Neutrophils are the most abundant leukocytes in the blood and the “first line” of defense against pathogens in the inflammation foci, where they perform effector functions such as phagocytosis, degranulation, generation of reactive oxygen species, and the formation of neutrophil extracellular traps. For a long time, it was believed that neutrophils are short-lived terminally differentiated phagocytes. However, this point of view has been changed after it was found that these cells are able to interact with other populations of leukocytes, as well as mediate the relationship between innate and adaptive immunity. In recent years, a lot of data has accumulated indicating the ability of neutrophils to acquire the function of antigenpresenting cells in a number of pathological and inflammatory conditions. In addition, neutrophils can express major histocompatibility complex class II and costimulatory molecules under the influence of specific cytokines in the in vitro system and activate T lymphocytes. This review summarizes current data on the antigen-presenting function of neutrophils, the proposed mechanisms of regulation of this process and its significance in normal and pathological conditions.

The absorption and circular dichroism spectra of chlorosomes isolated from green photosynthetic bacteria Chloroflexus aurantiacus grown under different illumination were studied. It was found that as the intensity of the growth light decreases, the spectra shift to the red side and become narrower and larger in amplitude. Theoretical modeling of the data obtained was performed using the theory of excitons. The conclusion was formulated that the number of bacteriochlorophyll c molecules in linear chains, which form the basis of the elementary blocks of chlorosomes, become greater as the intensity of light at which bacteria are grown decreases. It was suggested that this phenomenon increases the efficiency of capturing weak light fluxes and thereby increases the chances of bacterial survival in conditions of sunlight deficiency.

Neurodegenerative disorders, particularly Alzheimer’s disease, have become a major healthcare issue all over the world. Despite extensive research, the molecular mechanisms underlying these conditions are yet to be identified. APOE is the apolipoprotein E-coding gene. Its polymorphisms have been found to be significantly associated with both neurodegenerative disorders (rs429358, C112R) and protective effects against these disorders (rs7412, R158C). Humans carry three apolipoprotein E isoforms: ε2 (protein with a protective mutation), ε3 (wild-type protein), and ε4 (protein with a pathogenic mutation). The study sought to investigate how these substitutions affect the lipid-binding site, which is the functional region of the protein. Molecular dynamics simulation was used to analyze all three isoforms. We found that, unlike the wild-type isoform, both the pathogenic and protective mutations caused changes in the lipid-binding site. The changes, however, were different. Both ε2 and ε4 lead to an increased distance between the N-terminal (amino acids 88-104) and the C-terminal (amino acids 251-266) helices. However, in ε2, the C-terminal helix retained its structure, whereas in ε4, it unwound between amino acids 260 and 266. The opposite was true for the N-terminal helix. It is safe to assume that it is these structural differences in the lipid-binding site that account for the different effects of these two isoforms and clinical characteristics of their carriers. The clustering analysis allowed for the identification of the structures, most typical of ε2 and ε4, which could be used as the foundation for further molecular dynamics studies.

Mast cells (MCs) play a key role in the development of allergic diseases. The interaction of antigens with immunoglobulin E and the subsequent binding of these complexes to the FcεRI receptor, which ultimately leads to rapid exocytosis of granules and subsequent production of cytokines, play a major role in MC activation in allergy. There is data on the role of the mitochondrial membrane potential in the FcεRI-dependent activation of MC. Thus, the use of classical uncouplers of oxidative phosphorylation reduces MC degranulation. However, their effect on the production of MC cytokines has not been studied. In the present work, it was demonstrated that pretreatment of RBL-2H3 mast cells with the uncoupler carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) leads to a decrease not only in FcεRI-dependent degranulation, but also in a decrease in the production of TNFα and IL-4 cytokines. At the same time, FCCP prevents the phosphorylation of the LAT adapter molecule, as well as the Erk1/2 kinase, which may underlie the inhibitory effect of the uncoupler on FcεRI-dependent activation of RBL-2H3 cell line. The data obtained indicate that the mitochondrial membrane potential plays an important role in the FcεRI-dependent activation of MC, and the uncoupling of oxidative phosphorylation and respiration of mitochondria with the help of uncouplers can be used to regulate this process.

To assess the ecotoxicity of low doses of dioxins is almost impossible without considering the influence of real exposure conditions on these substances’ properties. The best approach to take these into account is the biomonitoring of the initial toxic effects’ manifestation. We studied bank voles from population naturally exposed to dioxins, the summer-born adults and overwintered functional groups of animals differed by dioxin body burden. Dioxin-free samples of a vivarium bank voles’ line served as a control. Initial effects of ecotoxicity were characterized by transcriptional levels of genetic markers: ahr, cyp1a2, keap1, dnmt1, dnmt3a, dnmt3b, LINE-1 and B1-SINE. Summer-born functional group had significantly higher expression levels of ahr, keap1, dnmt3a and dnmt3b genes versus their control group. Overwintered functional group had elevated expression levels of cyp1a2 and keap1, but no changes were found versus controls for dnmt1, LINE-1 and SINE B1. The increased expression of marker genes in dioxin-exposed voles was quite well associated with toxic process’ mechanisms – their formation and progression under exposure of several generations to low sub-toxic doses. The data obtained will contribute to the development of a biomonitoring method for assessing the initial effects of dioxin ecotoxicity.

Peripheral populations are considered more vulnerable than central ones, but recent studies have questioned the existence of clear patterns within species ranges. We studied reproductive and demographic characteristics of the rare orchid Dactylorhiza traunsteineri at the northeastern limit of its distribution range (the Subpolar Urals) and compared them with the data of four populations located closer to the center of the range (south of the Komi Republic). In peripheral populations, number of individuals per population, plant sizes, number of flowers per individual and seeds per fruit were significantly lower than those in populations located closer to the center of the area. Contrary to expectations, the peripheral populations were renewed better than the central ones, which may be due to the high level of moisture availability in the Subpolar Urals. The proportion of juvenile individuals in the peripheral populations was 18.7%, in populations in the south of the Komi Republic – 6.3–6.9%. In addition, we found that in the direction from the center to the periphery of the species range, the proportion of empty space in seeds increased (from 63.9 to 75.6%). This provides the seeds with better volatility and increases the chances of reaching places favorable for germination, which are becoming fewer at the edge of the range.

In this work, it was found that Ac-D-MPRG, a tetrapeptide synthesized on the basis of the C-terminal fragment of arginine-vasopressin(6-9), upon chronic neonatal administration, affects anxiety and exploratory behavior in rats of three age groups. The most significant effect of the peptide was manifested under more stressful conditions. The rats of the experimental group showed less anxiety. They did less grooming in the Elevated Plus Maze test and increased time in light in the Light-Dark Chamber test. Motor activity changed from passive holding in the prepubertal period to active avoidance in puberty and adulthood. Based on the data obtained, we conclude that the effects of the peptide are manifested only when exposed to a biologically significant stimulus.

For five species of Aspergillus micromycetes, the diversity of proteolytic activities against human hemostasis proteins was assessed. For every strain, absence of activities similar to hemostatic proteases – thrombin, plasmin, factor Xa, urokinase, and protein C was shown. In addition, no activating activities towards precursors of the named proteases were demonstrated. For A. glaucus, proteases of high activity (58,52 U_tyr) and specificity against fibrinogen were found. A. athecius, A. caespitosus и A. wentii, were capable of proteolysis at acidic pH.

The history of the creation of the course of lectures “Basics of the Biology of Aging” at the School of Biology of Lomonosov Moscow State University, as well as at the Department of Life Science and Engineering of Harbin Institute of Technology is briefly described. In the process of teaching this course, the author got the impression that its main provisions may also be of interest to students of non-biological specialties, who have recently been quite often involved in the work on the implementation of gerontological grants. This is largely determined, apparently, by the significantly increased funding for this kind of research in recent years. In turn, this is a consequence of the fact that the average life span of people in developed countries has increased dramatically over the past decades. However, the maximum life span has not changed much (it is now the same as it was thousands of years ago, it is just that the chances of living to the age of a centenarian have become much greater). If earlier people often died at an early age from various diseases not related to age (mainly infectious diseases), now, due to significant advances in medicine, most people live to old age. As a result, death “from aging” is becoming more common. At the same time, many people have a very vague idea of what aging is, what are its mechanisms and how to fight it. In this regard, in 2022, an interschool elective course of lectures was organized at MSU for students of any departments of the university, except for the School of Biology itself. It is called “Basics of the biology of aging, or everything you wanted to know about aging (but were afraid to ask).” The material of the lectures was specially adapted for students who are not biologists by their main specialty. The main emphasis in the course, consisting of 12 lectures, is made on the fundamental definitions and methodical/methodological approaches used in gerontology. The article lists the questions submitted for the students’ test and briefly analyzes its results.