Influence of the polyamine, spermidine, on intestinal maturation and dietary antigen uptake in the neonatal rat

Dynamics and Crosstalk between Gut Microbiota, Metabolome, and Fecal Calprotectin in Very Preterm Infants: Insights into Feeding Intolerance

BACKGROUND

Feeding intolerance (FI) is a significant concern in the care of preterm infants, impacting their growth and development. We previously reported that FI is linked to lower fecal calprotectin (FC) levels. This study aims to explore the postnatal dynamics and interplay between microbiota, metabolic profiles, and host immunity in preterm infants with and without FI.

METHODS

Infants with gestational age <32 weeks or birth weight <1500 g were enrolled at the Children's Hospital of Fudan University between January 2018 and October 2020. Weekly fecal samples were analyzed for bacterial profiling, metabolome, and calprotectin levels, exploring their longitudinal development and interrelationships.

RESULTS

Of the 118 very preterm infants studied, 48 showed FI. These infants experienced an interrupted microbial-immune trajectory, particularly at 3-4 weeks of age, marked by a reduced bacterial abundance, alpha diversity, and FC levels. Metabolic changes in FI were pronounced between 3 and 6 weeks. Pantothenic acid and two polyamine metabolites were closely associated with bacterial abundance and FC levels and negatively correlated with the duration to attain full enteral feeding.

CONCLUSIONS

FI infants demonstrated compromised microbiome-immune interactions, potentially influenced by specific metabolites. This research underscored the importance of early microbial and metabolic development in the pathogenesis of FI in very preterm infants.

The effects of polyamines on human colonic mucosal function

Electrogenic ion transport in human colon is a surrogate marker for colonic mucosal function, and may be manipulated by a variety of hormonal, neural, immune and paracrine mediators. Polyamines are present in vast quantities in the colonic lumen and appear to be integral to cellular function. This study explores some of the mechanisms of polyamine action on colonic tissue through study of their effects on differential secretory pathways, as well as examining their actions on intracellular cAMP and Ca(2+) accumulation. Human colonic mucosa was mounted in Ussing chambers and treated with polyamines (spermine, spermidine and putrescine) with changes in ion transport recorded. In separate experiments colonic crypts were treated with polyamines and intracellular cAMP levels determined by ELISA and intracellular calcium concentrations were quantified by fluorescent imaging. Polyamines at physiological concentrations (1mM) exert no effects on basal mucosal chloride secretion or transepithelial electrical resistance. Polyamines inhibit electrogenic ion secretion as stimulated by forskolin (cAMP-mediated), but not carbachol (Ach-mediated). All the polyamines used in this study inhibited intracellular cAMP accumulation, according to potency (spermine>spermidine>putrescine). Spermine increased intracellular Ca(2+) in a PKC-dependent manner, likely due to its effects on the extracellular calcium-sensing receptor (CaSR). Polyamines act to prevent cAMP-mediated Cl(-) hypersecretion in the colon, acting through CaSR to inhibit PKC-mediated [Ca(2+)]i release from intracellular stores.

Hypocaloric diet supplemented with probiotic cheese improves body mass index and blood pressure indices of obese hypertensive patients--a randomized double-blind placebo-controlled pilot study

Background

Gut lactobacilli can affect the metabolic functions of healthy humans. We tested whether a 1500 kcal/d diet supplemented with cheese containing the probiotic Lactobacillus plantarum TENSIA (Deutsche Sammlung für Mikroorganismen, DSM 21380) could reduce some symptoms of metabolic syndrome in Russian adults with obesity and hypertension.

Methods

In this 3-week, randomized, double-blind, placebo-controlled, parallel pilot study, 25 subjects ingested probiotic cheese and 15 ingested control cheese. Fifty grams of each cheese provided 175 kcal of energy. Blood pressure (BP), anthropometric characteristics, markers of liver and kidney function, metabolic indices (plasma glucose, lipids, and cholesterol), and urine polyamines were measured. Counts of fecal lactobacilli and L. plantarum TENSIA were evaluated using molecular methods. The data were analyzed by t-test for independent samples and Spearman’s partial correlation analysis.

Results

The probiotic L. plantarum TENSIA was present in variable amounts (529.6 ± 232.5 gene copies) in 16/25 (64%) study subjects. Body mass index (BMI) was significantly reduced (p = 0.031) in the probiotic cheese group versus the control cheese group. The changes in BMI were closely associated with the water content of the body (r = 0.570, p = 0.0007) when adjusted for sex and age. Higher values of intestinal lactobacilli after probiotic cheese consumption were associated with higher BMI (r = 0.383, p = 0.0305) and urinary putrescine content (r = 0.475, p = 0.006). In patients simultaneously treated with BP-lowering drugs, similar reductions of BP were observed in both groups. A positive association was detected between TENSIA colonization and the extent of change of morning diastolic BP (r = 0.617, p = 0.0248) and a trend toward lower values of morning systolic BP (r = −0.527, p = 0.0640) at the end of the study after adjusting for BMI, age, and sex.

Conclusion

In a pilot study of obese hypertensive patients, a hypocaloric diet supplemented with a probiotic cheese helps to reduce BMI and arterial BP values, recognized symptoms of metabolic syndrome.

Trial registration

Current Controlled Trials ISRCTN76271778

Polyamine levels in breast milk are associated with mothers' dietary intake and are higher in preterm than full-term human milk and formulas

BACKGROUND

Polyamine intake from milk is considered essential for post-natal maturation of the immune system and small intestine. The present study aimed to determine polyamine content in human milk after preterm delivery and the association with mothers' dietary intake. In comparison, the polyamine levels were compared with those in term breast milk and some corresponding formulas.

METHODS

Transitional breast milk was collected from 40 mothers delivering after 24-36 weeks of gestation, and from 12 mothers delivering after full term. Food intake was assessed in mothers delivering preterm babies using a 3-day diary. Polyamines were analysed by high-performance liquid chromatography.

RESULTS

The dietary intake of polyamines was significantly associated with breast milk content but weaker for spermine than for spermidine and putrescine. Total polyamine level was higher in preterm than term milk and lower in the corresponding formulas. Putrescine, spermidine and spermine contents [mean (SEM)] in preterm milk were 165.6 (25), 615.5 (80) and 167.7 (16) nmol dL⁻¹, respectively, with the levels of putrescine and spermidine being 50% and 25% higher than in term milk. The content of spermine did not differ.

CONCLUSIONS

Dietary intake of polyamines has an impact on the content in breast milk. The difference between human milk after preterm and term delivery might be considered when using donor human milk for preterm infants. The corresponding formulas had lower contents. Further studies are important for determining the relationship between tissue growth and maturation and optimal intake.

Pharmacokinetics, pharmacodynamics and physiologically-based pharmacokinetic modelling of monoclonal antibodies

Development of monoclonal antibodies (mAbs) and their functional derivatives represents a growing segment of the development pipeline in the pharmaceutical industry. More than 25 mAbs and derivatives have been approved for a variety of therapeutic applications. In addition, around 500 mAbs and derivatives are currently in different stages of development. mAbs are considered to be large molecule therapeutics (in general, they are 2-3 orders of magnitude larger than small chemical molecule therapeutics), but they are not just big chemicals. These compounds demonstrate much more complex pharmacokinetic and pharmacodynamic behaviour than small molecules. Because of their large size and relatively poor membrane permeability and instability in the conditions of the gastrointestinal tract, parenteral administration is the most usual route of administration. The rate and extent of mAb distribution is very slow and depends on extravasation in tissue, distribution within the particular tissue, and degradation. Elimination primarily happens via catabolism to peptides and amino acids. Although not definitive, work has been published to define the human tissues mainly involved in the elimination of mAbs, and it seems that many cells throughout the body are involved. mAbs can be targeted against many soluble or membrane-bound targets, thus these compounds may act by a variety of mechanisms to achieve their pharmacological effect. mAbs targeting soluble antigen generally exhibit linear elimination, whereas those targeting membrane-bound antigen often exhibit non-linear elimination, mainly due to target-mediated drug disposition (TMDD). The high-affinity interaction of mAbs and their derivatives with the pharmacological target can often result in non-linear pharmacokinetics. Because of species differences (particularly due to differences in target affinity and abundance) in the pharmacokinetics and pharmacodynamics of mAbs, pharmacokinetic/pharmacodynamic modelling of mAbs has been used routinely to expedite the development of mAbs and their derivatives and has been utilized to help in the selection of appropriate dose regimens. Although modelling approaches have helped to explain variability in both pharmacokinetic and pharmacodynamic properties of these drugs, there is a clear need for more complex models to improve understanding of pharmacokinetic processes and pharmacodynamic interactions of mAbs with the immune system. There are different approaches applied to physiologically based pharmacokinetic (PBPK) modelling of mAbs and important differences between the models developed. Some key additional features that need to be accounted for in PBPK models of mAbs are neonatal Fc receptor (FcRn; an important salvage mechanism for antibodies) binding, TMDD and lymph flow. Several models have been described incorporating some or all of these features and the use of PBPK models are expected to expand over the next few years.

Nonclassical major histocompatibility complex I-like Fc neonatal receptor (FcRn) expression in neonatal human tissues

The neonatal Fc receptor (FcRn) was demonstrated to play a role both in the recycling and thus the protection of immunoglobulin G (IgG) from catabolism and in the maternal-fetal transfer of IgG. The expression of this particular receptor was evidenced in a variety of cell types, but the endothelial cell was considered the main cell able to perform both recycling and IgG catabolism. Based on preliminary data obtained in adult human mammary glands and skin, this study focused on a number of neonatal human tissues, targeting FcRn expression mainly in epithelial versus endothelial cells. Our results demonstrate that in most of the investigated tissues, the neonatal Fc receptor is not detectable in the endothelial cells lining the capillaries, whereas most epithelial cells are positive. We could also observe the receptor's expression in most macrophages, smooth muscle cells, and neurons. Taken together, these data suggest that the main sites of IgG catabolism might in fact be other than endothelial cells in human neonates.

Probiotics-induced increase of large intestinal luminal polyamine concentration may promote longevity

Many mechanisms contribute to senescence, such as telomere shortening in replicative cells, cumulative damage to DNA leading to genomic instability, and oxidative damage to molecules by reactive oxygen species (ROS). These include chronic low-grade inflammation (inflammageing), a major risk factor for ageing and age-related diseases, such as Alzheimer's disease and type II diabetes. Furthermore, the prevention of inflammageing seems to be one of the most effective approaches to increase longevity. Here, I discuss the rationale and recent evidence for probiotic-induced upregulation of intestinal luminal polyamine (PA) production in the extension of lifespan by preventing inflammageing.

Neonatal Fc receptor: from immunity to therapeutics

The neonatal Fc receptor (FcRn), also known as the Brambell receptor and encoded by Fcgrt, is a MHC class I like molecule that functions to protect IgG and albumin from catabolism, mediates transport of IgG across epithelial cells, and is involved in antigen presentation by professional antigen presenting cells. Its function is evident in early life in the transport of IgG from mother to fetus and neonate for passive immunity and later in the development of adaptive immunity and other functions throughout life. The unique ability of this receptor to prolong the half-life of IgG and albumin has guided engineering of novel therapeutics. Here, we aim to summarize the basic understanding of FcRn biology, its functions in various organs, and the therapeutic design of antibody- and albumin-based therapeutics in light of their interactions with FcRn.

Chapter 4: Multitasking by exploitation of intracellular transport functions the many faces of FcRn

The MHC Class I-related receptor, FcRn, transports antibodies of the immunoglobulin G (IgG) class within and across a diverse array of different cell types. Through this transport, FcRn serves multiple roles throughout adult life that extend well beyond its earlier defined function of transcytosing IgGs from mother to offspring. These roles include the maintenance of IgG levels and the delivery of antigen in the form of immune complexes to degradative compartments within cells. Recent studies have led to significant advances in knowledge of the intracellular trafficking of FcRn and (engineered) IgGs at both the molecular and cellular levels. The engineering of FcRn-IgG (or Fc) interactions to generate antibodies of increased longevity represents an area of active interest, particularly in the light of the expanding use of antibodies in therapy. The strict pH dependence of FcRn-IgG interactions, with binding at pH 6 that becomes essentially undetectable as near neutral pH is approached, is essential for efficient transport. The requirement for retention of low affinity at near neutral pH increases the complexity of engineering antibodies for increased half-life. Conversely, engineered IgGs that have gained significant binding for FcRn at this pH can be potent inhibitors of FcRn that lower endogenous IgG levels and have multiple potential uses as therapeutics. In addition, molecular studies of FcRn-IgG interactions indicate that mice have limitations as preclinical models for FcRn function, primarily due to cross-species differences in FcRn-binding specificity.

LKM512 yogurt consumption improves the intestinal environment and induces the T-helper type 1 cytokine in adult patients with intractable atopic dermatitis

BACKGROUND

In atopic dermatitis (AD) patients, the intestinal mucosal barrier function is weakened, permiting frequent invasion by antigens. Polyamines and short-chain fatty acids (SCFA) produced by intestinal bacteria are involved in the promotion of intestinal mucosal barrier functions.

AIM

Our aim was to investigate the effect of pro-biotic yogurt containing Bifidobacterium animalis subsp. lactis LKM512 (LKM512 yogurt) on subjective symptoms, intestinal microbiota, intestinal bacterial metabolites (polyamines and SCFA), and T-helper type 1 (Th1)/Th2 balance in intractable AD patients.

METHODS

In a double-blind, placebo-controlled, crossover study, LKM512 yogurt was given for 4 weeks to 10 adult AD patients who were diagnosed with moderate AD (four males and six females; average age, 22.1 years). The subjective symptoms were recorded after each intervention. The dynamics of fecal microbiota were analysed by the terminal-restriction fragment length polymorphism method. The effects of LKM512 yogurt on fecal polyamines, SCFA, and serum cytokines were evaluated.

RESULTS

Scores of itch and burning tended to improve to a greater extent by LKM512 yogurt consumption than by placebo consumption. LKM512 yogurt (P<0.005) and placebo consumption (P<0.05) significantly increased the serum IFN-gamma concentration by six- and threefold, respectively. Fecal microbiota was altered dynamically by LKM512 yogurt consumption, in particular, the bacterial species and phylotypes of Bifidobacterium, Clostridium cluster IV and subcluster XIVa were increased in number. In addition, fecal spermidine concentration was significantly (P<0.05) increased, while fecal butyrate also tended to be increased by LKM512 yogurt consumption.

CONCLUSION

We conclude that LKM512 yogurt consumption may be effective against intractable adult-type AD and this effect depends on the recovery of the intestinal mucosal barrier function and the induction of the Th1-type cytokine by polyamines and SCFA, particularly, butyrate, produced by the altered intestinal microbiota.

The relationship between microbiota and polyamine concentration in the human intestine: a pilot study

The fecal microbiota of 10 hospitalized elderly subjects and 14 healthy adults were analyzed by terminal-restriction fragment length polymorphism (T-RFLP) analysis using Hha I, Msp I, Hae III, and Alu I, as well as fecal polyamine (PA) concentration. The T-RFLP profiles of the fecal microbiota of the subjects were roughly divided into 2 clusters-I (9 out of 11 were derived from hospitalized elderly subjects) and II (12 out of 13 were derived from healthy adults). The average concentration of putrescine in Cluster II was 5.8 times higher than that of putrescine in Cluster I (P=0.0015). Using a phylogenetic assignment database for T-RFLP analysis of human colonic microbiota, the terminal-restriction fragments (T-RFs) characteristically detected in the case of subjects with high fecal PA concentration were predicted to be derived from bacterial species and phylotypes belonging to Clostridium subcluster XIVa, particularly including Clostridium xylanolyticum, Clostridium saccharolyticum, the uncultured human intestinal bacterium clone JW1H4 (a relative of Desulfotomaculum guttoideum), Roseburia intestinalis, the uncultured bacterium clone 41F10 (a relative of Eubacterium ramulus), Roseburia cecicola, Ruminococcus obeum and its relatives. From these results, we concluded that fecal microbiota may be linked with fecal PA concentration and that some bacterial species belonging to Clostridium subcluster XIVa may play a major role in the control of intestinal PA concentration in humans.

Enhancement of intestinal absorption of macromolecules by spermine in rats

The aim of this study was to investigate the enhancing effect of polyamines on intestinal absorption of fluorescein isothiocyanate-labeled dextran (MW 4400, FD-4) in the in situ loop study and in vivo oral absorption study. Absorption of FD-4 from the jejunum was significantly enhanced by 5 mM spermine without serious membrane damage in the jejunum. An in vivo oral absorption study was also performed, and plasma FD-4 levels increased significantly after co-administration of 30 mM spermine. In the in vitro transport studies with Caco-2 cells, prolonged incubation with spermine resulted in a gradual decrease in transepithelial electrical resistance. This finding suggests that the absorption-enhancing mechanism of spermine partly includes opening the tight junctions of the epithelium via the paracellular route. These results indicate that excess oral ingestion of polyamines may have widespread health effects via the modulation of the intestinal epithelial barrier function.

Modulation of intestinal urea cycle by dietary spermine in suckling rat

Argininosuccinate synthetase, an ubiquitous enzyme in mammals, catalyses the formation of argininosuccinate, the precursor of arginine. Arginine is recognised as an essential amino acid in foetuses and neonates, but also as a conditionally essential amino acid in adults. Argininosuccinate synthetase is initially expressed in enterocytes during the developmental period, it disappeared from this organ then appeared in the kidneys. Although the importance of both intestinal and renal argininosuccinate synthetases has been recognised for a long time, nutrients have not yet been identified as inducers of the gene expression. In the context of a proteomic screening of intestinal modifications induced by dietary spermine in suckling rats, we showed that argininosuccinate synthetase and carbamoyl phosphate synthase disappeared from enterocytes after this treatment. The disappearance of argininosuccinate synthetase in small intestine was confirmed by immunodetection. Expression of carbamoyl phosphate synthase and argininosuccinate synthetase coding genes decreased also after spermine administration. Expression of other urea cycle enzyme coding genes was modulated by spermine administration: argininosuccinate lyase decreased and arginase increased. Our results fit with the developmental variation of argininosuccinate synthetase and carbamoyl phosphate synthase. Modulation of the gene expression for several urea cycle enzymes suggests a coordination between all the pathway steps and switch toward polyamine (or proline and glutamate) biosynthesis from ornithine.

Effects of human milk and spermine on hydrogen peroxide-induced oxidative damage in IEC-6 cells

OBJECTIVE

Oxidative stress is intimately involved in the pathologic processes of serious diseases in the perinatal period. Human milk (HM) contains various bioactive substances, some of which are known as antioxidants, including polyamines such as spermine (SPM). We examined the antioxidative properties of HM and SPM in an intestinal epithelial cell line.

METHOD

Confluent Intestinal Epithelial Cells-6 (IEC-6) cells were preincubated with 100-fold dilutions of defatted HM, bovine milk, or three artificial milks for 24 hours, followed by hydrogen peroxide (H2O2) challenge (0.5 mM, 30 min) for oxidative stress. Cells were preincubated with either HM or increasing concentrations (within the range of HM) of SPM for 24 hours followed by an H2O2 challenge (0.25 mM, 30 min).

RESULTS

HM-treated cells showed the highest survival rate (50%) compared with no pretreatment (27%), bovine milk-treated (6%), or artificial formula-treated (13-16%) cells. Significantly higher survival rates were observed in the cells treated with HM (44.0%) and in those treated with 0.5, 1, or 5 microM of SPM (12.6, 13.1, or 22.2%, respectively) in comparison with the nontreated cells (7.0%).

CONCLUSION

Our results demonstrated that HM and SPM alleviated H2O2-induced oxidative damage in IEC-6 cells, whereas bovine milk and artificial formula did not show any antioxidative capacity. These results suggest that HM acts as an antioxidant in the gastrointestinal tract of infants and that SPM plays an important role in the antioxidative properties of HM.

Enhancement of lysozyme stability and activity by polyamines

Spermine, a low molecular weight polyamine, administered orally to suckling rats induces the maturation of the small intestine. In this organ, lysozyme is an important component of the innate immunity. In this report, we analysed the binding of spermine to lysozyme and its effect on thermal inactivation of the protein by spectroscopy techniques. The activity of the enzyme was analysed in presence of spermine by lysoplate technique. We studied the effects of spermine ingestion by suckling rats on intestinal lysozyme activity and gene expression. We reported that spermine binds to lysozyme and increases in vitro the thermal stability and the activity of the protein. When administered orally to suckling rats, spermine increases the lysozyme activity in jejunum, but not in ileum. This increase is not due to a modification of the gene expression. The observed effects lead us to postulate that spermine could be used in some mammals as a promoter of the innate immunity.

Differential effect of dietary spermine on alkaline phosphatase activity in jejunum and ileum of unweaned rats

Spermine is a low molecular weight polyamine involved in the postnatal maturation of the gut. When it is administered orally to suckling rats it induces the maturation of their spleen, liver, pancreas, and small intestine. We showed that this polyamine modulates differently the activity of alkaline phosphatase in jejunum and ileum in suckling rat. In 14-day-old rat which had received spermine orally for 3 days, once daily, an increase of alkaline phosphatase activity in the jejunum and a decrease of this activity in the ileum was observed. Alkaline phosphatase was located at the bottom of the villus in the control jejunum and in the whole length of the villus in spermine-treated rats. On the contrary, in ileum of controls, this enzyme was present in the whole length of the villus but disappeared in the spermine-treated animals. An enzyme mass shift was observed in the small intestine after spermine administration. Spermine administration did not change the expression of genes coding for alkaline phosphatase, suggesting a post-transcriptional modification.

Functional analysis of the mouse Fcgrt 5′ proximal promoter

The Brambell receptor (FcRB, FcRn) mediates transmission of immunity from mother to young perinatally and plays a central role in IgG protection and homeostasis throughout life. Developmental and tissue specific expression is via transcriptional regulation of the gene for the receptor heavy chain, Fcgrt. In neonatal mouse intestine, expression is high to absorb IgG from mother's milk, but then nearly absent in adult intestine and in most other tissues. In this initial functional characterization, reporter gene assays revealed at least two upstream promoter regions (-372/-140 and -105/-1), each with repressor and activator functions, and a downstream activator domain (+1/+78). The gene carries no upstream TATA element or Inr sequence, and an apparent downstream promoter feature (DPE) lacks typical context for an active element, rendering uncertain the nature of the organizing feature for the transcription initiation complex. Electrophoretic mobility shift analysis of the proximal upstream region identified transcription factor (TF) binding to motifs for NF1, Sp1 (GT box) and Ets. Binding to the GT box and Ets motif was observed only with mature cell sources, and not with neonatal enterocyte extracts. Site-directed mutagenesis confirmed that TF binding to the GT box up-regulates promoter activity in adult (NIH3T3) cells, whereas binding to the Ets motif represses activity. Binding of NF1 protein to the Fcgrt promoter was confirmed in nuclear extracts of NIH3T3 cells and in adult mouse enterocytes, whereas an apparently different TF bound uniquely to the NF1 site in neonatal enterocyte extracts as the sole identified candidate for an expected developmental-specific high-level activator in this tissue. These data indicate regions of potential importance in the Fcgrt proximal promoter and additionally suggest that the selective temporal and spatial availability of specific TFs may contribute to the developmental and tissue-specific regulation of Fcgrt expression.

Regulation of the intestinal glycoprotein glycosylation during postnatal development: role of hormonal and nutritional factors

This review focuses on the regulation of the glycoprotein glycosylation process in small intestine and colon during postnatal development. Glycoproteins play a prominent part in intestine as mucins secreted by the goblet cells and as molecules of biological interest largely present in the microvillus membrane of the enterocytes (digestive enzymes, transporters). The age-related changes in the intestinal glycosylation control the quality of glycan chains of glycoproteins. Postnatal maturation is observed at all stages of the glycoprotein glycosylation. But it is essentially characterised in the external glycosylation by a shift from sialylation to fucosylation depending on the transcriptional regulation of the corresponding glycosyltransferases, but also on coordinate changes in the activities of glycosyltransferases and of their regulatory proteins, in nucleotide-sugar bioavailability and in product degradation by oxidases. Many factors have been evoked to trigger these changes, among which are hormonal (glucocorticoids, insulin) and dietary factors. Changes in the structure of the glycoprotein glycans might be important for the transport, the barrier function, the implantation of the immune defences and of the microflora and even probably for the biological activity of some digestive enzymes.

Fructooligosaccharides and Lactobacillus acidophilus modify bowel function and protein catabolites excreted by healthy humans

The objective of this experiment was to determine whether supplementation with fructooligosaccharides (FOS) and (or) Lactobacillus acidophilus (LAC) affected bowel function and fermentative end-product concentrations in feces of healthy humans. Subjects (n = 68) were enrolled in a randomized, double-blind, placebo-controlled, parallel study design. After a 4-wk baseline period, subjects consumed one of the following treatments twice daily for 4 wk: 1) 3 g sucrose + 80 mg cornstarch; 2) 3 g FOS + 80 mg cornstarch; 3) 3 g sucrose + 1 x 10(9) colony-forming units (cfu) LAC; or 4) 3 g FOS + 1 x 10(9) cfu LAC. Subjects completed 7-d bowel function forms and 3-d dietary records before collection of fresh stool samples at wk 4, 6 and 8. Statistical analyses were performed on differences from baseline using the General Linear Models procedure of SAS. Fructooligosaccharides decreased fecal ammonia (P = 0.07) and isovalerate (P = 0.12) concentrations at wk 6. At wk 8, FOS tended (P = 0.11) to increase fecal putrescine concentrations. Lactobacillus decreased fecal organic matter percentage at wk 6 (P < 0.05) and 8 (P = 0.07). At wk 6 and 8, LAC increased (P < 0.05) fecal 2-methylindole, total indole, and total indole and phenol concentrations. At wk 8, LAC decreased fecal agmatine (P = 0.08) and phenylethylamine (P < 0.05) concentrations. In conclusion, FOS and LAC modified several metabolites associated with gut health, with FOS tending to be beneficial (decreased fecal protein catabolites) and LAC being negative (increased fecal protein catabolites).

Polyamine participation in the maturation of glycoprotein fucosylation, but not sialylation, in rat small intestine

The aim of this study was to determine the role of polyamines in the diet-related maturation of the intestinal glycoprotein glycosylation during postnatal development in the rat. The activity of alpha-2,6-sialyltransferase and the sialylated forms of glycoproteins in the intestinal brush-border membranes were found to decrease considerably after weaning, in parallel with the intestinal level of putrescine. By contrast, the activity of alpha-1,2-fucosyltransferases, the mRNA levels for two alpha-1,2-fucosyltransferase genes, FTA and FTB, and the fucosylated forms of glycoproteins all increased after weaning, in parallel with the levels of spermidine and spermine. These results suggest a possible role of polyamines in the evolution of glycosylation. The treatment of suckling rats with spermidine or spermine reproduced the high intestinal levels of these polyamines corresponding to those normally found after weaning. After these treatments, a rise in the activity of the alpha-1,2-fucosyltransferase was observed, associated with a fall in alpha-L-fucosidase activity. The alpha-1,2-fucosyltransferase FTB gene was found to be regulated at the transcriptional level, but not by its inhibitor, fuctinin. The result of these variations was the precocious appearance of several alpha-1,2-fucoproteins, which are normally found in brush-border membranes after weaning. The treatment of suckling rats with putrescine, which induced only a transitory rise in intestinal putrescine, had a similar but weaker effect on the fucosylation process than spermidine or spermine, and treatment with ornithine was ineffective. alpha-2,6-Sialylation was not affected by any of the treatments. Spermidine and spermine turned out to be more effective than putrescine for intestinal glycoprotein fucosylation, but did not affect their sialylation. Spermidine and spermine, whose intestinal levels where found to increase at weaning time, may have been partly responsible for the natural evolution of the intestinal glycoprotein fucosylation that occurred during this period.

Impact of LKM512 yogurt on improvement of intestinal environment of the elderly

Improvement of the intestinal environment by administration of LKM512 yogurt was examined using polyamine, haptoglobin and mutagenicity as indexes which directly reflect the health condition of the host. The concentration of spermine in feces increased significantly by 3-fold (P<0.05) at week 2 of administration of LKM512 yogurt compared with before administration, and that of putrescine, spermidine, and cadaverine also tended to increase with administration of LKM512 yogurt. The haptoglobin content in feces decreased significantly (P<0.05) at week 2 of administration of LKM512 yogurt, and it showed a negative correlation with the polyamine content, indicating that acute intestinal inflammation was suppressed. Fecal mutagenicity was measured using fecal extract and fecal precipitate. Both preparations showed similar significant decreases (P<0.05) by the administration of LKM512 yogurt, as well as a negative correlation with polyamine content. This result indicated that antimutagenicity due to administration of LKM512 yogurt was not based on binding of the mutagen to the bacterial cell wall. Many reports have suggested that polyamines increased by the administration of LKM512 yogurt led to inhibition of inflammation and antimutagenicity in the intestinal tract.

Dietary polyamines and non-neoplastic growth and disease

This review presents the data that are now available concerning the effects of dietary polyamines at either postnatal or adult stages in non-neoplastic growth and disease. Polyamines provided by food have a potential role in growth and development of the digestive system in neonatal mammals (and fishes). In humans, this property could be of importance in preventing the appearance of food allergies. Dietary polyamines also seem necessary for the maintenance of normal growth and general properties of adult digestive tract. Their possible therapeutic effects have been investigated in gastric, intestinal, and, more recently, whole-body healing.

Dietary spermidine and spermine participate in the maturation of galactosyltransferase activity and glycoprotein galactosylation in rat small intestine

This study considered the role of dietary polyamines in the maturation of intestinal glycoprotein galactosylation during postnatal development. In the rat small intestine, O-glycan: beta-1,3-galactosyltransferase and N-glycan: beta-1,4-galactosyltransferase are, respectively, involved in the glycan chain biosynthesis of mucins and of glycoproteins in the brush border membranes. Their activities increase significantly at weaning, in parallel with a rise in the intestinal content of spermidine and spermine (as determined by high performance liquid chromatography) and in proportion to the polyamine increase in food intake. The oral ingestion of spermidine or spermine (at 0.4 micromol/g body) by immature suckling rats for 4 d reproduced the levels of spermine and spermidine in their intestines at the time of weaning and induced precocious and significant rises in O-glycan: and N-glycan: galactosyltransferase activities to those normally found after weaning. In parallel, more galactose residues (detected in the complex oligosaccharide chains of glycoproteins by specific lectins after electrophoresis and transfer to nitrocellulose membranes) were observed in the brush border membranes of spermidine- and spermine-treated rats. In contrast, the ingestion of putrescine or ornithine had no effect. Diets with different levels of polyamines (milks and commercial diet), when given at weaning, induced variable evolutions of the galactosylation process, partly in relation to the amounts of polyamines ingested. These results indicate that spermidine and spermine are maturation factors that can reproduce, in immature rats, the same increase in intestinal glycoprotein galactosylation that is normally observed during weaning. They also suggest that the maturation of glycoprotein galactosylation may be a multifactorial event in which spermidine and spermine are both involved.

Effect of ulceration on rat gastric tissue polyamine contents in response to different procedures; inhibition of these effects by cimetidine

The effects of cimetidine an H2 receptor histamine antagonist on aspirin- and cold-restraint-stress-induced gastric lesions have been studied in rats. Cimetidine had a pronounced inhibitory effect on gastric lesions induced by either oral administration of aspirin (400 mg kg-1) or by cold-restraint stress in rats. These inhibitory effects were dose-related in the aspirin treatment group being 47 and 85% (P<0.05 and P<0.001) at 37.5 and 75 mg kg-1 doses, respectively, when compared to the control. Cimetidine was found effective in cold stress but inhibition with the low dose was not significant. However, high dose (75 mg kg-1) showed a significant reduction (P<0.01) in lesion index. In another series of experiments with the same regimen, the effects of different ulcerogenic procedures on the rat gastric tissue polyamine contents (putrescine, spermine and spermidine) and monoacetyl derivatives (N1- and N8-acetylspermidine) have been investigated by using HPLC method. The procedure permits use of n-octane sulphonate as an ion pairing agent on the reversed-phase column. The treatment of rats with aspirin caused a substantial decrease in the concentration of different polyamine contents in the glandular part of stomach tissue. Pretreatment with cimetidine showed a marked protection against this decline in polyamine contents at both the doses tested (37.5 mg kg-1 and 75 mg kg-1) and increased the contents of spermidine and spermine above the control values. In the other part, cold-restraint stress also declined the polyamine contents. Low dose of cimetidine was found ineffective in this model. However, a high dose of cimetidine caused a significant rise in the levels of spermidine and spermine (P<0.001 and P<0.01, respectively) above the control levels. These findings suggest that cimetidine, besides being a H2-receptor antagonist, prevents ulcer formation due to its growth promotional properties, possibly through an increase in tissue polyamine contents that offer a defense barrier against the oxygen-derived free radicals involved in the etiology of ulceration. It is also suggested that the rise in polyamine contents of gastric tissue is a crucial event in cytoprotection against destructive stimuli.

Spermidine-induced glycoprotein fucosylation in immature rat intestine

In rat small intestine, during postnatal development, the glycoprotein fucosylation is markedly increased at weaning. At the same time, a rise in the intestinal spermidine level was observed, partly due to the increase in the spermidine content of solid food given to animals at this period as compared to the spermidine content of milk. In order to mimic the spermidine increase observed in weanling rat intestines, we had treated suckling rats with spermidine by oral ingestion to study its role as maturation factor of the small intestine. In spermidine-treated suckling rats, the spermidine and N-acetyl-spermidine contents were highly increased. Spermidine treatment induced the rise in alpha-1,2-fucosyltransferase activity and the precocious appearance in the brush-border membrane of some alpha-1,2-fucoproteins in weaned rats. Such results indicate that spermidine could be a maturation factor implicated in the appearance of alpha-1,2-fucoproteins naturally observed at weaning time.

Two distinct classes of rat intestinal mucosal enzymes incorporating putrescine into protein

Tissue-transglutaminase (t-TGase) is a family of calcium-dependent enzymes. A Ca2+-independent soluble enzyme, in addition to t-TGase, capable of incorporating polyamines into proteins was demonstrated in rat intestinal mucosa. The Ca2+-independent enzyme was stimulated 2- to 5-fold by Fe2+ and Co2+ ions but inhibited by Cu2+ and Zn2+ ions. The Ca2+-stimulated t-TGase activity was inhibited by divalent ions in the following order: Zn2+, Fe2+ >Co2+ > Cu2+. The opposite effects of EGTA, Fe2+ and Co2+ on these two enzyme activities indicate that they are two distinct classes of enzymes. Competition studies demonstrated differential preferences of the two enzymes for substrates. The Ca2+-dependent enzyme preferred putrescine, monodansylcadaverine > cadaverine, spermidine, spermine > 1,10-diaminodecane > triethylbutylamine. On the other hand, the Ca2+-independent enzyme preferred putrescine > cadaverine > spermine, I,10-diaminodecane > spermidine > monodansylcadaverine > triethylbutylamine. Further studies with divalent ions excluded the possible association of this novel Ca2+-independent enzyme with diamine oxidase. Finally, the Ca2+-independent enzyme had a higher affinity for putrescine (Km = 0.02 mM) than did Ca2+-dependent t-TGase (0.2 mM). As judged by gel filtration on HiPrep Sephacryl 200 column, the Ca2+-independent enzyme had a molecular weight of approximately 48 kDa, the intestinal Ca2+-dependent t-TGase was about 188 kDa while that of testicular t-TGase was about 96 kDa. In conclusion, the Ca2+-independent enzyme is stimulated by cobalt or ferric ions, and selectively incorporates aliphatic diamines or polyamines with symmetric amino groups. The observed Ca2+-independent enzyme activity is not related to diamine oxidase or its products. With a 10 times greater affinity for putrescine, the calcium-independent, 48-kDa intestinal enzyme may mediate polyamine function better than calcium dependent, 188-kDa intestinal tissue transglutaminase in the intestinal mucosa.

Polyamines in human and rat milk influence intestinal cell growth in vitro

BACKGROUND

Polyamines are required for intestinal growth and development. In this study, we examined whether milk can supply the polyamines needed for growth of IEC-6 cells, a line on non-transformed rat intestinal crypt cells.

METHODS

Human, bovine, and rat milk, and cow's milk-based infant formula were studied. Human, bovine, and rat milk were defatted and sterilized by filtration. IEC-6 cells were stabilized in Dulbecco's modified Eagle's medium (DMEM) containing 0.5% fetal bovine serum, 5 mM L-glutamine, 100 U/mL penicillin and 100 microg/mL streptomycin for 24 h at 37 degrees C. Thereafter, to initiate active growth, cells were placed in fresh DMEM containing 5% FBS (plus the other ingredients) supplemented with 5% (vol/vol) milk or infant formula. In some experiments, cells were also treated with difluoromethylornithine (2.5 mM) (DFMO), an inhibitor of polyamine synthesis, or dialyzed milk plus DFMO. After 44 hours of culture, cells were pulsed with 3H-thymidine (3H-TdR) for 4 hours, harvested and the radioactivity incorporated into DNA was measured.

RESULTS

Human and rat milk stimulated proliferation of IEC-6 cells (p < 0.05 compared to controls); addition of DFMO did not reverse the stimulatory effect. Bovine milk and the infant formula did not stimulate proliferation or prevent the growth inhibition induced by DFMO. After dialysis, human milk had less ability to reverse the DFMO inhibition (p < 0.05).

CONCLUSIONS

These experiments suggest that both human and rat milk, but neither bovine milk nor the infant formula, contain sufficient bioactive polyamines to sustain cell growth during inhibition of polyamine synthesis.

Dietary guar gum and pectin stimulate intestinal microbial polyamine synthesis in rats

The effects of two highly fermentable dietary fibers (guar gum and pectin) on the type and concentrations of cecal polyamines as affected by the intestinal microflora were studied in groups of germ-free (n = 10/group) and conventional rats (n = 6/group). Both germ-free and conventional rats were randomly assigned to one of three treatments as follows: 1) fiber-free control diet, 2) control diet + 10% guar gum and 3) control diet + 10% pectin. In germ-free rats, guar gum and pectin had no effect on cecal polyamine concentrations. Putrescine was confirmed to be the major endogenous polyamine within the gut lumen. In cecal contents of conventional rats, both guar gum and pectin led to the appearance of cadaverine and to elevated putrescine concentrations in comparison with the fiber-free control diet (1.35 +/- 0.15 and 2.27 +/- 0.32, respectively, vs. 0.20 +/- 0.03 micromol/g dry weight, P < 0.05). The cecal cadaverine concentration was higher in pectin- than in guar-fed rats (8.20 +/- 0.89 vs. 1.92 +/- 0.27 micromol/g dry weight, P < 0.05). Counts of total bacteria, bacteroides, fusobacteria and enterobacteria were higher (P < 0.05) in rats fed guar gum and pectin. Bifidobacteria were found exclusively in guar-fed rats. In vitro studies on selected species representing the numerically dominant population groups of the human gut flora (bacteroides, fusobacteria, anaerobic cocci and bifidobacteria) were examined for their ability to synthesize intracellular polyamines. These experiments demonstrated the ability of bacteroides, fusobacteria and anaerobic cocci to synthesize high amounts of putrescine and spermidine. Calculations based on these results suggest that the intestinal microflora are a major source of polyamines in the contents of the large intestine.

A novel calcium-independent enzyme capable of incorporating putrescine into proteins

A Ca(++)-independent enzyme capable of incorporating [3H]-putrescine into proteins was detected in the rat intestine mucosa. The Ca(++)-independent incorporation of [3H]-putrescine into proteins was temperature-, pH-, time-, and dose-dependent. However, this enzyme was absent in the gastric mucosa. Similar to testicular Ca(++)-dependent transglutaminase, the optimal pH of intestinal Ca(++)-independent enzyme was 9.0. At 10(-5) M or less putrescine concentrations, the Ca(++)-independent enzyme in an intestinal cytosol preparation showed a greater activity than did the Ca(++)-dependent transglutaminase. However, at higher putrescine concentrations, the latter showed a greater activity than did the former. Both the intestinal Ca(++)-dependent and independent enzymes were inhibited by cystamine, thermal labile at 50 degrees C and precipitated by 30 to 50% saturation of ammonium sulfate. The fact that these two enzymes shared many similar characteristics, with the exceptions of Ca(++)-requirement, suggests that they may have similar active site and intrinsic molecular function(s).

Oral administration of deuterium-labelled polyamines to sucking rat pups: luminal uptake, metabolic fate and effects on gastrointestinal maturation

Non-physiological amounts of oral polyamines have been reported to induce precocious gut maturation in rat pups. The aim of the present study was to investigate organ distribution and metabolic fate of orally administered stable-isotopically labelled polyamines in rat pups. Pups received tetradeuterium-labelled putrescine (Pu-d4; 3 mumol), spermidine (Sd-d4; 5 mumol), spermine (Sp-d4; 3 mumol), or physiological saline twice daily on postnatal days 7-10 or 12-15. They were killed on days 10 and 15. We determined activities of ileal lactase (EC 3.2.1.23), maltase (EC 3.2.1.20), sucrase (EC 3.2.1.48) and diamine oxidase (EC 1.4.3.6) and established villus and crypt lengths. Polyamines and their labelling percentages in organs were determined by GC and mass fragmentography. Treatments did not affect growth rate, but caused lower weights of liver, kidneys and heart. Maltase activity increased, lactase decreased, whereas sucrase and diamine oxidase did not change. Villus and crypt lengths increased. Organ polyamine pools were labelled to different extents. Irrespective of the orally administered polyamine, all organs contained Pu-d4, SD-d4 and Sp-d4. Administered Pu-d4 and Sd-d4 were recovered mainly as Sd-d4, whereas Sp-d4 was recovered as Sp-d4 and Sd-d4. Total polyamines in a caecum, colon and erythrocytes increased, but increases were only to a minor extent with regard to labelled polyamines. Our data confirm precocious gut maturation by exogenous polyamines. Putrescine appears to be limiting factor. The exogenous polyamines were distributed among all investigated organs. They are not only used for the synthesis of higher polyamines, but also retroconverted to their precursors. Changes in erythrocyte polyamine contents suggest precocious stimulation of erythropoiesis.

Spermine induces maturation of the immature intestinal immune system in neonatal mice

BACKGROUND

In mice, immunological adaptation of the gut to microbial and nutritional antigens occurs at weaning in parallel with biochemical and morphological maturation. Because oral administration of spermine to neonatal rats has been shown to induce biochemical and morphological maturation, we investigated whether spermine also affects maturation of the mucosal immune system.

METHODS

Swiss mice 7, 12, and 27 days old were given spermine orally (0.5 mumol/g body weight) during 3 days. Intestinal length was measured, and lactase and sucrase activities were determined. The phenotype of intraepithelial and lamina propria lymphocytes was assessed by FACS analysis using markers for CD3, TCR alpha beta, TCR gamma delta, CD4, CD8 alpha, CD8 beta, CD5, CD18, CD54, and CD49d.

RESULTS

Similar to what occurs during natural development, spermine treatment of neonatal mice increased intestinal length, decreased lactase activity, and increased sucrase activity. The percentage of intraepithelial lymphocytes expressing TCR alpha beta, CD4, CD5, and CD54, as well as the levels of expression of these antigens, increased after spermine treatment on day 12, similarly to natural maturation. The increase in expression of CD3, TCR gamma delta, CD18, and CD49d did not reach statistical significance. No effect was observed on CD8 expression. The phenotype of lamina propria lymphocytes was not affected. Spermine administration to 7- and 27-day-old mice had no effect on the phenotype of either intraepithelial or lamina propria lymphocytes.

CONCLUSIONS

Oral spermine administration to neonatal mice induced, in parallel with biochemical maturation, precocious maturation of the murine intestinal immune system and particularly affected differentiation of the intraepithelial lymphocyte population.

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.