RESUMEN
Hematopoietic stem and progenitor cells (HSPCs) are regulated by various bone marrow stromal cell types. Here we identified rare activated bone marrow monocytes and macrophages with high expression of α-smooth muscle actin (α-SMA) and the cyclooxygenase COX-2 that were adjacent to primitive HSPCs. These myeloid cells resisted radiation-induced cell death and further upregulated COX-2 expression under stress conditions. COX-2-derived prostaglandin E(2) (PGE(2)) prevented HSPC exhaustion by limiting the production of reactive oxygen species (ROS) via inhibition of the kinase Akt and higher stromal-cell expression of the chemokine CXCL12, which is essential for stem-cell quiescence. Our study identifies a previously unknown subset of α-SMA(+) activated monocytes and macrophages that maintain HSPCs and protect them from exhaustion during alarm situations.
Asunto(s)
Actinas/inmunología , Médula Ósea/inmunología , Células Madre Hematopoyéticas/inmunología , Macrófagos/inmunología , Monocitos/inmunología , Actinas/genética , Animales , Médula Ósea/metabolismo , Médula Ósea/efectos de la radiación , Comunicación Celular/genética , Comunicación Celular/inmunología , Movimiento Celular/genética , Movimiento Celular/inmunología , Supervivencia Celular/genética , Supervivencia Celular/inmunología , Supervivencia Celular/efectos de la radiación , Quimiocina CXCL12/genética , Quimiocina CXCL12/inmunología , Ciclooxigenasa 2/genética , Ciclooxigenasa 2/inmunología , Dinoprostona/biosíntesis , Dinoprostona/inmunología , Rayos gamma , Regulación de la Expresión Génica/inmunología , Regulación de la Expresión Génica/efectos de la radiación , Células Madre Hematopoyéticas/citología , Células Madre Hematopoyéticas/efectos de la radiación , Macrófagos/citología , Macrófagos/efectos de la radiación , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/inmunología , Células Madre Mesenquimatosas/efectos de la radiación , Ratones , Monocitos/citología , Monocitos/efectos de la radiación , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/inmunología , Especies Reactivas de Oxígeno/inmunología , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/genética , Transducción de Señal/inmunología , Transducción de Señal/efectos de la radiaciónRESUMEN
The chemokine CXCL12 is essential for the function of hematopoietic stem and progenitor cells. Here we report that secretion of functional CXCL12 from human bone marrow stromal cells (BMSCs) was a cell contact-dependent event mediated by connexin-43 (Cx43) and Cx45 gap junctions. Inhibition of connexin gap junctions impaired the secretion of CXCL12 and homing of leukocytes to mouse bone marrow. Purified human CD34(+) progenitor cells did not adhere to noncontacting BMSCs, which led to a much smaller pool of immature cells. Calcium conduction activated signaling by cAMP-protein kinase A (PKA) and induced CXCL12 secretion mediated by the GTPase RalA. Cx43 and Cx45 additionally controlled Cxcl12 transcription by regulating the nuclear localization of the transcription factor Sp1. We suggest that BMSCs form a dynamic syncytium via connexin gap junctions that regulates CXC12 secretion and the homeostasis of hematopoietic stem cells.
Asunto(s)
Células de la Médula Ósea/inmunología , Quimiocina CXCL12/inmunología , Conexinas/inmunología , Uniones Comunicantes/inmunología , Células Madre Hematopoyéticas/inmunología , Células Madre Mesenquimatosas/inmunología , Células del Estroma/inmunología , Animales , Calcio/inmunología , Movimiento Celular/inmunología , Técnicas de Cocultivo , Proteínas Quinasas Dependientes de AMP Cíclico/inmunología , Humanos , Inmunohistoquímica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Microscopía Fluorescente , Proteínas de Unión al GTP ral/inmunologíaRESUMEN
The fate of hematopoietic stem and progenitor cells (HSPC) is tightly regulated by their bone marrow (BM) microenvironment (ME). BM transplantation (BMT) frequently requires irradiation preconditioning to ablate endogenous hematopoietic cells. Whether the stromal ME is damaged and how it recovers after irradiation is unknown. We report that BM mesenchymal stromal cells (MSC) undergo massive damage to their mitochondrial function after irradiation. Donor healthy HSPC transfer functional mitochondria to the stromal ME, thus improving mitochondria activity in recipient MSC. Mitochondrial transfer to MSC is cell-contact dependent and mediated by HSPC connexin-43 (Cx43). Hematopoietic Cx43-deficient chimeric mice show reduced mitochondria transfer, which was rescued upon re-expression of Cx43 in HSPC or culture with isolated mitochondria from Cx43 deficient HSPCs. Increased intracellular adenosine triphosphate levels activate the purinergic receptor P2RX7 and lead to reduced activity of adenosine 5'-monophosphate-activated protein kinase (AMPK) in HSPC, dramatically increasing mitochondria transfer to BM MSC. Host stromal ME recovery and donor HSPC engraftment were augmented after mitochondria transfer. Deficiency of Cx43 delayed mesenchymal and osteogenic regeneration while in vivo AMPK inhibition increased stromal recovery. As a consequence, the hematopoietic compartment reconstitution was improved because of the recovery of the supportive stromal ME. Our findings demonstrate that healthy donor HSPC not only reconstitute the hematopoietic system after transplantation, but also support and induce the metabolic recovery of their irradiated, damaged ME via mitochondria transfer. Understanding the mechanisms regulating stromal recovery after myeloablative stress are of high clinical interest to optimize BMT procedures and underscore the importance of accessory, non-HSC to accelerate hematopoietic engraftment.
Asunto(s)
Médula Ósea/fisiología , Conexina 43/metabolismo , Células Madre Hematopoyéticas/metabolismo , Mitocondrias/trasplante , Regeneración , Animales , Humanos , RatonesRESUMEN
Bone marrow endothelial cells (BMECs) form a network of blood vessels that regulate both leukocyte trafficking and haematopoietic stem and progenitor cell (HSPC) maintenance. However, it is not clear how BMECs balance these dual roles, and whether these events occur at the same vascular site. We found that mammalian bone marrow stem cell maintenance and leukocyte trafficking are regulated by distinct blood vessel types with different permeability properties. Less permeable arterial blood vessels maintain haematopoietic stem cells in a low reactive oxygen species (ROS) state, whereas the more permeable sinusoids promote HSPC activation and are the exclusive site for immature and mature leukocyte trafficking to and from the bone marrow. A functional consequence of high permeability of blood vessels is that exposure to blood plasma increases bone marrow HSPC ROS levels, augmenting their migration and differentiation, while compromising their long-term repopulation and survival. These findings may have relevance for clinical haematopoietic stem cell transplantation and mobilization protocols.
Asunto(s)
Vasos Sanguíneos/citología , Vasos Sanguíneos/fisiología , Médula Ósea/irrigación sanguínea , Hematopoyesis , Animales , Antígenos Ly/metabolismo , Arterias/citología , Arterias/fisiología , Células de la Médula Ósea/citología , Diferenciación Celular , Movimiento Celular , Autorrenovación de las Células , Supervivencia Celular , Quimiocina CXCL12/metabolismo , Células Endoteliales/fisiología , Femenino , Movilización de Célula Madre Hematopoyética , Trasplante de Células Madre Hematopoyéticas , Células Madre Hematopoyéticas/citología , Leucocitos/citología , Masculino , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Nestina/metabolismo , Pericitos/fisiología , Permeabilidad , Plasma/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Receptores CXCR4/metabolismoRESUMEN
The mechanisms of hematopoietic progenitor cell egress and clinical mobilization are not fully understood. Herein, we report that in vivo desensitization of Sphingosine-1-phosphate (S1P) receptors by FTY720 as well as disruption of S1P gradient toward the blood, reduced steady state egress of immature progenitors and primitive Sca-1(+)/c-Kit(+)/Lin(-) (SKL) cells via inhibition of SDF-1 release. Administration of AMD3100 or G-CSF to mice with deficiencies in either S1P production or its receptor S1P(1), or pretreated with FTY720, also resulted in reduced stem and progenitor cell mobilization. Mice injected with AMD3100 or G-CSF demonstrated transient increased S1P levels in the blood mediated via mTOR signaling, as well as an elevated rate of immature c-Kit(+)/Lin(-) cells expressing surface S1P(1) in the bone marrow (BM). Importantly, we found that S1P induced SDF-1 secretion from BM stromal cells including Nestin(+) mesenchymal stem cells via reactive oxygen species (ROS) signaling. Moreover, elevated ROS production by hematopoietic progenitor cells is also regulated by S1P. Our findings reveal that the S1P/S1P(1) axis regulates progenitor cell egress and mobilization via activation of ROS signaling on both hematopoietic progenitors and BM stromal cells, and SDF-1 release. The dynamic cross-talk between S1P and SDF-1 integrates BM stromal cells and hematopoeitic progenitor cell motility.
Asunto(s)
Quimiocina CXCL12/metabolismo , Movilización de Célula Madre Hematopoyética , Células Madre Hematopoyéticas/citología , Lisofosfolípidos/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/fisiología , Especies Reactivas de Oxígeno/metabolismo , Receptores de Lisoesfingolípidos/fisiología , Esfingosina/análogos & derivados , Animales , Bencilaminas , Médula Ósea/metabolismo , Movimiento Celular , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Ciclamas , Femenino , Citometría de Flujo , Técnica del Anticuerpo Fluorescente , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Células Madre Hematopoyéticas/metabolismo , Compuestos Heterocíclicos , Masculino , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Transducción de Señal , Esfingosina/metabolismo , Células del Estroma/citología , Células del Estroma/metabolismoRESUMEN
Cytokine-induced expansion of hematopoietic stem and progenitor cells (HSPCs) is not fully understood. In the present study, we show that whereas steady-state hematopoiesis is normal in basic fibroblast growth factor (FGF-2)-knockout mice, parathyroid hormone stimulation and myeloablative treatments failed to induce normal HSPC proliferation and recovery. In vivo FGF-2 treatment expanded stromal cells, including perivascular Nestin(+) supportive stromal cells, which may facilitate HSPC expansion by increasing SCF and reducing CXCL12 via mir-31 up-regulation. FGF-2 predominantly expanded a heterogeneous population of undifferentiated HSPCs, preserving and increasing durable short- and long-term repopulation potential. Mechanistically, these effects were mediated by c-Kit receptor activation, STAT5 phosphorylation, and reduction of reactive oxygen species levels. Mice harboring defective c-Kit signaling exhibited abrogated HSPC expansion in response to FGF-2 treatment, which was accompanied by elevated reactive oxygen species levels. The results of the present study reveal a novel mechanism underlying FGF-2-mediated in vivo expansion of both HSPCs and their supportive stromal cells, which may be used to improve stem cell engraftment after clinical transplantation.
Asunto(s)
Proliferación Celular , Quimiocina CXCL12/metabolismo , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Células Madre Hematopoyéticas/metabolismo , Proteínas Proto-Oncogénicas c-kit/metabolismo , Células del Estroma/metabolismo , Animales , Secuencia de Bases , Trasplante de Médula Ósea , Ciclo Celular/efectos de los fármacos , Células Cultivadas , Quimiocina CXCL12/genética , Regulación hacia Abajo/efectos de los fármacos , Factor 2 de Crecimiento de Fibroblastos/genética , Factor 2 de Crecimiento de Fibroblastos/farmacología , Citometría de Flujo , Expresión Génica/efectos de los fármacos , Células Madre Hematopoyéticas/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Modelos Biológicos , Hormona Paratiroidea/farmacología , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-kit/genética , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Factor de Transcripción STAT5/metabolismo , Células del Estroma/efectos de los fármacosRESUMEN
Rearrangements of the MLL (ALL1) gene are very common in acute infant and therapy-associated leukemias. The rearrangements underlie the generation of MLL fusion proteins acting as potent oncogenes. Several most consistently up-regulated targets of MLL fusions, MEIS1, HOXA7, HOXA9, and HOXA10 are functionally related and have been implicated in other types of leukemias. Each of the four genes was knocked down separately in the human precursor B-cell leukemic line RS4;11 expressing MLL-AF4. The mutant and control cells were compared for engraftment in NOD/SCID mice. Engraftment of all mutants into the bone marrow (BM) was impaired. Although homing was similar, colonization by the knockdown cells was slowed. Initially, both types of cells were confined to the trabecular area; this was followed by a rapid spread of the WT cells to the compact bone area, contrasted with a significantly slower process for the mutants. In vitro and in vivo BrdU incorporation experiments indicated reduced proliferation of the mutant cells. In addition, the CXCR4/SDF-1 axis was hampered, as evidenced by reduced migration toward an SDF-1 gradient and loss of SDF-1-augmented proliferation in culture. The very similar phenotype shared by all mutant lines implies that all four genes are involved and required for expansion of MLL-AF4 associated leukemic cells in mice, and down-regulation of any of them is not compensated by the others.
Asunto(s)
Genes Homeobox , Proteínas de Homeodominio/genética , Proteína de la Leucemia Mieloide-Linfoide/genética , Proteínas de Neoplasias/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Animales , Secuencia de Bases , Línea Celular Tumoral , Proliferación Celular , Regulación hacia Abajo , Técnicas de Silenciamiento del Gen , Reordenamiento Génico , N-Metiltransferasa de Histona-Lisina , Humanos , Ratones , Ratones Endogámicos NOD , Ratones SCID , Proteína 1 del Sitio de Integración Viral Ecotrópica Mieloide , Trasplante de Neoplasias , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , ARN Interferente Pequeño/genética , Trasplante HeterólogoRESUMEN
Proteolytic processes on cell surfaces and extracellular matrix (ECM) sustain cell behavior and tissue integrity in health and disease. Matrix metalloproteases (MMPs) and a disintegrin and metalloproteases (ADAMs) remodel cell microenvironments through irreversible proteolysis of ECM proteins and cell surface bioactive molecules. Pan-MMP inhibitors in inflammation and cancer clinical trials have encountered challenges due to promiscuous activities of MMPs. Systems biology advances revealed that MMPs initiate multifactorial proteolytic cascades, creating new substrates, activating or suppressing other MMPs, and generating signaling molecules. This review highlights the intricate network that underscores the role of MMPs beyond individual substrate-enzyme activities. Gaining insight into MMP function and tissue specificity is crucial for developing effective drug discovery strategies and novel therapeutics. This requires considering the dynamic cellular processes and consequences of network proteolysis.
Asunto(s)
Metaloproteasas , Neoplasias , Humanos , Proteolisis , Metaloproteasas/análisis , Metaloproteasas/metabolismo , Neoplasias/metabolismo , Matriz Extracelular/metabolismo , Inflamación/metabolismo , Microambiente TumoralRESUMEN
Ineffective endometrial matrix remodeling, a key factor in infertility, impedes embryo implantation in the uterine wall. Our study reveals the cellular and molecular impact of human collagenase-1 administration in mouse uteri, demonstrating enhanced embryo implantation rates. Collagenase-1 promotes remodeling of the endometrial ECM, degrading collagen fibers and proteoglycans. This process releases matrix-bound bioactive factors (e.g., VEGF, decorin), facilitating vascular permeability and angiogenesis. Collagenase-1 elevates embryo implantation regulators, including NK cell infiltration and the key cytokine LIF. Remarkably, uterine tissue maintains structural integrity despite reduced endometrial collagen fiber tension. In-utero collagenase-1 application rescues implantation in heat stress and embryo transfer models, known for low implantation rates. Importantly, ex vivo exposure of human uterine tissue to collagenase-1 induces collagen de-tensioning and VEGF release, mirroring remodeling observed in mice. Our research highlights the potential of collagenases to induce and orchestrate cellular and molecular processes enhancing uterine receptivity for effective embryo implantation. This innovative approach underscores ECM remodeling mechanisms critical for embryo implantation.
Asunto(s)
Colagenasas , Implantación del Embrión , Útero , Femenino , Animales , Ratones , Colagenasas/metabolismo , Humanos , Útero/metabolismo , Matriz Extracelular/metabolismo , Endometrio/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismo , Embarazo , Transferencia de Embrión/métodos , Colágeno/metabolismo , Ratones Endogámicos C57BLRESUMEN
Mechanisms governing stress-induced hematopoietic progenitor cell mobilization are not fully deciphered. We report that during granulocyte colony-stimulating factor-induced mobilization c-Met expression and signaling are up-regulated on immature bone marrow progenitors. Interestingly, stromal cell-derived factor 1/CXC chemokine receptor-4 signaling induced hepatocyte growth factor production and c-Met activation. We found that c-Met inhibition reduced mobilization of both immature progenitors and the more primitive Sca-1(+)/c-Kit(+)/Lin(-) cells and interfered with their enhanced chemotactic migration to stromal cell-derived factor 1. c-Met activation resulted in cellular accumulation of reactive oxygen species by mammalian target of rapamycin inhibition of Forkhead Box, subclass O3a. Blockage of mammalian target of rapamycin inhibition or reactive oxygen species signaling impaired c-Met-mediated mobilization. Our data show dynamic c-Met expression and function in the bone marrow and show that enhanced c-Met signaling is crucial to facilitate stress-induced mobilization of progenitor cells as part of host defense and repair mechanisms.
Asunto(s)
Movimiento Celular/fisiología , Factor Estimulante de Colonias de Granulocitos/metabolismo , Células Madre Hematopoyéticas/metabolismo , Proteínas Proto-Oncogénicas c-met/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/fisiología , Animales , Quimiocina CXCL12/metabolismo , Ensayo de Inmunoadsorción Enzimática , Citometría de Flujo , Células Madre Hematopoyéticas/citología , Factor de Crecimiento de Hepatocito/metabolismo , Inmunoprecipitación , Ratones , Ratones Endogámicos C57BL , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
Here we investigated the potential role of bone-resorbing osteoclasts in homeostasis and stress-induced mobilization of hematopoietic progenitors. Different stress situations induced activity of osteoclasts (OCLs) along the stem cell-rich endosteum region of bone, secretion of proteolytic enzymes and mobilization of progenitors. Specific stimulation of OCLs with RANKL recruited mainly immature progenitors to the circulation in a CXCR4- and MMP-9-dependent manner; however, RANKL did not induce mobilization in young female PTPepsilon-knockout mice with defective OCL bone adhesion and resorption. Inhibition of OCLs with calcitonin reduced progenitor egress in homeostasis, G-CSF mobilization and stress situations. RANKL-stimulated bone-resorbing OCLs also reduced the stem cell niche components SDF-1, stem cell factor (SCF) and osteopontin along the endosteum, which was associated with progenitor mobilization. Finally, the major bone-resorbing proteinase, cathepsin K, also cleaved SDF-1 and SCF. Our findings indicate involvement of OCLs in selective progenitor recruitment as part of homeostasis and host defense, linking bone remodeling with regulation of hematopoiesis.
Asunto(s)
Resorción Ósea , Huesos/anatomía & histología , Movimiento Celular/fisiología , Células Madre Hematopoyéticas/fisiología , Osteoclastos/metabolismo , Animales , Proteínas Portadoras/metabolismo , Catepsina K , Catepsinas/genética , Catepsinas/metabolismo , Línea Celular , Quimiocina CXCL12 , Quimiocinas CXC/metabolismo , Femenino , Células Madre Hematopoyéticas/citología , Homeostasis , Humanos , Metaloproteinasa 9 de la Matriz/metabolismo , Glicoproteínas de Membrana/metabolismo , Ratones , Ratones Endogámicos , Ratones Noqueados , Osteoclastos/citología , Proteínas Tirosina Fosfatasas/genética , Proteínas Tirosina Fosfatasas/metabolismo , Ligando RANK , Receptor Activador del Factor Nuclear kappa-B , Proteínas Tirosina Fosfatasas Clase 4 Similares a Receptores , Receptores CXCR4/metabolismo , Factor de Células Madre/metabolismoRESUMEN
Heparanase is involved in tumor growth and metastasis. Because of its unique cleavage of heparan sulfate, which binds cytokines, chemokines and proteases, we hypothesized that heparanase is also involved in regulation of early stages of hematopoiesis. We report reduced numbers of maturing leukocytes but elevated levels of undifferentiated Sca-1(+)/c-Kit(+)/Lin(-) cells in the bone marrow (BM) of mice overexpressing heparanase (hpa-Tg). This resulted from increased proliferation and retention of the primitive cells in the BM microenvironment, manifested in increased SDF-1 turnover. Furthermore, heparanase overexpression in mice was accompanied by reduced protease activity of MMP-9, elastase, and cathepsin K, which regulate stem and progenitor cell mobilization. Moreover, increased retention of the progenitor cells also resulted from up-regulated levels of stem cell factor (SCF) in the BM, in particular in the stem cell-rich endosteum and endothelial regions. Increased SCF-induced adhesion of primitive Sca-1(+)/c-Kit(+)/Lin(-) cells to osteoblasts was also the result of elevation of the receptor c-Kit. Regulation of these phenomena is mediated by hyperphosphorylation of c-Myc in hematopoietic progenitors of hpa-Tg mice or after exogenous heparanase addition to wildtype BM cells in vitro. Altogether, our data suggest that heparanase modification of the BM microenvironment regulates the retention and proliferation of hematopoietic progenitor cells.
Asunto(s)
Médula Ósea , Proliferación Celular , Glucuronidasa/fisiología , Células Madre Hematopoyéticas/citología , Animales , Células de la Médula Ósea , Adhesión Celular , Movimiento Celular , Quimiocina CXCL12/metabolismo , Inmunofenotipificación , Ratones , Ratones Transgénicos , Proteínas de Neoplasias , Péptido Hidrolasas/metabolismoRESUMEN
Therapeutic mobilization of vasculogenic progenitor cells is a novel strategy to enhance neovascularization for tissue repair. Prototypical mobilizing agents such as granulocyte colony-stimulating factor mobilize vasculogenic progenitor cells from the bone marrow concomitantly with inflammatory cells. In the bone marrow, mobilization is regulated in the stem cell niche, in which endosteal cells such as osteoblasts and osteoclasts play a key role. Because Wnt signaling regulates endosteal cells, we examined whether the Wnt signaling antagonist Dickkopf (Dkk)-1 is involved in the mobilization of vasculogenic progenitor cells. Using TOP-GAL transgenic mice to determine activation of beta-catenin, we demonstrate that Dkk-1 regulates endosteal cells in the bone marrow stem cell niche and subsequently mobilizes vasculogenic and hematopoietic progenitors cells without concomitant mobilization of inflammatory neutrophils. The mobilization of vasculogenic progenitors required the presence of functionally active osteoclasts, as demonstrated in PTPepsilon-deficient mice with defective osteoclast function. Mechanistically, Dkk-1 induced the osteoclast differentiation factor RANKL, which subsequently stimulated the release of the major bone-resorbing protease cathepsin K. Eventually, the Dkk-1-induced mobilization of bone marrow-derived vasculogenic progenitors enhanced neovascularization in Matrigel plugs. Thus, these data show that Dkk-1 is a mobilizer of vasculogenic progenitors but not of inflammatory cells, which could be of great clinical importance to enhance regenerative cell therapy.
Asunto(s)
Células de la Médula Ósea/metabolismo , Movimiento Celular , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Neovascularización Fisiológica , Osteoclastos/metabolismo , Transducción de Señal , Células Madre/metabolismo , Proteínas Wnt/metabolismo , Animales , Células de la Médula Ósea/enzimología , Catepsina K , Catepsinas/metabolismo , Diferenciación Celular , Células Cultivadas , Colágeno , Combinación de Medicamentos , Femenino , Factor Estimulante de Colonias de Granulocitos/metabolismo , Laminina , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Ratones Transgénicos , Osteoclastos/enzimología , Proteoglicanos , Ligando RANK/metabolismo , Proteínas Tirosina Fosfatasas Clase 4 Similares a Receptores/genética , Proteínas Tirosina Fosfatasas Clase 4 Similares a Receptores/metabolismo , Proteínas Recombinantes/metabolismo , Células Madre/enzimología , Factores de Tiempo , beta Catenina/metabolismoRESUMEN
Neutrophils provide first line of host defense against bacterial infections utilizing glycolysis for their effector functions. How glycolysis and its major byproduct lactate are triggered in bone marrow (BM) neutrophils and their contribution to neutrophil mobilization in acute inflammation is not clear. Here we report that bacterial lipopolysaccharides (LPS) or Salmonella Typhimurium triggers lactate release by increasing glycolysis, NADPH-oxidase-mediated reactive oxygen species and HIF-1α levels in BM neutrophils. Increased release of BM lactate preferentially promotes neutrophil mobilization by reducing endothelial VE-Cadherin expression, increasing BM vascular permeability via endothelial lactate-receptor GPR81 signaling. GPR81-/- mice mobilize reduced levels of neutrophils in response to LPS, unless rescued by VE-Cadherin disrupting antibodies. Lactate administration also induces release of the BM neutrophil mobilizers G-CSF, CXCL1 and CXCL2, indicating that this metabolite drives neutrophil mobilization via multiple pathways. Our study reveals a metabolic crosstalk between lactate-producing neutrophils and BM endothelium, which controls neutrophil mobilization under bacterial infection.
Asunto(s)
Células de la Médula Ósea/inmunología , Ácido Láctico/metabolismo , Neutrófilos/inmunología , Receptores Acoplados a Proteínas G/metabolismo , Infecciones por Salmonella/inmunología , Animales , Médula Ósea/irrigación sanguínea , Células de la Médula Ósea/metabolismo , Modelos Animales de Enfermedad , Endotelio Vascular/metabolismo , Femenino , Humanos , Lipopolisacáridos/inmunología , Masculino , Ratones , Ratones Noqueados , Neutrófilos/metabolismo , Receptores Acoplados a Proteínas G/genética , Infecciones por Salmonella/microbiología , Salmonella typhimurium/inmunología , Transducción de Señal/inmunologíaRESUMEN
Aminoglycoside-arginine conjugates (AACs) are multi-target HIV-1 inhibitors. The most potent AAC is neomycin hexa-arginine conjugate, NeoR6. We here demonstrate that NeoR6 interacts with CXCR4 without affecting CXCL12-CXCR4 ordinary chemotaxis activity or loss of CXCR4 cell surface expression. Importantly, NeoR6 alone does not affect cell migration, indicating that NeoR6 interacts with CXCR4 at a distinct site that is important for HIV-1 entry and mAb 12G5 binding, but not to CXCL12 binding or signaling sites. This is further supported by our modeling studies, showing that NeoR6 and CXCL12 bind to two distinct sites on CXCR4, in contrast with other CXCR4 inhibitors, e.g. T140 and AMD3100. This complementary utilization of chemical, biology, and computation analysis provides a powerful approach for designing anti-HIV-1 drugs without interfering with the natural function of CXCL12/CXCR4 binding.
Asunto(s)
Aminoglicósidos/farmacología , Fármacos Anti-VIH/farmacología , Arginina/análogos & derivados , Quimiocina CXCL12/metabolismo , Quimiotaxis/efectos de los fármacos , VIH-1/metabolismo , Neomicina/análogos & derivados , Receptores CXCR4/metabolismo , Aminoglicósidos/química , Fármacos Anti-VIH/química , Anticuerpos Monoclonales/farmacología , Arginina/química , Arginina/farmacología , Bencilaminas , Línea Celular Tumoral , Ciclamas , Regulación de la Expresión Génica/efectos de los fármacos , Compuestos Heterocíclicos/farmacología , Humanos , Neomicina/química , Neomicina/farmacología , Oligopéptidos/farmacología , Unión Proteica/efectos de los fármacos , Receptores CXCR4/antagonistas & inhibidoresRESUMEN
The nervous system regulates immunity through hormonal and neuronal routes as part of host defense and repair mechanism. Here, we review the emerging evidence for regulation of human hematopoietic stem and progenitor cells (HSPC) by the nervous system both directly and indirectly via their bone marrow (BM) niche-supporting stromal cells. Functional expression of several neurotransmitter receptors was demonstrated on HSPC, mainly on the more primitive CD34(+)/CD38(-/low) fraction. The myeloid cytokines, G-CSF and GM-CSF, dynamically upregulate neuronal receptor expression on human HSPC. This is followed by an increased response to neurotransmitters, leading to enhanced proliferation and motility of human CD34(+) progenitors, repopulation of the murine BM and their egress to the circulation. Importantly, recent observations showed rapid mobilization of human HSPC to high SDF-1 expressing ischemic tissues of stroke individuals followed by neoangiogenesis, neurological and functional recovery. Along with decreased levels of circulating immature CD34(+) cells and SDF-1 blood levels found in patients with early-stage Alzheimer's disease, these findings suggest a possible involvement of human HSPC in brain homeostasis and thus their potential clinical applications in neuropathology.
Asunto(s)
Antígenos CD34/metabolismo , Células Madre Hematopoyéticas/metabolismo , Sistema Nervioso/metabolismo , Receptores de Neurotransmisores/metabolismo , Médula Ósea/metabolismo , Hematopoyesis , Humanos , Neurotransmisores/metabolismo , Células del Estroma/metabolismoRESUMEN
Hematopoietic stem and progenitor cells (HSPCs) are essential for daily mature blood cell production, host immunity, and osteoclast-mediated bone turnover. The timing at which stem cells give rise to mature blood and immune cells while maintaining the bone marrow (BM) reservoir of undifferentiated HSPCs and how these opposite tasks are synchronized are poorly understood. Previous studies revealed that daily light onset activates norepinephrine (NE)-induced BM CXCL12 downregulation, followed by CXCR4+ HSPC release to the circulation. Recently, we reported that daily light onset induces transient elevations of BM NE and tumor necrosis factor (TNF), which metabolically program BM HSPC differentiation and recruitment to replenish the blood. In contrast, darkness onset induces lower elevations of BM NE and TNF, activating melatonin production, which metabolically reprograms HSPCs, increasing their short- and long-term repopulation potential, and BM maintenance. How the functions of BM-retained HSPCs are influenced by daily light and darkness cycles and their clinical potential are further discussed.