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1.
Food Funct ; 8(4): 1519-1525, 2017 Apr 19.
Article in English | MEDLINE | ID: mdl-28379266

ABSTRACT

This study evaluated the acute effect of keto analogue and amino acid (AA-KAAA) supplementation on both white blood cell counts and the established biomarkers of muscle damage during exercise under thermoneutral conditions. Sixteen male cyclists received a ketogenic diet for two days and were divided into two equal groups: a group taking AA-KAAA (KA) or a control group (PL). The athletes performed a two hour cycling session followed by a maximum incremental test until voluntary exhaustion (VExh). Blood samples were obtained at rest and during exercise for further hematological and biochemical analyses. Exercise-induced ammonemia increased in the PL group at VExh (75%) but remained unchanged in the KA group. Both groups exhibited a significant increase in leukocyte and neutrophil counts of ∼85% (∼13 × 109 L-1), but the shape of the lymphocytes and the eosinophil counts suggest that AA-KAAA supplementation helps prevent lymphocytosis. AA-KAAA supplementation induced a decrease in creatine kinase and aspartate aminotransferase levels at VExh while showing a significant decrease in lactate dehydrogenase at 120 min. We found that AA-KAAA supplementation decreases both the lymphocyte count response in blood and the established biomarkers of muscle damage after intense exercise under a low heat stress environment.


Subject(s)
Amino Acids/metabolism , Dietary Supplements/analysis , Leukocytes/cytology , Muscle, Skeletal/metabolism , Resistance Training , Adult , Amino Acids/administration & dosage , Amino Acids/chemistry , Athletes , Creatine Kinase , Hot Temperature , Humans , L-Lactate Dehydrogenase , Leukocyte Count , Leukocytes/drug effects , Male , Muscle, Skeletal/enzymology , Muscle, Skeletal/injuries
2.
Breast ; 22(6): 1101-7, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24074879

ABSTRACT

PURPOSE OF THE STUDY: Trastuzumab combined with sequential chemotherapy with taxanes and anthracyclines as primary systemic therapy achieved high rates of pathologic complete response (pCR). Non-pegylated liposome-encapsulated doxorubicin (NPLD) has shown equal efficacy but minor cardiotoxicity compared to doxorubicin. This phase II study aimed to evaluate the activity and safety of trastuzumab with sequential chemotherapy for early or locally advanced HER2 positive BC. METHODS: Preoperative treatment included NPLD (60 mg/mq iv) plus cyclophosphamide (600 mg/mq iv) every 3 weeks for 4 cycles followed by docetaxel (35 mg/mq iv) plus trastuzumab (4 mg/mq loading dose iv, then 2 mg/mq iv) weekly for 16 weeks. Primary endpoint was pCR defined as the absence of residual invasive cancer both in the breast and regional nodes. Clinical staging was exploratory evaluated by CT-PET. RESULTS: 43 pts were treated from december 2005 to September 2011, 39 of them were evaluable for the purpose of study. Median age was 53 years (range: 31-78), the majority of pts had tumour stage cT2 (63%), tumour grade 3 (86%), clinical nodes involvement N+ (77%), ER positive (56%) and Ki-67 ≥20% (77%). pCR was reported in 19 (49%) of 39 pts. There was an association between Ki-67 ≥20% at baseline and pCR (p = 0.018). No cardiac toxicity or discontinuation of trastuzumab was reported. CT-PET modified the clinical stage for 10 patients showing new loco-regional lymph nodes. CONCLUSIONS: This study confirms that integrating anti-HER2 therapy in primary treatment for HER2 positive breast cancer is active. NPLD is a safe option to minimize cardiotoxicity.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Breast Neoplasms/drug therapy , Breast Neoplasms/pathology , Carcinoma/drug therapy , Carcinoma/pathology , Receptor, ErbB-2/blood , Adult , Aged , Antibodies, Monoclonal, Humanized/administration & dosage , Breast Neoplasms/blood , Carcinoma/blood , Chemotherapy, Adjuvant , Cyclophosphamide/administration & dosage , Docetaxel , Doxorubicin/administration & dosage , Doxorubicin/analogs & derivatives , Female , Fluorodeoxyglucose F18 , Humans , Middle Aged , Neoadjuvant Therapy , Neoplasm Staging , Polyethylene Glycols/administration & dosage , Positron-Emission Tomography , Radiopharmaceuticals , Taxoids/administration & dosage , Tomography, X-Ray Computed , Trastuzumab
3.
Food Addit Contam ; 23(2): 126-32, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16449054

ABSTRACT

Conflicting findings regarding the boldenone content of bovine faeces suggest it may be synthesized de novo in emitted faeces. We tested this hypothesis by analysing uncontaminated urine, fresh and various forms of dried faeces from 10 calves (not given boldenone) by liquid chromatography/tandem mass spectrometry for 17alpha- and 17beta-boldenone (alpha and beta BOL); 1,4-androstadiene-3,17-dione (ADD); 4-androstene-3,17-dione (AED), testosterone (T) and epitestosterone (ET). Urine contained no alpha BOL, beta BOL or ADD. The analysed substances were variably present in the rectal faeces, and at generally higher levels in faeces scraped from skin or stall floor. In pooled rectal faeces naturally dried for 13 days, alpha BOL, ADD, AED and ET levels were extremely high (much higher than accounted for by increases due to drying), and beta BOL and T were absent. It is concluded that de novo synthesis of alpha BOL and metabolites occurs naturally in bovine faeces and only uncontaminated urine should be analysed for illegal boldenone.


Subject(s)
Feces/chemistry , Testosterone/analogs & derivatives , Anabolic Agents/analysis , Anabolic Agents/urine , Androgens/analysis , Androgens/urine , Androstadienes/analysis , Androstadienes/urine , Androstenedione/analysis , Androstenedione/urine , Animals , Cattle , Epitestosterone/analysis , Epitestosterone/urine , Gas Chromatography-Mass Spectrometry/methods , Rectum , Testosterone/analysis , Testosterone/urine
4.
Food Addit Contam ; 21(8): 756-62, 2004 Aug.
Article in English | MEDLINE | ID: mdl-15370825

ABSTRACT

European Directive 96/22/EC, which controls veterinary residues in animals, does not permit the presence of synthetic growth promoters in products of animal origin or in livestock. Boldenone is categorized in class A3 (growth promoters -- steroids) and is thus a banned substance. Testing of veal urine for banned substances is part of the European Union statutory programme for animals going into the food chain. In relation to this monitoring, three studies were conducted to investigate the apparent presence of the banned growth promoter boldenone in veal urine, which was suspected as being caused by interference from faecal contamination of the sample. In the first study, urine samples were collected at different times (time 0 and after 30 min) using (1) a conventional zoonotechnical apron and (2) a technique designed specifically to avoid faecal contamination ('kettle'). This resulted in samples that were, respectively, positive and negative for the presence of alpha-boldenone (alpha-BOL). In a second study, urine samples negative to alpha-BOL were collected from eight veal calves, but became positive after deliberate faecal contamination. In a third study, data obtained from the Italian RNP (Residual National Program) indicated that 18.1% of 3295 urine samples collected using the zootechnical apron were positive for alpha-BOL and 2.1% for beta-boldenone (beta-BOL), whilst of 902 samples collected using the kettle, beta-BOL was not detected in any samples and only 0.2% were positive to alpha-BOL, in concentrations lower than 2 ng ml(-1). These results further support the supposition that faecal contamination of the urine during sample collection can lead to false-positive results during boldenone analysis.


Subject(s)
Carcinogens/analysis , Feces/chemistry , Food Contamination/analysis , Testosterone/analogs & derivatives , Testosterone/analysis , Animals , Cattle , False Positive Reactions , Hydrolysis , Meat/analysis , Testosterone/urine
5.
Leukemia ; 15(6): 910-4, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11417476

ABSTRACT

The t(10;11)(p13;q14-21) is a non-random translocation described in acute lymphoblastic and myeloid leukaemias. It results in the fusion of the gene CALM, which encodes a clathrin assembly protein, on 11q14 to the gene AF10, a putative transcription factor on 10p13. Here we describe for the first time, the occurrence of a CALM-AF10 fusion in a case of acute megakaryoblastic leukaemia. Fluorescence in situ hybridisation and reverse transcriptase polymerase chain reaction were used to confirm the presence of a CALM-AF10 fusion. A novel splice variant of CALM missing nt 1927-2091 was also detected. Though CALM is a cytoplasmic protein, the chimaeric fusion product is able to localise to both the nucleus and cytoplasm. Analysis of the fusion variants suggests, however, that the critical fusion product is likely to be cytoplasmic and contain the interactive leucine zipper of AF10.


Subject(s)
Chromosomes, Human, Pair 10/genetics , Chromosomes, Human, Pair 11/genetics , Leukemia, Megakaryoblastic, Acute/genetics , Neoplasm Proteins/genetics , Oncogene Proteins, Fusion/genetics , Translocation, Genetic , Active Transport, Cell Nucleus , Blotting, Southern , Cell Nucleus/metabolism , Child , Chromosome Banding , Chromosomes, Human, Pair 10/ultrastructure , Chromosomes, Human, Pair 11/ultrastructure , Cloning, Molecular , Cote d'Ivoire , Cytoplasm/metabolism , Humans , In Situ Hybridization, Fluorescence , Leucine Zippers/genetics , Leukemia, Megakaryoblastic, Acute/complications , Leukemia, Megakaryoblastic, Acute/diagnosis , Leukemia, Megakaryoblastic, Acute/metabolism , Malaria, Falciparum/complications , Male , Neoplasm Proteins/chemistry , Oncogene Proteins, Fusion/chemistry , RNA Splicing
6.
Br J Haematol ; 111(2): 432-40, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11122082

ABSTRACT

CXC chemokine receptor 4 (CXCR4), the high-affinity receptor for stroma-derived factor 1alpha (SDF-1alpha), shows distinct patterns of expression in human CD34+ haematopoietic progenitor cells induced to differentiate in vitro along the granulocytic and erythroid lineages. In serum-free liquid cultures supplemented with stem cell factor (SCF), interleukin 3 (IL-3) and granulocyte colony-stimulating factor, the expression of surface CXCR4 progressively increased in cells differentiating along the granulocytic lineage. The addition in culture of 200 ng/ml of SDF-1alpha, a concentration which maximally activated intracellular Ca2+ flux, only modestly affected the expression levels of CD15 and CD11b granulocytic antigens, as well as the total number of viable cells. On the other hand, in liquid cultures supplemented with SCF, IL-3 and erythropoietin, SDF-1alpha induced the downregulation of glycophorin A erythroid antigen, accompanied by a progressive decline in the number of viable erythroblasts. Moreover, in semisolid assays, SDF-1alpha significantly reduced the number of plurifocal erythroid colonies (erythroid blast-forming units; BFU-E), whereas it did not affect granulocyte-macrophage colony-forming units (CFU-GM). We also demonstrated that the inhibitory effect of SDF-1alpha on glycophorin A+ erythroid cell development was mediated by the functional upregulation of CD95L in erythroid cultures. These data indicate that SDF-1alpha plays a role as a negative regulator of erythropoiesis.


Subject(s)
Antigens, CD34 , Chemokines, CXC/pharmacology , Erythropoiesis/drug effects , Hematopoietic Stem Cells/metabolism , Membrane Glycoproteins/metabolism , Receptors, CXCR4/metabolism , Calcium/metabolism , Cell Differentiation/drug effects , Cells, Cultured , Chemokine CXCL12 , Depression, Chemical , Fas Ligand Protein , Fetal Blood/cytology , Glycophorins/metabolism , Granulocyte Colony-Stimulating Factor/pharmacology , Hematopoietic Stem Cells/drug effects , Humans , Interleukin-3/pharmacology , Stem Cell Factor/pharmacology
7.
Acta Neuropathol ; 100(3): 291-8, 2000 Sep.
Article in English | MEDLINE | ID: mdl-10965799

ABSTRACT

Emerin is an almost ubiquitous protein which is abnormal in X-linked Emery-Dreifuss muscular dystrophy (EMD), a syndrome characterized by muscle weakness, joint contractures and cardiac arrhythmia. Emerin is localized in the cells at the nuclear rim and its function is still unknown. In some models, emerin has also been described in the cytoplasm; however, its presence outside the nucleus is still matter of debate. We report the presence of emerin in circulating normal human platelets and its absence in platelets from X-linked EMD patients. Since platelets are cytoplasmic fragments derived from megakaryocytes, the presence of emerin in platelets confirms cytoplasmic localization of this protein, probably related to specific functions. We found also that emerin is present in the cytoplasm of megakaryocytes, while it is absent in circulating granulocytes.


Subject(s)
Blood Platelets/metabolism , Blood Platelets/ultrastructure , Membrane Proteins/deficiency , Muscular Dystrophy, Emery-Dreifuss/metabolism , Thymopoietins/deficiency , Humans , Megakaryocytes/metabolism , Megakaryocytes/ultrastructure , Muscular Dystrophy, Emery-Dreifuss/pathology , Muscular Dystrophy, Emery-Dreifuss/physiopathology , Nuclear Proteins
8.
Blood ; 95(12): 3716-24, 2000 Jun 15.
Article in English | MEDLINE | ID: mdl-10845902

ABSTRACT

The impact of tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) on normal hematopoietic development was investigated using adult peripheral blood CD34(+) hematopoietic progenitor cells, induced to differentiate along the erythroid, megakaryocytic, granulocytic, and monocytic lineages by the addition of specific cytokine cocktails. TRAIL selectively reduced the number of erythroblasts, showing intermediate levels of glycophorin A (glycophorin A(interm)) surface expression, which appeared in liquid cultures supplemented with stem cell factor + interleukin 3 + erythropoietin at days 7-10. However, neither immature (day 4) glycophorin A(dim) erythroid cells nor mature (day 14) glycophorin A(bright) erythroblasts were sensitive to TRAIL-mediated apoptosis. Moreover, pre-exposure to TRAIL significantly decreased the number and size of erythroid colonies in semisolid assays. These adverse effects of TRAIL were selective for erythropoiesis, as TRAIL did not significantly influence the survival of cells differentiating along the megakaryocytic, granulocytic, or monocytic lineages. Furthermore, TRAIL was detected by Western blot analysis in lysates obtained from normal bone marrow mononuclear cells. These findings indicate that TRAIL acts in a lineage- and stage of differentiation-specific manner, as a negative regulator of normal erythropoiesis. (Blood. 2000;95:3716-3724)


Subject(s)
Apoptosis , Bone Marrow Cells/cytology , Erythropoiesis/physiology , Hematopoietic Stem Cells/cytology , Membrane Glycoproteins/pharmacology , Tumor Necrosis Factor-alpha/pharmacology , Adult , Antigens, CD/analysis , Antigens, CD34/analysis , Apoptosis/drug effects , Apoptosis Regulatory Proteins , Cell Survival/drug effects , Cells, Cultured , Colony-Forming Units Assay , Erythropoiesis/drug effects , Flow Cytometry , Hematopoietic Stem Cells/drug effects , Hematopoietic Stem Cells/physiology , Humans , Lewis X Antigen/analysis , Ligands , Recombinant Proteins/pharmacology , TNF-Related Apoptosis-Inducing Ligand
10.
Anat Rec ; 258(1): 90-9, 2000 01 01.
Article in English | MEDLINE | ID: mdl-10603452

ABSTRACT

The aim of this study was to evaluate the ultrastructural features of human megakaryocytes cultured in vitro. For this purpose, pluripotent CD34(+) (cluster of differentiation 34) hematopoietic progenitor cells, obtained from the peripheral blood of healthy adult donors, were differentiated along the megakaryocytic lineage in liquid cultures by the addition of the megakaryocyte-specific growth factor thrombopoietin (TPO, 100 ng/ml). After only 6-8 days, virtually all of the CD34-derived cells expressed the early megakaryocytic CD61 antigen, while, after 15-16 days, most cells also expressed the late megakaryocytic CD42a antigen. Ultrastructural analysis of cells obtained after 7 days of culture showed aspects typical of developing megakaryocytes (MK), such as formation of platelet territories and cytoplasmic fragmentation. At later (15-16 day) culture times, two distinct cell populations were observed: fully developed megakaryocytes releasing platelets into the culture medium and senescent megakaryocytes, characterized by morphological features of apoptosis. Analysis of DNA fragmentation in these cells revealed that apoptosis in megakaryocytes occurred in the absence of the internucleosomic cleavage, which is characteristic of most, but not all, types of apoptosis in cells of hematopoietic origin. On the other hand, flow cytometry of the DNA content of senescent megakaryocytes showed a subdiploid peak that was likely due to a loss of micronuclei during processing.


Subject(s)
Aging/physiology , Blood Platelets/ultrastructure , Cellular Senescence/physiology , Megakaryocytes/ultrastructure , Antigens, CD/immunology , Antigens, CD34/immunology , Apoptosis/physiology , Blood Platelets/physiology , Cell Separation , Cells, Cultured , DNA/analysis , Electrophoresis, Agar Gel , Flow Cytometry , Hematopoietic Stem Cells/drug effects , Hematopoietic Stem Cells/immunology , Hematopoietic Stem Cells/physiology , Hematopoietic Stem Cells/ultrastructure , Humans , Integrin beta3 , Megakaryocytes/drug effects , Megakaryocytes/metabolism , Microscopy, Electron, Scanning , Phenotype , Platelet Glycoprotein GPIb-IX Complex/immunology , Platelet Membrane Glycoproteins/immunology , Thrombopoietin/pharmacology
11.
Sao Paulo Med J ; 117(3): 113-20, 1999 May 06.
Article in English | MEDLINE | ID: mdl-10511729

ABSTRACT

CONTEXT: Ras gene mutations have been associated to a wide range of human solid tumors. Members of the ras gene family (Ki-ras, Ha-ras and N-ras) are structurally related and code for a protein (p21) known to play an important role in the regulation of normal signal transduction and cell growth. The frequency of ras mutations is different from one type of tumor to another, suggesting that point mutations might be carcinogen-specific. OBJECTIVES: To study the occurrence of Ki-ras and Ha-ras mutations. We also studied the relative level of Ha-ras mRNA in 32 of the head and neck tumors. DESIGN: Case series. SETTING: University referral unit. PARTICIPANTS: 60 head and neck tumors and in 28 Juvenile Nasopharyngeal Angiofibromas (JNA). DIAGNOSTIC TEST: Using PCR-SSCP we examined the occurrence of Ki-ras and Ha-ras mutations. The relative level of Ha-ras mRNA was examined by Northern blot analysis. RESULTS: None of the head and neck tumors or JNA samples showed evidence of mutations within codons 12, 13, 59 and 61 of Ki-ras or Ha-ras genes. However, 17 (53%) of the tumors where gene expression could be examined exhibited increased levels of Ha-ras mRNA compared with the normal tissue derived from the same patient. CONCLUSIONS: Our results demonstrate for the first time that mutations of Ki-ras and Ha-ras genes are not associated with the development of JNA and confirm previous reports indicating that activating ras mutations are absent or rarely involved in head and neck tumors from western world patients. Furthermore, our findings suggest that overexpression of Ha-ras, rather than mutations, might be an important factor in the development and progression of head and neck tumors.


Subject(s)
Angiofibroma/genetics , Carcinoma, Squamous Cell/genetics , Genes, ras/genetics , Head and Neck Neoplasms/genetics , Nasopharyngeal Neoplasms/genetics , Adult , Aged , Aged, 80 and over , Blotting, Northern , Codon/genetics , DNA, Neoplasm/genetics , Female , Humans , Male , Middle Aged , Mutation/genetics , Polymerase Chain Reaction , Polymorphism, Single-Stranded Conformational
13.
Br J Haematol ; 104(4): 820-8, 1999 Mar.
Article in English | MEDLINE | ID: mdl-10192445

ABSTRACT

Mammalian megakaryocyte development is characterized by a progressive accumulation of cells exhibiting a polylobated nucleus with a polyploid DNA content. In this study human megakaryocytes were obtained from CD34+ haemopoietic progenitors by in vitro liquid culture in the presence of 100 ng/ml of recombinant thrombopoietin (TPO). Ultrastructural examination of polyploid megakaryocytes showed the presence of a large number of centrioles, the breakdown of the nuclear envelope, and the progressive chromatin condensation, all aspects characteristic of mitosis. At both indirect immunofluorescence and Western blot analyses, cyclin B and its related cyclin-dependent kinase (CDK)1, which forms the mitosis promoting factor (MPF), showed an increased expression in maturating megakaryoblasts and megakaryocytes (day 8 of culture) with respect to freshly isolated CD34+ progenitors. This expression tended to decline in fully developed megakaryocytes (day 15 of culture). The amount of cyclin D and of the related CDK4, governing the G1 phase of the cell cycle, increased during megakaryocyte development, maintaining high levels of expression also in mature megakaryocytes. These results indicate that megakaryocyte polyploidization depends on a true, although incomplete, mitotic process, and that cyclin D/CDK4 probably plays a crucial role throughout megakaryocytopoiesis.


Subject(s)
CDC2 Protein Kinase/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins , Cyclin-Dependent Kinase Inhibitor p16 , Enzyme Inhibitors/metabolism , Megakaryocytes/cytology , Tumor Suppressor Proteins , Cell Division , Cells, Cultured , Cyclin-Dependent Kinase Inhibitor p15 , Humans , Megakaryocytes/ultrastructure , Mitosis
14.
Blood ; 93(4): 1178-88, 1999 Feb 15.
Article in English | MEDLINE | ID: mdl-9949160

ABSTRACT

The pattern of expression of several protein kinase C (PKC) isoforms (alpha, betaI, delta, epsilon, eta, and zeta) during the course of hematopoietic development was investigated using primary human CD34(+) hematopoietic cells and stable cell lines subcloned from the growth factor-dependent 32D murine hematopoietic cell line. Each 32D cell clone shows the phenotype and growth factor dependence characteristics of the corresponding hematopoietic lineage. Clear-cut differences were noticed between erythroid and nonerythroid lineages. (1) The functional inhibition of PKC-epsilon in primary human CD34(+) hematopoietic cells resulted in a twofold increase in the number of erythroid colonies. (2) Erythroid 32D Epo1 cells showed a lower level of bulk PKC catalytic activity, lacked the expression of epsilon and eta PKC isoforms, and showed a weak or absent upregulation of the remaining isoforms, except betaI, upon readdition of Epo to growth factor-starved cells. (3) 32D, 32D GM1, and 32D G1 cell lines with mast cell, granulo-macrophagic, and granulocytic phenotype, respectively, expressed all the PKC isoforms investigated, but showed distinct responses to growth factor readdition. (4) 32D Epo 1.1, a clone selected for interleukin-3 (IL-3) responsiveness from 32D Epo1, expressed the epsilon isoform only when cultured with IL-3. On the other hand, when cultured in Epo, 32D Epo1.1 cells lacked the expression of both epsilon and eta PKC isoforms, similarly to 32D Epo1. (5) All 32D cell lines expressed the mRNA for PKC-epsilon, indicating that the downmodulation of the epsilon isoform occurred at a posttranscriptional level. In conclusion, the PKC isoform expression during hematopoiesis appears to be lineage-specific and, at least partially, related to the growth factor response.


Subject(s)
Cell Lineage , Hematopoiesis , Hematopoietic Stem Cells/enzymology , Protein Kinase C/biosynthesis , Animals , Biomarkers , Blotting, Western , Cell Line , Gene Expression Regulation, Enzymologic , Hematopoietic Stem Cells/cytology , Humans , Isoenzymes/biosynthesis , Isoenzymes/genetics , Mice , Protein Kinase C/genetics
15.
Br J Haematol ; 104(1): 81-6, 1999 Jan.
Article in English | MEDLINE | ID: mdl-10027715

ABSTRACT

We have previously demonstrated that the addition in culture of recombinant HIV-1 IIIB envelope gp120 affects the survival/growth of pluripotent haemopoietic progenitors, and, in particular, of those committed towards the megakaryocytic lineage. To characterize some of the molecular mechanisms involved in this phenomenon, we investigated the expression of members of the activating protein-1 (AP-1) complex in the HEL megakaryoblastic cell line. Following the treatment of HEL cells with recombinant IIIB envelope gp120, we noticed: (i) increased levels of endogenous c-fos and c-jun mRNA and proteins, (ii) activation of both c-fos and c-jun promoters, and (iii) a very rapid stimulation of a MAPK/ERK pathway.


Subject(s)
Genes, fos/genetics , Genes, jun/genetics , HIV Envelope Protein gp120/pharmacology , HIV-1 , Hematopoietic Stem Cells/metabolism , Megakaryocytes/metabolism , Cell Line , Gene Expression Regulation , Humans , Proto-Oncogene Proteins c-fos/metabolism , Proto-Oncogene Proteins c-jun/metabolism , RNA, Messenger/metabolism , Transcription Factor AP-1 , Transcription, Genetic
16.
Blood ; 92(2): 472-80, 1998 Jul 15.
Article in English | MEDLINE | ID: mdl-9657746

ABSTRACT

The addition of thrombopoietin (TPO) to HEL cells, cultured in a chemically defined serum-free medium, induced a rapid and dose-dependent phosphorylation of the transcription factor CREB on serine133 (PSer133), as detected by Western blot analysis. TPO also significantly increased the transactivation of CRE-dependent promoter, as determined in transient transfection experiments. On the other hand, neither erythropoietin (Epo; 1 to 10 U) nor hemin (10 (-7) mol/L) were able to significantly stimulate CREB-PSer133 or to activate CRE-promoter in HEL cells. Although pharmacological inhibitors of protein kinase C (chelerytrine and BIM) and protein kinase A (H-89) failed to block the TPO-mediated CREB phosphorylation, a specific inhibitor of the mitogen-activated protein kinases (PD98059) completely blocked the ability of TPO to stimulate CREB-PSer133. Moreover, PD98059 significantly decreased the ability of TPO to upregulate the surface expression of the alphaIIIbbeta3 megakaryocytic marker in HEL cells. In parallel, primary CD34+ hematopoietic cells were seeded in liquid cultures supplemented with 100 ng/mL of TPO and examined by immunofluorescence for the coexpression of alphaIIIbbeta3 and CREB-PSer133 at various time points. High levels of nuclear CREB-PSer133 were unequivocally demonstrated in alphaIIIbbeta3+ cells, including morphologically recognizable megakaryocytes. Taken together, these data suggest that CREB plays a role in modulating the expression of genes critical for megakaryocyte differentiation and that the TPO-mediated CREB phosphorylation seems to be regulated via mitogen-activated protein kinases.


Subject(s)
Cyclic AMP Response Element-Binding Protein/physiology , Hematopoietic Stem Cells/cytology , Hematopoietic Stem Cells/physiology , Megakaryocytes/cytology , Megakaryocytes/physiology , Signal Transduction/physiology , Antigens, CD34 , Blotting, Western , Cell Differentiation/physiology , Cell Line , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Flow Cytometry , Humans , Phosphorylation , Protein Kinase Inhibitors , Protein Kinases/physiology , Serine , Signal Transduction/drug effects , Thrombopoietin/pharmacology
17.
J Immunol ; 160(8): 3891-8, 1998 Apr 15.
Article in English | MEDLINE | ID: mdl-9558095

ABSTRACT

Extracellular HIV-1 Tat protein (0.1-100 ng/ml) induced a rapid (peak at 30 min) increase in the Ser133 phosphorylation levels of the transcription factor CREB in serum-starved Jurkat cells, as revealed by Western blot and indirect immunofluorescence analyses. Nuclear cAMP-responsive element (CRE) binding activity in electrophoretic mobility shift assays was constitutive in unstimulated Jurkat cells, showing only a small increase upon Tat treatment. However, transient transfection experiments performed with various chloramphenicol acetyl-transferase (CAT) constructs showed that Tat produced a fourfold induction of CAT activity only in the presence of a CRE-dependent CAT construct. Moreover, the use of plasmids encoding for GAL4-CREB fusion proteins demonstrated that Tat induction of pG4-CAT reporter gene required the CREB moiety of the GAL4-CREB fusion protein and that Ser133 CREB was essential for Tat activity. Extracellular Tat also stimulated Ser133 CREB phosphorylation in freshly isolated PBMC; this effect was completely blocked by either staurosporin, a broad-spectrum inhibitor of various protein kinases, or PD 98059, a specific inhibitor of mitogen-activated protein kinases (MAPK). Furthermore, extracellular Tat induced a rapid (peak at 5-15 min) stimulation of the MAPK catalytic activity in primary PBMC. Altogether, these findings suggest that HIV-1 Tat protein activates CREB in lymphoid cells through a signal cascade involving the MAPK pathway.


Subject(s)
Cyclic AMP Response Element-Binding Protein/metabolism , Gene Products, tat/pharmacology , HIV-1/physiology , Base Sequence , Binding Sites/genetics , Calcium-Calmodulin-Dependent Protein Kinases/antagonists & inhibitors , Calcium-Calmodulin-Dependent Protein Kinases/metabolism , Cells, Cultured , Chloramphenicol O-Acetyltransferase/genetics , Cyclic AMP Response Element-Binding Protein/chemistry , DNA/genetics , DNA/metabolism , Enzyme Inhibitors/pharmacology , Flavonoids/pharmacology , Genes, Reporter , Humans , Jurkat Cells , Leukocytes, Mononuclear/drug effects , Leukocytes, Mononuclear/metabolism , Phosphorylation , Serine/chemistry , Signal Transduction , Staurosporine/pharmacology , Transfection , tat Gene Products, Human Immunodeficiency Virus
18.
Blood ; 90(6): 2234-43, 1997 Sep 15.
Article in English | MEDLINE | ID: mdl-9310474

ABSTRACT

To investigate the fate of human megakaryocytes, CD34+ hematopoietic progenitor cells were purified from the peripheral blood or bone marrow of healthy donors and seeded in serum-free chemically defined suspension cultures. In the presence of thrombopoietin (TPO; 100 ng/mL), CD34-derived cells showed an eightfold numerical expansion and a progressive maturation along the megakaryocytic lineage. Megakaryocyte maturation was characterized ultrastructurally by the presence of a demarcation membrane system and phenotypically by a high surface expression of alpha(IIb)beta3 integrin. The number of mature megakaryocytes peaked at days 12 to 15 of culture. On the other hand, the number of platelets released in the culture supernatant by CD34-derived megakaryocytes peaked at days 18 to 21, when a high percentage of megakaryocytes showed the characteristic features of apoptosis, as evaluated by electron microscopy, terminal deoxynucleotidyl transferase (TdT)-mediated d-UTP-biotin nick end-labeling technique (TUNEL) and uptake of propidium iodide. In other experiments, primary alpha(IIb)beta3+ megakaryocytic cells were directly purified from the bone marrow aspirates of normal donors and seeded in serum-free suspension cultures. In the absence of cytokines, alpha(IIb)beta3+ megakaryocytes progressively underwent apoptotic cell death. The addition of TPO but not interleukin-3 or erythropoietin showed some protection of alpha(IIb)beta3+ cells from apoptosis at early culture times (days 2 to 4), but it did not show any significant effect at later time points. These findings suggest that the terminal phase of the megakaryocyte life span is characterized by the onset of apoptosis, which can be modulated only to a certain extent by TPO.


Subject(s)
Apoptosis , Cellular Senescence , Megakaryocytes/cytology , Antigens, CD34/analysis , Cell Differentiation/drug effects , Cell Separation , DNA Fragmentation , Erythropoietin/pharmacology , Humans , Interleukin-3/pharmacology , Microscopy, Electron , Platelet Glycoprotein GPIIb-IIIa Complex/metabolism , Ploidies , Thrombopoietin/pharmacology
19.
Blood ; 89(3): 883-95, 1997 Feb 01.
Article in English | MEDLINE | ID: mdl-9028319

ABSTRACT

The effect of thrombopoietin (TPO) on the functional activity of surface alpha IIb beta 3 (GPIIbIIIa) was investigated in both primary human megakaryocytic cells, derived from peripheral blood CD34+ cells, and HEL hematopoietic cell line. TPO (100 ng/mL) induced a sixfold to ninefold enhancement of adhesion of both primary megakaryocytic and HEL cells to plates coated with either fibrinogen or fibronectin and a parallel increase of immunoreactivity to the PAC1 monoclonal antibody (MoAb) and fluorescein isothiocyanate-fibrinogen, both of which recognize an activated state of alpha IIb beta 3. The enhanced adhesion to fibrinogen or fibronectin was mediated by the Arg-Gly-Asp (RGD) recognition sequence of alpha IIb beta 3, as it was abolished by pretreatment of cells with saturating concentrations of RGDS peptide. A MoAb specific for the alpha IIb beta subunit of alpha IIb beta 3 also inhibited cell attachment to fibrinogen or fibronectin, while MoAb to anti-alpha v beta 3 or anti-alpha 5 integrins were completely ineffective, clearly indicating that alpha IIb beta 3 participates in this association. A role for PI 3 kinase (PI 3-K) in the TPO-mediated increase in alpha IIb beta 3 function in megakaryocytic cells was suggested by the ability of the PI 3-K inhibitor wortmannin (100 nmol/L) and antisense oligonucleotides directed against the p85 regulatory subunit of PI 3-K to completely block the TPO-induced increase in alpha IIb beta 3 integrin activity upon TPO stimulation. The modulation of adhesiveness to extracellular matrix proteins containing the RGD motif mediated by TPO likely plays a physiologic role in megakaryocytopoiesis, as pretreatment of CD34+ cells with RGDS or anti-alpha IIb MoAb significantly reduced the number of megakaryocytic colonies obtained in a fibrinclot semisolid assay.


Subject(s)
Fibrinogen/metabolism , Fibronectins/metabolism , Megakaryocytes/drug effects , Megakaryocytes/physiology , Phosphotransferases (Alcohol Group Acceptor)/physiology , Platelet Glycoprotein GPIIb-IIIa Complex/physiology , Thrombopoietin/pharmacology , Actins/biosynthesis , Androstadienes/pharmacology , Antigens, CD34/pharmacology , Blood Coagulation , Blood Platelets/drug effects , Blood Platelets/physiology , Cell Adhesion/drug effects , Cell Division/drug effects , Enzyme Activation/drug effects , Fibrin , Fibrinogen/drug effects , Fibronectins/drug effects , Humans , Leukemia, Erythroblastic, Acute , Megakaryocytes/enzymology , Phosphatidylinositol 3-Kinases , Phosphotransferases (Alcohol Group Acceptor)/antagonists & inhibitors , Phosphotransferases (Alcohol Group Acceptor)/metabolism , Platelet Glycoprotein GPIIb-IIIa Complex/biosynthesis , Platelet Glycoprotein GPIIb-IIIa Complex/drug effects , Protein Binding/drug effects , Tumor Cells, Cultured , Up-Regulation , Wortmannin
20.
Appl Opt ; 36(4): 885-91, 1997 Feb 01.
Article in English | MEDLINE | ID: mdl-18250754

ABSTRACT

Particle-size distribution and the concentration of polystyrene particles suspended in water were accurately recovered from the inversion of spectral extinction data measured with a commercial spectrophotometer. The instrument was modified by placing a spatial filter in the collection optics to prevent low-angle scattered light from affecting the measurement of transmitted power. The data were inverted by use of a nonlinear iterative algorithm. When the extinction coefficient is measured in the lambda range of 0.3-1.1 microm, the particle distributions can be retrieved over a diameter range of 0.6-2.8 microm for a wide interval of sample concentrations. The average diameters are recovered with a precision of better than +/-1% and with accuracies consistent with the uncertainties by which the nominal diameters are known. The relative standard deviations of distributions corresponding to monodisperse samples are +/-5-10%, whereas the accuracy on the measured concentrations is approximately 5%.

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