Ildo Nicoletti - Academia.edu (original) (raw)
Papers by Ildo Nicoletti
Chemistry and Physics of Lipids, 2004
PubMed, Sep 1, 1995
PML/RAR alpha is the putative transforming sequence of acute promyelocytic leukemias. We investig... more PML/RAR alpha is the putative transforming sequence of acute promyelocytic leukemias. We investigated the effects of PML/RAR alpha on cell survival by expressing the fusion protein in the growth factor-dependent TF-1 cell line and analyzing the kinetics of cell death after GM-CSF deprivation. Results showed that PML/RAR alpha expression markedly delayed apoptotic cell death (3 weeks vs 1 week) without inducing growth factor independence. Growth factor deprivation caused rapid and massive apoptosis of control TF-1 cells (>95% apoptotic cells after 4-5 days). Factor-deprived control cells were synchronously and irreversibly committed to apoptosis as shown by their inability to re-enter the cell cycle after GM-CSF re-addition. The percentage of apoptotic cells in the PML/RAR alpha expressing cells was low (approximately 30-35%) and constant over the 4 weeks of factor deprivation. GM-CSF re-addition produced rapid increase in cell number at all time points during the 4 weeks of factor deprivation, suggesting that commitment to apoptosis was asynchronous and delayed in PML/RAR alpha-expressing TF-1 cells. We conclude that PML/RAR alpha interferes with the genetic pathways which regulate survival by reducing the frequency of commitment to apoptosis. This biological effect of PML/RAR alpha may contribute to its leukemogenetic potential.
Leukemia, Feb 15, 2007
Identification and functional characterization of a cytoplasmic nucleophosmin leukaemic mutant ge... more Identification and functional characterization of a cytoplasmic nucleophosmin leukaemic mutant generated by a novel exon-11 NPM1 mutation
Leukemia, 2008
In acute myeloid leukaemia (AML), nucleophosmin-1 (NPM1) mutations create a nuclear export signal... more In acute myeloid leukaemia (AML), nucleophosmin-1 (NPM1) mutations create a nuclear export signal (NES) motif and disrupt tryptophans at NPM1 C-terminus, leading to nucleophosmin accumulation in leukaemic cell cytoplasm. We investigated how nucleophosmin NES motifs (two physiological and one created by the mutation) regulate traffic and interaction of mutated NPM1, NPM1wt and p14 ARF. Nucleophosmin export into cytoplasm was maximum when the protein contained all three NES motifs, as naturally occurs in NPM1-mutated AML. The two physiological NES motifs mediated NPM1 homo/ heterodimerization, influencing subcellular distribution of NPM1wt, mutated NPM1 and p14 ARF in a 'dose-dependent tug of war' fashion. In transfected cells, excess doses of mutant NPM1 relocated completely NPM1wt (and p14 ARF) from the nucleoli to the cytoplasm. This distribution pattern was also observed in a proportion of NPM1-mutated AML patients. In transfected cells, excess of NPM1wt (and p14 ARF) relocated NPM1 mutant from the cytoplasm to the nucleoli. Notably, this distribution pattern was not observed in AML patients where the mutant was consistently cytoplasmic restricted. These findings reinforce the concept that NPM1 mutants are naturally selected for most efficient cytoplasmic export, pointing to this event as critical for leukaemogenesis. Moreover, they provide a rationale basis for designing small molecules acting at the interface between mutated NPM1 and other interacting proteins.
The International journal of developmental biology, 1993
The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic c... more The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic chick skin fibroblasts at different ages (7-14 days) and in different cell-cycle stages evaluated by flow cytometry (cells maintained with and without serum). Proliferation was estimated by 3H-thymidine incorporation and cell counting. The results demonstrated hyaluronic acid inhibits cell multiplication in all different environmental conditions examined. The inhibitory effect of HA is more evident in 14-day than 7-day old fibroblasts. The ability of HA to modulate 3H-thymidine incorporation did not involve a change in the time required for cells entering the S phase of the replicating cycle, but is due to a smaller number of cells entering in this phase. As the relationships between components of the extracellular matrix (ECM) and the cytoskeleton are known, parallel studies were carried out on some cytoskeleton proteins. Furthermore, by modifying the capacity of cells to adhere to the s...
Giornale di Clinica Nefrologica e Dialisi, 2015
Biomedical research at the time of "Publish or Perish" "Publish or Perish" describes the pressure... more Biomedical research at the time of "Publish or Perish" "Publish or Perish" describes the pressure exerted on scientific researchers to continually and rapidly publish, to demonstrate academic talent, to obtain financial support for their research, and to progress in their career. The pressure to publish seems to be one of the main causes of the reduction in the quality of scientific work submitted for publication, and in some cases leads to scientific misconduct and fraud. The number of articles retracted for fraud has sharply increased in the last years, indicating a crisis of the "peer-review" system, producing a waste of financial resources, mining the reliability of researchers and in some cases posing risks for human health. Although the solution of this problem lies on the full recovery of "research ethics", institutions should apply strict oversight to ensure research integrity. Furthermore, funders and research agencies must support and reward researchers who do solid science and hold to account those whose methods are questionable.
Recenti progressi in medicina, 1987
Journal of Clinical Gastroenterology, 1992
Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids, 2011
The mitochondrial electron transport chain is a source of oxygen superoxide anion (O 2-) that is ... more The mitochondrial electron transport chain is a source of oxygen superoxide anion (O 2-) that is dismutated to H 2 O 2. Although low levels of ROS are physiologically synthesized during respiration, their increase contributes to cell injury. Therefore, an efficient machinery for H 2 O 2 disposal is essential in mitochondria. In this study, the ability of brain mitochondria to acquire cardiolipin (CL), phosphatidylglycerol (PG), and phosphatidylserine (PS) in vitro through a fusion process was exploited to investigate lipid effects on ROS. MTT assay, oxygen consumption, and respiratory ratio indicated that the acquired phospholipids did not alter mitochondrial respiration and O 2 − production from succinate. However, in CL-enriched mitochondria, H 2 O 2 levels where 27% and 47% of control in the absence and in the presence of antimycin A, respectively, suggesting an increase in H 2 O 2 elimination. Concomitantly, cytochrome c (cyt c) was released outside mitochondria. Since free oxidized cyt c acquired peroxidase activity towards H 2 O 2 upon interaction with CL in vitro, a contribution of cyt c to H 2 O 2 disposal in mitochondria through CL conferred peroxidase activity is plausible. In this model, the accompanying CL peroxidation should weaken cyt c-CL interactions, favouring the detachment and release of the protein. Neither cyt c peroxidase activity was elicited by PS in vitro, nor cyt c release was observed in PS-enriched mitochondria, although H 2 O 2 levels were significantly decreased, suggesting a cyt c-independent role of PS in ROS metabolism in mitochondria.
AIDS, 2000
... Cited Here... 8. Vecchiarelli A, Monari C, Baldelli F. et al. ... Gorczyca W, Gong J, Darzynk... more ... Cited Here... 8. Vecchiarelli A, Monari C, Baldelli F. et al. ... Gorczyca W, Gong J, Darzynkiewicz Z. Detection of the DNA strand breaks in individual apoptotic cells by the in situ terminal deoxynucleotidyl transferase and nick translation assays. Cancer Res 1993, 53: 1945 -1951. ...
Journal of Immunological Methods, 1991
Corticosteroids, calcium ionophores and anti-CD3 monoclonal antibodies kill mouse thymocytes incu... more Corticosteroids, calcium ionophores and anti-CD3 monoclonal antibodies kill mouse thymocytes incubated in vitro. Cell death is preceded by extensive DNA fragmentation into ohgonucleosomal subumts. Tins type of cell death (apoptosis), which physiologically occurs m the intrathymic process of immune cell selection, is usually evaluated by either electrophoretic or colorimetric methods which measure DNA fragmentation in the nuclear extracts. These techniques are unable to determine the percentage of apoptotic nuclei or recognize the apoptotic cells in a heterogeneous cell population. We have developed a flow cytometric method for measuring the percentage of apoptotic nuclei after propidium iodide staining in hypotonic buffer and have compared it with the classical colonmetric and electrophoretic techniques using dexamethasone (DEX)-treated mouse thymocytes. Apoptotic nuclei appeared as a broad hypodiploxd DNA peak which was easily discriminable from the narrow peak of thymocytes with normal (diploid) DNA content in the red fluorescence channels. When the DEX-induced apoptosis was inhibited by either low-temperature (4°C) incubation or cyclohexlmide treatment, no hypodiploid DNA peak appeared. Similarly, thymocyte death induced by sodmm azide, a substance with cell-kilhng activity through non-apoptotic mechanisms, &d not result in any variation in the normal DNA peak. The flow cytometrlc data showed an excellent correlatton with the results obtained with both electrophoret~c and colorimetric methods. This new rapid, simple and reproducible method should prove useful for assessing apoptos~s of specific cell populations in heterogeneous tissues such as bone marrow, thymus and lymph nodes.
Chemistry and Physics of Lipids, 2004
PubMed, Sep 1, 1995
PML/RAR alpha is the putative transforming sequence of acute promyelocytic leukemias. We investig... more PML/RAR alpha is the putative transforming sequence of acute promyelocytic leukemias. We investigated the effects of PML/RAR alpha on cell survival by expressing the fusion protein in the growth factor-dependent TF-1 cell line and analyzing the kinetics of cell death after GM-CSF deprivation. Results showed that PML/RAR alpha expression markedly delayed apoptotic cell death (3 weeks vs 1 week) without inducing growth factor independence. Growth factor deprivation caused rapid and massive apoptosis of control TF-1 cells (>95% apoptotic cells after 4-5 days). Factor-deprived control cells were synchronously and irreversibly committed to apoptosis as shown by their inability to re-enter the cell cycle after GM-CSF re-addition. The percentage of apoptotic cells in the PML/RAR alpha expressing cells was low (approximately 30-35%) and constant over the 4 weeks of factor deprivation. GM-CSF re-addition produced rapid increase in cell number at all time points during the 4 weeks of factor deprivation, suggesting that commitment to apoptosis was asynchronous and delayed in PML/RAR alpha-expressing TF-1 cells. We conclude that PML/RAR alpha interferes with the genetic pathways which regulate survival by reducing the frequency of commitment to apoptosis. This biological effect of PML/RAR alpha may contribute to its leukemogenetic potential.
Leukemia, Feb 15, 2007
Identification and functional characterization of a cytoplasmic nucleophosmin leukaemic mutant ge... more Identification and functional characterization of a cytoplasmic nucleophosmin leukaemic mutant generated by a novel exon-11 NPM1 mutation
Leukemia, 2008
In acute myeloid leukaemia (AML), nucleophosmin-1 (NPM1) mutations create a nuclear export signal... more In acute myeloid leukaemia (AML), nucleophosmin-1 (NPM1) mutations create a nuclear export signal (NES) motif and disrupt tryptophans at NPM1 C-terminus, leading to nucleophosmin accumulation in leukaemic cell cytoplasm. We investigated how nucleophosmin NES motifs (two physiological and one created by the mutation) regulate traffic and interaction of mutated NPM1, NPM1wt and p14 ARF. Nucleophosmin export into cytoplasm was maximum when the protein contained all three NES motifs, as naturally occurs in NPM1-mutated AML. The two physiological NES motifs mediated NPM1 homo/ heterodimerization, influencing subcellular distribution of NPM1wt, mutated NPM1 and p14 ARF in a 'dose-dependent tug of war' fashion. In transfected cells, excess doses of mutant NPM1 relocated completely NPM1wt (and p14 ARF) from the nucleoli to the cytoplasm. This distribution pattern was also observed in a proportion of NPM1-mutated AML patients. In transfected cells, excess of NPM1wt (and p14 ARF) relocated NPM1 mutant from the cytoplasm to the nucleoli. Notably, this distribution pattern was not observed in AML patients where the mutant was consistently cytoplasmic restricted. These findings reinforce the concept that NPM1 mutants are naturally selected for most efficient cytoplasmic export, pointing to this event as critical for leukaemogenesis. Moreover, they provide a rationale basis for designing small molecules acting at the interface between mutated NPM1 and other interacting proteins.
The International journal of developmental biology, 1993
The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic c... more The action that hyaluronic acid (HA) exerts on cell proliferation was investigated in embryonic chick skin fibroblasts at different ages (7-14 days) and in different cell-cycle stages evaluated by flow cytometry (cells maintained with and without serum). Proliferation was estimated by 3H-thymidine incorporation and cell counting. The results demonstrated hyaluronic acid inhibits cell multiplication in all different environmental conditions examined. The inhibitory effect of HA is more evident in 14-day than 7-day old fibroblasts. The ability of HA to modulate 3H-thymidine incorporation did not involve a change in the time required for cells entering the S phase of the replicating cycle, but is due to a smaller number of cells entering in this phase. As the relationships between components of the extracellular matrix (ECM) and the cytoskeleton are known, parallel studies were carried out on some cytoskeleton proteins. Furthermore, by modifying the capacity of cells to adhere to the s...
Giornale di Clinica Nefrologica e Dialisi, 2015
Biomedical research at the time of "Publish or Perish" "Publish or Perish" describes the pressure... more Biomedical research at the time of "Publish or Perish" "Publish or Perish" describes the pressure exerted on scientific researchers to continually and rapidly publish, to demonstrate academic talent, to obtain financial support for their research, and to progress in their career. The pressure to publish seems to be one of the main causes of the reduction in the quality of scientific work submitted for publication, and in some cases leads to scientific misconduct and fraud. The number of articles retracted for fraud has sharply increased in the last years, indicating a crisis of the "peer-review" system, producing a waste of financial resources, mining the reliability of researchers and in some cases posing risks for human health. Although the solution of this problem lies on the full recovery of "research ethics", institutions should apply strict oversight to ensure research integrity. Furthermore, funders and research agencies must support and reward researchers who do solid science and hold to account those whose methods are questionable.
Recenti progressi in medicina, 1987
Journal of Clinical Gastroenterology, 1992
Biochimica et Biophysica Acta (BBA) - Molecular and Cell Biology of Lipids, 2011
The mitochondrial electron transport chain is a source of oxygen superoxide anion (O 2-) that is ... more The mitochondrial electron transport chain is a source of oxygen superoxide anion (O 2-) that is dismutated to H 2 O 2. Although low levels of ROS are physiologically synthesized during respiration, their increase contributes to cell injury. Therefore, an efficient machinery for H 2 O 2 disposal is essential in mitochondria. In this study, the ability of brain mitochondria to acquire cardiolipin (CL), phosphatidylglycerol (PG), and phosphatidylserine (PS) in vitro through a fusion process was exploited to investigate lipid effects on ROS. MTT assay, oxygen consumption, and respiratory ratio indicated that the acquired phospholipids did not alter mitochondrial respiration and O 2 − production from succinate. However, in CL-enriched mitochondria, H 2 O 2 levels where 27% and 47% of control in the absence and in the presence of antimycin A, respectively, suggesting an increase in H 2 O 2 elimination. Concomitantly, cytochrome c (cyt c) was released outside mitochondria. Since free oxidized cyt c acquired peroxidase activity towards H 2 O 2 upon interaction with CL in vitro, a contribution of cyt c to H 2 O 2 disposal in mitochondria through CL conferred peroxidase activity is plausible. In this model, the accompanying CL peroxidation should weaken cyt c-CL interactions, favouring the detachment and release of the protein. Neither cyt c peroxidase activity was elicited by PS in vitro, nor cyt c release was observed in PS-enriched mitochondria, although H 2 O 2 levels were significantly decreased, suggesting a cyt c-independent role of PS in ROS metabolism in mitochondria.
AIDS, 2000
... Cited Here... 8. Vecchiarelli A, Monari C, Baldelli F. et al. ... Gorczyca W, Gong J, Darzynk... more ... Cited Here... 8. Vecchiarelli A, Monari C, Baldelli F. et al. ... Gorczyca W, Gong J, Darzynkiewicz Z. Detection of the DNA strand breaks in individual apoptotic cells by the in situ terminal deoxynucleotidyl transferase and nick translation assays. Cancer Res 1993, 53: 1945 -1951. ...
Journal of Immunological Methods, 1991
Corticosteroids, calcium ionophores and anti-CD3 monoclonal antibodies kill mouse thymocytes incu... more Corticosteroids, calcium ionophores and anti-CD3 monoclonal antibodies kill mouse thymocytes incubated in vitro. Cell death is preceded by extensive DNA fragmentation into ohgonucleosomal subumts. Tins type of cell death (apoptosis), which physiologically occurs m the intrathymic process of immune cell selection, is usually evaluated by either electrophoretic or colorimetric methods which measure DNA fragmentation in the nuclear extracts. These techniques are unable to determine the percentage of apoptotic nuclei or recognize the apoptotic cells in a heterogeneous cell population. We have developed a flow cytometric method for measuring the percentage of apoptotic nuclei after propidium iodide staining in hypotonic buffer and have compared it with the classical colonmetric and electrophoretic techniques using dexamethasone (DEX)-treated mouse thymocytes. Apoptotic nuclei appeared as a broad hypodiploxd DNA peak which was easily discriminable from the narrow peak of thymocytes with normal (diploid) DNA content in the red fluorescence channels. When the DEX-induced apoptosis was inhibited by either low-temperature (4°C) incubation or cyclohexlmide treatment, no hypodiploid DNA peak appeared. Similarly, thymocyte death induced by sodmm azide, a substance with cell-kilhng activity through non-apoptotic mechanisms, &d not result in any variation in the normal DNA peak. The flow cytometrlc data showed an excellent correlatton with the results obtained with both electrophoret~c and colorimetric methods. This new rapid, simple and reproducible method should prove useful for assessing apoptos~s of specific cell populations in heterogeneous tissues such as bone marrow, thymus and lymph nodes.