Production of Interleukin-6 on Periodontal cells

1992 Fiscal Year Final Research Report Summary

• Project/Area Number: 03670961
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: 外科・放射線系歯学
• Research Institution: Nihon University
• Principal Investigator: IZUMI Hirotsugu Nihon University, Professor, 松戸歯学部, 教授 (00050005)
• Co-Investigator(Kenkyū-buntansha): OGURA Naomi Nihon University, Assistant, 松戸歯学部, 副手 (10152448) ; MINATO Kouichi Nihon University, Research Associate, 松戸歯学部, 助手 (10174088)
• Project Period (FY): 1991 – 1992
• Keywords: Interleukin-6 / Plasmin / Plasminogen activator / Lipopolysaccharide / Campyrobacter rectus / Porphyromonas endodontalis / Gingival Fibroblasts / Periodontal Ligament

Research Abstract

Intherleukin-6 (IL-6), a multifunctional cytokine that has previously been called B-cell stimulatory factor 2, hepatocyte stimulating factor, interferon- beta _2,is produced by lymphoid and non-lymphoid cells. This cytokine can apparently induce osteoclastic bone resorption through an effect on osteoclastogesis. Furthermore, it has been reported that human gingival tissue from patients with periodontitis contain a high level of IL-6. Thus, we have examined whether human gingival fibroblast cells (Gin cells) and human periodontal ligament fibroblast cells (PDL cells) have the capacity to synthesize and secrete IL-6 in response to Campyrobacter rectus (C. rectus) LPS and Porphyromonas endodontalis (P. endodontalis) LPS. IL-6 in conditioned medium from these cells by treatment of LPS was measured ELISA assay using monoclonal antibody against IL-6. The expression rate of IL-6 mRNA was also investigated by Northern blot DNA hybridization with IL-6 cDNA probe.
IL-6 release and the expression of IL-6 mRNA on Gin cells were stimulated by C. rectus LPS. And IL-6 release and the expression of IL-6 mRNA on PDL cells were stimulated by P. endodntalis LPS.
On the other hand, plasminogen activator-plasmin system is implicated the degradation of extracrllular matrix, the inflammation through activating latent collagenase and prekallikrein. In this study we have measured th activities of plasmin and plasminogen activator on human gingival fibroblast cells (Gin-1) treated by of C. rectus LPS. Plasmin activity in the conditioned medium of Gin-1 was stimulated by treatment of C. rectus LPS in a time and dose-dependent manner. C. rectus LPS stimulated plasminogen activator activity in Gin-1 condition medium and cell lysate. The molecular size of plasminogen activator of Gin-1 was identified about 50 kDa by zymogrphy. Furthermore, Gin-1 conditioned medium treated with C. rectus LPS stimulated the conversion of prekallikrein to Kallikrein in serum.
These data suggested that C. rectus LPS and P. endodontalis LPS is a potent stimulator in the inflammation and the degradation on the extracellular matrix of periodontitis through stimulates the releases of IL-6 or plasminogen activator-plasmin system.