Potential therapeutic role of spermine via Rac1 in osteoporosis:Insights from zebrafish and mice

Osteoporosis(OP)is a prevalent metabolic bone disease.While drug therapy is essential to prevent bone loss in osteoporotic patients,current treatments are limited by side effects and high costs,necessitating the development of more effective and safer targeted therapies.Utilizing a zebrafish(Danio rerio)larval model of osteoporosis,we explored the influence of the metabolite spermine on bone homeostasis.Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption.Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity.Notably,spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae.At the molecular level,Rac1 was identified as playing a pivotal role in mediating the antiosteoporotic effects of spermine,with P53 potentially acting downstream of Rac1.These findings were confirmed using mouse(Mus musculus)models,in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions,suggesting strong potential as a bonestrengthening agent.This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development,highlighting pivotal molecular mediators.Given their efficacy and safety,human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.

Effect of spermine on the melting curve and melting temperature of some tRNAs

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High Concentration of Spermine Induces the Dedifferentiation of Somatic Cells into Pluripotent Stem Cells

Cancer tissues contain cancer stem cells (CSCs), which play important roles in cancer metastasis. However, the mechanisms through which cancer cells dedifferentiate into stem cells have not yet been elucidated. In this study, the effects of high concentrations of polyamines produced in cancer cells on dedifferentiation were examined. The results showed that when normal human fibroblasts were cultured with high concentrations of spermine, the obtained polyamine-induced cells expressed alkaline phosphatase and marker proteins of pluripotent stem cells, although apoptosis occurred in most cells. In contrast, another polyamine-induced stem (PIS) cell line (Spe-2 PIS cells), obtained by culture in medium containing Rock, p53, and Bax inhibitors plus spermine, did not show signs of apoptosis. These Spe-2 PIS cells expressed marker proteins of pluripotent stem cells and differentiated into cardiomyocytes, brown adipocytes, and nerve cells. These results suggest that a high concentration of spermine, which often induces apoptosis in normal cells, has the capacity to dedifferentiate somatic cells into pluripotent stem cells and may be associated with the dedifferentiation of cancer cells, which continuously produce high concentrations of spermine. Moreover, the procedure to obtain Spe-2 PIS cells, which is simple and efficient, may have potential applications in regenerative medicine.

Supramolecular cyclization induced emission enhancement in a pillar[5]arene probe for discrimination of spermine

Early diagnosis and treatment of cancer requires the development of tools that are both sensitive and selective in detecting spermine.In this study,we presented a"supramolecular cyclization-induced emission enhancement"strategy for the sensitive and selective detection of spermine.A new pillar[5]arene probe(P1)demonstrated excellent solution/solid dual-state emission properties,and the addition of certain spermine(Spm)resulted in fluorescence enhancement due to the synergy of multiple weak interactions that restricted the free motion of P1 in the P1⊃Spm complex.This mechanism was further confirmed by time-resolved spectroscopy,DFT calculations,and IGM analysis.With its low limit of detection and high selectivity,P1 is a promising tool for measuring spermine in artificial urine samples.

New insights into the role of spermine in enhancing the antioxidant capacity of rat spleen and liver under oxidative stress

Oxidative stress can damage cellular antioxidant defense and reduce livestock production efficiency.Spermine is a ubiquitous cellular component that plays important roles in stabilizing nucleic acids,modulating cell growth and differentiation, and regulating ion channel activities. Spermine has the potential to alleviate the effects of oxidative stress. However, to date no information is available about the effect of spermine administration on antioxidant property of the liver and spleen in any mammalian in vivo system. This study aims to investigate the protective effect of spermine on rat liver and spleen under oxidative stress. Rats received intragastric administration of either 0.4 μmol/g body weight of spermine or saline once a day for 3 days. The rats in each treatment were then injected with either diquat or sterile saline at 12 mg/kg body weight. Liver and spleen samples were collected 48 h after the last spermine ingestion.Results showed that regardless of diquat treatment, spermine administration significantly reduced the malondialdehyde(MDA) content by 23.78% in the liver and by 5.75% in the spleen, respectively(P < 0.05).Spermine administration also enhanced the catalase(CAT) activity, anti-hydroxyl radical(AHR) capacity and glutathione(GSH) content by 38.68%, 15.53% and 1.32% in the spleen, respectively(P< 0.05). There were interactions between spermine administration and diquat injection about anti-superoxide anion(ASA),AHR capacity, CAT activity, GSH content, and total antioxidant capacity(T-AOC) in the liver and about ASA capacity and T-AOC in the spleen of weaned rats(P < 0.05). Compared with the control group, spermine administration significantly increased the AHR capacity, CAT activity, GSH content, and T-AOC by 40.23%,31.15%, 30.25%, 35.37% in the liver, respectively(P < 0.05) and increased the T-AOC by 8% in the spleen of weaned rats(P < 0.05). Compared with the diquat group, spermine + diquat group significantly increased ASA capacity by 15.63% in the liver and by 73.41% in the spleen of weaned rats, respectively(P < 0.05).Results demonstrate that spermine administration can increase the antioxidant capacity in the liver and spleen and can enhance the antioxidant status in the spleen and liver under oxidative stress.

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 and0.4 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 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-g1(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 a(TNF-a)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 mmol/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-a challenge(P<0.05).Collectively,spermine protects intestinal barrier integrity through Rac1/PLC-γ1 signaling pathway in piglets.

Spermine increases bactericidal activity of silver-nanoparticles against clinical methicillin-resistant Staphylococcus aureus

Methicillin-resistant Staphylococcus aureus(MRSA) has emerged worldwide as a major multidrugresistant pathogen that causes notable morbidity and mortality. Fast emerging of MRSA prevalence requires special attention for strengthening the inventory of antimicrobial compounds. Silver nanoparticles(AgNPs) have been widely used to treat multi-drug resistant pathogens due to the unique antibacterial properties, meanwhile spermine has been proven to exert outstanding inhibition effect to S.aureus with not yet fully understood mechanisms. The aim of this study was to investigate the synergistic effect of AgNPs and spermine as well as to determine the antibacterial activity of their combination against MRSA strains. Several clinical MRSA isolates and ATCC BAA-1026 were used to determine minimum inhibitory concentration(MIC) and fractional inhibitory concentration indices(FICI) of AgNPs and spermine, and a synergistic effect was observed. This phenomenon was further confirmed by growth curve and time-killing assays, showed that spermine could be used as an adjuvant for AgNPs in the treatment of MRSA infections.

SPERMINE——AN INHIBITION OF in vitro CAPACITATION AND FERTILIZATION IN HAMSTER SPERM

I. INTRODUCTION The polyamines, putrescine, spermidine and spermine exist in all mammalian tissues and fluids. In semen, spermine is frequently present in high concentrations. However, the

Spermine induced reversible collapse of deoxyribonucleic acid-bridged nanoparticle-based assemblies

DNA-linked 2D and 3D nano-assemblies find use in a diverse set of applications, ranging from DNA-origami in drug delivery and medical imaging, to DNA-linked nanoparticle structures for use in plasmonics and （bio）sensing. However, once these structures have been fully assembled, few options are available to modulate structure geometry. Here, we investigated the use of the polycation spermine to induce DNA collapse in small oligonucleotide-linked （54 bp） gold nanoparticle structures by monitoring shifts in the localized surface plasmon resonance （LSPR） peak and by comparing the data with finite-difference time-domain （FDTD） simulations. Our data shows that low concentrations of spermine can be applied to induce large changes in DNA conformation, leading to a significant reduction in interparticle distance （from - 25 to - 3 nm） and enhanced plasmonic coupling. The DNA collapse is near-instantaneous and reversible, and its application at low and high DNA densities is demonstrated with surface plasmon resonance imaging （SPRi）, showing the potential of spermine to dynamically modulate distances and geometry in DNA-based nano-assemblies.

Changes in the sugars,amino acids and organic acids of postharvest sperminetreated immature vegetable soybean(Glycine max L.Merr.)as determined by^(1)H NMR spectroscopy

^(1)H NMR spectroscopy was adopted to determine compositional changes(mainly sugars,organic acids and amino acids)involved in cold-stored immature soybean grains after exogenous spermine treatment.Significant changes of sugars,including sucrose,galactose,myo-inositol,glucose and fructose were detected in soybean after spermine treatment.As for the organic acids related to tricarboxylic acid cycle,the levels of malic and fumaric acids decreased but the level of citric acid increased.However,no significant changes were observed for amino acids in spermine-treated soybeans.By using metabolic profile analysis,a difference was observed between the aging of soybean grains as such and those treated with spermine.This study provides an insight into the accumulation of metabolites in postharvest immature soybeans after exogenous spermine-treatment.

Effects of the mitochondrial calcium uniporter on cerebral edema in a rat model of cerebral ischemia reperfusion injury

The present study investigated the effects of the mitochondrial calcium uniporter inhibitor ruthenium red and the agonist spermine on cerebral edema in rats with cerebral ischemia reperfusion injury. Left middle cerebral artery occlusion （MCAO） was induced in rats using the suture method. Following 24 hours of ischemic reperfusion, neurological function scores of rats with MCAO, and rats pretreated with ruthenium red and spermine were significantly lower, however, water content of brain tissue, aquaporin 4 expression and immunoglobulin G （IgG） exudation were significantly higher than those of sham-operated rats. Compared with MCAO rats and spermine-treated rats, neurological function scores were considerably higher, and brain tissue water content, aquaporin 4 expression and IgG exudation decreased in ruthenium red-treated rats. These findings suggest that preventive application of the mitochondrial calcium uniporter inhibitor ruthenium red can significantly decrease aquaporin 4 and IgG expression, influence the permeability of the blood brain barrier, and thereby decrease the extent of cerebral edema.

Interacted Effect of Arbuscular Mycorrhizal Fungi and Polyamines on Root System Architecture of Citrus Seedlings

Either arbuscular mycorrhizal fungi （AMF） or polyamines （PAs） may change root system architecture （RSA） of plants, whereas the interaction of AMF and PAs on RSA remains unclear. In the present study, we studied the interaction between AMF （Paraglomus occultum） and exogenous PAs, including putrescine （Put）, spermidine （Spd） and spermine （Spin） on mycorrhizal development of different parts of root system, plant growth, RSA and carbohydrate concentrations of 6-m-old citrus （Citrus tangerine Hort. ex Tanaka） seedlings. After 14 wk of PAs application, PA-treated mycorrhizal seedlings exhibited better mycorrhizal colonization and numbers of vesicles, arbuscules, and entry points, and the best mycorrhizal status of taproot, first-, second-, and third-order lateral roots was respectively found in mycorrhizal seedlings supplied with Put, Spd and Spm, suggesting that PAs might act as a regulated factor of mycorrhizal development through transformation of root sucrose more into glucose for sustaining mycorrhizal development. AMF usually notably increases RSA traits （taproot length, total length, average diameter, projected area, surface area, volume, and number of first-, second-, and third-order lateral roots） of only PA-treated seedlings. Among the three PA species, greater positive effects on RSA change and plant biomass increment of the seedlings generally rank as Spd〉Spm〉Put, irrespective of whether or not AMF colonization. PAs significantly changed the RSA traits in mycorrhizal but not in non-mycorrhizal seedlings. It suggests that the application of PAs （especially Spd） to AMF plants would optimize RSA of citrus seedlings, thus increasing plant growth （shoot and root dry weight）.

Effect of diethylstilbestrol on polyamine metabolism in hamster epididymis

<abstract>Aim: To investigate the effect of diethylstilbestrol (DES), one of the most potent endocrine disruptors, on the metabolism of polyamines in hamster epididymis. Methods: Male golden hamsters of 7-week-old were kept under a light and dark cycle of 14 h and 10 h for 1 week to stimulate maximally the gonadal function. DES was injected subcutaneously at doses of 0.01 mg·kg-1·day-1, 0.1 mg·kg-1·day-1 and 1 mg·kg-1·day-1 for one week. Results: DES treatment caused a significant decrease in the weight of epididymis. The activity of epididymal ornithine decar boxylase (ODC) increased 1 day after DES treatment, kept at a high level for 4 days and then decreased to nearly normal level at day 7. The activity of spermidine/spermine N1-acetyltransferase (SSAT) also increased transiently after DES treatment. The contents of putrescine, spermidine, spermine and N1-acetylspermidine were increased 1 day -4 days after DES treatment and restored to normal at day 7. All these changes showed a marked difference between the caput and the cauda. Conclusion: The polyamine biosynthesis in the hamster epididymis can be affected by DES, a xenoestrogen. DES may probably affect polyamine metabolism in the epididymis by regulating the rate-limiting enzymes involved in the polyamine biosynthesis.

High Performance Liquid Chromatography Separation and Simultaneous Fluorometric Detection of Trace Amount of Polyamines in Ce

A highly sensitive and precise method for the determination of the polyamines (including putrescine, spermidine and spermine) in cell culture media is described. The samples were concentrated by C18 column and the polyamines were converted to fluorometric derivatives with DNS-Cl. The polyamine derivatives were then completely separated by HPLC and determined by simultaneous fluorometric detection. The CV of intragroup and intergroup were 2. 49 %-4. 26% and 4. 29 %-5. 16 %, respectively. The rate of recovery was 103%- 99%. There was trace amount of polyamines detected by this method in the media of F12, 8900, RPMI1640, DMEM and M199 even without incubation with cells. So this method can be used for detecting the changes of polyamines in a medium before and after incubation with cells. It is helpful for the researches on the regulation of cell proliferation by polyamines.

Polyamines and polyamine-metabolizing enzymes in schizophrenia: Current knowledge and concepts of therapy

Polyamines play preeminent roles in a variety of cellular functions in the central nervous system and other organs.A large body of evidence suggests that the polyamine pathway is prominently involved in the etiology and pathology of schizophrenia.Alterations in the expression and activity of polyamine metabolizing enzymes,as well as changes in the levels of the individual polyamines,their precursors and derivatives,have been measured in schizophrenia and animal models of the disease.Additionally,neuroleptic treatment has been shown to influence polyamine concentrations in brain and blood of individuals with schizophrenia.Thus,the polyamine system may appear to be a promising target for neuropharmacological treatment of schizophrenia.However,for a number of practical reasons there is currently only limited hope for a polyamine-based schizophrenia therapy.

Changes in the Ovarian Polyamine Content and Seed Set Efficiency of Cotton by the Plant Growth Regulator BM86

Naturally occurring polyamines in plants have been implicated in floral initiation, and fruit development. The plant growth regulator BM86 was formulated to stimulate seed production and fruit growth by enhancing polyamine synthe-sis. The objectives of this study were to determine the effect of BM86 on free polyamine content in cotton (Gos-sypium hirsutum L.) ovaries and on seed set efficiency, and also to investigate genotypic differences in ovarian polyamine content. BM86 was applied at the first flower stage and two weeks later at 2.34 mL/ha. This study showed that application of BM86 had a significant positive effect on ovarian polyamine content of cotton. Putrescine and sper-midine one week after the 1st BM86 application and putrescine two week after the 1st BM86 application, were significantly increased compared to the untreated control. Higher seed set efficiency with the BM86 application was observed when the total number of seeds was used for the calculation. However, when the number of harvestable seeds was used to calculate seed set efficiency BM86 had no significant effect. In addition, application of BM86 did not significantly alter seedcotton yield of the crop. Only small differences in ovarian polyamine content were detected among the genotypes tested, possibly due to the narrow genetic pool of the commercial cotton genotypes used. Application of BM86 can significantly increase cotton seed number by enhancing polyamines biosynthesis, but further research is needed to determine how to capitalize on the increased potential number of harvestable seeds.

Fluorescent Nile blue-functionalized poly(N-isopropylacrylamide)microgels responsive to temperature and polyamines

Fluorescent poly(N-isopropylacrylamide-co-Nile blue)(pNIPAm-co-NB)microgels were synthesized that exhibited fluorescence intensity changes in a water temperature-dependent fashion.NB is well known to exhibit fluorescence intensity that depends on the hydrophobicity of the environment,while pNIPAm-based microgels are well known to transition from swollen(hydrophilic)to collapsed(relatively hydrophobic)at temperatures greater than 32℃;hence,we attribute the above behavior to the hydrophobicity changes of the microgels with increasing temperature.This phenomenon is ultimately due to NB dimers(relatively quenched fluorescence)being broken in the hydrophobic environment of the microgels leading to relatively enhanced fluorescence.We went on to show that the introduction of cucurbit[7]uril(CB[7])into the pNIPAm-co-NB microgels enhanced their fluorescence allowing them to be used for polyamine(e.g.,spermine[SPM])detection.Specifically,CB[7]forms a host–guest interaction with NB in the microgels,which prevents NB dimerization and enhances their fluorescence.When SPM is present,it forms a host–guest complex that is favored over the CB[7]-NB host–guest interaction,which frees the NB for dimerization and leads to fluorescence quenching.As a result,we could generate an SPM sensor capable of SPM detection down to~0.5µmol/L in complicated matrixes such as serum and urine.

Metagenomes of polyamine-transforming bacterioplankton along a nearshore-open ocean transect

Short-chained aliphatic polyamines (PAs) have recently been recognized as an important carbon, nitrogen, and/or energy source for marine bacterioplankton. To study the genes and taxa involved in the transformations of different PA compounds and their potential variations among marine systems, we collected surface bacterioplankton from nearshore, offshore, and open ocean stations in the Gulf of Mexico and examined their metagenomic responses to additions of single PA model compounds (putrescine, spermidine, or spermine). Genes affiliated with PA uptake and all three known PA degradation pathways, i.e., transamination, γ-glutamylation, and spermidine cleavage, were significantly enriched in most PA-treated metagenomes. In addition, identified PA-transforming taxa were mostly the alpha and gamma classes of Proteobacteria, with less important contributions from members of Betaproteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria, Firmicutes, and Planctomycetes. These findings suggest that PA transformations are ubiquitous, have diverse pathways, and are carried out by a broad range of the bacterioplankton taxa in the Gulf of Mexico. Identified PA-transforming bacterial genes and taxa were different among nearshore, offshore, and open ocean sites, but were little different among individual compound-amended metagenomes at any specific site. These observations further indicate that PA-transforming taxa and genes are site-specific and with high similarities among PA compounds.