2004 Fiscal Year Final Research Report Summary
Elucidation of the mechanisms regulating the vascular tone and proliferation : Development of a novel technique to introduce protein into the intact cells and its applications
| Project/Area Number |
15590758
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Circulatory organs internal medicine
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
HIRANO Katsuya Kyushu University, Graduate School of Medical Sciences, Assistant Professor, 大学院・医学研究院, 講師 (80291516)
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| Project Period (FY) |
2003 – 2004
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| Keywords | protein transduction / vascular smooth muscle cells / vascular endothelial cells / nitric oxide / thrombin receptor / apoptosis / cell cycle / vascular tone |
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| Research Abstract |
By using a cell-penetrating peptide, which is found in the human immunodeficiency viral transcription factor Tat and is composed of 11 amino acids, I have developed a novel technique to rapidly, reversibly and quantitatively introduce proteins into the vascular tissues and cells. The cargo protein to be introduced into the cells was prepared as a recombinant protein fused to the cell-penetrating peptide using a bacterial expression system. I have developed the expression vectors. Using this new technique of the protein transduction, I have made the following contribution to the vascular biology.
(1)I have for the first time found that the N-terminal region of the regulatory subunit of myosin phosphatase, MYPT1, plays a physiological role in regulating the vascular tone in an intact artery.
(2)By introducing the inhibitor proteins of the small G proteins RhoA and Rac1 in a time-specific manner, I have for the first time found that the activity of Rho proteins is required at the late G1 ph
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ase for the cell cycle to progress from the G1 phase to the S phase in the vascular endothelial cells.
(3)I found that the 24 h treatment of the arterial tissue with the RhoA inhibitor protein attenuated the arterial contractility in a manner dependent on the endothelial NO production. However, Rac1 inhibitor protein had no such effect. This finding thus for the first time present direct evidence that RhoA plays a physiological role in the production of NO in in situ endothelial cells.
(4)I found that the 24 h treatment of the cultured smooth muscle cells with the Rac1 inhibitor protein reduced the cell surface expression of the thrombin receptor PAR1. However, the RhoA inhibitor protein had no such effect. This observation thus suggests that Rac1 plays a critical role in determining the expression of PAR1 in the vascular smooth musclecells.
(5)Estrogen inhibited the TNF-α-induced apoptosis in the vascular endothelial cells. However, the introduction of the dominant negative mutant of Akt inhibited the anti-apoptotic effect of estrogen. This finding thus provide the first direct evidence that Akt plays a critical role in the anti-apoptotic signaling elicited by estrogen in the vascular endothelial cells. Less
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Research Products
(12 results)
