Autocrine regulation of osteoclast formation and bone resorption by IL-1 alpha and TNF alpha.

Bone resorption is regulated by the cytokines within marrow cells that mediate osteoclast formation and activation. IL-1 and TNF induce bone resorption by stimulating the production of osteoclast-like multinucleated cells and by increasing the bone-resorbing activity of formed osteoclasts. This study was designed to detect IL-1 and TNF in osteoclasts in vitro and to determine whether these cytokines up-regulate osteoclast differentiation and bone resorption. The production of IL-1 alpha, -beta, and TNF alpha, beta in osteoclasts was examined immunohistochemically and by in situ hybridization. In the co-culture of C57BL/6N mouse bone marrow and MC3T3-G2/PA6 cells, a colony of osteoclasts formed, and IL-1 alpha and TNF alpha were detected. However, IL-1 beta and TNF beta were not detected. To investigate the role of IL-1 alpha and TNF alpha from osteoclasts, we enumerated TRAP-positive cells and measured the resorption pit areas in the presence of antibodies against IL-1 alpha and TNF alpha. The addition of antibodies against IL-1 alpha and TNF alpha to the co-culture system decreased the number of TRAP-positive colonies at seven days after incubation (anti-IL-1 alpha, 25.0 +/- 2.3%; anti-TNF alpha, 41.7 +/- 3.7%; anti-IL-1 alpha + anti-TNF alpha, 40.5 +/- 1.3%; and control, 100%), and the ratio of mononuclear to multinuclear cells had changed (anti-IL-1 alpha, 90:10; anti-TNF alpha, 75:25; anti-IL-1 alpha+ anti-TNF alpha, 88:12; and control, 60:40). The total pit areas per dentin slice also decreased with the addition of antibodies (anti-IL-1 alpha, 28,828; anti-TNF alpha, 49,249; anti-IL-1 alpha + anti-TNF alpha, 30,685; and control, 303,139 mm2). These results suggest that local production of IL-1 alpha and TNF alpha by osteoclasts is an important mechanism for regulating the osteoclast differentiation and bone resorptive process.     

Study of cytokine production in inflamed human gingival tissues in periodontitis. Interleukin-1 (IL-1 alpha, beta) and tumor necrosis factor (TNF alpha)

It seems to be generally agreed that periodontal disease is a local manifestation of a systemic immune response. Interleukin-1 (IL-1), which has multiple biologic activities, is detected in the gingival sulcus fluid of periodontitis sites. Recent investigations have revealed that IL-1 and tumor necrosis factor (TNF) are analogous to osteoclast activating factor and promote bone resorption. These findings have suggested the possibility that IL-1 and TNF may play a significant role in the initiation and development of periodontal disease. However, it remains to be determined whether these cytokines influence periodontal tissue breakdown in periodontitis. To elucidate the mechanisms of tissue breakdown in periodontitis, we examined cytokine production by human periodontitis gingival tissue. Twelve periodontitis patients were included in this study. Control subjects with healthy periodontium consisted of nine individuals. Gingival samples were biopsied from inflamed or healthy gingival tissues. Biopsy specimens were dissected into fragments 3 mm in diameter and plated onto 24 well culture plates with RPMI 1640 medium. IL-1 activity was measured by a growth inhibition assay using melanoma cell line A 375. An enzyme-linked immunosorbent assay (ELIZA) was used for measuring levels of human IL-1 alpha, IL-1 beta. TNF alpha activity was measured by a growth inhibition assay using cell line LM2D6. IL-1 activity was detected in significantly (p less than 0.001) higher levels in culture supernatants from gingival tissues in periodontitis (48.0 +/- 23.3 units/ml) than in control tissues (2.3 +/- 0.6 units/ml), however, levels of IL-1 activity were not associated with periodontal pocket depth or extent of alveolar bone resorption in periodontitis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Measurement of interleukin 1 alpha and 1 beta (IL-1 alpha and IL-1 beta) in human cystic lesions of the jaw. Implications for the pathogenesis of radicular cysts.

Human radicular cystic tissue of jaws was found to contain between 0.823 pg/mg to 18.026 pg/mg interleukin 1 beta and from 0.34 pg/mg to 0.708 pg/mg interleukin 1 alpha. No IL-1 beta and alpha could be found in specimens from healthy patients. A finding which may be extremely relevant in cystic growth and episodes of alveolar bone resorption around the cystic lesion.     

The relationship between IL-1 gene polymorphism and marginal bone loss around dental implants.

PURPOSE: Early marginal bone loss around dental implants has been found during the bone healing period before stage II surgery despite a lack of apparent cause, and the etiology of this bone loss is unclear. This study was designed to investigate whether interleukin-1 gene polymorphism is associated with the marginal bone loss around the implants before stage II. MATERIALS AND METHODS: One hundred forty-three implants were placed in 59 patients. The patients were divided into 2 groups: 1) test group: with 1 or more marginal bone loss greater than 0.5 mm; and 2) control group: with marginal bone resorption less than 0.5 mm. Polymorphisms of the IL-1alpha and IL-1beta genes (IL-1A-889, IL-1B-511, and IL-1B+3954) were detected by restriction fragment length polymorphism using Ncol, AvaI, and TaqI digestion after polymerase chain reactions. RESULTS: The frequency of IL-1B-511 II/II was significantly higher among patients in early marginal bone loss (+) group than those in early marginal bone loss (-) group (P < .05). Multiple logistic regressions showed the OR of the II/II versus the I/I+I/II of the IL-1B-511 genotype was 3.933 between the 2 groups. The difference was statistically significant (P < .05). There was no significant difference between the other risk factors. CONCLUSION: These results suggest that the IL-1B-511 II/II genotype in individuals is associated with early marginal bone loss around implants.     

MMPs, IL-1, and TNF are regulated by IL-17 in periodontitis

Periodontitis is characterized by periodontal tissue destruction. Since interleukin-17 (IL-17) has been reported to up-regulate IL-1beta and tumor necrosis factor-alpha (TNF-alpha), it was hypothesized that it is increased in periodontitis and up-regulates these cytokines and tissue-destructive matrix metalloproteinases (MMP) in local migrant and resident cells. Immunocytochemistry disclosed elevated IL-1beta, TNF-alpha, and IL-17 levels in periodontitis. These cytokines induced proMMP-1 and especially MMP-3 in gingival fibroblasts, whereas MMP-8 and MMP-9 were not induced. IL-17 was less potent as a direct MMP inducer than IL-1beta and TNF-alpha, but it induced IL-1beta and TNF-alpha production from macrophages, and IL-6 and IL-8 from gingival fibroblasts. In accordance with these findings, immunocytochemistry disclosed that MMP-1 and MMP-3 were increased in periodontitis. Gingival fibroblasts may play an important role in tissue destruction in periodontitis via cytokine-inducible MMP-1 and MMP-3 production, in which IL-17 plays a role as a key regulatory cytokine.     

108颗牙种植体修复一年后的临床及X线评价

目的评价牙种植体负重1年后的临床疗效,并分析种植体周围粘膜炎症与骨吸收的关系。方法对70例种植义齿修复患者共108颗负重1年以上的IMZ和Frialit-2种植体进行临床及X线检查。结果所有种植体均无松动及种植体周围X线透射影等种植失败症状,牙槽骨高度降低的均值为（0.63±0.78）mm;粘膜有炎症的位点占所有检测位点的32.9%。重度炎症位点的骨吸收值明显高于轻度炎症位点和健康位点（P<0.05）。大多数种植义齿修复患者的口腔卫生及牙周健康状况均较差。结论IMZ和Frialit-2种植体负重1年后的临床效果满意;种植体周围粘膜炎症是种植体骨吸收的主要原因之一;消除或控制粘膜炎症、改善口腔卫生和邻牙的牙周健康状况,是接受种植的患者迫切需要解决的问题。     

Genetic polymorphisms of the IL-1alpha and IL-1beta genes in African-American LJP patients and an African-American control population

BACKGROUND: A functional polymorphism of the interleukin-1 beta (IL-1beta) gene has been proposed to be a risk factor for periodontitis. In adult forms of periodontitis, non-smokers of northern European heritage carrying the "2" allele of the IL-1alpha-889 and the IL-1beta +3953 RFLPs in either the heterozygous or the homozygous state at both loci were observed to have a greater risk for developing severe periodontitis. Studies of early-onset periodontitis (EOP) found that allele "1" of both IL-1alpha-889 and IL-1beta +3953 was transmitted more frequently with the EOP phenotype. The purpose of the present study was to determine the prevalence of the IL-1alpha and IL-1beta genotype polymorphisms in an African-American (AA) control population and in 37 African-Americans with localized juvenile periodontitis (LJP). METHODS: The IL-1alpha +4845 and IL-1beta +3953 loci were genotyped by PCR amplification, followed by restriction enzyme digestion and gel electrophoresis. The IL-1alpha +4845 locus, in linkage disequilibrium (>99%) with IL-1alpha-889, was genotyped because it is technically easier. Data were analyzed using r x c contingency tables. RESULTS: The IL-1beta +3953 allele "1" was carried by >99% of the AA control population and by 100% of the AA LJP group, with most individuals being homozygous 1,1. The prevalence of the composite genotype with at least one allele "2" at each of the IL-1beta +3953 and IL-1alpha +4845 loci was 14% (AA control group) and 8% (AA LJP group). CONCLUSIONS: Given the high frequency of the IL-1beta allele "1" in the African-American population, it would appear that knowledge of this +3953 polymorphism would provide little diagnostic or predictive information for LJP.     

影响牙种植体早期边缘骨吸收的相关因素的临床初步研究

目的:探讨白细胞介素-1受体拮抗剂基因(IL-1RN)多态性是否与种植体Ⅱ期手术前边缘骨吸收有关.方法:采用病例对照研究,选取44 例种植患者根据有无边缘骨吸收分为病例组和对照组;同时收集所有患者的颊黏膜拭子提取DNA;采用聚合酶链式反应测定IL-1RN的基因型.结果:携带IL-1RNⅠ/Ⅱ基因型的患者早期边缘骨吸收的发生率明显高于Ⅰ/Ⅰ基因型和Ⅰ/Ⅳ基因型的患者.据多元logistic 回归分析,IL-1RN Ⅰ/Ⅱ基因型相对Ⅰ/Ⅰ基因型和Ⅰ/Ⅳ基因型的比值比是23.036 倍(P<0.05),并且吸烟的比值比是15.385 倍(P<0.05).结论:IL-1RN基因多态性与早期边缘骨吸收发生有关,吸烟可能是早期边缘骨吸收发生的重要危险因素.     

Smoking and polymorphisms of the interleukin-1 gene cluster (IL-1alpha, IL-1beta, and IL-1RN) in patients with periodontal disease

BACKGROUND: Polymorphisms within the interleukin-1 cluster are known to be associated with adult periodontal disease. However, interactions of genetic with other risk factors, especially smoking, remain questionable. The aim of this cross-sectional study was to evaluate the genetic influence on periodontal variables in relation to environmental factors. METHODS: One-hundred fifty-four (154) Caucasian subjects were clinically and radiographically assessed for their periodontal status, their smoking history recorded, and their allelic pattern of IL-1alpha, IL-1beta, and IL-1RN polymorphisms determined by genotyping. RESULTS: In assessing periodontitis with mean probing depth, mean attachment loss, or mean bone loss, no differences were found in allele frequencies or combined allotypes between subjects with mild or moderate versus those with severe signs of periodontitis. However, the extent of attachment loss defined as percentage of sites >4 mm was significantly associated with the composite genotype of IL-1alpha/1beta in smokers (odds ratio [OR] = 4.00; 95% confidence interval [CI] 1.03 to 16.70; P= 0.02). No differences were found in genotype negative subjects irrespective of their smoking status. They had nearly identical attachment loss as genotype positive non-smokers. Similar non-significant results were found with respect to extent of bone loss. An increased risk of more extended attachment loss was observed also in individuals carrying mutations of the combined genotype IL-1alpha/IL-1RN, again showing enhanced risk only in genotype-positive and smoking subjects. CONCLUSIONS: The results provide evidence that the composite genotypes studied show interaction with smoking, the main exposition-related risk factor of periodontal disease. Non-smoking subjects are not at increased risk, even if they are genotype-positive.     

Creep and beta1 formation in dental amalgam.

Measurements of creep, beta1 phase content and gamma1 lattice parameter were performed on four conventional amalgams stored at 37 degrees C up to 2 years. The creep values and lattice parameters decreased and the beta1 content increased during this period; the most prominent alterations took place within the first 6 months.     

后牙区种植义齿修复完成一年后并发症的临床分析

目的:总结分析后牙区种植义齿修复完成一年后并发症的发生,为提高临床种植义齿长期修复成功率提供参考。方法:统计分析山东大学口腔医院种植中心自2001年至今完成永久修复一年后出现并发症的后牙区种植体共68颗。结果:出现的并发症有:种植体松动脱落7颗,发生率10.3%;慢性种植体周围炎18颗,发生率26.5%;冠、基台、固位螺丝等部件松动19颗,发生率28.0%;种植体、基台、中央螺丝折断7颗,发生率10.3%;食物嵌塞22颗,发生率32.3%。结论:后牙区种植义齿修复完成后一年出现的并发症主要是食物嵌塞、慢性种植体周围炎、上部修复结构松动。这主要与不同种植系统的选择、种植外科操作、上部修复结构的设计制作及患者的使用维护情况有关。采用规范的外科操作、制作精良的上部修复体,以及注重种植修复体的长期随访维护,就会尽可能地避免种植修复并发症的发生,有效地提高种植义齿修复的长期成功率。     

Periodontal pathogens stimulate CC-chemokine production by mononuclear and bone-derived cells

BACKGROUND: Chemokines are chemotactic cytokines that stimulate recruitment of leukocytes. Monocyte chemoattractant protein-1, macrophage inflammatory protein-1alpha, and RANTES (regulated on activation, normal T cell expressed, and secreted) are 3 well-characterized CC-chemokines that regulate mononuclear cell recruitment. The recruitment of inflammatory cells is of particular importance in the oral cavity because of the likelihood that cells will be challenged with bacteria either during acute infection or following surgical procedures. Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans are putative periodontal pathogens that may be harbored in subgingival and supragingival plaque. The capacity of the host to respond to these bacteria by the elaboration of chemoattractants may represent an important defense mechanism. METHODS: In the present study, we examined CC-chemokine production by human mononuclear cells and bone-derived cells in response to P. gingivalis, A. actinomycetemcomitans and lipopolysaccharides (LPS) stimulation in vitro. The chemokines produced were measured by ELISA. RESULTS: The results demonstrate that P. gingivalis and A. actinomycetemcomitans induce high levels of MIP-1alpha in mononuclear cells. P. gingivalis and A. actinomycetemcomitans stimulated high levels of MCP-1 in bone-derived cells and induced moderate levels of RANTES production in both mononuclear and osteoblastic cells. In mononuclear cells, LPS induced high levels of MIP-1alpha and RANTES and moderate levels of MCP-1; in osteoblasts LPS only induced MCP-1. CONCLUSIONS: The capacity of bacteria to induce a given chemokine depends upon the cell type stimulated. That different cell types would exhibit differences in the CC-chemokines produced under the same stimulus provides a mechanism to explain tissue-specific recruitment of leukocytes.     

白细胞介素-10对人牙囊细胞OPG表达的影响

目的：研究人牙囊细胞白细胞介素-10（IL-10）蛋白的表达及其对骨保护素（08teoprotegerin，OPG）表达的影响。方法：采用组织块加胶原酶消化法培养人牙囊细胞，进行IL-10免疫组化染色。将25ng／ml IL-10作用于牙囊细胞0h、1h,3h,6h,9h，用ELISA法检测上清液中OPG含量变化。结果：人牙囊细胞IL-10表达阳性。25ng／ml IL-10作用于人牙囊细胞3-6hOPG表达显著增加（P〈0．05）。结论：人牙囊细胞表达IL-10，IL-10通过增加人牙囊细胞OPG表达，在牙齿萌出过程中起重要的调控作用。     

Release of prostaglandin E2, IL-6 and IL-8 from human oral epithelial culture models after exposure to compounds of dental materials

A three-dimensional human tissue model based on TR146 cells isolated from a squamous cell carcinoma of the buccal mucosa was used to test for the release of the proinflammatory molecules prostaglandin E2 (PGE2), interleukin 6 (IL-6), and interleukin 8 (IL-8) after exposure to nickel chloride (NiCl2), cobalt chloride (COCl2), palladium chloride (PdCl2), and triethylene glycol dimethacrylate (TEGDMA). These compounds have documented adverse biological effects in vitro. The release of PGE2 from the tissue culture models was inversely correlated with cell viability (MTT assay). Toxic concentrations of NiCl2 and CoCl2 induced the release of PGE2 by factors of about 200-300 compared to controls, but PdCl2 which was nontoxic enhanced PGE2 levels about 10-fold. TEGDMA, however, did not stimulate PGE2 release. None or weakly toxic concentrations of Ni and Co chloride induced IL-6 and IL-8 release by a factor of 5-10 compared to controls. The amounts of IL-6 were induced 25- to 30-fold by PdCl2 under physiological conditions, and IL-8 levels were also slightly enhanced. Nontoxic TEGDMA concentrations induced IL-6 levels 5-fold, but IL-8 amounts increased only slightly. We conclude that a steep rise of PGE2 is closely associated with cytotoxicity. On the other hand, the specific induction of IL-6 occurs at much lower concentrations. Therefore, the measurement of this cytokine may be included as another parameter in evaluating the biological activity of dental materials under nontoxic experimental conditions in vitro.     

Glucocorticoids induced the production and gene expression of IL-1alpha through AP-1 and partially NF-kappaB activation in murine epidermal cells

To investigate the mechanism of the glucocorticoids-induced augmentation of skin response, we have recently reported the modulatory effect of glucocorticoids on the regulation of cytokines production in keratinocytes stimulated with various chemicals in vitro through both NF-kappaB and AP-1 activation. Further to clarify the mechanism in the glucocorticoids-induced augmentation of cytokines production from keratinocytes, we examined the effect of glucocorticoids to keratinocytes without chemical stimulation. Glucocorticoids 10(-4) M inhibited the production of IL-1alpha from Pam 212 cells. However, lower concentration (10(-8)-10(-10) M) of glucocorticoids significantly enhanced the production of IL-1alpha by Pam 212 cells at both the protein and mRNA levels. In contrast, glucocorticoids had no effect on the production of either TNF-alhpa, IL-6, nor GM-CSF by Pam 212 cells cultured for 6 h. Electrophoretic mobility shift assays (EMSA) revealed that 10(-10)-10(-12) M glucocorticoids induced the NF-kappaB activation in Pam 212 cells, however, augmented AP-1 activation by 10(-8)-10(-10) M of glucocorticoids was observed in Pam 212 cells. Furthermore, pyrrolidine dithiocarbamate (PDTC) partially inhibited the IL-1alpha production and completely inhibited NF-kappaB expression by Pam 212 cells. On the other hand, MAP-kinase inhibitors (PD98059, SB202190) completely abrogated not only AP-1 activation but the low concentration glucocorticoids-induced IL-1alpha production. These data indicated that lower concentration of glucocorticoids induced the augmentation of IL-1alpha production from keratinocytes mediated through the AP-1 pathway and partially through NF-kappaB pathway.     

Expression of integrin subunits alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 in different histological types of ameloblastoma compared with dental germ, dental lamina and adult lining epithelium

OBJECTIVE: To analyze integrin expression and distribution in different histological types of ameloblastoma, compared with dental germ, dental lamina and adult lining epithelium. MATERIALS AND METHODS: Three-micrometer sections from paraffin-embedded specimens were evaluated employing a streptavidin-biotin immunohistochemical method and anti-integrin alpha2, alpha3, alpha5, alphav, beta1, beta3 and beta4 antibodies. RESULTS: All integrins were present in all specimens, exhibiting different patterns. In follicular ameloblastoma, the integrin staining was stronger in the periphery while integrin alpha2 was not present in the central cells. Acanthomatous ameloblastoma showed a similar pattern, with positive staining for integrins alpha3, alpha5, alphav, beta1 and beta4 in the metaplastic cells. In the unicystic, integrin staining was uniform except for integrins alpha5 and beta3 which showed weaker staining in the upper layers. In the plexiform ameloblastoma, dental germ and lamina integrin staining was uniform. In the adult lining epithelium, staining for integrins alpha2, alpha5 and beta4 was confined to the basal layer, while integrins alphav and beta3 were present in the basal and parabasal, with integrins alpha3 and beta1 in the upper layers. CONCLUSION: Acanthomatous, follicular and unicystic ameloblastomas showed integrin staining patterns similar to the adult lining epithelium while the plexiform ameloblastoma was similar to the dental germ and lamina.     

Measurement of submucosal forces transmitted to dental implants.

Early loading of dental implants after placement is believed to be a major cause for premature implant failure. If a transitional denture or partial denture is used during the healing period, occlusal forces may be transmitted to the submerged implant, leading to poorly differentiated growth of bone cells and/or potential inhibition of osseointegration at the bone-implant interface. The objective of this study was to develop an experimental model to measure the force transmission and to characterize the effect of selected loading conditions and relief methods on the forces transmitted to the implant. The loading conditions studied included unilateral and bilateral loading of the prosthesis. Forces were measured at two different relief conditions (relief with and without soft liner) and were compared against a control with no relief. The results show that fabrication of the prosthesis with a proper relief at the implant-denture junction can eliminate the submucosal force transmission to the implant on loading the denture both under unilateral and bilateral loading conditions. When a soft liner is used at the relief site, the transmitted force is small, but a finite value is reproducibly recorded. With no relief, the submucosal force transmission is high and may adversely affect the healing process or osseointegration. The experimental model is valuable in measuring and understanding the submucosal forces that are transmitted to the implant by loading the transitional prosthesis, and such measurement may assist in the proper design of the prosthesis for improved clinical durability and for other uses.