Search

Osteoporosis 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 anti-osteoporotic 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 bone-strengthening 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.

Purpose: The combination of cisplatin and gemcitabine-based chemotherapy has been recommended as a preferred regimen for pancreatic ductal adenocarcinoma (PDAC) patients with germline-based mutations. However, the underlying mechanism remains poorly elucidated. Therefore, our study aimed to explore the mechanistic basis of the cell-killing activity of gemcitabine plus cisplatin and identify potential therapeutic targets., Methods: First, we explored the synergistic cytotoxic effects of gemcitabine and cisplatin on PDAC through in vitro and in vivo experiments. Then, we investigated ferroptosis-related biomarkers, to assess the impact of the combination therapy on ferroptosis. Using bioinformatics methods, we identified SAT1 as a potential key mediator of ferroptosis induced by gemcitabine and cisplatin. We tested the polyamine levels in PDAC cells by LC-MS after overexpressed or knocked down SAT1, and explored the role of polyamines in ferroptosis using exogenous supplementation. Finally, we explored the regulatory effect of Sp1 on SAT1 through ChIP-qPCR and dual-luciferase reporter assay., Results: Gemcitabine plus cisplatin enhanced cell death and induced ferroptosis in PDAC. This combination upregulated SAT1 transcription by inhibiting Sp1. SAT1 activation promoted the catabolism of spermine and spermidine, leading to iron accumulation and lipid peroxide generation, ultimately resulting in ferroptosis., Conclusions: In summary, our findings suggested the gemcitabine and cisplatin combination therapy induced ferroptosis in a GSH-independent manner in PDAC. The combined treatment inhibited Sp1 and upregulated SAT1 transcription, leading to the breakdown of spermine and spermidine. Therefore, targeting SAT1-induced polyamine metabolism may represent a promising therapeutic strategy for PDAC., (© 2023. Springer Nature Switzerland AG.)

Importance: This is the first study that attempted to demonstrate the mechanisms of reactive oxygen species (ROS) generation by spermine (Spm) in Mycobacterium tuberculosis (M.tb). Furthermore, this is the first study to demonstrate that it is able to enhance the activity of currently available and World Health Organization (WHO)-approved tuberculosis (TB) drugs. Spermine can easily be obtained since it is already found in our diet. Moreover, as opposed to conventional antibiotics, it is less toxic to humans since it is found in millimolar concentrations in the body. Finally, with the difficulty of curing TB with conventional antibiotics, this study suggests that less toxic molecules, such as Spm, could in a long-term perspective be incorporated in a TB regimen to boost the treatment., Competing Interests: The authors declare no conflict of interest.

Purpose: To evaluate the safety, tolerability, pharmacokinetics, and efficacy of kukoamine B (KB), an alkaloid compound with high affinity for both lipopolysaccharide (LPS) and oligodeoxynucle-otides containing CpG motifs (CpG DNA), in patients with sepsis-induced organ failure., Materials and Methods: This was a multicenter, randomized, double-blind, placebo-controlled phase IIa trial. Patients with sepsis-induced organ failure were randomized to receive either KB (0.06, 0.12, or 0.24 mg/kg) or placebo, every 8 h for 7 days. Primary endpoint was safety, and secondary endpoints included pharmacokinetic (PK) parameters, changes in inflammatory mediators' level, and prognostic parameters., Results: Of 44 patients enrolled, adverse events occurred in 28 patients [n = 20, 66.7% (KB pooled); n = 8, 57.1% (placebo)], while treatment emergent adverse events were reported in 14 patients [n = 10, 33.3% (KB pooled); n = 4, 28.6% (placebo)]. Seven patients died at 28-day follow-up [n = 4, 13.3% (KB pooled); n = 3, 21.4% (placebo)], none was related to study drug. PK parameters suggested dose-dependent drug exposure and no drug accumulation. KB did not affect clinical outcomes such as ΔSOFA score, vasopressor-free days or ventilator-free days., Conclusions: In patients with sepsis-induced organ failure, KB was safe and well tolerated. Further investigation is warranted., Trial Registration: http://ClinicalTrials.gov, NCT03237728., Competing Interests: Declaration of Competing Interest All authors declare that they have no competing interests., (Copyright © 2023. Published by Elsevier Inc.)

Asthma is a heterogeneous chronic airway disease with an unmet need for improved therapeutics in uncontrolled severe disease. The calcium-sensing receptor (CaSR) is a G protein-coupled receptor upregulated in asthma. The CaSR agonist, spermine, is also increased in asthmatic airways and contributes to bronchoconstriction. CaSR negative allosteric modulators (NAMs) oppose chronic airway inflammation, remodeling, and hyperresponsiveness in murine and guinea pig asthma models, but whether CaSR NAMs are effective acute bronchodilators compared with standard of care has not yet been established. Furthermore, the ability of different classes of NAMs to inhibit spermine-induced CaSR signaling or methacholine (MCh)-induced airway contraction has not been quantified. Here, we show CaSR NAMs differentially inhibit spermine-induced intracellular calcium mobilization and inositol monophosphate accumulation in HEK293 cells stably expressing the CaSR. NAMs reverse MCh-mediated airway contraction in mouse precision-cut lung slices with similar maximal relaxation compared with the standard treatment, salbutamol. Of note, the bronchodilator effects of CaSR NAMs are maintained under conditions of β 2 -adrenergic receptor desensitization when salbutamol efficacy is abolished. Furthermore, overnight treatment with some, but not all, CaSR NAMs prevents MCh-mediated bronchoconstriction. These findings further support the CaSR as a putative drug target and NAMs as alternative or adjunct bronchodilators in asthma.

Chemotherapy based on molecular drugs remains the most frequently used approach for the therapy of tumors, however their poor specificity, severe side effects and tumor resistance often seriously hinder their applications. It is therefore desirable to develop a new, alternative therapeutic strategy for tumor treatment without traditional chemotherapeutic drugs. Herein, we report a drug-free tumor therapy approach involving spermine (SPM)-responsive intracellular biomineralization in tumor cells. In this work, we designed calcium carbonate (CaCO 3 ) nanoparticles capped with folic acid and supramolecular peptides, which could target tumor cells and rapidly self-aggregate into micron-sized CaCO 3 aggregates in SPM-overexpressed tumor cells. Due to the extended intracellular retention, CaCO 3 aggregates could induce intracellular biomineralization and Ca 2+ overload of tumor cell, leading to mitochondrial damage and cellular apoptosis, resulting in effective inhibition of tumor growth without serious side effects otherwise seen in conventional chemotherapy., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

The polyamines putrescine, spermidine and spermine are nutrient-like polycationic molecules involved in metabolic processes and signaling pathways linked to cell growth and cancer. One important pathway is the PI3K/Akt pathway where studies have shown that polyamines mediate downstream growth effects. Downstream of PI3K/Akt is the mTOR signaling pathway, a nutrient-sensing pathway that regulate translation initiation through 4EBP1 and p70S6K phosphorylation and, along with the PI3K/Akt, is frequently dysregulated in breast cancer. In this study, we investigated the effect of intracellular polyamine modulation on mTORC1 downstream protein and general translation state in two breast cancer cell lines, MCF-7 and MDA-MB-231. The effect of mTORC1 pathway inhibition on the growth and intracellular polyamines was also measured. Results showed that polyamine modulation alters 4EBP1 and p70S6K phosphorylation and translation initiation in the breast cancer cells. mTOR siRNA gene knockdown also inhibited cell growth and decreased putrescine and spermidine content. Co-treatment of inhibitors of polyamine biosynthesis and mTORC1 pathway induced greater cytotoxicity and translation inhibition in the breast cancer cells. Taken together, these data suggest that polyamines promote cell growth in part through interaction with mTOR pathway. Similarly intracellular polyamine content appears to be linked to mTOR pathway regulation. Finally, dual inhibition of polyamine and mTOR pathways may provide therapeutic benefits in some breast cancers.

Natural polyamines (PAs) are key players in cellular homeostasis by regulating cell growth and proliferation. Several observations highlight that PAs are also implicated in pathways regulating cell death. Indeed, the PA accumulation cytotoxic effect, maximized with the use of bovine serum amine oxidase (BSAO) enzyme, represents a valuable strategy against tumor progression. In the present study, along with the design, synthesis, and biological evaluation of a series of new spermine (Spm) analogues ( 1-23 ), a mixed structure-based (SB) and ligand-based (LB) protocol was applied. Binding modes of BSAO-PA modeled complexes led to clarify electrostatic and steric features likely affecting the BSAO-PA biochemical kinetics. LB and SB three-dimensional quantitative structure-activity relationship (Py-CoMFA and Py-ComBinE) models were developed by means of the 3d-qsar.com portal, and their analysis represents a strong basis for future design and synthesis of PA BSAO substrates for potential application in oxidative stress-induced chemotherapy.

The biogenic aliphatic polyamines (spermine, spermidine, and putrescine) are responsible for numerous cell functions, including cell proliferation, the stabilization of nucleic acid conformations, cell division, homeostasis, gene expression, and protein synthesis in living organisms. The change of polyamine concentrations in the urine or blood is usually related to the presence of malignant tumors and is regarded as a biomarker for the early diagnosis of cancer. Therefore, the detection of polyamine levels in physiological fluids can provide valuable information in terms of cancer diagnosis and in monitoring therapeutic effects. In this review, we summarize the recent advances in fluorescent methods for polyamine detection (supramolecular fluorescent sensing systems, fluorescent probes based on the chromophore reaction, fluorescent small molecules, and fluorescent nanoparticles). In addition, tumor polyamine-suppressing strategies (such as polyamine conjugate, polyamine analogs, combinations that target multiple components, spermine-responsive supramolecular chemotherapy, a combination of polyamine consumption and photodynamic therapy, etc.) are highlighted. We hope that this review promotes the development of more efficient polyamine detection methods and provides a comprehensive understanding of polyamine-based tumor suppressor strategies., Competing Interests: The authors declare no conflict of interest.

Multiple sclerosis (MS) is a chronic neuroinflammatory disease which causes demyelination, axonal damage and even disability. Th1 and Th17 cells, more precisely, the IFNγ/IL17a double producing CD4 + T cells, have been known to play critical roles in the pathogenesis of MS and EAE, a mouse model of MS. Polyamines not only regulate the immune system, but also are essential for the normal function of the central nervous system (CNS). In this study, we demonstrate that the supplementation of spermine (SPM), a biogenic polyamine, significantly suppresses EAE progression in both preventative and therapeutic ways. Further study suggests that spermine significantly reduces IFNγ + /IL17a - , IFNγ - /IL17a + and IFNγ + /IL17a + cells in periphery, and thus reducing the infiltration of these pathogenic cells into the CNS. In vitro, spermine has been shown to suppress the activation and proliferation of CD4 + T cells and also significantly impede the polarization of T effector cells in a dose-dependent manner, accompanied by the inhibition of ERK phosphorylation. Consistently, a number of MEK/ERK inhibitors (including PD0325901, FR180204 and selumetinib) have been found to mimic the effects of spermine in inhibiting CD4 + T cell activation and T effector cell differentiation. Collectively, spermine alleviates EAE progression by inhibiting CD4 + T cells activation and T effector cell differentiation in a MAPK/ERK-dependent manner, suggesting this pathway might be a target to develop effective therapies for MS., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Nitric oxide is a small gaseous molecule that plays important roles in the majority of biological functions. Impairments of NO-related pathways contribute to the majority of neurological disorders, such as Alzheimer's disease (AD), and mental disorders, such as schizophrenia. Cognitive decline is one of the most serious impairments accompanying both AD and schizophrenia. In the present study, the activities of NO donors, slow (spermine NONOate) or fast (DETANONOate) releasers, and selective inhibitor of neuronal nitric oxide synthase N(ω)-propyl-l-arginine (NPLA) were investigated in pharmacological models of schizophrenia and AD. Cognitive impairments were induced by administration of MK-801 or scopolamine and were measured in novel object recognition (NOR) and Y-maze tests. The compounds were investigated at doses of 0.05-0.5 mg/kg. The dose-dependent effectiveness of all the compounds was observed in the NOR test, while only the highest doses of spermine NONOate and NPLA were active in the Y-maze test. DETANONOate was not active in the Y-maze test. The impact of the investigated compounds on motor coordination was tested at doses of 0.5 and 1 mg/kg. Only NPLA at a dose of 1 mg/kg slightly disturbed motor coordination in animals., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Snyder Robinson Syndrome (SRS) is a rare disease associated with a defective spermine synthase gene and low intracellular spermine levels. In this study, a spermine replacement therapy was developed using a spermine prodrug that enters cells via the polyamine transport system. The prodrug was comprised of three components: a redox-sensitive quinone "trigger", a "trimethyl lock (TML)" aryl "release mechanism", and spermine. The presence of spermine in the design facilitated uptake by the polyamine transport system. The quinone-TML motifs provided a redox-sensitive agent, which upon intracellular reduction generated a hydroquinone, which underwent intramolecular cyclization to release free spermine and a lactone byproduct. Rewardingly, most SRS fibroblasts treated with the prodrug revealed a significant increase in intracellular spermine. Administering the spermine prodrug through feeding in a Drosophila model of SRS showed significant beneficial effects. In summary, a spermine prodrug is developed and provides a lead compound for future spermine replacement therapy experiments.

Mutations in the beta-amyloid protein (APP) cause familial Alzheimer's disease. In hAPP-J20 mice expressing mutant APP, pharmacological inhibition or genetic ablation of the tyrosine phosphatase PTP1B prevents CA3 hippocampus neuron loss and cognitive decline. However, how targeting PTP1B affects the cellular mechanisms underlying these cognitive deficits remains unknown. Changes in synaptic strength at the hippocampus can affect information processing for learning and memory. While prior studies have focused on post-synaptic mechanisms to account for synaptic deficits in Alzheimer's disease models, presynaptic mechanisms may also be affected. Here, using whole cell patch-clamp recording, coefficient of variation (CV) analysis suggested a profound presynaptic deficit in long-term potentiation (LTP) of CA3:CA1 synapses in hAPP-J20 mice. While the membrane-impermeable ionotropic NMDA receptor (NMDAR) blocker norketamine in the post-synaptic recording electrode had no effect on LTP, additional bath application of the ionotropic NMDAR blockers MK801 could replicate the deficit in LTP in wild type mice. In contrast to LTP, the paired-pulse ratio and short-term facilitation (STF) were aberrantly increased in hAPP-J20 mice. These synaptic deficits in hAPP-J20 mice were associated with reduced phosphorylation of NMDAR GluN2B and the synaptic vesicle recycling protein NSF (N-ethylmaleimide sensitive factor). Phosphorylation of both proteins, together with synaptic plasticity and cognitive function, were restored by PTP1B ablation or inhibition by the PTP1B-selective inhibitor Trodusquemine. Taken together, our results indicate that PTP1B impairs presynaptic NMDAR-mediated synaptic plasticity required for spatial learning in a mouse model of Alzheimer's disease. Since Trodusquemine has undergone phase 1/2 clinical trials to treat obesity, it could be repurposed to treat Alzheimer's disease., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Subanesthetic doses of ketamine induce schizophrenia-like behaviors in mice including hyperlocomotion and deficits in working memory and sensorimotor gating. Here, we examined the effect of in vivo ketamine administration on neuronal properties and endocannabinoid (eCB)-dependent modulation of synaptic transmission onto layer 2/3 pyramidal neurons in brain slices of the prefrontal cortex, a region tied to the schizophrenia-like behavioral phenotypes of ketamine. Since deficits in working memory and sensorimotor gating are tied to activation of the tyrosine phosphatase PTP1B in glutamatergic neurons, we asked whether PTP1B contributes to these effects of ketamine. Ketamine increased membrane resistance and excitability of pyramidal neurons. Systemic pharmacological inhibition of PTP1B by Trodusquemine restored these neuronal properties and prevented each of the three main ketamine-induced behavior deficits. Ketamine also reduced mobilization of eCB by pyramidal neurons, while unexpectedly reducing their inhibitory inputs, and these effects of ketamine were blocked or occluded by PTP1B ablation in glutamatergic neurons. While ablation of PTP1B in glutamatergic neurons prevented ketamine-induced deficits in memory and sensorimotor gating, it failed to prevent hyperlocomotion (a psychosis-like phenotype). Taken together, these results suggest that PTP1B in glutamatergic neurons mediates ketamine-induced deficits in eCB mobilization, memory and sensorimotor gating whereas PTP1B in other cell types contributes to hyperlocomotion. Our study suggests that the PTP1B inhibitor Trodusquemine may represent a new class of fast-acting antipsychotic drugs to treat schizophrenia-like symptoms., (Copyright © 2021 The Authors. Published by Elsevier Inc. All rights reserved.)

Myocardial fibrosis is one of the main pathological manifestations of diabetic cardiomyopathy (DCM). Spermine (SPM), a product of polyamine metabolism, plays an important role in many cardiac diseases including hypertrophy, ischemia, and infarction, but its role in diabetic myocardial fibrosis has not been clarified. This study aimed to investigate the role of polyamine metabolism, specifically SPM, in diabetic myocardial fibrosis and to explore the related mechanisms. We used intraperitoneal injection of streptozotocin (STZ, 60 mg/kg) in Wistar rats and high glucose (HG, 40 mM) stimulated cardiac fibroblasts (CFs) to established a type 1 diabetes (T1D) model in vivo and in vitro, which were pretreated with exogenous SPM (5 mg/kg per day and 5 μM). The results showed that hyperglycemia induced the expression of the key polyamine synthesis enzyme ornithine decarboxylase (ODC) decreased and the key catabolic enzyme spermidine/spermine N 1 -acetyltransferase (SSAT) increased compared with those in the control group. The body weight, blood insulin level, and cardiac ejection function were decreased, while blood glucose, heart weight, the ratio of heart weight to body weight, myocardial interstitial collagen deposition, and endoplasmic reticulum stress (ERS)-related protein (glucose-regulated protein-78, glucose-regulated protein-94, activating transcription factor-4, and C/EBP homology protein) expression in the T1D group were all significantly increased. HG also caused an increased expression of Wnt3, β-catenin (in cytoplasm and nucleus), while Axin2 and phosphorylated β-catenin decreased. Exogenous SPM improved the above changes caused by polyamine metabolic disorders. In conclusion, polyamine metabolism disorder occurs in the myocardial tissue of diabetic rats, causing myocardial fibrosis and ERS. Exogenous SPM plays a myocardial protective role via inhibiting of ERS and the canonical Wnt/β-catenin signaling pathway., (© 2020 International Federation for Cell Biology.)

Objective: To observe the protective effects of exogenous spermine on renal fibrosis induced by diabetic nephropathy (DN) and to explore its mechanism. Methods: Twenty-four male C57 mice were randomly divided into control group, type 1 diabetes group (TID) and spermine pretreatment group (TID+Sp, n=8 in each group). TID mice were induced by STZ (60 mg/kg), and TID+Sp mice were pretreated with spermine (5 mg/(kg·d)) for 2 weeks before STZ injection. The mice were killed at the 12th week. The renal function was determined by serum creatinine and urea nitrogen. HE, PAS and Masson staining were used to evaluate renal tissue injury and fibrosis. The expressions of matrix metalloproteinase (MMP-2, MMP-9) and collagen IV (Coll-IV) in the kidney of mice were detected by Western blot. Results: Compared with the control group, the blood glucose (5.67±0.22 vs 28.40±0.57 mmol/L), creatinine (14.33±1.22 vs 30.67±4.73 μmol/L) and urea nitrogen (6.93±4.94 vs 22.00±1.04 mmol/L) in the T1D group were increased significantly (P＜0.05), the glomerular basement membrane was thickened, the collagen was significantly increased, the expressions of MMP-2, MMP-9 and Coll-IV protein were increased (0.57±0.07 vs 1.06±0.20, 47.00±0.04 vs 1.29±0.09 and 0.42±0.16 vs 0.95±0.18,P＜0.05). Exogenous spermine significantly alleviates the above-mentioned changes. Conclusion: Exogenous spermine pretreatment could significantly alleviate renal fibrosis in diabetic mice by regulating the balance between MMPs and collagen.

Objective: To investigate the protective effect of spermine (Sp) on diabetic cardiomyopathy (DCM) and high glucose-induced cardiac fibroblasts (CFs), and to explore its mechanism. Methods: ①Animal experiments: 24 male Wistar rats were randomly divided into control group, type 1 diabetes group (TID) and spermine group (TID+Sp, each group n=8). TID rats were induced by streptozocin (STZ, 60 mg/kg), and TID+Sp rat were pretreated with spermine (Sp, 5 mg/(kg·d)) for 2 weeks before STZ injection. After 12 weeks of modeling, blood glucose, insulin levels, ejection fraction (EF) and shortening fraction (FS) were measured, and Masson staining and Sirius red staining were performed in the rat cardiac tissues. ②Cell experiments: primary CFs were extracted from newborn (1-3 d) Wistar rat hearts, and were randomly divided into control group, high-glucose group (HG) and HG+Sp group (n=6 per group). HG group was treated with 40 mmol/L glucose, and the HG+Sp group was pretreated with 5 μmol/L Sp for 30 min before HG treatment. The cell viability of CFs was detected by CCK8, the content of collagen in culture medium was analyzed by ELISA, and protein expressions of cell cycle related proteins (PCNA, CyclinD1 and P27) were detected by Western blot. Results: Compared with control group, the blood glucose and collagen content were increased, and the insulin level and heart function were decreased in the T1D group. Meanwhile, HG induced an increasing of the cell viability, the collagen content in the medium and the expressions of PCNA and CyclinD1, while the expression of P27 was down-regulated. Spermine could reduce the above changes, manifested as improving the cardiac function, regulating the expression of cyclin and reducing the level of myocardial fibrosis. Conclusion: Spermine can alleviate myocardial fibrosis in diabetic cardiomyopathy, which mechanism is related to the regulation of cell cycle.

Objective: To investigate whether Golgi stress (GAS) is involved in diabetic cardiomyopathy (DCM) and whether myocardial protection of exogenous spermine is associated with regulation of GAS., Methods: Sixty Wistar rats were randomly divided into normal control group (Control), diabetic group (T1D, STZ 60 mg/kg intraperitoneal injection) and spermine group (T1D+Sp, spermine 5 mg/(kg·d) intraperitoneal injection) for 12 weeks. H9C2 rat cardiomyocytes were randomly divided into control group (Control, 10% FBS-DMEM culture), high glucose group (HG, 10% FBS-DMEM+40 mmol/L glucose) and spermine group (HG+Sp, 10% FBS-DMEM+40 mmol/L glucose+5 μmol/L spermine). Rat serum creatine kinase isoenzyme (CK-MB) and cardiac troponin T (cTnT) were detected by ELISA; Golgi protein GOLPH3, GM130 and Cleaved Caspase3 protein expressions were analyzed using Western blot; immunofluorescence was used to detect GOLPH3 cell localization., Results: In the animal model, compared with the normal group, myocardial ultrastructural damage was obvious,the blood glucose, the serum myocardial enzymes CK-MB and cTnT, the expressions of GOLPH3 and cleaved caspase3 were increased or up-regulated significantly,meanwhile, the body weight,the ejection fraction (EF) and the expression of GM130 were decreased or down-regulated markedly in the diabetic group. In the cell model, similar results were obtained. Immunofluorescence showed stress fragmentation of Golgi apparatus. Exogenous spermine treatment could significantly alleviate the above mentioned damages., Conclusion: Golgi stress occurs in diabetic cardiomyopathy (DCM), and myocardial protection of exogenous spermine is associated with a reduction in Golgi stress (GAS).

Osteoporosis is an abnormal bone remodeling condition characterized by decreased bone density, which leads to high risks of fracture. Previous study has demonstrated that Lycii Radicis Cortex (LRC) extract inhibits bone loss in ovariectomized (OVX) mice by enhancing osteoblast differentiation. A bioactive compound, kukoamine B (KB), was identified from fractionation of an LRC extract as a candidate component responsible for an anti-osteoporotic effect. This study investigated the anti-osteoporotic effects of KB using in vitro and in vivo osteoporosis models. KB treatment significantly increased the osteoblastic differentiation and mineralized nodule formation of osteoblastic MC3T3-E1 cells, while it significantly decreased the osteoclast differentiation of primary-cultured monocytes derived from mouse bone marrow. The effects of KB on osteoblastic and osteoclastic differentiations under more physiological conditions were also examined. In the co-culture of MC3T3-E1 cells and monocytes, KB promoted osteoblast differentiation but did not affect osteoclast differentiation. In vivo experiments revealed that KB significantly inhibited OVX-induced bone mineral density loss and restored the impaired bone structural properties in osteoporosis model mice. These results suggest that KB may be a potential therapeutic candidate for the treatment of osteoporosis.

Transient oligomeric species formed during the aggregation process of the 42-residue form of the amyloid-β peptide (Aβ 42 ) are key pathogenic agents in Alzheimer's disease (AD). To investigate the relationship between Aβ 42 aggregation and its cytotoxicity and the influence of a potential drug on both phenomena, we have studied the effects of trodusquemine. This aminosterol enhances the rate of aggregation by promoting monomer-dependent secondary nucleation, but significantly reduces the toxicity of the resulting oligomers to neuroblastoma cells by inhibiting their binding to the cellular membranes. When administered to a C. elegans model of AD, we again observe an increase in aggregate formation alongside the suppression of Aβ 42 -induced toxicity. In addition to oligomer displacement, the reduced toxicity could also point towards an increased rate of conversion of oligomers to less toxic fibrils. The ability of a small molecule to reduce the toxicity of oligomeric species represents a potential therapeutic strategy against AD.

The aggregation of α-synuclein, an intrinsically disordered protein that is highly abundant in neurons, is closely associated with the onset and progression of Parkinson's disease. We have shown previously that the aminosterol squalamine can inhibit the lipid induced initiation process in the aggregation of α-synuclein, and we report here that the related compound trodusquemine is capable of inhibiting not only this process but also the fibril-dependent secondary pathways in the aggregation reaction. We further demonstrate that trodusquemine can effectively suppress the toxicity of α-synuclein oligomers in neuronal cells, and that its administration, even after the initial growth phase, leads to a dramatic reduction in the number of α-synuclein inclusions in a Caenorhabditis elegans model of Parkinson's disease, eliminates the related muscle paralysis, and increases lifespan. On the basis of these findings, we show that trodusquemine is able to inhibit multiple events in the aggregation process of α-synuclein and hence to provide important information about the link between such events and neurodegeneration, as it is initiated and progresses. Particularly in the light of the previously reported ability of trodusquemine to cross the blood-brain barrier and to promote tissue regeneration, the present results suggest that this compound has the potential to be an important therapeutic candidate for Parkinson's disease and related disorders.

Purpose: One of the recently developed polyamine (PA) analogues, N 1 ,N 11 -diethylnorspermine (DENSpm), has been found to act as an apoptotic inducer in melanoma, breast, prostate and colon cancer cells. Also, its potential to induce autophagy has been established. Unfolded protein responses and starvation of amino acids are known to trigger autophagy. As yet, however, the molecular mechanism underlying PA deficiency-induced autophagy is not fully clarified. Here, we aimed to determine the apoptotic effect of DENSpm after autophagy inhibition by 3-methyladenine (3-MA) or siRNA-mediated Beclin-1 silencing in colon cancer cells., Methods: The apoptotic effects of DENSpm after 3-MA treatment or Beclin-1 silencing were determined by PI and AnnexinV/PI staining in conjunction with flow cytometry. Intracellular PA levels were measured by HPLC, whereas autophagy and the expression profiles of PA key players were determined in HCT116, SW480 and HT29 colon cancer cells by Western blotting., Results: We found that DENSpm-induced autophagy was inhibited by 3-MA treatment and Beclin-1 silencing, and that apoptotic cell death was increased by PA depletion and spermidine/spermine N 1 -acetyltransferase (SSAT) upregulation. We also found that autophagy inhibition led to DENSpm-induced apoptosis through Atg5 down-regulation, p62 degradation and LC3 lipidation in both HCT116 and SW480 cells. p53 deficiency did not alter the response of the colon cancer cells to DENSpm-induced apoptotic cell death under autophagy suppression conditions., Conclusions: From our results we conclude that DENSpm-induced apoptotic cell death is increased when autophagy is inhibited by 3-MA or Beclin-1 siRNA through PA depletion and PA catabolic activation in colon cancer cells, regardless p53 mutation status.

Nonalcoholic fatty liver disease (NAFLD) refers to a pathological condition of hepatic steatosis. Insulin resistance is believed to be the key mechanism mediating initial accumulation of fat in the liver, resulting in hepatic steatosis. Kukoamine A (KuA), a spermine alkaloid, is a major bioactive component extracted from the root barks of Lycium chinense (L. chinense) Miller. In the current study, we aimed to explore the possible effect of KuA on insulin resistance and fatty liver. We showed that KuA significantly inhibited the increase of fasting blood glucose level and insulin level, and the glucose levels in response to glucose and insulin load in HFD-fed mice, which was in a dose-dependent manner. KuA dose-dependently decreased the histological injury of liver, levels of hepatic triglyceride (TG), and serum AST and ALT activities in HFD-fed mice. The increase of serum levels of TNFɑ, IL-1β, IL-6 and C reactive protein in HFD-fed mice was inhibited by KuA. HFD feeding-induced increase of hepatic expression of Srebp-1c and its target genes, including fatty acid synthase (FAS) and acetyl CoA carboxylase 1 (ACC1), was significantly inhibited by KuA. Moreover, upregulation of Srebp-1c notably inhibited KuA-induced improvement of insulin-stimulated glucose uptake, decrease of lipid accumulation and H 2 O 2 level in palmitic acid-treated AML-12 cells. In conclusion, we reported that KuA inhibited Srebp-1c and downstream genes expression and resulted in inhibition of lipid accumulation, inflammation, insulin resistance and oxidative stress. Overall, our results provide a better understanding of the pharmacological activities of KuA against insulin resistance and hepatic steatosis., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)

Combination of anticancer drugs with therapeutic microRNA (miRNA) has emerged as a promising anticancer strategy. However, the promise is hampered by a lack of desirable delivery systems. We report on the development of self-immolative nanoparticles capable of simultaneously delivering miR-34a mimic and targeting dysregulated polyamine metabolism in cancer. The nanoparticles were prepared from a biodegradable polycationic prodrug, named DSS-BEN, which was synthesized from a polyamine analog N 1 ,N 11 -bisethylnorspermine (BENSpm). The nanoparticles were selectively disassembled in the cytoplasm where they released miRNA. Glutathione (GSH)-induced degradation of self-immolative linkers released BENSpm from the DSS-BEN polymers. MiR-34a mimic was effectively delivered to cancer cells as evidenced by upregulation of intracellular miR-34a and downregulation of Bcl-2 as one of the downstream targets of miR-34a. Intracellular BENSpm generated from the degraded nanoparticles induced the expression of rate-limiting enzymes in polyamine catabolism (SMOX, SSAT) and depleted cellular natural polyamines. Simultaneous regulation of polyamine metabolism and miR-34a expression by DSS-BEN/miR-34a not only enhanced cancer cell killing in cultured human colon cancer cells, but also improved antitumor activity in vivo. The reported findings validate the self-immolative nanoparticles as delivery vectors of therapeutic miRNA capable of simultaneously targeting dysregulated polyamine metabolism in cancer, thereby providing an elegant and efficient approach to combination nanomedicines., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Polyamines are essential for cell growth and differentiation. They play important roles in protection from liver damage and promotion of liver regeneration. However, little is known about the effect of oral exogenous polyamine administration on liver damage and regeneration. This study investigated the impact of polyamines (spermidine and spermine) on ischemia/reperfusion injury (IRI) and liver regeneration. We used a rat model in which a 70% hepatectomy after 40 minutes of ischemia was performed to mimic the clinical condition of living donor partial liver transplantation (LT). Male Lewis rats were separated into 2 groups: a polyamine group given polyamines before and after operation as treatment and a vehicle group given distilled water as placebo. The levels of serum aspartate aminotransferase and alanine aminotransferase at 6, 24, and 48 hours after reperfusion were significantly lower in the polyamine group compared with those in the vehicle group. Polyamine treatment reduced the expression of several proinflammatory cytokines and chemokines at 6 hours after reperfusion. Histological analysis showed significantly less necrosis and apoptosis in the polyamine group at 6 hours after reperfusion. Sinusoidal endothelial cells were also well preserved in the polyamine group. In addition, the regeneration of the remnant liver at 24, 48, and 168 hours after reperfusion was significantly accelerated, and the Ki-67 labeling index and the expressions of proliferating cell nuclear antigen and phosphorylated retinoblastoma protein at 24 hours after reperfusion were significantly higher in the polyamine group compared with those in the vehicle group. In conclusion, perioperative oral polyamine administration attenuates liver IRI and promotes liver regeneration. It might be a new therapeutic option to improve the outcomes of partial LT. Liver Transplantation 22 1231-1244 2016 AASLD., (© 2016 by the American Association for the Study of Liver Diseases.)

Background/aims: Endoplasmic reticulum stress (ERS) plays an important role in the progression of acute myocardial infarction (AMI), in part by mediating apoptosis. Polyamines, including putrescine, spermidine, and spermine, are polycations with anti-oxidative, anti-aging, and cell growth-promoting activities. This study aimed to determine the mechanisms by which spermine protects against ERS-induced apoptosis in rats following AMI., Methods and Results: AMI was established by ligation of the left anterior descending coronary artery (LAD) in rats, and exogenous spermine was administered by intraperitoneal injection (2.5 mg/ml daily for 7 days pre-AMI). Spermine treatment limited infarct size, attenuated cardiac troponin I and creatinine kinase-MB release, improved cardiac function, and decreased ERS and apoptosis related protein expression. Isolated cardiomyocytes subjected to hypoxia showed significant increase in reactive oxygen species (ROS) and the expression of apoptosis and ERS related proteins; these effects occurred through PERK and eIF2α phosphorylation. The addition of spermine attenuated cardiomyocyte apoptosis, suppressed the production of ROS, and inhibited ERS related pathways., Conclusions: Spermine was an effective pre-treatment strategy to attenuate cardiac ERS injury in rats, and the cardioprotective mechanism occurring through inhibition of ROS production and down regulation of the PERK-eIF2α pathway. These findings provide a novel target for the prevention of apoptosis in the setting of AMI., (© 2016 The Author(s) Published by S. Karger AG, Basel.)

Angina pectoris is a common clinical symptom that often results from myocardial infarction. One typical characteristic of angina pectoris is that the pain does not match the severity of the myocardial ischemia. One possible explanation is that the intensity of cardiac nociceptive information could be dynamically regulated by certain brain areas. As an important nucleus for processing cardiac nociception, the nucleus of the solitary tract (NTS) has been studied to some extent. However, until now, the morphological and functional involvement of the NTS in chronic myocardial infarction (CMI) has remained unknown. In the present study, by exploring left anterior descending coronary artery ligation surgery, we found that the number of synaptophysin-immunoreactive puncta and Fos-immunoreactive neurons in the rat NTS two weeks after ligation surgery increased significantly. Excitatory pre- and postsynaptic transmission was potentiated. A bath application of a Ca2+ channel inhibitor GABApentin and Ca2+ permeable AMPA receptor antagonist NASPM could reverse the potentiated pre- and postsynaptic transmission, respectively. Meanwhile, rats with CMI showed significantly increased visceral pain behaviors. Microinjection of GABApentin or NASPM into the NTS decreased the CMI-induced visceral pain behaviors. In sum, our results suggest that the NTS is an important area for the process of cardiac afference in chronic myocardial infarction condition.

The clinical successful application of gene therapy critically depends upon the development of non-toxic and efficient delivery system. Although polycationic non-viral vectors hold great promise in nanomedicine, the exploring of application in clinics still remains a big challenge. To develop a non-toxic and efficient non-viral gene delivery system, two kinds of endogenous substance, citric acid (CA) and spermine (SPE), were used to prepare a new low charge density hyperbranched polyspermine (HPSPE) by one-pot polymerization. The biocompatibility evaluated by hemolytic activity and red blood cell (RBC) aggregation indicated that HPSPE was highly biocompatible without causing hemolysis and RBC aggregation compared with PEI as well as SPE. The MTS assay also demonstrated that the cell viability of HPSPE was above 90% even at 200 μg/mL at different time (24 and 72 h), which much higher than PEI 25K. Besides, HPSPE showed high transfection efficiency without any toxic effect after aerosol delivery to the mice. Moreover, aerosol delivery of HPSPE/Akt1 shRNA significantly reduced tumor size and numbers and efficiently suppressed lung tumorigenesis ultimately in K-ras(LA1) lung cancer model mice. These results suggest that low charge density as well as endogenous substance skeleton endow HPSPE with great potential for toxicity-free and efficient gene therapy., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Background: Lipopolysaccharide (LPS) induces neuroinflammation and memory deficit. Since polyamines improve memory in various cognitive tasks, we hypothesized that spermine administration reverses LPS-induced memory deficits in an object recognition task in mice. The involvement of the polyamine binding site at the N-methyl-D-aspartate (NMDA) receptor and cytokine production in the promnesic effect of spermine were investigated., Methods: Adult male mice were injected with LPS (250 μg/kg, intraperitoneally) and spermine (0.3 to 1 mg/kg, intraperitoneally) or ifenprodil (0.3 to 10 mg/kg, intraperitoneally), or both, and their memory function was evaluated using a novel object recognition task. In addition, cortical and hippocampal cytokines levels were measured by ELISA four hours after LPS injection., Results: Spermine increased but ifenprodil decreased the recognition index in the novel object recognition task. Spermine, at doses that did not alter memory (0.3 mg/kg, intraperitoneally), reversed the cognitive impairment induced by LPS. Ifenprodil (0.3 mg/kg, intraperitoneally) reversed the protective effect of spermine against LPS-induced memory deficits. However, spermine failed to reverse the LPS-induced increase of cortical and hippocampal cytokine levels., Conclusions: Spermine protects against LPS-induced memory deficits in mice by a mechanism that involves GluN2B receptors.

Chemoprevention is the long-term use of different chemical agents, both synthetic and natural, to prevent or delay the onset of disease. Since colorectal cancer has a significant environmental component, it is an ideal disease in which to evaluate the potential benefits of chemopreventive agents. The polyamines, spermine, spermidine and putrescine have been involved in almost all the steps of colorectal tumorigenesis. Consequently, polyamine biosynthesis and catabolism can be considered as promising targets for cancer chemoprevention. A variety of drug formulations have been tested for their efficacy in affecting polyamines in a strategy of colorectal cancer prevention. Different molecules, such as biosynthesis inhibitors and catabolism inducers, have been proposed alone or in combination with other drugs proved to diminish the colorectal cancer risk. Interestingly, also diet can play a role in cancer prevention by affecting polyamines. Several dietary components, such as probiotics or flavonoids, have been shown to affect the polyamine metabolic pathway in colorectal neoplastic tissue. On the other hand, the polyamines ingested with diet might contrast the above cited effects shown by both drugs and nutritional factors. It is, therefore, fundamental to acquire more data also on these aspects in view of an innovative approach to colorectal oncology. This review summarizes data on the role of polyamine metabolism in neoplastic transformation of colorectal mucosa and as possible target for colorectal cancer chemoprevention. Attention will be focused on the influence of drugs and nutritional factors on polyamine metabolism, as well as the role played by dietary polyamines.

Purpose: N(1),N(11)-diethylnorspermine (DENSPM), a synthetic analog of the naturally occurring polyamine spermine, can induce polyamine depletion and inhibit tumor cell growth. The objectives of this phase I study were to assess the safety, maximum-tolerated dose (MTD), pharmacokinetics, and preliminary antitumor activity of DENSPM in advanced HCC., Methods: Patients with measurable advanced HCC, Child-Pugh A or B cirrhosis, CLIP score ≤3, and Karnofsky score ≥60 % were eligible. DENSPM was given as a short intravenous infusion on days 1, 3, 5, 8, 10, and 12 of each 28-day cycle. The starting dose of 30 mg/m(2) was escalated at a fixed increment of 15 mg/m(2) until the MTD was identified. The plasma pharmacokinetics of DENSPM for the first and last doses given in cycle 1 was characterized., Results: Thirty-eight patients (male 79 %; median age 61 years; Child-Pugh A 84 %; ≥1 prior systemic therapy 45 %) were enrolled and treated. The most common adverse events (AEs) ≥grade 1 were fatigue (53 %), nausea (34 %), diarrhea (32 %), vomiting (32 %), anemia (29 %), and elevated AST (29 %). The most common grade 3-4 AEs were fatigue/asthenia (13 %), elevated AST (13 %), hyperbilirubinemia (11 %), renal failure (8 %), and hyperglycemia (8 %). The MTD was 75 mg/m(2). There were no objective responses, although 7/38 (18 %) patients achieved stable disease for ≥16 weeks. The overall mean (±SD) total body clearance for the initial dose, 66.3 ± 35.9 L/h/m(2) (n = 16), was comparable to the clearance in patients with normal to near normal hepatic function. Drug levels in plasma decayed rapidly immediately after the infusion but remained above 10 nM for several days after dosing at the MTD., Conclusions: N(1),N(11)-diethylnorspermine treatment at the MTD of 75 mg/m(2), given intravenously every other weekday for two consecutive weeks of each 28-day cycle, was relatively well tolerated in patients with advanced HCC including those with mild-to-moderate liver dysfunction. This administration schedule provided prolonged systemic exposure to potentially effective concentrations of the drug. Stable disease was seen in 18 % of patients receiving DENSPM treatment. Further evaluation of DENSPM monotherapy for advanced HCC does not appear to be justified because of insufficient evidence of clinical benefit in the patients evaluated in this study.

Objective: Natural polyamines are some of the most abundant polycationic molecules in eukaryotic cells, regulating gene expression. Polyamines have been reported to possess anti-inflammatory activities in many model inflammation systems. However, there is no report on their role in 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced dermal edema., Methods: Mouse ear edema was induced by TPA. Edema biopsies were investigated using H&E staining. Levels of nitric oxide (NO) were determined using the Griess reaction. Tumor necrosis factor α (TNFα) and interleukin (IL)-1β levels in cell supernatants were measured by TNFα and IL-1β ELISA kits., Results: Spermidine and spermine caused significant decreases in ear thickness, water content, and neutrophil infiltrations in comparison with negative control (p < 0.05). External polyamines reduced the levels of inflammatory mediators such as NO, TNFα, and IL-1β in lipopolysaccharide (LPS)-stimulated RAW264.7 murine macrophages. Spermine had a higher inhibitory effect on the production of cytokines such as IL-1β and TNFα in LPS-stimulated murine macrophages compared to other polyamines., Conclusion: Our findings clearly demonstrated that polyamines are involved in the anti-inflammatory effect by reducing dermal edema thickness and other inflammatory mediators like NO and cytokines in a dose-dependent manner.

Polyamines (spermine and spermidine) play many important roles in cellular function and are supplied from the intestinal lumen. We have shown that continuous high polyamine intake inhibits age-associated pathologies in mice. The mechanism by which polyamines elicit these effects was examined. Twenty-four week old Jc1:ICR male mice were fed one of three experimental chows containing different polyamine concentrations. Lifetime intake of high polyamine chow, which had a polyamine content approximately three times higher than regular chow, elevated polyamine concentrations in whole blood, suppressed age-associated increases in pro-inflammatory status, decreased age-associated pathological changes, inhibited age-associated global alteration in DNA methylation status and reduced the mortality in aged mice. Exogenous spermine augmented DNA methyltransferase activity in Jurkat and HT-29 cells and inhibited polyamine deficiency-induced global alteration in DNA methylation status in vitro. In addition, increased polyamine intake was associated with a decreased incidence of colon tumors in BALB/c mice after 1,2-demethylhydrazine administration; 12 mice (60%) in the low polyamine group developed tumors, compared with only 5 mice (25%) in the high polyamine group (Fisher's exact probability = 0.027, p = 0.025). However, increased polyamine intake accelerated the growth of established tumors; maximal tumor diameter in the Low and High groups was 3.85±0.90 mm and 5.50±1.93 mm, respectively (Mann-Whitney test, p = 0.039). Spermine seems to play important roles in inhibiting age-associated and polyamine-deficient induced abnormal gene methylation as well as pathological changes including tumorigenesis.

Background and Purpose: Although naturally occurring polyamines are indispensable for a variety of cellular events in eukaryotic cells, little attention has been paid to their physiological and pathological significance in bone remodelling to date. In this study, we evaluated the pharmacological properties of several natural polyamines on the functionality and integrity of bone in both in vitro and in vivo experiments., Experimental Approach: Mice were subjected to ovariectomy (OVX) and subsequent oral supplementation with either spermidine or spermine for determination of the bone volume together with different parameters regarding bone formation and resorption by histomorphometric analyses in vivo. Pre-osteoclasts were cultured with receptor activator of NF-κB ligand (RANKL), with or without spermidine and spermine to determine cellular maturation by tartrate-resistant acid phosphatase (TRAP) staining and cellular viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide reduction in vitro., Key Results: Spermidine or spermine, given in drinking water for 28 days, significantly prevented the increased osteoclast surface/bone surface ratio and the reduced bone volume following OVX in mice. Either spermidine or spermine significantly inhibited the increased number of multinucleated TRAP-positive cells in osteoclasts cultured with RANKL in a concentration-dependent manner without affecting cell survival., Conclusions and Implications: The natural polyamines spermidine and spermine prevented OVX-induced bone loss through the disruption of differentiation and maturation of osteoclasts, rather than affecting osteoblasts. The supplementation with these natural polyamines could be beneficial for the prophylaxis as well as therapy of metabolic bone diseases such as post-menopausal osteoporosis., (© 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.)

To observe the dynamic expression of calcium-sensing receptor (CaSR) in myocardium of diabetic rats and explore its role in diabetic cardiomyopathy (DCM), 40 male Wistar rats were randomly divided into 4 groups including control, diabetic-4 weeks, diabetic-8 weeks and spermine treatment groups (240 μM of spermine in drinking water). The type 2 Diabetes mellitus (DM) models were established by intraperitoneal injection of streptozotocin (STZ, 30 mg/kg) after high-fat and high-sugar diet for one month. The echocardiographic parameters were measured, cardiac morphology was observed by electron microscope and HE staining. The intracellular calcium concentration ([Ca(2+)](i)) was detected by laser-scanning confocal microscope. Western blot analyzed the expression of CaSR, protein kinase C α(PKC-α) and calcium handling regulators, such as phospholamban (PLN), Ca(2+)-ATPase (SERCA), and ryanodine receptor (RyR). Compared with control group, [Ca(2+)](i) and the expression of CaSR, RyR and SERCA/PLN were decreased, while PKC-α and PLN were significantly increased in a time-dependent manner in diabetic groups. Meanwhile diabetic rats displayed abnormal cardiac structure and systolic and diastolic dysfunction, and spermine (CaSR agonist) could prevent or slow its progression. These results indicate that the CaSR expression of myocardium is reduced in the progress of DCM, and its potential mechanism is related to the impaired intracellular calcium homeostasis., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Thalidomide, a sedative drug given to pregnant women, unfortunately caused limb deformities in thousands of babies. Recently the drug was revived because of its therapeutic potential; however the search is still ongoing for an antidote against thalidomide induced limb deformities. In the current study we found that nitric oxide (NO) rescues thalidomide affected chick (Gallus gallus) and zebrafish (Danio rerio) embryos. This study confirms that NO reduced the number of thalidomide mediated limb deformities by 94% and 80% in chick and zebrafish embryos respectively. NO prevents limb deformities by promoting angiogenesis, reducing oxidative stress and inactivating caspase-3 dependent apoptosis. We conclude that NO secures angiogenesis in the thalidomide treated embryos to protect them from deformities.

Polyethylenimine (PEI) has been commonly used as a cationic polymeric gene carrier due to high transfection efficiency, however, its cytotoxicity has hindered the practical application. In this study, we report the development of poly(amino ester) (PAE) based on glycerol propoxylate triacrylate (GPT) and spermine (SPE) as an alternative gene carrier for lung cancer therapy. GPT-SPE copolymer was prepared by Michael addition reaction between GPT and SPE, and the efficacy was evaluated using shAkt1 as a model therapeutic gene. The molecular weight and composition were characterized using gel permeability chromatography (GPC) and (1)H-nuclear magnetic resonance ((1)H-NMR), respectively. The GPT-SPE could effectively condense DNA with about 163 nm size and protect the DNA from nucleases. GPT-SPE/DNA complexes showed excellent transfection with low toxicity both in vitro and in vivo. Furthermore, aerosol delivery of GPT-SPE/Akt1 shRNA complexes significantly suppressed lung tumorigenesis in K-ras(LA1) lung cancer model mice. These results suggest that GPT-SPE can be used in shRNA-based lung cancer gene therapy., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Numerous studies have shown that platinum compounds stimulate the expression of the polyamine catabolic enzyme spermidine/spermine N(1)-acetyltransferase resulting in anti-proliferative activity and apoptosis. As many cancer cell types including pancreatic cancer cells express high levels of polyamines, the possibility to develop anti-tumor strategies to deplete polyamine pools has drawn considerable attention in recent years. This has been effectively accomplished by treating cells with platinum drugs in combination with polyamine analogs such as N(1),N(11)-diethylnorspermine (DENSPM). The present study, examined the cytotoxic effects of oxaliplatin in combination with stimulators of polyamine catabolism in human pancreatic cancer cells, that are notoriously resistant to chemotherapeutic treatment, and colorectal cancer cells. Additionally, as protein kinase CK2 has been shown to be an anti-apoptotic and pro-survival enzyme regulated by the intracellular polyamine pools, we aimed to investigate the effect of combined DENSPM and oxaliplatin treatment on CK2-mRNA and -protein levels. Results reported here show that treatment with oxaliplatin and DENSPM in combination impairs cell viability particularly in the case of colorectal cancer cells. The analysis of CK2 expression and activity indicates that the response to a specific treatment may depend on the impact that individual compounds exert on pro-survival and pro-death proteins at the transcription and translation levels that should be carefully evaluated in view of subsequent clinical studies.

Carbonic anhydrases (CAs, Enzyme Commission number 4.2.1.1) catalyze a simple but fundamental reaction, CO(2) hydration to yield bicarbonate and protons. CAs belonging to the α-, β-, γ-, δ- and ζ-families are found in many organisms all over the phylogenetic tree and their inhibition/activation have been studied in detail, leading to various therapeutic applications. Inhibition of mammalian α-CAs is exploited by some diuretics, whereas antiglaucoma, anticonvulsant, anti-obesity, altitude sickness and anti-tumor drugs/diagnostic agents target various of the 15 isoforms described so far in these organisms. Activation of some CAs may also have applications in therapy. Bacterial and fungal β-CA inhibitors or nematode α-CA inhibitors have been described that may lead to novel classes of anti-infectives.

Background: Overinduced polyamine catabolism (PC) in a transgenic rat model has been suggested to be a mediator of trypsin activation which is important in acinar cell necrosis. PC has also been observed in experimental taurodeoxycholate pancreatitis. We hypothesized that PC may be a mediator of trypsin activation in taurodeoxycholate pancreatitis., Methods: Pancreatitis was induced in wild-type rats by 2 or 6% taurodeoxycholate infusion or in transgenic rats by overexpressing spermidine/spermine N(1)-acetyltransferase (SSAT). The time courses of necrosis, caspase-3 immunostaining, SSAT, polyamine levels, and trypsinogen activation peptide (TAP) were monitored. The effect of the polyamine analogue bismethylspermine (Me(2)Spm) was investigated., Results: In a transgenic pancreatitis model, TAP and acinar necrosis increased simultaneously after the activation of SSAT, depletion of spermidine, and development of apoptosis. In taurodeoxycholate pancreatitis, necrosis developed along with the accumulation of TAP. SSAT was activated simultaneously or after TAP accumulation and less than in the transgenic model, with less depletion of spermidine than in the transgenic model. Supplementation with Me(2)Spm ameliorated the extent of acinar necrosis at 24 h, but contrary to previous findings in the transgenic model, in the taurodeoxycholate model it did not affect trypsin activation. Compared with the transgenic model, no extensive apoptosis was found in taurodeoxycholate pancreatitis., Conclusions: Contrary to transgenic SSAT-overinduced pancreatitis, PC may not be a mediator of trypsin activation in taurodeoxycholate pancreatitis. The beneficial effect of polyamine supplementation on necrosis in taurodeoxycholate pancreatitis may rather be mediated by other mechanisms than amelioration of trypsin activation. and IAP., (Copyright © 2011 S. Karger AG, Basel.)

The polyamines spermine, spermidine and putrescine are ubiquitous cell components. These molecules are substrates of a class of enzymes that includes monoamine oxidases, diamine oxidases, polyamine oxidases and copper-containing amine oxidases. Amine oxidases are important because they contribute to regulate levels of mono- and polyamines. In tumors, polyamines and amine oxidases are increased as compared to normal tissues. Cytotoxicity induced by bovine serum amine oxidase (BSAO) and spermine is attributed to H(2)O(2) and aldehydes produced by the reaction. This study demonstrated that multidrug-resistant (MDR) cancer cells (colon adenocarcinoma and melanoma) are significantly more sensitive than the corresponding wild-type (WT) ones to H(2)O(2) and aldehydes, the products of BSAO-catalyzed oxidation of spermine. Transmission electron microscopy (TEM) observations showed major ultrastructural alterations of the mitochondria. These were more pronounced in MDR than in WT cells. Increasing the incubation temperature from 37 to 42 degrees Celsius enhances cytotoxicity in cells exposed to spermine metabolites. The combination BSAO/spermine prevents tumor growth, particularly well if the enzyme has been conjugated to a biocompatible hydrogel polymers. Since both wild-type and MDR cancer cells after pre-treatment with MDL 72527, a lysosomotropic compound, are sensitized to subsequent exposure to BSAO/spermine, it is conceivable that combined treatment with a lysosomotropic compound and BSAO/spermine would be effective against tumor cells. It is of interest to search for such novel compounds, which might be promising for application in a therapeutic setting.

Sepsis, otherwise referred to as "blood poisoning" is a serious clinical problem, the incidence of which continues to rise in the US and worldwide despite advances in antimicrobial chemotherapy. The primary trigger in Gram-negative sepsis is endotoxin, a lipopolysaccharide (LPS) constituent of the outer membrane of all Gram-negative bacteria. The structurally highly conserved glycolipid called lipid A is the active moiety of LPS. Lipid A is composed of a hydrophilic, bis-phosphorylated di-glucosamine backbone, and a hydrophobic polyacyl domain. The bis-anionic, amphiphilic nature of lipid A enables it to interact with a variety of cationic hydrophobic ligands, including polymyxin B, a toxic peptide antibiotic which binds to lipid A and neutralizes endotoxicity. Having determined the structural basis of the interaction of polymyxin B with lipid A, our long-term goal has been to rationally design non-peptidic, nontoxic, small-molecule LPS-sequestrants. Our efforts began with defining the central pharmacophore that determined LPS-recognition and -neutralization properties in small molecules, which led to the discovery of a novel lipopolyamine lead, DS-96. DS-96 is an effective LPS-neutralizer, rivaling polymyxin B in a panel of vitro assays, as well as in protecting animals against endotoxicosis. Structure-activity relationships in our effort to rationally design endotoxin sequestering agents, preclinical assessment of hits and leads, and approaches to overcoming issues with toxicity are described in this chapter.

Huntington's disease (HD) is a progressive neurodegenerative disorder associated with motor and cognitive impairment. Intrastriatal administration of quinolinic acid (QA) causes neurodegeneration, glial proliferation and cognitive impairment in animals, which are similar to these seen in human HD. Since polyamines improve memory in cognitive tasks, we now tested if the post-training intrastriatal administration of spermine, an agonist of the polyamine site at the NMDA receptor, reverses the deficits in the object recognition task induced by QA. Bilateral striatal injections of QA (180 or 360 nmol/site) caused object recognition impairment, neuronal death and reactive astrogliosis. A single injection of spermine (0.1 and 1 nmol/site), 5 days after QA injection, reversed QA-induced impairment of object recognition task. Spermine (0.1 nmol/site) also inhibited QA-induced reactive astrogliosis measured by a semi-quantitative determination of GFAP immunolabelling, but did not alter neuronal death, measured by a semi-quantitative determination of fluoro-Jade C staining. These results suggest that polyamine binding sites may be considered a novel therapeutic target to prevent reactive astrogliosis and mnemonic deficits in HD.

Polyamine depletion causes S phase prolongation, and earlier studies indicate that the elongation step of DNA replication is affected. This led us to investigate the effects of polyamine depletion on enzymes crucial for Okazaki fragment maturation in the two breast cancer cell lines MCF-7 and L56Br-C1. In MCF-7 cells, treatment with N(1),N(11)-diethylnorspermine (DENSPM) causes S phase prolongation. In L56Br-C1 cells the prolongation is followed by massive apoptosis. In the present study we show that L56Br-C1 cells have substantially lower basal expressions of two Okazaki fragment maturation key proteins, DNA ligase I and FEN1, than MCF-7 cells. Thus, these two proteins might be promising markers for prediction of polyamine depletion sensitivity, something that can be useful for cancer treatment with polyamine analogues. DENSPM treatment affects the cellular distribution of FEN1 in L56Br-C1 cells, but not in MCF-7 cells, implying that FEN1 is affected by or involved in DENSPM-induced apoptosis.

Purpose: Our previous studies showed that combined treatment of oxaliplatin and N(1), N(11) diethyl-norspermine (DENSPM) results in massive induction of spermidine/spermine N(1)-acetyltransferase (SSAT) mRNA and activity. Since oxaliplatin and 5-fluorouracil (5FU) are used clinically in treatment of colorectal cancers, this study examines the effect of adding DENSPM to oxaliplatin/5FU combination on SSAT and spermine oxidase (SMO) in HCT-116 cells., Methods: HCT-116 cells were treated with clinically relevant concentrations of drugs for 20 h followed by 24 h in drug free medium. SSAT and SMO mRNA and protein were assayed by QRT-PCR and Westerns respectively; polyamine pools were measured by HPLC. SSAT and SMO mRNA in tumor biopsies from patients with rectal cancer receiving oxaliplatin, capecitabine and radiation were measured by QRT-PCR., Results: Oxaliplatin + 5FU + DENSPM produced significantly higher levels of SSAT and SMO mRNA, protein and activity than those seen with oxaliplatin+5FU with a significant depletion of cellular spermine and spermidine pools. Oxaliplatin/DENSPM was superior to 5FU/DENSPM in SSAT induction but similar for SMO. Oxaliplatin + DENSPM revealed synergistic growth inhibition at >IC(50) concentrations and antagonism at

Background: Stable polyamine homeostasis is important for cell survival and regeneration. Our experimental studies have shown that catabolism of spermidine and spermine to putrescine is associated with the development of pancreatitis. We investigated the pathogenetic role of polyamine catabolism by studying the effect of a methylated polyamine analog on taurodeoxycholate-induced acute experimental pancreatitis., Methods: Acute pancreatitis was induced by infusion of sodium taurodeoxycholate (2%) into the pancreatic duct. Bismethylspermine (Me(2)Spm) was administered as a pretreatment before the induction of pancreatitis or as a treatment after the induction of pancreatitis. The sham operation included laparotomy only. Pancreas tissue and blood were sampled at 24 h and 72 h after the infusion of taurodeoxycholate and studied for pancreatitis severity (serum amylase activity, pancreatic water content, and histology) and polyamine catabolism, which includes spermidine/spermine N(1)-acetyltransferase (SSAT) activity as well as spermidine, spermine, and putrescine concentrations in the pancreas., Results: Sodium taurodeoxycholate-induced acute pancreatitis manifests as increases in serum amylase and pancreatic water content, leukocytosis, and acinar cell necrosis in the pancreas. The activity of SSAT increased significantly together with an increase in the ratios of pancreatic putrescine/spermidine and putrescine/spermine at 24 h, which indicates SSAT-induced polyamine catabolism. Pancreatic water content and necrosis were reduced significantly by the treatment with Me(2)Spm at 24 h but not at 72 h when the polyamine homeostasis had recovered, and the pancreatitis had progressed., Conclusions: Taurodeoxycholate-induced acute pancreatitis was associated with activation of polyamine catabolism in the pancreas. The polyamine analog Me(2)Spm ameliorated the injury in the early stage, but it did not ameliorate the late progression of the pancreatic necrosis at 72 h. Thus, besides proteolytic enzyme activation and the cascades of inflammation, polyamine catabolism may be an important pathogenetic mediator of the early stages of acute pancreatitis.

This study aimed to investigate the effect of spermine (Spm) as a chemical chaperone and glycation inhibitor on the lipid profile and HDL functionality in the short- and long-term treatment of the STZ-induced diabetic rats. Male Wistar rats were divided into 4 groups (control, n=7; diabetic, n=9). Two groups (named 2 and 3) were injected intraperitoneally with streptozotocin. Control rats (named 1 and 4) were injected with vehicle alone. The treatment of diabetic and control animals (groups 3 and 4) with 60 micromol/l of Spm in drinking water was begun. The study continued up to the end of the fifth month. The serum glucose and insulin level, AGE formation, lipid profile, paraoxonase 1 (PON1), and lecithin: cholesterol acyl transferase (LCAT) activities were measured. Significantly lower plasma PON1, and LCAT activities and higher serum AGE, TG, TC and LDL-c, and lower HDL-c were seen in diabetic rats as compared to control groups (P<0.01). The increased AGE, TG, TC and LDL-c levels in diabetic groups decreased gradually after receiving Spm. In addition, due to Spm administration, an increase in the HDL-c level was observed after the first month of the experiment (P<0.01). The increase in the PON1 and LCAT activities in the diabetic group that received Spm was significant after the second and the forth month of the experiment, P<0.02 and P<0.05, respectively. In conclusion, spermine administration attenuated the changed parameters to near normal values in diabetic rats. Spermine, despite a lack of significant changes on glucose metabolism and insulin secretion, was found to improve diabetes complications.

Lipopolysaccharide (LPS), or endotoxin, a structural component of gram-negative bacterial outer membranes, plays a key role in the pathogenesis of septic shock, a syndrome of severe systemic inflammation which leads to multiple-system organ failure. Despite advances in antimicrobial chemotherapy, sepsis continues to be the commonest cause of death in the critically ill patient. This is attributable to the lack of therapeutic options that aim at limiting the exposure to the toxin and the prevention of subsequent downstream inflammatory processes. Polymyxin B (PMB), a peptide antibiotic, is a prototype small molecule that binds and neutralizes LPS toxicity. However, the antibiotic is too toxic for systemic use as an LPS sequestrant. Based on a nuclear magnetic resonance-derived model of polymyxin B-LPS complex, we had earlier identified the pharmacophore necessary for optimal recognition and neutralization of the toxin. Iterative cycles of pharmacophore-based ligand design and evaluation have yielded a synthetically easily accessible N(1),mono-alkyl-mono-homologated spermine derivative, DS-96. We have found that DS-96 binds LPS and neutralizes its toxicity with a potency indistinguishable from that of PMB in a wide range of in vitro assays, affords complete protection in a murine model of LPS-induced lethality, and is apparently nontoxic in vertebrate animal models.

We investigated the role of the NO/cGMP system in the vasodilatory response to hypercapnia after cortical spreading depression (CSD) in barbiturate anesthetized rats in vivo. Regional cerebral blood flow (rCBF) was measured by laser Doppler flowmetry (LDF). Hypercapnia (arterial pCO2 50-60 mm Hg) increased rCBF by 2.8+/-1.0%/mm Hg (n = 34). Fifteen minutes after CSD, resting rCBF was reduced to 87%, and rCBF response to hypercapnia was abolished (p < 0.001, n = 28). Within 1 h after CSD, only little restoration of vascular reactivity occurred. Topical application of the NO-donors S-nitroso-N-acetylpenicillamine (SNAP), 3-morpholinosydnonimine (SIN1), or spermine/NO complex (Sperm/NO), or of the cell permeable guanosine 3',5'-cyclic monophosphate (cGMP) analogue 8-Br-cGMP reestablished resting rCBF to values measured before CSD, and reversed CSD-induced attenuation of the cerebrovascular response to hypercapnia. Restoration of resting rCBF to pre-CSD level by the NO-independent vasodilator papaverine had no effect on the attenuated hypercapnic response. In conclusion, we have shown that the compromised vascular reactivity to hypercapnia after CSD can be reversed to normal reactivity by restoration of the basal NO or cGMP concentration in the cortex, suggesting a reduction of the cerebrovascular NO or cGMP concentration following CSD.