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1.
J Pediatr ; 2020 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-32037152

RESUMO

OBJECTIVE: To describe the hematologic outcome and long-term survival of patients enrolled in the Shwachman-Diamond syndrome Italian Registry. STUDY DESIGN: A retrospective and prospective study of patients recorded in the Shwachman-Diamond syndrome Italian Registry. RESULTS: The study population included 121 patients, 69 males and 52 females, diagnosed between 1999 and 2018. All patients had the clinical diagnosis confirmed by mutational analysis on the SBDS gene. During the study period, the incidence of SDS was 1 in 153 000 births. The median age of patients with SDS at diagnosis was 1.3 years (range, 0-35.6 years). At the first hematologic assessment, severe neutropenia was present in 25.8%, thrombocytopenia in 25.5%, and anemia in 4.6% of patients. A normal karyotype was found in 40 of 79 patients, assessed whereas the most frequent cytogenetic abnormalities were isochromosome 7 and interstitial deletion of the long arm of chromosome 20. The cumulative incidence of severe neutropenia, thrombocytopenia, and anemia at 30 years of age were 59.9%, 66.8%, and 20.2%, respectively. The 20-year cumulative incidence of myelodysplastic syndrome/leukemia and of bone marrow failure/severe cytopenia was 9.8% and 9.9%, respectively. Fifteen of 121 patients (12.4%) underwent allogeneic stem cell transplantation. Fifteen patients (12.4%) died; the probability of overall survival at 10 and 20 years was 95.7% and 87.4%, respectively. CONCLUSIONS: Despite an improvement in survival, hematologic complications still cause death in patients with SDS. Further studies are needed to optimize type and modality of hematopoietic stem cell transplantation and to assess the long-term outcome in nontransplanted patients.

2.
Ann Hematol ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31965272

RESUMO

Oral ferrous salts are standard treatment for children with iron deficiency anemia (IDA). The objective of our study was to monitor oral iron therapy in children, aged 3 months-12 years, with IDA. We prospectively collected clinical and hematological data of children with IDA, from 15 AIEOP (Associazione Italiana di Ematologia ed. Oncologia Pediatrica) centers. Response was measured by the increase of Hb from baseline. Of the 107 analyzed patients, 18 received ferrous gluconate/sulfate 2 mg/kg (ferrous 2), 7 ferrous gluconate/sulfate 4 mg/kg (ferrous 4), 7 ferric iron salts 2 mg/kg (ferric), 62 bis-glycinate iron 0.45 mg/kg (glycinate), and 13 liposomal iron 0.7-1.4 mg/kg (liposomal). Increase in reticulocytes was evident at 3 days, while Hb increase appeared at 2 weeks. Gain of Hb at 2 and 8 weeks revealed a higher median increase in both ferrous 2 and ferrous 4 groups. Gastro-intestinal side effects were reported in 16% (ferrous 2), 14% (ferrous 4), 6% (glycinate), and 0 (ferric and liposomal) patients. The reticulocyte counts significantly increased after 3 days from the start of oral iron supplementation. Bis-glycinate iron formulation had a good efficacy/safety profile and offers an acceptable alternative to ferrous iron preparations.

3.
Mar Genomics ; 49: 100721, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31711848

RESUMO

Since the discovery of new members of the globin superfamily such as Cytoglobin, Neuroglobin and Globin X, in addition to the most well-known members, Hemoglobin and Myoglobin, different hypotheses have been suggested about their function in vertebrates. Globins are ubiquitously found in living organisms and can carry out different functions based on their ability to bind ligands such as O2, and nitric oxide (NO) and to catalyze reactions scavenging NO or generating NO by reducing nitrite. NO is a highly diffusible molecule with a central role in signaling important for egg maturation, fertilization and early embryonic development. The globins ability to scavenge or generate NO makes these proteins ideal candidates in regulating NO homeostasis depending on the micro environment and tissue NO demands. Different amounts of various globins have been found in zebrafish eggs and developing embryos where it's unlikely that they function as respiratory proteins and instead could play a role in maintaining embryonic NO homeostasis. Here we summarize the current knowledge concerning the role of NO in adult fish in comparison to mammals and we discuss NO function during embryonic development with possible implications for globins in maintaining embryonic NO homeostasis.


Assuntos
Desenvolvimento Embrionário , Peixes/embriologia , Globinas/fisiologia , Óxido Nítrico/fisiologia , Animais , Homeostase
4.
Antioxid Redox Signal ; 32(6): 363-377, 2020 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-31724431

RESUMO

Aims: Nitrite is reduced to nitric oxide (NO) under physiological and pathological hypoxic conditions to modulate angiogenesis and improve ischemia-reperfusion injury. Although adult mammals lack the ability to regenerate the heart after injury, this is preserved in neonates and efforts to reactivate this process are of great interest. Unlike mammals, the adult zebrafish maintain the innate ability to regenerate their hearts after injury, providing an important model to study cardiac regeneration. We thus explored the effects of physiological levels of nitrite on cardiac and fin regeneration and downstream cellular and molecular signaling pathways in response to amputation and cryoinjury. Results: Nitrite treatment of zebrafish after ventricular amputation or cryoinjury to the heart in hypoxic water (∼3 parts per million of oxygen) increases cardiomyocyte proliferation, improves angiogenesis, and enhances early recruitment of thrombocytes, macrophages, and neutrophils to the injury. When tested in a fin regeneration model, neutrophil recruitment to the injury site was found to be dependent on NO. Innovation: This is the first study to evaluate effects of physiological levels of nitrite on cardiac regeneration in response to cardiac injury, with the observation that nitrite in water accelerates zebrafish heart regeneration. Conclusion: Physiological and therapeutic levels of nitrite increase thrombocyte, neutrophil, and macrophage recruitment to the heart after amputation and cryoinjury in zebrafish, resulting in accelerated cardiomyocyte proliferation and angiogenesis. Translation of this finding to mammalian models of injury during early development may provide an opportunity to improve outcomes during intrauterine fetal or neonatal cardiac surgery.

5.
J Allergy Clin Immunol Pract ; 8(1): 273-282, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31377437

RESUMO

BACKGROUND: Rituximab (RTX; anti-CD20 mAb) is a treatment option in children with refractory immune thrombocytopenia, autoimmune hemolytic anemia (AHA), and Evans syndrome (ES). Prevalence and clinical course of RTX-induced hypogammaglobulinemia in these patients are poorly known. OBJECTIVE: To evaluate the prevalence and risk factors for persistent hypogammaglobulinemia (PH) after RTX use. METHODS: Clinical and immunologic data from children treated with RTX for immune thrombocytopenia, AHA, and ES were collected from 16 Italian centers and 1 UK center at pre-RTX time point (0), +6 months, and yearly, up to 4 years post-RTX. Patients with previously diagnosed malignancy or primary immune deficiency (PID) were excluded. RESULTS: We analyzed 53 children treated with RTX for immune thrombocytopenia (n = 36), AHA (n = 13), and ES (n = 4). Median follow-up was 30 months (range, 12-48). Thirty-two percent of patients (17 of 53) experienced PH, defined as IgG levels less than 2 SD for age at last follow-up (>12 months after RTX). Significantly delayed B-cell recovery was observed in children experiencing PH (hazard ratio, 0.55; P < .05), and 6 of 17 (35%) patients had unresolved B-cell lymphopenia at last follow-up. PH was associated with IgA and IgM deficiency, younger age at RTX use (51 vs 116 months; P < .01), a diagnosis of AHA/ES, and better response to RTX. Nine patients with PH (9 of 17 [53%]) were eventually diagnosed with a PID. CONCLUSIONS: Post-RTX PH is a frequent condition in children with autoimmune cytopenia; a sizable proportion of patients with post-RTX PH were eventually diagnosed with a PID. In-depth investigation for PID is therefore recommended in these patients.

6.
Biochemistry ; 58(29): 3212-3223, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31257865

RESUMO

Cytoglobin is a heme protein evolutionarily related to hemoglobin and myoglobin. Cytoglobin is expressed ubiquitously in mammalian tissues; however, its physiological functions are yet unclear. Phylogenetic analyses indicate that the cytoglobin gene is highly conserved in vertebrate clades, from fish to reptiles, amphibians, birds, and mammals. Most proposed roles for cytoglobin require the maintenance of a pool of reduced cytoglobin (FeII). We have shown previously that the human cytochrome b5/cytochrome b5 reductase system, considered a quintessential hemoglobin/myoglobin reductant, can reduce human and zebrafish cytoglobins ≤250-fold faster than human hemoglobin or myoglobin. It was unclear whether this reduction of zebrafish cytoglobins by mammalian proteins indicates a conserved pathway through vertebrate evolution. Here, we report the reduction of zebrafish cytoglobins 1 and 2 by the zebrafish cytochrome b5 reductase and the two zebrafish cytochrome b5 isoforms. In addition, the reducing system also supports reduction of Globin X, a conserved globin in fish and amphibians. Indeed, the zebrafish reducing system can maintain a fully reduced pool for both cytoglobins, and both cytochrome b5 isoforms can support this process. We determined the P50 for oxygen to be 0.5 Torr for cytoglobin 1 and 4.4 Torr for cytoglobin 2 at 25 °C. Thus, even at low oxygen tensions, the reduced cytoglobins may exist in a predominant oxygen-bound form. Under these conditions, the cytochrome b5/cytochrome b5 reductase system can support a conserved role for cytoglobins through evolution, providing electrons for redox signaling reactions such as nitric oxide dioxygenation, nitrite reduction, and phospholipid oxidation.

7.
Pediatr Blood Cancer ; 66(5): e27657, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30724025

RESUMO

BACKGROUND: Sickle cell disease (SCD) is a chronic multisystem disorder requiring comprehensive care that includes newborn screening (NBS) as the first step of care. Italy still lacks a national SCD NBS program and policy on blood disorders. Pilot single-center screening programs and a regional targeted screening have been implemented so far, but more evidence is needed in order to impact health policies. POPULATION AND METHODS: NBS was offered to parents of newborns in gynecology clinics in Padova and Monza, tertiary care university hospitals in northern Italy. High-performance liquid chromatography (HPLC) was performed as the first test on samples collected on Guthrie cards. Molecular analysis of the beta-globin gene was performed on positive samples. RESULTS: A total of 5466 newborns were enrolled; for 5439, informed consents were obtained. A similar family origin was seen in the two centers (65% Italians, 9% mixed couples, 26% immigrants). Compared with SCD NBS programs in the United States and Europe, our results show a similar incidence of SCD patients and carriers. All SCD patients had a Sub-Saharan family background; HbS carriers were 15% Caucasians (Italian, Albanians) and 10% from other areas (North Africa-India-South America); carriers of other hemoglobin variants were mainly (47%) from other areas. CONCLUSIONS: Our results demonstrate the feasibility of a multicentric NBS program for SCD, give information on HbS epidemiology in two Northern Italian Areas, and support previous European recommendation for a universal NBS program for SCD in Italy: a high incidence of patients and carriers has been detected, with a high percentage of Caucasian carriers, impossible to identify in a targeted NBS.


Assuntos
Anemia Falciforme/diagnóstico , Anemia Falciforme/epidemiologia , Doenças do Recém-Nascido/diagnóstico , Doenças do Recém-Nascido/epidemiologia , Triagem Neonatal/métodos , Humanos , Incidência , Recém-Nascido , Itália/epidemiologia , Prognóstico
8.
Front Pediatr ; 6: 272, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30327760

RESUMO

We describe a previously healthy 14-year-old girl with acute onset autoimmune hemolytic anemia, associated with severe but transient lymphopenia during corticosteroid therapy, without infectious episodes during follow-up. After detailed investigations to rule out an underlying immunodeficiency, we detected a heterozygous ADA gene mutation. This was associated with slightly increased blood levels of adenosine and deoxyadenosine nucleotides and with reduced ADA activity in red blood cells, but within the normal range. This observation suggests that heterozygous ADA mutation might be a predisposing factor for lymphopenia in patients receiving corticosteroid therapy.

9.
Br J Haematol ; 182(1): 114-124, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29767474

RESUMO

Shwachman-Diamond syndrome (SDS) is a rare multi-organ recessive disease mainly characterised by pancreatic insufficiency, skeletal defects, short stature and bone marrow failure (BMF). As in many other BMF syndromes, SDS patients are predisposed to develop a number of haematopoietic malignancies, particularly myelodysplastic syndrome and acute myeloid leukaemia. However, the mechanism of cancer predisposition in SDS patients is only partially understood. In light of the emerging role of mesenchymal stromal cells (MSCs) in the regulation of bone marrow homeostasis, we assessed the ability of MSCs derived from SDS patients (SDS-MSCs) to recreate a functional bone marrow niche, taking advantage of a murine heterotopic MSC transplant model. We show that the ability of semi-cartilaginous pellets (SCPs) derived from SDS-MSCs to generate complete heterotopic ossicles in vivo is severely impaired in comparison with HD-MSC-derived SCPs. Specifically, after in vitro angiogenic stimuli, SDS-MSCs showed a defective ability to form correct networks, capillary tubes and vessels and displayed a marked decrease in VEGFA expression. Altogether, these findings unveil a novel mechanism of SDS-mediated haematopoietic dysfunction based on hampered ability of SDS-MSCs to support angiogenesis. Overall, MSCs could represent a new appealing therapeutic target to treat dysfunctional haematopoiesis in paediatric SDS patients.


Assuntos
Doenças da Medula Óssea/patologia , Medula Óssea/patologia , Insuficiência Pancreática Exócrina/patologia , Lipomatose/patologia , Células-Tronco Mesenquimais/fisiologia , Neovascularização Fisiológica/fisiologia , Adolescente , Adulto , Animais , Células da Medula Óssea/patologia , Doenças da Medula Óssea/genética , Doenças da Medula Óssea/fisiopatologia , Cartilagem/transplante , Diferenciação Celular , Células Cultivadas , Criança , Pré-Escolar , Condrócitos/patologia , Condrócitos/fisiologia , Condrogênese/fisiologia , Insuficiência Pancreática Exócrina/genética , Insuficiência Pancreática Exócrina/fisiopatologia , Feminino , Hematopoese/fisiologia , Xenoenxertos , Humanos , Lactente , Lipomatose/genética , Lipomatose/fisiopatologia , Masculino , Células-Tronco Mesenquimais/patologia , Camundongos SCID , Adulto Jovem
10.
Pediatr Blood Cancer ; 65(2)2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28868627

RESUMO

BACKGROUND: The number of patients with sickle cell disease (SCD) has increased in Italy in the past decade due to immigration. In spite of the established efficacy of hydroxyurea (HU) in childhood, population-based data regarding its prescription and effectiveness come mainly from studies performed in adults or outside Europe. POPULATION AND METHODS: The Hydroxyurea in SCD: A Large Nation-wide Cohort Study from Italy was a retrospective cohort study of adult and pediatric patients with SCD attending 32 centers. Pediatric data are analyzed separately. RESULTS: Out of 504 children followed in 11 centers, 206 (40%) were on HU (194 SS/Sß°, 12 SC/Sß+); 74% came from Sub-Saharian Africa and 18% from Europe. HU therapy indications for SS/Sß° patients were as follows: 57% painful vaso-occlusive crisis, acute chest syndrome or both, 24% anemia, 8% anemia, and other reasons (the majority had Hb ≤ 8-8.5 g/dl, revealing scarce acceptance of low Hb values by pediatric hematologist). Mean starting dose was 15.5 mg/kg, and dose at full regimen was 17.1 mg/kg. Mean age at HU therapy was 7.68 years, although it was lower for SS/Sß° patients. Only 10% started HU before 3 years. In 92%, 500 mg capsule was used; in 6%, the galenic was used; and in 2%, 100 mg tablet was used. Significant reduction of clinical events and inpatients admissions, with improvement in hematological parameters, was observed for SS/Sß° patients and a trend toward improvement for SC/Sß+ patients was also observed. CONCLUSIONS: HU effectiveness is demonstrated in a national cohort of children with SCD living in Italy, even at a lower dose than recommended, revealing good adherence to a treatment program by a socially vulnerable group of patients such as immigrants.


Assuntos
Anemia Falciforme/tratamento farmacológico , Prescrições de Medicamentos , Acesso aos Serviços de Saúde , Hidroxiureia/administração & dosagem , Adolescente , Anemia Falciforme/epidemiologia , Criança , Pré-Escolar , Emigrantes e Imigrantes , Feminino , Seguimentos , Humanos , Lactente , Itália/epidemiologia , Masculino
12.
Biochemistry ; 56(30): 3993-4004, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28671819

RESUMO

Cytoglobin is a heme-containing protein ubiquitous in mammalian tissues. Unlike the evolutionarily related proteins hemoglobin and myoglobin, cytoglobin shows a six-coordinated heme binding, with the heme iron coordinated by two histidine side chains. Cytoglobin is involved in cytoprotection pathways through yet undefined mechanisms, and it has recently been demonstrated that cytoglobin has redox signaling properties via nitric oxide (NO) and nitrite metabolism. The reduced, ferrous cytoglobin can bind oxygen and will react with NO in a dioxygenation reaction to form nitrate, which dampens NO signaling. When deoxygenated, cytoglobin can bind nitrite and reduce it to NO. This oxidoreductase activity could be catalytic if an effective reduction system exists to regenerate the reduced heme species. The nature of the physiological cytoglobin reducing system is unknown, although it has been proposed that ascorbate and cytochrome b5 could fulfill this role. Here we describe that physiological concentrations of cytochrome b5 and cytochrome b5 reductase can reduce human and fish cytoglobins at rates up to 250-fold higher than those reported for their known physiological substrates, hemoglobin and myoglobin, and up to 100-fold faster than 5 mM ascorbate. These data suggest that the cytochrome b5/cytochrome b5 reductase system is a viable reductant for cytoglobin in vivo, allowing for catalytic oxidoreductase activity.


Assuntos
Citocromo-B(5) Redutase/metabolismo , Citocromos b5/metabolismo , Globinas/metabolismo , Modelos Moleculares , NAD/metabolismo , Óxido Nítrico/metabolismo , Oxigenases/metabolismo , Animais , Antioxidantes/química , Biocatálise , Simulação por Computador , Citocromo-B(5) Redutase/química , Citocromo-B(5) Redutase/genética , Citocromos b5/química , Citocromos b5/genética , Citoglobina , Globinas/química , Globinas/genética , Humanos , Cinética , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Neuroglobina , Oxirredução , Oxigenases/química , Oxigenases/genética , Conformação Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Homologia Estrutural de Proteína , Proteínas de Peixe-Zebra/química , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
13.
Blood Cells Mol Dis ; 64: 45-50, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28380398

RESUMO

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare disease, especially in children, characterized by intravascular hemolysis, thrombotic events, serious infections and bone marrow failure. We describe 16 patients who were diagnosed with PNH in childhood or adolescence. The time interval between the onset of symptoms and the PNH diagnosis and its treatment were compared in patients with classic PNH versus PNH associated with bone marrow disorder (PNH/BMD). A greater delay in diagnosis was observed in classic PNH compared to PNH/BMD patients. The first group of patients had higher levels of LDH, total bilirubin and absolute reticulocyte count and a bigger PNH clone size compared to PNH/BMD patients; also thrombotic events were observed only in the classic form of PNH. Conversely, PNH/BMD patients showed lower median levels of platelets. Apart from standard supportive measures, four patients with classic PNH received eculizumab whereas four patients with PNH/BMD underwent hematopoietic stem cell transplantation. Our series confirm that the most frequent presentation of PNH in the pediatric-adolescent age is PNH/BMD. The delay between the onset of symptoms and PNH diagnosis is relevant principally in the classic form. Moreover, our study showed that any case of unexpected thrombosis represents a criterium to perform a PNH screening.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Doenças da Medula Óssea , Transplante de Células-Tronco Hematopoéticas , Hemoglobinúria Paroxística , Adolescente , Adulto , Aloenxertos , Bilirrubina/sangue , Plaquetas/metabolismo , Doenças da Medula Óssea/sangue , Doenças da Medula Óssea/complicações , Doenças da Medula Óssea/diagnóstico , Doenças da Medula Óssea/terapia , Criança , Feminino , Hemoglobinúria Paroxística/sangue , Hemoglobinúria Paroxística/complicações , Hemoglobinúria Paroxística/diagnóstico , Hemoglobinúria Paroxística/terapia , Humanos , Masculino , Contagem de Reticulócitos , Estudos Retrospectivos
16.
Genes Chromosomes Cancer ; 56(1): 51-58, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27553422

RESUMO

Shwachman-Diamond syndrome (SDS) (OMIM 260400) is a rare autosomal recessive disease characterized by exocrine pancreatic insufficiency, skeletal, and hematological abnormalities and bone marrow (BM) dysfunction. Mutations in the SBDS gene cause SDS. Clonal chromosome anomalies are often present in BM, i(7)(q10) and del(20q) being the most frequent ones. We collected 6 SDS cases with del(20q): a cluster of imprinted genes, including L3MBTL1 and SGK2 is present in the deleted region. Only the paternal allele is expressed for these genes. Based on these data, we made the hypothesis that the loss of this region, in relation to parental origin of deletion, may be of relevance for the hematological phenotype. By comparing hematological data of our 6 cases with a group of 20 SDS patients without evidence of del(20q) in BM, we observed a significant difference for Hb levels (P < 0.012), and a difference slightly above the significance level for RBC counts (P < 0.053): in both cases the values were higher in patients with del(20q). We also report preliminary evidence for an increased number of BFU-E colonies in cases with paternal deletion, data on the presence of the deletion in colonies and in mature circulating lymphocytes. © 2016 Wiley Periodicals, Inc.


Assuntos
Doenças da Medula Óssea/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos Humanos Par 20/genética , Insuficiência Pancreática Exócrina/genética , Impressão Genômica , Proteínas Imediatamente Precoces/genética , Lipomatose/genética , Proteínas Serina-Treonina Quinases/genética , Deleção de Sequência , Biomarcadores Tumorais , Aberrações Cromossômicas , Seguimentos , Humanos , Mutação/genética , Estadiamento de Neoplasias , Fenótipo , Prognóstico , Estudos Retrospectivos
17.
Proc Natl Acad Sci U S A ; 113(30): 8538-43, 2016 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-27407144

RESUMO

The discovery of novel globins in diverse organisms has stimulated intense interest in their evolved function, beyond oxygen binding. Globin X (GbX) is a protein found in fish, amphibians, and reptiles that diverged from a common ancestor of mammalian hemoglobins and myoglobins. Like mammalian neuroglobin, GbX was first designated as a neuronal globin in fish and exhibits six-coordinate heme geometry, suggesting a role in intracellular electron transfer reactions rather than oxygen binding. Here, we report that GbX to our knowledge is the first six-coordinate globin and the first globin protein apart from hemoglobin, found in vertebrate RBCs. GbX is present in fish erythrocytes and exhibits a nitrite reduction rate up to 200-fold faster than human hemoglobin and up to 50-fold higher than neuroglobin or cytoglobin. Deoxygenated GbX reduces nitrite to form nitric oxide (NO) and potently inhibits platelet activation in vitro, to a greater extent than hemoglobin. Fish RBCs also reduce nitrite to NO and inhibit platelet activation to a greater extent than human RBCs, whereas GbX knockdown inhibits this nitrite-dependent NO signaling. The description of a novel, six-coordinate globin in RBCs with dominant electron transfer and nitrite reduction functionality provides new insights into the evolved signaling properties of ancestral heme-globins.


Assuntos
Eritrócitos/metabolismo , Peixes/metabolismo , Globinas/metabolismo , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Animais , Células Cultivadas , Transporte de Elétrons , Eritrócitos/citologia , Peixes/sangue , Peixes/genética , Expressão Gênica , Globinas/genética , Hemoglobinas/genética , Hemoglobinas/metabolismo , Humanos , Oxirredução , Interferência de RNA , Peixe-Zebra/sangue , Peixe-Zebra/genética , Peixe-Zebra/metabolismo
18.
Nitric Oxide ; 53: 22-34, 2016 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-26721561

RESUMO

Neuroglobin (Ngb) and cytoglobin (Cygb) are two six-coordinate heme proteins of unknown physiological function. Although studies on the mammalian proteins have elucidated aspects of Ngb and Cygb biophysics and indicated potential functions, the properties of non-mammalian Ngbs and Cygbs are largely uncharacterized. We have expressed the recombinant zebrafish proteins Ngb, Cygb1, and Cygb2 in Escherichia coli and characterized their nitrite reduction rates, spectral properties, autoxidation rate constants, redox potentials and lipid binding properties. The three zebrafish proteins can catalyze the reduction of nitrite to nitric oxide with a broad range of reaction rate constants. (Ngb, 0.68 ± 0.04 M(-1) s(-1); Cygb1, 28.6 ± 3.1 M(-1) s(-1); Cygb2, 0.94 ± 0.18 M(-1) s(-1)). We observe that zebrafish Ngb and Cygb2 have comparable spectral features to those of human Ngb and Cygb, consistent with a six-coordinate heme, whereas unexpectedly Cygb1 has a five-coordinate heme, a slower autoxidation and in general has properties more akin to oxygen transport proteins. In agreement with a possible oxygen carrier and nitrite reductase role, we detect mRNA transcript for Cygb1 but not Cygb2 or Ngb in zebrafish blood. Unlike human Cygb, neither of the zebrafish globins binds oleic acid with high affinity. This finding suggests that lipid binding may be a trait acquired later during evolution and not an ancestral property of cytoglobins. Altogether, our results uncover unexpected properties of zebrafish globins and reveal the pivotal role of cytoglobins in the transition of heme globins from six-coordinate to five-coordinate oxygen carriers and nitrite reductases.


Assuntos
Globinas/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Peixe-Zebra/metabolismo , Animais , Globinas/genética , Humanos , Neuroglobina , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Peixe-Zebra/genética
19.
JIMD Rep ; 26: 37-43, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26238250

RESUMO

Pearson syndrome (PS) is a very rare and often fatal multisystemic mitochondrial disorder involving the liver, kidney, pancreas, and hematopoietic and central nervous system. It is characterized principally by a transfusion-dependent anemia that usually improves over time, a tendency to develop severe infections, and a high mortality rate. We describe a group of 11 PS patients diagnosed in Italy in the period 1993-2014. The analysis of this reasonably sized cohort of patients contributes to the clinical profile of the disease and highlights a rough incidence of 1 case/million newborns. Furthermore, it seems that some biochemical parameters like increased serum alanine and urinary fumaric acid can help to address an early diagnosis.

20.
PLoS One ; 10(9): e0138200, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26394034

RESUMO

Diamond-Blackfan Anaemia (DBA) is a rare inherited anaemia caused by heterozygous mutations in one of 13 ribosomal protein genes. Erythroid progenitors (BFU-E and CFU-E) in bone marrow (BM) show a proapoptotic phenotype. Suspicion of DBA is reached after exclusion of other forms of BM failure syndromes. To improve DBA diagnosis, which is confirmed by mutation analysis, we tested a new approach based on the study of extracellular vesicles (EVs) isolated from plasma by differential centrifugations and analysed by flow cytometry. We chose CD34, CD71 and CD235a markers to study erythroid EVs. We characterised the EVs immunophentoypic profiles of 13 DBA patients, 22 healthy controls and 16 patients with other haematological diseases. Among the three EVs clusters we found, only the CD34+/CD71low population showed statistically significant differences between DBA patients and controls (p< 0.05). The absence of this cluster is in agreement with the low levels of BFU-E found in DBA patients. The assessment of ROC curves demonstrated the potential diagnostic value of this population. We suggest that this assay may be useful to improve DBA diagnosis as a quicker and less invasive alternative to BM BFU-E culture analysis.


Assuntos
Anemia de Diamond-Blackfan/diagnóstico , Células Precursoras Eritroides/metabolismo , Vesículas Extracelulares/metabolismo , Imunofenotipagem/métodos , Adolescente , Adulto , Anemia de Diamond-Blackfan/sangue , Anemia de Diamond-Blackfan/genética , Antígenos CD/sangue , Antígenos CD34/sangue , Biomarcadores/sangue , Criança , Pré-Escolar , Ensaio de Unidades Formadoras de Colônias , Feminino , Citometria de Fluxo , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Curva ROC , Receptores da Transferrina/sangue , Adulto Jovem
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