SlRT1作为靶点治疗年龄相关性视网膜病变的研究进展

沉默信号调节蛋白1(silent information regulator protein 1, SIRT1)是sirtuins成员之一,属于组蛋白去乙酰化酶,它的活性依赖尼克酰胺腺苷酸二核苷酸( nicotinamide adenine dinucleotide, NAD+)并受其调节。实验及临床研究表明SIRT1在年龄相关性眼病中的神经保护作用。本综述对于SIRT1激动剂-白藜芦醇( RES)与视网膜细胞凋亡之间的关系进行了探讨,并提出SIRT1成为常见年龄相关性视网膜病潜在的治疗靶点。     

SIRT1作为靶点治疗年龄相关性视网膜病变的研究进展

沉默信号调节蛋白1(silent information regulator protein 1,SIRT1)是sirtuins成员之一,属于组蛋白去乙酰化酶,它的活性依赖尼克酰胺腺苷酸二核苷酸(nicotinamide adenine dinucleotide, NAD⁺)并受其调节。实验及临床研究表明SIRT1在年龄相关性眼病中的神经保护作用。本综述对于SIRT1激动剂-白藜芦醇(RES)与视网膜细胞凋亡之间的关系进行了探讨,并提出SIRT1成为常见年龄相关性视网膜病潜在的治疗靶点。     

SIRT1基因在糖尿病性白内障患者晶状体上皮细胞表达的初步研究

目的:探讨SIRT1基因在糖尿病性白内障晶状体上皮细胞的表达.方法:选取2012-01/2014-10来我院治疗的糖尿病性白内障患者、年龄相关性白内障患者和外伤性白内障患者各20例,采用RT-PCR法检测各组患者晶状体上皮细胞中SIRT1基因含量,Western blot法检测晶状体上皮细胞中SIRT1蛋白含量,TUNEL法检测晶状体上皮细胞的凋亡率.结果:RT-PCR检测结果显示,外伤性白内障患者组SIRT1 mRNA相对含量最高为1.000±0.078,其次为年龄相关性白内障患者组为0.427±0.067,糖尿病性白内障组为0.389±0.112,与外伤性白内障组比较,差异有统计学意义(P＜0.05);Western blot检测显示,外伤性白内障患者晶状体上皮细胞中SIRT1蛋白的表达量最高,其次是年龄相关性白内障组,糖尿病性白内障组SIRT1蛋白的表达量最低;TUNEL法检测结果显示,外伤性白内障组和年龄相关性白内障组患者LECs细胞凋亡率分别为(4.5±2.3)％和(8.7±4.1)％,差异无统计学意义;而糖尿病性白内障组LECs凋亡率为(24.3±6.1)％,与外伤性白内障组及年龄相关性白内障组比较差异有统计学意义(P＜0.05).结论:糖尿病性白内障患者晶体上皮细胞中SIRT1基因及蛋白表达下降,提示该基因参与了糖尿病性白内障的发生,这为我们今后进一步的研究提供了可靠的理论依据.探索调节SIRT1基因在晶状体上皮细胞中表达的有效途径,将为糖尿病性白内障的早期干预治疗提供新的思路.     

Sirtuins在眼科疾病中的研究进展

在各种眼科疾病,如青光眼、黄斑变性等疾病的发生发展中,细胞氧化应激的发生非常常见,氧化应激可以使细胞受损而凋亡。Sirtuins家族(Ⅲ类组蛋白去乙酰化酶)作为一类多种细胞的调控因子,在人体各种器官中广泛表达。Sirtuins的同源基因(SIRT1)在眼部也广泛表达,其表达与激活可以起到抗氧化应激的作用,防止细胞衰老及损伤,进而防止疾病的进展。本文就Sirtuins家族在青光眼、年龄相关性黄斑变性、视神经炎、年龄相关性白内障中的作用机制与表达进行论述。     

年龄相关性白内障患者miR-138的表达及其对人晶状体上皮细胞凋亡的影响

目的　检测miR-138在年龄相关性白内障晶状体组织中的表达情况,并探讨miR-138对人晶状体上皮细胞增殖和凋亡的影响及其可能的靶基因。方法　采用实时荧光定量PCR(real-time quantitative polymerase chain reaction,RT-qPCR)检测年龄相关性白内障患者（白内障组）与正常对照组中miR-138和预测靶基因沉默信息调节因子1(silent information regulator 1,SIRT1)的表达水平。向人晶状体上皮细胞系（SRA01/04）细胞中分别转染miR-138 模拟物、模拟物阴性对照物、miR-138抑制物、抑制物阴性对照物,采用RT-qPCR检测SIRT1的mRNA表达,Western blotting检测SIRT1的蛋白表达水平;转染72 h后细胞暴露于200 μmol·L^-1 H₂O₂ 1 h,Caspase-3活性检测试剂盒检测Caspase-3活性。双荧光素酶报告基因检测验证miR-138与SIRT1的靶向关系。结果　与正常对照组相比,白内障组miR-138的表达(3.64±0.19)显著升高（P<0.001）,SIRT1的mRNA表达(0.32±0.06)显著下降（P<0.001）;相对于模拟物阴性对照组,miR-138 模拟物组的SIRT1的mRNA(0.42±0.05)及蛋白(0.46±0.05)表达水平均明显降低,Caspase-3活性(3.24±0.17)明显升高（均为P<0.05）;相对于抑制物阴性对照组,miR-138抑制物组的SIRT1的mRNA(2.95±0.13)及蛋白(1.98±0.12)表达水平均明显升高,Caspase-3活性(0.42±0.05)均明显下降（均为P<0.05）;双荧光素酶报告基因检测确证SIRT1为miR-138的直接作用靶点。结论　miR-138在年龄相关性白内障患者晶状体囊膜中高表达,miR-138通过靶向性负性调控SIRT1表达,促进晶状体上皮细胞凋亡。     

年龄相关性白内障晶状体前囊膜中c-myc基因表达的研究

C—myc是原癌基因家族成员,是myc基因家族的重要成员之一。研究表明,在晶状体上皮细胞（lens epithelial cells,LECs）中c-myc mRNA水平与发育期增生细胞的百分数成正比,当这些细胞进入静止期时,c—mycmRNA表达静止或减少。C—myc的过度表达可能促进年龄相关性白内障的发生。本研究对年龄相关性白内障患者晶状体前囊膜及正常人晶状体中c-myc基因的表达进行检测,探讨c-myc在年龄相关性白内障发病机制中的作用。     

单核苷酸多态性与年龄相关性白内障的研究进展

年龄相关性白内障是最常见的白内障类型,也是全球首位的致盲性因素。大量研究表明,遗传因素在年龄相关性白内障发病过程中发挥着重要作用。单核苷酸多态性作为第３代分子遗传标志,是最常见的多态性表现形式,本文就近年来单核苷酸多态性与年龄相关性白内障相关性的最新研究成果作一简要综述。     

老年性白内障中p33ING1和p53的表达及临床意义

目的探讨生长抑制基因p33ING1和肿瘤抑制基因p53在年龄相关性白内障晶状体上皮细胞中的表达,并初步探讨p33ING1和p53在年龄相关性白内障发病中的作用,进一步展望二者在年龄相关性白内障术后与后发障发生的相关性。方法30例年龄相关性白内障及10例透明晶状体前囊,应用免疫组织化学法,分别观察对照组和白内障组晶状体上皮细胞中p33ING1和p53的阳性表达水平：结果透明品状体组中p33ING1和p53极低表达,年龄相关性白内障组中p33ING1和p53高表达。、两组相比较,p33ING1和p53表达均有显著性差异（P〈0．05）。对白内障组进行p33ING1和p53相关性分析,二者有正相关关系。结论p33ING1和p53在年龄相关性白内障的形成过程中起重要作用,且二者具有协同作用。     

端粒酶在年龄相关性白内障晶状体上皮细胞中的表达及意义

目的探讨年龄相关性白内障及正常晶状体上皮细胞的端粒酶活性的表达及其在年龄相关性白内障发生发展中的作用。方法采用TRAP-银染法及TRAP-ELISA两种方法检测9例年龄相关性白内障、3例正常晶状体上皮细胞的端粒酶活性。结果9例年龄相关性白内障及3例正常晶状体上皮细胞中端粒酶均呈阳性,年龄相关性白内障组晶状体上皮细胞中端粒酶活性明显低于正常组,经统计学分析差别具有显著意义(P<0.05)。结论端粒酶活性的降低可能是年龄相关性白内障晶状体上皮细胞发生凋亡的一个重要机制,端粒酶在年龄相关性白内障的发生发展中起着重要的作用。     

SlRT1与眼科疾病的研究进展

沉默信息调节因子相关酶1( sirtuin type1, SIRT1)是一种细胞代谢辅酶NAD+依赖的Ⅲ类组蛋白去乙酰化酶,通过转录调控,参与基因转录、能量代谢以及细胞衰老过程的调节,具有延长生物寿命和延缓多种年龄相关性疾病发展的作用,在抗衰老研究领域备受关注。近年的研究显示SIRT1在眼科多种疾病的发病机制中占有重要的地位,尤其是眼表疾病、青光眼、白内障、葡萄膜炎以及眼底病等,针对SIRT1活性的促进可能成为眼科新型药物的治疗靶点。本文将对SIRT1与眼科疾病的研究报道进行综述。     

Follow-up studies in pattern VECP in demyelinating diseases in children

Spectral sensitivity functions and the transient decrease of sensitivity to short wavelengths after the offset of yellow light (transient tritanopia) were measured by increment threshold techniques in patients suffering from hereditary macular degenerations. Color vision defects were determined by arrangement tests and the anomaloscope. Central areolar choroidal dystrophy was found to produce a mild protan defect and to reduce foveal spectral sensitivity throughout the visible spectrum by a factor of 100; it also abolishes transient tritanopia. Electroretinogram (ERG) was normal, electrooculogram (EOG) subnormal. Stargardt's disease, despite numerous fluorescent macular spots, does not abolish transient tritanopia nor does it reduce spectral sensitivity, although scotopic matches were performed on the Nagel anomaloscope. Only in severe, advanced cases was transient tritanopia reduced and spectral sensitivity found to follow the absorption spectrum of rods. Routine ERGs and EOGs were normal. Vitelliform macular degeneration, despite the ophthalmoscopically pronounced dystrophic macula, produced only very small changes in spectral sensitivity and transient tritanopia, although a widened matching range on the Nagel anomaloscope and electrophysiological abnormalities were found. Apparently damage of the retinal circuit which connects long and short wavelength-sensitive cones, caused by hereditary conditions, is different from that caused by retinotoxic drugs.     

p53 expression in pterygium in two climatic regions in Turkey

Purpose:

To assess accumulation of p53 protein in samples of primary pterygium from people living in two different climatic regions in Turkey.

Materials and Methods:

Group 1 included 101 pterygium specimens from people in Adana located in southern Turkey. Group 2 included 39 pterygium specimens from people in Ankara, located in the middle of Turkey. Climatic conditions throughout the year are sunnier and warmer in Adana than they are in Ankara. The control group (Group 3) included 30 specimens of conjunctiva that had been excised during cataract surgery from 30 patients without pterygium. The pterygial specimens and control conjunctiva were studied by immunohistochemistry using antibodies against p53 protein. Pearson''s chi-square test was used to compare the p53 immunoreactivity.

Results:

The p53 immunoreactivity in Groups 1 and 2 was greater than it was in the control group (P<0.001). There were no differences in p53 immunoreactivity between Groups 1 and 2 (P= 0.060).

Conclusion:

The p53 immunoreactivity was not correlated with ultraviolet irradiation exposure. The p53 immunoreactivity in our pterygium specimens suggests that pterygium could be a result of uncontrolled cell proliferation.     

Trends in Patterns of Anterior Uveitis in a Tertiary Institution in Singapore

Purpose: To report the trends in etiology of patients with anterior uveitis (AU) in Singapore over 6 years.

Methods: A retrospective review of the clinical records of all new patients who presented with anterior uveitis to the uveitis subspecialty clinic from 2005 to 2010 at Tan Tock Seng Hospital, Singapore.

Results: There were 552 new cases of AU. This comprised 59.5% of a total of 928 new patients diagnosed with uveitis from 2005 to 2010. The mean age was 48.0?±?17.2 years. There was a male predominance (62.5%), with a male:female ratio of 1.7:1. The majority were of Chinese ethnicity (69%), followed by Malays (13.2%). Most cases were unilateral (79.5%) and idiopathic (50.4%). Common etiological causes included Fuchs heterochromic iridocyclitis (FHI) (5.6%), ankylosing spondylitis (AS)-related AU (5.1%), herpes simplex virus (HSV) (4.7%), and herpes zoster virus (HZV) (4.5%). There were increasing trends in AS-related AU from 3.2% in 2008 to 6.5% in 2010, and psoriasis-associated AU from 1.7% in 2005 to 4.0% in 2008. There were decreasing trends in the incidence of FHI from 10.6% in 2006 to 4.7% in 2009. No change in incidence of viral etiologies was noted, but cytomegalovirus-related immune-recovery uveitis (IRU) comprised 7.4%. IRU showed an increasing trend from 1.7% in 2005 to 11.9% in 2007, then decreased to 3.3% in 2010. Using the Pearson chi-square test, there was no statistically significant association between ethnicities (Chinese, Malay, Indian) comparing infectious and noninfectious cases (p?=?0.788), idiopathic and nonidiopathic cases (p?=?0.170), or between the various etiologies of uveitis (p?=?0.168).

Conclusions: AU was the predominant form of uveitis seen at our centers. Infectious etiologies (18.5%) are the most common among nonidiopathic cases, with herpes viruses (9.2%) being most prevalent. Despite increased use of polymerase chain reaction (PCR) in the detection of microbial and viral DNA, there was no overall increase in detection of infectious causes for uveitis. The changes in CMV-related immune recovery uveitis from 2005 to 2010 could reflect a change in HIV management in Singapore.     

Changes in Bruch's membrane in experimental hypercholesteremia in rats

PURPOSE: We investigated the effect of high cholesterol diet for the aging changes in Bruch's membrane of rats. METHODS: After feeding a 4% cholesterol diet for 15 weeks to three young rats 3 months old and four aged rats 23 months old, we observed the morphological changes of Bruch's membrane by electron microscopy, and made a comparison with rats fed an ordinary diet. RESULTS: In one young rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris formed multiple folds separated from the plasma membrane of the endothelium and showed lamellar thickening and crack in some areas. The elastic fiber layer in Bruch's membrane disappeared partly and some new microfibrils appeared. In one aged rat fed a high-cholesterol diet, the endothelial basement membrane of the choriocapillaris showed more lamellar thickening with lumps in some parts. Compared with rats fed an ordinary diet, rats fed a high-cholesterol diet showed thickening of the basement membrane and the changes were more severe. CONCLUSIONS: Our data indicated that high-cholesterol diet might promote age-related changes of Bruch's membrane.     

Orthokeratology practice in children in a university clinic in Hong Kong*

Purposes: The aim of this study was to analyse clinical data of children undergoing orthokeratology (ortho‐k) and to investigate patients’/parents’ perspective on ortho‐k via telephone interviews. Methods: Clinical records of children undergoing ortho‐k from a university optometry clinic were reviewed and the effects of ortho‐k on refraction, vision and cornea were investigated. A telephone interview was conducted to solicit patients’/parents’ perspective of the treatment. Results: One hundred and eight files were reviewed. Median age of the children was nine years (range six to 15); mean (±SD) pre‐treatment refractive sphere was ‐3.56 ± 1.49 D and the median refractive cylinder was ‐0.50 D (range zero to ‐4.25 D). Significant refractive spherical reduction (58 per cent), improvement in unaided vision and corneal topographical changes were noted after only one night of wear. No significant change in astigmatism was found. Corneal staining was the most commonly observed complication with ortho‐k and more than 80 per cent of patients were advised to apply ocular lubricants to loosen the lens before lens removal. Ortho‐k was mainly undertaken for myopic control and about 90 per cent of the respondents reported good/very good unaided vision after ortho‐k and ranked the treatment as satisfactory or very good. Lens binding and ocular discharge were the most frequently reported problems during the treatment. Conclusion: Under close monitoring, overnight ortho‐k is effective and safe for reducing low to moderate myopia and the treatment is well accepted by the children.     

内毒素诱导的大鼠葡萄膜炎的巨噬细胞中Toll样受体4的表达

目的 探讨在内毒素诱导的Wistar大鼠葡萄膜炎中Toll样受体4(TLR4)阳性细胞与虹膜组织中巨噬细胞的动态变化和分布.方法 实验研究.Wistar大鼠50只,用随机数字法随机分为5组,每组10只,分别为正常对照(0 h)组、6 h组、12 h组、24 h组及48 h组.除0 h组外其余各组均足垫部注射霍乱弧菌内毒素200μg,注射后于裂隙灯显微镜下观察双眼前节炎症反应变化.按实验分组于0、6、12、24、48 h处死大鼠.取虹膜一睫状体及脉络膜组织.通过葡萄膜铺片免疫组织化学方法检测TLR4和巨噬细胞的标记CD163的表达.人工计数虹膜中TLR4~+与CD163~+的细胞并计算细胞密度,计算圆形和多形性的CD163~+细胞占所有CD163~+细胞的百分比.进一步采用免疫荧光双标记检测TLR4和CD163共表达的情况.通过单因素方差分析分别对大鼠虹膜内阳性细胞密度以及圆形、多形性CD163~+细胞的百分比进行统计学检验.结果 正常大鼠虹膜睫状体组织不表达TLR4.6 h组有2只大鼠虹膜内可见少量TLR4~+细胞,12～48 h组所有大鼠虹膜内TLR4~+细胞明显增多(F=167.2,P＜0.001),虹膜内TLR4~+细胞密度分别为(506.1±39.5)个/mm~2(12 h组)、(492.3±54.5)个/mm~2(24 h组)及(663.8±150.2)个/mm~2 (48 h组).在注射LPS后12～48 h期间TLR4~+细胞形态无明显变化.0～48 h组大鼠虹膜内均有CD163~+细胞,0 h组圆形和多形性CD163~+细胞百分比为13%,12～48 h组其百分比约为80%,且圆形细胞主要位于虹膜基质层.免疫荧光双标记可见TLR4和CD163的共表达,TLR4位于细胞膜,CD163位于细胞质.5组大鼠脉络膜内均未见TLR4表达.结论 内毒素诱导的大鼠葡萄膜炎中虹膜内TLR4表达增高,部分虹膜固有巨噬细胞表达TLR4.TLR4可能在葡萄膜炎的发生发展中起一定作用.     

弱视眼底光学相干断层扫描的研究进展

弱视是由于视觉发育关键期内各种异常的视觉经验导致单眼或双眼最佳矫正远视力低于正常同龄儿童,而眼部无明显器质性病变。目前普遍观点认为,弱视的发病机理主要源于视皮层。近年来,光学相干断层扫描（OCT）作为一种先进的活体成像技术,促进了对视网膜形态结构的大量研究,同时也被应用到弱视的研究领域。陆续有不同的研究人员利用OCT发现弱视患者眼底视网膜、脉络膜等眼部结构存在改变。笔者将对弱视眼底OCT的研究进展做一综述。     

实验性糖尿病视网膜微血管病变的病理研究

目的：观察糖尿病视网膜病变（diabetic retinopathy,DR）的组织学改变。方法：应用光镜、免疫组织化学、电镜及组织化学电镜等技术,研究在不同时间点Spregue-Dawley(SD)大鼠视网膜毛细血管基底膜中的Ⅳ型胶原蛋白及层黏蛋白和视网膜毛细胞血管基底膜的厚度,以及其负电荷位点数目的变化。结果：随着糖尿病病程的发展,视网膜毛细血管基底膜下不断增厚伴有Ⅳ型胶原蛋白及层黏蛋白的增加,同时负电荷位点数目减少。结论：视网膜毛细血管基底膜增厚,Ⅳ型胶原蛋白及层黏蛋白的增加,负电荷位点数目减少可能是导致DR渗出性病变的病理基础。