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Vol 67, No 2 (2025)
Articles
Maturation of oocytes in vitro: biological basis and prospects for clinical use
Abstract
In vitro oocyte maturation (IVM) involves the aspiration of prophase I oocytes in oocyte-cumulus complexes from small antral follicles and their subsequent maturation to metaphase II (MII). IVM is a promising method for obtaining MII oocytes in cases where hormonal stimulation of the ovaries is undesirable or impossible. At the same time, in terms of maturation rates and developmental capacity, oocytes obtained as a result of the IVM procedure are inferior to oocytes obtained in stimulated cycles; therefore, improving IVM protocols is a hot topic. The review discusses the possibilities of the IVM procedure in the context of key stages of oocyte maturation and their achievement of nuclear and cytoplasmic maturity. The advantages and disadvantages of various IVM techniques and the main directions for their further improvement are highlighted.
65-79
2-ethyl-6-methyl-3-hydroxypyridine carnitinate is a broad-spectrum adaptogen, that stimulates autophagy in liver tissue
Abstract
Background: Under stress conditions, mitochondria become sources of excessive generation of reactive oxygen species (ROS), which can serve either as signaling molecules or damage cell structures. Antioxidants, reducing ROS generation, can serve as adaptogens to stress effects. It has been shown that a number of antioxidants are able to induce autophagy, which is able to activate the antioxidant-response element system. In this regard, the aim of the study was to investigate the anti-stress properties of a new antioxidant 2-ethyl-6-methyl-3-hydroxypyridine carnitinate (CP) and its ability to activate the synthesis of autophagy proteins Beclin-1, LC3.
Methods: Since the body’s resistance to stress factors primarily depends on energy metabolism, the effects of acute hypobaric hypoxia and CP on the LPO intensity in the lipid fraction of mice liver mitochondrial membranes were studied using the spectrofluorescence method. Autophagy proteins were determined by Western blotting using primary mice antibodies to Beclin-1 and LС3B proteins, as well as secondary antibodies labeled with horseradish peroxidase.
Results: Injection of 10–6 mol/kg CP to mice for 5 days prevented the growth of LPO intensity under conditions of acute hypobaric hypoxia (AHH). This drug increased life expectancy and increased survival of mice under conditions of various types of the hypoxia. The initiation of autophagy biomarker proteins (LC3B) by the drug was shown. At the same time, the content of Beclin-1 proteins tended to increase, which characterizes the onset of the autophagy process.
Conclusion: The new antioxidant CP can probably be used as an adaptogen to various types of hypoxia and an activator of autophagy.
80-89
Mitochondria of endocrine cells of intestine mucosa epithelium in a melatonin-treated rats (electronic morphometric study)
Abstract
The ultrastructure of mitochondria of endocrinocytes of the epithelium of the mucous membrane of the duodenum and colon of rats was studied in 2 subgroups of the experiment: with the introduction of 1 and 100 therapeutic doses of melatonin solution. When melatonin was administered in the studied parts of the intestine, it was revealed: a change in the content of 95—90 % endocrine cells in the cytoplasm of the studied organelles, their swelling (85 % of organelles), fragmentation of crystals (70 % of organelles), enlightenment of their matrix (5 % of organelles) and the appearance of myelin-like structures (1—2 % of organelles) were revealed. The detected structural changes may indicate an increase in the metabolic activity of epithelial endocrinocytes in response to experimental exposure, which requires regenerative correction of mitochondrial dynamics.
90-103
Assessing the influence of xanthene dyes on the physical properties of lipid membranes using the molecular dynamics simulation
Abstract
Objective: The correct choice of dyes, especially those targeting cell membranes, is a primary task for successful scientific research. In this work, the effect of xanthene dyes, fluorescein, erythrosine, eosin Y and rose bengal, on the physical properties of model lipid membranes was studied using molecular dynamics simulation.
Methods: Molecular dynamics simulation.
Results and discussion: It was found that xanthene dyes increase the area per lipid, the effect increases in the series fluorescein ≈ eosin Y < erythrosine ≤ rose bengal. Calculation of the packing parameter of the phospholipid molecule “tails” shows that fluorescein, erythrosine and eosin Y have a disordering effect on membranes, while rose bengal has practically no effect on this parameter. Evaluation of the change in the dipole potential of the phospholipid membrane in the presence of dyes shows that their ability to reduce this value increases in the series fluorescein ≈ eosin Y ≈ erythrosine < rose bengal.
Conclusions: Comparison of the results of molecular dynamics simulation with electrophysiological data and the results of differential scanning microcalorimetry has revealed a number of discrepancies, the reasons for which are discussed.
104-110
In ovo — isolation of primordial germ cells from embryonic blood of gene pool breeds of chickens
Abstract
The article presents a new method (in ovo — inside the egg) for isolating primordial germ cells (PGC) from embryonic blood of gene pool chicken breeds, which is of great importance for preserving the genetic resources of birds and creating new innovative tools in the field of biotechnology. Despite the key role of PGC in the targeted modification of the genome, there are significant difficulties with the efficiency of their isolation. To analyze the efficiency of the in ovo method, experiments were conducted on collecting blood samples from 192 chicken embryos of various breeds, as well as subsequent cultivation of PGC and cell counting. It was found that the efficiency of sampling depends on the egg weight and breed. A high efficiency rate was observed in the Chinese Silkie breed (89.5 %), with an influence strength of η2 = 98 %, p-value <0.004. Analysis of PGC cultivation data showed an increase in the concentration of living cells and their survival by the 20th day. The highest survival rates were observed in the Chinese Silkie breed (69.1±2.56 %), and the Tsarskoye Selo (68.78±3.39 %) and Rhode Island (67.9±2.52 %) chicken breeds also had high rates. The results confirmed the importance of the in ovo method for optimizing the process of isolating PGCs from 4-day chicken embryos to increase the number of cells during further cultivation.
111-118