Titanium ion induces necrosis and sensitivity to lipopolysaccharide in gingival epithelial-like cells.
Gingival epithelial-like cells (GE-1) were cultured and used to examine the cellular responses of gingival tissues to varying concentrations of titanium (Ti) ions. Titanium ions at concentrations of more than 13 ppm significantly decreased the viability of GE-1 cells and increased LDH release from the cells into the supernatant, but had no significant effect on their caspase 3 activity. These data suggest that a high concentration of Ti ions induced necrosis of the GE-1 cells. Titanium ions at a concentration of 5 ppm significantly increased the level of CCL2 mRNA expression in GE-1 cells exposed to lipopolysaccharide derived from Porphyromonas gingivalis in a synergistic manner. Moreover, the mRNA expression levels of TLR-4 and ICAM-1 in GE-1 cells loaded with Ti ions at 9 ppm were significantly enhanced as compared with those in GE-1 cells without Ti stimulation. We suggest that Ti ions are in part responsible for monocyte infiltration in the oral cavity by elevating the sensitivity of gingival epithelial cells to microorganisms. Taken together, these data indicate that Ti ions may be involved in cytotoxicity and inflammation at the interfaces of dental implants and gingival tissue.
Makihira
Seicho
S
Department of Oral Biology and Engineering, Division of Oral Health Science, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan. seicho@hiroshima-u.ac.jp
Mine
Yuichi
Y
Nikawa
Hiroki
H
Shuto
Takahiro
T
Iwata
Satoshi
S
Hosokawa
Ryuji
R
Kamoi
Kohei
K
Okazaki
Shota
S
Yamaguchi
Yu
Y
D000818:Animals; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D004847:Epithelial Cells / Q000187:drug effects* / Q000473:pathology; D005786:Gene Expression Regulation / Q000187:drug effects; D005881:Gingiva / Q000166:cytology / Q000187:drug effects* / Q000473:pathology; D008070:Lipopolysaccharides / Q000633:toxicity; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009000:Monocytes / Q000378:metabolism; D009336:Necrosis / Q000139:chemically induced*; D012333:RNA, Messenger / Q000378:metabolism; D014025:Titanium / Q000008:administration & dosage / Q000633:toxicity*
D008070:Lipopolysaccharides; D012333:RNA, Messenger; D014025:Titanium