Intestinal effects of long-lasting spermine ingestion by suckling rats

Spermine protects intestinal barrier integrity through ras-related C3 botulinum toxin substrate 1/phospholipase C-γ1 signaling pathway in piglets

Weaning stress can cause tight junctions damage and intestinal permeability enhancement, which leads to intestinal imbalance and growth retardation, thereby causing damage to piglet growth and development. Spermine can reduce stress. However, the mechanism of spermine modulating the intestinal integrity in pigs remains largely unknown. This study aims to examine whether spermine protects the intestinal barrier integrity of piglets through ras-related C3 botulinum toxin substrate 1 (Rac1)/phospholipase C-γ1 (PLC-γ1) signaling pathway. In vivo, 80 piglets were categorised into 4 control groups and 4 spermine groups (10 piglets per group). The piglets were fed with normal saline or spermine at 0.4 mmol/kg BW for 7 h and 3, 6 and 9 d. In vitro, we investigated whether spermine protects the intestinal barrier after a tumor necrosis factor α (TNF-α) challenge through Rac1/PLC-γ1 signaling pathway. The in vivo study found that spermine supplementation increased tight junction protein mRNA levels and Rac1/PLC-γ1 signaling pathway gene expression in the jejunum of piglets. The serum D-lactate content was significantly decreased after spermine supplementation (P < 0.05). The in vitro study found that 0.1 μmol/L spermine increased the levels of tight junction protein expression, Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance, and decreased paracellular permeability (P < 0.05). Further experiments demonstrated that spermine supplementation enhanced the levels of tight junction protein expression, Rac1/PLC-γ1 signaling pathway and transepithelial electrical resistance, and decreased paracellular permeability compared with the NSC-23766 and U73122 treatment with spermine after TNF-α challenge (P < 0.05). Collectively, spermine protects intestinal barrier integrity through Rac1/PLC-γ1 signaling pathway in piglets.

In Silico Analysis of Putrefaction Pathways in Bacteria and Its Implication in Colorectal Cancer

Fermentation of undigested proteins in human gastrointestinal tract (gut) by the resident microbiota, a process called bacterial putrefaction, can sometimes disrupt the gut homeostasis. In this process, essential amino acids (e.g., histidine, tryptophan, etc.) that are required by the host may be utilized by the gut microbes. In addition, some of the products of putrefaction, like ammonia, putrescine, cresol, indole, phenol, etc., have been implicated in the disease pathogenesis of colorectal cancer (CRC). We have investigated bacterial putrefaction pathways that are known to be associated with such metabolites. Results of the comprehensive in silico analysis of the selected putrefaction pathways across bacterial genomes revealed presence of these pathways in limited bacterial groups. Majority of these bacteria are commonly found in human gut. These include Bacillus, Clostridium, Enterobacter, Escherichia, Fusobacterium, Salmonella, etc. Interestingly, while pathogens utilize almost all the analyzed pathways, commensals prefer putrescine and H₂S production pathways for metabolizing the undigested proteins. Further, comparison of the putrefaction pathways in the gut microbiomes of healthy, carcinoma and adenoma datasets indicate higher abundances of putrefying bacteria in the carcinoma stage of CRC. The insights obtained from the present study indicate utilization of possible microbiome-based therapies to minimize the adverse effects of gut microbiome in enteric diseases.

Effects of spermine supplementation on the morphology, digestive enzyme activities, and antioxidant capacity of intestine in weaning rats

The main objective of this study was to investigate the effects of different doses of spermine and its extended supplementation on the morphology, digestive enzyme activities, and intestinal antioxidant capacity in weaning rats. Nineteen-day-old male rats received intragastric spermine at doses of 0.2 and 0.4 μmol/g BW for 3 or 7 d, whereas control rats received similar doses of saline. The results are as follows: 1) In the jejunum, the seven-day supplementation with both doses of spermine significantly increased crypt depth (P < 0.05) compared with the control group; the supplementation extension of the high spermine dose increased villus height and crypt depth (P < 0.05); in the ileum, the low spermine dose significantly increased villus height and crypt depth compared with the control group for 7 days (P < 0.05). 2) The 3-day supplementation with high spermine dose increased alkaline phosphatase activity in the jejunum (P < 0.05). 3) In the jejunum, the anti-hydroxyl radical (AHR), total superoxide dismutase (T-SOD), catalase (CAT), and total antioxidant capacity (T-AOC) activities were increased (P < 0.05); however, the malondialdehyde (MDA) content was reduced (P < 0.05) in groups supplemented with the high spermine dose relative to those in the control groups after 3 and 7 d; moreover, the anti-superoxide anion (ASA) and glutathione (GSH) contents increased with the high spermine dose that lasted for 3 days (P < 0.05). Furthermore, the T-SOD and CAT activities (after 3 and 7 d), ASA (after 3 d), and AHR (after 7 d) increased with the high spermine dose compared with those of the low spermine dose (P < 0.05). Extending the supplementation duration (7 d) of the high spermine dose decreased the MDA content and ASA and T-AOC activities (P < 0.05). These results suggested that spermine supplementation can modulate gut development and enhance the antioxidant status of the jejunum in weaning rats, and a dosage of 0.4 μmol spermine/g BW had better effects than the dosage of 0.2 μmol spermine/g BW on accelerating gut development and increasing antioxidant capacity.

Spermine: new insights into the intestinal development and serum antioxidant status of suckling piglets

The present work aimed at investigating the effects of spermine supplementation and extended spermine administration on the intestinal morphology, enzyme activity, and serum antioxidant capacity of suckling piglets.

Effects of spermine on the morphology, digestive enzyme activities, and antioxidant status of jejunum in suckling rats

Spermine is a ubiquitous cellular component that plays vital roles in the maintenance of nucleic acids, regulation of kinase activities, protein synthesis, control of ion channel activities and renewal of the gut epithelium.

Nutrimetabolomic analysis provides new insights into spermine-induced ileum-system alterations for suckling rats

This study aimed to investigate the effects of spermine supplementation on the ileum metabolism of suckling rats.

Metabolomic strategy for the detection of metabolic effects of spermine supplementation in weaned rats

The purpose of this study is to examine the effects of spermine supplementation on weaned rat metabolism. A metabolomic strategy employing high-resolution (1)H NMR spectroscopy and multivariate data analysis was used to investigate rat biological responses to spermine ingestion. Rats received intragastric administration of either 0.2 or 0.4 μmol/g body weight of spermine or saline for 3 days. Plasma samples taken 48 h after the last spermine ingestion were analyzed. Spermine supplementation significantly increased the plasma levels of 1-methylhistidine, 3-hydroxybutyrate, alanine, glutamate, glycerolphosphocholine, phosphorylcholine, myo-inositol, phenylalanine, lysine, glutamine, trimethylanine, tyrosine, valine, formate, glucose, and lipids. These results suggest that spermine ingestion can alter common systemic metabolic processes, including cell membrane metabolism, lipid metabolism, glucose-alanine cycle metabolism, amino acid metabolism, and gut microbiota metabolism. This study also shows the important role of spermine administration in modulating the metabolism of weaned rats.

The function of spermine

Polyamines play important roles in cell physiology including effects on the structure of cellular macromolecules, gene expression, protein function, nucleic acid and protein synthesis, regulation of ion channels, and providing protection from oxidative damage. Vertebrates contain two polyamines, spermidine and spermine, as well as their precursor, the diamine putrescine. Although spermidine has an essential and unique role as the precursor of hypusine a post-translational modification of the elongation factor eIF5A, which is necessary for this protein to function in protein synthesis, no unique role for spermine has been identified unequivocally. The existence of a discrete spermine synthase enzyme that converts spermidine to spermine suggest that spermine must be needed and this is confirmed by studies with Gy mice and human patients with Snyder-Robinson syndrome in which spermine synthase is absent or greatly reduced. In both cases, this leads to a severe phenotype with multiple effects among which are intellectual disability, other neurological changes, hypotonia, and reduced growth of muscle and bone. This review describes these alterations and focuses on the roles of spermine which may contribute to these phenotypes including reducing damage due to reactive oxygen species, protection from stress, permitting correct current flow through inwardly rectifying K(+) channels, controlling activity of brain glutamate receptors involved in learning and memory, and affecting growth responses. Additional possibilities include acting as storage reservoir for maintaining appropriate levels of free spermidine and a possible non-catalytic role for spermine synthase protein.

Immunolocalization of NOS, VIP, galanin and SP in the small intestine of suckling pigs treated with red kidney bean (Phaseolus vulgaris) lectin

Lectins belong to a family of glycoproteins that can act both beneficially and detrimentally on the morphology of the small intestine. The aim of the study was to determine whether experimental treatment with red kidney bean (Phaseolus vulgaris) lectin influences the chemical code of the small intestine nervous system of suckling pigs. The immunolocalization sites of vasoactive intestinal polypeptide (VIP), nitric oxide synthase (NOS), substance P (SP) and galanin were determined in control and lectin-treated animals. In all segments of the small intestine (duodenum, jejunum, ileum), the subpopulations of VIP-, NOS-, SP- and galanin-immunoreactive (IR) myenteric neurons were unchanged. After lectin stimulation, increased proportions of NOS-IR and decreased numbers of VIP-IR submucous neurons/mucosa innervating nerve fibers were observed in the duodenum, jejunum and ileum. In lectin-treated animals down-regulation of submucous neurons expressing SP and up-regulation of galanin-IR submucous neurons were seen in the duodenum and jejunum (but not in the ileum). The distribution patterns of NOS-IR, galanin-IR and SP-IR nerve fibers supplying the duodenum, jejunum and ileum of the lectin-treated animals showed no substantial differences in relation to control piglets. We conclude that exposure to red kidney bean (P. vulgaris) lectin substantially changes the chemical content of VIP, NOS, SP and galanin in submucous neurons of the small intestine. These results are in line with previous findings outlining the key role(s) of these substances in enteric neuroplasticity processes and may constitute the basis for further functional studies on maturation of the gut.

Enhancement of gastrointestinal absorption of ovalbumin caused by spermine induces an increase in plasma histamine levels in mice sensitized to ovalbumin

The aim of this study was to determine whether a spermine (SPM)-induced increase in gastrointestinal absorption of an allergen leads to an anaphylactic response in sensitized mice. First, we examined the enhancing effect of SPM on the gastrointestinal absorption of ovalbumin (OVA) in an in situ jejunum loop study in rats and an in vivo oral absorption study in mice. Second, we investigated whether enhancement of gastrointestinal absorption of OVA caused by SPM induces an anaphylactic response in mice sensitized to OVA. In the in situ jejunum loop study in rats, a significant amount of immune-reactive OVA was detected in the plasma after co-administration of OVA and SPM. Oral co-administration of OVA and SPM to mice in vivo also increased plasma OVA concentrations in an SPM dose-dependent manner. Furthermore, in sensitized mice, a significant increase in plasma histamine levels occurred along with the increase in plasma OVA levels after co-administration of OVA with SPM. This finding suggests that an SPM-induced increase in gastrointestinal absorption of OVA leads to an anaphylactic response. These results indicate that excess oral ingestion of SPM may have widespread health effects, including the induction of food allergies, via modulation of the function of the gastrointestinal epithelial barrier.

Influence of breast milk polyamines on suckling rat immune system maturation

The aim of this study was to ascertain whether the supplementation of polyamines present in breast milk, i.e. spermine (SPM) and spermidine (SPD), influenced the post-natal maturation of the systemic and intestinal immune system in rats. From birth, pups daily received SPM or SPD. At 5, 11 and 18 days old, small intestine intraepithelial lymphocytes (IEL), lamina propria lymphocytes (LPL) and splenocytes were phenotypically characterized. SPM and, less evidently, SPD accelerated the maturation of CD8+ IEL, and enhanced the presence of intraepithelial NK cells and IEL related with specific immune responses on the proximal and distal small intestine, respectively. Polyamines increased the percentage of more mature CD4+ LPL and enhanced the early presence of splenic B cells and, later, that of NK cells. However, no effect on Ig-secretory function was detected. These results suggest that breast milk polyamines improve the maturation of the rat intestinal and systemic immune system.

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.