scholarly journals Identification of a novel substrate-derived spermine oxidase inhibitor

Acta Naturae ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 140-144
Author(s):  
T. T. Dunston ◽  
M. A. Khomutov ◽  
S. B. Gabelli ◽  
T. M. Stewart ◽  
J. R. Foley ◽  
...  
Keyword(s):  
Enzyme Inhibitors ◽  
Oxidase Inhibitor ◽  
Polyamine Metabolism ◽  
Spermine Oxidase ◽  
Irreversible Inhibitor ◽  
Inflammatory Stimuli ◽  
Biogenic Polyamines ◽  
Cell Growth And Viability

Homeostasis of the biogenic polyamines spermine (Spm) and spermidine (Spd), present in M-mM concentrations in all eukaryotic cells, is precisely regulated by coordinated activities of the enzymes of polyamine synthesis, degradation, and transport, in order to sustain normal cell growth and viability. Spermine oxidase (SMOX) is the key and most recently discovered enzyme of polyamine metabolism that plays an essential role in regulating polyamine homeostasis by catalyzing the back-conversion of Spm to Spd. The development of many types of epithelial cancer is associated with inflammation, and disease-related inflammatory stimuli induce SMOX. MDL72527 is widely used in vitro and in vivo as an irreversible inhibitor of SMOX, but it is also potent towards N1-acetylpolyamine oxidase. Although SMOX has high substrate specificity, Spm analogues have not been systematically studied as enzyme inhibitors. Here we demonstrate that 1,12-diamino-2,11-bis(methylidene)-4,9-diazadodecane (2,11-Met2-Spm) has, under standard assay conditions, an IC50 value of 169 M towards SMOX and is an interesting instrument and lead compound for studying polyamine catabolism.

scholarly journals A central role for polyamines in microtubule assembly in cells

2010 ◽  
Vol 430 (1) ◽  
pp. 151-159 ◽  
Author(s):  
Philippe Savarin ◽  
Aurélie Barbet ◽  
Stéphanie Delga ◽  
Vandana Joshi ◽  
Loïc Hamon ◽  
...  
Keyword(s):  
Binding Protein ◽  
Rat Kidney ◽  
Microtubule Assembly ◽  
Polyamine Metabolism ◽  
Cell Periphery ◽  
Irreversible Inhibitor ◽  
Spermine Synthase ◽  
Synthase Inhibitor

Owing to preferential electrostatic adsorption of multivalent cations on highly anionic surfaces, natural multivalent polyamines and especially quadrivalent spermine can be considered as potential regulators of the complex dynamical properties of anionic MTs (microtubules). Indeed, the C-terminal tails of tubulin display many negative residues in a row which should enable the formation of a correlated liquid-like phase of multivalent counterions on its surface. Although it is known that polyamine counterions promote MT assembly in vitro, little is known about the relevance of this interaction in vivo. In the present study, we have explored the relationship between polyamine levels and MT assembly in HeLa and epithelial NRK (normal rat kidney) cells using DFMO (α-difluoromethylornithine), an irreversible inhibitor of ornithine decarboxylase, and APCHA [N-(3-aminopropyl)-N-cyclohexylamine], a spermine synthase inhibitor. Under conditions of intracellular polyamine depletion, the MT network is clearly disrupted and the MT mass decreases. Addition of spermine to polyamine-depleted cells reverses this phenotype and rapidly promotes the extensions of the MT network. Finally, we show that polyamine levels modulate the coating of MTs with MAP4 (MT-associated protein 4), an MT-stabilizing protein, and the spatial distribution of EB1 (end-binding protein 1), an MT plus-end-binding protein. In addition, polyamines favour the formation of gap junctions in NRK cells, a process which requires MT extensions at the cell periphery. The present study provides a basis for a better understanding of the role played by polyamines in MT assembly and establishes polyamine metabolism as a potential cellular target for modulating MT functions.

Inflammatory stimuli increase local cortisol production in osteoblasts in vitro and in vivo.

Bone ◽  
2000 ◽  
Vol 27 (4) ◽  
pp. 33
Author(s):  
MS Cooper ◽  
E Rabbitt ◽  
P Emery ◽  
M Hewison ◽  
PM Stewart
Keyword(s):  
Inflammatory Stimuli

Advances in Anti-inflammatory Activity, Mechanism and Therapeutic Application of Ursolic Acid

2021 ◽  
Vol 21 ◽  
Author(s):  
Mingzhu Luan ◽  
Huiyun Wang ◽  
Jiazhen Wang ◽  
Xiaofan Zhang ◽  
Fenglan Zhao ◽  
...  
Keyword(s):  
Ursolic Acid ◽  
Inflammatory Diseases ◽  
Kidney Diseases ◽  
Inflammatory Activity ◽  
Inflammatory Factors ◽  
Inflammatory Stimuli ◽  
Bowel Diseases ◽  
Anti Inflammatory

: In vivo and in vitro studies reveal that ursolic acid (UA) is able to counteract endogenous and exogenous inflammatory stimuli, and has favorable anti-inflammatory effects. The anti-inflammatory mechanisms mainly include decreasing the release of histamine in mast cells, suppressing the activities of lipoxygenase, cyclooxygenase and phospholipase, and reducing the production of nitric oxide and reactive oxygen species, blocking the activation of signal pathway, down-regulating the expression of inflammatory factors, and inhibiting the activities of elastase and complement. These mechanisms can open up new avenues for the scientific community to develop or improve novel therapeutic approaches to tackle inflammatory diseases such as arthritis, atherosclerosis, neuroinflammation, liver diseases, kidney diseases, diabetes, dermatitis, bowel diseases, cancer. The anti-inflammatory activity, the anti-inflammatory mechanism of ursolic acid and its therapeutic applications are reviewed in this paper.

scholarly journals Mammalian deubiquitinating enzyme inhibitors display in vitro and in vivo activity against malaria parasites and potentiate artemisinin action

2020 ◽  
Author(s):  
Nelson V. Simwela ◽  
Katie R. Hughes ◽  
Michael T. Rennie ◽  
Michael P. Barrett ◽  
Andrew P. Waters
Keyword(s):  
Anticancer Agents ◽  
Drug Targets ◽  
Reverse Genetics ◽  
Enzyme Inhibitors ◽  
Artemisinin Resistance ◽  
Drug Repurposing ◽  
Antimalarial Drugs ◽  
Malaria Parasites

AbstractCurrent malaria control efforts rely significantly on artemisinin combinational therapies which have played massive roles in alleviating the global burden of the disease. Emergence of resistance to artemisinins is therefore, not just alarming but requires immediate intervention points such as development of new antimalarial drugs or improvement of the current drugs through adjuvant or combination therapies. Artemisinin resistance is primarily conferred by Kelch13 propeller mutations which are phenotypically characterised by generalised growth quiescence, altered haemoglobin trafficking and downstream enhanced activity of the parasite stress pathways through the ubiquitin proteasome system (UPS). Previous work on artemisinin resistance selection in a rodent model of malaria, which we and others have recently validated using reverse genetics, has also shown that mutations in deubiquitinating enzymes, DUBs (upstream UPS component) modulates susceptibility of malaria parasites to both artemisinin and chloroquine. The UPS or upstream protein trafficking pathways have, therefore, been proposed to be not just potential drug targets, but also possible intervention points to overcome artemisinin resistance. Here we report the activity of small molecule inhibitors targeting mammalian DUBs in malaria parasites. We show that generic DUB inhibitors can block intraerythrocytic development of malaria parasites in vitro and possess antiparasitic activity in vivo and can be used in combination with additive effect. We also show that inhibition of these upstream components of the UPS can potentiate the activity of artemisinin in vitro as well as in vivo to the extent that ART resistance can be overcome. Combinations of DUB inhibitors anticipated to target different DUB activities and downstream 20s proteasome inhibitors are even more effective at improving the potency of artemisinins than either inhibitors alone providing proof that targeting multiple UPS activities simultaneously could be an attractive approach to overcoming artemisinin resistance. These data further validate the parasite UPS as a target to both enhance artemisinin action and potentially overcome resistance. Lastly, we confirm that DUB inhibitors can be developed into in vivo antimalarial drugs with promise for activity against all of human malaria and could thus further exploit their current pursuit as anticancer agents in rapid drug repurposing programs.Graphical abstract

scholarly journals A therapeutic combination of two small molecule toxin inhibitors provides pancontinental preclinical efficacy against viper snakebite

2020 ◽  
Author(s):  
Laura-Oana Albulescu ◽  
Chunfang Xie ◽  
Stuart Ainsworth ◽  
Jaffer Alsolaiss ◽  
Edouard Crittenden ◽  
...  
Keyword(s):  
Small Molecules ◽  
Enzyme Inhibitors ◽  
Interspecific Variation ◽  
Medical Emergency ◽  
Dual Inhibitor ◽  
Mortality And Morbidity ◽  
Venom Composition ◽  
Inhibitor Combination

AbstractSnakebite is a medical emergency causing high mortality and morbidity in rural tropical communities that typically experience delayed access to unaffordable therapeutics. Viperid snakes are responsible for the majority of envenomings, but extensive interspecific variation in venom composition dictates that different antivenom treatments are used in different parts of the world, resulting in clinical and fiscal snakebite management challenges. Here, we show that a number of repurposed Phase 2-approved small molecules are capable of broadly neutralizing distinct viper venom bioactivities in vitro by inhibiting different enzymatic toxin families. Furthermore, using multiple in vivo models of envenoming, we demonstrate that a single dose of a rationally-selected dual inhibitor combination consisting of marimastat and varespladib prevents lethality caused by venom from the most medically-important vipers of Africa, South Asia and Central America. Our findings strongly support the translation of combinations of safe and affordable enzyme inhibitors as novel broad-spectrum therapeutics for snakebite.

Polyamine metabolism during cardiac hypertrophy

1980 ◽  
Vol 239 (5) ◽  
pp. E372-E378 ◽  
Author(s):  
A. E. Pegg ◽  
H. Hibasami
Keyword(s):  
Cardiac Hypertrophy ◽  
Polyamine Metabolism ◽  
Decarboxylase Activity ◽  
Elevated Concentration ◽  
Enzyme Protein ◽  
Carboxylase Activity ◽  
Rapid Reduction ◽  
Spermine Synthase

Treatment with thyroxine for 7 days to produce myocardial hypertrophy led to an increase in the content of putrescine, spermidine, and spermine in the rat heart. The content of decarboxylated S-adenosylmethionine, the source of the aminopropyl groups needed for polyamine synthesis, was increased by the thyroxine treatment as were the activities of ornithine and S-adenosylmethionine decarboxylases. The enhanced S-adenosylmethionine decarboxylase activity measured in vitro was due to an increase in the amount of enzyme protein as measured by immunotitration with a specific antiserum. In vivo, decarboxylation of S-adenosylmethionine was, therefore, increased both by the increased amount of enzyme protein and by the elevated concentration of putrescine (which activates the enzyme) brought about by the enhanced ornithine carboxylase activity. Spermine synthase did not change significantly during the treatment and spermidine synthase increased only slightly. Therefore, the accumulation of polyamines was mediated predominantly via the increased availability of both putrescine and decarboxylated S-adenosylmethionine. Administration of 1,3-diamino-2-propanol led to a rapid reduction in the activity of ornithine decarboxylase in the heart, and continued exposure to this substance by its inclusion in the drinking water completely prevented the increase in concentration of putrescine and polyamines in response to thyroxine. However, cardiac hypertrophy as measured by the increase in cardiac mass was not prevented by such treatment with 1,3-diaminopropanol, showing that the increased content of polyamines was not essential for the hypertrophic response.

scholarly journals Stimulation in vitro of vitamin B12-dependent methionine synthase by polyamines

1996 ◽  
Vol 316 (2) ◽  
pp. 661-665 ◽  
Author(s):  
Susan H. KENYON ◽  
Anna NICOLAOU ◽  
Tamara AST ◽  
William A. GIBBONS
Keyword(s):  
Enzyme Activity ◽  
Vitamin B12 ◽  
Cell Signalling ◽  
Methionine Synthase ◽  
Polyamine Metabolism ◽  
Physiological Concentration ◽  
Methylation Pathway ◽  
Important Enzyme

Vitamin B12-dependent methionine synthase is an important enzyme for sulphur amino acid, folate polyamine metabolism, S-adenosylmethionine metabolism and also in the methylation pathway of DNA, RNA, proteins and lipids. Consequently, studies aiming at exploring the control and regulation of methionine synthase are of particular interest. Here we report the modulation of enzyme activity in vitro by polyamines. Although putrescine, cadaverine, spermine and spermidine all stimulated enzyme activity, the last two were the most potent, causing increases in enzyme activity up to 400%. The EC50 for spermine was determined as 8 μM and for spermidine 40 μM. The physiological concentration for spermine has been reported to be 15–19 μM. Spermine was found to increase both the Km and the Vmax with respect to methyltetrahydrofolate for the enzyme. These data support the hypothesis that spermine and spermidine are feedback regulators of methionine synthase both in vivo and in vitro and are consistent with the polyamines' regulating cell signalling pathways.

scholarly journals Resistin Is Increased in Periodontal Cells and Tissues: In Vitro and In Vivo Studies

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Andressa V. B. Nogueira ◽  
Marjan Nokhbehsaim ◽  
Sema Tekin ◽  
Rafael S. de Molon ◽  
Luis C. Spolidorio ◽  
...  
Keyword(s):  
Bone Loss ◽  
Inflammatory Diseases ◽  
Inflammatory Cells ◽  
Male Rats ◽  
In Vivo Studies ◽  
Hard Tissue ◽  
Tissue Metabolism ◽  
Inflammatory Stimuli

Resistin, a proinflammatory adipokine, is elevated in many inflammatory diseases. However, little is known about its performance in periodontitis. The present study is aimed at evaluating resistin expression and synthesis in periodontal cells and tissues under inflammatory/microbial stress in addition to its effects on the periodontium. In vivo, 24 male rats were randomly divided into two groups: control and ligature-induced periodontal disease. After 6 and 12 days, animals were sacrificed to analyze gene expression of adipokines, bone loss, inflammation, and resistin synthesis. In vitro, human periodontal ligament (PDL) fibroblasts were used to evaluate the expression of resistin after inflammatory stimuli. In addition, PDL fibroblasts were exposed to resistin to evaluate its role on soft and hard tissue metabolism markers. The periodontitis group demonstrated significant bone loss, an increase in the number of inflammatory cells and vascular structures, an increase in resistin expression and synthesis, and a decrease in the expression of adiponectin, leptin, and its functional receptor. PDL fibroblasts showed a significant increase in resistin expression and synthesis in response to the inflammatory stimulus by IL-1β. Resistin induced an increase in cytokine expression and a decrease in the regulation of some hard tissue and matrix formation genes in PDL fibroblasts. These data indicate that resistin is produced by periodontal cells and tissues, and this effect is enhanced by inflammatory stimuli. Moreover, resistin seems to interfere with soft and hard tissue metabolism during periodontitis by reducing markers related to matrix formation and bone tissue.

scholarly journals The role of polyamine biosynthesis in hematopoietic precursor cell proliferation in mice

Blood ◽  
1983 ◽  
Vol 61 (4) ◽  
pp. 740-745 ◽  
Author(s):  
E Niskanen ◽  
A Kallio ◽  
PP McCann ◽  
DG Baker
Keyword(s):  
Ornithine Decarboxylase ◽  
Colony Formation ◽  
Calf Serum ◽  
Decarboxylase Activity ◽  
Irreversible Inhibitor ◽  
Host Animal ◽  
Polyamine Biosynthesis ◽  
Diffusion Chambers

Abstract Under the influence of a selective irreversible inhibitor of ornithine decarboxylase (ODC), DL-alpha-difluoromethylornithine (DFMO), early hematopoiesis was enhanced. In the bone marrow, the absolute number of cells that give rise to spleen colonies in lethally irradiated mice (CFU-S), granulocytic colonies in diffusion chambers in mice (CFU-DG), and granulocyte-monocyte colonies in agar in vitro (CFU-C) was increased 2–4 fold. This could be abrogated by administration of putrescine, confirming the association of the stimulatory effect with polyamine biosynthesis most likely via depression of ornithine decarboxylase activity and subsequent synthesis of putrescine. Analysis of cell cycle characteristics by 3H-TdR suicide technique demonstrated that the proportion of CFU-S, CFU-DG, and CFU-C in S-phase was significantly increased. Additionally, the stimulatory effect was reflected by enhanced colony formation in diffusion chambers implanted intraperitoneally in mice receiving DFMO. This could also be eliminated by treatment of the host animal with putrescine, again suggesting that polyamine biosynthesis plays an important role at the early stages of hematopoiesis in vivo. Effect of DFMO on colony formation in vitro (CFU- C) was inhibitory and not reversible with putrescine. It could be partially eliminated by aminoguanidine, which neutralizes diamine oxidase present in fetal calf serum used in the CFU-C assay. These data suggest that the effect of DFMO in vitro was nonspecific.

In vivo and in vitro effect of androstene derivatives as 5α-reductase type 1 enzyme inhibitors

2012 ◽  
Vol 28 (6) ◽  
pp. 1247-1254 ◽  
Author(s):  
Eugene Bratoeff ◽  
Araceli Sánchez ◽  
Yazmín Arellano ◽  
Yvonne Heuze ◽  
Juan Soriano ◽  
...  
Keyword(s):  
Enzyme Inhibitors ◽  
Vitro Effect
Sign in / Sign up

Export Citation Format

Share Document