地塞米松对人眼小梁细胞MMP-3及TIMP-1 mRNA表达的影响

目的:研究地塞米松对人眼小梁细胞MMP-3及TIMP-1mRNA表达的影响,探讨激素性青光眼的发病机制。方法:采用原代培养的人眼小梁细胞,用10-7mol/L的地塞米松培养24h,通过RT-PCR方法检测小梁细胞MMP-3及TIMP-1mRNA的表达。结果:地塞米松处理后MMP-3mRNA的表达明显减少,与正常对照组相比相差显著(0.74±0.10vs0.46±0.11,P<0.05),TIMP-1mRNA的表达与正常对照组相比无明显改变(2.01±0.13vs1.95±0.11,P>0.05)。结论:地塞米松抑制小梁细胞MMP-3mRNA的表达,提示激素性青光眼的发病与MMP-3的降低有关。     

地塞米松对人眼小梁细胞紧密连接相关蛋白表达的影响

病理性眼压升高多源于房水排出受阻,与小梁网内皮小梁细胞形态和功能的变化密切相关。小梁细胞间存在紧密连接,对细胞内外各种物质的交换起调节作用^[1-3]。紧密连接由跨膜蛋白、细胞质附着蛋白和细胞骨架蛋白组成,水控蛋白-1、闭合蛋白、连接黏附蛋白（Junctional Adhesion Molecule-1,JAM-1）组成紧密连接的跨膜结构^[4-9]。     

地塞米松对小梁细胞生长周期的影响

目的：探讨地塞米松对小梁细胞生长周期的影响。方法：按常规方法培养人眼小梁细胞,然后分为二组：常规DMEM培养液及含10^-7M地塞米松的DMEM培养液组,培养3d、5d、7d后,应用流式细胞仪检测细胞周期各阶段G1、S、G2期情况。结果：在正常未用地塞米松处理组,G2期细胞为2．0％;地塞米松处理3、5、7d后,G2期细胞比例各为8．0％、16．3％、19．87％,其差异有显著性意义。结论：地塞米松可使小梁细胞生长周期中G2期的比例增加,提示这种作用可能与激素性青光眼的发病 有关。     

地塞米松对永生化人眼小梁细胞流畅阻力和水通道蛋白-1表达的影响

目的探讨地塞米松对永生化人眼小梁细胞的流畅阻力和水通道蛋白-1(AQP-1)表达的影响。方法将永生化人眼小梁细胞株第18代接种于0.4μm孔径的滤膜上,待细胞近融合时加入含10-7mol/L地塞米松培养液。细胞融合后1、3、7d,应用内皮细胞电阻测量仪(EVOM)测定滤膜上单层小梁细胞电阻(TEER),评价其流畅阻力的变化;采用免疫印迹法检测小梁细胞AQP-1的表达情况。结果细胞融合后1、3、7d时,对照组TEER分别为(36.4±1.4)Ω、(34.0±1.7)Ω、(36.1±2.9)Ω,而经地塞米松处理组TEER则分别为(48.4±2.3)Ω、(60.3±3.1)Ω、(58.8±0.9)Ω,差异有统计学意义。用免疫印迹法检测,显示经地塞米松处理后的小梁细胞AQP-1表达量较未经处理组增多,差异亦有统计学意义。结论经地塞米松处理后的滤膜上小梁细胞AQP-1表达水平上调、表达量增多,小梁细胞TEER也升高,提示地塞米松上调AQP-1的表达水平可能与小梁细胞的流畅阻力改变有关。应用EVOM检测TEER可以体现内壁单层小梁细胞的流畅阻力,将为房水引流的研究提供新手段。(中华眼科杂志,2005,41:209-211)     

地塞米松对小梁细胞粘附及吞噬功能的影响

目的：探讨地塞米松对小梁细胞的粘附及吞噬功能的影响。方法：不同浓度地塞米松(10^-7M，10^-6M，10^-5M)处理体外培养的牛眼小梁细胞3d，消化、漂洗后加入用不同的细胞外基质(Extracellular matrix，ECM)包被的培养板中，37℃孵育90min后．采用甲基噻唑基四唑(Methyl thiazolyl tetrazolium，MW)法测定各组吸光度值反应粘附细胞的量；另外，以乳胶微球为标记，观察不同浓度的地塞米松对小梁细胞吞噬功能的影响。结果：与对照组比较，三种浓度的地塞米松均对小梁细胞与ECM粘附有抑制作用．且呈浓度依赖性；对小梁细胞的吞噬功能亦呈现浓度依赖性抑制作用。结论：地塞米松对小梁细胞的粘附及吞噬功能有抑制作用，抑制小梁细胞的粘附及吞噬功能可能是皮质类固醇性青光眼的发病原因之一。     

地塞米松诱导人小梁细胞bcl—2基因的表达

目的:探讨地塞米松对小梁细胞bcl-2基因表达的影响。方法:应用组织块培养的方法建立人小梁细胞培养。取第三代小梁细胞培养于载玻片上,含10~(-7)mol/L地塞米松的培养液作用6小时、12小时、24小时后,应用LSAB观察bcl-2基因表达的情况。结果:地塞米松作用6小时后可见bcl-2蛋白阳性细胞,且随时间的延长,阳性细胞有所增多。结论:地塞米松可诱导小梁细胞bcl-2基因表达,可能在激素性青光眼发病中起着一定的作用。眼科学报1998;14:187～189。     

地塞米松体外抑制人眼小梁细胞生长及表皮生长因子mRNA的表达

目的 探讨地塞米松对培养的人眼小梁细胞生长的影响及抑制小梁细胞表达表皮生长因子（epidermal growth factor EGF)mRNA的情况。方法 取人眼小梁组织进行小梁细胞体外培养,对传3代的小梁细胞进行地塞米松处理实验。实验组在传代后的培养液中按300ug/ml加入地塞米松,另一组作为对照组进行常规培养,观察生长5d后的细胞情况,取培养7d的两组的小梁细胞分别提取RNA,用EGFcDNA探针,a-^32P同位素标记进行斑点杂交,放射自显影。对显影片用计算机激光密度扫描,测定吸光度A值相对值进行组间比较。结果 加入地塞米松300ug/ml实验组,小梁细胞生长明显受到抑制,5d时对照组细胞已经融合,地塞米松组的细胞仍呈集落状态。从对照组小梁细胞提取RNA22.5ug,地塞米松组提取RNA 14ug,取14ug两组等量RNA,用EGFcNDA探针进行斑点杂交。结果阳性。激光密度扫描值地塞米松明显低于对照组。结论 地塞米松对培养的人眼小梁细胞有明显的生长抑制作用,通过抑制总RNA转录及EGFmRNA表达而抑制小梁细胞生长。提示糖皮质激素性青光眼是因抑制了小梁细胞的多种代谢和生理功能所致。     

尿激酶对组织培养人眼小梁细胞的影响

为检验尿激酶在临床应用时对小梁细胞有无不良影响。本研究应用组织培养人眼小梁细胞，观察不同浓度尿激酶对细胞形态的影响，并测定其对细胞DNA合成时氚（标胸腺嘧啶核着（3H-TdR）掺入的量，来判断药物对细胞增殖功能的影响。结果示5000u／ml浓度作用6小时细胞即出现胞突回缩、胞体皱缩等变化，至48小时细胞死亡；5000和500u／ml浓度均显著抑制DNA合成。提示在应用尿激酶冲洗前房积血时，一定要冲洗干净残留药物，以免对小梁细胞造成损害。     

地塞米松对牛眼小梁水通道蛋白表达的影响

目的观察地塞米松对牛眼小梁细胞的损伤使其水通道蛋白-1(aquaporin-1,AQP-1)表达的影响。方法体外培养牛眼小梁细胞,取第4代细胞鉴定后用于实验。应用浓度为5,25,50,250μg/L地塞米松的培养液培养7天,通过WesternBlot方法检测培养的牛眼小梁细胞在不同浓度地塞米松作用下AQP-1的蛋白表达水平。结果牛眼小梁细胞可见AQP-1蛋白条带表达,未经地塞米松作用的AQP-1蛋白条带表达灰度值为102.87±11.73。在浓度为5,25,50,250μg/L地塞米松的培养液培养7天后AQP-1蛋白条带表达灰度值分别为111.64±13.32,115.31±9.41,121.39±9.81,129.42±13.52。当地塞米松浓度≥25μg/L时,AQP-1表达出现抑制作用(P<0.05)。结论地塞米松使培养的牛眼小梁细胞AQP-1的表达减少,这可能是皮质类固醇性青光眼房水流出阻力增加的原因之一。     

地塞米松诱导牛眼小梁细胞凋亡的研究

目的：探讨地塞米松诱导牛眼小梁细胞凋亡的机制。方法：采取体外组织块培养法,培养新生牛眼小梁细胞。将1－500mg/L地塞米松加入融合的第3－5代小梁细胞培养液中,作用1－14d,用相差显微镜、荧光显微镜、透射电子显微镜、DNA电泳及流式细胞仪检测细胞凋亡情况。结果：125－500mg/L地塞米松作用1－14d,小梁细胞凋亡呈浓度时间依赖性。 凋亡的小梁细胞经Hoechst3258染色,于荧光显微镜下观察,细胞核呈致密度浓染的颗粒块状荧光;透射电镜下可见小梁细胞染色质固缩,并有凋亡小体,细胞器基本完好;DNA电泳呈梯状条带,流式细胞仪测到亚二倍体峰。结论：地塞米松可诱导体外培养的小梁细胞凋亡,可能是激素性青光眼的发病机制之一。     

Inhibition of latrunculin-A on dexamethasone-induced fibronectin production in cultured human trabecular meshwork cells

AIM: To determine the effects of a low dose latrunculin (LAT)-A on dexamethasone (Dex)-induced upregulation of extracellular matrix proteins fibronectin (FN) in cultured human trabecular meshwork (HTM) cells. METHODS: HTM cells were cultured to confluent and incubated with 0.4μmol/L Dex and/or 0.05μmol/L LAT-A. FN expression in HTM cells was evaluated by Western blot and immunofluorescence microscopy. RESULTS: Dex up-regulated FN production in HTM cells, failed to do so when co-incubated with LAT-A. LAT-A decreased production of FN in cultured HTM cells. CONCLUSION: This study indicated that LAT-A may modulate the expression of fibronectin in trabecular meshwork to achieve treatment for steroids and other types of glaucoma. It has an important prospect as an intraocular pressure- lowering drug.     

内皮素-1对体外培养人小梁网细胞纤维连接蛋白及Ⅰ型胶原表达的影响

目的观察内皮素-1（ET-1）对人小梁网细胞（TMCs）细胞外基质纤维连接蛋白（FN）、Ⅰ型胶原（COL Ⅰ）的影响。方法取死亡24h内尸眼小梁网组织,行TMCs原代和传代培养,并用FN、层黏连蛋白（LN）、神经元特异性烯醇化酶（NSE）和Ⅷ因子相关抗原（FⅧRAg）鉴定为人TMCs后,取传3代的人TMCs,给予不同浓度ET-1（10^-9、10^-8、10^-7mol／L）孵育72h后,免疫荧光和Western blot观察ET-1对TMCs中FN、COLⅠ表达的影响;然后取传3代的人TMCs,分别给予10^-7mol／L ET-1、10^-7mol／L ET-1＋10^-7mol／L ETA受体拈抗剂、10^-mol／L ET-1＋10^7mol／L ETB受体拈抗剂后孵育72h,Western blot观察ET受体拮抗剂对FN、COL Ⅰ表达的影响。结果研究受到伦理委员会的批准,取材前征得供体家属的知情同意。培养的细胞形态多样,含少许色素颗粒,FN、LN、NSE染色均呈阳性反应,FⅧRAg呈阴性反应。人TMCs与10^-9～10^-7mol／L ET-1共孵育后FN表达上调（F=18．41,P〈0．05）;与10^-8mol／L、10^-7mol／L ET-1共孵育后COLⅠ表达上调（F=39．81,P〈0．05）,并呈浓度依赖性,10^-7mol／L时作用最明显;给予ETA受体拮抗剂后,与ET-1组相比,FN、COLⅠ的表达均降低（qFN=7．213,P〈0．05;qCOLⅠ=6．187,P〈0．05）,但给予ETB受体拮抗剂后,FN、COLⅠ的表达均无明显变化。结论ET-1能够促进体外培养的人TMCs中FN、COLⅠ的表达,其机制可能是通过激动ETA受体而非ETB受体发挥作用的。     

Low dose latrunculin-A inhibits dexamethasone-induced changes in the actin cytoskeleton and alters extracellular matrix protein expression in cultured human trabecular meshwork cells

We determined the effects of a low dose of the actin-disrupting agent latrunculin (LAT)-A on dexamethasone (DEX)-induced changes in actin organization, focal adhesions, and production of extracellular matrix proteins in cultured human trabecular meshwork (HTM) cells. HTM cells were cultured to a highly confluent stage with stable endothelium-like morphology and incubated with 0.1 or 0.2 microM DEX and/or 0.1 microM LAT-A. Changes in the actin cytoskeleton and vinculin-containing focal contacts were evaluated by immunofluorescence microscopy. Expression of thrombospondin-1 (TSP1) and fibronectin (FN) in HTM cells was evaluated by Western blot analysis. The results showed that DEX induced morphological changes and actin reorganization in HTM cells. The cells partly recovered after DEX withdrawal, but the addition of low dose LAT-A hastened the recovery. In addition, DEX failed to induce changes when co-incubated with LAT-A for at least 4 weeks, and for at least 2 weeks when cells were pre-treated with LAT-A for 2 weeks. HTM cells treated with 0.1 microM LAT-A only for 5 days showed mild disorganization of the actin cytoskeleton and focal adhesions, which persisted during the 4 weeks of treatment. DEX stimulated production of FN in HTM cells independent of LAT-A treatment. LAT-A and, to a lesser extent, DEX inhibited production of TSP1 by HTM cells. Although LAT-A is not a DEX receptor antagonist, it is able to prevent the effects of DEX on the actin cytoskeleton in cultured HTM cells at a dose subthreshold for increasing outflow facility in monkeys. This suggests that LAT-A at low doses may be useful in treating steroid and other glaucomas. TSP1 may be an important target of LAT-A in HTM cells and modulation of TSP may influence the actin cytoskeleton of the trabecular meshwork (TM), and consequently, intraocular pressure.     

Expression profile analysis to identify potential gene changes induced by dexamethasone in the trabecular meshwork

AIM: To investigate potential gene changes in trabecular meshwork (TM) induced by dexamethasone (DEX) in steroid-induced glaucoma (SIG). METHODS: The expression data of 24 cases from a public functional genomics data were sorted to identify the mechanisms of action of DEX on the TM. The relationships of the differentially expressed genes (DEGs) were enriched using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. In addition, the hub genes were screened by the Search Tool for the Retrieval of Interacting Genes Database (STRING) and Cytoscape tools. Finally, human TM cells (HTMCs) were treated with DEX to preliminarily explore the function of hub genes. RESULTS: Totally 47 DEGs, including 21 downregulated and 26 upregulated genes were identified. The primary enriched results of the DEGs consisted of inflammatory response, extracellular matrix (ECM), negative regulation of cell proliferation, TNF signalling pathway and the regulation of tryptophan channels by inflammatory mediators. Subsequently, pro-melanin-enriched hormone (PMCH) and Bradykinin B1 receptor (BDKRB1) were screened as hub genes. It is verified in GSE37474 data set. Western blot and quantitative real-time polymerase chain reaction (qPCR) results showed that protein and RNA expression levels of BDKRB1 were significantly decreased after DEX treatment, while PMCH was not significantly changed. CONCLUSION: BDKRB1 may be a key gene involved in SIG onset, providing a suitable therapeutic target for improving the prognosis of SIG patients.     

氧化应激条件下miR-21对人眼小梁网细胞胞外基质蛋白表达的影响

目的 探讨氧化应激条件下miR-21对人眼小梁网细胞(human trabecular meshwork cells,HTMCs)胞外基质蛋白表达的影响.方法 用不同浓度H2O2(0μmol·L-1、200 μmol·L-1、400 μmol·L-1、600 μmol·L-1)刺激HTMCs l h,MTT法检测其对HTMCs活力的影响,从而确定后续实验所需H2O2浓度.随后将细胞分成正常组和H2O2组,Real-time PCR检测miR-21的表达,Western blot检测胞外基质蛋白(纤维连接蛋白和胶原蛋白I)的表达.然后将细胞分成5组:H2O2组(只用H2O2处理)、miR-21干预组(H2O2+ miR-21模拟物)、miR-21对照组(H2O2+ miR-21对照模拟物)、miR-21抑制组(H2O2+ miR-21抑制剂)和miR-21抑制对照组(H2O2+miR-21抑制剂对照物),Real-time PCR检测miR-21、转化生长因子(transforming growth factor,TGF)-β2和PTEN mRNA表达,Western blot检测胞外基质蛋白、TGF-β2和PTEN蛋白表达.最后将细胞分成3组:H2O2组(只用H2O2处理)、PTEN干扰组(H2O2 +PTEN siRNA)和干扰对照组(H2O2+ control siRNA),检测PTEN、胞外基质蛋白和TGF-β2蛋白水平表达.结果 当H2O2浓度≥400 μmol·L-1时,可显著抑制HTMCs的活性,后续实验选择此浓度.与正常组相比,H2O2组中miR-21、纤维连接蛋白和胶原蛋白Ⅰ的表达均增加,差异均有统计学意义(均为P＜0.05).检测氧化应激条件下miR-21对胞外基质蛋白、TGF-β2和PTEN表达的影响,发现与H2 O2组相比,miR-21对照组和miR-21抑制对照组中miR-21、纤维连接蛋白与胶原蛋白Ⅰ蛋白水平表达以及TGF-β2和PTEN mRNA及蛋白水平表达差异均无统计学意义(均为P＞0.05);与miR-21对照组相比,miR-21干预组miR-21、纤维连接蛋白和胶原蛋白Ⅰ蛋白水平及TGF-β2 mRNA和蛋白水平表达均增加,PTEN蛋白水平表达降低,差异均有统计学意义(均为P＜0.05),而PTEN mRNA表达差异均无统计学意义(均为P＞0.05);与miR-21抑制对照组相比,miR-21抑制组miR-21、纤维连接蛋白和胶原蛋白Ⅰ蛋白水平及TGF-β2 mRNA和蛋白水平表达均降低,PTEN蛋白水平表达增加,差异均有统计学意义(均为P＜O.05),而PTEN mRNA水平差异无统计学意义(P＞0.05).采用Western blot检测氧化应激条件下PTEN对TGF-β2和胞外基质蛋白表达的影响,发现与H2O2组相比,干扰对照组PTEN、TGF-β2、纤维连接蛋白和胶原蛋白Ⅰ的表达差异均无统计学意义(均为P＞0.05);与干扰对照组相比,PTEN干扰组PTEN的表达下调,TGF-β2、纤维连接蛋白和胶原蛋白Ⅰ的表达均升高,差异均有统计学意义(均为P＜0.05).结论 氧化应激条件下miR-21可增加HTMCs胞外基质产物,这可能与其靶向沉默PTEN基因,调节TGF-β2的表达相关.     

Latrunculin B effects on trabecular meshwork and corneal endothelial morphology in monkeys

To determine the mechanism of latrunculin B (LAT-B)-induced decrease in outflow resistance and the effect of LAT-B on the cornea, structural changes of the trabecular meshwork (TM) and the corneal endothelium following LAT-B were studied in the live monkey eye. LAT-B (0.5 microM) and vehicle were administered by anterior chamber exchange and infusion with cationized and non-cationized gold solution in opposite eyes. The eyes were fixed by infusing Ito's solution and enucleated. Anterior segments were quadrisected and embedded in Epon-Embed 812. Morphology of the TM and the corneal endothelium was studied by light and electron microscopy. LAT-B-induced morphological changes in the TM included: (1) loss of microfilament integrity in cells, especially in TM cells on the collagen beams; (2) development of numerous cytoplasmic projections of the sub-canalicular cells (SUB); (3) reorganization of intermediate filaments in Schlemm's canal inner wall (IW) cells; (4) massive 'ballooning' of the juxtacanalicular (JXT) region, leading to a substantial expansion of the space between the IW of Schlemm's canal and the trabecular collagen beams; and (5) retention of extracellular matrix (ECM), trapped between the SUB cell layer and IW cells. No detrimental effects on tight junctions, giant vacuoles, and cell-cell and cell-ECM adhesions were observed. Endocytosis of gold particles was not affected. Morphology of the corneal endothelium of the LAT-B-treated eye was unchanged. In conclusion, TM changes in the LAT-B-treated eye suggest that the expansion of the JXT space may account for the decrease in outflow resistance induced by latrunculins. The outflow-effective concentration of LAT-B administered intracamerally does not significantly affect the corneal endothelium.     

水通道蛋白1在培养人眼小梁细胞中的表达及意义

目的探讨培养人眼小梁细胞水通道蛋白1(AQPl)的存在、定位及意义。方法应用逆转录聚合酶链反应(RT-PCR)检测培养人眼小梁细胞AQP1mRNA的表达。Westernblot用兔抗人AQP1多克隆抗体检测AQP1蛋白表达。免疫荧光测定AQP1在培养人眼小梁细胞的所在部位。结果RT-PCR扩增出一条347bp标志AQP1mRNA的表达产物。Westernblot可见约28000相应位置的发光条带。免疫荧光定位AQP1在培养的人眼小梁细胞胞膜。结论AQP1在培养人眼小梁细胞的细胞膜表达,可能在调节房水通过小梁网流出系统中起到重要作用。     

内皮素-1体外对人小梁细胞骨架肌动蛋白的影响

目的：观察内皮素-1（endothelin-1,ET—1）对人眼小梁细胞细胞骨架肌动蛋白的影响。方法：培养3代人眼小梁细胞,随机分为4组：对照组（0mol／LET-1）;ET-1低剂量组（10^-9mol／LET—1）;ET-1中剂量组（10^-8mol／LET—1）;ET-1高剂量组（10^-7mol／LET—1）,各组细胞分别处理72h后,应用Western—blot方法检测小梁细胞骨架肌动蛋白（F—aetin）的表达,并用FITC—phalloidin荧光探针观察肌动蛋白在细胞内的分布。结果：ET—1作用后人小梁细胞肌动蛋白表达明显增高,在10^-9～10^-7mol／L浓度范围内呈剂量依耐性,荧光探针示ET-1处理组小梁细胞肌动蛋白应力纤维和周边肌动蛋白明显增多浓集,细胞微丝附着与胞膜,细胞间连接及细胞贴壁部位连接明显增多。结论：ET—1能促进小梁细胞肌动蛋白表达,参与了小梁细胞骨架的重构。