RESUMEN
Enamel has good optical and mechanical properties because of its multiscale hierarchical structure. Biomimetic construction of enamel-like 3D bulk materials at nano-, micro-, mesh- and macro-levels is a challenge. A novel facile, cost-effective, and easy large-scale bottom-up assembly strategy to align 1D hydroxyapatite (HA) nanowires bundles to 3D hierarchical enamel structure with the nanowires bundles layer-by-layer interweaving orientation, is reported. In the strategy, the surface of oleate templated ultralong HA nanowires with a large aspect ratio is functionalized with amphiphilic 10-methacryloyloxydecyl dihydrogen phosphate (MDP). Furtherly, the MDP functionalized HA nanowire bundles are assembled layer-by-layer with oriented fibers in a single layer and cross-locked between layers at a certain angle at mesoscale and macroscale in the viscous bisphenol A-glycidyl methacrylate (Bis-GMA) ethanol solution by shear force induced by simple agitation and high-speed centrifugation. Finally, the excessive Bis-GMA and ethanol are removed, and (Bis-GMA)-(MDP-HA nanowire bundle) matrix is densely packed under hot pressing and polymerized to form bulk enamel-like materials. The composite has superior optical properties and comparable comprehensive mechanic performances through a combination of strength, hardness, toughness, and friction. This method may open new avenues for controlling the nanowires assembly to develop hierarchical nanomaterials with superior properties for many different applications.
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We undertook a lab-scale evaluation of a novel autotrophic denitrification and nitrification integrated constructed wetland (ADNI-CW) for improved carbon (C), nitrogen (N), and sulfur (S) cycling to treat mariculture wastewater. The process involved an up-flow autotrophic denitrification constructed wetland unit (AD-CW) for sulfate reduction and autotrophic denitrification, and an autotrophic nitrification constructed wetland unit (AN-CW) for nitrification. The 400-day experiment investigated the performance of the AD-CW, AN-CW, and entire ADNI-CW processes under various hydraulic retention times (HRTs), nitrate concentrations, dissolved oxygen levels, and recirculation ratios. Under various HRTs, the AN-CW achieved a nitrification performance exceeding 92%. Correlation analysis of the chemical oxygen demand (COD) revealed that, on average, approximately 96% of COD was removed by sulfate reduction. Under different HRTs, increases in influent NO3--N concentrations caused the amount of sulfide to gradually decrease from sufficient to deficient, and the autotrophic denitrification rate also decreased from 62.18 to 40.93%. In addition, when the NO3--N load rate was above 21.53 g N/m2·d, the transformation of organic N by mangrove roots may have increased NO3--N in the top effluent of the AD-CW. The coupling of N and S metabolic processes mediated by various functional microorganisms (Proteobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, and unclassified_d__Bacteria) enhanced N removal. We intensively explored the effects of changing inputs as culture species developed on the physical, chemical, and microbial changes of CW to ensure a consistent and effective management of C, N, and S. This study lays the foundation for green and sustainable mariculture development.
Asunto(s)
Enfermedad de Alzheimer , Purificación del Agua , Humanos , Nitrificación , Desnitrificación , Humedales , Procesos Autotróficos , Bacterias/metabolismo , Nitrógeno/metabolismo , Sulfatos , Reactores BiológicosRESUMEN
Purpose: To investigate the deficits in contrast sensitivity in patients with Fuchs uveitis syndrome (FUS) and to explore the potential relationship between contrast sensitivity and ocular structure. Methods: In this prospective study, 25 patients with FUS and 30 healthy volunteers were recruited. Eyes were divided into three groups: FUS-affected eyes (AE), fellow eyes (FE), and healthy eyes. The contrast sensitivity function (CSF) of all participants was evaluated using the quick CSF (qCSF) method. Fundus photographs were collected for the analysis of refractive media, and vascular density (VD) was assessed using optical coherence tomography angiography (OCTA). Data were analyzed and compared using the generalized estimating equation (GEE). Results: The CSF of AE was significantly lower than that of FE and controls, while no significant difference was observed between FE and controls. Contrast sensitivity was negatively correlated with the grade of haze. No significant correlation was found between visual function and VDs in FUS eyes. Conclusions: We found that the CSF of FUS-affected eyes was significantly reduced, and the visual impairment was predominantly caused by the refractive media turbidity.
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We conducted a nested case-control study within a cohort of 6244 patients to assess risk factors for avascular necrosis (AVN) of bone in children and adolescents after allogeneic transplantation. Eligible patients were ≤21 years of age, received their first allogeneic transplant between 1990 and 2008 in the United States, and had survived ≥ 6 months from transplantation. Overall, 160 patients with AVN and 478 control subjects matched by year of transplant, length of follow-up and transplant center were identified. Patients and control subjects were confirmed via central review of radiology, pathology, and/or surgical procedure reports. Median time from transplant to diagnosis of AVN was 14 months. On conditional logistic regression, increasing age at transplant (≥5 years), female gender, and chronic graft-versus-host disease (GVHD) were significantly associated with increased risks of AVN. Compared with patients receiving myeloablative regimens for malignant diseases, lower risks of AVN were seen in patients with nonmalignant diseases and those who had received reduced-intensity conditioning regimens for malignant diseases. Children at high risk for AVN include those within the age group where rapid bone growth occurs as well as those who experience exposure to myeloablative conditioning regimens and immunosuppression after hematopoietic cell transplantation for the treatment of GVHD. More research is needed to determine whether screening strategies specifically for patients at high risk for developing AVN with early interventions may mitigate the morbidity associated with this complication.
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Huesos/patología , Neoplasias Hematológicas/terapia , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Osteonecrosis/patología , Acondicionamiento Pretrasplante , Adolescente , Huesos/inmunología , Estudios de Casos y Controles , Niño , Enfermedad Crónica , Femenino , Enfermedad Injerto contra Huésped/inmunología , Enfermedad Injerto contra Huésped/patología , Enfermedad Injerto contra Huésped/prevención & control , Neoplasias Hematológicas/inmunología , Neoplasias Hematológicas/patología , Humanos , Inmunosupresores/efectos adversos , Masculino , Agonistas Mieloablativos/efectos adversos , Osteonecrosis/etiología , Osteonecrosis/inmunología , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores Sexuales , Factores de Tiempo , Trasplante Homólogo , Adulto JovenRESUMEN
Fanconi anemia (FA) is an inherited chromosomal instability syndrome characterized by bone marrow failure, myelodysplasia (MDS), and acute myeloid leukemia (AML). Eight FA proteins associate in a nuclear core complex to monoubiquitinate FANCD2/FANCI in response to DNA damage. Additional functions have been described for some of the core complex proteins; however, in vivo genetic proof has been lacking. Here we show that double-mutant Fancc(-/-);Fancg(-/-) mice develop spontaneous hematologic sequelae including bone marrow failure, AML, MDS and complex random chromosomal abnormalities that the single-mutant mice do not. This genetic model provides evidence for unique core complex protein function independent of their ability to monoubiquitinate FANCD2/FANCI. Importantly, this model closely recapitulates the phenotypes found in FA patients and may be useful as a preclinical platform to evaluate the molecular pathogenesis of spontaneous bone marrow failure, MDS and AML in FA.
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Médula Ósea/fisiopatología , Proteína del Grupo de Complementación C de la Anemia de Fanconi/genética , Proteína del Grupo de Complementación G de la Anemia de Fanconi/genética , Anemia de Fanconi/genética , Leucemia Mieloide Aguda/genética , Mutación , Síndromes Mielodisplásicos/genética , Animales , Aberraciones Cromosómicas , Ratones , Ratones Endogámicos C57BLRESUMEN
Hereditary persistence of alpha-fetoprotein (HPAFP) is a rare benign autosomal dominant disorder. Here we report a 7-year-old healthy female who was found to have elevated alpha-fetoprotein (AFP) of 55-88 ng/ml over a 2-year period. Subsequently, AFP was also determined to be elevated in another 4 out of 8 family members in three generations, consistent with an autosomal dominant inheritance pattern. Elevated AFP levels are usually related to pregnancy, congenital disorders, liver diseases, or specific malignancies. However, HPAFP should be considered in the differential diagnosis of children with unexplained elevation of AFP. This disorder can be easily confirmed by measuring AFP levels in family members or checking specific point mutations of AFP gene promoter.
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alfa-Fetoproteínas/metabolismo , Niño , Femenino , Salud , Humanos , Masculino , LinajeRESUMEN
Improving approaches for hematopoietic stem cell (HSC) and hematopoietic progenitor cell (HPC) mobilization is clinically important because increased numbers of these cells are needed for enhanced transplantation. Chemokine stromal cell derived factor-1 (also known as CXCL12) is believed to be involved in retention of HSCs and HPCs in bone marrow. AMD3100, a selective antagonist of CXCL12 that binds to its receptor, CXCR4, was evaluated in murine and human systems for mobilizing capacity, alone and in combination with granulocyte colony-stimulating factor (G-CSF). AMD3100 induced rapid mobilization of mouse and human HPCs and synergistically augmented G-CSF-induced mobilization of HPCs. AMD3100 also mobilized murine long-term repopulating (LTR) cells that engrafted primary and secondary lethally-irradiated mice, and human CD34(+) cells that can repopulate nonobese diabetic-severe combined immunodeficiency (SCID) mice. AMD3100 synergized with G-CSF to mobilize murine LTR cells and human SCID repopulating cells (SRCs). Human CD34(+) cells isolated after treatment with G-CSF plus AMD3100 expressed a phenotype that was characteristic of highly engrafting mouse HSCs. Synergy of AMD3100 and G-CSF in mobilization was due to enhanced numbers and perhaps other characteristics of the mobilized cells. These results support the hypothesis that the CXCL12-CXCR4 axis is involved in marrow retention of HSCs and HPCs, and demonstrate the clinical potential of AMD3100 for HSC mobilization.
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Factor Estimulante de Colonias de Granulocitos/farmacología , Células Madre Hematopoyéticas/efectos de los fármacos , Compuestos Heterocíclicos/farmacología , Receptores CXCR4/antagonistas & inhibidores , Animales , Antígenos CD34 , Bencilaminas , Quimiocina CXCL12 , Quimiocinas CXC , Ensayo de Unidades Formadoras de Colonias , Ciclamas , Sinergismo Farmacológico , Humanos , Ratones , Ratones Endogámicos , Ratones SCIDRESUMEN
PTPN11 encodes the protein tyrosine phosphatase SHP-2, which relays signals from growth factor receptors to Ras and other effectors. Germline PTPN11 mutations underlie about 50% of Noonan syndrome (NS), a developmental disorder that is associated with an elevated risk of juvenile myelomonocytic leukemia (JMML). Somatic PTPN11 mutations were recently identified in about 35% of patients with JMML; these mutations introduce amino acid substitutions that are largely distinct from those found in NS. We assessed the functional consequences of leukemia-associated PTPN11 mutations in murine hematopoietic cells. Expressing an E76K SHP-2 protein induced a hypersensitive pattern of granulocyte-macrophage colony-forming unit (CFU-GM) colony growth in response to granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin 3 (IL-3) that was dependent on SHP-2 catalytic activity. E76K SHP-2 expression also enhanced the growth of immature progenitor cells with high replating potential, perturbed erythroid growth, and impaired normal differentiation in liquid cultures. In addition, leukemia-associated SHP-2 mutations conferred a stronger phenotype than a germline mutation found in patients with NS. Mutant SHP-2 proteins induce aberrant growth in multiple hematopoietic compartments, which supports a primary role of hyperactive Ras in the pathogenesis of JMML.
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Células Madre Hematopoyéticas/fisiología , Péptidos y Proteínas de Señalización Intracelular/genética , Leucemia Mielomonocítica Crónica/genética , Proteínas Tirosina Fosfatasas/genética , Sustitución de Aminoácidos , Animales , Diferenciación Celular , División Celular , Línea Celular , Femenino , Células Madre Hematopoyéticas/patología , Leucemia Mielomonocítica Crónica/patología , Leucemia Mielomonocítica Crónica/fisiopatología , Hígado/citología , Ratones , Ratones Endogámicos C57BL , Embarazo , Proteína Tirosina Fosfatasa no Receptora Tipo 11 , Proteínas ras/metabolismoRESUMEN
Current strategies for genetic therapy using Moloney retroviruses require ex vivo manipulation of hematopoietic cells to facilitate stable integration of the transgene. While many studies have evaluated the impact of ex vivo culture on normal murine and human stem/progenitor cells, the cellular consequences of ex vivo manipulation of stem cells with intrinsic defects in genome stability are incompletely understood. Here we show that ex vivo culture of Fancc(-/-) bone marrow cells results in a time-dependent increase in apoptosis of primitive Fancc(-/-) progenitor cells in conditions that promote the proliferation of wild-type stem/progenitor cells. Further, recipients reconstituted with the surviving Fancc(-/-) cells have a high incidence of cytogenetic abnormalities and myeloid malignancies that are associated with an acquired resistance to tumor necrosis factor alpha (TNF-alpha). Collectively, these data indicate that the intrinsic defects in the genomic stability of Fancc(-/-) stem/progenitor cells provide a selective pressure for cells that are resistant to apoptosis and have a propensity for the evolution to clonal hematopoiesis and malignancy. These studies could have implications for the design of genetic therapies for treatment of Fanconi anemia and potentially other genetic diseases with intrinsic defects in genome stability.
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Apoptosis , Aberraciones Cromosómicas , Proteínas de Unión al ADN/deficiencia , Neoplasias Hematológicas/etiología , Células Madre Hematopoyéticas/patología , Proteínas Nucleares/deficiencia , Animales , Células de la Médula Ósea/patología , Proteínas de Ciclo Celular/genética , Células Cultivadas , Células Clonales , Proteínas de Unión al ADN/genética , Anemia de Fanconi/patología , Anemia de Fanconi/terapia , Proteína del Grupo de Complementación C de la Anemia de Fanconi , Proteínas del Grupo de Complementación de la Anemia de Fanconi , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Ratones , Ratones Noqueados , Proteínas Nucleares/genética , Riesgo , Factor de Necrosis Tumoral alfa/farmacologíaRESUMEN
Fanconi anemia (FA) is a complex, heterogeneous genetic disorder composed of at least 11 complementation groups. The FA proteins have recently been found to functionally interact with the cell cycle regulatory proteins ATM and BRCA1; however, the function of the FA proteins in cell cycle control remains incompletely understood. Here we show that the Fanconi anemia complementation group C protein (Fancc) is necessary for proper function of the DNA damage-induced G2/M checkpoint in vitro and in vivo. Despite apparently normal induction of the G2/M checkpoint after ionizing radiation, murine and human cells lacking functional FANCC did not maintain the G2 checkpoint as compared with wild-type cells. The increased rate of mitotic entry seen in Fancc-/-mouse embryo fibroblasts correlated with decreased inhibitory phosphorylation of cdc2 kinase on tyrosine 15. An increased inability to maintain the DNA damage-induced G2 checkpoint was observed in Fancc -/-; Trp53 -/-cells compared with Fancc -/-cells, indicating that Fancc and p53 cooperated to maintain the G2 checkpoint. In contrast, genetic disruption of both Fancc and Atm did not cooperate in the G2 checkpoint. These data indicate that Fancc and p53 in separate pathways converge to regulate the G2 checkpoint. Finally, fibroblasts lacking FANCD2 were found to have a G2 checkpoint phenotype similar to FANCC-deficient cells, indicating that FANCD2, which is activated by the FA complex, was also required to maintain the G2 checkpoint. Because a proper checkpoint function is critical for the maintenance of genomic stability and is intricately related to the function and integrity of the DNA repair process, these data have implications in understanding both the function of FA proteins and the mechanism of genomic instability in FA.
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Proteínas de Ciclo Celular/fisiología , Daño del ADN , Proteínas de Unión al ADN/fisiología , Proteínas Nucleares/fisiología , Alelos , Animales , Bromodesoxiuridina/farmacología , Proteína Quinasa CDC2/metabolismo , División Celular , Línea Celular , Células Cultivadas , Colorantes/farmacología , ADN/metabolismo , Reparación del ADN , Anemia de Fanconi/metabolismo , Proteína del Grupo de Complementación C de la Anemia de Fanconi , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi , Proteínas del Grupo de Complementación de la Anemia de Fanconi , Femenino , Fibroblastos/metabolismo , Citometría de Flujo , Fase G2 , Histonas/química , Humanos , Immunoblotting , Queratinocitos/metabolismo , Masculino , Ratones , Ratones Transgénicos , Mitosis , Mutación , Fosforilación , Unión Proteica , Radiación Ionizante , Factores de Tiempo , Transgenes , Tirosina/químicaRESUMEN
Fanconi anemia (FA) is characterized by bone marrow (BM) failure and cancer susceptibility. Identification of the cDNAs of many FA complementation types allows the potential of using gene transfer technology to introduce functional cDNAs as transgenes into autologous stem cells and provide a cure for the BM failure in FA patients. Previous studies in FA murine models and in a phase 1 clinical trial suggest that myelopreparation is required for significant engraftment of exogenous, genetically corrected stem cells. Since myeloid progenitors from Fancc-/- mice and human Fanconi anemia group C protein (FANCC) patients have increased apoptosis in response to interferon gamma (IFN-gamma) in vitro, we hypothesized that IFN-gamma may be useful as a nongenotoxic, myelopreparative conditioning agent. To test this hypothesis, IFN-gamma was administered as a continuous infusion to Fancc-/- and wild-type (WT) mice for 1 week. Primitive and mature myeloid lineages were preferentially reduced in IFN-gamma-treated Fancc-/- mice. Further, IFN-gamma conditioning of Fancc-/- recipients was sufficient as a myelopreparative regimen to allow consistent engraftment of isogenic WT repopulating stem cells. Collectively, these data demonstrate that Fancc-/- hematopoietic cell populations have increased hypersensitivity to IFN-gamma in vivo and that IFN-gamma conditioning may be useful as a nongenotoxic strategy for myelopreparation in this disorder.
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Proteínas de Unión al ADN/deficiencia , Anemia de Fanconi/tratamiento farmacológico , Supervivencia de Injerto/efectos de los fármacos , Interferón gamma/administración & dosificación , Células Progenitoras Mieloides/efectos de los fármacos , Proteínas Nucleares/deficiencia , Animales , Apoptosis/efectos de los fármacos , Trasplante de Médula Ósea/métodos , Recuento de Células , Proteínas de Ciclo Celular , Anemia de Fanconi/terapia , Proteína del Grupo de Complementación C de la Anemia de Fanconi , Proteínas del Grupo de Complementación de la Anemia de Fanconi , Infusiones Parenterales , Interferón gamma/uso terapéutico , Ratones , Ratones Noqueados , Células Mieloides/efectos de los fármacos , Acondicionamiento Pretrasplante/métodos , Trasplante IsogénicoRESUMEN
To assess whether Fanconi anemia (FA) patients might be at risk for acute graft-versus-host disease (AGvHD) despite using low-intensity conditionings, we retrospectively analyzed the incidence of AGvHD and its impact on outcome in 37 FA patients and 73 patients with acquired aplastic anemia (AAA) that received transplants at Saint Louis Hospital from HLA-genotypic identical siblings with similar conditionings (thoraco-abdominal irradiation plus cyclophosphamide 20 [FA] or 150 mg/kg [AAA]). Despite being younger, FA patients had an increased risk of grades II to IV AGvHD (relative risk [RR], 2.00; P =.021), especially in younger patients (RR, 7.93; P =.014). The risks of requiring systemic corticosteroids to treat AGvHD and experiencing cortico-resistant AGvHD were significantly increased in FA patients. Although non-FA and FA patients had similar 10-year outcomes, acute and chronic GvHD had a biphasic effect on FA patient outcome with an additional cluster of lethal events starting by 5 years after transplantation. This late survival fall, restricted to FA patients, was closely related to head and neck carcinomas (15-year incidence: 53%). FA patients represent a group at risk regarding AGvHD when using irradiation-based conditionings. The impact of AGvHD on survival may not be limited to the early posttransplantation period and may be a major risk factor for head and neck carcinomas and late mortality in FA patients.
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Anemia Aplásica/terapia , Trasplante de Médula Ósea/efectos adversos , Anemia de Fanconi/terapia , Enfermedad Injerto contra Huésped/etiología , Enfermedad Aguda , Adolescente , Adulto , Anemia Aplásica/inmunología , Niño , Supervivencia sin Enfermedad , Anemia de Fanconi/inmunología , Femenino , Antígenos HLA , Humanos , Masculino , Neoplasias/etiología , Estudios Retrospectivos , Factores de Riesgo , Resultado del TratamientoRESUMEN
Fanconi anemia (FA) is a recessive genomic instability syndrome characterized by developmental defects, progressive bone marrow failure, and cancer. FA is genetically heterogeneous, however; the proteins encoded by different FA loci interact functionally with each other and with the BRCA1, BRCA2, and ATM gene products. Although patients with FA are highly predisposed to the development of myeloid leukemia and solid tumors, the alterations in biochemical pathways responsible for the progression of tumorigenesis in these patients remain unknown. FA cells are hypersensitive to a range of genotoxic and cellular stresses that activate signaling pathways mediating apoptosis. Here we show that ionizing radiation (IR) induces modestly elevated levels of p53 in cells from FA type C (Fancc) mutant mice and that inactivation of Trp53 rescues tumor necrosis factor alpha-induced apoptosis in myeloid cells from Fancc-/- mice. Further, whereas Fancc-/- mice failed to form hematopoietic or solid malignancies, mice mutant at both Fancc and Trp53 developed tumors more rapidly than mice mutant at Trp53 alone. This shortened latency was associated with the appearance of tumor types that are found in patients with FA but not in mice mutant at Trp53 only. Collectively, these data demonstrate that p53 and Fancc interact functionally to regulate apoptosis and tumorigenesis in Fancc-deficient cells.
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Apoptosis , Proteínas de Ciclo Celular , Proteínas de Unión al ADN , Anemia de Fanconi/patología , Neoplasias/etiología , Proteínas Nucleares , Proteínas/fisiología , Proteína p53 Supresora de Tumor/fisiología , Animales , Embrión de Mamíferos/citología , Anemia de Fanconi/complicaciones , Proteína del Grupo de Complementación C de la Anemia de Fanconi , Proteínas del Grupo de Complementación de la Anemia de Fanconi , Fibroblastos/patología , Predisposición Genética a la Enfermedad , Genotipo , Patrón de Herencia , Ratones , Ratones Noqueados , Ratones Mutantes , Neoplasias/genética , Neoplasias/patología , Proteínas/genética , Radiación Ionizante , Factor de Necrosis Tumoral alfa/fisiología , Proteína p53 Supresora de Tumor/genética , Proteína p53 Supresora de Tumor/efectos de la radiaciónRESUMEN
The pathogenesis of bone marrow failure in Fanconi anemia is poorly understood. Suggested mechanisms include enhanced apoptosis secondary to DNA damage and altered inhibitory cytokine signaling. Recent data determined that disrupted cell cycle control of hematopoietic stem and/or progenitor cells disrupts normal hematopoiesis with increased hematopoietic stem cell cycling resulting in diminished function and increased sensitivity to cell cycle-specific apoptotic stimuli. Here, we used Fanconi anemia complementation type C-deficient (Fancc-/-) mice to demonstrate that Fancc-/- phenotypically defined cell populations enriched for hematopoietic stem and progenitor cells exhibit increased cycling. In addition, we established that the defect in cell cycle regulation is not a compensatory mechanism from enhanced apoptosis occurring in vivo. Collectively, these data provide a previously unrecognized phenotype in Fancc-/- hematopoietic stem/progenitor cells, which may contribute to the progressive bone marrow failure in Fanconi anemia.
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Proteínas de Ciclo Celular , Proteínas de Unión al ADN , Anemia de Fanconi/patología , Células Madre Hematopoyéticas/patología , Proteínas Nucleares , Proteínas/genética , Animales , Apoptosis/fisiología , Médula Ósea/patología , Médula Ósea/fisiopatología , Ciclo Celular/fisiología , Anemia de Fanconi/etiología , Anemia de Fanconi/fisiopatología , Proteína del Grupo de Complementación C de la Anemia de Fanconi , Proteínas del Grupo de Complementación de la Anemia de Fanconi , Ratones , Ratones Endogámicos C57BL , Ratones Mutantes , FenotipoRESUMEN
Stromal cell-derived factor-1 (SDF-1/CXCL12) enhances survival of myeloid progenitor cells. The two main questions addressed by us were whether these effects on the progenitors were direct-acting and if SDF-1/CXCL12 enhanced engrafting capability of competitive, repopulating mouse stem cells subjected to short-term ex vivo culture with other growth factors. SDF-1/CXCL12 had survival-enhancing/antiapoptosis effects on human bone marrow (BM) and cord blood (CB) and mouse BM colony-forming units (CFU)-granulocyte macrophage, burst-forming units-erythroid, and CFU-granulocyte-erythroid-macrophage-megakaryocyte with similar dose responses. The survival effects were direct-acting, as assessed on colony formation by single isolated human BM and CB CD34(+++) cells. Effects were mediated through CXCR4 and G(alpha)i proteins. Moreover, SDF-1/CXCL12 greatly enhanced the engrafting capability of mouse long-term, marrow-competitive, repopulating stem cells cultured ex vivo with interleukin-6 and steel factor for 48 h. These results extend information on the survival effects mediated through the SDF-1/CXCL12-CXCR4 axis and may be of relevance for ex vivo expansion and gene-transduction procedures.
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Quimiocinas CXC/farmacología , Citocinas/farmacología , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/fisiología , Células Mieloides/efectos de los fármacos , Proteínas Proto-Oncogénicas/fisiología , Receptores CXCR4/efectos de los fármacos , Animales , Animales Congénicos , Apoptosis/efectos de los fármacos , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células Cultivadas/efectos de los fármacos , Quimiocina CXCL12 , Ensayo de Unidades Formadoras de Colonias , Femenino , Sangre Fetal/citología , Subunidad alfa de la Proteína de Unión al GTP Gi2 , Humanos , Recién Nacido , Interleucina-6/farmacología , Ratones , Ratones Endogámicos C57BL , Células Mieloides/citología , Toxina del Pertussis/farmacología , Quimera por Radiación , Receptores CXCR4/fisiología , Proteínas Recombinantes/farmacología , Factor de Células Madre/farmacologíaRESUMEN
Fanconi's anaemia (FA) is an autosomal recessive disorder characterized by progressive bone marrow failure and a susceptibility to cancer. Haematopoietic stem cell transplantation is the only curative method for restoring normal haematopoiesis, and survival is improved if the transplant is carried out before severe complications occur. However, the evolution of FA is difficult to predict because of the absence of known prognostic factors and the unknown function of the genes involved. In studying 71 FA patients, a correlation was found between severe aplastic anaemia (SAA) and the individual annual telomere-shortening rate (IATSR) in peripheral blood mononuclear cells (P < 10(-3)). Spontaneous apoptosis was highest in SAA patients or patients with high IATSR (> 200 bp/year) (P < 0.01, n = 18). Univariate and multivariate analyses showed that significant relative risks for evolution towards SAA were high IATSR (P < 10(-4)), and that a high number of chromosome breakages occurred in the presence of nitrogen mustard (P < 0.001). A high IATSR was also associated with an increased frequency of malignancy (P < 0.01). Thus, these biological parameters were related to the spontaneous evolution of FA and could be used as prognostic factors. These data indicated that telomeres might play a role in the evolution of bone marrow failure and malignant transformation in FA.
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Anemia Aplásica/etiología , Anemia de Fanconi/genética , Telómero/metabolismo , Enfermedad Aguda , Adolescente , Adulto , Anciano , Anemia Aplásica/patología , Apoptosis/genética , Células de la Médula Ósea/patología , Niño , Preescolar , Rotura Cromosómica , Anemia de Fanconi/patología , Femenino , Humanos , Lactante , Leucemia Mieloide/genética , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/genética , Pronóstico , Telómero/genética , Telómero/patologíaRESUMEN
Allogeneic bone marrow transplantation (BMT) from HLA-identical siblings is an accepted treatment for both thalassemia and sickle cell disease (SCD). However, it is associated with decided risk of both transplant-related mortality (TRM) and chronic graft-versus-host disease (GVHD). We analyzed 44 patients (median age, 5 years; range, 1-20 years) given an allogeneic related cord blood transplant for either thalassemia (n = 33) or SCD (n = 11). Thirty children were given cyclosporin A (CsA) alone as GVHD prophylaxis, 10 received CsA and methotrexate (MTX), and 4 patients received other combinations of immunosuppressive drugs. The median number of nucleated cells infused was 4.0 x 10(7)/kg (range, 1.2-10 x 10(7)/kg). No patient died and 36 of 44 children remain free of disease, with a median follow-up of 24 months (range, 4-76 months). Only one patient with SCD did not have sustained donor engraftment as compared with 7 of the 33 patients with thalassemia. Three of these 8 patients had sustained donor engraftment after BMT from the same donor. Four patients experienced grade 2 acute GVHD; only 2 of the 36 patients at risk developed limited chronic GVHD. The 2-year probability of event-free survival is 79% and 90% for patients with thalassemia and SCD, respectively. Use of MTX for GVHD prophylaxis was associated with a greater risk of treatment failure. Related CBT for hemoglobinopathies offers a good probability of success and is associated with a low risk of GVHD. Optimization of transplantation strategies could further improve these results.
Asunto(s)
Anemia de Células Falciformes/terapia , Trasplante de Células Madre de Sangre del Cordón Umbilical , Talasemia/terapia , Enfermedad Aguda , Plaquetas , Niño , Preescolar , Enfermedad Crónica , Ciclosporina/uso terapéutico , Supervivencia sin Enfermedad , Femenino , Supervivencia de Injerto , Enfermedad Injerto contra Huésped/epidemiología , Enfermedad Injerto contra Huésped/prevención & control , Humanos , Inmunosupresores/uso terapéutico , Lactante , Masculino , Metotrexato/uso terapéutico , Neutrófilos , Tasa de Supervivencia , Trasplante Homólogo , Resultado del TratamientoRESUMEN
Fanconi anemia (FA) is a chromosomal instability disorder characterized by a progressive bone marrow (BM) failure and an increased incidence of myeloid leukemias. Children with FA are currently being enrolled in clinical trials to evaluate the safety of retroviral-mediated gene transfer. Previously, we used Fancc(-/-) mice to show that Fancc(-/-) hematopoietic stem cells (HSCs) have a profound defect in repopulating ability. Here, we examined whether retroviral-mediated gene transfer of recombinant Fancc (rFancc) would restore the repopulating ability of Fancc(-/-) HSC to wild-type levels. Fancc(-/-) HSCs transduced with a retrovirus encoding rFancc exhibited a repopulating ability that approached wild-type levels. Interestingly, approximately 30% of primary recipients (7 of 22) transplanted with uncorrected Fancc(-/-) cells developed a range of hematopoietic abnormalities including pancytopenia and BM hypoplasia similar to individuals with FA. Hematopoietic abnormalities were detected in only 1 of 22 mice transplanted with Fancc(-/-) cells transduced with a retrovirus encoding rFancc. Moreover, several mice with hematopoietic defects had progenitors that displayed a marked resistance to IFN-gamma, TNF-alpha, and MIP-1alpha compared to both Fancc(-/-) progenitors, which are uniquely hypersensitive to these cytokines, and wild-type progenitors. These data are analogous to studies using progenitors from patients with myelodysplasia and provide functional support for clonal evolution in these mice. Collectively, these data show that gene transfer can enhance HSC repopulating ability and suppresses the tendency for clonal evolution. These studies also reveal potential detrimental effects of ex vivo manipulation for untransduced Fancc(-/-) HSCs.