| Project/Area Number |
08557009
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 展開研究 |
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| Research Field |
General medical chemistry
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| Research Institution | Tohoku University |
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Principal Investigator |
KATO Ichiro School of Medicine, Tohoku University Research Associate, 医学部, 助手 (50250741)
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| Co-Investigator(Kenkyū-buntansha) |
NATA Koji School of Medicine, Tohoku University Research Associate, 医学部, 助手 (90202233)
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| Project Period (FY) |
1996 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥18,400,000 (Direct Cost: ¥18,400,000)
Fiscal Year 1998: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1997: ¥7,400,000 (Direct Cost: ¥7,400,000)
Fiscal Year 1996: ¥7,400,000 (Direct Cost: ¥7,400,000)
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| Keywords | cyclic ADP-ribose / second messenger / knockout mouse / insulin / calcium ion / pancreatic beta cell / diabetes mellitus / transgenic mouse / グルコース / 糖負荷試験 |
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| Research Abstract |
1. We produced CD38 (+/-) mice by homologous recombination in ES cells and subsequent Cre-lox P recombination. By crosses between heterozygous mutants (+/-), homozygotes (-/-) were yielded in the F2 generation in a distribution following Mendelian rules ; hence CD38-/- mice seemed to survive fetal development normally.
2.RT-PCR and Western blot analysis showed that there was no detectable CD38 mRNA and protein in pancreatic islets from CD38-/- mice, suggesting that the gene disruption resulted in a null mutation of CD38.
3. As compared with CD38+/+ islet homogenates, the ADP-ribosyl cy clase, cADPR hydrolase and NAD+-glycohydrolase activities of CD38-/- islet homogenates were greatly reduced, indicating that CD38 is mainly responsible for the synthesis and hydrolysis of cADPR in pancreatic beta cells.
4. By radioimmunoassay, the cADPR content in CD38+/+ islets was greatly increased by high glucose stimulation. Although some amounts of cADPR were detected in CD3 8-I- islets when incubated
… More
in low glucose, the cADPR content was not at all increased by high glucose stimulation.
5. The glucose-stimulated [Ca2+]i rise in CD38-/- islets was much lower than that in CD38+/+ islets in the digital imaging of fura-2 fluorescence.
6. Although there were no significant differences in insulin secretion between CD38+/+ and CD38-/- islets at 2.5 and 10 mM glucose, insulin secretion from CD38-/- islets at 20 and 30 mM glucose was more than 50% decreased compared with CD38+/+ islets
.7. In glucose-tolerance test, At 30 and 60 min after glucose injection, CD38-/- mice had much higher glucose levels than CD38+/+ mice. In CD38-/- mice, serum insulin levels at 15 ruin after glucose injection were significantly lower than those of CD38+/+ mice.
8. CD38-/- mice carrying the human CD38 transgene were generated. The human CD38 transgene ameliorated the glucose intolerance and the decreased insulin secretion.
9. Overall results indicate that the CD38-/- mice are suitable animal model of noninsulin-dependent diabetes mellitus. In fact, we found CD38 missense mutation and autoantibodies against CD38 in noninsulin-dependent diabetic patients. Less
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