas de Ligação a DNA/metabolismo , Inflamassomos/metabolismo , Animais , Anticorpos/imunologia , Anticorpos/uso terapêutico , Aterosclerose/tratamento farmacológico , Aterosclerose/imunologia , Medula Óssea/metabolismo , Caspase 1/metabolismo , Caspases Iniciadoras/metabolismo , Modelos Animais de Doenças , Feminino , Humanos , Inflamação/metabolismo , Inflamação/patologia , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Interleucina-1beta/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Macrófagos/patologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Ligação a Fosfato/metabolismo , Piroptose , RNA-Seq , Análise de Célula ÚnicaRESUMO
ABSTRACT: Regulation of lineage biases in hematopoietic stem and progenitor cells (HSPCs) is pivotal for balanced hematopoietic output. However, little is known about the mechanism behind lineage choice in HSPCs. Here, we show that messenger RNA (mRNA) decay factors regnase-1 (Reg1; Zc3h12a) and regnase-3 (Reg3; Zc3h12c) are essential for determining lymphoid fate and restricting myeloid differentiation in HSPCs. Loss of Reg1 and Reg3 resulted in severe impairment of lymphopoiesis and a mild increase in myelopoiesis in the bone marrow. Single-cell RNA sequencing analysis revealed that Reg1 and Reg3 regulate lineage directions in HSPCs via the control of a set of myeloid-related genes. Reg1- and Reg3-mediated control of mRNA encoding Nfkbiz, a transcriptional and epigenetic regulator, was essential for balancing lymphoid/myeloid lineage output in HSPCs in vivo. Furthermore, single-cell assay for transposase-accessible chromatin sequencing analysis revealed that Reg1 and Reg3 control the epigenetic landscape on myeloid-related gene loci in early stage HSPCs via Nfkbiz. Consistently, an antisense oligonucleotide designed to inhibit Reg1- and Reg3-mediated Nfkbiz mRNA degradation primed hematopoietic stem cells toward myeloid lineages by enhancing Nfkbiz expression. Collectively, the collaboration between posttranscriptional control and chromatin remodeling by the Reg1/Reg3-Nfkbiz axis governs HSPC lineage biases, ultimately dictating the fate of lymphoid vs myeloid differentiation.
Assuntos
Medula Óssea , Células-Tronco Hematopoéticas , Linhagem da Célula/genética , Células-Tronco Hematopoéticas/metabolismo , Medula Óssea/metabolismo , Hematopoese/genética , RNA Mensageiro/metabolismo , Diferenciação Celular/genéticaRESUMO
ABSTRACT: Acute leukemia cells require bone marrow microenvironments, known as niches, which provide leukemic cells with niche factors that are essential for leukemic cell survival and/or proliferation. However, it remains unclear how the dynamics of the leukemic cell-niche interaction are regulated. Using a genome-wide CRISPR screen, we discovered that canonical BRG1/BRM-associated factor (cBAF), a variant of the switch/sucrose nonfermenting chromatin remodeling complex, regulates the migratory response of human T-cell acute lymphoblastic leukemia (T-ALL) cells to a niche factor CXCL12. Mechanistically, cBAF maintains chromatin accessibility and allows RUNX1 to bind to CXCR4 enhancer regions. cBAF inhibition evicts RUNX1 from the genome, resulting in CXCR4 downregulation and impaired migration activity. In addition, cBAF maintains chromatin accessibility preferentially at RUNX1 binding sites, ensuring RUNX1 binding at these sites, and is required for expression of RUNX1-regulated genes, such as CDK6; therefore, cBAF inhibition negatively impacts cell proliferation and profoundly induces apoptosis. This anticancer effect was also confirmed using T-ALL xenograft models, suggesting cBAF as a promising therapeutic target. Thus, we provide novel evidence that cBAF regulates the RUNX1-driven leukemic program and governs migration activity toward CXCL12 and cell-autonomous growth in human T-ALL.
Assuntos
Subunidade alfa 2 de Fator de Ligação ao Core , Leucemia-Linfoma Linfoblástico de Células T Precursoras , Humanos , Subunidade alfa 2 de Fator de Ligação ao Core/genética , Subunidade alfa 2 de Fator de Ligação ao Core/metabolismo , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Medula Óssea/metabolismo , Cromatina , Linfócitos T/metabolismo , Linhagem Celular Tumoral , Microambiente TumoralRESUMO
ABSTRACT: Hematopoietic stem cells (HSCs) are instrumental for organismal survival because they are responsible for lifelong production of mature blood lineages in homeostasis and response to external stress. To fulfill their function, HSCs rely on reciprocal interactions with specialized tissue microenvironments, termed HSC niches. From embryonic development to advanced aging, HSCs transition through several hematopoietic organs in which they are supported by distinct extrinsic cues. Here, we describe recent discoveries on how HSC niches collectively adapt to ensure robust hematopoietic function during biological aging and after exposure to acute stress. We also discuss the latest strategies leveraging niche-derived signals to revert aging-associated phenotypes and enhance hematopoietic recovery after myeloablation.