| Project/Area Number |
09671885
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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 |
Morphological basic dentistry
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| Research Institution | National Institute of Infectious Diseases |
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Principal Investigator |
NISHIHARA Tatsuji National Institute of Infectious Diseases, Department of Oral Science, Chief of Laboratory of Periodontology, 口腔科学部, 室長 (80192251)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥2,900,000 (Direct Cost: ¥2,900,000)
Fiscal Year 1998: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1997: ¥1,700,000 (Direct Cost: ¥1,700,000)
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| Keywords | periodontopathic bacteria / periodontitis / apoptosis / interleukin-1beta / caspase / 歯周病 / 細菌感染 / 歯周病細菌 / IL-1β / IL-1β変換酵素 / IL-1β変換酵素阻害剤 / マクロファージ |
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| Research Abstract |
We have previously reported the evidence for apoptosis in the mouse macrophage cell line J774.1 by the periodontopathic bacterium Actinobacillus actinomycetemcomitans. In this study, we examined the role of protein kinases in the induction of apoptosis in A.actinomycetemcomitans-infected J774.1 cells. After J774.1 cells were precultured with protein kinase C (PKC) activator, J774.1 cells infected with A.actinomycetemcomitans showed the increased percentage of apoptotic cells. On the contrary, PKA activator do not mimic the effect of PKC activator. In addition, PKC inhibitors suppressed apoptotic cell death in J774.1 cells infected with A.actinomycetemcomitans. The results presented here suggest that the signals through PKC may play crucial roles in the modulation of apoptosis in macrophages infected with A.actinomycetemcomitans. Next, we examined the role of caspases, interleukin-1beta (IL-1beta) converting enzyme family proteases, in the regulation of apoptosis in infected J774.1 cells. TWo peptide inhibitors of caspases, benzyloxycarbonyl-Val-Ala-Asp (OMe)-fluoromethyl ketone (Z-VAD-FMK ; caspase-1 inhibitor)and benzyloxycarbonyl-Asp-Glu-Val-ASP (OMe)-fluoromethyl ketone (DEVD-FMK ; caspase-3 inhibitor) inhibited the induction of apoptosis in J774.1 cells infected with A.actinomycetemcomitans. Furhtermore, Z-VAD-FMK suppressed the production of IL-1beta from A.actinomycetemcomitans-infected J774.1 cells. When endogenous caspase-3 activity of J774.1 cells were analyzed, caspase-3 activity was markedly increased after A.actinomycetemcomitans infection. In addition, Z-VAD-FMK and DEVD-FMK suppressed caspase-3 activity of J774.1 cells infected with A.actinomycetemcomitans. These findings suggest that caspase-1 and-3 are involved in the regulation of apoptosis in macrophages infected with A.actinomycetemcomitans.
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