scholarly journals Characterization of transgenic mice with widespread overexpression of spermine synthase

2004 ◽  
Vol 381 (3) ◽  
pp. 701-707 ◽  
Author(s):  
Yoshihiko IKEGUCHI ◽  
Xiaojing WANG ◽  
Diane E. McCLOSKEY ◽  
Catherine S. COLEMAN ◽  
Paul NELSON ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Ornithine Decarboxylase ◽  
Strong Support ◽  
Normal Growth ◽  
Early Gene ◽  
Transgenic Expression ◽  
Adenosylmethionine Decarboxylase ◽  
Spermine Synthase ◽  
Gene Enhancer ◽  
Actin Promoter

A widespread increase in SpmS (spermine synthase) activity has been produced in transgenic mice using a construct in which the human SpmS cDNA was placed under the control of a composite CMV-IE (cytomegalovirus immediate early gene) enhancer–chicken β-actin promoter. Four separate founder CAG/SpmS mice were studied. Transgenic expression of SpmS was found in all of the tissues examined, but the relative SpmS activities varied widely according to the founder animal and the tissue studied. Very large increases in SpmS activity were seen in many tissues. SpdS (spermidine synthase) activity was not affected. Although there was a statistically significant decline in spermidine content and increase in spermine, the alterations were small compared with the increase in SpmS activity. These results provide strong support for the concept that the levels of the higher polyamines spermidine and spermine are not determined only by the relative activities of the two aminopropyltransferases. Other factors such as availability of the aminopropyl donor substrate decarboxylated S-adenosylmethionine and possibly degradation or excretion must also influence the spermidine/spermine ratio. No deleterious effects of SpmS overexpression were seen. The mice had normal growth, fertility and behaviour up to the age of 12 months. However, breeding the CAG/SpmS mice with MHC (α-myosin heavy chain)/AdoMetDC (S-adenosylmethionine decarboxylase) mice, which have a large increase in S-adenosylmethionine decarboxylase expression in heart, was lethal. In contrast, breeding the CAG/SpmS mice with MHC/ODC (L-ornithine decarboxylase) mice, which have a large increase in cardiac ornithine decarboxylase expression, had a protective effect in preventing the small decrease in viability of the MHC/ODC mice.

scholarly journals Response of enzymes involved in the metabolism of polyamines to phytohaemagglutinin-induced activation of human lymphocytes

1981 ◽  
Vol 196 (3) ◽  
pp. 733-738 ◽  
Author(s):  
H Korpela ◽  
E Hölttä ◽  
T Hovi ◽  
J Jänne
Keyword(s):  
Ornithine Decarboxylase ◽  
Human Lymphocytes ◽  
Lymphocyte Activation ◽  
Decarboxylase Activity ◽  
Spermidine Synthase ◽  
Irreversible Inhibitor ◽  
Adenosylmethionine Decarboxylase ◽  
Spermine Synthase ◽  
Diamine Oxidase Activity ◽  
Stimulation Of

The stimulation of lymphocyte ornithine decarboxylase and adenosylmethionine decarboxylase produced by phytohaemagglutinin was accompanied by an equally marked, but delayed, stimulation of spermidine synthase, which is not commonly considered as an inducible enzyme. In contrast with the marked stimulation of these biosynthetic enzymes, less marked changes were observed in the biodegradative enzymes of polyamines in response to phytohaemagglutinin. Diamine oxidase activity was undetectable during all stages of the transformation. The activity of polyamine oxidase remained either constant or was slightly decreased several days after addition of the mitogen. The activity of polyamine acetylase (employing all the natural polyamines as substrates) distinctly increased both in the cytosolic and crude nuclear preparations of the cells during later stages of mitogen activation. Difluoromethylornithine, an irreversible inhibitor of ornithine decarboxylase, although powerfully inhibiting ornithine decarboxylase, produced a gradual enhancement of adenosylmethionine decarboxylase activity during lymphocyte activation, without influencing the activities of the two propylamine transferases (spermidine synthase and spermine synthase).

scholarly journals Effects of inhibitors of spermidine and spermine synthesis on polyamine concentrations and growth of transformed mouse fibroblasts

1981 ◽  
Vol 194 (1) ◽  
pp. 79-89 ◽  
Author(s):  
Anthony E. Pegg ◽  
Ronald T. Borchardt ◽  
James K. Coward
Keyword(s):  
Cell Growth ◽  
Ornithine Decarboxylase ◽  
Inhibitory Action ◽  
Competitive Inhibitor ◽  
Irreversible Inhibitor ◽  
Mouse Fibroblasts ◽  
Adenosylmethionine Decarboxylase ◽  
Spermine Synthase ◽  
Inhibition Of Growth

1. A number of compounds known to inhibit polyamine biosynthesis at various steps in the biosynthetic pathway were tested for their ability to inhibit growth and decrease polyamine concentrations in virally transformed mouse fibroblasts (SV-3T3 cells). 2. Virtually complete inhibition of growth was produced by the inhibitors of ornithine decarboxylase α-methylornithine and α-difluoromethylornithine and by the inhibitors of S-adenosylmethionine decarboxylase 1,1′-[(methylethanediylidene)dinitrilo]diguanidine and 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine). The former inhibitors decreased putrescine and spermidine contents in the cells to very low values, whereas the latter substantially increased putrescine but decreased spermidine concentrations. The inhibitory effects of all of these inhibitors on cell growth could be prevented by the addition of spermidine, suggesting that spermidine depletion is the underlying cause of their inhibition of growth. 3. α-Difluoromethylornithine, which is an irreversible inhibitor of ornithine decarboxylase, was a more potent inhibitor of growth and polyamine production (depleting spermidine almost completely and spermine significantly) than α-methylornithine, which is a competitive inhibitor. This was not the case with the inhibitors of S-adenosylmethionine decarboxylase where 1,1′-[(methylethanediylidene)dinitrilo]diguanidine, a reversible inhibitor, was more active than 1,1′-[(methylethanediylidene)dinitrilo]bis-(3-aminoguanidine), an irreversible inhibitor. It is suggested that this effect may be due to the lesser uptake and/or greater chemical reactivity of the latter compound. 4. Various nucleoside derivatives of S-adenosylhomocysteine that inhibited spermidine synthase in vitro did not have significant inhibitory action against polyamine accumulation in the cell. These compounds, which included S-adenosylhomocysteine sulphone, decarboxylated S-adenosylhomocysteine sulphone, decarboxylated S-adenosylhomocysteine sulphoxide and S-adenosyl-4-thio-butyric acid sulphone did not inhibit cell growth or polyamine content until cytotoxic concentrations were added. 5. 5′-Methylthioadenosine, 5′-isobutylthioadenosine and 5′-methylthiotubercidin, which inhibit aminopropyltransferase activity in vitro, all inhibited cell growth and decreased spermidine content. Although these compounds were most active against spermine synthase in vitro, they acted in the cell primarily to decrease spermidine content. Cell growth could not be restored to normal values by addition of spermidine, suggesting that these nucleosides have another inhibitory action towards cellular proliferation. 6. 5′-Methylthioadenosine and 5′-isobutylthioadenosine are degraded by a phosphorylase present in SV3T3 cells, yielding 5-methylthioribose-1-phosphate and 5-isobutylthioribose-1-phosphate respectively, and adenine. This degradation appears to decrease the inhibitory action towards cell growth, suggesting that the nucleosides themselves are exerting the inhibitory action. 5′-Methylthiotubercidin, which is not a substrate for the phosphorylase and is a competitive inhibitor of it, was the most active of these nucleosides in inhibiting cell growth and spermidine content. 5′-Methylthiotubercidin and α-difluoromethylornithine had additive effects on retarding cell growth, but not on cellular spermine accumulation, also suggesting that the primary growth-inhibiting action of the nucleoside was not on polyamine production. 7. These results support the concept that 5′-methylthioadenosine phosphorylase plays an important role in permitting cell growth to continue by preventing the build-up of inhibitory intracellular concentrations of 5′-methylthioadenosine.

scholarly journals Transgenic mice overexpressing ornithine and S-adenosylmethionine decarboxylases maintain a physiological polyamine homoeostasis in their tissues

1997 ◽  
Vol 323 (2) ◽  
pp. 457-462 ◽  
Author(s):  
Ritva HELJASVAARA ◽  
Ildiko VERESS ◽  
Maria HALMEKYTÖ ◽  
Leena ALHONEN ◽  
Juhani JÄNNE ◽  
...  
Keyword(s):  
Transgenic Mice ◽  
Ornithine Decarboxylase ◽  
Metabolic Flux ◽  
Pulse Labelling ◽  
Spermidine Synthase ◽  
Tissue Concentrations ◽  
Adenosylmethionine Decarboxylase ◽  
Normal Limits ◽  
Primary Fibroblasts ◽  
Hybrid Mice

Recent work has shown that transgenic mice overexpressing human ornithine decarboxylase display no marked changes in the tissue concentrations of spermidine or spermine in spite of a dramatic increase in putrescine levels. In the tissues of transgenic mice carrying the human spermidine synthase gene and in those of hybrid mice overexpressing both ornithine decarboxylase and spermidine synthase, spermidine and spermine levels remain within normal limits. To test whether the amount of the propylamine group donor, decarboxylated S-adenosylmethionine, limits the conversion of putrescine into the higher polyamines, we have produced transgenic mouse lines harbouring the rat S-adenosylmethionine decarboxylase gene in their genome. However, neither these mice nor the hybrid mice overexpressing both ornithine decarboxylase and S-adenosylmethionine decarboxylase displayed significant changes in their spermidine and spermine tissue levels. To study the mechanism by which cells maintain the constancy of the polyamine concentrations, we have determined the metabolic flux of polyamines in transgenic primary fibroblasts using pulse labelling. The results indicate that the polyamine flow is faster in transgenic primary fibroblasts than in non-transgenic fibroblasts and that the intracellular homoeostasis of higher polyamines is maintained at least partly by the acetylation of spermidine and spermine and their secretion into the medium.

scholarly journals Role of propylamine transferases in hormone-induced stimulation of polyamine biosynthesis

1980 ◽  
Vol 192 (1) ◽  
pp. 59-63 ◽  
Author(s):  
Kirsti Käpyaho ◽  
Hannu Pösö ◽  
Juhani Jänne
Keyword(s):  
Seminal Vesicle ◽  
Ornithine Decarboxylase ◽  
Ovarian Tissue ◽  
Ventral Prostate ◽  
Decarboxylase Activity ◽  
Spermidine Synthase ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Spermine Synthase ◽  
Stimulation Of

The effect of various hormones on the activities of the four enzymes engaged with the biosynthesis of the polyamines has been investigated in the rat. Human choriogonadotropin induced a dramatic, yet transient, stimulation of l-ornithine decarboxylase (EC 4.1.1.17) activity in rat ovary, with no or only marginal changes in the activities of S-adenosyl-l-methionine decarboxylase (EC 4.1.1.50), spermidine synthase (aminopropyltransferase; EC 2.5.1.16) or spermine synthase. A single injection of oestradiol into immature rats maximally induced uterine ornithine decarboxylase at 4h after the injection. This early stimulation of ornithine decarboxylase activity was accompanied by a distinct enhancement of adenosylmethionine decarboxylase activity and a decrease in the activities of spermidine synthase and spermine synthase. In the seminal vesicle of castrated rats, testosterone treatment elicited a striking and persistent stimulation of ornithine decarboxylase and adenosylmethionine decarboxylase activities. The activity of spermidine synthase likewise rapidly increased between the first and the second day after the commencement of the hormone treatment, whereas the activity of spermine synthase remained virtually unchanged during the whole period of observation. Testosterone-induced changes in polyamine formation in the ventral prostate were comparable with those found in the seminal vesicle, with the possible exception of a more pronounced stimulation of spermidine synthase activity. It thus appears that an enhancement in one or both of the propylamine transferase (aminopropyltransferase) activities in response to hormone administration is an indicator of hormone-dependent growth (uterus and the male accessory sexual glands), and is not necessarily associated with non-proliferative hormonal responses, such as gonadotropin-induced luteinization of the ovarian tissue.

scholarly journals Transgenic mice over-producing putrescine in their tissues do not convert the diamine into higher polyamines

1993 ◽  
Vol 291 (2) ◽  
pp. 505-508 ◽  
Author(s):  
M Halmekytö ◽  
L Alhonen ◽  
L Alakuijala ◽  
J Jänne
Keyword(s):  
Transgenic Mice ◽  
Transgenic Mouse ◽  
Ornithine Decarboxylase ◽  
Specific Inhibitor ◽  
Mouse Line ◽  
Transgenic Mouse Line ◽  
Adenosylmethionine Decarboxylase ◽  
Adult Tissues ◽  
Ornithine Transaminase

We recently described a transgenic mouse line over-expressing the human ornithine decarboxylase gene virtually in all tissues. Despite strikingly elevated tissue putrescine concentrations, no or minimal changes were found in the levels of the higher polyamines spermidine and spermine. We have now extended these studies by further increasing tissue putrescine with the aid of 5-fluoromethylornithine, a specific inhibitor of ornithine transaminase and hence the catabolism of L-ornithine. As a result of the treatment with the latter drug, the concentration of putrescine was further increased by a factor of 2-3 without any changes in the concentrations of spermidine and spermine. In the testis of transgenic mice treated with 5-fluoromethylornithine, the concentration of putrescine was nearly 60 times that in non-transgenic untreated animals, yet the concentration of spermidine was only 1.5-fold higher. A similar small increase in brain spermidine was accompanied by a 40-fold elevation in the concentration of putrescine. The apparent blockade between putrescine and spermidine was in all likelihood not attributable to an inhibition of S-adenosylmethionine decarboxylase, the rate-controlling enzyme in the biosynthesis of spermidine and spermine. Our results are more compatible with the view that in non-dividing adult tissues putrescine is sequestered through some unknown mechanisms in a way that makes it unavailable for the synthesis of the higher polyamines.

scholarly journals Overproduction of cardiac S-adenosylmethionine decarboxylase in transgenic mice

2005 ◽  
Vol 393 (1) ◽  
pp. 295-302 ◽  
Author(s):  
Oleg Nisenberg ◽  
Anthony E. Pegg ◽  
Patricia A. Welsh ◽  
Kerry Keefer ◽  
Lisa M. Shantz
Keyword(s):  
Transgenic Mice ◽  
Ornithine Decarboxylase ◽  
Fold Increase ◽  
Adrenergic Stimulation ◽  
Compensatory Mechanisms ◽  
Specific Expression ◽  
Adenosylmethionine Decarboxylase ◽  
Cardiac Phenotype ◽  
Founder Line ◽  
Do So

The present study was designed to provide a better understanding of the role played by AdoMetDC (S-adenosylmethionine decarboxylase), the key rate-controlling enzyme in the synthesis of spermidine and spermine, in controlling polyamine levels and the importance of polyamines in cardiac physiology. The αMHC (α-myosin heavy chain) promoter was used to generate transgenic mice with cardiac-specific expression of AdoMetDC. A founder line (αMHC/AdoMetDC) was established with a >100-fold increase in AdoMetDC activity in the heart. Transgene expression was maximal by 1 week of age and remained constant into adulthood. However, the changes in polyamine levels were most pronounced during the first week of age, with a 2-fold decrease in putrescine and spermidine and a 2-fold increase in spermine. At later times, spermine returned to near control levels, whereas putrescine and spermidine levels remained lower, suggesting that compensatory mechanisms exist to limit spermine accumulation. The αMHC/AdoMetDC mice did not display an overt cardiac phenotype, but there was an increased cardiac hypertrophy after β-adrenergic stimulation with isoprenaline (‘isoproterenol’), as well as a small increase in spermine content. Crosses of the αMHC/AdoMetDC with αMHC/ornithine decarboxylase mice that have a >1000-fold increase in cardiac ornithine decarboxylase were lethal in utero, presumably due to increase in spermine to toxic levels. These findings suggest that cardiac spermine levels are highly regulated to avoid polyamine-induced toxicity and that homoeostatic mechanisms can maintain non-toxic levels even when one enzyme of the biosynthetic pathway is greatly elevated but are unable to do so when two biosynthetic enzymes are increased.

scholarly journals p90 ribosomal S6 kinase 3 contributes to cardiac insufficiency in α-tropomyosin Glu180Gly transgenic mice

2013 ◽  
Vol 305 (7) ◽  
pp. H1010-H1019 ◽  
Author(s):  
Catherine L. Passariello ◽  
Marjorie Gayanilo ◽  
Michael D. Kritzer ◽  
Hrishikesh Thakur ◽  
Zoharit Cozacov ◽  
...  
Keyword(s):  
Heart Failure ◽  
Transgenic Mice ◽  
Cardiac Function ◽  
Interstitial Fibrosis ◽  
Cardiac Insufficiency ◽  
S6 Kinase ◽  
Transgenic Expression ◽  
P90 Ribosomal S6 Kinase ◽  
Ribosomal S6 Kinase

Myocardial interstitial fibrosis is an important contributor to the development of heart failure. Type 3 p90 ribosomal S6 kinase (RSK3) was recently shown to be required for concentric myocyte hypertrophy under in vivo pathological conditions. However, the role of RSK family members in myocardial fibrosis remains uninvestigated. Transgenic expression of α-tropomyosin containing a Glu180Gly mutation (TM180) in mice of a mixed C57BL/6:FVB/N background induces a cardiomyopathy characterized by a small left ventricle, interstitial fibrosis, and diminished systolic and diastolic function. Using this mouse model, we now show that RSK3 is required for the induction of interstitial fibrosis in vivo. TM180 transgenic mice were crossed to RSK3 constitutive knockout ( RSK3−/−) mice. Although RSK3 knockout did not affect myocyte growth, the decreased cardiac function and mild pulmonary edema associated with the TM180 transgene were attenuated by RSK3 knockout. The improved cardiac function was consistent with reduced interstitial fibrosis in the TM180; RSK3−/− mice as shown by histology and gene expression analysis, including the decreased expression of collagens. The specific inhibition of RSK3 should be considered as a potential novel therapeutic strategy for improving cardiac function and the prevention of sudden cardiac death in diseases in which interstitial fibrosis contributes to the development of heart failure.

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