Involvement of antigen I/II surface proteins in Streptococcus mutans and Streptococcus intermedius biofilm formation

BACKGROUND/AIM: Dental diseases are caused by microorganisms organized in biofilms. Streptococcus mutans and Streptococcus intermedius are commensals of the human oral cavity. S. mutans is associated with caries, whereas S. intermedius is associated with purulent infections. Oral streptococci including S. mutants and S. intermedius express a family of surface proteins termed antigen I/II (Ag I/II). Ag I/II is implicated in adhesion; however, its role in biofilm formation has not yet been investigated. METHODS: By using isogenic Ag I/II-deficient mutants of S. mutans and S. intermedius we studied the influence of Ag I/II on in vitro biofilm formation. Biofilm was quantified in polystyrene microtiter plates and visualized by scanning electron microscopy. Ag I/II expression in planktonic and biofilm cells, as well as in the presence or absence of saliva was investigated by immunoblotting. RESULTS: In the presence of saliva, the Ag I/II-deficient mutants formed 65% less biofilm than the wild-types. In the absence of saliva, no difference was observed in S. mutans, whereas the S. intermedius Ag I/II mutant formed 41% less biofilm. Ag I/II expression was reduced in the presence of saliva. No differences in expression were observed between biofilm and planktonic cells. CONCLUSION: The results indicated that Ag I/II may be important during biofilm formation particularly in the presence of saliva. These findings may provide useful information regarding the importance of Ag I/II in biofilm formation and in the search of new strategies to control biofilm-mediated infections.     

n-Butanol extracts of Panax notoginseng suppress LPS-induced MMP-2 expression in periodontal ligament fibroblasts and inhibit osteoclastogenesis by suppressing MAPK in LPS-activated RAW264.7 cells

Objective

Periodontitis is a group of inflammatory diseases that affect connective tissue attachments and the supporting bone that surround the teeth. Osteoclasts are responsible for skeletal modeling and remodeling but may also destroy bone in several bone diseases, including osteoporosis and periodontitis. This study examined the anti-inflammatory effects of Panax notoginseng (PN) on periodontal ligament fibroblasts (PDLFs) and RAW264.7 cells under lipopolysaccharide (LPS) induced inflammatory conditions.

Design

The effects of PN on PDLFs were determined by measuring the cell viability and mRNA expression of tissue-destructive proteins. The effects of PN on osteoclasts were examined by measuring the following: (1) the cell viability, (2) the formation of Tartrate-resistant acid phosphatase (TRAP)(+) multinucleated cells, (3) MAPK signaling pathways, (4) mRNA expression of inflammatory-related proteins and (5) nitric oxide (NO) production.

Results

The n-butanol extracts of PN (bPN) increased the cell proliferation of the PDLFs and decreased the mRNA expression of matrix metalloproteinase (MMP)-2 in the PDLFs. bPN inhibited the formation of LPS-stimulated TRAP(+) multinucleated cells. bPN also inhibited the LPS-stimulated activation of JNK and ERK signaling, and inhibited the LPS-stimulated degradation of I_KB in the RAW264.7 cells. In addition, bPN decreased the mRNA expression of MMP-9 and iNOS, which are involved in the range of pathophysiological processes, such as inflammation in the RAW264.7 cells. NO production was also decreased via the inhibition of iNOS.

Conclusions

These findings suggest that bPN has therapeutic effects on bone-destructive processes, such as those that occur in periodontal diseases.