Influences Of The Different Relaxation State Of Cell Substrate On The Morphology Of Endothelial Cells, The Cytoskeleton And The Distribution Of Rho In Cells

The environment for cells in vivo is extremely complicated. The outstanding example is that hemodynamics factors physiologically effect on endothelial cells in mammal cardiovascular system. Mechanical stretch is an important composing factor of complicated mechanics environment for endothelial cells in vivo as well as flow-shearing force and hydrostatic pressure. Mechanical stretch has widespreading relations with cell adhesion, spreading, migrating and proliferation, so it is worth to study the responses of cells to the mechanical stretch. This paper analysed the different respones of cells to different mechanical stretch in vitro, including the morphology changes of cells, the cytoskeleton rearrangement of cells, and the distribution of Rho in cellsâ‘ Development of a new substrate-stretching device for cultured cellsTo simulate the mechanical environment of cells in vivo and study of cellular signal transduction mechanisms,most of researchers applied cyclic strain and relaxation to cell culture substrate as mechanical loading methods in vitro.with the further study of cellular signal transduction mechanisms caused by mechanical stretch, it is necessary to culture massive cells for loading expriment.In order to meet the experimental need and benefit from domestic and foreign installment, we developed a device with single axis and bidirectional stretch to cell culture substrate,which could provide high cell yield, control the magnitude of time, strain, direction and frequency of stretch.this device is composed of five portion including data collecting system,function generator,step motor driver, Pressure Sensors,displacement sensors and cells loading element. This device provides versatile option for the study on the cellular responses of mechanical loading.â‘¡Influence of relaxation state of the different cell substrate on the morphology and cytoskeleton of endothelial cellsUsing above mentioned device,we applied a relaxation after static stretch and cyclic stretch to a cell culture substrate in different time and provided fully static control in the same time,then used the Computer image processing software to separately analyse the change of cells in different experimental way.The results show that, The spreading area of cells reduces obviously after static relaxation;after being cyclic stretched, morphology and cytoskeleton of relaxed cells are altered.with the increase of relaxed time, the ratio of long axis to short axis reduced, the cell also gradually spreads wide.The major axis of cells and the alignment of stress fibers are vertical to the orientation of cyclic stretch. the angle of cell major axis and loading direction is about 700-900,which is remarkable with the control group.â‘¢Influence of relaxation state of the different cell substrate on the distribution of Rho in endothelial cellsUsing above mentioned device,we applied a relaxation after static stretch to a cell culture substrate in different time and provided fully static control in the same time. First, EYFP-RBD plasmid was transfected into cells, then the distribution of Rho in endothelial cells was observed through EYFP - RBD plasmid and RhoA-CFP fluorescence markers. However this method was not perfectly succeed, so immuno- fluorescence marker was applied. The results showed that, Rho in static-relaxed endothelial cells is distributed mainly over cytoplasm and cytomembrane after relaxed 10min, and seldom in cell nucleus,as well as in fully static cells . Rho in static-relaxed endothelial cells is distributed over the whole cell and especial in cell nucleus after relaxed 40min. Rho in cyclic-stretched endothelial cells is distributed mainly over cytomembrane after relaxed 10min.