1997 Fiscal Year Final Research Report Summary
Host defense mechanism in human periodontitis
| Project/Area Number |
07407054
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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 | 一般 |
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| Research Field |
Conservative dentistry
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| Research Institution | Niigata University |
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Principal Investigator |
HARA Kohji Niigata University School of Dentistry, Professor, 歯学部, 教授 (20018419)
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| Co-Investigator(Kenkyū-buntansha) |
TAI Hideaki Niigata University Dental Hospital, Associate, 歯学部・附属病院, 助手 (30272826)
KOBAYASHI Tetsuo Niigata University School of Dentistry, Associate, 歯学部, 助手 (00215344)
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| Project Period (FY) |
1995 – 1997
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| Keywords | Periodontitis / Gingival Crericular Fluid / RT-PCR / in situ hybridization / complement Receptor / TIMP |
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| Research Abstract |
I.In this study we attempted to determine the mRNA levels of complement receptor type 1 and 3 (CR1, CR3) on PMNs in GCF by using reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization (ISH). Both CR1 and CR3 mRNA levels relative to b-actin were significantly lower in GCF-PMNs than in PB-PMNs (GCF-CR1 : 32.75 (]SY.+-。[) 22.93% PB-CR1 : 65.30 (]SY.+-。[) 43.25% p<0.005, GCF-CR3 : 9.09 (]SY.+-。[) 5.34% PB-CR3 : 30.14 (]SY.+-。[) 18.80% p<0.005). In ISH,a greater majority of PB-PMNs showed positive CR1 and CR3 mRNA expressions, while only a few PMNs showed positive signals in GCF.Our data in this study suggests that increased expressions of CR on the PMN cell surface appear to be unrelated to de novo synthesis.
DNA binding activity of NF-kB and AP-1 was examined in neutrophils stimulated with LPS purified from P.gingivalis, a major pathogenic bacteria of periodontitis lesion. Porphyromonas gingivalis LPS enhanced the activity reaching a Peak at a concentration of 5
… More
00ng/ml in the absence of serum. The NF-kB activation stimulated with 10ng/ml of P.gingivalis LPS was approximately 44% suppressed by treatment of neutrophils with anti-CD14 antibody under the presence of serum. Increase in the steady-state IL-8 mRNA level was concomitantly observed by stimulation of neutrophils with 500ng/ml of P.gingivalis LPS under the absence of serum. These results indicate that P-gingivalis LPS activates NF-kB and AP-1 both in serum-dependent and -independent manners, followed by increased IL-8 transcription in neutrophils, and suggesting a role for P.gingivalis LPS in IL-8 synthesis by neutrophils in inflamed gingiva and GCF.
II.This study presents the exact cell types and localization of tissue inhibitors of metalloproteinases (TIMPs) production sites in periodontal diseased gingiva by means of in situ hybridization. Gingival tissue specimens were fixed, embedded and hybridized in situ with specific digoxigenin-labeled cRNA probes (386 and 496 bp). TIMP-1 and -2 mRNAs were expressed on macrophages, mononuclear cells, capillary endothelial cells and some fibroblasts throughout the gingival tissue. In periodontitis, TIMP-1 and -2 mRNA-expressing cells showed significantly different localization. TIMP-1 mRNA was broadly observed in the gingival connective tissue while TIMP-2 mRNA was predominantly expressed in the connective tissue adjacent to the pocket epithelium (P<0.01). Fewer TIMPs mRNA were observed in minimal gingivitis than in periodontitis, especially in the middle zone of gingival tissue. Thus, TIMP-1 and TIMP-2 mRNA was detected differentially and site-specifically in periodontal diseased gingival tissue. Less
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