Evaluation of chemokines and receptors in gnotobiotic root canal infection by F. nucleatum and E. faecalis.

The present study aims to evaluate the longitudinal effects of induced experimental infections in gnotoxenic animals on the expression of inflammatory chemokines and their receptors in periradicular tissues. The null hypothesis tested was that Enterococcus faecalis and Fusobacterium nucleatum had no effect on CCR5, CCL5, CXCL10, CCL2/MCP-1, CXCR2 and CCR1 expression. Two groups of five animals (n = 5) aged between 8 and 12 weeks were used in this study. The animals were anaesthetized, and coronary access was performed in the first molar on the right and left sides. Microorganisms were inoculated into the left molar, and the right molar was sealed without contamination to function as a control. Animals were sacrificed 7 and 14 days after infection, and periapical tissues were collected. The cytokine mRNA expression levels were assessed using real-time PCR. The chemokine mRNA expression levels demonstrated that the experimental infection was capable of inducing increased chemokine expression on day 7 compared to that on day 14, except for CCR5 and CCL5, which showed no changes. The gnotoxenic animal model proved to be effective and allowed evaluation of the immune response against a known infection. Additionally, this study demonstrates that gene expression of chemokines and their receptors against the experimental infection preferentially prevailed during the initial phase of induction of the periradicular alteration (i.e., on day 7 post-infection).

Experimental furcal perforation treated with mineral trioxide aggregate plus selenium: immune response.

The aim of this study is to evaluate the expression of cytokines in response to mineral trioxide aggregate (MTA) plus selenium in germ-free mice with experimental furcal perforation. The first left maxillary molar was opened, and the furcal area was perforated and treated with post-MTA-Se (experimental group). The same surgical intervention was performed for the maxillary right first molar, which was treated with MTA (control group). Fifteen mice were sacrificed 7, 14, and 21 days after furcal perforation, and periapical tissue samples were collected. The mRNA expression levels of the cytokines TGF-ß, TNF-α, IFN-γ, HPRT, IL-10, IL-4, RANK, RANKL, IL-1, and IL-17 were assessed by using real-time polymerase chain reaction. In the experimental group, at 21-days post-MTA-Se sealing, the mRNA levels of TNF-α and IL-10 were upregulated compared with those in the control group (p < 0.05). Futher assessment revealed basal mRNA expression levels of IL-1α, IFN-γ, RANK, RANKL, IL-17A, IL-4, and TGF-ß, over long experimental times, in both the experimental and control groups (p > 0.05). In conclusion, MTA+Se sealing favoured increased expression of IL-10 and TNF-α at later time points (day 21).

Experimental furcal perforation treated with mineral trioxide aggregate plus selenium: immune response

Abstract The aim of this study is to evaluate the expression of cytokines in response to mineral trioxide aggregate (MTA) plus selenium in germ-free mice with experimental furcal perforation. The first left maxillary molar was opened, and the furcal area was perforated and treated with post-MTA-Se (experimental group). The same surgical intervention was performed for the maxillary right first molar, which was treated with MTA (control group). Fifteen mice were sacrificed 7, 14, and 21 days after furcal perforation, and periapical tissue samples were collected. The mRNA expression levels of the cytokines TGF-β, TNF-α, IFN-γ, HPRT, IL-10, IL-4, RANK, RANKL, IL-1, and IL-17 were assessed by using real-time polymerase chain reaction. In the experimental group, at 21-days post-MTA-Se sealing, the mRNA levels of TNF-α and IL-10 were upregulated compared with those in the control group (p < 0.05). Futher assessment revealed basal mRNA expression levels of IL-1α, IFN-γ, RANK, RANKL, IL-17A, IL-4, and TGF-β, over long experimental times, in both the experimental and control groups (p > 0.05). In conclusion, MTA+Se sealing favoured increased expression of IL-10 and TNF-α at later time points (day 21).

Assessment of Apical Expression of Alpha-2 Integrin, Heat Shock Protein, and Proinflammatory and Immunoregulatory Cytokines in Response to Endodontic Infection.

INTRODUCTION: The purpose of this study was to examine alpha-2 integrin, molecular mediators, cytokines, and chemokines from cells in periapical interstitial fluid from root canal infections before and after the reduction of the bacterial load using a cleaning procedure. METHODS: Subjects included 20 patients referred to the School of Dentistry at the Universidade Federal de Minas Gerais (Belo Horizonte, Minas Gerais, Brazil). Clinical samples were taken from teeth with pulp necrosis, and no patients had acute periapical symptoms at the time of the appointments. After cleaning and drying, 3 paper points were introduced into the root canal, passing passively through the root apex (2 mm) into the periapical tissues for 1 minute. The samples were collected immediately after root canal cleaning and 7 days later (restrained root canal bacterial load) to characterize those gene expressions using real-time polymerase chain reaction. RESULTS: Significantly lower levels of tumor necrosis factor alpha, chemokine ligand 5 (CCL5), chemokine ligand 2/monocyte chemotactic protein 1 (CCL2/MCP-1), and interleukin (IL)-8 in teeth with restrained bacterial loads (second collection) compared with the first collection were observed (P < .05). Similarly, the messenger RNA expression of the integrins secreted phosphoprotein 1 (SSP1)/ostepontin and focal adhesion kinase (FAK) decreased in samples from the second collection (P < .05). The messenger RNA for the regulatory cytokine IL-10 was significant higher in samples from the second collection (day 7) compared with the first collection (day 0) (P < .05). Messenger RNA expression of IL-1ß, IL-17A, interferon gamma, alpha-2 integrin, and Hsp47/SERPINH1 were similar at both time points (P > .05). CONCLUSIONS: These findings suggest that after reducing the root canal bacterial load a decrease in the inflammatory response took place in the periapical lesions.

Periapical cytokine expression in sickle cell disease.

INTRODUCTION: Sickle cell anemia (SCA) is the most prevalent genetic disease worldwide. Patients with SCA exhibit increased levels of proinflammatory mediators as part of a permanently activated immunoinflammatory status. METHODS: The aim of this study was to evaluate the mRNA expression levels of the cytokines interferon (IFN-γ), tumor necrosis factor, interleukin (IL-1ß, IL-17A, IL-10), receptor activator for nuclear factor kappa B ligand, and the chemokines CCL2/MCP-1 and CCL5 in the periapical interstitial fluid from SCA individuals compared with healthy individuals. Samples were collected from 12 teeth of SCA patients and 12 non-SCA patients with apical periodontitis. In addition, 12 teeth were sampled from the periapical region of healthy patients with vital pulp (control). The expression of cytokine mRNA was detected by using real-time polymerase chain reaction. RESULTS: The expression of mRNA for the Th1-associated cytokines IFN-γ, tumor necrosis factor-α, and IL-1ß were significantly higher in SCA individuals than in the control individuals (P < .05). Among Th1-associated cytokines, only IFN-γ was significantly increased in non-SCA compared with control patients (vital pulp). The expression of IL-17A mRNA was significant higher in SCA cases than in control samples (P < .05), whereas the IL-10 mRNA expression was significantly increased in SCA and non-SCA individuals when compared with the control group. Similar levels of receptor activator for nuclear factor kappa B ligand, CCL2, and CCL5 mRNA expression were observed in all samples. However, no significant differences were observed in the expression of cytokine or chemokine mRNA between SCA and non-SCA individuals (P > .05). CONCLUSIONS: The results were able to demonstrate that SCA patients presented prone proinflammatory ability, despite the fact that any differences in periapical immune responses between SCA and non-SCA individuals were not observed.

Papel da IL-17 na imunopatogênese de lesões periapicais experimentais / Role of IL-17 in the immunopathogenesis of experimental periapical lesions

A infecção dos sistemas de canais radiculares levará à consequente indução de uma lesão periapical, estando muitos mediadores inflamatórios envolvidos nesse processo. A IL-17 tem demonstrado impacto no processo de remodelação óssea, especialmente em casos de artrite, apresentando-se em altos níveis. Contudo, pouco se sabe a respeito do seu real papel na patogênese das periapicopatias. Neste estudo, procurou-se avaliar o papel da IL-17A na reabsorção óssea perirradicular, em infecções endodônticas experimentais em camundongos C57BL/6 e IL-17RA KO, bem como o efeito dessa infecção na artrite reumatóide experimental. Para se induzir a infecção endodôntica, cepas padrão de Porphyromonas gingivalis, Prevotella intermedia e Fusobacterium nucleatum foram inoculadas nos canais radiculares do primeiro molar superior esquerdo desses animais...

The impact of chlorhexidine-based endodontic treatment on periapical cytokine expression in teeth.

INTRODUCTION: Root canal treatment typically involves cleaning and shaping procedures followed by treatment with antibacterial endodontic dressing between appointments and, ultimately, 3-dimensional,hermetic filling. Chlorhexidine (CHX) is effective as an irrigation solution and is used as an endodontic dressing. The aim of this study was to examine the influence of CHX on periapical cytokine expression. METHODS: Expression levels of the cytokines interferon γ, tumor necrosis factor α, interleukin (IL)-1ß, IL-17A, IL-10, and the chemokine monocyte chemoattractant protein-1 (CCL2/MCP-1) were assayed by real-time polymerase chain reaction immediately after root canal cleaning and 15 days later. RESULTS: Messenger RNA expression of IL-1ß, interferon γ, IL-10, and CCL2/MCP-1 was increased on day 15 in teeth without endodontic dressing. No statistical change was observed in the messenger RNA expression of cytokines when comparing sampling times for teeth that received endodontic dressing. CONCLUSIONS: The results show that CHX application between appointments prevented the increase of both proinflammatory and immunoregulatory cytokines 15 days after the dental procedure.