bims-polyam 2019-12-29 papers

Biochem Biophys Res Commun. 2019 Dec 21. pii: S0006-291X(19)32408-8. [Epub ahead of print]

The regulation of triglyceride storage by ornithine decarboxylase (Odc1) in Drosophila.

Kelly E Leon, Austin M Fruin, Shannon L Nowotarski, Justin R DiAngelo.

Polyamines are low molecular weight, organic cations that play a critical role in many major cellular processes including cell cycle regulation and apoptosis, cellular division, tissue proliferation, and cellular differentiation; however, the functions of polyamines in regulating the storage of metabolic fuels such as triglycerides and glycogen is poorly understood. To address this question, we focused on the Drosophila homolog of ornithine decarboxylase (Odc1), the first rate-limiting enzyme in the synthesis of polyamines. Mutants in Odc1 are lethal, but heterozygotes were viable to adulthood. Odc1 heterozygotes appeared larger than their genetic background control flies and consistent with this observation, weighed more than the controls. However, the increased weight was not due to increased food consumption as heterozygotes ate less than the controls. Interestingly, Odc1 heterozygous flies had augmented triglyceride storage, and this lipid phenotype was due to increased triglyceride storage per cell and an increase in the number of fat cells produced. Odc1 heterozygous flies also displayed increased expression of the lipid synthesis genes fatty acid synthase (FASN) and acetyl-CoA carboxylase (ACC), suggesting increased lipid synthesis was the cause of the augmented triglyceride phenotype. These results provide a link between the expression of Odc1 and triglyceride storage suggesting that the polyamine pathway plays a role in regulating lipid metabolism.

Keywords: ACC; Drosophila; FASN; Odc1; Triglyceride

DOI: https://doi.org/10.1016/j.bbrc.2019.12.078

Exp Oncol. 2019 12;41(4): 363-365

Detection of polyamines using immunobiosensor based on zinc oxide nanoparticles.

M P Prylutskyi, M F Starodub.

AIM: To analyze the performance of biosensor based on nanoparticles of zinc oxide for the detection of spermine and spermidine in solution and in cell culture.
MATERIALS AND METHODS: Zinc oxide nanoparticles were used for preparing biosensor containing antibodies to spermine and spermidine. Polyamine concentration is solutions of spermine and spermidine as well as in lyophilisate of MCF-7 cells was measured by luminescence of the samples excited by laser beam at 380 nm.
RESULTS: The minimum concentration for the detection of polyamines in model solutions is 10 ng/ml, and maximum one is 100 ng/ml. A higher level of luminescence intensity of nanoparticles was found during analysis the polyamines in MCF-7 lyophilisate allowing for detecting polyamines at concentrations from 100 cells/ml to 100,000 cells/ml.
CONCLUSIONS: The proposed biosensor system for determining the level of biogenic polyamines in cell lyophilisate using the optical properties of zinc oxide nanoparticles is promising for further improvement of the methodology and its implementation for detection and measurement of polyamines in biological systems.

Sci Rep. 2019 Dec 23. 9(1): 19616

Spermidine protects from age-related synaptic alterations at hippocampal mossy fiber-CA3 synapses.

Aging is associated with functional alterations of synapses thought to contribute to age-dependent memory impairment (AMI). While therapeutic avenues to protect from AMI are largely elusive, supplementation of spermidine, a polyamine normally declining with age, has been shown to restore defective proteostasis and to protect from AMI in Drosophila. Here we demonstrate that dietary spermidine protects from age-related synaptic alterations at hippocampal mossy fiber (MF)-CA3 synapses and prevents the aging-induced loss of neuronal mitochondria. Dietary spermidine rescued age-dependent decreases in synaptic vesicle density and largely restored defective presynaptic MF-CA3 long-term potentiation (LTP) at MF-CA3 synapses (MF-CA3) in aged animals. In contrast, spermidine failed to protect CA3-CA1 hippocampal synapses characterized by postsynaptic LTP from age-related changes in function and morphology. Our data demonstrate that dietary spermidine attenuates age-associated deterioration of MF-CA3 synaptic transmission and plasticity. These findings provide a physiological and molecular basis for the future therapeutic usage of spermidine.

DOI: https://doi.org/10.1038/s41598-019-56133-3

PLoS One. 2019 ;14(12): e0216513

Differences of endogenous polyamines and putative genes associated with paraquat resistance in goosegrass (Eleusine indica L.).

Qiyu Luo, Jiping Wei, Zhaoxia Dong, Xuefeng Shen, Yong Chen.

BACKGROUND: Paraquat is one of the most effective herbicides used to control weeds in agricultural management, while the pernicious weed goosegrass (Eleusine indica) has evolved resistance to herbicides, including paraquat. Polyamines provide high-level paraquat resistance in many plants. In the present study, we selected three polyamines, namely, putrescine, spermidine, and spermine, as putative genes to investigate their correlation with paraquat resistance by using paraquat-resistant (R) and paraquat-susceptible (S) goosegrass populations.
RESULTS: There was no significant difference in the putrescine nor spermine content between the R and S biotypes. However, 30 and 90 min after paraquat treatment, the spermidine concentration was 346.14-fold and 421.04-fold (P < 0.001) higher in the R biotype than in the S biotype, but the spermidine concentration was drastically reduced to a marginal level after 90 min. Since the transcript level of PqE was low while the spermidine concentration showed a transient increase, the PqE gene was likely involved in the synthesis of the paraquat resistance mechanism, regulation of polyamine content, and synthesis of spermidine and spermine. PqTS1, PqTS2, and PqTS3 encode transporter proteins involved in the regulation of paraquat concentration but showed different transcription patterns with synchronous changes in polyamine content.
CONCLUSION: Endogenous polyamines (especially spermidine) play a vital role in paraquat resistance in goosegrass. PqE, PqTS1, PqTS2, and PqTS3 were speculated on the relationship between polyamine metabolism and paraquat resistance. To validate the roles of PqE, PqTS1, PqTS2, and PqTS3 in polyamine transport systems, further research is needed.

DOI: https://doi.org/10.1371/journal.pone.0216513

Viruses. 2019 Dec 23. pii: E20. [Epub ahead of print]12(1):

Chloroviruses.

James L Van Etten, Irina V Agarkova, David D Dunigan.

Chloroviruses are large dsDNA, plaque-forming viruses that infect certain chlorella-like green algae; the algae are normally mutualistic endosymbionts of protists and metazoans and are often referred to as zoochlorellae. The viruses are ubiquitous in inland aqueous environments throughout the world and occasionally single types reach titers of thousands of plaque-forming units per ml of native water. The viruses are icosahedral in shape with a spike structure located at one of the vertices. They contain an internal membrane that is required for infectivity. The viral genomes are 290 to 370 kb in size, which encode up to 16 tRNAs and 330 to ~415 proteins, including many not previously seen in viruses. Examples include genes encoding DNA restriction and modification enzymes, hyaluronan and chitin biosynthetic enzymes, polyamine biosynthetic enzymes, ion channel and transport proteins, and enzymes involved in the glycan synthesis of the virus major capsid glycoproteins. The proteins encoded by many of these viruses are often the smallest or among the smallest proteins of their class. Consequently, some of the viral proteins are the subject of intensive biochemical and structural investigation.

Keywords: NCLDVs; Phycodnaviridae; algal viruses; chloroviruses; giant viruses

DOI: https://doi.org/10.3390/v12010020