Liver regeneration is associated with lipid reorganization in membranes of the endoplasmic reticulum

BACKGROUND:In recent years, an adaptive endoplasmic reticulum (ER) stress response has been actively investigated. The ER membrane, isolated from the intact and regenerating liver, may be an appropriate model for investigating the association between structural and functional characteristics of ER in vivo and their corresponding behavioral characteristics in vitro. The rate of lipid synthesis and that of intracellular lipid exchange between the ER and cytosol were investigated in the intact and regenerating liver (13 h after partial hepatectomy). Particularly, membrane characteristics, surface potential, and glucose 6-phosphatase (G6Pase) activity were investigated, along with the degradation rate of G6Pase in vitro, which was estimated by the loss of G6Pase activity, formation of lipid peroxides, and size of excreted membrane vesicles. METHODS:The rate of lipid synthesis was determined by measuring the intensity of radioactive precursor (C14 - sodium acetate) in different fractions of lipids (phospholipids, non-esterified fatty acids, and triacylglycerides) after 30 min exposure. The rate of lipid metabolism was assessed by measuring the quantity of lipids with radioactive labels emerging in the cytosol of hepatocytes (CPM). Viscosity and surface potential were determined by fluorescent probes. RESULTS:It was observed that after 13 h of partial hepatectomy, the rate of lipid synthesis in the ER of hepatocytes in the regenerating liver was 3 times lower than that in ER of hepatocytes in the intact liver, wherein the rate of incorporation of newly synthesized lipids in cytosol was several times higher in the regenerating liver. Increase in the rate of exchange of neutral lipids in cells of the regenerating liver was accompanied by lipid reconstruction in the ER, changing the structural and functional characteristics of the membrane. Such membrane rebuilding also contributed to the rate of degradation of the ER in vitro,which that must be taken into account during development of systems for in vitro assessment of xenobiotic metabolism. CONCLUSIONS:An increase in the rate of direct (microsomes---cytosol) and reverse transport of lipids (cytosol --- microsomes) was observed in the regenerating liver. Microsomes, isolated from the regenerating liver, were degraded in the in vitro system at a higher rate

Dose-Dependent Effects of Nanoscale Forms of Humic Acids in a Hydroponic Culture of Triticum aestivum: Induction of Oxidative Stress and an Increase in the Number of Border Cells

В гидропонной культуре Triticum aestivum L. изучали биологическую активность гуминовых кислот в форме наночастиц размером 6,5 нм и 68 нм. Гуминовые наночастицы (мелкие и крупные) в изученных концентрациях не ингибировали рост корня и не вызывали деструктивных изменений корневого апекса 2-дневных проростков. На средах с гуминовыми наночастицами в корнях проростков наблюдалось дозозависимое увеличение содержания карбонилированных белков, малонового альдегида и пролина – маркеров индуцированного окислительного стресса. Для мелких наночастиц основным продуктом свободнорадикального окисления был малоновый диальдегид, для крупных – карбонилированные белки. Индуцированный гуминовыми наночастицами окислительный стресс сопровождался дозозависимым увеличением численности свободных пограничных клеток и размеров гелевого чехла в корневом апексе 2-дневных проростков. Для мелких наночастиц (6,5 нм) эти изменения были выражены в значительно большей степени, чем для крупных наночастиц (68 нм). Полученные результаты позволяют рассматривать гуминовые наночастицы в качестве адаптогенов: способствуя увеличению численности популяции пограничных клеток и системы гелевого чехла (как продукта экскреторной активности пограничных клеток), наночастицы увеличивают устойчивость корневого апекса к воздействию неблагоприятных биотических и абиотических факторовThe biological activity of humic acids in the form of nanoparticles with a size of 6.5 nm and 68 nm was studied in a hydroponic culture of Triticum aestivum L. Both smaller and larger humic nanoparticles at the studied concentrations neither inhibited root growth nor caused destructive changes in the root apexes of 2-day-old seedlings. A dose-dependent increase in the contents of markers of induced oxidative stress such as carbonylated proteins, malonaldehyde, and proline was observed in the roots of seedlings on media with humic nanoparticles. Malondialdehyde was the main product of free radical oxidation for smaller nanoparticles and carbonylated proteins – for larger ones. Oxidative stress induced by humic nanoparticles was accompanied by a dose-dependent increase in the number of free border cells and the size of the mucilaginous sheaths on the root apexes of 2-day-old seedlings. For smaller (6.5 nm) nanoparticles, these changes were much more pronounced than for larger (68 nm) nanoparticles. The results obtained allow us to consider humic nanoparticles as adaptogens: contributing to an increase in the population of border cells and the mucilaginous sheath system (as a product of the excretory activity of border cells), nanoparticles enhance the resistance of the root apex to the effects of unfavorable biotic and abiotic factor

Hydroponic Culture of Triticum aestivum as a Model System to Evaluate the Biological Effects of Fusariosis and Fungicides

Исследование потенциала гидропонной культуры Triticum aestivum в качестве модельной системы для изучения биологического действия фунгицидных препаратов включало определение содержания продуктов перекисного окисления липидов (малонового диальдегида) и белков (карбонилированных белков), свободного пролина в корнях, количествa пограничных клеток в корневом апексе 2-дневных проростков, инфицированных Fusarium graminearum. Показано, что в корнях инфицированных проростков содержание пролина, карбонилированных белков и пограничных клеток было в 1.4, 8.0 и 3 раза выше, чем в корнях неинфицированных проростков. Триазольный фунгицид тебуконазол в исследованных концентрациях (0.01; 0.10 и 1.00 мкг/мл среды) в корневом апексе инфицированных проростков вызывал дозозависимое уменьшение численности пограничных клеток. Результаты позволяют положительно оценить гидропонную культуру Triticum aestivum как модельную систему для изучения биологических эффектов фунгицидов (в частности, их фитотоксичности) и фузариозаThe research of the potential of hydroponic culture Triticum aestivum as a model system for the study of the biological effect of fungicides included determination of the content of peroxidation products of lipids (malondialdehyde) and proteins (carbonylated proteins), free proline in roots, and border cells in the root apex of 2-day-old seedlings infected with Fusarium graminearum. In the infected seedlings roots content of proline, carbonylated proteins and border cells was 1.4; 8.0 and 3.0 times, respectively, higher than in roots of non-infected seedlings. Triazole fungicide tebuconazole in the studied concentrations (0.01, 0.10 and 1.00 μg/ml medium) caused a dose-dependent decrease in the number of border cells in the root apex of infected seedlings. The results allow to positively evaluate hydroponic culture Triticum aestivum as a model system for studying of the biological effects of the fungicides (in particular, their phytotoxicity) and fusariosi

Hydroponic Culture of Triticum aestivum as a Model System to Evaluate the Biological Effects of Fusariosis and Fungicides

Исследование потенциала гидропонной культуры Triticum aestivum в качестве модельной системы для изучения биологического действия фунгицидных препаратов включало определение содержания продуктов перекисного окисления липидов (малонового диальдегида) и белков (карбонилированных белков), свободного пролина в корнях, количествa пограничных клеток в корневом апексе 2-дневных проростков, инфицированных Fusarium graminearum. Показано, что в корнях инфицированных проростков содержание пролина, карбонилированных белков и пограничных клеток было в 1.4, 8.0 и 3 раза выше, чем в корнях неинфицированных проростков. Триазольный фунгицид тебуконазол в исследованных концентрациях (0.01; 0.10 и 1.00 мкг/мл среды) в корневом апексе инфицированных проростков вызывал дозозависимое уменьшение численности пограничных клеток. Результаты позволяют положительно оценить гидропонную культуру Triticum aestivum как модельную систему для изучения биологических эффектов фунгицидов (в частности, их фитотоксичности) и фузариозаThe research of the potential of hydroponic culture Triticum aestivum as a model system for the study of the biological effect of fungicides included determination of the content of peroxidation products of lipids (malondialdehyde) and proteins (carbonylated proteins), free proline in roots, and border cells in the root apex of 2-day-old seedlings infected with Fusarium graminearum. In the infected seedlings roots content of proline, carbonylated proteins and border cells was 1.4; 8.0 and 3.0 times, respectively, higher than in roots of non-infected seedlings. Triazole fungicide tebuconazole in the studied concentrations (0.01, 0.10 and 1.00 μg/ml medium) caused a dose-dependent decrease in the number of border cells in the root apex of infected seedlings. The results allow to positively evaluate hydroponic culture Triticum aestivum as a model system for studying of the biological effects of the fungicides (in particular, their phytotoxicity) and fusariosi

Liver regeneration is associated with lipid reorganization in membranes of the endoplasmic reticulum

BACKGROUND:In recent years, an adaptive endoplasmic reticulum (ER) stress response has been actively investigated. The ER membrane, isolated from the intact and regenerating liver, may be an appropriate model for investigating the association between structural and functional characteristics of ER in vivo and their corresponding behavioral characteristics in vitro. The rate of lipid synthesis and that of intracellular lipid exchange between the ER and cytosol were investigated in the intact and regenerating liver (13 h after partial hepatectomy). Particularly, membrane characteristics, surface potential, and glucose 6-phosphatase (G6Pase) activity were investigated, along with the degradation rate of G6Pase in vitro, which was estimated by the loss of G6Pase activity, formation of lipid peroxides, and size of excreted membrane vesicles. METHODS:The rate of lipid synthesis was determined by measuring the intensity of radioactive precursor (C14 - sodium acetate) in different fractions of lipids (phospholipids, non-esterified fatty acids, and triacylglycerides) after 30 min exposure. The rate of lipid metabolism was assessed by measuring the quantity of lipids with radioactive labels emerging in the cytosol of hepatocytes (CPM). Viscosity and surface potential were determined by fluorescent probes. RESULTS:It was observed that after 13 h of partial hepatectomy, the rate of lipid synthesis in the ER of hepatocytes in the regenerating liver was 3 times lower than that in ER of hepatocytes in the intact liver, wherein the rate of incorporation of newly synthesized lipids in cytosol was several times higher in the regenerating liver. Increase in the rate of exchange of neutral lipids in cells of the regenerating liver was accompanied by lipid reconstruction in the ER, changing the structural and functional characteristics of the membrane. Such membrane rebuilding also contributed to the rate of degradation of the ER in vitro,which that must be taken into account during development of systems for in vitro assessment of xenobiotic metabolism. CONCLUSIONS:An increase in the rate of direct (microsomes---cytosol) and reverse transport of lipids (cytosol --- microsomes) was observed in the regenerating liver. Microsomes, isolated from the regenerating liver, were degraded in the in vitro system at a higher rate

Influence of PHA Substrate Surface Characteristics on the Functional State of Endothelial Cells

The needs of modern regenerative medicine for biodegradable polymers are wide and varied. Restoration of the viability of the vascular tree is one of the most important components of the preservation of the usefulness of organs and tissues. The creation of vascular implants compatible with blood is an important task of vascular bioengineering. The function of the endothelial layer of the vessel, being largely responsible for the development of thrombotic complications, is of great importance for hemocompatibility. The development of surfaces with specific characteristics of biomaterials that are used in vascular technologies is one of the solutions for their correct endothelialization. Linear polyhydroxyalkanoates (PHAs) are biodegradable structural polymeric materials suitable for obtaining various types of implants and tissue engineering, having a wide range of structural and physicomechanical properties. The use of PHA of various monomeric compositions in endothelial cultivation makes it possible to evaluate the influence of material properties, especially surface characteristics, on the functional state of cells. It has been established that PHA samples with the inclusion of 3-hydroxyhexanoate have optimal characteristics for the formation of a human umbilical vein endothelial cell, HUVEC, monolayer in terms of cell morphology as well as the levels of expression of vinculin and VE-cadherin. The obtained results provide a rationale for the use of PHA copolymers as materials for direct contact with the endothelium in vascular implants

Functional Activity of Macrophage Cells in the Assessment of Reaction to Biodegradable Implants

Показано, что манипулирование структурными и поверхностными характеристиками у каркасных синтетических материалов в тканевой инженерии может влиять на фенотип макрофагов. В частности, выявлено, что некоторые параметры подложки влияют на ответ макрофагов, формируя благоприятную реакцию. С другой стороны, показана возможность адаптировать биоматериалы для изменения фенотипа макрофагов с синтезом биологически активных молекул, таких как факторы роста и цитокиныThese studies suggest that manipulation of the structural and surface characteristics of synthetic scaffold materials can affect macrophage phenotype. Specifically, some of these manipulations appear to alter the macrophage response and are also associated with improved outcomes. Another manner in which biomaterials can be tailored to promote shifts in macrophage phenotype is through the use of biologically active molecules such as growth factors and cytokine

Effect of Biomaterials of Medical Purpose on the Structural and Functional Features of Monocytes

Изучены морфофункциональные особенности моноцитов в условиях кратковременного культивирования in vitro на носителях из биополимера полигидроксиалканоата (ПГА) в присутствии наноалмазов (НА) и фуллеренов (Ф). Показано, что НА и Ф в исследованных концентрациях не влияли на жизнеспособность моноцитов в кратковременной культуре. Соотношение морфологических классов моноцитов в присутствии НА и Ф существенно отличалось от контрольного варианта культивирования. Влияние НА и Ф характеризовалось дозовой зависимостью. Воздействие наночастиц на культуру моноцитов значительно изменялось при формировании белковой короны на поверхности НА и Ф, что приводило к возникновению новых количественных соотношений между морфологическими классами моноцитов в культуре in vitro. Полученные результаты позволяют рассматривать кратковременную культуру моноцитов in vitro как адекватную модельную систему для оценки влияния новых материалов на процессы дифференцировки субпопуляций моноцитов33-4

The Morphology and Phenotype of Monocyte-Macrophages When Cultured on Bionanofilms Substrates with Different Surface Relief Profiles

The effect of surface relief profiles of alkanoate-based bionanofilms to the monocyte-macrophages (MN-MPhs) from peripheral blood of patients with atherosclerosis was studied in vitro. Patients were subjected to coronary stenting. Cell morphology and phenotype (expression of CD antigens, levels of production of marker cytokines) in vitro were analyzed before and after the installation of stents. It was shown, that the mean square roughness (Rq) of the bionanofilms determined the variability of cell morphology, CD antigens spectraand activity of production interleukins-6 and -10. Also, it was revealed, that the “activity” of the surface topography of biopolymer substrates depends on the functional state of MNs, isolated in different time points: Before and after stenting the ratios of cell morphotypes and production of cytokines in MN-MPhs differed significantly

Functional Activity of Macrophage Cells in the Assessment of Reaction to Biodegradable Implants

Показано, что манипулирование структурными и поверхностными характеристиками у каркасных синтетических материалов в тканевой инженерии может влиять на фенотип макрофагов. В частности, выявлено, что некоторые параметры подложки влияют на ответ макрофагов, формируя благоприятную реакцию. С другой стороны, показана возможность адаптировать биоматериалы для изменения фенотипа макрофагов с синтезом биологически активных молекул, таких как факторы роста и цитокиныThese studies suggest that manipulation of the structural and surface characteristics of synthetic scaffold materials can affect macrophage phenotype. Specifically, some of these manipulations appear to alter the macrophage response and are also associated with improved outcomes. Another manner in which biomaterials can be tailored to promote shifts in macrophage phenotype is through the use of biologically active molecules such as growth factors and cytokine