| Project/Area Number |
26462816
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Functional basic dentistry
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| Research Institution | Nagasaki University |
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Principal Investigator |
MASUYAMA Ritsuko 長崎大学, 医歯薬学総合研究科(歯学系), 准教授 (60297596)
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| Co-Investigator(Kenkyū-buntansha) |
小守 壽文 長崎大学, 医歯薬学総合研究科(歯学系), 教授 (00252677)
山中 仁木 長崎大学, 先導生命科学研究支援センター, 助教 (30533921)
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Project Status |
Completed (Fiscal Year 2016)
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| Budget Amount *help |
¥4,810,000 (Direct Cost: ¥3,700,000、Indirect Cost: ¥1,110,000)
Fiscal Year 2016: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
Fiscal Year 2014: ¥2,210,000 (Direct Cost: ¥1,700,000、Indirect Cost: ¥510,000)
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| Keywords | カルシウム輸送 / リン / 小腸 / 骨 / ビタミンD / カルシウム / ATP / 石灰化 / 恒常性 / ピロリン酸 |
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| Outline of Final Research Achievements |
The impaired calcium absorption in intestinal Vdr null mice was improved by dietary phosphate restriction and resulted in increased bone mass, indicating that intestinal luminal phosphate levels influenced calcium absorption. Accordingly, transcellular calcium transport in cultured polarized intestinal epithelial cells was increased when apical side of cells were exposed to low extracellular phosphate levels (0.5 mM phosphate) compared to normal or high phosphate levels (1.0 and 5.0 mM). Mechanistically, low phosphate levels increased ATP contents at the apical extracellular side which stimulated the apical ATP receptor to promote calcium entry. The luminal ATP levels were regulated by the apical abundance of the ATP metabolizing enzyme, ectonucleotide pyrophosphatase/phosphodiesterase (ENPP1). Sub-cellular localization of ENPP1 was reduced when apical side of intestinal epithelial cells were exposed to low extracellular phosphate, and led to the increase in luminal ATP levels.
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