Том 13, № 5 (2019)

This paper describes the stages of osteogenic differentiation of chondrogenic graft in a culture medium and recipient bed (defect of bone tissue). In the culture medium, cell and matrix transformations, formation of vascular cavities with an endothelial lining and matrix vesicles in osteoblasts (the first stage of mineralization) take place in the chondrograft. The expression of chondrogenic genes and proteins is replaced by the expression of genes and proteins of the osteogenic stage of differentiation. Further stages of bone tissue histogenesis occur in the recipient bed. Humoral factors of regulation and ductile substance enter through the formed anastomosis of the vessels of osteodysplastica and recipient. On their basis, the formation of an organ-specific regenerate is completed with full integration into the recipient organism. These results are a starting point for further use of osteogenic grafts in clinical practice.

The role of autophagy in the development and progression of hepatocellular carcinoma (HCC) is ambiguous and still little known. Autophagy stimulation may be of exceptional interest in antitumor pharmacotherapy of HCC. Rapamycin and lithium are typical inducers of autophagy. The aim of this study was to compare the level of autophagy in hepatocellular carcinoma-29 (HCC-29) cells after single and combined administration of lithium carbonate and rapamycin. Autolysosomes formation and significant increase of LC3 beta (+)– and LAMP1 (+)– autophagic structures were revealed in HCC-29 cells after lithium carbonate and rapamycin coadministration by transmission electron microscopy and immunofluorescence analysis. Using this combination of drugs may be a promising strategy for HCC chemotherapy, since it will allow the integration of various cellular signaling pathways that regulate autophagy and apoptosis in tumor cells.

Neutrophils can form extracellular traps that consist of chromatin and granule proteins and can, acting as a net, trap bacteria. The trap formation process called NETosis that has been thoroughly characterized in cells exposed to phorbol ester (PMA) takes 2–3 h and depends on reactive oxygen species produced by NADPH oxidase (this is called classical NETosis). The aim of the present work was to study the distinctive features of the NETosis process evoked by stearylamine (SA) dissolved in DMSO or incorporated into phosphatidylcholine (PC) liposomes and to compare it to NETosis evoked by PMA. Human neutrophils were incubated with 0.2 mg/mL SA (at a 2% DMSO content in the medium) or with cationic PC liposomes that contained SA (PC–SA liposomes; PC and SA concentrations 1.8 and 0.2 mg/mL, respectively). Confocal fluorescence microscopy of fixed neutrophil preparations showed that SA (dissolved in DMSO or incorporated into liposomes) caused the formation of neutrophil extracellular traps. NETosis kinetics were analyzed in the real-time mode in live cells exposed to fluorescently labeled PC–SA liposomes. PC–SA liposomes added to the neutrophils were shown to adsorb to isolated patches of the plasma membrane at first and to occupy the entire membrane surface as the incubation time was prolonged. This was accompanied by chromatin decondensation and fusion of the nuclear material and the cytoplasm, that is, the stages observed for phorbol ester-induced NETosis. However, SA-evoked NETosis was much faster (30–90 min) than PMA-evoked NETosis. It is necessary to emphasize that SA did not induce an oxidative burst (in contrast to PMA), as revealed by analysis of luminol-dependent chemiluminescence. Trap formation by neutrophils exposed to PC–SA liposomes was not affected by apocynin and DPI (NADPH oxidase inhibitors) or catalase, and this also shows that SA stimulates ROS-independent formation of neutrophil extracellular traps.

This paper discusses the mechanical properties of chitosan-based film matrices, as well as optimization of these properties by adding chitin nanofibrils. It has been shown that the filler addition stabilizes the mechanical properties of the composite material. By changing the concentration of chitin nanofibrils, it is possible to obtain matrices with different bioactive properties for cultured human dermal fibroblasts. The optimal balance of mechanical properties and bioactivity in relation to the culture of human dermal fibroblasts is possessed by film matrices based on chitosan nanocomposite with the addition of 5% chitin nanofibrils. Film matrices based on chitosan nanocomposite with the addition of 5% chitin nanofibrils provide the optimal balance of mechanical properties and bioactivity for cultured human dermal fibroblasts.

The fatty acid composition of polar lipids, which are the structural and functional bases of cell membranes in the bud of Betula pendula Roth birch, growing under the conditions of the cryolithozone, was studied for the first time. The important role played by lipid metabolism in the winter–spring period, when the apical meristem is at the stage of intrarenal development, was established. It was shown that, during this period, unsaturated fatty acids prevail over saturated in phospholipids and glycolipids in silver birch buds. However, under the conditions of extremely low air temperatures (–40°C and below), the lowest values of double bond index (DBI) and fatty acid unsaturation coefficient (U/S) were recorded. The rise of negative temperatures under the conditions of the cryolithozone (in March) to values usually observed during the winter period throughout the range of silver birch (–20°C and higher) contributed to an increase in the level of membrane lipid unsaturation. It was found that diene fatty acids predominate in phospholipids, and diene and triene acids predominate in glycolipids, the latter reaching maximum values (80.7% of the amount of unsaturated fatty acids) by the beginning of budding. It was hypothesized that, in order to preserve the viability of the apical meristem in buds of silver birch trees under the specific conditions of the cryolithozone, various interrelated adaptive mechanisms were formed. These mechanisms are aimed not only at protecting the rudimentary organs from the effects of sharp fluctuations in daily temperatures during spring, but also at protecting them during winter under conditions of extremely low temperatures (down to –60°С), which do not occur in other parts of its range. One of these mechanisms appeared to be nonspecific, and it was associated with an increase in the unsaturation of the fatty acid composition corresponding to the liquid-crystalline state of membrane lipids. Another adaptive mechanism is probably aimed at protecting cells from dehydration with the involvement of dehydrin proteins, as well as a number of other hydrophilic cryoprotective compounds against the background of increased viscosity of membrane lipids.