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Togliatto G, Trombetta A, Dentelli P, Rosso A, Brizzi MF. Retraction Note to: MIR221/MIR222-driven post-transcriptional regulation of P27KIP1 and P57KIP2 is crucial for high-glucose- and AGE-mediated vascular cell damage. Diabetologia 2018; 61:1236. [PMID: 29427236 DOI: 10.1007/s00125-018-4569-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The authors are retracting this article [1]. Following publication, concerns were raised with respect to some of the western blots and the authors were asked to supply the original unmodified blots.
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Affiliation(s)
- G Togliatto
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Torino, Italy
| | - A Trombetta
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Torino, Italy
| | - P Dentelli
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Torino, Italy
| | - A Rosso
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Torino, Italy
| | - M F Brizzi
- Department of Medical Sciences, University of Turin, Corso Dogliotti 14, 10126, Torino, Italy.
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Togliatto G, Dentelli P, Gili M, Gallo S, Deregibus C, Biglieri E, Iavello A, Santini E, Rossi C, Solini A, Camussi G, Brizzi MF. Obesity reduces the pro-angiogenic potential of adipose tissue stem cell-derived extracellular vesicles (EVs) by impairing miR-126 content: impact on clinical applications. Int J Obes (Lond) 2015; 40:102-11. [PMID: 26122028 PMCID: PMC4722244 DOI: 10.1038/ijo.2015.123] [Citation(s) in RCA: 86] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Revised: 05/18/2015] [Accepted: 06/22/2015] [Indexed: 12/17/2022]
Abstract
BACKGROUND/OBJECTIVES Soluble factors and cell-derived extracellular vesicles (EVs) are crucial tissue repair mediators in cell-based therapy. In the present study, we investigate the therapeutic impact of EVs released by adipose tissue-derived stem cells (ASCs) recovered from obese subjects' visceral and subcutaneous tissues. METHODS ASCs were recovered from 10 obese (oASCs) and 6 non-obese (nASCs) participants and characterized. In selected experiments, nASCs and oASCs were cultured with palmitic acid (PA) or high glucose (HG), respectively. EVs from obese (oEVs) and non-obese (nEVs) subjects' visceral and subcutaneous ASCs were collected after ultracentrifugation and analyzed for their cargo: microRNA-126 (miR-126), vascular endothelial growth factor (VEGF), and matrix metalloproteinase 2 (MMP-2), and for their biological effects on endothelial cells (ECs). Western blotting analysis and loss- and gain-of function experiments were performed. RESULTS oEVs show impaired angiogenic potential compared with nEVs. This effect depends on EV cargo: reduced content of VEGF, MMP-2 and, more importantly, miR-126. We demonstrate, using gain- and loss-of-function experiments, that this reduced miR-126 content leads to Spred1 upregulation and the inhibition of the extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase pathway in ECs. We also show that PA treatment of nASCs translates into the release of EVs that recapitulate oEV cargo. Moreover, HG treatment of oASCs further reduces miR-126 EV content and EV-mediated in vitro angiogenesis. Finally, impaired pro-angiogenic potential is also detected in EVs released from obese subcutaneous adipose tissue-derived ASCs. CONCLUSIONS These results indicate that obesity impacts on EV pro-angiogenic potential and may raise concerns about the use of adipose tissue-derived EVs in cell-based therapy in the obese setting.
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Affiliation(s)
- G Togliatto
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - P Dentelli
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - M Gili
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - S Gallo
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - C Deregibus
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - E Biglieri
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - A Iavello
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - E Santini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - C Rossi
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - A Solini
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - G Camussi
- Department of Medical Sciences, University of Torino, Torino, Italy
| | - M F Brizzi
- Department of Medical Sciences, University of Torino, Torino, Italy
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Dentelli P, Barale C, Togliatto G, Trombetta A, Olgasi C, Gili M, Riganti C, Toppino M, Brizzi MF. A diabetic milieu promotes OCT4 and NANOG production in human visceral-derived adipose stem cells. Diabetologia 2013; 56:173-84. [PMID: 23064289 DOI: 10.1007/s00125-012-2734-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Accepted: 08/30/2012] [Indexed: 01/31/2023]
Abstract
AIMS/HYPOTHESIS Successful outcomes have been obtained by exploiting adipose-derived stem cells (ASCs) in regenerative medicine. NADPH oxidase (NOX)-generated reactive oxygen species (ROS) are known to control stem cell self-renewal. Several high glucose (HG)-mediated effects depend on NOX-generated ROS. In this study, we investigated whether, and how mechanistically, HG concentrations control ASC fate in patients with diabetes. METHODS ASCs from the visceral adipose tissue of non-diabetic (N-ASCs) and diabetic participants (D-ASCs), identified by surface markers, were counted and evaluated for ROS generation and stem cell properties. Their ability to release soluble factors was assessed by BioPlex analysis. To reproduce an in vitro diabetic glucose milieu, N-ASCs were cultured in HG (25 mmol/l) or normal glucose (NG) concentration (5 mmol/l), as control. ASC pluripotency was assessed by in vitro study. The p47(phox) NOX subunit, AKT and octamer-binding transcription factor 4 (OCT4; also known as POU5F1) were knocked down by small-interfering RNA technology. Stem-cell features were evaluated by sphere cluster formation. RESULTS The ASC number was higher in diabetic patients than in non-diabetic controls. Production of OCT4 and NANOG, stem-cell-specific transcription factors, was upregulated in D-ASCs compared with N-ASCs. Moreover, we found that ROS production and AKT activation drove D-ASC, but not N-ASC, secretion. When N-ASCs were cultured in vitro in the presence of HG, they also expressed OCT4/NANOG and formed spheres. By knock-down of the p47(phox) NOX subunit, AKT and OCT4 we demonstrated that NOX-generated ROS and their downstream signals are crucial for HG-mediated ASC de-differentiation and proinflammatory cytokine production. CONCLUSIONS/INTERPRETATION We herein provide a rationale for exploiting D-ASCs in regenerative medicine and/or exploiting HG preconditioning to increase ASCs ex vivo.
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Affiliation(s)
- P Dentelli
- Department of Medical Sciences, University of Torino, Corso Dogliotti 14, 10126 Torino, Italy
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Verhovez A, Williams TA, Morello F, Monticone S, Brizzi MF, Dentelli P, Fallo F, Fabris B, Amenta F, Gomez-Sanchez C, Veglio F, Mulatero P. Aldosterone does not modify gene expression in human endothelial cells. Horm Metab Res 2012; 44:234-8. [PMID: 22068811 DOI: 10.1055/s-0031-1291272] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
The toxic effects of aldosterone on the vasculature, and in particular on the endothelial layer, have been proposed as having an important role in the cardiovascular pathology observed in mineralocorticoid-excess states. In order to characterize the genomic molecular mechanisms driving the aldosterone-induced endothelial dysfunction, we performed an expression microarray on transcripts obtained from both human umbilical vein endothelial cells and human coronary artery endothelial cells stimulated with 10 - 7 M aldosterone for 18 h. The results were then subjected to qRT-PCR confirmation, also including a group of genes known to be involved in the control of the endothelial function or previously described as regulated by aldosterone. The state of activation of the mineralocorticoid receptor was investigated by means of a luciferase-reporter assay using a plasmid encoding a mineralocorticoid and glucocorticoid-sensitive promoter. Aldosterone did not determine any significant change in gene expression in either cell type both in the microarray and in the qRT-PCR analysis. The luciferase-reporter assay showed no activation of the mineralocorticoid receptor following aldosterone stimulation. The status of nonfunctionality of the mineralocorticoid receptor expressed in cultured human umbilical and coronary artery endothelial cells does not allow aldosterone to modify gene expression and provides evidence against either a beneficial or harmful genomic effect of aldosterone on healthy endothelial cells.
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Affiliation(s)
- A Verhovez
- Department of Internal Medicine, University of Torino, Torino, Italy.
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Togliatto G, Trombetta A, Dentelli P, Rosso A, Brizzi MF. MIR221/MIR222-driven post-transcriptional regulation of P27KIP1 and P57KIP2 is crucial for high-glucose- and AGE-mediated vascular cell damage. Diabetologia 2011; 54:1930. [PMID: 21461636 DOI: 10.1007/s00125-011-2125-5] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 02/23/2011] [Indexed: 11/30/2022]
Abstract
AIMS/HYPOTHESIS MicroRNAs (miRNAs) are a novel group of small non-coding RNAs that regulate gene expression at the post-transcriptional level and act on their target mRNAs in a tissue- and cell-type-specific manner. Herein, the relevance of MIR221/MIR222 in high-glucose- and AGE-mediated vascular damage was investigated. METHODS Functional studies were performed using human mature endothelial cells and endothelial progenitor cells subjected to high glucose or AGE. Quantitative real-time amplification was performed to analyse MIR221/MIR222 expression in these experimental conditions. Luciferase assay was used to identify MIR221/MIR222 targets. Functional studies were performed in vitro and in vivo in mice using gain- and loss-of-function approaches. RESULTS Using an in vivo mouse model we demonstrated that exposure to AGE and high glucose impaired vessel formation. Moreover, in vitro functional studies revealed that both high glucose and AGE inhibit cell-cycle progression by modulating the expression of P27KIP1 (also known as CDKN1B) and P57KIP2 (also known as CDKN1C), which encode cyclin-dependent kinase inhibitor 1B (p27, Kip1) (P27KIP1) and cyclin-dependent kinase inhibitor 1C (p57, Kip2) (P57KIP2), respectively. Crucial to AGE- and high-glucose-mediated cell-cycle arrest was the downregulation of MIR221/MIR222 expression. Luciferase assay showed that MIR221 and MIR222 specifically bind to the P27KIP1 and P57KIP2 mRNA 3'-untranslated regions, implicating P27KIP1 and P57KIP2 as MIR221/MIR222 targets. These results were confirmed by gain-of-function experiments in vitro, and by injecting mice with endothelial cells overexpressing MIR221 and MIR222. CONCLUSIONS/INTERPRETATION We provide evidence that high-glucose- and AGE-induced inhibition of vascular cell proliferation is controlled by MIR221/MIR222-driven post-transcriptional regulation of P27KIP1 and P57KIP2. These data add further insight to the possible contribution of miRNAs in vascular damage mediated by a high-glucose environment.
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Affiliation(s)
- G Togliatto
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - A Trombetta
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - P Dentelli
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - A Rosso
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - M F Brizzi
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy.
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Togliatto G, Trombetta A, Dentelli P, Rosso A, Brizzi MF. MIR221/MIR222-driven post-transcriptional regulation of P27KIP1 and P57KIP2 is crucial for high-glucose- and AGE-mediated vascular cell damage. Diabetologia 2011. [PMID: 21461636 DOI: 10.1007/s00125-011-2125 -5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
AIMS/HYPOTHESIS MicroRNAs (miRNAs) are a novel group of small non-coding RNAs that regulate gene expression at the post-transcriptional level and act on their target mRNAs in a tissue- and cell-type-specific manner. Herein, the relevance of MIR221/MIR222 in high-glucose- and AGE-mediated vascular damage was investigated. METHODS Functional studies were performed using human mature endothelial cells and endothelial progenitor cells subjected to high glucose or AGE. Quantitative real-time amplification was performed to analyse MIR221/MIR222 expression in these experimental conditions. Luciferase assay was used to identify MIR221/MIR222 targets. Functional studies were performed in vitro and in vivo in mice using gain- and loss-of-function approaches. RESULTS Using an in vivo mouse model we demonstrated that exposure to AGE and high glucose impaired vessel formation. Moreover, in vitro functional studies revealed that both high glucose and AGE inhibit cell-cycle progression by modulating the expression of P27KIP1 (also known as CDKN1B) and P57KIP2 (also known as CDKN1C), which encode cyclin-dependent kinase inhibitor 1B (p27, Kip1) (P27KIP1) and cyclin-dependent kinase inhibitor 1C (p57, Kip2) (P57KIP2), respectively. Crucial to AGE- and high-glucose-mediated cell-cycle arrest was the downregulation of MIR221/MIR222 expression. Luciferase assay showed that MIR221 and MIR222 specifically bind to the P27KIP1 and P57KIP2 mRNA 3'-untranslated regions, implicating P27KIP1 and P57KIP2 as MIR221/MIR222 targets. These results were confirmed by gain-of-function experiments in vitro, and by injecting mice with endothelial cells overexpressing MIR221 and MIR222. CONCLUSIONS/INTERPRETATION We provide evidence that high-glucose- and AGE-induced inhibition of vascular cell proliferation is controlled by MIR221/MIR222-driven post-transcriptional regulation of P27KIP1 and P57KIP2. These data add further insight to the possible contribution of miRNAs in vascular damage mediated by a high-glucose environment.
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Affiliation(s)
- G Togliatto
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - A Trombetta
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - P Dentelli
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - A Rosso
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy
| | - M F Brizzi
- Department of Internal Medicine, University of Torino, Corso Dogliotti 14, 10126, Torino, Italy.
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Uberti B, Dentelli P, Rosso A, Defilippi P, Brizzi MF. Inhibition of β1 integrin and IL-3Rβ common subunit interaction hinders tumour angiogenesis. Oncogene 2010; 29:6581-90. [DOI: 10.1038/onc.2010.384] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Abstract
Risk factors associated with cardiovascular diseases reduce the availability of endothelial progenitor cells (EPC) by affecting their mobilization and integration into injured vascular sites. The existence of a bone marrow reservoir of EPC has attracted interest, especially as target for therapeutic intervention in different pathological settings. Among the cardiovascular risk factors, hypertension has been shown to be a strongest predictor of EPC migratory impairment. However, at present, data concerning EPC biology are still limited. In this article we provide an overview of data relevant to their potential clinical implications in cardiovascular disorders. In addition, the recent advances in understanding the role of EPC in the pathophysiology of hypertension are discussed.
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Affiliation(s)
- A Zeoli
- Department of Internal Medicine, University of Turin, Corso Dogliotti 14, 10126, Turin, Italy
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9
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Brizzi MF, Formato L, Dentelli P, Rosso A, Pavan M, Garbarino G, Pegoraro M, Camussi G, Pegoraro L. Interleukin-3 stimulates migration and proliferation of vascular smooth muscle cells: a potential role in atherogenesis. Circulation 2001; 103:549-54. [PMID: 11157721 DOI: 10.1161/01.cir.103.4.549] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Cytokines released by activated T lymphocytes are key regulators of chronic inflammatory response, including atherosclerosis. The aim of this study was to investigate the presence of interleukin-3 (IL-3) in lymphocytes infiltrating the atherosclerotic plaque and the effect of this cytokine on primary vascular smooth muscle cells (SMCs). METHODS AND RESULTS Twenty atherosclerotic carotid arterial specimens and 5 early atherosclerotic lesions from the internal carotid were manually minced to fragments, and T lymphocytes infiltrating the atherosclerotic plaque were isolated on solid-phase anti-CD3 polystyrene plates. Southern blot analysis demonstrated that in all samples, lymphocytes expressed IL-3 and IL-2 receptor alpha-chain transcripts, indicating that in this context, the activated T lymphocytes may release IL-3. We further analyzed the expression of the IL-3 receptor and the biological effects exerted by the ligand on vascular SMCs. ss-IL-3-transducing subunit was detected both on cultured SMCs and on endothelial cells and SMCs within atheroma. The analysis of the IL-3-induced biological effects demonstrated that it was able to trigger both mitogenic and motogenic signals. Moreover, we demonstrated that the addition of PD98059, a known inhibitor of the MAP-extracellular signaling-regulated/MAP kinase pathway, completely inhibited IL-3-mediated MAP kinase activation and IL-3-induced migration and proliferation. Finally, IL-3 was found to stimulate vascular endothelial growth factor (VEGF) gene transcription. CONCLUSIONS IL-3, expressed by activated T lymphocytes infiltrating early and advanced atherosclerotic plaques, may sustain the atherosclerotic process either directly, by activating SMC migration and proliferation, or indirectly, via VEGF production.
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MESH Headings
- Arteriosclerosis/pathology
- Blotting, Northern
- Cell Division/drug effects
- Cell Movement/drug effects
- Cells, Cultured
- DNA/biosynthesis
- DNA/drug effects
- Endothelial Growth Factors/genetics
- Enzyme Activation/drug effects
- Enzyme Inhibitors/pharmacology
- Flavonoids/pharmacology
- Gene Expression
- Humans
- Immunoblotting
- Interleukin-3/genetics
- Interleukin-3/pharmacology
- Lymphocytes/cytology
- Lymphocytes/metabolism
- Lymphokines/genetics
- Mitogen-Activated Protein Kinase 1/drug effects
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases/drug effects
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Interleukin-3/genetics
- Receptors, Interleukin-3/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Transcription, Genetic/drug effects
- Vascular Endothelial Growth Factor A
- Vascular Endothelial Growth Factors
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Affiliation(s)
- M F Brizzi
- Department of Internal Medicine, University of Turin, Italy
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10
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Dentelli P, Del Sorbo L, Rosso A, Molinar A, Garbarino G, Camussi G, Pegoraro L, Brizzi MF. Human IL-3 stimulates endothelial cell motility and promotes in vivo new vessel formation. J Immunol 1999; 163:2151-9. [PMID: 10438956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Angiogenesis is a critical process for growth of new capillary blood vessels from preexisting capillaries and postcapillary venules, both in physiological and pathological conditions. Endothelial cell proliferation is a major component of angiogenesis and it is regulated by several growth factors. It has been previously shown that the human hemopoietic growth factor IL-3 (hIL-3), predominantly produced by activated T lymphocytes, stimulates both endothelial cell proliferation and functional activation. In the present study, we report that hIL-3 is able to induce directional migration and tube formation of HUVEC. The in vivo neoangiogenetic effect of hIL-3 was also demonstrated in a murine model in which Matrigel was used for the delivery of the cytokine, suggesting a role of hIL-3 in sustaining neoangiogenesis. Challenge of HUVEC with hIL-3 lead to the synthesis of platelet-activating factor (PAF), which was found to act as secondary mediator for hIL-3-mediated endothelial cell motility but not for endothelial cell proliferation. Consistent with the role of STAT5 proteins in regulating IL-3-mediated mitogenic signals, we herein report that, in hIL-3-stimulated HUVEC, the recruitment of STAT5A and STAT5B, by the beta common (betac) subunit of the IL-3R, was not affected by PAF receptor blockade.
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MESH Headings
- Animals
- Apolipoproteins
- Apolipoproteins D
- Azepines/pharmacology
- Carrier Proteins/metabolism
- Cell Division/drug effects
- Cell Line
- Cell Movement/drug effects
- Cell Movement/physiology
- DNA-Binding Proteins/antagonists & inhibitors
- DNA-Binding Proteins/metabolism
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Endothelium, Vascular/physiology
- Female
- Glycoproteins
- Humans
- Injections, Subcutaneous
- Interleukin-3/administration & dosage
- Interleukin-3/metabolism
- Interleukin-3/physiology
- Macromolecular Substances
- Membrane Transport Proteins
- Mice
- Mice, Inbred C57BL
- Milk Proteins
- Neovascularization, Physiologic/drug effects
- Neovascularization, Physiologic/physiology
- Platelet Activating Factor/antagonists & inhibitors
- Platelet Activating Factor/biosynthesis
- Platelet Membrane Glycoproteins/antagonists & inhibitors
- Protein Binding
- Receptors, Cell Surface
- Receptors, G-Protein-Coupled
- Receptors, Interleukin-3/metabolism
- STAT5 Transcription Factor
- Trans-Activators/antagonists & inhibitors
- Trans-Activators/metabolism
- Triazoles/pharmacology
- Tumor Suppressor Proteins
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Affiliation(s)
- P Dentelli
- Dipartimento di Medicina Interna, Fisiopatologia Clinica, Università di Torino, Italy
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Abstract
Stem cell factor (SCF) and its tyrosine kinase receptor, c-Kit, play a crucial role in regulating migration and proliferation of melanoblasts, germ cells, and hemopoietic cell progenitors by activating a number of intracellular signaling molecules. Here we report that SCF stimulation of myeloid cells or fibroblasts ectopically expressing c-Kit induces physical association with and tyrosine phosphorylation of three signal transducers and activators of transcription (STATs) as follows: STAT1alpha, STAT5A, and STAT5B. Other STAT proteins are not recruited upon SCF stimulation. Recruitment of STATs leads to their dimerization, nuclear translocation, and binding to specific promoter-responsive elements. Whereas STAT1alpha, possibly in the form of homodimers, binds to the sis-inducible DNA element, STAT5 proteins, either as STAT5A/STAT5B or STAT5/STAT1alpha heterodimers, bind to the prolactin-inducible element of the beta-casein promoter. The tyrosine kinase activity of Kit appears essential for STAT activation since a kinase-defective mutant lacking a kinase insert domain was inactive in STAT signaling. However, another mutant that lacked the carboxyl-terminal region retained STAT1alpha activation and nuclear translocation but was unable to fully activate STAT5 proteins, although it mediated their transient phosphorylation. These results indicate that different intracellular domains of c-Kit are involved in activation of the various STAT proteins.
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Affiliation(s)
- M F Brizzi
- Department of Internal Medicine, University of Turin, Turin 10126, Italy
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12
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Brizzi MF, Battaglia E, Montrucchio G, Dentelli P, Del Sorbo L, Garbarino G, Pegoraro L, Camussi G. Thrombopoietin stimulates endothelial cell motility and neoangiogenesis by a platelet-activating factor-dependent mechanism. Circ Res 1999; 84:785-96. [PMID: 10205146 DOI: 10.1161/01.res.84.7.785] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this study, we demonstrate that human umbilical cord vein-derived endothelial cells (HUVECs) expressed c-Mpl, the thrombopoietin (TPO) receptor, and that TPO activates HUVECs in vitro, as indicated by directional migration, synthesis of 1-alkyl-/1-acyl-platelet-activating factor (PAF) and interleukin-8 (IL-8), and phosphorylation of the signal transducers and activators of transcription (STAT) STAT1 and STAT5B. The observation that WEB 2170 and CV3988, 2 structurally unrelated PAF receptor antagonists, prevented the motility of HUVECs induced by TPO suggests a role of PAF as secondary mediator. Moreover, kinetic analysis of TPO-induced tyrosine phosphorylation of STAT demonstrated that STAT5B activation temporally correlated with the synthesis of PAF. PAF, in turn, induced a rapid tyrosine phosphorylation of STAT5B and PAF receptor blockade, by WEB 2170, preventing both TPO- and PAF-mediated STAT5B activation. The in vivo angiogenic effect of TPO, studied in a mouse model of Matrigel implantation, demonstrated that TPO induced a dose-dependent angiogenic response that required the presence of heparin. Moreover, the in vivo angiogenic effect of TPO was inhibited by the PAF receptor antagonist WEB 2170 but not by the anti-basic fibroblast growth factor neutralizing antibody. These results indicate that the effects of TPO are not restricted to cells of hematopoietic lineages, because TPO is able to activate endothelial cells and to induce an angiogenic response in which the recruitment of endothelial cells is mediated by the synthesis of PAF. Moreover, biochemical analysis supports the hypothesis that STAT5B may be involved in the signaling pathway leading to PAF-dependent angiogenesis.
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Affiliation(s)
- M F Brizzi
- Dipartimento di Medicina Interna, Università di Torino and Dipartimento di Scienze Cliniche e Biologiche, Torino, Italy
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Brizzi MF, Rosso A, Dentelli P, Ferrero D, Lanfrancone L, Pegoraro L. c-Cbl tyrosine phosphorylation and subcellular localization in human primary leukemic cells. Exp Hematol 1998; 26:1229-39. [PMID: 9845379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
Several studies indicate that a number of signal-transducing molecules involved in the proliferation, differentiation, and functional activation of normal hemopoietic cells may be constitutively activated in primary leukemic cells and play a role in the outcome or in the progression of these neoplastic disorders. In this study we show that the product of the proto-oncogene c-Cbl, whose function is still unknown, is constitutively tyrosine phosphorylated not only in cells from chronic myelogenous leukemias (CMLs) in the blast phase, but also in cells from acute myeloblastic leukemias (AMLs), Ph-negative acute T-lymphoblastic leukemias (T-ALLs), and Ph-negative pre-B lymphoblastic leukemias (pre-B ALL). Moreover, in acute leukemia cells, c-Cbl was not stably complexed with the tyrosine-phosphorylated adaptor protein CrkL. The analysis of Grb2/c-Cbl interaction demonstrated that, in both acute leukemia and CML blasts, c-Cbl was stably complexed with the N-terminal Src homology (SH) 3 domain of Grb2 and, in blasts from ALL patients, with the Grb2 SH2 domain. The analysis of c-Cbl subcellular distribution showed that in all cases of leukemia tested, as well as in growth factor-stimulated M-07e cells, c-Cbl was present in the cytosolic, in the membrane, and in the detergent-insoluble fractions. Finally, in polymorphonuclear neutrophils (PMNs) from CML patients, c-Cbl was found stably associated with the detergent-insoluble fraction, whereas in PMNs from normal donors, it was detected only in the cytosolic fraction. Our findings that c-Cbl is constitutively tyrosine phosphorylated and associated with the detergent-insoluble fraction in AML and ALL blasts and in PMNs from CML patients suggest that this event represents a common step in the neoplastic transformation of both myeloid and lymphoid progenitor cells.
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MESH Headings
- Adaptor Proteins, Signal Transducing
- Blotting, Western
- GRB2 Adaptor Protein
- Humans
- Immunosorbent Techniques
- Leukemia/metabolism
- Leukemia/pathology
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/metabolism
- Leukemia, Myelogenous, Chronic, BCR-ABL Positive/pathology
- Leukemia, Myeloid, Acute/metabolism
- Leukemia, Myeloid, Acute/pathology
- Leukemia-Lymphoma, Adult T-Cell/metabolism
- Leukemia-Lymphoma, Adult T-Cell/pathology
- Nuclear Proteins/analysis
- Nuclear Proteins/metabolism
- Phosphorylation
- Phosphotyrosine/metabolism
- Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/pathology
- Precursor Cell Lymphoblastic Leukemia-Lymphoma/metabolism
- Proteins/metabolism
- Proto-Oncogene Mas
- Proto-Oncogene Proteins/analysis
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-cbl
- Subcellular Fractions/chemistry
- Ubiquitin-Protein Ligases
- src Homology Domains
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Affiliation(s)
- M F Brizzi
- Department of Internal Medicine, University of Turin, Italy
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Brizzi MF, Dentelli P, Lanfrancone L, Rosso A, Pelicci PG, Pegoraro L. Discrete protein interactions with the Grb2/c-Cbl complex in SCF- and TPO-mediated myeloid cell proliferation. Oncogene 1996; 13:2067-76. [PMID: 8950973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Hemopoietic cell proliferation is mediated by non-tyrosine and tyrosine kinases that signal via uncommon and common sets of downstream effector molecules including the Grb2/c-Cbl. In the present study we evaluated tyrosine phosphorylation of c-Cbl and the interaction of the Grb2/c-Cbl complex with signaling proteins upon activation of non-tyrosine (c-Mpl) and tyrosine kinase (c-Kit) receptors leading to myeloid cell proliferation. By using the growth factor dependent M-07e cell line, we found that both c-Mpl and c-Kit ligands, namely: SCF and TPO, induce c-Cbl tyrosine phosphorylation. In these cells the adaptor protein Grb2 constitutively binds a substantial fraction of c-Cbl through the N-terminal SH3 domain. In vitro experiments showed that the stable Grb2/c-Cbl complex interacts, through the Grb2 SH2 domain, with the SCF-activated c-Kit. By contrast stimulation with TPO leads to the formation of a Grb2 complex containing JAK2. In vitro and in vivo experiments support the hypothesis that Grb2 mediates the association of c-Kit with c-Cbl. Moreover we found that, upon SCF stimulation, the Grb2/c-Cbl complex recruits Shc, probably via Grb2. By contrast the Ras exchanger factor (Sos1) was not detected in anti-c-Cbl immunoprecipitates suggesting that Grb2/Sos1 and Grb2/c-Cbl are present in different complexes. Taken together our results demonstrate that c-Cbl plays an important role in coupling both tyrosine and non-tyrosine kinase receptors to downstream effector molecules and that different signaling molecules interact with Grb2/c-Cbl complex when non-tyrosine or tyrosine kinase receptors are activated.
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Affiliation(s)
- M F Brizzi
- Dipartimento di Medicina Interna, Università di Torino, Italy
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Aronica MG, Brizzi MF, Dentelli P, Rosso A, Yarden Y, Pegoraro L. p91 STAT1 activation in interleukin-3-stimulated primary acute myeloid leukemia cells. Oncogene 1996; 13:1017-26. [PMID: 8806691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Interleukin-3 (IL-3) stimulates in vitro blast cell proliferation in a consistent proportion of acute myeloid leukemia (AML) cases, however the degree of response varies from case to case and it is not related to the FAB subtype or to other clinical parameters. IL-3-induced proliferation of myeloid cells is mediated by the interaction with an heterodimeric receptor (IL-3R) comprised of a ligand binding subunit denoted alpha and a common transducing subunit designated as beta (beta). Ligand binding to the receptor activates a number of signaling molecules including proteins of the STATs (signal transducing and activators of transcription) family. To elucidate the mechanisms responsible for the abnormal proliferative response of AML cells to IL-3, we evaluated, both in the IL-3-dependent M-07e cell line and in 20 AML cases, the activation of STAT1 p91 and its association with the beta c subunit. On the basis of the in vitro proliferation assay, 11 out of 20 cases were found to be responsive to IL-3 and eight out of 16 to GM-CSF. Our results demonstrated that in M-07e cells and in six AML cases (five IL-3 responsive and one unresponsive) p91 tyrosine phosphorylation was ligand dependent. Ligand independent p91 tyrosine phosphorylation was detected in 10 AML cases (five responsive and five unresponsive). p91 association with the beta c subunit was consistent with its ligand dependent activation and with the ability to form a DNA-binding complex containing p91. In the remaining four cases (three unresponsive and one responsive) no p91 tyrosine phosphorylation and/or association were detected. These findings, together with the observation that in five IL-3 responsive cases p91 was constitutively phosphorylated, suggest that IL-3-mediated AML proliferation is only partially sustained by p91 activation and that other post-receptor molecules are required to achieve maximal proliferative response. Moreover structural abnormalities of the receptor or of post-receptor signaling proteins may account for the constitutive p91 phosphorylation and growth factor independent proliferation observed in the unresponsive AML cases.
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Affiliation(s)
- M G Aronica
- Dipartimento di Scienze Biomediche e Oncologia Umana, Università di Torino, Italy
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Limone P, Scipioni T, Calvelli P, Scaglione E, Barberis AM, Dentelli P, Isaia GC, Molinatti GM. Alpha-melanocyte-stimulating hormone antagonizes the inhibitory effect of corticotropin-releasing hormone on luteinizing hormone secretion during the luteal phase in normal women. J Clin Endocrinol Metab 1994; 79:571-5. [PMID: 8045978 DOI: 10.1210/jcem.79.2.8045978] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
CRH inhibits the secretion of gonadotropins by activating endogenous opioids, whereas alpha MSH, which displays various behavioral and neuroendocrine effects contrary to those of the opioids, stimulates their release. To evaluate the possible interaction of CRH and alpha MSH, eight women in the luteal phase underwent the following tests: 1) ovine CRH infused at 100 micrograms/h for 3 h, 2) alpha MSH (2.5 mg as an iv bolus 60 min after the start of saline infusion), 3) CRH plus alpha MSH (injected 60 min after the start of CRH infusion), and 4) placebo. LH, FSH, PRL, ACTH, and cortisol were determined every 15 min for 180 min. CRH significantly (P < 0.001) reduced serum LH. alpha MSH alone significantly (P < 0.001) increased LH to a peak within 15-30 min (baseline, 3.3 +/- 0.7 mIU/mL; maximum increase, 3.5 +/- 0.9 mIU/mL) and induced an even greater rise when injected during the CRH infusion (baseline, 2.8 +/- 03 mIU/mL; maximum increase 7.5 +/- 1.6 mIU/mL; P < 0.05 vs. alpha MSH alone). FSH was always unaffected. ACTH and cortisol increased (P < 0.001) during the CRH infusion and fell significantly (P < 0.001) during the placebo infusion. alpha MSH had no effect on these changes. PRL fell during the placebo infusion (P < 0.001). No changes were induced by CRH or alpha MSH. In conclusion, alpha MSH antagonizes CRH inhibition of LH secretion. This finding lends support to the view that differential posttranslational processing of POMC contributes to the regulation of LH secretion. Further investigation is needed to clarify the mechanism of the antagonism between alpha MSH and CRH.
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Affiliation(s)
- P Limone
- Institute of Internal Medicine, University of Turin, Torino, Italy
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Bellone J, Ghigo E, Procopio M, Arvat E, Valente F, Boffano GM, Maccario M, Dentelli P, Camanni F. Comparison of the potentiating effect of pyridostigmine, arginine and propranolol on the GHRH-induced GH release in short children. Panminerva Med 1993; 35:1-4. [PMID: 8316397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The effect of pyridostigmine (60 mg orally), arginine (0.5 g/kg iv) and propranolol (PROP, 40 mg orally) on GHRH (1 microgram/kg iv)-induced GH release was studied in seven short children. Pyridostigmine and arginine induced a similar potentiating effect on GHRH-induced GH rise (Peak, mean +/- SEM: 56.9 +/- 12.8 and 48.6 +/- 8.5 micrograms/L, respectively vs 12.3 +/- 1.6 micrograms/L; p < 0.05). Combination of GHRH with propranolol induced an increase of GH that was significant only with regard to peak (28.9 +/- 8.4 micrograms/L) but not to AUC. However, GH rises observed after GHRH combined with PD or ARG did not significantly differ from that recorded after coadministration of GHRH and PROP both for peak and AUC. Our results confirm that pyridostigmine and arginine have a striking potentiating effect on the GHRH-induced GH rise in children and show that the tests with GHRH + PD and GH + H + ARG are ore reliable than that with GHRH + PROP to explore the secretory capacity of somatotroph cells.
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Affiliation(s)
- J Bellone
- Department of Clinical Pathophysiology, University of Turin, Italy
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