| Project/Area Number |
22590996
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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 |
Metabolomics
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| Research Institution | Juntendo University |
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Principal Investigator |
|
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| Co-Investigator(Kenkyū-buntansha) |
WATADA Hirotaka 順天堂大学, 医学部, 教授 (60343480)
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| Project Period (FY) |
2010 – 2012
|
| Project Status |
Completed (Fiscal Year 2012)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2012: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2011: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000)
Fiscal Year 2010: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
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| Keywords | オートファジー / 亜鉛 / トランスポーター / 2型糖尿病 / インスリン / 糖代謝 / 糖尿病 / 膵ベータ細胞 / 亜鉛トランスポーター / 膵β細胞 |
|---|
| Research Abstract |
Recent genome-wide association studies demonstrated that common variants of SLC30A8 increase susceptibility to type 2 diabetes. SLC30A8 encodes zinc transporter-8 (ZnT8), which delivers zinc ion from the cytoplasm into insulin granules. In this study, we generated ・-cell-specific Slc30a8-deficient mice, and demonstrated an unexpected functional linkage between Slc30a8 deletion and hepatic insulin clearance. The mutant mice had low peripheral blood insulin levels, despite insulin h ypersecretion from pancreatic ・ cells. In a series of experiments, we showed that a substantial amount of the hypersecreted insulin was degraded during its first passage through the liver. Consistent with these findings, slc30a8-deficient mice exhibited increased insulin clearance, as assessed by the c-peptide/insulin ratio. As one of the explanations for the above findings, we demonstrated that zinc cosecreted with insulin suppressed insulin clearance by inhibiting clathrin-dependent insulin endocytosis.
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