RESUMO
The endoplasmic reticulumï¼ERï¼is the largest membranous network serving as a region for protein, lipid and steroid synthesis, transport and storage. Detailed information about ER-cisternae, ER-tubules and rough endoplasmic reticulum (rER) is scarce in human blood cells. This study describes a series of giant inclusions and Auer bodies in promyeloblasts in six patients with acute promyelocytic leukemia (APL), by light microscopy, transmission electron microscopy (TEM) and cytochemical stains. TEM revealed that giant inclusions and pro-Auer bodies were associated with rER and surrounded by tubular structures composed of degenerated or redundant membrane in promyeloblasts, which corresponded with elements of the ER system. This paper reveals that in the promyeloblasts of APL, ER is the source of and transforms progressively into giant inclusions and Auer bodies.
Assuntos
Retículo Endoplasmático , Corpos de Inclusão , Leucemia Promielocítica Aguda , Microscopia Eletrônica de Transmissão , Humanos , Leucemia Promielocítica Aguda/patologia , Corpos de Inclusão/ultraestrutura , Masculino , Feminino , Retículo Endoplasmático/ultraestrutura , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Adolescente , Células Precursoras de Granulócitos/ultraestrutura , Células Precursoras de Granulócitos/patologiaAssuntos
Crise Blástica/patologia , Medula Óssea/patologia , Células Precursoras de Granulócitos/ultraestrutura , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Adolescente , Corantes Azur , Crise Blástica/diagnóstico , Grânulos Citoplasmáticos/química , Diabetes Mellitus Tipo 1/complicações , Diagnóstico Diferencial , Proteínas de Fusão bcr-abl/análise , Células Precursoras de Granulócitos/química , Antígenos HLA-DR/análise , Humanos , Subunidade alfa de Receptor de Interleucina-3/análise , Leucemia Mielogênica Crônica BCR-ABL Positiva/diagnóstico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucocitose/etiologia , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Coloração e Rotulagem , Trombocitopenia/etiologiaAssuntos
Anemia Sideroblástica/diagnóstico , Medula Óssea/patologia , Células Precursoras Eritroides/ultraestrutura , Células Precursoras de Granulócitos/ultraestrutura , Inflamação/etiologia , Síndrome de Sweet/etiologia , Enzimas Ativadoras de Ubiquitina/genética , Vacúolos/ultraestrutura , Idoso , Anemia Sideroblástica/complicações , Anemia Sideroblástica/genética , Anemia Sideroblástica/patologia , Humanos , Inflamação/genética , Inflamação/patologia , Masculino , Mutação de Sentido Incorreto , Mutação Puntual , SíndromeRESUMO
Progenitor cells of the human erythroid and granulocytic cell lineages are characterized by the presence of several nucleoli. One of these nucleoli is larger and possesses more fibrillar centres than others. Such nucleolus is apparently dominant in respect of both size and main nucleolar function such as nucleolar-ribosomal RNA transcription. Such nucleolus is also visible in specimens using conventional visualization procedures, in contrast to smaller nucleoli. In the terminal differentiation nucleated stages of the erythroid and granulocytic development, dominant nucleoli apparently disappeared, since these cells mostly contained very small nucleoli of a similar size with one fibrillar centre. Thus, the easily visible dominant nucleoli appear to be useful markers of the progenitor cell state, such as proliferation, and differentiation potential.
Assuntos
Nucléolo Celular/fisiologia , Células Precursoras Eritroides/ultraestrutura , Células Precursoras de Granulócitos/ultraestrutura , Diferenciação Celular , Divisão Celular , Linhagem da Célula , Nucléolo Celular/ultraestrutura , Núcleo Celular/ultraestrutura , Granulócitos/ultraestrutura , Humanos , RNA Ribossômico/metabolismoRESUMO
INTRODUCTION: Vacuolization is a frequently found morphological feature in acute myeloid leukemia (AML) blasts. Subcellular origin and biological function as well as prognostic impact are currently unknown. The aim of this study was to evaluate whether vacuolization correlates with clinically relevant AML features. MATERIALS & METHODS: Bone marrow smears of patients diagnosed with AML at the University Hospital Frankfurt between January 2011 and August 2013 were analyzed for blast vacuolization and correlated with clinically relevant AML features. Patients undergoing standard induction chemotherapy were further analyzed for molecular and cytogenetic features as well as treatment response and survival. RESULTS: 14 of 100 patients diagnosed with AML receiving standard induction chemotherapy had evidence of blast vacuolization. Positivity for vacuolization correlated with a CD15 positive immunophenotype and with a higher incidence of high-risk AML according to the European LeukemiaNet risk stratification. AML patients with blast vacuolization had a poor blast clearance after standard induction chemotherapy and poor survival. DISCUSSION: In conclusion, our findings demonstrate that vacuolization can easily be determined in myeloid leukemia blasts and may be a useful biomarker to predict AML risk groups as well as early treatment response rates and survival.
Assuntos
Medula Óssea/patologia , Células Precursoras de Granulócitos/patologia , Quimioterapia de Indução/métodos , Leucemia Mieloide Aguda/diagnóstico , Vacúolos/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/imunologia , Medula Óssea/metabolismo , Medula Óssea/ultraestrutura , Feminino , Células Precursoras de Granulócitos/metabolismo , Células Precursoras de Granulócitos/ultraestrutura , Humanos , Leucemia Mieloide Aguda/metabolismo , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Antígenos CD15/genética , Antígenos CD15/imunologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Medição de Risco , Análise de Sobrevida , Vacúolos/metabolismo , Vacúolos/ultraestruturaRESUMO
CD81 is a cell surface protein which belongs to the tetraspanin family. While in multiple myeloma its expression on plasma cells is associated with worse prognosis, this has not yet been explored in acute myeloid leukemia (AML). We measured membrane expression of CD81 on AML cells at diagnosis, evaluated its association with AML characteristics and its influence on patient outcome after intensive chemotherapy in a cohort of 134 patients. CD81 was detected in 92/134 (69%) patients. Patients with AML expressing CD81 had elevated leukocyte count (P=0.02) and were more likely classified as intermediate or adverse-risk by cytogenetics (P<0.001). CD81 expression had a negative impact on survival (event-free survival, overall survival and relapse-free survival) in univariate (P<0.001) and in multivariate analyses (P=0.003, 0.002 and <0.001, respectively). CD81 has a negative impact on OS in patients with NPM1 mutation (P=0.01) and in patients ELN-favorable (P=0.002). In conclusion, this cell surface marker may be a new prognostic marker for diagnostic risk classification and a potential therapeutic target for drug development in AML.
Assuntos
Biomarcadores Tumorais/metabolismo , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Tetraspanina 28/metabolismo , Adulto , Fatores Etários , Idoso , Membrana Celular/metabolismo , Intervalo Livre de Doença , Feminino , Citometria de Fluxo , Seguimentos , Células Precursoras de Granulócitos/metabolismo , Células Precursoras de Granulócitos/ultraestrutura , Humanos , Estimativa de Kaplan-Meier , Leucemia Mieloide Aguda/sangue , Leucemia Mieloide Aguda/genética , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas Nucleares/genética , Nucleofosmina , Prognóstico , Adulto JovemRESUMO
The transcription factor XBP1 has been linked to the development of highly secretory tissues such as plasma cells and Paneth cells, yet its function in granulocyte maturation has remained unknown. Here we discovered an unexpectedly selective and absolute requirement for XBP1 in eosinophil differentiation without an effect on the survival of basophils or neutrophils. Progenitors of myeloid cells and eosinophils selectively activated the endoribonuclease IRE1α and spliced Xbp1 mRNA without inducing parallel endoplasmic reticulum (ER) stress signaling pathways. Without XBP1, nascent eosinophils exhibited massive defects in the post-translational maturation of key granule proteins required for survival, and these unresolvable structural defects fed back to suppress critical aspects of the transcriptional developmental program. Hence, we present evidence that granulocyte subsets can be distinguished by their differential reliance on secretory-pathway homeostasis.
Assuntos
Diferenciação Celular/imunologia , Proteínas de Ligação a DNA/imunologia , Eosinófilos/imunologia , Expressão Gênica/imunologia , Fatores de Transcrição/imunologia , Animais , Diferenciação Celular/genética , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Estresse do Retículo Endoplasmático/genética , Estresse do Retículo Endoplasmático/imunologia , Endorribonucleases/genética , Endorribonucleases/imunologia , Endorribonucleases/metabolismo , Eosinófilos/metabolismo , Eosinófilos/ultraestrutura , Citometria de Fluxo , Perfilação da Expressão Gênica , Células Precursoras de Granulócitos/imunologia , Células Precursoras de Granulócitos/metabolismo , Células Precursoras de Granulócitos/ultraestrutura , Células HEK293 , Humanos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/imunologia , Proteínas Serina-Treonina Quinases/metabolismo , Fatores de Transcrição de Fator Regulador X , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína 1 de Ligação a X-BoxAssuntos
Células Precursoras de Granulócitos/ultraestrutura , Leucemia Mielomonocítica Aguda/diagnóstico , Leucemia Mielomonocítica Aguda/patologia , Adolescente , Feminino , Células Precursoras de Granulócitos/enzimologia , Células Precursoras de Granulócitos/patologia , Humanos , Leucemia Mielomonocítica Aguda/enzimologia , Peroxidase/metabolismoAssuntos
Leucemia Mieloide Aguda/complicações , Derrame Pleural Maligno/diagnóstico , Idoso , Antimetabólitos Antineoplásicos/uso terapêutico , Azacitidina/uso terapêutico , Bleomicina/uso terapêutico , Células Clonais/patologia , Terapia Combinada , Drenagem , Evolução Fatal , Células Precursoras de Granulócitos/ultraestrutura , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/tratamento farmacológico , Masculino , Derrame Pleural Maligno/patologia , Derrame Pleural Maligno/terapia , Pleurodese/métodos , Soluções Esclerosantes/uso terapêuticoRESUMO
The frequent serious bleeding and thrombotic complications in acute promyelocytic leukemia (APL) are major causes of early mortality, but the complex mechanisms causing the bleeding have not been completely elucidated. Because microparticles (MPs) are known to be elevated in thromboembolic disorders, we hypothesized a role for MPs in the pathogenesis of coagulopathy in APL. MPs were isolated from 30 APL patients and 20 healthy subjects and from cultured NB4/APL cells. The morphology of the MPs was examined, and they were quantified and analyzed for their thrombin-generating potential. We confirmed the existence of promyelocytic-derived MPs by morphology using transmission electron microscopy and laser scanning confocal microscopy. Counts of MPs in APL were elevated and were typically from promyelocytic cells (CD33(+) TF(+) MPs). Importantly, the CD33(+) MPs strongly correlated with patient leukocyte count (R = 0.64, p = 0.002) and D-dimer (R = 0.51, p = 0.0038). Moreover, the MPs from patients with APL decreased the coagulation times and induced thrombin generation. APL MP-associated thrombin generation was reduced by 54 % when the extrinsic pathway was blocked using an anti-human tissue factor (TF) antibody. However, neither anti-factor XI nor anti-tissue factor pathway inhibitor had any significant inhibitory effect. Our results show that the procoagulant state in APL is partially due to the TF-dependent procoagulant properties of circulating promyelocytic-derived MPs. TF(+) MPs may be a novel potential risk factor for coagulopathy in APL.
Assuntos
Transtornos da Coagulação Sanguínea/etiologia , Micropartículas Derivadas de Células/fisiologia , Células Precursoras de Granulócitos/ultraestrutura , Leucemia Promielocítica Aguda/complicações , Adolescente , Adulto , Idoso , Transtornos da Coagulação Sanguínea/epidemiologia , Estudos de Casos e Controles , Extensões da Superfície Celular/patologia , Extensões da Superfície Celular/fisiologia , Micropartículas Derivadas de Células/patologia , Células Cultivadas , Feminino , Células Precursoras de Granulócitos/patologia , Células Precursoras de Granulócitos/fisiologia , Humanos , Leucemia Promielocítica Aguda/sangue , Leucemia Promielocítica Aguda/patologia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto JovemRESUMO
The present study was undertaken to provide more information on the differentiation and maturation of human granulocytes using computer-assisted image RNA densitometry at single-cell level. The bone marrow of patients suffering from chronic phase of chronic myeloid leukemia represents a very convenient model for such measurements because of the satisfactory number of early stages, as well as advanced stages, of the granulocytic cell lineage represented by neutrophils. In contrast to the erythroid cell lineage, similar nucleolar and cytoplasmic RNA density-concentration values were found only in early granulocytic progenitors such as myeloblasts and promyelocytes. In advanced stages of the granulocytic development starting with myelocytes, these cells were characterized by a larger decrease in the cytoplasmic RNA concentration in comparison with that of the nucleoli. Thus, the nucleolar to cytoplasmic RNA concentration ratio in these cells was above 1. On the other hand, it should be pointed out that late differentiation stages of granulocytes, starting with myelocytes, possessed nucleolar bodies (nucleoli without surrounding perinucleolar chromatin) of a markedly reduced size.
Assuntos
Diferenciação Celular , Nucléolo Celular/ultraestrutura , Citoplasma/ultraestrutura , Células Precursoras de Granulócitos , RNA , Biópsia , Linhagem da Célula , Doença Crônica , Citoplasma/metabolismo , Densitometria , Células Precursoras de Granulócitos/metabolismo , Células Precursoras de Granulócitos/ultraestrutura , Humanos , Processamento de Imagem Assistida por Computador , Leucemia Mieloide/sangue , Leucemia Mieloide/metabolismo , Leucemia Mieloide/patologia , Tamanho da Partícula , RNA/análiseRESUMO
The present study was designed to provide more information on nucleoli in apoptotic cells,which were represented in the present study by cultured leukemic myeloblasts (Kasumi-1 cells). The apoptotic process in these cells was produced by trichostatin A (TSA) that is a histone deacetylase inhibitor with strong cytostatic effects. The selected TSA concentration added to cultures facilitated to study apoptotic and not-apoptotic cells in one and the same specimen. The nucleolar diameter and density were determined using computer assisted measurement and densitometry in specimens stained for RNA. In comparison with not-apoptotic cells, in apoptotic cells, nucleolar mean diameter did not change significantly and nucleolar RNA density was also not apparently different. On the other hand, the cytoplasmic RNA density in apoptotic cells was markedly reduced. Thus it seemed to be possible that the transcribed RNA remained "frozen"within the nucleolus but its transport to the cytoplasm decreased or stopped. However, the possibility of the RNA degradation in the cytoplasm of apoptotic cells based on the present study cannot be eliminated. At this occasion it should be added that AgNORs reflecting nucleolar biosynthetic and cell proliferation activity in apoptotic cells decreased in number or disappeared. The presented results also indicated that large nucleoli intensely stained for RNA need not be necessarily related to the high nucleolar biosynthetic or cell proliferation activity and may be also present in apoptotic cells responding to the cytostatic treatment.
Assuntos
Apoptose , Nucléolo Celular/ultraestrutura , Células Precursoras de Granulócitos/ultraestrutura , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Antígenos Nucleares/análise , Antígenos Nucleares/ultraestrutura , Linhagem Celular Tumoral , Nucléolo Celular/química , Nucléolo Celular/efeitos dos fármacos , Células Precursoras de Granulócitos/efeitos dos fármacos , Humanos , Ácidos Hidroxâmicos/farmacologia , RNA/análiseRESUMO
The diameter of nucleoli was measured in human bone marrow early granulocytic precursors after visualization by a simple cytochemical method for demonstration of RNA. Such method facilitated to clearly see nucleolar bodies without perinucleolar chromatin, including those of micronucleoli. The bone marrow of patients suffering from chronic myeloid leukaemia (untreated with cytostatics) provided a satisfactory number of both myeloblasts and promyelocytes for nucleolar measurements because of prevailing granulopoiesis. The direct nucleolar measurement was carried out on digitized and processed images on the screen at magnification 4,300x. It seems to be likely that the nucleolar size is directly related to the number of nucleoli per cell. The largest nucleoli were present in both myeloblasts and promyelocytes that possessed a single nucleolus. In contrast, the nucleolar diameter was significantly smaller in cells with multiple nucleoli. However, in cells with small multiple nucleoli, one of them was always larger and dominant with a large number of AgNORs. Such large nucleoli are possibly visible in specimens stained with panoptic procedures or methods staining nuclear chromatin or DNA. It should also be mentioned that both myeloblasts and promyelocytes mostly possessed two nucleoli with the mean diameter close to 1.5 microm. The incidence of early granulocytic precursors classified according to the nucleolar number and size strongly suggested that the various nucleolar number and nucleolar size in these cells might be related to the different stage of the cell cycle and might also explain their heterogeneity.
Assuntos
Nucléolo Celular/ultraestrutura , Células Precursoras de Granulócitos/ultraestrutura , Histocitoquímica , Humanos , Cariometria , Região Organizadora do Nucléolo/ultraestrutura , RNA/análiseRESUMO
Human myeloblasts were studied in bone marrow of patients suffering from chronic phase of chronic myeloid leukaemia to provide more information on the nucleolar diameter in these early granulocytic progenitors. These cells are a convenient model for such study since the number of myeloblasts in diagnostic bone marrow smears of investigated patients is larger than in not-leukemic persons because of the increased granulopoiesis. The nucleolar diameter was measured in myeloblasts after various cytochemical procedures such as methods for visualisation of RNA, DNA and proteins of AgNORs using digitized images and image processing. The results clearly demonstrated that values of the nucleolar diameter depended on the procedures used for visualising nucleoli. It seems to be also clear that a close relationship exists between the diameter of nucleoli and their number since the larger the number of nucleoli per cell the smaller their mean size. However, one of multiple nucleoli present in the nucleus is usually significantly larger. Moreover, the possibility exists that the variability of nucleolar diameter of leukemic myeloblasts and thus the heterogeneity of these cells might depend on various stages of the cell cycle as supported by nucleolar measurements on aging leukemic myeloblasts (K 562 cells) in vitro. Since the staining density of small and large nucleoli did not differ substantially after staining for RNA, it seems to be likely that the nucleolar size is directly related to the total RNA content in myeloblasts. In addition, karyometry combined with RNA cytochemistry still appears to be an useful tool to study nucleoli at the single cell level.
Assuntos
Nucléolo Celular/ultraestrutura , Células Precursoras de Granulócitos/patologia , Granulócitos/patologia , Células-Tronco Hematopoéticas/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , RNA/análise , Tamanho Celular , Células Cultivadas , Células Precursoras de Granulócitos/química , Células Precursoras de Granulócitos/ultraestrutura , Humanos , Células K562 , Coloração e RotulagemRESUMO
Unlike nuclear-targeted anthracyclines, the extranuclear-targeted doxorubicin congener, N-benzyladriamycin-14-valerate (AD 198), does not interfere with normal topoisomerase II activity, but binds to the C1b regulatory domain of conventional and novel isoforms of protein kinase C (PKC). The resulting interaction leads to enzyme activation and rapid apoptosis in a variety of mammalian cell lines through a pathway involving mitochondrial events such as membrane depolarization (Deltapsim) and cytochrome c release. Unlike other triggers of apoptosis, AD 198-mediated apoptosis is unimpeded by the expression of Bcl-2 and Bcl-XL. We have further examined AD 198-induced apoptosis in 32D.3 mouse myeloid cells to determine how the anti-apoptotic effects of Bcl-2 are circumvented. The PKC-delta inhibitor, rottlerin, and transfection with a transdominant-negative PKC-delta expression vector both inhibit AD 198 cytotoxicity through inhibition of Deltapsim and cytochrome c release. While the pan-caspase inhibitor Z-VAD-FMK blocks AD 198-induced PKC-delta cleavage, however, it does not inhibit Deltapsim and cytochrome c release, indicating that AD 198 induces PKC-delta holoenzyme activation to achieve apoptotic mitochondrial effects. AD 198-mediated Deltapsim and cytochrome c release are also unaffected by cellular treatment with either the mitochondrial permeability transition pore complex (PTPC) inhibitor cyclosporin A or the Ca chelators EGTA and BAPTA-AM. These results suggest that AD 198 activates PKC-delta holoenzyme, resulting in Deltapsim and cytochrome c release through a mechanism that is independent of both PTPC activation and Ca flux across the mitochondria. PTPC-independent mitochondrial activation by AD 198 is consistent with the inability of Bcl-2 and Bcl-XL expression to block AD 198-induced apoptosis.
Assuntos
Apoptose/efeitos dos fármacos , Clorometilcetonas de Aminoácidos/farmacologia , Animais , Apoptose/fisiologia , Transporte Biológico/efeitos dos fármacos , Cálcio/metabolismo , Linhagem Celular , Citocromos c/metabolismo , Doxorrubicina/análogos & derivados , Doxorrubicina/farmacologia , Ativação Enzimática/efeitos dos fármacos , Células Precursoras de Granulócitos/efeitos dos fármacos , Células Precursoras de Granulócitos/metabolismo , Células Precursoras de Granulócitos/ultraestrutura , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/metabolismo , Membranas Mitocondriais/efeitos dos fármacos , Membranas Mitocondriais/fisiologia , Poro de Transição de Permeabilidade Mitocondrial , Proteína Quinase C-delta/antagonistas & inibidores , Proteína Quinase C-delta/metabolismoRESUMO
We have previously shown that the overexpression of a Src family kinase, Lyn, and its kinase-negative form, LynKN, in a granulocyte progenitor cell line, GM-I62M, accelerates neutrophilic nuclear lobulation when the cells are cultured in the presence of granulocyte colony-stimulating factor. In this study, we investigated the role of the Src homology 2 (SH2) and SH3 domains of Lyn in the accelerated induction of nuclear lobulation. In contrast to wild-type Lyn, the overexpression of its SH2 domain mutant did not induce the accelerated nuclear morphological changes, but the overexpressed SH3 domain mutant had the same effects as wild-type Lyn. Therefore, the SH2 domain of Lyn is responsible for the accelerated induction of neutrophilic nuclear lobulation upon G-CSF stimulation.
Assuntos
Núcleo Celular/ultraestrutura , Fator Estimulador de Colônias de Granulócitos/farmacologia , Células Precursoras de Granulócitos/enzimologia , Células Precursoras de Granulócitos/ultraestrutura , Domínios de Homologia de src , Quinases da Família src/metabolismo , Animais , Linhagem Celular , Camundongos , Fosfoproteínas/metabolismo , Transfecção , Quinases da Família src/genéticaRESUMO
The objective of this study was to investigate the ultrastructural characteristics of hybrid acute leukemia (HAL). Fifteen cases of HAL were studied by transmission electron microscopy (TEM), focusing on organelles and myeloperoxidase (MPO) reaction of leukemic cells. By TEM, 5 out 15 cases of HAL were consistent with immunophenotyping (3 cases of biphenotypic type, and 2 cases of biclonal type with granulocytes and lymphocytes); 2 cases were suspected as HAL. On other hand, 5 cases of HAL were assigned to ALL, and 2 cases were misinterpreted as M5a and 1 as M4b. Most of the blast cells of biphenotypic HAL showed lymphoid features, except some cases containing MPO positive granules in blasts, while a few cases exhibited monocytic or nonspecific features. TEM offers advantages in the diagnosis of biclonal type HAL and biphenotypic HAL positive for MPO. However, it is difficult to differentiate MPO-negative cases of biphenotypic HAL from ALL and a few cases may be misinterpreted as M5 by TEM.
Assuntos
Células Precursoras de Granulócitos/ultraestrutura , Leucemia Mieloide Aguda/diagnóstico , Linfócitos/ultraestrutura , Leucemia-Linfoma Linfoblástico de Células Precursoras/diagnóstico , Adolescente , Adulto , Criança , Feminino , Células Precursoras de Granulócitos/enzimologia , Humanos , Imunofenotipagem , Leucemia Mieloide Aguda/enzimologia , Leucemia Mieloide Aguda/patologia , Linfócitos/enzimologia , Masculino , Microscopia Eletrônica de Transmissão , Pessoa de Meia-Idade , Peroxidase/metabolismo , Fenótipo , Leucemia-Linfoma Linfoblástico de Células Precursoras/enzimologia , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologiaRESUMO
The present study was undertaken to provide missing information on the distribution of AgNORs in large nucleoli of human leukaemic early granulocytic precursors in vivo as well as in vitro. In vivo, the distribution of AgNORs was studied in early granulocytic precursors of patients suffering from chronic myeloid leukaemia who were both untreated and treated with imatinib mesylate. AgNORs were visualized by silver reaction under conditions which facilitated to see their distribution by light microscopy. In vitro, the distribution of AgNORs was studied in proliferating and ageing K 562 cells which originated from chronic myeloid leukaemia. In vitro, the ageing of K 562 cells produced intranucleolar translocation of AgNORs to the nucleolar periphery. Such translocation was also observed in some leukaemic early granulocytic precursors in vivo, e.g. in bone marrow myeloblasts and promyelocytes of leukaemic patients. As was expected, the intranucleolar translocation of AgNORs in early granulocytic precursors was more frequent in patients treated with the cytostatic therapy--imanitib mesylate. The abovementioned findings suggest that myeloblasts and promyelocytes with AgNORs translocated to the periphery of large nucleoli might be in the ageing state, similarly as blastic cells of leukaemic myeloid origin (K 562 cells) in ageing cultures. Thus, the translocation of AgNORs might be a useful marker of premature ageing in the future and might contribute to the evaluation of the single cell state under various experimental as well as clinical conditions. However, more clinically oriented studies are required in this direction.
Assuntos
Nucléolo Celular/patologia , Células Precursoras de Granulócitos/patologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Região Organizadora do Nucléolo/patologia , Linhagem Celular Tumoral , Nucléolo Celular/ultraestrutura , Senescência Celular , Células Precursoras de Granulócitos/ultraestrutura , Humanos , Células K562 , Região Organizadora do Nucléolo/ultraestrutura , Coloração pela PrataRESUMO
Transmission electron microscopy (TEM) is still a very useful adjunct for hematological diagnosis in the era of molecular techniques. In this article, the main applications of TEM to the cellular identification of normal myeloid cells, the study of dyserythropoietic conditions, myelodysplastic syndromes, congenital dyserythropoietic anemias, acute myeloid leukemias, and lymphoproliferative disorders, as well as the application of ultrastructural cytochemical reactions in hematological diagnosis, are reviewed.
Assuntos
Doenças Hematológicas/diagnóstico , Microscopia Eletrônica de Transmissão/métodos , Plaquetas/patologia , Plaquetas/ultraestrutura , Células Precursoras de Granulócitos/patologia , Células Precursoras de Granulócitos/ultraestrutura , Granulócitos/patologia , Granulócitos/ultraestrutura , Doenças Hematológicas/sangue , Doenças Hematológicas/classificação , Humanos , Monócitos/patologia , Monócitos/ultraestruturaRESUMO
Alpha-1-acid glycoprotein (AGP) is an acute-phase protein produced by hepatocytes and secreted into plasma in response to infection/injury. We recently assessed the transcriptional program of terminal granulocytic differentiation by microarray analysis of bone marrow (BM) populations highly enriched in promyelocytes, myelocytes/metamyelocytes (MYs), and BM neutrophils. These analyses demonstrated a transient, high mRNA expression of genuine secondary/tertiary granule proteins and AGP in MYs. In agreement with this, immunocytochemistry revealed the presence of AGP protein and the secondary granule protein lactoferrin in cells from the MY stage and throughout granulocytic differentiation. Immunoelectron microscopy demonstrated the colocalization of AGP and lactoferrin in secondary granules of neutrophils. This finding was substantiated by the failure to detect AGP and lactoferrin in blood cells from a patient with secondary/tertiary (specific) granule deficiency. In addition, Western blot analysis of subcellular fractions isolated from neutrophils revealed that neutrophil-derived AGP, localized in secondary granules, was abundant and highly glycosylated compared with endocytosed, plasma-derived AGP localized in secretory vesicles. Exocytosis studies further demonstrated a marked release of AGP and lactoferrin by activated neutrophils. Finally, induction of CCAAT/enhancer-binding protein (C/EBP)-epsilon in a myeloid cell line was shown to increase AGP transcript levels, indicating that AGP expression in myeloid cells, like in hepatocytes, is partially regulated by members of the C/EBP family. Overall, these findings define AGP as a genuine secondary granule protein of neutrophils. Hence, neutrophils, which constitute the first line of defense, are likely to serve as the primary local source of AGP at sites of infection or injury.