Cleaved inflammatory lactoferrin peptides in parotid saliva of periodontitis patients

Saliva as Biomarker for Oral and Chronic Degenerative Non-Communicable Diseases

Saliva is a very complex fluid and it is essential to maintain several physiological processes and functions, including oral health, taste, digestion and immunological defenses. Saliva composition and the oral microbiome can be influenced by several factors, like diet and smoking habits, and their alteration can represent an important access point for pathogens and, thus, for systemic illness onset. In this review, we explore the potentiality of saliva as a new tool for the early detection of some pathological conditions, such as oral diseases, chronic degenerative non-communicable diseases, among these chronic kidney disease (CKD). We also examined the possible correlation between oral and systemic diseases and oral and gut microbiota dysbiosis. In particular, we deeply analyzed the relationship between oral diseases and CKD. In this context, some salivary parameters can represent a new device to detect either oral or systemic pathologies. Moreover, the positive modulation of oral and gut microbiota induced by prebiotics, postbiotics, or symbiotics could represent a new possible adjuvant therapy in the clinical management of oral diseases and CKD.

The rationale and potential for using Lactobacillus in the management of periodontitis

Periodontitis refers to a wide range of the inflammatory conditions of supporting dental structures. For some patients with periodontitis, antibacterial agents are needed as an adjuvant to mechanical debridement treatments and oral hygiene maintenance. However, the widespread use of broad-spectrum antibiotics for the prophylaxis and treatment of periodontal infections results in the emergence of resistant pathogens. Therefore, probiotics have become markedly interesting to researchers as a potentially safe alternative to periodontal treatment and maintenance. Probiotics have been used in medicine for decades and extensively applied to the treatment of inflammatory diseases through the modulation of microbial synergy and other mechanisms. A growing amount of evidence has shown that using Lactobacillus strains for oral cavity maintenance could improve periodontal health. In this study, we reviewed studies showing proof of the inhibitory effects of Lactobacillus species on periodontal inflammation. We also explored the rationale and potential for using Lactobacillus species in the management of periodontitis.

Effects of Saliva From Periodontally Healthy and Diseased Subjects on Barrier Function and the Inflammatory Response in in vitro Models of the Oral Epithelium

Background: Periodontitis is a multifactorial, bacteria-mediated chronic inflammatory disease that results in the progressive destruction of the tooth-supporting tissues. It is well-known that saliva from subjects suffering from this disease generally contains higher levels of pro-inflammatory mediators, matrix metalloproteinases (MMP), and bacteria-derived toxic products. The aim of this study was to investigate and compare the effects of saliva from periodontally healthy and diseased subjects on the barrier function and inflammatory response in in vitro models of the oral epithelium.

Methods: Unstimulated saliva samples from two groups of subjects, one with a healthy periodontium (n = 12) and one with severe generalized periodontitis (n = 11), were filter-sterilized. All the saliva samples were analyzed using an immunological multiplex assay to determine the levels of various cytokines and MMPs relevant to periodontitis. The impact of saliva on epithelial barrier integrity was assessed by monitoring transepithelial electrical resistance (TER) in an oral epithelium model using the B11 keratinocyte cell line. GMSM-K oral epithelial cells were treated with saliva from both groups to determine their ability to induce the secretion of interleukin-6 (IL-6) and interleukin-8 (IL-8), as determined by an enzyme-linked immunosorbent assay (ELISA).

Results: Saliva from the periodontitis subjects contained significantly higher concentrations of matrix metalloproteinase-8 (MMP-8), matrix metalloproteinase-9 (MMP-9), IL-8, and C-X-C motif chemokine ligand 1 (CXCL1) compared to saliva from the healthy subjects. Saliva from the healthy and periodontitis subjects affected cytokine secretion and TER in a similar manner. More specifically, saliva from both groups increased TER and induced IL-6 and IL-8 secretion in the in vitro oral epithelium models used.

Conclusion: Independently of the presence or absence of periodontitis, saliva can increase the relative TER and the secretion of IL-6 and IL-8 in in vitro models of the oral epithelium.

Origin of MMP-8 and Lactoferrin levels from gingival crevicular fluid, salivary glands and whole saliva

Background

Pathologically elevated levels of matrix metalloproteinase-8 (MMP-8) and Lactoferrin in oral fluids have been associated with the presence of gingivitis/periodontitis. This study aimed to assess the origin of MMP-8 and Lactoferrin in periodontitis patients and to identify the degree to which conventional clinical parameters correlate with their presence.

Methods

A total of ten periodontitis and ten healthy patients were included in this study. Whole saliva (stimulated and unstimulated), parotid/sublingual glandular fluid and gingival crevicular fluid from pockets and sulci were tested for MMP-8 and Lactoferrin and protein concentrations were quantified using an ELISA assay. Clinical parameters were checked for potential associations with MMP-8 and Lactoferrin levels.

Results

Periodontal patients presented higher concentrations of MMP-8 and Lactoferrin in pockets than other sources (P = 0.03). Lactoferrin measurement was higher in the parotid compared to sublingual glandular fluid in periodontitis patients (P = 0.03). Increased probing pocket depth was positively correlated with high MMP-8 and Lactoferrin levels.

Conclusions

Periodontal pockets appear to be the major source of active matrix metalloproteinase and Lactoferrin, which also may also enter the oral cavity through the salivary glands. Since clinically healthy sites in periodontitis patients also had elevated biomarker levels, gingival crevicular fluid biomarker testing may be more predictive of future tissue breakdown than conventional clinical parameters.

Does peri-implant bone loss affect the LL-37 and proteinase 3 levels in peri-implant sulcus fluid?

BACKGROUND

Inactive human cathelicidin antimicrobial peptide is present in neutrophils, and proteinase 3 activates this peptide by producing active LL-37 peptide. LL-37 acts as a defensive peptide in the oral tissues. In the present study, the aim was to evaluate LL-37 and proteinase 3 levels in peri-implant sulcus fluid (PISF) in implants with and without peri-implantitis.

METHODS

Patients who simultaneously had dental implants with peri-implantitis and without peri-implantitis were included in the study. Forty-four samples with peri-implantitis and 34 samples without peri-implantitis from 16 patients were obtained. Intraoral evaluations such as pocket depth, modified sulcus bleeding index, and modified plaque index were noted. Enzyme-linked immunosorbent assay was used for the evaluation of PISF LL-37 and proteinase 3 levels.

RESULTS

PISF volume was significantly increased in the implants with peri-implantitis than those without peri-implantitis (p < 0.05). No difference was present between PISF LL-37 and proteinase 3 total amounts between the implants with and without peri-implantitis (p > 0.05). Pocket depths and PISF LL-37 and proteinase 3 levels were not correlated in the groups (p > 0.05).

CONCLUSIONS

PISF volume might be increased in response to peri-implant bone destruction. However, peri-implant tissue destruction caused by peri-implantitis does not seem to affect PISF LL-37 and proteinase 3 levels.

Resolution-Associated Lactoferrin Peptides Limit LPS Signaling and Cytokine Secretion from Human Macrophages

The neutrophil granule protein lactoferrin is cleaved and accumulates in efferocytic macrophages as inflammation is resolved. Two peptides present within a resolution-associated 17 kDa fragment of lactoferrin promote the termination of inflammation in vivo by enhancing murine macrophage reprogramming. Here, we report that these two bioactive tripeptides, phenylalanine-lysine-aspartic acid and phenylalanine-lysine-glutamic acid (FKD and FKE, respectively), inhibit ERK and cJun activation following human macrophage exposure to LPS. In addition, these peptides at low concentrations (1–10 μM) modulate human macrophage reprogramming to an anti-inflammatory/pro-resolving phenotype. This was reflected by inhibition of LPS-induced TNF-α and IL-6 secretion and increased IL-10 levels. Moreover, we found naturally occurring FKE analogs (FKECH and FKECHLA) can recapitulate the activity of the short peptide in regulating macrophage cytokine secretion, whereas a reversed EKF peptide was inert in this respect. Curiously, FKD and FKE also regulated cytokine production by bone marrow-derived mouse macrophages, but in a very different fashion than their effect on human macrophages. Thus, lactoferrin peptides limit pro-inflammatory signaling and cytokine production by LPS-activated human macrophages and thereby enhance the resolution of inflammation.

A Novel Proposal of Salivary Lymphocyte Detection and Phenotyping in Patients Affected by Sjogren's Syndrome

A preliminary evaluation of the parotid secretion cellular composition in patients with Sjogren’s Syndrome (SS) and a diagnostic accuracy assessment of salivary lymphocyte detection and immunophenotyping in Sjogren’s Syndrome diagnosis and prognosis were performed. The study included 40 consecutive patients, aged 19–60 years, with parenchymal sialadenitis associated with Sjogren’s Syndrome, and 20 healthy donors. The exclusion criteria were exacerbation of sialadenitis, chronic infections, malignant neoplasms, and lymphoproliferative diseases. The standard diagnostic tests were minor salivary gland biopsy and parotid sialography. Immunophenotyping of parotid secretion lymphocytes was performed by multicolor flow cytometry. Lymphocytes were detectable in parotid secretion of patients affected by Sjogren’s Syndrome, both primary (pSS) and secondary (sSS) form, but not in that from healthy donors. Sensitivity, specificity, positive, and negative predictive values of lymphocytes detection in parotid saliva were 77.5%, 100%, 100%, and 69%, respectively. The mean numbers of the total T-cell population, T-helper cells, and T-cytotoxic cells were 71.7%, 41.6%, and 53%, respectively. The immunophenotype of lymphocytes obtained by patients’ parotid flow resembles the immunophenotypes of glandular biopsies currently known. Our preliminary data suggest the use of saliva as an alternative and non-invasive method for evaluating the prognosis of Sjogren’s Syndrome.

The N125S polymorphism in the cathepsin G gene (rs45567233) is associated with susceptibility to osteomyelitis in a Spanish population

Background

Osteomyelitis is a bone infection, most often caused by Staphylococcus aureus, in which neutrophils play a key role. Cathepsin G (CTSG) is a bactericidal serine protease stored in the neutrophil azurophilic granules. CTSG regulates inflammation, activating matrix metalloproteinases (MMPs), and coagulation. Lactoferrin (LF), a neutrophil glycoprotein, increases CTSG catalytic activity and induces inflammation. The aim of this study was to analyze a potential association between a CTSG gene polymorphism (Asn125Ser or N125S, rs45567233), that modifies CTSG activity, and could affect susceptibility to, or outcome of, bacterial osteomyelitis.

Methods

CTSG N125S polymorphism was genotyped in 329 osteomyelitis patients and 415 controls), Blood coagulation parameters, serum CTSG activity, LF, MMP-1, MMP-13, and soluble receptor activator for nuclear factor κ B ligand (sRANKL) levels were assessed in carriers of the different CTSG genotypes.

Results

CTSG N125S (AG) genotype was significantly more frequent among osteomyelitis patients than controls (15.5% vs. 9.4%, p = 0.014). CTSG N125S variant G allele (AG +GG) was also more frequent among osteomyelitis patients (8.1% vs. 4.7%, p = 0.01). Serum CTSG activity and LF levels were significantly higher in osteomyelitis patients carrying the G allele compared to those with the AA genotype, (p<0.04). Serum MMP-1 was lower in the G allele carriers (p = 0.01). There was no association between these genotypes and clinical characteristics of osteomyelitis, or coagulation parameters, MMP-13, and sRANKL serum levels.

Conclusions

Differences in the CTSG gene might enhance osteomyelitis susceptibility by increasing CTSG activity and LF levels.

Purification and functional characterization of serum transferrin from Nile tilapia (Oreochromis niloticus)

Transferrin (TF), an iron-binding multifunctional protein, could participate in the iron-withholding strategy, an effective antimicrobial defense mechanism in innate immunity, and is involved in host defense against pathogenic infection. In this study, a TF homologue (OnTF) was purified from serum of Nile tilapia (Oreochromis niloticus) through a two-step affinity chromatography, and characterized its antibacterial function and the role in inflammatory response. The identification by mass spectrometry showed that peptide sequence of the purified OnTF was highly consistent with its amino acids sequence, containing two conserved iron binding lobes: N-lobe and C-lobe. The native OnTF was able to bond iron ions, and possessed capability to inhibit the growth of both bacterial pathogens (Streptococcus agalactiae and Aeromonas hydrophila) in vitro. Upon infections of S. agalactiae and A. hydrophila, the expression of OnTF protein was significantly up-regulated in vivo and in vitro. In addition, the OnTF participated in the regulation of inflammation, migration, and enhancement of phagocytosis and respiratory burst activity in head kidney macrophages/monocytes. Taken together, the results of this study indicated that OnTF is likely to involve in innate immunity to play a role in host defense against bacterial infection in Nile tilapia.

A 17-kDa Fragment of Lactoferrin Associates With the Termination of Inflammation and Peptides Within Promote Resolution

During the resolution of inflammation, macrophages engulf apoptotic polymorphonuclear cells (PMN) and can accumulate large numbers of their corpses. Here, we report that resolution phase macrophages acquire the neutrophil-derived glycoprotein lactoferrin (Lf) and fragments thereof in vivo and ex vivo. During the onset and resolving phases of inflammation in murine peritonitis and bovine mastitis, Lf fragments of 15 and 17 kDa occurred in various body fluids, and the murine fragmentation, accumulation, and release were mediated initially by neutrophils and later by efferocytic macrophages. The 17-kDa fragment contained two bioactive tripeptides, FKD and FKE that promoted resolution phase macrophage conversion to a pro-resolving phenotype. This resulted in a reduction in peritoneal macrophage numbers and an increase in the CD11b^low subset of these cells. Moreover, FKE, but not FKD, peptides enhanced efferocytosis of apoptotic PMN, reduced TNFα and interleukin (IL)-6, and increased IL-10 secretion by lipopolysaccharide-stimulated macrophages ex vivo. In addition, FKE promoted neutrophil-mediated resolution at high concentrations (100 µM) by enhancing the formation of cytokine-scavenging aggregated NETs (tophi) at a low cellular density. Thus, PMN Lf is processed, acquired, and “recycled” by neutrophils and macrophages during inflammation resolution to generate fragments and peptides with paramount pro-resolving activities.

High Levels of Chemokine C-C Motif Ligand 20 in Human Milk and Its Production by Oral Keratinocytes

BACKGROUND

Chemokine C-C motif ligand 20 (CCL20) is implicated in the formation and function of mucosal lymphoid tissues. Although CCL20 is secreted by many normal human tissues, no studies have evaluated the presence of CCL20 in human milk or its production by oral keratinocytes stimulated by human milk.

OBJECTIVE

To evaluate the presence of CCL20 in breast milk and verify CCL20 secretion in vitro by oral keratinocytes stimulated with human and bovine milk, as well as its possible association with breast milk lactoferrin levels.

MATERIALS AND METHODS

The levels of CCL20 and lactoferrin were measured by enzyme-linked immunosorbent assay in human milk at three different stages of maturation from 74 healthy breastfeeding mothers. In vitro, oral keratinocytes were stimulated with human and bovine milk, and CCL20 was measured in their supernatant.

RESULTS

High concentrations of CCL20 were detected in the human breast milk samples obtained during the first week (1,777.07 pg/mL) and second week postpartum (1,523.44 pg/mL), with a significantly low concentration in samples at 3-6 weeks postpartum (238.42 pg/mL; p < 0.0001). Human breast milk at different weeks postpartum stimulated higher CCL20 secretion by oral keratinocytes compared with bovine milk (p < 0.05). Such stimulation had no association with breast milk lactoferrin concentration.

CONCLUSION

CCl20 is present at high levels in human milk, predominantly in the first and second week postpartum, but at significantly lower levels at 3-6 weeks postpartum. Human milk is capable of stimulating CCL20 secretion by oral keratinocytes, and this induction had no association with breast milk lactoferrin concentration.

Lactoferrin: Balancing Ups and Downs of Inflammation Due to Microbial Infections

Lactoferrin (Lf) is a glycoprotein of the primary innate immune-defense system of mammals present in milk and other mucosal secretions. This protein of the transferrin family has broad antimicrobial properties by depriving pathogens from iron, or disrupting their plasma membranes through its highly cationic charge. Noteworthy, Lf also exhibits immunomodulatory activities performing up- and down-regulation of innate and adaptive immune cells, contributing to the homeostasis in mucosal surfaces exposed to myriad of microbial agents, such as the gastrointestinal and respiratory tracts. Although the inflammatory process is essential for the control of invasive infectious agents, the development of an exacerbated or chronic inflammation results in tissue damage with life-threatening consequences. In this review, we highlight recent findings in in vitro and in vivo models of the gut, lung, oral cavity, mammary gland, and liver infections that provide experimental evidence supporting the therapeutic role of human and bovine Lf in promoting some parameters of inflammation and protecting against the deleterious effects of bacterial, viral, fungal and protozoan-associated inflammation. Thus, this new knowledge of Lf immunomodulation paves the way to more effective design of treatments that include native or synthetic Lf derivatives, which may be useful to reduce immune-mediated tissue damage in infectious diseases.

The role of probiotic bacteria in managing periodontal disease: a systematic review

INTRODUCTION

The frequent recolonization of treated sites by periodontopathogens and the emergence of antibiotic resistance have led to a call for new therapeutic approaches for managing periodontal diseases. As probiotics are considered a new tool for combating infectious diseases, we systematically reviewed the evidences for their effectiveness in the management of periodontitis.

AREAS COVERED

An electronic search was performed in the MEDLINE, SCOPUS and Cochrane Library databases up to March 2016 using the terms 'periodontitis', 'chronic periodontitis', 'probiotic(s)', 'prebiotic(s)', 'symbiotic(s)', 'Bifidobacterium and 'Lactobacillus'. Only randomized controlled trials (RCTs) were included in the present study. Analysis of 12 RCTs revealed that in general, oral administration of probiotics improved the recognized clinical signs of chronic and aggressive periodontitis such as probing pocket depth, bleeding on probing, and attachment loss, with a concomitant reduction in the levels of major periodontal pathogens. Continuous probiotic administration, laced mainly with Lactobacillus species, was necessary to maintain these benefits. Expert commentary: Oral administration of probiotics is a safe and effective adjunct to conventional mechanical treatment (scaling) in the management of periodontitis, specially the chronic disease entity. Their adjunctive use is likely to improve disease indices and reduce the need for antibiotics.

Lack of cathelicidin processing in Papillon-Lefèvre syndrome patients reveals essential role of LL-37 in periodontal homeostasis

Background

Loss-of-function point mutations in the cathepsin C gene are the underlying genetic event in patients with Papillon-Lefèvre syndrome (PLS). PLS neutrophils lack serine protease activity essential for cathelicidin LL-37 generation from hCAP18 precursor.

Aim

We hypothesized that a local deficiency of LL-37 in the infected periodontium is mainly responsible for one of the clinical hallmark of PLS: severe periodontitis already in early childhood.

Methods

To confirm this effect, we compared the level of neutrophil-derived enzymes and antimicrobial peptides in gingival crevicular fluid (GCF) and saliva from PLS, aggressive and chronic periodontitis patients.

Results

Although neutrophil numbers in GCF were present at the same level in all periodontitis groups, LL-37 was totally absent in GCF from PLS patients despite the large amounts of its precursor, hCAP18. The absence of LL-37 in PLS patients coincided with the deficiency of both cathepsin C and protease 3 activities. The presence of other neutrophilic anti-microbial peptides in GCF from PLS patients, such as alpha-defensins, were comparable to that found in chronic periodontitis. In PLS microbial analysis revealed a high prevalence of Aggregatibacter actinomycetemcomitans infection. Most strains were susceptible to killing by LL-37.

Conclusions

Collectively, these findings imply that the lack of protease 3 activation by dysfunctional cathepsin C in PLS patients leads to the deficit of antimicrobial and immunomodulatory functions of LL-37 in the gingiva, allowing for infection with A. actinomycetemcomitans and the development of severe periodontal disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13023-014-0148-y) contains supplementary material, which is available to authorized users.

Are proteinase 3 and cathepsin C enzymes related to pathogenesis of periodontitis?

Aim. Cathepsin C is the activator of the polymorphonuclear leukocyte-derived proteinase 3, which contributes to inflammatory processes. The aim of the present study was to investigate gingival crevicular fluid (GCF) proteinase 3 and cathepsin C levels in periodontal diseases. Design. Eighteen patients with chronic periodontitis (CP), 20 patients with generalized aggressive periodontitis (G-AgP), 20 patients with gingivitis, and 18 healthy subjects were included in the study. Periodontal parameters including probing depth, clinical attachment level, papilla bleeding index, and plaque index were assessed in all study subjects. GCF proteinase 3 and cathepsin C levels were analyzed by ELISA. Results. GCF proteinase 3 total amount was significantly higher in diseased groups compared to control group, after adjusting age (P < 0.05). No differences were found in GCF cathepsin C levels among the study groups (P > 0.05). Periodontal parameters of sampling sites were positively correlated with GCF proteinase 3 total amounts (P < 0.01) but not with cathepsin C total amounts (P > 0.05). Conclusions. Elevated levels of GCF proteinase 3 in CP, G-AgP, and gingivitis might suggest that proteinase 3 plays a role during inflammatory periodontal events in host response. However, cathepsin C in GCF does not seem to have an effect on the pathogenesis of periodontal diseases.

Semen lactoferrin promotes CCL20 production by epithelial cells: Involvement in HIV transmission

AIM: To study the effect of seminal plasma on Chemokine (C-C motif) ligand 20 (CCL20) production by epithelial cells and its relationship with lactoferrin.

METHODS: HEC-1A cells, a cell line derived from a monostratified endocervical epithelium, were incubated with samples of seminal plasma (diluted 1:10 in culture medium) recovered from human immunodeficiency virus (HIV) seronegative (HIV-) or HIV seropositive (HIV+) subjects. Recombinant human interleukin 1 beta (IL-1β) was used as positive control, and culture medium only as negative control. The measurement of CCL20 production in the supernatants of HEC-1A cells and of lactoferrin in seminal plasma was determined by enzyme-linked immunosorbent assay techniques. A fractionation of seminal plasma proteins was performed by ion exchange chromatography on a pool of seminal plasma specimens from HIV- subjects. Each fraction was tested for its ability to stimulate the production of CCL20 by HEC-1A cells and for its lactoferrin concentration. The HIV viral load in seminal plasma samples from HIV+ patients was measured using the HIV-Monitor kit (Roche Diagnostic Systems, Branchburg, NJ, United States).

RESULTS: The positive control IL-1β was responsible for an increase of 11.36 ± 3.36 times in the production of CCL20. Stimulation of HEC-1A cells was performed in 34 seminal plasma samples (22 from HIV+ subjects and 12 from HIV- subjects). The mean production of CCL20 by HEC-1A in presence of seminal plasma from HIV- and HIV+ subjects was respectively 5.38 ± 0.91 and 7.57 ± 3.26 times higher than that obtained with the untreated cells (P < 0.05 between the two groups). Using the same 34 specimens of seminal plasma, no correlation was observed between the concentration of total proteins in seminal plasma and their ability to stimulate the secretion of CCL20 by HEC-1 cells. In contrast, the ability to produce CCL20 by HEC-1A cells correlated to the concentration of lactoferrin in the seminal plasma samples (r coefficient = 0.56; CI: 0.26-0.76; P < 0.001). After fractionation by ion exchange chromatography, the seminal plasma fractions exhibiting the highest concentrations of lactoferrin were responsible for the greatest stimulation of CCL20 production by HEC-1A cells (r coefficient = 0.89; CI: 0.78-0.95; P < 0.0001).

CONCLUSION: Lactoferrin present in seminal plasma correlated with an increased production of CCL20 by HEC-1A cells and therefore could facilitate HIV entry through the genital mucosa.

Sterile-filtered saliva is a strong inducer of IL-6 and IL-8 in oral fibroblasts

OBJECTIVES

Saliva has been implicated to support oral wound healing, a process that requires a transient inflammatory reaction. However, definitive proof that saliva can provoke an inflammatory response remained elusive.

MATERIALS AND METHODS

We investigated the ability of freshly harvested and sterile-filtered saliva to cause an inflammatory response of oral fibroblasts and epithelial cells. The expression of cytokines and chemokines was assessed by microarray, RT-PCR, immunoassays, and Luminex technology. The involvement of signaling pathways was determined by Western blot analysis and pharmacologic inhibitors.

RESULTS

We report that sterile-filtered whole saliva was a potent inducer of IL-6 and IL-8 in fibroblasts from the gingiva, the palate, and the periodontal ligament, but not of oral epithelial cells. This strong inflammatory response requires nuclear factor-kappa B and mitogen-activated protein kinase signaling. The pro-inflammatory capacity is heat stable and has a molecular weight of <40 kDa. Genome-wide microarrays and Luminex technology further revealed that saliva substantially increased expression of other inflammatory genes and various chemokines. To preclude that the observed pro-inflammatory activity is the result of oral bacteria, sterile-filtered parotid saliva, collected under almost aseptic conditions, was used and also increased IL-6 and IL-8 expression in gingiva fibroblasts. The inflammatory response was, furthermore, independent of MYD88, an adapter protein of the Toll-like receptor signaling pathway.

CONCLUSIONS

We conclude that saliva can provoke a robust inflammatory response in oral fibroblasts involving the classical nuclear factor-kappa B and mitogen-activated protein kinase signaling pathway.

CLINICAL RELEVANCE

Since fibroblasts but not epithelial cells show a strong inflammatory response, saliva may support the innate immunity of defect sites exposing the oral connective tissue.

Defining salivary biomarkers using mass spectrometry-based proteomics: a systematic review

Recent advancements in mass spectrometric proteomics provide a promising result in utilizing saliva to explore biomarkers for diagnostic purposes. However, the issues of specificity or redundancy of disease-associated salivary biomarkers have not been described. This systematic review was therefore aimed to define and summarize disease-related salivary biomarkers identified by mass spectrometry proteomics. Peer-reviewed articles published through July 2009 within three databases were reviewed. Out of 243 articles, 21 studies were selected in this systematic review with conditions including Sjögren's syndrome, squamous cell carcinoma, dental caries, diabetes, breast cancer, periodontitis, gastric cancer, systemic sclerosis, oral lichen planus, bleeding oral cavity, and graft-versus-host disease. The sample size ranged from 3-41 in both diseased and control subjects, with no consensus on sample collection protocol. One hundred eighty biomarkers were identified in total; 87 upregulated, 63 downregulated, and 30 varying based on disease. Except for Sjögren's syndrome, the majority of studies with the same disease produce inconsistent biomarkers. Larger sample size and standardization of sample collection/treatment protocol may improve future studies.

Antimicrobial activity of certain bacteria and fungi isolated from soil mixed with human saliva against pathogenic microbes causing dermatological diseases

Soil samples (collected from El-Madina El-Monawara, Kingdom Saudi Arabia) were mixed with human saliva, incubated in media suitable for bacterial and fungal growth and filtered. Eighteen bacterial and five fungal species were isolated and identified. The bacterial and fungal filtrates as well as the isolated species were evaluated for their antimicrobial activities against some pathogenic microbes causing dermatological diseases (Staphylococcus aureus, methicillin resistant S. aureus (MRSA) and Aspergillus niger). The bacterial filtrate showed significant antagonistic effect against S. aureus and methicillin resistant S. aureus (MRSA), whereas showed non inhibitory action on the pathogenic fungus. In contrast, the fungal filtrate antagonized the growth of the pathogenic fungus (A. niger) and did not produce any inhibitory effect on the two tested pathogenic bacteria. The isolated bacterial species showed different levels of antagonistic activities against the three tested microbes. Bacillus subtilis was described as potent isolate against the three pathogens, followed by Esherichia coli. However, Bacillus megaterium strongly inhibited the growth of the pathogenic bacteria only. On the other side, all the fungal filtrates of the isolated species, except Cochliobolus lanatus showed antagonistic activity against the pathogenic fungus (A. niger). The filtrate of Fusarium oxysporum and Emericella nidulans counteracted the growth of S. aureus, whereas, the growth of MRSA was inhibited only by the filtrate of E. nidulans. From the passage way of our respected prophet, how is never tells from him self, if any person complains from awound or ulcer, the messenger of Allah (prayers and peace be upon him) put his forefinger on the ground and lift it then he says: (In the Name of God, soil of our land, with the saliva of some of us, our sick person will get well after the permission of our God) Al-Bukhari. The meaning of this Hadith that the prophet takes his saliva on the forefinger then he put it on the soil and wipe on the wound place while saying the above Hadith that is shows the Prophet's miracle, which is evidence of healing by using soil and saliva.

Lactoferrin protects against concanavalin A-induced liver injury in mice

BACKGROUND

Liver diseases, caused by viral infection, autoimmune conditions, alcohol ingestion or the use of certain drugs, are a significant health issue, as many can develop into liver failure. Lactoferrin (Lac) is an iron-binding glycoprotein that belongs to the transferrin family. Owing to its multiple biological functions, Lac has been evaluated in a number of clinical trials to treat infections, inflammation and cancer.

AIM

The present study aims to reveal a profound hepatoprotective effect of Lac, using a mouse model of Concanavalin A (Con A)-induced hepatitis, which mimics the pathophysiology of human viral and autoimmune hepatitis.

METHOD

C57Bl/6J mice were injected with bovine Lac following Con A challenge. The effects of Lac on interferon (IFN)-gamma and interleukin (IL)-4 expression were determined. The roles of Lac on T-cell apoptosis and activation, and leukocytes infiltration were examined.

RESULT

The data demonstrated that the protective effect of Lac was attributed to its ability to inhibit T-cell activation and production of IFN-gamma, as well as to suppress IL-4 production by hepatic natural killer T cells.

CONCLUSION

These findings indicate a great therapeutic potential of Lac in treating in treating inflammatory hepatitis and possibly other inflammatory diseases.

A preliminary approach to creating an overview of lactoferrin multi-functionality utilizing a text mining method

Lactoferrin is a multi-functional metal-binding glycoprotein that exhibits many biological functions of interest to many researchers from the fields of clinical medicine, dentistry, pharmacology, veterinary medicine, nutrition and milk science. To date, a number of academic reports concerning the biological activities of lactoferrin have been published and are easily accessible through public data repositories. However, as the literature is expanding daily, this presents challenges in understanding the larger picture of lactoferrin function and mechanisms. In order to overcome the "analysis paralysis" associated with lactoferrin information, we attempted to apply a text mining method to the accumulated lactoferrin literature. To this end, we used the information extraction system GENPAC (provided by Nalapro Technologies Inc., Tokyo). This information extraction system uses natural language processing and text mining technology. This system analyzes the sentences and titles from abstracts stored in the PubMed database, and can automatically extract binary relations that consist of interactions between genes/proteins, chemicals and diseases/functions. We expect that such information visualization analysis will be useful in determining novel relationships among a multitude of lactoferrin functions and mechanisms. We have demonstrated the utilization of this method to find pathways of lactoferrin participation in neovascularization, Helicobacter pylori attack on gastric mucosa, atopic dermatitis and lipid metabolism.

Periodontitis, periodontopathic bacteria and lactoferrin

Lactoferrin (LF) is a component of saliva and is suspected to be a defense factor against oral pathogens including Streptococcus mutans and Candida albicans. Periodontitis is a very common oral disease caused by periodontopathic bacteria. Antimicrobial activities and other biological effects of LF against representative periodontopathic bacteria, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia, have been widely studied. Association of polymorphisms in LF with incidence of aggressive periodontitis and the role of LF in the gingival crevicular fluid as a marker of periodontitis severity have also been reported. Periodontopathic bacteria reside as a biofilm in supragingival and subgingival plaque. Our recent study indicated that LF exhibits antibacterial activity against planktonic forms of P. gingivalis and P. intermedia at higher concentrations, and furthermore, LF effectively inhibits biofilm formation and reduces the established biofilm of these bacteria at physiological concentrations. A small-scale clinical study indicated that oral administration of bovine LF reduces P. gingivalis and P. intermedia in the subgingival plaque of chronic periodontitis patients. LF seems to be a biofilm inhibitor of periodontopathic bacteria in vitro and in vivo.

Premastication: the second arm of infant and young child feeding for health and survival?

Premastication of foods for infants was a crucial behavioural adaptation to neoteny that ensured nutritional adequacy during the period of complementary feeding throughout the course of human evolution until recent times.While the paps and gruels of agricultural systems provided an alternative and modern food technology appears to make it unnecessary, we argue that, in addition to its role in nutrition, premastication also played a crucial role in supporting infant health. Its abandonment, particularly in poor communities, has placed children at increased risk of inadequate nutrition and decreased ability to confront infections associated with the introduction of complementary foods.We present two empirical studies. Section I is a cross-cultural study of the ethnographic literature in order to estimate prevalence in non-Western societies.One-third of ethnographies in the worldwide sample with data on infant feeding report premastication. Section II presents the results of a qualitative study in China, conducted in order to provide data on the likelihood that this percent is incorrect due to under-reporting.The finding that 63% of Chinese university students received premasticated food as infants, whereas none of eight ethnographic studies performed in Han China identified premastication in their reports, provides support for the conclusion that the cross-cultural study grossly underestimates its prevalence in non-Western societies. Section III is a discussion of potential benefits and risks of infant exposure to maternal saliva.We conclude with the argument for a concerted research effort to determine whether premastication can solve not only the 'weanling dilemma' in poor countries but also some of the health problems among the better-off.

The induction of nitric oxide response of carp macrophages by transferrin is influenced by the allelic diversity of the molecule

The central role of transferrin (Tf) as an iron transporting protein has been extended by observations that modified versions of Tf also participate in the regulation of innate immunity. We report on the isolation of two carp Tf proteins (alleles D and G) to purity using rivanol precipitation and ion-exchange chromatography, and describe the activation of head kidney-derived carp macrophages by cleaved Tf. We demonstrate the superiority of the D-type over the G-type Tf in inducing nitric oxide (NO) and confirm previous observations that full-length Tf cannot induce NO in fish macrophages. We believe that cleaved Tf fragments should be considered to be "alarmins". We discuss the possibility that parasites such as Trypanoplasma borreli cleave Tf and use Tf fragments to their advantage by modulating the NO induction in carp macrophages.

Association between lactoferrin gene polymorphisms and aggressive periodontitis among Taiwanese patients

BACKGROUND AND OBJECTIVE

A dramatic difference in the frequencies of the Lys/Arg single nucleotide polymorphism in the lactoferrin genotype between a small population of patients with localized juvenile periodontitis and healthy subjects has been reported. As the single nucleotide polymorphism could be associated with ethnicity, the present study aimed to investigate the association between polymorphisms of the lactoferrin gene and periodontitis.

MATERIAL AND METHODS

Sixty-five patients with aggressive periodontitis, 278 with chronic periodontitis and 88 healthy controls were genotyped for the Lys/Arg polymorphism of the lactoferrin gene at position 29 [reference sequence (rs) 1126478] in the N-terminal alpha-helical region.

RESULTS

The frequencies of the GG genotype and the G allele were highest in the aggressive periodontitis group, followed by the chronic periodontitis group and then the healthy controls. The frequency of the G allele was significantly higher in aggressive periodontitis and chronic periodontitis groups than in healthy controls (p = 0.0037 and 0.0212). Although the difference of the GG genotype distribution between subjects with chronic periodontitis and healthy controls did not reach significance, the distribution of genotypes between aggressive periodontitis and healthy controls was significantly different. The association of the gene polymorphism and aggressive periodontitis still existed, even after adjusting for age, gender and smoking status by logistic regression analysis (GG/AG+AA: odds ratio = 2.16, 95% confidence interval = 1.09-4.35, p = 0.0287). After the study, subjects were further stratified by their smoking status; the GG genotype was still significantly associated with the risk of aggressive periodontitis in the nonsmoking group (odds ratio = 2.69, p = 0.018). However, there were no statistical differences between chronic periodontitis vs. healthy controls and aggressive periodontitis vs. healthy controls in the smoking group.

CONCLUSION

The present study revealed that the A/G polymorphism in the lactoferrin gene might be associated with aggressive periodontitis. The A allele might reduce the risk of development of aggressive periodontitis in a Taiwanese population. Our results also support the hypothesis that lactoferrin genetic polymorphisms could play a role in the risk for periodontitis separate from the smoking factor. The functionality of this gene's polymorphisms has to be further elucidated.

Improvement of periodontal condition by probiotics with Lactobacillus salivarius WB21: a randomized, double-blind, placebo-controlled study

AIM

This randomized clinical study was designed to evaluate the effect of probiotic intervention using lactobacilli on the periodontal condition of volunteers without severe periodontitis.

MATERIAL AND METHODS

Freeze-dried Lactobacillus salivarius WB21 (WB21)-containing tablets or a placebo were given to volunteers in a double-blind randomized study. A total of 66 volunteers were finally enrolled and randomly assigned to receive tablets containing WB21 (6.7 x 10(8) CFU) with xylitol or xylitol alone (placebo) three times a day for 8 weeks. Periodontal clinical parameters and whole saliva samples were obtained at baseline (BL), 4 weeks, and the end of the interventional period (8 weeks). Salivary lactoferrin (Lf) levels were measured by enzyme-linked immunosorbent assay. Lactobacilli in saliva and plaque samples was detected by semi-quantitative RT-PCR using 16S rRNA primers.

RESULTS

Periodontal clinical parameters were improved in both groups after an 8-week intervention. Current smokers in the test group showed a significantly greater improvement of plaque index and probing pocket depth from BL when compared with those in the placebo group. Salivary Lf level was also significantly decreased in the test group smokers.

CONCLUSION

Our results indicate that probiotics could be useful in the improvement/maintenance of oral health in subjects at a high risk of periodontal disease.

Cathepsin G enhances mammary tumor-induced osteolysis by generating soluble receptor activator of nuclear factor-kappaB ligand

Breast cancer commonly causes osteolytic metastases in bone, a process that is dependent on tumor-stromal interaction. Proteases play an important role in modulating tumor-stromal interactions in a manner that favors tumor establishment and progression. Whereas several studies have examined the role of proteases in modulating the bone microenvironment, little is currently known about their role in tumor-bone interaction during osteolytic metastasis. In cancer-induced osteolytic lesions, cleavage of receptor activator of nuclear factor-kappaB ligand (RANKL) to a soluble version (sRANKL) is critical for widespread osteoclast activation. Using a mouse model that mimics osteolytic changes associated with breast cancer-induced bone metastases, we identified cathepsin G, cathepsin K, matrix metalloproteinase (MMP)-9, and MMP13 to be proteases that are up-regulated at the tumor-bone interface using comparative cDNA microarray analysis and quantitative reverse transcription-PCR. Moreover, we showed that cathepsin G is capable of shedding the extracellular domain of RANKL, generating active sRANKL that is capable of inducing differentiation and activation of osteoclast precursors. The major source of cathepsin G at the tumor-bone interface seems to be osteoclasts that up-regulate production of cathepsin G via interaction with tumor cells. Furthermore, we showed that in vitro osteoclastogenesis is reduced by inhibition of cathepsin G in a coculture model and that in vivo inhibition of cathepsin G reduces mammary tumor-induced osteolysis. Together, our data indicate that cathepsin G activity at the tumor-bone interface plays an important role in mammary tumor-induced osteolysis and suggest that cathepsin G is a potentially novel therapeutic target in the treatment of breast cancer bone metastasis.