Tumor Necrosis Factor‐α and Porphyromonas gingivalis Lipopolysaccharides Decrease Periostin in Human Periodontal Ligament Fibroblasts

Background: Periostin is a matricellular protein essential for tissue integrity and maturation and is believed to have a key function as a modulator of periodontal ligament (PDL) homeostasis. The aim of this study is to evaluate whether periodontal disease‐associated pathogen‐related virulence factors (endotoxins/lipopolysaccharides [LPS]) and proinflammatory cytokines alter the expression of periostin in PDL cells. Methods: Human PDL cultures were exposed to inflammatory mediators (tumor necrosis factor‐α [TNF‐α]), bacterial virulence factors (Porphyromonas gingivalis LPS) or a combination in a biomechanically challenged environment. Culture conditions were applied for 24 hours, 4 days, and 7 days. Periostin and TGF‐β inducible gene clone H3 (βIGH3) mRNA expression from cell lysates were analyzed. Periostin and βIGH3 proteins were also detected and semiquantified in both cell lysates and cell culture supernatants by Western blot. In addition, periostin localization by immunofluorescence was performed. Analysis of variance and Fisher tests were used to define the statistical differences among groups (P <0.05). Results: In a mechanically challenged environment, periostin protein was more efficiently incorporated into the matrix compared to the non‐loaded controls (higher levels of periostin in the supernatant in the non‐loaded group). Interestingly, chronic exposure to proinflammatory cytokines and/or microbial virulence factors significantly decreased periostin protein levels in the loaded cultures. There was greater variability on βIGH3 levels, and no particular pattern was clearly evident. Conclusions: Inflammatory mediators (TNF‐α) and bacterial virulence factors (P. gingivalis LPS) decrease periostin expression in human PDL fibroblasts. These results support a potential mechanism by which periostin alterations could act as a contributing factor during periodontal disease progression.     

Effects of interleukin‐1β and tumor necrosis factor‐α on macrophage inflammatory protein‐3α production in synovial fibroblast‐like cells from human temporomandibular joints

Background

Interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α) are key mediators of the intracapsular pathological conditions of the temporomandibular joint (TMJ). Therefore, the gene expression profiles in synovial fibroblast‐like cells (SFCs) from patients with internal derangement of the TMJ were examined after they were stimulated with IL‐1β or TNF‐α to determine which genes were altered.

Methods

Ribonucleic acid was isolated from SFCs after IL‐1β or TNF‐α treatment. Gene expression profiling was performed using oligonucleotide microarray analysis. On the basis of the results of this assay, we investigated the kinetics of macrophage inflammatory protein‐3α (MIP‐3α) gene expression using PCR, and protein production in TMJ SFCs stimulated by IL‐1β or TNF‐α using an ELISA. Inhibition experiments were performed with MAPK and NFκB inhibitors. SFCs were stimulated with IL‐1β or TNF‐α after treatment with inhibitors. The MIP‐3α levels were measured using an ELISA.

Results

Macrophage inflammatory protein‐3α was the gene most upregulated by IL‐1β‐ or TNF‐α stimulation. The mRNA and protein levels of MIP‐3α increased in response to IL‐1β in a time‐dependent manner. In contrast, during TNF‐α stimulation, the MIP‐3α mRNA levels peaked at 4 h, and the protein levels peaked at 8 h. In addition, the IL‐1β‐ and TNF‐α‐stimulated MIP‐3α production was potently reduced by the MAPK and NFκB signaling pathway inhibitors.

Conclusion

Interleukin‐1β and TNF‐α increased the MIP‐3α production in SFCs via the MAPK and NFκB pathways. These results suggest that the production of MIP‐3α from stimulation with IL‐1β or TNF‐α is one factor associated with the inflammatory progression of the internal derangement of the TMJ.     

Orthodontic Force Increases Interleukin‐1β and Tumor Necrosis Factor‐α Expression and Alveolar Bone Loss in Periodontitis

Background: The present study aims to evaluate the effects of orthodontic movement (OM) on the periodontal tissues of rats with ligature‐induced periodontal disease. Methods: Eighty‐eight rats were divided into four groups: 1) negative control (sham operated); 2) periodontal disease; 3) OM; and 4) periodontal disease followed by OM (OMP). Rats were sacrificed 3 hours or 1, 3, or 7 days after OM commencement. Bone volume fraction (BVF) and bone mineral density (BMD) were assessed in hemimaxillae by microcomputed tomography analysis. Expression of the proinflammatory cytokines interleukin (IL)‐1β and tumor necrosis factor (TNF)‐α were evaluated in gingival samples by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay, and in the furcation region by immunohistochemistry analysis (IHC). Results: The OMP group had lower BVF and BMD levels compared to the other groups at day 7 (P <0.05). Maximum messenger ribonucleic acid expression of both cytokines was observed in the OMP group at day 1 (P <0.05). In the same period, all proteins were expressed in high levels for all test groups compared to the control group. The number of cells positive for IL‐1β and TNF‐α by IHC was highest in the OMP group at day 1, with progressive reduction thereafter. Conclusion: The results suggest that OM acts synergistically with periodontal disease in periodontal breakdown through upregulation of proinflammatory cytokines.     

Saliva and Serum Levels of B‐Cell Activating Factors and Tumor Necrosis Factor‐α in Patients With Periodontitis

Background: B‐lymphocytes play a central and critical role in the adaptive immune response against invading pathogens. This study evaluates saliva and serum levels of APRIL (a proliferation‐inducing ligand), B‐cell activating factor (BAFF), tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐6, and IL‐10 in patients with chronic periodontitis (CP) or aggressive periodontitis (AgP) and periodontally healthy individuals. Methods: Twenty‐five patients with AgP, 20 patients with CP, and 20 periodontally healthy individuals were included. Smoking status was recorded, and all individuals were divided into non‐smokers and smokers. Saliva and serum samples were collected before clinical periodontal measurements. APRIL, BAFF, TNF‐α, IL‐6, and IL‐10 levels in serum and saliva samples were determined by enzyme‐linked immunosorbent assay. Statistical analysis was performed using multivariate analysis of variance and bivariate correlation. Results: Serum and saliva levels of TNF‐α, APRIL, BAFF, IL‐6, and IL‐10 were similar in CP and AgP groups. Serum levels of TNF‐α, APRIL, and BAFF and saliva levels of BAFF were significantly higher in periodontitis groups than healthy controls (P <0.05). Non‐smokers with CP or AgP had lower levels of saliva TNF‐α and APRIL and serum APRIL and IL‐6 than smokers with CP or AgP (P <0.05). Saliva APRIL and serum TNF‐α and IL‐6 levels were significantly higher in healthy smokers than healthy non‐smokers (P <0.05). Clinical periodontal parameters correlated positively with TNF‐family cytokines and negatively with IL‐10 (P <0.05). Conclusions: Within the limits of this study, it may be suggested that elevated salivary and serum TNF‐α, APRIL, and BAFF in patients with periodontitis may contribute to the dominance of B cells in periodontitis lesions. Moreover, higher levels in healthy smokers than non‐smoking counterparts may play a role in detrimental effects of smoking on periodontal tissues.     

Tumor Necrosis Factor‐α and Oral Inflammation in Patients With Crohn Disease

Background: Crohn disease (CD) is a chronic inflammatory bowel disease often accompanied by periodontal symptoms. Based on its function in immune response, tumor necrosis factor (TNF)‐α and its genetic variants have been discussed as risk indicators in inflammatory processes. Therefore, the aim of the present study is to investigate the impact of TNF‐α polymorphisms on periodontal parameters and inflammatory lesions of oral mucosa as a characteristic of CD. Methods: A total of 142 patients with CD were included in the study. Oral soft tissue alterations and periodontal parameters were assessed. Genotypes, alleles, and haplotypes of TNF‐α polymorphisms (rs1800629, cDNA?308G > A; and rs361525, cDNA?238G > A) were determined by polymerase chain reaction with sequence‐specific primers (PCR‐SSP). Results: Patients with CD who exhibit more severe oral soft tissue alterations were significantly more often A allele carriers of rs361525 than G allele carriers (14.2% versus 2.2%; P <0.001). Furthermore, A allele carriers had a higher mean periodontal probing depth (P <0.05), mean clinical attachment level (P <0.05), and sites with bleeding on probing (not significant). Similar results were obtained when evaluating A allele‐containing genotypes (AG + AA) and haplotypes (GA). In multivariate analyses considering age, sex, smoking, and medication as confounders, the A allele was proven to be an independent risk indicator for oral soft tissue alterations in patients with CD. No genotype‐dependent influence of rs1800629 was observed. Conclusion: The TNF‐α A allele of rs361525 represents a significant risk indicator for oral soft tissue alterations in patients with CD.     

Experience with anti‐TNF‐α therapy for orofacial granulomatosis

J Oral Pathol Med (2011) 40 : 14–19 Background: Orofacial granulomatosis (OFG) can be challenging to treat and experience with anti‐TNF‐α therapy is limited. We report our experience with infliximab (IFX) and adalimumab (ADA) for OFG in 14 patients, the largest reported series to date. Methods: A review of patients receiving induction and maintenance IFX for OFG +/? Crohn’s disease (CD) for active oral disease failing other therapies was performed. Clinical response defined by global physician assessment, aided by oral disease activity scores, was assessed at 2 months, 1 and 2 years. ADA was considered for patients failing IFX. Adverse events were recorded. Predictors of need for anti‐TNF‐α therapy were determined by comparison with OFG patients not requiring anti‐TNF‐α from our overall OFG database (n = 207). Results: Fourteen patients (9 men) were treated with IFX [OFG only (n = 7), OFG with CD (n = 7)]. Nine patients received concomitant immunosuppression. Median duration of treatment was 18 months. Short‐term response was achieved in 10/14 (71%) patients. Eight of 14 (57%) and 4/12 (33%) patients remained responsive at 1 and 2 years, respectively. Two patients who failed IFX responded to ADA. Factors predicting need for anti‐TNF‐α therapy were oral sulcal involvement, intestinal CD and a raised C‐reactive protein (CRP). Oral sulcal involvement predicted response at 1 and 2 years. Intestinal CD did not predict response. The only significant adverse event was an IFX infusion reaction. Conclusion: IFX provided good short‐term response for most OFG patients; however, a significant proportion lost response long term. Adverse events were uncommon. Patients failing IFX may respond to ADA.     

PI3K/Akt mediates expression of TNF‐α mRNA and activation of NF‐κB in calyculin A‐treated primary osteoblasts

Objective: The effect of calyculin A (CA), a serine/threonine protein phosphatase inhibitor, on tumor necrosis factor‐α (TNF‐α) in primary osteoblasts was investigated to determine whether protein phosphatases could affect primary osteoblasts and if so which signaling pathways would be involved. Materials and methods: Primary osteoblasts were prepared from newborn rat calvaria. Cells were treated with 1 nM CA for different time periods. The expressions of TNF‐α and GAPDH mRNA were determined by RT‐PCR. Cell extracts were subjected to SDS‐PAGE and the activation of Akt and NF‐κB were analyzed by western blotting. Results: Calyculin A‐treatment markedly increased the expression of TNF‐α mRNA and enhanced the phosphorylation level of Akt (Ser473) in these cells. Pretreatment with the PI3K inhibitor LY294002 suppressed the increase in TNF‐α mRNA expression and the phosphorylation of Akt in response to CA. Western blot analysis showed that CA stimulated the phosphorylation and nuclear translocation of NF‐κB in primary osteoblasts, and these responses were blocked by pretreatment with LY294002. Conclusion: Calyculin A elicits activation of PI3K/Akt pathway which leads to expression of TNF‐α mRNA and activation of NF‐κB. This NF‐κB activation involves both phosphorylation and nuclear translocation of NF‐κB.     

Quantitative messenger RNA expression of Toll‐like receptors and interferon‐α1 in gingivitis and periodontitis

Introduction: In addition to bacteria, viruses have been reportedly implicated in periodontitis. However, the available data are confined to Toll‐like receptor 2 (TLR2) and TLR4, which recognize bacterial products in periodontitis. In the present study, we investigated the expression levels of TLR5, ‐7, and ‐9 messenger RNAs (mRNAs) in addition to those of TLR2 and ‐4, and compared gingivitis and periodontitis. Interferon‐α1 (IFN‐α1), which is important for the antiviral response, was also compared. Methods: Gene expression was analyzed using quantitative real‐time polymerase chain reaction for 59 periodontitis and 27 gingivitis tissue samples together with viral serology in some patients. The presence of plasmacytoid dendritic cells (pDCs), a robust producer of IFN‐α, was immunohistochemically analyzed in an additional seven periodontitis and two gingivitis specimens. Results: The expression levels of TLR2, ‐4, ‐7, and ‐9 were significantly higher in periodontitis lesions than gingivitis lesions. The expression level of TLR5 was comparable to levels of TLR2 and ‐4; however, no significant difference was found between gingivitis and periodontitis. Although the expression of IFN‐α1 mRNA was higher in periodontitis lesions compared with gingivitis lesions, the level was quite low. Only a few pDCs were found in some periodontitis specimens. No difference was found for antibody‐positivity between gingivitis and periodontitis. Conclusion: This is the first study to show that a variety of TLRs are up‐regulated in periodontitis lesions compared with gingivitis lesions, suggesting that diverse microbial and possibly viral antigens are involved in the pathogenic mechanisms for periodontal diseases. However, the ligands recognized by the various TLRs in periodontal lesions remain to be determined.