Progression Of Apical Periodontitis Research Articles

Involvement of CCR5 in bone resorption associated to apical periodontitis

Abstract The involvement of Cysteine-cysteine chemokine receptor 5 (CCR5) in the protection or stimulation of bone resorption associated with apical periodontitis that occur as consequence of endodontic infection has not yet been elucidated. The present study proposes to characterize the involvement of CCR5 in the genesis and progression of apical periodontitis, using animals deficient for this molecule. Experimental induction of periapical lesions was performed in CCR5 −/− (knockout) or wild type transgenic mice through the coronary opening of the lower 1st molars and exposure of the root canals to the oral environment for their contamination. After the death of the animals (at 0, 7, 21 and 42 days), the samples obtained in different experimental periods were evaluated by conventional microscopy and fluorescence (morphometry and characterization of the lesions), histoenzimology (TRAP for osteoclasts), immunohistochemistry, immunofluorescence and real-time PCR, to characterize the inflammatory cell in the presence or absence of CCR5 (neutrophils, macrophages and CD4 and CD8 lymphocytes), expression of cytokines (IL-1±, TNF-±, IFN-³, IL 4, IL-6 and IL-10), their ligands (RANTES and MIP- 1±) and factors involved in bone formation and resorption (RUNX2, NFATc1, ALP, RANK, RANKL, OPG and cathepsin K) and infection of tissues. Our results shows that CCR5 knockout mice developed more extense and severe inflammation and alveolar bone destruction at periapical region at 21 and 42 days after endodontic infection. It was concluded that CCR5 deficiency results in development of more severe periapical alveolar bone resorption associated to endodontic infection.

Interaction of biologic therapy with apical periodontitis and periodontitis: a systematic review.

Biologic medications (BMs) are increasingly used for the management of systemic chronic inflammatory diseases. These diseases are often associated with a higher prevalence of apical periodontitis (AP) and periodontitis (P). The purpose of this systematic review was to ascertain the interactions between AP and/or P and BMs. The review was registered in the PROSPERO database (CRD42017054756). Electronic searches were performed on Pubmed Medline, Scopus and The Web of Science from their inception through to 20 March 2018. The references of the articles selected were checked. The keywords were chosen based on a pilot search, which aimed to find the most frequently prescribed BMs. The included studies were appraised qualitatively using appropriate tools. Thirty-five articles met the inclusion criteria, comprising 16 non-randomized clinical studies, 12 invivo animal studies and 7 case reports. Quality of information was assessed as high in 18 articles, moderate in 16 articles and low in 1 article. BMs in patients suffering from chronic inflammatory diseases seems to inhibit the progression of AP and P, and to enhance the healing response to periodontal and endodontic treatment. A healthier condition of the periodontal tissues seems to be associated with a better response of the patient to BMs therapy.

Conservative management of periapical lesions of endodontic origin - a review of the different techniques

Introduction : Periapical lesions of endodontic origin are common pathological conditions affecting the periradicular tissues. Mainly responsible for the initiation and progression of apical periodontitis is the microbial infection of pulpal tissues. There are different conservative techniques that can be applied in order to establish a healing process of periapical lesions of endodontic origin. Materials and Methods : We have conducted a research that covers related articles and publications, in order to review the different conservative management treatment techniques for lesions affecting the periradicular tissues. Results: Different non-surgical management techniques have been described, namely: conservative root canal therapy, decompression technique, a method using calcium hydroxide, aspiration-irrigation technique, lesion sterilization and repair therapy, active non-surgical decompression technique, and the apexum procedure. Conclusion: All of the described management techniques present with advantages, disadvantages and specific indications that should be taken into consideration when managing the treatment plan of every specific clinical case.

Immunohistochemical and mRNA expression of RANK, RANKL, OPG, TLR2 and MyD88 during apical periodontitis progression in mice.

Objective To evaluate and correlate, in the same research, the mRNA expression and the staining of RANK, RANKL, OPG, TLR2 and MyD88 by immunohistochemistry in the apical periodontitis (AP) progression in mice.Material and Methods AP was induced in the lower first molars of thirty-five C57BL/6 mice. They were assigned to four groups according to their euthanasia periods (G0, G7, G21 and G42). The jaws were removed and subjected to histotechnical processing, immunohistochemistry and real-time reverse transcription-PCR (qRT-PCR). Data were analyzed with parametric and nonparametric tests (α=0.05).Results An increase of positive immunoreactivity for RANK, RANKL, OPG, TLR2 and MyD88 was observed over time (p<0.05). The RANKL expression was different between the groups G0 and G42, G21 and G42 (p=0.006), with G42 presenting the higher expression in both comparations. The OPG expression was statistically different between the groups G0 and G7, G7 and G21 and G7 and G42 (p<0.001), with G7 presenting higher expression in all the time points. The TLR2 expression was different between the groups G0 and G42 (p=0.03), with G42 showing the higher expression. The MyD88 expression presented a statistical significant difference between groups G7, G21 and G42 compared with G0 (p=0.01), with G0 presenting the smallest expression in all the comparisons. The Tnfrsf11/Tnfrsf11b (RANKL/OPG) ratio increased with the AP progression (p=0.002). A moderate positive correlation between MyD88 and RANKL (r=0.42; p=0.03) and between MyD88 and TLR2 (r=0.48; p<0.0001) was observed.Conclusion The expression of the RANK, RANKL, OPG, MyD88 and TLR2 proteins as well as the ratio Tnfrsf11/Tnfrsf11b (RANKL/OPG) increased with AP progression. There was also a moderate positive correlation between the expression Myd88-Tnfrsf11 and Tlr2-Myd88, suggesting the relevance of Tlr2-Myd88 in bone loss due to bacterial infection.

MMP2 and MMP9 are Associated with Apical Periodontitis Progression and Might be Modulated by TLR2 and MyD88.

The aim of this study was to evaluate the expression of MMP2 and MMP9 during apical periodontitis (AP) progression in TLR2 (TLR2 KO) and in MyD88 (MyD88 KO) knockout mice compared to wild type (WT) mice. AP was induced in mandibular first molars of TLR2 KO (n= 18), MyD88 KO (n= 18), and WT mice (n= 18). After 7, 21, and 42 days, the animals were euthanized and the jaws were dissected and subjected to histotechnical processing. Subsequent sections were stained by immunohistochemistry and evaluated for detection of MMP2 and MMP9. Statistical analysis of the semi-quantitative analysis of immunohistochemistry was performed using chi-square test (α = 0.05). In the initial periods of AP progression, an increased expression of MMP9 in the TLR2 KO and MyD88 KO mice was observed. In the final periods of AP progression, a reduction of MMP2 expression and an increase of MMP9 expression in the TLR2 KO mice were observed. MMP2 and MMP9 production was modulated for TLR2 and MyD88 during apical periodontitis progression.

The extent of pyroptosis varies in different stages of apical periodontitis

Apical periodontitis (AP) is an inflammation affecting the periapical region of tooth root. Microbial pathogens activate inflammasomes and promote the production of pro-inflammatory cytokines. Caspase-1-mediated pyroptosis is a possible mechanism involved in the initiation and progression of AP. The purpose of this study was to evaluate the role of caspase-1 and pyroptosis on AP at different stages. Human periapical inflammatory tissue was collected to study chronic AP stage. Human periodontal ligament fibroblasts (hPDLFs) were stimulated with lipopolysaccharide in vitro for 24h to simulate early AP stage. Experimental AP rat model was established to study acute AP stage from 0d to 28d. The results showed that NLRP3, cleaved caspase-1 and Interleukin (IL)-1β were enhanced in all AP stages. Caspase-1 activation was detectable in most cells. However, the level of pyroptosis was in accordance with the degree of AP inflammation. Early and chronic AP showed a comparable hemostasis state, with pyroptosis remaining in a reduced level. On the contrary, extensive pyroptosis accelerated inflammation and induced cell death in acute AP. VX765, a caspase-1 inhibitor, was used in an experimental AP rat model. The results showed that VX765 suppressed bone loss, suggesting a role of pyroptosis on bone resorption in acute AP. VX765 also inhibited the expressions of IL-1β, Monocyte chemoattractant protein-1 (MCP-1), IL-6 and IL-8 in vitro, thus decreased inflammatory responses during AP. In conclusion, caspase-1 and pyroptosis contributed to AP inflammation and lesion and pyroptosis extent was in line with AP progression.

Expression Profiles of Inflammation-associated microRNAs in Periapical Lesions and Human Periodontal Ligament Fibroblasts Inflammation

IntroductionmicroRNAs (miRNAs) have been identified to be closely related to inflammatory diseases. The aim of our study was to identify expression profiles of miRNAs associated with inflammation in apical periodontitis (AP) lesions and human periodontal ligament fibroblasts (HPDLFs) inflammation. MethodsTotal RNAs were extracted from 10 AP lesions, 6 control tissues, and HPDLFs using lysis buffer. Expressions of miRNAs (miR-29b, 106b, 125b, 143, 155, and 198) were detected by real-time polymerase chain reaction. The dual luciferase assay was used to test miR-155 directly targeted semaphorein3a (SEMA3A). Western Blot and the enzyme-linked immunosorbent assay were used to detect the protein expressions of SEMA3A and proinflammatory cytokines, respectively. All experiments were repeated at least 3 times. Data were analyzed using the independent sample t test. ResultsThe previously mentioned miRNAs were all significantly up-regulated in AP lesions (P < .05), whereas they were not in HPDLFs inflammation, in which miR-29b, 106b, 125b, and 198 were down-regulated (P < .05) and miR-143 and 155 were unchanged (P > .05). Overexpression of miR-155 induced proinflammatory phenotype, and down-regulation reduced the other miRNAs in HPDLFs (P < .05). Moreover, miR-155 directly targeted SEMA3A, which was significantly up-regulated (increased) in acute HPDLFs inflammation and down-regulated (decreased) in AP lesions (P < .05). Knockdown of SEMA3A led to induction of the proinflammatory phenotype; down-regulation of miR-29b, 106b, 125b, 143, and 198 (P < .05); and, more importantly, up-regulation of miR-155 (P < .01). ConclusionsOur study showed that the expression profiles of inflammation-associated miRNAs associated with inflammation in AP lesions and HPDLFs inflammation were different. miR-155 may play a crucial role in apical periodontitis progression by directly inhibiting SEMA3A.

Blood Profile and Histology in Oral Infections Associated with Diabetes

IntroductionWe aimed to investigate the relationship between blood profile and histologic findings in both apical periodontitis (AP) and periodontal disease (PD) associated with diabetes. MethodsWistar rats (N = 80) were assigned to the following 8 groups: control, AP, PD, AP associated with PD, diabetes, diabetes with AP, diabetes with PD, and diabetes with AP and PD. Diabetes mellitus (DM) was induced with streptozotocin, AP was induced by exposure to the oral environment, and PD was induced using periodontal ligature. After 30 days, blood samples were collected, and the rats were euthanized. Subsequently, the maxillae were processed for light microscopy. Hematologic examinations were conducted to determine the total number of erythrocytes and leukocytes, erythrocyte constant, and blood glucose level. One-way analysis of variance and Kruskal-Wallis tests were used for statistical analysis, and the significance was set at P < .05. ResultsA significant correlation was found between the histologic findings and blood parameters. ConclusionsIn conclusion, diabetes accelerated the development and progression of AP and PD in the rats and caused an increase in the average erythrocyte volume as well as the leukocyte and neutrophil counts. Oral infections increase the total number of leukocytes, the number of neutrophils and lymphocytes, and blood glucose concentrations in DM rats.

Simvastatin Suppresses Osteoblastic Expression of Cyr61 and Progression of Apical Periodontitis through Enhancement of the Transcription Factor Forkhead/Winged Helix Box Protein O3a

IntroductionIn this study, the role of transcription factor Forkhead/winged helix box protein O3a (FoxO3a) in Cyr61 expression and its modulation by simvastatin were investigated in cultured murine osteoblasts and a rat model of induced apical periodontitis. We also examined the effects of simvastatin on the synthesis of chemokine CCL2 and chemotaxis of macrophages in vitro. MethodsWe assessed tumor necrosis factor (TNF)-α–stimulated expression of Cyr61 and phosphorylated inactive FoxO3a (p-FoxO3a) in MC3T3-E1 murine osteoblasts by Western analysis. Forced expression of FoxO3a by lentiviral-based gene transduction was performed, and its effect on Cyr61 expression was evaluated. The modulation of CCL2 secretion and macrophage chemotaxis by simvastatin were examined by enzyme-linked immunosorbent assay and transwell migration assay, respectively. In a rat model of induced apical periodontitis, the relation between disease progression and osteoblastic expression of Cyr61, p-FoxO3a, and CCL2 and macrophage recruitment were studied by radiographic and immunohistochemistry analyses. ResultsWestern blot analysis showed enhanced expression of Cyr61 and p-FoxO3a after TNF-α treatment in a time-dependent manner. Simvastatin significantly counteracted the actions of TNF-α. Forced expression of FoxO3a reduced TNF-α–stimulated Cyr61 synthesis. Simvastatin and FoxO3a diminished TNF-α–induced CCL2 secretion and macrophage recruitment, whereas Cyr61 partially restored the stimulating action. In rat periapical lesions, simvastatin significantly attenuated bone resorption, reduced osteoblastic expressions of Cyr61, p-FoxO3a, and CCL2, and suppressed macrophage recruitment. ConclusionsSimvastatin may alleviate periapical lesions by enhancing FoxO3a activity to suppress the synthesis of Cyr61 in osteoblasts. Moreover, the downstream effector mechanism of Cyr61 may involve CCL2 production and macrophage recruitment.

Pathogenicity of exopolysaccharide‐producing Actinomyces oris isolated from an apical abscess lesion

AimTo demonstrate a capacity for producing exopolysaccharides (EPSs) and an ability to form biofilm on abiotic materials of Actinomyces oris strain K20.MethodologyThe productivity of EPSs and the ability to form biofilm of strain K20 were evaluated by measuring viscosity of spent culture media and by scanning electron microscopy (SEM) and the biofilm assay on microtitre plates, respectively. High-performance liquid chromatography was used to determine the chemical composition of the viscous materials. To examine the role of the viscous materials attributable to the pathogenicity in this organism, the ability of strain K20 to induce abscess formation was compared in mice to that of ATCC 27044.ResultsThe viscosity of the spent culture media of K20 was significantly higher than that of ATCC 27044. Strain K20 showed dense meshwork structures around the cells and formed biofilms on microtitre plates, whereas ATCC 27044 did not. Chemical analysis of the viscous materials revealed that they were mainly composed of neutral sugars with mannose constituting 77.5% of the polysaccharides. Strain K20 induced persistent abscesses in mice lasting at least 5 days at a concentration of 108 cells mL−1, whereas abscesses induced by ATCC 27044 healed and disappeared or decreased in size at day 5.ConclusionsStrain K20 produced EPSs, mainly consisting of mannose, and formed biofilms. This phenotype might play an important role for A. oris to express virulence through the progression of apical periodontitis.

Proteomic analysis of endodontic infections by liquid chromatography–tandem mass spectrometry

Endodontic infections are very prevalent and have a polymicrobial etiology characterized by complex interrelationships between endodontic microorganisms and the host defenses. Proteomic analysis of endodontic infections can provide global insights into the invasion, pathogenicity mechanisms, and multifactorial interactions existing between root canal bacteria and the host in the initiation and progression of apical periodontitis. The purpose of this study was to apply proteomic techniques such as liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the identification of proteins of bacterial origin present in endodontic infections. Endodontic specimens were aseptically obtained from seven patients with root canal infections. Protein mixtures were subjected to tryptic in-solution digestion and analysed by reverse-phase nano-LC-MS/MS followed by a database search. Proteins, mainly of cell wall or membrane origin, from endodontic bacteria especially Enterococcus faecalis, Enterococcus faecium, Porphyromonas gingivalis, Fusobacterium nucleatum, and Treponema denticola were identified from all the samples tested. Identified proteins included adhesins, autolysins, proteases, virulence factors, and antibiotic-resistance proteins. LC-MS/MS offers a sensitive analytical platform to study the disease processes in the root canal environment. The array of proteins expressed in endodontic infections reflects the complex microbial presence and highlights the bacterial species involved in the inflammatory process.