Medical academic journal

In recent decades, the steadily increasing pressure of extreme, life-threatening stressors worldwide has significantly contributed to a rise in the prevalence of mental and behavioral disorders. One of the most severe consequences of experiencing psychotraumatic situations is the development of post-traumatic stress disorder. Current therapeutic approaches benefit only a minority of patients and are frequently accompanied by high non-response and relapse rates. In this case, the possible reasons for the lack of therapeutic effectiveness include not only genetic but also epigenetic factors, which may determine individual characteristics of the pharmacokinetics and pharmacodynamics of the drugs used.

This review outlines epigenetic mechanisms that may underlie interindividual differences in treatment resistance, risk of development, and clinical severity of post-traumatic stress disorder. It summarizes the roles of DNA methylation, histone modifications, non-coding RNAs, chromatin remodeling, and the three-dimensional genome architecture in post-traumatic and stress-related disorders. Data are presented on the potential use of epigenetic modifications as biomarkers of traumatic stress and as factors responsible for the transmission to offspring of the adverse consequences of psychogenic trauma experienced by the parents. The possibilities and limitations of applying epigenetic therapy for post-traumatic stress disorder are discussed.

BACKGROUND: The development of a universal influenza vaccine remains a critical goal to enhance protection against diverse influenza virus strains. While vaccines against influenza type A viruses have benefited from the use of chimeric hemagglutinin designs, strategies for influenza type B vaccines still lag.

AIM: The study aimed to investigate the efficacy of chimeric vaccine strains to induce humoral immune response targeting conserved antigenic sites of influenza type B virus.

METHODS: A chimeric hemagglutinin was engineered by combining the head domain from the B/Brisbane/60/2008 virus (Victoria lineage) with the stalk domain from the B/Phuket/3073/2013 virus (Yamagata lineage). The gene encoding the chimeric hemagglutinin was incorporated into a vaccine virus based on the cold-adapted B/USSR/60/69 master donor virus to produce live-attenuated influenza vaccine. Mice were sequentially vaccinated with the conventional live-attenuated influenza vaccine and then with the recombinant live-attenuated influenza vaccine expressing the chimeric hemagglutinin. Immune responses and cross-protection against both homologous and heterologous influenza type B virus strains were assessed.

RESULTS: The engineered chimeric hemagglutinin did not impair the replication or assembly of the vaccine virus. Sequential vaccination induced a robust humoral immune response and provided protection against both homologous and heterologous influenza type B virus strains in the mouse model.

CONCLUSION: Live-attenuated influenza type B vaccines expressing chimeric hemagglutinin show promise in broadening protection against influenza type B virus infection. These findings support the development of a universal influenza type B vaccine using a chimeric hemagglutinin design.

BACKGROUND: The delivery of nucleic acids to mesenchymal stem cells, which are used as model objects in in vitro experiments or as therapeutic agents in regenerative medicine and oncology, is an actively developing area of research. Existing non-viral delivery systems either have low effectiveness or highly toxic to mesenchymal stem cells. Therefore, the development of new carriers has become an urgent priority.

AIM: To demonstrate the feasibility of delivering model messenger RNA and small interfering RNA to rat heart mesenchymal stem cells (MSCs) in vitro using original cationic liposomes 2X3-DOPE (1:3 molar ratio) and to evaluate the influence of exosomes incorporated into hybrid nanoparticles with 2X3-DOPE on the efficiency of RNA delivery.

METHODS: Exosomes were isolated using a standard ultracentrifugation technique followed by characterization of the obtained vesicles through Western blotting, transmission electron microscopy, atomic force microscopy, and hydrodynamic diameter measurement using dynamic light scattering. Small interfering RNA was chemically synthesized; whereas messenger RNA was obtained by in vitro transcription. Complexes of liposomes or hybrid nanoparticles with RNA were prepared by mixing; the properties of the resulting particles were assessed using dynamic light scattering and atomic force microscopy. To evaluate the efficiency of RNA delivery to rat heart mesenchymal stem cells derived from both healthy and ischemic myocardium, we used fluorescence microscopy, laser scanning confocal microscopy, and flow cytometry.

RESULTS: Complexes of cationic liposomes 2X3-DOPE (1:3 molar ratio) with messenger RNA and 2X3-DOPE modified with DSPE-PEG₂₀₀₀ (0.62 mol%) complexed with small interfering RNA were successfully prepared and characterized. It was demonstrated that 2X3-DOPE is ineffective for messenger RNA delivery to rat cardiac mesenchymal stem cells; whereas hybrid nanoparticles incorporating exosomes based on these liposomes exhibited up to 40% transfection efficiency. In addition, 2X3-DOPE modified with DSPE-PEG₂₀₀₀ (0.62 mol%) was effective for small interfering RNA delivery to rat cardiac mesenchymal stem cells, achieving up to 90% transfection efficiency; whereas the use of hybrid nanoparticles based on this formulation resulted in 100% transfected cells with more than a twofold increase in small interfering RNA in the cells as indicated by the average fluorescence intensity.

CONCLUSION: Cationic liposomes 2X3-DOPE (1:3 molar ratio) modified with DSPE-PEG₂₀₀₀ (0.62 mol%) are promising vehicles for small interfering RNA delivery to mesenchymal stem cells, both independently and in combination with exosomes. Exosomes integrated in hybrid nanoparticles based on 2X3-DOPE improve the transfection efficiency of both messenger RNA and small interfering RNA in rat cardiac mesenchymal stem cells in vitro.

BACKGROUND: Neutrophils are essential in tumor growth, and their functional state can serve as a prognostic biomarker. However, the functional characteristics of peripheral blood neutrophils, such as chemotaxis and predisposition to NETosis, in female patients with luminal breast cancer have not been sufficiently explored. Studying these parameters may provide new insights into the mechanisms of disease progression and response to therapy.

AIM: This work aimed to analyze the chemotactic activity of neutrophils and predisposition to NETosis in blood samples of female patients with locally advanced luminal breast cancer undergoing treatment (neoadjuvant chemotherapy) at the Loginov Moscow Clinical Scientific Center.

METHODS: The study was conducted on blood samples from six patients with stage 3 luminal B, HER2-negative breast cancer before and 2 months after the start of antitumor therapy. Blood samples from healthy adult volunteers were used as controls. The work was performed using fluorescence microscopy methods for neutrophil chemotaxis with the growth of blood clots and the number of extracellular DNA traps of neutrophils by reaction with Hoechst 33342 and antibodies against myeloperoxidase and neutrophil elastase in smears of blood plasma rich in leukocytes.

RESULTS: Before the start of neoadjuvant therapy, the level of NETosis is significantly increased (30% ± 14% versus 4.6% ± 3.4% in healthy donors), whereas most female patients undergoing therapy experience its reduction (17% ± 17%). The speed of neutrophil movement is increased in some female patients (0.17 ± 0.06 versus 0.113 ± 0.009 μm/s in healthy donors) and goes down during therapy (0.10 ± 0.03 μm/s). At the same time, the number of neutrophils associated with blood clots decreases during therapy (25 ± 18 versus 61 ± 23) even in patients with neutrophilia.

CONCLUSION: It has been demonstrated for the first time that in female patients with luminal B, HER2-negative breast cancer, the neutrophil chemotaxis speed deviates from the standard; at the same time, their adhesion is reduced, and peripheral blood neutrophils are significantly more predisposed to NETosis than in healthy donors.

BACKGROUND: The analgesic properties of arginine vasopressin and its synthetic analogue, 1-deamino-8-D-arginine vasopressin, are known. However, it is difficult to use neuropeptides in clinical practice due to the possible development of side effects. The study of the molecular mechanisms and effects of 1-deamino-8-D-arginine-vasopressin in the management of various types of pain will allow us to identify new therapeutic targets and determine the conditions for the safe use of the peptide.

AIM: The study aimed to evaluate the effect of intranasal 1-deamino-8-D-arginine-vasopressin administration on pain sensitivity, the content of monoamines and BDNF in the parietal cortex and spinal cord in thermal and electrocutaneous stimulation in rats.

METHODS: 1-deamino-8-D-arginine-vasopressin was administered intranasally in a thermal pain model at 0.002 µg/day (0.01 µg/course) and 2 µg/day (10 µg/course); 0.02 µg/day (0.1 µg/course) and 2 µg/day (10 µg/course) for electrocutaneous stimulation. Serum corticosterone and brain-derived neurotrophic factor levels in the parietal cortex and spinal cord were determined using enzyme-linked immunosorbent assay. The levels of norepinephrine (NE), dopamine (DA), serotonin (5-HT), and their metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA), and 5-hydroxyindoleacetic acid (5-HIAA), in the brain were determined using high-performance liquid chromatography.

RESULT: 1-deamino-8-D-arginine vasopressin reduced pain sensitivity regardless of the type of pain and doses administered. The involvement of monoamines and brain-derived neurotrophic factor in the analgesic effects depended on the type of exposure and dose of the drug. NE and brain-derived neurotrophic factor at the supraspinal and spinal levels, 5-HT at the spinal cord level have been implicated in analgesia in the thermal pain model.

During electrocutaneous stimulation, DA and 5-HT contributed to analgesia at the supraspinal level; 5-HT, DA and NE at the spinal level. 1-deamino-8-D-arginine-vasopressin did not affect the blood corticosterone in rats with different types of pain.

CONCLUSION: The peptide caused reduced pain sensitivity under various influences. However, this effect in different conditions was due to different neurochemical mechanisms; in thermal pain, it was associated with the modulatory effect of the peptide on monoamine and BDNF levels in the brain or only monoamines in electrocutaneous stimulation.

BACKGROUND: Inflammatory bowel diseases are characterized by inflammation of the intestinal mucosa and increased intestinal barrier permeability. When studying the biological effects of drugs, it is important that experimental models adequately reproduce the key pathogenic factors of the disease.

AIM: The work aimed to compare the parameters of intestinal epithelial barrier permeability and inflammatory response in inflammatory bowel disease models: Caco-2 cells stimulated with lipopolysaccharides and mice with a knockout of the mucin 2 gene (Muc2^–/–).

METHODS: In the in vitro model of inflammatory bowel disease, Caco-2 cells were cultured in the presence of lipopolysaccharide at concentrations ranging from 0.1 to 100.0 μg/mL, and its effects on transepithelial electrical resistance, monolayer permeability, expression of the tight junction genes ZO-1 and Claudin-1 and the pro-inflammatory cytokines IL-8 and TNF-α, as well as IL-8 secretion, were evaluated. In the in vivo model of inflammatory bowel disease, mice with a knockout of the mucin 2 gene (Muc2^–/–) were used. Intestinal permeability was determined by plasma fluorescein isothiocyanate-dextran concentration after intragastric administration. Histological analysis of colon samples was performed, with evaluation of TNF-α, IL-1β, and IL-10 gene expression and IL-1β and IL-10 protein levels.

RESULTS: In in vitro experiments on Caco-2 cells, lipopolysaccharide at a concentration of 10 μg/mL reduced transepithelial electrical resistance by 57% and increased monolayer permeability to fluorescein isothiocyanate-dextran by 38%. At the same time, it increased IL-8 and TNF-α expression 2.8- and 2.3-fold, decreased ZO-1 and Claudin-1 expression by 54% and 53%, and increased IL-8 secretion 27-fold compared with the control. In vivo, intestinal permeability in Muc2^–/– mice was 5.8-fold higher; IL-1β and TNF-α expression was 9.9- and 6.8-fold higher; IL-10 expression in Muc2^–/– mice was 71% lower; IL-1β content in the colon was 94% higher, and IL-10 content was 44% lower compared with healthy mice.

CONCLUSION: The studied in vitro and in vivo models of inflammatory bowel disease exhibit similar trends in intestinal permeability and inflammatory response parameters. These models adequately reproduce the relevant pathogenic factors and complement each other.

The previously unknown facts of the biography of Maria K. Petrova, a student and colleague of academician I.P. Pavlov, are presented. Archival research and analysis of previously inaccessible materials allowed to restore her biography hidden from the public by shedding light on the development of her personality and scientific perspective. Maria spent her early childhood far from St. Petersburg, in a small military garrison in the Caucasus. However, she graduated from high school in the capital of the Russian Empire. The discovered data both shed light on her childhood and youth and provide background information on her parents, spouse, brothers and sisters. This information allows us to reinterpret her decision to get a higher education and practice medicine and reveals the roots of her loyalty to Ivan Pavlov. The article describes Maria Petrova’s character traits, which allowed her to become an outstanding researcher rather than just a mother of a family. Her decision to get a medical degree could not but affect her relationship with her husband, Grigory S. Petrov, from whom she later divorced. Undoubtedly, the new findings will be an impetus for historians of science.