Spermidine is not an independent factor regulating limb muscle mass in mice following androgen deprivation

Maintaining a critical amount of skeletal muscle mass is linked to reduced morbidity and mortality. In males, testicular androgens regulate muscle mass with a loss of androgens being critical as it is associated with muscle atrophy. Atrophy of the limb muscles is particularly important, but the pathways by which androgens regulate limb muscle mass remain equivocal. We used microarray analysis to identify changes to genes involved with polyamine metabolism in the tibialis anterior (TA) muscle of castrated mice. Of the polyamines, the concentration of spermidine (SPD) was significantly reduced in the TA of castrated mice. To assess whether SPD was an independent factor by which androgens regulate limb muscle mass, we treated castrated mice with SPD for 8 weeks and compared them with sham operated mice. Though this treatment paradigm effectively restored SPD concentrations in the TA muscles of castrated mice, mass of the limb muscles (i.e., TA, gastrocnemius, plantaris, and soleus) were not increased to the levels observed in sham animals. Consistent with those findings, muscle force production was also not increased by SPD treatment. Overall, these data demonstrate for the first time that SPD is not an independent factor by which androgens regulate limb skeletal muscle mass. Novelty: Polyamines regulate growth in various cells/tissues. Spermidine concentrations are reduced in the limb skeletal muscle following androgen depletion. Restoring spermidine concentrations in the limb skeletal muscle does not increase limb muscle mass or force production.

Serum Spermidine as a Novel Potential Predictor for Fragility Fractures

CONTEXT

Metabolomics is an emerging tool that provides insights into the dynamics of phenotypic changes. It is a potential method for the discovery of novel serum markers of fracture.

OBJECTIVE

To identify metabolite parameters that can be used as a proxy for osteoporotic fracture risk.

DESIGN

Prospective study based on the Ansung cohort in Korea.

SETTING

The general community.

PARTICIPANTS

A total of 1504 participants with metabolomic analyses.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Fragility fractures.

RESULTS

We measured 135 baseline metabolite profiles in fasting serum of the participants. The participants had a mean age of 60.2 years and were comprised of 585 (38.9%) men. During a mean 9-year follow-up, 112 osteoporotic fracture events occurred. Of all metabolites measured, only serum spermidine concentrations were positively associated with the risk of fracture (hazard ratio [HR] per 1 μM of spermidine 1.35, 95% confidence interval [CI] = 1.03-1.65, P = 0.020) after adjusting for age, sex, body mass index, diabetes, hypertension, smoking status, previous fracture history, and baseline tibial quantitative ultrasound. Participants with spermidine concentrations >1.57 μM had a 2.2-fold higher risk of fractures (95% CI 1.08-4.51, P = 0.030) compared with those with concentrations ≤1.57 μM after adjustment. In a subgroup analysis, women with baseline spermidine concentrations >1.57 μM also had a 2.4-fold higher risk of fracture than those with concentrations ≤1.57 μM (95% CI 1.02-5.48, P = 0.047).

CONCLUSIONS

Increased baseline spermidine concentrations were associated with a risk of osteoporotic fracture during a mean 9-year follow-up. The biological significance of the metabolites in the musculoskeletal system could be a subject for future studies.

Autophagy in T cells from aged donors is maintained by spermidine and correlates with function and vaccine responses

Vaccines are powerful tools to develop immune memory to infectious diseases and prevent excess mortality. In older adults, however vaccines are generally less efficacious and the molecular mechanisms that underpin this remain largely unknown. Autophagy, a process known to prevent aging, is critical for the maintenance of immune memory in mice. Here, we show that autophagy is specifically induced in vaccine-induced antigen-specific CD8+ T cells in healthy human volunteers. In addition, reduced IFNγ secretion by RSV-induced T cells in older vaccinees correlates with low autophagy levels. We demonstrate that levels of the endogenous autophagy-inducing metabolite spermidine fall in human T cells with age. Spermidine supplementation in T cells from old donors recovers their autophagy level and function, similar to young donors' cells, in which spermidine biosynthesis has been inhibited. Finally, our data show that endogenous spermidine maintains autophagy via the translation factor eIF5A and transcription factor TFEB. In summary, we have provided evidence for the importance of autophagy in vaccine immunogenicity in older humans and uncovered two novel drug targets that may increase vaccination efficiency in the aging context.

Circulating plasma metabolites and risk of rheumatoid arthritis in the Nurses' Health Study

OBJECTIVES

RA develops slowly over years. We tested for metabolic changes prior to RA onset using a large non-targeted metabolomics platform to identify novel pathways and advance understanding of RA development.

METHODS

Two hundred and fifty-four incident RA cases with plasma samples drawn pre-RA onset in the Nurses' Health Study (NHS) cohorts were matched 1:2 to 501 controls on age, race, menopause/post-menopausal hormone use and blood collection features. Relative abundances of 360 unique, known metabolites were measured. Conditional logistic regression analyses assessed associations between metabolites and incidence of RA, adjusted for age, smoking and BMI, accounting for multiple comparisons. Subgroup analyses investigated seropositive (sero+) RA and RA within 5 years of sample collection. Significant metabolites were then tested in a female military pre-RA case-control study (n = 290).

RESULTS

In the NHS, metabolites associated with RA and sero+RA in multivariable models included 4-acetamidobutanoate (odds ratio (OR) = 0.80/S.d., 95% CI: 0.66, 0.95), N-acetylputrescine (OR = 0.82, 95% CI: 0.69, 0.96), C5 carnitine (OR = 0.84, 95% CI: 0.71, 0.99) and C5:1 carnitine (OR = 0.81, 95% CI: 0.68, 0.95). These were involved primarily in polyamine and leucine, isoleucine and valine metabolism. Several metabolites associated with sero+RA within 5 years of diagnosis were replicated in the independent military cohort: C5 carnitine (OR = 0.55, 95% CI: 0.33, 0.92), C5:1 carnitine (OR = 0.62, 95% CI: 0.39, 0.99) and C3 carnitine (OR = 0.57, 95% CI: 0.36, 0.91).

CONCLUSION

Several metabolites were inversely associated with incidence of RA among women. Three short-chain acylcarnitines replicated in a smaller dataset and may reflect inflammation in the 5-year period prior to sero+RA diagnosis.

Protein precipitation coupled to paper spray with a tube for one-step analysis of blood

RATIONALE

Accurate measurement of trace compounds in blood samples is important in clinical diagnosis and life science. Ambient ionization mass spectrometry, however, suffers from the matrix effect when dealing with complex samples such as blood. Therefore, it is important to reduce the matrix effects in blood samples.

METHODS

A low-cost and disposable Teflon tube was used as a platform to precipitate the protein in blood. The analytes are extracted into organic solvent, and the precipitated protein can be adsorbed by the chromatography paper inserted. Therefore, the Teflon tube after precipitation can be directly subjected to paper spray ionization mass spectrometry, achieving one-step analysis of blood.

RESULTS

High sensitivity and satisfactory stability were achieved for pharmaceuticals, acids, and endogenic metabolites in blood. The absolute signal intensities of characteristic product ions of the tested analytes were 8-20 times higher after protein precipitation than those obtained using paper spray. Detection limits and quantitative performance were evaluated for three drugs: carbamazepine, metformin, and tioconazole. In addition, the limits of detection and quantitation were improved 9-14- and 8-12-fold, respectively.

CONCLUSIONS

Protein precipitation coupled to paper spray with a tube and then to mass spectrometry was successfully achieved and applied in the one-step analysis of trace compounds in blood samples. The experimental results showed that this method was sensitive, stable, convenient, and economic for the direct analysis of blood.

Serum polyamine metabolic profile in autoimmune thyroid disease patients

OBJECTIVE

Polyamines are indispensable polycations and play important physiological roles in living cells. Some polyamine metabolites have been associated with autoimmune disorders. The aims of this study were to profile polyamine metabolites in autoimmune thyroid disease (AITD) and predict whether polyamine metabolites are associated with thyroid hormone, thyroid autoantibodies or disease progression.

DESIGN, PATIENTS AND MEASUREMENTS

A total of 136 participants were recruited, including Graves' disease (GD) (n = 36), Hashimoto's thyroiditis (HT) (n = 33) and thyroid autoantibody-positive (pTAb) (n = 29) patients and 38 age- and sex-matched healthy controls (HCs). Fourteen polyamine metabolites, including polyamine precursors, polyamines and polyamine catabolite, were measured by UFLC-MS/MS RESULTS: Both GD and HT patients had higher L-arginine, L-ornithine, lysine and agmatine levels and lower putrescine, 1,3-diaminopropane, spermine, N-acetylputrescine levels than HCs. Some polyamine metabolite levels were different only in GD or HT patients compared to HCs: GD patients had significantly higher spermidine, N-acetylspermidine and γ-aminobutyric acid and lower cadaverine, whereas HT patients had significantly decreased N-acetylspermine. Only spermine and N-acetylspermine were significantly lower in pTAb than HCs. The spermine:spermidine ratio was significantly reduced in all AITD patients. In addition, spermine was negatively correlated with thyroid-specific antibodies grade. N-acetylspermidine might be a risk factor for pTAb progression to overt hypothyroidism.

CONCLUSIONS

Compared with the HCs, most metabolites of GD and HT showed similar patterns, suggesting the possibility of a common pathophysiological basis or metabolic pathway. Moreover, pTAb progression to overt hypothyroidism may be related to high N-acetylspermidine. Thyroid autoimmunity was associated with low spermine.

Clinical Significance of Serum Spermine in Breast Cancer

The diagnostic significance of three polyamines (putrescine, spermidine and spermine), of carcinoembryonic antigen and of phosphoglucose isomerase have been compared in sera of patients with breast cancer or benign breast disease and normal age matched controls. The results of the study indicate that the performance of spermine was more striking than that of any of the other markers. The estimation of spermine may prove to be a valuable parameter not only in detection but also in prediction of recurrence of the disease.

[POLYAMINE CONCENTRATION IN ERYTHROCYTES IN THE BLOOD OF PREGNANT WOMEN WITH INTRAUTERINE GROWTH RETARDATION]

The aim of the study was to determine polyamine concentration in erythrocytes in the blood of pregnant women with intrauterine growth retardation of different severity. The study included 100 pregnant women (from 23 to 40 weeks of gestation). The main group consisted of 80 pregnant women with intrauterine growth retardation. The control group consisted of 20 women with physiological course of pregnancy. The patients of the main group were divided into three clinical groups regarding intrauterine growth retardation staging. Group I included 38 pregnant women with stage I IUGR, 22 pregnant women with stage II IUGR were in group II and 20 pregnant women with stage III IUGR - in group III.Polyamine concentration in erythrocytes in the blood of pregnant women with intrauterine growth retardation was determined by using Agilent 1200 series (USA) high performance liquid chromatography [4]. The standards of polyamine hydrochlorides were obtained from Sigma-Aldrich Company (USA). The variational methods were used to make the statistical analysis of outcomes by standard licensed computer programs: STATISTICA 6.0, Microsoft Excel, ANOVA «Statistica». The study results were presented in the form of M±m and differences were considered reliable at р<0,05 by Student's t-criterion. The conducted study has revealed that polyamine concentration in erythrocytes in the blood of pregnant women with intrauterine growth retardation is drastically lower if compared with pregnant women with physiological course of pregnancy. At the same time the putrescine concentration is higher, andspermidineandspermine concentrations are significantly reduced in the pregnant women with intrauterine growth retardation in comparison with the control group.According to the obtained results the polyamine exchange proves to be disturbed in pregnant women with intrauterine growth retardation. The progression of polyamine imbalance depends on the severity of fetal growth retardation in pregnant women.

N(8)-acetylspermidine as a potential plasma biomarker for Snyder-Robinson syndrome identified by clinical metabolomics

Clinical metabolomics has emerged as a powerful tool to study human metabolism in health and disease. Comparative statistical analysis of untargeted metabolic profiles can reveal perturbations of metabolite levels in diseases and thus has the potential to identify novel biomarkers. Here we have applied a simultaneous genetic-metabolomic approach in twin boys with epileptic encephalopathy of unclear etiology. Clinical exome sequencing identified a novel missense mutation in the spermine synthase gene (SMS) that causes Snyder-Robinson syndrome (SRS). Untargeted plasma metabolome analysis revealed significantly elevated levels of N(8)-acetylspermidine, a precursor derivative of spermine biosynthesis, as a potential novel plasma biomarker for SRS. This result was verified in a third patient with genetically confirmed SRS. This study illustrates the potential of metabolomics as a translational technique to support exome data on a functional and clinical level.

Amine oxidase-based biosensors for spermine and spermidine determination

The present work describes the development and optimization of electrochemical biosensors for specific determination of the biogenic polyamine spermine (Spm) and spermidine (Spmd) whose assessment represents a novel important analytical tool in food analysis and human diagnostics. These biosensors have been prepared using novel engineered enzymes: polyamine oxidase (PAO) endowed with selectivity towards Spm and Spmd and spermine oxidase (SMO) characterized by strict specificity towards Spm. The current design entails biosensors in which the enzymes were entrapped in poly(vinyl alcohol) bearing styrylpyridinium groups (PVA-SbQ), a photocrosslinkable gel, onto an electrode surface. Screen-printed electrodes (SPEs) were used as electrochemical transducers for enzymatically produced hydrogen peroxide, operating at different potential vs Ag/AgCl according to the material of the working electrode (WE): +700 mV for graphite (GP) or -100 mV for Prussian blue (PB)-modified SPE, respectively. Biosensor performances were evaluated by means of flow injection amperometric (FIA) measurements. The modified electrodes showed good sensitivity, long-term stability and reproducibility. Under optimal conditions, the PAO biosensor showed a linear range 0.003-0.3 mM for Spm and 0.01-0.4 mM for Spmd, while with the SMO biosensor, a linear range of 0.004-0.5 mM for Spm has been obtained. The main kinetic parameters apparent Michaelis constant (K M), turnover number (K cat) and steady-state current (I max) were determined. The proposed device was then applied to the determination of biogenic amines in blood samples. The results obtained were in good agreement with those obtained with the GC-MS reference method.

The biological response of spermidine induced by ionization radiation

Globally, there are concerns over the risks associated with radiation exposure, so it is important to understand the biological effects of radiation exposure. Driven by the need to detect the presence of radiation exposure, biomarkers to monitor potential exposure after radiological accidents can be developed and would be extremely valuable for biological response. In this study, the behavior of spermidine as a biomarker was investigated in a C57BL/6 mouse model exposed to an acute whole-body sublethal dose of 6 Gy. The spermidine content values in serum increased for up to two days after 6 Gy irradiation. However, the enhanced spermidine content observed on day +3 in irradiated mice returned to normal levels on the subsequent five days. The result indicates that spermidine can be used as a biomarker of biological response to radiation exposure.

Increased blood spermine levels decrease the cytotoxic activity of lymphokine-activated killer cells: a novel mechanism of cancer evasion

Increased blood polyamine levels, often observed in cancer patients, have negative impacts on patient prognosis and are associated with tumor progression. The purpose of our study was to examine the effects of polyamines on cellular immune function. Peripheral blood mononuclear cells (PBMCs) from healthy volunteers were cultured with the human natural polyamines spermine, spermidine, or putrescine, and the effects on immune cell function were examined. The correlation between post-operative changes in blood polyamine levels and lymphokine-activated killer (LAK) activity was also examined in cancer patients. Spermine decreased the adhesion of non-stimulated PBMCs to tissue culture plastic in a dose- and a time-dependent manner without affecting cell viability or activity. This decrease in adhesion capacity was accompanied by a decrease in the number of CD11a bright-positive and CD56 bright-positive cells. Upon stimulation with interleukin 2 to activate LAK cytotoxicity, PBMCs cultured overnight with 100 or 500 microM spermine showed decreased cytotoxic activity against Daudi cells (91.5 +/- 1.7 and 84.9 +/- 3.0%, respectively (n = 6) compared to PBMC cultured without polyamines). In a group of 25 cancer patients, changes in blood spermine levels after surgery were negatively correlated with changes in LAK cytotoxicity after surgery (r = -0.510, P = 0.008: n = 25). Increased blood spermine levels may be an important factor in the suppression of anti-tumor immune cell function.

Liver I/R injury is improved by the arginase inhibitor, N(omega)-hydroxy-nor-L-arginine (nor-NOHA)

Liver ischemia-reperfusion (I/R) injury is associated with profound arginine depletion due to arginase release from injured hepatocytes. The purpose of this study was to determine whether arginase inhibition with N(omega)-hydroxy-nor-l-arginine (nor-NOHA) would increase circulating arginine levels and decrease hepatic damage during liver I/R injury. The effects of nor-NOHA were initially tested in normal animals to determine in vivo toxicity. In the second series of experiments, orthotopic syngeneic liver transplantation (OLT) was performed after 18 h of cold ischemia time in Lewis rats. Animals were given nor-NOHA (100 mg/kg) or saline before and after graft reperfusion. In normal animals treated with nor-NOHA, there were no histopathological changes to organs, liver enzymes, serum creatinine, or body weight. In the OLT model, animals treated with saline exhibited markedly elevated serum transaminases and circulating arginase protein levels. Nor-NOHA administration blunted the increase in serum arginase activity by 80% and preserved serum arginine levels at 3 h after OLT. Nor-NOHA treatment reduced post-OLT serum liver enzyme release by 50%. Liver histology (degree of necrosis) in nor-NOHA-treated animals was markedly improved compared with the saline-treated group. Furthermore, use of the arginase inhibitor nor-NOHA did not influence polyamine synthesis owing to the decrease in ornithine levels. Arginase blockade represents a potentially novel strategy to combat hepatic I/R injury associated with liver transplantation.

Molecular recognition of protonated polyamines at calix[4]crown-5 self-assembled monolayer modified electrodes by impedance measurements

Molecular recognition of protonated aliphatic polyamines has been studied at calix[4]crown-5 self-assembled monolayer modified gold electrodes by electrochemical impedance spectroscopic (EIS) experiments. The energy of complex formation between the calix [4]crown-5 molecule and a series of alkyl ammonium ions was shown by molecular modeling and EIS experiments to depend on the number of amine groups in the alkyl chain as well as the number of methylene groups between the amine groups. The structures of complexes formed between the crown ether on the lower rim of calix[4]arene and protonated amines were determined by minimizing the complex formation energies. The adducts thus formed on the SAM rendered the electron transfer from the electrode to the probe (Fe(CN)63-/4- pair) easier or more difficult depending on the number of ammonium groups and their arrangement in linear alkyl chains. Analytical procedures have been developed to detect protonated spermidine (a recognized cancer marker) in simulated urine, blood, erythrocyte, and cerebrospinal fluids.

Polyamines in renal failure

The levels of polyamines (putrescine, spermidine and spermine) and polyamine oxidase in plasma of patients with chronic renal failure were determined. The level of putrescine was increased but the level of spermine was decreased in the plasma of these patients. The patients also had increased plasma polyamine oxidase activity leading to increased degradation of spermine. As acrolein was a major toxic compound produced from spermine by polyamine oxidase, the levels of free and protein-conjugated acrolein in plasma were also measured. Acrolein levels were enhanced in plasma of patients with chronic renal failure. The accumulated acrolein found as protein conjugates was equivalent to 170 microM, which was about 5-fold higher than in plasma of normal subjects. It was found that acrolein is mainly produced by spermine oxidase in plasma. An increase in putrescine, spermine oxidase and acrolein in plasma was observed in all cases such as diabetic nephropathy, chronic glomerulonephritis and nephrosclerosis. After patients with chronic renal failure had undergone hemodialysis, their levels of plasma polyamines, spermine oxidase and acrolein returned towards normal. It is likely that acrolein produced from spermine accumulates in the blood due to decreased excretion into urine and may function as a uremic "toxin".

EFFECTS OF POLYAMINES ON TWO STRAINS OF TRYPANOSOMA BRUCEI IN INFECTED RATS AND IN VITRO CULTURE

We studied the effects of polyamines, which are necessary for proliferation and antioxidation in Trypanosoma brucei gambiense Wellcome strain (WS) and Trypanosoma brucei brucei ILtat 1.4 strain (IL). No difference was found in activity of ornithine decarboxylase (ODC), a key enzyme in polyamine synthesis in trypanosomes, in both strains maintained in vitro; higher (P < 0.05) ODC values were found in IL in vivo. However, WS in vivo exhibited higher proliferation rates with higher spermidine content and decreased host survival times than IL. The in vitro proliferation and polyamine contents of WS increased with the addition of polyamine to the 1-difluoromethylornithine culture medium, but not IL. These results suggested that WS uses extracellular polyamine for proliferation. In the in vitro culture, WS was less tolerant of hydrogen peroxide (oxidative stress) than IL, and malondialdehyde levels in WS were higher than in IL. The expression of trypanothione synthetase mRNA in WS in vitro was higher than in IL. These results suggest that IL is dependent on the synthesis of polyamines for proliferation and reduction of oxidative stress, whereas WS is dependent on the uptake of extracellular polyamines. A thorough understanding of the differences in the metabolic capabilities of various trypanosomes is important for the design of more effective medical treatments.

Polyamine levels in brain and plasma after acute restraint or water-immersion restraint stress in mice

To investigate the relationship between polyamines and stress, we measured polyamine levels in the frontal cortex, hippocampus, hypothalamus, and plasma of mice after acute restraint or water-immersion restraint stress. In all parts of the brain, putrescine levels were elevated (139-157% of the control) 24 h after water-immersion restraint stress. In the case of restraint, however, elevation of the putrescine level (130% of the control) was detected only in the frontal cortex. Spermidine and spermine levels were unchanged or slightly reduced (80-85% of the control) in the brain 6 and 24 h after water-immersion restraint stress. There was no change in plasma polyamine levels at any time subsequent to the stress. Pretreatment with diazepam (5 mg/kg, i.p.) completely blocked the stress-induced putrescine increases. These results indicate that the magnitude of the putrescine increase is dependent upon the intensity of the stressor, and suggest that polyamine metabolism is linked to psychological stress.

Cellular uptake of a catechol iron chelator and chloroquine into Plasmodium falciparum infected erythrocytes

Our study demonstrates the capacity of FR160, a catechol iron chelator, to reach and accumulate into infected Plasmodium falciparum erythrocytes and parasites (cellular accumulation ratio between 12 and 43). Steady-state FR160 accumulation is obtained after 2 hr of exposure. After 2 hr exposure, it reaches intracellular levels that are 4- to 10-fold higher in infected red blood cells than those attained in normal erythrocytes. There is quite a good correlation between the accumulation of chloroquine and FR160 in the different strains (r=0.939) and in the IC(50) values (r=0.719). In contrast, the accumulation of FR160 and its activity is poorly correlated (r=0.500), suggesting that activity of FR160 may be independent of its penetration into infected erythrocytes. The mechanism of accumulation is yet unknown but based on inhibitor studies, the uptake of FR160 seems to be not associated with the calcium pump or channel, the potassium channel or the Na(+)/H(+) exchanger. Combinations of FR160 with verapamil, diltiazem, clotrimazole, amiloride, diazoxide, 4-aminopyridine, and picrotoxin should be avoided (antagonistic effects). The potent in vitro activity of FR160 on chloroquine-resistant strains or isolates, its lower toxicity against Vero cells, its mechanisms of action, its capacity to reach rapidly and accumulate into infected erythrocytes suggest that FR160 holds much promise as a new structural lead and effective antimalarial agent or at least a promising adjuvant in treatment of malaria.

Acrolein produced from polyamines as one of the uraemic toxins

It is well known that the addition of spermine or spermidine to culture medium containing ruminant serum inhibits cellular proliferation. This effect is caused by the products of oxidation of polyamines that are generated by serum amine oxidase. Among the products, we found that acrolein is a major toxic compound produced from spermine and spermidine by amine oxidase. We then analysed the level of polyamines (putrescine, spermidine and spermine) and amine oxidase activity in plasma of patients with chronic renal failure. It was found that the levels of putrescine and the amine oxidase activity were increased, whereas spermidine and spermine were decreased in plasma of patients with chronic renal failure. The levels of free and protein-conjugated acrolein were also increased in plasma of patients with chronic renal failure. An increase in putrescine, amine oxidase and acrolein in plasma was observed in all cases such as diabetic nephropathy, chronic glomerulonephritis and nephrosclerosis. These results suggest that acrolein is produced during the early stage of nephritis through kidney damage and also during uraemia through accumulation of polyamines in blood due to the decrease in their excretion into urine.

Moderate folate deficiency influences polyamine synthesis in rats

Spermidine, spermine and putrescine are polyamines, essential growth factors in mammalian cells. Decarboxylated S-adenosylmethionine (SAM) is an essential precursor in the formation of both spermidine and spermine. SAM is formed from methionine through the addition of adenosine. Because 5-methyltetrahydrofolate donates a methyl group to homocysteine to produce methionine, folate deficiency may decrease polyamine synthesis. Weanling male Sprague-Dawley rats were fed an amino acid-defined diet with 2 mg folic acid/kg diet (control) or no added folic acid (test). Blood, liver, brain, jejunum, ileum and colon samples were collected at the end of 5 wk. Compared with controls, rats fed the test diet had a 72% reduction in plasma folate (123.6 +/- 13.1 vs. 34.6 +/- 2.2 nmol/L, P < 0.001) and a 42% reduction in RBC folate (2834.4 +/- 218.3 vs. 1651.8 +/- 75.9 nmol/L, P < 0.001). Hepatic spermidine and spermine in folate-depleted rats were 58 (P < 0.001) and 67% (P < 0.01) higher, respectively, than in controls. Plasma putrescine was 27% higher (P < 0.05) than in controls. The polyamine concentrations of the jejunum, ileum, colon and brain did not differ. This study suggests that mild folate deficiency influences polyamine synthesis, but contrary to our hypothesis, hepatic spermidine and spermine were increased, as was circulating putrescine. This may have occurred for a number of reasons including increased enzyme activity or overcompensation by the betaine-homocysteine transmethylation pathway in the liver. Further study is necessary to clarify interactions between folate and polyamine metabolism and to determine whether polyamines are involved in the damaging effects of folate deficiency.

Arginase expression in peritoneal macrophages and increase in circulating polyamine levels in mice infected with Schistosoma mansoni

We investigated the nitric oxide (NO) synthase and arginase pathways in resident peritoneal macrophages of mice infected with the tropical parasite Schistosoma mansoni. The two enzymes may have opposite effects, insofar as NO may be involved in the killing of the parasite whereas arginase may stimulate parasite growth via polyamine synthesis. We determined the effects of the infection on the expression and activity of the two enzymes in macrophages, before and after cytokine activation. Cells from infected mice expressed the hepatic type I arginase, whereas in control cells, the enzyme was expressed only after cytokine activation, as were NO synthase II and type II arginase in both groups of cells. Moreover, we found that in infected mice, arginase expression in macrophages was associated with a ten fold increase in the concentration of circulating ornithine-derived polyamines. This may be of pathological importance, since parasitic helminths are though to be dependent on their hosts for the uptake and interconversion of polyamines.

Blood polyamine levels after oral ornithine load, a diagnostic marker of hyperproliferative premalignant and malignant stages in a model of colon carcinogenesis

This study was performed to determine whether a single oral dose of ornithine (Orn), the substrate of ornithine decarboxylase (ODC), increases blood concentrations of polyamines premalignant stage, and whether blood polyamine levels could be used as predictive markers of cancer development. Male Wistar rats were divided into two groups, control and 1,2-dimethylhydrazine (DMH)-treated rats. DMH (20 mg/kg body weight) was injected intraperitoneally once weekly for 10 weeks. Five, 7, and 10 weeks after the last injection when premalignant aberrant crypt foci have developed in the colon, blood levels of putrescine (PUT), spermidine (SPD), and spermine (SPM) were estimated before and after an oral load of ORN. The results showed that after a single oral load of Orn, blood PUT, but not SPD and SPM, concentrations were significantly higher in DMH-treated rats compared with control rats, indicating enhancement of ODC activity. These results support the view that the increased blood concentration of PUT after administration of Orn may be a useful marker to detect hyperproliferative premalignant and malignant stages of cancer development.

Polymeric protein-polyamine conjugates: a new class of uremic toxins affecting erythropoiesis

BACKGROUND

Preliminary evidence on the accumulation of polyamine-protein conjugates (PPCs) was obtained in uremic patients. The presence of these substances in the plasma of hemodialysis (HD) patients was evaluated, and their possible contribution to uremic anemia was investigated by testing the effect of PPC synthesized in vitro on erythroid cell proliferation.

METHODS

Plasma PPC was measured by high-performance liquid chromatography. The in vitro synthesis of PPC from human plasma was carried out by means of the enzyme transglutaminase in the presence of either [3H]-labeled or unlabeled spermidine (SPD). After gel filtration chromatography and detection of the fractions containing [3H]SPD, the latter were tested for their effect on mononuclear bone marrow cell proliferation.

RESULTS

In three out of four patients examined, mainly SPD-protein conjugates (SPD-PC) were observed to accumulate during HD. The levels ranged from 0.17 to 4.93 pmol/mg proteins before dialysis, and these values increased at 30 minutes and at the end of the dialysis up to levels 11.90 pmol/mg. SPD-PC levels in healthy controls were 1.46 +/- 0.82. SPD-PCs synthesized in vitro were recovered in two main fractions showing a molecular weight of> 100 kD (peak 1) and of approximately 30 to 50 kD (peak 3), respectively. The SPD-PC contained in peak 1 showed the greatest inhibitory effect on colony-forming units-erythroid (CFU-E) proliferation without any appreciable effect on burst-forming units-erythroid (BFU-E).

CONCLUSION

We demonstrate that SPD-PC can accumulate in HD patients. These substances, which affect CFU-E proliferation, can be considered as an at yet unrevealed class of uremic toxins contributing to the onset of the uremic anemia.

Spermidine: A predictor for neurological outcome and infarct size in focal cerebral ischemia?

BACKGROUND AND PURPOSE

Polyamines are mainly restricted to the intracellular space. During focal cerebral ischemia, polyamines are released from the intracellular compartment. Experimental studies have implicated a marked elevation in brain tissue and blood. The aim of our study was to investigate whether the elevation of polyamines in the blood of patients with focal cerebral ischemia correlates with the clinical outcome and the infarct volume.

METHODS

Polyamines were measured in 16 patients with focal cerebral ischemia and in 8 healthy control subjects. Blood samples for polyamine measurement were taken at admission and at fixed time points for the next 28 days. Polyamines were analyzed in red blood cells by a high-pressure liquid chromatography system. Clinical findings were recorded with the NIH Stroke Scale score. Volume of infarction was analyzed from cranial CT at admission and on days 4 to 6 after ischemia.

RESULTS

A significant increase of the spermidine level in the peripheral blood could be observed in all patients with focal cerebral ischemia as compared with control subjects (P:<0.01), starting with the admission. Spermidine values correlated positively with the clinical outcome at several time points in the first 48 hours (r=0.90 to 0.40; P:<0.01) and with the infarct volume in cranial CT on days 4 to 6 (r=0.91; P:<0.01).

CONCLUSIONS

As hypothesized from experimental data, polyamine levels in blood increase in patients after focal cerebral ischemia. The results indicate that the peripheral spermidine level is closely associated with the clinical outcome as well as with the infarction volume. Therefore, polyamines may be used as a novel predictor for the prognosis of patients with focal cerebral ischemia.

Dietary fructans modulate polyamine concentration in the cecum of rats

Nondigestible but fermentable dietary fructans such as oligofructose exert many effects on gut physiology through their fermentation end products such as short-chain fatty acids. Could other metabolites be produced in the gut and contribute to the physiologic effects of dietary fructans? The aim of the study was to evaluate the influence of oligofructose on putrescine, spermidine and spermine concentrations in the cecum, the portal vein and the liver of rats and to assess their involvement in cecal enlargement and the modulation of hepatic lipid metabolism. Putrescine, spermidine and spermine were quantified by HPLC in samples obtained from male Wistar rats fed a nonpurified standard diet (controls) or the same diet enriched with 10 g/100 g oligofructose (OFS) for 4 wk. OFS-fed rats had significantly greater cecal content and tissue weights. OFS almost doubled the concentration of putrescine in the cecal contents. The concentration of all three polyamines in the cecal tissue was significantly greater than in controls. The concentration of spermidine in portal plasma was lower in rats fed OFS, whereas the treatment did not affect the polyamine concentrations in the liver. The fermentation of dietary fructans contributed to an increase in the concentration of putrescine in the gut without modifying putrescine concentration in either the portal blood or liver. Moreover, the greater levels of polyamines in cecal tissue may be related to the cell proliferation resulting from OFS fermentation in the gut.

Pancreatic exocrine secretions as a source of luminal polyamines in pigs

The goal of the present study was twofold: (1) to detect the possible storage of dietary polyamines (PAs) in various tissues and (2) to investigate the role of dietary PAs in the differentiation of the pig intestinal epithelium. A first experimental series was designed to assess the accumulation of either milk PAs (mostly spermidine) or orally administered spermine (SPM) in piglet red blood cells (RBCs) and plasma, a preliminary stage in their distribution to growing and storage organs. Though PA concentrations of piglet RBCs and plasma were generally significantly higher than their sow counterparts, our experimental conditions failed to demonstrate that this increase could stem from ingested PAs. A second experimental series dealt with the determination of disaccharidase specific activities in proximal and distal parts of piglet gut on the 26th and 29th days after birth (preweaning time). In agreement with observations made previously on rat pups, we observed an increase in maltase specific activity (SA) at the end of the suckling period (the observed increase in sucrase SA was not significant). However, orally administered SPM did not affect this activity. Compared to the constant protein concentrations observed in both parts of the gut, the pancreatic protein content decreased sharply between the 26th and 29th postnatal days. At the same time pancreatic concentrations of spermidine (SPD) also decreased, suggesting that some pancreatic PAs were released as the organ secreted its proteins. In accordance with this hypothesis, we recorded SPM and SPD in pancreatic juice. The increases in PA concentrations seemed to follow the protein secretion pattern (i.e. PA concentrations reached a maximal value when the protein concentration was highest). The presence of PAs in pancreatic juice could be indicative of a control mechanism exerted by the pancreas on PA-induced growth and differentiation of porcine intestinal epithelium.

Polyamines in human breast cancer and its relations to classical prognostic features: clinical implications

Experimental evidence suggest an important role of polyamines in breast cancer development. Polyamines have been determined in tissue and erythrocyte samples from 100 patients with primary invasive breast cancer and 30 patients with fibroadenomas. Statistical analysis was performed in order to determine the prognostic value of the polyamine patterns of tumor tissues and erythrocytes in comparison with clinical and histological prognostic factors. In malignant tissues, polyamine levels were significantly higher than in benign tissues. They correlated with markers of tumor aggressivity (axillary node involvement and especially with markers of high mitotic rate as Ki-67 staining, histological grade). No correlation was found between estrogen and progesterone status, tumor size and polyamine concentrations. Erythrocyte polyamines levels were identical between cancer patients and controls. The knowledge of the polyamine pattern in breast cancer could become useful in clinical practice particularly if polyamine metabolism is targeted as a therapeutic approach.

Effects of soy protein diet on digestive lumenal polyamines and colonic cell proliferation in pigs

This study was performed to determine whether erythrocyte and digestive lumenal polyamine concentrations are affected by a soy protein diet when compared to a casein diet. We also determined the effects of these diets on colonic cell proliferation. Sixteen pigs received either a 16% soy protein or casein diet for 25 days. The erythrocyte putrescine was higher in pigs fed the soy protein diet. Significant levels of polyamines were observed in the digestive lumen on both diets. Lumenal putrescine and cadaverine were higher in the proximal colon in the casein group. Lumenal spermidine was higher in the caecum and colon in the soy protein group. No significant differences in the ornithine decarboxylase activity nor in the proliferative cell nuclear antigen labelling index were observed in the colonic mucosa regardless of the regimen. These results indicate that the dietary source of protein induces significant changes in lumenal polyamines in the colon. The physiological effects of these changes need to be further investigated.

Development of a simple high-performance capillary electrophoretic method with on-line mode in capillary derivatization for the determination of spermidine

A new high-performance capillary electrophoretic (HPCE) method with an on-line mode in-capillary derivatization (ICD) procedure for determinations of some amines using 20 mmol/L sodium dodecyl sulfate (SDS) - 2 mmol/L o-phthalaldehyde (OPA) - 2 mmol/L N-acetylcysteine (NAC) - 20 mmol/L phosphate-borate buffer [9] has previously been shown. Although this technique offers direct fluorescence detection of free amines without any derivatization procedures before or after HPCE separation, the presence of spermidine (Spd) is difficult to detect due to low fluorescence intensity. The purpose of this study is to improve the detection sensitivity of Spd by reoptimizing this method with regard to the run buffer; the reoptimized method was applied to the determination of Spd in human plasma. To enhance the fluorescence intensity of the Spd signal, it is effective to use the run buffer in the presence of both beta-cyclodextrin (beta-CD: 8.8 mmol/L) and NAC at high concentration (16 mmol/L). By contrast, the intensity was remarkably decreased when SDS was used in the presence of beta-CD. After ultrafiltrating (UF) spiked human plasma with Spd, UF plasma was directly analyzed using the reoptimized method. Spd peak was detected and separated from the other peaks of blank plasma. The present method gave good linearity (r = 0.999), reproducibility (3.85% coefficient of variation at 5 micromol/L level; n = 10) and specificity. The detection limit and lower limit of quantitation is for 0.2 micromol/L and 1 micromol/L, respectively.

[Changes in tissue and blood polyamine levels following chemotherapy in rats with urinary bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl) nitosamine in rats]

BACKGROUND

Polyamines are recognized as cell growth factors. We attempted to determine whether alterations in the levels of tissue and blood polyamines were useful biochemical makers for monitoring the efficacy of the chemotherapy for bladder tumors.

METHODS

The concentrations of three polyamines of diamine, spermidine and spermine in urinary bladder and blood were determined in male F344 rats with urinary bladder carcinoma induced by N-butyl-N-(4-hydroxybutyl) nitrosamine (BBN), following chemotherapy with cisplatin, methotrexate and pirarubicin.

RESULTS

Bladder carcinoma was observed in 5 of 20 rats of the chemotherapeutic group, and 16 of 20 rats of the control group given saline alone. The levels of spermidine, spermine and total polyamine in both bladder and blood of the treated rats were significantly lower than those of the control rats.

CONCLUSION

The study suggested that the levels of tissue and blood polyamines could be used as biochemical markers for monitoring the efficacy of the chemotherapy for bladder tumors.

Raised erythrocyte polyamine levels in non-insulin-dependent diabetes mellitus with great vessel disease and albuminuria

Erythrocyte content of polyamines has been previously found increased in insulin-dependent diabetes mellitus with microalbuminuria. Since increased urinary albumin excretion (AER) is associated with the presence of vascular diseases in non-insulin-dependent diabetes mellitus (NIDDM) the aim of this study was to verify the hypothesis that the presence of increased urinary albumin excretion (AER), and of macroangiopathy in NIDDM would be related to a significant modification in polyamine erythrocyte levels. The erythrocyte content of spermine and spermidine was measured by a HPLC method in 39 patients affected with NIDDM and in 24 age- and sex-matched healthy control subjects, evaluating the relationship between erythrocyte polyamines of NIDDM patients with the presence of macroangiopathy as well as with retinopathy or increased AER (> or = 20 micrograms/ml). Both spermidine and spermine were not modified in the group of NIDDM patients while the presence of raised urinary AER was characterised by an increase in erythrocyte spermine (11 +/- 1.7 vs. 7.7 +/- 1.7 nmol/ml packed erythrocytes; P = 0.04) and spermidine (18.9 +/- 1.7 vs. 12.6 +/- 1.5 nmol/ml packed erythrocytes; P = 0.02), being both polyamines significantly related to AER and to metabolic control. Erythrocyte spermidine and spermine were moreover significantly higher in the group of patients with macroangiopathy (22.8 +/- 1.5 vs. 12.3 +/- 1.5 nmol/ml; P = 0.0001 and 11.5 +/- 1.7 vs. 7.8 +/- 1.7 nmol/l packed erythrocytes; P = 0.04) and being, moreover, erythrocyte spermidine augmented in patients with retinopathy (24.2 +/- 1.5 vs. 12.2 +/- 1.5 nmol/ml packed erythrocytes; P = 0.009). In conclusion the levels of erythrocyte spermine and spermidine are both associated with the presence of albuminuria and macroangiopathy in NIDDM, while spermidine is on the average increased in the group of diabetic patients with retinopathy.

Human erythrocyte polyamine levels after partial hepatectomy

BACKGROUND/AIM

There are various indices of liver regeneration, but no clinically useful index that reflects the current status of liver regeneration. We assayed human erythrocyte polyamine levels after partial hepatectomy to define the relationship between erythrocyte polyamine levels and liver regeneration.

MATERIALS AND METHODS

Levels of human erythrocyte polyamines (putrescine, spermidine, and spermine) were assayed by high-pressure liquid chromatography in 91 patients after partial hepatectomy and in 13 patients after surgery other than partial hepatectomy (controls). Of the patients after partial hepatectomy, 37 underwent hepatectomy of 20% or more of the liver (group A), 27 underwent segmentectomy or subsegmentectomy of the liver amounting to less than 20% of the liver (group B), and 27 underwent an operation smaller in scale than sub-segmentectomy (group C).

RESULTS

The greater the proportion of the liver resected, the greater was the percent increase. In groups A, B, and C, erythrocyte levels of spermidine and spermine increased after surgery compared with the base line, and were significantly higher at 7 or 14 days, decreasing later. The differences in spermidine among the three groups were significant.

CONCLUSIONS

After partial hepatectomy, the erythrocyte polyamine levels, especially the level of spermidine, were related to the proportion of liver resected. They seemed to reflect the degree of liver regeneration.

Erythrocyte spermine levels: a prognostic parameter in childhood common acute lymphoblastic leukemia

Polyamines have been implicated to play a role in cell proliferation and in cancer development. Ninety percent of the circulating spermidine (Spd) and spermine (Spm) are transported by red blood cells (RBC). RBC Spd and Spm levels were prospectively determined in 63 unselected children with common acute lymphoblastic leukemia. The Spm and Spd levels were not correlated with white blood cell (WBC) count. On the basis of the polyamine levels it was possible to discriminate four groups with P< 10(-3). In C1, C2, C3 and C4 group the Spm level was respectively 90 (39-597), 3.75 (1-7.45), 9.95 (2.9-12.6) and 17(6.3-33.8). The probability of relapse-free survival (RFS) of the 58 children who entered complete remission was 55% +/- 9. For the groups C1 (n = 6), C2 (n = 16), C3 (n = 21) and C4 (n= 15) groups, the RFS was 25% +/- 20, 73% +/- 12, 73% +/- 13 and 32% +/- 13 respectively. For children with Spm levels <13/> or = 13nmol/8 x 10(9) RBC, event-free survival (EFS) was 54% +/- 11/33% +/- 10 and RFS was 64% +/- 12/38% +/- 11 respectively (P < 0.03, P < 0.005). Our clinical study shows clearly that an RBC spermine level could be used as parameter of prognosis at the time of diagnosis, particularly for patients with intermediary WBC count.

Estimation of 24-hour polyamine intake from mature human milk

It has been suggested that milk polyamines stimulate GI tract proliferation and maturation in newborns. We determined human milk polyamine concentrations and estimated 24-h outputs on days 16 +/- 4 (n = 98), 44 +/- 3 (n = 97) and 91 +/- 6 (n = 25) after delivery. Median concentrations in micromolars were, respectively, putrescine 0.77, 0.63, and 0.63; spermidine 4.54, 3.07, and 2.73; spermine 3.76, 2.90, and 2.22; and total polyamines 9.82, 6.83, and 5.71. Concentrations of spermidine, spermine, and total polyamines decreased during the observation period. Putrescine, spermidine, and spermine milk/maternal plasma ratios were estimated to be 16-19, 14-24, and 44-75, respectively. It would appear that milk polyamines are derived from the high polyamine contents in the mammary gland and that they may be important in infant nutrition.

A kinetic characterization of putrescine and spermidine uptake and export in human erythrocytes

Using human erythrocytes as a model system for the study of mammalian polyamine transport, detailed kinetic parameters regarding the uptake and export of putrescine and spermidine were determined. The putrescine uptake data indicated a multi-component uptake system comprised of a low-capacity saturable component and a non-saturable component. The saturable putrescine uptake component demonstrated a calculated Km of 21.0 microM and a V(max) of only 6.52 x 10(-13) M/s. The non-saturable linear putrescine uptake rate was defined by a significant pH dependence, a lack of uptake inhibition by related polyamines, and a permeability pi of 3.19 x 10(-8) s-1. These findings suggested that non-saturable putrescine uptake involved a process of simple diffusion. Spermidine uptake exhibited Michaelis-Menten kinetics with a Km and Vmax of 12.5 microM and 1.36 x 10(-12) M/s, respectively. Spermidine uptake did not demonstrate pH dependence and was not significantly inhibited by any of the tested polyamines. The Arrhenius plot of spermidine uptake was determined to be biphasic with calculated activation energies of spermidine uptake of 135.2 kJ/mol for 19-21 degrees C and 59.3 kJ/mol for 21-35 degrees C. These data suggest the possibility of multiple spermidine uptake processes which are not mediated by simple diffusion across the cell membrane. The putrescine export process demonstrated both saturable and non-saturable components. The calculated Km, V(max) and pi for putrescine export were 33.8 microM, 1.19 x 10(-11) M/s and 2.81 x 10(-7) s-1, respectively. The spermidine export process was non-saturable up to intracellular spermidine concentrations of 4 microM. At similar intracellular and extracellular concentrations of putrescine and spermidine, however, export processes displayed rates which were an order of magnitude greater than their respective uptake rates. This finding supports the possible presence of mediated putrescine and spermidine export processes different than simple diffusion.

Polyamine modification increases the permeability of proteins at the blood-nerve and blood-brain barriers

The permeability of the blood-nerve barrier (BNB) and the blood-brain barrier (BBB) to superoxide dismutase (SOD), insulin, albumin, and IgG in normal adult rats was quantified by measuring the permeability coefficient-surface area product (PS) with the intravenous bolus injection technique before and after covalent protein modification with naturally occurring polyamines-putrescine (PUT), spermidine (SPD), and spermine (SPM). The PS value of the BNB for PUT-SOD was 21.1-fold greater than the native SOD, and the PS values of the BBB for PUT-SOD ranged from 17.6-fold greater for the thalamus to 23.6-fold greater for the caudate-putamen compared with native SOD. In a similar manner, polyamine-modified insulin showed a 1.7-2.0-fold increase in PS of the BNB and BBB compared with the high values of native insulin. Polyamine-modified albumin showed a remarkable 54-165-fold increase in PS of the BNB and BBB compared with native albumin, whereas PUT-IgG resulted in an even higher increase in the PS that ranged from 111- to 349-fold for nerve and different brain regions compared with native IgG. Polyamine modification of proteins, therefore, can dramatically increase the permeability at the BNB and BBB of a variety of proteins with widely differing M(r) and function. It is surprising that the PS values of the BNB and BBB decreased with the increasing number of positive charges of the protonated amino groups on the polyamines (PUT>SPD>SPM). Although cationic proteins are known to interact with fixed anionic charges on the lumen of the microvascular endothelium, this observation of decreased permeability with increased positive charge distribution along the aliphatic carbon chain of the polyamines implies mechanisms other than simple electrostatic interaction involving charge density. It is suggested that the polyamine transporter may be responsible for the transport of these polyamine-modified proteins. Systemic administration of polyamine-modified peptides and proteins might prove to be an efficient approach to deliver therapeutic agents into the CNS and PNS for the treatment of a variety of neurological diseases.

Determination of erythrocyte polyamines as a predictive method in tumour diagnosis. An animal study with chemically induced tumours

There have been numerous attempts in the past to use polyamine determinations in body fluids for tumour diagnosis. Since spermidine (Spd) and spermine (Spm) are mainly transported in blood by erythrocytes, this study was concerned with the diagnostic possibilities of red blood cell (RBC) polyamine determinations. In tumour-grafted animals we observed that RBC polyamine levels correlated with the tumour mass progression and increased before the tumour was palpable. Discrepancies between the evolution of RBC polyamine levels in tumour-grafted animals and in cancer patients were probably due to the non-continuous growth of the tumours in patients. Therefore, an animal model was sought which mimicked the clinical situation. In the present experiments, ethylnitrosourea induced tumours were used which, in analogy to the clinical situation, had an undetermined time of the appearance in a non-predetermined proportion of the animals. RBC polyamines were determined over a period of 7 months in 154 rats. A total of 2,290 RBC polyamine determinations were performed during this study. The data clearly demonstrate the appearance of elevated Spd concentrations in advance of tumour diagnosis by conventional clinical methods. In 71% of the rats which later developed a tumour, abnormal Spd levels (> 40 nmol/8.109 RBC) preceded, by 35 +/- 31 days, the first clinical symptoms for the presence of a tumour. In 29% of the animals, abnormal RBC Spd concentrations were observed at the time of tumour diagnosis. Elevation of Spm concentrations (> 6 nmol/8.10(9) RBC) was less frequent. RBC polyamine levels did not allow discrimination between malignant and non malignant tumours. This confirms earlier findings that RBC polyamines are markers of the cell proliferation rate, but not for the presence of a malignant tumour. Elevated RBC polyamine concentrations are an index of the intensity of hyperplastic processes, which can be clinically used for the early detection of proliferative phases of tumours, thus allowing timely therapeutic measures.

Blood polyamines in the rat

The physiological concentrations of polyamines in plasma, serum and red blood cells were determined in male Wistar rats, using HPLC with fluorometric detection. The analysis of the metabolic ratio between polyamines and the frontal cortex/plasma relationship for putrescine, spermidine and spermine, suggest the existence of common mechanisms in the regulation of spermidine in blood and brain.

Increased spermidine or spermine level is essential for hepatocyte growth factor-induced DNA synthesis in cultured rat hepatocytes

BACKGROUND/AIMS

Hepatocyte growth factor is a potent mitogen for mature hepatocytes and seems to act as a trigger for liver regeneration. Hepatocyte growth factor was first purified from human and rabbit plasma and rat platelets. Additionally, putrescine, spermidine, and spermine are widely distributed in many different cells; intracellular concentrations of these polyamines are closely related to cell proliferation. The present study examined whether polyamine metabolism is involved in hepatocyte growth factor-induced DNA synthesis in primary cultured rat hepatocytes.

METHODS

Hepatocytes were isolated from rats by the collagenase perfusion method. Ornithine decarboxylase and S-adenosylmethionine decarboxylase activities were measured as the release of 14CO2 from L-[1-14C]ornithine and S-adenosyl-L-[carboxyl-14C]methionine, respectively.

RESULTS

alpha-Difluoromethylornithine inhibited hepatocyte growth factor-induced DNA synthesis by only 21%. On the other hand, methylglyoxal bis(guanylhydrazone) completely inhibited hepatocyte growth factor-induced DNA synthesis to nontreated control level. The inhibitory effect of methylglyoxal bis(guanylhydrazone) on hepatocyte growth factor-induced DNA synthesis was reversed by exogenously added spermidine or spermine.

CONCLUSIONS

Spermidine or spermine is essential for hepatocyte growth factor-induced DNA synthesis in primary cultured rat hepatocytes.

Acute and chronic hyperbaric oxygen exposure in humans: effects on blood polyamines, adrenocorticotropin and beta-endorphin

Plasma beta-endorphin, adrenocorticotropin (ACTH) and blood polyamine (spermidine and spermine) concentrations were evaluated in healthy adult male athletes undergoing hyperbaric oxygen exposure for 10 days (2.8 atm, 100% O2, 60 min daily). In the "acute phase", corresponding to the first day of treatment, and in the "acute in the chronic phase", corresponding to the values obtained on the 5th and 10th days after 60 min of hyperbaric O2, both ACTH and beta-endorphin levels increased significantly, whereas no variations were observed for polyamine concentrations. In the "chronic phase", corresponding to the basal values of the 5th and 10th days of treatment, we found a different pattern. In fact, the concentration of polyamines showed a remarkable enhancement, while ACTH and beta-endorphin levels remained unchanged. No significant variations were observed during hyperbarism with air. These results demonstrate different modifications of polyamines and beta-endorphin and ACTH in subjects submitted to hyperbaric oxygen exposure.

Urinary and erythrocyte polyamines during the evaluation of oral alpha-difluoromethylornithine in a phase I chemoprevention clinical trial

Pharmacokinetics of alpha-difluoromethylornithine (DFMO) in plasma and polyamine levels in urine and erythrocytes (RBC) of subjects considered to be at a higher-than-normal risk for developing cancer and receiving DFMO in a phase I chemoprevention trial were monitored over a period of 6 months at DFMO doses ranging from 200 to 6400 mg/m2/day. DFMO pharmacokinetics was linear and attained an average peak plasma concentration of 58 micrograms/ml and an average area under the concentration x time curve from 0 to 6 h of 240 micrograms/ml.h at an administered dose of 1600 mg/m2. Transient decreases in RBC polyamine levels were observed in only 3 of 22 subjects; all of the others showed an increase in the levels at some time during DFMO administration. In contrast to these findings, 17 of 22 subjects showed a decline in urinary polyamines; 10 of 22 showed this decline by the end of the first month and the remaining subjects during subsequent administration of the drug. One subject with familial polyposis who had high RBC and urinary polyamine levels prior to DFMO treatment showed a significant decline in urinary polyamines and responded to DFMO treatment with nearly complete resolution of the polyps in the rectal stump. Our results suggest that (a) DFMO concentrations achieved in this study are adequate to modulate polyamine pools as reflected by their reduced urinary excretion; (b) the red blood cell polyamines are not reliable indicators of DFMO activity; and (c) the modulation of polyamines occurs at doses of DFMO that are tolerated by a majority of the subjects.

Polyamines and prostatic carcinoma: clinical and therapeutic implications

The erythrocyte polyamines, spermidine and spermine, are known proliferation markers. The authors present their experience with polyamines and prostatic carcinoma. 229 patients with prostatic carcinoma had polyamine erythrocyte determination at diagnosis. Previous results confirmed a tendency to spermidine increase with tumor stage and a significant increase in spermine in metastatic and hormonal escape patients. No correlation was found between polyamine erythrocyte levels and hemoglobin, prostate-specific antigen or tumor grade. 148 prostatic carcinoma patients were followed up. Their pretreatment erythrocyte polyamine levels were correlated to progression. Patients (whatever stage) with rapid progression present significantly enhanced pretreatment erythrocyte spermine levels compared to patients with a favorable outcome. Polyamines are not only proliferation markers but are also necessary for cell division. The authors present their results on polyamine deprivation, combining a polyamine-free diet, polyamine synthesis inhibitors and intestinal tract decontamination, on in vivo tumor growth inhibition of the murine prostatic carcinoma Dunning Mat LyLu tumor model.

Elevated levels of peripheral-blood, naturally occurring aliphatic polyamines in bronchial asthmatic patients with active symptoms

The levels of peripheral-blood, naturally occurring aliphatic polyamines, such as putrescine, spermidine, and spermine, from 21 bronchial asthmatic patients (11 atopics and 10 nonatopics) were measured by postcolumn derivatization high-performance liquid chromatography analysis. None of the patients, except the 44-year-old woman in the case report below, were given prednisolone, and they were instructed to take only regular medication during the tests. Blood was drawn from the patients in a fasting state, and the polyamine levels were compared between the times when they were free of asthmatic symptoms and when they had mild spontaneous attacks. Nine (5 atopics and 4 nonatopics), 6 (3 atopics and 3 nonatopics), and 4 (3 atopics and 1 nonatopic) out of 20 patients, when they had relatively mild asthmatic attacks, showed higher putrescine, spermidine, and spermine levels, respectively, than those of normal healthy control subjects. The levels of peripheral blood polyamines from a 44-year-old atopic bronchial asthmatic woman, who was admitted to the hospital with severe asthmatic attacks, were measured serially, and the putrescine and spermidine levels were found to be elevated during the asthmatic attacks, returning to normal levels in parallel with the clinical course. These data may suggest a role for naturally occurring aliphatic polyamines in bronchial asthma.

Polyamines are involved in retinoic acid-mediated induction of tissue transglutaminase in human peripheral blood monocytes

The differentiation of human peripheral blood monocytes (HPBM) into macrophages, when cultured in vitro, has been associated with an increase in the expression of tissue transglutaminase (TGc). Retinoic acid (RA) addition to 5-day-old cultured monocytes, 36 h later induced about 5-folds increase of TGc content. The preliminary exposure of cultured monocytes to alpha-difluoromethylornithine (DFMO) significantly reduced TGc induction caused by RA. DFMO alone does not induce significant changes in the time-course of TGc activity. In cultured monocytes exposed to DFMO, putrescine and spermidine, but not spermine were significantly depleted. The supplementation of putrescine (1 mM) or spermidine (0.5 mM) to culture medium reversed the inhibiting effect of DFMO on RA-mediated induction of TGc. However, the addition of polyamines in the absence of RA or DFMO did not mimic the induction of TGc by RA. We conclude that TGc induction by RA during in vitro maturation of monocytes to macrophages may be modulated by polyamine availability.

Polyamines in ejaculated ram spermatozoa and their relationship with sperm motility

Intracellular polyamine levels in ejaculated spermatozoa and seminal fluid from rams were determined by fluorescent spectroscopy of their dansyl derivatives. Relationships between the sperm polyamine content and sperm motility of six mature and eight pubescent rams were studied. Samples were collected from both groups once a month from August through October. Mature rams had a greater percentage of motile sperm cells than lambs (94% versus 73% in September and 92% versus 78% in October); higher spermidine content (36 versus 9 pmol/10(8) cells in September and 162 versus 55 pmol/10(8) cells in October); higher spermine content (984 versus 205 pmol/10(8) cells in September and 1,229 versus 414 pmol/10(8) cells in October); and higher total sperm polyamine content (1,021 versus 216 pmol/10(8) cells in September and 2,258 versus 973 pmol/10(8) cells in October). In the lambs, spermidine content increased (55 versus 9 pmol/10(8) cells); spermine content increased (414 versus 205 pmol/10(8) cells); and total sperm polyamine content increased (973 versus 215 pmol/10(8) cells) in October compared to September. Ejaculates with sperm motility higher than 85% had greater spermine (848 versus 234 pmol/10(8) cells in September and 1064 versus 449 pmol/10(8) cells in October), and total sperm polyamine content (882 versus 244 pmol/10(8) cells in September and 2,015 versus 1,008 pmol/10(8) cells in October) than ejaculates with less than 450 pmol total sperm polyamines/10(8) cells was 68% +/- 6% compared to 90% +/- 4% in cells with greater than 450 pmol (average for all ejaculates) total sperm polyamines/10(8) cells. These data suggest a positive relationship between sperm polyamine constant and sperm motility.(ABSTRACT TRUNCATED AT 250 WORDS)

Erythrocyte spermidine levels in IDDM patients

OBJECTIVES

To evaluate whether erythrocyte levels of polyamines spermidine and spermine (expressed in nmol/ml packed erythrocytes [PRBCs]) are modified in insulin-dependent diabetes mellitus (IDDM) and are associated with the presence of retinopathy or nephropathy.

RESEARCH DESIGN AND METHODS

We studied erythrocyte spermidine and spermine levels in 38 IDDM patients with or without persistent microalbuminuria (urinary albumin excretion rate [AER] between 20 and 200 micrograms/min), macroalbuminuria (AER greater than 200 micrograms/min), or retinopathy compared with 60 sex- and age-matched control subjects.

RESULTS

Mean +/- SD erythrocyte spermine content was similar in both diabetic (9.7 +/- 5.5 nmol/ml PRBCs) and control (8.8 +/- 3.5 nmol/ml PRBCs) subjects, whereas spermidine was higher in diabetic (19.1 +/- 7.2 nmol/ml PRBCs) than in control (14.5 +/- 4 nmol/ml PRBCs, P = 0.0007) subjects. Moreover, spermidine was significantly higher in the groups with microalbuminuria (n = 11, 22.5 +/- 9.2 nmol/ml PRBCs) and macroalbuminuria (n = 4, 22.2 +/- 5.7 nmol/ml PRBCs) than in both normoalbuminuric (n = 23, 16.9 +/- 5.6 nmol/ml PRBCs) and control (F = 9.78, P = 0.0001) subjects, and correlated with log AER (r = 0.41, P = 0.009). Similarly, proliferative retinopathy was associated with a significant increase in spermidine (n = 5, 20 +/- 7 nmol/ml PRBCs compared with control subjects [P = 0.0009]).

CONCLUSIONS

Our data suggest that erythrocyte spermidine content is increased in IDDM patients associated with both diabetic nephropathy and advanced retinopathy.

[The diagnostic value of erythrocyte polyamines (EPA) in prostatic adenocarcinoma (PA): apropos of 100 patients]

Spermidine and spermine are ubiquitous polyamines which are intensely metabolised in the prostate. Polyamines are involved in the processes of proliferation and differentiation of normal and neoplastic cells. As the erythrocyte levels of these polyamines are correlated with the intratumoral levels, we assayed EPA in 45 controls, 66 patients with benign prostatic hypertrophy and 100 patients with prostatic cancer. Erythrocytic polyamines are markers of proliferation and prostatic metastases and can be used to distinguish between hormone-sensitive and hormone-resistant patients. Although non-specific, polyamines constitute circulating markers of the state of tumour proliferation of a given patient and definitely have a prognostic value which needs to be evaluated by further studies.

Ethanol-associated alterations in the kinetics of putrescine uptake and metabolism by the regenerating liver

Biosynthesis of the polyamines, putrescine, spermidine, and spermine is required for DNA synthesis and liver regeneration after partial hepatectomy. We have previously reported that chronic ethanol consumption impairs polyamine synthesis and significantly retards liver regeneration after partial hepatectomy. In those studies, supplementation with putrescine restored hepatic DNA synthesis in ethanol-fed rats but exerted no effect in pair-fed controls. These differences in the response to putrescine treatment may have resulted from ethanol-associated differences in hepatic uptake, release, or metabolism of putrescine. To resolve these issues and define more completely how putrescine treatment affects DNA synthesis, we now assess the kinetics of putrescine uptake and metabolism after intraperitoneal or intravenous injection of radiolabeled putrescine (1.2 mmol/kg, specific activity 1 microCi/mmol) into rats fed 36% ethanol diets or isocaloric, nonethanol diets for 6 weeks prior to partial hepatectomy. After putrescine treatment, hepatic putrescine concentrations were greater in ethanol-fed rats than controls. Differences in post-treatment hepatic putrescine levels between ethanol and pair-fed groups could not be explained by differences in the rates of hepatic putrescine uptake or excretion into bile; residual de novo synthesis of putrescine from ornithine or metabolism of hepatic putrescine to its polyamine products, spermidine and spermine. Indeed, supplemental putrescine was not appreciably converted to spermidine or spermine in either ethanol or control rats. Hence, these latter polyamines are unlikely to be responsible for the treatment-associated improvement in DNA synthesis that has been noted in ethanol-fed rats. This suggests that putrescine itself acts to restore hepatic DNA synthesis in ethanol-fed rats.

Determination of erythrocytic polyamines by reversed-phase liquid chromatography

A simple and rapid semiautomated procedure for determining polyamines in erythrocytes by high-performance liquid chromatography is described. Putrescine, spermidine, and spermine are converted to fluorescent dansyl derivatives, extracted with cyclohexane, and separated in less than 10 min on a reversed-phase C18 ODS column, with an acetonitrile-water gradient as the mobile phase. The method showed a coefficient of variation of 2.73% for spermidine and 3.27% for spermine. The respective reference values, evaluated in 10 healthy patients, were 7.88 (SD 2.09) and 5.42 (SD 1.55) mumol/L of packed erythrocytes. Only negligible amounts of putrescine were found.