Spectrophotometric Analysis of Streptococcus mutans Growth and Biofilm Formation in Saliva and Histatin-5 Relate to pH and Viscosity

ABSTRACT Objective: To analyze the ability of saliva in controlling the growth and the biofilm formation of Streptococcus mutans (S. mutans) as well as the effect of histatin-5 anti-biofilm relate to pH and saliva viscosity. Material and Methods: The S. mutans biofilm assayed by crystal violet 1% and its growth measured by spectrophotometer. The saliva viscosity was analyzed by viscometer, and pH of saliva was measured by pH meter. Results: Based on the optical density values, growth of S. mutans in saliva ranged <300 CFU/mL (0.1 nm) at concentrations of 25%, 12.5% and 6.25% for 24 hours. Whereas at the 48 h and 72 h period of incubation shown an increase in growth of S. mutans ranged 300-600 CFU/mL (0.2-0.36 nm). The inhibitory biofilm formation of S. mutans in saliva was significantly higher at concentrations of 12.5% and 6.25% at 24 h incubation times on a moderate scale, whereas the histatin-5 was effective to inhibit S. mutans biofilm on the 50 and 25 ppm. The saliva possessed a higher inhibitory of biofilm S. mutans than histatin-5 and good level viscosity (0.91-0.92 cP). Conclusion: The saliva was able to control the growth of S. mutans, and histatin-5 can inhibit the biofilm formation S. mutans. Furthermore, the saliva was also able to respond to the pH change with good viscosity of saliva.

Peptídeos peptidomiméticos da película adquirida do esmalte: efeitos no crescimento de cristal de hidroxiapatita / Peptidomimetics of acquired enamel pellicle peptides: effects on hydroxyapatite crystal growth

Os peptídeos da estaterina (DR9) e da histatina 3 (RR14), que ocorrem naturalmente na película in vivo, amplificam o efeito inibitório do crescimento de cristais de hidroxiapatita, função relacionada à remineralizarão do esmalte e formação de cálculos dentários. A hipótese da duplicação/hibridação de domínios funcionais dos peptídeos DR9 da estaterina e RR14 da histatina 3 foi testada. Para isto, os peptídeos peptidomiméticos (DR9-DR9, DR9-RR14), além deles individualmente e suas proteínas intactas (DR9, RR14, estaterina e histatina 3) foram estudados em sete concentrações diferentes para avaliar o efeito da inibição do crescimento de cristais de hidroxiapatita. Foi utilizado um ensaio colorimétrico de microplaca para quantificar o crescimento de cristais de hidroxiapatita. As experiências foram feitas em triplicata e a concentração inibitória (IC50) foi estabelecida para cada grupo. A IC50 foi calculada para todos os peptídeos e proteínas testados. A histatina 3 e o RR14 não atingiram o valor de IC50. O DR9- RR14 atingiu o valor de IC50 a 3,80 M. Como esperado, DR9 e DR9-DR9 demonstraram um efeito inibitório significativo na atividade de crescimento de cristais, atingindo o valor de IC50 a 2,82 M e 1,07 M, respectivamente. A estaterina atingiu o valor de IC50 a 2,50 M. Na análise estatística, foram aplicados os testes ANOVA e Student-Newman-Keuls para comparações por pares, para comparar os valores entre os grupos. O DR9-DR9 amplificou o efeito inibitório do crescimento de cristais de hidroxiapatita quando comparado com DR9 único (p <0,05), demonstrando que a multiplicação do domínio funcional é uma forte tendência evolutiva da proteína. De forma interessante, o peptídeo híbrido DR9-RR14 demonstrou um efeito inibitório intermediário quando comparado com outros dois grupos: DR9 único e DR9-DR9. Este estudo utilizou a abordagem peptidomimética para investigar uma via potencial de evolução da proteína relacionada com a duplicação/hibridação dos constituintes peptídicos naturais da película adquirida de esmalte. O conhecimento obtido por meio dos resultados deste trabalho pode fornecer uma base para o desenvolvimento de peptídeos sintéticos para uso terapêutico, tanto contra cárie dentária, como para a doença periodontal.(AU)

The statherin and histatin 3 peptides (DR9 and RR14 respectively), which occur naturally in the film in vivo, amplify the inhibitory effect for the growth of hydroxyapatite crystals, a function related to remineralization of the enamel and formation of dental calculi. The hypothesis of duplication/hybridization of functional domains of the DR9 peptides of the statherin and RR14 of histatin 3 was tested. For this, the peptidomimetic peptides (DR9-DR9, DR9-RR14), in addition to them individually and their intact proteins (DR9, RR14, statherin and histatin 3) were studied at seven different concentrations to evaluate the effect of growth inhibition of hydroxyapatite crystals. A colorimetric assay of microplate was used to quantify the growth of hydroxyapatite crystals. The experiments were done in triplicate and the inhibitory concentration (IC50) was established for each group. The IC50 was calculated for all peptides and proteins tested. Histatin 3 and RR14 did not reach the IC50 value. DR9-RR14 reached the IC50 value at 3.80 M. As expected, DR9 and DR9-DR9 demonstrated a significant inhibitory effect on crystal growth activity, reaching the IC50 value at 2.82 M and 1.07 M, respectively. Statherin reached the IC50 value at 2.50 M. ANOVA and Student-Newman-Keuls tests for paired comparisons were applied to compare the values between the groups. DR9-DR9 amplified the inhibitory effect of hydroxyapatite crystal growth when compared to single DR9 (p <0.05), demonstrating that the multiplication of the functional domain is a strong protein evolution pathway. Interestingly, the hybrid peptide DR9-RR14 demonstrated an intermediate inhibitory effect when compared to other two groups: single DR9 and DR9-DR9. This study utilized the peptidomimetic approach to investigate a potential pathway of protein evolution related to duplication/hybridization of the natural peptidic constituents of the acquired enamel film. The knowledge obtained through the results of this work can provide a basis for the development of synthetic peptides for therapeutic use, both against dental caries and for periodontal disease.(AU)

A study on ß-defensin-2 and histatin-5 as a diagnostic marker of early childhood caries progression

BACKGROUND: Recently, a continuous growth of interest has been observed in antimicrobial peptides (AMPs) in the light of an alarming increase in resistance of bacteria and fungi against antibiotics. AMPs are used as biomarkers in diagnosis and monitoring of oral cavity pathologies. Therefore, the determination of specific protein profiles in children diagnosed with early childhood caries (ECC) might be a basis for effective screening tests and specialized examinations which may enable progression of disease. METHODS: The objective of the studies was to determine the role of histatin-5 and ß-defensing-2 as a diagnostic marker of early childhood caries progression. In this work, results of concentration determination of two salivary proteins (histatin-5 and ß-defensin-2) were presented. In addition, bacterial profiles from dental plaque in various stages of ECC and control were marked. The assessment of alteration in the concentration of these two proteins in a study group of children with various stages of ECC and a control group consisting of children with no symptoms was performed by enzyme-linked immunosorbent assays. RESULTS: The statistical analysis showed a significant increase in the concentration of histatin-5 and ß-defensin-2 in the study group compared to the control group and correlated with the progression of the disease. CONCLUSIONS: The confirmation of concentration changes in these proteins during the progression of dental caries may discover valuable disease progression biomarkers.

Influence of histatin 1 on the proliferation and migration of HaCaT cells / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the influence of histatin 1 (Hst1) on the proliferation and migration of human epidermal cell line HaCaT.</p><p><b>METHODS</b>(1) HaCaT cells were routinely cultured and divided into control group, 100, 30, and 3 µg/mL Hst1 groups, 10 ng/mL recombinant human epidermal growth factor (rhEGF) group, and 30 µg/mL Hst1 + 10 ng/mL rhEGF group, according to the random number table (the same dividing method used for following grouping), with 27 samples in each group. NO stimulating factor was added in control group, while Hst1 and(or) rhEGF in corresponding concentration(s) was (were) added in the latter 5 groups. Cell proliferation was assayed by cell counting method at post culture hour (PCH) 24, 48, and 72. (2) HaCaT cells were divided into control group and 100, 30, and 3 µg/mL Hst1 groups, with 27 samples in each group. NO stimulating factor was added in control group, while Hst1 in corresponding concentration was added in the latter 3 groups. Cell cycle was assayed with flow cytometry at PCH 24, 48, and 72, and PI was calculated. (3) HaCaT cells were divided into control group, 30 µg/mL Hst1 group, 10 ng/mL rhEGF group, 30 µg/mL Hst1 + 10 ng/mL rhEGF group, 15 µg/mL Hst1 + 5 ng/mL rhEGF group, and 15 µg/mL Hst1 + 10 ng/mL rhEGF group, with 10 samples in each group. NO stimulating factor was added in control group, while Hst1 and(or) rhEGF in corresponding concentration(s) was (were) added in the latter 5 groups. Cells in each group were divided into two portions: cells in one portion were treated by mitomycin C for 2 hours, while cells in the other portion were not. Scratching assay was conducted in both portions of cells. Cell migration was measured at post scratching hour (PSH) 0, 16, and 24, and the wound-area healing rate was calculated. Data were processed with analysis of variance, and LSD- t test or Dunnett t test was applied in paired comparison among groups.</p><p><b>RESULTS</b>(1) At PCH 24, the cell numbers in 10 ng/mL rhEGF group and 30 µg/mL Hst1 + 10 ng/mL rhEGF group were significantly higher than that in control group (with t values respectively 3.813, 5.410, P < 0.05 or P < 0.01). Except for cell numbers in 30 µg/mL Hst1 group and 3 µg/mL Hst1 group at PCH 48, cell numbers in the other groups as treated by Hst1 and (or) rhEGF were significantly higher than those in control group at PCH 48 and 72 (with t values from 7.754 to 24.979, P values all below 0.01). At PCH 72, the cell number was obviously higher in 100 µg/mL Hst1 group [(19.21 ± 0.59)×10⁴] than in 30 µg/mL Hst1 group [(16.19 ± 0.53)×10⁴)] and 3 µg/mL Hst1 group [(15.38 ± 0.13)×10⁴], with t values respectively 11.391, 19.017, P values all below 0.01. The cell number was higher in 30 µg/mL Hst1 + 10 ng/mL rhEGF group than in 30 µg/mL Hst1 group, 3 µg/mL Hst1 group, and 10 ng/mL rhEGF group (with t values from 4.579 to 34.884, P < 0.05 or P < 0.01). Cell numbers in all groups increased with prolongation of time. (2) Compared with those in control group at PCH 24 and 48, the percentage of cells in G0/G1 phase was decreased, the percentage of cells in S phase was increased (except for cell percentage of 30 µg/mL Hst1 group at PCH 24), and PI value was significantly increased in 100 µg/mL Hst1 group and 30 µg/mL Hst1 group (with t values from 4.752 to 16.104, P values all below 0.01). The PI value in 3 µg/mL Hst1 group was obviously higher than that in control group only at PCH 48 (t = 4.609, P < 0.01). At PCH 72, only the PI value in 100 µg/mL Hst1 group was higher than that in control group (t = 8.005, P < 0.01). Compared among the groups treated by Hst1, the percentage of cells in G0/G1 phase showed an elevating trend, and the percentage of cells in S phase and the PI value showed a declining trend along with the decrease in Hst1 concentration at each time point. Compared within each group treated by Hst1, the percentage of cells in G0/G1 phase declined first and then elevated, while the percentage of cells in S phase and the PI value elevated first and then declined along with prolongation of time. (3) Without treatment of mitomycin C, the wound-area healing rate in 30 µg/mL Hst1 group (75.9 ± 3.9)% at PSH 16 was significantly higher than those in control group and 10 ng/mL rhEGF group [(53.0 ± 3.5)%, (61.7 ± 2.5)%, with t values respectively 12.241, 7.598, P values all below 0.01], but lower than those in 30 µg/mL Hst1 + 10 ng/mL rhEGF group, 15 µg/mL Hst1 + 5 ng/mL rhEGF group, and 15 µg/mL Hst1 + 10 ng/mL rhEGF group [(95.0 ± 4.1)%, (97.0 ± 3.7)%, (80.5 ± 5.9)%, with t values from -11.324 to -2.502, P < 0.05 or P < 0.01]. After being treated by mitomycin C, the wound-area healing rate in 30 µg/mL Hst1 group at PSH 16 [(54.1 ± 4.5)%] was higher than that in control group [(35.8 ± 5.7)%, t = 7.790, P < 0.01], but lower than that in the same Hst1 concentration but without mitomycin C treatment group (t = -10.863, P < 0.01). There was no statistically significant difference in the wound-area healing rate between 30 µg/mL Hst1 group and other groups treated by Hst1 and rhEGF at PSH 16 (with t values from 0.061 to 2.030, P values all above 0.05). Compared within each group with or without treatment of mitomycin C, the wound-area healing rate at PSH 16 was not significantly different from that at PSH 24 (with F values from 0.856 to 3.062, P values all above 0.05).</p><p><b>CONCLUSIONS</b>Hst1 can promote the proliferation and migration of HaCaT cells. It has synergic effect with rhEGF on the promotion of cell proliferation, but their synergic effect on cell migration is not obvious.</p>

Determination of histatins 5 in salivary by reversed-phase high performance liquid chromatography method with ultraviolet detection / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The determination method of histatins 5 in human saliva with reversed-phase high performance liquid chromatography (HPLC) was developed.</p><p><b>METHODS</b>Salivary samples were collected and diluted with phosphate buffer (pH 2.5). The upper solution was determined with HPLC. Phosphate buffer (pH 3.5) of the mobile phase and C18 column was used throughout the experiment. The detection wavelength was 276 nm.</p><p><b>RESULTS</b>The linear ranges were 1.0-50.0 microg x mL(-1). The detection limit was 0.12 microg x mL(-1). The relative standard derivations (RSD) of standard solution for reserved time and peak area were 0.68% and 4.13% respectively. The proposed method was applied for analysis of salivary samples and the satisfactory results were obtained. RSD for sample determination was 4.41% and the average recoveries were 88.4%-109.0%.</p><p><b>CONCLUSION</b>The method was quick, simple and accurate. Analytical time was less than 15 min. It was adapted for analysis of salivary histatins 5 in salivary samples.</p>