Background: Streptococcus gordonii, a pioneer colonizer of dental plaque biofilm, expresses surface protein adhesin SspB by which the bacteria bind to salivary agglutinin (gp340). SspB has extensive homology with PAc,...Background: Streptococcus gordonii, a pioneer colonizer of dental plaque biofilm, expresses surface protein adhesin SspB by which the bacteria bind to salivary agglutinin (gp340). SspB has extensive homology with PAc, a surface adhesin of Streptococcus mutans. Hence, SspB of S. gordonii competes with PAc of S. mutans for the same niche environment in the salivary pellicles. The aim of this study was to develop anti-adherence agents that enabled us to control cariogenic biofilms by using the streptococcal SspB peptide analog SspB (A4K-A11K). Methods: First, we performed ELISA to determine the S. mutans-saliva interaction and saliva-binding activities of SspB (A4K- A11K). The inhibitory effects of SspB (A4K-A11K) were then evaluated by examining S. mutans adhesion to saliva-coated hydroxyapatite disks (s-HA). To determine peptide interference with biofilm formation, S. mutans biofilms were quantified by counting CFUs on MS agar plates and by measuring the absorbance at 492 nm of safranin-stained biofilms on s-HA. Results: Saliva, particularly salivary gp340 peptide, promoted adherence of S. mutans to polystyrene surfaces. SspB (A4K-A11K) significantly bound to saliva and inhibited the adhesion of S. mutans to s-HA without bactericidal activity. Furthermore, biofilms of S. mutans on s-HA were successfully reduced by pretreatment with SspB (A4K-A11K). Conclusion: SspB (A4K-A11K) peptide competitively blocked S. mutans adhesion to experimental pellicles through SspB-gp340 interaction, thereby inhibiting biofilm formation. These findings will contribute to the control cariogenic biofilms.展开更多
Background: Porphyromonas gingivalis is a major periodontal pathogen that binds efficiently to Streptococcus gordonii, which in turn binds to salivary agglutinin (gp340). The SspB of S. gordonii appears to mediate thi...Background: Porphyromonas gingivalis is a major periodontal pathogen that binds efficiently to Streptococcus gordonii, which in turn binds to salivary agglutinin (gp340). The SspB of S. gordonii appears to mediate this association. We previously reported that the strepto-coccal SspB peptide analog, designated SspB (390-T400K-402), showed high binding activity with saliva. To understand the three-way interaction among S. gordonii, P. gingivalis and salivary gp340 as a unit, we established a peptide binding assay using SspB (390-T400K-402). Methods: The binding activity of the SspB (390-T400K-402) to P. gingivalis was detected by ELISA. Ninety-six well plates were coated with whole bacterial cell (P. gingivalis strains ATCC 33277, and W83;S. gordonii DL1) in Na2CO3 coating buffer. After blocking, bacterial cells were incubated with saliva or salivary agglutinin peptide (SRCRP2). Biotinylated SspB (390-T400K-402) was applied and incubated with 1:1000 streptoavidin-conjugated alkaline phosphatase. After development, A405 was recorded. Results: P. gingivalis 33277 showed the highest binding activity of the tested bacteria, whereas P. gingivalis W83, which was deficient in Mfa1 fimbriae, exhibited poor binding activity, as did S. gordonii. The binding of SspB (390-T400K-402) peptide in saliva- or SRCRP2-treated P. gingivalis was significantly higher than that in non-treated cells. Conclusion: The SspB (390-T400K-402) peptide binding assay revealed that initial attachment of P. gingivalis to the substrata of S. gordonii may require gp340-mediated SspB-Mfa1 interactions. The assay is available to assess the relationships among SspB, Mfa1 and salivary gp340 as a unit.展开更多
Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study ...Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study of human tooth agenesis. Our previous congenic breeding strategy using EL mice confined a major locus for agenesis of M3, designated am3, within an approximately 1 Mega base pair (Mbp) interval on chromosome 3, which contains five known genes;Lef1, Hadh, Cyp2u1, Sgms2 and Papss1. The aim of this study was to identify the strongest candidate for am3 among the five genes using real-time PCR analysis. The tooth germs of M3 in the bud stage of EL and control mice were dissected out, and total RNA was extracted. In real-time PCR analysis, a significantly low level of expression of Lef1, which is one of the essential transcription factors for early tooth development, was observed in M3 of EL mice. In addition, a significantly low level of expression of Fgf4, which is a direct transcriptional target for LEF1 in early tooth development, was observed in M3 of EL mice. Our results suggest that the cause of M3 agenesis of EL mice may be a low level of Lef1 expression in M3 in the bud stage of EL mice.展开更多
文摘Background: Streptococcus gordonii, a pioneer colonizer of dental plaque biofilm, expresses surface protein adhesin SspB by which the bacteria bind to salivary agglutinin (gp340). SspB has extensive homology with PAc, a surface adhesin of Streptococcus mutans. Hence, SspB of S. gordonii competes with PAc of S. mutans for the same niche environment in the salivary pellicles. The aim of this study was to develop anti-adherence agents that enabled us to control cariogenic biofilms by using the streptococcal SspB peptide analog SspB (A4K-A11K). Methods: First, we performed ELISA to determine the S. mutans-saliva interaction and saliva-binding activities of SspB (A4K- A11K). The inhibitory effects of SspB (A4K-A11K) were then evaluated by examining S. mutans adhesion to saliva-coated hydroxyapatite disks (s-HA). To determine peptide interference with biofilm formation, S. mutans biofilms were quantified by counting CFUs on MS agar plates and by measuring the absorbance at 492 nm of safranin-stained biofilms on s-HA. Results: Saliva, particularly salivary gp340 peptide, promoted adherence of S. mutans to polystyrene surfaces. SspB (A4K-A11K) significantly bound to saliva and inhibited the adhesion of S. mutans to s-HA without bactericidal activity. Furthermore, biofilms of S. mutans on s-HA were successfully reduced by pretreatment with SspB (A4K-A11K). Conclusion: SspB (A4K-A11K) peptide competitively blocked S. mutans adhesion to experimental pellicles through SspB-gp340 interaction, thereby inhibiting biofilm formation. These findings will contribute to the control cariogenic biofilms.
文摘Background: Porphyromonas gingivalis is a major periodontal pathogen that binds efficiently to Streptococcus gordonii, which in turn binds to salivary agglutinin (gp340). The SspB of S. gordonii appears to mediate this association. We previously reported that the strepto-coccal SspB peptide analog, designated SspB (390-T400K-402), showed high binding activity with saliva. To understand the three-way interaction among S. gordonii, P. gingivalis and salivary gp340 as a unit, we established a peptide binding assay using SspB (390-T400K-402). Methods: The binding activity of the SspB (390-T400K-402) to P. gingivalis was detected by ELISA. Ninety-six well plates were coated with whole bacterial cell (P. gingivalis strains ATCC 33277, and W83;S. gordonii DL1) in Na2CO3 coating buffer. After blocking, bacterial cells were incubated with saliva or salivary agglutinin peptide (SRCRP2). Biotinylated SspB (390-T400K-402) was applied and incubated with 1:1000 streptoavidin-conjugated alkaline phosphatase. After development, A405 was recorded. Results: P. gingivalis 33277 showed the highest binding activity of the tested bacteria, whereas P. gingivalis W83, which was deficient in Mfa1 fimbriae, exhibited poor binding activity, as did S. gordonii. The binding of SspB (390-T400K-402) peptide in saliva- or SRCRP2-treated P. gingivalis was significantly higher than that in non-treated cells. Conclusion: The SspB (390-T400K-402) peptide binding assay revealed that initial attachment of P. gingivalis to the substrata of S. gordonii may require gp340-mediated SspB-Mfa1 interactions. The assay is available to assess the relationships among SspB, Mfa1 and salivary gp340 as a unit.
文摘Tooth agenesis is the most common developmental anomaly of the human dentition. Epilepsy-like disorder (EL) mice, which have a 100% incidence of agenesis of the third molars, may be a good model for the genetic study of human tooth agenesis. Our previous congenic breeding strategy using EL mice confined a major locus for agenesis of M3, designated am3, within an approximately 1 Mega base pair (Mbp) interval on chromosome 3, which contains five known genes;Lef1, Hadh, Cyp2u1, Sgms2 and Papss1. The aim of this study was to identify the strongest candidate for am3 among the five genes using real-time PCR analysis. The tooth germs of M3 in the bud stage of EL and control mice were dissected out, and total RNA was extracted. In real-time PCR analysis, a significantly low level of expression of Lef1, which is one of the essential transcription factors for early tooth development, was observed in M3 of EL mice. In addition, a significantly low level of expression of Fgf4, which is a direct transcriptional target for LEF1 in early tooth development, was observed in M3 of EL mice. Our results suggest that the cause of M3 agenesis of EL mice may be a low level of Lef1 expression in M3 in the bud stage of EL mice.
