DNA修复基因的多态性以及DNA损伤与年龄相关性白内障的关系

目的 探讨DNA氧化损伤修复基因BLM、WRN、ERCC6以及OGG1的单核苷酸多态性(single nucleotide polymorphisms,SNP)是否影响年龄相关性白内障(age-related cataract,ARC)的发生,并检测SNP是否会引起外周血淋巴细胞DNA损伤程度的改变.方法 从“江苏眼病研究”人群收集ARC患者789例及对照组531例.提取DNA分析BLM、OGG1、ERCC6及WRN基因18个SNP位点的基因型.同时应用彗星试验检测部分受试者外周血淋巴细胞的DNA损伤程度.结果 WRN-rs11574311与ARC、皮质型以及混合型ARC相关(P=0.003,OR=1.49;P=0.001,OR=1.68;P＜0.000 1,OR=2.08),BLMrs1063147与核型ARC相关(P=0.03,OR=1.31),WRN-rs2725383与皮质型ARC相关(P =0.01,OR=1.49),WRN-rs4733220以及WRN-rs2725338与混合型ARC相关(P=0.04,OR =0.74;P =0.003,OR =0.60).经过Bonferroni校正后,WRN-rs11574311仍与皮质型以及混合型ARC相关,WRN-rs2725338仍然与混合型ARC相关.SNP位点不同基因型的外周血淋巴细胞DNA损伤程度的差异无统计学意义.结论 WRN基因在ARC的发生发展过程中起重要作用,而且在不同亚型ARC中所起的作用也有所不同,说明不同亚型ARC可能具有特异性的危险因素以及致病机制.     

DNA修复基因在年龄相关性白内障患者晶状体皮质中表达的研究

目的　研究ＤＮＡ修复基因在年龄相关性白内障（ａｇｅ-ｒｅｌａｔｅｄｃａｔａｒａｃｔ,ＡＲＣ）患者晶状体皮质和正常对照晶状体皮质之间的表达差异。方法　使用ＴａｑＭａｎ人类ＤＮＡ修复基因表达芯片板检测年龄和性别匹配的３例ＡＲＣ患者和３例正常对照晶状体皮质组织中ＤＮＡ修复基因的表达。表达差异在１．５倍以上的基因使用实时荧光定量聚合酶链式反应（ｒｅａｌ-ｔｉｍｅＰＣＲ）进行验证（３０例ＡＲＣ患者和３０例正常对照）。数据使用ＳＰＳＳ１７．０软件进行分析,ＡＲＣ患者与正常对照间数据的比较采用独立样本ｔ检验。结果　ＴａｑＭａｎ人类ＤＮＡ修复基因表达芯片板检测显示:相对于正常对照晶状体皮质,在ＡＲＣ患者晶状体皮质中有７个ＤＮＡ修复基因（ＡＴＭ、ＥＲＣＣ６、ＰＯＬＡ１、ＰＯＬＤ１、ＰＯＬＱ、ＰＳＭＢ８、ＣＣＮＯ）表达下调１．５倍以上（０．３５±０．０７、０．２６±０．０９、０．４１±０．０７、０．３７±０．１４、０．３７±０．０７、０．１５±０．０５、０．５７±０．１３）,差异均有统计学意义（ｔ＝８．９８,Ｐ＝０．０１;ｔ＝４．７１,Ｐ＝０．０４;ｔ＝１０．４２,Ｐ＝０．０１;ｔ＝４．６５,Ｐ＝０．０４;ｔ＝８．９２,Ｐ＝０．０１;ｔ＝４．９４,Ｐ＝０．０４;ｔ＝７．６３,Ｐ＝０．０２）,４个基因（ＣＨＥＫ２、ＥＲＣＣ１、ＦＡＮＣＥ、ＧＡＤＤ４５Ｇ）表达上调１．５倍以上（２．５８±０．２５、１．９５±０．０９、８．８２±０．７８、３．１８±０．８９）,差异均有统计学意义（ｔ＝１８．１８,Ｐ＝０．００;ｔ＝２０．９２,Ｐ＝０．０１;ｔ＝１９．５５,Ｐ＝０．０１;ｔ＝６．２０,Ｐ＝０．０２）。ｒｅａｌ-ｔｉｍｅＰＣＲ的验证结果与其一致。结论　ＡＲＣ患者晶状体皮质和正常对照晶状体皮质中部分ＤＮＡ修复基因的表达存在差异,这些表达有差异的基因可能在ＡＲＣ的形成和发展中起到一定作用。     

DNA修复基因的拷贝数变异与年龄相关性白内障的关系

目的　探讨中国汉族人群中DNA修复基因的拷贝数多态性（copy number variations，CNV）与年龄相关性白内障（age-related cataract，ARC）易感性的关系。方法　研究对象来自“江苏眼病研究”流行病学人群，包括ARC组780例和对照组525人。采集受试者外周静脉血，提取全血基因组DNA。通过实时荧光定量PCR方法检测四种DNA修复基因的拷贝数（copy number，CN），分析ARC组和对照组基因CN的差异以及相对危险度（odds ratio，OR）。结果　在WRN基因中发现了新的CNV。WRN基因高拷贝（CN=3+）与ARC的易感性有关（OR=1.88，P=0.02）；HSF4基因低拷贝（CN=1）的人群对ARC易感（OR=4.09，P=0.004）。WRN基因高拷贝与核性以及后囊下性ARC的易感性有关（OR=2.06、3.72，均为P=0.02）。HSF4基因低拷贝与核性以及后囊下性ARC的易感性有关（OR=5.73，P=0.001；OR=6.80，P=0.01）。WRN和HSF4基因的联合作用显著增加了ARC的易感性。经过多重校正以后，仅有HSF4的CNV与ARC的易感性有关，尤其与核性和后囊下性ARC的易感性有关。结论　HSF4基因与WRN基因的CNV可能与中国汉族人群ARC的易感性有关。DNA修复基因对ARC易感性有一定的作用，并且对不同亚型ARC产生不同的影响。     

Association between DNA repair genes (XPD and XRCC1) polymorphisms and susceptibility to age-related cataract (ARC): a meta-analysis

Background

DNA repair gene (XPD and XRCC1) polymorphisms have been considered as risk factors for the development of age-related cataract (ARC). To confirm the association between DNA repair gene (XPD and XRCC1) polymorphisms and the risk of ARC, a meta-analysis was conducted.

Methods

A search was made of published literature from Institute for Scientific Information (ISI) Web of Knowledge, PubMed, Google Scholar, China National Knowledge Infrastructure (CNKI), and Wanfang Data. In addition, all studies evaluating the association between DNA repair genes (XPD and XRCC1) polymorphisms and the risk for ARC were included in our analysis. Pooled odds ratio (OR) and 95 % confidence interval (CI) were calculated by using fixed- or random-effects model. The Egger’s test was used to check the publication bias.

Results

Six studies on XRCC1 Arg399Gln (1,300 cases, 1,222 controls) and five studies on XPD Lys751Gln (1,092 cases, 1,061 controls) were included. For the XPD Lys751Gln (A/C) SNP, the overall analysis demonstrated that the CC genotype showed a significant association with a decreased risk for ARC compared with the AA genotype (OR?=?0.59, 95 % CI, 0.38–0.92, P?=?0.019). Similarly, the CC genotype showed a significant association with a decreased risk for ARC compared with the (AA + AC) genotype (OR?=?0.65, 95 % CI, 0.43–0.98, P?=?0.040). Subgroup analysis showed that the association between the CC genotype and decreased risk for ARC is statistically significant in Caucasians (OR?=?0.41, 95 % CI, 0.24–0.73, P?=?0.002) but not in Asians (OR?=?1.06, 95 % CI, 0.51–2.19, P?=?0.877). For the XRCC1 Arg399Gln (G/A) SNP, the overall analysis demonstrated that the A allele showed a significant association with an increased risk for ARC compared with the G allele (OR?=?1.16, 95 % CI, 1.03–1.31, P?=?0.015). Subgroup analyses exhibited that the association between the A allele and the risk for ARC was statistically significant in Asians (OR?=?1.23, 95 % CI, 1.07–1.41, P?=?0.003) but not in Caucasians (OR?=?0.94, 95 % CI, 0.73–1.22, P?=?0.660). Compared with the GG genotype, the GA genotype showed a significant association with an increased risk for ARC in Asians (OR?=?1.32, 95 % CI, 1.08–1.61, P?=?0.006) but not in Caucasians (OR?=?0.58, 95 % CI, 0.27–1.26, P?=?0.171). The Egger’s test did not reveal an obvious publication bias among the included studies.

Conclusions

Our meta-analysis suggested that the CC genotype of XPD Lys751Gln (A/C) SNP seemed to portend a decreased risk for ARC in Caucasian populations but not in Asian populations. The A allele and GA genotype of XRCC1 Arg399Gln (G/A) SNP might increase risk for ARC in Asian populations but not in Caucasian populations. More researches with larger and more different ethnic populations on this issue are therefore necessary.     

Screening of methylation genes in age-related cataract

AIM: To analyze and screen the methylation status of whole-genome in age-related cataract samples. METHODS: Anterior lens capsule samples were collected from age-related cortical cataract patients over 50 years of age with LOCS III score of nuclear color ≥4 along with control subjects. DNAs were extracted and subjected to methylation microarray for the identification of methylated genes employing the high-throughput sequencing approach. RESULTS: Compared with the control group, 843 sites were found methylated, including 802 hypermethylation sites with 542 corresponding genes, 41 demethylation sites with 29 corresponding sites. COL4A1, GJA3, SIPA1L3 were confirmed by mass spectrometry, the results were consistent with high-throughput sequencing. CONCLUSION: DNA methylation microarrays is an efficient way for screening the aberrantly methylated genes. In this study, we are able to screen a few age-related cataract genes such as COL4A1, GJA3, and SIPA1L3 for their aberrant methylation patterns in cataract patients however further work is warranted to understand the significance of these findings.     

错配修复基因MSH3在人晶状体中的表达

目的　研究错配修复基因MSH3在人晶状体上皮细胞系SRA01/04、年龄相关性白内障（age-related cataract,ARC）患者晶状体组织以及24周人胎眼晶状体组织中的表达情况，探讨其与ARC形成的关系。方法　采用RT-PCR检测人晶状体上皮细胞系SRA01/04、ARC患者晶状体组织和健康人脐带（阳性对照）中MSH3基因的表达水平，免疫荧光检测24周人胎眼晶状体中MSH3蛋白的表达。结果　MSH3在晶状体上皮细胞系SRA01/04中高表达，在ARC患者晶状体组织中表达下调。MSH3在24周人胎眼晶状体纤维细胞、晶状体上皮细胞以及晶状体前囊组织中均有表达，且在晶状体上皮细胞中高表达。结论　MSH3在人胎眼晶状体组织和SRA01/04中高表达，而在ARC患者晶状体组织中表达下调，这种表达差异可能会影响DNA的错配修复过程，进而影响晶状体发育导致ARC的发生。     

Oxidative DNA damage in patients with cataract

Acta Ophthalmol. 2010: 88: 891–895

Abstract.

Purpose: This study examines the levels of oxidative damage in patients with cataract. Methods: Blood samples were collected from 60 patients with cataract and 60 age‐ and gender‐matched healthy individuals to measure 8‐hydroxy 2‐deoxyguanosine (8‐OHdG) and malondialdehyde (MDA) levels. Results: A significant difference was observed in leukocyte 8‐OHdG levels in patients with cataract in comparison with healthy persons (p < 0.001). Similarly, a significant difference was observed in plasma MDA levels in patients with cataract in comparison with healthy persons (p < 0.001). In addition, a significant correlation was found between levels of 8‐OHdG in leukocyte DNA and plasma MDA (r = 0.859, p < 0.001). Conclusion: This study measured the oxidative DNA damage by measuring the 8‐OHdG in the leukocyte DNA in patients with cataract. In addition, the level of MDA – a marker for lipid peroxidation – was measured to determine lipid peroxidation.     

白内障病人晶状体上皮细胞DNA损伤初探

目的欲研究白内障病人晶状体上皮细胞是否存在DNA损伤及损伤的程度.方法用单细胞电泳测定白内障手术中取下的白内障病人晶状体上皮细胞DNA损伤的情况.结果11例白内障病人晶状体上皮细胞中有6例确实存在DNA损伤,占54.54%.白内障病人晶状体上皮细胞中DNA损伤程度与年龄无关.每例白内障病人晶状体上皮细胞中DNA损伤程度的分布是轻＞中＞重.结论白内障的发生与晶状体上皮细胞DNA损伤有关,但只是众多诱因之一.     

DNA甲基化在晶状体发育及白内障中的研究进展

表观遗传学是指基因碱基序列在未发生改变的情况下调控基因表达的一门学科,其研究领域主要涉及DNA甲基化、组蛋白修饰和非编码RNA,其中DNA甲基化沉默基因的表达是表观遗传学重要的调控机制.DNA甲基化状态受环境因素的影响,而晶状体发育异常及白内障形成由多种致病因素决定,其中包括环境因素.因此,研究DNA甲基化在晶状体发育及白内障形成过程中的作用机制尤为重要.本文就近年来DNA甲基化在晶状体发育、年龄相关性白内障、并发性白内障、后发性白内障发病机制中的作用进行综述,通过对DNA甲基化在上述眼部疾病及晶状体发育过程中作用机制的认识及研究,有望在白内障临床治疗中开辟新的途径.     

Study of association between pre-senile cataracts and rs11615 of ERCC1, rs13181 of ERCC2, and rs25487 of XRCC1 polymorphisms in a Spanish population

Background: The purpose of this study was to attempt to determine if the presence of certain polymorphisms in the DNA repair genes (ERCC1, ERCC2, and XRCC1) is associated with pre-senile cataract development.

Materials and methods: We performed a retrospective study over three groups of patients. The first group with pre-senile cataract was formed by 72 patients younger than 55 years with cataract surgery. The second group with senile cataract was formed by 101 patients older than 55 years with cataract surgery. And the third group, without cataract, was formed by 42 subjects older than 55 years without lens opacities. We analyzed the presence of SNP rs11615 from ERCC1, rs13181 from ERCC2, and rs25487 from XRCC1 and the relationship between risk factors such as smoking, alcohol intake, hypertension, and diabetes.

Results: The comparison of the genotype distribution in ERCC1 and ERCC2 did not show any statistically significant association in any of our analyses (p > 0.05). The comparison of the genotype distribution in XRCC1 within the different groups did not show any statistically significant associations (p > 0.05), except for the comparison between the pre-senile cataract group and the group without cataract, where an increased risk of developing pre-senile cataract for the genotype Gln/Gln (p = 0.029; OR = 1.02–40.67) in recessive inheritance models was observed when adjusting for risk factors.

Conclusions: Allelic variants in ERCC1 and ERCC2 are not associated with an increased risk of developing pre-senile cataract. The presence of Gln/Gln in XRCC1 in the pre-senile cataract group with regard to the group without cataract is associated with a major risk of developing pre-senile cataract.     

年龄相关性白内障患者氧化损伤修复基因表观遗传学研究进展

氧化损伤是目前较为公认的年龄相关性白内障(ARC)发病机制.晶状体上皮细胞的氧化损伤会引起DNA损伤,而DNA氧化损伤修复能力不足或不及时均会引起ARC的发生.近年来发现,许多眼睛疾患的发病机制受表观遗传、环境及遗传等因素的影响,并且表观遗传学通过调控DNA氧化损伤修复基因的表达在ARC发生机制中起重要作用.本文系统阐...     

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。     

年龄相关性白内障患者沉默信息调节因子1(SIRT1)的单核苷酸多态性研究

目的 探讨江苏汉族人群中沉默信息调节因子1(silent information regulator 1,SIRTl)基因的单核苷酸多态性(single nucleotide polymorphism,SNP)与年龄相关性白内障(age-related cataract,ARC)的关系.方法 采用分子流行病学病例对照研究方法和Taq-Man RT-PCR法,检测江苏眼病研究苏南无锡市滨湖区、苏北盐城市阜宁县基地人群720例ARC,701例与患者年龄、性别相匹配且无亲属关系的健康者为正常对照组的SIRT1基因5个位点(rs2236319、rs1885472、rs10997868、rs2273773、rs4746720) SNP的基因型,入选者均为汉族.结果 SIRT1基因rs10997868位点不符合哈迪-温伯格平衡,故排除出结果分析.SIRT1基因SNP位点rs2236319及rs1885472在对照组中基因型(AA/AG/GG、CC/CG/GG)的分布频率分别为40.08％、52.60％、7.32％及35.81％、35.23％、28.96％,在ARC组中的基因型分布频率分别为36.94％、56.25％、6.81％及36.67％、32.92％、30.42％.SNP位点rs2273773及rs4746720在对照组中基因型(CC/CT/TT)的分布频率分别为38.37％、54.78％、5.85％及74.75％、17.69％、7.56％,在ARC组中的基因型分布频率分别为39.58％、54.17％、6.25％及71.81％、20.97％、7.22％.两组间各基因型分布频率差异均无统计学意义(均为P＞0.05).结论 SIRT1基因SNP(rs2236319、rs1885472、rs2273773、rs4746720)与江苏汉族人群中ARC发病不相关.     

Delay of cataract development in hereditary cataract UPL rats by disulfiram and aminoguanidine

The UPL rat is a newly developed hereditary cataract model. We previously found that the administration of disulfiram, a dimer of diethyldithiocarbamate that possesses antioxidant activity, and aminoguanidine, which is known to inhibit inducible nitric oxide synthase, inhibits cataract development in selenite-induced cataract rats. In this study, we investigated the anti-cataract effects and mechanism of disulfiram and aminoguanidine on UPL rats. The opacities of UPL rat lenses, as documented by the anterior eye segment analysis system, EAS-1000 (Nidek, Aichi, Japan), increased from 39 days, and apparently mature cataracts were observed at 53 days. Accompanied with the increase in lens opacity, glutathione concentrations in UPL rat lenses decreased. The Na(+) to K(+) and water-insoluble to water-soluble protein ratios, as well as the Ca(2+) contents in UPL rat lenses increased with the development of cataracts. Oral administration of disulfiram and aminoguanidine delayed the lens opacification as well as the changes in glutathione, Na(+) to K(+) ratio, water-insoluble to soluble protein ratio, and Ca(2+) content in UPL rat lenses. The opacity and Ca(2+) content of UPL rat lenses were closely associated. The present study demonstrates that disulfiram and aminoguanidine have potency of the delay of cataract development in UPL rats, probably caused by inhibiting the rise in Ca(2+) levels.     

独眼白内障人工晶状体植入手术的效果与风险

目的:探讨独眼白内障患者人工晶状体植入手术的效果与风险。方法:对43例另眼已经眼球摘除或完全致盲的独眼白内障患者行人工晶状体植入手术治疗。其中28例行现代白内障囊外摘出人工晶状体植入术,15例行超声乳化人工晶状体植入术。随访6～15mo。结果:术后视力均有不同程度提高,矫正视力≥0.8者5眼(12%),0.3～0.8者28眼(65%),0.05～0.2者9眼(21%),0.05以下者1眼(2%)。脱残率77%,脱盲率98%。结论:独眼白内障患者眼部情况复杂多变。对独眼白内障患者应当采取认真负责的态度,结合具体情况制定个性化的手术方案。为减少纠纷,术前详细检查,与家属坦诚沟通,取得家属的理解和信任是十分必要的。在细致慎重的操作下,独眼白内障已不再是人工晶状体植入的禁忌证。手术仍是安全和有效的。     

遗传性白内障致病基因及其机制的研究进展

先天性白内障是导致儿童失明的主要原因之一，占儿童致盲眼病的第2位。先天性白内障种类较多，且病因不同。随着分子生物学技术的发展，对于先天性白内障发病机制的研究有了很大的进展。遗传性白内障在先天性白内障中所占的比例较大，近来不断有致病基因被发现。就遗传性白内障的致病基因及其分子发病机制的研究进展进行综述。     

人8-羟基鸟嘌呤糖苷酶1与年龄相关性白内障关系的临床研究

目的探讨与年龄相关性白内障（ARC）患者晶状体上皮细胞（LECs）中参与DNA损伤后碱基清除修复途径的氧化损伤修复基因—人8-羟基鸟嘌呤糖苷酶1（HOGG1）水平与ARC的关系。方法收集三种ARC（皮质性、核性、后囊下性）LECs样本,以透明晶状体LECs为对照组,用免疫组化、RT-PCR方法测定HOGG1在LECs的表达情况。结果对照组LECs中可见HOGG1的表达,三种ARC患者LECs中可见HOGG1表达较对照组增高（F=107.62,P〈0.01）,但三种ARC之间没有统计学差异。对照组与ARC组HOGG1均位于细胞质和细胞核。说明ARC LECs的细胞核和细胞质中HOGG1的表达量上调。结论 HOGG1表达上调参与ARC的发生发展。