scholarly journals Antizyme Inhibitors in Polyamine Metabolism and Beyond: Physiopathological Implications

2018 ◽  
Vol 6 (4) ◽  
pp. 89 ◽  
Author(s):  
Bruno Ramos-Molina ◽  
Ana Lambertos ◽  
Rafael Peñafiel
Keyword(s):  
Neurodegenerative Diseases ◽  
Negative Control ◽  
Cellular Growth ◽  
Transport Systems ◽  
Polyamine Metabolism ◽  
Cellular Functions ◽  
Polyamine Transport ◽  
Key Enzyme ◽  
Independent Effects ◽  
Antizyme Inhibitors

The intracellular levels of polyamines, cationic molecules involved in a myriad of cellular functions ranging from cellular growth, differentiation and apoptosis, is precisely regulated by antizymes and antizyme inhibitors via the modulation of the polyamine biosynthetic and transport systems. Antizymes, which are mainly activated upon high polyamine levels, inhibit ornithine decarboxylase (ODC), the key enzyme of the polyamine biosynthetic route, and exert a negative control of polyamine intake. Antizyme inhibitors (AZINs), which are proteins highly homologous to ODC, selectively interact with antizymes, preventing their action on ODC and the polyamine transport system. In this review, we will update the recent advances on the structural, cellular and physiological functions of AZINs, with particular emphasis on the action of these proteins in the regulation of polyamine metabolism. In addition, we will describe emerging evidence that suggests that AZINs may also have polyamine-independent effects on cells. Finally, we will discuss how the dysregulation of AZIN activity has been implicated in certain human pathologies such as cancer, fibrosis or neurodegenerative diseases.

Regulation of cellular polyamine levels and cellular proliferation by antizyme and antizyme inhibitor

2009 ◽  
Vol 46 ◽  
pp. 47-62 ◽  
Author(s):  
Chaim Kahana
Keyword(s):  
Turnover Rate ◽  
Cellular Proliferation ◽  
Cellular Growth ◽  
26S Proteasome ◽  
Cellular Viability ◽  
Cellular Functions ◽  
Polyamine Biosynthesis ◽  
Cellular Processes ◽  
Antizyme Inhibitor ◽  
Key Enzyme

Polyamines are small aliphatic polycations present in all living cells. Polyamines are essential for cellular viability and are involved in regulating fundamental cellular processes, most notably cellular growth and proliferation. Being such central regulators of fundamental cellular functions, the intracellular polyamine concentration is tightly regulated at the levels of synthesis, uptake, excretion and catabolism. ODC (ornithine decarboxylase) is the first key enzyme in the polyamine biosynthesis pathway. ODC is characterized by an extremely rapid intracellular turnover rate, a trait that is central to the regulation of cellular polyamine homoeostasis. The degradation rate of ODC is regulated by its end-products, the polyamines, via a unique autoregulatory circuit. At the centre of this circuit is a small protein called Az (antizyme), whose synthesis is stimulated by polyamines. Az inactivates ODC and targets it to ubiquitin-independent degradation by the 26S proteasome. In addition, Az inhibits uptake of polyamines. Az itself is regulated by another ODC-related protein termed AzI (antizyme inhibitor). AzI is highly homologous with ODC, but it lacks ornithine-decarboxylating activity. Its ability to serve as a regulator is based on its high affinity to Az, which is greater than the affinity Az has to ODC. As a result, it interferes with the binding of Az to ODC, thus rescuing ODC from degradation and permitting uptake of polyamines.

scholarly journals Overexpression of arginine decarboxylase in transgenic plants

1997 ◽  
Vol 325 (2) ◽  
pp. 331-337 ◽  
Author(s):  
Daniel BURTIN ◽  
Anthony J. MICHAEL
Keyword(s):  
Transgenic Plants ◽  
Arginine Decarboxylase ◽  
Polyamine Metabolism ◽  
Morphological Development ◽  
Polyamine Biosynthesis ◽  
Adenosylmethionine Decarboxylase ◽  
Two Generations ◽  
Key Enzyme ◽  
Polyamine Conjugate ◽  
And Control

The activity of arginine decarboxylase (ADC), a key enzyme in plant polyamine biosynthesis, was manipulated in two generations of transgenic tobacco plants. Second-generation transgenic plants overexpressing an oat ADC cDNA contained high levels of oat ADC transcript relative to tobacco ADC, possessed elevated ADC enzyme activity and accumulated 10–20-fold more agmatine, the direct product of ADC. In the presence of high levels of the precursor agmatine, no increase in the levels of the polyamines putrescine, spermidine and spermine was detected in the transgenic plants. Similarly, the activities of ornithine decarboxylase and S-adenosylmethionine decarboxylase were unchanged. No diversion of polyamine metabolism into the hydroxycinnamic acid–polyamine conjugate pool or into the tobacco alkaloid nicotine was detected. Activity of the catabolic enzyme diamine oxidase was the same in transgenic and control plants. The elevated ADC activity and agmatine production were subjected to a metabolic/physical block preventing increased, i.e. deregulated, polyamine accumulation. Overaccumulation of agmatine in the transgenic plants did not affect morphological development.

scholarly journals Comparison of the Essential Cellular Functions of the Two murA Genes of Bacillus anthracis

2008 ◽  
Vol 52 (6) ◽  
pp. 2009-2013 ◽  
Author(s):  
G. C. Kedar ◽  
Vickie Brown-Driver ◽  
Daniel R. Reyes ◽  
Mark T. Hilgers ◽  
Mark A. Stidham ◽  
...  
Keyword(s):  
Gene Expression ◽  
Bacillus Anthracis ◽  
High Resistance ◽  
Gene Replacement ◽  
Cellular Growth ◽  
Cellular Functions

ABSTRACT Targeted antisense and gene replacement mutagenesis experiments demonstrate that only the murA1 gene and not the murA2 gene is required for the normal cellular growth of Bacillus anthracis. Antisense-based modulation of murA1 gene expression hypersensitizes cells to the MurA-specific antibiotic fosfomycin despite the normally high resistance of B. anthracis to this drug.

scholarly journals The STK2 gene, which encodes a putative Ser/Thr protein kinase, is required for high-affinity spermidine transport in Saccharomyces cerevisiae.

1997 ◽  
Vol 17 (6) ◽  
pp. 2994-3004 ◽  
Author(s):  
M Kaouass ◽  
M Audette ◽  
D Ramotar ◽  
S Verma ◽  
D De Montigny ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Fusion Gene ◽  
Transport Systems ◽  
Coding Region ◽  
Kinase Gene ◽  
Lower Affinity ◽  
High Affinity ◽  
Polyamine Transport ◽  
Exogenous Spermidine

Eukaryotic polyamine transport systems have not yet been characterized at the molecular level. We have used transposon mutagenesis to identify genes controlling polyamine transport in Saccharomyces cerevisiae. A haploid yeast strain was transformed with a genomic minitransposon- and lacZ-tagged library, and positive clones were selected for growth resistance to methylglyoxal bis(guanylhydrazone) (MGBG), a toxic polyamine analog. A 747-bp DNA fragment adjacent to the lacZ fusion gene rescued from one MGBG-resistant clone mapped to chromosome X within the coding region of a putative Ser/Thr protein kinase gene of previously unknown function (YJR059w, or STK2). A 304-amino-acid stretch comprising 11 of the 12 catalytic subdomains of Stk2p is approximately 83% homologous to the putative Pot1p/Kkt8p (Stk1p) protein kinase, a recently described activator of low-affinity spermine uptake in yeast. Saturable spermidine transport in stk2::lacZ mutants had an approximately fivefold-lower affinity and twofold-lower Vmax than in the parental strain. Transformation of stk2::lacZ cells with the STK2 gene cloned into a single-copy expression vector restored spermidine transport to wild-type levels. Single mutants lacking the catalytic kinase subdomains of STK1 exhibited normal parameters for the initial rate of spermidine transport but showed a time-dependent decrease in total polyamine accumulation and a low-level resistance to toxic polyamine analogs. Spermidine transport was repressed by prior incubation with exogenous spermidine. Exogenous polyamine deprivation also derepressed residual spermidine transport in stk2::lacZ mutants, but simultaneous disruption of STK1 and STK2 virtually abolished high-affinity spermidine transport under both repressed and derepressed conditions. On the other hand, putrescine uptake was also deficient in stk2::lacZ mutants but was not repressed by exogenous spermidine. Interestingly, stk2::lacZ mutants showed increased growth resistance to Li+ and Na+, suggesting a regulatory relationship between polyamine and monovalent inorganic cation transport. These results indicate that the putative STK2 Ser/Thr kinase gene is an essential determinant of high-affinity polyamine transport in yeast whereas its close homolog STK1 mostly affects a lower-affinity, low-capacity polyamine transport activity.

Polyamine transport systems in isolated rat hepatocytes derived from resting and regenerating livers

1992 ◽  
Vol 263 (2) ◽  
pp. G169-G173
Author(s):  
G. Y. Minuk ◽  
A. Bennaroch ◽  
L. X. Ding
Keyword(s):  
Partial Hepatectomy ◽  
Specific Binding ◽  
Rat Hepatocytes ◽  
Eukaryotic Cell ◽  
Transport Systems ◽  
Affinity Constant ◽  
Hepatic Regeneration ◽  
Gamma Aminobutyric Acid ◽  
Isolated Rat Hepatocytes ◽  
Polyamine Transport

Polyamines and their principal metabolite, gamma-aminobutyric acid (GABA), modulate eukaryotic cell growth. To determine whether the liver possesses specific polyamine transport sites and whether changes occur to these or GABA transport sites during hepatic regeneration, suspensions of rat hepatocytes derived from in situ collagenase perfusions of livers at times 0, 24, 48, and 72 h post-partial hepatectomy were incubated at 4, 20, and 37 degrees C with various concentrations of the following ligands: [3H]putrescine, [3H]spermidine, [14C]spermine, and [3H]GABA together with or without excess unlabeled ligand, KCN, ouabain, or digitoxigenin. Of the ligands studied, only [14C]spermine and [3H]GABA were associated with specific binding to hepatocytes derived from nonregenerating livers. Spermine binding correlated with the concentration of hepatocytes in the incubation mixture and reached equilibrium within 60 min. The approximate affinity constant (KD) was 5.5 x 10(-5) mol/10(6) hepatocytes, and maximum number of binding sites (Bmax) was 1.8 +/- 1.2 x 10(-7) mol.10(6) hepatocytes-1.min-1. Binding was neither temperature nor sodium dependent and was not inhibited by KCN, ouabain, digitoxigenin, other polyamines, or GABA. Aside from a 43% decrease in spermine binding at 24 h post-partial hepatectomy [5.1 +/- 1.1 vs. 8.9 +/- 3.1 x 10(3) disintegrations per minute (dpm)/10(6) hepatocytes at time 0, P less than 0.05] and a 39% decrease in GABA binding (3.4 +/- 1.3 vs. 5.5 +/- 1.9 x 10(3) dpm/10(6) hepatocytes, P less than 0.05), there were no significant changes in ligand binding during hepatic regeneration.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Microglial Progranulin: Involvement in Alzheimer’s Disease and Neurodegenerative Diseases

Cells ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 230 ◽  
Author(s):  
Anarmaa Mendsaikhan ◽  
Ikuo Tooyama ◽  
Douglas G. Walker
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Neurodegenerative Diseases ◽  
Neuronal Ceroid Lipofuscinosis ◽  
Experimental Models ◽  
Lysosomal Storage ◽  
Cellular Functions ◽  
New Treatments ◽  
Regulatory Properties ◽  
Microglial Inflammation

Neurodegenerative diseases such as Alzheimer’s disease have proven resistant to new treatments. The complexity of neurodegenerative disease mechanisms can be highlighted by accumulating evidence for a role for a growth factor, progranulin (PGRN). PGRN is a glycoprotein encoded by the GRN/Grn gene with multiple cellular functions, including neurotrophic, anti-inflammatory and lysosome regulatory properties. Mutations in the GRN gene can lead to frontotemporal lobar degeneration (FTLD), a cause of dementia, and neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Both diseases are associated with loss of PGRN function resulting, amongst other features, in enhanced microglial neuroinflammation and lysosomal dysfunction. PGRN has also been implicated in Alzheimer’s disease (AD). Unlike FTLD, increased expression of PGRN occurs in brains of human AD cases and AD model mice, particularly in activated microglia. How microglial PGRN might be involved in AD and other neurodegenerative diseases will be discussed. A unifying feature of PGRN in diseases might be its modulation of lysosomal function in neurons and microglia. Many experimental models have focused on consequences of PGRN gene deletion: however, possible outcomes of increasing PGRN on microglial inflammation and neurodegeneration will be discussed. We will also suggest directions for future studies on PGRN and microglia in relation to neurodegenerative diseases.

scholarly journals Role of Human Galectins in Inflammation and Cancers Associated with Endometriosis

Biomolecules ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 230 ◽  
Author(s):  
Brooke V. Hisrich ◽  
R. Brant Young ◽  
Alison M. Sansone ◽  
Zachary Bowens ◽  
Lisa J. Green ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Immune Surveillance ◽  
Chronic Inflammatory Disease ◽  
Cellular Growth ◽  
Unknown Etiology ◽  
Cancer Therapies ◽  
Cellular Functions ◽  
Inflammatory Conditions ◽  
Galectin 3 ◽  
Kras Protein

Galectins are a family of β-galactoside-binding proteins that contribute to multiple cellular functions, including immune surveillance and apoptosis. Human galectins are also important regulators of inflammation, making them a research target for various inflammatory diseases and tumorigenesis associated with pro-inflammatory conditions. This review focuses on the involvement of human galectins in modulation of inflammation and in the pathophysiology of endometriosis and endometriosis-associated neoplasms. Endometriosis is a chronic inflammatory disease with unknown etiology. Galectins-1, -3 and -9 were found to be overexpressed in ectopic and eutopic endometrium of females with endometriosis compared to those without endometriosis. These findings suggest galectins’ role in the progression on endometriotic lesions and their potential use as diagnostic biomarkers and/or targets for therapeutic approaches. Galectins-1, -3, and -9 have also been implicated in the development of endometriosis-associated neoplasms. Furthermore, galectin-3 has been shown to interact with KRAS protein and contribute to cellular growth, proliferation, inflammation, and the uptake of nutrients in endometriotic lesions and may be involved in the maintenance and propagation of endometriosis. These galectins have been shown to be upregulated in certain forms of cervical, ovarian, endometrial, and colon cancer associated with endometriosis and have become a potential target for anti-cancer therapies.

1 PATHWAYS AND CELLULAR FUNCTIONS INFLUENCED BY INSULIN TREATMENT DURING OOCYTE MATURATION – A TRANSCRIPTOME STUDY OF IN VITRO-PRODUCED BOVINE DAY 8 BLASTOCYSTS

2015 ◽  
Vol 27 (1) ◽  
pp. 93 ◽  
Author(s):  
D. Laskowski ◽  
Y. Sjunnesson ◽  
R. Båge ◽  
M. A. Sirard ◽  
H. Gustafsson ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Lipid Metabolism ◽  
Energy Metabolism ◽  
Metabolic Disorders ◽  
Insulin Treatment ◽  
Oxidative Stress Response ◽  
Cellular Growth ◽  
Cellular Functions

Insulin as a key metabolic hormone has crucial functions in metabolic regulation in all mammals. Deviation of its physiological concentration occurs in metabolic disorders as obesity and diabetes in humans or negative energy balance and overfeeding in the cow. As these metabolic disorders are strongly correlated with reproductive disturbances, we investigated the effect of insulin during oocyte maturation on gene expression of bovine Day 8 blastocysts (BC8) by transcriptome analysis. Abattoir-derived oocytes (n = 882) were divided into 3 groups and in vitro matured for 22 h by adding insulin (H: High 10 µg mL–1; L: Low 0.1 µg mL–1 and Z: Zero, control). This was followed by standard in vitro production (IVP) and evaluation of developmental rates up to blastocyst stage. BC8 (n = 120) were pooled in groups of 10 and total RNA was extracted by parallel gDNA and total RNA-extraction (AllPrepDNA/RNA micro kit, cat no. 80284, Qiagen®, Valencia, CA, USA) for analyses of the transcriptome. All samples (4 biological replicates/group) resulted in RIN-values >7.5. RNA amplification, cDNA synthesis, purification, and labelling were performed and 825 ng of Cy3- and Cy5-labelled linearly amplified aRNA was hybridized on the Agilent-manufactured EmbryoGENE-slides in a 2-colour dye swap design. An empirical Bayes moderated t-test was applied to search for the differentially expressed transcripts (DET) between control and insulin-treated groups, using the ‘limma’ package in R (www.r-project.org). The DET were defined as having a 1.5-fold change difference between treatment and control and P < 0.05. Pathways and molecular functions influenced by insulin treatment were analysed by using Ingenuity Pathway Analysis (IPA; Ingenuity® Systems, www.ingenuity.com). As a global pattern, insulin treatment induced an up-regulation of genes. In total, 202 DET in the H and 142 DET in the L group were found where 104 DET were common in both insulin groups. Fifteen selected candidate genes chosen for qPCR validation and 12 (80%) showed similar expression patterns as the microarray data. DET relevant for following cellular functions were found in H: Cell Cycle, Cellular Compromise, Lipid Metabolism, Molecular Transport, Small Molecule Biochemistry respective L: Cell Morphology, Cellular Growth and Proliferation, Cell Cycle, Carbohydrate Metabolism and Cellular Assembly and Organization. The top canonical pathways influenced were Epithelial Adherens Junction Signalling and Remodelling, Germ Cell Sertoli Cell Junction Signalling and NRF2-mediated Oxidative Stress Response. Correlatively, blastocyst rates on Day 8 were significantly lower in H and L v. Z (P < 0.05). The transcriptome data could explain the mechanisms behind the impaired development, as genes involved in cellular growth and energy metabolism in Day 8 blastocysts were affected. The fact that transcripts related to NRF2-mediated oxidative stress response and lipid metabolism are up-regulated suggests that insulin induces dysregulation of cellular functions and energy metabolism leading to impaired embryo developmental potential.Funded by FORMAS.

Producing Neurospheroids and Hydrogels to Create a Three-dimensional in Vitro Model for the Use of Conduits in Peripheral Nerve Regeneration

Neurosurgery ◽  
2019 ◽  
Vol 84 (5) ◽  
pp. E272-E272
Author(s):  
Devyani Shete ◽  
Aran Batth ◽  
Aditi Nijhawan ◽  
Jaffer Choudhary ◽  
Ian Thompson
Keyword(s):  
Peripheral Nerve ◽  
Nerve Regeneration ◽  
Schwann Cells ◽  
Peripheral Nerve Regeneration ◽  
3D Structure ◽  
Three Dimensional ◽  
Negative Control ◽  
Cellular Growth ◽  
Live Cells

Abstract INTRODUCTION Peripheral nerve regeneration is a complex challenge that requires suitable nerve guidance systems to bridge the severed ends of 2 nerves back together. Current polymeric conduits on the market provide good cellular growth but are limited by the length of gap defect they can repair, and complete functional recovery is rare. This project focused on creating a three-dimensional (3D) in Vitro spheroidal sprouting assay for peripheral nerve regeneration, as well as producing and testing different polymeric hydrogels as potential scaffold materials for the conduit. METHODS Different concentrations of chitosan, methylcellulose (MC) and sodium alginate were produced, as well as blends of these materials. These hydrogels were seeded with 3D neurospheroids, along with NG108-15 (neuronal) cells and Schwann cells to test their biocompatibility. RESULTS MTT assays showed the mean absorbance of chitosan gels with NG108-15 cells at 24 hr (P < .001) and 72 hr (P > .05) was similar/slightly higher than the negative control. Live-Dead data showed 93.4% of live cells at DIV7 on MC: Ch blends, compared to 72% with chitosan alone. CONCLUSION Overall, both chitosan and MC were nontoxic and biocompatible with NG108-15 and Schwann cells. Blending chitosan with MC improved its chemical and physical properties. The cells formed spheroids that well on a gel; this pseudo-3D structure is excellent for research purposes compared to 2D as it mimics the body's internal environment.

scholarly journals Effects of the S-adenosylmethionine decarboxylase inhibitor, 5′-{[(Z)-4-amino-2-butenyl]methylamino)-5′-deoxyadenosine, on cell growth and polyamine metabolism and transport in Chinese hamster ovary cell cultures

1994 ◽  
Vol 303 (1) ◽  
pp. 89-96 ◽  
Author(s):  
T L Byers ◽  
R S Wechter ◽  
R H Hu ◽  
A E Pegg
Keyword(s):  
Cell Growth ◽  
Transport System ◽  
Chinese Hamster Ovary ◽  
Cho Cells ◽  
Chinese Hamster ◽  
Ovary Cell ◽  
Polyamine Metabolism ◽  
Decarboxylase Inhibitor ◽  
Transport Activity ◽  
Polyamine Transport

The regulation of polyamine transport and the roles of polyamine transport and synthesis in cell growth were investigated using cultured Chinese hamster ovary (CHO) cells and CHOMG cells which are mutants lacking polyamine-transport activity. Metabolically stable methylated polyamine analogues were used to measure polyamine accumulation, and the irreversible S-adenosyl-L-methionine decarboxylase inhibitor, 5′-([(Z)-4-amino-2-butenyl]methylamino)-5′-deoxyadenosine (AbeAdo), was used to inhibit synthesis. Exposure to AbeAdo lead to a dose-dependent decrease in growth for both cell lines, although CHOMG cells were more sensitive. Intracellular putrescine levels were greatly increased in AbeAdo-treated CHO cells and to a lesser extent in CHOMG cells, whereas intracellular spermidine and spermine levels were substantially reduced in both. Treatment with AbeAdo increased putrescine content in the culture medium to a much greater extent in CHOMG cultures indicating that a portion of the excess putrescine synthesized in response to AbeAdo treatment is excreted, but that CHO cells salvage this putrescine whereas it is lost to CHOMG cells which cannot take up polyamines. AbeAdo treatment increased polyamine transport into CHO cells despite high intracellular putrescine, suggesting that spermidine and/or spermine, and not putrescine, are the major factors regulating transport activity. The accumulation of either 1-methylspermidine or 1,12-dimethylspermine was significantly increased by AbeAdo treatment. Accumulation was increased even further when protein synthesis was blocked by cycloheximide, indicating that a short-lived protein is involved in the regulation of polyamine uptake. In the presence of cycloheximide and AbeAdo or alpha-difluoromethylornithine, methylated polyamine derivatives accumulated to very high levels leading to cell death. These results show that the polyamine-transport system plays an important role in retaining intracellular polyamines and that down-regulation of the transport system in response to increased intracellular polyamine content is necessary to prevent accumulation of toxic levels of polyamines.

Sign in / Sign up

Export Citation Format

Share Document