Association between periodontitis treatment outcomes and peri-implantitis: A long-term retrospective cohort study.

OBJECTIVES: Retrospectively evaluate the association of periodontal treatment outcomes and the prevalence of peri-implant diseases around tissue-level implants. MATERIALS AND METHODS: Eighty-six patients with 260 tissue-level implants attending supporting periodontal and implant therapy for more than 3 years were evaluated. Clinical and radiographic periodontal and implant data were recorded at initial examination (T0), before implant placement (T1) and at final re-examination (T2). Two definitions of peri-implantitis severity, PIBE and PIKA, were used corresponding to the presence of periodontal pocket ≥5 mm or ≥6 mm with bleeding on probing or suppuration and radiographic signs of a bone level ≥2 mm, or ≥3 mm during implant follow-up, respectively. Analyses were performed at patient level. RESULTS: The mean implant follow-up per patient was 9.4 years and 38.0% of patients had implant for at least 10 years. Two implants were lost due to peri-implantitis. The prevalence of patients with PIKA and PIBE was 15.1% and 12.8%, respectively. Residual periodontal pockets, clinical attachment loss and bone loss/age at T2 were more pronounced in patients with PIKA and PIBE. Cox regression analysis adjusted with the number of implants per patient showed that residual pockets at T1 were independently associated with PIKA and PIBE. Initial diagnosis of severe periodontitis was associated with PIBE incidence. CONCLUSIONS: The present study showed that periodontal conditions before implant placement are a risk indicator for peri-implantitis incidence. During implant follow-up, the severity of periodontal status appeared to be a reliable indicator of patient susceptibility to peri-implantitis.

Interests of Exosomes in Bone and Periodontal Regeneration: A Systematic Review.

Periodontitis is an infectious inflammatory disease characterized by clinical attachment loss and tooth supporting tissue destruction. As exosomes demonstrated pro-regenerative ability, their use in periodontal treatment has been suggested. The aim of this systematic review is to gather and summarize the most recent data regarding exosomes to determine their potential impact in bone and periodontal regeneration. Electronic databases (Pubmed, Web of Science) were searched up to February 2020. Studies assessing the impact of exosomes administration in experimental bone and periodontal defects have been identified according to PRISMA guidelines. Among the 183 identified articles, 16 met the inclusion criteria and were included in this systematic review. Experimental bone defects were mainly surgically induced with a dental bur or distraction tools. All studies considered bone healing after exosomes administration as the primary outcome. Results showed that mesenchymal stem cells derived exosomes administration promoted bone healing and neovascularization. Nevertheless, a dose-effect relationship was observed. Exosomes administration appears to promote significantly the bone healing and periodontal regeneration. However, only a limited number of studies have been carried out so far and the optimized protocols in this context need to be evaluated.

Risk factors associated with long-term outcomes after active and supporting periodontal treatments: impact of various compliance definitions on tooth loss.

OBJECTIVES: The aim of this retrospective study was to determine factors influencing tooth loss during a long-term follow-up, emphasizing the impact of various compliance definitions. MATERIALS AND METHODS: Patients with periodontitis who were treated and presenting for maintenance care for at least up to 6 years were included. The effects of compliance and other patient- and treatment-related factors on tooth loss were assessed. Lack of compliance was defined in three ways: (1) fewer than 1.4 visits per year (irregular compliers), (2) no maintenance visit over a 2-year period (erratic compliers), and (3) no maintenance visit over a 2- to 5-year period (partial compliers) and no maintenance visit for a period of more than 5 years (non-compliers). RESULTS: One hundred and one patients were selected. The mean follow-up was 9.72 ± 1.17 years. Tooth loss per patient-year was significantly higher in erratic compliers (0.35 ± 0.19) and non-compliers (0.40 ± 0.20) compared with compliers (0.18 ± 0.10). No significant differences were found for irregular (0.30 ± 0.17) and partial (0.25 ± 0.15) compliers. Similar results were obtained for the number of patients who lost more than three teeth. Multivariable regression analysis showed that lack of compliance and periodontitis severity (more than 3% of periodontal pockets > 7 mm at baseline) were independent risk factors for tooth loss. CONCLUSIONS: During long-term follow-up, non-compliance and initial periodontitis severity were the principal risk factors that increased tooth loss. CLINICAL RELEVANCE: Tooth loss associated with lack of compliance was essentially observed in patients with long continuous periods without maintenance visits and was less influenced by patients' attended mean visit frequency.

Identification and Characterization of MicroRNA Differentially Expressed in Macrophages Exposed to Porphyromonas gingivalis Infection.

MicroRNAs (miRNAs) are short, noncoding RNAs involved in the regulation of several processes associated with inflammatory diseases and infection. Bacterial infection modulates miRNA expression to subvert any innate immune response. In this study we analyzed, using microarray analysis, the bacterial modulation of miRNAs in bone marrow-derived macrophages (BMMs) in which activity was induced by infection with Porphyromonas gingivalis The expression of several miRNAs was modulated 3 h postinfection (at a multiplicity of infection of 25). A bioinformatic analysis was performed to further identify pathways related to the innate immune host response under the influence of selected miRNAs. To assess the effects of the miRNAs identified on cytokine secretion (tumor necrosis factor alpha [TNF-α] and interleukin-10 [IL-10]), BMMs were transfected with selected miRNA mimics and inhibitors. Transfection with mmu-miR-155 and mmu-miR-2137 did not modify TNF-α secretion, while their inhibitors increased it. Inhibitors of mmu-miR-2137 and mmu-miR-7674 increased the secretion of the anti-inflammatory factor IL-10. In P. gingivalis-infected BMMs, mmu-miR-155-5p significantly decreased TNF-α secretion while inhibitor of mmu-miR-2137 increased IL-10 secretion. In vivo, in a mouse model of P. gingivalis-induced calvarial bone resorption, injection of mmu-miR-155-5p or anti-mmu-miR-2137 reduced the size of the lesion significantly. Furthermore, anti-mmu-miR-2137 significantly reduced inflammatory cell infiltration, osteoclast activity, and bone loss. Bioinformatic analysis demonstrated that pathways related to cytokine- and chemokine-related pathways but also osteoclast differentiation may be involved in the effects observed. This study contributes further to our understanding of P. gingivalis-induced modulation of miRNAs and their physiological effects. It highlights the potential therapeutic merits of targeting mmu-miR-155-5p and mmu-miR-2137 to control inflammation induced by P. gingivalis infection.

Long-term prospective cohort study on dental implants: clinical and microbiological parameters.

OBJECTIVE: The aim of the present prospective cohort study is to evaluate clinical and microbiological data of dental implants after at least 8 years of follow-up. MATERIAL AND METHODS: A total of 110 patients and 232 implants were included at baseline and followed during 1 year. Fifty-two patients and 108 implants could be evaluated at the final examination. Clinical and microbiological data were taken at baseline, 1 year and at least 8 years. RESULTS: The mean follow-up time was 10.8 ± 1.7 years. Plaque index was, respectively, 0.50 ± 0.50 at baseline, 0.50 ± 0.50 at 1 year and 0.33 ± 0.67 at ≥8 years. Gingival index was, respectively, 1.08 ± 0.19 at baseline, 1.01 ± 0.39 at 1 year and 0.22 ± 0.47 at ≥8 years. Sulcular bleeding index was, respectively, 0.17 ± 0.22 at baseline, 0.11 ± 0.33 at 1 year and 0.17 ± 0.22 at ≥8 years. Probing depth was, respectively, 2.67 ± 0.75 at baseline, 3.00 ± 0.83 at 1 year and 2.74 ± 1.00 at ≥8 years. Clinical attachment level was, respectively, 3.75 ± 1.17 at baseline, 4.00 ± 1.06 at 1 year and 4.00 ± 1.17 at ≥8 years. Peri-implant mucositis was detected around 60.2% of implants in 73.1% of patients, while peri-implantitis was affecting 12% of implants in 15.4% of patients. Some bacteria species were associated with worsened clinical parameters. CONCLUSIONS: About 69.4% of implants (75/108) and 67.3% of the patients (35/52) were considered as success in the present prospective cohort study after a mean follow-up of 10.8 years. Microbial follow-up may help to identify patients at risk for peri-implant disease.

Association between periodontitis and arterial hypertension: A systematic review and meta-analysis.

BACKGROUND: Several studies have shown that periodontal diseases are associated with hypertension (HT). However, heterogeneity among populations, diagnosis criteria, and shared risk factors represent some difficulties in terms of interpretation. Therefore, the aim of this study was to determine the magnitude of the association between periodontal diseases and HT. METHODS AND RESULTS: A systematic review and meta-analysis, including studies published up to June 2016, have been performed. Sixteen studies assessing the association between periodontal diseases and HT have been included. The meta-analysis considering all included studies (moderate to severe periodontitis) showed that the presence of HT was associated with the presence of periodontal diseases (OR, 1.50; 95% CI, 1.27-1.78). To reduce potential bias, a stratified analysis has been performed illustrating the impact of inclusion criteria and adjustments on the magnitude of the association. Interestingly, when only studies with secure diagnosis of severe periodontitis and HT were considered, an OR=1.64 (95% CI, 1.23-2.19) has been measured. CONCLUSIONS: Periodontal diseases are associated with a higher risk of HT especially for severe periodontitis. However, no conclusions could be made regarding the causative involvement of periodontal diseases mainly due to the reduced number of available prospective studies and remaining questions regarding underlying biological mechanisms.

Clinical efficacy of probiotics as an adjunctive therapy to non-surgical periodontal treatment of chronic periodontitis: a systematic review and meta-analysis.

FOCUSED QUESTION: What is the clinical influence of probiotics as an adjunctive therapy of scaling and root planing (SRP) when compared with SRP alone or in combination with placebo in the treatment of chronic periodontitis (CP). METHODS: Electronic databases were searched up to July 2015. Randomized controlled trials (RCTs) comparing SRP + probiotic versusSRP were included. PPD reduction and CAL gain were selected as primary outcome variables. RESULTS: Independent screening resulted in four eligible publications for the systematic review and three were included in the meta-analysis. Meta-analysis showed a statistically significant CAL gain (-0.42 mm, p = 0.002) and bleeding on probing (BOP) reduction (-14.66, p = 0.003) for SRP + probiotic treatment versusSRP at short-term. Only a tendency (p = 0.06) has been observed in terms of overall PPD reduction, whereas results were significant when stratified for moderate (-0.18, p = 0.001) and deep pockets (-0.67, p < 0.001). CONCLUSION: Within the limitations of this study, the findings of this meta-analysis seem to support the adjunctive use of L. reuteri to SRP in CP treatment at short-term, especially in deep pockets. Heterogeneity and limited available data may reduce the impact of these conclusions. Future long-term RCTs evaluating the clinical efficacy of adjunctive probiotics to SRP are needed.

Selective and uncoupled role of substrate elasticity in the regulation of replication and transcription in epithelial cells.

Actin cytoskeleton forms a physical connection between the extracellular matrix, adhesion complexes and nuclear architecture. Because tissue stiffness plays key roles in adhesion and cytoskeletal organization, an important open question concerns the influence of substrate elasticity on replication and transcription. To answer this major question, polyelectrolyte multilayer films were used as substrate models with apparent elastic moduli ranging from 0 to 500 kPa. The sequential relationship between Rac1, vinculin adhesion assembly, and replication becomes efficient at above 200 kPa because activation of Rac1 leads to vinculin assembly, actin fiber formation and, subsequently, to initiation of replication. An optimal window of elasticity (200 kPa) is required for activation of focal adhesion kinase through auto-phosphorylation of tyrosine 397. Transcription, including nuclear recruitment of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1), occurred above 50 kPa. Actin fiber and focal adhesion signaling are not required for transcription. Above 50 kPa, transcription was correlated with alphav-integrin engagement together with histone H3 hyperacetylation and chromatin decondensation, allowing little cell spreading. By contrast, soft substrate (below 50 kPa) promoted morphological changes characteristic of apoptosis, including cell rounding, nucleus condensation, loss of focal adhesions and exposure of phosphatidylserine at the outer cell surface. On the basis of our data, we propose a selective and uncoupled contribution from the substrate elasticity to the regulation of replication and transcription activities for an epithelial cell model.

Influence of Periodontitis, Implant, and Prosthesis Characteristics on the Peri-Implant Status: A Cross-Sectional Study.

BACKGROUND: The association between peri-implant diseases and the periodontal, implant, and prosthesis characteristics has been characterized in various ways. PURPOSE: The aim of this study was to evaluate the link between the peri-implant and periodontal status and the influence of implant and prosthesis parameters during implant follow-up. MATERIALS AND METHODS: One hundred and seven patients with a total of 310 implants that had at least one year of function who were attending periodontal and implant maintenance at a university clinic setting were included in this cross-sectional study. The demographic, periodontal, peri-implant tissue, implant, and prosthesis parameters were recorded. A pocket depth > 4 mm with bleeding on probing defined periodontal/peri-implant soft tissue diseased sites. Analyses were performed at the patient and implant levels using univariable and multivariable mixed regression analysis. RESULTS: The mean implant follow-up was 7.22 years. At the patient level, the bleeding on probing and pocket depth measurements were more pronounced around the implant than around the teeth. The opposite was observed for plaque and the clinical attachment levels. At the implant level, multivariable analysis showed that the periodontal and corresponding peri-implant tissue parameters, such as diseased sites, were closely related. The implant location, bone level, and number were selectively associated with the implant bone level, while cemented retention and emergence restoration profile influenced the implant pocket depth. CONCLUSIONS: The present study suggested that clinical peri-implant and periodontal soft tissue statuses were different, which could be a consequence of the initial implant and prosthesis healing process. However, during implant follow-up, the peri-implant parameters were predominantly associated with their corresponding periodontal parameters regardless of an association with the implant and prosthesis characteristics. This trial is registered with ClinicalTrials.gov ID: NCT03841656.

Comparison of Two Risk Assessment Scores in Predicting Peri-Implantitis Occurrence during Implant Maintenance in Patients Treated for Periodontal Diseases: A Long-Term Retrospective Study.

BACKGROUND: There is a need for reliable risk assessment tools to better predict peri-implantitis occurrence. This study compared the long-term prognosis value of two models of risk assessment scoring in predicting peri-implantitis. METHODS: Seventy-three patients with treated periodontitis representing 232 implants and attending long-term implant maintenance were evaluated. The Periodontal Risk Assessment (PRA) score, which combines only periodontal risk factors/indicators, and the Implant Risk Assessment (IRA) score, which combines both periodontal and implant risk factors/indicators, were calculated during implant maintenance. Peri-implantitis was defined by the presence of probing depth ≥6 mm with bleeding on probing/suppuration and bone level ≥3 mm. Analyses were performed at the patient level. RESULTS: The mean implant follow-up was 6.5 years. Peri-implantitis incidence was 17.8%, and high-risk PRA and IRA percentages were 36.9% and 27.3%, respectively. High-risk PRA and IRA were significantly associated with peri-implantitis incidence, with hazard ratio (HR) = 4.8 and 3.65, respectively. Risk factors/indicators considered separately showed reduced associations with peri-implantitis. CONCLUSIONS: The PRA score combining periodontal parameters and IRA score combining both periodontal and implant parameters have comparable value in predicting peri-implantitis. These scores could allow practicians to intercept the risk of peri-implantitis and to manage follow-up modalities in patients with treated periodontitis.

Modified periodontal risk assessment score: long-term predictive value of treatment outcomes. A retrospective study.

OBJECTIVE: The aim of this study was to evaluate the long-term clinical predictive value of the periodontal risk assessment diagram surface (PRAS) score and the influence of patient compliance on the treatment outcomes. MATERIALS AND METHODS: Thirty subjects suffering from periodontitis were re-examined 6-12 years after the initial diagnosis and periodontal treatments. The baseline PRAS score was calculated from the initial clinical and radiograph records. Patients were then classified into a low-to-moderate (0-20) or a high-risk group (>20). Patients who did not attend any supportive periodontal therapy were classified into a non-compliant group. PRAS and compliance were correlated to the mean tooth loss (TL)/year and the mean variation in the number of periodontal pockets with a probing depth (PPD) >4 mm. RESULTS: TL was 0.11 for the low-to-moderate-risk group and 0.26 for the high-risk group (p<0.05); PPD number reduction was 2.57 and 2.17, respectively, and bleeding on probing reduction was 6.7% and 23.3%, respectively. Comparing the compliance groups, the PPD number reduction was 3.39 in the compliant group and 1.40 in the non-compliant group (p<0.05). CONCLUSION: This study showed the reliability of PRAS in evaluating long-term TL and patient susceptibility to periodontal disease. Our data confirmed the positive influence of patient compliance on periodontal treatment outcomes.

Long-term implant survival and success: a 10-16-year follow-up of non-submerged dental implants.

OBJECTIVES: The aim of the present study was to evaluate the long-term results of dental implants using implant survival and implant success as outcome variables. METHODS: Of the 76 patients who received 162 implants of the Straumann Dental Implant System during the years 1990-1997, 55 patients with 131 implants were recalled 10-16 years after implant placement for a complete clinical and radiographic examination, followed by a questionnaire that examined the degree of satisfaction. The incidence of biological and technical complications has been carefully analysed for each implant. Success was defined as being free of all these complications over the entire observation period. Associated factors related to peri-implant lesions were analysed for each implant. RESULTS: The long-term implant cumulative survival rate up to 16 years was 82.94%. The prevalence of biological complications was 16.94% and the prevalence of technical complications was 31.09%. The cumulative complication rate after an observation period of 10-16 years was 48.03%, which meant that substantial amounts of chair time were necessary following implant placement. The majority of implant losses and biological complications were concentrated in a relatively small number of patients. CONCLUSION: Despite a relatively high long-term survival rate, biological and technical complications were frequent. Patients with a history of periodontitis may have lower implant survival rates than patients without a history of periodontitis and were more prone to biological complications such as peri-implant mucositis and peri-implantitis.

Selective Influence of Smoking on Periodontal Treatment Outcomes after 3 Years of Follow-up.

PURPOSE: The impact of smoking habits on periodontal treatment has not been clearly elucidated. This study aimed to specify the effects of cigarette consumption and nicotine addiction on periodontal therapy. MATERIALS AND METHODS: In this retrospective case-control study, 20 moderate smokers and 20 non-smokers with severe periodontitis were examined after initial diagnosis, and non-surgical active and supportive therapies for 1-6 years (mean follow-up = 3.37 years). Fagerström's test of nicotine dependence (FTND) was evaluated at re-examination. Treatment efficacy was assessed by periodontal pocket probing depth (PPD) changes and number of teeth lost per year (TL). Bayesian multilevel and regression analyses were performed at site, tooth, and patient levels. RESULTS: During the mean follow-up period of > 3 years including active and supportive periodontal therapies, mean PPD, PPD > 3 mm and PPD > 7 mm percentage reductions were 1.03, 1.48 and 2.57 times statistically significantly less pronounced, respectively, in smokers than in non-smokers. Multilevel analysis showed that the variability of PPD > 7 mm reduction was mainly associated with patient-level factors. Smokers presented a higher risk for periodontitis progression. In smokers, periodontal parameter improvement was less pronounced in the maxilla and molars. The mean TL was related to the FTND score, not to cigarette consumption. Regression analysis did not demonstrate other influences of demographic and periodontal treatment characteristics on treatment outcomes, except patient age. CONCLUSION: Smoking negatively impacted periodontal treatment outcomes at specific tooth sites (deep pockets, maxillary molars) and periodontitis progression, independent of other risk factors.

Experimental periodontitis in Msx2 mutant mice induces alveolar bone necrosis.

BACKGROUND: Msx2 homeoprotein is a key transcription factor of dental and periodontal tissue formation and is involved in many molecular pathways controlling mineralized tissue homeostasis such as Wnt/sclerostin pathway. This study evaluated the effect of Msx2-null mutation during experimental periodontitis in mice. METHODS: Experimental periodontitis was induced for 30 days in wild-type and Msx2 knock-in Swiss mice using Porphyromonas gingivalis infected ligatures. In knock-in mice, Msx2 gene was replaced by n-LacZ gene encoding ß-galactosidase. Periodontal tissue response was assessed by histomorphometry, tartrate-resistant acid phosphatase histoenzymology, ß-galactosidase, sclerostin immunochemistry, and terminal deoxynucleotidyl transferase-mediated dUTP nickend labeling assay. Expression of Msx2 gene expression was also evaluated in human gingival biopsies using RT-qPCR. RESULTS: During experimental periodontitis, osteonecrosis area and osteoclast number were significantly elevated in knock-in mice compared with wild-type mice. Epithelial downgrowth and bone loss was similar. Sclerostin expression in osteocytes appeared to be reduced during periodontitis in knock-in mice. Msx2 expression was detected in healthy and inflamed human gingival tissues. CONCLUSION: These data indicated that Msx2 pathway influenced periodontal tissue response to experimental periodontitis and appeared to be a protective factor against alveolar bone osteonecrosis. As shown in other inflammatory processes such as atherothrombosis, genes initially characterized in early development could also play an important role in human periodontal pathogenesis.

In-situ forming implants loaded with chlorhexidine and ibuprofen for periodontal treatment: Proof of concept study in vivo.

Control of infection and inflammation is crucial for the success of periodontal treatment. In this study, in-situ forming implants (ISFI) loaded with chlorhexidine dihydrochloride (CHX) and ibuprofen (IBU) were developed and tested to optimize periodontal treatment outcomes. Release profiles were promising. Exposure to 1.5% and 5.3% CHX-IBU loaded ISFI's release media decreased significantly the P. gingivalis growth up to 20-fold and 35-fold, respectively, after 48 h (p < 0.05). The metabolic activity assay of gingival epithelial cells (EC) demonstrated 1.5% CHX-IBU-loaded ISFI to be non-toxic, therefore, it was selected for further experimentation. Furthermore, significant down-regulation of TNF-α release (34% at 6 h and 43% at 24 h, p < 0.05) in P. gingivalis lipopolysaccharide (Pg-LPS) stimulated EC exposed to 1.5% CHX-IBU ISFI release medium was demonstrated by ELISA. In vivo, 1.5% CHX-IBU ISFI was injected into the periodontal pocket in an experimental periodontitis mouse model and the reduction in inflammation and improvement in periodontal wound healing was evaluated through inflammatory cell scoring and histomorphometry at 7- and 15-days post-treatment. The results indicate that CHX-IBU loaded ISFI could be efficient as adjuvant to periodontal therapy for the control of infection and inflammation. Moreover, other (e.g., pro-regenerative) drugs could be incorporated into ISFI to further improve periodontal treatment outcomes.

Management of localized aggressive periodontitis: A 30-year follow-up.

This case report describes the long-term follow-up of a patient with localized aggressive periodontitis over a 30-year period. A 16-year-old woman was referred for periodontal assessment after starting orthodontic treatment. The patient was treated initially by combined nonsurgical and antimicrobial therapy, and autotransplantation of maxillary third molars in place of maxillary first molars, followed by a regular supportive periodontal treatment program. This challenging case demonstrated that elimination of putative bacterial pathogens and long-term supportive periodontal treatments provide an effective treatment modality for localized aggressive periodontitis.

Synthesis of a Novel Electrospun Polycaprolactone Scaffold Functionalized with Ibuprofen for Periodontal Regeneration: An In Vitro andIn Vivo Study.

Ibuprofen (IBU) has been shown to improve periodontal treatment outcomes. The aim of this study was to develop a new anti-inflammatory scaffold by functionalizing an electrospun nanofibrous poly-ε-caprolactone membrane with IBU (IBU-PCL) and to evaluate its impact on periodontal inflammation, wound healing and regeneration in vitro and in vivo. IBU-PCL was synthesized through electrospinning. The effects of IBU-PCL on the proliferation and migration of epithelial cells (EC) and fibroblasts (FB) exposed to Porphyromonas gingivlais lipopolysaccharide (Pg-LPS) were evaluated through the AlamarBlue test and scratch assay, respectively. Anti-inflammatory and remodeling properties were investigated through Real time qPCR. Finally, the in vivo efficacy of the IBU-PCL membrane was assessed in an experimental periodontitis mouse model through histomorphometric analysis. The results showed that the anti-inflammatory effects of IBU on gingival cells were effectively amplified using the functionalized membrane. IBU-PCL reduced the proliferation and migration of cells challenged by Pg-LPS, as well as the expression of fibronectin-1, collagen-IV, integrin α3ß1 and laminin-5. In vivo, the membranes significantly improved the clinical attachment and IBU-PCL also reduced inflammation-induced bone destruction. These data showed that the IBU-PCL membrane could efficiently and differentially control inflammatory and migratory gingival cell responses and potentially promote periodontal regeneration.

Porphyromonas gingivalis and its LPS differentially regulate the expression of peptidyl arginine deiminases in human chondrocytes.

Periodontitis, an inflammatory disease initiated by Gram-negative bacteria such as Porphyromonas gingivalis ( Pg), is considered as a risk factor for rheumatoid arthritis (RA). Our study aimed to determine the effect of Pg and its LPS on the expression of peptidyl arginine deiminase isotypes (PADs) in human primary chondrocytes (HC). HCs were infected with Pg and activated by its LPS (LPS- Pg). The mRNA expression levels of human PADs (1, 2, 3, 4 and 6) and bacterial enzyme (PADPg) were quantified by RT-qPCR. Cellular extracts served to measure the enzymatic activities of PADs and PADPg and to visualize the profiles of citrullinated proteins/peptides by Western blotting. Our data showed significant inhibitions of mRNA expressions of human PAD-2, PAD-3 and PAD-4 during infection of HC with live Pg. Activation of HC by LPS- Pg increased mRNA expressions of human PAD-2 and PAD-3. The PADPg enzymatic activity was significantly increased in only infected HC. Analysis of citrullinated proteins/peptides profiles revealed the occurrence of low molecular bands only in cellular extracts from HC infected with Pg. Our data showed that Pg and its LPS differentially regulate the expression of PADs in human chondrocytes and that Pg favors the apparition of new citrullinated proteins/peptides.

Anti-inflammatory effect of active nanofibrous polymeric membrane bearing nanocontainers of atorvastatin complexes.

AIM: We developed polymeric membranes for local administration of nonsoluble anti-inflammatory statin, as potential wound patch in rheumatic joint or periodontal lesions. METHODS: Electrospun polycaprolactone membranes were fitted with polysaccharide-atorvastatin nanoreservoirs by using complexes with poly-aminocyclodextrin. Characterization methods are UV-Visible and X-ray photoelectron spectroscopy, molecular dynamics, scanning and transmission electron microscopy. In vitro, membranes were seeded with macrophages, and inflammatory cytokine expression were monitored. RESULTS & CONCLUSION: Stable inclusion complexes were formed in solution (1:1 stability constant 368 M-1, -117.40 kJ mol-1), with supramolecular globular organization (100 nm, substructure 30 nm). Nanoreservoir technology leads to homogeneous distribution of atorvastatin calcium trihydrate complexes in the membrane. Quantity embedded was estimated (70-90 µg in 30 µm × 6 mm membrane). Anti-inflammatory effect by cell contact-dependent release reached 60% inhibition for TNF-α and 80% for IL-6. The novelty resides in the double protection offered by the cyclodextrins as drug molecular chaperones, with further embedding into biodegradable nanoreservoirs. The strategy is versatile and can target other diseases.

Paxillin phosphorylation and integrin expression in osteoblasts infected by Porphyromonas gingivalis.

OBJECTIVE: We investigated early biological events initiated by Porphyromonas gingivalis infection of human osteoblasts, focusing on tyrosine-phosphorylation and the expression of key components in focal adhesion and cell signalling. DESIGN: Human primary osteoblasts were challenged for 1h with Porphyromonas gingivalis. Tyrosine-phosphorylation of paxillin and focal adhesion kinase (FAK) was examined by Western blotting. Changes in alpha3- and beta1-integrin mRNA expression were quantified by RT-PCR. RESULTS: Tyrosine-phosphorylation of paxillin was proportional to the size of the Porphyromonas gingivalis inoculum. FAK, a potential kinase for paxillin, was not activated. The amount of alpha3- and beta1-integrins, determined by Western blotting, did not vary significantly, while the corresponding mRNA levels fell significantly when a large bacterial inoculum was used. CONCLUSIONS: These results indicate that Porphyromonas gingivalis infection of osteoblasts in vitro triggers tyrosine-phosphorylation of paxillin but not FAK and modify alpha3- and beta1-integrin mRNA expression. This infection thus appears to have different effects on components with essential roles in focal adhesion (paxillin) and cell signalling (FAK and integrins).