Ceruloplasmin induces polymorphonuclear leukocyte priming in localized aggressive periodontitis

Periostin regulates integrin expression in gingival epithelial cells

OBJECTIVE

Human gingival epithelial cells (HGECs) function as a mechanical barrier against invasion by pathogenic organisms through epithelial cell-cell junction complexes, which are complex components of integrin. Integrins play an important role in the protective functions of HGECs. Human periodontal ligament (HPL) cells regulate periodontal homeostasis. However, periodontitis results in the loss of HPL cells. Therefore, as replenishment, HPL cells or mesenchymal stem cells (MSCs) can be transplanted. Herein, HPL cells and MSCs were used to elucidate the regulatory mechanisms of HGECs, assuming periodontal tissue homeostasis.

METHODS

Human gingival fibroblasts (HGFs), HGECs, HPL cells, and MSCs were cultured, and the conditioned medium was collected. With or without silencing periostin mRNA, HGECs were cultured under normal conditions or in a conditioned medium. Integrin and periostin mRNA expression was determined using real-time polymerase chain reaction. Integrin protein expression was analyzed using flow cytometry, and periostin protein expression was determined via western blotting.

RESULTS

The conditioned medium affected integrin expression in HGECs. Higher expression of periostin was observed in MSCs and HPL cells than in HGFs. The conditioned medium that contained periostin protein regulated integrin expression in HGECs. After silencing periostin in MSCs and HPL cells, periostin protein was not detected in the conditioned medium, and integrin expression in HGECs remained unaffected.

CONCLUSIONS

Integrins in HGECs are regulated by periostin secreted from HPL cells and MSCs. This result suggests that periostin maintains gingival cell adhesion and regulates bacterial invasion/infection. Therefore, the functional regulation of periostin-secreting cells is important in preventing periodontitis.

Ceruloplasmin Reduces the Lactoferrin/Oleic Acid Antitumor Complex-Mediated Release of Heme-Containing Proteins from Blood Cells

Our previous study showed that not only bovine lactoferrin (LF), the protein of milk and neutrophils, but also the human species forms complexes with oleic acid (OA) that inhibit tumor growth. Repeated injections of human LF in complex with OA (LF/8OA) to hepatoma-carrying mice decelerated tumor growth and increased animals' longevity. However, whether the effect of the LF/8OA complex is directed exclusively against malignant cells was not studied. Hence, its effect on normal blood cells was assayed, along with its possible modulation of ceruloplasmin (CP), the preferred partner of LF among plasma proteins. The complex LF/8OA (6 μM) caused hemolysis, unlike LF alone or BSA/8OA (250 μM). The activation of neutrophils with exocytosis of myeloperoxidase (MPO), a potent oxidant, was induced by 1 μM LF/8OA, whereas BSA/8OA had a similar effect at a concentration increased by an order. The egress of heme-containing proteins, i.e., MPO and hemoglobin, from blood cells affected by LF/8OA was followed by a pronounced oxidative/halogenating stress. CP, which is the natural inhibitor of MPO, added at a concentration of 2 mol per 1 mol of LF/8OA abrogated its cytotoxic effect. It seems likely that CP can be used effectively in regulating the LF/8OA complex's antitumor activity.

Biomarkers of Periodontitis and Its Differential DNA Methylation and Gene Expression in Immune Cells: A Systematic Review

The characteristic epigenetic profile of periodontitis found in peripheral leukocytes denotes its impact on systemic immunity. In fact, this profile not only stands for periodontitis as a low-grade inflammatory disease with systemic effects but also as an important source of potentially valuable clinical biomarkers of its systemic effects and susceptibility to other inflammatory conditions. Thus, we aimed to identify relevant genes tested as epigenetic systemic biomarkers in patients with periodontitis, based on the DNA methylation patterns and RNA expression profiles in peripheral immune cells. A detailed protocol was designed following the Preferred Reporting Items for Systematic Review and Meta-analysis -PRISMA guideline. Only cross-sectional and case-control studies that reported potential systemic biomarkers of periodontitis in peripheral immune cell types were included. DNA methylation was analyzed in leukocytes, and gene expression was in polymorphonuclear and mononuclear cells. Hypermethylation was found in TLR regulators genes: MAP3K7, MYD88, IL6R, RIPK2, FADD, IRAK1BP1, and PPARA in early stages of periodontitis, while advanced stages presented hypomethylation of these genes. TGFB1I1, VNN1, HLADRB4, and CXCL8 genes were differentially expressed in lymphocytes and monocytes of subjects with poorly controlled diabetes mellitus, dyslipidemia, and periodontitis in comparison with controls. The DAB2 gene was differentially overexpressed in periodontitis and dyslipidemia. Peripheral blood neutrophils in periodontitis showed differential expression in 163 genes. Periodontitis showed an increase in ceruloplasmin gene expression in polymorphonuclears in comparison with controls. Several genes highlight the role of the epigenetics of peripheral inflammatory cells in periodontitis that could be explored in blood as a source of biomarkers for routine testing.

Nutritional immunity: the impact of metals on lung immune cells and the airway microbiome during chronic respiratory disease

Nutritional immunity is the sequestration of bioavailable trace metals such as iron, zinc and copper by the host to limit pathogenicity by invading microorganisms. As one of the most conserved activities of the innate immune system, limiting the availability of free trace metals by cells of the immune system serves not only to conceal these vital nutrients from invading bacteria but also operates to tightly regulate host immune cell responses and function. In the setting of chronic lung disease, the regulation of trace metals by the host is often disrupted, leading to the altered availability of these nutrients to commensal and invading opportunistic pathogenic microbes. Similarly, alterations in the uptake, secretion, turnover and redox activity of these vitally important metals has significant repercussions for immune cell function including the response to and resolution of infection. This review will discuss the intricate role of nutritional immunity in host immune cells of the lung and how changes in this fundamental process as a result of chronic lung disease may alter the airway microbiome, disease progression and the response to infection.

Endodontic Infection-induced Inflammation Resembling Osteomyelitis of the Jaws in Toll-like Receptor 2/Interleukin 10 Double-knockout Mice

INTRODUCTION

In general, mice develop chronic and nonhealing periapical lesions after endodontic infection. Surprisingly, we recently found that toll-like receptor 2 (TLR2)/interleukin 10 (IL-10) double-knockout (dKO) mice exhibited acute but resolving osteomyelitislike inflammation. In this study, we examined the kinetics of endodontic infection-induced inflammation in TLR2/IL-10 dKO mice and explored a potential mechanism of periapical wound healing mediated by the hypoxia-inducible factor 1 alpha (HIF-1α) subunit and arginase 1.

METHODS

TLR2/IL-10 dKO and wild-type C57BL/6J mice were subjected to endodontic infection in the mandibular first molars. Mice were sacrificed on days 0 (noninfected), 10, and 21 postinfection. The extent of bone destruction, inflammation, bone deposition, and gene expression were determined by micro-computed tomographic imaging, histology, bone polychrome labeling, and microarray analysis. In addition, the effect of blocking endogenous HIF-1α was tested in infected TLR2/IL-10 dKO mice using the specific inhibitor YC-1.

RESULTS

Infected TLR2/IL-10 dKO mice exhibited extensive bone destruction and inflammation on day 10 followed by spontaneous periapical wound healing including bone formation and resolution of inflammation by day 21 postinfection. In contrast, WT mice developed increasing chronic periapical inflammation over the 21-day observation period. Gene expression analyses and immunohistochemistry revealed that HIF-1α and arginase 1 were up-regulated in spontaneous wound healing in TLR2/IL-10 dKO mice. Blocking of HIF-1α in TLR2/IL-10 dKO mice using YC-1 resulted in significant inhibition of regenerative bone formation.

CONCLUSIONS

The TLR2/IL-10 dKO mouse is a novel model resembling osteomyelitis of the jaws in which HIF-1α and arginase 1 appear to be crucial factors in spontaneous wound healing and bone repair.

Looking for a partner: ceruloplasmin in protein-protein interactions

Ceruloplasmin (CP) is a mammalian blood plasma ferroxidase. More than 95% of the copper found in plasma is carried by this protein, which is a member of the multicopper oxidase family. Proteins from this group are able to oxidize substrates through the transfer of four electrons to oxygen. The essential role of CP in iron metabolism in humans is particularly evident in the case of loss-of-function mutations in the CP gene resulting in a neurodegenerative syndrome known as aceruloplasminaemia. However, the functions of CP are not limited to the oxidation of ferrous iron to ferric iron, which allows loading of the ferric iron into transferrin and prevents the deleterious reactions of Fenton chemistry. In recent years, a number of novel CP functions have been reported, and many of these functions depend on the ability of CP to form stable complexes with a number of proteins.

Capacity of ceruloplasmin to scavenge products of the respiratory burst of neutrophils is not altered by the products of reactions catalyzed by myeloperoxidase

CP is a copper-containing ferroxidase of blood plasma, which acts as an acute phase reactant during inflammation. The effect of oxidative modification of CP induced by oxidants produced by MPO, such as HOCl, HOBr, and HOSCN, on its spectral, enzymatic, and anti-inflammatory properties was studied. We monitored the chemiluminescence of lucigenin and luminol along with fluorescence of hydroethidine and scopoletin to assay the inhibition by CP of the neutrophilic respiratory burst induced by PMA or fMLP. Superoxide dismutase activity of CP and its capacity to reduce the production of oxidants in respiratory burst of neutrophils remained virtually unchanged upon modifications caused by HOCl, HOBr, and HOSCN. Meanwhile, the absorption of type I copper ions at 610 nm became reduced, along with a drop in the ferroxidase and amino oxidase activities of CP. Likewise, its inhibitory effect on the halogenating activity of MPO was diminished. Sera of either healthy donors or patients with Wilson disease were co-incubated with neutrophils from healthy volunteers. In these experiments, we observed an inverse relationship between the content of CP in sera and the rate of H2O2 production by activated neutrophils. In conclusion, CP is likely to play a role of an anti-inflammatory factor tempering the neutrophil respiratory burst in the bloodstream despite the MPO-mediated oxidative modifications.

Hypoxia-inducible transcription factors, HIF1A and HIF2A, increase in aging mucosal tissues

Hypoxia (i.e. oxygen deprivation) activates the hypoxia-signalling pathway, primarily via hypoxia-inducible transcription factors (HIF) for numerous target genes, which mediate angiogenesis, metabolism and coagulation, among other processes to try to replenish tissues with blood and oxygen. Hypoxia signalling dysregulation also commonly occurs during chronic inflammation. We sampled gingival tissues from rhesus monkeys (Macaca mulatta; 3-25 years old) and total RNA was isolated for microarray analysis. HIF1A, HIF1B and HIF2A were significantly different in healthy aged tissues, and both HIF1A and HIF3A were positively correlated with aging. Beyond these transcription factor alterations, analysis of patterns of gene expression involved in hypoxic changes in tissues showed specific increases in metabolic pathway hypoxia-inducible genes, whereas angiogenesis pathway gene changes were more variable in healthy aging tissues across the animals. With periodontitis, aging tissues showed decreases in metabolic gene expression related to carbohydrate/lipid utilization (GBE1, PGAP1, TPI1), energy metabolism and cell cycle regulation (IER3, CCNG2, PER1), with up-regulation of transcription genes and cellular proliferation genes (FOS, EGR1, MET, JMJD6) that are hypoxia-inducible. The potential clinical implications of these results are related to the epidemiological findings of increased susceptibility and expression of periodontitis with aging. More specifically the findings describe that hypoxic stress may exist in aging gingival tissues before documentation of clinical changes of periodontitis and, so, may provide an explanatory molecular risk factor for an elevated capacity of the tissues to express destructive processes in response to changes in the microbial biofilms characteristic of a more pathogenic microbial challenge.

Porphyromonas gingivalis-induced production of reactive oxygen species, tumor necrosis factor-α, interleukin-6, CXCL8 and CCL2 by neutrophils from localized aggressive periodontitis and healthy donors: modulating actions of red blood cells and resolvin E1

BACKGROUND AND OBJECTIVES

Porphyromonas gingivalis is regarded as a significant contributor in the pathogenesis of periodontitis and certain systemic diseases, including atherosclerosis. P. gingivalis occasionally translocates from periodontal pockets into the circulation, where it adheres to red blood cells (RBCs). This may protect the bacterium from contact with circulating phagocytes without affecting its viability.

MATERIAL AND METHODS

In this in vitro study, we investigated whether human peripheral blood neutrophils from 10 subjects with localized aggressive periodontitis (LAgP) and 10 healthy controls release the proinflammatory cytokines interleukin (IL)-6, tumor necrosis factor α (TNF-α), the chemokine (C-X-C motif) ligand 8 (CXCL8; also known as IL-8) and chemokine (C-C motif) ligand 2 (CCL2; also known as monocyte chemotactic protein-1) and intracellular reactive oxygen species (ROS) in response to challenge with P. gingivalis. In addition, the impact of RBC interaction with P. gingivalis was investigated. The actions of resolvin E1 (RvE1), a known regulator of P. gingivalis induced neutrophil responses, on the cytokine and ROS responses elicited by P. gingivalis in cultures of neutrophils were investigated.

RESULTS

Upon stimulation with P. gingivalis, neutrophils from subjects with LAgP and healthy controls released similar quantities of IL-6, TNF-α, CXCL8, CCL2 and intracellular ROS. The presence of RBCs amplified the release of IL-6, TNF-α and CCL2 statistically significant in both groups, but reduced the generation of ROS in the group of healthy controls, and showed a similar tendency in the group of subjects with LAgP. RvE1 had no impact on the production of intracellular ROS, TNF-α, IL-6, CXCL8 and CCL2 by neutrophils from either group, but tended to reduce the generation of ROS in subjects with LAgP in the absence of RBCs.

CONCLUSIONS

Our data support that binding to RBCs protects P. gingivalis from ROS and concomitantly enhances neutrophil release of proinflammatory cytokines providing a selective advantage for P. gingivalis growth.

Malondialdehyde, superoxide dismutase and melatonin levels in gingival crevicular fluid of aggressive and chronic periodontitis patients

BACKGROUND

The aim of this study was to investigate malondialdehyde (MDA), superoxide dismutase (SOD) and melatonin levels in the gingival crevicular fluid (GCF) of patients with chronic periodontitis (CP) and generalized aggressive periodontitis (GAgP) as biomarkers for oxidative stress.

METHODS

The study comprised 65 subjects: 15 healthy individuals, 25 CP patients and 25 GAgP patients. Plaque index, gingival index, pocket depth, clinical attachment level measurements and GCF samples were obtained from all subjects. MDA, SOD and melatonin levels were determined utilizing enzyme-linked immunosorbent assay.

RESULTS

GCF-MDA levels were significantly higher in the GAgP group compared to the CP and control groups (p < 0.001) and significantly higher in the CP group than the C group (p < 0.001). SOD and melatonin GCF levels were significantly higher in the control than the GAgP and CP groups (p < 0.05), and significantly lower in the GAgP than the CP group (p < 0.05). The CP group demonstrated a significant negative correlation between GCF-MDA and melatonin concentrations. A positive correlation was observed between SOD and CAL in the CP group and PD in the GAgP group.

CONCLUSIONS

MDA, melatonin and SOD could be considered as biomarkers for oxidative stress in periodontal diseases and might be useful diagnostic aids in distinguishing CP and GAgP patients.

Evaluation of serum ceruloplasmin in aggressive and chronic periodontitis patients

Background:

Pro-inflammatory markers are seen to increase in inflammatory diseases like periodontitis. Detecting an increase in these markers is one of the diagnostic modality. One such marker, which can be detected, is the ceruloplasmin. Ceruloplasmin induces hypoxia and generates oxygen radicals at the site of aggressive periodontitis. It also causes a state of hypoferremia leading to increase in the natural resistance of the body. The aim of this study was to evaluate the serum levels of cerruloplasmin in both aggressive and chronic periodontitis patients.

Materials and Methods:

Blood samples were collected from aggressive periodontitis patients (n = 20), chronic periodontitis patients (n = 20) and periodontally healthy patients (n = 20). The serum was extracted from all the blood samples and ceruloplasmin levels were spectroscopically evaluated through a new kinetic method, which used a norfloxacin based reagent.

Results:

Serum ceruloplasmin levels were found to be significantly higher in aggressive periodontitis patients (P > 0.05) than in chronic periodontitis patients (P > 0.05) even though increase in the level of ceruloplasmin was found in chronic periodontitis. Periodontally healthy patients did not show increase in the levels of serum ceruloplasmin. The levels of serum ceruloplasmin also increased with the disease severity whose manifestations were increased bleeding on probing, increased pocket depth and increased attachment loss.

Conclusion:

Serum ceruloplasmin levels increased in both aggressive and chronic periodontitis patients, but more in aggressive periodontitis patients making it a potential marker for diagnosis of periodontitis.

Evaluation of ceruloplasmin levels in patients undergoing surgical interventions with nasal polyps

OBJECTIVE

Oxidative stress is believed to have a role in the development of nasal polyps (NPs). It is also known that ceruloplasmin (CP), an acute phase protein, limits oxidative stress. The purpose of this study was to evaluate the ceruloplasmin levels in patients with NPs.

METHODS

One hundred and twenty patients with NPs, septal deviations and concha hypertrophies were recruited to the study. Patients were divided in two groups; group 1 (n=60) consisted of patients with NPs, and group 2 (n=60) consisted of septal deviations and concha hypertrophies. Polyp specimens were taken from all patients who underwent endoscopic surgery due to NPs, as well as control specimens were acquired who underwent an operation due to septoplasty or concha hypertrophy. Blood and tissue samples were obtained to assess CP levels.

RESULTS

There were no statistical differences in gender, age and biochemical values between two groups (p>0.05 for all). Compared to group 2, group 1 had significantly higher CP levels both in serum and the tissue samples (both p<0.001).

CONCLUSION

As a result of our study; CP levels both in serum and the tissue in patients with NPs were higher, may be consequence of the inflammation, than in patients without NPs.

Expression and possible immune-regulatory function of ghrelin in oral epithelium

Originally found in stomach mucosa, ghrelin is a peptide appetite hormone that has been implicated as an immuno-modulatory factor. Ghrelin has also been found in salivary glands and saliva; however, its expression patterns and biological properties in the oral cavity remain unclear. Therefore, we investigated the expression patterns of ghrelin in saliva, gingival crevicular fluid (GCF), and gingival tissue, as well as its in vitro effects on IL-8 production by TNF-α or LPS-stimulated oral epithelial cells. In the clinical samples obtained from 12 healthy volunteers, the concentration of ghrelin in GCF remarkably exceeded that detected in saliva. The expression of ghrelin mRNAs and growth hormone secretagogue (GHS) receptors could be detected in human oral epithelial cells. Immunohistochemical analysis revealed the expression of ghrelin in gingival epithelium, as well as in fibroblasts in the lamina propria. Ghrelin increased intracellular calcium mobilization and cAMP levels in oral epithelial cells, suggesting that ghrelin acts on epithelial cells to induce cell signaling. Furthermore, synthetic ghrelin inhibited the production of IL-8 from TNF-α or LPS-stimulated oral epithelial cells. These results indicate that ghrelin produced in the oral cavity appears to play a regulatory role in innate immune responses to inflammatory infection.

Inhibition of peripheral blood neutrophil oxidative burst in periodontitis patients with a homeopathic medication Traumeel S

Background

The anti-inflammatory effects of a homeopathic remedy, Traumeel S, have been observed in experimental and clinical studies; however, its antioxidant properties have not been elucidated. The aim of the present study was to evaluate the antioxidant effects of Traumeel S on peripheral blood neutrophils in patients with periodontitis.

Material/Methods

The study was performed using venous blood of 22 individuals with chronic periodontitis and 21 healthy subjects. The antioxidant effects of Traumeel S on the production of reactive oxygen species by unstimulated and stimulated with unopsonized E. coli neutrophils were investigated using luminol- and lucigenin-dependent chemiluminescence (CL).

Results

Polymorphonuclear leukocytes of periodontitis patients produced higher levels (p<0.01) of light output of lucigenin-dependent chemiluminescence and significantly reduced (p<0.01) light output of luminol-dependent chemiluminescence than analogous cells of healthy subjects. Highly diluted (10⁻⁴ of the stem solution) Traumeel S significantly (by approximately 50%) reduced superoxide-induced oxidation of lucigenin by unstimulated and stimulated with unopsonized E. coli polymorphonuclear leukocytes of periodontitis patients and had a tendency to intensify luminol-dependent chemiluminescence. Preincubation of the unstimulated and stimulated with unopsonized E. coli polymorphonuclear leukocytes of healthy subjects with Traumeel S exerts no inhibitory action on the luminol- and lucigenin-dependent chemiluminescence of the above-mentioned cells.

Conclusions

This study indicates that Traumeel S may significantly reduce production of superoxide anion by unstimulated and stimulated peripheral blood polymorphonuclear neutrophils of periodontitis patients.