1997 Fiscal Year Final Research Report Summary
Vascular Endothelial Cell Response to Mechanical Stimuli
| Project/Area Number |
07044112
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Field |
Biomedical engineering/Biological material science
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| Research Institution | Tohoku University |
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Principal Investigator |
SATO Masaaki Tohoku Univ.Grad Sch Engng, Prof, 大学院・工学研究科, 教授 (30111371)
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| Co-Investigator(Kenkyū-buntansha) |
HELLUMS J David Rice Univ, Chemical Engng, Prof, 化学工学科, 教授
GIRARD Peggy R Georgia Tech, Sch Biology, Assistant Prof, 生物学科, 講師
NEREM Robert M Georgia Tech, Sch Mech Engng, Prof, 機械工学科, 教授
KATAOKA Noriyuki Tohoku Univ.Grad Sch Engng, Res Associate, 大学院・工学研究科, 助手 (20250681)
MATSUMOTO Takeo Tohoku Univ.Grad Sch Engng, Assoc Prof, 大学院・工学研究科, 助教授 (30209639)
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| Project Period (FY) |
1995 – 1997
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| Keywords | vascular endothelial cells / actin filament / shear stress / permeability / atherosclerosis / GFP |
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| Research Abstract |
As this year was the last term of this project, we examined our results obtained for the past two years form global point of view, and decided to develop some new experimental methods to overcome methodological problems in the previous studies.
1. DEVELOPMENT OF A NEW TECHNIQUE TO OBSERVE ACTIN FILAMENTS IN ALIVE CELLS
Immunofluorescence technique which has been utilized widely to observe intracellular actin filaments requires fixation of the cells, and it was vey difficult to observe actin filament dynamics in intact cells. To overcome this problem, we have introduced a combined gene of alpha-actinin, a bridging element of actin filaments and GFP (Green Fluorescent Protein) into vascular endothelial cells. Cells introduced such genes have autofluorescence in their alpha-actinin, and thus their actin filaments. We successfully observed actin filament dynamics in cells under static and shear-exposed conditions.
2. DEVELOPMENT OF A FLOW-LOADING SYSTEM FOR ENDOTHELIAL CELLS ON ARTERIAL INTRALUMINAL SURFACE
There have been a lot of contradictions between results obtained from animal experiments and that based on cultured endothelial cells. To establish a new method compensating shortcomings of both experiments, we have developed a new flow-loading system to impose shear stress on the endothelial surface of an arterial segment, in which a piece of a cut-opened arterial segment is laid flat to expose its intraluminal surface to flow in a parallel plate chamber. We applied 1 Pa of shear stress to rabbit thoracic aortas perpendicularly to their vessel axis, and found that most of the endothelial cells changed their alignment parallel to the direction of flow in 72 hours. We concluded that this system can be widely used for the future studies on the mechanical response of vascular endothelial cells to shear stress.
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