Sirtuins are NAD-dependent class III histone deacetylases, represented in mammals by seven isoforms that differ in substrate specificity and intracellular localization. Nuclear sirtuins 1 (SIRT1) and 6 (SIRT6) deacetylate components of pro-inflammatory signaling pathways, playing a key role in the resolution of inflammation. Leitragin, a peptide agonist of δ-opioid receptors, is a representative of a new promising class of anti-inflammatory drugs, whose known mechanism of action is associated with the activation of SIRT1 transcription. The aim of this study was to investigate the effect of inhaled Leitragin on the transcription of all seven isoforms of mammalian sirtuins in the lungs of C57BL/6Y mice under conditions of acute lung inflammation and ARDS modeling. This study is the first to demonstrate that inhalation of Leitragin significantly increases SIRT6 transcription in the lungs, in addition to the previously known effect of activating SIRT1 transcription under inflammatory conditions. This work clarifies the anti-inflammatory action of Leitragin, which involves the upregulation of SIRT1 and SIRT6 transcription, known negative regulators of pro-inflammatory signaling pathways where the NF-κB transcription factor plays a key role.

The prevalence and antibiotic resistance of ESKAPE bacteria cause difficulties in the prevention and treatment of their infections. Specialists of the Protective Antigen Laboratory of I.I. Mechnikov Scientific Research Institute of Vaccines and Serums continue work on  developing immunostimulating drugs for the prevention of diseases caused by some representatives of this group, including Klebsiella pneumoniae. When producing a drug and isolating a protective antigen, hydroxylamine is used as an inactivating agent. Purification of the final product from this toxic substance is complicated by a polysaccharide capsule secreted by K. pneumoniae. In this work, we evaluate the diafiltration efficiency of various washing solutions and their effect on the specific activity and chemical composition of the resulting antigen complexes of K. pneumoniae. To that end, a submerged cultured strain of K. pneumoniae 204 was used. The cells of the resulting culture were isolated by centrifugation and inactivated with hydroxylamine. The inactivating agent was removed by ultrafiltration in diafiltration mode using water or Tris-HCl buffers (pH=9.0) of  various concentrations. The as-obtained antigens were assessed in terms of the content of residual hydroxylamine, polysaccharides, protein by the Lowry method, nucleic acids by the Spirin method, and specific activity by hemagglutination inhibition assay. Samples of antigen-containing fluid of K. pneumoniae 204 were obtained. The use of Tris-HCl buffers (pH=9.0) for hydroxylamine removal led to a reduction in the hydroxylamine content to acceptable values (less than 1 μg/mL) when using a 25-fold volume of  the solution in any of the studied concentrations. At the same time, the use of distilled water as a purifying solution in  similar volumes did not produce a comparable result. The chemical composition of the resulting antigenic complexes was analyzed. The use of a Tris-HCl buffer solution (pH=9.0) at a concentration of 10 mM proves optimal for removing hydroxylamine from an antigen-containing fluid of K. pneumoniae, having no effect on the chemical composition and activity of its antigen complexes.

Quantitative determination of excipients is a pharmacopoeial requirement for assessing the quality of biological medicinal products. For determination of carbohydrate stabilizers (sorbitol, mannitol, trehalose, glucose, lactose, sucrose, and maltose), the Scientific Center for Expert Evaluation of Medical Products of the Ministry of Health of the Russian Federations prescribes the method of anionic exchange HPLC with pulse amperometric detection. Routine application of this method requires a reference material of in tralaboratory analytical control, since the suitability of  chromatographic systems must be checked prior to use of all chromatographic methods for quality control of pharmaceutical substances and medicinal prod ucts. In addition, certified reference materials permit interlaboratory comparison of test results. In this study, we set out to develop the composition and a release form of a certified reference material for stability con trol of determination of carbohydrate stabilizers. The range of the resolution factor between the peak pairs of  sorbitol/mannitol and mannitol/trehalose was used as a certified characteristic, being1.8–2.4 and 2.1–2.9, respectively. For other peak pairs (trehalose/glucose, glucose/lactose, lactose/sucrose, and sucrose/maltose), a semi-quantitative certified characteristic was assigned, i.e., a resolution factor of at least 3.0.

The effects of various D-glucose concentrations (0.5; 1; 3; 5; 7; 10; 12; 14; 17; 20; 22; and 25 mM) were studied using brain slices of the rat olfactory cortex to determine changes in the activities of AMPA and NMDA ionotropic glutamatergic mechanisms. The dependence of the amplitudes of the AMPA and NMDA potentials on D-glucose concentrations was dome-shaped. Lower concentrations (0.5; 1; 3; 5 mM) caused a progressive increase in the amplitudes of AMPA and NMDA potentials. Under D-glucose concentra tions in the extracellular medium of 7 and 10 mM, the amplitudes of AMPA and NMDA potentials were maximal and stable. Under a D-glucose concentration of 14 mM, the activities of AMPA and NMDA mechanisms decreased and, following a further increase in carbon, were irreversibly blocked. Long-term post-tetanic potentiation (model of non-associative learning) developed only at a D-glucose concentration of 10 mM. Heat shock protein (Mw70 kDa) protected the activities of AMPA and NMDA mechanisms from the negative effects of high hyperglycemic D-glucose concentration of 14 mM. The data obtained indicate the response of AMPA and NMDA mechanisms during the development of hyperglycemia. This model can be used to search for substances to protect neuronal mechanisms in the nervous tissue during the develop ment of hyperglycemic diabetes mellitus.

When creating cell lines expressing recombinant proteins, the type of selection marker and selection conditions are of essential importance. In this work, we aim to obtain and compare cell lines based on CHO and CHO-GS as potential aflibercept producers to identify the most suitable cell line for obtain ing an aflibercept biosimilar. As a result, 10 monoclonal cell lines-producers of a potential aflibercept biosimilar were obtained based on СНО and CHO-GS cell platforms. In the two groups, the productivity on the 15th day of periodic cultivation with feeding achieved 2.5 g/L. The СНО-GS group showed an in crease in the specific cell productivity of aflibercept producers. The conclusion is made that the СНО-GS glutamine auxotroph line is a more preferable option. This cell line enables a comparable yield of target protein at lower concentrations of  viable cells, which has a favorable effect on further stages of purification and isolation of target protein.

This work addresses the issues of male reproductive health caused by pathozoospermia, which leads to a decrease in the number and motility of sperm cells. In many cases, this pathology is associated with ox idative stress. Seaweed is known to increase cellular resistance, making selenium-enriched brown algae (Saccharina japonica) a promising research object. In this paper, we report a preclinical study into the ef f icacy of a biologically active supplement obtained from selenium-enriched brown algae using modeled pathospermia (oligo- and asthenospermia) in rats. Pathospermia was induced by an intravenous adminis tration of etoposide. Five days before and after etoposide administration, the animals were intragastrically administered the supplement under study in the amount of 10 µg Se per 100 g of animal weight. Laminaria not enriched with selenium was used as a reference preparation. The supplement under study proved to be effective in reducing the severity of oligospermia. The total number of sperm cells in rats receiving sele nium-enriched laminaria increased by 41.2%; however, the share of motile forms remained at the level of control values, not exceeding 65%. The study revealed a significant decrease in the number of free radicals and an increase in antioxidant activity compared to the control (by 33 and 20%, respectively). A normalization of the redox balance of testicular tissue cells against the background values was noted. In  rats receiving the control preparation, a significant increase in the share of motile forms of sperm cells (by 36%) and a decrease in the number of free radicals by 38.6% were observed, although the redox bal ance of testicular tissue cells was not restored. The antiradical effect was shown to be a more important factor in the restoration of cell motility than the normalization of the redox potential. Therefore, the studied biologically active supplement based on selenium-enriched brown algae (Saccharina japonica) proved effective in  stimulating spermatogenesis in modeled pathospermia (oligospermia, asthenospermia).