p53和 bcl-2在老年性白内障晶状体上皮细胞中的蛋白表达

目的：研究p53,bcl-2基因在老年性白内障晶状体上皮细胞中的蛋白表达，探讨p53,bcl-2在老年性白内障晶状体上皮细胞凋亡中的作用。方法：应用免疫组织化学方法，对30例老年性白内障及10例正常透明晶状体上皮细胞进行p53,bcl-2基因蛋白表达的检测，计算p53,bcl-2基因蛋白表达阳性细胞百分率，结果：p53在正常晶状体上皮细胞中无蛋白表达，在老年性白内障晶状体上皮细胞中蛋白表达率为16．9％－19．1％，bcl-2在2组中均无蛋白表达，结论：p53在老年性白内障晶状体上皮细胞中蛋白高表达，p53可能促进了老年性白内障中晶状体上皮细胞的凋亡。     

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。     

Na^＋-K^＋-ATP酶活性及其α1催化亚基在鸡晶状体中的分布

目的对Na^＋-K^＋-ATP酶催化亚基蛋白在鸡晶状体的上皮层、周边部和中央部纤维的分布和酶活性进行检测和比较。方法将部分胚胎第10天（E10）的鸡晶状体显微解剖为晶状体上皮部、周边部纤维和中央部纤维3个部分，剩余部分制备冰冻切片。利用免疫荧光染色和Western blot方法检测Na^＋-K^＋-ATP酶催化亚基（α）在晶状体各部分的表达，通过检测哇巴因敏感的ATP水解率测定Na^＋-K^＋-ATP酶的活性。结果在晶状体切片上，α1催化亚基蛋白在晶状体上皮细胞（LECs）膜上有很强的表达，而在晶状体纤维细胞膜的表达明显减弱，在周边部上皮细胞的表达有明显的极性，而在中央部上皮细胞中未见表达。Western blotting检测也再次证实α1催化亚基蛋白在LECs中的表达明显高于在晶状体纤维中的表达。上皮层Na^＋-K^＋-ATP酶的活性是周边部纤维酶活性的2倍，是中央部纤维酶活性的11倍。结论Na^＋-K^＋-ATP酶α1催化亚基蛋白在鸡晶状体的上皮细胞和纤维上表达；在鸡晶状体上Na^＋-K^＋-ATP酶及其活性的分布是不均一的。     

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。     

凋亡相关蛋白TFAR19在老年性白内障晶状体上皮细胞中的表达与定位

目的 探讨凋亡相关蛋白TFAR19在老年性白内障晶状体上皮细胞中的表达。方法 以TFAR19蛋白的单克隆抗体为工具，利用过氧化酶标定的链霉卵白素染色试剂盒对老年性白内障晶状体上皮细胞行免疫组化染色，观察TFAR19蛋白在晶状体上皮细胞中的表达及定位。结果 发现正常人晶状体上皮细胞中有TFAR19蛋白低水平的表达，老年性白内障晶状体上皮细胞中有3种高表达的细胞；一种为少部分细胞呈胞浆高表达，胞核不表达；另一种为偶见胞核，胞浆均高表达；第3种为凋亡晚期的细胞仅在凋亡小体上有表达。结论 老年性白内障晶状体上皮细胞中有凋亡相关蛋白TFAR19的特征性表达，该结果对进一步揭示细胞凋亡是否参与白内障的发病有着重要意义。     

老年性白内障晶状体上皮细胞超微结构观察

目的 研究老年性白内障晶状体上皮细胞的超微结构,探讨老年性白内障与晶状体上皮细胞凋亡关系。方法 用透射电镜对20例老年白内障及10例正常透明晶状体上皮细胞的超微结构进行观察,拍照。结果 老年白内障组晶状体上皮细胞中发现了典型的凋亡小体,正常对照组未见凋亡细胞。结论 老年性白内障的发生与晶体上皮细胞的凋亡有关。     

老年性白内障晶状体上皮细胞超微结构观察

目的 研究老年性白内障晶状体上皮细胞的超微结构。探讨老年性白内障与晶状体上皮细胞凋亡关系。方法 用透射电镜对20例老年白内障及10例正常透明晶状体上皮细胞的超微结构进行观察。拍照。结果 老年白内障组晶状体上皮细胞中发现了典型的凋亡小体。正常对照组未见凋亡细胞。结论 老年性白内障的发生与晶体上皮细胞的凋亡有关。     

氧化性白内障中晶状体上皮细胞内Ca2+浓度的变化

目的 通过测定过氧化氢诱发的白内障中晶状体上皮细胞内Ca^2 浓度的变化，探讨Ca^2 浓度的改变在氧化性白内障发生机制中的作用。方法 用过氧化氢诱发实验组离体培养的大鼠晶状体产生白内障，用Fura-2／AM荧光标记法测定晶状体上皮细胞胞浆内Ca^2 的浓度，并与对照组正常晶状体相比。结果 经过氧化氢作用的实验组，6、12和24h时，晶状体上皮细胞胞浆内Ca^2 浓度与对照组相比明显升高，差异有显著性(P=0．001，0．000，0．000)。结论 本研究证实过氧化氢作用于大鼠晶状体后，其上皮细胞内Ca^2 浓度明显升高，从而为Ca^2 依赖的蛋白水解酶如钙蛋白酶等的激活创造必要条件。     

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。     

老年性白内障合并2型糖尿病患者晶状体上皮细胞转化生长因子β表达及其与晚期糖基化终末产物的相关性

目的研究转化生长因子p（transforminggrowthfactor—β,TGF—β）在老年性白内障合并2型糖尿病患者中的表达变化及其可能的作用机制,为进一步阐明老年性白内障合并2型糖尿病患者发病的分子机制提供实验数据。方法分别采用点杂交和实时荧光聚合酶链反应方法定量检测和分析老年性白内障患者及老年性白内障合并2型糖尿病患者晶状体前囊膜上皮细胞中TGF-β蛋白、mRNA表达水平。免疫荧光方法观察晚期糖基化终末产物（advanced glycation endoproducts,AGEs）对体外培养人晶状体上皮细胞TGF-β表达的影响。结果与老年性白内障患者相比,老年性白内障合并2型糖尿病患者晶状体前囊膜上皮细胞中TGF-β（TGF-β／2／3）蛋白表达增加（P〈0．05）,mRNA表达变化分别为TGF—β1升高（P〈0．05）,TGF—β2降低（P〈0．01）,TGF-β3未见显著改变（P〉0．05）。AGEs与晶状体上皮细胞共培养后,细胞表面TGF—β（TGF-β1／2／3）表达上调。结论TGF—β在老年性白内障合并2型糖尿病患者晶状体上皮细胞中的表达上调。AEGs可诱导晶状体上皮细胞TGF—β表达上调。（中国眼耳鼻喉科杂志,2010,10：212514）     

正常和老年性白内障晶体的钙调节

测定了正常和白内障晶体上皮、皮质和核的钙-ATP酶、钙调蛋白和钙含量，分析了它们之间的相关性。发现正常晶体钙、钙调蛋白与钙-ATP酶呈正相关。老年性白内障晶体钙调蛋白与钙-ATP酶活性无相关性，钙-ATP酶活性下降。提示老年性白内障晶体钧-ATP酶活性下降是钙含量升高的重要原因，推测与氧化性损伤累及钙-ATP酶流基有关。     

Nucleotide levels in human lens: regional distribution in different forms of senile cataract

Sensitive high-performance liquid chromatography methods were employed to assess regional distribution of adenine, guanosine and uridine nucleotides in clear and cataractous human eye lenses. According to slit-lamp examination, three forms of senile cataract were distinguished: (1) supranuclear or deep cortical cataract (typical senile cataract), (2) primary nuclear cataract (cataracta brunescens) and (3) subcapsular cortical cataract associated either with a supranuclear (3a) or a secondary nuclear cataract (3b). Except for AMP, which was highest in the nuclear fraction, all other nucleotides (ATP, ADP, GTP, and UTP) were predominantly located in the anterior cortex (plus epithelium) of clear as well as cataractous lenses, that is, ATP levels in the nucleus amounted to 20% of those found in the anterior cortex (plus epithelium); ATP levels in the posterior cortex were about 60% of those in the anterior cortex (plus epithelium). Significant differences in the absolute regional nucleotide level existed between the different forms of cataract. Highest ATP levels were found in the anterior cortex (plus epithelium) of clear lenses and deep or supranuclear cortical cataract. The ATP level was slightly diminished in primary nuclear cataract and in supranuclear cortical cataract when associated with an early subcapsular cortical cataract. ATP levels were depressed to less than 30% in the anterior cortex (plus epithelium) of lenses with a subcapsular cortical cataract when associated with either an early secondary nuclear or a mature cataract. Furthermore, the ATP/ADP ratio was decreased in this form of senile cataract. The decrease in lens nucleotide level did not correlate with increased age. These data suggest that decreases in regional ATP level are a secondary event and do not appear to be causally involved in the genesis of the 'cataracta senilis'.     

人及小鼠白内障晶状体上皮细胞凋亡的超微结构

目的 探讨人老年性白内障及小鼠先天性白内障与其晶状体上皮细胞凋亡的关系。方法 用透射电镜观察４例老年性白内障患者及２例先天性白内障小鼠晶状体上皮细胞凋亡的超微结构,并分别与同类正常晶状体上皮细胞超微结构进行比较。结果 老年性白内障患者及先天性白内障小鼠晶状体上皮细胞中均可见凋亡细胞,而正常晶状体未见凋亡细胞。结论 人老年性白内障及小鼠先天性白内障的发生均与其晶体上皮细胞的凋亡有关。     

老年性白内障与透明晶状体上皮内蛋白酶体活性的比较

目的:比较老年性白内障晶状体上皮与透明晶状体上皮内蛋白酶体的糜蛋白酶样、胰蛋白酶样酶活性是否存在差异,进而探讨蛋白酶体在老年性白内障发生发展中的作用机制。方法:白内障晶状体囊膜取自在我院行白内障超声乳化及人工晶状体植入的患者,透明晶状体囊膜取自广东省眼库,年龄与白内障病人相匹配。反复冻融囊膜使细胞脱落,将囊膜从溶液中除去。各组样品中分别加入LLVY或VGR,在不同时间测定荧光强度。结果:透明晶状体上皮的蛋白酶体活性明显高于白内障组(P<0.01);皮质型与非皮质型白内障晶状体上皮的糜蛋白酶样酶活性无明显区别(P>0.05);MG-132明显抑制各组蛋白酶体的活性。结论:与透明晶状体相比,白内障晶状体上皮内蛋白酶体的糜蛋白酶样、胰蛋白酶样酶活性明显降低,蛋白酶体活性降低可能在老年性白内障的形成中起重要的调节作用。     

Cation pump activity and membrane permeability in human senile cataractous lenses

The majority of human senile cataractous lenses show a progressive alteration of electrolyte levels resulting in increased lens sodium and decreased potassium, and a concomitant increase in lens water. These changes are known to be associated with the cortical type of senile cataract. The aim of this study was to investigate the mechanisms responsible for the osmotic imbalance in cortical cataract.Determination of Na,K-ATPase activity gave a wide range of values that were not significantly different from normal controls, but rubidium influx showed a normal accumulation in cataractous lenses demonstrating a normal functioning of the cation pump. Both sodium influx and rubidium efflux are increased in the cataractous lenses and the increase is proportional to the absolute level of lens sodium. These results suggest that the biochemical change responsible for the osmotic imbalance in human senile cataract is not a defect in the cation pump mechanism but rather an increase in lens membrane permeability.     

Pigment Epithelium-derived Factor in Cataractous Aqueous Humor and Lens Epithelial Cells

Purpose: To study the characteristics of PEDF in cataractous aqueous humor and its expression in human lens epithelium. Methods: The PEDF concentration in the aqueous humor was measured by enzyme -linked immunosorbent assay in senile (130cases) and congenital (18cases) cataract patients who underwent cataract phacoemulsification extraction surgery. Anterior lens capsular specimens were obtained from these patients to count lens epithelial cells (LEC) density. The Lens Opacities Classification System Ⅲ was used to classify the senile cataracts as cortical, nuclear, posterior subcapsular and mixed types of opacity, and quantitative analysis of the nuclear opacities was performed by Pentacam Scheimpflug imaging system. Anterior lens capsular specimens from another senile (10cases) and congenital (10cases) cataract were collected for immunofluorescence with polyclonal antibodies specific to human pigment epithelium -derived factor (PEDF). Results:The mean aqueous level of PEDF was(178. 9±87. 5)ng/ml, and there was negative linear correlation of PEDF level and age (r=0. 811, P<0. 001). In senile cases, the aqueous PEDF concentration decreased with increasing nuclear opacities (r=0. 447, P < 0.01) , and the mean PEDF level in nuclear cataract was significantly lower than that in posterior subcapsular opacity (P < 0.01) . PEDF immunostaining was detected in LEC of all capsular specimens. Conclusion : The PEDF level in human aqueous humor is related to age, types of cataracts and lens opacity. PEDF also express in human LEC. The study results suggest PEDF may regulate and/or protect LEC by paracrine and autocrine, and lack of PEDF may play a role in cataractogenesis.