A trend of increase in periodontal interleukin-6 expression across patients with neither diabetes nor periodontal disease, patients with periodontal disease alone, and patients with both diseases

Background and Objective: Epidemiological studies have established that patients with diabetes have increased prevalence and severity of periodontal disease. However, the periodontal expression of inflammatory cytokines and matrix metalloproteinases (MMPs) in diabetic patients has not been well characterized. The objective of this study was to determine the difference in the periodontal expression of MMP‐1, MMP‐8, interleukin‐6, tumor necrosis factor‐α and interleukin‐1β between diabetic and nondiabetic patients. Material and Methods: Periodontal tissue specimens were collected from nine nondiabetic patients without periodontal disease (group 1), from 11 nondiabetic patients with periodontal disease (group 2) and from seven diabetic patients with periodontal disease (group 3). The expression of MMP‐1, MMP‐8, interleukin‐6, tumor necrosis factor‐α and interleukin‐1β was quantified using real‐time polymerase chain reaction. Results: The nonparametric Kruskal–Wallis test showed that the difference in interleukin‐6 expression among the groups was statistically significant (p = 0.04). Furthermore, the generalized Kruskal–Wallis nonparametric linear‐by‐linear association test showed a statistically significant trend of increase in the expression of interleukin‐6 from group 1 to group 2 to group 3 (p = 0.02) and a suggestion of such a trend for MMP‐1 (p = 0.05). No increase in MMP‐8 expression was observed in patients in group 3 compared to patients in groups 1 and 2. Although the average expression levels of MMP‐1, interleukin‐1β and tumor necrosis factor‐α were increased from group 1 to group 3, the differences were not statistically significant. Conclusion: A trend of increased interleukin‐6 expression in periodontal tissues was observed across patients with neither diabetes nor periodontal disease, patients with periodontal disease alone, and patients with both diseases.     

Periodontal disease and its connection to systemic biomarkers of cardiovascular disease in young American Indian/Alaskan natives

1 Background

Periodontal disease has been shown to be associated with cardiovascular disease (CVD). No known studies evaluate the relationship between periodontal disease status and biomarkers of CVD risk in the American Indian/Alaskan Native (AI/AN) population despite their disproportionately high rates of poor oral health and cardiovascular disease–related outcomes. This study compared levels of interleukin (IL)‐6 and C‐reactive protein (CRP) across increasing severity of periodontal disease status among younger adults between the ages of 21 and 43 years.

2 Methods

Plasma levels of IL‐6 and CRP were measured in adult participants (ages 21 to 43 years) as part of a study of periodontal disease and CVD risk among an AI/AN population in southern California (n = 59). Periodontal evaluations were performed and disease status was classified into three categories based on highest probing depth (none/mild: < 3 mm; moderate: 4 to 5 mm; severe: ≥6 mm). Participants with known systemic disease or active infection were excluded.

3 Results

Severe periodontitis was significantly associated with increased levels of IL‐6 compared with those with none or mild periodontitis before controlling for other variables (P = 0.02), but lacked significance after controlling for sex, BMI, smoking status, and high‐density lipoprotein (P = 0.09). Moderate periodontal disease was positively associated with IL‐6 levels after controlling for potential confounders (P = 0.01). Periodontal status was not associated with CRP, before or after adjusting for covariates.

4 Conclusions

In this otherwise healthy AI/AN adult sample, moderate periodontal disease compared with none or mild periodontal disease was associated with increased levels of IL‐6. High levels of CRP found in this population warrant further research.     

Evaluation of periodontal status and effectiveness of non-surgical treatment in patients with type 2 diabetes mellitus in Taiwan for a 1-year period

Background: The periodontal status and effects of non‐surgical periodontal treatment in patients with type 2 diabetes mellitus and periodontal disease are assessed. Methods: One‐hundred patients with type 2 diabetes (mean ± SD hemoglobin (Hb)A1c level: 7.3% ± 0.94%) and periodontal disease were recruited for this study. The group with moderate‐to‐severe periodontal disease included patients with >1 tooth with a probing depth (PD) ≥5 mm and >2 teeth with a clinical attachment loss (AL) ≥6mm, and the group with mild periodontal disease included patients with <1 affected tooth, and >2 affected with a clinical AL ≥6mm. Patients (28 patients in the mild group and 72 patients in the moderate‐to‐severe group) underwent non‐surgical periodontal treatments. We analyzed differences in serum concentrations of metabolic parameters (glycated hemoglobin and low‐density lipoprotein), inflammatory parameters (interleukin [IL]‐1β and C‐reactive protein [CRP]), and periodontal parameters between the two groups before treatment and at 3, 6, 9, and 12 months post‐therapy. Results: Seventy‐five patients with diabetes (21 patients in the mild group and 54 patients in the moderate‐to‐severe group) completed the study. Significant differences in the plaque index (PI), gingival index (GI), PD, and clinical AL at examination times were observed in the whole cohort (P <0.05). We observed significant differences in the PI, GI, and PD in the moderate‐to‐severe group (P <0.05), whereas there was only a significant difference in PD in the mild group (P <0.05) between baseline and 12 months post‐treatment. Both groups experienced improved glycemic control, but the difference was insignificant. CRP and IL‐1β levels were significantly different at examination times for the whole cohort (P <0.05). No significant positive association among metabolic and inflammatory parameters at 12 months post‐therapy were found. Conclusion: Non‐surgical periodontal treatment improved and maintained the periodontal health of patients with well‐controlled diabetes, but no significant reduction of metabolic parameters was observed over a 1‐year period.     

Proinflammatory cytokine levels in hyperlipidemic patients with periodontitis after periodontal treatment

Oral Diseases (2012) 18 , 299–306 Objective: The aim of this study was to evaluate the effects of periodontal treatment on serum and gingival crevicular fluid (GCF) proinflammatory cytokine levels in hyperlipidemic patients with periodontitis. Materials and Methods: Fifty‐two patients with hyperlipidemia and periodontitis and 28 systemically healthy controls with periodontitis (C) were included in the study. Hyperlipidemic groups were divided into two groups as suggested diet (HD) and prescribed statin (HS). The clinical periodontal parameters, fasting venous blood, and GCF samples were obtained, and serum tumor necrosis factor‐alpha (TNF‐α), interleukin (IL) 1‐beta, and IL‐6 levels were evaluated at baseline and at 3 months follow‐up (3MFU) after the completion of the non‐surgical periodontal treatment that included scaling and root planning. Results: Percentage of bleeding on probing was significantly higher in the HS group than both the HD and C groups. In the HD and HS groups, there were significant decreases in serum IL‐6 and GCF TNF‐α levels between the 3MFU and baseline. A significant decrease was also found in GCF IL‐6 at the end of the study period in the HS group. Conclusion: The combination of the periodontal therapy and antilipemic treatment may provide beneficial effects on the metabolic and inflammatory control of hyperlipidemia.     

Serum cytokine levels and periodontal parameters in ankylosing spondylitis

Sezer U, Erciyas K, Pehlivan Y, Üstün K, Tarakç?o?lu M, ?enyurt SZ, Onat AM. Serum cytokine levels and periodontal parameters in ankylosing spondylitis. J Periodont Res 2012; 47: 396–401. © 2011 John Wiley & Sons A/S Background and Objective: Multiple studies support the role of periodontal disease in contributing to the chronic systemic inflammatory burden in a variety of diseases, including ankylosing spondylitis (AS), in the progression which the inflammatory process plays an important role. We assume that patients with AS are more likely to have periodontal disease than healthy individuals. The aim of this study was to determine the possible relationship between inflammatory periodontal diseases and AS by evaluating clinical periodontal parameters and serum cytokine levels. Material and Methods: Forty‐eight adults with AS (35 women and 13 men; age range 18–56 years; mean age 34.27 years) and 48 age‐ and sex‐matched systemically healthy control subjects participated in the study. The clinical periodontal parameters, venous blood and Bath Ankylosing Spondylitis Disease Activity Score were obtained, and serum C‐reactive protein, tumour necrosis factor‐α and interleukin‐6 (IL‐6) levels were evaluated. Results: There was statistically no significant difference in the frequency of periodontitis between AS patients and the control group. Furthermore, there was no significant difference in probing depth, clinical attachment level and plaque index, and the only significant clinical difference between groups was in levels of bleeding on probing (p < 0.001). Serum concentrations of IL‐6, tumour necrosis factor‐α and C‐reactive protein in the AS group were significantly higher than those in the control group (p < 0.001). In the AS group, there was a correlation between serum IL‐6 levels and clinical attachment level (p < 0.001). Conclusion: The results of present study suggest that bleeding on probing was the only different periodontal parameter between the AS and the control group, and the periodontal status of patients with AS may be affected by IL‐6 levels.     

Efect of periodontal disease and non surgical periodontal treatment on C-reactive protein. Evaluation of type 1 diabetic patients

Objectives: The purpose of this study was to analyze how anti-infectious periodontal treatment affects C reactive protein (CRP) values in patients with type 1 diabetes, and correlate baseline CRP levels with periodontal disease severity. Study Design: A cohort of fifty three subjects with type 1 diabetes and moderate to severe periodontitis were recruited. Periodontal parameters were measured, and blood samples were obtained to evaluate high-sensitivity C-reactive protein (hs-CRP). Group 1 was treated with scaling, root planning, and systemic administration of doxycycline. Group 2 received only scaling and root planning. Results: Hs-CRP was reduced after periodontal treatment in group 1 (-0.22 mg/l) and 2 (-0.21 mg/l ) but this reduction was not statistically significant, even in the patients with the best response to periodontal treatment. However, significant correlation appeared between hs-CRP and mean probing pocket depth (PPD) (p=0, 01) and mean clinical attachment level (CAL) (p=0,03). Conclusions: Non-surgical periodontal treatment couldn’t reduce hs-CRP values, however, it was found an association between advanced periodontitis and elevated blood hs-CRP levels in patients with type 1 diabetes. It can be speculated that periodontal disease increases production of pro-inflammatory mediators in patients with type 1 diabetes, but other producing sources of these pro-inflammatory substances may exist. Key words:Periodontal disease, periodontitis, diabetes mellitus type 1, periodontal therapy, C reactive protein.     

Analysis of YKL‐40 Acute‐Phase Protein and Interleukin‐6 Levels in Periodontal Disease

Background: YKL‐40, a new acute‐phase protein, is shown to be elevated in inflammatory diseases, such as rheumatoid arthritis, type 2 diabetes mellitus, and coronary artery diseases. However, there is no data indicating a relationship between YKL‐40 and periodontal disease. Interleukin‐6 (IL‐6) is the major regulator of acute‐phase protein synthesis and one of the most studied inflammatory markers in periodontal disease. The purpose of the present study is to evaluate YKL‐40 and IL‐6 levels in gingival crevicular fluid (GCF) and serum of patients with periodontal disease and healthy individuals. Methods: Periodontally healthy individuals (n = 15), patients with gingivitis (n = 15), and patients with severe chronic periodontitis (CP) (n = 15) without any systemic disease were included in the study. Clinical measurements were recorded; GCF and blood samples were obtained from each participant. GCF and serum YKL‐40 and IL‐6 levels were analyzed by enzyme‐linked immunosorbent assay. Statistical analysis was performed by parametric and non‐parametric tests. Results: Total amounts of YKL‐40 and IL‐6 in GCF as well as serum YKL‐40 and IL‐6 levels were significantly higher in patients with gingivitis and CP compared with healthy controls (P <0.01). YKL‐40 levels in GCF and serum as well as serum IL‐6 levels were significantly higher in patients with CP compared with patients with gingivitis (P <0.01). Conclusions: YKL‐40 levels in GCF as well as serum YKL‐40 and IL‐6 levels increased from gingivitis to periodontitis. Within the limits of the present study, the YKL‐40 molecule might be a potential novel inflammatory marker of periodontal disease.     

Assessment of Interleukin‐6 Receptor Inhibition Therapy on Periodontal Condition in Patients With Rheumatoid Arthritis and Chronic Periodontitis

Background: Overproduction of interleukin (IL)‐6 may play a pathologic role in rheumatoid arthritis (RA) and chronic periodontitis (CP). The present study assesses IL‐6 receptor (IL‐6R) inhibition therapy on the periodontal condition of patients with RA and CP. Methods: The study participants were 28 patients with RA and CP during treatment with IL‐6R inhibitor, and 27 patients with RA and CP during treatment without IL‐6R inhibitor. Periodontal and rheumatologic parameters and serum levels of cytokine and inflammatory markers and immunoglobulin G against periodontopathic bacteria were examined after medication with IL‐6R inhibitor for 20.3 months on average (T1) and again 8 weeks later (T2). Results: No differences were observed between the groups in any parameter values at T1, except for serum IL‐6 levels. The anti–IL‐6R group showed a significantly greater decrease in gingival index, bleeding on probing (BOP), probing depth (PD), clinical attachment level (CAL), and serum levels of IL‐6 and matrix metalloproteinase (MMP)‐3 from T1 to T2 than the control group (P <0.05). A significant correlation was found between changes in serum anticyclic citrullinated peptide levels and those in PD and CAL in the anti–IL‐6R group (P <0.05), whereas both groups exhibited a significant association between changes in serum MMP‐3 levels and those in BOP (P <0.05). Conclusion: Changes in periodontal and serum parameter values were different between the patients with RA and CP during treatment with and without IL‐6R inhibitor.     

Correlation between periodontal disease, inflammatory alterations and pre-eclampsia

Politano GT, Passini R, Nomura ML, Velloso L, Morari J, Couto E. Correlation between periodontal disease, inflammatory alterations and pre‐eclampsia. J Periodont Res 2011; 46: 505–511. © 2011 John Wiley & Sons A/S Background and Objective: Several studies have hypothesized that periodontal disease may increase the risk of pre‐eclampsia. The correlation between the two diseases would probably be based on hypertension‐related cytokine release in the local periodontal environment. The aim of this study was to evaluate the association between periodontal disease and pre‐eclampsia, and the correlation of the two conditions with interleukin‐6 (IL‐6) and tumor necrosis factor‐α(TNFα) mRNA expression. Material and Methods: A case–control analysis of 116 pregnant women, 58 with pre‐eclampsia (cases) and 58 normotensive pregnant women (controls) was performed. In addition to collection of socio‐demographic data and periodontal evaluation, peripheral blood samples were collected for laboratory analysis of IL‐6 and TNFα mRNA expression by real‐time PCR. Results: There was an association between periodontitis and pre‐eclampsia (adjusted odds ratio 3.73; 95% confidence interval 1.32–10.58). Increased TNFα mRNA expression was observed in pre‐eclamptic women; however, there was no correlation between periodontitis and systemic cytokine expression. In the case group, systemic cytokine mRNA levels were similar in pregnant women with and without periodontitis (means ± SD): 0.73 ± 0.24 vs. 0.82 ± 0.38 for TNFα and 1.31 ± 1.49 vs. 1.09 ± 0.74 for IL‐6, respectively. Conclusion: Periodontitis was clinically related to pre‐eclampsia; however, the supposed mechanism that correlates the two diseases, i.e. a systemic inflammatory process involving cytokines TNFα and IL‐6 in the presence of periodontal disease, could not be confirmed in this study.     

Systemic Inflammatory Biomarkers and Their Association With Periodontal and Diabetes‐Related Factors in the Diabetes and Periodontal Therapy Trial,A Randomized Controlled Trial

Background: The present study evaluates effects of non‐surgical periodontal treatment on serum biomarkers in patients with type 2 diabetes mellitus (t2DM) and chronic periodontitis who participated in the Diabetes and Periodontal Therapy Trial (DPTT); and associations among diabetes markers, serum biomarkers, and periodontal measures in these patients. Methods: DPTT participants randomized to receive immediate or delayed non‐surgical periodontal therapy were evaluated at baseline and 6 months. Serum samples from 475 participants with 6‐month data were analyzed for the following biomarkers: 1) high sensitivity C‐reactive protein; 2) E‐selectin; 3) tumor necrosis factor (TNF)‐α; 4) vascular cell adhesion molecule (VCAM); 5) interleukin (IL)‐6; 6) IL‐8; 7) intercellular adhesion molecule; and 8) IL‐10. Changes in biomarker levels from baseline and correlations among biomarker levels and clinical findings were analyzed. Results: No differences between treatment and control groups were observed for any biomarkers at baseline or 6 months (P >0.05 for all variables). VCAM levels increased by an average (standard deviation) of 17.9 (99.5); ng/mL (P = 0.006) and E‐selectin decreased by 2.33 (16.08) ng/mL (P = 0.03) in the treatment group after 6 months. E‐selectin levels were significantly correlated with DM‐related variables (hemoglobin A1c [HbA1c] and fasting glucose) at baseline and with 6‐month change in both groups; no significant correlations were found among periodontal clinical parameters and serum biomarkers or DM‐related variables. Neither HbA1c or body mass index varied during the study period in either study group. Conclusions: Non‐surgical periodontal therapy and periodontal disease severity were not associated with significant changes in serum biomarkers in DPTT participants during the 6‐month follow‐up. Correlations among changes in E‐selectin, IL‐6, and DM‐related variables suggest that t2DM may be the primary driver of systemic inflammation in these patients.     

Interaction between periodontal disease and systemic secondary amyloidosis: from inflammation to amyloidosis

Background: It has become increasingly clear in recent years that periodontal disease can cause a dramatic increase in the levels of markers of systemic inflammation, and that periodontal treatment can result in reduction in the levels of these markers. We have previously shown that the prevalence of moderate to severe periodontitis was significantly higher in patients with familial Mediterranean fever (FMF) with amyloidosis than in patients with FMF without amyloidosis. Thus, the aim of this study is to investigate if chronic periodontitis is associated with secondary amyloidosis in the Black Sea region of Turkey. Methods: A total of 112 patients with biopsy‐proven secondary amyloidosis (59 patients with FMF, 40 patients who were either chronically infected or had malignant disease, 13 patients with periodontitis) and 22 healthy subjects, were included in this study. Periodontal health and disease were evaluated using gingival index (GI), papillary bleeding index (PBI), plaque index (PI), and periodontal disease index (PDI). The concentrations of serum acute phase reactants (APRs) were measured at baseline and at 4 to 6 weeks after completion of the non‐surgical periodontal therapy. Results: The prevalence of moderate to severe periodontitis was 47.5% in patients with FMF, 72.5% in patients who were either chronically infected or had malignant disease, and 84.6% in patients with periodontitis. Serum levels of APRs in patients with amyloidosis were reduced significantly after non‐surgical periodontal therapy (P <0.01). Conclusions: Periodontitis can increase the levels of APRs and potentiate the development of amyloidosis either by themselves or association with traditional factors, such as FMF and other chronic inflammatory diseases. Thus, preventing or treating periodontitis might prevent or at least alleviate the progression of amyloidosis. Periodontal evaluation should be performed as part of a medical assessment and considered as an etiologic factor for secondary amyloidosis.     

Influence of smoking on interleukin-1beta level, oxidant status and antioxidant status in gingival crevicular fluid from chronic periodontitis patients before and after periodontal treatment

Toker H, Akp?nar A, Ayd?n H, Poyraz O. Influence of smoking on interleukin‐1beta level, oxidant status and antioxidant status in gingival crevicular fluid from chronic periodontitis patients before and after periodontal treatment. J Periodont Res 2012; 47: 572–577. © 2012 John Wiley & Sons A/S Background and Objective: The aim of this study was to evaluate the impact of smoking on the relationship between interleukin‐1 (IL‐1β) and oxidation in patients with periodontitis and response to nonsurgical periodontal therapy. Material and Methods: Data were obtained from 30 patients with generalized chronic periodontitis (15 smokers and 15 nonsmokers) and from 10 periodontally healthy controls. IL‐1β level, total oxidant status (TOS) and total antioxidant status (TAS) were recorded in gingival crevicular fluid. Probing depth, clinical attachment level, gingival and plaque indices and bleeding on probing were also measured. The gingival crevicular fluid and clinical parameters were recorded at baseline and 6 wk after periodontal treatment. Results: The study showed statistically significant improvement of clinical parameters in both smokers and nonsmokers after periodontal treatment. Moreover, the baseline IL‐1β levels were significantly higher in smokers compared with nonsmokers (p < 0.05). After periodontal treatment, the IL‐1β levels were significantly reduced in both smokers and nonsmokers (p < 0.05). There were no significant differences in TOS and TAS between periodontitis patients and healthy controls at baseline and 6 wk after periodontal treatment. The level of IL‐1β in gingival crevicular fluid was positively correlated with TOS in both smokers and nonsmokers. Conclusions: Periodontal treatment improved the clinical parameters in both smokers and nonsmokers. The results confirm that periodontal therapy has an effect on IL‐1β levels in gingival crevicular fluid, but not on TOS and TAS.     

Effect of nonsurgical periodontal therapy on serum and gingival crevicular fluid cytokine levels during pregnancy and postpartum

Background and Objective: A low‐grade systemic inflammatory status originating from periodontal infection has been proposed to explain the association between periodontal disease and systemic conditions, including adverse obstetric outcomes. The aim of this study was to evaluate the effect of periodontal therapy during pregnancy on the gingival crevicular fluid and serum levels of six cytokines associated with periodontal disease and preterm birth. Material and Methods: A subsample of 60 women (18–35 years of age) up to 20 gestational weeks, previously enrolled in a larger randomized clinical trial, was recruited for the present study. Participants were randomly allocated to receive either comprehensive nonsurgical periodontal therapy before 24 gestational weeks (n = 30, test group) or only one appointment for supragingival calculus removal (n = 30, control group). Clinical data, and samples of blood and gingival crevicular fluid, were collected at baseline, at 26–28 gestational weeks and 30 d after delivery. The levels of interleukin (IL)‐1β, IL‐6, IL‐8, IL‐10, IL‐12p70 and tumor necrosis factor‐α were analyzed by flow cytometry. Results: After treatment, a major reduction in periodontal inflammation was observed in the test group, with bleeding on probing decreasing from 49.62% of sites to 11.66% of sites (p < 0.001). Periodontal therapy significantly reduced the levels of IL‐1β and IL‐8 in gingival crevicular fluid (p < 0.001). However, no significant effect of therapy was observed on serum cytokine levels. After delivery, the levels of IL‐1β in the gingival crevicular fluid of the test group were significantly lower than were those in the control group (p < 0.001), but there were no significant differences between test and control groups regarding serum cytokine levels. Conclusion: Although periodontal therapy during pregnancy successfully reduced periodontal inflammation and gingival crevicular fluid cytokine levels, it did not have a significant impact on serum biomarkers.     

Periodontal and Systemic Responses in Various Mice Models of Experimental Periodontitis: Respective Roles of Inflammation Duration and Porphyromonas gingivalis Infection

Background: The great variability of periodontal and systemic responses to experimental periodontitis reflects the inherent pathogenic complexity of mice models and could limit the resulting interpretations and their extension to human diseases. This study compared the effect of Porphyromonas gingivalis (Pg) infection and experimental periodontitis duration at local and systemic levels in various models. Methods: Periodontitis was induced in C57BL/6J mice by ligatures previously incubated with Pg (LIGPG group) or not (LIG group) or by oral gavage (GAV) with Pg ATCC 33277. Blood samples were taken, and mice were euthanized at different times. Periodontal tissue destruction, osteoclast number, and inflammation were assessed by histomorphometry, tartrate‐resistant acid phosphatase histoenzymology, and cathepsin B (CATB) and matrix metalloproteinase 9 (MMP9) immunochemistry. Serum levels of interleukin‐6 (IL‐6) and IL‐1β were measured using enzyme‐linked immunosorbent assay bioplex methods. Results: Periodontal tissue destruction and osteoclast numbers were significantly elevated in LIGPG models compared to LIG and GAV models. They increased with time with the exception of osteoclast numbers in the LIG model. CATB and MMP9 expression was related to bone destruction processes and Pg infection. The highest serum levels of IL‐6 and IL‐1β were observed in the LIGPG group. A decrease of IL‐6 and an increase of IL‐1β serum level were observed with time in LIGPG group contrary to LIG group. Conclusions: These data indicate that Pg infection worsened periodontal tissue destruction through specific pathogenic pathways and modified systemic response to periodontal inflammation. Furthermore, the blood cytokine response to ligature models showed their relevance for evaluating the systemic impact of periodontal disease.     

The antimicrobial peptide LL-37 is anti-inflammatory and proapoptotic in human periodontal ligament cells

Jönsson D, Nilsson B‐O. The antimicrobial peptide LL‐37 is anti‐inflammatory and proapoptotic in human periodontal ligament cells. J Periodont Res 2012; 47: 330–335. © 2011 John Wiley & Sons A/S Background and Objective: The antimicrobial peptide LL‐37 is expressed in periodontal tissue, and variations in LL‐37 levels have been associated with periodontal disease. The effects of LL‐37 on periodontal ligament cell function have not been described before. Here, we assess anti‐inflammatory properties of LL‐37 and investigate the effects of LL‐37 on cell differentiation, cell proliferation and apoptosis in human periodontal ligament cells. Material and Methods: Periodontal ligament cells were obtained from teeth extracted for orthodontic reasons. Cytokine (interleukin‐6) and chemokine (monocyte chemoattractant protein‐1) expression was determined by quantitative PCR, cell differentiation by alkaline phosphatase activity, cell proliferation by counting cells in a Bürker chamber, DNA synthesis by incorporation of radiolabeled thymidine and apoptosis by cell morphology and activated caspase 3 quantities. Results: Treatment with 0.1 and 1 μm of LL‐37 totally reversed lipopolysaccharide‐induced monocyte chemoattractant protein‐1 expression and suppressed lipopolysaccharide‐induced interleukin‐6 expression by 50–70%. LL‐37 had no effect on alkaline phosphatase activity. Incubation with 8 μm LL‐37 strongly reduced cell number. DNA synthesis was attenuated by about 90% in response to 8 μm LL‐37, confirming its antiproliferative effect. Cell morphology was altered in an apoptosis‐like fashion in cells treated with 8 μm LL‐37. Furthermore, the quantity of activated caspase 3 was increased in cells treated with 1 and 8 μm of LL‐37, suggesting apoptosis. Conclusion: LL‐37 strongly attenuates lipopolysaccharide‐induced cytokine and chemokine expression and, in high concentrations, reduces cell proliferation through inhibition of DNA synthesis and by promoting apoptosis in human periodontal ligament cells.     

Chemerin as a Novel Crevicular Fluid Marker of Patients With Periodontitis and Type 2 Diabetes Mellitus

Background: The objectives of the present study are to: 1) determine whether gingival crevicular fluid (GCF) chemerin is a novel predictive marker for patients with chronic periodontitis (CP) with and without type 2 diabetes mellitus (t2DM); 2) analyze the relationship between chemerin and interleukin (IL)‐6 in periodontally healthy individuals and in patients with CP and with and without t2DM; and 3) evaluate the effect of non‐surgical periodontal therapy on GCF chemerin levels. Methods: Eighty individuals were split into four groups: 20 who were systemically and periodontally healthy (CTRL), 20 with t2DM and periodontally healthy (DM‐CTRL), 20 systemically healthy with CP (CP), and 20 with CP and t2DM (DM‐CP). Individuals with periodontitis were treated with non‐surgical periodontal therapy. GCF sampling procedures and clinical periodontal measures were performed before and 6 weeks after treatment. Enzyme‐linked immunosorbent assay was used to measure chemerin and IL‐6 levels. Results: Greater values for GCF chemerin and IL‐6 levels were found in CP groups than in periodontally healthy groups, in DM‐CP than in CP, and in DM‐CTRL than in CTRL (P <0.008). GCF chemerin and IL‐6 levels decreased following therapy in CP groups (P <0.02). A comprehensive overview of all groups showed a statistically significant positive correlation of chemerin with IL‐6, glycated hemoglobin, sampled‐site clinical attachment level, and gingival index (P <0.05). Conclusions: In this study, periodontitis and t2DM induced aberrant secretion of chemerin, and non‐surgical periodontal therapy influenced the decrease of GCF chemerin levels in patients with CP with and without t2DM. Furthermore, it suggests GCF chemerin levels may be considered a potential proinflammatory marker for diabetes, periodontal disease, and treatment outcomes.     

Interactions of regenerative, inflammatory and biomechanical signals on bone morphogenetic protein-2 in periodontal ligament cells

Nokhbehsaim M, Deschner B, Winter J, Bourauel C, Rath B, Jäger A, Jepsen S, Deschner J. Interactions of regenerative, inflammatory and biomechanical signals on bone morphogenetic protein‐2 in periodontal ligament cells. J Periodont Res 2011; 46: 374–381.© 2011 John Wiley & Sons A/S Background and Objective: Regeneration of periodontal tissues by EMD remains a major challenge because a number of modifying factors are as yet unknown. The effects of EMD seem to be mediated, at least in part, by bone morphogenetic protein‐2 (BMP‐2). This in vitro study was performed to examine whether the effects of EMD on BMP‐2 activity are modulated by inflammatory and/or biomechanical signals. Material and Methods: Periodontal ligament cells were seeded on BioFlex^® plates and exposed to EMD under normal, inflammatory or biomechanical loading conditions for 1 and 6 d. In order to mimic proinflammatory or biomechanical loading conditions in vitro, cells were stimulated with interleukin‐1β (IL‐1β), which is increased at inflamed periodontal sites, and cyclic tensile strain of various magnitudes, respectively. The synthesis of BMP‐2, its receptors (BMPR‐1A, BMPR‐1B and BMPR‐2) and its inhibitors (follistatin, matrix gla protein and noggin) were analyzed using real‐time RT‐PCR and ELISA. Results: In EMD‐treated cells, BMP‐2 synthesis was increased significantly at 1 d. EMD also induced the expression of all BMP receptors, and of the BMP inhibitors follistatin and noggin. In general, IL‐1β and biomechanical loading neither down‐regulated BMP‐2 nor up‐regulated BMP inhibitors in EMD‐stimulated cells. However, IL‐1β and biomechanical loading, when applied for a longer time period, caused a down‐regulation of EMD‐induced BMP receptors. Conclusion: EMD induces not only BMP‐2, but also its receptors and inhibitors, in PDL cells. IL‐1β and biomechanical forces may counteract the beneficial effects of EMD on BMP‐2 activity via the down‐regulation of BMP receptors.     

The Influence of Glycated Hemoglobin on the Cross Susceptibility Between Type 1 Diabetes Mellitus and Periodontal Disease

Background: Periodontal disease is a major complication of type 1 diabetes mellitus (T1DM). The aim of the present study is to investigate the relationship between glycated hemoglobin and circulating levels of interleukin (IL)‐6, IL‐8, and C‐X‐C motif chemokine ligand 5 (CXCL5) in non‐smoking patients suffering from T1DM, with and without periodontitis. In addition, to determine the effect of advanced glycation end products (AGE) in the presence and absence of Porphyromonas gingivalis lipopolysaccharide (LPS) on IL‐6, IL‐8, and CXCL5 expression by THP‐1 monocytes and OKF6/TERT‐2 cells. Methods: There were 104 participants in the study: 19 healthy volunteers, 23 patients with periodontitis, 28 patients with T1DM, and 34 patients with T1DM and periodontitis. Levels of blood glucose/glycated hemoglobin (International Federation of Clinical Chemistry [IFCC]) were determined by high‐performance liquid chromatography. Levels of IL‐6, IL‐8, and CXCL5 in plasma were determined by enzyme‐linked immunosorbent assay (ELISA). In vitro stimulation of OKF6/TERT‐2 cells and THP‐1 monocytes was performed with combinations of AGE and P. gingivalis LPS. Changes in expression of IL‐6, IL‐8, and CXCL5 were monitored by ELISA and real‐time polymerase chain reaction. Results: Patients with diabetes and periodontitis had higher plasma levels of IL‐8 than patients with periodontitis alone. Plasma levels of IL‐8 correlated significantly with IFCC units, clinical probing depth, and attachment loss. AGE and LPS, alone or in combination, stimulated IL‐6, IL‐8, and CXCL5 expression in both OKF6/TERT‐2 cells and THP‐1 monocytes. Conclusions: Elevated plasma levels of IL‐8 potentially contribute to the cross‐susceptibility between periodontitis and T1DM. P. gingivalis LPS and AGE in combination caused significantly greater expression of IL‐6, IL‐8, and CXCL5 from THP‐1 monocytes and OKF6/TERT‐2 cells than LPS alone.