03. Науково-дослідний інститут експериментальної та клінічної медицини ХНМУ
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Item Human HMGB1 does not induce eryptosis in vitro(2022) Tkachenko, Maryna; Onishchenko, Anatolii; Butov, Dmytro; Butova, Tetyana; Tkachenko, AntonAim: To study the ability of human high mobility group box protein 1 (HMGB1) to induce eryptosis in vitro. Material and methods: Blood collected from six healthy volunteers was incubated with HMGB1 (0-0.2-1-5 ng per ml). Eryptosis of red blood cells was assessed by Annexin V staining and 2',7'-dichlorodihydrofluorescein diacetate (H2DCFDA) staining by flow cytometry. The forward scatter (FSC) fluorescence was used to evaluate the morphology of red blood cells. Results: Exposure of erythrocytes to HMGB1 did not affect the morphology of erythrocytes, evidenced by no changes in the percentage of cells with small volume, i.e. shrunken cells, and erythrocytes with large volume, i.e. enlarged cells. HMGB1 had no impact on phosphatidylserine externalization, which is confirmed by the absence of statistically significant changes in the amount of phosphatidylserine-displaying cells and the mean fluorescence intensity (MFI) values of Annexin V-FITC in cells exposed to different concentrations of HMGB1. Furthermore, H2DCFDA staining revealed that the HMGB1 did not induce oxidative stress. Conclusion: HMGB1 does not promote eryptosis of human erythrocytes at concentrations of up to 5 ng/ml.Item Semi-refined carrageenan induces eryptosis in a Ca2+-dependent manner(2022) Tkachenko, Anton; Prokopiuk, Volodymyr; Onishchenko, AnatoliiBackground: Semi-refined carrageenan (food additive E407a) is a widely used thickener, which has been reported to exert toxic and pro-inflammatory effects. In particular, there is accumulating evidence that it induces eryptosis, i.e. a programmed cell death of eryptocytes, via ROS-mediated pathways. However, the role of Ca2+-dependent mechanisms in E407a-induced eryptosis is not elucidated. Material and methods: Semi-refined carrageenan at concentrations of 0 mg/ml, 1 mg/ml, 5 mg/ml and 10 mg/ml was incubated with blood of intact female WAG rats (n=9) for 24 h in RPMI and fetal bovine serum. After 24 h, the samples were used to obtain erythrocyte suspensions. The obtained suspensions were stained with a Ca2+-sensitive FLUO4 AM probe (30 min, 2.5 µM). The fluorescence of FLUO4 in erythrocytes was detected by a BD FACSCanto II flow cytometer. Results: The intracellular Ca2+ levels are proportional to the fluorescence of FLUO4. The mean fluorescence intensities (MFI) were compared. Low levels (1 mg/ml) of E407a had no impact on Ca2+ concentrations in erythrocytes (p>0.05). On the contrary, high concentrations (5 mg/ml and 10 mg/ml) of this food additive promoted an increase in the intracellular Ca2+ levels. The MFI values were 2.3- and 2.5-fold higher, respectively (p<0.0001). In addition, the exposure to E407a at concentrations of 5 mg/ml and 10 mg/ml (p<0.0001) increased the percentage of cells with high FLUO4 fluorescence. Conclusion: Food additive E407a induces eryptosis in a Ca2+-dependent manner.Item Intake of semi-refined carrageenan causes low-grade colonic inflammation and alters expression of epithelial-mesenchymal transition markers(2022) Onishchenko, Anatolii; Gubina-Vakulyck, Galina; Knigavko, Oleksandr; Sharashydze, Ketino; Pionova, Olena; Butov, Dmytro; Polikarpova, Hanna; Tkachenko, AntonThe aim of this research was to evaluate the effects of semi-refined carrageenan consumed orally on the amount of CD3 and CD68 positive cells residing in the colon and the expression of endothelial-mesenchymal transition (EMT) markers. Materials and methods. To assess colonic expression of CD3+, CD68+, fascin, vimentin and E-cadherin, sections obtained from 8 rats orally exposed to semi-refined carrageenan (E407a) at a dose of 140 mg / kg of weight during 14 consecutive days and 8 control animals were immunostained with the corresponding antibodies. Levels of expression were assessed quantitatively. Results. Oral exposure to semi-refined carrageenan resulted in an increase in CD3 and CD68 positive cells in the colonic lamina propria. Quantitative analysis of fascin, vimentin and E-cadherin immunostaining revealed changes in expression of these EMT markers both in the colonic stroma and epithelial cells. Vimentin and fascin were overexpressed in stromal and epithelial cells, while E-cadherin was upregulated in the stroma and downregulated in epithelia. Conclusions. Our observations suggest that oral intake of semi-refined carrageenan results in the development of low-grade colonic inflammation accompanied by infiltration with CD3 and CD68 positive cells and changes in the expression of EMT markers.Item Cytotoxicity of Hybrid Noble Metal-Polymer Composites(2022-10-11) Tkachenko, Anton; Virych, Pavlo; Myasoedov, Valeriy; Prokopiuk, Volodymyr; Onishchenko, Anatolii; Butov, Dmytro; Kuziv, Yuliia; Yeshchenko, Oleg; Zhong, Sican; Nie, Guochao; Kutsevol, NataliyaThe aim of the present research was to assess the cytotoxicity of gold and silver nanoparticles synthesized into dextran-graft-polyacrylamide (D-PAA) polymer nanocarrier, which were used as a basis for further preparation of multicomponent nanocomposites revealed high efficacy for antitumor therapy. The evaluation of the influence of Me-polymer systems on the viability and metabolic activity of fibroblasts and eryptosis elucidating the mechanisms of the proeryptotic effects has been done in the current research. The nanocomposites investigated in this study did not reduce the survival of fibroblasts even at the highest used concentration. Our findings suggest that hybrid Ag/D-PAA composite activated eryptosis via ROS- and Ca2+-mediated pathways at the low concentration, in contrast to other studied materials. Thus, the cytotoxicity of Ag/D-PAA composite against erythrocytes was more pronounced compared with D-PAA and hybrid Au/polymer composite. Eryptosis is a more sensitive tool for assessing the biocompatibility of nanomaterials compared with fibroblast viability assays.Item The study of phospholipid bilayer of cell membranes in leukocytes incubated with high concentrations of the food additive E407a(2021) Tkachenko, Anton; Onishchenko, Anatolii; Roshal, Alexander; Posokhov, YevgenAim: The aim of the study was to assess the impact of semi-refined carrageenan (E407a) on the hydrophobic region of phospholipid bilayer in cell membranes of leukocytes exposed to the solution with high concentrations of this food additive. Material and methods: Fluorescent probe (2-phenylphenanthro[ 9,10-d]-1,3-oxazole) was used to investigate the influence of E407a on the state of lipid bilayer in leukocytes extracted from rats and treated with a 5% solution of the food additive E407a during 4 hours. Results: The shapes of the probe fluorescence spectra did not differ in leukocytes of rats treated with the 5% solution of semi-refined carrageenan and white blood cells of control samples. Such findings suggest that exposure to the E407a solution causes no changes in the proton-donor ability of the media in the lipid membranes of leukocytes in the region where the probe locates. Conclusion: Exposure of white blood cell suspensions to the semirefined carrageenan solution does not affect the membrane hydration of the hydrophobic region of leukocyte phospholipid bilayer.Item Changes in cell membranes of white blood cells treated with a common food additive E407a(2021) Tkachenko, Anton; Onishchenko, Anatolii; Posokhov, Yevgen; Roshal, Alexander; Myasoedov, Valeriy; Nakonechna, OksanaObjectives: To estimate the state of phospholipid bilayer of rats WBCs exposed to a common food additive E407a, which is used as a thickener and emulsifier, during 4 h using a fluorescent probe − ortho-hydroxy derivative of 2,5-diaryl-1,3-oxazole. Materials and methods: Steady-state fluorescence spectroscopy: a study by the environment-sensitive fluorescent probe − 2-(2′-hydroxy-phenyl)-5-phenyl-1,3-oxazole (probe O1O). Results: Changes are detected in the spectra of the fluorescent probe bound to rat WBCs treated with the solutions of E407a of various concentrations in comparison with the corresponding spectra of the probe incubated with the untreated leukocytes. The decrease in polarity and protondonor ability is observed in the lipid membranes of leukocytes in the region, where the probe locates. Conclusions: Our findings suggest a higher dehydration of leukocyte membranes of rats treated with a common food additive E407a at high concentrations and, thus, indicate that exposure to high doses of E407a leads to the increase in the lipid order (i.e. to decrease in fluidity) of the membranes of rat WBCs.Item Effects of semi-refined carrageenan (food additive E407a) oncell membranes of leukocytes assessed in vivo and in vitro(2021) Tkachenko, Anton; Onishchenko, Anatolii; Roshal, Alexander; Nakonechna, Oksana; Chumachenko, Tetyana; Posokhov, YevgenAim: To assess the impact of semi-refined carrageenan (E407a) on hydrophobic regions of phosphololipid bilayer in cell membranes of leukocytes collected from rats orally administered this food additive and white blood cells incubated with E407a. Methods: Fluorescent probes (ortho-hydroxy derivatives of 2,5-diaryl-1,3-oxazole) were used to estimate the state of lipid bilayer in leukocytes obtained from rats orally exposed to the food additive E407a and in white blood cells incubated with E407a. Results: No noticeable changes in the physico-chemical properties were observed in the lipid membranes of leukocytes in the region where the probes locate in response to oral intake of semi-refined carrageenan. Incubation of leukocytes with E407a solutions resulted in a decrease in polarity and proton-donor ability of leukocytes in the area of carbonyl groups of phospholipids and in the area of hydrocarbon chains of phospholipids near the polar region of the bilayer. Conclusion: Membrane fluidity abnormalities found in cells exposed to E407a are similar to those observed in patients with IBD suggesting that contribution of carrageenan to IBD development may be partially explained by leukocyte membrane modifications.Item Experimental Evaluation of Food-Grade Semi-Refined Carrageenan Toxicity(2021-10-16) Pogozhykh, Denys; Posokhov, Yevgen; Myasoedov, Valeriy; Gubina-Vakulyck, Galina; Chumachenko, Tetyana; Knigavko, Oleksandr; Polikarpova, Hanna; Kalashnyk-Vakulenko, Yuliia; Sharashydze, Ketino; Nakonechna, Oksana; Prokopyuk, Volodymyr; Onishchenko, Anatolii; Tkachenko, AntonAbstract: The safety of food additives E407 and E407a has raised concerns in the scientific community. Thus, this study aims to assess the local and systemic toxic effects of the common food additive E407a in rats orally exposed to it for two weeks. Complex evaluations of the effects of semi-refined carrageenan (E407a) on rats upon oral exposure were performed. Local effects of E407a on the intestine were analyzed using routine histological stains and CD68 immunostaining. Furthermore, circulating levels of inflammatory markers were assessed. A fluorescent probe O1O (2- (20-OH-phenyl)-5-phenyl- 1,3-oxazole) was used for evaluating the state of leukocyte cell membranes. Cell death modes of leukocytes were analyzed by flow cytometry using Annexin V and 7-aminoactinomycin D staining. Oral administration of the common food additive E407a was found to be associated with altered small and large intestinal morphology, infiltration of the lamina propria in the small intestine with macrophages (CD68+ cells), high systemic levels of inflammation markers, and changes in the lipid order of the phospholipid bilayer in the cell membranes of leukocytes, alongside the activation of their apoptosis. Our findings suggest that oral exposure to E407a through rats results in the development of intestinal inflammation.Item Effects of E407a on the viability, metabolic and functional activity of dermal fibroblasts(2021) Tkachenko, Anton; Prokopiuk, Volodymyr; Onishchenko, Anatolii; Shevchenko, MariaAim: To evaluate the effects of semi-refined carrageenan (E407a) on the viability, metabolic and functional activity of skin fibroblasts in vitro. Material and methods: Various concentrations of E407a (0 – 10 mg/ml) were incubated for 24 h with skin fibroblast cultures isolated from rat embryos. The viability of cells exposed to semi-refined carrageenan was assessed by the neutral red uptake assay. MTT test was selected to estimate the metabolic activity of cells. In addition, scratch assay was used to determine the functional activity of dermal fibroblasts. Results: Direct exposure to semi-refined carrageenan did not affect the viability of rat dermal fibroblasts, evidenced by the results of MTT and neutral red uptake assays. However, experimental data of MTT and scratch assays revealed that high concentrations of this food additive increased the metabolic activity of fibroblasts and diminished the motility of these cells, suggesting that E407a is cytotoxic at high concentrations. Conclusion: Food-grade semi-refined carrageenan is cytotoxic towards skin fibroblasts at high concentrations.Item The science in modern society: opportunities for medical postgraduate students(2021) Prokopiuk, Volodymyr; Onishchenko, Anatolii; Tkachenko, Anton