Profiling the Cytokines in Gingival Crevicular Fluid Using a Cytokine Antibody Array

TGF-β Signaling in Gingival Fibroblast-Epithelial Interaction

The underlying mechanism and the therapeutic regimen for the transition of reversible gingivitis to irreversible periodontitis are unclear. Since transforming growth factor (TGF)-β has been implicated in differentially regulated gene expression in gingival fibroblasts, we hypothesized that TGF-β signaling is activated in periodontitis-affected gingiva, along with enhanced collagen degradation, that is reversed by TGF-β inhibition. A novel three-dimensional (3D) gel-culture system consisting of primary human gingival fibroblasts (GF) and gingival epithelial (GE) cells in collagen gels was applied. GF populations from patients with severe periodontitis degraded collagen gels, which was reduced by TGF-β-receptor kinase inhibition. Up-regulation of TGF-β-responsive genes was evident in GF/GE co-cultures. Furthermore, the TGF-β downstream transducer Smad3C was highly phosphorylated in periodontitis-affected gingiva and 3D cultures. These results imply that TGF-β signaling is involved in fibroblast-epithelial cell interaction in periodontitis, and suggest that the 3D culture system is a useful in vitro model for therapeutic drug screening for periodontitis.

Salivary chemokine levels in patients with primary Sjogren's syndrome

OBJECTIVE

The present study aimed to investigate the salivary chemokine levels in patients with primary SS (pSS) and compare them with those in patients with non-SS sicca symptoms or non-sicca controls.

METHODS

Unstimulated and stimulated whole saliva samples were obtained from pSS patients (n = 30) and age- and gender-matched patients with non-SS sicca (n = 30) and non-sicca healthy controls (n = 25). Salivary CCL2, CCL3, CCL4, CXCL8 and CXCL10 levels were measured using a Luminex bead-based multiplex assay.

RESULTS

Patients with pSS had significantly different distributions of salivary CCL3 (P = 0.0001 by the Kruskal-Wallis test), CCL4 (P < 0.00001), CXLC8 (P < 0.0001) and CXCL10 (P < 0.05) levels in unstimulated saliva and all chemokine levels in stimulated saliva when compared with non-SS sicca and non-sicca controls. In comparison with chemokine production rate, the CXCL8 and CXCL10 production rates were significantly higher in pSS than in non-SS sicca controls (P < 0.01 by the Mann-Whitney test). Logistic regression analyses revealed that salivary CXCL8 (P < 0.05) and CXCL10 (P < 0.05) were the significant discriminating chemokines between the pSS and non-SS sicca groups. Although CXCL8 and CXCL10 levels were not correlated with the focus scores, CXCL8 and CXCL10 levels were significantly associated with salivary gland dysfunction.

CONCLUSION

These results support the notion that CXCL8 or CXCL10 chemokine plays a role in the pathogenesis of pSS.

Non-healing is associated with persistent stimulation of the innate immune response in chronic venous leg ulcers

BACKGROUND

The molecular pathogenesis of chronic skin wounds is complex and not fully understood. Although these wounds are often characterized as being in a state of persistent inflammation, the impact and participation of the innate immune responses in sustaining this inflammation needs further investigation.

OBJECTIVE

We investigated the cytokine profiles, Toll-like receptor (TLR)-stimulating activities and the levels of the antibacterial peptide Lipocalin-2 (Lcn-2) in a series of healing and non-healing chronic venous leg ulcers (CVLUs) through a study time of 8 weeks.

METHODS

Wound fluids from healing and non-healing CVLUs were run on a Human Cytokine Antibody Array, and Lcn-2 levels measured with ELISA. HEK 293 cells transfected with TLR2 or TLR4 and their respective co-receptors, and human peripheral blood monocytes were then stimulated with the wound fluids from healing and non-healing venous leg ulcers.

RESULTS

Healing wounds were associated with decreasing levels of IL-1alpha, IL-1beta and MIP-1delta, whereas in non-healing wounds decreasing levels of IL-8 and MIP-1alpha were found. Accordingly, wound fluid from non-healing CVLUs contained persistent Lcn-2 levels and TLR2- and TLR4-stimulating activities, while, in healing wounds, the TLR-stimulating activities decreased over time with significantly diminished levels of Lcn-2 (p<0.005).

CONCLUSIONS

Innate immune responses contribute to the chronic inflammation in non-healing CVLUs through participation of Toll-like receptors. The levels of the antimicrobial peptide Lcn-2 in wound fluids from these ulcers are elevated as a reflection of this contribution.

Epithelial cell pro-inflammatory cytokine response differs across dental plaque bacterial species

AIM

The dental plaque is comprised of numerous bacterial species, which may or may not be pathogenic. Human gingival epithelial cells (HGECs) respond to perturbation by various bacteria of the dental plaque by production of different levels of inflammatory cytokines, which is a putative reflection of their virulence. The aim of the current study was to determine responses in terms of interleukin (IL)-1beta, IL-6, IL-8 and IL-10 secretion induced by Porphyromonas gingivalis, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Streptococcus gordonii in order to gauge their virulence potential.

MATERIALS AND METHODS

HGECs were challenged with the four bacterial species, live or heat killed, at various multiplicity of infections and the elicited IL-1beta, IL-6, IL-8 and IL-10 responses were assayed by enzyme-linked immunosorbent assay.

RESULTS

Primary HGECs challenged with live P. gingivalis produced high levels of IL-1beta, while challenge with live A. actinomycetemcomitans gave high levels of IL-8. The opportunistic pathogen F. nucleatum induces the highest levels of pro-inflammatory cytokines, while the commensal S. gordonii is the least stimulatory.

CONCLUSION

We conclude that various dental plaque biofilm bacteria induce different cytokine response profiles in primary HGECs that may reflect their individual virulence or commensal status.

A multiplex immunoassay demonstrates reductions in gingival crevicular fluid cytokines following initial periodontal therapy

BACKGROUND AND OBJECTIVE

Cytokines and chemokines play an important role in the pathogenesis of periodontal diseases. The objective of this study was to quantitatively assess the effect of initial periodontal therapy on gingival crevicular fluid levels of a comprehensive panel of cytokines and chemokines, including several less extensively studied mediators.

MATERIAL AND METHODS

Clinical examinations were performed and gingival crevicular fluid samples obtained from six subjects with generalized severe chronic periodontitis prior to initial periodontal therapy and at re-evaluation (6-8 weeks). Four diseased and two healthy sites were sampled in each subject. Twenty-two gingival crevicular fluid mediators were examined using a multiplex antibody capture and detection platform. Statistical analyses were performed by fitting mixed effects linear models to log-transformed gingival crevicular fluid values.

RESULTS

Gingival crevicular fluid interleukin (IL)-1alpha and IL-1beta were the only cytokines to differ in initially diseased vs. initially healthy sites. Following initial therapy, 13 of the 16 detectable cytokines and chemokines decreased significantly in diseased sites, including IL-1alpha, IL-1beta, IL-2, IL-3, IL-6, IL-7, IL-8, IL-12 (p40), CCL5/regulated on activation, normally T cell expressed and secreted (RANTES), eotaxin, macrophage chemotactic protein-1, macrophage inflammatory protein-1alpha and interferon-gamma. At healthy sites, only three of the 16 mediators were significantly altered following therapy.

CONCLUSION

This is the first study, to our knowledge, to evaluate such an extensive panel of gingival crevicular fluid mediators within the same sample prior to and following initial therapy. The results confirm that periodontal therapy effectively reduces pro-inflammatory cytokines and chemokines, including less well-described mediators that may be important in initiation and progression of periodontitis. The multiplex assay will prove useful for future gingival crevicular fluid studies.

The gingipains: scissors and glue of the periodontal pathogen, Porphyromonas gingivalis

The anaerobic bacterium, Porphyromonas gingivalis, is associated with chronic periodontal disease (periodontitis or gum disease). The disease is not only the leading cause of tooth loss in the developed world, but is associated with a number of systemic diseases, such as cardiovascular disease and diabetes. The most potent virulence factors of this bacterium are the gingipains, three cysteine proteases that bind and cleave a wide range of host proteins. This article summarizes current knowledge of the structure and function of the enzymes, with a particular focus on what remains to be elucidated regarding the structure and function of the nonenzymatic adhesin domains of the high-molecular-weight forms of the proteases.

The major outer membrane protein of a periodontopathogen induces IFN-beta and IFN-stimulated genes in monocytes via lipid raft and TANK-binding kinase 1/IFN regulatory factor-3

Surface molecules of pathogens play an important role in stimulating host immune responses. Elucidation of the signaling pathways activated by critical surface molecules in host cells provides insight into the molecular pathogenesis resulting from bacteria-host interactions. MspTL is the most abundant outer membrane protein of Treponema lecithinolyticum, which is associated with periodontitis, and induces expression of a variety of proinflammatory factors. Although bacteria and bacterial components like LPS and flagellin are known to induce IFN-beta, induction by bacterial surface proteins has not been reported. In the present study, we investigated MspTL-mediated activation of signaling pathways stimulating up-regulation of IFN-beta and IFN-stimulated genes in a human monocytic cell line, THP-1 cells, and primary cultured human gingival fibroblasts. MspTL treatment of the cells induced IFN-beta and the IFN-stimulated genes IFN-gamma-inducible protein-10 (IP-10) and RANTES. A neutralizing anti-IFN-beta Ab significantly reduced the expression of IP-10 and RANTES, as well as STAT-1 activation, which was also induced by MspTL. Experiments using specific small interfering RNA showed that MspTL activated TANK-binding kinase 1 (TBK1), but not inducible IkappaB kinase (IKKi). MspTL also induced dimerization of IFN regulatory factor-3 (IRF-3) and translocation into the nucleus. The lipid rapid-disrupting agents methyl-beta-cyclodextrin, nystatin, and filipin inhibited the MspTL internalization and cellular responses, demonstrating that lipid raft activation was a prerequisite for MspTL cellular signaling. Our results demonstrate that MspTL, the major outer protein of T. lecithinolyticum, induced IFN-beta expression and subsequent up-regulation of IP-10 and RANTES via TBK1/IRF-3/STAT-1 signaling secondary to lipid raft activation.

LPS induces GROalpha chemokine production via NF-kappaB in oral fibroblasts

OBJECTIVE AND DESIGN

Chemotaxis of neutrophils from blood to the inflammation process plays an important role in development of periodontal inflammation. The novel chemokine GROalpha, also named CXCL1, is a strong chemoattractant for neutrophils. Data on production and regulation of GROalpha by oral fibroblasts have not previously been presented.

MATERIALS AND METHODS

GROalpha mRNA and protein levels were determined in human periodontal ligament cells and mouse gingival fibroblasts by quantitative real-time PCR and ELISA.

RESULTS

We disclose that both human periodontal ligament cells and mouse gingival fibroblasts produce GROalpha in response to LPS stimulation. Stimulation with LPS for 24 h increased both mRNA for GROalpha and GROalpha protein. The steroid hormone estrogen had no effect on LPS-induced GROalpha mRNA expression. Treatment with the glucocorticoid dexamethasone attenuated LPS-induced GROalpha production, and the NF-kappaB blocker MG 132 fully prevented LPS-induced GROalpha.

CONCLUSIONS

Oral fibroblasts respond to LPS stimulation by increasing GROalpha production via the transcription factor NF-kappaB, suggesting that this mechanism may be involved in development of periodontal inflammation.

The host cytokine response to Porphyromonas gingivalis is modified by gingipains

BACKGROUND/AIMS

Clinical studies indicate that primary proinflammatory cytokines, such as interleukin-1beta (IL-1beta) are elevated in the gingival crevice around teeth with periodontitis but the secondary cytokines and chemokines, IL-6 and IL-8, are not. The human gingival epithelial cells (HGECs) lining the gingival sulcus respond to perturbation by microbes of dental plaque by releasing a wide range of cytokines. Porphyromonas gingivalis, a putative periodontal pathogen, possesses numerous virulence factors some of which directly impact on the host response. In the present study, we sought to determine how P. gingivalis influences the inflammatory cytokine responses.

METHODS

HGECs were challenged with P. gingivalis and other putative periodontal pathogens, and the resultant production of IL-1beta, IL-6, and IL-8 was assayed by enzyme-linked immunosorbent assay (ELISA). Culture supernatants and recombinant human cytokines were challenged with live P. gingivalis wild-type and gingipain-deficient strains and the resultant cytokine profile was assessed by ELISA and Western blot.

RESULTS

We show here that primary HGECs challenged with live P. gingivalis result in high levels of IL-1beta but not the related secondary cytokines IL-6 and IL-8. We further demonstrate that cytokine response differences are the result of the action of P. gingivalis proteases, with lysine gingipain being the most effective.

CONCLUSION

We conclude that P. gingivalis, through lysine gingipain, can subvert the protective host proinflammatory response by direct cytokine degradation. Changes in the crevicular cytokine profile have consequences in periodontal disease pathogenesis that should be considered in the development of diagnostic and therapeutic modalities.

Regulation of CXCL9/10/11 in Oral Keratinocytes and Fibroblasts

Th1 and Th2 cytokines such as interferon-γ (IFN-γ ) , tumor necrosis factor- α (TNF-α ), and IL-4 are expressed in T-cell-mediated inflammation in the oral cavity. We tested the hypothesis that those cytokines may act on CXCR3-agonistic chemokines, T-cell recruiting factors, and on neighboring cells, including oral keratinocytes and fibroblasts. Human immortalized oral keratinocytes (RT7) and fibroblasts (GT1) after 24-hour stimulation with IFN-γ showed increased mRNA levels of CXCL9 (600- and 700-fold), CXCL10 (10,000- and 150-fold), and CXCL11 (5000- and 300-fold), respectively. In contrast, TNF-α caused an increase in CXCL9 (300-fold), CXCL10 (2000-fold), and CXCL11 (2000-fold) mRNA levels in GT1, but not RT7 cells, at 24 hrs. IL-4 reinforced the promotion of CXCL9, CXCL10, and CXCL11 expression by IFN-γ in RT7 cells, whereas IL-4 inhibited the increased levels by IFN-γ and TNF-α in GT1 cells. Thus, IFN-γ , TNF-α , and IL-4 appear cooperatively to regulate CXCR3-agonistic chemokines in oral keratinocytes and fibroblasts in T-cell-mediated oral inflammation sites.

Effects of periodontal therapy on glycemic control and inflammatory markers

BACKGROUND

Periodontitis, a complication of diabetes mellitus (DM), can induce or perpetuate systemic conditions. This double-masked, placebo-controlled study evaluated the effects of periodontal therapy (scaling and root planing [SRP]) on the serum levels of glycated hemoglobin (HbA1c) and on inflammatory biomarkers.

METHODS

Thirty subjects with type 2 DM and periodontitis were treated with SRP + placebo (SRP; N = 15) or with SRP + doxycycline (SRP+Doxy; N = 15), 100 mg/day, for 14 days. Clinical and laboratory data were recorded at baseline and at 3 months after treatment.

RESULTS

After 3 months, the reduction in probing depth was 0.8 mm for the SRP group (P <0.01) and 1.1 mm for the SRP+Doxy group (P <0.01) followed by a 0.9% (SRP; P = 0.17) and 1.5% (SRP+Doxy; P <0.01) reduction in HbA1c levels. A significant reduction in interleukin (IL)-6; interferon-inducible protein 10; soluble fas ligand; granulocyte colony-stimulating factor; RANTES; and IL-12 p70 serum levels were also verified (N = 30). To our knowledge, this is the first report on the effects of periodontal therapy on multiple systemic inflammatory markers in DM.

CONCLUSIONS

Periodontal therapy may influence the systemic conditions of patients with type 2 DM, but no statistical difference was observed with the adjunctive systemic doxycycline therapy. Moreover, it is possible that the observed improvement in glycemic control and in the reduction of inflammatory markers could also be due to diet, which was not controlled in our study. Therefore, a confirmatory study with a larger sample size and controlled diet is necessary.

IL-1beta and TNF-alpha regulate IL-6-type cytokines in gingival fibroblasts

Interleukin-6 (IL-6)-type cytokines are pleiotropic molecules capable of stimulating bone resorption and expressed by numerous cell types. In the present study, we tested the hypothesis that gingival fibroblasts may exert local osteotropic effects through production of IL-6 and related cytokines. IL-6-type cytokine expression and regulation by IL-1beta and tumor necrosis factor-alpha (TNF-alpha) were studied in fibroblasts from the non-inflamed gingiva of healthy individuals. Constitutive mRNA expression of IL-6, IL-11, and leukemia inhibitory factor (LIF), but not of oncostatin M (OSM), was demonstrated, as was concentration-dependent stimulation of IL-6 and LIF mRNA and of protein by IL-1beta and TNF-alpha. IL-11 mRNA and protein were concentration-dependently stimulated by IL-1beta. The signaling pathway involved in IL-6 and LIF mRNA stimulation involved MAP kinases, but not NF-kappaB. The findings support the view that resident cells may influence the pathogenesis of periodontal disease through osteotropic IL-6-type cytokine production mediated by activation of MAP kinases.

ABBREVIATIONS

IL-1alpha (interleukin-1alpha); IL-1beta (interleukin-1beta); IL-6 (interleukin-6); IL-11 (interleukin-11); LIF (leukemia inhibitory factor); OSM (oncostatin M); alpha(1)-coll. I (alpha(1)-collagen I); ALP (alkaline phosphatase); BMP-2 (bone morphogenetic protein-2); OC (osteocalcin); BSP (bone sialoprotein); TNFR I (tumor necrosis factor receptor I); TNFR II (tumor necrosis factor receptor II); IL-1R1 (interleukin-1 receptor 1); GAPDH (glyceraldehyde-3-phosphate dehydrogenase); RPL13A (ribosomal protein L13A); mRNA (messenger ribonucleic acid); cDNA (complementary deoxyribonucleic acid); PCR (polymerase chain-reaction); BCA (bicinchoninic acid); ELISA (enzyme-linked immunosorbent assay); alpha-MEM (alpha modification of Minimum Essential Medium); and FCS (fetal calf serum).

Gelatinolytic activity in gingival crevicular fluid from teeth with periapical lesions

OBJECTIVE

Many matrix metalloproteinases (MMPs) have been associated with periodontal tissue destruction during chronic and apical periodontitis. The aim of this study was to determine gelatinolytic activity in gingival crevicular fluid (GCF) from teeth with apical lesions and healthy controls.

STUDY DESIGN

Case-control study.

MATERIALS AND METHODS

After clinical examination, 30 GCF samples were obtained from 20 affected and 20 control teeth. Subjects with periodontal diseases were excluded. Gelatinolytic activity was determined by gelatin zymography and densitometric analysis.

RESULTS

ProMMP-9 levels were significantly increased when compared with controls and were positively correlated with MMP-9 activity in diseased GGF. Similarly, MMP-2 activity, when detected it was exclusively in diseased samples. Additional bands of estimated molecular weights of 60 and 48 kDa were observed.

CONCLUSIONS

MMP-9 and -2 are highly increased in GCF from teeth with periapical lesions. These gelatinases could represent useful markers in monitoring chronic apical periodontitis in GCF.

MMP-13 and TIMP-1 determinations in progressive chronic periodontitis

Matrix metalloproteinase (MMP)-13 is a collagenase involved in extracellular matrix degradation either by its direct degradative effects or by processing bioactive substrates. The aim of this study was to determine the levels of MMP-13 and tissue inhibitor of metalloproteinase (TIMP)-1 in gingival crevicular fluid (GCF) and gingival biopsies obtained from active and inactive sites during chronic periodontitis progression.

MATERIALS AND METHODS

This was a longitudinal study in which chronic periodontitis patients with moderate to severe disease were included and followed until they developed progression determined by the tolerance method. GCF samples were obtained from periodontitis, active, inactive and healthy sites and additional gingival biopsies were taken from active and inactive sites. MMP-13 and TIMP-1 determinations were carried out by immunodot blots and immunowestern blots.

RESULTS

In progressive periodontitis, MMP-13 and TIMP-1 remained unchanged between active and inactive sites, but as the TIMP-1 relative levels increased together with MMP-13 elevation in inactive samples, an inverse correlation was observed in active sites. Besides, MMP-13 was undetectable in healthy controls.

CONCLUSION

Chronic periodontitis is characterized by increased MMP-13 expression. During disease progression, active sites tended to decrease TIMP-1 levels in association with MMP-13 elevation.

Gingival Crevicular Fluid VEGF Levels in Periodontal Health and Disease

BACKGROUND

Vascular endothelial growth factor (VEGF), a glycoprotein, has attracted attention as a potential inducer of angiogenesis. It is detectable in periodontal tissues within endothelial cells, plasma cells, and macrophages and in junctional, sulcular, and gingival epithelium. In periodontitis patients, the volume of gingival crevicular fluid (GCF) and the total amount of VEGF collected from diseased sites were greater than from clinically healthy sites. The aim of the present study was to investigate the role of VEGF in periodontal disease progression and to investigate the effect of periodontal therapy on VEGF concentrations in GCF.

METHODS

Forty-five subjects were divided into three groups based on gingival index, clinical attachment loss, and radiographic evidence of alveolar bone loss: healthy (group 1), gingivitis (group 2), and chronic periodontitis (group 3). A fourth group consisted of subjects from group 3, 8 weeks after treatment (scaling and root planing). GCF samples collected from each patient were quantified for VEGF levels using enzyme-linked immunosorbent assay. Further, the correlation between VEGF levels in situ and the clinical parameters was analyzed in all groups and was analyzed before and after treatment in the periodontitis group.

RESULTS

The highest mean VEGF concentration (99.375 pg/ml) was observed in group 3, and the lowest was observed in group 1 (42.025 pg/ml). Its mean level in group 3 decreased to 54.60 pg/ml after treatment (group 4). Further, GCF VEGF levels showed a positive correlation with all of the clinical parameters.

CONCLUSIONS

VEGF levels in GCF increased from health to periodontitis, and periodontal treatment resulted in a reduction in their concentrations. These data indicated that VEGF plays a key role in periodontal disease progression and can be considered a biomarker of periodontal disease progression.

Mapping of the proinflammatory domains of MspTL of Treponema lecithinolyticum

The major surface protein (MspTL) of Treponema lecithinolyticum, associated with periodontitis and endodontic infections, has been reported to induce proinflammatory mediators such as intercellular adhesion molecule (ICAM)-1, and interleukin (IL)-1beta, IL-6 and IL-8. The purpose of this study was to examine the role of MspTL in cell adhesion/migration and to identify its proinflammatory domains. Using the human monocytic cell line THP-1 and human dermal microvascular endothelial cells (HMEC-1), it was demonstrated that MspTL increased adhesion of monocytes to endothelial cells and transendothelial migration. To analyse the proinflammatory domains of the protein, four gene constructs covering different regions of MspTL were designed and expressed in Escherichia coli using the expression vector pQE-30. Histidine-tagged recombinant proteins were purified using Ni-NTA agarose and polymyxin B agarose to remove LPS contamination. Recombinant truncated polypeptides were assessed for the ability to induce ICAM-1 and proinflammatory factors in THP-1 cells by real-time RT-PCR and ELISA. Of the four polypeptides, the one spanning the N-terminal 86 amino acids significantly induced ICAM-1, IL-1beta, IL-6, IL-8, tumour necrosis factor-alpha (TNF-alpha), cyclooxygenase (COX)-2, and prostaglandin E2 (PGE2). The results indicate that MspTL may induce cell adhesion and inflammation via its N-terminal region.

Effects of insulin-like growth factor binding proteins in bone -- a matter of cell and site

The actions of the insulin-like growth factor (IGF)-system are controlled by six IGF-binding proteins (IGFBPs). The IGFBPs are thought to affect local effects of IGF-I and IGF-II due to higher affinity if compared to IGF-I receptors and due to cell-type specific IGFBP expression patterns. It was found in IGFBP knockout models that the IGFBP family is functionally redundant. Thus, functional analysis of potential effects of IGFBPs is dependent on descriptive studies and models of IGFBP overexposure in vitro and in vivo. In the literature, the role of the IGFBPs for bone growth is highly controversial and, to date, no systematic look has been taken at IGFBPs resolving functional aspects of IGFBPs at levels of cell types and specific locations within bones. Since IGFBPs are thought to represent local modulators of the IGF actions and also exert IGF-independent effects, this approach is particularly reasonable on a physiological level. By sorting the huge number of in part controversial results on IGFBP effects in bone present in the literature for distinct cell types and bone sites it is possible to generate a focused, more specific and a less controversial picture of IGFBP functions in bone.

Analysis of gingival crevicular fluid as applied to the diagnosis of oral and systemic diseases

Gingival crevicular fluid (GCF), a serum transudate or inflammatory exudate, can be collected from the gingival crevice surrounding the teeth. As such, the fluid reflects the constituents of serum, the cellular response in the periodontium, and contributions from the gingival crevice. The study of GCF has focused on defining the pathophysiology of periodontal disease, and identification of a potential diagnostic test for active periodontitis. The majority of markers that have been identified as potential candidates for such a test are measures of inflammation (i.e., prostaglandin E2 (PGE2), neutrophil elastase, and the lysosomal enzyme beta-glucuronidase). Further, analysis of inflammatory markers in GCF may assist in defining how certain systemic disorders (e.g., diabetes mellitus) can modify periodontal disease, and how periodontal disease/periodontal inflammation can influence certain systemic disorders (i.e., cardiovascular/cerebrovascular diseases). Methodological concerns related to the collection and analysis of GCF are important factors that need to be considered when studying GCF. Practical concerns argue against the widespread clinical application of GCF as an adjunct to periodontal diagnosis. Rather, analysis of GCF-derived mediators in saliva may serve as a means of rapid screening for periodontal disease.

Treponema denticola induces interleukin-8 and macrophage chemoattractant protein 1 production in human umbilical vein epithelial cells

Treponema denticola, a major pathogen of periodontitis, has also been detected in the lesions of atherosclerosis. The aim of this study was to investigate induction of chemokine production in human umbilical vein endothelial cells (HUVECs) by T. denticola and determine whether those chemokines were degraded by a protease, dentilisin. T. denticola ATCC35405 or dentilisin-deficient mutant K1 were added to HUVECs and levels of interleukin-8 (IL-8) and monocyte chemoattractant protein-1 (MCP-1) in the culture supernatants were determined by enzyme-linked immunosorbent assay. T. denticola ATCC35405 induced production of IL-8 in a time-dependent manner, with both production of IL-8 and expression of IL-8 mRNA showing higher levels than with exposure to dentilisin-deficient mutant K1. Although exposure to ATCC35405 induced expression of MCP-1 mRNA in the HUVECs, MCP-1 levels were remained similar to that in unstimulated cells. IL-8 and MCP-1 showed partial hydrolysis with exposure to T. denticola ATCC35405, but not with T. denticola K1. These results suggest that T. denticola can evade host defense mechanisms by modulating production of IL-8 and MCP-1, and that this play a role in the development of chronic infections such as periodontitis. The association of T. denticola infection to atherosclerosis was also discussed based on the present study.

Nicotine and Lipopolysaccharide Affect Cytokine Expression From Gingival Fibroblasts

BACKGROUND

This in vitro study investigated the influence of nicotine, lipopolysaccharide (LPS), and a combination of both agents on cytokine expression from human gingival fibroblasts (HGFs).

METHODS

HGFs were exposed for 48 hours to 250 microg/ml nicotine, 1 microg/ml Porphyromonas gingivalis LPS, or both. The expression of multiple cytokines was detected in the HGFs conditioned media using cytokine protein arrays.

RESULTS

The untreated HGFs expressed several cytokines, which included relatively high levels of interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1 (MCP-1). They also expressed low levels of growth-regulated oncogene (GRO), IL-3, and IL-10. Nicotine had the greatest effect on the expression of GRO-alpha, IL-7, IL-10, and IL-15 compared to the untreated control. P. gingivalis LPS had the greatest effect on the expression of GRO-alpha; IL-7; IL-10; and RANTES (regulated on activation, normal T-cell expressed, and presumably secreted) compared to the untreated control. The combination of both agents had the biggest impact on the expression of GRO-alpha, IL-7, IL-10, IL-15, RANTES, and interferon-gamma (IFN-gamma) compared to the untreated control.

CONCLUSION

HGFs exposed to nicotine, P. gingivalis LPS, or a combination of both agents increased the expression of multiple cytokines.