Increase In Spermine Content Research Articles

Biostimulant properties of cyanobacterial hydrolysate related to polyamines

Developing new and natural sources of plant growth promotors is essential to ensure the safe and sustainable production of vegetables for human consumption. In recent years, the potential of microalgae as plant biostimulants has been investigated. Arthrospira platensis (Spirulina platensis) biomass is a recognized protein source and its enzymatic hydrolysis contains molecules such as polyamines with potential to promote plant growth. Therefore, the aim of the present study was to investigate the biostimulant properties of hydrolyzed biomass of A. platensis. Bioassays were performed to determine auxin-like and cytokinin-like bioactivity of the hydrolysates. In addition, its effect on lettuce seedling growth was investigated and an organic system field trail performed where yield and free polyamine levels in leaves quantified. The hydrolysates had a cytokinin-like effect in the bioassay. Foliar applications promoted the growth of lettuce seedlings with the 4-h reaction hydrolysate (Sph4) being the most effective at promoting growth and increasing the spermine content by 64% in the lettuce leaves. The polyamine concentration was also compared in non-hydrolyzed A. platensis and Sph4. Hydrolysis resulted in a 34% increase in spermine content. It was concluded that Sph4 is a natural plant growth promoter that can be used as a raw material for biostimulants, and spermine could be an active compound and a metabolic indicator of Sph4 bioactivity.

Overproduction of cardiac S-adenosylmethionine decarboxylase in transgenic mice

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 alphaMHC (alpha-myosin heavy chain) promoter was used to generate transgenic mice with cardiac-specific expression of AdoMetDC. A founder line (alphaMHC/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 alphaMHC/AdoMetDC mice did not display an overt cardiac phenotype, but there was an increased cardiac hypertrophy after beta-adrenergic stimulation with isoprenaline ('isoproterenol'), as well as a small increase in spermine content. Crosses of the alphaMHC/AdoMetDC with alphaMHC/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.

Ability of bisbenzylputrescine and propanediamine analogs to modulate the intracellular polyamine pool of P388D1 cells.

The effects of a series of bisbenzyldiamine analogs have been tested on P388D1 cell line in vitro. Their effects on cell growth, polyamine oxidase (PAO) activity and intracellular polyamine content were determined. The cytotoxicity tests were performed in culture medium supplemented with 100 micromol/L aminoguanidine (I), 100 micromol/L aminoguanidine and 100 micromol/L N,N'-bis(2,3-butadienyl)-1,4-butanediamine (MDL 72,527) (II), and finally 100 micromol/L aminoguanidine and 200 micromol/L D,L-difluoromethylornithine (DFMO) (III). The IC50 values under conditions I and III were similar, suggesting that inhibition of ornithine decarboxylase by DFMO did not affect the biological effect of our derivatives. Spermine and spermidine remained nontoxic in conditions I and III. However in the condition II, the toxicity of all tested compounds (excepted spermidine) was increased, suggesting that the inhibition of cellular PAO increased their toxicity. The enzymatic test of PAO showed that at high doses inhibition of this enzyme by putrescine analogs occurred, while the N-methylated propanediamine derivative increased the enzyme activity; however, these results do not correlate with cytotoxicity tests. When these derivatives were incubated for 48 h with the cells, all of them increased the cell content in putrescine (approximately 160%) and spermine (approximately 145%) and decreased the spermidine content (approximately 75%) without any modification of the total amount of polyamine. The correlation between the cytotoxic results and the intracellular polyamine determination shows that the increase in spermine content along with the inhibition of retroconverting PAO enzyme increases the toxic effect of tested compounds (including spermine), suggesting that spermine toxicity is more important in the absence of intracellular oxidation processes.

Increase in spermine content coordinated with siderophore production in Paracoccus denitrificans

Spermine is present in relatively low amounts in Paracoccus denitrificans cultured aerobically in an ammonium succinate minimal salts medium supplemented with 50 microM iron(III). However, in iron-deprived cultures [minimal salts medium containing 0.5 microM iron(III)], spermine content increases by an order of magnitude in coordination with the well-known responses to iron derivation, e.g., derepression of siderophore synthesis and siderophore excretion. When iron-deprived cultures exhibiting both high spermine content and strong siderophore production are reseeded into fresh minimal salts medium containing 50 microM iron[III], both siderophore production and spermine content fall rapidly. Five hours after iron supplementation, spermine is below limits of detection. These results suggest a specific role for spermine in the response of P. denitrificans to low-iron stress.

Polyamines and Ornithine Decarboxylase Activity during Growth and Differentiation in Sclerotium rolfsii

Changes in polyamine content and in the activity of ornithine decarboxylase (ODC) were followed during growth and differentiation of the plant pathogenic fungus Sclerotium rolfsii, in submerged mycelium liquid cultures and on solid agar cultures. Mycelial growth in submerged cultures was characterized by high putrescine content and ODC activity. Growth cessation, resulting from glucose exhaustion in the medium, was accompanied by a sharp decrease in putrescine content and ODC activity. Spermine, the level of which was initially low, was detected in high amounts after all of the glucose was consumed and when the fungus developed the potential for sclerotium formation. A decrease in spermidine, and especially putrescine content, and an increase in spermine content, were observed during the transition from mycelium to mature sclerotia on solid agar medium. Addition of spermine to solid agar medium increased the number of sclerotia by 40%. The changes in the content of the three polyamines were reversed when sclerotia were allowed to germinate. Moreover, α-difluoromethylornithine, the enzyme-activated inhibitor of ODC, greatly inhibited mycelium growth, sclerotium germination and ODC activity, and this inhibition was completely reversed by the addition of putrescine. Cycloheximide delayed sclerotium germination and initially inhibited ODC activity, but ODC inhibition was relieved as soon as sclerotia began to germinate. The data indicate that specific changes in polyamines are linked with two distinct developmental events in S. rolfsii. Mycelial growth and sclerotium germination are positively correlated, and possibly causally linked, with a marked increase in putrescine content and biosynthesis (while spermine cannot be detected). Differentiation (sclerotium formation), however, is accompanied by a major increase in spermine content.

Effect of methotrexate on the intestinal mucosa of PGE 2-treated rats

In the present study, we aimed to protect the intestinal mucosa from small bowel damage in methotrexate (MTX)- treated rats. The protective effect of prostaglandin E2 (PGE2) was investigated. Ileal integrity was evaluated making use of different biochemical parameters : content of sucrase and maltase activities, contents of DNA, proteins, AMPc, PGE2, putrescine (Put), spermine (Spm) and spermidine (Spd). Rats were orally administered 0.5 ml of NaCl solution (0.9%) containing or not containing 400 μg.ml −1 of PGE2 twice daily, during three or ten days. Half an hour after the 18th ingestion of PGE2, 0.5 ml of NaCl solution (0.9%) containing MTX (16 mg.ml −1) was injected intravenously. Rats were killed exactly 48 hours after this injection. MTX had no effect on the Put content, increased the AMPc content and decreased the contents of DNA, proteins, Spm, Spd, PGE2 and sucrase or maltase activity. PGE2 had no effect on the biochemical parameters we studied, except on the contents of DNA (10-day treatment) and of PGE2 (3-and 10-day treatment). When MTX was injected after PGE2 treatment, as compared with what was observed when MTX was used as reported above, we observed — an increase in spermine content after 3-day PGE2 treatment and-an increase in the contents of DNA, Spm, Spd and disaccharidase activity after 10-day PGE2 treatment. No other significant variation in the other biochemical parameters was recorded, whatever the duration of the PGE2 treatment. These results indicate that PGE2 could partially protect the intestinal mucosa against the biochemical effects of MTX. Other experimental conditions may need to be chosen in order to obtain a better cytoprotective effect of PGE.

Polyamine metabolism during the perinatal development of the rabbit right and left ventricle.

The right ventricular (RV) and left ventricular (LV) free wall weights, ornithine decarboxylase (ODC) specific activity and polyamine content were determined in fetal, 1-, 2-, 7-, 14-, and 21-day-old rabbit hearts. There was a significant increase in the LV free wall weight and a decrease in RV free wall weight between 1-7 days. By day 7 the LV/RV mass ratio doubled and reached a ratio comparable to that seen in adult rabbit hearts. The rate of change in the LV and RV free wall weights were comparable after day 7. There was a significant increase in LV ODC specific activity and a decrease in RV ODC specific activity after birth. The LV ODC specific activity was significantly greater than RV ODC specific activity in both 1 and 2 day old rabbit hearts whereas they were not significantly different in 7 and 14 day old rabbit hearts. The molar content (nmoles/mg wet weight or nmoles/mg protein) of putrescine decreased approximately 3-fold after birth in the RV but increased approximately 2-fold in the LV. The molar content of spermidine and spermine was transiently increased after birth (1 day old) in both RV and LV with approximately a 2-fold increase in spermidine and a 2.5-fold (LV) and 4-fold (RV) increase in spermine content. The increase in LV putrescine content after birth was due, at least in part, to the observed increase in ODC specific activity in the LV free wall. The putrescine/spermidine ratio increased in the LV and decreased in the RV immediately after birth up to day 7. As opposed to the short-lived increase in spermidine and spermine observed in both the RV and the LV free wall, increased ODC specific activity and putrescine accumulation uniquely characterized the preferential growth of the LV between day 1 and 7.