Doklady Biochemistry and Biophysics最新文献

The study presents a numerical parametric investigation of flow structures in channels with a longitudinal-radial profile zR^N = Const and a spherical dome at the base. The goal of the study was to examine the flow structures in these channels depending on the exponent N of the profile and the height of the dome, to determine the conditions that provide optimal centripetal swirling flow, analogous to blood flow in the heart chambers and major vessels. The investigation was conducted using a comparative analysis of flow structures in channel configurations zR^N = Const, carried out in two stages. In the first stage, the convergence parameter N was varied from 1.25 to 2.75 to identify the value that ensures optimal flow conditions. In the second stage, for the established value of N, the dome height was varied from 2.5 to 15 mm to identify the beneficial effects associated with its presence. The method of investigation involved numerical modeling in a steady-state regime. The results of the study on the influence of the convergence parameter revealed that the profile zR² = Const provides optimal conditions for the formation of swirling flow with minimal specific losses and a uniform distribution of velocity gradients. This channel configuration also showed the best agreement with the analytical solutions for Burgers' vortex, confirming its effectiveness in the static approximation of flows. The parametric investigation of dome height indicated that an optimal dome height of 7 mm contributes to the smoothing of velocity gradients and the reduction of viscous losses due to the optimal enhancement of the centripetal swirling flow scale.

One of the principles of prevention and non-drug treatment of liver diseases, including hepatitis of various etiologies, is the normalization of the diet, including the use of daily diet foods with physiologically active ingredients, in particular betulin, which helps to reduce metabolic and oxidative processes within liver cells. The aim of the work was to evaluate the in vivo effect of triterpene alcohol betulin Roth isolated from the bark of birch Betula pendula Roth. added to fat-containing products (for example, mayonnaise) on the biochemical parameters of blood and the morphological structure of the liver of rats with initiated acute toxic hepatitis.

Materials and methods: The composition of mayonnaise (67% fat) was developed with the addition of 0.2% betulin solution in vegetable oil in an amount of 6%. The hepatoprotective activity of betulin in mayonnaise samples was studied on a model of toxic hepatitis initiated by carbon tetrachloride in male Wistar rats. Disturbance of metabolic and oxidative processes in the liver cells of animals was assessed by biochemical parameters of blood plasma and the enzyme activity of the liver sample. The effect of experimental samples of mayonnaise with betulin on the morphological structure of the liver of rats with toxic hepatitis was evaluated by microscopy of prepared sections of liver tissue.

Results: The preventive efficacy of betulin in mayonnaise was confirmed in an in vivo experiment: its administration weakens the hepatotoxic effect of carbon tetrachloride, as indicated by a significant decrease in the activity of ALT, AST, and alkaline phosphatase enzymes in the blood plasma of animals MG-1 compared with the blood of rats CG-2-ALT by 22.1%, AST by 21.9%, and alkaline phosphatase by 42.5%. A 13.9% decrease in GGT activity in MG-1 animals indicates a more intensive nitrogen metabolism with a decrease in the level of hepatocyte cytolysis compared to animals of the experimental MG-2 group. It was shown that the introduction of mayonnaise with betulin in a dose of 1 ml into the diet of animals, which corresponds to 35 mg of betulin, prevented the development of cytolytic syndrome and suppressed peroxidation by direct neutralization of free radicals.

Conclusions: The experiment showed a significant decrease in cholesterol, glucose, and enzyme activity of the liver sample and normalization of albumin and triglyceride concentrations in animals of the experimental group in comparison with similar indices in the control group. Betulin in mayonnaise contributed to the antioxidant protection of the body, expressed in the effect on the activity of antioxidant enzymes that are involved in the destruction of organic peroxides, especially lipid peroxides, disturbing the integrity of cell membranes.

One of the most obvious manifestations of the negative impact of space flight factors on the human physiology is osteopenia. With the active development of manned space flights and the increase in the duration of humans' persistence in weightlessness, there is a growing need to understand the mechanisms of changes occurring at the cellular level involved in the replenishment of bone tissue. Using the RNA sequencing method, changes in the transcriptome profile of MMSCs were studied after a 5-day simulation of the microgravity effects. During the analysis, a pronounced downregulation of genes, which products are involved in processes associated with cell proliferation, in particular, in the mitotic phase of the cell cycle, was found in the experimental group of cells. These shifts in the transcriptional profile of MMSCs were confirmed using fluorescence microscopy. The results obtained indicate a decrease in the proliferative activity of MMSCs cultured under conditions of simulated microgravity for 5 days.

Demyelinating diseases are a group of heterogeneous pathologies that affect the nervous system and reduce the quality of life. One of such diseases is multiple sclerosis (MS), an inflammatory autoimmune neurodegenerative disease of the central nervous system (CNS). At the initial stages, MS can mimic some infectious, neoplastic, genetic, metabolic, vascular, and other pathologies. Accurate differential diagnosis of this disease is important to improve the quality of life of patients and reduce possible irreversible damage to the central nervous system. In this work, we confirmed the possibility of using our previously proposed candidate panel of MS biomarkers to distinguish MS from neuromyelitis optica spectrum disorder (NMOSD) and amyotrophic lateral sclerosis (ALS). We have shown that our proposed panel (SPTAN1_601-644 + PRX_451-494 + PTK6_301-344 + LMP1_285-330) allows us to distinguish MS from ALS (AUC = 0.796) and NMOSD (AUC = 0.779).

Introduction. One of the key stages of wound healing is the phase of inflammation, which is a transitional process between hemostasis and wound healing. Each stage of the inflammatory-reparative process is characterized by its own value of the acidity of the wound bed. For example, in the acute stage of inflammation, the acidity of the medium in the wound bed decreases to pH 5.5–6. The chronic stage of the inflammatory process, on the contrary, is accompanied by an increase in pH to 8. To date, the effect of biomaterials containing components of the intercellular matrix of the human dermis on fibroblasts under acidosis and alkalosis has not been fully investigated.

Aim. The aim of this study was to characterize the effect of bioplastic material based on collagen, hyaluronic acid, and elastin on the viability and proliferative activity of human fibroblasts in conditions simulating the acidity of acute and chronic wounds.

Materials and methods. Bioplastic material was made according to the method described in RF patent no. 2722744. Adhesive properties and proliferative activity of human fibroblasts were assessed visually using fluorescent microscopy. The number of apoptotic and necrotic cells was assessed by flow cytometry (BD FACSCanto II) using the commercial FITC Annexin V Apoptosis Detection Kit I (BD Pharmingen). The strength, Young’s modulus, and elasticity of the gels were determined on a TA.XT-plus texture analyzer (Stable Micro Systems, Great Britain).

Results. Using the methods of luminescent microscopy and flow cytometry, we found that the cell viability (namely, adhesive properties and proliferative activity) decreases after incubation on condition mimic of physiological acidosis. We found that bioplastic material contributes to the preservation of adhesive properties, viability, and proliferative activity of fibroblasts in physiological acidosis conditions. The results obtained indicate that bioplastic material based on soluble dermis components can be used as a biologically active component of wound dressings to increase the effectiveness of reparative regeneration, especially in cases of excessive acute inflammation.

Purpose. The purpose of the study was to investigate the effect of γ,n-irradiation of the mouse head on the brain cells damage, behavior, and cognition and to examine the possibility of using lactoferrin (LF) to alleviate radiation-induced impairments.

Materials and methods. Mouse heads were irradiated in a beam of neutrons and gamma rays from the IR-8 nuclear reactor. The brain cells of control and irradiated mice were isolated using Percoll. Neurons and resting and activated microglial cells were analyzed using the fluorescently labeled antibodies and flow cytometry. The level of DNA double-strand breaks in neurons was determined by γH2AX histone content. Cytokine gene expression in the hippocampus was studied by RT-PCR. Behavior and cognitive functions were studied using the open field, Morris water maze, and novel object recognition tests. LF was isolated from female colostrum by preparative ion-exchange chromatography and purified by affinity chromatography on heparin-Sepharose.

Results. γ,n-Irradiation of the mouse head at a dose of 1.5 Gy led to an increase in the level of DNA double-strand breaks in neurons. Twenty-four hours after irradiation the total number of cells and the number of neurons in the isolated fraction of brain cells decreased, but the number of microglial cells remained unchanged. The number of resting and activated microglia did not change within 3–72 h after γ,n-irradiation. The expression level of the TNFα, IL-1β, and IL-6 genes increased 2 months after γ,n-irradiation of the mouse head at a dose of 1.5 Gy, indicating the development of neuroinflammation. At this time, irradiated mice demonstrated the anxiety-like behavior and impaired spatial and episodic memory. A single i.p. administration of human LF to mice immediately after γ,n-irradiation of the head did not affect the observed radiation-induced disturbances, but decreased the gene expression levels of TNFα, IL-1β, and IL-6 pro-inflammatory cytokines and increased the gene expression level of TGFβ anti-inflammatory cytokine in the hippocampus 2 months after radiation exposure. The obtained results indicate a partial decrease in the level of hippocampal neuroinflammation of irradiated animals treated with LF.

Conclusions. γ,n-Irradiation of the mouse head at a dose of 1.5 Gy leads to DNA damage of neurons and the decrease in the number of neurons. Microglia cells are more resistant to such radiation exposure. Late after head-only γ,n-irradiation, mice develop neuroinflammation, which is detected by an increase in the pro-inflammatory cytokine gene expression in the hippocampus and also by anxiety-like behavior and impaired cognitive functions. A single LF administration leads to a partial decrease in the neuroinflammation level, but does not affect the other studied parameters. The optimal dosing regimen of LF remains to be determined to preserve cognitive functions after γ,n-irradiation of the brain.

Introduction. It is known that monocytes can make a significant contribution to the development of chronic obstructive pulmonary disease (COPD); however, the features of the transcriptome of these cells associated with the disease remain poorly understood.

Aim. The aim of the study was to perform monocyte transcriptome analysis for identification of differentially expressed genes and key disturbances in biological processes in these cells in COPD.

Materials and methods. The study included three COPD patients and three smokers without bronchial obstruction. Monocytes were obtained from peripheral blood mononuclear cells using the plastic adhesion method. The cell purity achieved as a result of enrichment was approximately 90% according to flow cytometry data. The isolated RNA samples were purified from genomic DNA and ribosomal RNA. The samples were sequenced on a MGISEQ-200 sequencer in SE50 mode. Read mapping and transcript counting were performed in Salmon v1.10.1 software; further data processing was carried out in R software environment.

Results. As a result of the analysis, 21 upregulated and 29 downregulated genes were found in monocytes from COPD patients. Among the genes with increased expression, the most significant were the noncoding RNAs PKD1P5-LOC105376752 and PKD1P4-NPIPA8, the role of which remains unclear, as well as SETDB2, RNASE6, SERPINE1, and MRC1. Downregulated genes, of which F8A2, ZDHHC19, CXCL9, CXCL10, HBA1, HBB, C2, CFB, CFD, MT1B, MT1G, and TIMP3 were of most interest, showed enrichment in seven gene ontology (GO) terms, including those related to response to lipopolysaccharides, hydrogen peroxide, copper ions, and complement activation.

Conclusions. The data obtained indicate inhibition of monocyte functional activity in COPD patients with a decrease in the ability to provide effective protection against microbial pathogens while weakening self-protection against reactive oxygen species. Upregulation of SERPINE1 and downregulation of TIMP3 may significantly contribute to airway remodeling and emphysema development in COPD.

Chronic lymphocytic leukemia is a hemoblastosis of CD5⁺ B lymphocytes with lymphocytosis, damage to the lymphatic organs, occurring in the older age group, the etiology and pathogenesis of which are not fully understood. Oxidative stress is an important factor in the regulation of stem cells and the activation of intracellular survival signaling pathways in chronic lymphocytic leukemia cells. The aim of the study was to analyze the current data on the role of redox status changes in the pathogenesis of chronic lymphocytic leukemia. A review of published relevant studies 2018–2023, scientific articles in scientific electronic bibliographic databases PubMed and Social Sciences Citation Index, devoted to the pathogenesis of chronic lymphocytic leukemia and the role of free-radical oxidation processes in it was carried out. In chronic lymphocytic leukemia, oxidative stress with a systemic excess of reactive oxygen species, an imbalance in the effectiveness of antioxidant defense is caused mainly by activation of oxidative phosphorylation in mitochondria, low levels of NADPH-oxidase type 2, increased expression of heme oxygenase-1, glutathione peroxidase and glutathione recycling enzymes, superoxide dismutase-2, thioredoxins and decreased expression of catalase. One of the mechanisms of resistance to drug therapy and oxidative stress of chronic lymphocytic leukemia cells is the intracellular signaling pathway dependent on erythroid nuclear factor-2, due to the activation of expression in cells of superoxide dismutase-2, catalase, glutathione peroxidase, peroxiredoxin-3 and -5, heme oxygenase-1, thioredoxin-1 and -2, reduced glutathione, natural killer cell activity, which is associated with lifespan, chemotaxis, proliferation, and survival. FOXO family proteins are believed to suppress carcinogenesis. FOXO3a increases the expression of superoxide dismutase-2, catalase, glutathione peroxidase, peroxiredoxin-3 and -5, and the activity of natural killer cells, which promotes the survival of tumor cells. The development of new targeted pharmacological agents that are capable of accumulating reactive oxygen species and reducing antioxidant protection due to the degradation of erythroid nuclear factor-2 and activation of NADPH-quinone oxidoreductase-1 is underway, which modernizes the therapy of chronic lymphocytic leukemia.

The article presents the results of studies of the drug Tigerase® (inhalation solution manufactured by JSC GENERIUM, Russia), conducted to obtain evidence of its similarity (comparability) to the reference drug Pulmozyme® (inhalation solution, manufactured by Hoffmann-La Roche Ltd., Switzerland). Both drugs contain human recombinant deoxyribonuclease I (dornase alfa) as an active substance and are intended for the treatment of cystic fibrosis with pulmonary manifestations (mucoviscidosis). The enzymatic activity of dornase alfa, contained in the studied drugs, was investigated in vitro and ex vivo on samples of purulent sputum of patients. The pharmacokinetic parameters of the drugs in the blood serum, bronchi, and lungs, as well as the main physiological parameters (body weight and temperature, the state of the cardiovascular, respiratory, excretory systems, hematological and biochemical blood parameters, pathomorphological changes in internal organs (including the state of the cornea), and mortality rates) were investigated in comparative studies of subchronic toxicity in juvenile and mature rats with 28-day inhalation at doses of 0.2 mg/kg for mature animals and 0.26 mg/kg for juvenile animals (the dose was 6 times higher than the dose recommended for clinical use). The results of the studies allow us to conclude that the drugs are comparable in enzymatic, mucolytic (secretolytic) DNase activity, safety profile and main pharmacokinetic parameters.

Reduced expression of the IGFBP6 protein leads to an increase in the metastatic potential of breast cancer (BC) cells. The level of protein synthesis in tumor cells is increased, leading to a compensatory adjustment of proteostasis. One of the tools used to study proteostasis is protein toxins of the RIP-II family, which irreversibly inactivate ribosomes (particularly, viscumin). We investigated the effect of IGFBP6 gene knockdown on the proteostasis in the BC cell line MDA-MB-231. Ribosomes from MDA-MB-231^IGFBP6 cells, knockdown for the IGFBP6 gene, are less efficiently modified by the toxin. This is probably due to the reduced transport of the viscumin catalytic subunit from the ER to the cytoplasm. MDA-MB-231^IGFBP6 cells showed reduced expression of the retrotranslocon HRD1/Derlin subunit, which is a component of the ER-associated protein degradation system (ERAD). For ATF4 transcription factor, which is a part of the ER unfolded protein response (UPR) pathway, an increased expression of its targets was found.