| Project/Area Number |
18590361
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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 |
Experimental pathology
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| Research Institution | Akita University |
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Principal Investigator |
ENOMOTO Katsuhiko Akita University, School of Medicine, Professor (20151988)
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| Co-Investigator(Kenkyū-buntansha) |
NISHIKAWA Yuji Akita University, School of Medicine, Associate Professor (90208166)
OMORI Yasufumi Akita University, School of Medicine, Lecturer (90323138)
YOSHIOKA Toshiaki Akita University, School of Medicine, Assistant Professor (80302264)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥3,580,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥480,000)
Fiscal Year 2007: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2006: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | liver sinusoidal endothelial cells / apoptosis / Bad siRNA / hepatic ischemic-reperfusion iniury / Rad siRNA / 肝類洞内皮細胞 |
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| Research Abstract |
Our previous study revealed that Bad, a proapoptotic protein, plays an important role in apoptosis of hepatic sinusoidal endothelial cells (SEC). Therefore, this study was carried out to establish an appropriate rat model for hepatic ischemia-reperfusion injury (I/R injury) as well as developing methods of the in vivo Bad siRNA delivery to suppress hepatic reperfusion injury.
1) We have established an analytical rat I/R injury model in which the portal veins and hepatic arteries of 2 hepatic lobes were clumped for 90 min and subsequently reperfused. Massive coagulative necrotic lesions appeared in the liver at 3-6 hr after reperfusion and the necrotic lesions were repaired and reorganized by 24 hr. TUNEL staining showed occurrence of a large number of SEC apoptosis within 1 hr after reperfusion but not after 6 hr. The evidence suggests that SEC apoptosis is important for triggering I/R injury of the liver.
2) Before Bad siRNA delivery, we tried injections of the GFP expression plasmid wh
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ich was mixed with atelocollagen as carrier matrix through the mesenteric veins, distal portion of portal vein and tail veins. However, no positive signal was detected in both SEC and hepatocytesin the liver. We tried siRNA transfection into the cultured SEC with different carrier matrix, but no efficient suppression of apoptosis was observed so far. Further study on the vivo siRNA delivery method is currently in progress.
3) We have successfully induced fetal SEC maturation in the cultured fetal liver cells of 13.5 embryo with VEGF and SB-431542, an inhibitor of TGF-β1 signaling. Treatment of TGF-β1 induced apoptosis of the cultured SEC from both fetal and adult liver. Thus, we are planning a further study on the effects of TGF-β1 in I/R injury.
In this study, we could establish an appropriate hepatic I/R injury model. Analysis of this model revealed that SEC apoptosis was observed at the very early time after reperfusion and thereafter necrosis of hepatocytes followed, suggesting an initial triggering role of SEC apoptosis in hepatic I/R injury. The method of siRNA delivery to SEC has not yet been established even several different ways of delivery we examined. Studies on fetal liver SEC development, we showed for the first time that TGF-β1 signaling plays a crucial role in SEC apoptosis. Less
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