晶状体上皮细胞转分化对老年性白内障形成的影响研究

目的 :为研究晶状体上皮细胞转分化对老年性白内障形成的影响。方法 :对 14例老年性白内障晶状体前囊上皮细胞进行角质蛋白 -8、波形纤维蛋白和纤维粘连蛋白表达的免疫组化研究。结果 :皮质性白内障晶状体上皮的波形纤维蛋白表达明显强于核性白内障 (P <0 0 5 ) ;角质蛋白 -8在皮质性白内障晶状体上皮的表达比核性白内障弱 ((P <0 0 1) ;纤维粘连蛋白在皮质性白内障晶状体上皮的表达明显强于核性白内障 ,而在正常晶状体上皮不表达。结论 :晶状体上皮细胞具有转分化为成纤维样细胞的双向化潜能。晶状体上皮获得转分化能力后而失去原来的细胞学特性。在老年皮质性白内障中 ,晶状体上皮细胞转分化成为成纤维样细胞 ,伴随波形纤维蛋白的过度表达和角质蛋白表达下降。同时合成包括纤维粘连蛋白在内的细胞外基质增多 ,而纤维粘连蛋白能促进晶状体上皮的增殖、迁移及粘附 ,因而晶状体上皮细胞转分化对老年性白内障形成及后囊混浊的形成发挥重要作用。     

晶体体上皮细胞转分化对老年性白内障形成的影响研究

目的：为研究晶状体上皮细胞转化对老年性白内障形成的影响。方法：对14例老年性白内障晶状前囊上皮细胞进行角质蛋白－8、波形纤维蛋白和纤维粘连蛋白表达的免疫组化研究，结果：皮质性白内障晶状体上皮的波形纤维蛋白表达明显强于核性白内障（P＜0．05），角质蛋白－8在皮质性白内障晶状体上皮的表达比核性白内障弱（P＜0．01）；纤维粘连蛋白在皮质性白内障晶状体上皮的表达明显强于核性白内障，而在正常晶状体上皮不表达，结论：晶状体上皮细胞具有转分化为成纤维样细胞的双向化潜能，晶状体上皮获转分化能力后而失去原来的细胞学特性，在老年皮质性白内障中，晶状体上皮细胞转化成为纤维样细胞，伴随波形纤维蛋白的过度表达和角质蛋白表达下降，同时合成包括纤维粘连蛋白在内的细胞外基质增多，而纤维粘连蛋白能促进晶状体上皮的增殖，迁移及粘附，因而晶状体上皮细胞转化分对老年性白内障表成及后囊混浊的形成发挥重要作用。     

水通道蛋白1在老年性白内障及透明晶状体前囊膜上皮细胞的表达

目的明确水通道蛋白1(aquaporin1,AQP1)在透明晶状体及老年性白内障晶状体上皮细胞及前囊膜的表达及分布,并初步探讨AQP1在老年性白内障发病中的重要作用。方法收集52例老年性白内障及10例正常透明晶状体前囊膜,通过HE染色和免疫组化方法检测AQP1的表达。结果老年性白内障及正常透明晶状体上皮细胞中均可见AQP1的表达,透明晶状体组中AQP1的阳性细胞表达率(100%)显著高于老年性白内障组(53.8%)(P<0.05)。而在晶状体纤维中未见表达。结论晶状体上皮细胞是晶状体代谢最活跃的部位,终身进行有丝分裂,并移行至赤道部分化成晶状体纤维。晶状体上皮细胞有AQP1的活性表达,这对于维持晶状体上皮细胞一定的增殖潜能,保证晶状体的生理动态平衡和晶状体的透明性起到了重要的作用。提示AQP1在老年性白内障晶状体前囊膜及上皮细胞中的异常表达与老年性白内障的发生密切相关,具体调控机制有待进一步研究。     

波形蛋白在老年性白内障晶状体上皮细胞中的表达及其意义

目的 :进一步明确波形蛋白的异常表达在老年性白内障形成中所起的作用。方法 :用链酶菌抗生物素蛋白 碱性磷酸酶 (streptavidin alkalinephosphatase,S P)免疫组化方法检测波形蛋白在 31例皮质性白内障、2 0例核性白内障及5例正常透明晶体上皮中的表达情况。结果 :波形蛋白在皮质性白内障晶体上皮中的表达比在核性白内障及正常透明晶状体中高。结论 :老年性皮质性白内障与老年性核性白内障的发生有不同的发病机制 ,皮质性白内障的发生与波形蛋白的过度表达有关     

老年性白内障的氧化损伤与酶组织化学观察

研究老年性白内障晶状体上皮酶活性变化和氧化损伤对培养的牛晶状体上皮细胞酶活性的影响。方法：1取老年性白内障晶状体和正常透明晶状体进行酶组织化学染色，观察SDH，LDH，G6PD，ATPase活性的变化。2观察培养牛晶状体上皮细胞氧化损伤后及维生素C治疗后SDH，LDH，G6PD活性的改变。结果：1老年性白内障SDH，LDH，G6PD，ATPase活性降低。2培养的牛晶状体上此细胞经过氧化损伤后SDH，LDH，G6PD活性显降低，维生素C可使酶活性显提高，结论：氧化损伤使能量产生减少，可能是白内障发生的原因之一，维生素C对氧化损伤具有部分保护作用。     

老年性和糖尿病性白内障晶状体上皮细胞的超微结构改变

目的 观察正常人,老年性白内障、糖尿病性白内障晶状体上皮细胞的超微结构,探讨细胞凋亡在白内障发生中的作用。方法 收集正常人、老年性白内障、糖尿病性白内障晶状体前囊膜送透射电镜扫描,取老年性白内障和糖尿病性白内障前囊膜各15例,用脱氧核苷酸末端转移酶缺口标记原位细胞检测法,检测晶状体上皮的凋亡细胞。结果 老年性和糖尿病性白内障晶状体上皮细胞的超微结构在形态上为扁平状,胞浆出现空泡变性,胞核出现固缩,染色质边聚,浓缩等改变。糖尿病性白内障晶状体上皮细胞的胞浆空泡变性更加严重。在光镜下老年性和糖尿病性白内障的晶状体上皮均有凋亡细胞。结论 老年性白内障和糖尿病性白内障的发生与晶状体上皮的细胞凋亡密切相关。     

色素上皮衍生因子在人晶状体上皮细胞表达的意义

目的:观察色素上皮衍生因子(PEDF)在人晶状体内的分布,探讨人晶状体上皮细胞(LEC)中PEDF表达水平与年龄及白内障发生发展的关系。方法:收集老年性和先天性白内障患者术中所取前囊膜、新鲜眼库眼透明晶状体样品,冰冻切片标本用间接免疫荧光组织化学法检测PEDF蛋白在人晶状体中的分布,前囊膜标本分别用蛋白质免疫印迹(Western-blot)及逆转录聚合酶链反应(RT-PCR)技术检测LEC中PEDF蛋白和基因的表达水平。结果:人晶状体中存在PEDF蛋白,主要分布于前囊下LEC胞浆中。按透明晶状体、轻度白内障、重度白内障及年龄分组分析,人LEC内PEDF基因及蛋白的表达水平在晶状体由透明变混浊、混浊由轻变重的过程中呈下调趋势(P<0.01),且随着机体的衰老显著下降(P<0.01)。结论:人LEC中PEDF表达随晶状体衰老和白内障发生发展显著下调。     

老年性白内障的氧化损伤与酶组织化学观察

目的 研究老年性白内障晶状体上皮酶活性变化和氧化损伤对培养的牛晶状体上皮细胞酶活性的影响。方法 １．取老年性白内障晶状体和正常透明晶状体进行酶组织化学染色,观察ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ,ＡＴＰａｓｅ活性的变化。２．观察培养牛晶状体上皮细胞氧化损伤后及维生素Ｃ治疗后ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ活性的改变。结果 １．老年性白内障ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ,ＡＴＰａｓｅ活性降低。２．培养的牛晶状体上皮细胞经过氧化损伤后ＳＤＨ,ＬＤＨ,Ｇ６ＰＤ活性显著降低,维生素Ｃ可使酶活性显著提高。结论 氧化损伤使能量产生减少,可能是白内障发生的原因之一,维生素Ｃ对氧化损伤具有部分保护作用。     

老年性和糖尿病性白内障晶状体上皮细胞的超微结构改变

目的 观察正常人，老年性白内障、糖尿病性白内障晶状体上皮细胞的超微结构，探讨细胞凋亡在白内障发生中的作用。方法 收集正常人、老年性白内障、糖尿病性白内障晶状体前囊膜送透射电镜扫描，取老年性白内障和糖尿病性白内障前囊膜各15例，用脱氧核苷酸末端转移酶缺口标记原位细胞检测法，检测晶状体上皮细胞的凋亡细胞。结果 老年性和糖尿病性白内障晶状体上细胞的超微结构在形态上为扁平状，胞浆出现空泡变性，胞核出现固缩，染色质边聚，浓缩等改变。糖尿病性白内障晶状体上皮细胞的胞浆空泡变性更加严重。在光镜下老年性和糖尿病性白内障的晶状体上皮均有凋亡细胞。结论 老年性白内障和糖尿病性白内障的发生与晶状体上皮的细胞凋亡密切相关。     

热休克蛋白27在老年性白内障晶状体上皮细胞中的表达及意义

目的　探讨热休克蛋白(HSP) 27在老年性白内障晶状体上皮细胞中的表达及意义。 方法　采用Westernblot蛋白印迹法,检测老年性白内障 50例(其中皮质型 17例、核型 18例、后囊下型 15例 )、正常人晶状体 4例上皮细胞中HSP27的表达。 结果　HSP27在老年性白内障(0 411±0 188)和正常人 (0 147±0 006)晶状体上皮细胞表达有显著性差异,老年性白内障皮质型、核型、后囊下型HSP27表达也不相同。 结论　HSP27可能在老年性白内障的发生、发展中起重要作用,HSP27在皮质型、核型、后囊下型白内障发生的作用机制可能不完全相同。     

波形纤维蛋白在老年性白内障晶状体上皮细胞的表达

目的观察波形纤维蛋白在老年性白内障晶状体上皮细胞的变化.方法用卵白素-生物素过氧化物酶法对22例老年性白内障患者晶状体前囊膜上皮细胞进行波形纤维蛋白染色,采用包埋前免疫酶电镜技术处理6个晶状体前囊膜标本,并观察其超微结构;利用十二烷基硫酸钠聚丙烯酰胺凝胶电泳及Westemnblot法分析4个晶状体表层组织(前囊膜、上皮细胞和表层皮质)中的波形纤维蛋白.结果老年性白内障晶状体上皮细胞的波形纤维蛋白表达减弱,与对照组比较差异有显著性(t=2.0948,P<     

Proteasome activity in human lens nuclei and correlation with age,gender and severity of cataract

PURPOSE: The aim of this study was to measure proteasome activity in human lens nuclei resulting from cataract surgery and in different regions of donor lenses. METHODS: The chymotrypsin-like, the trypsin-like and the peptidylglutamyl-peptide hydrolysing activities of the proteasome were studied using synthetic flourogenic substrates. RESULTS: Proteasome activity did not show any correlation with age of the patients or with gender. Increased opacification of the lens nucleus, as estimated prior to surgery using a 4-grade scale, was significantly correlated with decreased activity of all peptidase activities in the insoluble fraction. In the donor lenses, all peptidase activities were highest in the epithelium and decreased rapidly towards the nucleus. CONCLUSIONS: The present study demonstrates that proteasome activity is preserved in the nucleus of lenses from elderly individuals, although a decrease can be seen with cataract formation. This finding may be of importance for elucidating the mechanism behind the formation of nuclear cataract.     

Biochemical alterations of the lens capsule in mice with hereditary cataract

Lens capsules from normal and cataractous mice (Nakano strain) were compared histologically and chemically. Histologically, the anterior capsule of the cataract lens was thicker than the normal, while the posterior capsule appeared almost the same. Amino acid analysis revealed some differences between normal and cataractous lens capsules: more glycine, hydroxylysine and arginine and less hydroxyproline and tyrosine were found in cataractous capsules. Hydroxyproline showed the largest difference, cataract lens being about 11% lower than normal.To see if the content of hydroxylysine-linked carbohydrates is different in normal and cataractous lenses, as has been shown for renal basement membranes from normal and diabetic animals, a procedure was developed to separate basic amino acids, including the hydroxylysine-linked carbohydrates, from other amino acids. It was found that the content of hydroxylysine-linked disaccharide (Glc-Gal-Hyl) was slightly but significantly higher in cataractous lenses.The possibility was suggested that the compositional alterations observed for the cataract lens might be correlated with functional changes in the lens capsule of the cataract, e.g. lowered elasticity, decreased permeability etc.     

猕猴白内障晶体上皮细胞超微结构研究

目的 探讨猕猴白内障晶体上皮细胞的超微结构,为将猕猴白内障作为人类白内障理想的动物模型提供病理学研究资料。方法 采用透射电镜对猕猴正常眼和猕猴白内障眼的晶体上皮细胞超微结构进行观察。结果 猕猴白内障眼晶体上皮细胞发生明显的变化：线粒体肿胀、空化、嵴消失,甚至形成凹空细胞;细胞水肿,细胞质溶解,甚至细胞崩解破坏;细胞核固缩、畸形,核膜间隙与核孙消失,核内异染色质浓集、周边化。结论 猕猴白内障上皮细胞     

老年性白内障晶状体上皮细胞凋亡及相关基因蛋白的表达

目的 探讨老年性白内障与晶状体上皮细胞凋亡的关系。方法透射电镜下观察老年性白内障晶状体上皮细胞的超微结构；Tunel法检测凋亡细胞百分率；并对其晶状体上皮细胞DNA进行琼脂糖凝胶电泳；免疫组化法检测P53、bcl-2在老年性白内障晶状体上皮细胞中的蛋白表达。结果 透射电镜下发现老年性白内障晶状体上皮细胞中有凋亡细胞；凋亡细胞百分率为8．4％～37．8％，琼脂糖凝胶电泳出现梯状条带；P53在老年白内障晶状体上皮细胞中蛋白表达率为16．9％～19．1％，bcl-2无蛋白表达。结论 老年性白内障的发生可能与其晶状体上皮细胞凋亡有关。     

核因子κB在年龄相关性白内障晶状体前囊膜的表达

目的研究核因子κB（NF-κB）在正常人、年龄相关性白内障患者晶状体前囊膜上皮细胞中表达的差异,探讨NF-κB在年龄相关性白内障发病机制中的作用。方法收集白内障术中60例60眼年龄相关性白内障的前囊膜组织（白内障组）,选取正常供体5例10眼的透明晶状体前囊膜组织作为正常对照组。取白内障组30眼标本和正常对照组5眼标本用于免疫组织化学法检测NF-κBp65蛋白在晶状体前囊膜上皮细胞中的表达;另外白内障组30例标本及正常对照组的5例标本采用实时荧光定量聚合酶链反应（PCR）方法检测NF-κBp65mRNA在晶状体前囊膜上皮细胞中的表达。结果正常晶状体前囊膜上皮细胞细胞质和细胞核中可见NF-κBp65蛋白的弱阳性表达,以细胞质为主;年龄相关性白内障晶状体前囊膜上皮细胞的细胞质和细胞核中NF-κBp65蛋白呈强阳性表达。白内障组NF-κBp65吸光度（A）值为0.1658±0.022,正常对照组为0.2889±0.043,差异有统计学意义（t=6.2109,P〈0.05）。白内障组NF-κBp65mRNA表达量为1.454±0.081,正常对照组为0.951±0.075,差异有统计学意义（t=12.9683,P〈0.05）。结论 NF-κB表达水平的升高与年龄相关性白内障的发病密切相关,其表达异常可能参与年龄相关性白内障的发生发展。     

Ca2+-ATP酶在透明晶状体及白内障晶状体上皮细胞上的表达

目的通过研究Ca^2＋ -ATP酶在透明晶状体及白内障晶状体上皮细胞上的表达情况，从分子水平探讨老年性白内障的发生机制。方法利用半定量RT—PCR技术测定6种Ca^2＋ -ATP酶的n1KNA在透明晶状体和3种常见类型老年性白内障晶状体上皮细胞上的表达．结果6种Ca^2＋ -ATP酶在透明晶状体和白内障晶状体上皮细胞上均有表达，但表达的量不同，其中PMCA3在白内障晶状体上皮细胞上的表达明显减少，差异有显著性（P〈0．01）。不同类型的老年性白内障晶状体上皮细胞上Ca^2＋ -ATP酶的表达形式亦不相同。结论PMCA3在老年性白内障的发生中可能起着关键性作用；不同形式的Ca^2＋ -ATP酶表达的减少可能导致不同类型老年性白内障的发生。     

Age-related changes in the rat lens: morphological and morphometrical studies

Age-related changes in the lenses of 90 Wistar male rats, whose ages ranged from 7 to 26 months, were studied morphologically and morphometrically. Morphological studies were performed using biomicroscopy, light microscopy, scanning electron microscopy and transmission electron microscopy. Early cataract formation was observed biomicroscopically in rats of 19 months of age and the number of cataractous lenses increased with aging. Age-related morphological changes in the lenses were observed before cataract formation and these histological changes showed various forms with aging. Flat preparations of the lens epithelium were examined with a computer-assisted cell-analyzer. The mean cell density decreased and the mean cell area enlarged in both central and germinative zones of the lens epithelium with aging. These results suggest that age-related changes of lens epithelial cells do occur and may be associated with the formation of Wistar rat cataract.     

Changes in the lens epithelium with respect to cataractogenesis—light microscopic and Scheimpflug densitometric analysis of the cataractous and the clear lens of diabetics and non-diabetics

Background We compared the human lens documented, using the Scheimpflug densitometry, with the light microscopic changes in the epithelium of the anterior central lens in patients with age-related cataract and diabetes mellitus type II and verified the findings on the control tissue of the clear eye lens. We wanted to determine the relevance of the lens epithelium in cataract formation in type II diabetics compared to non-diabetics.Materials and methods One hundred fifty central lens capsules (138 cataract and 12 clear lenses) of type II diabetics (n=77, 45 female, 32 male) and non-diabetics (n=73, 41 female, 32 male) were examined by light microscope, regarding defined histomorphological parameters. Further criteria were duration of diabetes, diabetic retinopathy, cataract (PENTACAM, scheimpflug densitometric definition), protein content in the aqueous humour (laser flare meter 500 KOWA, tyndallometry), different blood parameters and glucose content in the aqueous humour.Results The mean cell density in the cataractous lens in type II diabetics was 3,951±528 cells/mm² and in non-diabetics 4,329±580 cells/mm² (P<0.001); in the clear lens it corresponded to 4,593±409 cells/mm² (type II diabetics) and 4,894±333 cells/mm² (non-diabetics, P=0.207). The cell density of the cataractous lens in type II diabetics (P=0.005) and in non-diabetics (P=0.035) is smaller than that of the clear lens. The cell area of the lens epithelium in the cataractous diabetic lens is larger (P<0.001) and the nucleus-plasma ratio is lower (P<0.001) than those of the clear non-diabetic lens. The increase in damage of the lens epithelium correlates with the decrease of cell density (P< 0.001), the increase of nucleus area and volume (P< 0.001), and the decrease of nucleus-plasma ratio (P< 0.001). Risk factors for the decrease of cell density are advanced age (P=0.015), type II diabetes (P=0.01), increase in glucose content in the aqueous humour (P=0.014), increase in blood sugar (P=0.003) and increase in glycosylated haemoglobin (P=0.039).Conclusions The lens epithelium is primarily damaged in type II diabetics who develop age-related cataract. This might play an important role in cataract formation.     

半乳糖性白内障大鼠晶状体中二肽基肽酶II的表达

目的:研究二肽基肽酶II(dipeptidyl peptidase II,DPPII)在D-半乳糖性白内障大鼠晶状体和正常大鼠晶状体中含量的变化,探讨DPPII与白内障发病的关系。方法:建立D-半乳糖性白内障大鼠动物模型,进行相应分期分组,应用Western blot方法检测DPPII在各组白内障大鼠及正常大鼠晶状体中含量变化。结果:DPPII在各组D-半乳糖性白内障大鼠晶状体中的含量明显高于同期正常对照组,并且随着晶状体混浊程度的加重而增加。结论:DPPII在D-半乳糖性白内障大鼠晶状体中的含量增加,可能与白内障发病相关。