Evaluation of CD44 antigen in type 2 diabetic patients with periodontitis: An immunohistochemical study.

BACKGROUND: Type 2 diabetes mellitus (DM) is a known systemic risk factor for periodontitis. An increased expression of CD44 has been suggested in type 2 diabetics and periodontitis patients. OBJECTIVES: The present study aimed to assess the expression of CD44 antigen in patients with chronic periodontitis (CP) and type 2 DM in a South Indian urban population. Additionally, the relationships between the expression of CD44 antigen in gingival tissues, periodontal clinical parameters, and the random blood sugar (RBS) and glycated hemoglobin (HbA1c) levels were assessed. MATERIAL AND METHODS: A total of 63 subjects were divided into 3 groups: systemically and periodontally healthy controls (group H); CP patients, otherwise healthy (group CP); and CP patients with type 2 DM (group CP+DM). Periodontal parameters were recorded for all groups, and additionally the RBS and HbA1c levels for group CP+DM. Gingival tissue samples were obtained and subjected to immunohistochemical analysis for CD44. RESULTS: The expression of CD44 was significantly higher in the diseased groups. Epithelial CD44 expression was significantly stronger in group CP+DM as compared to groups CP and H (p < 0.001), whereas connective tissue CD44 expression was similar in groups CP and CP+DM (p = 0.657). Furthermore, an inverse relationship was observed between blood glucose parameters and CD44 expression in the epithelium and connective tissue. CONCLUSIONS: The expression of CD44 increased with the severity of periodontal disease. Additionally, glycemic control in patients with CP and type 2 DM had an impact on CD44 expression. Our findings indicate a possible destructive role of CD44 in the pathogenesis of periodontal diseases in individuals with type 2 DM.

Therapeutic Effect of a Novel M1 Macrophage-Targeted Nanodrug in Chronic Periodontitis Mice.

Chronic periodontitis is a chronic, progressive, and destructive disease. Especially, the large accumulation of advanced glycation end products (AGEs) in a diseased body will aggravate the periodontal tissue damage, and AGEs induce M1 macrophages. In this project, the novel nanodrugs, glucose-PEG-PLGA@MCC950 (GLU@MCC), are designed to achieve active targeting with the help of glucose transporter 1 (GLUT1) which is highly expressed in M1 macrophages induced by AGEs. Then, the nanodrugs release MCC950, which is a kind of NLRP3 inhibitor. These nanodrugs not only can improve the water solubility of MCC950 but also exhibit superior characteristics, such as small size, stability, innocuity, etc. In vivo experiments showed that GLU@MCC could reduce periodontal tissue damage and inhibit cell apoptosis in periodontitis model mice. In vitro experiments verified that its mechanism of action might be closely related to the inhibition of the NLRP3 inflammatory factor in M1 macrophages. GLU@MCC could effectively reduce the damage to H400 cells caused by AGEs, decrease the expression of NLRP3, and also obviously reduce the M1-type macrophage pro-inflammatory factors such as IL-18, IL-1ß, caspase-1, and TNF-α. Meanwhile, the expression of anti-inflammatory factor Arg-1 in the M2 macrophage was increased. In brief, GLU@MCC would inhibit the expression of inflammatory factor NLRP3 and exert antiperiodontal tissue damage in chronic periodontitis via GLUT1 in the M1 macrophage as the gating target. This study provides a novel nanodrug for chronic periodontitis treatment.

Effect of non-surgical periodontal therapy on CD14 + CD16+ monocyte counts in peripheral blood samples: a clinical interventional study.

Monocytes and their macrophage progeny are thought to be involved in tissue and alveolar bone destruction in periodontal disease. It has been documented that the proportion of (CD14 + CD16+) non-classical monocytes in the blood are elevated in chronic periodontitis;A total of 20 chronic generalized periodontitis patients who were otherwise healthy, were recruited for this study. At baseline and 3 weeks after non-surgical periodontal treatment, peripheral blood was obtained to assess the levels of C-reactive protein (CRP) and the proportion of monocyte subsets. Monocyte subsets were assessed using flow cytometry;The mean percentage of CD14 + CD16+ non-classical monocytes in the peripheral blood sample at baseline was 13.95 + 2.09, that reduced to 8.94 + 1.23 3 weeks after non-surgical treatment. A distinct significant reduction in the percentage of non-classical monocytes and a concomitant increase in classical monocytes were observed following periodontal treatment compared to baseline. There was a significant reduction in the all the periodontal parameters and CRP levels 3 weeks post non-surgical periodontal treatment. A positive correlation between CRP and percentage of non-classical monocytes was also observed; Periodontal treatment potentially modulates the host response effectively.

Sirtuin6 and Lipoxin A4 levels are decreased in severe periodontitis.

OBJECTIVE: Sirtuin6 plays an important role in the regulation of inflammation, homeostasis, and apoptosis, and it has anti-inflammatory effects on several diseases. Lipoxin A4 is a pro-resolving lipid mediator of inflammation and inhibits hypoxia-induced apoptosis and oxidative stress. Considering that Lipoxin A4 and Sirtuin6 have protective effects on inflammatory diseases, the aim of this study is to determine the possible roles of these molecules on periodontitis inflammation in saliva and serum and to reveal the relationship of these data with clinical periodontal parameters. MATERIAL AND METHODS: A total of 20 stage III/grade B periodontitis and 20 periodontally healthy subjects were included in this cross-sectional study (all never smokers and systemically healthy). Clinical periodontal parameters (plaque index, probing pocket depth, bleeding on probing, clinical attachment loss) were recorded. Saliva and serum levels of Sirtuin6 and Lipoxin A4 were analyzed by enzyme-linked immunosorbent assay. RESULTS: Serum Sirtuin6 and saliva Lipoxin A4 levels were significantly lower in the periodontitis group than the control group (respectively, p = 0.0098, p = 0.0008). There were negative correlations between all periodontal clinical parameters and saliva Lipoxin A4 level (p < 0.05) and between probing pocket depth, clinical attachment loss, and serum and saliva Sirtuin6 levels (respectively, r = - 0.465 and r = - 0.473, p < 0.05). CONCLUSIONS: Decreased levels of serum Sirtuin6 and saliva Lipoxin A4 in periodontitis patients and their correlation with clinical periodontal parameters suggest that serum Sirtuin6 and saliva Lipoxin A4 may be related with periodontal inflammation. CLINICAL RELEVANCE: Scientific rationale for the study: Sirtuin6 is one of seven members of the family of NAD + dependent protein that played an important role in the regulation of inflammation, energy metabolism, homeostasis, and apoptosis. Sirtuin6 is associated with the pathogenesis of several diseases. Lipoxin A4 is a lipid mediator that inhibits hypoxia-induced apoptosis and oxidative stress, and it has an active role in the resolution of periodontal inflammation. No studies that investigated the potential role Sirtuin6 and its relationship with inflammation resolution and apoptosis mechanisms in severe periodontitis patients. PRINCIPAL FINDINGS: the serum Sirtuin6 and saliva Lipoxin A4 levels were significantly lower and negatively correlated with clinical periodontal parameters in the patients with periodontitis than the healthy controls. PRACTICAL IMPLICATIONS: this study shows that serum Sirtuin6 and saliva Lipoxin A4 may be candidate biomarkers related with periodontal inflammation and estimating to periodontal status. CLINICAL TRIAL REGISTRATION: NCT05417061.

Chronic periodontitis induces the proliferation of pancreatic ß-cells to cause hyperinsulinemia in a rat model.

BACKGROUND AND OBJECTIVE: The purpose of this study was to determine if chronic periodontitis (CP) may induce hyperinsulinemia and may have the effect of on pancreatic ß-cell proliferation in a rat model. MATERIALS AND METHODS: Twelve male Sprague-Dawley rats were divided into two groups: the CP group and the control group (Con group). The following contents were evaluated: pathological changes in periodontal soft and hard tissues; serum lipopolysaccharide (LPS) level, serum fasting insulin (FINS) level, fasting blood glucose (FBG) level, and homeostasis model assessment (HOMA) ß (HOMA-ß) index; histopathological examination of islets; immunohistochemistry of insulin and p-Smad2 expression in islets; immunofluorescence of changes in the relative number of ß-cells and the number of Ki67-positive ß-cells. Western blotting was used to analyze p-Smad2/Smad2 levels. Results were analyzed by two independent samples t tests. RESULTS: Increased serum LPS level, FINS level, and HOMA-ß index were observed in the rats of the CP group; FBG level did not change significantly; histological assessments showed an enlarged islet area, increased insulin content, relatively increased ß-cells, increased Ki67-positive ß-cells, and decreased p-Smad2 expression in islets in the rats of the CP group. CONCLUSION: Our study results link CP-induced hyperinsulinemia with changes in islets, such as islet hyperplasia and compensatory ß-cell proliferation, by using a CP rat model.

Influence of type 2 diabetes on immunohistochemical detection of TRAF6, cFos and NFATC1 in the gingiva in cases of chronic periodontitis.

Type 2 diabetes (T2D) and chronic periodontitis (CP) are common diseases worldwide. Although T2D increases the severity of CP and alveolar bone loss, the mechanism of this is not well understood. We investigated using immunohistochemistry the expression of three osteoclast proteins, TRAF6, cFos and NFATc1, in gingival tissues. Gingival tissues were obtained from three groups: HC group, healthy controls; CP group, patients with CP; T2D + CP group, patients with both T2D and CP. Strong immunostaining for TRAF6, cFos and NFATc1 was observed in the gingival epithelium as well as in inflammatory cells in the CP and T2D + CP groups. Immunostaining was most intense in the T2D + CP group. We found strong up-regulation of TRAF6, cFos and NFATC1 in gingiva tissue of subjects with both T2D and CP, which corroborates our hypothesis that T2D potentiates osteoclastogenesis in CP.

Evaluation of salivary IL-8 and calcium levels in postmenopausal females with and without periodontitis-A comparative study.

Background and Objective: Menopause is a normal developmental stage in a woman's life marking the permanent cessation of menstruation. Calcium is predominant in intracellular signalling and its intracellular increase can affect the cell's proliferation, phagocytosis and cytokine secretion. IL-8 expression in various cells such as neutrophils and osteoblasts was reported to involve a calcium signalling pathway. Well-known functions of IL-8 includes help in angiogenesis, role in tumour progression, tissue remodelling, etc., Hence, the aim of this study was to establish the relationship between calcium-dependent IL-8 and periodontal disease in postmenopausal females. Method: The study population included 52 postmenopausal women aged 45-57 years. The patients were divided into two groups in which group I included postmenopausal women without periodontitis and group II with periodontitis. Unstimulated salivary samples were collected from all the participants to evaluate IL-8 and calcium levels. Results: There was a statistically significant difference in salivary IL-8 levels between the two groups (P < 0.001), but there was no statistical difference in salivary calcium levels between the two groups (P = 0.730). A weak negative correlation between salivary IL-8 and calcium was found in group I, while a weak positive correlation was found between the same in group II. Conclusion: Analysis of salivary IL-8 from the present study was in accordance with several previous studies. It can be concluded that saliva can also be used as a reliable oral diagnostic fluid for IL-8 and calcium detection in periodontitis.

Periostin level in gingival crevicular fluid in periodontal disease: a systematic review and meta-analysis.

BACKGROUND: Periostin, a secreted adhesion molecule, is a matricellular protein secreted most in periodontal ligament and periosteum. Periostin is also needed for integrity and maturation of periodontal tissue. This meta-analysis was conducted to compare the gingival crevicular fluid (GCF) periostin levels in subjects having periodontal disease and healthy periodontium. METHODS: In this meta-analysis, three international database including PubMed, Scopus and Web of Science were searched and 207 studies retrieved. Also, the Google Scholar was searched to find more related studies (two studies were found). To assess the risk of bias of included studies, the Newcastle-Ottawa assessment scale adapted for case-control was used. Finally, required data was extracted and included into analysis. All statistical analysis were done using Stata software. RESULTS: Eight studies were included in this meta-analysis. Results showed that GCF periostin level is significant lower in chronic periodontitis group compare to healthy people (the standardized mean difference (SMD) = -3.15, 95% CI = -4.45, -1.85, p < 0.001). The syntheses of studies shown a significant decrease in the periostin level of chronic periodontitis patients compared to the gingivitis patients (SMD = -1.50, 95%CI = -2.52, -0.49, P = 0.003), while the mean level of periostin between the gingivitis patients and healthy group has no significant difference (SMD = -0.88, 95%CI = -2.14, 0.38, P = 0.173). CONCLUSION: The mean concentration of GCF periostin in people with chronic periodontitis significantly decreased compared to people with gingivitis and also compared to healthy people, while no significant difference was observed between the two groups with gingivitis and healthy people. Therefore, this marker may be used as a diagnostic criterion for the disease, which requires further studies.

Association between lipid metabolism and periodontitis in obese patients: a cross-sectional study.

BACKGROUND: To investigate the association between clinical periodontal parameters of periodontitis, serum lipid metabolism markers and adipokines' levels in patients with obesity and periodontitis. METHODS: A total of 112 patients admitted to Hospital of Xi'an Jiaotong University were included in this study. They were divided into normal body weight group (18.5 < body mass index, BMI < 25, n = 36), overweight group (25 ≤ BMI < 30, n = 38), and obesity group (BMI ≥ 30, n = 38) accordingly. The diagnosis of periodontitis was based on the newest international classification of periodontitis. Full-mouth clinical periodontal measurements included: plaque index, periodontal pocket depth, clinical attachment level, and bleeding on probing. Gingival crevicular fluid samples were analyzed for: Interleukin-1ß, tumor necrosis factor-α, Interleukin-6 and C-reactive protein. Serum triglycerides, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol and glycosylated hemoglobin levels were measured. Visfatin, leptin, resistin, and adiponectin levels in serum were also measured. RESULTS: The ratio of participants without periodontitis was significantly highest in normal weight group, and the proportion of severe periodontitis (stage III and IV) was highest in obesity group. The periodontal pocket depth, clinical attachment level, and the inflammatory cytokines in gingival crevicular fluid in obesity group and overweight group were higher than those in normal body weight group. The BMI and waist-to-hip ratio (WHR) were significantly positive correlated with periodontal pocket depth and clinical attachment level. Using a Multivariate logistic regression model, periodontitis correlates to BMI, WHR, serum levels of triglyceride, total cholesterol, low density lipoprotein, and adipokines such as visfatin, leptin, and resistin. CONCLUSIONS: Obesity is positively correlated with the aggravation of periodontitis. Obesity may aggravate the damage to periodontal tissue by regulating the secretion level of adipokines.

Gingival crevicular fluid periodontal ligament-associated protein-1, sclerostin, and tumor necrosis factor-alpha levels in periodontitis.

BACKGROUND: In periodontitis, the equilibrium between bone formation and resorption skews in favor of bone loss. Periodontal ligament-associated protein-1 (PLAP-1) and sclerostin play a significant role in the suppression of bone formation. Tumor necrosis factor-alpha (TNF-α) is a central proinflammatory cytokine related to periodontal bone loss. This study aims to assess gingival crevicular fluid (GCF) PLAP-1, sclerostin, and TNF-α levels in individuals with periodontal disease. METHODS: Seventy-one individuals diagnosed with generalized stage III grade C periodontitis (n = 23), gingivitis (n = 24), and periodontal health (n = 24) were included in the study. Full-mouth clinical periodontal measurements were performed. PLAP-1, sclerostin, and TNF-α total amounts in GCF were quantified by ELISA. Nonparametric methods were used for the data analyses. RESULTS: Periodontitis group exhibited significantly higher GCF PLAP-1, sclerostin and TNF-α levels compared with gingivitis and periodontally healthy groups (p < 0.05). GCF PLAP-1 and TNF-α levels of gingivitis group were higher than healthy controls (p < 0.05) whereas GCF sclerostin levels were similar in two groups (p > 0.05). Significant positive correlations were found between GCF PLAP-1, sclerostin and TNF-α levels and all clinical parameters (p < 0.01). CONCLUSIONS: To our knowledge, this is the first study showing GCF PLAP-1 levels in periodontal health and disease. Increased GCF PLAP-1 and sclerostin levels and their correlations with TNF-α in periodontitis imply that those molecules might be involved in the pathogenesis of periodontal disease. Further studies in larger mixed cohorts are needed to enlighten the possible role of PLAP-1 and sclerostin in periodontal bone loss.

Salivary bactericidal/permeability-increasing protein: A novel inflammatory marker associated with periodontitis.

OBJECTIVES: The present case-control study aims to investigate the salivary levels of bactericidal/permeability-increasing protein (BPI) and interleukin-1beta (IL-1ß) in systemically healthy individuals with periodontitis and periodontally healthy for the evaluation of BPI's relation with periodontal inflammation and clinical diagnosis of periodontitis. MATERIALS AND METHODS: A total of 100 participants were enrolled in this study and divided into periodontitis (P group) (n = 50) and periodontally healthy (H group) (n = 50) groups based on their full-mouth periodontal examination results including plaque index, probing pocket depth, gingival index, bleeding on probing, and clinical attachment level. Unstimulated whole saliva was collected. Salivary BPI and IL-1ß levels were determined using an enzyme-linked immunosorbent assay. Receiver operating characteristic (ROC) curves were created to determine the diagnostic value of BPI. RESULTS: The levels of BPI and IL-1ß in saliva were significantly higher in the P group than in the H group (p<0.001). Moreover, salivary BPI and IL-1ß levels correlated significantly with all clinical periodontal parameters (all p<0.001). Interestingly, there was a strong positive correlation between salivary levels of BPI and IL-1ß (r=0.544, p<0.001). In addition, the results of the ROC curve analysis showed that BPI had a high diagnostic potential to distinguish periodontitis from healthy controls with an area under the curve value of 0.94% (p<0.000). CONCLUSION: The significantly higher salivary levels of BPI in periodontitis patients together with strong positive correlations between all periodontal parameters and salivary IL-1ß levels suggest that BPI may be involved in the inflammatory process of periodontal disease. CLINICAL RELEVANCE: The present study for the first time report that salivary BPI levels may serve as a potential biomarker of inflammation in periodontal disease. TRIAL REGISTRATION NUMBER: Thai Clinical Trials.gov (TCTR20211222008) (22 December 2021).

Cyclic di-adenosine monophosphate regulates the osteogenic and adipogenic differentiation of hPDLSCs via MAPK and NF-κB signaling.

Cyclic di-adenosine monophosphate (c-di-AMP) is a bacterial second messenger that can be recognized by infected host cells and activate the immunoinflammatory response. The purpose of this study is to demonstrate the effect of c-di-AMP on the differentiation of human periodontal ligament stem cells (hPDLSCs) and its underlying mechanisms. In the present study, we find that the gingival crevicular fluid (GCF) of patients with chronic periodontitis has a higher expression level of c-di-AMP than that of healthy people. In vitro, c-di-AMP influences the differentiation of hPDLSCs by upregulating Toll-like receptors (TLRs); specifically, it inhibits osteogenic differentiation by activating NF-κB and ERK/MAPK and promotes adipogenic differentiation through the NF-κB and p38/MAPK signaling pathways. Inhibitors of TLRs or activated pathways reduce the changes induced by c-di-AMP. Our results establish the potential correlation among bacterial c-di-AMP, periodontal tissue homeostasis and chronic periodontitis pathogenesis.

Salivary irisin level is higher and related with interleukin-6 in generalized periodontitis.

OBJECTIVES: Irisin plays an important role in energy homeostasis, inflammation, glucose, and lipid metabolism, and it is shown to have relations with many inflammatory diseases. The aim of the study was to determine saliva and serum irisin and IL-6 levels in patients with stage III/grade B periodontitis compared with individuals with healthy periodontium. MATERIALS AND METHODS: Twenty patients with stage III grade B periodontitis (P) and 20 periodontally healthy subjects (control; C) were included in this study. Clinical periodontal measurements were recorded. Saliva and serum levels of irisin and interleukin-6 (IL-6) were analyzed by enzyme-linked immunosorbent assay. RESULTS: Salivary irisin and IL-6 levels were significantly higher in the periodontitis group (p < 0.001, p = 0.002, respectively). Furthermore, serum IL-6 levels were found significantly higher in the periodontitis group compared with controls (p = 0.011). There was no significant difference between the periodontitis and control for serum irisin levels (p > 0.05). Significant positive correlations were found between all periodontal parameters and salivary irisin and IL-6 (p < 0.05) and also between BMI and saliva and serum IL-6 (respectively; r = 0.530, r = 0.329, p < 0.05). There was a positive correlation between salivary irisin and IL-6 (r = 0.369, p < 0.05). CONCLUSIONS: Monitoring of salivary irisin and IL-6 might be potential biomarker for predicting the susceptibility to periodontitis. CLINICAL RELEVANCE: Scientific rationale for the study: Irisin is a novel adipomyokine that has played an important role in energy homeostasis, glucose and lipid metabolism, angiogenesis, immunity, and inflammation. Irisin is involved in the pathogenesis of diseases affecting many body systems. IL-6, another adipomyokine, is a major inflammatory mediator and homeostatic regulator of glucose and lipid metabolism and is associated with periodontitis. No studies investigated the relationship between advanced periodontal disease, irisin, and IL-6 together. PRINCIPAL FINDINGS: The salivary irisin and IL-6 levels were significantly higher and positively correlated in patients with periodontitis relative to healthy controls. Furthermore, serum IL-6 levels were significantly increased in patients with periodontitis. PRACTICAL IMPLICATIONS: The study shows that irisin and IL-6 can be candidate salivary biomarkers for periodontitis and predict to periodontal status.

Exosomal miR-205-5p derived from periodontal ligament stem cells attenuates the inflammation of chronic periodontitis via targeting XBP1.

INTRODUCTION: Chronic periodontitis (CP) is an inflammatory periodontal disease with high incidence and complex pathology. This research is aimed to investigate the function of exosomal miR-205-5p (Exo-miR-205-5p) in CP and the underlying molecular mechanisms. METHOD: Exo-miR-205-5p was isolated from miR-205-5p mimics-transfected periodontal ligament stem cells (PDLSCs), and subsequently cocultured with lipopolysaccharide (LPS)-induced cells or injected into LPS-treated rats. The mRNA expression of inflammatory factors and Th17/Treg-related factors were measured by quantitative real-time PCR. The contents of inflammatory factors and the percentages of Th17/Treg cells were measured by enzyme-linked immunosorbent assay and flow cytometry, respectively. Besides, the target relation between miR-205-5p and X-box binding protein 1 (XBP1) was explored. RESULTS: MiR-205-5p was downregulated in LPS-induced PDLSCs and corresponding exosomes. Exo-miR-205-5p inhibited inflammatory cell infiltration, decreased the production of TNF-α, IL-1ß, and IL-6, and decreased the percentage of Th17 cells in LPS-treated rats. In addition, XBP1 was a target of miR-205-5p. Overexpression of XBP1 weakened the effects of Exo-miR-205-5p on inhibiting inflammation and regulating Treg/Th17 balance in LPS-induced cells. CONCLUSIONS: Exo-miR-205-5p derived from PDLSCs relieves the inflammation and balances the Th17/Treg cells in CP through targeting XBP1.

Role of ubiquitin-specific protease 5 in the inflammatory response of chronic periodontitis.

BACKGROUND: The systemic inflammatory response caused by chronic periodontitis is a risk factor for multiple diseases. Ubiquitin-specific protease 5 (USP5) is a kind of deubiquitinase which mainly responsible for dissociating unanchored polyubiquitin. However, the functions of USP5 in chronic periodontitis have not been reported. METHODS: Chronic periodontitis patients were recruited, and their periodontal samples were collected. The levels of USP5, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and interleukin-1ß (IL-1ß) in gingival crevicular fluid were evaluated by ELISA. The expression of USP5, TNF-α, IL-6, and IL-1ß in human periodontal ligament stem cells (PDLSCs) was estimated by qRT-PCR assay. The activation of STAT3 signaling was examined by Western blot. RESULTS: USP5 was upregulated in the gingival crevicular fluid and gingival tissues of chronic periodontitis patients. USP5 expression was positively correlated with the expression of proinflammatory factors. USP5 knockdown and deubiquitinase inhibitor inhibited LPS-induced inflammatory responses in PDLSCs. Suppressing USP5 inhibited STAT3 signaling in PDLSCs. CONCLUSION: Suppression deubiquitinase USP5 inhibits the inflammatory response of chronic periodontitis by suppressing STAT3 signaling.

Chemerin contributes to inflammatory responses and suppresses osteogenic differentiation in chronic periodontitis.

BACKGROUND: Chronic periodontitis (CP) is a common disease of oral cavity, and approximately 35% of adults suffered from CP. Therefore, its underlying mechanism needs to be explored for new therapeutic approaches. Chemerin, as a multifunctional adipokine, is found to be highly expressed in the gingival crevicular fluid (GCF), gingival tissues and the plasma of periodontitis patients. Thus, we aimed to uncover the underlying mechanism of chemerin in CP. METHODS: Thirty six CP patients and 25 healthy volunteers were enrolled. Periodontal ligament stem cells (PDLSCs) were isolated from CP patients and healthy ones, respectively. Then, normal PDLSCs or PDLSCs-differentiated osteoblasts were treated with different doses of recombinant human chemerin. RESULTS: Chemerin and inflammatory cytokines, including interleukin-1ß, interleukin-6, and tumor necrosis factor-α, were higher in the GCF and serum of CP patients than healthy ones. Moreover, chemerin was positively correlated with these three inflammatory cytokines, respectively, in CP patients. PDLSCs isolated from CP patients had higher expressions of chemerin and these cytokines than the ones isolated from normal individuals. Furthermore, chemerin dose-dependently increased inflammatory responses and inhibited osteogenic differentiation of PDLSCs. CONCLUSION: Chemerin accelerated inflammatory responses and suppressed osteogenic differentiation of PDLSCs, thus chemerin might sever as a therapeutic target of CP.

Oxidative stress in human gingival fibroblasts from periodontitis versus healthy counterparts.

OBJECTIVE: Elevated p53 promotes oxidative stress and production of pro-inflammatory cytokines in liposaccharide (LPS)-treated healthy human gingival fibroblasts (HGFs). This study compared oxidative stress, production of inflammatory cytokines, and p53 expression in HGFs from patients with chronic periodontitis (CP) and healthy subjects in vitro upon LPS from Porphyromonas gingivalis challenge. METHODS: Human gingival fibroblasts were isolated from 6 biopsies-3 from healthy donors and 3 from diseased area in CP (Grade B, Stage III). HGFs were cultured with or without 1 µg/ml 24 h LPS. Oxidative stress was assessed by analyzing the level of reactive oxygen species (ROS). Mitochondrial membrane potential and respiration were determined by immunofluorescence and respirometry, respectively. Tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-1ß were determined by enzyme-linked immunosorbent assay. P53 expression was monitored by Western blot and immunofluorescence. RESULTS: Human gingival fibroblasts from CP exhibited increased levels of mitochondrial p53, enhanced ROS production, decreased mitochondrial membrane potential, increased mitochondrial oxygen consumption, and increased secretion of TNF-α, IL-6, and IL-1ß, as compared to HGFs from healthy donors. Moreover, LPS exacerbated these changes. CONCLUSION: Human gingival fibroblasts from CP exhibited stronger basal and LPS-inducible oxidative stress and inflammatory response as compared to HGFs from healthy subjects by increased p53 in mitochondria.

Study on the imbalance of M1/M2 macrophage polarization in severe chronic periodontitis.

BACKGROUND: Macrophages commonly exist in two distinct subsets in different microenvironments: classically activated macrophages (M1) and alternatively activated macrophages (M2). The imbalance of M1-M2 macrophage polarization is often related to various diseases or inflammatory states. OBJECTIVE: The purpose of this study was to determine whether there is an imbalance in the expression of M1 and M2 macrophage-related cytokines in severe chronic periodontitis. METHODS: A total of 30 clinical specimens, including severe chronic periodontitis tissues (n= 15) and healthy control tissues (n= 15), were used in this study. Reverse transcription polymerase chain reaction (RT-PCR) and Western blot methods were used to detect the mRNA and protein expression levels of M1 macrophage-related cytokines (inducible nitric oxide synthase (iNOS) and signal transducer and activator of transcription 1 (STAT1)) and M2 macrophage-related cytokines (arginase-1 (Arg-1) and STAT6), respectively. RESULTS: The mRNA and protein expression levels of M1 macrophage-related cytokines (iNOS and STAT1) and M2 macrophage-related cytokines (Arg-1 and STAT6) were significantly increased in severe chronic periodontitis patients. In addition, the ratios of iNOS/Arg-1 and STAT1/STAT6 in the severe chronic periodontitis group were also significantly increased (P< 0.01). CONCLUSION: The imbalance of M1/M2 macrophages exists in the pathogenesis of severe chronic periodontitis, and has a tendency towards M1 polarization. Therefore, maintaining the immune balance of M1/M2 macrophages may be a novel therapeutic alternative for the management of severe chronic periodontitis.

Comparative analysis of sulfiredoxin and total oxidative stress levels in diabetic individuals with periodontitis: A case-control study.

BACKGROUND: The delicate balance between oxidative stress and its antioxidant system can be disrupted in diabetes mellitus (DM), making the tissue susceptible to injury. Hence, this case-control study aims to estimate and correlate the gingival tissue sulfiredoxin and crevicular total oxidative stress (TOS) levels in generalized periodontitis Stage II individuals Grade C (PSII) with and without type II DM. MATERIAL AND METHODS: A total of 72 individuals were grouped based on their glycosylated hemoglobin (HbA1c) levels and clinical parameters: group I, periodontally healthy non-diabetic (HbA1c < 5.7%) (n = 24); group II, non-diabetic with PSII (n = 24); and group III, diabetic individuals (HbA1c > 6.5%) with PSII (n = 24). Gingival tissues and crevicular fluid samples were collected. The samples with adequate protein concentrations (n = 72) were further estimated for sulfiredoxin and TOS levels by enzyme-linked immunosorbent assay (ELISA) and calorimetric method, respectively. RESULTS: Tissue sulfiredoxin and crevicular TOS levels are increased significantly in the periodontitis group compared to the non-periodontitis group (p < 0.001).The tissue sulfiredoxin levels did not vary significantly between the two periodontitis groups (p < 0.179). The TOS levels are significantly higher in the diabetic compared to non-diabetic periodontitis group (p < 0.001). Correlation statistics showed a significant positive correlation (r = 0.65 and p < 0.005) between sulfiredoxin and TOS levels in diabetes with PSII group, however, no such significant correlation was observed in the non-diabetic PSII group (r = 0.255 and p < 0.422). CONCLUSION: Diabetic individuals showed inadequate sulfiredoxin-mediated antioxidant response to an increase in oxidative stress levels in periodontitis Stage II Grade C individuals.

Salivary levels of NLRC4 inflammasome in different periodontal clinical status.

OBJECTIVE: Nucleotide-binding and oligomerization domain (NOD)-like receptor family CARD domain-containing protein 4 (NLRC4) has a critical role in the regulation of interleukin-1ß (IL-1ß), an important cytokine in the pathogenesis of the periodontal diseases. In this study, we aimed to evaluate levels of salivary NLRC4 inflammasomes in different periodontal clinical statuses. METHODS: The individuals with 20 periodontally healthy (healthy), 20 gingivitis, and 20 periodontitis were periodontally examined. Saliva samples were collected, after the clinical measurements (plaque index, gingival index, gingival bleeding index, probing depth, and clinical attachment level). The levels of salivary NLRC4, IL-1ß, and interleukin 10 (IL-10) were examined by enzyme-linked immunosorbent assay. RESULTS: The results demonstrated that levels of salivary NLRC4 (p < 0.01), and IL-1ß (p < 0.001) were significantly higher in gingivitis and periodontitis than in the healthy group. No significant difference was salivary IL-10 levels between the groups (p > 0.05). Positive significant correlations among NLRC4 and IL-1ß salivary levels and clinical parameters were detected (p < 0.05). CONCLUSION: The findings of this study suggest that the NLRC4 is elevated in periodontal disease. Larger randomized controlled clinical studies are needed to use salivary NLRC4 levels as a potential marker for detecting the presence and/or severity of the periodontal disease.