Fetuin-A, serum amyloid A and tumor necrosis factor alpha levels in periodontal health and disease

In Vitro Bioassay for Damage-Associated Molecular Patterns Arising from Injured Oral Cells

Gingival fibroblasts are a significant source of paracrine signals required to maintain periodontal homeostasis and to mediate pathological events linked to periodontitis and oral squamous cell carcinomas. Among the potential paracrine signals are stanniocalcin-1 (STC1), involved in oxidative stress and cellular survival; amphiregulin (AREG), a growth factor that mediates the cross-talk between immune cells and epithelial cells; chromosome 11 open reading frame 96 (C11orf96) with an unclear biologic function; and the inflammation-associated prostaglandin E synthase (PTGES). Gingival fibroblasts increasingly express these genes in response to bone allografts containing remnants of injured cells. Thus, the gene expression might be caused by the local release of damage-associated molecular patterns arising from injured cells. The aim of this study is consequently to use the established gene panel as a bioassay to measure the damage-associated activity of oral cell lysates. To this aim, we have exposed gingival fibroblasts to lysates prepared from the squamous carcinoma cell lines TR146 and HSC2, oral epithelial cells, and gingival fibroblasts. We report here that all lysates significantly increased the transcription of the entire gene panel, supported for STC1 at the protein level. Blocking TGF-β receptor 1 kinase with SB431542 only partially reduced the forced expression of STC1, AREG, and C11orf96. SB431542 even increased the PTGES expression. Together, these findings suggest that the damage signals originating from oral cells can change the paracrine activity of gingival fibroblasts. Moreover, the expression panel of genes can serve as a bioassay for testing the biocompatibility of materials for oral application.

Clinical diagnostic value of IL-14, 1L-16 and SAA in periodontitis

OBJECTIVES

Periodontitis is a chronic infectious disease, which leads to inflammatory destruction of periodontal supporting tissues. Interleukin 14 (IL-14), Interleukin 16 (IL-16) and serum amyloid A (SAA) have been demonstrated to be abnormally expressed in inflammatory diseases. Therefore, this study was performed to analyzed the expression and potential clinical values of IL-14, 1L-16 and SAA in periodontitis.

MATERIALS AND METHODS

A total of 100 periodontitis patients and 100 healthy volunteers were recruited and the saliva and serum samples were collected. Then the C-reactive protein (CRP), procalcitonin (PCT), IL-14, 1L-16 and SAA levels in the saliva and serum of periodontitis patients were measured by Elisa kits. Besides, the significance of CRP, PCT, IL-14, 1L-16 and SAA in periodontitis patients were analyzed by receiver operating characteristic (ROC) analysis.

RESULTS

The results showed that CRP, PCT, IL-14, 1L-16 and SAA levels were significantly increased in the the saliva and serum of the periodontitis patients. Additionally, the area under the curve (AUC) of saliva CRP, PCT, IL-14, 1L-16 and SAA for the diagnosis of periodontitis were 0.9035, 0.9435, 0.9508, 0.9500 and 0.9467, respectively. The AUC of serum CRP, PCT, IL-14, 1L-16 and SAA for the diagnosis of periodontitis were 0.9035, 0.9435, 0.9508, 0.9500 and 0.9467, respectively. What's more, the diagnostic value of IL-14, 1L-16 and SAA were enhanced when combining with CRP and PCT.

CONCLUSION AND CLINICAL RELEVANCE

This study demonstrated that IL-14, IL-16 and SAA expressions were upregulated in periodontitis patients and exhibited a significant significance for periodontitis diagnosis.

Evaluation of Pentraxin 3 and Serum Amyloid A in the Gingival Crevicular Fluid of Patients with Periodontal Disease and Obesity

BACKGROUND

Pentraxin 3 (PTX3) is associated with periodontal tissue inflammation, a condition that precedes alveolar bone resorption. It is also elevated in obese tissues and is a useful biomarker of proinflammatory status. Serum amyloid A (SAA) is a proinflammatory and lipolytic adipokine. Adipocytes strongly express SAA, which suggests that it may have a significant role in the production of free fatty acids and local and systemic inflammation.

MATERIALS AND METHODS

We statistically analyzed the gingival crevicular fluid (GCF) values of PTX3 and SAA in patients with periodontal disease, who were diagnosed with obesity, and compared them with the values of inflammatory markers from patients diagnosed with one of the diseases and with healthy patients.

RESULTS

The patients with obesity and periodontitis had significantly higher levels of PTX3 and SAA than the patients diagnosed with either obesity or periodontitis.

CONCLUSIONS

These two markers are involved in the association between the two pathologies, as evidenced by the correlations between these levels and some clinical parameters.

Tumour necrosis factor-alpha polymorphism -308 G/a and its protein in subjects with gingivitis

OBJECTIVE

This study examined the association between tumour necrosis factor-alpha (TNF- α) (-308 G/A) polymorphism and gingivitis, and serum and salivary TNF- α levels, in a Mexican population.

MATERIAL AND METHODS

This study enrolled 171 subjects, divided into two groups: healthy subjects and gingivitis patients. TNF- α (-308 G/A) gene polymorphism was analyzed by PCR-RFLP assay. Salivary and serum samples were used to measure cytokine levels through the ELISA technique.

RESULTS

TNF- α (-308 G/A) polymorphism was shown to have a protective effect in carriers of the A/A genotype and allele A. The G/A genotype is associated with an increase in high-density lipoprotein cholesterol (HDL-C) levels in the gingivitis group. Healthy individuals had higher levels of salivary TNF- α and HDL-C, and increased salivary flow. Triglycerides, low-density lipoprotein cholesterol, and very low-density lipoprotein cholesterol levels were increased in the gingivitis group. No statistical differences were found in serum TNF- α levels.

CONCLUSION

Our data demonstrate that the TNF- α -308 A/A genotype exerts a protective effect against gingivitis. Moreover, oral conditions are associated with some biochemical parameters.

The secretion of cytokines by peripheral blood mononuclear cells of patients with periodontitis and healthy controls when exposed to H2S

Background: Hydrogen sulfide(H2S) is a bacterial metabolite produced as a result of bacterial growth in subgingival pockets, suggested to partake in the pathogenesis of periodontitis. H2S has previously been shown to induce the secretion of the pro-inflammatory cytokines IL-1β and IL-18 via the NLRP3 inflammasome in monocytes. Objective: To investigate the non-NLRP3 inflammasome-dependent immunological response of human peripheral blood mononuclear cells (PBMCs) of periodontitis patients and healthy controls exposed to H2S in vitro. Methods: PBMCs of periodontitis patients(N = 31) and healthy controls(N = 32) were exposed to 1 mM sodium hydrosulfide (NaHS) at 37°C for 24 h and the secretion of cytokines was compared to resting cells. TNF-α, IFN-γ, IL-6, IL-8, IL-12p40, IL-12p70, IL-17, MCP-1, and IL-1Ra secretions were measured with Bio-Plex Pro™ Human Cytokine Assay. Results: H2S triggered the secretion of the pro-inflammatory IFN-γ, IL-6, IL-17, TNF-α, IL-12p40, and IL-12p70, while the reverse was seen for IL-1Ra. In addition, a higher basal secretion of IFN-γ, IL-6, IL-12p70, IL-17 and MCP-1 was seen from PBMCs of periodontitis patients compared to healthy controls. Conclusion: The bacterial metabolite H2S triggers the secretion of pro-inflammatory cytokines from PBMCs and may thus have a prominent role in the host-bacteria interplay in periodontitis.

Evaluation of the effect of scaling and root planing on salivary and serum fetuin-A levels in patients with stages II and III periodontitis

BACKGROUND

Fetuin-A has garnered recognition in the etiopathogenesis of several systemic disorders. It has been recently acknowledged as an anti-inflammatory marker for periodontal disease. This study aimed to compare and correlate salivary and serum fetuin-A levels in health and patients with stages II-III periodontitis along with evaluating the effect of non-surgical periodontal therapy (NSPT) on the same.

METHODS

Group 1 comprised of 30 healthy subjects. Group 2 embodied 30 patients with stages II-III periodontitis. Clinical periodontal parameters were recorded. Saliva and serum samples were assembled. Periodontitis patients received non-surgical periodontal treatment. They were recalled after 6 months, and collection of samples and recording of clinical parameters were reiterated. Fetuin-A levels were analyzed using ELISA.

RESULTS

Salivary and serum fetuin-A levels were significantly lower in periodontitis patients when compared with the healthy subjects (P < 0.001) at baseline. Their concentrations significantly upregulated 6 months after active periodontal therapy (P < 0.001). Salivary fetuin-A levels revealed a significant positive correlation with their serum levels in Group 1 at baseline (P < 0.001). They also displayed a positive correlation in Group 2 at baseline and 6 months post periodontal therapy, nevertheless failed to establish a statistically significant association.

CONCLUSION(S)

Our study concluded that salivary and serum fetuin-A levels diminished with increasing severity of periodontal inflammation, and NSPT remarkably improved their levels. They also displayed a significant positive correlation in health, and a non-significant, yet positive correlation in patients with periodontitis.

Infection of Porphyromonas gingivalis Increases Phosphate-Induced Calcification of Vascular Smooth Muscle Cells

Accumulating evidence suggests a link between periodontal disease and cardiovascular diseases. Vascular calcification is the pathological precipitation of phosphate and calcium in the vasculature and is closely associated with increased cardiovascular risk and mortality. In this study, we have demonstrated that the infection with Porphyromonas gingivalis (P. gingivalis), one of the major periodontal pathogens, increases inorganic phosphate-induced vascular calcification through the phenotype transition, apoptosis, and matrix vesicle release of vascular smooth muscle cells. Moreover, P. gingivalis infection accelerated the phosphate-induced calcium deposition in cultured rat aorta ex vivo. Taken together, our findings indicate that P. gingivalis contributes to the periodontal infection-related vascular diseases associated with vascular calcification.

Oxidized Low-Density Lipoprotein Promotes In Vitro Calcification

Calcification plays an important role in the human body in maintaining homeostasis. In the human body, the presence of a high amount of oxidized low-density lipoprotein (ox-LDL) is a consistent feature of the local areas that are common sites of ectopic calcification, namely dental calculus, renal calculus, and the areas affected by arteriosclerosis. Hence, ox-LDL may have some effect on calcification. Scanning electron microscopy (SEM) observation revealed a high amount of amorphous calcium phosphate (ACP) when ox-LDL was included in the solution. In the in vitro experiment, the highest amount of precipitation of calcium phosphate was observed in the solution containing ox-LDL compared to the inclusion of other biomaterials and was 4.2 times higher than that of deionized water for 4.86 mM calcium and 2.71 mM phosphate. The morphology of calcium phosphate precipitates in the solution containing ox-LDL differed from that of the precipitates in solutions containing other biomaterials, as determined by transmission electron microscopy (TEM). Through the time course observation of the sediments using TEM, it was observed that the sediments changed from spherical or oval shape to a thin film shape. These results indicate that sediments acquired a long-range order array, and the phase transitioned from non-crystalline to crystalline with an increased time and density of ACP. Thus, it is concluded that ox-LDL promoted ACP precipitation and it plays an important role in ectopic calcification.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

Peroxisome proliferator activated receptor γ promotes mineralization and differentiation in cementoblasts via inhibiting Wnt/β-catenin signaling pathway

Peroxisome proliferator activated receptor γ (PPARγ) is a member of the nuclear receptor family of transcription factors, which involved in inflammation regulating and bone remodeling. Rare studies explored the effects of PPARγ on mineralization and differentiation in cementoblasts. To explore the potential approaches to repair the damaged periodontal tissues especially for cementum, the present study aims to investigate the effects and the regulating mechanism of PPARγ on mineralization and differentiation in cementoblasts. Murine cementoblast cell lines (OCCM-30) were cultured in basic medium for 24 hours/48 hours or in mineralization medium for 3/7/10 days, respectively at addition of dimethyl sulphoxide, rosiglitazone (PPARγ agonist), GW9662 (PPARγ antagonist), lithium chloride (LiCl), tumor necrosis factor-α (TNF-α), or respective combination. Expression of mineralization genes alkaline phosphatase (ALP), runt related transcription factors 2 (RUNX2), and osteocalcin (OCN) were detected by quantitative real-time polymerase chain reaction or/and Western blot. ALP staining and alizarin red staining were used to evaluate the mineralization in OCCM-30 cells. The change of β-catenin expression and translocation in cytoplasm/nucleus was analyzed by Western blot and immunofluorescence. The results showed that PPARγ agonist rosiglitazone improved the expression of ALP, RUNX2, and OCN, deepened ALP staining, increased mineralized nodules formation, and decreased β-catenin expression in the nucleus. LiCl, an activator of the Wnt signaling pathway, inhibited the expression of mineralization genes and reversed the upregulated expression of mineralization genes resulted from rosiglitazone. Under inflammatory microenvironment, rosiglitazone not only suppressed the expression of interleukin-1β caused by TNF-α, but improved the expression of mineralization genes in OCCM-30 cells. In conclusion, PPARγ could promote mineralization and differentiation in cementoblasts via inhibiting the Wnt/β-catenin signaling pathway, which would shed new light on the treatment of periodontitis and periodontal tissue regeneration.

Gingival crevicular fluid levels of interleukin-18 and tumor necrosis factor-alpha in type 1 diabetic children with gingivitis

OBJECTIVE

This study aimed to evaluate the levels of interleukin-18 and tumor necrosis factor-alpha in gingival crevicular fluid of diabetic children with gingivitis.

METHODOLOGY

Eighty-eight children (44 with type 1 diabetes mellitus and 44 systemically healthy) were recruited for the study. The children were divided into four subgroups based on their periodontal and systemic condition: (1) systemically and periodontally healthy children (H), (2) systemically healthy children with gingivitis (G), (3) periodontally healthy children with T1DM (T1DM + H), and (4) children with T1DM and gingivitis (T1DM + G). The plaque index, gingival index, probing pocket depth, and GCF volume were recorded. The IL-18 and TNF-α levels in GCF were determined by ELISA.

RESULTS

The clinical periodontal parameters, GCF IL-18 level, and TNF-α level were similar between diabetic and systemically healthy children (p > 0.05). The gingivitis subgroups had a significantly higher GI, PI, PPD, GCF volume, and TNF-α total amounts than the H subgroups (p < 0.0001). The IL-18 concentrations in the gingivitis subgroups were significantly lower than in the periodontally healthy subgroups.

CONCLUSIONS

In diabetic children with good metabolic control, T1DM did not affect the GCF levels of IL-18 and TNF-α in the presence of gingivitis. However, increased GCF TNF-α levels in children with gingivitis confirm that TNF-α is closely related to gingival inflammation.

CLINICAL RELEVANCE

Type 1 diabetes mellitus is not associated with GCF interleukin-18 and tumor necrosis factor-alpha levels in children with gingivitis.

Association of low fetuin-A levels with periodontitis in community-dwelling adults

Fetuin-A is a liver-secreted glycoprotein isolated from fetal bovine serum. Recent reports of its several pathological functions suggest an association between fetuin-A and systemic diseases. This study therefore examined the correlation between serum fetuin-A level and periodontal status. Data from 356 middle-aged and elderly adults who underwent health examinations in Goto, Japan, during the period from 2008 through 2010 were analyzed. Systemic and periodontal measurements were recorded, and serum fetuin-A level was determined by using an enzyme-linked immunosorbent assay. Fetuin-A levels for participants with moderate to severe periodontitis were significantly lower than those for participants with no or mild periodontitis. Additionally, fetuin-A level negatively correlated with periodontal clinical attachment loss. Moderate to severe periodontitis was significantly correlated with low serum fetuin-A levels (odds ratio, 1.69; 95% confidence interval, 1.01-2.69) in logistic regression analysis. Low serum fetuin-A level was correlated with worse periodontal status and could thus potentially serve as a marker of periodontitis.

The interaction between serum amyloid A and Toll-like receptor 2 pathway regulates inflammatory cytokine secretion in human gingival fibroblasts

BACKGROUND

Serum amyloid A (SAA) has been identified to trigger inflammation response, and play a crucial role in chronic inflammatory diseases. However, the regulatory mechanism of SAA still remains unclear during the development of periodontitis METHODS: SAA mRNA and protein expression were detected in healthy and inflammatory gingival tissues using real-time polymerase chain reaction (PCR) and immunohistochemistry. Human recombinant SAA (Apo-SAA), Pam3CSK4 (a Toll-like receptor (TLR) 2 ligand), siRNA-SAA, or TLR2 neutralizing antibody was applied to treat human gingival fibroblasts, respectively, or combined. SAA, TLRs, and inflammatory cytokines interleukin (IL)-6 and IL-8 were analyzed by real-time PCR, western blotting, or enzyme-linked immunosorbent assay.

RESULTS

SAA expression increased in human inflammatory gingival tissues from patients with periodontitis (P <0.05). Apo-SAA could increase not only the mRNA expression of TLR2 (P <0.05), but also IL-6 and IL-8 mRNA and protein levels (P <0.05) which was suppressed by TLR2 antibody in human gingival fibroblasts. Pam3CSK4 increased SAA, IL-6, and IL-8 levels (P <0.05). However, the expression of SAA, IL-6, and IL-8 decreased after transfection of siRNA-SAA (P <0.05).

CONCLUSION

SAA not only increases in inflammatory gingiva, but also triggers inflammatory cytokine secretion via interacting with TLR2 pathway in human gingival fibroblasts, which indicates that SAA is involved in periodontal inflammation.

Serum Amyloid A Contributes to Chronic Apical Periodontitis via TLR2 and TLR4

In the current concept of bacterial infections, pathogen-associated molecular patterns (PAMPs) derived from pathogens and damage-associated molecular patterns (DAMPs) released from damaged/necrotic host cells are crucial factors in induction of innate immune responses. However, the implication of DAMPs in apical and marginal periodontitis is unknown. Serum amyloid A (SAA) is a DAMP that is involved in the development of various chronic inflammatory diseases, such as rheumatoid arthritis. In the present study, we tested whether SAA is involved in the pathogenesis of periapical lesions, using human periapical surgical specimens and mice deficient in SAA and Toll-like receptors (TLR). SAA1/2 was locally expressed in human periapical lesions at the mRNA and protein levels. The level of SAA protein appeared to be positively associated with the inflammatory status of the lesions. In the development of mouse periapical inflammation, SAA1.1/2.1 was elevated locally and systemically in wild-type (WT) mice. Although SAA1.1/2.1 double-knockout and SAA3 knockout mice had redundant attenuation of the extent of periapical lesions, these animals showed strikingly improved inflammatory cell infiltration versus WT. Recombinant human SAA1 (rhSAA1) directly induced chemotaxis of WT neutrophils in a dose-dependent manner in vitro. In addition, rhSAA1 stimulation significantly prolonged the survival of WT neutrophils as compared with nonstimulated neutrophils. Furthermore, rhSAA1 activated the NF-κB pathway and subsequent IL-1α production in macrophages in a dose-dependent manner. However, TLR2/TLR4 double deficiency substantially diminished these SAA-mediated proinflammatory responses. Taken together, the SAA-TLR axis plays an important role in the chronicity of periapical inflammation via induction of inflammatory cell infiltration and prolonged cell survival. The interactions of PAMPs and DAMPs require further investigation in dental/oral inflammation.

Gingival crevicular fluid levels of prolidase and alkaline phosphatase in periodontitis

Background/Aim: The purpose of this study was to investigate gingival crevicular fluid (GCF) alkaline phosphatase (ALP) and prolidase levels in subjects with different periodontal status. Material and Methods: Fifteen periodontitis, fifteen gingivitis and fifteen healthy subject were included. GCF samples were collected from participants. Probing depth, clinical attachment level, gingival index was recorded. ALP and prolidase levels were determined in GCF by spectrophotometrically. Results: Higher values of ALP were found in periodontitis compared with gingivitis and healthy control (p<0.001). The values of prolidase were lower in periodontitis than healthy control (p<0.05). A statistically significant positive correlation was found between clinical parameters and ALP levels (p<0.001). There is no significant correlation between clinical parameters and prolidase levels (p>0.05). Additionally, no significant correlation was detected between ALP and prolidase (r= -0.309, p>0.05). Conclusion: Our preliminary data suggest that low prolidase level in periodontitis was not associated with ALP and clinical parameters, which represent periodontal destruction and inflammation.