92-kD gelatinase is released by the prolonged survival neutrophils in gingival crevicular fluid and cleaves the extracellar domain of recombinant 180-kD bullous pemphigoid autoantigen.

1996 Fiscal Year Final Research Report Summary

• Project/Area Number: 07672087
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Conservative dentistry
• Research Institution: Meikai University
• Principal Investigator: SHIMOJIMA Takahiro Meikai Univ.Sch.of Dentistry, Lecturer, 歯学部, 講師 (60146230)
• Co-Investigator(Kenkyū-buntansha): ICHIMURA Koh Meikai Univ.Sch.of Dentistry, Assistant, 歯学部, 助手 (00232413) ; TATSUMI Junichi Meikai Univ.Sch.of Dentistry, Lecturer, 歯学部, 講師 (60227105) ; IKEDA Katumi Meikai Univ.Sch.of Dentistry, Professor, 歯学部, 教授 (50049350)
• Project Period (FY): 1995 – 1996
• Keywords: periodontitis / junctional epithelium / hemidesmosome / neutrophils / 92-kD gelatinase / apoptosis

Research Abstract

This report presents the results of experiments designed to examine the possibility that the exposure of neutrophils to agents known to regulate inflammatory reactions can influence neutrophils survival and interfere with the physiologic process of apoptosis these cells. Moreovere, we examined whether neutrophils were a possible source of the 92-kD gelatinase and this enzyme cleaved hemidesmosomal elements, the extracelular domain of recombinant 180-kD bullous pemphigoid (BP) autoantigen, a transmembrane molecule of the epidermal hemidesmosome. After 72 hrs of culture, 100 ng/mL LPS treated neutrophils showed a survival of 96.7%(]SY+-[)10.5%, and also when neutrophils were treated with GCF samples, at 72 hrs the survival percentages were for AP-derived GCF 42.7%(]SY+-[)3.8%. Based on the migration patterns of GCF gelatinase on SDS-PAGE and the effects of APMA activation, the major GCF enzymes were identified as the latent 92-kD progelatinase that comigrated with progelatinase from lysed neutrophils, and the faster migrating activated forms. Patients with periodontitis showed higher levels of total (active plus latent) gelatinase activity than control patients (median gelatinase activity of 1843 units for AP,2241 units for EOP and 452 units for controls). Furthermore, to assess if 92-kD gelatinase contributes to the destruction of hemidesmosomal elements, we incubated purified, activated enzyme with a 42-kD recombinant fusion protein, including a large portion of the first and largest collagenous domain. Based on a decrease of -8-kD,92-kD gelatinase cleaved recombinant BP180 at the beginning of the collagenous ectodomain, and as for gelatin, degraded the collagenous sequences into fragments too small to be seen on the gel. In conclusion, our findings suggest that the release of 92-kD gelatinase by intact senescent neutrophils in GCF may be a critical event in pocket formation and its development seen in periodontal disease.