CCT-1 induces cell detachment and growth arrest in fibroblasts
Objectives:We have previously reported the novel virulence factor of Tannerella forsythia designated as the cytocidal toxin (CCT) that induced G2 cell cycle arrest and cell detachment to MA-1 cells (human epidermoidal carcinoma cell line KB introduced adenovirus E1A12S cDNA). Further purification of CCT revealed that this toxin consists of at least two factors: CDT-like factors and CCT-1. In this study, morphological and molecular biological analyses were carried out to clarify the pathogenesis of CCT-1. Methods:In order to explore the effects of CCT-1 on fibroblasts, TIG-3 cells (embryonic human fibroblasts) were exposed to recombinant CCT-1 (rCCT-1). Cellular toxicity was evaluated by cell proliferation, viability and glucose consumption. To investigate the cell cycle status, TIG-3 cells treated with the rCCT-1 were subjected to flowcytometry following staining with propidium iodide. Furthermore, the intracellular localization of CCT-1 was investigated by Western blotting for cytoplasmic or nuclear fractions of target cells. The distribution of adhesion molecules, cell cycle regulators and CCT-1 were evaluated by Western blotting and immunofluorescence confocal microscopy. Results:CCT-1 degraded cellular signaling molecules, including components of focal adhesion kinase, mitogen-activated protein kinases (MAPK) and retinoblastoma susceptibility protein (Rb) family immediately. Moreover, TIG-3 cells shrunk and detached from culture surface and from each other in the presence of CCT-1. Western blot analysis for localizing of adhesion molecules and CCT-1 showed that ƒ"-actin and N-terminal region of CCT-1 transferred to intranuclear area. CCT-1 did not induce cell death directly, and flowcytometric anlysis indicated significant growth arrest with an excess consumption of glucose. Conclusion:The CCT-1 (rCCT-1) mediates the detachment, morphological changes, and growth arrest of fibroblasts through affecting cellular signaling molecules and glucose consumption, implicating the CCT-1 in the°@pathogenesis of this bacterium.
Division: IADR General Session
Meeting:2006 IADR General Session (Brisbane, Australia) Location: Brisbane, Australia
Year: 2006 Final Presentation ID:360 Abstract Category|Abstract Category(s):Periodontal Research - Pathogenesis
Authors
Tomi, Naoko
( Tokyo Medical & Dental University, Tokyo, N/A, Japan
)
Arakawa, Shinichi
( Tokyo Medical & Dental University, Tokyo, N/A, Japan
)
Nakajima, Takuma
( Tokyo Medical & Dental University, Tokyo, N/A, Japan
)
Ishikawa, Isao
( Tokyo Medical & Dental University, Tokyo, N/A, Japan
)