PSIII-1 Activity of nucleolar organizers depending on genotype

The level of protein proliferation and biosynthesis in various physiological and pathological processes depends on the functional activity in the nucleolar apparatus of cell. The activity degree of the nucleolar organizers varies depending on the level of functional load on the cells. It is associated with the exogenous and endogenous factors and the manifestation of polygenic traits, such as the synthesis intensity of subunits rRNA (18S and 28S) that enter the ribosome. The aim of this research was to study the relationship between the activity of nucleolar organizers and the animal genotype. The objects of study were goats with different genotypes divided by 3 groups of goats hybrids were used: group_I was 5 individuals of Karachay × F1(C.sibirica×C.hircus); group_II - 4 individuals of Boer × F1; group_III - 3 individuals of F2(C.sibirica×C.hircus) × F1. The material for the study was venous blood. Blood smears were fixed with Lillie’s solution and were stained using the Havel and Blake technique. Microscopic studies were performed using a Nikon Eclipse Ni equipped with Nikon DS-Qi2 camera (4908×3264). For statistical analysis of the obtained data, the SPSSv.23 was used. We used the average optical density AgNOR (DNOR) as an indicator reflecting the total amount of Ag bound to the argyrophilic proteins of the nucleolar organizer, It was found that in goats of the second group this indicator was 158.58±10.18, which was significantly inferior in terms of AgNOR to animals in group_I (211.10±3.62) and in group_III (206.77±4.43). No significant differences between the goats of groups I and III were found. Thus, the AgNOR criterion depends on the goat genotype to a certain extent and is of interest for assessing the activity of the nucleolar organizers in goats. Supported by RFBR project №20-016-00116А and the Ministry of Science and Higher Education of Russia (№АААА-А18-118021590132-9).

Cytoprotective effect of non-opioid leu-enkephalin analogue in primary culture of pulmonary fibroblasts in oxidative stress

Aim. Analysis of the cytoprotective effect of non-opioid leu-enkephalin analogue (Phe-D-Ala-Gly-Phe-Leu-Arg) in the primary culture of pulmonary fibroblasts in conditions of oxidative stress. Methods. Pulmonary fibroblasts were incubated with the peptide of non-opioid leu-enkephalin analogue (Phe-D-Ala-Gly-Phe-Leu-Arg) in the concentration 0.1 μM for 6 hours. To simulate oxidative stress, 60 μM H2O2 was added to the culture medium for 2 hours. Experimental series included (1) «control»; (2) «non-opiate leu-enkephalin analogue» (the peptide was added to the culture medium 44 hours after the final passage); (3) «oxidative stress» (H2O2 was added to the culture medium 48 hours after the final passage); (4) «non-opiate leu-enkephalin analogue + oxidative stress» (the peptide and H2O2 were added to the culture medium 44 and 48 hours respectively after the final passage). In order to evaluate the generation of superoxide anion by pulmonary fibroblasts, the method of lucigenin-dependent chemiluminescence was used. Computer morphometry of the nucleo-nucleolar apparatus of fibroblasts stained with silver nitrate by the AgNOR method was used to assess the cell state: the area of fibroblast nuclei, the total nucleoli area in the nucleus, and the number of nucleoli in the nucleus were measured. These parameters correlate with the activity of anabolic processes in the cells. Results. The effect of H2O2 on the primary culture of pulmonary fibroblasts caused an increase of superoxide anion generation by the fibroblasts, reduction of fibroblast nuclei size, decrease of nucleoli amount and size. Pre-incubation of pulmonary fibroblasts with a non-opioid leu-enkephalin analogue reduced the H2O2-induced generation of superoxide anion, corrected changes in the nucleo-nucleolar apparatus of fibroblasts caused by oxidative stress. In our previous studies, similar effect in the same model was shown for non-selective μ/δ-opioid receptor agonist peptide sedatin (dermorphin analogue). The mechanism of cytoprotective effect of non-opioid leu-enkephalin analogue may include the affinity of this peptide to nociceptin receptors (NOR receptors) that requires further studies. Conclusion. The results of the study indicate a direct cytoprotective effect of the peptide Phe-D-Ala-Gly-Phe-Leu-Arg (non-opioid leu-enkephalin analogue) in oxidative stress.