A Cross Sectional Sampling Reveals Novel Coronaviruses in Bat Populations of Georgia

Mammal-associated coronaviruses have a long evolutionary history across global bat populations, which makes them prone to be the most likely ancestral origins of coronavirus-associated epidemics and pandemics globally. Limited coronavirus research has occurred at the junction of Europe and Asia, thereby investigations in Georgia are critical to complete the coronavirus diversity map in the region. We conducted a cross-sectional coronavirus survey in bat populations at eight locations of Georgia, from July to October of 2014. We tested 188 anal swab samples, remains of previous pathogen discovery studies, for the presence of coronaviruses using end-point pan-coronavirus RT-PCR assays. Samples positive for a 440 bp amplicon were Sanger sequenced to infer coronavirus subgenus or species through phylogenetic reconstructions. Overall, we found a 24.5% positive rate, with 10.1% for Alphacoronavirus and 14.4% for Betacoronavirus. Albeit R. euryale, R. ferrumequinum, M. blythii and M. emarginatus were found infected with both CoV genera, we could not rule out CoV co-infection due to limitation of the sequencing method used and sample availability. Based on phylogenetic inferences and genetic distances at nucleotide and amino acid levels, we found one putative new subgenus and three new species of Alphacoronavirus, and two new species of Betacoronavirus.

Short-Term Effect of Induced Alterations in Testosterone Levels on Fasting Plasma Amino Acid Levels in Healthy Young Men

Long term effect of testosterone (T) deficiency impairs metabolism and is associated with muscle degradation and metabolic disease. The association seems to have a bidirectional nature and is not well understood. The present study aims to investigate the early and unidirectional metabolic effect of induced T changes by measuring fasting amino acid (AA) levels in a human model, in which short-term T alterations were induced. We designed a human model of 30 healthy young males with pharmacologically induced T changes, which resulted in three time points for blood collection: (A) baseline, (B) low T (3 weeks post administration of gonadotropin releasing hormone antagonist) and (C) restored T (2 weeks after injection of T undecanoate). The influence of T on AAs was analyzed by spectrophotometry on plasma samples. Levels of 9 out of 23 AAs, of which 7 were essential AAs, were significantly increased at low T and are restored upon T supplementation. Levels of tyrosine and phenylalanine were most strongly associated to T changes. Short-term effect of T changes suggests an increased protein breakdown that is restored upon T supplementation. Fasting AA levels are able to monitor the early metabolic changes induced by the T fluctuations.

Bioefficacy of rainbow trout flesh lipids depending on amino acid levels in compound feeds

The article examines the effect of complete compound feeds with different lysine and methionine levels on lipid bioefficacy indicators in rainbow trout flesh. The experiment was aimed at determining the effect of different types of amino acid nutrition of commercial rainbow trout on the fatty acid composition of flesh lipids as well as their bioefficacy. For this purpose, we formed five experimental groups by the method of analogs. The experiment lasted 210 days and consisted of two periods, namely equalizing (10 days) and main (200 days). Throughout the equalizing period, the feeding ration was the same for fish in the control and experimental groups. Throughout the main period, lysine and methionine levels in the experimental compound feeds for various experimental trout groups ranged from 2.5 to 2.9% and from 0.8 to 1.0%, respectively. During the study, rainbow trout was fed 4–6 times a day, in the daytime and at regular intervals. The required amount of feeds was calculated based on the indices of individual fish body weight and temperature at the time of feeding. Commercial two-year-olds were reared in ponds with an area of 100 m2 at a stocking density of 50 specimens/m2, and a water level of 1 m. The total number of trout in experimental studies was 25 thousand specimens. It was found that the main share of fatty acids in rainbow trout flesh lipids is saturated and monounsaturated fatty acids. The study demonstrated that the use of compound feeds with increased lysine and methionine levels for the fish of the 4th experimental group resulted in an increase in the content of saturated fatty acids in the flesh by 5.84% versus control. An increase in the amino acid nutritional value of the compound feeds subsequently led to an increase in the content of linoleic acid in the trout flesh by 0.19–0.24% versus control.

Legume plant defenses and nutrients mediate indirect interactions between soil rhizobia and chewing herbivores

Soil bacteria that form mutualisms with plants, such as rhizobia, affects susceptibility of plants to herbivores and pathogens. Soil rhizobia also promote nitrogen fixation, which mediates host nutrient levels and defenses. However, whether aboveground herbivores affect the function of soil rhizobia remains poorly understood. We assessed reciprocal interactions between Sitona lineatus, a chewing herbivore, and pea (Pisum sativum) plants grown with or without rhizobia (Rhizobium leguminosarum biovar viciae). We also examined the underlying plant-defense and nutritional mechanisms of these interactions. In our experiments, soil rhizobia influenced feeding and herbivory by chewing herbivores. Leaf defoliation by S. lineatus was lower on plants treated with rhizobia, but these insects had similar amino acid levels compared to those on un-inoculated plants. Plants grown with soil rhizobia had increased expression of gene transcripts associated with phytohormone-mediated defense, which may explain decreased susceptibility to S. lineatus. Rhizobia also induced expression of gene transcripts associated with physical and antioxidant-related defense pathways in P. sativum. Conversely, S. lineatus feeding reduced the number of root nodules and nodule biomass, suggesting a disruption of the symbiosis between plants and rhizobia. Our study shows that aboveground herbivores can engage in mutually antagonistic interactions with soil microbes mediated through a multitude of plant-mediated pathways.

Amino acids predict prognosis in patients with acute dyspnea

Background To identify amino acids that can predict risk of 90-day mortality in patients with acute dyspnea. Method Plasma levels of nine amino acids were analyzed 663 adult patients admitted to the Emergency Department (ED) with acute dyspnea. Cox proportional hazards models were used to examine the relation between amino acid levels and the risk of 90-day mortality. Result Eighty patients (12.1%) died within 90 days of admission. An “Amino Acid Mortality Risk Score” (AMRS), summing absolute plasma levels of glycine, phenylalanine and valine, demonstrated that among the patients belonging to quartile 1 (Q1) of the AMRS, only 4 patients died, compared to 44 patients in quartile 4. Using Q1 of the AMRS as reference, each increment of 1 SD in the AMRS was associated with a hazard ratio (HR) of 2.15 for 90-day mortality, and the HR was > 9 times higher in Q4. Conclusion Glycine, phenylalanine and valine are associated with a risk of 90-day mortality in patients admitted to the ED for acute dyspnea, suggesting that these amino acids may be useful in risk assessments.

Functional Amino Acids and Autophagy: Diverse Signal Transduction and Application

Functional amino acids provide great potential for treating autophagy-related diseases by regulating autophagy. The purpose of the autophagy process is to remove unwanted cellular contents and to recycle nutrients, which is controlled by many factors. Disordered autophagy has been reported to be associated with various diseases, such as cancer, neurodegeneration, aging, and obesity. Autophagy cannot be directly controlled and dynamic amino acid levels are sufficient to regulate autophagy. To date, arginine, leucine, glutamine, and methionine are widely reported functional amino acids that regulate autophagy. As a signal relay station, mammalian target of rapamycin complex 1 (mTORC1) turns various amino acid signals into autophagy signaling pathways for functional amino acids. Deficiency or supplementation of functional amino acids can immediately regulate autophagy and is associated with autophagy-related disease. This review summarizes the mechanisms currently involved in autophagy and amino acid sensing, diverse signal transduction among functional amino acids and autophagy, and the therapeutic appeal of amino acids to autophagy-related diseases. We aim to provide a comprehensive overview of the mechanisms of amino acid regulation of autophagy and the role of functional amino acids in clinical autophagy-related diseases and to further convert these mechanisms into feasible therapeutic applications.

Dietary Supplementation with Casein Glycomacropeptide, Leucine and Tryptophan Reduces Plasma Amino Acid Levels in Men

Background The treatment of mania in bipolar disorders needs to be more efficient, as the manic condition creates severe problems for the patient when it comes to work, finances, relationships, and health. This proof-of-concept study examines to what extent casein glycomacropeptide (CGMP) may reduce the precursors of dopamine, phenylalanine, and tyrosine, in plasma, and therefore be a potential new intervention to treat acute manic episodes. Method The study was designed as a double-blind randomised dose-response study of CGMP (with added leucine and tryptophan) in 15 healthy men, receiving 3 different doses of CGMP with an interval of at least 14 days. Results Administration of CGMP produced a dose dependent depletion of plasma aromatic amino acids. The total area under the curve of plasma ratios of phenylalanine-tyrosine compared to the level of leucine-isoleucine-valine-tryptophan was CGMP(20g): 3.648 [SE:0.3281]; CGMP(40g): 2.368 [SE:0.1858]; CGMP(60g)1.887 [SE:0.2591]. A comparison of the groups showed a dose dependent statistical difference, with a One-Way ANOVA summary (Dunnett) F= 11.87, p= 0.0003, CGMP 20g vs CGMP 40g, p= 0.0042, CGMP 20g vs CGMP 60g, p= 0.0002. No significant side effects were observed. Conclusions This study demonstrate CGMP is a well-tolerated and effective mixture, and that 60 g CGMP produced the highest depletion of plasma aromatic amino acids (phenylalanine and tyrosine). The effect seems to be highest after 3-4 hours. We therefore conclude that this dose should be the one considered for future studies involving CGMP in humans.

OGT controls mammalian cell viability by regulating the proteasome/mTOR/ mitochondrial axis

O-GlcNAc transferase (OGT) is an essential X-chromosome-encoded enzyme that catalyzes the addition of N-acetylglucosamine (GlcNAc) to the hydroxyl groups of serine and threonine residues on many nuclear and cytosolic proteins. This posttranslational modification is reversible and is actively removed by the O-GlcNAc’ase OGA. It was shown more than two decades ago that OGT is essential for mammalian cell viability, but the underlying mechanisms are still enigmatic. Given the close association between OGT and human diseases, such as cancer, diabetes and cardiovascular disease, identification of the mechanisms by which OGT controls cell viability will facilitate the development of therapeutic strategies to manipulate OGT activity. Here, we employ a genome-wide CRISPR-Cas9 viability screen in mouse embryonic stem cells (mESCs) with inducible Ogt deletion to show that the block in cell viability induced by Ogt-deficiency stems from a deleterious increase in mitochondrial oxidative phosphorylation (OXPHOS). Mechanistically, we demonstrate that OGT safeguards mTOR (mechanistic target of rapamycin) activity to maintain mitochondrial fitness through modulation of proteasome activity and intracellular amino acid homeostasis. In the absence of OGT, increased proteasome activity results in increased steady-state amino acid levels, which in turn promote mTOR translocation and activation and increased oxidative phosphorylation. This mechanism also operates in CD8+ T cells, indicating its generality across mammalian cell types. Genome-wide proteomic and phosphoproteomic analyses show extensive changes in global signaling and confirm our finding of mTOR hyperactivation in OGT-deficient cells. In sum, our study highlights a novel function for OGT in regulating the proteasome/ mTOR/ mitochondrial axis in a manner that maintains homeostasis of intracellular amino acid levels, mitochondrial fitness and cell viability. Since many of the proteins involved in proteasome, mTOR and mitochondrial activity are aberrantly expressed in cancer, and since inhibitors for proteasome and mTOR have been used in cancer therapy, manipulating OGT activity may have therapeutic potential in diseases in which this signaling axis is impaired.