Acquired enamel pellicle protects gastroesophageal reflux disease patients against erosive tooth wear

Abstract The objective of this study was to compare the protein profile of the acquired enamel pellicle (AEP) formed in vivo in patients with or without gastroesophageal reflux disease (GERD), and with or without erosive tooth wear (ETW). Twenty-four volunteers were divided into 3 groups: 1) GERD and ETW; 2) GERD without ETW; and 3) control (without GERD). The AEP formed 120 min after prophylaxis was collected from the lingual/palatal surfaces. The samples were subjected to mass spectrometry (nLC-ESI-MS/MS) and label-free quantification by Protein Lynx Global Service software. A total of 213 proteins were identified, or 119, 92 and 106 from each group, respectively. Group 2 showed a high number of phosphorylated and calcium-binding proteins. Twenty-three proteins were found in all the groups, including 14-3-3 protein zeta/delta and 1-phosphatidylinositol. Several intracellular proteins that join saliva after the exfoliation of oral mucosa cells might have the potential to bind hydroxyapatite, or participate in forming supramolecular aggregates that bind to precursor proteins in the AEP. Proteins might play a central role in protecting the dental surface against acid dissolution

Estimated Dietary Fluoride Intake by 24-Month-Olds from Chocolate Bars, Cookies, Infant Cereals, and Chocolate Drinks in Brazil

The use of fluoride (F) in the prevention of dental caries is established. However, a high amount of F intake during tooth development can cause dental fluorosis The aim of this study was to analyze variations in F concentrations in chocolate bars (CB), chocolate cookies (CC), infant cereals (IC), and chocolate milk drinks (CD) to determine the daily intake of F from different sources by children at the age of risk for developing dental fluorosis. Distinct brands of CB, CC, IC, and CD were analyzed. Fluoride was separated by hexamethyldisiloxane-facilitated diffusion. Analysis was made in triplicate with an F ion-specific electrode. F ingestion (mg/kg body weight) was evaluated with the suggested consumption (0.05–0.07 mg/kg/day) for children aged 24 months (12 kg). The concentrations for all the analyzed products ranged from 0.025 to 1.827 µg/g F. The mean (range) F concentrations were CB= 0.210 ± 0.205 µg/g (0.073–0.698, n = 8), CC = 0.366 ± 0.416 µg/g (0.320–1.827, n = 9), IC = 0.422 ± 0.395 µg/g (0.073–1.061, n = 5), and CD = 0.169 ± 0.170 µg/mL (0.025–0.443, n = 12). The products that had the highest concentration in the categories CB, CC, IC, and CD, respectively, were Nescau-Ball (0.698 µg/g), Passatempo (1.827 µg/g), Milnutri (1.061 µg/g), and Toddynho (0.443 µg/mL). The consumption of only one unit of Toddynho (CD) is equivalent to more than 11% of the maximum suggested daily intake for a 24-month-old child (0.07 mg/kg body weight). When one product from each category is consumed together only once a day, this consumption is equivalent to approximately 24% of the suggested daily intake of fluoride for a 24-month-old child. The presence of high levels of fluoride in certain products suggests that they play a significant role in overall fluoride intake. It is crucial to closely monitor the fluoride content of food and drinks that are consumed by children who are at risk for dental fluorosis, and for product labels to clearly display the fluoride concentrations

Estimated Dietary Fluoride Intake by 24-Month-Olds from Chocolate Bars, Cookies, Infant Cereals, and Chocolate Drinks in Brazil

The use of fluoride (F) in the prevention of dental caries is established. However, a high amount of F intake during tooth development can cause dental fluorosis The aim of this study was to analyze variations in F concentrations in chocolate bars (CB), chocolate cookies (CC), infant cereals (IC), and chocolate milk drinks (CD) to determine the daily intake of F from different sources by children at the age of risk for developing dental fluorosis. Distinct brands of CB, CC, IC, and CD were analyzed. Fluoride was separated by hexamethyldisiloxane-facilitated diffusion. Analysis was made in triplicate with an F ion-specific electrode. F ingestion (mg/kg body weight) was evaluated with the suggested consumption (0.05–0.07 mg/kg/day) for children aged 24 months (12 kg). The concentrations for all the analyzed products ranged from 0.025 to 1.827 µg/g F. The mean (range) F concentrations were CB= 0.210 ± 0.205 µg/g (0.073–0.698, n = 8), CC = 0.366 ± 0.416 µg/g (0.320–1.827, n = 9), IC = 0.422 ± 0.395 µg/g (0.073–1.061, n = 5), and CD = 0.169 ± 0.170 µg/mL (0.025–0.443, n = 12). The products that had the highest concentration in the categories CB, CC, IC, and CD, respectively, were Nescau-Ball (0.698 µg/g), Passatempo (1.827 µg/g), Milnutri (1.061 µg/g), and Toddynho (0.443 µg/mL). The consumption of only one unit of Toddynho (CD) is equivalent to more than 11% of the maximum suggested daily intake for a 24-month-old child (0.07 mg/kg body weight). When one product from each category is consumed together only once a day, this consumption is equivalent to approximately 24% of the suggested daily intake of fluoride for a 24-month-old child. The presence of high levels of fluoride in certain products suggests that they play a significant role in overall fluoride intake. It is crucial to closely monitor the fluoride content of food and drinks that are consumed by children who are at risk for dental fluorosis, and for product labels to clearly display the fluoride concentrations

Fluoride Intensifies Hypercaloric Diet-Induced ER Oxidative Stress and Alters Lipid Metabolism.

BACKGROUND:Here, we evaluated the relationship of diet and F-induced oxidative stress to lipid metabolism in the liver of rats eating normocaloric or hypercaloric diets for two time periods (20 or 60 days). METHODS:Seventy-two 21-day-old Wistar rats were divided into 2 groups (n = 36) based on the type of diet they were eating; each of these groups was then further divided into another two groups (n = 18) based on the time periods of either 20 or 60 days, for a total of four groups. Each of these was divided into 3 subgroups (n = 6 animals/subgroup), dependent on the dose of F administered in the drinking water (0 mg/L(control), 15 mg/L or 50 mg/L). After the experimental period, blood samples and the liver were collected. Plasma samples were analyzed for HDL, cholesterol and triglycerides. Western blots were performed to probe for GRP78, Erp29, SOD2, Apo-E and SREBP in hepatic tissues. RESULTS:As expected,the expression of target proteins involved in oxidative stress increased in the F-treated groups, especially in liver tissue obtained from animals eating a hypercaloric diet. Most changes in the lipid levels and pathological conditions were seen earlier in the time period, at day 20. The morphometric analyses showed a reduction in steatosis in groups on ahypercaloric diet and treated with 50 mg F/L compared to the control, while no changes were obtained in normocaloric-fed rats. Accordingly, plasma TG was reduced in the F-treated group. The reduced expression of Apo-E in a time- and diet-dependent pattern may account for the particular decrease in steatosis in hypercaloric-fed F-treated rats. CONCLUSIONS:These results suggest that F changes liver lipid homeostasis, possibly because of the induction of oxidative stress, which seems to be higher in animals fed hypercaloric diets

Intestinal changes associated with fluoride exposure in rats: Integrative morphological, proteomic and microbiome analyses

Gastrointestinal signs and symptoms are the first signs of toxicity due to exposure to fluoride (F). This suggests the possibility that lower levels of subchronic F exposure may affect the gut. The aim of this study was to evaluate changes in the morphology, proteome and microbiome of the ileum of rats, after subchronic exposure to F. Male rats ingested water with 0, 10, or 50 mgF/L for thirty days. Treatment with F, regardless of the dose, significantly decreased the density of HuC/D-IR neurons, whereas CGRP-IR and SP-IR varicosities were significantly increased compared to the control group. Increased VIP-IR varicosities were significantly increased only in the group treated with 50 mgF/L. A significant increase in thickness of the tunica muscularis, as well as in the total thickness of the ileum wall was observed at both F doses when compared to controls. In proteomics analysis, myosin isoforms were increased, and Gastrotopin was decreased in F-exposed mice. In the microbiome metagenomics analysis, Class Clostridia was significantly reduced upon exposure to 10 mgF/L. At the higher F dose of 50 mg/L, genus Ureaplasma was significantly reduced in comparison with controls. Morphological and proteomics alterations induced by F were marked by changes associated with inflammation, and alterations in the gut microbiome. Further studies are needed to determine whether F exposure increases inflammation with secondary effects of the gut microbiome, and/or whether primary effects of F on the gut microbiome enhance changes associated with inflammation

Representative expression of proteins GRP-78, APO-E, SOD2, ERP-29 and of the constitutive protein β-tubulin in samples of individual animals (n = 3) from each group.

<p>Densitometric analysis was performed for 6 animals per group. <b>A.</b> Protein expression in the liver of rats in the group treated with the hypercaloric diet for 20 days; <b>B.</b> Protein expression in the liver of rats treated with the normocaloric diet for 20 days; <b>C.</b> Protein expression in the liver of rats in in the group treated with the hypercaloric diet for 60 days; <b>D.</b> Protein expression in the liver of rats treated with the normocaloric diet for 60 days. Densitometry was analyzed using the software <i>Image Studio Lite</i>. Vertical bars represent standard deviations. For each condition, distinct superscripts denote significant differences among the groups (ANOVA and Tukey’s test, p<0.05, n = 6).</p

Proposed mechanism by which fluoride affects lipid metabolism depending on the type of diet consumed and time of exposure.

<p>The diet-dependency effects of fluoride in lipid metabolism are observed strictly at earlier periods and are related with ER oxidative stress. Upon consumption of normocaloric diet, fluoride-induced oxidative stress leads to increase of GRP78, which in turn reduces SREBP, thus deactivating TG synthesis. However, in the presence of hypercaloric diet, fluoride exposition induces oxidative stress highlighted by GRP78, ERp29 and SOD2 increases, which in turn, by undetermined mechanism, leads to reduction of Apo-E, which diminishes precursors of Acetyl–Coa and leads to less formation of liver TG.</p

Representative expression of proteins SREBP, and of the constitutive protein β-tubulin ou α-tubulin in samples of individual animals (n = 3) from each group.

<p>Densitometric analysis was performed for 6 animals per group. <b>A.</b> Protein expression in the liver of rats in the group treated with the hypercaloric diet for 20 and 60 days; <b>B.</b> Protein expression in the liver of rats treated with the normocaloric diet for 20 and 60 days. Densitometry was analyzed using the software <i>Image Studio Lite</i>. Vertical bars represent standard deviations. Distinct superscript denote significant differences among the groups (ANOVA and Tukey’s test, p<0.05, n = 6).</p

Proteomic analysis of stimulated saliva in gastroesophageal reflux disease patients with and without erosive tooth wear: observational study.

OBJECTIVE To evaluate the difference in the proteomic profile of stimulated saliva in patients with gastroesophageal reflux disease (GERD) with (GE) and without (GNE) erosive tooth wear (ETW), regarding both human and bacterial proteins. METHODS Stimulated saliva (SS) was collected from 16 patients (8/group). Samples were centrifuged at 4.500g for 15 min under refrigeration to remove all debris. The supernatant from each saliva sample was taken and frozen at -80°C. After extracting the proteins, they were submitted to reverse phase liquid chromatography and mass spectrometry (nLC-ESI-MS/MS). Label-free proteomic quantification was performed using Protein Lynx Global Service (PLGS) software (p < 0.05) for human and bacterial proteins. RESULTS In total, 67 human proteins were common for GNE and GE groups. GNE group presented, compared to GE group, increase in proteins that confer antimicrobial and acid resistant properties, such as cystatins, histatin and immunoglobulins. However, GNE group had a marked decrease in subunits of hemoglobin (α, β and delta). Regarding bacterial proteins, for SS, 7 and 10 unique proteins were identified in the GE and GNE groups, respectively. They are related to protein synthesis and energy metabolism and interact with human proteins typically found in saliva and supramolecular complexes of the acquired pellicle. CONCLUSIONS Our data indicate that the stimulation of the salivary flow increases acid resistant and antimicrobial proteins in saliva, which might protect against ETW. CLINICAL SIGNIFICANCE This pioneer study showed important differences in the human and bacterial proteome of SS in patients with GERD with or without ETW