人类β防御素在角膜组织中的表达

目的观察人类β防御素(humanβdefensins,HBD)在角膜组织中的分布,分析其在眼表疾病中的潜在作用。方法 选取正常供体眼角膜组织15眼,炎症性角膜组织15眼。炎症性样本包含病毒性角膜炎6眼、真菌性角膜炎4眼和细菌性角膜炎5眼。采用免疫组织化学法检测HBD-1和HBD-2,以及逆转录聚合酶链反应检测HBD-1、HBD-2、HBD-3在正常及炎症性角膜组织中的表达。结果 逆转录聚合酶链反应发现HBD-1和HBD-3在所有被检的16眼角膜组织中均显示阳性,HBD-2仅在7眼炎症性角膜被检组织中表达阳性,其余9眼样本均为阴性表达。炎症性角膜组织和正常角膜组织之间存在明显的表达差异(χ2=12.444,P=0.0014),免疫组织化学法也显示了相似的结果(χ2=7.143,P=0.029)。HBD-1表达于所有14眼角膜样本中,HBD-2则仅在6眼炎症性角膜和1眼正常角膜样本中显示阳性,其余7眼均显示阴性。结论 HBD-1和HBD-3表达于角膜组织。HBD-2在正常角膜组织几乎不表达,而是呈诱导式表达于炎性角膜。     

人类防御素在眼科的研究进展

人类防御素是一类阳离子抗微生物肽大家族,分子量为4～5kDa,分子内含有6个二硫键相连的半胱氨酸残基。近年来,随着防御素的发现和研究,其广泛的抗微生物特性受到人们的关注,有可能成为一条新的抗感染途径。防御素已成为医学生物学和分子生物学研究的热点。本研究主要就防御素的结构特点、眼组织分布、眼表上皮表达与调控、生物学活性等相关研究进展进行综述。     

β-防御素在中耳炎发病机制中的作用

β-防御素是抗菌肽的一种,其各个亚型广泛表达于哺乳动物呼吸道,包括中耳上皮,与其他抗菌肽一起构成中耳上皮先天免疫屏障,对抗外界病原体的入侵.本文综述β-防御素的表达或功能变化与中耳炎发生、发展的关系.     

β—防御素及其在眼内组织中的表达

β-防御素是一些具有广谱抗菌活性的内源性抗生肽,在许多器官的粘膜防御中起重要作用。它存在于多种物种中,对革兰阳性和阴性菌、霉菌、厌氧菌、钩端螺旋体、分枝杆菌及某些包膜病莓等均有杀伤活发现 。本主要针对β-防御素及其在眼内组织中的表达作一综述,为各种原因起的眼表和眼内感染性疾病的防治提供新思路。     

眼表微生物菌落在眼科疾病中的研究进展

大多数眼表微生物菌落的数量和质量会因疾病的发生发展、手术或用药治疗而产生改变,但是关于该领域的相关文献很少。近年来,由于大量抗生素的滥用,各类超级细菌不断出现,这使得愈发需要探索眼科疾病治疗新思路。因此,本文主要通过总结因疾病、手术或用药治疗而引起的眼表微生物菌落的变化,为眼科疾病的治疗提供一种新方向。     

大鼠β-防御素2真核表达载体构建及转染大鼠角膜上皮细胞的研究

目的：应用基因工程技术构建含大鼠β-防御素2(rat beta defensin 2,rBD-2)目的基因的真核重组质粒,通过脂质体法转染大鼠角膜上皮细胞,检测目的基因在转染细胞中的表达,探讨应用该载体获得重组rBD-2在眼表细胞中表达的可行性,并为进一步研究rBD-2的体内外抗微生物活性提供实验基础,以期为感染性角膜病防治提供新方法。

方法：将采用PAS(PCR-based Accurate Synthesis)的方法合成rBD-2 DNA片段连接到真核表达载体pIRES2-ZsGreen1的XhoⅠ与BamHⅠ酶切位点之间,构建pIRES2-ZsGreen1-rBD-2真核重组表达载体,重组质粒转化大肠杆菌DH5a感受态细胞,卡那霉素筛选出阳性克隆子,经酶切、测序鉴定重组载体构建成功后,采用脂质体法转染大鼠角膜上皮细胞,此处实验分为三组即重组载体pIRES2-ZsGreen1-rBD-2转染的大鼠角膜上皮细胞组、未转染的空细胞组以及空载体pIRES2-ZsGreen1所转染的大鼠角膜上皮细胞组,在倒置荧光显微镜下观察细胞转染情况,最后经实时荧光定量RT-PCR相对定量法检测各组转染细胞中rBD-2基因mRNA的表达差异。

结果：成功构建pIRES2-ZsGreen1-rBD-2真核重组质粒,应用实时荧光定量RT-PCR相对定量法检测到重组质粒pIRES2-ZsGreen1-rBD-2转染组的大鼠角膜上皮细胞中rBD-2基因的mRNA表达水平明显多于另两组。

结论：应用基因工程技术构建的rBD-2真核表达载体pIRES2-ZsGreen1-rBD-2,通过脂质体法转染大鼠角膜上皮细胞,能够使外源rBD-2基因在大鼠角膜上皮细胞中被转录成mRNA。     

急性中耳炎小鼠咽鼓管管旁腺腺体中β-防御素2的表达及意义

目的研究小鼠咽鼓管管旁腺腺体中β-防御素2(β-defensin 2,BD2)在急性炎症期间的表达,探讨咽鼓管管旁腺腺体在中耳防御体系中的作用.方法20只小鼠经鼓膜途径注射3型肺炎链球菌悬液建立小鼠急性中耳炎模型,采用免疫组化技术结合图像处理技术检测急性模型1 d组、3 d组和7 d组的咽鼓管管旁腺腺体中BD2的表达.结果1.急性模型组的咽鼓管管旁腺腺体中BD2的表达明显高于生理盐水对照组(P＜0.05);2.急性模型1、3、7 d组BD2的表达呈现时间依赖性的增强7 d组的表达显著高于前两组(P＜0.05),3 d组的表达数值上略强于1 d组,但无统计学意义(P＞0.05).结论咽鼓管管旁腺体在炎症的早期可增加BD2的释放,并可能在中耳固有免疫防御体系中起着清除病原体的重要作用.     

咽鼓管管旁腺腺体中表面活性蛋白-A和β防御素2的表达及意义

目的检测表面活性蛋白-A(surfactant protein A,SP-A)和β防御素2(β-defensin-2,BD2)在小鼠咽鼓管管旁腺腺体的表达和分布,初步探讨咽鼓管管旁腺腺体的分泌功能及其在中耳防御机制中的作用.方法 取SPF级昆明小鼠的咽鼓管,石蜡切片,HE染色显示管旁腺体正常位置和组成成分,采用免疫组织化学技术链霉菌抗生物素蛋白过氧化物酶(strept-avidin oxidase,SP)法检测SP-A和BD2在小鼠咽鼓管管旁腺腺体的表达及分布.结果①咽鼓管管旁腺腺体位于咽鼓管管腔内侧壁,由浆液性、黏液性及混合性腺体组成;②SP-A和BD2在小鼠的咽鼓管管旁腺腺体中呈阳性表达.免疫阳性产物定位于浆液性腺体细胞胞浆和部分黏液性腺体细胞核周胞浆.阳性产物集中于咽部及咽口部腺体.结论咽鼓管管旁腺腺体可分泌SP-A和BD2.SP-A降低咽鼓管管腔表面张力,维持纤毛黏液系统的正常功能,BD2和SP-A清除入侵的病原体,对维持正常中耳的无菌状态起着一定的作用.咽鼓管管旁腺腺体是中耳防御体系中的机体保护屏障.(中国眼耳鼻喉科杂志,2006,678～80)     

人抗微生物肽LL-37在眼表感染和创伤修复中的作用研究进展

LL-37是抗微生物肽cathelicidin家族迄今在人体内发现的惟一成员,具有广谱抗微生物作用,在抗细菌、真菌、包膜病毒感染方面功能较强,且靶菌株不易产生耐药性.LL-37具有创伤修复、中和内毒素和免疫调节等活性,因此近年来逐渐成为眼部抗感染和抗炎药物研究的热点.本文就LL-37的结构特点、眼表分布与表达、眼部生物学活性及眼科应用前景和存在问题等相关研究进展进行综述.     

胸腺肽β4在眼表疾病中的保护作用

胸腺肽是一种在多种组织结构中广泛分布且具有多种生物活性的蛋白。分为三种亚型：胸腺肽α、胸腺肽β、胸腺肽γ。其中胸腺肽β家族中以胸腺肽β4(Tβ4)在正常人体中的分布最为广泛。已有大量研究证实,Tβ4具有抗炎、抗凋亡、促增殖等作用。而眼表疾病大多与眼表上皮的损伤及炎症有关,因此促进损伤修复、愈合及抗炎成为治疗眼表疾病的关键。本文将主要介绍Tβ4的分布、结构、合成及其在眼表疾病中的保护作用。     

胸腺素β4及其在眼表疾病中的研究进展

胸腺素β4(thymosin beta4,Tβ4)足一种重要的肌动蛋白耦联蛋白.近年来,Tβ4因具有促进创伤愈合、调控炎性反应等作用而受到广泛关注.在眼科其促进角膜创伤愈合及角膜恢复透明的作用尤其显著,而且临床应用前景广阔.本文就Tβ4的一般性质、生物学作用及其在角膜、结膜疾病中的相关研究进展作一综述.     

胸腺素β4及其在眼表疾病中的研究进展

胸腺素β4(thymosin beta4,Tβ4)足一种重要的肌动蛋白耦联蛋白.近年来,Tβ4因具有促进创伤愈合、调控炎性反应等作用而受到广泛关注.在眼科其促进角膜创伤愈合及角膜恢复透明的作用尤其显著,而且临床应用前景广阔.本文就Tβ4的一般性质、生物学作用及其在角膜、结膜疾病中的相关研究进展作一综述.     

Membrane-associated mucins of the human ocular surface in health and disease

Mucins are a family of high molecular weight, heavily-glycosylated proteins produced by wet epithelial tissues, including the ocular surface epithelia. Densely-packed O-linked glycan chains added post-translationally confer the biophysical properties of hydration, lubrication, anti-adhesion and repulsion. Membrane-associated mucins (MAMs) are the distinguishing components of the mucosal glycocalyx. At the ocular surface, MAMs maintain wetness, lubricate the blink, stabilize the tear film, and create a physical barrier to the outside world. In addition, it is increasingly appreciated that MAMs function as cell surface receptors that transduce information from the outside to the inside of the cell. Recently, our team published a comprehensive review/perspectives article for molecular scientists on ocular surface MAMs, including previously unpublished data and analyses on two new genes MUC21 and MUC22, as well as new MAM functions and biological roles, comparing human and mouse (PMID: 31493487). The current article is a refocus for the audience of The Ocular Surface. First, we update the gene and protein information in a more concise form, and include a new section on glycosylation. Next, we discuss biological roles, with some new sections and further updating from our previous review. Finally, we provide a new chapter on MAM involvement in ocular surface disease. We end this with discussion of an emerging mechanism responsible for damage to the epithelia and their mucosal glycocalyces: the unfolded protein response (UPR). The UPR offers a novel target for therapeutic intervention.     

Expression pattern of sonic hedgehog and effect of topical mitomycin C on its expression in human ocular surface neoplasms

PURPOSE: To examine if the cells of human ocular surface neoplasms express sonic hedgehog (Shh) and the effects of topical mitomycin C on its expression. METHODS: Conjunctival tissues obtained from two normal subjects, two patients with squamous cell carcinoma of the ocular surface (conjunctiva), and one patient with ocular epithelial dysplasia were used in this study. Histological sections were processed for light microscopic immunohistochemical analysis for Shh. RESULTS: Faint immunoreactivity for Shh was detected in basal epithelial cells of limbus, bulbar, and palpebral conjunctival epithelial cells. On the other hand, squamous cell carcinoma cells markedly expressed Shh with positive staining for Patched 1(Ptc), the cell surface receptor of Shh. Similar marked expression of Shh was detected in the patient with ocular epithelial dysplasia, and this Shh expression was almost eliminated following topical mitomycin C treatment. A cell culture experiment was conducted to examine the effect of mitomycin C on Shh expression in a cultured squamous cell carcinoma cell line. CONCLUSIONS: Conjunctival epithelium constitutively expresses a low level of Shh, and its expression increases during malignant conversion of epithelial cells. Reduction of Shh expression might be involved in the therapeutic efficacy of topical mitomycin C for ocular surface epithelial neoplasms.     

Toll-like receptors in ocular surface disease

The ability of the ocular surface to mount an immune response is in part attributed to a family of proteins called toll-like receptors (TLRs). The latter are evolutionary conserved receptors that recognize and respond to various microbes and endogenous ligands. In addition to their recognition function, TLR activation triggers a complex signal transduction cascade that induces the production of inflammatory cytokines and co-stimulatory molecules, thus initiating innate and adaptive immunity. Toll-like receptor expression at the ocular surface is modulated during infection (e.g. Herpes simplex, bacterial keratitis and fungal keratitis) as well as during various inflammatory conditions (allergic conjunctivitis and dry-eye syndrome). Here recent findings regarding TLR expression and their involvement in various ocular surface diseases are discussed.