The in vivo expression of the collagenolytic matrix metalloproteinases (MMP-2, -8, -13, and -14) and matrilysin (MMP-7) in adult and localized juvenile periodontitis

Periodontal inflammation is characterized by irreversible degradation of periodontal ligament collagen fibers leading to loss of tooth attachment. Cultured gingival keratinocytes and fibroblasts express, in vitro, various matrix metalloproteinases (MMPs) which can degrade fibrillar collagens. We hypothesized that several MMPs are also synthesized in vivo by sulcular epithelium, and analyzed the collagenolytic MMPs (MMP-2, -8, -13, and -14) and matrilysin (MMP-7) in gingival tissue specimens and gingival crevicular fluid from adult and localized juvenile periodontitis patients by in situ hybridization, immunohistochemistry, and Western immunoblotting. MMP-2, -7, -8, and -13 were expressed in gingival sulcular epithelium. MMP-7 and -13 were also located in fibroblasts and macrophages, and MMP-8 in neutrophils. MMP-8- and -13-positive cells/mm2 were higher in periodontitis gingiva when compared with healthy control tissue (p < 0.01). In periodontal diseases, gingival sulcular epithelium expresses several, rather than a single, collagenolytic MMPs, and this proteolytic cascade is evidently responsible for the tissue destruction characteristic of adult and juvenile periodontitis.     

Gingival tissue and crevicular fluid co-operation in adult periodontitis

Activated matrix metalloproteinase-3 (MMP-3) can contribute to periodontal ligament destruction in adult periodontitis. Since MMP-3 has been reported to activate proMMP-8 and -9, it was speculated that gingival tissue fibroblast-derived MMP-3 might, in periodontitis, be responsible for activation of gingival crevicular fluid (GCF) neutrophil-derived proMMP-8 and -9. Immunohistochemistry disclosed MMP-3 in gingival fibroblasts in periodontitis. Cultured gingival fibroblasts released only pro-MMP-3 when stimulated with tumor necrosis factor-alpha. However, Western blot revealed partially activated MMP-3, MMP-8, and MMP-9 in periodontitis GCF. Active MMP-8 (p < 0.05) and MMP-9 (p < 0.05) correlated with the presence of active MMP-3. It seems that resident gingival fibroblasts produce pro-MMP-3 in GCF, where it becomes activated, probably by cathepsin G or elastase released by neutrophils. Active MMP-3 then activates neutrophil-derived pro-MMP-8 and -9. Different tissue compartments/cells exert co-operative actions in mutual local MMP activation cascades.     

Proteinase-activated receptor-2 (PAR2) agonist causes periodontitis in rats

Proteinase-activated receptor-2 (PAR2) is a G-protein-coupled receptor that mediates cellular responses to extracellular proteinases. Since PAR2 is expressed by oral epithelial cells, osteoblasts, and gingival fibroblasts, where its activation releases interleukin-8, we hypothesized that PAR2 activation may participate in periodontal disease in vivo. We investigated the role of PAR2 activation in periodontal disease in rats. Radiographic and enzymatic (myeloperoxidase) analysis revealed that topical application of PAR2 agonist causes periodontitis but also exacerbates existing periodontitis, leading to significant alveolar bone loss and gingival granulocyte infiltration. Inhibition of matrix metalloproteinase (MMP) and cyclo-oxygenase (COX) decreased PAR2 agonist-induced periodontitis. More specifically, the overexpression of COX-1, COX-2, MMP-2, and MMP-9 in gingival tissues suggests that they are involved in PAR2-induced periodontitis. In conclusion, PAR2 agonist causes periodontitis in rats through a mechanism involving prostaglandin release and MMP activation. Inhibition of PAR2 may represent a novel approach to modulate host response in periodontitis.     

牙龈卟啉单胞菌膜泡对牙龈上皮细胞MMPs基因表达的影响

目的:探讨牙龈卟啉单胞菌膜泡对牙龈上皮细胞基质金属蛋白酶(MMPs)基因表达的影响,揭示牙龈卟啉单胞菌在牙周炎中的致病作用.方法:以Real-time RT-PCR法检测牙龈卟啉单胞菌膜泡刺激下牙龈上皮细胞MMP-1和MMP-3的mRNA表达水平.结果:牙龈卟啉单胞菌膜泡显著地上调MMP-1和MMP-3 mRNA表达水平.结论:牙龈卟啉单胞菌诱导牙龈上皮细胞发生细胞炎症反应,可能是牙周炎发生、发展的重要因素.     

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.     

基质金属蛋白酶-2和基质金属蛋白酶-3在大鼠牙周炎模型中的表达

目的 研究不同时期、不同严重程度的大鼠牙周炎模型中基质金属蛋白酶-2（MMP-2）和基质金属蛋白酶-3（MMP-3）的表达和分布特征,探讨二者在牙周炎发生发展中的作用。方法 对大鼠牙周组织标本的石蜡切片进行MMP-2和MMP-3的免疫组化染色,并进行图像定量分析。结果 MMP-2和MMP-3在牙龈炎和牙周炎的牙龈上皮中呈强阳性表达,在牙周炎的牙周组织中,主要在牙周膜成纤维细胞、破骨细胞等细胞中呈强阳性表达。MMP-2和MMP-3的变化趋势为在健康牙周组织中呈弱阳性表达,急性龈炎和急性牙周炎中呈强阳性表达,到慢性牙周炎时期,表达较急性期有所降低。结论 MMP-2和MMP-3在牙周炎症组织中,随着炎症进程呈现不同特征的表达,可能直接参与牙周组织的炎性破坏。     

慢性牙周炎患者唾液中miR-146a的表达及其与龈沟炎症、MMP-8/TIMP-1水平的关系

目的： 探讨慢性牙周炎患者唾液中miR-146a的表达及其与龈沟炎症、基质金属蛋白酶8（MMP-8）、基质金属蛋白酶抑制剂1（TIMP-1）水平的关系。方法： 选择2015年3月—2017年1月间收治的慢性牙周炎患者68例作为慢性牙周炎组,同期在本院进行体检的健康志愿者50例作为正常对照组。检测2组研究对象唾液中miR-146a的表达量,龈沟液中炎症因子、MMP-8/TIMP-1的水平及牙周临床症状指标。采用SPSS24.软件中的Pearson检验评估慢性牙周炎患者唾液中miR-146a的表达量与病情严重程度的相关关系。结果： 慢性牙周炎患者唾液中miR-146a的表达量显著高于正常对照组（P<0.05）,龈沟液中炎症因子（IL-1β、IL-6、IL-35、TNF-α）水平、牙周临床症状指标（PD、AL、PLI、BI）以及龈沟液中MMP-8、TIMP-1的水平显著高于正常对照组（P<0.05）。Pearson检验发现,慢性牙周炎患者唾液中miR-146a表达量与龈沟炎症程度、牙周临床症状严重程度及MMP-8/TIMP-1水平呈正相关。结论： 慢性牙周炎患者唾液中miR-146a表达量异常增高,且与龈沟炎症程度、牙周损伤程度一致。     

罗格列酮对牙周炎大鼠牙龈脂联素受体表达的影响

目的:探讨罗格列酮(ROS)对牙周炎大鼠牙龈脂联素受体1(AdipoRl) mRNA、脂联素受体2(AdipoR2) mRNA和TNF-α等炎症因子表达的影响及在牙周炎中对牙槽骨保护的潜能.方法:50只SD大鼠随机分为5组(n=10),大鼠不干预处理作为空白对照,40只大鼠用于制作牙周炎模型后分别用蒸馏水(牙周炎组)、1、3、10 mg/kg ROS(低、中、高剂量组)灌胃1次/d,持续4周.然后取样,RT-PCR测定牙龈组织AdipoR1和AdipoR2 mRNA表达水平,ELISA测牙龈组织TNF-α、MMP-9和血浆脂联素浓度,标准化的数码摄影测量釉牙骨质界到牙槽骨嵴顶(CEJ-A)距离.结果:牙周炎组和空白对照组相比,牙龈组织AdipoR1和AdipoR2的mRNA表达水平显著降低(P＜0.01),血浆脂联素水平无差异(P＞0.05),TNF-α和MMP-9浓度显著上升(P＜0.01).和牙周炎组相比,低、中、高剂量治疗组牙龈组织AdipoRl mRNA表达均升高(P＜0.05),TNF-α浓度显著降低(P＜0.01);中、高剂量治疗组牙龈组织AdipoR2 mRNA表达显著升高(P＜0.01),MMP-9浓度显著降低(P＜0.01),血浆脂联素浓度升高(P＜0.05),牙槽骨吸收量显著降低(P＜0.01).结论:ROS可能通过上调牙龈组织中AdipoR1和AdipoR2 mRNA表达水平,降低TNF-α、MMP-9浓度,缓解牙周组织炎症,降低牙槽骨吸收.     

The effects of selective COX-2 inhibitor/celecoxib and omega-3 fatty acid on matrix metalloproteinases, TIMP-1, and laminin-5gamma2-chain immunolocalization in experimental periodontitis

BACKGROUND: Matrix metalloproteinases (MMPs) play important roles in tissue-destruction mechanisms-associated periodontitis. MMP-8 and -13 are the predominant collagenases that are important in the extracellular matrix degradation in periodontal tissues. MMP-14 is a membrane-type MMP, whereas laminin-5 indicates basal membrane modification and epithelial induction. The purpose of the present study was to evaluate the effects of celecoxib and omega-3 fatty acid administration on the gingival tissue expression of MMP-8, -13, and -14, tissue inhibitor of MMP (TIMP)-1, and laminin (Ln)-5gamma2-chain in rat experimental periodontitis induced by Escherichia coli endotoxin (lipopolysaccharide [LPS]). METHODS: Experimental periodontitis was induced in rats by repeated LPS injection. Fifty-one adult male Sprague-Dawley rats were divided into six study groups: saline control, LPS, LPS + celecoxib, LPS + therapeutic omega-3 (TO3), prophylactic omega-3 + LPS + omega-3 (P+TO3), and LPS + celecoxib + omega-3 fatty acid. Celecoxib and omega-3 fatty acid were given as a single agent or as combination therapy for 14 days. On day 15, all rats were sacrificed, and gingival tissues were analyzed immunohistochemically for the expression of MMP-8, -13, and -14, TIMP-1, and Ln-5gamma2-chain. Alveolar bone loss was evaluated morphometrically under a stereomicroscope. Data were tested statistically by Kruskal-Wallis and Mann-Whitney tests and Spearman correlation analysis. RESULTS: Alveolar bone loss was significantly higher in all study groups compared to the saline control group (all P <0.01). MMP-8 expression was significantly higher in the LPS group than in the saline group (P = 0.001). Very low expression of MMP-8 was found in the celecoxib, P+TO3, and combination groups. TO3 increased TIMP-1 expression significantly compared to the LPS group (P <0.05). Individual celecoxib and P+TO3 administration increased MMP-14 significantly compared to saline control and LPS groups (P <0.05). No significant differences were found among the study groups with regard to Ln-5gamma2-chain and MMP-13 expressions (P >0.05). CONCLUSIONS: Selective cyclooxygenase-2 inhibitor, prophylactic omega-3 fatty acid, and a combination of these two agents can inhibit gingival tissue MMP-8 expression. Moreover, the individual administration of therapeutic omega-3 may increase gingival TIMP-1 expression in contrast to no effect on MMP-8, -13, and -14 expressions in experimental periodontitis. These experimental findings in a rat model of LPS-induced periodontitis need to be verified by clinical human studies.     

Human skin and gingival keratinocytes show differential regulation of matrix metalloproteinases when combined with fibroblasts in 3-dimensional cultures

BACKGROUND: Matrix metalloproteinases (MMP) and their inhibitors are expressed in tissues during interactions between keratinocytes and fibroblasts. Maintaining the balance between MMPs and their inhibitors is critical; failure to do so can lead to severe tissue damage or complete destruction, as seen in periodontal disease. Previously we showed that 3-dimensional (3-D) cultures of homotypically-combined skin and gingival cells mimicked the tissues in protein and lipid production, but heterotypic cultures did not. METHODS: We examined the production and activation of MMPs in these homotypic and heterotypic combinations of skin and gingival keratinocytes and fibroblasts during the critical time that they reformed the tissues. Primary fibroblasts and keratinocytes were isolated from normal human gingiva and skin and grown in 3-D cultures for up to 42 days. MMP-1, MMP-2, and MMP-9 in the media and inhibition of MMPs from these cultures were analyzed. RESULTS: These experiments determined that skin fibroblasts grown with skin or gingival keratinocytes secrete increased amounts of MMP-1 compared to gingival fibroblasts; that the interaction of keratinocytes with fibroblasts decreases the amount of MMP-2 produced by the fibroblasts in 3-D cultures; that skin keratinocytes, but not gingival keratinocytes, interact with fibroblasts to upregulate expression of the active form of MMP-9; and that medium conditioned by gingival 3-D cultures does not contain an inhibitor of MMP-9. CONCLUSION: Varying the type of fibroblast beneath the keratinocytes allowed us to determine that skin and gingival keratinocytes differentially regulate the production and activation of MMP-9, but not MMP-2, a finding that could influence the success of tissue grafting after periodontal surgery.     

MMP-1及MMP-8在大鼠牙周炎模型牙周组织中的表达与分布

目的:研究不同时期、不同严重程度的大鼠牙周炎模型的牙周组织中MMP-1及MMP-8的表达及分布特征,探讨MMP-1、MMP-8在牙周炎发生发展中的作用。方法:对大鼠牙周炎模型牙周组织标本的石蜡切片进行MMP-1、MMP-8的免疫组化染色,并进行图像定量分析。结果:MMP-1、MMP-8在牙龈炎、牙周炎的牙龈上皮中呈强阳性表达,在牙周炎的牙周组织中,主要在牙周膜成纤维细胞、破骨细胞等细胞中呈强阳性表达,其变化趋势为:由健康牙周组织的弱阳性表达,变为急性龈炎、急性牙周炎的强阳性表达,到慢性牙周炎时期,表达较急性期有所降低。结论:MMP-1、MMP-8在牙周炎症组织中,随着炎症进程呈现不同特征的表达,可能直接参与牙周组织的炎症破坏。     

MMP-13 and TIMP-1 determinations in progressive chronic periodontitis

Matrix metalloproteinase (MMP)-13 is a collagenase involved in extracellular matrix degradation either by its direct degradative effects or by processing bioactive substrates. The aim of this study was to determine the levels of MMP-13 and tissue inhibitor of metalloproteinase (TIMP)-1 in gingival crevicular fluid (GCF) and gingival biopsies obtained from active and inactive sites during chronic periodontitis progression. MATERIALS AND METHODS: This was a longitudinal study in which chronic periodontitis patients with moderate to severe disease were included and followed until they developed progression determined by the tolerance method. GCF samples were obtained from periodontitis, active, inactive and healthy sites and additional gingival biopsies were taken from active and inactive sites. MMP-13 and TIMP-1 determinations were carried out by immunodot blots and immunowestern blots. RESULTS: In progressive periodontitis, MMP-13 and TIMP-1 remained unchanged between active and inactive sites, but as the TIMP-1 relative levels increased together with MMP-13 elevation in inactive samples, an inverse correlation was observed in active sites. Besides, MMP-13 was undetectable in healthy controls. CONCLUSION: Chronic periodontitis is characterized by increased MMP-13 expression. During disease progression, active sites tended to decrease TIMP-1 levels in association with MMP-13 elevation.     

MMP-2在吸烟牙周炎患者牙龈组织中的表达

目的:从MMP-2的酶活性和mRNA水平探讨吸烟与牙周病的关系。方法:利用明胶酶活性分析(zymog-raphy)和RT-PCR方法,分别检测6例吸烟牙周病、6例不吸烟牙周病、6例吸烟正常人、6例不吸烟正常人的牙龈组织中MMP-2的酶活性和mRNA表达。结果:吸烟和牙周病牙龈组织中MMP-2酶活性都较正常组有增加,但吸烟牙周病组的MMP-2的酶活性与吸烟无牙周病组和不吸烟牙周病组有明显差异(P<0.01),吸烟牙周病患者牙周组织中MMP-2的mRNA水平较正常组明显增加(P<0.01)。结论:MMP-2在吸烟牙周炎牙周组织的破坏中起重要作用。     

Gingival crevicular fluid matrix metalloproteinase-25 and -26 levels in periodontal disease

BACKGROUND: Tissue destruction associated with the progression of periodontal disease is caused by a cascade of host and microbial proteolytic enzymes. Host-derived matrix metalloproteinases (MMPs) play an important role in the degradation of the extracellular matrix. Leukolysin/membrane-type 6 (MT-6)/MMP-25, the latest member of the MT-MMP subgroup of the MMP family, is primarily expressed by neutrophils and involved in extracellular matrix turnover. Matrilysin-2/MMP-26 (endometase), a novel member of the matrilysin subgroup of the MMP family, can degrade the extracellular matrix, alpha1-antitrypsin, and activate pro-MMP-9. Our study aimed to examine the levels, molecular forms, and degrees of activation of MMP-25 and MMP-26 in gingival crevicular fluid (GCF) from patients with different periodontal diseases. METHODS: A total of 105 subjects, 35 with generalized aggressive periodontitis (GAgP), 29 with chronic periodontitis (CP), 20 with gingivitis, and 21 periodontally healthy subjects, were included in this study. Periodontal status was evaluated by measuring probing depth, clinical attachment loss, presence of bleeding on probing, and plaque. GCF MMP-25 and MMP-26 levels were analyzed by computer-quantitated Western immunoblotting using specific antibodies. RESULTS: The 57-kDa soluble pro-MMP-25 and 45- to 47-kDa active form of MMP-25 were detected by Western immunoblots in CP and GAgP GCF, and lesser levels of these soluble MMP-25 immunoreactive bands were detected in gingivitis GCF. An enhanced and similar degree of MMP-25 activation was found in GAgP, CP, and gingivitis groups. There were no detectable MMP-25 immunoreactivities in the healthy subjects' GCF. GAgP and CP groups had elevated GCF MMP-26 levels and degrees of activation compared to the gingivitis and healthy groups (P <0.008). The gingivitis group had higher GCF MMP-26 levels and degree of activation compared to the healthy group (P <0.008). CONCLUSIONS: The present study demonstrated the presence of soluble or shed forms of MMP-25 and MMP-26 in GCF of patients with different periodontal diseases. Increased levels and activation of MMP-25 and MMP-26 in GCF are associated with an enhanced severity of periodontal inflammation, suggesting that these novel MMPs can participate in the progression of periodontal diseases. They may prove to be diagnostically useful and could be targets of medication in the future.     

β-防御素-2多肽在不同类型牙周炎及健康牙龈组织中的表达

目的:检测人β-防御素-2(humanbetadefensin-2,HBD-2)在牙周病病变牙龈和健康牙龈中的表达。方法:应用SP法检测健康牙龈(HC组,11例)、慢性牙周炎(CP组,18例)和侵袭性牙周炎(AgP组,9例)牙龈中HBD-2蛋白的表达水平,所得数据用SPSS11.5统计分析软件进行单因素方差分析。结果:HBD-2蛋白在所有牙龈标本中均有表达;HBD-2蛋白表达可见于牙龈复层鳞状上皮全层,主要位于棘层以上细胞胞质内。3组的表达水平分别为:健康牙龈组(31.55±12.66)%、慢性牙周炎组(17.31±7.64)%、侵袭性牙周炎组(25.06±8.04)%,健康组表达水平显著高于慢性牙周炎组(P<0.05),其他组间差异无统计学意义。结论:HBD-2多肽在健康牙龈和牙周病牙龈上皮中广泛表达,提示其在维系牙周健康及宿主免疫防御反应中可能发挥重要作用。