Salivary Antimicrobial Peptides Research Articles

The Variability of the Salivary Antimicrobial Peptide Profile: Impact of Lifestyle.

Saliva is crucial in maintaining oral health; its composition reflects the body's physiological and diseased state. Among salivary components, antimicrobial peptides (AMPs) stand out for their broad antimicrobial activities and role in modulating the oral microbiota and innate immune response. Local and systemic diseases can affect the levels of AMPs in saliva, making them attractive biomarkers. However, the large variability in their concentrations hampers their use in diagnostics. Knowledge of the various factors influencing the profile of salivary AMPs is essential for their use as biomarkers. Here, we examine how lifestyle factors such as physical activity, dietary supplementation, tobacco smoking, and psychological stress impact salivary AMP levels. By understanding these sources of variability, we can take a step forward in using AMPs for diagnostics and prognostics and develop new tailored and preventative approaches.

Salivary Antimicrobial Peptide in Patients With Dementia Before and After Clinical Oral Rehabilitation Programme: A Randomised Controlled Trial.

Emerging evidence suggests a link between salivary metabolite changes and neurodegenerative dementia, with antimicrobial peptides (AMPs) implicated in its pathogenesis. We investigated the effects of a clinical oral rehabilitation programme tailored for dementia patients on salivary flow rate, AMP levels and oral health-related quality of life (OHRQoL). Eligible patients were randomly assigned to either the experimental group (EG; n = 28) or the control group (CG; n = 27). Both groups received a leaflet on oral health. In addition, the EG received an oral care intervention that included individual lessons on oral muscle exercises and oral self-care practices. Saliva samples and OHRQoL data were collected at baseline and follow-up visits. Generalised estimating equation models were used to analyse the changes over time. At the 3-month follow-up, EG showed significantly lower histatin 5 (HTN-5) levels (β = -0.08; effect size [ES] = 0.72) than CG. At 6 months, EG exhibited improved salivary flow rate (β = 0.89; ES = 0.89) and OHRQoL (β = 6.99; ES = 1.31) compared to CG. Changes in salivary flow rate (β = 4.03), HTN-5 level (β = -0.78) and beta-defensin 2 level (BD-2) (β = -0.91) at 3 months predicted improved OHRQoL at 6 months (all p < 0.05). Our clinical oral rehabilitation programme reduced the level of salivary HTN-5, increased salivary flow rate and enhanced OHRQoL in dementia patients. Furthermore, changes in salivary flow rate, HTN-5 level and BD-2 level were associated with improvements in patients' OHRQoL.

Acute salivary antimicrobial peptide secretion response to different exercise intensities and durations.

Antimicrobial peptides, key players of innate mucosal immunity in the oral cavity, exert antibacterial and bacteriolytic effects. This study aimed to clarify the effects of acute exercise at different intensities and durations on salivary antimicrobial peptide levels. In a randomized crossover trial, 14 young healthy untrained men performed intensity trials (cycling at 35%, 55%, and 75% of maximal oxygen uptake [VO2max] for 30 min) and duration trials (cycling at 55% VO2max for 30, 60, and 90 min). Saliva samples were collected at baseline and 0 and 60 min after exercise. In intensity trials, the change in salivary Lactoferrin levels from baseline to 0 min after 30-min exercise was greater at 75% VO2max exercise intensity compared to that at 35% VO2max. Furthermore, the change in salivary human beta defensin-2 (HBD-2) levels was greater at 75% VO2max compared to that at 35% and 55% VO2max. Salivary Lysozyme levels increased after exercise, independent of exercise intensity. However, salivary LL-37 levels did not change after exercise at any intensity. Additionally, in duration trials, the change in salivary levels of LL-37 and HBD-2 from baseline to 0 min after exercise at 55% VO2max was greater after 60 min and 90 min of exercise compared to that after 30 min of exercise. However, salivary Lactoferrin and Lysozyme levels increased after exercise, independent of exercise duration. Our findings suggest that secretory responses to acute exercise with exercise intensity and duration differ among salivary antimicrobial peptides.

Zn(II) coordination influences the secondary structure, but not antimicrobial activity of the N-terminal histatin 3 hydrolysis product.

The relationship between the coordination chemistry and antimicrobial activity of Zn(II) and Cu(II)-bound histatins, salivary antimicrobial peptides, remains enigmatic. We focus on metal complexes of histatin 3 and its two products of hydrolysis: histatin 4 and its N-terminal fragment (histatin 3-4). The thermodynamic stability of these complexes is quite expected - the binding of Cu(II) via the ATCUN motif results in the formation of very stable complexes. In histatin-Zn(II) complexes, the {2Nim} type of coordination dominates, with polymorphic binding sites observed for histatin 3-4 and 5-8, resulting in their low thermodynamic stability compared to the complexes of histatin 3, 4, 5 and 8 with Zn(II), in which we observe a {2Nim, O-} type of coordination. Histatin 3, 3-4 and 4 have greater activity against Gram-positive bacteria than against Gram-negative ones, and Cu(II) or Zn(II) binding can, in some cases, moderately increase the antimicrobial activity of the native histatin 3 and 4, but not the remaining 3-4 fragment. The most probable reason for the metal-enhanced antimicrobial activity is, in this case, a local change of charge, while the chemically fascinating metal binding induced structural changes do not result in a change of biological activity. Neither histatin 3-4, the N-terminal fragment of histatin 3, which remains in solution after cleavage, nor its metal complexes have any antimicrobial activity, but histatin 3-4 presents intriguing Zn(II)-induced structural behavior, changing its secondary structure, with a tendency to form an α-helix.

Development of a Novel Histatin-5 Mucoadhesive Gel for the Treatment of Oral Mucositis: In Vitro Characterization and In Vivo Evaluation.

Antimicrobial peptides have appeared to be promising candidates for therapeutic purposes due to their broad antimicrobial activity and non-toxicity. Histatin-5 (Hst-5) is a notable salivary antimicrobial peptide that exhibited therapeutic properties in the oral cavity. Oral mucositis is an acute inflammation of the oral cavity, following cancer therapy. The current treatment methods of oral mucositis have low effectiveness. The aim of this study was to design, formulate and characterize a mucoadhesive gel delivery system for Hst-5 usage in the treatment of oral mucositis. Carbopol 934 and hydroxypropyl methylcellulose (HPMC) have been used in the development of a Hst-5 mucoadhesive gel that was optimized by using Box-Behnken design. The optimized formulation was evaluated in-vitro, based on mucoadhesive strength, viscoelasticity, spreadability, release rate, peptide secondary structure analysis, antimicrobial activity, and storage stability. The efficacy of Hst-5 gel was assessed in vivo in a chemotherapy-induced mucositis model. The results showed a sustained release of Hst-5 from the new formulation. Hst-5 gel exerted antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans. The histopathological, immunohistochemical and statistical analysis showed that the Hst-5 gel had wound healing activity in vivo. The findings of this study indicate that the mentioned compound possesses promising potential as a novel and efficient therapeutic agent in managing oral mucositis. Moreover, the results suggest that the compound is commercially feasible for further development and utilization.

Combating fungal phytopathogens with human salivary antimicrobial peptide histatin 5 through a multi-target mechanism.

Blast disease caused by Magnaporthe oryzae is a major contributor to decreased crop yield and rice production globally. The use of chemical fungicides to combat crop pathogens is not only unsafe but also promotes the emergence of pathogenic variants, leading to recurrent host infections. To address plant diseases, antimicrobial peptides have emerged as a promising alternative as they are effective, safe, and biodegradable antifungal agents. This study examines the antifungal activity and mechanism of action of the human salivary peptide histatin 5 (Hst5) on M. oryzae. Hst5 causes morphogenetic defects in the fungus, including non-uniform chitin distribution on the fungal cell wall and septa, deformed hyphal branching, and cell lysis. Importantly, a pore-forming mechanism of Hst5 in M. oryzae was ruled out. Furthermore, the interaction of Hst5 with the M. oryzae genomic DNA suggests that the peptide may also influence gene expression in the blast fungus. In addition to its effects on morphogenetic defects and cell lysis, Hst5 also inhibits conidial germination, appressorium formation, and the appearance of blast lesions on rice leaves. The elucidated multi-target antifungal mechanism of Hst5 in M. oryzae provides an environmentally friendly alternative to combating blast infections in rice by preventing fungal pathogenicity. The promising antifungal characteristics of the AMP peptide may also be explored for other crop pathogens, making it a potential biofungicide for the future.

Oral Health Status in relation to Salivary Antimicrobial Peptide in Pregnant Women

Background: Oral health is a mirror of general health. During pregnancy, oral health is affected by changes in saliva and oral hygiene measures which may lead to more dental caries. Objective: Assess oral health status in relation to salivary antimicrobial peptides in pregnant women. Subjects and Method: This cross sectional study was carried out in different primary health care centers in Rusafa sectors/ Baghdad city. The total sample included was 80 women (their age range from 21-30). The study group consisted of 40 pregnant women: half of them were in the first trimester and others were in third trimester, while the control group included 40 non-pregnant married females. Dental Plaque was recorded according to simplified oral hygiene index. Dental caries were diagnosed by using WHO (2013) criteria. Unstimulated salivary samples were collected. Chemical analysis of salivary samples was performed for the detection of human β-Defensin 2. Results: The current study revealed that dental caries experiences (decayed surfaces(DS), missed surfaces (MS) and decayed, missing, filled surfaces(DMFS)) were higher among pregnant than non-pregnant females especially in the third trimester, add percentage with no significant differences, while filled surfaces (FS) were higher in the control group with also no significant difference. Regarding plaque index, results revealed that pregnant women had higher plaque index than non-pregnant women, with significant higher per-centage (53.3%) in the third trimester, P value = 0.027. The salivary human β-Defensin 2 was higher among the pregnant group in the third trimester with statistically no significant difference. Conclusion: More plaque accumulation during pregnancy may explain the higher preva-lence of dental caries as the dental plaque considered to be the chief contributing factor in dental caries.

Effects of acrylic dentures on oral mucosa and salivary antimicrobial peptide content in denture wearers

Relevance. Aging of the body leads to the development of an imbalance in the secretory immunity of the oral mucosa, with the loss of natural teeth leading to an even more rapid decline in the host’s oral defense reactions. However, studies on salivary antimicrobial peptides in denture users and their potential role in protecting against the development of inflammation are still scarce at this time.Purpose. To evaluate the effects of full removable acrylic dentures on the oral mucosa and analyze the content of antimicrobial peptides in the saliva of wearers of such dentures.Materials and methods. Sixty-seven (21 men and 46 women) elderly patients (61 to 74 years old) with complete tooth loss were examined and divided into 3 study groups. In the 1st control group the patients did not use any dentures. Patients in groups 2 and 3 were made full removable acrylic dentures for the upper and lower jaws, and in group 2 from the first day of the adaptation period was used domestic denture fixation cream ASEPTA PARODONTAL. Assessment of the denture bed on the hard palate was performed visually using the Schiller – Pisarev test. Microbiological examination for Candida albicans was performed by PCR-diagnostics. The content of antimicrobial peptides in saliva was assessed using ELISA kits by Hycult Biotech.Results. The use of the adhesive cream was found to improve the condition of the palatal mucosa by 25% on the 15th day and by 50% on the 30th day of the adaptation period. Candida albicans was detected in oral material in more than 55% of patients in all groups during their initial examination. In the group of patients using denture fixation cream, a significant decrease in Candida albicans carriage was noted, while an increase in Candida albicans detection of up to 70% was noted in those not using the cream. There was also an increase in the level of cathelicidin LL-37 in the saliva of patients without the use of the cream and with a marked increase in inflammation. One month after dentures in patients without cream use the content of alpha-defensins (HNP 1-3) was significantly lower than that of the group with cream and the control group.Conclusion. On the basis of the carried out clinical and laboratory study, the domestic ACEPTA adhesive cream should be recommended for optimization of the adaptation period to removable acrylic dentures as well as for their permanent use.

Aging envisage imbalance of the periodontium: A keystone in oral disease and systemic health.

Aging is a gradual and progressive deterioration of integrity across multiple organ systems that negatively affects gingival wound healing. The cellular responses associated with wound healing, such as collagen synthesis, cell migration, proliferation, and collagen contraction, have been shown to be lower in gingival fibroblasts (the most abundant cells from the connective gingival tissue) in aged donors than young donors. Cellular senescence is one of the hallmarks of aging, which is characterized by the acquisition of a senescence-associated secretory phenotype that is characterized by the release of pro-inflammatory cytokines, chemokines, growth factors, and proteases which have been implicated in the recruitment of immune cells such as neutrophils, T cells and monocytes. Moreover, during aging, macrophages show altered acquisition of functional phenotypes in response to the tissue microenvironment. Thus, inflammatory and resolution macrophage-mediated processes are impaired, impacting the progression of periodontal disease. Interestingly, salivary antimicrobial peptides, such as histatins, which are involved in various functions, such as antifungal, bactericidal, enamel-protecting, angiogenesis, and re-epithelization, have been shown to fluctuate with aging. Several studies have associated the presence of Porphyromonas gingivalis, a key pathogen related to periodontitis and apical periodontitis, with the progression of Alzheimer's disease, as well as gut, esophageal, and gastric cancers. Moreover, herpes simplex virus types 1 and 2 have been associated with the severity of periodontal disease, cardiovascular complications, and nervous system-related pathologies. This review encompasses the effects of aging on periodontal tissues, how P. gingivalis and HSV infections could favor periodontitis and their relationship with other pathologies.

The Relationship between Mutations in Gene-Specific Domains of Salivary Fibronectin (cFn) and Dynamin-2 (Dynm-2) and the Development of Porphyromonas gingivalis-Initiated Periodontitis

Periodontitis is a chronic inflammatory disease characterized by the destruction of the supporting structures of the teeth. Its high prevalence and negative effects on quality of life make it one of the current problems in dentistry. Porphyromonas gingivalis (P. gingivalis) is the predominant periodontal pathogen that expresses a number of virulence factors involved in the pathogenesis of periodontitis. P. gingivalis fimbriae are a critical factor in the interaction between the organism and the host tissue. They promote both bacterial adhesion and invasion into the target sites. Fimbriae are capable of binding to human saliva components, extracellular matrix proteins, and commensal bacteria, as well as firmly binding to the cellular integrin α5β1. After attachment to α5β1-integrin, P. gingivalis is captured by cellular pseudopodia, which makes invagination through an actin-mediated pathway possible. It has been proven that the invagination event also requires the participation of the host cell dynamin, actin fibers, microtubules and lipid rafts. Work has emerged investigating mutations in the proline-rich terminal domain (PRD) and their impact on disease development. Salivary antimicrobial peptides are early protective factors against microbial attack. Of great interest is fibronectin (FN) as the main competitor of P. gingivalis fimbriae. The FN can interact with cells in three different regions: the central cell-binding domain (CCBD), the COOH terminal heparin-binding domain (Hep2), and the type III connecting segment (IIICS), including the CS1 region (Yamada, 1991). CCBD is the major cell-adhesion domain of FN and contains an Arg–Gly–Asp (RGD) motif that is recognized by members of the cell adhesion receptor integrin family, including a5b1, which is the primary FN receptor in many cell types. The work focuses on identifying the relationship between the development of periodontitis and the presence of mutations in the adhesion domains of salivary proteins such as cellular fibronectin (cFN) and dynamin-2 (DYNM2).

Correlation of salivary biomarkers and dental caries in children exposed to passive smoking

Salivary antimicrobial peptides (AMP’s) play an important role in the local defence of oral cavity and expression of these are altered by various factors. Among them cigarette smoke has known to have detrimental effects on salivary immune defence mechanisms. The effect of passive smoking on salivary AMP’s and correlation to dental caries in children has not yet been reported. Thus, this study was aimed to assess the correlation between passive smoking and dental caries in exposed and unexposed children. A randomized cross-sectional study was designed &amp; Self-reported questionnaire was filled by the parents of the participants to obtain the data. Participants were divided into passive exposed (PE) and unexposed (UE) group based on exposure parameters. Clinical examination was performed and DMFS were marked for each subject. Unstimulated saliva was collected for 1 min and SFR was measured by analysing saliva in the graduated tubes after which the saliva was subjected for analysis of salivary cotinine and LL-37 concentration through ELISA kit. The mean DMFS and Salivary cotinine levels were elevated in Passive smoking exposed individuals, showing a positive correlation between DMFS and Salivary cotinine levels to passive smoking, but, the mean salivary LL-37 levels were reduced in passive smoking exposed individuals, showing a negative correlation between Salivary LL-37 levels to passive smoking. There was also a dose-dependent relationship between caries experience and smoking exposure. Reduction of passive smoking is important not only for the prevention of various systemic ill-effects, but also for the promotion of health.

The Association of Early Childhood Caries with Salivary Antimicrobial Peptide LL37 and Mutans Streptococci.

This study aims to determine the relation of salivary LL37 level and mutans streptococci levels in early childhood caries (ECC). A case-control study was performed in children ≤71 months old. Unstimulated whole saliva was collected and the level of salivary LL37 was measured using an enzyme-linked immunosorbent assay kit. The mutans streptococci oral bacteria were isolated from saliva and identified using a modified SB-20 culture medium (SB-20M). Data were analyzed using descriptive statistics, bivariate, and Spearman's rank correlation analysis. The was a variability of salivary LL37 level among the children and the level was significantly associated with age and races. The median (IQR) value of salivary LL37 in caries-free (CF) children was significantly higher 393.50 (580.55) ng/mL compared to 172.50 (234.65) ng/mL in the ECC group. The ECC children exhibited a significantly higher count of S. mutans and S. sobrinus compared to the CF children. An inverse weak correlation between salivary LL37 and dmft was also observed. The low salivary LL37 level and higher S. mutans and S. sobrinus count in ECC supported the protective role of salivary LL37 against dental caries. Further studies are required to explore the definite relation between salivary LL37 levels and dental caries.

Association between passive smoking and dental caries among 3-8 years children in Bangalore city

Salivary antimicrobial peptides (AMP’s) play an important role in the local defense of oral cavity and expression of these are altered by various factors. Among them cigarette smoke has known to have detrimental effects on salivary immune defense mechanisms. The effect of passive smoking on salivary AMP’s and correlation to dental caries in children has not yet been reported. Thus, this study was aimed to assess the correlation between passive smoking and dental caries in exposed and unexposed children. A randomized cross-sectional study was designed to target children aged between 3 to 8 years. Self-reported questionnaire was filled by the parents of the participants to obtain the data. Questionnaires included in the study comprised sections related to demographic part and smoking characteristics. Participants were divided into passive exposed (PE) and unexposed (UE) group based on exposure parameters. Clinical examination and Salivary flow rate were assessed and the obtained data was subjected to statistical analysis. TPE group (5.58+/-4.66) than UE group (3.15+/-3.26) where (p=0.003)and under educated parents (p=0.02). Comparison of smoking related parameters to caries prevalence have shown direct positive correlation.[K1] [M2] The mean DMF scores were higher among children in [K3] [K4] [M5] E group (5.58+/-4.66) than UE group (3.15+/-3.26) where (p=0.003). Also it was seen that the DMF were higher in children who belonged to lower socio-economic status (p= 0.001) and under educated parents (p=0.02). Comparison of smoking related parameters to caries prevalence have shown direct positive correlation. Reduction of passive smoking is important not only for the prevention of various systemic ill-effects, but also for the promotion of children's dental health.

Method of salivary histatins determination.

Histatins are the most significant antimicrobial peptides (AMP) of saliva and there are 12 types of such AMP. Histatin molecules contain relatively high percent of histidine and tyrosine residues. This property allows to use well known from organic chemistry Pauly reaction for detection of protein bounded histidine and tyrosine residues (BHT), which are in fact characterize the summary content of all histatins in saliva. Aim of the present study was comparison of BHT with antimicrobial activity of salivary AMP fraction in patients with inflammatory diseases of upper airways (IDUA). Group of examined persons include 28 patients with different diagnoses: chronic pharyngitis (n=11), chronic tonsillitis (n=7), nasopharyngitis (n=5), pollinosis (n=5). Degree of intensity of inflammatory symptoms was estimated in balls. The algorithm of BHT analysis include following steps: freezing - thawing of saliva; removal of microparticles by centrifugation; separation of fraction lower than100 kDa; dialysis for free amino acids removal; Pauly reaction carrying out. Antimicrobial activities of saliva and its low molecular fractions were estimated towards Candida albicans cells by the spectrophotometric method with bromocresol purpur. Analysis of saliva sediments for coccoid microbiota was carried out by PCR method. Pauly reaction for histatins estimation in saliva of IDUA patients use here for the first time. The histatins levels (BHT) were significantly correlated with the intensity of inflammatory symptoms (r=0,975) and activity of low molecular salivary fraction (AMP activity) (r=0,824). The AMP activity/ BHT ratio, i.e. antimicrobial activity of histatin unit, decreased together with growth of inflammatory symptoms intensity (r=-0,944). Any considerable differences in coccoid microbiota frequency of finding at different diagnoses were not detected. The S. aureus frequency of occurrence was connected neither with inflammatory symptoms intensity (r=0,118), nor with BHT concentration (r=0,318). However S. pyogenes and S. pneumoniae frequencies of occurrence demonstrated the invert correlation towards these indexes: (r=-0,627/-0,614) and (r=-0,827/-0,864). Probably at the exacerbation forms of IDUA the S. pyogenes and S. pneumoniae growth controlled by high levels of histatins.

Study of the ultrastructure of Enterococcus faecalis and Streptococcus mutans incubated with salivary antimicrobial peptides.

Objectives Enterococcus faecalis has been associated with root canal infections, while Streptococcus mutans has a central role in the etiology of dental caries. One of the main reasons of endodontic failure has been associated to the presence of E. faecalis and the formation of biofilms. S. mutans inhabits the oral cavity, specifically the dental plaque, which is a multispecies biofilm formed on the hard surfaces of the tooth. The biofilm formation is the main factor determining the pathogenicity of numerous bacteria. Natural antimicrobial peptides in the saliva protect against pathogenic bacteria and biofilms. The aim of this study was to assess the ultrastructural damage induced by salivary peptides in bacteria involved in biofilms has not been previously studied.Material and methods Enterococcus faecalis and S. mutans incubated with cystatin C, chromogranin A, or histatin 5 were morphologically analyzed and counted. The ultrastructural damage was evaluated by transmission electron microscopy (TEM).ResultsA decrease in bacterial numbers was observed after incubation with cystatin C, chromogranin A, or histatin 5, compared to the control group (P < 0.001). Ultrastructural damage in E. faecalis and S. mutans incubated with salivary peptides was found in the cell wall, plasma membrane with a decreased distance between the bilayers, a granular pattern in the cytoplasm, and pyknotic nucleoids.ConclusionsThis study demonstrated that salivary peptides exert antibacterial activity and induce morphological damage on E. faecalis and S. mutans. Knowledge on the ultrastructural damage inflicted by salivary antimicrobial peptides on two important bacteria causing dental caries and root canal infections could aid the design of new therapeutic approaches to facilitate the elimination of these bacteria.

Association between Antimicrobial Peptide Histatin 5 Levels and Prevalence of Candida in Saliva of Patients with Down Syndrome.

There are no studies on Candida colonization and micropeptides of saliva in any patient. Therefore, we studied the effects of the salivary antimicrobial peptide histatin 5 on oral fungal colonization; subjects were subdivided into Down syndrome (D) and normal (N) groups by age: N-1 and D-1, age <20 years; N-2 and D-2, age >40 years. Histatin 5 concentration in saliva was measured by enzyme-linked immunosorbent assay. Oral Candida species were identified using CHROMagar Candida. Candida colonization was significantly enhanced in the D-1 and D-2 groups compared to the N-1 and N-2 groups. There was no predominant difference in salivary histatin 5 concentration between the D-1 and N-1 groups, but it was significantly lower in the D-2 group than in the N-2 group. Only in the N-2 group was there a correlation between the concentration of histatin 5 and total protein, while no correlation was found in the other groups. In elderly patients with Down syndrome, the decrease in histatin 5 shown in this study may lead to oral Candida colony formation. Therefore, the results of this study suggest that a deficiency of the antimicrobial peptide histatin 5 could possibly induce oral Candida infection in DS.

Histatin‐1 is a novel osteogenic factor that promotes bone cell adhesion, migration, and differentiation

Histatin-1 is a salivary antimicrobial peptide involved in the maintenance of enamel and oral mucosal homeostasis. Moreover, Histatin-1 has been shown to promote re-epithelialization in soft tissues, by stimulating cell adhesion and migration in oral and dermal keratinocytes, gingival and skin fibroblasts, endothelial cells and corneal epithelial cells. The broad-spectrum activity of Histatin-1 suggests that it behaves as a universal wound healing promoter, although this is far from being clear yet. Here, we report that Histatin-1 is a novel osteogenic factor that promotes bone cell adhesion, migration and differentiation. Specifically, Histatin-1 promoted cell adhesion, spreading and migration of SAOS-2 cells and MC3T3-E1 pre-osteoblasts in vitro, when placed on a fibronectin matrix. Besides, Histatin-1 induced the expression of osteogenic genes, including osteocalcin, osteopontin and Runx2, and increased both activity and protein levels of alkaline phosphatase. Furthermore, Histatin-1 promoted mineralization in vitro, as it augmented the formation of calcium deposits in both SAOS-2 and MC3T3-E1 cells. Mechanistically, although Histatin-1 failed to activate ERK1/2, FAK and Akt, which are signaling proteins associated with osteogenic differentiation or cell migration, it triggered nuclear re-localization of β-catenin. Strikingly, the effects of Histatin-1 were recapitulated in cells that are non-osteogenically committed, since it promoted surface adhesion, migration and the acquisition of osteogenic markers in primary mesenchymal cells derived from the apical papilla and dental pulp. Collectively, these observations indicate that Histatin-1 is a novel osteogenic factor that promotes bone cell differentiation, surface adhesion and migration, as crucial events required for bone tissue regeneration. This article is protected by copyright. All rights reserved.

Can Salivary Biomarkers Be Used as Predictors of Dental Caries in Young Adolescents?

BackgroundIdentifying caries predictors in the subpopulation at risk is one of the preconditions for developing effective caries prevention measures. The present exploratory study aimed to examine the significance of socio-demographic characteristics, dietary-hygiene habits, salivary pH, and salivary antimicrobial HNP-1, hBD-2, and LL-37 peptides as potential caries risk predictors in children ages 11–13 years.Material/MethodsThis prospective 1-year study enrolled 213 children ages 11–13 years. The subjects underwent a dental examination and their mothers were interviewed. Unstimulated saliva was collected from the subjects to determine its pH value, as well as the salivary levels of HNP-1, hBD-2, and LL-37 peptides in 85 of the subjects. After 12 months, the 1-year caries incidence rate was recorded. Logistic regression analysis was used to estimate the ability of selected variables to predict caries risk.ResultsThe univariable logistic regression analysis determined that the most significant independent caries risk predictors were: sex (female) (OR=2.132, p=0.007), mothers’ education (OR=1.986, p=0.020), salivary pH (OR=0.270, p=0.043), oral hygiene index (OR=1.886, p=0.015), and daily tooth brushing frequency (OR=0.565, p=0.042). The multivariable model showed that sex and oral hygiene-related variables were the most important caries predictors.ConclusionsSalivary HNP-1, hBD-2, and LL-37 peptides were not found to have a significant predictive value. Therefore, socio-demographic and oral hygiene variables remain important caries predictors in early adolescents, suggesting the importance of the mechanical control of biofilm as the key measure for preventing caries. However, there is still a need for effective caries risk biomarkers, and additional research is needed in this area of caries risk prediction.

The effect of glycemic control on salivary antimicrobial peptide levels in patients with periodontitis and type 2 diabetes mellitus

The effect of glycemic control on salivary antimicrobial peptide levels in patients with periodontitis and type 2 diabetes mellitus

The Human Salivary Antimicrobial Peptide Profile according to the Oral Microbiota in Health, Periodontitis and Smoking

Antimicrobial peptides (AMPs) are a diverse family of peptides that defend the mucosal surfaces of the oral cavity and other locations. Many AMPs have multiple functions and properties that influence aspects of innate defense and colonization by microorganisms. The human oral cavity is home to the second-most diverse microbiome, and the health of the mouth is influenced by the presence of these bacteria as well as by extrinsic factors such as periodontitis and smoking. This study hypothesized that the AMP profile is different in the presence of extrinsic factors and that this would also be reflected in the bacteria present. The AMP profile was analyzed by quantitative selected-reaction-monitoring mass spectrometry analysis and 40 bacterial species were quantified by DNA-DNA hybridization in saliva donated by 41 individuals. Periodontal status was assessed through dental examination and smoking status through medical charting. Periodontal health (in nonsmokers) was associated with a higher abundance of ribonuclease 7, protachykinin 1, β-defensin 128, lipocalin 1, bactericidal permeability-increasing protein fold-containing family B member 3, and bone-marrow proteoglycan. Nonsmoking periodontal disease was associated with an abundance of neutrophil defensin 1 and cathelicidin. However, 7 AMPs were overabundant in periodontal disease in smokers: adrenomedullin, eosinophil peroxidase, 3 different histones, myeloperoxidase, and neutrophil defensin 1. There were no differentially abundant AMPs in smokers versus nonsmokers with periodontal health. Correlation network inference of healthy nonsmokers, healthy smokers, nonsmoking periodontitis, or smoking periodontitis donors demonstrated very different networks growing in complexity with increasing numbers of stressors. The study highlights the importance of the interaction between the oral cavity and its resident microbiota and how this may be influenced by periodontal disease and smoking.