Salivary Carbonic Anhydrase VI Research Articles

Salivary carbonic anhydrase VI concentration and the state of the oral cavity

Salivary carbonic anhydrase VI concentration and the state of the oral cavity

Salivary proteome of a Neotropical primate: potential roles in host defense and oral food perception.

BackgroundSaliva contains a very complex mixture of proteins for defense against microbiological pathogens and for oral food perception. Howler monkeys are Neotropical primates that can consume a mostly leaf diet. They are well known to thrive in highly disturbed habitats where they may cope with a diversity of dietary challenges and infection risks. We aimed to describe the salivary proteome of howlers to contribute to better understanding of their physiology.MethodsWe analyzed the salivary proteins of wild black howler monkeys (Alouatta pigra), by SDS-PAGE-1-D and Nano LC-MS/MS and categorized them by their function involved in host defense and oral food perception.ResultsOur proteomic analysis identified 156 proteins in howler saliva including a number of host defense peptides that are the first line of defense in mammals, such as defensin, cathelicidin, dermcidin, and lactotransferrin, and proteins with anti-bacterial, anti-fungal, and anti-viral capacity, such as IgA, IgG, IgM, BPI, salivary heat shock 70 kDa protein, beta-2-microbulin, and protein S-100. We also identified key proteins necessary for taste perception, including salivary carbonic anhydrase VI, cystatin D, IgA, and fatty acid-binding protein. Proteins to detect astringent foods were identifying, including four members of cystatins (A, B, C and D), lactoperoxidase, and histidine-rich proteins. No chitinase and amylase were identified as would be expected because howlers do not eat insects and little starch. These findings provide basic information to future studies in oral biology, ingestive physiology, and physiological ecology of mammals and non-human primates.

Polymorphism in the CAVI gene, salivary properties and dental caries

Objectives: Carbonic anhydrase (CA) VI is supposed to take part in pH or buffering capacity regulation, which can influence the caries risk of an individual. Its expression in the saliva can be modified by single nucleotide polymorphism (SNP). The aim was to investigate SNP in the CA VI gene in relation to active dental caries and physiochemical properties of saliva.Materials and methods: One hundred and thirty participants aged 11–16 years were involved. Clinical examinations were carried out using standardized WHO criteria, DMFT/DMFS and white spot lesions score was evaluated. Saliva samples were examined for salivary properties and CA VI concentration. DNA evaluated in the investigation was extracted from the buccal smear. Three SNP within CAVI gene (rs2274327; rs2274328; rs2274333) were selected and genotyping was performed.Results: In the active caries group, the mean CAVI concentration was significantly lower than in caries free group (p = .014). No association between increased or decreased risk of caries and analysed SNPs was found. There were some significant relations concerning SNPs and salivary buffer capacity and flow rate in rs2274327 and rs2274328.Conclusions: Polymorphism in the CAVI gene can affect salivary properties but there is no direct connection with dental caries.

Children with a Higher Activity of Carbonic Anhydrase VI in Saliva Are More Likely to Develop Dental Caries

Objective: This study aimed to analyze the concentration and activity of carbonic anhydrase (CA) VI in the saliva of school children. We investigated the relationship among caries, CA VI concentration/activity, flow rate, pH, and buffering capacity. Materials and Methods: Seventy-four school children were divided into a caries-free group and a caries group. Clinical examinations were conducted by one examiner according to World Health Organization criteria + early caries lesions. Salivary flow rate, pH, and buffering capacity were analyzed. Salivary CA VI concentration and activity were evaluated by ELISA and zymography, respectively. The data were analyzed using Student's t test and the Mann-Whitney test, and Pearson and Spearman correlation analyses were also done. In multivariate modeling, associations between variables were expressed as odds ratios. Results: The results showed that salivary flow rate, salivary pH, and BC were significantly higher in the saliva of caries-free children. Also, the salivary CA VI concentration was significantly higher in the saliva of caries-free children. The salivary CA VI activity was higher in children with caries. We found a negative correlation between BC and dental caries. Also, in the caries group we found a positive correlation between the concentration and the activity of CA VI and a negative correlation between BC and CA VI activity. A negative correlation between salivary pH and CA VI concentration was observed in the caries-free group. A high activity of CA and a low salivary flow rate were associated with dental caries. Conclusion: These results support the conclusion that dental caries is highly affected by the activity of CA VI in saliva as well as by the salivary flow rate.

Salivary proteome and glucose levels are related with sweet taste sensitivity in young adults

ABSTRACTSweet taste plays a critical role in determining food preferences and choices. Similar to what happens for other oral sensations, individuals differ in their sensitivity for sweet taste and these inter-individual differences may be responsible for variations in food acceptance. Despite evidence that saliva plays a role in taste perception, this fluid has been mainly studied in the context of bitterness or astringency. We investigated the possible relationship between sweet taste sensitivity and salivary composition in subjects with different sucrose detection thresholds. Saliva collected from 159 young adults was evaluated for pH, total protein concentration and glucose. One- and bi-dimensional electrophoresis (2-DE) were performed and protein profiles compared between sweet sensitivity groups, with proteins that were differently expressed being identified by MALDI-FTICR-MS. Moreover, Western blotting was performed for salivary carbonic anhydrase VI (CA-VI) and cystatins and salivary amylase enzymatic activity was assessed in order to compare groups. Females with low sensitivity to sweet taste had higher salivary concentrations of glucose compared to those with sensitivity. For protein profiles, some differences were sex-dependent, with higher levels of α-amylase and CA-VI in low-sensitivity individuals and higher levels of cystatins in sensitive ones for both sexes. Body mass index was not observed to affect the association between salivary proteome and taste sensitivity. To our knowledge, these are the first data showing an association between sweet taste and saliva proteome.

SALIVARY CARBONIC ANHYDRASE VI, ZINC SULFATE TASTE ACUITY AND FREQUENCY OF ILLNESS: A PILOT STUDY

Salivary Carbonic Anhydrase VI (CA6) is a zinc-dependent metalloenzyme which may be important for normal taste function. Though many taste assessment methods exist, the assessment of zinc sulfate taste acuity is a method that has been suggested to have diverse relationships to human health. A double-blinded pilot study was conducted among 21 individuals to analyze the relationships between salivary CA6 concentrations, zinc sulfate taste acuity and self-reported frequency of illness. ELISA was performed to quantify CA6 concentrations, the Bryce-Smith and Simpson "Zinc Taste Test" (BS-ZTT) protocol and a Taste Intensity Visual Analog Scale (TI-VAS) were utilized to assess zinc sulfate taste acuity and a health history questionnaire was used to determine the frequency of illness. A statistically significant correlation existed between CA6 concentration and zinc sulfate taste acuity determined via the BS-ZTT (rs = 0.62; p = 0.03). A moderate statistically significant negative correlation was found between self-reported frequency of illness and BS-ZTT scores (rs = -0.64, p = 0.034). Likewise, a strong statistically significant negative correlation was found between self-reported frequency of illness and TI-VAS scores (rs = -0.81, p = 0.003). The results of this pilot study suggest that zinc sulfate taste acuity may be reflective of salivary CA6 concentration in addition to being a retrospective indicator of illness frequency.

Effect of Genetic Polymorphisms in CA6 Gene on the Expression and Catalytic Activity of Human Salivary Carbonic Anhydrase VI

Carbonic anhydrase isoenzyme VI (CA VI) plays an important role in the homeostasis of oral tissues participating in the processes of taste, protection of dental tissues against the loss of minerals, caries, and possibly in the formation of dental calculus in periodontal disease. This study aimed to verify the correlation between changes in the expression and activity of human salivary carbonic anhydrase VI and genetic polymorphisms in its gene (CA6). The study population consisted of 182 healthy volunteers (female and male, aged 18-22). Samples of total saliva were assayed for CA VI concentrations using a specific time-resolved immunofluorometric assay. CA VI catalytic activity was detected by a modified protocol of Kotwica et al. [J Physiol Pharmacol 2006;57(suppl 8):107-123], adapted to CA VI in saliva. Samples of genomic DNA were genotyped for polymorphisms rs2274327 (C/T), rs2274328 (A/C) and rs2274333 (A/G) by TaqMan® SNP Genotyping Assays. The concentration and catalytic activity of the salivary CA VI obtained for the different genotypes were analyzed using the Kruskal-Wallis nonparametric test and the Dunn test. The results showed that individuals with TT genotype (rs2274327) had significantly lower CA VI concentrations than the individuals with genotypes CT or CC (p < 0.05). There was also an association between polymorphism rs2274333 and salivary CA VI concentrations. There were no associations between the three polymorphisms analyzed and variations in CA VI activity. Our results suggest that polymorphisms in the CA6 gene are associated with the concentrations of secreted CA VI.

Salivary carbonic anhydrase VI, zinc taste perception, and the frequency of illness: a pilot study

Zinc is an essential mineral which is known to play an important role in immune function and taste perception. Our study used the Bryce‐Smith Zinc Taste Test (ZTT) and a novel visual analog scale (VAS) to assess zinc taste perception. Additionally, a health history questionnaire was utilized to assess latent factors in zinc nutriture among the 18 research participants. Whole saliva was sampled and salivary carbonic anhydrase VI (CA6) concentrations were quantified via ELISA. The individual with the lowest taste perception score of “1” on the ZTT also had among the lowest VAS score (0 mm) and CA6 concentration (4.05 ug/mL). The two individuals with the highest taste perception scores of “4” on the ZTT also had among the highest VAS scores (64 mm and 96 mm, respectively) and CA6 concentrations (16.59 ug/mL and 18.70 ug/mL, respectively). No similar trend existed among those who were scored with a “2” or “3” on the ZTT (n=8). The individual with a ZTT score of “1” noted illness occurring four times per year. The individuals with a ZTT of “4” both noted illness occurring once per year. When the frequency of illness was assessed among the group (n=18; M=2 illnesses/year), a significant difference was found between the VAS scores of individuals noting illness 0–2 times per year (n=11) and &gt;;2 times per year (n=7) (p=0.03). However, when analyzing the frequency of illness among the same groups with regard to ZTT scores, no significant difference existed (p=0.42). Although data is limited, the VAS appears to be a better alternative in assessing correlations between zinc taste perception and illness frequency than the ZTT. Our study warrants further investigation of zinc taste perception, CA6 concentrations, and the frequency of illness, particularly among those individuals with weak and strong zinc taste perception. Funding for the research was awarded by a West Liberty University Faculty Development Grant.

Are increased salivary carbonic anhydrase VI levels related to the amount of supragingival dental calculus formation and clinical periodontal scores?

Background/purposeCarbonic anhydrase (CA) VI is a unique salivary isoenzyme that regulates the pH in the oral environment. Its increased levels result in a more-alkaline saliva, hence it was hypothesized to contribute to dental calculus formation together with salivary inorganic salts. In this study, we evaluated the relationship between salivary CA VI levels and the amount of supragingival dental calculus formation on human teeth. Materials and methodsSeventy-five volunteers were grouped according to their oral hygiene status, and the amount of supragingival dental calculus was measured by the Volpe–Manhold Index (VMI). Group I included control individuals who had no dental calculus formation clinically (VMI = 0). Group II included light calculus formers (VMI < 7), and group III included heavy calculus formers (VMI ≥ 7). Clinical periodontal indices and salivary CA VI levels were measured in all individuals, and were compared among the groups and correlated within groups. ResultsDifferences among the groups according to clinical scores and CA VI levels were found to be statistically significant (P < 0.05). The correlation between the oral hygiene index and salivary CA VI levels was found statistically significant in group III (P < 0.05), but was not statistically significant in group II (P > 0.05). Significant positive correlations were found between salivary CA levels and amount of dental calculus in groups II and III (P < 0.05 and < 0.01, respectively). ConclusionThis study found positive correlations between increased salivary CA VI activity and the amount of supragingival dental calculus; however, further investigations are needed to clarify the exact association between these parameters.

Relationship among Salivary Carbonic Anhydrase VI Activity and Flow Rate, Biofilm pH and Caries in Primary Dentition

This study aimed to determine the activity of carbonic anhydrase isoenzyme VI (CAVI) in the saliva of preschool children with caries and to investigate the relationship between caries and salivary CAVI activity, salivary flow rate and biofilm pH before and after a 20% sucrose rinse. Thirty preschool children aged 45.3–80.3 months were divided into two groups: a caries-free group and a caries group. Clinical examinations were conducted by one examiner (ĸ = 0.95) according to WHO criteria (dmfs) and early caries lesions. From each subject, CAVI activity, salivary flow rate and plaque pH were determined before and after a sucrose rinse. The results were submitted to Wilcoxon, Mann-Whitney and Spearman correlation tests (α = 0.05). The results showed that prerinse CAVI activity and its variation were higher in the saliva from caries children than from caries-free children. No difference was found between the two groups in postrinse salivary CAVI activity. After rinsing, biofilm pH differences were lower in both groups (p = 0.0012 and p = 0.0037 for the caries and caries-free groups, respectively). Also, after the sucrose rinse, salivary flow rate significantly increased in caries and caries-free groups (p = 0.0003, p = 0.0037). The variation of salivary CAVI activity was negatively correlated with caries (r = –0.501, p = 0.005). Child’s age showed a positive correlation with caries (r = 0.456, p = 0.011). These results suggest that variation of salivary CAVI activity and child’s age are associated with dental caries in preschool children.

Carbonic Anhydrase I, II, and VI, Blood Plasma, Erythrocyte and Saliva Zinc and Copper Increase After Repetitive Transcranial Magnetic Stimulation

IntroductionRepetitive transcranial magnetic stimulation (rTMS) has been used to treat symptoms from many disorders; biochemical changes occurred with this treatment. Preliminary studies with rTMS in patients with taste and smell dysfunction improved sensory function and increased salivary carbonic anhydrase (CA) VI and erythrocyte CA I, II. To obtain more information about these changes after rTMS, we measured changes in several CA enzymes, proteins, and trace metals in their blood plasma, erythrocytes, and saliva. MethodsNinety-three patients with taste and smell dysfunction were studied before and after rTMS in an open clinical trial. Before and after rTMS, we measured erythrocyte CA I, II and salivary CA VI, zinc and copper in parotid saliva, blood plasma, and erythrocytes, and appearance of novel salivary proteins by using mass spectrometry. ResultsAfter rTMS, CA I, II and CA VI activity and zinc and copper in saliva, plasma, and erythrocytes increased with significant sensory benefit. Novel salivary proteins were induced at an m/z value of 21.5K with a repetitive pattern at intervals of 5Km/z. ConclusionsrTMS induced biochemical changes in specific enzymatic activities, trace metal concentrations, and induction of novel salivary proteins, with sensory improvement in patients with taste and smell dysfunction. Because patients with several neurologic disorders exhibit taste and smell dysfunction, including Parkinson disease, Alzheimer disease, and multiple sclerosis, and because rTMS improved their clinical symptoms, the biochemical changes we observed may be relevant not only in our patients with taste and smell dysfunction but also in patients with neurologic disorders with these sensory abnormalities.

Carbonic anhydrase II is secreted from bovine parotid glands.

Besides carbonic anhydrase VI (CA-VI), CA-II is suggested to be a second secreted isoenzyme in ruminant saliva. Therefore, the aim of the present study was to investigate the expression of salivary CA-II in bovine parotid glands at the protein level. Moreover, we intended to identify the cells which secrete the enzyme into the saliva. Two commercially available CA-II specific antibodies were tested for use in immunohistochemistry on frozen sections of bovine parotid tissue. Intense positive staining for CA-II was found in luminal duct cells and for the first time also inside the duct lumen, clearly demonstrating the expression and secretion of salivary CA-II in bovine parotid glands. The presence of CA-II protein was verified for parotid tissue and whole saliva using immunoblot analysis. Both salivary CA-II and CA-VI are highly active in supplying the alimentary tract with bicarbonate. It is suggested that a decrease in the expression of either one of these enzymes might severely disturb digestion and/or increase susceptibility to acidosis in ruminants.

A role of salivary carbonic anhydrase VI in dental plaque

Carbonic anhydrase (CA) VI is a unique secreted isozyme of CA, which catalyzes the reversible reaction CO2 +H2O<-->H+ +HCO3-. CA VI has been thought to provide a greater buffering capacity to fluids into which it is secreted. This study was performed to confirm this in saliva. Nine healthy subjects participated in the study. The pH of the dental plaque from each subject was monitored after a mouth rinse with 10% sucrose with or without 10(-5)M acetazolamide, a specific inhibitor of CA. Also CA was examined in plaque by enzyme histochemistry, immunohistochemistry and Western blot analysis. Though sucrose and sucrose plus inhibitor yielded Stephan curves with a similar temporal pattern, the pH values of the latter were significantly lower than those of the former. Plaque exhibited CA activity by enzyme histochemistry. Immunohistochemistry and Western analysis demonstrated that the activity was due to CA VI but not to CA I or CA II. The results indicate that CA VI in saliva penetrates plaque and facilitates acid neutralization by salivary bicarbonate. Therefore, CA VI may be considered an anti-caries protein in saliva.

Salivary carbonic anhydrase VI and its relation to salivary flow rate and buffer capacity in pregnant and non-pregnant women

Objective: Previous studies have shown that pregnancy may have unfavourable effects on oral health. The pH and buffer capacity (BC) of paraffin-stimulated saliva, for example, have been found to decrease towards late pregnancy. Salivary carbonic anhydrase VI (CA VI) probably protects the teeth by accelerating the neutralization of hydrogen ions in the enamel pellicle on dental surfaces. Since estrogens and androgens are known to regulate CA expression in some tissues, we studied here whether salivary CA VI concentration shows pregnancy-related changes. Design: Paraffin-stimulated salivary samples were collected from nine pregnant women 1 month before delivery and about 2 months afterwards and assayed for salivary CA VI concentration, BC and flow rate. The enzyme concentration was determined using a specific time-resolved immunofluorometric assay. The control group consisted of 17 healthy non-pregnant women. Results: The results indicated that salivary CA VI levels varied markedly among individuals, but no significant differences in mean concentrations were seen between the samples collected during late pregnancy and postpartum. BC values were lower during pregnancy, however. Conclusions: Our findings suggest that CA VI secretion is not significantly affected by the hormonal alterations associated with pregnancy, and confirm the earlier reports that CA VI is not involved in the regulation of actual salivary BC.

Secretion of Carbonic Anhydrase Isoenzyme VI (CA VI) from Human and Rat Lingual Serous von Ebner's Glands

Salivary carbonic anhydrase VI (CA VI) appears to contribute to taste function by protecting taste receptor cells (TRCs) from apoptosis. The serous von Ebner's glands locating in the posterior tongue deliver their saliva into the bottom of the trenches surrounding the TRC-rich circumvallate and foliate papillae. Because these glands deliver their saliva directly into the immediate vicinity of TRCs, we investigated whether CA VI is secreted by the von Ebner's glands, using immunochemical techniques. The immunohistochemical results showed that CA VI is present in the serous acinar cells, ductal cells, and ductal content of von Ebner's glands and in the demilune and ductal cells plus ductal content of rat lingual mucous glands. More importantly, CA VI was also detected in taste buds and in the taste pores. Western blotting of saliva collected from the orifices of human von Ebner's glands and CAs purified from rat von Ebner's glands confirmed that CA VI is expressed in these glands and secreted to the bottom of the trenches surrounding the circumvallate and foliate papillae. These findings are consistent with the hypothesis that locally secreted CA VI is implicated in the paracrine modulation of taste function and TRC apoptosis. (J Histochem Cytochem 49:657-662, 2001)

Circadian periodicity in salivary carbonic anhydrase VI concentration.

Carbonic anhydrase VI (CA VI) is secreted into the saliva by the serous acinar cells of the parotid and submandibular glands. Saliva samples from six healthy male volunteers were analysed for concentrations of CA VI throughout the 24 h period by means of a specific time-resolved immunofluorometric assay and the levels were compared with amylase activity. The sleeping period was from 00.10 h to 07.30 h and the subjects had breakfast at 07.30 h and regular meals at 13.30 h and 19.30 h. Saliva secretion decreased markedly during the sleeping period in all the subjects except one. The levels of both CA VI and amylase activity varied greatly among the subjects, but in a parallel manner, and declined to a very low level during the sleeping period. Dexamethasone intake at midnight had no effect on the morning rise in either enzyme. When the sleeping period was postponed from 06.10 h to 11.30 h both enzyme concentrations declined during the night and continued to be low until the subjects awoke at 11.30 h, whereas salivary secretion was low only during the sleeping period. Our results suggest that CA VI secretion follows a circadian periodicity that is comparable to amylase secretion but independent of salivary secretion.