Adenosine is a multifunctional nucleoside with several roles across various levels in organisms. Beyond its intracellular involvement in cellular metabolism, extracellular adenosine potently influences both physiological and pathological processes. In relation to its blood level, adenosine impacts the cardiovascular system, such as heart beating rate and vasodilation. To exploit the adenosine levels in the blood, we employed the liquid chromatography method coupled with mass spectrometry (LC-MS). Immediately after the collection, a blood sample mixed with acetonitrile solution that is either enriched with 13C-labeled adenosine or a newly generated mixture is transferred into the tubes containing the defined amount of 13C-labeled adenosine. The 13C-enriched isotopic adenosine is used as an internal standard, allowing for more accurate quantification of adenosine. This novel protocol for LC-MS-based estimation of adenosine delivers a rapid, highly sensitive, and reproducible means for quantitative estimation of total adenosine in blood. The method also allows quantification of a few catabolites of adenosine, i.e., inosine, hypoxanthine, and xanthine. This advancement provides the analytical tool that has the potential to enhance our understanding of adenosine's systemic impact and pave the way for further investigations into its intricate regulatory mechanisms.

Lactobacilli are considered an inexhaustible source of potentially bioactive substances; indeed, several products from their metabolism are known to have immunomodulatory and anti-inflammatory activity. Recently, we demonstrated that cell-free supernatants (CFS) obtained from Lactobacillus (L.) acidophilus, L. plantarum, L. rhamnosus and L. reuteri can impair Candida pathogenic potential in an in vitro model of epithelial vaginal infection. This effect could be ascribed to a direct effect of living lactobacilli on Candida virulence and to the production of metabolites which are able to impair fungal virulence. In the present work, stemming from those data, we deepened our knowledge on the CFS from these 4 lactobacilli by performing a metabolomic analysis to better characterize their composition. By using an untargeted metabolomic approach, we detected consistent differences in the metabolites produced by these four different lactobacilli. Interestingly, L. rhamnosus showed the most peculiar metabolic profile. Specifically, after a hierarchical clustering analysis in positive and negative ionization mode, L. rhamnosus showed a specific area of significant overexpressed metabolites that strongly differed from the same area in other lactobacilli. In this area, inosine was identified among the overexpressed metabolites of L. rhamnosus. This molecule has been described to have antioxidant, anti-inflammatory, anti-infective and neuroprotective properties. The biological significance of its overproduction by L. rhamnosus might be important in its probiotic and/or postbiotic activity.

The gene translation system possesses inherent complexity in distinguishing codons with degeneracy through repertoires of aminoacyl-tRNAs in the ribosome. Implementation of inosine nucleoside at the anticodon wobble-position in certain tRNAs, especially in eukaryotes, might be arisen to establish complex decoding systems. This report introduces the novel concept of “decoding tables”, which serve as concise summaries of codon-anticodon pairings provided in codon table-like format. Utilizing tRNA genome database information and a procedure based on compiled tRNA studies, the tRNA repertoire and the use of wobble pairings can be depicted for any organisms. The decoding table sheds light on the use of wobble pairings across diverse organisms.

Inosine 5'-monophoaphate (IMP) allows animals to sense umami. Intake of IMP in C57/KsJ-db/db (db/db) mice induced lipohyperplasia causing the liver cirrhosis, however, how to that of in normal mammals injure health is still unclear. Thus, we had investigated that intake of IMP in C57BL/6J mice effected its metabolic functions. We found that intake of 255 M/d IMP in C57BL/6J mice for 4 months induced hyperlipidemia and body fat rate raised. In mechanism, the expressions of ACC1 and phosphorylated ACC2 in hepatocytes were increased though IMP promoting phosphorylation of AMPK. The increased ACC1 promoted the conversion of acetyl-CoA into TG. These TG were transported out of hepatocytes to avoid NAFLD, causing a deficiency of acetyl-CoA in liver, and then the increased phosphorylated ACC2 promoted cytoplasm fatty acids into mitochondria to convert into acetyl-CoA though the fatty acids β-oxidation pathway, causing a deficiency of fatty acids. Therefore, liver enhanced the absorption of exogenous fatty acids, which were converted into TG caused lipohyperplasia. Moreover, intake of IMP in normal mice induced complement system weaken in liver causing mild inflammation. Our data not only alerted that humans avoid excessive intake of IMP, but also provided novel insights into the adipose of metabolic dysfunctions.

The genetic code evolved around the reading of the tRNA anticodon on the primitive ribosome, and tRNA-34 wobble and tRNA-37 modifications coevolved with the code. We posit that EF-Tu, the closing mechanism of the 30S ribosomal subunit, methylation of wobble U34 at the 5-carbon and suppression of wobbling at the tRNA-36 position were partly redundant and overlapping functions that coevolved to establish the code. The genetic code devolved in evolution of mitochondria to reduce the size of the tRNAome (all of the tRNAs of an organism or organelle). “Superwobbling” or four-way wobbling describes a major mechanism for shrinking the mitochondrial tRNAome. In superwobbling, unmodified wobble tRNA-U34 can recognize all four codon wobble bases (A, G, C and U), allowing a single unmodified tRNA-U34 to read a 4-codon box. During code evolution, to suppress superwobbling in 2-codon sectors, U34 modification by methylation at the 5-carbon position appears essential. As expected, at the base of code evolution, tRNA-37 modifications mostly related to the identity of the adjacent tRNA-36 base. TRNA-37 modifications help maintain the translation frame during elongation.