scholarly journals Discovery of ancestral L-ornithine and L-lysine decarboxylases reveals parallel, pseudoconvergent evolution of polyamine biosynthesis

2021 ◽  
pp. 101219
Author(s):  
Bin Li ◽  
Jue Liang ◽  
Colin C. Hanfrey ◽  
Margaret A. Phillips ◽  
Anthony J. Michael
Keyword(s):  
Polyamine Biosynthesis

scholarly journals Radical Hemithoracic Radiotherapy Induces Systemic Metabolomics Changes That Are Associated with the Clinical Outcome of Malignant Pleural Mesothelioma Patients

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 508
Author(s):  
Emanuela Di Gregorio ◽  
Gianmaria Miolo ◽  
Asia Saorin ◽  
Elena Muraro ◽  
Michela Cangemi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Overall Survival ◽  
Clinical Outcome ◽  
Malignant Pleural Mesothelioma ◽  
Therapeutic Option ◽  
Enrichment Analysis ◽  
Metabolic Effects ◽  
Pleural Mesothelioma ◽  
Polyamine Biosynthesis ◽  
The Individual

Radical hemithoracic radiotherapy (RHRT) represents an advanced therapeutic option able to improve overall survival of malignant pleural mesothelioma patients. This study aims to investigate the systemic effects of this radiotherapy modality on the serum metabolome and their potential implications in determining the individual clinical outcome. Nineteen patients undergoing RHRT at the dose of 50 Gy in 25 fractions were enrolled. Serum targeted metabolomics profiles were investigated at baseline and the end of radiotherapy by liquid chromatography and tandem mass spectrometry. Univariate and multivariate OPLS-DA analyses were applied to study the serum metabolomics changes induced by RHRT while PLS regression analysis to evaluate the association between such changes and overall survival. RHRT was found to affect almost all investigated metabolites classes, in particular, the amino acids citrulline and taurine, the C14, C18:1 and C18:2 acyl-carnitines as well as the unsaturated long chain phosphatidylcholines PC ae 42:5, PC ae 44:5 and PC ae 44:6 were significantly decreased. The enrichment analysis showed arginine metabolism and the polyamine biosynthesis as the most perturbed pathways. Moreover, specific metabolic changes encompassing the amino acids and acyl-carnitines resulted in association with the clinical outcome accounting for about 60% of the interpatients overall survival variability. This study highlighted that RHRT can induce profound systemic metabolic effects some of which may have a significant prognostic value. The integration of metabolomics in the clinical assessment of the malignant pleural mesothelioma could be useful to better identify the patients who can achieve the best benefit from the RHRT treatment.

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 Early transcriptional responses in Solanum peruvianum and Solanum lycopersicum account for different acclimation processes during water scarcity events

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. Tapia ◽  
M. González ◽  
J. Burgos ◽  
M. V. Vega ◽  
J. Méndez ◽  
...  
Keyword(s):  
Solanum Lycopersicum ◽  
Water Scarcity ◽  
Plant Architecture ◽  
Early Response ◽  
Severe Drought ◽  
Water Shortages ◽  
Transcriptional Responses ◽  
Polyamine Biosynthesis ◽  
Tomato Species ◽  
Protein Ubiquitination

AbstractCultivated tomato Solanum lycopersicum (Slyc) is sensitive to water shortages, while its wild relative Solanum peruvianum L. (Sper), an herbaceous perennial small shrub, can grow under water scarcity and soil salinity environments. Plastic Sper modifies the plant architecture when suffering from drought, which is mediated by the replacement of leaf organs, among other changes. The early events that trigger acclimation and improve these morphological traits are unknown. In this study, a physiological and transcriptomic approach was used to understand the processes that differentiate the response in Slyc and Sper in the context of acclimation to stress and future consequences for plant architecture. In this regard, moderate (MD) and severe drought (SD) were imposed, mediating PEG treatments. The results showed a reduction in water and osmotic potential during stress, which correlated with the upregulation of sugar and proline metabolism-related genes. Additionally, the senescence-related genes FTSH6 protease and asparagine synthase were highly induced in both species. However, GO categories such as “protein ubiquitination” or “endopeptidase inhibitor activity” were differentially enriched in Sper and Slyc, respectively. Genes related to polyamine biosynthesis were induced, while several cyclins and kinetin were downregulated in Sper under drought treatments. Repression of photosynthesis-related genes was correlated with a higher reduction in the electron transport rate in Slyc than in Sper. Additionally, transcription factors from the ERF, WRKY and NAC families were commonly induced in Sper. Although some similar responses were induced in both species under drought stress, many important changes were detected to be differentially induced. This suggests that different pathways dictate the strategies to address the early response to drought and the consequent episodes in the acclimation process in both tomato species.

scholarly journals Inhibition of polyamine synthesis induces p53 gene expression but not apoptosis

1999 ◽  
Vol 276 (4) ◽  
pp. C946-C954 ◽  
Author(s):  
Li Li ◽  
Ji Li ◽  
Jaladanki N. Rao ◽  
Minglin Li ◽  
Barbara L. Bass ◽  
...  
Keyword(s):  
Gene Expression ◽  
Growth Inhibition ◽  
P53 Protein ◽  
Specific Inhibitor ◽  
P53 Gene ◽  
Mrna Levels ◽  
Intestinal Epithelial ◽  
Polyamine Biosynthesis ◽  
Fetal Bovine ◽  
P53 Mrna

The nuclear phosphoprotein p53 acts as a transcription factor and is involved in growth inhibition and apoptosis. The present study was designed to examine the effect of decreasing cellular polyamines on p53 gene expression and apoptosis in small intestinal epithelial (IEC-6) cells. Cells were grown in DMEM containing 5% dialyzed fetal bovine serum in the presence or absence of α-difluoromethylornithine (DFMO), a specific inhibitor of polyamine biosynthesis, for 4, 6, and 12 days. The cellular polyamines putrescine, spermidine, and spermine in DFMO-treated cells decreased dramatically at 4 days and remained depleted thereafter. Polyamine depletion by DFMO was accompanied by a significant increase in expression of the p53 gene. The p53 mRNA levels increased 4 days after exposure to DFMO, and the maximum increases occurred at 6 and 12 days after exposure. Increased levels of p53 mRNA in DFMO-treated cells were paralleled by increases in p53 protein. Polyamines given together with DFMO completely prevented increased expression of the p53 gene. Increased expression of the p53 gene in DFMO-treated cells was associated with a significant increase in G1 phase growth arrest. In contrast, no features of programmmed cell death were identified after polyamine depletion: no internucleosomal DNA fragmentation was observed, and no morphological features of apoptosis were evident in cells exposed to DFMO for 4, 6, and 12 days. These results indicate that 1) decreasing cellular polyamines increases expression of the p53 gene and 2) activation of p53 gene expression after polyamine depletion does not induce apoptosis in intestinal crypt cells. These findings suggest that increased expression of the p53 gene may play an important role in growth inhibition caused by polyamine depletion.

scholarly journals Regulation of hematopoiesis II: the role of polyamine inhibition on helper or suppressor influences of the thymus

Blood ◽  
1983 ◽  
Vol 61 (3) ◽  
pp. 604-607 ◽  
Author(s):  
SJ Sharkis ◽  
GD Luk ◽  
MI Collector ◽  
PP McCann ◽  
SB Baylin ◽  
...  
Keyword(s):  
Suppressor Cells ◽  
Model Systems ◽  
Accessory Cell ◽  
Suppressor Activity ◽  
Polyamine Biosynthesis ◽  
Erythroid Progenitor ◽  
Rate Limiting Step ◽  
Helper Activity ◽  
Cell Subpopulations

Abstract We have previously suggested in murine model systems, that two cell subpopulations with differing proliferative capacity, from the thymus, modify the growth of erythroid progenitor cells in vitro. In order to further characterize these populations, we have specifically inhibited polyamine biosynthesis; this pathway is essential for the process of cell replication. Thus, alpha-difluoromethyl ornithine (DFMO) was used to block the conversion of ornithine to putrescine, the first and rate- limiting step in polyamine biosynthesis. We observed a threefold increase in hematopoietic progenitors (CFU-S and CFU-E) from bone marrow in animals treated with DFMO. We further examined the effect of DFMO on accessory “helper” and “suppressor” cells from the thymus and observed an increase in helper activity with an elimination of suppressor activity. All of these effects of DFMO were specific for inhibition of polyamine biosynthesis, since simultaneous addition of the depleted biosynthetic product, putrescine, restored suppressor activity. We conclude that polyamine biosynthesis is required acutely for accessory cell regulation of hematopoiesis.

A possible role of arginase in the regulation of polyamine biosynthesis in the rat thyroid

1981 ◽  
Vol 98 (1) ◽  
pp. 57-61 ◽  
Author(s):  
Shigeru Matsuzaki ◽  
Mitsuo Suzuki ◽  
Koei Hamana
Keyword(s):  
Amino Acids ◽  
Enzyme Activity ◽  
Arginase Activity ◽  
Polyamine Biosynthesis ◽  
Rat Thyroid ◽  
Arginine Concentration

Abstract. Effect of chronic methylthiouracil (MTU) treatment on the thyroid arginase activity and thyroidal concentration of arginine, ornithine and other amino acids was studied in the rat. The activity of thyroid arginase increased significantly at 15 days of MTU treatment and the elevated enzyme activity was reduced to normal by l-thyroxine (T4) injection. The thyroidal concentration of polyamines was increased by MTU and decreased by T4 with the exception of spermine. The thyroidal concentration of arginine and lysine, a substrate and an inhibitor for arginase respectively decreased significantly, while that of ornithine remained unchanged after MTU treatment. T4 injected to MTU-pretreated rats restored the decreased arginine concentration to normal. These results suggest that ornithine supply for polyamine biosynthesis is regulated by the level of both arginase and lysine in the thyroid.

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