The antimicrobial peptide gramicidin S alters proliferation and inhibits adhesion of L929 cell line fibroblasts

Background: Natural antimicrobial peptides are used in the fight against pathogens resistant to existing synthetic antibiotics. The non-specific mechanism of cytostatic action of antimicrobial peptides, in particular gramicidin S, against bacteria is also effective for damaging the cells of neoplasms. The existence of such a property in a registered antibiotic will indicate its antineoplastic potential and can be used to expand the spectrum of its therapeutic application. Aim of work is to clarify the possible antitumor effect of the antimicrobial peptide gramicidin S. Materials and Methods: Using the methods of confocal laser microscopy and light microscopy, the morphological and functional features of connective tissue cells under the influence of gramicidin S in the concentration range 0.5–50 μg/ml were studied using L929 fibroblasts cell culture. The cell area, nucleus area, and nucleus-to-cytoplasm ratio were determined. To study the migratory and proliferative activity of cells in vitro, the “scratch assay” was used, the confluency of the monolayer of cells was evaluated, morphometric studies were performed, and the relative area of the scratch was measured after 24, 48, and 72 hours. Results: The lytic effect of gramicidin S in a concentration of 50 μg/ml on L929 cells was established, in concentrations of 0.5 μg/ml and 5.0 μg/ml, the antibiotic increases the synthetic activity of cells and stimulates the proliferation of fibroblasts in a monolayer. Cell anisomorphism is more pronounced in the presence of 5.0 μg/ml gramicidin S added to the culturing medium during monolayer formation, while a one-third of the cells in the sample form a population that is morphologically different from other cells in the culture. The addition of gramicidin S at non-lytic concentrations of 0.5 and 5.0 μg/ml to unattached fibroblasts reliably inhibits monolayer formation. Under the influence of 5.0 μg/ml gramicidin S, the rate of monolayer formation is low, even despite the significant content of cells with a high nuclear-cytoplasmic ratio. The kinetics of filling the cell monolayer defect using the “scratch assay” shows that GS in concentrations of 0.5 and 5.0 μg/ml can control the migratory and proliferative properties of L929 cells. Conclusions: The effect of gramicidin S on the morphometric parameters of cells depends on the concentration of the peptide and the cell status in the culture. GS corrupts the adhesive properties of L929 fibroblasts in monolayer cell culture and the rate of cell monolayer formation. Cells at the stage of attachment and monolayer formation were most sensitive to non-lytic concentrations of GS. Inhibition of the adhesive properties of connective tissue cells by gramicidin S is a new non-canonical effect of a known antimicrobial drug, which may indicate the possibility of using gramicidin S as an anti-neoplasm agent

ВОЗМОЖНАЯ РОЛЬ ПРОТЕАСОМ ПЕЧЕНИ В РЕАЛИЗАЦИИ МЕХАНИЗМОВ ТРАНСПЛАНТАЦИОННОЙ ТОЛЕРАНТНОСТИ

In contrast to the majority of organs in liver non-specific immunity predominates over adaptive one, and in response to the antigen presentation develops preferably not immune reaction but immunological tolerance. Tolerance is considered to provide some processes, such as apoptosis of reactive T-cells, immune deviation and active suppression of immune reactions. At the same time there are the grounds for believing that an important role in regulation of liver immune response is played by proteasomes, intracellular multiprotease protein complexes. This is confirmed by the fact of application of proteasome inhibitor bortezomib as immune suppressor in transplantology. Immune 26S- and 20S-proteoasomes participate in the formation of antigen oligopeptides and play a key role in T-cell immune response. It has been shown that the pool of proteasomes is subjected to significant changes during ontogenesis of immune competent organs. The changes in the pool of proteasosmes occur likely during the development of specific tolerance in transplantation too. The knowledge of the peculiarities of proteasome functioning and regularities of alterations of their shapes will enable the revealing of the mechanisms responsible for either graft rejection or acceptance. В отличие от большинства органов в печени неспецифический иммунитет преобладает над адаптивным, а в ответ на презентацию антигена предпочтительнее развивается не защитная иммунная реакция, а им- мунологическая толерантность. Считается, что толерантность обеспечивают ряд процессов, таких, как апоптоз реактивных Т-клеток, уклонение их от иммунного ответа и активная супрессия иммунных ре- акций. В то же время есть основания полагать, что важную роль в регуляции иммунного ответа печени играют протеасомы, внутриклеточные мультипротеазные белковые комплексы. Об этом свидетельствует факт применения протеасомного ингибитора бортезомиба в трансплантологии в качестве иммуносупрес- санта. Иммунные 26S- и 20S-протеасомы участвуют в образовании антигенных олигопептидов и выпол- няют ключевую роль в Т-клеточном иммунном ответе. Было показано, что пул протеасом подвергается существенным изменениям в процессе онтогенеза иммуно-компетентных органов. Знание особенностей функционирования протеасом и закономерностей изменения соотношения их форм позволит выявить механизмы, отвечающие за направленность вектора иммунного ответа на отторжение или принятие трансплантата.

WAYS TO OVERCOME THE PROBLEMS OF INTANGIBLE ASSETS ACCOUNTING OF THE UKRAINIAN ENTERPRISES

Introduction. In modern conditions, one of the priority instruments of profit formation is the use of assets that do not have a material form. Using intangible assets (IA) is performed the capitalization of enterprises, i.e. the conversion of their capacity in the market outcome. Improvement of intangible assets accounting will enhance the competitiveness of Ukrainian enterprises. Purpose of the article is identification and justification of improvement areas of intangible assets accounting by means of the study and use of the foreign countries experience, taking into account the specific conditions of Ukrainian enterprises activity. Results. The paper analyzes the characteristics of intangible assets (IA) accounting of enterprises in accordance with the national and international accounting standards. The most important aspects of intangible assets accounting in the publications of domestic and foreign scientists are investigated. Designated the unresolved issues related to the development of clear algorithm of crediting, acknowledgement, assessment and accounting of intangible assets. Conclusions. As a result of the study it was found out that the existing problems of intangible assets accounting are related to the complexity of the identification, evaluation and classification of intangible assets. These problems can be eliminated by harmonization of Ukrainian Accounting Standards 8 and the International Financial Reporting Standard 38, the development of a single criterion for inclusion of assets to the intangible ones and determination of the optimal approach to intangible assets evaluation

POSSIBLE ROLE OF LIVER PROTEASOMES IN THE REALIZATION OF MECHANISMS OF TRANSPLANTATION TOLERANCE

In contrast to the majority of organs in liver non-specific immunity predominates over adaptive one, and in response to the antigen presentation develops preferably not immune reaction but immunological tolerance. Tolerance is considered to provide some processes, such as apoptosis of reactive T-cells, immune deviation and active suppression of immune reactions. At the same time there are the grounds for believing that an important role in regulation of liver immune response is played by proteasomes, intracellular multiprotease protein complexes. This is confirmed by the fact of application of proteasome inhibitor bortezomib as immune suppressor in transplantology. Immune 26S- and 20S-proteoasomes participate in the formation of antigen oligopeptides and play a key role in T-cell immune response. It has been shown that the pool of proteasomes is subjected to significant changes during ontogenesis of immune competent organs. The changes in the pool of proteasosmes occur likely during the development of specific tolerance in transplantation too. The knowledge of the peculiarities of proteasome functioning and regularities of alterations of their shapes will enable the revealing of the mechanisms responsible for either graft rejection or acceptance

Histopathological features of papillary thyroid carcinomas detected during four screening examinations of a Ukrainian-American cohort

BACKGROUND: There are limited data on the histopathology of papillary thyroid carcinomas (PTCs) diagnosed in irradiated populations. We evaluated the associations between iodine-131 dose and the histopathological characteristics of post-Chernobyl PTCs, the changes in these characteristics over time, and their associations with selected somatic mutations. METHODS: This study included 115 PTCs diagnosed in a Ukrainian-American cohort (n=13 243) during prescreening and four successive thyroid screenings. Of these PTCs, 65 were subjected to somatic mutation profiling. All individuals were <18 years at the time of the Chernobyl accident and had direct thyroid radioactivity measurements. Statistical analyses included multivariate linear and logistic regression. RESULTS: We identified a borderline significant linear-quadratic association (P=0.063) between iodine-131 dose and overall tumour invasiveness (presence of extrathyroidal extension, lymphatic/vascular invasion, and regional or distant metastases). Irrespective of dose, tumours with chromosomal rearrangements were more likely to have lymphatic/vascular invasion than tumours without chromosomal rearrangements (P=0.020) or tumours with BRAF or RAS point mutations (P=0.008). Controlling for age, there were significant time trends in decreasing tumour size (P<0.001), the extent of lymphatic/vascular invasion (P=0.005), and overall invasiveness (P=0.026). CONCLUSIONS: We determined that the invasive properties of PTCs that develop in iodine-131-exposed children may be associated with radiation dose. In addition, based on a subset of cases, tumours with chromosomal rearrangements appear to have a more invasive phenotype. The increase in small, less invasive PTCs over time is a consequence of repeated screening examinations