IL-17A stimulates the expression of inflammatory cytokines via celecoxib-blocked prostaglandin in MC3T3-E1 cells

Objective

The prostaglandins (PGs) released from osteoblasts can alter the process of bone remodelling. Recently, we showed that compressive force induced the expression of pro-inflammatory cytokine interleukin (IL)-17s and their receptors in osteoblastic MC3T3-E1 cells and that IL-17A was expressed most highly. Consequently, in the current study we examined the effect of IL-17A and/or celecoxib on PGE₂ production and the expression of cyclooxygenases (COXs) and inflammatory cytokines in MC3T3-E1 cells. We also examined the effects of PGE₂ and cyclohexamide on the expression of inflammatory cytokines.

Methods

Cells were cultured with or without IL-17A (0.1, 1.0, or 10 ng/ml) in the presence or absence of 10 μM celecoxib, a specific inhibitor of COX-2, for up to 72 h. Cells were pretreated with or without 10 μg/ml cycloheximide, protein synthesis inhibitor, for 30 min, and then cultured with 10 ng/ml IL-17A for 24 h. Cells were also cultured with or without 1.5 ng/ml PGE₂ for 24 h. PGE₂ production was determined by ELISA. The expression of COX-1, COX-2, IL-1α, IL-6, IL-8, IL-11, and TNF-α mRNAs and proteins was determined by real-time PCR and ELISA, respectively.

Results

The expression of COX-2, IL-1α, IL-6, IL-8, IL-11, and TNF-α, as well as PGE₂ production increased in the presence of IL-17A, whereas COX-1 expression did not change. Celecoxib blocked the stimulatory effect of IL-17A on the expression of COX-2, IL-1α, IL-6, IL-8, and IL-11 as well as PGE₂ production, whereas it did not block TNF-α expression. Cycloheximide pretreatment suppressed the expression of IL-17-induced inflammatory cytokines. The expression of IL-1α, IL-6, IL-8, and IL-11 increased by the addition of PGE₂, whereas TNF-α expression was not affected.

Conclusion

These results suggest that IL-17A stimulates the expression of bone resorption-related inflammatory cytokines through an autocrine mechanism involving celecoxib-blocked PGs, mainly PGE₂, in osteoblasts.     

Curcumin abrogates LPS-induced pro-inflammatory cytokines in RAW 264.7 macrophages. Evidence for novel mechanisms involving SOCS-1, -3 and p38 MAPK

Curcumin is the active compound in the extract of Curcuma longa rhizomes with anti-inflammatory properties mediated by inhibition of intracellular signalling. SOCS and MAPKinases are involved in the signalling events controlling the expression of IL-6, TNF-α and PGE₂, which have important roles on chronic inflammatory diseases. The aim was to assess if these pathways are involved in curcumin-mediated effects on LPS-induced expression of these cytokines in macrophages. RAW 264.7 murine macrophages were stimulated with Escherichia coli LPS in the presence and absence of non-cytotoxic concentrations of curcumin. Curcumin potently inhibited LPS-induced expression of IL-6, TNF-α and COX-2 mRNA and prevented LPS-induced inhibition of SOCS-1 and -3 expression and the inhibition of the activation of p38 MAPKinase by modulation of its nuclear translocation. In conclusion, curcumin potently inhibits expression of LPS-induced inflammatory cytokines in macrophages via mechanisms that involve modulation of expression and activity of SOCS-1 and SOCS-3 and of p38 MAPK.     

Effect of lipopolysaccharide from Porphyromonas gingivalis on prostaglandin E2 and interleukin-1β release from rat periosteal and human gingival fibroblasts in vitro

Lipopolysaccharide (LPS) was extracted from Porphyromonas gingivalis (W83) by the Westphal procedure, nuclease-digested and ultracentrifuged. Fibroblasts were obtained from human gingival tissue and rat periosteum, grown to confluence then stimulated in serum-free medium with 0.1, 1.0 and 10.0μg/ml LPS. The levels of prostaglandin E₂ (PGE₂) and interleukin-1β (IL-1β) released were measured after 2, 4 and 6 d by specific radioimmunoassays. Unstimulated gingival fibroblasts produced low levels of PGE₂ (24.5 ± 1.5 (SD) ng/ml) and IL-1β (0.34 ± 0.29 ng/ml). LPS stimulated statistically significant dose-related increases hi PGE₂ and IL-1β at the concentrations of LPS tested. At 10.0μg/ml, LPS-stimulated fibroblasts produced 363.5 ± 40.3 ng/ml PGE, and 1.81±0.1 ng/ml IL-1β in 6 d. These results demonstrate that LPS from P. gingivalis is capable of stimulating PGE, and IL-1β release from fibroblasts. This would appear to be an additional mechanism by which LPS can induce tissue breakdown in periodontal disease.     

Prostaglandin E2 potentiates interleukin-1β induced interleukin-6 production by human gingival fibroblasts

Abstract Increased levels of cytokines and prostanoids have been detected in inflamed gingival tissue and may play an important role in periodontal pathogenesis. Recent studies suggest that monocytic products, such as interleukin (IL)-1β, could stimulate IL-6 production by human gingival fibroblasts (HGF). In this context, the production of local cytokines and inflammatory mediators could regulate the secretory capacity of resident gingival fibroblasts. Therefore, the purpose of this study was to determine if PGE₂ induced by IL-1β could potentiate the IL-6 response by HGF. Utilizing an ELISA, it was determined that maximal IL-6 occurred when HGF were stimulated with 0.10–10 nM IL-1β. These concentrations of IL-1β also induced a small, but significant increase in PGE₂ production by HGF. Interestingly, the combination of ILγβ and PGE₂ induced a synergistic rise in IL-6 production by HGF. Moreover, inclusion of indomethacin caused a 20% reduction in IL-6 production and totally eliminated PGE₂ production. These findings provide additional rationale for the clinical use of NSAIDs in the management of periodontal disease due to their ability to attenuate production of both PGE₂, and IL-6. These results suggest the endogenous PGE₂ induced by IL-1β plays an important regulatory role in IL 6 production by HGF. Moreover, they support the concept that elevated PGE₂ induced during inflammation can regulate HGF secretory function.     

Cytokine levels in gingival crevicular fluid during orthodontic treatment with aligners compared to conventional labial fixed appliances: a 3-week clinical study

Objective: To test the hypothesis that the levels of IL-1ß and TNF-α increased more and IL-1α, IL-2, IL-6, IL-8 increased less, after 3 weeks of treatment with conventional labial fixed appliance and with aligners.

Material and methods: Forty patients who were treated either with labial brackets (n?=?20) or aligners (n?=?20). Gingival crevicular fluid (GCF) samples were collected at baseline and after 21 days. Cytokine levels were evaluated by enzyme-linked immune sorbent assay (ELISA). Plaque index (PI), gingival index (GI), and bleeding on probing (POB) were also examined.

Results: The levels of IL-1α, IL-1ß, IL-2, IL-6, IL-8 and TNF-α in the GCF were significantly increased in both groups. The levels of IL-2, IL-6, IL-8 increased more in patients treated with aligners compared to those treated by labial fixed appliances. There was a statistically significant difference in change of the mean cytokine levels of IL-1α, IL-2, IL-6, IL-8 and TNF-α compared to labial fixed appliances and aligners.

Conclusions: The levels of the six studied cytokines in GCF (IL-1α, IL-1ß, IL-2, IL-6, IL-8 and TNF-α) increased after 3 weeks both after treatment with conventional labial fixed appliance and with aligners. IL-1ß and TNF-α showed a prominent increase compared to the other cytokines in the GCF of teeth by both the labial fixed appliance and aligners. However, there were only minor differences in the changes of the cytokine levels from baseline to 3 weeks between the two groups. There were no differences between the groups regarding PI, GI or POB.     

Nicotine and smokeless tobacco effects on gingival and peripheral blood mononuclear cells

Abstract. The pathogenesis of tobacco-related periodontal diseases is not well understood. The purpose of this study was therefore to investigate smokeless tobacco extract (ST) and nicotine effects on prostaglandin E₂ (PGE₂) and interleukin-1β (IL-1β) secretion by peripheral blood mononuclear cells (PBMC, consisting of monocytes and lymphocytes) and gingival mononuclear cells (GMC). Both peripheral blood and gingival tissue adjacent to the alveolar crest were taken from non-smoking adult periodontitis patients. Gingival tissue was treated with collagenase and deoxyribonuclease and GMC and PBMC were isolated by Ficoll-Hypaque centrifugation. GMC and PBMC (100,000 cells/200 μl) were cultured for 24 hours in supplemented RPMI 1640 alone (control), or in supplemented RPMI 1640 containing 1% ST, 100μg/ml nicotine, 1 μg/ml Porphyromonas gingivalis LPS, or 1 μg/ml P. gingivalis LPS and either 100 μg/ml nicotine or 1% ST. Enzyme immunoassays were used to quantity PGE₂ and IL-1β. Treatments were compared by repeated measures ANOVA. 100 μg/ml nicotine (7-fold, p<0.02) and 1% ST (3.5-fold, p<0.004) significantly increased secretion of PGE₂ by PBMC relative to control cultures. 100 μg/ml nicotine and 1% ST, however, had no effect on IL-1β secretion by PBMC. Enhanced PGET secretion also was seen when PBMC were treated with P. gingivalis LPS+100 μg/ml nicotine relative to P. gingivalis LPS alone (p<0.007). In contrast, 100 μg/ml nicotine significantly downregulated IL-1β secretion by GMC relative to medium alone (p<0.008) and had no effect on PGE₂ secretion by GMC, These data indicate that while nicotine and ST can stimulate PBMC to secrete PGE₂, they cannot activate further mononuclear cells extracted from gingiva, possibly due to maximal previous stimulation in the periodontitis lesion.     

Triclosan reduces prostaglandin biosynthesis in human gingival fibroblasts challenged with interleukin-1 in vitro

Abstract The effect of the toothpaste ingredient triclosan (2,4,4′-trichloro-2′-hydroxyldiphenyl ether) on the prostaglandins biosynthesis in human gingival fibroblasts challenged with interleukin-1β (IL-1β) or tumor necrosis factor α (TNFα) was studied in vitro. When gingival fibroblasts were treated simultaneously with triciosan and IL-1β, the stimulatory effect of IL-1β on prostaglandin E₂ (PGE₂) and PGI₂ formation was reduced in a dose-dependent manner by triclosan. Triclosan also reduced the PGE: formation induced by TNFα. Furthermore, the capacity of IL-1β to induce release of [³H] arachidonic acid from prelabelled gingival fibroblasts was reduced in the presence of triclosan. Addition of exogenous unlabelled arachidonic acid (AA) to the cells resulted in enhanced PGE₂ formation which was reduced by triclosan. The upregulation of the metabolism of AA to PGE₂ induced by IL-lβ, was markedly reduced in the presence of triclosan. The study indicates that the stimulatory effect of IL-1β on prostanoid formation (PGE₂, PGI₂) in human gingival fibroblasts was diminished in the presence of triciosan partly at the level of phospholipase A₂ and partly at the level of cyclooxygenase. The present data that triclosan. in vitro, inhibits the production of inflammatory mediators such as prostaglandins suggests that this can be an aspect of its clinical effect on gingivitis, in addition to its antibacterial effect.     

Roles of IL-1α in the Growth of Keratocystic Odontogenic Tumor

Keratocystic odontogenic tumors have a high level of proliferative activity in epithelial cells and they tend to grow aggressively in the jaw. The tumor dramatically decreases in size by decompression of the intracystic fluid pressure. We herein focused on the roles of interleukin (IL)-1α and demonstrated the biochemical mechanisms of the tumor growth. We found that IL-1α is strongly expressed in the lining epithelial cells of the tumors, and the intracystic fluid levels of IL-1α are significantly higher than the levels of the other inflammatory cytokines of IL-6 and tumor necrosis factor-α (TNF-α). The expression of IL-1α in the epithelial cells decreases after the marsupialization of the tumor. In vitro experiments also reveal that positive pressure enhances the expression of IL-1α in the tumor epithelial cells in culture. IL-1α stimulates the production of matrix metalloproteinase (MMP)-9, and activates the released proMMP-9 by increasing the expression of proMMP-3 and plasminogen activator urokinase (u-PA) in the tumor epithelial cells. In the fibroblasts isolated from the tumors, IL-1α increases the expression of proMMP-1, proMMP-2, and proMMP-3. IL-1α also activates proMMP-2 by inducing the expression of membrane-type 1 matrix metalloproteinase (MT1-MMP) synergistically with type I collagen. Furthermore, IL-1α increases the expression of macrophage colony-stimulating factor (M-CSF) and cyclooxygenase (COX)-2 in the fibroblasts. The COX-2 synthesizes prostaglandin E₂ (PGE₂), and the secreted PGE₂ stimulates the expression of receptor activator of nuclear factor-κB ligand (RANKL), while neither IL-1α nor PGE₂ affects the expression of osteoprotegerin (OPG) in the fibroblasts. The fibroblasts express Ca²⁺-sensing receptor (CasR) on the cell surface, and extracellular Ca²⁺ activates COX-2 expression via the CasR. A strong relationship may thus be present between the intracystic fluid pressure and IL-1α expression in epithelial cells, and the released IL-1α may play a crucial role in the growth of keratocystic odontogenic tumors by stimulating proteolytic enzyme production and osteoclastogenesis.     

microRNA-223在牙龈卟啉单胞菌诱导牙龈成纤维细胞炎症调控的研究

目的 探讨microRNA-223在牙龈卟啉单胞菌脂多糖(Porphyromonas gingivalis lipopolysaccharides, P.g-LPS)诱导牙龈成纤维细胞(gingival fibroblasts,GFs)炎症过程中对相关炎症因子表达水平的调控作用。 方法 采用慢病毒转染、干扰GFs中的microRNA-223的表达,在最适P.g-LPS刺激浓度(800 μg/L)分别刺激过表达、抑制以及正常表达microRNA-223的GFs,采用实时聚合酶联反应（Real-time quantitative polymerase chain reaction,qPCR）检测TNF-α、IL-1β、IL-6的mRNA表达水平变化,酶联免疫吸附试验(enzyme linked immunosorbent assay, ELISA)检测其蛋白水平的变化。 结果 LPS刺激GFs产生炎症反应时,细胞内microRNA-223以及相关促炎因子TNF-α、IL-1β、IL-6的mRNA和蛋白表达水平较正常细胞中的表达量明显上调。当细胞内microRNA-223上调时,促炎因子的mRNA和蛋白表达水平也会上调(P<0.001);当细胞内microRNA-223下调时,促炎因子TNF-α、IL-1β的蛋白水平会显著下降(P<0.001)。 结论 当GFs受P.gingivalis-LPS刺激发生炎症时,microRNA-223的表达量增多,上调促炎因子TNF-α、IL-1β、IL-6,进一步加重组织细胞的炎症。     

Cyclic Mechanical Strain Induces Interleukin-6 Expression via Prostaglandin E2 Production by Cyclooxygenase-2 in MC3T3-E1 Osteoblast-like Cells

Interleukin (IL)-6, produced by osteoblasts, is one of the key cytokines that promote bone resorption. This study examined the effect of cyclic mechanical strain on the expression of IL-6 mRNA and protein, and the induction mechanism of IL-6 in MC3T3-E1 osteoblast-like cells using RT-PCR and ELISA. MC3T3-E1 cells were cultured in α-MEM with 10% FBS on flexible, collagen I-coated membranes and subjected to cyclic mechanical strain at 6 cycles/min. The production of IL-6 protein was increased at 3 h, reached a peak at 6 h, and was maintained up to 24 h by the cyclic mechanical strain. The strain increased the production of IL-6 protein in a force-dependent manner. The expression of IL-6 mRNA was increased by the cyclic mechanical strain. Prostaglandin(PG)E₂ production was induced at 1 h, dramatically increased to 3 h, and was gradually increased from 3 to 24 h by the cyclic mechanical strain. The strain increased PGE₂ production in a force-dependent manner. Treatment with PGE₂ increased the production of IL-6 protein from MC3T3-E1 cells. The cyclic mechanical strain promoted cyclooxygenase (COX)-2 but not COX-1 mRNA expression. Pretreatment with indomethacin and NS-398 prevented PGE₂ production and partly inhibited the production of IL-6 protein induced by the cyclic mechanical strain. These findings suggest that cyclic mechanical strain increases IL-6 expression in osteoblasts, the induction of which is in part mediated via PGE₂ production by COX-2.     

富血小板纤维蛋白促进组织愈合机制的探讨

目的:通过检测富血小板纤维蛋白(platelet-rich fibrin,PRF)中多种细胞因子的表达,探讨其在组织再生修复中的作用.方法:取健康志愿者肘静脉全血制备PRF标本,通过免疫组化的实验方法,检测标本中IL-1 β、IL-4、IL-6、TNF、PDGF-BB和TGF-β 1的表达.结果:免疫组化结果表明富血小板纤维蛋白标本中IL-1 β、IL-4、IL-6、TNF、PDGF-BB和TGF-β 1均为阳性表达.结论:富血小板纤维蛋白中含有多种细胞因子,这些细胞因子与纤维蛋白共同发挥作用使PRF具有减少术后反应、降低术后感染风险和促进组织愈合的作用.     

Proinflammatory cytokines detectable in synovial fluids from patients with temporomandibular disorders

Objective. To measure the levels of the proinflammatory cytokines, interleukin (IL)-1β, IL-6, tumor necrosis factor- (TNF)α, IL-8, and interferon- (IFN) γ in synovial fluid samples taken from patients with temporomandibular disorders (TMD).Study design. We studied 6 asymptomatic volunteers and 51 patients with TMD. The IL-1β, IL-6, TNF-α, IL-8, and IFN-γ levels in temporomandibular joint synovial fluid were measured using enzyme-linked immunosorbent assay.Results. Measurable level of at least one cytokine in the synovial fluid was found in 40 (64.5%) of 62 joints in the patients: IL-1β and IFN-γ were each detected in 18 (29.0%) of 62 joints; IL-6 in 13 (21.0%) of 62 joints; IL-8 in 11 (19.3%) of 57 joints; and TNF-α in only 5 (8.1%) of 62 joints. None of these cytokines was detectable in the synovial fluid in the control group. Furthermore, there was a strong correlation between the detection of IL-1β and pain in the joint area.Conclusions. These data clearly demonstrate increased levels of several proinflammatory cytokines in certain patients with TMD and suggest that these cytokines may play a role in the pathogenesis of synovitis and degenerative changes of the cartilaginous tissue and bone of the temporomandibular joint.     

Reduced proinflammatory activity of outer membrane vesicles of Tannerella forsythia treated with quorum sensing inhibitors

Outer membrane vesicles (OMVs) of bacteria harbor physiologically active molecules, and quorum sensing inhibitors (QSIs) are expected to regulate bacterial virulence. In this study, we analyzed the proinflammatory activity of OMVs of the periodontal pathogen Tannerella forsythia treated with d -arabinose and d -galactose as QSIs, which inhibit the biofilm formation of periodontal pathogens and autoinducer 2 activity. Compared to OMVs of nontreated T. forsythia (TF OMVs), OMVs released from QSI-treated T. forsythia, designated TF ara-OMVs and TF gal-OMVs, showed reduced production of TNF-α, IL-1β, IL-6, and IL-8 in THP-1 monocytes through decreased activation of NF-κB/MAPKs. Using a human NF-κB reporter cell line and bone marrow-derived macrophages from TLR2^−/− mice, TF ara-OMVs and TF gal-OMVs showed less activation of TLR2 than TF OMVs. These results demonstrated that QSIs provide a dual advantage against bacterial infection by inhibiting bacterial biofilm formation and generating OMVs with reduced proinflammatory activity.     

Effects of gender on serum biomarkers of systemic inflammation coincident to experimentally-induced periapical lesions

Objective

The literature suggests that females have less adverse effects to infection than males, due to the protective effects of oestrogen. The purpose of our study is to compare the systemic effects of induced periapical lesions between groups of animals with various serum concentrations of oestrogen.

Methods

To induce periapical inflammation, two molar tooth pulps were exposed in ovariectomized (OVX) and normal female (F) and castrated (Cast-M) and normal male (M) Sprague–Dawley rats (Experimental group, E). Sham-operated control animals from each group were also studied (Control group, C). Twenty-eight days later, serum and maxillas were collected. Serum 17β-oestradiol, testosterone, MMP-9, IL-18, IL-6, TNF-α, and IL-1β concentrations were measured by ELISA. Maxillas were cleaned of residual tissue and digital radiographs were made to verify the presence of periapical lesions. Data were compared by factorial ANOVA, post hoc Tukey, and Pearson correlation tests. Groups were considered to be significantly different when p < 0.05.

Results

The serum concentration of IL-18, TNF-α, IL-1-β, IL-6 and MMP-9 was greatest in OVX-E animals, compared to all other groups (p < 0.001). F-E rats had significantly higher serum concentrations of these cytokines, compared to F-C. The fold difference in serum concentration of the biomarkers (between E and C groups) was significantly greater in females than males, even though males had higher baseline concentrations of all these biomarkers.

Conclusion

When females are oestrogen-deficient, their systemic response to periapical lesions is significantly greater than males, suggesting that oestrogen is essential in protecting females from the effects of this type of inflammation.     

Effects and interactions of tumour necrosis factor α and bradykinin on interleukin-1 production in gingival fibroblasts

Effects of and interactions between tumour necrosis factor α (TNFα) and bradykinin (BK) on production of interleukin-1 (IL-lα, IL-lβ) in human gingival fibroblasts were studied. The cytokine TNFα induced production of cell-associated IL-lα and IL-1β in gingival fibroblasts, with IL-lβ being most abundant. Addition of BK, in the presence of TNFα, for 1 h and 6 h, respectively, synergistically enhanced the TNFα induced IL-lβ production, whereas BK alone did not induce 1L-1 production. Similar to BK, two phorbol esters, phorbol 12,13 dibutyrate (PDBu) and phorbol 12-myristate-13-acetate (PMA) which are known to stimulate protein kinase C (PKC), synergistically enhanced the TNFα induced IL-lβ production in the gingival fibroblasts. On the contrary, a phorbol ester which does not activate protein kinase C, 13-phorbolacetate (13-PA), did not potentiate the TNFα induced IL-lβ production. Similar to BK, the phorbol esters (PMA, PDBu, 13-PA) alone did not induce IL-1β production in the gingival fibroblasts. The results indicate that TNFα induces production of cell-associated IL-1 in gingival fibroblasts, which can be upregulated by a PKC dependent pathway.     

Interleukin-1 beta affects cyclooxygenase-2 expression and cartilage metabolism in mandibular condyle

Extracellular matrix degradation in mandibular condylar cartilage is mediated by various cytokines in the temporomandibular joint (TMJ). Interleukin-1 beta (IL-1β) is detected in joint structures with pathologic status, and participates in catabolic action in the extracellular matrix. The purpose of this study was to investigate the effects of IL-1β on cyclooxygenase-2 (COX-2) expression and cartilage metabolism using cultured chondrocytes from mandibular condyle. Articular chondrocytes from the porcine mandibular condylar cartilage around the surface were cultured and treated with 0–10 ng/ml IL-1β or 0–1000 ng/ml prostaglandin (PGE₂) for 0–24 h. The mRNA levels of COX-2, MMP-1, -3, and -13 were evaluated by real-time PCR analysis. The protein levels of PGE₂ and MMPs were examined by ELISA and Western blot analysis, respectively. The expression levels of COX-2 and PGE₂ were enhanced by exogenous IL-1β in chondrocytes. The mRNA levels of MMP-1, -3, and -13 were up-regulated by PGE₂ treatment dose-dependently. It is shown that the expression of COX-2/PGE₂ was enhanced by IL-1β in articular chondrocytes from mandibular condyle, and that MMP-1, -3, and -13 were induced by PGE₂, suggesting that IL-1β-induced COX-2/PGE₂ play a crucial role in catabolic processes of mandibular condylar cartilage under inflammatory conditions.     

The influence of prostaglandins on steroid conversions by human gingival fibroblasts

The aim of this investigation was to study the effects of prostaglandins E₁ and E₂ (PGE₁ and PGE₂) on the accumulation, release and metabolism of C₁₉ steroids by human gingival fibroblasts (HGF) and gingivae, due to their anabolic potential in inflammatory repair. For the accumulation studies, HGF were incubated with 14C-testosterone at timed intervals and the cell-digests analysed for label uptake. The release of 5α-dihydrotestosterone (DHT) by HGF was studied by preincubating the cells with 14C-DHT and reincubating with cold steroid to quantify its release at timed intervals. For the metabolic studies, HGF/gingival tissue were incubated with 14C-testosterone and serial concentrations of PGE₁ and PGE₂ to study their effects on the synthesis of DHT. The incubations were terminated at 24 h and extracted metabolites were analysed and quantified. The accumulation of 14C-testosterone by human gingival fibroblasts was elevated 3-fold at 24 h by PGE₁ (n = 3, p < 0.001; 1-way ANOVA). The release of 14C-DHT was enhanced nearly 2-fold by PGE_X (n = 3, p < 0.001), compared with controls. Both PGE₁ and PGE₂ caused 2-fold increases in DHT synthesis by HGF and 3-fold increases in 4-androstenedione formation (n=4, p < 0.001). With the tissue incubations PGE₁/PGE₂ caused 3-4-fold increases in DHT synthesis (n = 5, p<0.005; Wilcoxon signed rank statistic for paired observations). Direct stimulation of the accumulation/release and metabolism of these steroids by prostaglandins in gingivae may contribute to the anabolic potential of androgens in inflammatory periodontal disease.     

Effect of iRoot SP and mineral trioxide aggregate (MTA) on the viability and polarization of macrophages

ObjectiveThis study was performed to investigate the effect of iRoot SP and mineral trioxide aggregate (MTA) on the viability and polarization of macrophages.MethodsThe effect of iRoot SP and MTA on the viability of RAW 264.7 macrophages was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay after 1 and 2 days of culture. The gene expression levels of interleukin 1β (IL-1β), tumor necrosis factor α (TNF-α), interleukin 10 (IL-10), interleukin 12p40 (IL-12p40) were measured by quantitative real time polymerase chain reaction (qRT-PCR) after stimulation of the RAW 264.7 macrophages with iRoot SP and MTA. The expression levels of CD11c and CD206 in RAW 264.7 macrophages were examined by immunofluorescence and flow cytometry after stimulation with iRoot SP and MTA. The data were analyzed by one-way analysis of variance and the Tukey test.ResultsBoth iRoot SP and MTA were non-toxic to the RAW 264.7 macrophages. The use of iRoot SP and MTA increased the expression of IL-1β, TNF-α, IL-10, IL-12p40 on the first day of culture and could promote macrophage M1 and M2 polarization.ConclusionsMTA and iRoot SP have good biocompatibility with macrophages, and they induced both M1 and M2 polarization of the RAW 264.7 macrophages.