Some pleiotropic effects of statins on hepatocellular carcinoma cells: Comparative study on atorvastatin, rosuvastatin and simvastatin.

PURPOSE: For many years, statins have been the most commonly used drugs in cholesterol-lowering therapy. In addition to these therapeutic effects, statins exhibit other, pleiotropic effects that can be beneficial, but also harmful to cells and tissues. The aim of this research was to determine and compare the pleiotropic effects of structurally different statins: atorvastatin, simvastatin and rosuvastatin at different concentrations on hepatocellular carcinoma (HepG2) cells. MATERIALS AND METHODS: The MTT assay was used to determine the cytotoxic effects of statins. The influence of statins on the production of reactive oxygen species (ROS) was determined by measuring fluorescent response of 2,7-dichlorofluorescein diacetate (DCFH-DA). The effect of statins on glucose production and excretion was determined with glucose production assay. RESULTS: The obtained results confirmed that all tested statins exhibit cytotoxic effects, increase the production of ROS as well as the production and excretion of glucose from HepG2 cells. It was observed that all the mentioned effects are more pronounced with lipophilic statins, atorvastatin and simvastatin compared to hydrophilic rosuvastatin. CONCLUSION: The less pronounced pleiotropic effects of rosuvastatin on HepG2 cells are probably due to differences in structure and solubility compared to atorvastatin and simvastatin. Transporter-dependent and a slower influx of rosuvastatin into cells compared to the tested lipophilic statins probably lead to a weaker accumulation of rosuvastatin in HepG2 cells, which results in less pronounced pleiotropic effects compared to lipophilic atorvastatin and simvastatin.

Knowledge and Attitudes regarding Covid-19 Vaccination among Medical and Non-medical Students in Bosnia and Herzegovina.

OBJECTIVE: The aim of this study was to investigate students' knowledge, attitudes and hesitancy regarding COVID-19 vaccination. METHODS: A cross-sectional questionnaire-based survey was conducted among a total of 1282 medical students and 509 non-medical students at four public universities in Bosnia and Herzegovina: Tuzla, Sarajevo, Banja Luka, and Mostar. RESULTS: A significantly higher rate of vaccination was observed in the group of medical students as well as a higher level of knowledge about vaccination in general and vaccines against the COVID-19 disease. Students who received the COVID-19 vaccine had a higher level of knowledge about vaccination in general and COVID-19 vaccines in particular compared to the non-vaccinated students in the medical and non-medical groups, respectively. Furthermore, vaccinated students, regardless of the course they are taking, showed generally stronger positive attitudes compared to non-vaccinated students, regarding the safety and effectiveness of the COVID-19 vaccine. Both groups of students believe that the rapid development of the vaccine is contributing to refusal or hesitancy to receive a vaccine against COVID-19. Social media/networks were the main sources of information about the COVID-19 vaccine. We did not find any contribution of social media to the reduced level of COVID-19 vaccine coverage. CONCLUSION: Education of students about the benefits of the COVID-19 vaccine will lead to its better acceptance as well as the development of more positive attitudes towards vaccination in general, especially having in mind that students are the future population of parents, who will make decisions about vaccinating their children.

Assessment of Pb, Cd and Hg soil contamination and its potential to cause cytotoxic and genotoxic effects in human cell lines (CaCo-2 and HaCaT).

Soil contamination by heavy metals is a serious global environmental problem, especially for developing countries. A large number of industrial plants, which continually pollute the environment, characterize Tuzla Canton, Bosnia and Herzegovina. The aim of this study was to assess the level of soil pollution by heavy metals and to estimate cytotoxicity and genotoxicity of soil leachates from this area. Lead (Pb), cadmium (Cd) and mercury (Hg) were analyzed by ICP-AES and AAS. Soil contamination was assessed using contamination factor, degree of contamination, geoaccumulation index and pollution load index. To determine the connection of variables and understanding their origin in soils, principal component analysis (PCA) and cluster analysis (CA) were used. The results indicate that Cd and Hg originated from natural and anthropogenic activities, while Pb is of anthropogenic origin. For toxicity evaluation, CaCo-2 and HaCaT cells were used. PrestoBlue assay was used for cytotoxicity testing, and γH2A.X for genotoxicity evaluation. Concerning cytotoxicity, Cd and Hg had a positive correlation with cytotoxicity in HaCaT cells, but only Hg induced cytotoxicity in CaCo-2 cells. We also demonstrate that soil leachates contaminated by heavy metals can induce genotoxicity in both used cell lines. According to these results, combining bioassays with standard physicochemical analysis can be useful for evaluating environmental and health risks more accurately. These results are important for developing proper management strategies to decrease pollution. This is one of the first studies from this area and an important indication of soil quality in Southeast Europe.

The cross-road between the mechanisms of protein folding and aggregation; study of human stefin B and its H75W mutant.

The role of the aromatic residue at site 75 to protein stability, the mechanism of folding and the mechanism of amyloid-fibril formation were investigated for the human stefin B variant (bearing Y at site 31) and its point mutation H75W. With an aim to reveal the conformation at the cross-road between folding and aggregation, first, the kinetics of folding and oligomer formation by human stefin B(Y31) variant were studied. It was found to fold in three kinetic phases at pH 4.8 and 10% TFE; the pH and solvent conditions that transform the protein into amyloid fibrils at longer times. The same pH leads to the formation of native-like intermediate (known from previous studies of this variant), meaning that the process of folding and amyloid-fibril formation share the same structural intermediate, which is in this case native-like and dimeric. At pH 5.8 and 7.0 stefin B folded to the native state in four kinetic phases over two intermediates. In distinction, the mutant H75W did not fold to completion, ending in intermediate states at all pH values studied: 4.8, 5.8 and 7.0. At pH 4.8 and 5.8, the mutant folded in one kinetic phase to the intermediate of the "molten globule" type, which leads to the conclusion that its mechanism of folding differs from the one of the parent stefin B at the same pH. At pH 7.0 the mutant H75W folded in three kinetic phases to a native-like intermediate, analogous to folding of stefin B at pH 4.8.

Essential role of Pro 74 in stefin B amyloid-fibril formation: dual action of cyclophilin A on the process.

We report that Pro74 in human stefin B is critical for fibril formation and that proline isomerization plays an important role. The stefin B P74S mutant did not fibrillate over the time of observation at 25 degrees C, and it exhibited a prolonged lag phase at 30 degrees C and 37 degrees C. The peptidyl prolyl cis/trans isomerase cyclophilin A, when added to the wild-type protein, exerted two effects: it prolonged the lag phase and increased the yield and length of the fibrils. Addition of the inactive cyclophilin A R55A variant still resulted in a prolonged lag phase but did not mediate the increase of the final fibril yield. These results demonstrate that peptidyl prolyl cis/trans isomerism is rate-limiting in stefin B fibril formation.