Impact of periodontitis on chemokines in smokers

CCL5's Role in Periodontal Disease: A Narrative Review

Persistent host inflammatory and immune responses to biofilm play a critical role in the mechanisms that govern soft and hard tissue destruction in periodontal disease. Among the less explored facets of these mechanisms are chemokines, including CCL5 (C-C motif chemokine ligand 5), also known as RANTES (regulated on activation, normal T cell expressed and secreted), a proinflammatory CC subfamily chemokine synthesized by T lymphocytes. Despite its importance, there is currently no comprehensive review of the role of CCL5 in periodontitis in the literature. Therefore, this paper aims to fill this gap by summarizing the existing knowledge on the involvement of CCL5 in the onset and progression of periodontitis. In addition, we aim to stimulate interest in this relatively overlooked factor among periodontitis researchers, potentially accelerating the development of drugs targeting CCL5 or its receptors. The review examines the association of CCL5 with periodontitis risk factors, including aging, cigarette smoking, diabetes, and obesity. It discusses the involvement of CCL5 in pathological processes during periodontitis, such as connective tissue and bone destruction. The data show that CCL5 expression is observed in affected gums and gingival crevicular fluid of periodontitis patients, with bacterial activity contributing significantly to this increase, but the reviewed studies of the association between CCL5 expression and periodontal disease have yielded inconclusive results. Although CCL5 has been implicated in the pathomechanism of periodontitis, a comprehensive understanding of its molecular mechanisms and significance remains elusive, hindering the development of drugs targeting this chemokine or its receptors.

The impact of smoking on periodontitis patients' GCF/serum cytokine profile both before and after periodontal therapy: a meta-analysis

BACKGROUND

Smoking is an established modifying factor for the host immune response of periodontitis patients. However, its exact influence remains unclear. We aimed to compare the cytokine profile of periodontitis patients with and without smoking habits both before and after periodontal therapy to preliminarily explore its influence on the host immune response to periodontitis.

METHODS

The protocol of the present meta-analysis was registered in the International Prospective Register of Systematic Reviews (PROSPERO) under the code CRD42021255656. Meta-analysis was performed for each cytokine if at least three studies were included. We synthesized the evidence to compare the cytokine profile of periodontitis with and without smoking both in gingival cervical fluid (GCF) and serum to explore the impact of smoking on periodontitis both locally and systemically. Moreover, we also compared the cytokine profile of the two groups of patients after periodontal therapy to explore the effect of smoking on the outcome of periodontal therapy.

RESULTS

Fifteen studies were included in this meta-analysis. We found that there was no significant difference between the two groups of patients in the baseline cytokine profile. However, after periodontal therapy, smoking periodontitis patients showed significantly higher IL-1β levels in their GCF than nonsmoking patients.

DISCUSSION

There was no significant difference between smoking and nonsmoking periodontitis patients in the baseline cytokine profile. However, after periodontal therapy, smoking periodontitis patients showed significantly higher IL-1β levels in their GCF than nonsmoking patients, which indicates that smoking may impair the response of periodontitis to periodontal treatment.

Do smokers have a different gingival crevicular fluid cytokine/chemokine profile than nonsmokers in clinically healthy periodontal sites? A systematic review and meta-analysis

OBJECTIVES

Assessing the evidence and comparing the levels of cytokines in gingival crevicular fluid (GCF) of periodontal healthy sites of smokers and nonsmokers.

MATERIALS AND METHODS

Seven databases were surveyed for observational studies up to April 8, 2021. Studies comparing cytokine levels on GCF in periodontally healthy sites of smokers vs. nonsmokers were included in the study. The risk of bias was evaluated using NIH (2014) tool. For meta-analyses, levels in GCF were analyzed, followed by evidence certainty assessment using the GRADE approach.

RESULTS

Eighteen studies were included for qualitative evaluation, and eight were included in meta-analysis. Qualitatively, despite high heterogeneity and risk of bias observed among the studies, most of them presented no significant difference in the gingival crevicular cytokine fluid levels between groups. Regarding meta-analyses, interleukin-8 (IL-8) and superoxide dismutase (SOD) levels in GCF were analyzed. The significant difference was observed only in SOD levels, where heavy smokers had lower levels compared to nonsmokers (MD - 30.06 [- 40.17, - 19.96], p = 0.07, 95%CI), as well as light smokers had lower levels compared to nonsmokers (MD - 15.22 [- 16.05, - 14.39], p < 0.00001, 95%CI).

CONCLUSION

No distinct GCF cytokine profiles were detected for smokers and non-smokers. However, despite the limitations observed in the included studies, lower levels of SOD were identified in smokers.

CLINICAL RELEVANCE

Indicating a distinct GCF profile of cytokines in periodontal healthy smokers may help to understand the mechanism whereby smoking may affect the host response.

Salivary and serum markers of angiogenesis in periodontitis in relation to smoking

OBJECTIVE

Angiogenesis is essential in maintenance of periodontal homeostasis, and it is regulated by growth factors and cytokines, including basic fibroblast growth factor (b-FGF), endoglin, platelet and endothelial cell adhesion molecule (PECAM-1), vascular endothelial growth factor (VEGF), soluble intercellular adhesion molecule-1 (sICAM-1), and soluble vascular cell adhesion molecule-1 (sVCAM-1). In this study, the salivary and serum concentrations of these angiogenesis-related proteins in relation to smoking and periodontitis were examined.

MATERIAL AND METHODS

Full-mouth periodontal status together with unstimulated whole saliva and serum samples was collected from 78 individuals, including 40 periodontitis patients (20 smokers and 20 nonsmokers) and 38 periodontally healthy controls (20 smokers and 18 nonsmokers). The Luminex®-xMAP™ technique was used for protein analyses.

RESULTS

Concentrations of all tested proteins in saliva as well as VEGF in serum were significantly higher in periodontitis patients than in healthy controls. In smokers, serum concentrations of endoglin (p = 0.017) and sICAM-1 (p = 0.001) were elevated in comparison to nonsmokers. After adjusting for smoking and gender, periodontitis associated significantly with salivary concentrations of b-FGF, PECAM-1, VEGF, sICAM-1, and sVCAM-1 (p < 0.01).

CONCLUSION

Taken together, salivary concentrations of b-FGF, PECAM-1, and VEGF associate with periodontitis. The suppressive effect of smoking on salivary marker levels is limited to periodontitis patients only.

CLINICAL RELEVANCE

Smoking-related suppression of salivary marker levels is observed only in periodontitis patients.

The effect of smoking on inflammatory cell infiltrate subtypes in gingival tissue of patients with chronic periodontitis

Background

Examinations on blood samples and gingival crevicular fluid of subjects with chronic periodontitis showed that smoking increased production of cytokines.

Objective

To evaluate the expression of immune markers on mononuclear inflammatory cell infiltrate at periodontitis and healthy tissue among smoking and non-smoking subjects.

Methods

This case-control study was performed on 41 patients who referred to a clinic of periodontology at a Mashhad dental school in Iran in 2016. The participants were all of Iranian Khorasanian ethnicity with age range of 35–65 years. Gingival biopsies were obtained during routine periodontal flap procedure. Immunohistochemistry using markers of CD20, CD3, CD68, and CD45RO was carried out. Data was analyzed by SPSS version 15, using one-way ANOVA and Tukey HSD test.

Results

Nonsmoker subjects showed significantly greater numbers of CD20+, CD68+, CD3+ cells compared to smoker subjects, both at healthy and periodontitis tissue biopsies (p<0.00), whereas there was no significant difference in terms of CD45RO (p=0.120).

Conclusion

Cigarette smoking, results in infiltrative mononuclear chronic inflammatory cells reduction in connective periodontium.

The effect of smoking on inflammatory and bone remodeling markers in gingival crevicular fluid and subgingival microbiota following periodontal therapy

BACKGROUND AND OBJECTIVE

Periodontal health is mediated by suppressing microorganisms inducing a local inflammatory host response. Smoking may impair this process. This study compares gingival crevicular fluid levels of inflammatory and bone remodeling markers in heavy smokers and non-smokers following active and supportive periodontal therapy in patients with chronic periodontitis.

MATERIAL AND METHODS

Gingival crevicular fluid and subgingival plaque were collected from the deepest periodontal pocket in 50 patients, 25 smokers and 25 non-smokers, at baseline (T0), following active (T1) and 12 mo of supportive periodontal therapy (T2). Smoking status was validated measuring serum cotinine levels. Gingival crevicular fluid levels of 27 inflammatory and two bone remodeling markers were analyzed using multiplex and singleplex micro-bed immunoassays, and subgingival plaque samples using checkerboard DNA-DNA hybridization. Amounts of markers in smokers and non-smokers were compared calculating the effect size.

RESULTS

Expression of inflammatory and bone-remodeling markers in smokers demonstrated an overall reduced effect size at T0 and T2 (p < 0.001). In particular, proinflammatory markers (p < 0.001), chemokines (p = 0.007) and growth factors (p = 0.003) at T0, osteoprotegerin (p = 0.003) at T1, proinflammatory markers (p = 0.019) and chemokines (p = 0.005) at T2. At T2, interleukin-8 was detected in significantly higher levels in smokers. Ten different markers in non-smokers and none in smokers responded to periodontal therapy (p < 0.05). An overall negative association was revealed between smoking and subgroups of markers at sites presenting ≥ 10⁵ red complex periodontal microbial species.

CONCLUSION

Except for an upregulation of interleukin-8, smokers exhibited reduced gingival crevicular fluid levels of several inflammatory markers at baseline and following active and supportive periodontal therapy. Only inflammatory responses in non-smokers adapted to periodontal therapy. Apparently, there seems to be an immunosuppressant effect of smoking regulating the local inflammatory response and bone remodeling markers captured in gingival crevicular fluid following periodontal therapy.

Integrated biomarker profiling of smokers with periodontitis

BACKGROUND

In the context of precision medicine, understanding patient-specific variation is an important step in developing targeted and patient-tailored treatment regimens for periodontitis. While several studies have successfully demonstrated the usefulness of molecular expression profiling in conjunction with single classifier systems in discerning distinct disease groups, the majority of these studies do not provide sufficient insights into potential variations within the disease groups.

AIM

The goal of this study was to discern biological response profiles of periodontitis and non-periodontitis smoking subjects using an informed panel of biomarkers across multiple scales (salivary, oral microbiome, pathogens and other markers).

MATERIAL & METHODS

The investigation uses a novel ensemble classification approach (SVA-SVM) to differentiate disease groups and patient-specific biological variation of systemic inflammatory mediators and IgG antibody to oral commensal and pathogenic bacteria within the groups.

RESULTS

Sensitivity of SVA-SVM is shown to be considerably higher than several traditional independent classifier systems. Patient-specific networks generated from SVA-SVM are also shown to reveal crosstalk between biomarkers in discerning the disease groups. High-confidence classifiers in these network abstractions comprised of host responses to microbial infection elucidated their critical role in discerning the disease groups.

CONCLUSIONS

Host adaptive immune responses to the oral colonization/infection contribute significantly to creating the profiles specific for periodontitis patients with potential to assist in defining patient-specific risk profiles and tailored interventions.

Gingival crevicular fluid levels of cytokines/chemokines in chronic periodontitis: a meta-analysis

AIMS

To compare gingival crevicular fluid (GCF) cytokines/chemokines levels between periodontally healthy subjects and subjects diagnosed with chronic periodontitis (ChP), before and after non-surgical periodontal treatment, and to establish their predictive value for periodontal disease progression.

METHODS

Studies indexed in MEDLINE and EMBASE published in English, Portuguese and Spanish were eligible for this review. Database searches up to December 2015, and manual search of the reference list from reviews and selected articles was performed. Only studies providing data on GCF cytokines/chemokines levels in subjects diagnosed with ChP and periodontally healthy controls were included. Cross-sectional, case series, single-arm clinical studies, randomized controlled trials and prospective/retrospective cohort studies were included. Meta-analyses were conducted for those cytokines/chemokines with at least three available studies.

RESULTS

GCF levels of IL-1β, IL-6, IFN-γ and MCP-1/CCL2 were significantly higher in subjects diagnosed with ChP than periodontally healthy subjects. A significant decrease in GCF levels of IL-1β and IL-17 was observed after non-surgical periodontal treatment, whereas a significant increase was observed for IL-4.

CONCLUSION

Evidence for significant differences between periodontal health and ChP was observed for a few cytokines and one chemokine. No conclusions could be drawn with regards to increased risk of disease progression.

Increased Eotaxin and MCP-1 Levels in Serum from Individuals with Periodontitis and in Human Gingival Fibroblasts Exposed to Pro-Inflammatory Cytokines

Periodontitis is a chronic inflammatory disease of tooth supporting tissues resulting in periodontal tissue destruction, which may ultimately lead to tooth loss. The disease is characterized by continuous leukocyte infiltration, likely mediated by local chemokine production but the pathogenic mechanisms are not fully elucidated. There are no reliable serologic biomarkers for the diagnosis of periodontitis, which is today based solely on the degree of local tissue destruction, and there is no available biological treatment tool. Prompted by the increasing interest in periodontitis and systemic inflammatory mediators we mapped serum cytokine and chemokine levels from periodontitis subjects and healthy controls. We used multivariate partial least squares (PLS) modeling and identified monocyte chemoattractant protein-1 (MCP-1) and eotaxin as clearly associated with periodontitis along with C-reactive protein (CRP), years of smoking and age, whereas the number of remaining teeth was associated with being healthy. Moreover, body mass index correlated significantly with serum MCP-1 and CRP, but not with eotaxin. We detected higher MCP-1 protein levels in inflamed gingival connective tissue compared to healthy but the eotaxin levels were undetectable. Primary human gingival fibroblasts displayed strongly increased expression of MCP-1 and eotaxin mRNA and protein when challenged with tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β), key mediators of periodontal inflammation. We also demonstrated that the upregulated chemokine expression was dependent on the NF-κΒ pathway. In summary, we identify higher levels of CRP, eotaxin and MCP-1 in serum of periodontitis patients. This, together with our finding that both CRP and MCP-1 correlates with BMI points towards an increased systemic inflammatory load in patients with periodontitis and high BMI. Targeting eotaxin and MCP-1 in periodontitis may result in reduced leukocyte infiltration and inflammation in periodontitis and maybe prevent tooth loss.