层粘连蛋白-5结构及功能的研究进展

层粘连蛋白-5是基底膜的主要组成蛋白之一,对上皮细胞与基底膜之间的稳定结合起着重要的作用。层粘连蛋白-5通过受体介导,具有促进上皮细胞粘附、迁移和扩散的功能。层粘连蛋白-5与结合上皮和种植体上皮的关系密切,在牙周炎性疾病中有异常表达。本文就层粘连蛋白-5的结构及功能等作一综述。     

口腔鳞癌IV型胶原和层粘连蛋白的表达与颈淋巴结转移的关系

目的 探讨口腔鳞癌ＩＶ型胶原（ｃｏｌ ＩＶ）和层粘连蛋白（ＬＮ）的表达及其与临床病理参数的关系。方法 应用免疫组化ＳＡＢＣ法检测了３０例口腔鳞癌组织和５例人正常口腔膜组ＣｏｌⅣ和ＬＮ的表达,并用病理图像分析软件定量分析了两者的表达程度;对ＣｏｌⅣ和ＬＮ的表达与临床病理参数的关系进行了统计学分析。结果 ＣｏｌⅣ和ＬＮ的表达部位相同,主要分布于口腔粘膜和鳞癌组织基底膜;正常粘膜ＣｏｌⅣ和ＬＮ表达完整连     

口腔鳞癌组织中Ⅳ型胶原和层粘连蛋白含量测定的临床意义

目的:探讨口腔鳞癌组织中Ⅳ型胶原(ColⅣ)及层粘连蛋白(LN)含量的变化与临床病理参数的关系.方法:应用放射免疫技术测定30例口腔鳞癌及6例正常口腔粘膜组织抽提液中ColⅣ及LN的含量,并对其与临床病理参数的关系进行统计学分析.结果:肿瘤组织中ColⅣ及LN含量分别为1.83±0.21μg/ml和1.02±0.11μg/ml,而正常组织分别为2.87±0.45μg/ml及1.98±0.23μg/ml,两组比较,分别为P＜0.05和P＜0.01;肿瘤组织中ColⅣ和LN含量的变化与病理分级及肿瘤部位无关,而与是否有颈淋巴结转移和浸润方式有关.结论:测量口腔鳞癌组织中ColⅣ和LN含量对判断口腔鳞癌有无转移和预后有一定价值.     

纤维粘连蛋白影响成骨细胞增殖和Ⅰ型胶原表达的研究

目的探讨纤维粘连蛋白(fibronectin,FN)对成骨细胞增殖和表达Ⅰ型胶原的影响,明确FN促进成骨细胞成骨功能的作用。方法体外原代培养大鼠成骨细胞,加入一定浓度的FN作用细胞,采用MTT法检测成骨细胞的增殖率,并利用免疫组化方法观察成骨细胞表达Ⅰ型胶原的变化,SPSS10.0统计软件进行数据分析。结果FN作用成骨细胞后,能够明显提高细胞的增殖率,细胞增殖率的差异变化有统计学意义(P<0.05),并且其作用具有剂量依赖性。以50μg/ml浓度的FN作用细胞48h,细胞表达Ⅰ型胶原的能力比空白对照组相比有显著提高。结论FN能够促进成骨细胞的增殖,并能诱导成骨细胞Ⅰ型胶原的表达。     

口腔组织层粘连蛋白研究现状

层粘连蛋白是基底膜的重要成分之一,通过与其受体间的相互作用而具有广泛的生物学功能。本文就层粘连蛋白的结构、功能及其在口腔医学中的研究现状进行综述。     

葡聚糖结合蛋白A抗体对变形链球菌黏附影响的研究

目的：了解葡聚糖结合蛋白(CbP)A抗体对变形链球菌黏附的影响情况。方法：利用核素闪烁计数法，测定不同浓度的葡聚糖结合蛋白抗体影响两种变形链球菌对羧基磷灰石(HA)的黏附率。结果：葡聚糖结合蛋白抗体可明显抑制两种变形链球菌对羧基磷灰石的黏附率，并且随着葡聚糖结合蛋白抗体浓度的提高，抑制作用增强。结论：葡聚糖结合蛋白抗体可抑制变形链球菌对羧基磷灰石的黏附，在免疫防龋方面具有一定的意义。     

层粘连蛋白在修复性牙本质形成中的免疫定位

目的 研究层粘连蛋白（laminin,LN）在牙髓修复中的免疫定位和分布特征。方法 在大鼠第一磨牙制备单面洞,分别观察3d、15d和30d后修复性牙本质的形成情况。以免疫组化技术检测LN的免疫反应。结果 术后3d,修复性牙本质尚未形成。牙髓内成牙本质细胞呈阳性染色,前期牙本质为弱阳性。术后15d,可见修复性牙本质形成和成牙本质细胞样细胞的出现,成牙本质细胞样细胞和牙髓细胞免疫染色呈阳性。术后30d,已形成的修复性牙本质内LN染色阳性,免疫活性特别集中于修复性牙本质与牙髓交界处,成牙本质细胞样细胞染色呈强阳性。结论 LN的分布特征提示,在修复性牙本质形成过程中,LN可能是牙髓细胞附着的一个有利因素。     

层粘连蛋白及其受体在涎腺腺样囊性癌表达的意义

目的 :研究涎腺腺样囊性癌中层粘连蛋白 (laminin ,LN)及其受体 (lamininreceptor ,LN R)表达特征及其与腺样囊性癌的某些临床病理指标的关系。方法 :用超敏S P免疫组化方法检测 3 4例涎腺腺样囊性癌LN和LN R的表达。结果 :LN R的表达与涎腺腺样囊性癌组织分型、临床分期有关 (P <0 .0 5 ) ,LN的表达仅与腺样囊性癌的组织分型有关 (P <0 .0 5 ) ,而与临床分期无关 (P >0 .0 5 )。结论 :LN及其受体LN R的表达可作为涎腺腺样囊性癌恶性程度的一个指标。     

变异链球菌葡聚糖结合蛋白B的生物学特性研究进展

变异链球菌是人类龋病的主要致病菌,葡聚糖结合蛋白是其重要的毒力因子之一.葡聚糖结合蛋白B在变异链球菌的致龋、维持细菌形态、发挥细胞壁生理功能等方面有重要作用,同时其N端具有免疫原性,可应用于免疫防龋.下面就葡聚糖结合蛋白B的生物学特性研究进展作一综述.     

Identification and characterization of a collagen-binding protein, Cbm, in Streptococcus mutans

Streptococcus mutans, a major pathogen of dental caries, is occasionally isolated from the blood of patients with infective endocarditis. Bacterial attachment of exposed collagen tissue in the impaired endothelium is an important step in the onset of infective endocarditis. In our previous studies, some S. mutans strains were shown to possess collagen-binding activities and most of them had an approximately 120-kDa cell-surface collagen-binding protein called Cnm. However, several strains without Cnm proteins show collagen-binding properties. In the present study, another collagen-binding protein, Cbm, was characterized and its coding gene cbm was sequenced in these strains. The amino acid alignment in the putative collagen-binding domain of Cbm was shown to have approximately 80% identity and 90% similarity to the comparable region of Cnm. Cbm-deficient isogenic mutant strains constructed by insertional inactivation of the cbm gene, lacked collagen-binding properties, which were recovered in the complemented mutant. Analyses of a large number of clinical isolates from Japan, Thailand and Finland revealed that cbm-positive strains were present in all of these countries and that cnm-positive and cbm-positive strains were detected in the oral cavity of approximately 10 and 2% of systemically healthy subjects, respectively. In addition, cnm-positive strains were predominantly identified in the serotype f group, whereas cbm-positive strains were frequently detected in serotype k. These results suggest that Cbm as well as Cnm are major cell surface proteins of S. mutans associated with binding to type I collagen and predominantly identified in serotype k strains.     

不同浓度硒对变形链球菌粘附功能的影响

目的：通过体外模拟口腔环境,观察不同浓度硒作用下,变形链球菌粘附作用的改变情况,以确定硒是否对变形链球菌粘附功能产生影响。方法：4个实验组培养基中分别含硒0.4、0.8、1.0、2.0（×10-6）,对照组培养基含硒浓度为0。各组分别加入0.1mL吸光度调至0.33的菌液,及稀释后的3H-TdR（调整各组浓度至0.37×107Bq/L）,厌氧连续培养24h。将羟磷灰石研磨过筛、灭菌,用全唾液处理以形成人工获得性膜,用人白蛋白包被,分别在每组中加入5mg,继续培养1h,离心后收集沉淀,加入闪烁液,液闪仪测定。结果：与对照相比,加入不同浓度硒培养的变链菌每分钟闪烁强度值（CPM）均有所降低,单因素方差分析各组间有显著性差异（P〈0.05）,说明变形链球菌粘附在羟磷灰石颗粒上的数量较少。结论：一定浓度的硒可使变形链球菌在体外形成的羟磷灰石获得性膜上的粘附量减少,这可能是硒抑制了变形链球菌的粘附功能。     

Binding of streptococci of the "mutans" group to type 1 collagen associated with apatitic surfaces

The present study surveyed the ability of 21 strains of cariogenic streptococci of the "mutans" group to bind to human type 1 collagen adsorbed on hydroxyapatite (HA) surfaces. All strains of Streptococcus cricetus (serotype a) and Streptococcus rattus (serotype b) tested attached strongly to collagen-treated HA (C-HA). Streptococcus mutans strains of serotype c and Streptococcus sobrinus strains of serotype d or g attached poorly; or not at all, to C-HA. S. mutans strains OMZ-175 (serotype f) and B14 (serotype e) were exceptions which exhibited significant binding to C-HA. Binding of S. cricetus AHT and S. rattus LB-1 to C-HA occurred in a dose-dependent manner, and was specific since it was inhibited by the presence of soluble collagen, but not by egg albumin, or by human fibrinogen or fibronectin. Binding occurred maximally between pH 6 and 8 and was not affected by any of several sugars tested. Trypsin treatment the streptococci had little affect, but heating at 100 degrees C reduced their ability to bind to C-HA.     

Binding of streptococci of the “mutans” group to type 1 collagen associated with apatitic surfaces

The present study surveyed the ability of 21 strains of cariogenic streptococci of the “mutans” group to bind to human type 1 collagen adsorbed on hydroxyapatite (HA) surfaces. All strains of Streptococcus cricetus (serotype a) and Streptococcus rattus (serotype b) tested attached strongly to collagen-treated HA (C-HA). Streptococcus mutans strains of serotype c and Streptococcus sobrinus strains of serotype d or g attached poorly, or not at all, to C-HA. S. mutans strains OMZ-175 (serotype f) and B14 (serotype e) were exceptions which exhibited significant binding to C-HA. Binding of S. cricetus AHT and S. rattus LB-1 to C-HA occurred in a dose-dependent manner, and was specific since it was inhibited by the presence of soluble collagen, but not by egg albumin, or by human fibrinogen or fibronectin. Binding occurred maximally between pH 6 and 8 and was not affected by any of several sugars tested. Trypsin treatment the streptococci had little affect, but heating at 100°C reduced their ability to bind to C-HA.     

口腔变异链球菌表面蛋白与转肽酶的关系

口腔变异链球菌表面蛋白P1是变异链球菌的主要黏附素之一,其存在与否影响着变异链球菌的黏附能力、疏水性和致龋性。srtA是变异链球菌转肽酶的编码基因,下面就srtA基因与变异链球菌表面蛋白P1的关系以及srtA基因在变异链球菌中的作用作一综述。     

变形链球菌表面蛋白PAc不同表达株的蔗糖粘附实验(英)

目的研究变形链球菌表面蛋白PAc不同表达株在含蔗糖培养基中，及加氟至lppm或洗必太至0．005％的含蔗糖培养基中对玻壁表面粘附能力的差异。方法在厌氧培养条件下培养各株变形链球菌，用OD值测量法计算粘附量。结果在普通及加入氟至IPPm的含蔗糖培养基中，变链菌表面蛋白PAc不同表达株对玻壁的粘附无差异；而在含0．005％洗必太的培养基中，变形链球菌各菌株的粘附量显著下降。结论在变形链球菌大量合成葡聚糖的条件下，表面蛋白PAc在变形链球菌对玻壁粘附过程中未起决定作用。洗必太可能具有抑制葡聚糖合成的作用，而氟则没有。     

Interaction between surface protein antigens of Streptococcus mutans and human salivary components

The potential involvement of surface antigens (Ags) I/II and III of Streptococcus mutans in its adherence to salivary pellicle-coated tooth surfaces was investigated. The binding of radiolabelled Ag I/II to hydroxyapatite was increased by pretreating the mineral with human parotid saliva, and binding was maintained in the continuous presence of saliva. Binding of Ag III to hydroxyapatite was inhibited by pretreatment with, or in the presence of, saliva. Various aminohexoses, and also tris, inhibited the binding of Ag I/II. When Ags I/II and III were tested for their ability to bind to salivary components separated by SDS gel electrophoresis, several proteins capable of binding Ag I/II were identified, notably 2 proteins of apparent relative molecular mass 28,000 and 38,000. Analysis of these proteins, isolated by micro-preparative electrophoresis, indicated high proportions of proline, glycine, and glutamic acid, and overall compositions similar to basic proline-rich salivary proteins.     

Biological functions of glucan-binding protein B of Streptococcus mutans

INTRODUCTION: Streptococcus mutans has been implicated as a major causative agent of dental caries in humans. Bacterial components associated with the adhesion phase of S. mutans include glucosyltransferases, protein antigen C and proteins that bind glucan. At least four glucan-binding proteins (Gbp) have been identified; GbpA, GbpB, GbpC and GbpD. METHODS: In our previous study, the contributions of GbpA and GbpC to the virulence of S. mutans were investigated; however, the biological function of GbpB and its role in the virulence of S. mutans remain to be elucidated. Using a GbpB-deficient mutant strain (BD1), we demonstrated in the present study that GbpB has a role in the biology of S. mutans. RESULTS: The growth rate of BD1 was lower than that of other strains, while it was also shown to be less susceptible to phagocytosis and to form longer chains than the parental strain MT8148. In addition, electron microscope observations of the cell surfaces of BD1 showed that the cell-wall layers were obscure. CONCLUSION: These results suggest that GbpB may have an important role in cell-wall construction and be involved in cell separation and cell maintenance.     

变形链球菌UA159上葡聚糖结合蛋白C的定位探讨

目的探索C端结构变异为亮氨酸-脯氨酸-任意氨基酸-丙氨酸-甘氨酸（LPXAG）的葡聚糖结合蛋白C（glucan binding proteinC，GbpC）是否在变形链球菌UA159的细胞壁上。方法用PCR法扩增变形链球菌UA159GbpCC端的编码基因片段，推测和分析C端氨基酸序列组成；分别提取上清蛋白、胞内蛋白和胞壁蛋白，用Western blot法在变形链球菌UA159各成分中检测GbpC；用免疫金标直接观察GbpC的表达位置；应激条件下进行多聚糖依赖黏附实验。结果变形链球菌UA159GbpCC端亮氨酸-脯氨酸-任意氨基酸-苏氨酸-甘氨酸（LPXTG）的结构变异为LPXAG；免疫印迹叮以在细菌的壁蛋白中检测到GbpC；电镜下可以观察到金颗粒围绕细菌细胞壁聚集；变形链球菌UA159在应激条件下表现为多糖依赖黏附实验阳性。结论C端为LPXAG的GbpC仍然锚定在细菌的细胞壁上。     

Molecular interactions of alanine-rich and proline-rich regions of cell surface protein antigen c in Streptococcus mutans

Introduction:  Streptococcus mutans has been implicated as a primary causative agent of dental caries in humans, and its cell surface protein antigen c (PAc) is known to be associated with sucrose-independent adhesion to tooth surfaces. PAc is composed of several domains, including an N-terminal signal sequence, an alanine-rich repeat region (A-region), a proline-rich repeat region (P-region), and an anchor region.
Methods:  To investigate the functions of each domain, an A-region-deficient mutant strain of S. mutans was constructed, and recombinant PAc and A- and P-region proteins were also constructed. The interactions of each domain with the recombinant proteins were analyzed using surface plasmon resonance spectroscopy with a biomolecular interaction analyzing system.
Results:  The A-region-deficient mutant strain showed the lowest levels of adherence to saliva-coated hydroxyapatite. Furthermore, findings in an immunoblot assay indicated that the A-region protein reacted strongly with proline-rich proteins in saliva, while the recombinant P-region protein interacted more quickly with PAc than the recombinant A-region protein.
Conclusion:  These results suggest that the A-region has a strong relationship with adhesion to tooth surfaces, while the P-region has a high affinity for PAc.