Resistin in gingival crevicular fluid and induction of resistin release by Porphyromonas gingivalis lipopolysaccharide in human neutrophils

Comparative Study of Azithromycin Versus Doxycycline Effect on the Resistin Level in Periodontitis Patients With Type 2 Diabetes: A Randomized Controlled Clinical Trial

AIM

The present study aimed to determine if azithromycin (AZM) and doxycycline therapy, as an adjunct to scaling and root planning (SRP), modulate host response and improve clinical outcomes in periodontitis patients with type 2 diabetes mellitus (T2DM).

PATIENTS AND METHODS

Forty-five periodontal sites in 15 periodontitis patients with T2DM received nonsurgical periodontal therapy (NSPT). In Group I, patients were placebo (not receiving any medication), Group II patients received systemic AZM therapy (AZM 250 mg/day for five days), and Group III patients received doxycycline (20 mg twice per day for three months. The resistin level was collected and measured by enzyme-linked immunosorbent assay (ELISA). Gingival index (GI), probing depth (PD), and clinical attachment level (CAL) were recorded at baseline, one-month, and three-month intervals.

RESULTS

All groups showed improvement in clinical parameters and resistin levels throughout the study. The mean resistin level at three months was the highest in Group I and the lowest in Group III. Patients in Group II showed a larger decrease in mean PD than those in Group I and III. Group III had the highest gain in mean CAL, with an increase of 1.78 mm in attachment.

CONCLUSION

Resistin might be a useful indicator of current disease status. In addition, benefits from adjunctive systemic use of AZM and doxycycline have been administered with non-surgical periodontal therapy.

Diabetes mellitus promotes susceptibility to periodontitis-novel insight into the molecular mechanisms

Diabetes mellitus is a main risk factor for periodontitis, but until now, the underlying molecular mechanisms remain unclear. Diabetes can increase the pathogenicity of the periodontal microbiota and the inflammatory/host immune response of the periodontium. Hyperglycemia induces reactive oxygen species (ROS) production and enhances oxidative stress (OS), exacerbating periodontal tissue destruction. Furthermore, the alveolar bone resorption damage and the epigenetic changes in periodontal tissue induced by diabetes may also contribute to periodontitis. We will review the latest clinical data on the evidence of diabetes promoting the susceptibility of periodontitis from epidemiological, molecular mechanistic, and potential therapeutic targets and discuss the possible molecular mechanistic targets, focusing in particular on novel data on inflammatory/host immune response and OS. Understanding the intertwined pathogenesis of diabetes mellitus and periodontitis can explain the cross-interference between endocrine metabolic and inflammatory diseases better, provide a theoretical basis for new systemic holistic treatment, and promote interprofessional collaboration between endocrine physicians and dentists.

Host insulin resistance caused by Porphyromonas gingivalis-review of recent progresses

Porphyromonas gingivalis (P. gingivalis) is a Gram-negative oral anaerobic bacterium that plays a key role in the pathogenesis of periodontitis. P. gingivalis expresses a variety of virulence factors that disrupt innate and adaptive immunity, allowing P. gingivalis to survive and multiply in the host and destroy periodontal tissue. In addition to periodontal disease, P.gingivalis is also associated with systemic diseases, of which insulin resistance is an important pathological basis. P. gingivalis causes a systemic inflammatory response, disrupts insulin signaling pathways, induces pancreatic β-cell hypofunction and reduced numbers, and causes decreased insulin sensitivity leading to insulin resistance (IR). In this paper, we systematically review the studies on the mechanism of insulin resistance induced by P. gingivalis, discuss the association between P. gingivalis and systemic diseases based on insulin resistance, and finally propose relevant therapeutic approaches. Overall, through a systematic review of the mechanisms related to systemic diseases caused by P. gingivalis through insulin resistance, we hope to provide new insights for future basic research and clinical interventions for related systemic diseases.

Resistin, a Novel Host Defense Peptide of Innate Immunity

Resistin, a cysteine-rich protein, expressed in adipocytes, was initially proposed as a link between obesity and diabetes in mice. In humans, resistin is considered to be a pro-inflammatory molecule expressed in immune cells, which plays a regulatory role in many chronic inflammatory diseases, metabolic diseases, infectious diseases, and cancers. However, increasing evidence shows that resistin functions as a host defense peptide of innate immunity, in terms of its wide-spectrum anti-microbial activity, modulation of immunity, and limitation of microbial product-induced inflammation. To date, the understanding of resistin participating in host defense mechanism is still limited. The review aims to summarize current knowledge about the biological properties, functions, and related mechanisms of resistin in host defense, which provides new insights into the pleiotropic biological function of resistin and yields promising strategies for developing new antimicrobial therapeutic agents.

Levels of proinflammatory chemokines and advanced glycation end products in patients with type-2 diabetes mellitus undergoing fixed orthodontic treatment

OBJECTIVES

To explore the effect of diabetic status on the proinflammatory chemokine profile and levels of advanced glycation end products (AGEs) in gingival crevicular fluid (GCF) derived from patients with type 2 diabetes mellitus (T2DM) undergoing fixed orthodontic treatment.

MATERIALS AND METHODS

Two groups, nondiabetic and T2DM, were included. Their demographics, biochemical parameters including hemoglobin A1c, fasting blood glucose, body mass index, and oral hygiene status were recorded. GCF sampling was performed after 2 months of placement of stainless steel archwires and chemokines (primary outcome) were quantified using Human Magnetic Luminex multiplex assay. Secondary outcomes were assessment of clinical periodontal status, unstimulated whole saliva flow rate, and GCF flow rate.

RESULTS

Twenty participants each in the nondiabetic (mean age: 26.4 years) and T2DM (mean age: 27.2 years) groups gave consent to participate. Biochemical analysis showed significantly increased values for hemoglobin A1c (P < .001), fasting blood glucose (P < .0001), body mass index(P = .047), and unstimulated whole saliva flow rate (P = .041) for the T2DM group. Bleeding on probing was significantly higher in participants with T2DM than nondiabetic participants (P = .039). Resistin (P = .034) and AGEs (P = .017) showed significantly higher values in participants with T2DM than nondiabetic participants. Pearson correlation analysis indicated a significant positive correlation between resistin (r = 0.1372; P = .022) and AGEs (r = 0.0194; P = .0186) against bleeding on probing in participants with T2DM.

CONCLUSIONS

The biochemical profile of GCF samples from participants with T2DM after alignment demonstrated higher levels of resistin and AGEs. The data suggest the presence of a proinflammatory response in patients with T2DM undergoing fixed orthodontic treatment.

Resistin Is Increased in Periodontal Cells and Tissues: In Vitro and In Vivo Studies

Resistin, a proinflammatory adipokine, is elevated in many inflammatory diseases. However, little is known about its performance in periodontitis. The present study is aimed at evaluating resistin expression and synthesis in periodontal cells and tissues under inflammatory/microbial stress in addition to its effects on the periodontium. In vivo, 24 male rats were randomly divided into two groups: control and ligature-induced periodontal disease. After 6 and 12 days, animals were sacrificed to analyze gene expression of adipokines, bone loss, inflammation, and resistin synthesis. In vitro, human periodontal ligament (PDL) fibroblasts were used to evaluate the expression of resistin after inflammatory stimuli. In addition, PDL fibroblasts were exposed to resistin to evaluate its role on soft and hard tissue metabolism markers. The periodontitis group demonstrated significant bone loss, an increase in the number of inflammatory cells and vascular structures, an increase in resistin expression and synthesis, and a decrease in the expression of adiponectin, leptin, and its functional receptor. PDL fibroblasts showed a significant increase in resistin expression and synthesis in response to the inflammatory stimulus by IL-1β. Resistin induced an increase in cytokine expression and a decrease in the regulation of some hard tissue and matrix formation genes in PDL fibroblasts. These data indicate that resistin is produced by periodontal cells and tissues, and this effect is enhanced by inflammatory stimuli. Moreover, resistin seems to interfere with soft and hard tissue metabolism during periodontitis by reducing markers related to matrix formation and bone tissue.

Gingival crevicular fluid and salivary resistin and tumor necrosis factor-alpha levels in obese children with gingivitis

BACKGROUND

This study aimed to evaluate the levels of resistin and tumor necrosis factor-alpha (TNF-α) in gingival crevicular fluid (GCF) and saliva of obese children with gingivitis.

METHODS

One-hundred and thirty children (65 obese and 65 normal weight; age range 8 to 12 years) were recruited for the study. The children were classified into four subgroups based on their body mass and periodontal status; 1) obese children with gingivitis (OG, n = 33); 2) obese children with healthy periodontium (OH, n = 32); 3) normal weight children with gingivitis (NWG, n = 32); 4) normal weight children with healthy periodontium (NWH, n = 33). Body mass index (BMI) percentile, probing pocket depth (PPD), gingival index (GI), and plaque index (PI) were recorded. Resistin and TNF-α were analyzed in GCF and saliva samples by ELISA.

RESULTS

Obese children had higher BMI percentiles than normal weight children (p < 0.0001). PPD, GI, PI, GCF volume, GCF, and salivary resistin and TNF-α levels were similar between obese and normal weight children (P > 0.05). OG and NWG subgroups had significantly higher GI, PI, GCF volume, GCF resistin total amounts, and salivary resistin concentrations but lower GCF resistin and TNF-α concentrations than OH and NWH (P < 0.0001 for all). GCF resistin total amounts were positively correlated with GI, PI, and GCF TNF-α total amounts (P < 0.05).

CONCLUSIONS

To our knowledge, this is the first study evaluated the levels of resistin in GCF and saliva of children. Obesity is not associated with GCF and salivary resistin and TNF-α levels in children in the presence of gingival inflammation.

Porphyromonas gingivalis lipopolysaccharide induces pro-inflammatory adipokine secretion and oxidative stress by regulating Toll-like receptor-mediated signaling pathways and redox enzymes in adipocytes

Gut microbiota LPS contributes to obesity-related chronic inflammation and oxidative stress, promoting insulin resistance. Periodontal disease also represents a risk factor for type 2 diabetes and is associated with obesity. This study compared the effect of LPS from P. gingivalis periodontopathogen and E. coli enterobacteria on inflammatory adipokine secretion and redox status of 3T3-L1 adipocytes. We found that both LPS activated TLR2- and TLR4-mediated signaling pathways involving MyD88 adaptor and NFκB transcription factor, leading to an increased secretion of leptin, resistin, IL-6 and MCP-1. These effects were partly blocked by inhibitors targeting p38 MAPK, JNK and ERK. Moreover, P. gingivalis LPS reduced adiponectin secretion. Both LPS also enhanced ROS production and the expression of NOX2, NOX4 and iNOS genes. P. gingivalis LPS altered catalase gene expression. Collectively, these results showed that LPS of periodontal bacteria induced pro-inflammatory adipokine secretory profile and oxidative stress in adipocytes which may participate to obesity-related insulin resistance.

The Relation between Periodontopathogenic Bacterial Levels and Resistin in the Saliva of Obese Type 2 Diabetic Patients

This study aims to investigate the relation between resistin and periodontopathogenic bacterial levels in the saliva of obese adults compared to healthy control and to examine whether salivary resistin can serve as a biomarker of type 2 diabetes in obese patients. A total of 78 saliva samples were collected from patients attending to the University Dental Hospital, Sharjah, UAE. The patients were divided into three equal groups: obese diabetics, obese nondiabetics, and nonobese nondiabetic control. Salivary resistin was measured using ELISA. The levels of bacterial species associated with periodontitis (Treponema denticola, Porphyromonas gingivalis, Tannerella forsythia, and Actinobacillus actinomycetemcomitans) and gingivitis (Fusobacterium spp.) were measured using real-time PCR. Both salivary resistin and periodontopathogenic bacteria including Fusobacterium spp., P. gingivalis, and T. forsythia were detected in significantly higher quantities in the obese patients (diabetics and nondiabetics) than nonobese nondiabetic control. Resistin concentrations were significantly correlated with BMI; however, its level was not correlated with the blood glucose. In this study, high salivary resistin was associated with obesity, which is a major predisposing factor for type 2 diabetes and also a risk factor for oral diseases. The high levels of salivary periodontopathogenic bacteria could upregulate the local release of salivary resistin in obese people.

Resistin as potential biomarker for chronic periodontitis: A systematic review and meta-analysis

OBJECTIVES

To determine the serum and gingival crevicular fluid (GCF) levels of resistin between individuals with chronic periodontitis (CP) and those without CP, and to evaluate the role of resistin in CP.

MATERIALS AND METHODS

The addressed focused question was "Is there a difference in the resistin levels between individuals with CP and those without CP?" four electronic databases: Medline, PubMed (National Institutes of Health, Bethesda), EMBASE, and Science direct databases from 1977 up to March 2016 for appropriate articles addressing the focused question. EMBASE and Medline were accessed using OVID interface which facilitated simultaneous search of text words, MeSH or Emtree. Unpublished studies (gray literature) were identified by searching the Open-GRAY database and references of the included studies (cross referencing) were performed to obtain new studies. In-vitro studies, animal studies, studies that reported levels of other cytokines but not resistin, letters to the editor and review papers were excluded.

RESULTS

Ten studies were included. Nine studies compared resistin levels between CP and periodontally healthy (H) individuals and reported higher mean serum and GCF levels of resistin in CP patients than the H controls. Two studies showed comparable resistin levels from GCF and serum between diabetes mellitus with CP (DMCP) and CP groups. Three studies included obese subjects and showed comparable serum and GCF resistin levels between obese subjects with CP (OBCP) and CP subjects.

CONCLUSIONS

CP patients were presented with elevated levels of GCF or serum resistin as compared with H individuals. Resistin modulates inflammation in chronic periodontal disease and may be used as surrogate measure to identify subjects at risk for periodontitis. Resistin levels in patients with CP and systemic inflammatory disorders such as diabetes, obesity, or rheumatoid arthritis was not significantly higher than the levels in patients with only CP.

A review of the evidence for pathogenic mechanisms that may link periodontitis and diabetes

AIMS

To review the evidence for the molecular and cellular processes that may potentially link periodontal disease and diabetes. The pathogenic roles of cytokines and metabolic molecules (e.g. glucose, lipids) are explored and the role of periodontal bacteria is also addressed. Paradigms for bidirectional relationships between periodontitis and diabetes are discussed and opportunities for elaborating these models are considered.

METHODS

Database searches were performed using MeSH terms, keywords, and title words. Studies were evaluated and summarized in a narrative review.

RESULTS

Periodontal microbiota appears unaltered by diabetes and there is little evidence that it may influence glycaemic control. Small-scale clinical studies and experiments in animal models suggest that IL-1β, TNF-α, IL-6, OPG and RANKL may mediate periodontitis in diabetes. The AGE-RAGE axis is likely an important pathway of tissue destruction and impaired repair in diabetes-associated periodontitis. A role for locally activated pro-inflammatory factors in the periodontium, which subsequently impact on diabetes, remains speculative.

CONCLUSION

There is substantial information on potential mechanistic pathways which support a close association between diabetes and periodontitis, but there is a real need for longitudinal clinical studies using larger patient groups, integrated with studies of animal models and cells/tissues in vitro.

Local and serum levels of adipokines in patients with obesity after periodontal therapy: one-year follow-up

AIM

This study evaluated the effects of scaling and root planing (SRP) on gingival crevicular fluid (GCF) and serum levels of adipokines in patients with chronic periodontitis (CP) with or without obesity.

METHODS

Twenty patients with obesity and 20 patients without obesity, all with CP, received SRP. Serum and GCF levels of resistin, adiponectin, leptin, tumour necrosis factor [TNF]-α and interleukin [IL]-6 were evaluated by enzyme-linked immunosorbent assay at baseline, 3, 6 and 12 months post-therapy.

RESULTS

SRP reduced the amounts of TNF-α in deep sites and increased the concentration of adiponectin in shallow sites of non-obese patients (p < 0.05). SRP increased the concentrations of TNF-α and leptin in patients with obesity (p < 0.05). GCF levels of TNF-α were higher in patients with obesity than in patients without obesity at all time-points (p < 0.05). There were no changes in serum levels of any adipokines for any group after therapy (p > 0.05). Patients with obesity exhibited higher serum levels of leptin at all time-points and IL-6 at 3 months post-therapy (p < 0.05).

CONCLUSIONS

Obesity may modulate systemic and periodontal levels of adipokines in favour of pro-inflammation, independently of periodontal therapy. SRP did not affect the circulating levels of adipokines in patients with or without obesity.

YKL-40 level in gingival crevicular fluid from patients with periodontitis and type 2 diabetes

OBJECTIVE

YKL-40 is a chitin-binding glycoprotein, the level of which increases in inflammatory diseases, diabetes mellitus (DM), cardiovascular diseases, and tumors. Gingival crevicular fluid (GCF) contains many proteins and markers of periodontitis. The purpose of this study was to investigate YKL-40 level in GCF from patients with periodontitis and DM and the association between YKL-40 level and chronic periodontitis (CP) or DM.

SUBJECTS AND METHODS

The subjects were 121 patients with DM, CP, DM and periodontitis (DM-P), and healthy subjects (H). GCF was collected using paper strips after the sites for GCF collection were clinically evaluated for probing depth (PD), gingival index (GI), and bleeding on probing (BOP). YKL-40 in GCF was identified by Western blotting, and its level was determined by ELISA.

RESULTS

YKL-40 was contained in GCF samples from H, DM, CP, and DM-P sites, and its levels (amount and concentration) in CP and DM-P were significantly higher than those in H and DM. GCF YKL-40 level significantly correlated with PD and GI, and its level in BOP-positive sites was significantly higher than that in BOP-negative ones.

CONCLUSIONS

GCF YKL-40 level was elevated in periodontitis, but not DM. YKL-40 in GCF may be an inflammatory marker for periodontitis.

Gingival crevicular fluid and serum levels of resistin in obese and non-obese subjects with and without periodontitis and association with single nucleotide polymorphism at -420

OBJECTIVE

Resistin is an adipocytokine, which have been studied for its role in insulin resistance and recently in inflammation. The present study was designed to study the gingival crevicular fluid (GCF) and serum levels of resistin in obese and non-obese subjects with and without periodontitis and to further study the association of single-nucleotide polymorphism (SNP) -420 with these levels.

MATERIALS AND METHODS

A total of 90 subjects were divided based on gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), body mass index (BMI) and waist circumference (WC) into: Non-obese healthy (Group 1, n = 30, BMI ≤ 22.9 and WC < 90 for male subjects and < 80 for female subjects, PPD ≤ 3 mm, CAL = 0, GI = 0), non-obese periodontitis (Group 2, n = 30, BMI ≤ 22.9 and WC < 90 for male subjects and < 80 for female subjects, PPD ≥ 5 mm, CAL ≥ 3, GI ≥ 1) and obese periodontitis (Group 3, n = 30, BMI ≥ 25.0 and WC ≥ 90 for male subjects and ≥ 80 for female subjects, PPD ≥ 5 mm, CAL ≥ 3, GI ≥ 1). The GCF and serum levels of resistin were quantified using enzyme-linked immunosorbent assay and compared amongst the study groups. Further, the association of the resistin levels with periodontal inflammation and SNP at -420 was studied.

RESULTS

The mean resistin levels were highest in Group 3 (14.66 ± 5.93 ng/ml and 9.99 ± 7.22 μg/ml), followed by Group 2 (12.34 ± 4.31 ng/ml and 7.47 ± 3.94 μg/ml) and least in Group 1 (7.09 ± 3.34 ng/ml and 6.05 ± 3.61 μg/ml) in serum and GCF respectively. The levels positively correlated with GI, PPD, CAL, BMI, WC and waist-hip ratio (r < 0.6). The SNP at -420 showed that GG genotype was associated with Group 2 and 3 i.e. periodontitis, while CC genotype was associated with periodontal health. The GG genotype was also associated with high serum resistin levels as compared to CC and CG genotypes.

CONCLUSION

Resistin levels increased with periodontal inflammation indicating its possible inflammatory role in periodontitis. GG genotype at -420 is associated with increased serum resistin and with periodontal disease. Thus, further research is needed to study GG genotype and increased serum and GCF resistin levels as putative risk factors for periodontal diseases.

Role of resistin in the inflammatory response induced by nicotine plus lipopolysaccharide in human periodontal ligament cells in vitro

BACKGROUND AND OBJECTIVE

Resistin was recently reported to play a role in inflammation-related diseases such as arthritis. However, the precise role of resistin in chronic inflammatory diseases, such as periodontal disease, remains unclear. The aim of this study was to investigate the combined effects of nicotine and lipopolysaccharide (LPS) on the expression of resistin and to assess whether resistin expression influences the levels of inflammatory cytokines, extracellular matrix (ECM) molecules and MMPs in human periodontal ligament cells (PDLCs) stimulated with both nicotine and LPS.

MATERIAL AND METHODS

PDLCs were pretreated with isoproterenol or resistin-specific small interfering RNA (siRNA), stimulated with LPS plus nicotine for 24 h, and then monitored for the production of inflammatory mediators. The concentrations of prostaglandin E2 (PGE2) and nitric oxide (NO) were measured by radioimmunoassay and the Griess method, respectively. RT-PCR and western blot analysis were used to measure the levels of mRNA and protein, respectively. Western blot analysis was also used to assess the activation of various signal-transduction pathways.

RESULTS

Treatment with nicotine plus LPS up-regulated the expression of resistin mRNA and the production of resistin protein in PDLCs in a time- and concentration-dependent manner. Isoproterenol-mediated interference with the function of resistin, or siRNA-mediated knockdown of resistin expression, markedly attenuated the LPS plus nicotine-mediated stimulation of PGE2 and NO production, the production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase proteins and the expression of proinflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1β, IL-6 and IL-12] and MMPs (MMP-1, MMP-2 and MMP-9); however, these treatments restored the expression of ECM molecules. Furthermore, pretreatment with isoproterenol or resistin-specific siRNA blocked nicotine plus LPS-induced activation of phosphoinositide-3-kinase, glycogen synthase kinase-3 beta, β-catenin, p38, ERK, JNK and nuclear factor-κB.

CONCLUSION

This is the first study to show that the inhibition of resistin, by either a pharmacological or a genetic silencing approach, has anti-inflammatory effects. These effects include decreased levels of inflammatory cytokines and the prevention of ECM breakdown in a nicotine plus LPS-stimulated PDLC model.

Multifactorial relationship of obesity and periodontal disease

Obesity is a chronic disease of mutifactorial origin, where there is increase in body fat. Periodontitis is an inflammatory disease of tooth supporting tissues resulting in destruction of periodontal ligament and alveolar bone. Periodontitis and obesity are both chronic health problems and the literature supports this association. A hyperinflammatory state observed in obesity is proposed as a mechanism to explain this association. This low grade inflammation in obese subjects triggers the worsening of non transmissible chronic diseases like periodontitis. So the aim of this article is to get the overview of association between adipose tissue derived cytokines and periodontal disease.

Resistin: a potential biomarker for periodontitis influenced diabetes mellitus and diabetes induced periodontitis

Biomarkers are highly specific and sensitive indicators of disease activity. Resistin is a recently discovered adipocytokine, having a potent biomarker quality. Initially resistin was thought to be produced by adipocytes alone; however, emerging evidence suggests that it is also produced in abundance by various cells of the immunoinflammatory system, indicating its role in various chronic inflammatory diseases. Data suggests that resistin plays a role in obesity, insulin resistance, cardiovascular diseases, and periodontitis. Resistin derived its name from the original observation that it induced insulin resistance (resist-in: resist insulin) in mice and is downregulated in mature murine adipocytes cultured in the presence of insulin sensitizing drugs like thiazolidinediones. It is well recognized that obesity, is associated with insulin resistance and diabetes. A three-way relationship has been established between diabetes, obesity and periodontitis. Recent evidence also suggests an association between obesity and increased risk for periodontitis. Our previous research showed incremental elevation of resistin with periodontal disease activity and a reduced level of resistin, after periodontal therapy. Thus resistin would be one of the molecular links connecting obesity, periodontitis, and diabetes and may serve as a marker that links periodontal disease with other systemic diseases. A Medline/PubMed search was carried out for keywords “Diabetes Mellitus,” “Periodontitis,” and “Resistin,” and all relevant research papers from 1990 in English were shortlisted and finalized based on their importance. This review provides an insight into the biological action of resistin and its possible role in periodontitis influenced diabetes mellitus and diabetes induced periodontitis.

Resistin in serum and gingival crevicular fluid as a marker of periodontal inflammation and its correlation with single-nucleotide polymorphism in human resistin gene at -420

AIMS

Resistin is an adipocytokine, which have been studied for its role in insulin resistance and recently in inflammation. The aim of the present study is to assess the concentration of resistin in serum and gingival crevicular fluid (GCF) and to compare the levels between subjects with and without periodontitis and type 2 diabetes mellitus (T2DM) and to further correlate the resistin levels with the single-nucleotide polymorphism (SNP) at -420.

SETTING AND DESIGNS

A total of 96 subjects (48 males and 48 females) were divided on the basis of gingival index (GI), probing pocket depth (PD), clinical attachment level (CAL) and hemoglobin A1c levels into healthy (group 1, n = 24), uncontrolled-diabetes related periodontitis (group 2, n = 24), controlled-diabetes related periodontitis (group 3, n = 24) and chronic periodontitis without T2DM (group 4, n = 24).

MATERIALS AND METHODS

The GCF and serum levels of resistin were quantified using the enzyme-linked immunosorbent assay and compared among the study groups. Further, the association of the resistin levels with periodontal inflammation and SNP at -420 was studied.

RESULTS AND CONCLUSION

The resistin levels in GCF and serum from patients with periodontitis or diabetes mellitus related periodontitis (controlled or uncontrolled) were higher than that of healthy subjects and correlated positively with GI. Further, subjects with GG genotype at -420 showed significantly higher GI, PD, CAL as compared with genotype group CC. Resistin was detected in all serum and GCF samples and was significantly higher in periodontitis. Further, GG genotype at -420 was associated significantly with periodontal inflammation and resistin levels.

Porphyromonas gingivalis and Escherichia coli lipopolysaccharide causes resistin release from neutrophils

OBJECTIVES

It was reported that periodontitis is associated with increased serum resistin levels. We examined whether there was a difference between the release of resistin from neutrophils incubated lipopolysaccharide (LPS) from Porphyromonas gingivalis and with LPS from Escherichia coli, and which cell-surface receptors and intracellular kinases were involved in this process.

METHODS

Several concentrations of P. gingivalis-LPS and E. coli-LPS were added to neutrophils, supernatant from cultured neutrophils was collected, and resistin levels were measured by ELISA. To examine signaling pathways, neutrophils were pretreated with monoclonal antibodies against CD14, CD18, TLR2, and TLR4, and specific inhibitors of PI3K and MAPKs.

RESULTS

Resistin release from neutrophils was induced both by P. gingivalis-LPS and E. coli-LPS, but resistin release by P. gingivalis-LPS was weaker than E. coli-LPS in low concentrations. Resistin release was decreased by pretreatment with monoclonal antibodies against CD14, CD18, and TLR4, but not by TLR2. Moreover, it was decreased by inhibitors of PI3K, JNK, and p38 MAPK, but not by ERK1/2.

CONCLUSIONS

Resistin release from neutrophils was induced by both P. gingivalis-LPS and E. coli-LPS. This was decreased by CD14, CD18, and TLR4 and was dependent on PI3K, JNK, and p38 MAPK, but not on ERK1/2 in intracellular pathways of neutrophils.