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Biochemistry of bioluminescence of the marine parchment tubeworm Chaetopterus has been in research focus for over a century; however, the results obtained by various groups contradict each other. Here, we report the isolation and structural elucidation of three compounds from Chaetomorpha linum algae, which demonstrate bioluminescence activity with Chaetopterus luciferase in the presence of Fe2+ ions. These compounds are derivatives of polyunsaturated fatty acid peroxides. We have also obtained their structural analogues and demonstrated their activity in the bioluminescence reaction, thus confirming the broad substrate specificity of the luciferase.

Objective: The objective of this study was to determine the level of methotrexate (MTX) toxicity in the intestines of mice and to evaluate the protective effect of probiotics composed of Streptococcus, Bifidobacterium, and Lactobacillus species on intestinal cells during MTX treatment. Methods: Mice were divided into three groups: control, MTX group (received MTX injections), and MTX + probiotics group (received MTX injections along with a diet containing probiotics). Morphological and histological changes, the level of mitochondrial DNA (mtDNA) damage, the level of lipid peroxidation products, and gene expression in the mice’s small intestine were assessed. Results: We demonstrated that intraperitoneal MTX injections significantly increased mtDNA damage in the liver (p < 0.001), small intestine (p < 0.001), and blood of mice (p < 0.01). MTX elevated the quantity of lipid peroxidation products in the liver and small intestine, indicating its strong prooxidative properties. MTX induced structural changes in the mice’s intestines, characterized by leukocytic infiltration of tissues. Probiotic therapy in mice partially mitigated the morphological and histological changes in the small intestine induced by MTX, reduced oxidative stress, and promoted increased expression of quinone oxidoreductase 1 (Nqo1), which participates in both cell protection against oxidative stress and drug/xenobiotic detoxification. Probiotics prevented the upregulation of the pro-inflammatory cytokine IL-1b in the small intestine and induced increased expression of genes associated with the Nuclear factor erythroid 2-related factor 2/Antioxidant response element (Nrf2/ARE) pathway, an important mechanism of cell protection. Conclusions: Probiotics can be considered an effective approach to reducing the toxicity of MTX during psoriasis or cancer treatment.

Biochemistry of bioluminescence of the marine parchment tubeworm Chaetopterus has been in research focus for over a century; however, the results obtained by various groups contradict each other. Here, we report the isolation and structural elucidation of three compounds from Chaetomorpha linum algae, which demonstrate bioluminescence activity with Chaetopterus luciferase in the presence of Fe[sup.2+] ions. These compounds are derivatives of polyunsaturated fatty acid peroxides. We have also obtained their structural analogues and demonstrated their activity in the bioluminescence reaction, thus confirming the broad substrate specificity of the luciferase.

The effect of uridine on the myocardial ischemic and reperfusion injury was investigated. A possible mechanism of its cardioprotective action was established. Two rat models were used: (1) acute myocardial ischemia induced by occlusion of the left coronary artery for 60 min; and (2) myocardial ischemia/reperfusion with 30-min ischemia and 120-min reperfusion. In both models, treatment with uridine (30 mg/kg) prevented a decrease in cell energy supply and in the activity of the antioxidant system, as well as an increase in the level of lipid hydroperoxides and diene conjugates. This led to a reduction of the necrosis zone in the myocardium and disturbances in the heart rhythm. The blocker of the mitochondrial ATP-dependent potassium (mitoK ATP ) channel 5-hydroxydecanoate limited the positive effects of uridine. The data indicate that the cardioprotective action of uridine may be related to the activation of the mitoK ATP channel. Intravenously injected uridine was more rapidly eliminated from the blood in hypoxia than in normoxia, and the level of the mitoK ATP channel activator UDP in the myocardium after uridine administration increased. The results suggest that the use of uridine can be a potentially effective approach to the management of cardiovascular diseases.

Raman, NMR and EPR spectroscopy and electrophysiology methods were used to investigate the excitability and the packaging of myelin lipid layers and its viscosity during nerve exposure to pronase E. It was established that during exposure of nerve to pronase E the action potential (AP) conduction velocity and the Schwann cell (SC) (or myelin) water ordering increases, but the nerve myelin refractive index and internode incisions numbers decrease. This effect included two periods-short- and long-time period, probably, because the first one depends on SC protein changes and the second one-on the nerve fiber internode demyelination. It was concluded that high electrical resistance of myelin, which is important for a series of AP conduction velocity, not only depends on nerve fiber diameter and the myelin lipid composition, but also on the regularity of myelin lipid fatty acids and myelin lipid layer packing during the axoglial interaction.

Background The histidine metabolism and transport ( his ) genes are controlled by a variety of RNA-dependent regulatory systems among diverse taxonomic groups of bacteria including T-box riboswitches in Firmicutes and Actinobacteria and RNA attenuators in Proteobacteria. Using a comparative genomic approach, we previously identified a novel DNA-binding transcription factor (named HisR) that controls the histidine metabolism genes in diverse Gram-positive bacteria from the Firmicutes phylum. Results Here we report the identification of HisR-binding sites within the regulatory regions of the histidine metabolism and transport genes in 395 genomes representing the Bacilli, Clostridia, Negativicutes, and Tissierellia classes of Firmicutes, as well as in 97 other HisR-encoding genomes from the Actinobacteria, Proteobacteria, and Synergistetes phyla. HisR belongs to the TrpR family of transcription factors, and their predicted DNA binding motifs have a similar 20-bp palindromic structure but distinct lineage-specific consensus sequences. The predicted HisR-binding motif was validated in vitro using DNA binding assays with purified protein from the human gut bacterium Ruminococcus gnavus . To fill a knowledge gap in the regulation of histidine metabolism genes in Firmicutes genomes that lack a hisR repressor gene, we systematically searched their upstream regions for potential RNA regulatory elements. As result, we identified 158 T-box riboswitches preceding the histidine biosynthesis and/or transport genes in 129 Firmicutes genomes. Finally, novel candidate RNA attenuators were identified upstream of the histidine biosynthesis operons in six species from the Bacillus cereus group, as well as in five Eubacteriales and six Erysipelotrichales species. Conclusions The obtained distribution of the HisR transcription factor and two RNA-mediated regulatory mechanisms for histidine metabolism genes across over 600 species of Firmicutes is discussed from functional and evolutionary points of view.

Previous research has demonstrated that a combined magnetic field (CMF) plays a critical role in modifying the properties of aqueous solutions, leading to an increase in the luminol-enhanced chemiluminescence of neutrophils. Using this model, the distant interaction between aqueous solutions was demonstrated, and the role of a CMF in the regulation of this phenomenon was established. In the current study, highly diluted (HD) phorbol myristate acetate (PMA) solution (the donor) was incubated with aqueous ethanol (the acceptor), both in a CMF-generating device and under geomagnetic field (GMF), for 0, 20, and 60 min. After a 60 min incubation at a 0 cm distance with HD PMA under both GMF and CMF, acceptor samples added to neutrophils increased neutrophil chemiluminescence by approximately sevenfold. The ability of HD PMA, which had been incubated with an acceptor, to activate ROS production diminished within 60 min of observation. However, the HD PMA sample remained an effective donor for up to 6 days after preparation. At a 10 cm distance between the donor and acceptor, the activation of the acceptor did not occur. These findings provide new insights into the phenomenon of distant interaction of solutions, whose mechanisms are suggested to be related to the quantum electrodynamics of water molecular dynamic structures.

Aqueous solutions are not homogeneous and could be considered supramolecular systems. They can emit electromagnetic waves. Electromagnetic emission from one supramolecular system (“source”) can be received by another supramolecular system (“receiver”) without direct contact (distantly). This process represents a transfer of a “molecular signal” and causes changes in conformation and symmetry of the “receiver”. The aim of the current work is to theoretically describe such changes primarily using a solution of the chiral protein interferon-gamma (IFNγ) as an example. We provide theoretical evidence that supramolecular systems of highly diluted (HD) aqueous solutions formed by self-assembly after mechanical activation generate a stronger molecular signal compared to non-activated solutions, due to their higher energy-saturated state. Additionally, molecular signals cause supramolecular systems with complex (including chiral) structures to undergo easier changes in conformation and symmetry compared to simpler systems, enhancing their biological activity. Using statistical physics, we obtained the parameter Ic, characterizing the magnitude of conformational and symmetry changes in supramolecular (including chiral) systems caused by molecular signals. In quantum information science, there is an analogue of the parameter Ic, which characterizes the entanglement depth of quantum systems. This study contributes to the understanding of the physico-chemical basis of distant molecular interactions and opens up new possibilities for controlling the properties of complex biological and chemical systems.

Flat-panel photobioreactors are effective systems for microalgae cultivation. This paper presents the growth characteristics of the microalgae Chlorella sorokiniana IPPAS C-1 as a result of three-stage scale-up cultivation in a specially designed cultivation system. First, C. sorokiniana was grown aseptically in 250 mL glass vessels; then, it was diluted and inoculated into a 5-liter flat-panel horizontal photobioreactor; and, at the last stage, the culture was diluted and inoculated into a 70-liter flat-panel vertical photobioreactor. In the presented cycle, the cultured biomass increased by 326 times in 13 days (from 0.6 to 195.6 g dw), with a final biomass concentration of 2.8 g dw L−1. The modes of semi-continuous cultivation were considered. The biomass harvest and dilution of the suspension were carried out either every day or every 3–4 days. For C. sorokiniana IPPAS C-1, a conversion coefficient of optical density values to dry biomass (g L−1) was refined through a factor of 0.33. The key parameters of the photobioreactors tested in this work are discussed.

In the original publication [...]