MicroRNA-663 antagonizes apoptosis antagonizing transcription factor to induce apoptosis in epithelial cells.

MicroRNAs are small functional RNAs that modulate various biological processes in cells by interfering with gene translation. We have previously demonstrated that certain miRNAs play a crucial role in the innate immune responses of human oral epithelial cells to Porphyromonas gingivalis. While addressing the mechanisms of P. gingivalis induced apoptosis in these cells, we discovered that certain miRNAs are upregulated upon stimulation with live bacteria. These upregulated miRNAs include hsa-miR-584, hsa-miR-572, hsa-miR-210, hsa-miR-492, hsa-miR-623 and hsa-miR-663. Further analysis revealed an unexpected role for hsa-miR-663 (miR-663). To further evaluate miR-663 function, we overexpressed miR-663 in epithelial cells which resulted in cellular apoptosis. The bioinformatics analysis of the miR-663 target prediction, revealed a strong binding affinity to a 3' UTR region of Apoptosis Antagonizing Transcription Factor (AATF) mRNA. To demonstrate the binding of miR-663 to AATF mRNA, the putative miR-663 target site within the 3'-UTR region of AATF was cloned in luciferase vector and transfected to HEK293T cells. Luminescence data showed the downregulation of luciferase activity in cells that had the full length target region of the putative binding site, confirming that AATF is one of the targets for miR-663. This prompted us to further evaluate its role in a cancer cell line (MCF-7) to determine miR-663s' apoptotic function. The overexpression of miR-663 led to a significant increase in apoptosis of MCF-7 cells. Taken together, miR-663 may function as an 'apoptomiR' by inhibiting the anti-apoptotic gene AATF to induce apoptosis. These findings could have therapeutic implications for epithelial cell targeting in cancer therapy.

Salivary and serum adiponectin and C-reactive protein levels in acute myocardial infarction related to body mass index and oral health.

BACKGROUND AND OBJECTIVE: Adiponectin is produced by adipose cells and is considered an anti-inflammatory molecule. In contrast, C-reactive protein (CRP) has been identified as a hallmark of systemic inflammation and used as a risk marker of cardiovascular disease (CVD). Of interest was the relationship of these two biomarkers to oral health and CVD risk. MATERIAL AND METHODS: This investigation examined these two molecules in serum and unstimulated whole saliva of patients within 48 h of an acute myocardial infarction (AMI) compared to control subjects. We hypothesized a differential response in these biomolecules resulting from the heart attack that would be affected by both the body mass index and oral health characteristics of the individuals. RESULTS: Significantly lower adiponectin levels were observed in the serum of patients with AMI. Serum adiponectin in both groups and salivary adiponectin in patients with AMI decreased with increasing body mass index. Oral health was significantly worse in patients with AMI, and both serum and salivary adiponectin were elevated with better oral health in control subjects. Serum CRP levels were increased in patients with AMI regardless of their oral health, and both serum and salivary CRP were significantly elevated in S-T wave elevated patients with MI. CONCLUSIONS: These initial data provide evidence relating obesity and oral health to salivary and serum analyte levels that occur in association with cardiac events. Relationships have been described between CVD risk and periodontal disease. Additionally, various systemic inflammatory biomarkers appear to reflect both the CVD risk and the extent/severity of periodontitis. Our findings indicated that oral health and obesity contribute to altering levels of these salivary and serum analytes in association with cardiac events. The potential that serum and/or salivary biomarkers could aid in evaluating CVD risk requires knowledge regarding how the oral health of the individual would impact the effectiveness of these biological measures.

The effect of periodontal scaling and root polishing on serum IL-17E concentrations and the IL-17A:IL-17E ratio.

OBJECTIVES: The serum IL-17A:IL-17E ratio has previously been demonstrated to be a clinical marker of periodontitis. The aim of this study was to determine the effects of non-surgical periodontal treatment on the serum IL-17A:IL-17E ratio. MATERIALS AND METHODS: Forty chronic periodontitis patients completed this study and received periodontal treatment comprising scaling and root planing plus ultrasonic debridement. Clinical data were recorded at baseline, 6 weeks (R1) after treatment completion (full-mouth or quadrant-scaling and root planing) and 25 weeks after baseline (R2). Serum samples were taken at each time point and cytokines concentrations determined by ELISA. RESULTS: Following treatment, statistically significant reductions were noted in clinical parameters. However, IL-17A and IL-17E concentrations were significantly greater than baseline values before- and after-adjusting for smoking. The IL-17A:IL-17E ratio was lower at R1 and R2. Serum IL-6 and TNF levels were significantly lower at R1 only. Also exclusively at R1, serum IL-17A and IL-17E correlated positively with clinical parameters, while the IL-17A:IL-17E ratio correlated negatively with probing pocket depth and clinical attachment. CONCLUSION: Increased serum IL-17E and a reduced IL-17A:IL-17E ratio may be indicative and/or a consequence of periodontal therapy. Therefore, the role of IL-17E in periodontal disease progression and the healing process is worthy of further investigation. CLINICAL RELEVANCE: IL-17E may be a valuable biomarker to monitor the healing process following periodontal treatment as increased IL-17E levels and a reduced IL-17A:IL-17E ratio could reflect clinical improvements post-therapy. Therefore, monitoring serum IL-17E might be useful to identify individuals who require additional periodontal treatment.

Experimental gingivitis, bacteremia and systemic biomarkers: a randomized clinical trial.

BACKGROUND AND OBJECTIVE: Bacteremia and systemic inflammatory markers are associated with periodontal and systemic diseases and may be linking mechanisms between these conditions. We hypothesized that in the development of gingival inflammation, systemic markers of inflammation and bacteremia would increase. MATERIAL AND METHODS: To study the effect of bacteremia on systemic inflammatory markers, we recruited 80 subjects to participate in an experimental gingivitis study. Subjects were stratified based on gender, smoking and the number of bleeding sites and then randomized to one of two groups: control group (n = 40) or experimental gingivitis group (n = 40). Subjects in the control group conducted an oral hygiene regimen: brushing twice daily with a regular sodium fluoride cavity protection dentifrice and a standard manual toothbrush, flossing twice daily, and mouth rinsing with an anti-cavity fluoride rinse once daily. The experimental group stopped brushing and flossing, and used only the fluoride anti-cavity mouth rinse for 21 d. RESULTS: Seventy-nine of 80 subjects were evaluable. One subject in the control group was excluded from the results due to antibiotic use during the study. Our data showed the experimental gingivitis group exhibited a significant (p < 0.05) increase in dental plaque level and gingival inflammatory indices relative to baseline and the control group but a decrease in bacteremia and soluble intercellular adhesion molecule-1 levels vs. baseline. Bacteremia was negatively correlated with gingival inflammatory indices and soluble intercellular adhesion molecule-1 levels in the experimental gingivitis group, thus negating our hypothesis. CONCLUSION: We conclude that there are marked differences in systemic cytokine levels over the course of short-term experimentally induced gingivitis and further conclude that a long-term periodontitis study must be considered to address mechanisms whereby oral diseases may affect systemic diseases.

TLR2 promoter hypermethylation creates innate immune dysbiosis.

Periodontitis is a common chronic inflammatory disease that is initiated by a complex microbial biofilm that poses significant health and financial burdens globally. Porphyromonas gingivalis is a predominant pathogen that maintains chronic inflammatory periodontitis. Toll-like receptors (TLRs) play an important role in periodontitis by recognizing pathogens and maintaining tissue homeostasis. Deficiencies in TLR expression and downstream signaling may reduce the host's innate defenses against pathogens, leading to bacterial persistence and exacerbated inflammation, which are now being better appreciated in disease pathologies. In the case of periodontitis, gingival epithelial cells form the first line of defense against pathogens. Innate immune dysregulation in these cells relates to severe disease pathology. We recently identified a blunted TLR2 expression in certain gingival epithelial cells expressing diminished cytokine signaling upon P. gingivalis stimulation. Upon detailed analysis of the TLR2 promoter CpG Island, we noted higher CpG methylation in this dysregulated cell type. When these cells were treated with DNA methyltransferase inhibitor, TLR2 mRNA and cytokine expression were significantly increased. If TLR2 expression plasmid was ectopically expressed in dysfunctional cells prior to P. gingivalis stimulation, the cytokine expression was increased, confirming the requirement of TLR2 in the P. gingivalis-mediated inflammatory response. We designed a chronic in vitro infection model to test if P. gingivalis can induce DNA methylation in normal gingival epithelial cells that express higher TLR2 upon agonist stimulation. Chronic treatment of normal epithelial cells with P. gingivalis introduced de novo DNA methylation within the cells. In addition, increased DNA methylation was observed in the gingiva of mice infected with P. gingivalis in a periodontitis oral gavage model. Moreover, tissues obtained from periodontitis patients also exhibited differential TLR2 promoter methylation, as revealed by bisulfite DNA sequencing. Taken together, DNA methylation of TLR2 can modulate host innate defense mechanisms that may confer increased disease susceptibility.

Utility of salivary biomarkers for demonstrating acute myocardial infarction.

The comparative utility of serum and saliva as diagnostic fluids for identifying biomarkers of acute myocardial infarction (AMI) was investigated. The goal was to determine if salivary biomarkers could facilitate a screening diagnosis of AMI, especially in cases of non-ST elevation MI (NSTEMI), since these cases are not readily identified by electrocardiogram (ECG). Serum and unstimulated whole saliva (UWS) collected from 92 AMI patients within 48 hours of chest pain onset and 105 asymptomatic healthy control individuals were assayed for 13 proteins relevant to cardiovascular disease, by Beadlyte technology (Luminex(®)) and enzyme immunoassays. Data were analyzed with concentration cut-points, ECG findings, logistic regression (LR) (adjusted for matching for age, gender, race, smoking, number of teeth, and oral health status), and classification and regression tree (CART) analysis. A sensitivity analysis was conducted by repetition of the CART analysis in 58 cases and 58 controls, each matched by age and gender. Serum biomarkers demonstrated AMI sensitivity and specificity superior to that of saliva, as determined by LR and CART. The predominant discriminators in serum by LR were troponin I (TnI), B-type natriuretic peptide (BNP), and creatine kinase-MB (CK-MB), and TnI and BNP by CART. In saliva, LR identified C-reactive protein (CRP) as the biomarker most predictive of AMI. A combination of smoking tobacco, UWS CRP, CK-MB, sCD40 ligand, gender, and number of teeth identified AMI in the CART decision trees. When ECG findings, salivary biomarkers, and confounders were included, AMI was predicted with 80.0% sensitivity and 100% specificity. These analyses support the potential utility of salivary biomarker measurements used with ECG for the identification of AMI. Thus, saliva-based tests may provide additional diagnostic screening information in the clinical course for patients suspected of having an AMI.

Is obesity a possible modifier of periodontal disease as a chronic inflammatory process? A case-control study.

BACKGROUND AND OBJECTIVE: This cross-sectional case-control study was conducted to provide a comparative evaluation of clinical periodontal measurements, together with serum levels of certain bioactive peptides and inflammatory cytokines, in relation to obesity. For this purpose, clinical periodontal measurements and the levels of serum leptin, adiponectin, interleukin-6 (IL-6), C-reactive protein and soluble intercellular adhesion molecule-1 of obese female individuals and their nonobese counterparts were compared. MATERIAL AND METHODS: Sixty obese (body mass index (BMI) > 30) and 31 nonobese (BMI < 30) female subjects were recruited for the present study. Before any periodontal intervention, serum samples were obtained and full-mouth clinical periodontal measurements were recorded at six sites per tooth. ELISA was used for the biochemical analysis. Data were tested statistically. RESULTS: Clinical attachment level was significantly higher in the obese group compared with the nonobese control group (p < 0.05). Serum levels of leptin and IL-6 were significantly higher in the obese group (p < 0.05). BMI correlated with the serum levels of inflammatory molecules (p < 0.05), but not with clinical periodontal parameters, in the obese group. CONCLUSION: In conclusion, obesity does not seem to have a prominent effect on clinical periodontal parameters but it does have many correlations with circulating inflammatory molecules. As suggested in the literature, increased levels of leptin and IL-6 in the obese group might be one explanation for a possible relationship between obesity and periodontal disease. A prospective study is warranted to clarify, in greater detail, the effects of obesity on periodontal health.

Neutrophils alter epithelial response to Porphyromonas gingivalis in a gingival crevice model.

A gingival crevice model (epithelial cell-Porphyromonas gingivalis-neutrophil) was established and used to profile gingipain, matrix metalloproteinase (MMP), MMP mediators [neutrophil gelatinase-associated lipocalin (NGAL) and tissue inhibitor of metalloproteinases 1 (TIMP-1)] and cytokine networks. Smoking is the primary environmental risk factor for periodontitis. Therefore, the influence of cigarette smoke extract (CSE) was also monitored in the same model. Porphyromonas gingivalis alone induced low levels of interleukin-1ß and interleukin-8 from epithelial cells, but high levels of both cytokines were produced on the addition of neutrophils. Exposure to CSE (100 and 1000 ng ml(-1) nicotine equivalency) significantly compromised P. gingivalis-induced cytokine secretion (both P < 0.05). P. gingivalis induced impressive secretion of NGAL (P < 0.05) that was not influenced by CSE. The influence of CSE on gingipain production was strain-specific. Purified gingipains effectively and rapidly degraded both TIMP-1 and MMP-9. Induction of large amounts of NGAL, degradation of TIMP-1, and increased gingipain activity would each be expected to prolong collagen degradation and promote disease progression. However, gingipains also degrade MMP-9. Hence, P. gingivalis exerts a complex influence on the proteolytic balance of a gingival crevice model. Exposure to CSE reduces the proinflammatory cytokine burden, which may be expected to promote P. gingivalis survival. In addition to novel findings that provide mechanistic insight into periodontal disease progression, these results are in keeping with the recognized clinical dogma of decreased inflammation/increased disease in smokers. This straightforward gingival crevice model is established as a suitable vehicle for the elucidation of mechanisms that contribute to susceptibility to periodontitis.

Chlorhexidine decreases the risk of ventilator-associated pneumonia in intensive care unit patients: a randomized clinical trial.

BACKGROUND AND OBJECTIVE: The aim was to evaluate whether oral swabbing with 0.2% chlorhexidine gluconate (CHX) decreases the risk of ventilator-associated pneumonia (VAP) in intensive care unit (ICU) patients. MATERIAL AND METHODS: Sixty-one dentate patients scheduled for invasive mechanical ventilation for at least 48 h were included in this randomized, double-blind, controlled study. As these patients were variably incapacitated, oral care was provided by swabbing the oral mucosa four times/d with CHX in the CHX group (29 patients) and with saline in the control group (32 patients). Clinical periodontal measurements were recorded, and lower-respiratory-tract specimens were obtained for microbiological analysis on admission and when VAP was suspected. Pathogens were identified by quantifying colonies using standard culture techniques. RESULTS: Ventilator-associated pneumonia developed in 34/61 patients (55.7%) within 6.8 d. The VAP development rate was significantly higher in the control group than in the CHX group (68.8% vs. 41.4%, respectively; p = 0.03) with an odds ratio of 3.12 (95% confidence interval = 1.09-8.91). Acinetobacter baumannii was the most common pathogen (64.7%) of all species identified. There were no significant differences between the two groups in clinical periodontal measurements, VAP development time, pathogens detected or mortality rate. CONCLUSION: The finding of the present study, that oral care with CHX swabbing reduces the risk of VAP development in mechanically ventilated patients, strongly supports its use in ICUs and indeed the importance of adequate oral hygiene in preventing medical complications.

Total NIH support to US dental schools, 2005-2009.

This study compared total NIH research funding across US dental institutions from 2005 to 2009. Utilizing the online NIH RePORT, we obtained comprehensive award data for US dental schools by funding NIH Institutes/Centers (ICs). Fifty dental schools were awarded a total of $974.393 million, 69.3% from NIDCR and 30.7% from 21 other ICs. These provided the majority of support to 12 schools. Greater than 50% of non-NIDCR support came from 4 ICs. The median dental school NIH portfolio was $14.572 million, with a minimum of $0.241 million and a maximum of $88.609 million. Forty-six schools received $544.899 million for R01 awards. Thirty-five schools were awarded $100 million in research training and career development grants. Several dramatic differences are found for dental schools' rankings based on total NIH dollars compared with NIDCR-only support. Dollars from ICs other than NIDCR increased 34.6% between 2005 and 2009. Grants to US dental institutions comprised 50% or less of total NIDCR awards globally from 2005 through 2009. Funds received from all NIH ICs are an objective metric for evaluation of the research performance of dental schools. NIDCR has played a diminishing role in funding research at US dental schools between 2005 and 2009.

The host cytokine response to Porphyromonas gingivalis is modified by gingipains.

BACKGROUND/AIMS: Clinical studies indicate that primary proinflammatory cytokines, such as interleukin-1beta (IL-1beta) are elevated in the gingival crevice around teeth with periodontitis but the secondary cytokines and chemokines, IL-6 and IL-8, are not. The human gingival epithelial cells (HGECs) lining the gingival sulcus respond to perturbation by microbes of dental plaque by releasing a wide range of cytokines. Porphyromonas gingivalis, a putative periodontal pathogen, possesses numerous virulence factors some of which directly impact on the host response. In the present study, we sought to determine how P. gingivalis influences the inflammatory cytokine responses. METHODS: HGECs were challenged with P. gingivalis and other putative periodontal pathogens, and the resultant production of IL-1beta, IL-6, and IL-8 was assayed by enzyme-linked immunosorbent assay (ELISA). Culture supernatants and recombinant human cytokines were challenged with live P. gingivalis wild-type and gingipain-deficient strains and the resultant cytokine profile was assessed by ELISA and Western blot. RESULTS: We show here that primary HGECs challenged with live P. gingivalis result in high levels of IL-1beta but not the related secondary cytokines IL-6 and IL-8. We further demonstrate that cytokine response differences are the result of the action of P. gingivalis proteases, with lysine gingipain being the most effective. CONCLUSION: We conclude that P. gingivalis, through lysine gingipain, can subvert the protective host proinflammatory response by direct cytokine degradation. Changes in the crevicular cytokine profile have consequences in periodontal disease pathogenesis that should be considered in the development of diagnostic and therapeutic modalities.

Interleukin-24, RANTES and CCR5 gene polymorphisms are not associated with chronic adult periodontitis.

BACKGROUND AND OBJECTIVE: Cytokines, such as interleukin-10, and related genetic polymorphisms, have been implicated in the pathogenesis of chronic periodontitis. The aim of this study was to investigate a possible correlation between chronic periodontitis and genetic polymorphisms coding for two interleukin-10 related chemokines [interleukin-24 and regulated on activation, normal T cells expressed and secreted (RANTES)] as well as a RANTES receptor [CC chemokine receptor 5 (CCR5)]. MATERIAL AND METHODS: A single-blind, two-centre, case-controlled study was carried out with test patients from the Clinic of Periodontics, Göteborg University, and from the Department of Periodontology, Glasgow University, and control subjects from the undergraduate clinics of both schools. Blood samples were collected from 106 patients (56 women and 50 men, mean age 51.7 yr) with generalized, severe chronic periodontitis and from 69 periodontally healthy subjects (37 women and 32 men, mean age 53.3 yr). The polymerase chain reaction (PCR) was used to identify the genetic coding for interleukin-24, RANTES and CCR5. Genotype and allele frequencies were compared between the test and control groups using Fischer's exact test at the 5% level of significance. RESULTS: There were no statistically significant differences between patients with chronic periodontitis and control subjects, regarding genotype distribution or allele frequency, irrespective of smoking status, in the combined Glasgow and Gothenburg cohort or in the specific location cohorts. The allele frequencies for healthy and control subjects for RANTES gave a p-value of 0.80 (allele G was 58.8% in healthy subjects and and 54.4% in subjects with periodontitis), for interleukin-24 the p-value was 0.90 (allele T was 56.2% in healthy subjects and and 54.9% in subjects with periodontitis) and for CCR5 the p-value was 0.90 (the wild-type allele was 85% in healthy subjects and and 82.7% in subjects with periodontitis). CONCLUSION: The interleukin-24, RANTES and CCR5 polymorphisms investigated are not associated with chronic periodontitis.

Monitoring periodontal disease status in smokers and nonsmokers using a gingival crevicular fluid matrix metalloproteinase-8-specific chair-side test.

BACKGROUND AND OBJECTIVE: With current periodontal diagnostic tools it is difficult to identify susceptible individuals or sites at risk. The aim of this study was to evaluate the efficacy of the matrix metalloproteinase (MMP)-8-specific chair-side dip-stick test in longitudinally monitoring the periodontal status of smoking (S) and nonsmoking (NS) patients with chronic periodontitis, using their gingival crevicular fluid (GCF) MMP-8 concentrations. MATERIAL AND METHODS: Clinical parameters, MMP-8 test results and concentrations were monitored in 16 patients after initial treatment and in 15 patients after scaling and root planing (SRP), every other month, over a 12-mo time period. Progressing and stable sites, and sites with exceptionally high MMP-8 concentrations, were analysed in smokers and nonsmokers. RESULTS: SRP reduced the mean GCF MMP-8 levels, test scores, probing depth (PD), attachment loss (AL) and bleeding on probing (BOP). In sites of periodontal disease progression, the distribution of MMP-8 concentrations was broader than in stable sites, indicating a tendency for elevated concentrations in patients with periodontal disease. The mean MMP-8 concentrations in smokers were lower than in nonsmokers, but in smokers' and nonsmokers' sites with progressive disease, MMP-8 concentrations were similar. Sites with exceptionally elevated MMP-8 concentrations were clustered in smokers who also showed a poor response to SRP. In these sites, the MMP-8 concentration did not decrease with SRP and these sites were easily identified by the MMP-8 test. CONCLUSION: Persistently elevated GCF MMP-8 concentrations may indicate sites at risk, as well as patients with poor response to conventional periodontal treatment (e.g. SRP). MMP-8 testing may be useful as an adjunct to traditional periodontal diagnostic methods during the maintenance phase.

Gingival epithelial cells heterozygous for Toll-like receptor 4 polymorphisms Asp299Gly and Thr399ile are hypo-responsive to Porphyromonas gingivalis.

The Toll-like receptor (TLR)4 is the major sensor for bacterial lipopolysaccharide and its two common co-segregating polymorphisms, Asp299Gly and Thr399Ile, which occur at a frequency of between 6 and 10%, have been associated with infectious diseases, LPS hypo-responsiveness and cardiovascular disease. Porphyromonas gingivalis is a Gram-negative bacterium implicated in chronic periodontitis and is a known TLR4 and TLR2 agonist. We obtained two gingival epithelial cell primary cultures from subjects heterozygous for the TLR4 polymorphism Asp299Gly and compared response characteristics with similar cells from patients (four) with the wild-type TLR4 genes. Cytokine responses and transcriptome profiles of gingival epithelial cell primary culture cells to TNFalpha challenge were similar for all primary epithelial cell cultures. P. gingivalis challenge, however, gave markedly different responses for Asp299Gly heterozygous and wild-type epithelial cell cultures. The epithelial cells heterozygous for the TLR4 polymorphism Asp299Gly were functionally hypo-responsive, evidenced by differences in BD-2 mRNA expression, mRNA response profile by microarray analysis and by pro-inflammatory and chemokine cytokines at the protein and mRNA level. These findings emphasize variance in human epithelial cell TLRs, linked with Asp299Gly carriage, which results in a hypo-responsive epithelial cell phenotype less susceptible to Gram-negative diseases and associated systemic conditions.

Generation of inflammatory stimuli: how bacteria set up inflammatory responses in the gingiva.

OBJECTIVES: The primary aetiologic factor of periodontal disease is the bacterial biofilm. Gram-positive and gram-negative bacteria possess a plethora of structural or secreted components that may cause direct destruction to periodontal tissues or stimulate host cells to activate a wide range of inflammatory responses. These responses are intended to eliminate the microbial challenge, but may often cause further tissue damage. METHODS: This review has been divided into three parts: (a) bacterial virulence factors, which includes basic information on bacterial virulence factors, and the principle inflammatory responses that host cells elicit against these factors, (b) main receptors and signalling pathways, which includes basic information about the main receptors that interact with the bacterial virulence factors, the nature of these interactions, and the activated signalling pathways that lead to inflammatory responses, and (c) initiation of inflammation, which includes a model by which the virulence factors may interact with host cells and lead to inflammatory responses in the gingiva. FINDINGS AND CONCLUSIONS: Bacterial components/virulence factors may be involved in modulating inflammatory responses and include: lipopolysaccharides (LPS), peptidoglycans, lipotechoic acids, fimbriae, proteases, heat-shock proteins, formyl-methionyl peptides, and toxins. Potential host cell receptors involved in recognizing bacterial components and initiating signalling pathways that lead to inflammatory responses include: Toll-like receptors (TLRs), CD14, nucleotide-binding oligomerization domain proteins (Nod) and G-protein-coupled receptors, including formyl-methionyl peptide receptors and protease-activated receptors. Of the above bacterial and host molecules, evidence from experimental animal studies implicate LPS, fimbriae, proteases, TLRs, and CD14 in periodontal tissue or alveolar bone destruction. However, evidence verifying the involvement of any of the above molecules in periodontal tissue destruction in humans does not exist.

Impact of smoking on the clinical, microbiological and immunological parameters of adult patients with periodontitis.

OBJECTIVES: The aim of the current study was to assess the impact of smoking on the clinical indices, the humoral immune response and the detection frequency of putative periodontal pathogens in patients with periodontitis cross-sectionally and following therapy. MATERIAL AND METHODS: Clinical measurements, subgingival plaque samples, gingival crevicular fluid (GCF) and sera were collected from 40 untreated patients with moderate-to-advanced chronic periodontitis before and after treatment over a period of 6 months. The treatment consisted of the initial therapy of scaling and root planing. Smoking status was self-reported and was confirmed by cotinine enzyme inhibition assay (CEIA). Whole-mouth clinical measurements were recorded with a manual periodontal probe at baseline (BAS) and at 6 months (RAS). Selected-site analyses were performed on the deepest site in each quadrant before and after therapy and clinical indices were recorded with an electronic pressure-sensitive probe. GCF sample volume was quantified using the Periotron 6000. Polymerase chain reaction (PCR) was utilized to determine the presence of Porphyromonas gingivalis, Actinobacillus actinomycetemcomitans, Prevotella intermedia, Treponema denticola and Tanerella forsythensis in subgingival plaque. Enzyme-linked immunosorbent assay examined the systemic antibody titres to these bacteria, and thiocyanate disassociation determined the antibody avidity to these organisms. RESULTS: At baseline, smokers showed significantly less gingival inflammation and lower GCF volume compared with non-smokers. After treatment, a compromised clinical outcome was noted for smokers in terms of pocket depth reduction and gain in attachment levels. No significant differences in the detection of putative periodontal pathogens in subgingival plaque existed between smokers and non-smokers. A consistent trend was noted in that smokers had lower sera immunoglobulin G antibody titres to these organisms before and after treatment (statistically significant for A. actinomycetemcomitans). This pattern was less clear when antibody avidities were considered, revealing only small differences, if any, between the two groups of patients. CONCLUSION: Current data indicate that smokers with periodontal disease have a suppressed inflammatory response, a significantly less favourable clinical outcome and seem to have an altered host antibody response to antigenic challenge than non-smokers. In contrast, the subgingival microflora of smokers appears similar to that of non-smokers.

Lipoprotein-associated phospholipase A2 and plasma lipids in patients with destructive periodontal disease.

OBJECTIVES: Periodontitis is believed to be an independent risk factor of cardiovascular disease (CVD) and to be associated with a moderate systemic inflammatory reaction and hyperlipidaemia. Lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) is an enzyme that has been shown to be a risk factor of CVD and that is involved in the degradation of the phospholipid mediator platelet-activating factor (PAF), a potent mediator of inflammation. MATERIAL AND METHODS: In the present study, we measured concentrations of plasma lipids and plasma activity of Lp-PLA(2) in 32 patients (mean age 43+/-11 years) with moderate-to-severe periodontitis before and 3 months after local treatment. RESULTS: Periodontal therapy resulted in a significant reduction of local inflammation and tissue destruction as reflected in reduced pocket depths and reduced bleeding indices. Pre- and post-treatment plasma lipid levels were (median and range, mmol/l): total cholesterol (C) 5.01 (3.94-7.15) and 4.91 (3.32-8.01); low-density lipoprotein-cholesterol (LDL-C) 3.14 (2.40-4.84) and 2.96 (1.39-5.04); HDL-C 1.27 (0.73-2.17) and 1.25 (0.74-2.55); triglycerides 1.37 (0.48-5.11) and 1.14 (0.38-792). Using the Wilcoxon's rank test, neither parameter showed a significant change. In contrast to the lacking response of plasma lipids, we observed a significant reduction in the activity of Lp-PLA(2). Local treatment lowered the enzyme activity by about 10% from 3.61+/-0.99 to 3.29+/-0.94 micromol/ml/h (mean+/-SD; p<0.001). The pre-treatment values of Lp-PLA(2) and LDL-C significantly correlated with clinical parameters of inflammation and periodontal destruction. CONCLUSION: This study indicates that treatment of periodontitis significantly reduces the serum activity of Lp-PLA(2), which is believed to be an independent cardiovascular risk factor.