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 devel...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.展开更多
BACKGROUND Colorectal cancer(CRC),the third most common cancer worldwide,has increasingly detrimental effects on human health.Radiotherapy resistance diminishes treatment efficacy.Studies suggest that spermine synthas...BACKGROUND Colorectal cancer(CRC),the third most common cancer worldwide,has increasingly detrimental effects on human health.Radiotherapy resistance diminishes treatment efficacy.Studies suggest that spermine synthase(SMS)may serve as a potential target to enhance the radiosensitivity.AIM To investigate the association between SMS and radiosensitivity in CRC cells,along with a detailed elucidation of the underlying mechanisms.METHODS Western blot was adopted to assess SMS expression in normal colonic epithelial cells and CRC cell lines.HCT116 cells were transfected with control/SMS-specific shRNA or control/pcDNA3.1-SMS plasmids.Assessments included cell viability,colony formation,and apoptosis via MTT assays,colony formation assays,and flow cytometry.Radiosensitivity was studied in SMS-specific shRNA-transfected HCT116 cells post-4 Gy radiation,evaluating cell viability,colony formation,apoptosis,DNA damage(comet assays),autophagy(immunofluorescence),and mammalian target of rapamycin(mTOR)pathway protein expression(western blot).RESULTS Significant up-regulation of SMS expression levels was observed in the CRC cell lines.Upon down-regulation of SMS expression,cellular viability and colonyforming ability were markedly suppressed,concomitant with a notable increase in apoptotic indices.Furthermore,attenuation of SMS expression significantly augmented the sensitivity of HCT116 cells to radiation therapy,evidenced by a pronounced elevation in levels of cellular DNA damage and autophagy.Impor tantly,down-regulation of SMS corresponded with a marked reduction in the expression levels of proteins associated with the mTOR signaling pathway.CONCLUSION Knocking down SMS attenuates the mTOR signaling pathway,thereby promoting cellular autophagy and DNA damage to enhance the radiosensitivity of CRC cells.展开更多
Casein kinase G (CKG) with more than 2500-fold enrichment was purified from Bufo bufo gargarizans ovaries. The catalytic activity of the enzyme was found to be associated with its 42 kD subunit, and its 26 kD subunit ...Casein kinase G (CKG) with more than 2500-fold enrichment was purified from Bufo bufo gargarizans ovaries. The catalytic activity of the enzyme was found to be associated with its 42 kD subunit, and its 26 kD subunit was found to be the major target for the enzyme auto-phosphorylation. Each full-grown oocyte contained 1.9 units of CKG corresponding to an intracellular concentration of 93 nM. After injecting an amount of 0.38 units of the enzyme into the oocyte, approximately 50% of the progesterone-induced maturation was inhibited. The inhibitory effect was enhanced in oocytes pretreated with spermine, which was consistent with the results that the enzyme was activated in vitro in the presence of spermine. The MPF-induced oocyte maturation was delayed and even prohibited in the kinase-microinjected oocytes. A 55 kD oocyte protein was identified as an substrate of CKG both in vivo and in vitro, and the enhancement of the 55 kD protein phosphorylation was associated with kinase inhibition on maturation and on protein synthesis in kinase-microinjected oocytes. As the endogenous spermine level decreased in the course of progesterone-induced oocyte maturation, 55 kD protein was dephospho-rylated. Heparin, a specific inhibitor of CKG, potentiated the progesterone-induced oocyte maturation. Altogether the experimental results indicated strongly that CKG may be the physiological target of spermine.展开更多
Spermidine or spermine but not putrescine inhibited progesterone induced Bufo bufo gargarizans oocyte maturation. The ID50 for spermine inhibition via intra - oocyte mi-croinjection on maturation induced by progestero...Spermidine or spermine but not putrescine inhibited progesterone induced Bufo bufo gargarizans oocyte maturation. The ID50 for spermine inhibition via intra - oocyte mi-croinjection on maturation induced by progesterone was 6. 8 mM(100 nl). Spermine could inhibit MPF induced toad oocyte maturation with a much higher ID50.A 55 kD protein was dephosphorylated during the process of progesterone induced oocyte maturation. Spermine selectively promoted the level of phosphorylation of ?this protein in both progesterone - stimulated and hormone - untreated oocytes. The extent of its dephosphorylation was fairly correlated with the percentage of GVBD in the hormone stimulated oocytes.The level of endogenous spermine was reduced by 28% between the period of 0. 40 GVBD50 and 0. 60 GVBD50, at which 55 kD protein was dephosphorylated.Spermine inhibited progesterone - stimulated protein synthesis in almost the same dose dependent manner as its inhibitory effect on the hormone - induced maturation. The endogenous spermine regulated 55 kD protein dephosphorylation which may trigger the increase of protein synthesis and in turn promote the activation of MPF. It is possible that 55 kD protein may be one of the components of messenger ribonucleoprotein (mRNP) particles.展开更多
Using purified bovine liver tRNA￣(Ile) and yeast tRNA￣(Phe), we studied the effects of spermine on the melting curve and melting temperature(Tm) of the tRNAs. The results showed that the absorbance at 260 nm of tRNA...Using purified bovine liver tRNA￣(Ile) and yeast tRNA￣(Phe), we studied the effects of spermine on the melting curve and melting temperature(Tm) of the tRNAs. The results showed that the absorbance at 260 nm of tRNAs decreases with the increase of temperature in the presence of 2 mmol/L spermine. We called this phenomenon hypochromism and reverse-Tm of the tRNAs. It is suggested that spermine binds to tRNAs and stabilizes the secondary structure of the tRNAs.展开更多
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 thi...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.展开更多
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 enhan...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.展开更多
Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-pur...Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-purpose tumor PET imaging and internal radiation therapy.The probe,radiolabeled with either[68Ga]Ga for diagnostic applications or[177Lu]Lu for therapeutic use,was synthesized with exceptional purity,stability,and specific activity.Extensive testing involving 12 different tumor cell lines revealed remarkable specificity towards B16 melanoma cells,showcasing outstanding tumor localization and target-to-non-target ratio.Mechanistic investigations employing polyamines,non-labeled precursor,and polyamine transport system(PTS)inhibitor,consistently affirmed the probe?s targetability through recognition of the PTS.Notably,while previous reports indicated PTS upregulation in various tumor types for targeted therapy,this study observed no positive signals,highlighting a concentration-dependent discrepancy between targeting for therapy and diagnosis.Furthermore,when labeled with[177Lu],the probe demonstrated its therapeutic potential by effectively controlling tumor growth and extending mouse survival.Investigations into biodistribution,excretion,and biosafety in healthy humans laid a robust foundation for clinical translation.This study introduces a versatile SPM-based nuclear probe with applications in precise tumor theranostics,offering promising prospects for clinical implementation.展开更多
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 g...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.展开更多
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 we...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.展开更多
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 r...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.展开更多
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）sen...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.展开更多
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 f...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.展开更多
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
^(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 ...^(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.展开更多
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 cereb...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.展开更多
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 ...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）.展开更多
<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-o...<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.展开更多
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 pol...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.展开更多
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 a...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.展开更多
基金supported by the National Natural Science Foundation of China (81921002,81900970,82130027)Innovative Research Team of High-Level Local Universities in Shanghai (SHSMUZLCX20212400)+1 种基金Young Physician Innovation Team Project (QC202003)of Ninth People’s Hospital affiliated to Shanghai Jiao Tong University School of MedicineShanghai“Rising Stars of Medical Talent”Youth Development Program is also acknowledged。
文摘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.
基金Supported by National Natural Science Foundation of China,No.82102996Guangdong Provincial Natural Science Foundation,No.2022A1515010517+1 种基金Guangzhou Science and Technology Plan Project,No.202201011016President Foundation of Nanfang Hospital,Southern Medical University,No.2020C038.
文摘BACKGROUND Colorectal cancer(CRC),the third most common cancer worldwide,has increasingly detrimental effects on human health.Radiotherapy resistance diminishes treatment efficacy.Studies suggest that spermine synthase(SMS)may serve as a potential target to enhance the radiosensitivity.AIM To investigate the association between SMS and radiosensitivity in CRC cells,along with a detailed elucidation of the underlying mechanisms.METHODS Western blot was adopted to assess SMS expression in normal colonic epithelial cells and CRC cell lines.HCT116 cells were transfected with control/SMS-specific shRNA or control/pcDNA3.1-SMS plasmids.Assessments included cell viability,colony formation,and apoptosis via MTT assays,colony formation assays,and flow cytometry.Radiosensitivity was studied in SMS-specific shRNA-transfected HCT116 cells post-4 Gy radiation,evaluating cell viability,colony formation,apoptosis,DNA damage(comet assays),autophagy(immunofluorescence),and mammalian target of rapamycin(mTOR)pathway protein expression(western blot).RESULTS Significant up-regulation of SMS expression levels was observed in the CRC cell lines.Upon down-regulation of SMS expression,cellular viability and colonyforming ability were markedly suppressed,concomitant with a notable increase in apoptotic indices.Furthermore,attenuation of SMS expression significantly augmented the sensitivity of HCT116 cells to radiation therapy,evidenced by a pronounced elevation in levels of cellular DNA damage and autophagy.Impor tantly,down-regulation of SMS corresponded with a marked reduction in the expression levels of proteins associated with the mTOR signaling pathway.CONCLUSION Knocking down SMS attenuates the mTOR signaling pathway,thereby promoting cellular autophagy and DNA damage to enhance the radiosensitivity of CRC cells.
文摘Casein kinase G (CKG) with more than 2500-fold enrichment was purified from Bufo bufo gargarizans ovaries. The catalytic activity of the enzyme was found to be associated with its 42 kD subunit, and its 26 kD subunit was found to be the major target for the enzyme auto-phosphorylation. Each full-grown oocyte contained 1.9 units of CKG corresponding to an intracellular concentration of 93 nM. After injecting an amount of 0.38 units of the enzyme into the oocyte, approximately 50% of the progesterone-induced maturation was inhibited. The inhibitory effect was enhanced in oocytes pretreated with spermine, which was consistent with the results that the enzyme was activated in vitro in the presence of spermine. The MPF-induced oocyte maturation was delayed and even prohibited in the kinase-microinjected oocytes. A 55 kD oocyte protein was identified as an substrate of CKG both in vivo and in vitro, and the enhancement of the 55 kD protein phosphorylation was associated with kinase inhibition on maturation and on protein synthesis in kinase-microinjected oocytes. As the endogenous spermine level decreased in the course of progesterone-induced oocyte maturation, 55 kD protein was dephospho-rylated. Heparin, a specific inhibitor of CKG, potentiated the progesterone-induced oocyte maturation. Altogether the experimental results indicated strongly that CKG may be the physiological target of spermine.
文摘Spermidine or spermine but not putrescine inhibited progesterone induced Bufo bufo gargarizans oocyte maturation. The ID50 for spermine inhibition via intra - oocyte mi-croinjection on maturation induced by progesterone was 6. 8 mM(100 nl). Spermine could inhibit MPF induced toad oocyte maturation with a much higher ID50.A 55 kD protein was dephosphorylated during the process of progesterone induced oocyte maturation. Spermine selectively promoted the level of phosphorylation of ?this protein in both progesterone - stimulated and hormone - untreated oocytes. The extent of its dephosphorylation was fairly correlated with the percentage of GVBD in the hormone stimulated oocytes.The level of endogenous spermine was reduced by 28% between the period of 0. 40 GVBD50 and 0. 60 GVBD50, at which 55 kD protein was dephosphorylated.Spermine inhibited progesterone - stimulated protein synthesis in almost the same dose dependent manner as its inhibitory effect on the hormone - induced maturation. The endogenous spermine regulated 55 kD protein dephosphorylation which may trigger the increase of protein synthesis and in turn promote the activation of MPF. It is possible that 55 kD protein may be one of the components of messenger ribonucleoprotein (mRNP) particles.
文摘Using purified bovine liver tRNA￣(Ile) and yeast tRNA￣(Phe), we studied the effects of spermine on the melting curve and melting temperature(Tm) of the tRNAs. The results showed that the absorbance at 260 nm of tRNAs decreases with the increase of temperature in the presence of 2 mmol/L spermine. We called this phenomenon hypochromism and reverse-Tm of the tRNAs. It is suggested that spermine binds to tRNAs and stabilizes the secondary structure of the tRNAs.
文摘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.
基金the National Natural Science Foundation of China(Nos.22071066,22071065)the National Key Research and Development Program of China(No.2016YFA0602900)+1 种基金the Guangdong Natural Science Foundation,China(No.2018B030311008)the Guangzhou Science and Technology Project,China(No.202102020802).
文摘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.
基金supported by the Science and Technology Innovation Team Talent Project of Hunan Province(No.2021RC4056)the clinical research foundation of the National Clinical Research Center for Geriatric Diseases(XIANGYA)(No.2020LNJJ01)+1 种基金the Natural Science Foundation of Hunan Province in China(No.2021JJ20084)the Science and Technology Innovation Program of Hunan Province(No.2021RC3020)。
文摘Polyamine metabolism dysregulation is a hallmark of many cancers,offering a promising avenue for early tumor theranostics.This study presents the development of a nuclear probe derived from spermidine(SPM)for dual-purpose tumor PET imaging and internal radiation therapy.The probe,radiolabeled with either[68Ga]Ga for diagnostic applications or[177Lu]Lu for therapeutic use,was synthesized with exceptional purity,stability,and specific activity.Extensive testing involving 12 different tumor cell lines revealed remarkable specificity towards B16 melanoma cells,showcasing outstanding tumor localization and target-to-non-target ratio.Mechanistic investigations employing polyamines,non-labeled precursor,and polyamine transport system(PTS)inhibitor,consistently affirmed the probe?s targetability through recognition of the PTS.Notably,while previous reports indicated PTS upregulation in various tumor types for targeted therapy,this study observed no positive signals,highlighting a concentration-dependent discrepancy between targeting for therapy and diagnosis.Furthermore,when labeled with[177Lu],the probe demonstrated its therapeutic potential by effectively controlling tumor growth and extending mouse survival.Investigations into biodistribution,excretion,and biosafety in healthy humans laid a robust foundation for clinical translation.This study introduces a versatile SPM-based nuclear probe with applications in precise tumor theranostics,offering promising prospects for clinical implementation.
基金supported by the National Natural Science Foundation of China (No. 31301986)the Academy of Kechuang Feed Industry in Sichuan and Program for Discipline Construction in Sichuan Agricultural University (to G. Liu) for financial support
文摘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.
基金financially supported by the National Natural Science Foundation of China (No. 31301986)the Academy of Kechuang Feed Industry in Sichuan and Specific Research Supporting Program for Discipline Construction in Sichuan Agricultural University (to G. Liu)
文摘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.
基金This research is supported by the Sichuan Science and Technology Program(No.2020YJ0398).
文摘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.
文摘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.
基金supported by the Fundamental Research Funds for the Jiangsu Province Medical Talent(No.ZDRCA2016065)Science and Technology Support Project of Jiangsu Province(No.BE2017763)+1 种基金Central Universities(No.3332018178)Jiangsu Planned Projects for Postdoctoral Research Funds(No.2018K240C)
文摘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.
基金Project supported by the National Natural Science Foundation of China, No.3861213 and Rockefeller Foundation RF 85049-22.
文摘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
基金The work was financially supported by the North Jiangsu Science and Technology project(No.SZ-YC2018002)the Tongzhou 510 talent project.
文摘^(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.
基金the National Natural Science Foundation of China, No. 30972855/C160203
文摘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.
基金supported by the National Natural Science Foundation of China (30800747)the Key Project of Ministry of Education of China (211107)the Science-Technology Research Project of Hubei Provincial Department of Education, China (Q20111301)
文摘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）.
文摘<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.
文摘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.
文摘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.
