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Bengt-olof Nilsson - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of Polyamine Uptake Potentiates the Anti-Proliferative Effect of Polyamine Synthesis Inhibition and Preserves the Contractile Phenotype of Vascular Smooth Muscle Cells.
Journal of cellular physiology, 2015Co-Authors: Mario Grossi, Karl Swärd, Per Hellstrand, Otto Phanstiel, Catarina Rippe, Azra Alajbegovic, Sebastian Albinsson, Amalia Forte, Lo Persson, Bengt-olof NilssonAbstract:Increased vascular smooth muscle cell (VSMC) proliferation is a factor in atherosclerosis and injury-induced arterial (re) stenosis. Inhibition of Polyamine Synthesis by α-difluoro-methylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, attenuates VSMC proliferation with high sensitivity and specificity. However, cells can escape Polyamine Synthesis blockade by importing Polyamines from the environment. To address this issue, Polyamine transport inhibitors (PTIs) have been developed. We investigated the effects of the novel trimer44NMe (PTI-1) alone and in combination with DFMO on VSMC Polyamine uptake, proliferation and phenotype regulation. PTI-1 efficiently inhibited Polyamine uptake in primary mouse aortic and human coronary VSMCs in the absence as well as in the presence of DFMO. Interestingly, culture with DFMO for 2 days substantially (>95%) reduced putrescine (Put) and spermidine (Spd) contents without any effect on proliferation. Culture with PTI-1 alone had no effect on either Polyamine levels or proliferation rate, but the combination of both treatments reduced Put and Spd levels below the detection limit and inhibited proliferation. Treatment with DFMO for a longer time period (4 days) reduced Put and Spd below their detection limits and reduced proliferation, showing that only a small pool of Polyamines is needed to sustain VSMC proliferation. Inhibited proliferation by Polyamine depletion was associated with maintained expression of contractile smooth marker genes. In cultured intact mouse aorta, PTI-1 potentiated the DFMO-induced inhibition of cell proliferation. The combination of endogenous Polyamine Synthesis inhibition with uptake blockade is thus a viable approach for targeting unwanted vascular cell proliferation in vivo, including vascular restenosis.
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Polyamine Synthesis inhibition induces S phase cell cycle arrest in vascular smooth muscle cells.
Amino acids, 2008Co-Authors: Malin Odenlund, Bo Holmqvist, Bo Baldetorp, Per Hellstrand, Bengt-olof NilssonAbstract:Polyamines are important for cell growth and proliferation and they are formed from arginine and ornithine via arginase and ornithine decarboxylase (ODC). Arginine may alternatively be metabolised to NO via NO synthase. Here we study if vascular smooth muscle cell proliferation can be reversed by Polyamine Synthesis inhibitors and investigate their mechanism of action. Cell proliferation was assessed in cultured vascular smooth muscle A7r5 cells and in endothelium-denuded rat arterial rings by measuring [3H]-thymidine incorporation and by cell counting. Cell cycle phase distribution was determined by flow cytometry and Polyamines by HPLC. Protein expression was determined by Western blotting. The ODC inhibitor DFMO (1–10 mM) reduced Polyamine concentration and attenuated proliferation in A7r5 cells and rat tail artery. DFMO accumulated cells in S phase of the cell cycle and reduced cyclin A expression. DFMO had no effect on cell viability and apoptosis as assessed by fluorescence microscopy. Polyamine concentration and cellular proliferation were not affected by the arginase inhibitor NOHA (100–200 μM) and the NO synthase inhibitor l-NAME (100 μM). Lack of effect of NOHA was reflected by absence of arginase expression. Polyamine Synthesis inhibition attenuates vascular smooth muscle cell proliferation by reducing DNA Synthesis and accumulation of cells in S phase, and may be a useful approach to prevent vascular smooth muscle cell proliferation in cardiovascular diseases.
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Effects of Polyamine Synthesis inhibition on Polyamines, growth and mechanical properties in hypertrophic rat urinary bladder
Pharmacology & toxicology, 1998Co-Authors: Bengt-olof Nilsson, Anders Lindqvist, Raj Kumar Pandita, Karl Swärd, Katarina PerssonAbstract:The Polyamines putrescine, spermidine and spermine, are ubiquitous intracellular metabolites associated with growth and protein Synthesis. In this study effects of Polyamine Synthesis inhibition on bladder growth, Polyamine levels and mechanical properties were investigated in rat urinary bladder subjected to partial outflow obstruction that causes bladder hypertrophy. The S-adenosyl methionine decarboxylase inhibitor CGP-48664 (5 and 20 mg kg-1) was administered alone or in combination with the ornithine decarboxylase inhibitor DFMO (500 mg kg-1), starting one day before creation of partial outflow obstruction and then daily for 7 days. The bladder muscle level of putrescine was increased 38 times and that of spermine reduced by 4 times while spermidine was unchanged after treatment with CGP-48664 (20 mg kg-1). The increase in putrescine was abolished in animals receiving CGP-48664 in combination with DFMO. Treatment with Polyamine Synthesis inhibitors could not prevent or reduce the hypertrophy of the bladder as judged by bladder wet weight and protein contents. The effects on Polyamine quantities were not associated with changes in Ca(2+)-force relationship or in agonist and electrically stimulated force. In summary, treatment of rats with Polyamine Synthesis inhibitors resulted in changes in Polyamine levels in the growing urinary bladder but did not affect growth or mechanical properties.
Per Hellstrand - One of the best experts on this subject based on the ideXlab platform.
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Inhibition of Polyamine Uptake Potentiates the Anti-Proliferative Effect of Polyamine Synthesis Inhibition and Preserves the Contractile Phenotype of Vascular Smooth Muscle Cells.
Journal of cellular physiology, 2015Co-Authors: Mario Grossi, Karl Swärd, Per Hellstrand, Otto Phanstiel, Catarina Rippe, Azra Alajbegovic, Sebastian Albinsson, Amalia Forte, Lo Persson, Bengt-olof NilssonAbstract:Increased vascular smooth muscle cell (VSMC) proliferation is a factor in atherosclerosis and injury-induced arterial (re) stenosis. Inhibition of Polyamine Synthesis by α-difluoro-methylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, attenuates VSMC proliferation with high sensitivity and specificity. However, cells can escape Polyamine Synthesis blockade by importing Polyamines from the environment. To address this issue, Polyamine transport inhibitors (PTIs) have been developed. We investigated the effects of the novel trimer44NMe (PTI-1) alone and in combination with DFMO on VSMC Polyamine uptake, proliferation and phenotype regulation. PTI-1 efficiently inhibited Polyamine uptake in primary mouse aortic and human coronary VSMCs in the absence as well as in the presence of DFMO. Interestingly, culture with DFMO for 2 days substantially (>95%) reduced putrescine (Put) and spermidine (Spd) contents without any effect on proliferation. Culture with PTI-1 alone had no effect on either Polyamine levels or proliferation rate, but the combination of both treatments reduced Put and Spd levels below the detection limit and inhibited proliferation. Treatment with DFMO for a longer time period (4 days) reduced Put and Spd below their detection limits and reduced proliferation, showing that only a small pool of Polyamines is needed to sustain VSMC proliferation. Inhibited proliferation by Polyamine depletion was associated with maintained expression of contractile smooth marker genes. In cultured intact mouse aorta, PTI-1 potentiated the DFMO-induced inhibition of cell proliferation. The combination of endogenous Polyamine Synthesis inhibition with uptake blockade is thus a viable approach for targeting unwanted vascular cell proliferation in vivo, including vascular restenosis.
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Polyamine Synthesis inhibition induces S phase cell cycle arrest in vascular smooth muscle cells.
Amino acids, 2008Co-Authors: Malin Odenlund, Bo Holmqvist, Bo Baldetorp, Per Hellstrand, Bengt-olof NilssonAbstract:Polyamines are important for cell growth and proliferation and they are formed from arginine and ornithine via arginase and ornithine decarboxylase (ODC). Arginine may alternatively be metabolised to NO via NO synthase. Here we study if vascular smooth muscle cell proliferation can be reversed by Polyamine Synthesis inhibitors and investigate their mechanism of action. Cell proliferation was assessed in cultured vascular smooth muscle A7r5 cells and in endothelium-denuded rat arterial rings by measuring [3H]-thymidine incorporation and by cell counting. Cell cycle phase distribution was determined by flow cytometry and Polyamines by HPLC. Protein expression was determined by Western blotting. The ODC inhibitor DFMO (1–10 mM) reduced Polyamine concentration and attenuated proliferation in A7r5 cells and rat tail artery. DFMO accumulated cells in S phase of the cell cycle and reduced cyclin A expression. DFMO had no effect on cell viability and apoptosis as assessed by fluorescence microscopy. Polyamine concentration and cellular proliferation were not affected by the arginase inhibitor NOHA (100–200 μM) and the NO synthase inhibitor l-NAME (100 μM). Lack of effect of NOHA was reflected by absence of arginase expression. Polyamine Synthesis inhibition attenuates vascular smooth muscle cell proliferation by reducing DNA Synthesis and accumulation of cells in S phase, and may be a useful approach to prevent vascular smooth muscle cell proliferation in cardiovascular diseases.
C. Axel Innis - One of the best experts on this subject based on the ideXlab platform.
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Ornithine capture by a translating ribosome controls bacterial Polyamine Synthesis
Nature Microbiology, 2020Co-Authors: Alba Herrero Del Valle, Britta Seip, Iñaki Cervera-marzal, Guénaël Sacheau, A. Carolin Seefeldt, C. Axel InnisAbstract:A combination of cellular, molecular and structural biology approaches explains how the translating ribosome and the nascent peptide SpeFL interact to form a binding pocket that serves as an ornithine sensor to regulate Polyamine bioSynthesis in pathogenic bacteria. Polyamines are essential metabolites that play an important role in cell growth, stress adaptation and microbial virulence^ 1 – 3 . To survive and multiply within a human host, pathogenic bacteria adjust the expression and activity of Polyamine biosynthetic enzymes in response to different environmental stresses and metabolic cues^ 2 . Here, we show that ornithine capture by the ribosome and the nascent peptide SpeFL controls Polyamine Synthesis in γ-proteobacteria by inducing the expression of the ornithine decarboxylase SpeF^ 4 , via a mechanism involving ribosome stalling and transcription antitermination. In addition, we present the cryogenic electron microscopy structure of an Escherichia coli ribosome stalled during translation of speFL in the presence of ornithine. The structure shows how the ribosome and the SpeFL sensor domain form a highly selective binding pocket that accommodates a single ornithine molecule but excludes near-cognate ligands. Ornithine pre-associates with the ribosome and is then held in place by the sensor domain, leading to the compaction of the SpeFL effector domain and blocking the action of release factor 1. Thus, our study not only reveals basic strategies by which nascent peptides assist the ribosome in detecting a specific metabolite, but also provides a framework for assessing how ornithine promotes virulence in several human pathogens.
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Ornithine capture by a translating ribosome controls bacterial Polyamine Synthesis
2019Co-Authors: Alba Herrero Del Valle, Britta Seip, Iñaki Cervera-marzal, Guénaël Sacheau, A. Carolin Seefeldt, C. Axel InnisAbstract:Polyamines are essential metabolites that play an important role in cell growth, stress adaptation, and microbial virulence. In order to survive and multiply within a human host, pathogenic bacteria adjust the expression and activity of Polyamine biosynthetic enzymes in response to different environmental stresses and metabolic cues. Here, we show that ornithine capture by the ribosome and the nascent peptide SpeFL controls Polyamine Synthesis in γ-proteobacteria by inducing the expression of the ornithine decarboxylase SpeF, via a mechanism involving ribosome stalling and transcription antitermination. In addition, we present the cryo-EM structure of an Escherichia coli (E. coli) ribosome stalled during translation of speFL in the presence of ornithine. The structure shows how the ribosome and the SpeFL sensor domain form a highly selective binding pocket that accommodates a single ornithine molecule but excludes near-cognate ligands. Ornithine pre-associates with the ribosome and is then held in place by the sensor domain, leading to the compaction of the SpeFL effector domain and blocking the action of release factor RF1. Thus, our study not only reveals basic strategies by which nascent peptides assist the ribosome in detecting a specific metabolite, but also provides a framework for assessing how ornithine promotes virulence in several human pathogens.
Malin Odenlund - One of the best experts on this subject based on the ideXlab platform.
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Polyamine Synthesis inhibition induces S phase cell cycle arrest in vascular smooth muscle cells.
Amino acids, 2008Co-Authors: Malin Odenlund, Bo Holmqvist, Bo Baldetorp, Per Hellstrand, Bengt-olof NilssonAbstract:Polyamines are important for cell growth and proliferation and they are formed from arginine and ornithine via arginase and ornithine decarboxylase (ODC). Arginine may alternatively be metabolised to NO via NO synthase. Here we study if vascular smooth muscle cell proliferation can be reversed by Polyamine Synthesis inhibitors and investigate their mechanism of action. Cell proliferation was assessed in cultured vascular smooth muscle A7r5 cells and in endothelium-denuded rat arterial rings by measuring [3H]-thymidine incorporation and by cell counting. Cell cycle phase distribution was determined by flow cytometry and Polyamines by HPLC. Protein expression was determined by Western blotting. The ODC inhibitor DFMO (1–10 mM) reduced Polyamine concentration and attenuated proliferation in A7r5 cells and rat tail artery. DFMO accumulated cells in S phase of the cell cycle and reduced cyclin A expression. DFMO had no effect on cell viability and apoptosis as assessed by fluorescence microscopy. Polyamine concentration and cellular proliferation were not affected by the arginase inhibitor NOHA (100–200 μM) and the NO synthase inhibitor l-NAME (100 μM). Lack of effect of NOHA was reflected by absence of arginase expression. Polyamine Synthesis inhibition attenuates vascular smooth muscle cell proliferation by reducing DNA Synthesis and accumulation of cells in S phase, and may be a useful approach to prevent vascular smooth muscle cell proliferation in cardiovascular diseases.
Alba Herrero Del Valle - One of the best experts on this subject based on the ideXlab platform.
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Ornithine capture by a translating ribosome controls bacterial Polyamine Synthesis
Nature Microbiology, 2020Co-Authors: Alba Herrero Del Valle, Britta Seip, Iñaki Cervera-marzal, Guénaël Sacheau, A. Carolin Seefeldt, C. Axel InnisAbstract:A combination of cellular, molecular and structural biology approaches explains how the translating ribosome and the nascent peptide SpeFL interact to form a binding pocket that serves as an ornithine sensor to regulate Polyamine bioSynthesis in pathogenic bacteria. Polyamines are essential metabolites that play an important role in cell growth, stress adaptation and microbial virulence^ 1 – 3 . To survive and multiply within a human host, pathogenic bacteria adjust the expression and activity of Polyamine biosynthetic enzymes in response to different environmental stresses and metabolic cues^ 2 . Here, we show that ornithine capture by the ribosome and the nascent peptide SpeFL controls Polyamine Synthesis in γ-proteobacteria by inducing the expression of the ornithine decarboxylase SpeF^ 4 , via a mechanism involving ribosome stalling and transcription antitermination. In addition, we present the cryogenic electron microscopy structure of an Escherichia coli ribosome stalled during translation of speFL in the presence of ornithine. The structure shows how the ribosome and the SpeFL sensor domain form a highly selective binding pocket that accommodates a single ornithine molecule but excludes near-cognate ligands. Ornithine pre-associates with the ribosome and is then held in place by the sensor domain, leading to the compaction of the SpeFL effector domain and blocking the action of release factor 1. Thus, our study not only reveals basic strategies by which nascent peptides assist the ribosome in detecting a specific metabolite, but also provides a framework for assessing how ornithine promotes virulence in several human pathogens.