The aim of the work was behavioral and pathomorphological phenotyping of the mice knockout for the DYSF gene, which plays an important role in the development and progression of dysferlinopathy.Materials and methods. A B6.A-Dysf^prmd/GeneJ (Bla/J) mice subline was used in the work. During the study, a muscle activity was determined basing on the following tests: “Inverted grid”, “Grip strength”, “Wire Hanging”, “Weight-loaded swimming”, Vertical Pole”. Histological and immunofluorescent examinations of skeletal muscles (m. gastrocnemius, m. tibialis) were performed. The presence and distribution of the dysferlin protein was assessed, and general histological changes in the skeletal muscle characteristics of mice at the age of 12 and 24 weeks, were described. A morphometric analysis with the determination of the following parameters was performed: the proportion of necrotic muscle fibers; the proportion of fibers with centrally located nuclei; the mean muscle fiber diameter.Results. The “Grip strength” test and the “Weight-loaded swimming” test revealed a decrease in the strength of the forelimbs and endurance in the studied mice of the Bla/J subline compared to the control line. The safety of physical performance was checked using the “Wire Hanging” test and the “Vertical Pole” test, which showed a statistically significant difference between the studied mice and control. The coordination of movements and muscle strength of the limbs examined in the “Inverted Grid” test did not change in these age marks. Decreased grip strength of the forelimbs, decreased physical endurance with age, reflects the progression of the underlying muscular disease. Histological methods in the skeletal muscles revealed signs of a myopathic damage pattern: necrotic muscle fibers, moderate lympho-macrophage infiltration, an increase in the proportion of fibers with centrally located nuclei, and an increase in the average fiber diameter compared to the control. The dysferlin protein was not found out in the muscle tissues.Conclusion. Taking into account the results of the tests performed, it was shown that the absence of Dysf^-/^- gene expressionin Bla/J subline mice led to muscular dystrophy with the onset of the development of phenotypic disease manifestations at the age of 12 weeks and their peak at 24 weeks. Histopathological phenotypic manifestations of the disease are generally nonspecific and corresponded to the data of intravital pathoanatomical examination in diferlinopathy patients. The mice of the studied subline Bla/J are a representative model of dysferlinopathy and can be used to evaluate new therapeutic agents for the treatment of this disease.

Introduction: The aim was to evaluate the structural and functional changes of bone tissue in mice with null expression of 11β-HSD2 or both 11β-HSD2 and Apolipoprotein E. Materials and methods: The experimental study was performed in 60 male mice, weighting 24–30 g. The animals were kept in accordance with the rules of laboratory practice for preclinical studies on the territory of the Russian Federation. Mice lacking 11β-HSD2 (Hsd2-/-) and male mice lacking 11β-HSD2 and Apolipoprotein E (Hsd2-/-/Apoe-/-) were used in the study. We studied and characterized the state of bone tissue, indicators of bone density, microcircu­lation in bone tissue, endothelial dysfunction coefficient, width of bone trabeculae, as well as serum concentrations of bone alkaline phosphatase, hydroxyproline, deoxyprinoline and expression levels of p53, Bcl2, Bax, eNOS genes. Results and discussion: We showed that mice with the Hsd2-/- genotype with no expression of 11ß-HSD2 by the 6th month of life showed a statistically significant decrease in bone density, which progresses to the 7th and 8th months of life. At the 8th month of animal life, a decrease in bone density is accompanied by a statistically significant decrease in the level of microcirculation in the bone and an increase in the coefficient of endothelial dysfunction. Taking into account the relationship of endothelial dysfunction, atherogenesis and disorders in the processes of bone remodeling, in the framework of this study, we also assessed the state of bone tissue in double transgenes with the genotype Hsd2-/-/Apoe-/-, which lack the expression of both 11ß-HSD2 and Apolipoprotein E. In this study, we also saw increased acti­vation of processes leading to disruption of bone remodeling processes. In the group of the animals with the genotype Hsd2-/-/Apoe-/-, we found statistically significant differences from the mice with no expression of 11ß-HSD2 in bone density and microcirculation, and the width of bone trabeculae. Also, a statistically significant increase in hydroxypro­line and deoxyprinoline was found in the group of double transgenes, in the absence of significant changes in the con­centration of bone alkaline phosphatase. This fact indicates a pronounced activation of bone resorption processes in the absence of activation of osteosynthesis processes, which leads to the detected violation of bone remodeling processes. Conclusion: Thus, we have shown that a violation of the metabolic regulation of steroid hormone metabolism in ani­mals with null expression of the 11ß-HSD2 (Hsd2-/- genotype) leads to the development of signs of osteoporosis – bone density decreases, which is accompanied by a decrease in the width of bone trabeculae, the level of microcirculation in bone tissue decreases simultaneously with an increase in the coefficient of endothelial dysfunction. The additional null expression of ApoE gene in double transgenes with the genotype Hsd2-/-/Apoe-/- leads to an increase in the severity of changes associated with a violation of bone remodeling processes and, in addition to a more pronounced change in bone tissue density, bone trabecular width, microcirculation and the coefficient of endothelial dysfunction leads to an increase in the concentration of biochemical markers of bone resorption. These changes indicate the important role of the enzyme 11ß-hydroxysteroid dehydrogenase type 2 in the processes of bone remodeling disorders. Graphical

Introduction: The aim of this study was to evaluate the processes of bone remodeling and osteoreparation in modeling femoral fracture in mice with zero expression of 11β-HSD2 (11β-HSD2-/-) or both 11β-HSD2 and apolipoprotein e (11β-HSD2-/-/ApoE-/-). Materials and Methods: The experimental study was conducted on 60 male mice weighing 24-30 g. The study used male mice that lacked the expression of 11β-HSD2 (knockout mice with the Hsd2-/- genotype) and male mice that lacked the expression of 11β-HSD2 and apolipoprotein E (double knockout mice with the Hsd2-/-/ApoE-/- genotype). The control group includes wild type C57bl/6 animals. Modeling of a fracture of the proximal metaphysis of the femur was performed in animals at the age of 6 months using a closed technique. Fracture fusion and bone remodeling and osteoreparation processes were evaluated 6 weeks after fracture modeling. Results and Discussion: It has been shown that a violation of the regulation of steroid hormone metabolism in groups of animals with the Hsd2-/- and Hsd2-/-/ApoE-/- genotypes leads to an increase in the number of ungrown fractures by 3 and 3.5 times, respectively, in comparison with wild-type animals. It was found that the microcirculation level of the proximal metaphysis of the left femur in the area of the formed bone callus in the group of animals with the genotype 11β-HSD2-/- significantly decreased from 92.075±4.33 perfusion units (PE) in the group of wild-type animals to 82.67±3.54 PE (p=0.0002) in the group of animals with the genotype HSD2-/- and up to 75.85±5.64 (p<0.0001) in the group of mice with the Hsd2-/-/ApoE-/- genotype. When calculating the coefficient of endothelial dysfunction, an increase in the coefficient of endothelial dysfunction was found from 1.297±0.19 in intact animals to 2.115±0.45 (p<0.00001) in the group of mice with the Hsd2-/- genotype and to 2.41±0.04 (p<0.00001) in the group of mice with the Hsd2-/-/ApoE-/- genotype. In animals with impaired cortisol metabolism, there was a slowdown in the formation of bone tissue in the fracture area, bone trabeculae had a smaller width, large amounts of fibrous and connective tissue were observed in the lumen between bone fragments, and an increase in intertrabecular spaces was noted Conclusion: The close relationship between the metabolism of 11β-HSD2 and NO, confirmed in this study, can be considered as a promising pharmacotherapeutic target. It is obvious that approaches to changing the activity of 11β-HSD have significant therapeutic potential in the treatment of osteoporosis, bone remodeling disorders and osteoreparation in fractures against the background of formed osteoporotic changes in the violation of steroid hormone metabolism.

Introduction: In this review, the analysis of technologies for obtaining biologically active proteins from various sources is carried out, and the comparative analysis of technologies for creating producers of biologically active proteins is presented. Special attention is paid to genetically modified animals as bioreactors for the pharmaceutical industry of a new type. The necessity of improving the technology of development transgenic rabbit producers and creating a platform solution for the production of biological products is substantiated. The advantages of using TrB for the production of recombinant proteins: The main advantages of using TrB are the low cost of obtaining valuable complex therapeutic human proteins in readily accessible fluids, their greater safety relative to proteins isolated directly from human blood, and the greater safety of the activity of the native protein. The advantages of the mammary gland as a system for the expression of recombinant proteins: The mammary gland is the organ of choice for the expression of valuable recombinant proteins because milk is easy to collect in large volumes. Methods for obtaining transgenic animals: The modern understanding of the regulation of gene expression and the discovery of new tools for gene editing can increase the efficiency of creating bioreactors for animals and help to obtain high concentrations of the target protein. The advantages of using rabbits as bioreactors producing recombinant proteins in milk: The rabbit is a relatively small animal with a short duration of gestation, puberty and optimal size, capable of producing up to 5 liters of milk per year per female, receiving up to 300 grams of the target protein.

Alzheimer’s disease, first described over a century ago, is currently among the most common neurodegenerative diseases whose significance is increasingly growing with the aging of populations. Throughout the entire period of its study, no remedies have been found that would be effective in treating – or at least significantly slowing – the pathological process, while being sufficiently safe. In this regard, significant attention is paid to the development and application of natural peptide drugs lacking side effects. The present study assessed the effect of the known neuroprotective peptide Semax and its derivative on the behavioral characteristics and development of amyloidosis in transgenic APPswe/PS1dE9/Blg mice acting as a model of Alzheimer’s disease. The open field, novel object recognition, and Barnes maze tests demonstrated that both Semax and its derivative improved cognitive functions in mice. Histological examination showed that these peptides reduced the number of amyloid inclusions in the cortex and hippocampus of the animals’ brains. These findings demonstrate the high potential of Semax and its derivatives when used to develop therapeutic and corrective strategies for Alzheimer’s disease.

The aim of the research was to study antiatherosclerotic and endothelial kinds of a protective activity of peptides mimicking an erythropoietin a-helix B tertiary structure with laboratory codes EP-11-1 (UEHLERALNSS), EP-11-2. (UEQLERALNCS), EP-11-3 (UEQLERALNTS).Materials and methods. The study was conducted on 96 C57Bl/6J male double transgenic Polg^mut/mut/Cdh5-CRE mice. Atherosclerosis was induced by a balloon injury accompanied by Western diet. Then, for 27 days, the drugs under study were administered once per 3 days at the dose of 20 μg/kg. On the 28^th day, the animals were euthanized and the area of atherosclerotic plaques was collected for an assessment. The expression of genes associated with the processes of inflammation, apoptosis, and angiogenesis was determined in the tissues of the aorta. In addition, the endothelial protective effect of peptides in isolated segments of the thoracic aorta of wild and transgenic ransgenic Polg^mut/mut mice was studied.Results. The assessment of the plaque size in the animals with the Polg^mut/mut/Cdh5-CRE genotype against the background of the peptides under study did not reveal statistically significant differences in comparison to control. However, a quantitative PCR showed a statistically significant decreased expression of pro-apoptotic factors p-53 and Bax, and also increase the expression of anti-apoptotic factor Bcl-2 against the background of the peptides EP-11-1 and EP-11-2 administration. The administration of EP-11-1 and the original peptide pHBSP resulted in a statistically significant decrease in the Bax/Bcl-2 ratio. Compounds EP-11-1, EP-11-2, and EP-11-3 were more effective than the original peptide pHBSP, in reducing the increased expression of genes for inflammatory markers iNos, intercellular adhesion molecules Icam-1, Vcam-1 and E-selectin. The use of EP-11-1 led to a more efficient, in comparison with pHBSP, restoration of endothelial-dependent vasodilation of the aortic segments in mice with endothelial-specific overexpression of the mutant Polg gene.Conclusion. The study carried out on a murine model of the endothelial-specific expression of mutant gamma polymerase has shown that derivatives of the pHBSP peptide with laboratory codes EP-11-1, EP-11-2, EP-11-3, obtained by BLAST-searching for groups of pHBSP related peptides, have atheroprotective and endothelial protective kinds of a protective activity, which is more pronounced in comparison with the original peptide pHBSP.