Нелинейные локальные деформации мембран эритроцитов: действие токсинов и фармпрепаратов (Часть 2)

Modifiers of membranes cause local defects on the cell surface. Measurement of the rigidity at the sites of local defects can provide further information about the structure of defects and mechanical properties of altered membranes.The purpose of the study: a step-by-step study of the process of a nonlinear deformation of red blood cells membranes under the effect of modifiers of different physico-chemical nature.Materials and methods. The membrane deformation of a viscoelastic composite erythrocyte construction inside a cell was studied by the atomic force spectroscopy. Nonlinear deformations formed under the effect of hemin, Zn2+ ions, and verapamil were studied.Results. The process of elastic deformation of the membrane with the indentation of a probe at the sites of local defects caused by modifiers was demonstrated. The probe was inserted during the same step of the piezo scanner z displacement; the probe indentation occured at the different discrete values of h, which are the functions of the membrane structure. At the sites of domains, under the effect of the hemin, tension areas and plasticity areas appeared. A mathematical model of probe indentation at the site of membrane defects is presented.Conclusion. The molecular mechanisms of various types of nonlinear deformations occurring under the effect of toxins are discussed. The results of the study may be of interest both for fundamental researchers of the blood cell properties and for practical reanimatology and rehabilitology. Модификаторы мембран порождают локальные дефекты на поверхности клеток. Измерение жесткости в зонах локальных дефектов может дать дополнительную информацию о структуре дефектов и механических свойствах мембран в целом.Цель работы: пошаговое исследование процесса нелинейной деформации мембран эритроцитов при действии на них модификаторов различной физико-химической природы.Материалы и методы. Методом атомно-силовой спектроскопии провели исследование деформации мембран внутрь клетки вязко-упругой композитной конструкции эритроцита. Исследовали нелинейные деформации при действии гемина, ионов Zn2+, фармпрепарата верапамила.Результаты. Показали процесс упруго-эластичной деформации мембраны по мере индентации зонда в областях локальных дефектов, вызванных модификаторами. На один и тот же шаг смещения z пьезосканера зонд погружался на разные дискретные величины h, которые являются функциями структуры мембраны. В областях доменов при действии гемина возникали зоны натяжения и зоны пластичности. Привели математическая модель индентации зонда в области дефектов мембран.Заключение. Обсудили молекулярные механизмы различных видов нелинейных деформаций, возникающих при действии токсинов. Результаты работы могут представлять интерес как для фундаментальных исследований свойств клеток крови, так и для практической реаниматологии и реабилитологии

Дефекты мембран эритроцитов у пациентов с нарушениями функции головного мозга (пилотное исследование)

The aim of the paper: to identify promising diagnostic and prognostic biomarkers of pathological processes development based on the red blood cell membrane morphology and nanostructure in patients with brain disorders in the Intensive Care Unit.Materials and methods. The study included 24 patients from the anesthesiology and resuscitation ward of the Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology. Blood was acquired from the patients for standard tests, and all further tests were performed in vitro. The images of red blood cells were obtained using the atomic force microscope «NTEGRA Рrima» (NT-MDT, Russia) in semi-contact mode.Results. Patients from the anesthesiology and intensive care ward with traumatic brain injury, ischemic and hemorrhagic stroke, cerebral edema, and post-hypoxic encephalopathy had different blood cell shapes and localized defects of different topology on the surface of erythrocyte membranes including defects of pallor, torus, and nanostructure.Conclusion. In this pilot study we have shown that several defects represent the trigger mechanisms for the development of a total membrane damage. Local topographic defects of nanostructures and abnormalities of erythrocyte morphology are irreversible. The number and quality of these abnormalities may eventually be used as a diagnostic and prognostic biomarker of pathological processes.Цель работы. Выявление перспективных диагностических и прогностических биомаркеров развития патологических процессов на основе особенностей морфологии и наноструктуры мембран эритроцитов у пациентов с нарушениями функции головного мозга, находящихся в отделении анестезиологии и реанимации.Материалы и методы. В исследование включили 24 пациента отделения анестезиологии и реанимации ФНКЦ РР. Кровь забирали у данных пациентов для стандартных анализов, и все дальнейшие исследования проводили in vitro. Изображения эритроцитов получали с помощью атомного силового микроскопа «NTEGRA Рrima» (NT-MDT, Россия) в полуконтактном режиме.Результаты. У пациентов отделения анестезиологии и реанимации с черепно-мозговой травмой, ишемическим и геморрагическим инсультом, отеком головного мозга, постгипоксической энцефалопатией имели место различные формы клеток крови, на поверхности мембраны эритроцитов возникали локальные дефекты различной топологии: дефекты пэллора, тора, наноструктуры.Заключение. В данном пилотном исследовании мы показали, что ряд дефектов являются стартовым механизмов развития тотальных повреждений мембран. Локальные топографические дефекты наноструктур, а также нарушения морфологии эритроцитов необратимы. Количество и качество этих нарушений в перспективе могут быть использованы как диагностический и прогностический биомаркер патологических процессов

Defects of Red Blood Cell Membranes in Patients with Brain Dysfunction (Pilot Study)

The aim of the paper: to identify promising diagnostic and prognostic biomarkers of pathological processes development based on the red blood cell membrane morphology and nanostructure in patients with brain disorders in the Intensive Care Unit.Materials and methods. The study included 24 patients from the anesthesiology and resuscitation ward of the Federal Research and Clinical Center of Intensive Care Medicine and Rehabilitology. Blood was acquired from the patients for standard tests, and all further tests were performed in vitro. The images of red blood cells were obtained using the atomic force microscope «NTEGRA Рrima» (NT-MDT, Russia) in semi-contact mode.Results. Patients from the anesthesiology and intensive care ward with traumatic brain injury, ischemic and hemorrhagic stroke, cerebral edema, and post-hypoxic encephalopathy had different blood cell shapes and localized defects of different topology on the surface of erythrocyte membranes including defects of pallor, torus, and nanostructure.Conclusion. In this pilot study we have shown that several defects represent the trigger mechanisms for the development of a total membrane damage. Local topographic defects of nanostructures and abnormalities of erythrocyte morphology are irreversible. The number and quality of these abnormalities may eventually be used as a diagnostic and prognostic biomarker of pathological processes

Nonlinear Local Deformations of Red Blood Cell Membranes: Effects of Toxins and Pharmaceuticals (Part 2)

Modifiers of membranes cause local defects on the cell surface. Measurement of the rigidity at the sites of local defects can provide further information about the structure of defects and mechanical properties of altered membranes.The purpose of the study: a step-by-step study of the process of a nonlinear deformation of red blood cells membranes under the effect of modifiers of different physico-chemical nature.Materials and methods. The membrane deformation of a viscoelastic composite erythrocyte construction inside a cell was studied by the atomic force spectroscopy. Nonlinear deformations formed under the effect of hemin, Zn2+ ions, and verapamil were studied.Results. The process of elastic deformation of the membrane with the indentation of a probe at the sites of local defects caused by modifiers was demonstrated. The probe was inserted during the same step of the piezo scanner z displacement; the probe indentation occured at the different discrete values of h, which are the functions of the membrane structure. At the sites of domains, under the effect of the hemin, tension areas and plasticity areas appeared. A mathematical model of probe indentation at the site of membrane defects is presented.Conclusion. The molecular mechanisms of various types of nonlinear deformations occurring under the effect of toxins are discussed. The results of the study may be of interest both for fundamental researchers of the blood cell properties and for practical reanimatology and rehabilitology